Empowering communities: the impact of citizen science on radon measurement and mitigation

Empowering communities: the impact of citizen science on radon measurement and mitigation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Empowering communities: the impact of citizen science on radon measurement and mitigation Meritxell Martell, Tanja Perko This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7120379/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Radon exposure poses a significant public health risk, yet authorities often struggle to engage residents in high-risk areas to test and mitigate radon levels. Traditional top-down approaches have shown limited success in motivating citizen engagement in radon mitigation. This study aims to assess the effectiveness of citizen science (CS) approaches in enhancing radon measurement and mitigation efforts across Europe, with a focus on citizen engagement and impact of the RadoNorm CS incubator. To evaluate the impact of CS projects, a mixed-methods approach was used, including computer-assisted web interviews with 231 citizen scientists, interviews with seven researchers, and group discussions with ten CS coordinators. The CS evaluation method developed by Hoedoafia et al ( 2024 ) has been used. The RadoNorm CS Incubator engaged over 800 citizens and 57 research organizations across the EU. Pilot CS projects related to radon in France, Hungary, Ireland, and Norway informed the design of an open call, resulting in the selection and funding of six CS projects related to radon in Italy, Poland, Portugal, Slovakia, Slovenia, and Spain. The results show that these projects employed diverse methodologies to address specific community needs and improve radon awareness, measurement and mitigation strategies. The study highlights the successful outcomes of these projects, including the development of new radon dosimeters, innovative mitigation techniques, increased public awareness, improved local policies, and expanded school curricula. The findings demonstrate the potential of CS to enhance public engagement, improve risk communication, address research and scientific gaps and contribute to more effective radon protection strategies. Environmental Policy Sociology Health Policy citizen engagement citizen science radon awareness crowdsourcing radon mitigation Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction The overarching aim of this study is to define the impact and effectiveness of citizen science (CS) projects on awareness, behaviour, and community engagement related to an environmental health issue. As a case study, this paper focuses on the indoor air pollutant radon—a significant yet often overlooked public health risk. Across European Member States, awareness campaigns have been launched to address radon exposure, increase radon testing and promote mitigation efforts, including the installation of ventilation systems in private dwellings when radon concentrations exceed national reference levels. However, the effectiveness of these awareness campaigns is limited and often fails to translate into practical actions (European Commission, 2023). Research indicates that even when residents are aware of the health risks associated with elevated indoor radon levels, they may show little concern about living in such environments (Perko and Hevey, 2024) and are not taking any actions to reduce radon concentrations. Low intention to take actions to protect from risk is also due to difficult accessibility and high complexity of the testing and mitigation process, the lack of support from relevant organizations and institutions, or the general public's preoccupation with more familiar and widely recognized issues (Hevey et al. 2023). In addition, the gap between awareness of radon-related health risks and the adoption of protective measures may be attributed to the limited involvement of communication and behavioural experts employing theory- and evidence-based approaches, as well as the lack of comprehensive social studies assessing existing behaviours, knowledge, experiences, and attitudes of citizens toward radon risk protection. (Perko et al., 2023; Bouder et al., 2023). Empirical evidence shows that awareness alone is rarely enough to drive protective behaviour against radon. Large scale surveys in the United Kingdom, Ireland, Belgium and the United States indicate that, while awareness is a necessary pre condition for action, it does not reliably predict either home testing or remediation (Cronin et al. 2020; Poortinga et al. 2011; Perko et al. 2024; Hevey, 2017). Similarly, factual knowledge acquired through formal education, personal experience or targeted communication campaigns has displayed little or no consistent association with protective action (Desvousges et al. 1992; Nwako & Cahil, 2020; Hahn et al. 2014; Ryan & Kelleher, 1998; Golding et al. 1991; Kennedy et al. 1991; Peterson & Howland, 1996; Davis et al. 2018). In contrast, studies repeatedly link heightened risk perception - especially when respondents personally know someone with lung cancer - to stronger intentions to test for and mitigate radon (Perko et al. 2024; Davis et al. 2018; Duckworth et al. 2002; Khan & Chreim, 2019). Perceived susceptibility not only predicts the acquisition of test kits but also follow‑through in measurement campaigns (Perko et al. 2024; D’Antoni et al. 2019; Weinstein et al. 1991; Niemeyer & Keller, 1999). Yet the link is not deterministic: Poortinga et al. (2011) found that participants who regarded radon as highly hazardous often still failed to act. Protection motivation theory applied in the field of radon (DiPofi et al. 2011) help explain this gap: effective action depends on coping appraisal - belief that mitigation works (response efficacy), confidence in one’s ability to carry it out (self-efficacy) and acceptable perceived costs. These three elements have consistently emerged as key predictors of both testing and remediation (Weinstein et al. 1990; Weinstein et al. 1992; Witte et al. 1998; Dragojevic et al. 2014) and higher self-efficacy is associated with substantially greater adoption of radon protective measures (Davis et al. 2018). The involvement of citizen scientists in radon research presents a promising strategy not only for raising awareness and enhancing risk perception, but also for closing the persistent gap between knowledge and action in radon protection. Citizen participation has been shown to positively influence key psychological drivers of behaviour - such as response efficacy, self-efficacy, and perceived response costs - thereby increasing the likelihood of meaningful engagement with radon testing and mitigation measures. Recent studies (Martell et al., 2024) demonstrate that citizens across the globe have actively contributed to both scientific data collection and the implementation of radon mitigation strategies, underscoring the practical impact of CS initiatives. By integrating citizens into the research process, CS offers a powerful means to address the disconnection between public concern and the often-limited uptake of mitigation actions (Martell et al., 2021). Beyond supplying valuable local data, citizen scientists foster a sense of agency and collective responsibility, which can help dismantle psychological and structural barriers to action. In this way, CS emerges not only as a tool for engagement, but as a transformative approach that may enable more comprehensive and effective responses to radon exposure risks across the EU (Martell et al. 2024, Hoedoafia et al. 2024). For instance, several CS projects have been conducted in schools with the intention to raise awareness about radon risks both within the school and at home by involving students in radon measurements and data collection (De Cicco et al., 2017; Tsapalov et al., 2021; Hahn et al., 2020; Ambrosino et al., 2024). These initiatives help not only to educate students but also serve as a bridge to engage families and the broader community, fostering a shared responsibility for radon awareness and mitigation. In addition, pilot projects in radon CS showed promising effects of involving citizens in radon testing and mitigation in France, Hungary, Ireland, and Norway (Hoedoafia et al., 2024; Martell et al., 2024). For instance, in France, as part of this pilot project, Andresz et al. (2023) found that involving citizens can improve fostering action in the radon post-measurement phase and can increase knowledge and behavioural uptake. Moreover, in the United States, Stanifer et al. (2022) carried out a CS project with 60 homeowners in rural Kentucky. The project increased participants' self-efficacy in testing and mitigation, but their confidence in the effectiveness of radon mitigation (response efficacy) remained low. Despite growing interest in CS as a tool for environmental health communication and community engagement, there is a lack of empirical evidence on the effectiveness of CS projects in enhancing both public understanding and behaviour related to radon exposure. According to our knowledge there is no study which would systematically examine how participation in CS initiatives in the field of radon impacts participants’ awareness, knowledge, risk perception, and willingness to adopt protective behaviours. Furthermore, the role of CS in generating scientifically valuable data, fostering collaboration between scientists and the public, and contributing to long-term community engagement remains systematically underexplored (Hoedoafia et al. 2024). There is a need to assess not only the individual-level benefits of such projects (e.g., knowledge gain and behaviour change) but also the broader scientific and social outcomes, including the challenges encountered during project implementation. This study addresses this gap by evaluating the impact and effectiveness of CS projects focused on radon, with attention to both participant outcomes and project-level contributions. It responds on the following research question and hypothesis: RQ: How effective are CS projects in increasing public awareness, knowledge, and protective behaviour regarding radon exposure, while fostering scientific outcomes and community engagement? H1: Participation in a CS project on radon significantly increases participants' awareness, knowledge, risk perception, and willingness to engage in protective behaviours. The study critically examines the societal and individual’s impact of CS initiatives in the field of radon testing and mitigation using the evaluation framework developed for the radon context by Hoedoafia et al. (2024) in combination with a dedicated survey (Perko et al. 2024, 2021) conducted with citizen scientists comparing results of a survey with general public representative for gender, age and level of urbanisation (Perko T., 2025). 2. Background and context of the case study RadoNorm project addresses the critical issue of radon, a dangerous indoor air pollutant causing over 19,000 annual lung cancer cases in Europe (European Environment Agency, 2022 ; Murray et al., 2020 ). Recognising the limited awareness, testing efforts and low mitigation numbers in high radon risk areas, RadoNorm established a Citizen Science Incubator involving citizens and scientists from diverse scientific disciplines. The aim was to create a model for grassroots CS projects in radon risk areas. The CS Incubator engaged more than 800 citizen scientists across Europe. The project started with four pilot projects to address radon testing and mitigation during a period of six months. In France, citizens improved cutting-edge radon diagnostic tools by answering the question: How can diagnostics be improved to identify entry points in homes, and how can the computer program be made more user-friendly? Ireland investigated whether citizens can successfully mitigate their homes using do-it-yourself (DIY) tools through the development of a DIY toolkit. In Norway, citizens decided to take on the role of science communicators by trying to answer what type of communication is necessary to influence radon protection behavior? In Hungary, the pilot CS project explored the question can an ordinary CO 2 meter, prevalent in classrooms post-COVID-19, be combined with radon measurements? The CS project in Hungary continued after the pilot stage given the high level of interest from both the CS coordinator and the teachers involved (Martell et al, 2024 ). Transitioning from the four pilot projects to grassroots projects, the CS Incubator supported community-specific research questions in six countries (see Table 1 ). In Italy, citizens measured radon levels, analysed data and developed an interactive radon map. Polish high school students collected and analysed samples of soil, water and air, contributing to both education and research. In Portugal students run a nationwide radon measurement, filling a radon mapping data gap in their country. In Slovakia citizens, high school for builders and authorities investigated building mitigation strategies, while Slovenia's team conducted research on the effectiveness of different mitigation techniques. Finally, the Spanish CS project targeted both workplaces and homes for radon exposure improvement. In addition, the pilot citizen science project in Hungary evolved into a full-scale initiative in which high school students measured indoor air quality and developed communication channels to share the results with a wider audience. The research questions, objectives and participants in the seven CS initiatives funded by RadoNorm are compiled in Table 1 . Table 1 Research questions, objectives, and participants of CS projects Country, CS project Research question (Response level to RQ: 0 = Not addressed, 1 = Partly addressed, 2 = Fully addressed) Objectives Level of objective fulfilment) 0 = No, 1 = Partly, 2 = Achieved No. and description of citizen scientists (Coordinator-Reported) (number of survey respondents) Italy, OCRA What are the levels of radon concentrations in various buildings, and how can an understandable infographic and active radon map be created? (2) To reduce indoor radon levels through measurement of exposure and increased awareness of radon risks and mitigation measures in houses, school rooms and working places in Abbadia San Salvatore, Siena, one of the most radon-affected municipalities in Italy and to create a radon distribution map to increase radon communication risk. (2) Participants included workers, retired people, families, teachers and students of the municipality of Abbadia SS, Siena and the indirect involvement of 700 students of four schools. 216 citizens were initially recruited but 43 people never returned the radon samplers for the analysis. 173 at the end joined the project. Remark: Considering the number of citizen scientists, the participation of 25 participants in the CS survey is woefully inadequate. Possible reasons for the low response rate as proffered by the coordinators is the large number of older participants who are not technology savvy. Hungary, RadoNorm-Aerosol Can an ordinary CO 2 meter, prevalent in classrooms post-COVID-19, be effectively combined with radon measurements to achieve a more liveable environment? (1) To test whether it is feasible to develop an affordable toolkit measuring several air quality and radiation components, including radon, CO 2 , particulate matter and CO. (1) 10 students from two high schools in Budapest and Székesfehérvár. (6) Poland, AHS RadonHunt Where and to what extent is radon present in mining, drinking water, and (indoor air) air in Poland? (2) To introduce citizen science as a pedagogical approach that builds students’ agency and deepens their understanding and carrying out measurements where radon can be found as well as sharing the scientific journey of students via social media, TikTok. (2) the main participants were teachers and students. Ten Y10 students (ages 14–15) from the Akademaie high school. (12) Portugal, RadAR Can a local campaign designed and implemented by students improve monitoring rates and promote action to reduce indoor radon exposure? (2) To engage students as the main driving force and central pillar to create a local communication strategy to increase radon awareness in the population and to promote the behavioural change necessary to conduct citizens to take action to reduce radon levels in their dwellings. (2) 60 citizen scientists from three high schools in inland areas of Portugal (consistent with the number outlined in the proposal). Other citizens of the municipalities who measured radon in their dwellings and participated in public events. (81) Slovakia, RadonGPS How can future building professionals help improve the implementation of the radon concentration reducing measures in Slovakian private dwellings? (2) To compare short-term (2 weeks by active radon detector) and long-term (3 month by passive radon detectors) indoor radon measurements in family houses in the municipalities around the town of Banská Bystrica in the Slovak Republic and to engage students of secondary construction school (as future building professionals) to design tailor-made remediation projects for owners of the family houses. (2) 50 citizen scientists at the initial stage (consistent with the number outlined in the proposal), 47 citizen scientists until the end (including 14 secondary construction students); 3 drop-out citizen scientists (including 2 secondary construction students and 1 adult citizen). (31) Slovenia, RadoNorm-SLO How effective are different radon mitigation techniques in reducing indoor radon levels as measured and implemented by citizen scientists in the Bela Krajina region (municipalities of Črnomelj, Metlika, and Semič). (1) To explore public perception & behavior related to radon measurement and mitigation. Specifically, to understand why people are reluctant to measure radon levels in their homes and take mitigation actions, despite radon being a known health risk in certain regions of Slovenia, such as Bela krajina. To raise awareness, foster a deeper understanding of radon risks, and empower individuals to take action to reduce radon exposure in their homes. (1) At the beginning, 105 citizens from Bela Krajina completed the entry questionnaires. 90 citizen scientists; 40% were over 60 years old, 30% were between 45 and 60 years old, and 30% were between 26 and 45 years old; 35 citizen scientists by the time of radon mitigation and 20 citizen scientists at the final event; Citizens with elevated radon levels measured during a national campaign in 2023 were invited to participate in the RadoNorm-SLO project. Many citizen scientists remained engaged throughout the project, but motivation declined for those whose homes had low radon levels; Some older participants, in particular, faced challenges with the technical aspects of the project. (55) Spain, RadoHow What is the radon exposure of residents in specific regions of Spain at home compared to their workplaces? (2) To compare the levels of radon exposure of citizen scientists at work versus at home, across various geographical, geological, and building environments in Spain. The project also aims to raise awareness about the potential health effects, emphasising that these two doses are received continuously, as individuals spend most of their time in these two locations. (2) 20 participants from 5 different provinces from Spain (4 from each) - Galicia: Radon prone area in Spain. - Cantabria: Karst zone in Spain, - Salamanca: Uranium mining area, - Zaragoza: Low potential radon area, - Madrid: Radon prone area with high population (21) Incorporating various scientific disciplines related to radiation protection, including physics, engineering, communication, radiobiology, computer sciences, chemistry, sociology, architecture and education sciences, the CS projects leveraged a broad knowledge spectrum. Specific disciplines take precedence in different regions; for example, construction engineering and physics in Slovakia and Slovenia, communication science in Norway, physics and education sciences in Hungary, Poland, and Portugal, and radiobiology and physics in Italy, with computer sciences being the focus in France. RadoNorm CS Incubator was also featured on the European Union Prize for Citizen Science – Honorary Mentions List in June 2024. The prize honours innovative and creative projects that demonstrate significant merit and societal impact. Thus, the project earned official recognition by being selected from an impressive 288 entries for an 'Honorary Mention' in the European Union Prize for Citizen Science. RadoNorm has thus secured a position among the top 10% of European citizen science projects. 3. Method and data A mixed-method approach was employed, combining a quantitative online survey with qualitative methods, including group discussions and content analysis of project reports. The RadoNorm Ethical Committee provided guidance and oversight throughout the study. The survey employed is mainly based on the European Radon Behaviour Atlas questionnaire developed by (Perko et al., 2024 ). Additionally, scales developed by (Levontin et al., 2022 ) were utilized to measure motivation of citizen scientists. The sequence of main topics used in the survey are as follows: a) CS project: name of CS project and description of project (2 items); b) level of involvement in the CS project (4 items); c) participants expectations (1 open-ended question); d) social cooperation (6 items); e) motivation to participate in the CS project (37 items); f) radon awareness (4 items); g) risk perception (1 item); h) radon knowledge (11 items); i) radon protection behaviour (4 items); j) intention to protect from radon (4 items); k) cue to action/actual behaviour (1 item); l) severity for self and for others (4 items); m) susceptibility for self and for others (4 items); n) response efficacy (4 items); o) self-efficacy (4 items); p) perceived burden (2 items); q) perceived cost (2 items); r) perceived ease (2 items); s) subjective norms (4 items) ; t) descriptive norms (4 items); u) health effect perception (1 item), v) willingness to engage in future research (1 item); w) affective response to information (2 items); x) socio-demographic items: gender, region, age, year of birth (control), education, size of household, dwelling ( 10 items). For this study, only a specific subset of concepts, derived from the theoretical framework, was analysed. The sample size is (N = 231) and consists of citizen scientists of the initiatives in Hungary, Italy, Poland, Portugal, Slovakia, Slovenia, and Spain. A shorter version of the survey was administered to students and their teachers/project coordinators participating in the CS initiatives in Hungary and to all young adults in Poland and Portugal (N = 105). The survey was implemented via a computer assisted web interviewing (CAWI) by the independent marketing company MEDIANA, a member of ESOMAR, headquartered in Slovenia between February 24 and May 6, 2024. Table 2 Survey sample and response rate CS project No. of responses % of total No participants in the initiative Response rate RadoNorm-Aerosol, Hungary 6 2.60 10 60.00% OCRA, Italy 25 10.80 173* 14.45% AHS RadonHunt, Poland 12 5.20 14 85.71% RadAR, Portugal 81 35.10 360 22.50% RadonGPS, Slovakia 31 13.40 49 63.27% RadoNorm-SLO, Slovenia 55 23.80 90 61.11% RadoHow, Spain 21 9.10 25 84.00% Total 231 100.00 721 32.04% * Only adult participants were included in the survey. Respondents’ description: Socio-demographics of respondents: In terms of gender, respondents were fairly evenly split: 44.2% male, 53.2% female, and 2.6% preferred not to disclose their gender. The survey revealed that participants generally have high levels of education, with the largest group (25.1%) holding a bachelor’s degree. Overall, 63.2% of respondents have at least a bachelor's degree, including 19.5% with a master's and 18.6% with a doctorate. A smaller proportion (5.6%) hold less than a second-level certificate, and 24.7% have a second-level certificate. Most participants live in medium-sized households, typically without children, and have long-term residence in detached houses. Homeownership is high, with 70.1% of respondents owning or co-owning their homes, and 92.6% have lived in their current dwelling for more than one year. A significant portion (51.1%) use ground floor or basement spaces as living areas. Regarding radon awareness, about 42% of respondents know they live in a radon-prone area, while 32.9% are unsure. CS Information channels and prior engagement in CS Projects: When asked how participants learned about the CS projects, with multiple responses allowed, the results revealed a wide range of information sources. The majority of respondents (32.5%) learned about the project through schools, making educational institutions the primary channel. Friends were the second most common source, with 17.7% indicating they found out through personal networks. Social media (10%) and traditional media (3%) together accounted for 13% of the information dissemination, with social media playing a more prominent role. The "Other" category (22.1%) suggests additional, unspecified sources were also involved in spreading information. A small percentage (3.5%) either did not know or did not answer. Most participants across all countries had not previously engaged in similar CS projects, with about 86% indicating this was their first experience. Among countries, Italy, Hungary, and Poland had particularly low levels of prior participation, indicating a strong opportunity for promoting CS in these regions. While Portugal, Slovenia, Slovakia, and Spain showed slightly higher levels of prior involvement, the majority of respondents in these countries were also new to CS. The CS questionnaire data - covering awareness, knowledge, risk perception, and radon protection behaviour - were compared with data from the RadoNorm European Radon Behavioural Atlas (Perko, 2025 ), an open data set. The study comprises over 17,000 respondents and includes more than 250 items per questionnaire, with an average completion time of 17 minutes. Data collection for this part of the study was conducted via computer-assisted web interviews (CAWI) between 2021 and 2024. For this analysis and comparison, nationally and regionally representative subsamples for gender, age, level of urbanisation and education were used from Portugal (N = 1,200), Spain (N = 1,005), and Slovenia (N = 2,012). For other countries included in the CS projects, no comparable representative data were available. A 120-minute in-person group discussion with the ten CS project coordinators was held on June 11, 2024. Following a structured protocol, it explored participant engagement, CS project implementation, societal impact, and long-term sustainability. Additionally, seven semi-structured interviews with radon experts were conducted between June and July 2024 to gather their perspectives on the contributions of citizen scientists. Inductive coding in NVivo was used for thematic analysis. 4. Results The following section discusses the impact of the CS projects related to the changes on: 1) radon awareness; 2) radon knowledge; 3) radon perception; 4) radon protection behaviour; 5) willingness to test and mitigate radon exposure; 6) scientific impact; 7) internal evaluation of the coordinators and 8) effectiveness of engagement. 1. Increased radon awareness among citizen scientists Radon awareness refers to knowledge of its existence and associated health risks. This was assessed by the question, “ Did you know anything about radon before joining the CS project? ”. The results revealed significant variation in awareness across countries. Participants from Spain (81%) and Italy (64%) had the highest levels of awareness, while Slovenia (62%) and Poland (58%) showed moderate awareness. In contrast, Hungary (50%), Slovakia (45%), and Portugal (41%) had the lowest awareness levels. Overall, 54% of participants (124 out of 231) were aware of radon before joining the project, while 44% (101 participants) had no prior knowledge, and 2% (6 participants) either didn’t know or did not answer. When asked about their awareness of radon during the project, a significant increase was observed. After participating, 64.1% of respondents reported a good understanding of radon, while 35.1% had some familiarity with it. This indicates that the CS project played a crucial role in raising awareness, particularly in countries with initially lower levels of knowledge. Regarding the question, “ How much did you learn about protecting yourself from radon exposure in the CS project? ”, a substantial majority of participants (44.2%) indicated they learned “ a lot ,” and 22.1% said they learned “ a great deal .” Together, these responses suggest that 66.3% of participants gained considerable knowledge on radon protection. Some 23.8% of participants reported learning “ a little, but not much, ” while a small fraction (6.5%) reported learning “ very little or nothing at all. ” Figure 1 compares radon awareness between the general population and participants in CS projects in Slovenia, Spain, and Portugal, as assessed before the participants joined the projects. The results indicate that in Slovenia, citizen scientists were slightly less aware of radon compared to the general population, whereas in Spain and Portugal, citizen scientists showed slightly higher awareness levels prior to their involvement. It is important to note that, following their participation in the CS projects, all citizen scientists became highly aware of radon. 2. High radon related knowledge acquired during the CS project Radon-related knowledge refers to an individual’s understanding and information about radon, acquired through media, informational interventions, personal communication, or educational processes. In this study, radon knowledge among citizen scientists was assessed through their agreement or disagreement with 13 statements developed by Perko et al. (2024) to assess understanding of radon-related topics. The results show that a minority of respondents (24.2%) incorrectly believe that radon causes headaches. Nearly half of the respondents (49.4%) correctly disagreed with this statement, while 26.4% were uncertain or did not provide an answer. This suggests that while approximately half of the respondents demonstrated a correct understanding, the other half either held misconceptions or lacked clarity regarding the non-existent link between radon exposure and headaches. A substantial majority of 86.1% knows that radon exposure is linked to lung cancer. Moreover, most respondents 89.2% correctly disagree with the statement that radon is a radioactive liquid, recognizing that radon is a gas. An overwhelming majority of 90.9% correctly disagree that radon has a strong odor, knowing that radon is odorless. A high percentage of respondents, 93.5% agree that radon is invisible, demonstrating awareness of the characteristics of radon. Most respondents, 83.1% correctly disagree that radon levels are usually higher in the attic than the basement. A majority of 88.3% agree that testing is the only way to determine if a home has elevated radon levels. A significant majority, 90.5% agree that radon can enter homes through cracks in walls and floors, which aligns with common knowledge about radon infiltration pathways. A majority of respondents, 71.4% agree that the health effects of radon do not show for years, acknowledging the long latency period associated with radon-induced lung cancer. An overwhelming majority of 95.2% agree that the risks from radon exposure increase with longer exposure durations. Most respondents, 70.1% correctly disagree that indoor radon concentrations are expressed in Watt, knowing that radon levels are typically measured in becquerels per cubic meter (Bq/m³). 3. Higher radon risk perception among citizen scientists The responses highlight a generally high level of concern about the health risks of radon exposure among participants, with the majority perceiving a moderate to very high risk. For instance, the largest proportion of respondents, 45.0%, perceive a moderate risk to their health from radon exposure and a significant number of participants, 24.2%, consider the risk to be high with an additional 10.0% viewing the risk as very high. These categories combined indicate that 79.2% of respondents perceive a moderate to very high risk. A smaller group of participants perceive the risk to be low (10.8%) or very low (5.2%). Only 0.4% of respondents believe there is no risk at all. 4.3% of respondents selected "I don't know, no answer," indicating some level of uncertainty or lack of awareness regarding the risks associated with radon. Figure 2 presents a comparison of radon risk perception between the general population and citizen scientists in Slovenia, Spain, and Portugal. It clearly shows that citizen scientists perceive radon risk to be higher in all three countries. Notably, none of the citizen scientists selected “no risk at all,” and across all countries, they consistently expressed a greater perception of risk compared to the general population. 4. Better radon protection behaviour among citizen scientists Regarding radon testing of dwellings before the CS project, only 33 out of 126 respondents (26.2%) reported that their residence had been tested for radon, which highlights a relatively low rate of radon testing among the surveyed group before the CS project. A significant majority of 72.2% of valid responses indicated that their residence had not been tested for radon, suggesting that the CS project is the main channel through which this large group of people have had an opportunity to test their homes for radon. Considering that in most of the countries, the CS projects were undertaken in radon priority areas, this is quite a significant contribution. Figure 3 presents the intention to test for radon among the general population and citizen scientists in Slovenia and Spain. The difference in intention highlights a significantly greater willingness among citizen scientists to test radon levels in their homes when advised, compared to the general population. The results show that participation in CS projects positively influences individuals’ motivation to take action regarding radon exposure. 5. Positive impact on willingness to test and mitigate radon exposure Before the CS project, only 10.3% of respondents reported that their building was remediated after discovering a radon problem. Additionally, 4.0% indicated that protective measures were installed during construction. This implies that a combined 14.3% of respondents took some form of action to mitigate radon risks in their homes before the CS project. A significant portion of respondents expressed a high willingness to test for radon concentrations in their homes if advised. Specifically, 44.0% agreed and 25.0% strongly agreed, totalling 69.0% of valid responses. Around 15.5% were neutral, showing uncertainty or indifference, while only a small percentage (2.4% strongly disagreed and 6.0% disagreed, totalling 8.4%) opposed testing for radon. Regarding the intention to test for radon as a precaution, 72.6% of respondents (50.0% agreed and 22.6% strongly agreed) indicated their intention to measure radon in their homes. On the statement, “ I intend to start the remediation of my home if advised, ” 42.6% (27.8% agreed and 14.8% strongly agreed) expressed their intention to begin remediation. Similarly, when asked, “ I would do what is necessary to remove radon if advised ,” 61.1% (40.7% agreed and 20.4% strongly agreed) demonstrated a strong willingness to take action. Additionally, 77.5% of respondents (49.3% agreed and 28.2% strongly agreed) stated that learning about radon through the citizen science project motivated them to test radon levels in their homes . This highlights the project's significant impact on encouraging protective behaviours related to radon testing. 5. Wide range of scientific data and products generated during the CS projects The number of publications from the CS projects was limited to several abstracts for conferences and presentations. However, the products and data generated are multiple and are summarized in Table 3. Table 3. Examples of data and products generated by CS projects Country/project Data and products generated Italy, OCRA Communication materials (e.g., leaflets), radon measurements in 231 places (147 homes, 37 rooms in 4 schools, and 47 workplaces) with passive radon detectors, scientific report 1 , radon distribution digital map, questionnaire, project video. Hungary, RadoNorm-Aerosol Low-cost sensor toolkit, technical documentation in Hungarian and easy to read English, radon measurements Poland, AHS RadonHunt Communication materials (e.g., leaflets), 50 indoor air measurements (using CR39 detectors), 27 water measurements, 2 soil air measurements, active measurements in 10 locations, videos Portugal, RadAR Communication materials (e.g., flyers, posters), radon measurements in 300 dwellings, online registration forms Slovakia, RadonGPS Roll-up banners, 14 tailor-made radon remediation projects for family houses, radon measurements in 47 family houses (91 rooms with passive detectors) and 34 family houses (126 rooms with active detectors), answers to frequently asked questions (FAQ) on radon, communication materials (e.g., leaflets, roll-up banners), YouTube Video on reducing radon – a DIY approach, record forms for measurements, cooperation agreement, certificate of participation Slovenia, RadoNorm-SLO 73 passive measurements and 56 active measurements, educational workshops, mitigation of three homes (two through the installation of active sub-slab depressurization systems and one through a heat recovery ventilation system), regional map of radon measurement data, communication materials (e.g. flyers); policy recommendations to authorities Spain, RadoHow Communication materials (e.g., infographics, leaflets), 20 radon measurements in both homes and workplaces, initial questionnaire, guidelines on how to use radon detectors, tracking calendar. As a result of the collaboration in RadoNorm CS Incubator, the Polish and Hungarian teams have put a proposal together with another Romanian partner with new research questions. Portugal continues the CS project in three different districts. A new research question resulted also from the Spanish project and will be implemented in another province in Spain. Future projects are also foreseen in Italy to co-create research questions with regional authorities. The software used in the RadoNorm CS projects varied depending on the country and included: · An existing online tool to self-evaluate radon indoors which was tested by citizen scientists who had performed radon measurements in their homes and had elevated radon concentrations (only in the case of France). · Radon Vision was used to set the measurement device and manage data as well as to get interactive graphical displays of measuring data. · DataView softwares is a powerful tool for configuration, transfer and processing of measurement data for different radon measuring instruments. · Rstudio and Excel were used for data evaluation. · VideoPad, GoogleWebDesigner, Audacity, Inkscape and GIMP were used for video editing and translations. · Slido was used for Q&A and pooling online. · For data presentation, an interactive web application based on Plotly jascript library was used. Hardware used varied depending on the country and included passive detectors (CR39, Radtrack) and radon active detectors, (RadonEye, RadonEye+2). In Slovakia, AlphaGuard was used to ensure metrological traceability of active detectors. 6. Expected outcomes achieved and challenges of CS projects identified All CS projects were evaluated internally using a self-evaluation by the coordinator. The outcomes of the evaluation are provided in Table 4. In addition to the internal self-evaluation, in Poland, the project leader designed a self-assessment questionnaire for students which was completed half-way through the project and at the end. Also at the end, self-reflection essays by students summarizing their perspectives were provided as means of evaluation. In Slovakia, the internal evaluation was completed by the feedback gathered from both online and face-to-face verbal communication between all participants involved in the CS project. In Spain, the internal evaluation was completed by the verbal feedback from citizen scientists during project final event. Table 4. Outcomes of CS project evaluation and recognized challenges based on the self-evaluation and discussion with coordinators Country Outcome of evaluation Italy, OCRA The project's main goals—raising citizen awareness and collecting radon data in homes, school rooms, and workplaces—were successfully achieved. The project provided a significant opportunity for citizens to protect their health and advocate for concrete actions to reduce indoor radon levels. All deadlines were met. More funds than initially anticipated were allocated in the first stage to increase citizen engagement and participation. Although no formal internal evaluation of citizen satisfaction was conducted, many participants expressed their appreciation for the project, particularly during the final public event. Hungary, RadoNorm-Aerosol Completion of the first version of the toolkit, sparking numerous ideas for further development Students’ recruitment via personal invitations proved easy and effective, while flyer advertisements were less effective. Initial project's results only accessible to students and immediate families (limited circle). Use of project designed website helps to reach a wider audience. The toolbox has reached a point where experts need to take over. Recruitment must begin at the start of each school year as students progress to higher levels, and become busier with demanding exams, or complete high school and are no longer available to continue. As a result, the entire process must be restarted, which can be challenging. Poland, AHS RadonHunt “Doing” science is way more interesting than listening about it, even though it requires a lot of time and resources. RadoNorm funding paved the way to set up a new path in high school curriculum regarding ionising radiation. Portugal, RadAR The CS project facilitated the participation of individuals from various backgrounds, effectively bridging the gap between professionals and the public. The researchers, teachers, students and volunteers of the CS project are of the opinion that CS empowers individuals, enriches scientific research, and nurtures a sense of shared responsibility. Citizen science advances scientific knowledge and fosters collaboration between researchers and the public. Without such projects, large-scale data collection is often much more challenging. The CS project involved a large number of participants which enabled extensive data collection across diverse locations and timeframes, contributing to the monitoring of radon exposures which would have been difficult for a small research team like the size of the project coordinators to achieve alone. Participation in CS provides education to volunteers, particularly in remote areas, on scientific methods, data analysis, and critical thinking which enhances not only scientific literacy but also empowers citizens to become advocates for conservation and environmental protection. Slovakia, RadonGPS Six months is inadequate for such a CS project. Personal invitations to kick-off meetings proved easy and effective, while invitations via public address system through the mayor were less effective. Facebook proved less effective for communication and dissemination. RadoNorm funding played a crucial role in enabling the non-governmental organization NatuRadon to implement its goals on a wider scale, thereby meeting a key expectation outlined in the proposal. The research question of the CS project was answered through student projects of anti-radon measures, which are freely available on the website on NatuRadon. The discussion platform created on the CS project webpage did not receive a positive response from the citizen scientists. Citizen scientists valued the opportunity to independently measure radon using active radon detectors and appreciated the expert assistance in evaluating the radon levels in their homes. Citizen scientists found the up-to-date information available on the project webpage helpful, as well as access to student projects and cost estimates for potential radon remediation measures. Most of the citizen scientists indicated their intention to implement radon remediation measures in their own homes. The students found their participation in the project motivating for their future academic pursuits. The CS project successfully established cooperation not only with the citizen scientists and other stakeholders but also with the broader communities, including the secondary construction school, and collaboration with the Faculty of Wood Sciences and Technology at the Technical University in Zvolen. The project coordinators observed that the development and rapid updating of communication strategies for other stakeholders and citizen scientists involved in the project was the most challenging aspect. Slovenia, RadoNorm-SLO 90 participants joined the CS project, exceeding the originally anticipated number of about 50. The number of participants gradually declined as project progressed due to the loss in motivation for those who measured lower radon levels. Limited budget and short duration of the project made it impossible to monitor whether additional homes have been mitigated based on information provided via the CS project The experience gained through the project will be shared with radiation protection authority, with the aim of enhancing the impact of the national annual radon measurement program for residential environments CS project achieved significant dissemination efforts and was well publicized through various channels. Sustainability of the project remains a challenge due to a lack of additional funding. The 6-months timeframe did not allow for extensive follow-up with participants or a comprehensive evaluation of the long-term impact of the project. Strong collaborations with national authorities is essential for providing the necessary tools and support to citizens and ensuring that project outcomes feed into national radon awareness campaigns Spain, RadoHow Participants evaluated the project as positive by expressing their satisfaction with the knowledge gained and the activities conducted. Participants highlighted the creation of a strong community within the project, which they can consult for sharing information, asking questions about future legislation, or getting support for continuing to monitor their homes and workplaces, in cases of higher levels of radon. Activities were mostly conducted online since coordinating in-person activities was difficult, as participants came from five different provinces in Spain. Maintaining participant engagement over the long term was a challenge. However, citizen scientists stayed to the end of the project since they were interested in knowing their results, learning how to interpret them, and discussing findings. The project benefited greatly by engaging citizens scientists with and without prior knowledge of radon. Those without became informed and community actively learned together. Additionally, engaging both newcomers and experts provided diverse perspectives and enriched the project with varied insights. 7. Effectiveness of CS projects with a focus on community engagement and impact The CS evaluation method developed by Hoedoafia et al (2024) has been used to evaluate the effectiveness of CS projects in enhancing radon protection efforts. The assessment considers both outcome and process level indicators and includes the five dimensions: 1) scientific, 2) participants, 3) wider societal impact, 4) learning gains to researchers and 5) process evaluation. Out of these five dimensions proposed by Hoedoafia et al (2024), we focus in this section on those indicators directly related to community engagement and impact (Table 5). The coordinators of the CS projects reported high levels of engagement following Haklay’s (2013) classification, from distributed intelligence to participatory and extreme citizen science. In some case the initial intention of the CS project coordinators was not achieved, or they claimed it was not achieved, but the distinction between one level and the other are not clear-cut and there is a level of subjectivity. Based on the information from the coordinators and our own interpretation of the levels of engagement, we have developed Figure 4 to show levels of participation in the different countries. In Hungary, the research objective of RadoNorm Aerosol was defined as level 3 as “participatory science”. Nearly 30 students from three high schools participated in the development, communication and dissemination of the project which consisted of creating a toolkit with various low-cost measurement sensors to measure air quality, including radon. The evaluation of the measurement results was carried out jointly by the lead researchers and the citizen scientists in the form of personal discussions. In Italy, citizens contributed to research by conducting radon measurements and collecting data such as information on their buildings and radon perception risks. While the coordinators classified the project as participatory science, we claim that scientists designed the project and members of the public contributed with data and helped with basic interpretation. Thus, we propose the level of “distributed intelligence” for OCRA in Italy. In Poland, the project was classified as participatory science with some components of extreme CS. Citizen scientists placed detectors, decided where to collect samples, participated in introductory sessions to gain knowledge on radon, co-analysed measurement results during weekly meetings, took decisions on the next steps (where to redo measurements) and disseminated the project via TikTok. Due to legal reasons of working with minors, the coordinator and teacher needed to take the main lead in logistics of trips and other formal arrangements. Similarly, in Portugal, student citizen scientists disseminated information about radon, engaged the population to conduct radon measurements, co-developed the research question via meetings and class sections and co-analyzed/interpreted data from the results. The coordinators of RadoNorm-SLO in Slovenia classified their project as distributed intelligence, but we claim that a higher level of engagement was achieved. Most participants contributed by conducting radon measurements in their homes and some of them with elevated radon levels, had one on one discussions with scientists and even home visits with a radon mitigation specialist to provide tailored guidance and support through direct discussions with the homeowners. While the involvement of citizen scientists in the scientific process was limited, some participants showed a deeper interest and ability to engage with radon data and its interpretation and even mitigated. In one case, a citizen scientist mitigated himself using mechanical ventilation with a small overpressure. He also did the control measurement with his own digital radon monitor. According to the coordinators in Slovakia, the CS project was classified as “distributed intelligence”. Citizens were involved in the distribution of detectors, conducted radon measurements, evaluated data from measurements by active detectors on their own decision and evaluated data from measurements by passive detectors. The project allowed the cooperation with students during the design of tailor-made radon remediation projects, communicating their questions with experts. Students’ citizen scientists also designed tailor-made remedial projects and disseminated the project. The coordinators of RadonGPS claim that the initial intention was to achieve a higher level of participatory science, but the lack of time limited the possibilities for further engagement. However, the authors of this paper claim that the fact that one of the project’s outputs are tailor-made radon remediation projects alongside with the calculation of costs of radon remedial measures, moves up the level of the project to be considered participatory science. In Spain, citizen scientists were engaged from the very beginning, co-determining the measurement methodology alongside key stakeholders and the project team, using an extreme science approach. Citizen scientists participated in various stages of the scientific process in RadoHOW, together with researchers: defining the research question, collecting data, interpreting the data, and disseminating the methodology. They developed skills that enable them to interpret their results and communicate the outcomes, allowing them to take a more active role during and after the project. Based on the reports provided by the CS coordinators, the projects contributed to the collective capacity in different ways: in Hungary, through the development of a toolkit to measure air quality; in Italy, through the creation of an interactive map of radon exposure; in Poland, by co-creating content for public dissemination on the social media used (TikTok); in Portugal, the project brought citizens and students together to achieve the common goal of environmental stewardship by communicating their assessment on radon measurements and mitigation needs to the local communities; in Slovakia, the collective capacity was related to the co-creation of radon mitigation projects and empower citizens to take protective action; in Slovenia, the direct involvement of citizens in the scientific process fostered a more community-driven effort to address radon risks and in Spain, the project fostered a sense of community among participants. Table 5. Summary of CS project results on public outreach, collaboration and feedback Indicators/CS project Hungary Italy Poland Portugal Slovakia Slovenia Spain Public outreach 30 students, website, households involved 231 citizen scientists, (multiply by average number of household) newspaper articles, project webpage, social media - Facebook & Instagram. 10 students (30 people involved), TikTok, conferences, press releases, online magazines, news portal interview 60 students, newspaper articles, project webpage, conferences, social media - Facebook & Instagram. 47 citizen scientists (multiply by average number of household) 90 citizen scientists (multiply by average number of households) 20 citizen scientists (multiply by average number of households); social media (Instagram and Twitter); project webpage Collaboration and synergies High schools Local and regional authorities Senior high school, external laboratories, Atomic Forum Foundation 3 high schools collaboration with authority local authorities (e.g., collaboration with mayor), with Faculty of Wood Sciences and Technology at the Technical University in Zvolen and with secondary construction school Slovenian Ministry of Health, Radiation Protection Authority, community centre National, regional and local (Nuclear Safety council, public authorities) Feedback to participants Results of radon measurements Results of radon measurements, project outcome at final event Results of radon measurements. Informed consent. Results of radon measurements, public local events at each municipality. Citizen scientists informed of their data usage via informed consent Results of radon measurements, tailor-made remediation projects, final public meeting – project outcome; citizen scientists informed of their data usage via informed consent for data processing (citizens & legal representative of students) Results of radon measurements; discussion of possible solutions to householders on mitigation; final project event. Radon measurement results, simple mitigation recommendations. 5. Discussion This research provides evidence that the CS approach to radon research is an effective method to increase awareness, knowledge, risk perception and willingness to engage in protective behaviors. regarding radon exposure, confirming our hypothesis. Furthermore, it fosters scientific outcomes and enhances community engagement. The results were collected through a dedicated survey with citizen scientists (Perko et al. 2024, 2021) which was compared with results of a survey with general public, representative for gender, age and level of urbanisation (Perko T., 2025). A group discussion and content analysis of the final reports of CS projects complemented the data collection. The raw responses to the survey can be found online at Radon Behaviour Atlas.[1] The evaluation framework developed for the radon context by Hoedoafia et al. (2024) was used. The study critically examines the societal and individual’s impact of CS initiatives in the field of radon testing and mitigation. The findings show that following their participation in the CS projects, all citizen scientists became highly aware of radon. Regarding knowledge acquisition, the results indicate that while a majority of citizen scientists demonstrated accurate knowledge of key radon characteristics and health risks – e.g. link to lung cancer, odourless and invisible gas, long-term exposure effects – misconceptions persist among a minority regarding symptoms like headaches and the units used to measure radon levels. Citizen scientists also show higher levels of risk perception compared to the general population and better radon protection behaviour. Prior to participation in the CS project, radon mitigation actions among respondents were relatively uncommon, with only 14.3% reporting either remediation or the installation of preventive measures during construction. This is consistent with prior research indicating that, in many European contexts, awareness of and action on residential radon exposure remains low despite public health recommendations (Poortinga et al., 2011; Perko et al. 2024). However, the data reveal a strong behavioural intention toward radon testing and mitigation following engagement in the CS projects. Notably, 69% of respondents expressed a clear willingness to test for radon if advised and over 72% indicated they would test as a precaution. Furthermore, approximately 61% declared they would undertake necessary remediation actions if recommended. This suggests that participatory approaches like CS can stimulate protective behaviours and empower individuals to make informed decisions about their health, as suggested in previous studies (Hoedoafia et al., 2024; Martell et al. 2024; Stanifer et al., 2022). The wide variety of software and hardware used across countries involved in the RadoNorm CS Incubator show the adaptability of CS projects to different institutional and technical settings. Furthermore, the range of outputs ad data generated underscore the value and scalability of CS initiatives in the field of environmental health. Several countries have leveraged their experiences to expand ongoing or future CS efforts. Although the approach to the evaluation of CS projects across countries varied – from student self-reflection to verbal feedback or written input – the projects involving young students found that citizen science (“doing science” or hand-on scientific activities) is more engaging than traditional lectures or classroom approaches. The projects also contributed to the collective capacity in different ways, which is in line with other CS studies (Bonney et al. 2016). Insights from the evaluation highlight the importance of timely recruitment and tailored communication strategies. While this study provides valuable insights into CS engagement, several limitations must be acknowledged. First, the short-time frame of the CS projects (i.e. six months) and the limited budget provided (i.e. 25,000 euros in total) are the main limitations observed by some of the RadoNorm CS projects. These drawbacks made it impossible to monitor whether additional homes were mitigated based on the information and engagement provided through the CS projects. Additionally, it was not possible to assess the willingness of students to engage in remediation activities, which could have improved the understanding on motivational factors. Second, the number of participants in some initiatives was relatively small, potentially affecting the generalizability of the findings. Moreover, the survey response rate was notably low in some countries, largely due to limited computer access, which may have introduced sampling bias and limited cross-country comparisons. Except in the CS projects with schools, the engagement of younger participants more adept at using technology was generally missing, as most citizens involved were elderly persons. Targeting younger generations through educational efforts could enhance data collection and analysis. Maintaining participant engagement over time is an additional challenge and often, the participants whose measurements indicated low radon levels lost motivation and disengaged from the project. In some CS projects, authorities were involved from the outset, while in others, their collaboration came later. Nevertheless, cooperation with authorities was essential for providing tools and support to citizens and for ensuring that project outcomes were integrated into national radon awareness campaigns. Our findings confirm that while increasing awareness of radon is important, it is insufficient on its own to drive behavioural change or risk mitigation, as proved in different studies (Perko et al. 2024; Davis et al. 2018; Duckworth et al. 2002 Khan & Chreim, 2019). Future efforts should prioritize actionable engagement strategies that empower citizens to participate in the different stages of the research process. Authorities at national, regional and local levels should support CS as a complementary approach to testing campaigns by providing funding, infrastructure and technical support for these initiatives. Collaboration with schools, local non-governmental organizations and municipalities can enhance both participation and the societal relevance of the outcomes. Integrating CS into national radon action plans and radiation protection policies can strengthen monitoring capacity, increase risk communication and enhance the coproduction of knowledge between scientists, authorities and the public. [1] https://radonbehaviouratlas.wixstudio.com/radonorm 6. Conclusions This study addresses the gap between awareness of radon-related health risks and the adoption of protective measures by evaluating the impact and effectiveness of CS projects, with attention to both participant outcomes and project-level contributions. Through a mixed-methods approach, including computer-assisted web interviews with 231 citizen scientists, interviews with seven researchers, and group discussions with ten CS coordinators and the CS evaluation method developed by Hoedoafia et al ( 2024 ), this paper has shown through empirical evidence that participation in CS projects on radon can significantly increase participants’ awareness, knowledge, risk perception and willingness to engage in protection behaviours related to radon exposure. We have assessed both the individual-level benefits of CS projects (e.g., knowledge gain and behaviour change) as well as the broader scientific and social outcomes, including the challenges encountered during project implementation. Future research should investigate what motivates citizens to engage at deeper levels and over extended periods. In addition, further investigation is needed into how CS influences descriptive and social norms as well as the broader social environment in which participants operate. Understanding these dynamics can contribute to the design of more resilient and socially embedded CS projects. Declarations Funding This project has received funding from the Euratom research and training programme 2019–2020 RadoNorm under grant agreement No 900009 and from PIANOFORTE Euratom research and innovation program under the 101061037 grant agreement. Acknowledgements The authors would like to express their sincere gratitude to Mabel Akosua Hoedoafia, postdoctoral researcher at SCK CEN, for their dedicated contribution to the RadoNorm project. Over the course of 18 months, she worked exclusively on RadoNorm, playing a key role in data collection and helping to lay the groundwork for this study. Mabel’s efforts and commitment are deeply appreciated. We would like to express our sincere thanks to the coordinators of the citizen science projects. Our heartfelt gratitude also goes to the interviewees who took the time to share their insights with us. All these contributions were invaluable to the success of this project. References Ambrosino, F., La Verde, G., Colucci, M., Fanti, V., Barrale, D., Caciolli, A., Hemmer, S., De Giorgi, M. L., Ventura, A., Imm., J., Pagano, A., Budinich, M., Vascotto, M., Montalbano, V., Capua, M., Tucci, R., Chiosso, M., Visca, L., Groppi, F., & Pugliese, M. (2024). RadioLab project: Knowledge of radon gas in Italy. Scientific Reports, 14(1), 1224. https://doi.org/10.1038/s41598-023-45809-6 Andresz, S., Marchand-Moury, A., Goyette-Pernot, J., Rivi.re, A. L., & Schieber, C. (2023). When citizen science meets radon building diagnosis: Synthesis of a French pilot project developed in the framework of the European RadoNorm research project. Open Res Eur, 3, 106. https://doi.org/10.12688/openreseurope.15968.2 Bonney, R., Phillips, T.B., Ballard, H.L., Enck, J.W. Can citizen science enhance public understanding of science? Public Underst Sci. 2016 Jan;25(1):2-16. doi: 10.1177/0963662515607406. Bouder, F., Perko, T., Lofstedt, R., Renn, O., Rossmann, C., Hevey, D., Siegrist, M., Ringer, W., P.lzl-Viol, C., Dowdall, A., Fojt.kov., I., Barazza, F., Hoffmann, B., Lutz, A., Hurst, S., & Reifenh.user, C. (2019). The Potsdam radon communication manifesto. Journal of Risk Research, 24(7), 909-912. https://doi.org/10. 1080/13669877.2019.1691858 De Cicco, F., Balzano, E., Limata, B. N., Masullo, M. R., Quarto, M., Roca, V., Sabbarese, C., & Pugliese, M. (2017). Radon measurement laboratories: An educational experience based on school and university cooperation. Physics Education, 52(6), 065003. https://doi.org/10.1088/1361-6552/aa811e European Environment Agency. (2022). Radon. Retrieved 11 July 2025. Murray, C. J. L., Aravkin, A. Y., Zheng, P., Abbafati, C., Abbas, K. M., Abbasi-Kangevari, M., Abd-Allah, F., Abdelalim, A., Abdollahi, M., Abdollahpour, I., Abegaz, K. H., Abolhassani, H., Aboyans, V., Abreu, L.G., Abrigo, M. R. M., Abualhasan, A., Abu-Raddad, L. J., Abushouk, A. I., Adabi, M., . . . Lim, S. S. (2020). 251 Global burden of 87 risk factors in 204 countries and territories, 1990–2019: A systematic analysis for the Global Burden of Disease Study 2019. The Lancet, 396(10258), 1223-1249. https://doi.org/10.1016/S0140-6736(20)30752-2 Hahn, E. J., Wilmhoff, C., Rayens, M. K., Conley, N. B., Morris, E., Larck, A., Allen, T., & Pinney, S. M. (2020). High school students as citizen scientists to decrease radon exposure. International Journal of Environmental Research and Public Health, 17(24), 9178. https://doi.org/10.3390/ijerph17249178 Haklay, M. (2013) Citizen science and volunteered geographic information – overview and typology of participation. In: Sui, D, Z., Elwood, S., Goodchild , M.F. (Eds.), Crowdsourcing Geographic Knowledge: Volunteered Geographic Information (VGI) in Theory and Practice. Springer, Berlin, pp. 105- 122 . https://doi .org/10.1007 /978 -94 -007 -4587 -2_7. Hevey, D., Perko, T., Martell, M., Bradley, G., Apers, S., & Rovensk., K. N. (2023). A psycho-social-environmental lens on radon air pollutant: Authorities’, mitigation contractors’, and residents’ perceptions of barriers and facilitators to domestic radon mitigation [Original Research]. Frontiers in Public Health, 11. https://doi.org/10.3389/fpubh.2023.1252804 Hoedoafia MA, Martell M and Perko T (2024) Evaluating citizen science projects: insights from radon research. Front. Environ. Sci. 12:1436283. doi: 10.3389/fenvs.2024.1436283 Levontin, L., Gilad, Z., Shuster, B., Chako, S., Land-Zandstra, A., Lavie-Alon, N., Shwartz, A., 2022. Standardizing the Assessment of Citizen Scientists’ Motivations: A Motivational Goal-Based Approach 7, 25. https://doi.org/10.5334/cstp.459 Martell, M., Perko, T., Andresz, S., Schieber, C., Tomkiv, Y., Dowdall, A., McKittrick, L., & Groma, V. O. (2024). Radon and citizen science. In J. Sixto-Garcia, S. P.rez-Seijo, & B. Garcia-Orosa (Eds.), Communicating Public Health Risk: The Case of Radon Gas. Routledge. https://doi.org/10.4324/9781032618180 Martell, M., Perko, T., Tomkiv, Y., Long, S., Dowdall, A., & Kenens, J. (2021). Evaluation of citizen science contributions to radon research. Journal of Environmental Radioactivity, 237, 106685. https://doi.org/10.1016/j.jenvrad.2021.106685 Perko T. (2025): RadoNorm European Radon Behavioural Atlas: Portugal, H2020 project RadoNorm, No 900009 https://www.radonorm.eu/ , DOI:10.20348/STOREDB/1179/1306 Perko, T., Thijssen, P., Hevey, D., Turcanu, C., & Muric, M. (2024). Measuring societal attitudes and behaviours towards radon indoors: A case study of Slovenia. Journal of Environmental Radioactivity, 272 , 107355. https://doi.org/10.1016/j.jenvrad.2023.107355 Perko, T., Martell, M., Rovenska, K., Fojtikova, I., Paridaens, J., & Geysmans, R. (2023). Review and evaluation of national radon action plans in EU Member States according to the requirements of Council Directive 2013/59/Euratom. (199). Luxembourg: European Commission Perko, T., Turcanu, C., Hoti, F., Thijssen, P., & Muric, M. (2021) RadoNorm pilot study report from public opinion survey, Belgium 2020-2021. Development of a modular questionnaire for investigating societal aspects of radon and NORM. Stanifer, S., Hoover, A. G., Rademacher, K., Rayens, M. K., Haneberg, W., & Hahn, E. J. (2022). Citizen science approach to home radon testing, environmental health literacy and efficacy. Citiz Sci, 7(1). https://doi.org/10.5334/cstp.472 Tsapalov, A., & Kovler, K. (2021). Studying temporal variations of indoor radon as a vital step towards rational and harmonized international regulation. Environmental Challenges, 4, 100204. https://doi.org/10.1016/j.envc.2021.100204 Cronin, C., Trush, M., Bellamy, W., Russell, J., & Locke, P. (2020). An examination of radon awareness, risk communication, and radon risk reduction in a Hispanic community. International Journal of Radiation Biology, 96 (6), 803–813. Retrieved from ://WOS:000517180600001 D'Antoni, D., Auyeung, V., Walton, H., Fuller, G. W., Grieve, A., & Weinman, J. (2019). The effect of evidence and theory-based health advice accompanying smartphone air quality alerts on adherence to preventative recommendations during poor air quality days: A randomised controlled trial. Environ Int, 124 , 216–235. doi:10.1016/j.envint.2019.01.002 Davis, S. F. J., J.D.; Magnusson, B.M.; Novilla, M.L.B.; Torgersen, B.K.; Schnell, A.J.; Crandall, A. (2018). Predictors of radon testing among Utah residents using a theory-based approach. J. Environ. Health 80 , 20–27. Desvousges, W. H., Smith, V. K., & Rink, H. H. (1992). COMMUNICATING RADON RISKS EFFECTIVELY - THE MARYLAND EXPERIENCE. Journal of Public Policy & Marketing, 11 (2), 68–78. Retrieved from ://WOS:A1992JW96500007 DiPofi, J. A., LaTour, M. S., & Henthorne, T. L. (2001). The new social marketing challenge to promote radon testing. Health Mark Q, 19 (1), 79–90. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/11727294 Dragojevic, M., Bell, B., & M., M. (2014). Giving Radon Gas Life Through Language: Effects of Linguistic Agency Assignment in Health Messages About Inanimate Threats. Journal of Language and Social Psychology, 33 (1). doi:https://doi.org/10.1177/0261927X13495738 Duckworth, L. T., Frank-Stromborg, M., Oleckno, W. A., Duffy, P., & Burns, K. (2002). Relationship of perception of radon as a health risk and willingness to engage in radon testing and mitigation. Oncology Nursing Forum, 29 (7), 1099–1107. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036674504&doi=10.1188%2f02.ONF.1099-1107&partnerID=40&md5=08e99058c8ab0a2e47aeeae4ab3f49e5 European Commission: Directorate-General for Energy, MERIENCE, SCK CEN, SURO, Perko, T. et al., Review and evaluation of national radon action plans in EU Member States according to the requirements of Council Directive 2013/59/Euratom , Publications Office of the European Union, 2023, https://data.europa.eu/doi/10.2833/531667 Golding, D., Krimsky, S., & Plough, A. (1991). Evaluating risk communication: narrative vs. technical presentations of information about radon. Risk Anal, 12 (1), 27–35. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1574615 Hahn, E. J., Rayens, M. K., Kercsmar, S. E., Robertson, H., & Adkins, S. M. (2014). Results of a Test and Win Contest to Raise Radon Awareness in Urban and Rural Settings. American Journal of Health Education, 45 (2), 112–118. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897711978&doi=10.1080%2f19325037.2013.875960&partnerID=40&md5=8aa2d94e4366b40f4609cbc52d88a67a Hevey, D. (2017). Radon Risk and Remediation: A Psychological Perspective. Frontiers in public health, 5 , 63. doi:https://doi.org/10.3389/fpubh.2017.00063 Kennedy, C. J., Probart, C. K., & Dorman, S. M. (1991). The relationship between radon knowledge, concern and behavior, and health values, health locus of control and preventive health behaviors. Health Educ Q, 18 (3), 319–329. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1917508 Khan, S. M., & Chreim, S. (2019). Residents' perceptions of radon health risks: a qualitative study. BMC Public Health, 19 (1), 1114. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/31412828 Niemeyer, S., & Keller, B. (1999). Radon Publication Information: Impact on Readers’ Knowledge, Attitudes and Intentions. Housing and Society, 26 (1-3), 54–62. doi:10.1080/08882746.1999.11430435 Nwako, P., & Cahill, T. (2020). Radon gas exposure knowledge among public health educators, health officers, nurses, and registered environmental health specialists: A cross-sectional study. Journal of Environmental Health, 82 (6), 22–29. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078222393&partnerID=40&md5=ad67b4ee0b416f102a8810a6c14147fa Perko, T., Thijssen, P., Hevey, D., Turcanu, C., & Muric, M. (2024). Measuring societal attitudes and behaviours towards radon indoors: A case study of Slovenia. Journal of Environmental Radioactivity, 272 , 107355. doi:https://doi.org/10.1016/j.jenvrad.2023.107355 Perko, T. and Hevey, D. (2024). Communicating radon risks: the impact ofdifferent risk formulations on risk perception andprotection intention. Journal of Risk Research , 27 (4), 562-580. https://doi.org/10.1080/13669877.2024.2387346Peterson, E. W., & Howland, J. (1996). Predicting radon testing among university employees. Journal of the Air & Waste Management Association, 46 (1), 2–11. Retrieved from ://WOS:A1996TN47700001 Poortinga, W., Bronstering, K., & Lannon, S. (2011). Awareness and perceptions of the risks of exposure to indoor radon: a population-based approach to evaluate a radon awareness and testing campaign in England and Wales. Risk Anal, 31 (11), 1800–1812. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/21477087 Ryan, D., & Kelleher, C. C. (1998). A survey of householders' mitigation strategy - Response to raised radon levels. European Journal of Public Health, 9 (1), 62–64. Retrieved from ://WOS:000079648300014 Weinstein, N. D., man, P. M., & Roberts, N. E. (1990). Determinants of Self‐Protective Behavior: Home Radon Testing. Journal of Applied Social Psychology, 20 (10), 783–801. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000075296&doi=10.1111%2fj.1559-1816.1990.tb00379.x&partnerID=40&md5=20f23078cdac72adadbb7a453006b418 Weinstein, N. D., man, P. M., & Roberts, N. E. (1991). Perceived susceptibility and self-protective behavior: a field experiment to encourage home radon testing. Health Psychol, 10 (1), 25–33. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/2026127 Weinstein, N. D., Roberts, N. E., & Pflugh, K. K. (1992). Evaluating Personalized Risk Messages. Evaluation Review, 16 (3), 235–246. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973744433&doi=10.1177%2f0193841X9201600302&partnerID=40&md5=65c3c25e30ef6ee55130337838452041 Witte, K., Berkowitz, J. M., Lillie, J. M., Cameron, K. A., Lapinski, M. K., & Liu, W. Y. (1998). Radon awareness and reduction campaigns for African Americans: A theoretically based evaluation. Health Education & Behavior, 25 (3), 284–303. doi:10.1177/109019819802500305 Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7120379","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":485091106,"identity":"ac75f1b2-0930-49ff-bb61-e5280a92edf4","order_by":0,"name":"Meritxell Martell","email":"data:image/png;base64,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","orcid":"https://orcid.org/0000-0003-4335-117X","institution":"Merience SCP","correspondingAuthor":true,"prefix":"","firstName":"Meritxell","middleName":"","lastName":"Martell","suffix":""},{"id":485091152,"identity":"eea9b08a-4056-4412-bdc3-e3dfea907472","order_by":1,"name":"Tanja Perko","email":"","orcid":"https://orcid.org/0000-0001-8405-6631","institution":"SCK CEN","correspondingAuthor":false,"prefix":"","firstName":"Tanja","middleName":"","lastName":"Perko","suffix":""}],"badges":[],"createdAt":"2025-07-14 10:58:16","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-7120379/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7120379/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":86915987,"identity":"f014ed55-3f30-4a2a-b6d8-98c49b7ae1f9","added_by":"auto","created_at":"2025-07-17 06:36:45","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":134689,"visible":true,"origin":"","legend":"\u003cp\u003eRadon awareness among general population and citizen scientists before the CS project\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7120379/v1/4091f47c7ba5be6e4e0e35b8.png"},{"id":86915988,"identity":"838252c5-b3cb-4af7-8e3c-9a4968a4c45c","added_by":"auto","created_at":"2025-07-17 06:36:45","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":202628,"visible":true,"origin":"","legend":"\u003cp\u003eRadon risk perception among general population and citizen scientists\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7120379/v1/5681b156b4b7d054f9fd72d6.png"},{"id":86915866,"identity":"ecbfaff4-7179-44fa-9823-cd1bc6ab19ba","added_by":"auto","created_at":"2025-07-17 06:28:45","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":131112,"visible":true,"origin":"","legend":"\u003cp\u003eIntention to test radon among general population and citizen scientists\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7120379/v1/b1a63235b802053c4811e7d0.png"},{"id":86915864,"identity":"8bb669f1-7238-4964-8630-f42059602100","added_by":"auto","created_at":"2025-07-17 06:28:45","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":189181,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eLevels of participation in the RadoNorm CS projects\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7120379/v1/866841ac89523df88cfffb13.png"},{"id":86916596,"identity":"141c475d-f400-4034-8684-a1f7d47cc6d7","added_by":"auto","created_at":"2025-07-17 06:44:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1642582,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7120379/v1/b1a1b153-fa6c-4ad6-a52d-ecc7d6a532a5.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eEmpowering communities: the impact of citizen science on radon measurement and mitigation\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"1.\tIntroduction","content":"\u003cp\u003eThe overarching aim of this study is to define the impact and effectiveness of citizen science (CS) projects on awareness, behaviour, and community engagement related to an environmental health issue. As a case study, this paper focuses on the indoor air pollutant radon\u0026mdash;a significant yet often overlooked public health risk. Across European Member States, awareness campaigns have been launched to address radon exposure, increase radon testing and promote mitigation efforts, including the installation of ventilation systems in private dwellings when radon concentrations exceed national reference levels.\u0026nbsp;However, the effectiveness of these awareness campaigns is limited and often fails to translate into practical actions (European Commission, 2023).\u0026nbsp;Research indicates that even when residents are aware of the health risks associated with elevated indoor radon levels, they may show little concern about living in such environments (Perko and Hevey, 2024) and are not taking any actions to reduce radon concentrations. Low intention to take actions to protect from risk is also due to difficult accessibility and high complexity of the testing and mitigation process, the lack of support from relevant organizations and institutions, or the general public\u0026apos;s preoccupation with more familiar and widely recognized issues (Hevey et al. 2023). In addition, the gap between awareness of radon-related health risks and the adoption of protective measures may be attributed to the limited involvement of communication and behavioural experts employing theory- and evidence-based approaches, as well as the lack of comprehensive social studies assessing existing behaviours, knowledge, experiences, and attitudes of citizens toward radon risk protection.\u0026nbsp;(Perko et al., 2023; Bouder et al., 2023).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEmpirical evidence shows that awareness alone is rarely enough to drive protective behaviour against radon. Large scale surveys in the United Kingdom, Ireland, Belgium and the United States indicate that, while awareness is a necessary pre condition for action, it does not reliably predict either home testing or remediation\u0026nbsp;(Cronin et al. 2020; Poortinga et al. 2011; Perko et al. 2024; Hevey, 2017). Similarly, factual knowledge acquired through formal education, personal experience or targeted communication campaigns has displayed little or no consistent association with protective action (Desvousges et al. 1992; Nwako \u0026amp; Cahil, 2020; Hahn et al. 2014; Ryan \u0026amp; Kelleher, 1998; Golding et al. 1991; Kennedy et al. 1991; Peterson \u0026amp; Howland, 1996; Davis et al. 2018). In contrast, studies repeatedly link heightened risk perception - especially when respondents personally know someone with lung cancer - to stronger intentions to test for and mitigate radon (Perko et al. 2024; Davis et al. 2018; Duckworth et al. 2002; Khan \u0026amp; Chreim, 2019). Perceived susceptibility not only predicts the acquisition of test kits but also follow‑through in measurement campaigns (Perko et al. 2024; D\u0026rsquo;Antoni et al. 2019; Weinstein et al. 1991; Niemeyer \u0026amp; Keller, 1999).\u0026nbsp;Yet the link is not deterministic: Poortinga\u0026nbsp;et al. (2011) found that participants who regarded radon as highly hazardous often still failed to act. Protection motivation theory applied in the field of radon (DiPofi et al. 2011) help explain this gap: effective action depends on coping appraisal - belief that mitigation works (response efficacy), confidence in one\u0026rsquo;s ability to carry it out (self-efficacy) and acceptable perceived costs. These three elements have consistently emerged as key predictors of both testing and remediation (Weinstein et al. 1990; Weinstein et al. 1992; Witte et al. 1998; Dragojevic et al. 2014)\u0026nbsp;and higher self-efficacy is associated with substantially greater adoption of radon protective measures (Davis et al. 2018).\u003c/p\u003e\n\u003cp\u003eThe involvement of citizen scientists in radon research presents a promising strategy not only for raising awareness and enhancing risk perception, but also for closing the persistent gap between knowledge and action in radon protection. Citizen participation has been shown to positively influence key psychological drivers of behaviour - such as response efficacy, self-efficacy, and perceived response costs - thereby increasing the likelihood of meaningful engagement with radon testing and mitigation measures. Recent studies\u0026nbsp;(Martell et al., 2024) demonstrate that citizens across the globe have actively contributed to both scientific data collection and the implementation of radon mitigation strategies, underscoring the practical impact of CS initiatives. By integrating citizens into the research process, CS offers a powerful means to address the disconnection between public concern and the often-limited uptake of mitigation actions\u0026nbsp;(Martell et al., 2021). Beyond supplying valuable local data, citizen scientists foster a sense of agency and collective responsibility, which can help dismantle psychological and structural barriers to action. In this way, CS emerges not only as a tool for engagement, but as a transformative approach that may enable more comprehensive and effective responses to radon exposure risks across the EU (Martell et al. 2024, Hoedoafia et al. 2024).\u0026nbsp;For instance, several CS projects have been conducted in schools with the intention to raise awareness about radon risks both within the school and at home by involving students in radon measurements and data collection (De Cicco et al., 2017; Tsapalov et al., 2021; Hahn et al., 2020; Ambrosino et al., 2024). These initiatives help not only to educate students but also serve as a bridge to engage families and the broader community, fostering a shared responsibility for radon awareness and mitigation. In addition, pilot projects in radon CS showed promising effects of involving citizens in radon testing and mitigation in France, Hungary, Ireland, and Norway (Hoedoafia et al., 2024; Martell et al., 2024). For instance, in France, as part of this pilot project, Andresz et al. (2023) found that involving citizens can improve fostering action in the radon post-measurement phase and can increase knowledge and behavioural uptake. Moreover, in the United States, Stanifer et al. (2022) carried out a CS project with 60 homeowners in rural Kentucky. The project increased participants\u0026apos; self-efficacy in testing and mitigation, but their confidence in the effectiveness of radon mitigation (response efficacy) remained low.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDespite growing interest in CS as a tool for environmental health communication and community engagement, there is a lack of empirical evidence on the effectiveness of CS projects in enhancing both public understanding and behaviour related to radon exposure. According to our knowledge there is no study which would systematically examine how participation in CS initiatives in the field of radon impacts participants\u0026rsquo; awareness, knowledge, risk perception, and willingness to adopt protective behaviours. Furthermore, the role of CS in generating scientifically valuable data, fostering collaboration between scientists and the public, and contributing to long-term community engagement remains systematically underexplored (Hoedoafia et al. 2024). There is a need to assess not only the individual-level benefits of such projects (e.g., knowledge gain and behaviour change) but also the broader scientific and social outcomes, including the challenges encountered during project implementation. This study addresses this gap by evaluating the impact and effectiveness of CS projects focused on radon, with attention to both participant outcomes and project-level contributions. It responds on the following research question and hypothesis:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eRQ: How effective are CS projects in increasing public awareness, knowledge, and protective behaviour regarding radon exposure, while fostering scientific outcomes and community engagement?\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eH1: Participation in a CS project on radon significantly increases participants\u0026apos; awareness, knowledge, risk perception, and willingness to engage in protective behaviours.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe study critically examines the societal and individual\u0026rsquo;s impact of CS initiatives in the field of radon testing and mitigation using the evaluation framework developed for the radon context by Hoedoafia et al. (2024) in combination with a dedicated survey (Perko et al. 2024, 2021) conducted with citizen scientists comparing results of a survey with general public representative for gender, age and level of urbanisation (Perko T., 2025).\u003c/p\u003e"},{"header":"2. Background and context of the case study","content":"\u003cp\u003eRadoNorm project addresses the critical issue of radon, a dangerous indoor air pollutant causing over 19,000 annual lung cancer cases in Europe (European Environment Agency, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Murray et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Recognising the limited awareness, testing efforts and low mitigation numbers in high radon risk areas, RadoNorm established a Citizen Science Incubator involving citizens and scientists from diverse scientific disciplines. The aim was to create a model for grassroots CS projects in radon risk areas. The CS Incubator engaged more than 800 citizen scientists across Europe. The project started with four pilot projects to address radon testing and mitigation during a period of six months. In France, citizens improved cutting-edge radon diagnostic tools by answering the question: \u003cem\u003eHow can diagnostics be improved to identify entry points in homes, and how can the computer program be made more user-friendly?\u003c/em\u003e Ireland investigated \u003cem\u003ewhether citizens can successfully mitigate their homes using do-it-yourself (DIY) tools\u003c/em\u003e through the development of a DIY toolkit. In Norway, citizens decided to take on the role of science communicators by trying to answer \u003cem\u003ewhat type of communication is necessary to influence radon protection behavior?\u003c/em\u003e In Hungary, the pilot CS project explored the question \u003cem\u003ecan an ordinary CO\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e \u003cem\u003emeter, prevalent in classrooms post-COVID-19, be combined with radon measurements?\u003c/em\u003e The CS project in Hungary continued after the pilot stage given the high level of interest from both the CS coordinator and the teachers involved (Martell et al, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2024\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eTransitioning from the four pilot projects to grassroots projects, the CS Incubator supported community-specific research questions in six countries (see Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In Italy, citizens measured radon levels, analysed data and developed an interactive radon map. Polish high school students collected and analysed samples of soil, water and air, contributing to both education and research. In Portugal students run a nationwide radon measurement, filling a radon mapping data gap in their country. In Slovakia citizens, high school for builders and authorities investigated building mitigation strategies, while Slovenia's team conducted research on the effectiveness of different mitigation techniques. Finally, the Spanish CS project targeted both workplaces and homes for radon exposure improvement. In addition, the pilot citizen science project in Hungary evolved into a full-scale initiative in which high school students measured indoor air quality and developed communication channels to share the results with a wider audience.\u003c/p\u003e\u003cp\u003eThe research questions, objectives and participants in the seven CS initiatives funded by RadoNorm are compiled in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eResearch questions, objectives, and participants of CS projects\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCountry, CS project\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eResearch question\u003c/p\u003e\u003cp\u003e(Response level to RQ: 0\u0026thinsp;=\u0026thinsp;Not addressed, 1\u0026thinsp;=\u0026thinsp;Partly addressed, 2\u0026thinsp;=\u0026thinsp;Fully addressed)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eObjectives\u003c/p\u003e\u003cp\u003eLevel of objective fulfilment)\u003c/p\u003e\u003cp\u003e0\u0026thinsp;=\u0026thinsp;No, 1\u0026thinsp;=\u0026thinsp;Partly, 2\u0026thinsp;=\u0026thinsp;Achieved\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNo. and description of citizen scientists (Coordinator-Reported) (number of survey respondents)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eItaly, OCRA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWhat are the levels of radon concentrations in various buildings, and how can an understandable infographic and active radon map be created?\u003c/p\u003e\u003cp\u003e(2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo reduce indoor radon levels through measurement of exposure and increased awareness of radon risks and mitigation measures in houses, school rooms and working places in Abbadia San Salvatore, Siena, one of the most radon-affected municipalities in Italy and to create a radon distribution map to increase radon communication risk. (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eParticipants included workers, retired people, families, teachers and students of the municipality of Abbadia SS, Siena and the indirect involvement of 700 students of four schools.\u003c/p\u003e\u003cp\u003e216 citizens were initially recruited but 43 people never returned the radon samplers for the analysis. 173 at the end joined the project.\u003c/p\u003e\u003cp\u003eRemark: Considering the number of citizen scientists, the participation of 25 participants in the CS survey is woefully inadequate. Possible reasons for the low response rate as proffered by the coordinators is the large number of older participants who are not technology savvy.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHungary, RadoNorm-Aerosol\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCan an ordinary CO\u003csub\u003e2\u003c/sub\u003e meter, prevalent in classrooms post-COVID-19, be effectively combined with radon measurements to achieve a more liveable environment? (1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo test whether it is feasible to develop an affordable toolkit measuring several air quality and radiation components, including radon, CO\u003csub\u003e2\u003c/sub\u003e, particulate matter and CO. (1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10 students from two high schools in Budapest and Sz\u0026eacute;kesfeh\u0026eacute;rv\u0026aacute;r. (6)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePoland, AHS RadonHunt\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWhere and to what extent is radon present in mining, drinking water, and (indoor air) air in Poland? (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo introduce citizen science as a pedagogical approach that builds students\u0026rsquo; agency and deepens their understanding and carrying out measurements where radon can be found as well as sharing the scientific journey of students via social media, TikTok. (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ethe main participants were teachers and students. Ten Y10 students (ages 14\u0026ndash;15) from the Akademaie high school. (12)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePortugal, RadAR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCan a local campaign designed and implemented by students improve monitoring rates and promote action to reduce indoor radon exposure? (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo engage students as the main driving force and central pillar to create a local communication strategy to increase radon awareness in the population and to promote the behavioural change necessary to conduct citizens to take action to reduce radon levels in their dwellings. (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e60 citizen scientists from three high schools in inland areas of Portugal (consistent with the number outlined in the proposal).\u003c/p\u003e\u003cp\u003eOther citizens of the municipalities who measured radon in their dwellings and participated in public events. (81)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSlovakia, RadonGPS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHow can future building professionals help improve the implementation of the radon concentration reducing measures in Slovakian private dwellings? (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo compare short-term (2 weeks by active radon detector) and long-term (3 month by passive radon detectors) indoor radon measurements in family houses in the municipalities around the town of Bansk\u0026aacute; Bystrica in the Slovak Republic and to engage students of secondary construction school (as future building professionals) to design tailor-made remediation projects for owners of the family houses. (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e50 citizen scientists at the initial stage (consistent with the number outlined in the proposal), 47 citizen scientists until the end (including 14 secondary construction students); 3 drop-out citizen scientists (including 2 secondary construction students and 1 adult citizen). (31)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSlovenia, RadoNorm-SLO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eHow effective are different radon mitigation techniques in reducing indoor radon levels as measured and implemented by citizen scientists in the Bela Krajina region (municipalities of Črnomelj, Metlika, and Semič). (1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo explore public perception \u0026amp; behavior related to radon measurement and mitigation. Specifically, to understand why people are reluctant to measure radon levels in their homes and take mitigation actions, despite radon being a known health risk in certain regions of Slovenia, such as Bela krajina. To raise awareness, foster a deeper understanding of radon\u003c/p\u003e\u003cp\u003erisks, and empower individuals to take action to reduce radon exposure in their homes. (1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAt the beginning, 105 citizens from Bela Krajina completed the entry questionnaires. 90 citizen scientists; 40% were over 60 years old, 30% were between 45 and 60 years old, and 30% were between 26 and 45 years old; 35 citizen scientists by the time of radon mitigation and 20 citizen scientists at the final event; Citizens with elevated radon levels measured during a national campaign in 2023 were invited to participate in the RadoNorm-SLO project. Many citizen scientists remained engaged throughout the project, but motivation declined for those whose homes had low radon levels; Some\u003c/p\u003e\u003cp\u003eolder participants, in particular, faced challenges with the technical aspects of the project. (55)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSpain, RadoHow\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWhat is the radon exposure of residents in specific regions of Spain at home compared to their workplaces? (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTo compare the levels of radon exposure of citizen scientists at work versus at home, across various geographical, geological, and building environments in Spain. The project also aims to raise awareness about the potential health effects, emphasising that these two doses are received continuously, as individuals spend most of their time in these two locations. (2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e20 participants from 5 different provinces from Spain (4 from each) - Galicia: Radon prone area in Spain.\u003c/p\u003e\u003cp\u003e- Cantabria: Karst zone in Spain,\u003c/p\u003e\u003cp\u003e- Salamanca: Uranium mining area,\u003c/p\u003e\u003cp\u003e- Zaragoza: Low potential radon area,\u003c/p\u003e\u003cp\u003e- Madrid: Radon prone area with high population (21)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eIncorporating various scientific disciplines related to radiation protection, including physics, engineering, communication, radiobiology, computer sciences, chemistry, sociology, architecture and education sciences, the CS projects leveraged a broad knowledge spectrum. Specific disciplines take precedence in different regions; for example, construction engineering and physics in Slovakia and Slovenia, communication science in Norway, physics and education sciences in Hungary, Poland, and Portugal, and radiobiology and physics in Italy, with computer sciences being the focus in France.\u003c/p\u003e\u003cp\u003eRadoNorm CS Incubator was also featured on the European Union Prize for Citizen Science \u0026ndash; Honorary Mentions List in June 2024. The prize honours innovative and creative projects that demonstrate significant merit and societal impact. Thus, the project earned official recognition by being selected from an impressive 288 entries for an 'Honorary Mention' in the European Union Prize for Citizen Science. RadoNorm has thus secured a position among the top 10% of European citizen science projects.\u003c/p\u003e"},{"header":"3. Method and data","content":"\u003cp\u003eA mixed-method approach was employed, combining a quantitative online survey with qualitative methods, including group discussions and content analysis of project reports. The RadoNorm Ethical Committee provided guidance and oversight throughout the study.\u003c/p\u003e\u003cp\u003e\u003cb\u003eThe survey\u003c/b\u003e employed is mainly based on the European Radon Behaviour Atlas questionnaire developed by (Perko et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Additionally, scales developed by (Levontin et al., \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) were utilized to measure motivation of citizen scientists. The sequence of main topics used in the survey are as follows: a) CS project: name of CS project and description of project (2 items); b) level of involvement in the CS project (4 items); c) participants expectations (1 open-ended question); d) social cooperation (6 items); e) motivation to participate in the CS project (37 items); f) radon awareness (4 items); g) risk perception (1 item); h) radon knowledge (11 items); i) radon protection behaviour (4 items); j) intention to protect from radon (4 items); k) cue to action/actual behaviour (1 item); l) severity for self and for others (4 items); m) susceptibility for self and for others (4 items); n) response efficacy (4 items); o) self-efficacy (4 items); p) perceived burden (2 items); q) perceived cost (2 items); r) perceived ease (2 items); s) subjective norms (4 items) ; t) descriptive norms (4 items); u) health effect perception (1 item), v) willingness to engage in future research (1 item); w) affective response to information (2 items); x) socio-demographic items: gender, region, age, year of birth (control), education, size of household, dwelling ( 10 items). For this study, only a specific subset of concepts, derived from the theoretical framework, was analysed. The sample size is (N\u0026thinsp;=\u0026thinsp;231) and consists of citizen scientists of the initiatives in Hungary, Italy, Poland, Portugal, Slovakia, Slovenia, and Spain. A shorter version of the survey was administered to students and their teachers/project coordinators participating in the CS initiatives in Hungary and to all young adults in Poland and Portugal (N\u0026thinsp;=\u0026thinsp;105). The survey was implemented via a computer assisted web interviewing (CAWI) by the independent marketing company MEDIANA, a member of ESOMAR, headquartered in Slovenia between February 24 and May 6, 2024.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSurvey sample and response rate\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCS project\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNo. of responses\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e% of total\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNo participants in the initiative\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eResponse rate\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRadoNorm-Aerosol, Hungary\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.60\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e60.00%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOCRA, Italy\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e10.80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e173*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e14.45%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAHS RadonHunt, Poland\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e5.20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e85.71%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRadAR, Portugal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e81\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e35.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e360\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e22.50%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRadonGPS, Slovakia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e31\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e13.40\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e49\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e63.27%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRadoNorm-SLO, Slovenia\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e55\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e23.80\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e61.11%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRadoHow, Spain\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e9.10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e84.00%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e231\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e100.00\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e721\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e32.04%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e* \u003cem\u003eOnly adult participants were included in the survey.\u003c/em\u003e\u003c/p\u003e\u003cp\u003eRespondents\u0026rsquo; description: Socio-demographics of respondents: In terms of gender, respondents were fairly evenly split: 44.2% male, 53.2% female, and 2.6% preferred not to disclose their gender. The survey revealed that participants generally have high levels of education, with the largest group (25.1%) holding a bachelor\u0026rsquo;s degree. Overall, 63.2% of respondents have at least a bachelor's degree, including 19.5% with a master's and 18.6% with a doctorate. A smaller proportion (5.6%) hold less than a second-level certificate, and 24.7% have a second-level certificate. Most participants live in medium-sized households, typically without children, and have long-term residence in detached houses. Homeownership is high, with 70.1% of respondents owning or co-owning their homes, and 92.6% have lived in their current dwelling for more than one year. A significant portion (51.1%) use ground floor or basement spaces as living areas.\u003c/p\u003e\u003cp\u003eRegarding radon awareness, about 42% of respondents know they live in a radon-prone area, while 32.9% are unsure.\u003c/p\u003e\u003cp\u003eCS Information channels and prior engagement in CS Projects: When asked how participants learned about the CS projects, with multiple responses allowed, the results revealed a wide range of information sources. The majority of respondents (32.5%) learned about the project through schools, making educational institutions the primary channel. Friends were the second most common source, with 17.7% indicating they found out through personal networks. Social media (10%) and traditional media (3%) together accounted for 13% of the information dissemination, with social media playing a more prominent role. The \"Other\" category (22.1%) suggests additional, unspecified sources were also involved in spreading information. A small percentage (3.5%) either did not know or did not answer.\u003c/p\u003e\u003cp\u003eMost participants across all countries had not previously engaged in similar CS projects, with about 86% indicating this was their first experience. Among countries, Italy, Hungary, and Poland had particularly low levels of prior participation, indicating a strong opportunity for promoting CS in these regions. While Portugal, Slovenia, Slovakia, and Spain showed slightly higher levels of prior involvement, the majority of respondents in these countries were also new to CS.\u003c/p\u003e\u003cp\u003eThe CS questionnaire data - covering awareness, knowledge, risk perception, and radon protection behaviour - were compared with data from the RadoNorm European Radon Behavioural Atlas (Perko, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2025\u003c/span\u003e), an open data set. The study comprises over 17,000 respondents and includes more than 250 items per questionnaire, with an average completion time of 17 minutes. Data collection for this part of the study was conducted via computer-assisted web interviews (CAWI) between 2021 and 2024. For this analysis and comparison, nationally and regionally representative subsamples for gender, age, level of urbanisation and education were used from Portugal (N\u0026thinsp;=\u0026thinsp;1,200), Spain (N\u0026thinsp;=\u0026thinsp;1,005), and Slovenia (N\u0026thinsp;=\u0026thinsp;2,012). For other countries included in the CS projects, no comparable representative data were available.\u003c/p\u003e\u003cp\u003eA 120-minute in-person \u003cb\u003egroup discussion\u003c/b\u003e with the ten CS project coordinators was held on June 11, 2024. Following a structured protocol, it explored participant engagement, CS project implementation, societal impact, and long-term sustainability. Additionally, seven semi-structured interviews with radon experts were conducted between June and July 2024 to gather their perspectives on the contributions of citizen scientists. Inductive coding in NVivo was used for thematic analysis.\u003c/p\u003e"},{"header":"4. Results","content":"\u003cp\u003eThe following section discusses the impact of the CS projects related to the changes on: 1) radon awareness; 2) radon knowledge; 3) radon perception; 4) radon protection behaviour; 5) willingness to test and mitigate radon exposure; 6) scientific impact; 7) internal evaluation of the coordinators and 8) effectiveness of engagement.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e1. Increased radon awareness among citizen scientists\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eRadon awareness refers to knowledge of its existence and associated health risks. This was assessed by the question, \u0026ldquo;\u003cem\u003eDid you know anything about radon before joining the CS project?\u003c/em\u003e\u0026rdquo;. The results revealed significant variation in awareness across countries. Participants from Spain (81%) and Italy (64%) had the highest levels of awareness, while Slovenia (62%) and Poland (58%) showed moderate awareness. In contrast, Hungary (50%), Slovakia (45%), and Portugal (41%) had the lowest awareness levels. Overall, 54% of participants (124 out of 231) were aware of radon before joining the project, while 44% (101 participants) had no prior knowledge, and 2% (6 participants) either didn\u0026rsquo;t know or did not answer. When asked about their awareness of radon during the project, a significant increase was observed. After participating, 64.1% of respondents reported a good understanding of radon, while 35.1% had some familiarity with it. This indicates that the CS project played a crucial role in raising awareness, particularly in countries with initially lower levels of knowledge.\u003c/p\u003e\n\u003cp\u003eRegarding the question, \u0026ldquo;\u003cem\u003eHow much did you learn about protecting yourself from radon exposure in the CS project?\u003c/em\u003e\u0026rdquo;, a substantial majority of participants (44.2%) indicated they learned \u0026ldquo;\u003cem\u003ea lot\u003c/em\u003e,\u0026rdquo; and 22.1% said they learned \u0026ldquo;\u003cem\u003ea great deal\u003c/em\u003e.\u0026rdquo; Together, these responses suggest that 66.3% of participants gained considerable knowledge on radon protection. Some 23.8% of participants reported learning \u0026ldquo;\u003cem\u003ea little, but not much,\u003c/em\u003e\u0026rdquo; while a small fraction (6.5%) reported learning \u0026ldquo;\u003cem\u003every little or nothing at all.\u003c/em\u003e\u0026rdquo;\u003c/p\u003e\n\u003cp\u003eFigure 1 compares radon awareness between the general population and participants in CS projects in Slovenia, Spain, and Portugal, as assessed before the participants joined the projects. The results indicate that in Slovenia, citizen scientists were slightly less aware of radon compared to the general population, whereas in Spain and Portugal, citizen scientists showed slightly higher awareness levels prior to their involvement. It is important to note that, following their participation in the CS projects, all citizen scientists became highly aware of radon.\u003c/p\u003e\n\u003cp\u003e2.\u0026nbsp; \u0026nbsp;High radon related knowledge\u0026nbsp;acquired during the CS project\u003c/p\u003e\n\u003cp\u003eRadon-related knowledge refers to an individual\u0026rsquo;s understanding and information about radon, acquired through media, informational interventions, personal communication, or educational processes. In this study, radon knowledge among citizen scientists was assessed through their agreement or disagreement with 13 statements developed by Perko et al. (2024) to assess understanding of radon-related topics.\u003c/p\u003e\n\u003cp\u003eThe results show that a minority of respondents (24.2%) incorrectly believe that radon causes headaches. Nearly half of the respondents (49.4%) correctly disagreed with this statement, while 26.4% were uncertain or did not provide an answer. This suggests that while approximately half of the respondents demonstrated a correct understanding, the other half either held misconceptions or lacked clarity regarding the non-existent link between radon exposure and headaches.\u003c/p\u003e\n\u003cp\u003eA substantial majority of 86.1% knows that radon exposure is linked to lung cancer. Moreover, most respondents 89.2% correctly disagree with the statement that radon is a radioactive liquid, recognizing that radon is a gas. An overwhelming majority of 90.9% correctly disagree that radon has a strong odor, knowing that radon is odorless. A high percentage of respondents, 93.5% agree that radon is invisible, demonstrating awareness of the characteristics of radon. Most respondents, 83.1% correctly disagree that radon levels are usually higher in the attic than the basement. A majority of 88.3% agree that testing is the only way to determine if a home has elevated radon levels. A significant majority, 90.5% agree that radon can enter homes through cracks in walls and floors, which aligns with common knowledge about radon infiltration pathways. A majority of respondents, 71.4% agree that the health effects of radon do not show for years, acknowledging the long latency period associated with radon-induced lung cancer.\u0026nbsp;An overwhelming majority of 95.2% agree that the risks from radon exposure increase with longer exposure durations. Most respondents, 70.1% correctly disagree that indoor radon concentrations are expressed in Watt, knowing that radon levels are typically measured in becquerels per cubic meter (Bq/m\u0026sup3;).\u003c/p\u003e\n\u003cp\u003e3. \u0026nbsp;Higher radon\u0026nbsp;risk perception\u0026nbsp;among citizen scientists\u003c/p\u003e\n\u003cp\u003eThe responses highlight a generally high level of concern about the health risks of radon exposure among participants, with the majority perceiving a moderate to very high risk. For instance, the largest proportion of respondents, 45.0%, perceive a moderate risk to their health from radon exposure and a significant number of participants, 24.2%, consider the risk to be high with an additional 10.0% viewing the risk as very high. These categories combined indicate that 79.2% of respondents perceive a moderate to very high risk. A smaller group of participants perceive the risk to be low (10.8%) or very low (5.2%). Only 0.4% of respondents believe there is no risk at all. 4.3% of respondents selected \u0026quot;I don\u0026apos;t know, no answer,\u0026quot; indicating some level of uncertainty or lack of awareness regarding the risks associated with radon.\u003c/p\u003e\n\u003cp\u003eFigure 2 presents a comparison of radon risk perception between the general population and citizen scientists in Slovenia, Spain, and Portugal. It clearly shows that citizen scientists perceive radon risk to be higher in all three countries. Notably, none of the citizen scientists selected \u0026ldquo;no risk at all,\u0026rdquo; and across all countries, they consistently expressed a greater perception of risk compared to the general population.\u003c/p\u003e\n\u003cp\u003e4.\u0026nbsp; \u0026nbsp;Better radon protection behaviour\u0026nbsp;among citizen scientists\u003c/p\u003e\n\u003cp\u003eRegarding radon testing of dwellings before the CS project, only 33 out of 126 respondents (26.2%) reported that their residence had been tested for radon, which highlights a relatively low rate of radon testing among the surveyed group before the CS project. A significant majority of 72.2% of valid responses indicated that their residence had not been tested for radon, suggesting that the CS project is the main channel through which this large group of people have had an opportunity to test their homes for radon. Considering that in most of the countries, the CS projects were undertaken in radon priority areas, this is quite a significant contribution.\u003c/p\u003e\n\u003cp\u003eFigure 3 presents the intention to test for radon among the general population and citizen scientists in Slovenia and Spain. The difference in intention highlights a significantly greater willingness among citizen scientists to test radon levels in their homes when advised, compared to the general population. The results show that participation in CS projects positively influences individuals\u0026rsquo; motivation to take action regarding radon exposure.\u003c/p\u003e\n\u003cp\u003e5.\u0026nbsp; \u0026nbsp;Positive impact on willingness to test and mitigate radon exposure\u003c/p\u003e\n\u003cp\u003eBefore the CS project, only 10.3% of respondents reported that their building was remediated after discovering a radon problem. Additionally, 4.0% indicated that protective measures were installed during construction. This implies that a combined 14.3% of respondents took some form of action to mitigate radon risks in their homes before the CS project.\u003c/p\u003e\n\u003cp\u003eA significant portion of respondents expressed a high willingness to test for radon concentrations in their homes if advised. Specifically, 44.0% agreed and 25.0% strongly agreed, totalling 69.0% of valid responses. Around 15.5% were neutral, showing uncertainty or indifference, while only a small percentage (2.4% strongly disagreed and 6.0% disagreed, totalling 8.4%) opposed testing for radon. Regarding the intention to test for radon as a precaution, 72.6% of respondents (50.0% agreed and 22.6% strongly agreed) indicated their intention to measure radon in their homes. On the statement, \u0026ldquo;\u003cem\u003eI intend to start the remediation of my home if advised,\u003c/em\u003e\u0026rdquo; 42.6% (27.8% agreed and 14.8% strongly agreed) expressed their intention to begin remediation. Similarly, when asked, \u0026ldquo;\u003cem\u003eI would do what is necessary to remove radon if advised\u003c/em\u003e,\u0026rdquo; 61.1% (40.7% agreed and 20.4% strongly agreed) demonstrated a strong willingness to take action. Additionally, 77.5% of respondents (49.3% agreed and 28.2% strongly agreed) stated that \u003cem\u003elearning about radon through the citizen science project motivated them to test radon levels in their homes\u003c/em\u003e. This highlights the project\u0026apos;s significant impact on encouraging protective behaviours related to radon testing.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e5. \u0026nbsp; Wide range of scientific data and products generated during the CS projects\u003c/p\u003e\n\u003cp\u003eThe number of publications from the CS projects was limited to several abstracts for conferences and presentations. However, the products and data generated are multiple and are summarized in Table 3.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Examples of data and products generated by CS projects\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCountry/project\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eData and products generated\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eItaly, OCRA\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003eCommunication materials (e.g., leaflets), radon measurements in 231 places (147 homes, 37 rooms in 4 schools, and 47 workplaces) with passive radon detectors, scientific report\u003csup\u003e1\u003c/sup\u003e, radon distribution digital map, questionnaire, project video. \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eHungary,\u0026nbsp;RadoNorm-Aerosol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003eLow-cost sensor toolkit, technical documentation in Hungarian and easy to read English, radon measurements \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003ePoland, AHS\u0026nbsp;RadonHunt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003eCommunication materials (e.g., leaflets), 50 indoor air measurements (using CR39 detectors), 27 water measurements, 2 soil air measurements, active measurements in 10 locations, videos \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003ePortugal, RadAR\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003eCommunication materials (e.g., flyers, posters), radon measurements in 300 dwellings, online registration forms\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eSlovakia, RadonGPS\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003eRoll-up banners, 14 tailor-made radon remediation projects for family houses, radon measurements in 47 family houses (91 rooms with passive detectors) and 34 family houses (126 rooms with active detectors), answers to frequently asked questions (FAQ) on radon, communication materials (e.g., leaflets, roll-up banners), YouTube Video on reducing radon \u0026ndash; a DIY approach, record forms for measurements, cooperation agreement, certificate of participation\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eSlovenia, RadoNorm-SLO\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003e73 passive measurements and 56 active measurements, educational workshops, mitigation of three homes (two through the installation of active sub-slab depressurization systems and one through a heat recovery ventilation system), regional map of radon measurement data, communication materials (e.g. flyers); policy recommendations to authorities\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 85px;\"\u003e\n \u003cp\u003eSpain, RadoHow\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 519px;\"\u003e\n \u003cp\u003eCommunication materials (e.g., infographics, leaflets), 20 radon measurements in both homes and workplaces, initial questionnaire, guidelines on how to use radon detectors, tracking calendar.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eAs a result of the collaboration in RadoNorm CS Incubator, the Polish and Hungarian teams have put a proposal together with another Romanian partner with new research questions. Portugal continues the CS project in three different districts. A new research question resulted also from the Spanish project and will be implemented in another province in Spain. Future projects are also foreseen in Italy to co-create research questions with regional authorities.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe software used in the RadoNorm CS projects varied depending on the country and included:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; An existing online tool to self-evaluate radon indoors which was tested by citizen scientists who had performed radon measurements in their homes and had elevated radon concentrations (only in the case of France). \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Radon Vision was used to set the measurement device and manage data as well as to get interactive graphical displays of measuring data.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; DataView softwares is a powerful tool for configuration, transfer and processing of measurement data for different radon measuring instruments. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Rstudio and Excel were used for data evaluation. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; VideoPad, GoogleWebDesigner, Audacity, Inkscape and GIMP were used for video editing and translations. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; Slido was used for Q\u0026amp;A and pooling online. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026middot; For data presentation, an interactive web application based on Plotly jascript library was used. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHardware used varied depending on the country and included passive detectors (CR39, Radtrack) and radon active detectors, (RadonEye, RadonEye+2). In Slovakia, AlphaGuard was used to ensure metrological traceability of active detectors.\u003c/p\u003e\n\u003ch2\u003e6. \u0026nbsp; Expected outcomes achieved and challenges of CS projects identified\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eAll CS projects were evaluated internally using a self-evaluation by the coordinator. The outcomes of the evaluation are provided in Table 4. In addition to the internal self-evaluation, in Poland, the project leader designed a self-assessment questionnaire for students which was completed half-way through the project and at the end. Also at the end, self-reflection essays by students summarizing their perspectives were provided as means of evaluation. In Slovakia, the internal evaluation was completed by the feedback gathered from both online and face-to-face verbal communication between all participants involved in the CS project. In Spain, the internal evaluation was completed by the verbal feedback from citizen scientists during project final event.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. Outcomes of CS project evaluation and recognized challenges based on the self-evaluation and discussion with coordinators\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"604\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCountry\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOutcome of evaluation\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003eItaly, OCRA\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003eThe project\u0026apos;s main goals\u0026mdash;raising citizen awareness and collecting radon data in homes, school rooms, and workplaces\u0026mdash;were successfully achieved.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe project provided a significant opportunity for citizens to protect their health and advocate for concrete actions to reduce indoor radon levels.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eAll deadlines were met.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMore funds than initially anticipated were allocated in the first stage to increase citizen engagement and participation.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eAlthough no formal internal evaluation of citizen satisfaction was conducted, many participants expressed their appreciation for the project, particularly during the final public event.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003eHungary,\u0026nbsp;RadoNorm-Aerosol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003eCompletion of the first version of the toolkit, sparking numerous ideas for further development\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eStudents\u0026rsquo; recruitment via personal invitations proved easy and effective, while flyer advertisements were less effective.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eInitial project\u0026apos;s results only accessible to students and immediate families (limited circle).\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eUse of project designed website helps to reach a wider audience.\u003c/p\u003e\n \u003cp\u003eThe toolbox has reached a point where experts need to take over.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eRecruitment must begin at the start of each school year as students progress to higher levels, and become busier with demanding exams, or complete high school and are no longer available to continue. As a result, the entire process must be restarted, which can be challenging.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003ePoland, AHS\u0026nbsp;RadonHunt\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003e\u0026ldquo;Doing\u0026rdquo; science is way more interesting than listening about it, even though it requires a lot of time and resources. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eRadoNorm funding paved the way to set up a new path in high school curriculum regarding ionising radiation.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003ePortugal, RadAR\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003eThe CS project facilitated the participation of individuals from various backgrounds, effectively bridging the gap between professionals and the public.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe researchers, teachers, students and volunteers of the CS project are of the opinion that CS empowers individuals, enriches scientific research, and nurtures a sense of shared responsibility.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCitizen science advances scientific knowledge and fosters collaboration between researchers and the public. Without such projects, large-scale data collection is often much more challenging. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe CS project involved a large number of participants which enabled extensive data collection across diverse locations and timeframes, contributing to the monitoring of radon exposures which would have been difficult for a small research team like the size of the project coordinators to achieve alone. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eParticipation in CS provides education to volunteers, particularly in remote areas, on scientific methods, data analysis, and critical thinking which enhances not only scientific literacy but also empowers citizens to become advocates for conservation and environmental protection. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003eSlovakia, RadonGPS\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003eSix months is inadequate for such a CS project.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003ePersonal invitations to kick-off meetings proved easy and effective, while invitations via public address system through the mayor were less effective. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eFacebook proved less effective for communication and dissemination.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eRadoNorm funding played a crucial role in enabling the non-governmental organization NatuRadon to implement its goals on a wider scale, thereby meeting a key expectation outlined in the proposal. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe research question of the CS project was answered through student projects of anti-radon measures, which are freely available on the website on \u0026nbsp;NatuRadon.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe discussion platform created on the CS project webpage did not receive a positive response from the citizen scientists. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCitizen scientists valued the opportunity to independently measure radon using active radon detectors and appreciated the expert assistance in evaluating the radon levels in their homes.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCitizen scientists found the up-to-date information available on the project webpage helpful, as well as access to student projects and cost estimates for potential radon remediation measures.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMost of the citizen scientists indicated their intention to implement radon remediation measures in their own homes.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe students found their participation in the project motivating for their future academic pursuits.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe CS project successfully established cooperation not only with the citizen scientists and other stakeholders but also with the broader communities, including the secondary construction school, and collaboration with the Faculty of Wood Sciences and Technology at the Technical University in Zvolen.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe project coordinators observed that the development and rapid updating of communication strategies for other stakeholders and citizen scientists involved in the project was the most challenging aspect.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003eSlovenia, RadoNorm-SLO\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003e90 participants joined the CS project, exceeding the originally anticipated number of about 50.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe number of participants gradually declined as project progressed due to the loss in motivation for those who measured lower radon levels.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eLimited budget and short duration of the project made it impossible to monitor whether additional homes have been mitigated based on information provided via the CS project\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe experience gained through the project will be shared with radiation protection authority, with the aim of enhancing the impact of the national annual radon measurement program for residential environments\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eCS project achieved significant dissemination efforts and was well publicized through various channels.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSustainability of the project remains a challenge due to a lack of additional funding.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe 6-months timeframe did not allow for extensive follow-up with participants or a comprehensive evaluation of the long-term impact of the project.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eStrong collaborations with national authorities is essential for providing the necessary tools and support to citizens and ensuring that project outcomes feed into national radon awareness campaigns\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 63px;\"\u003e\n \u003cp\u003eSpain, RadoHow\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 542px;\"\u003e\n \u003cp\u003eParticipants evaluated the project as positive by expressing their satisfaction with the knowledge gained and the activities conducted.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eParticipants highlighted the creation of a strong community within the project, which they can consult for sharing information, asking questions about future legislation, or getting support for continuing to monitor their homes and workplaces, in cases of higher levels of radon. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eActivities were mostly conducted online since coordinating in-person activities was difficult, as participants came from five different provinces in Spain. \u0026nbsp;\u003c/p\u003e\n \u003cp\u003eMaintaining participant engagement over the long term was a challenge. However, citizen scientists stayed to the end of the project since they were interested in knowing their results, learning how to interpret them, and discussing findings.\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eThe project benefited greatly by engaging citizens scientists with and without prior knowledge of radon. Those without became informed and community actively learned together. Additionally, engaging both newcomers and experts provided diverse perspectives and enriched the project with varied insights.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch2\u003e7. \u0026nbsp; Effectiveness of CS projects with a focus on community engagement and impact\u003c/h2\u003e\n\u003cp\u003eThe CS evaluation method developed by Hoedoafia et al (2024) has been used to evaluate the effectiveness of CS projects in enhancing radon protection efforts. The assessment considers both outcome and process level indicators and includes the five dimensions: 1) scientific, 2) participants, 3) wider societal impact, 4) learning gains to researchers and 5) process evaluation. Out of these five dimensions proposed by Hoedoafia et al (2024), we focus in this section on those indicators directly related to community engagement and impact (Table 5).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe coordinators of the CS projects reported high levels of engagement following Haklay\u0026rsquo;s (2013) classification, from distributed intelligence to participatory and extreme citizen science. In some case the initial intention of the CS project coordinators was not achieved, or they claimed it was not achieved, but the distinction between one level and the other are not clear-cut and there is a level of subjectivity. Based on the information from the coordinators and our own interpretation of the levels of engagement, we have developed Figure 4 to show levels of participation in the different countries.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn Hungary, the research objective of RadoNorm Aerosol was defined as level 3 as \u0026ldquo;participatory science\u0026rdquo;. Nearly 30 students from three high schools participated in the development, communication and dissemination of the project which consisted of creating a toolkit with various low-cost measurement sensors to measure air quality, including radon. The evaluation of the measurement results was carried out jointly by the lead researchers and the citizen scientists in the form of personal discussions. In Italy, citizens contributed to research by conducting radon measurements and collecting data such as information on their buildings and radon perception risks. While the coordinators classified the project as participatory science, we claim that scientists designed the project and members of the public contributed with data and helped with basic interpretation. Thus, we propose the level of \u0026ldquo;distributed intelligence\u0026rdquo; for OCRA in Italy. In Poland, the project was classified as participatory science with some components of extreme CS.\u0026nbsp;Citizen scientists placed detectors, decided where to collect samples, participated in introductory sessions to gain knowledge on radon, co-analysed measurement results\u0026nbsp;during weekly meetings, took decisions on the next steps (where to redo measurements) and disseminated the project via TikTok. Due to legal reasons of working with minors, the coordinator and teacher needed to take the main lead in logistics of trips and other formal arrangements. Similarly, in Portugal, student citizen scientists disseminated information about radon, engaged the population to conduct radon measurements, co-developed the research question via meetings and class sections and co-analyzed/interpreted data from the results. The coordinators of RadoNorm-SLO in Slovenia classified their project as distributed intelligence, but we claim that a higher level of engagement was achieved. Most participants contributed by conducting radon measurements in their homes and some of them with elevated radon levels, had one on one discussions with scientists and even home visits with a radon mitigation specialist to provide tailored guidance and support through direct discussions with the homeowners. While the involvement of citizen scientists in the scientific process was limited, some participants showed a deeper interest and ability to engage with radon data and its interpretation and even mitigated. In one case, a citizen scientist mitigated himself using mechanical ventilation with a small overpressure. He also did the control measurement with his own digital radon monitor.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAccording to the coordinators in Slovakia, the CS project was classified as \u0026ldquo;distributed intelligence\u0026rdquo;. Citizens were involved in the distribution of detectors, conducted radon measurements, evaluated data from measurements by active detectors on their own decision and evaluated data from measurements by passive detectors. The project allowed the cooperation with students during the design of tailor-made radon remediation projects, communicating their questions with experts. Students\u0026rsquo; citizen scientists also designed tailor-made remedial projects and disseminated the project. The coordinators of RadonGPS claim that the initial intention was to achieve a higher level of participatory science, but the lack of time limited the possibilities for further engagement. However, the authors of this paper claim that the fact that one of the project\u0026rsquo;s outputs are tailor-made radon remediation projects alongside with the calculation of costs of radon remedial measures, moves up the level of the project to be considered participatory science. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn Spain, citizen scientists were engaged from the very beginning, co-determining the measurement methodology alongside key stakeholders and the project team, using an extreme science approach. Citizen scientists participated in various stages of the scientific process in RadoHOW, together with researchers: defining the research question, collecting data, interpreting the data, and disseminating the methodology. They developed skills that enable them to interpret their results and communicate the outcomes, allowing them to take a more active role during and after the project.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eBased on the reports provided by the CS coordinators, the projects contributed to the collective capacity in different ways: in Hungary, through the development of a toolkit to measure air quality; in Italy, through the creation of an interactive map of radon exposure; in Poland, by co-creating content for public dissemination on the social media used (TikTok); in Portugal, the project brought citizens and students together to achieve the common goal of environmental stewardship by communicating their assessment on radon measurements and mitigation needs to the local communities; in Slovakia, the collective capacity was related to the co-creation of radon mitigation projects and empower citizens to take protective action; in Slovenia, the direct involvement of citizens in the scientific process fostered a more community-driven effort to address radon risks and in Spain, the project fostered a sense of community among participants.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5. Summary of CS project results on public outreach, collaboration and feedback\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"28\"\u003e\u003c/table\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"897\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003eIndicators/CS project\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eHungary\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eItaly\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003ePoland\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003ePortugal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eSlovakia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 128px;\"\u003e\n \u003cp\u003eSlovenia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eSpain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003ePublic outreach\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003e30 students, website, households involved\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003e231 citizen scientists, (multiply by average number of household) newspaper articles, project webpage, social media - Facebook \u0026amp; Instagram.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003e10 students (30 people involved), TikTok, conferences, press releases, online magazines, news portal interview \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003e60 students, \u0026nbsp;newspaper articles, project webpage, conferences, social media - Facebook \u0026amp; Instagram.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003e47 citizen scientists (multiply by average number of household)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 128px;\"\u003e\n \u003cp\u003e90 citizen scientists (multiply by average number of households)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e20 citizen scientists (multiply by average number of households); social media (Instagram and Twitter); project webpage\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003eCollaboration and synergies\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eHigh schools\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eLocal and regional authorities\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003eSenior high school, external laboratories, Atomic Forum Foundation\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003e3 high schools collaboration with authority\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003elocal authorities (e.g., collaboration with mayor), with Faculty of Wood Sciences and Technology at the Technical University in Zvolen and with secondary construction school\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 128px;\"\u003e\n \u003cp\u003eSlovenian Ministry of Health, Radiation Protection Authority, community centre\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eNational, regional and local (Nuclear Safety council, public authorities)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 102px;\"\u003e\n \u003cp\u003eFeedback to participants\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eResults of radon measurements\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eResults of radon measurements,\u003c/p\u003e\n \u003cp\u003eproject outcome at final event\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 94px;\"\u003e\n \u003cp\u003eResults of radon measurements. Informed consent. \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eResults of radon measurements, public local events at each municipality. \u0026nbsp; \u0026nbsp; Citizen scientists informed of their data usage via informed consent\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 111px;\"\u003e\n \u003cp\u003eResults of radon measurements, tailor-made remediation projects, final public meeting \u0026ndash; project outcome; citizen scientists informed of their data usage via informed consent for data processing (citizens \u0026amp; legal representative of students)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 128px;\"\u003e\n \u003cp\u003eResults of radon measurements; discussion of possible solutions to householders on mitigation; final project event.\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eRadon measurement results, simple mitigation recommendations.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"5. Discussion","content":"\u003cp\u003eThis research provides evidence that the CS approach to radon research is an effective method to increase awareness, knowledge, risk perception and willingness to engage in protective behaviors. regarding radon exposure, confirming our hypothesis. Furthermore, it fosters scientific outcomes and enhances community engagement. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe results were collected through a dedicated survey with citizen scientists (Perko et al. 2024, 2021) which was compared with results of a survey with general public, representative for gender, age and level of urbanisation (Perko T., 2025). A group discussion and content analysis of the final reports of CS projects complemented the data collection. The raw responses to the survey can be found online at Radon Behaviour Atlas.[1] The evaluation framework developed for the radon context by Hoedoafia et al. (2024) was used.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe study critically examines the societal and individual\u0026rsquo;s impact of CS initiatives in the field of radon testing and mitigation. The findings show that\u0026nbsp;following their participation in the CS projects, all citizen scientists became highly aware of radon. Regarding knowledge acquisition, the results indicate that while a majority of citizen scientists demonstrated accurate knowledge of key radon characteristics and health risks \u0026ndash; e.g. link to lung cancer, odourless and invisible gas, long-term exposure effects \u0026ndash; misconceptions persist among a minority regarding symptoms like headaches and the units used to measure radon levels. Citizen scientists also show higher levels of risk perception compared to the general population and better radon protection behaviour.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePrior to participation in the CS project, radon mitigation actions among respondents were relatively uncommon, with only 14.3% reporting either remediation or the installation of preventive measures during construction. This is consistent with prior research indicating that, in many European contexts, awareness of and action on residential radon exposure remains low despite public health recommendations (Poortinga\u0026nbsp;et al., 2011; Perko et al. 2024). However, the data reveal a strong behavioural intention toward radon testing and mitigation following engagement in the CS projects. Notably, 69% of respondents expressed a clear willingness to test for radon if advised and over 72% indicated they would test as a precaution. Furthermore,\u0026nbsp;approximately 61% declared they would undertake necessary remediation actions if recommended. This suggests that participatory approaches like CS can stimulate protective behaviours and empower individuals to make informed decisions about their health, as suggested in previous studies (Hoedoafia et al., 2024; Martell et al. 2024; Stanifer et al., 2022).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe wide variety of software and hardware used across countries involved in the RadoNorm CS Incubator show the adaptability of CS projects to different institutional and technical settings. Furthermore, the range of outputs ad data generated underscore the value and scalability of CS initiatives in the field of environmental health. Several countries have leveraged their experiences to expand ongoing or future CS efforts. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAlthough the approach to the evaluation of CS projects across countries varied \u0026ndash; from student self-reflection to verbal feedback or written input \u0026ndash; the projects involving young students found that citizen science (\u0026ldquo;doing science\u0026rdquo; or hand-on scientific activities) is more engaging than traditional lectures or classroom approaches. The projects also contributed to the collective capacity in different ways, which is in line with other CS studies (Bonney et al. 2016). Insights from the evaluation highlight the importance of timely recruitment and tailored communication strategies.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWhile this study provides valuable insights into CS engagement, several limitations must be acknowledged. First, the short-time frame of the CS projects (i.e. six months) and the limited budget provided (i.e. 25,000 euros in total) are the main limitations observed by some of the RadoNorm CS projects. These drawbacks made it impossible to monitor whether additional homes were mitigated based on the information and engagement provided through the CS projects. Additionally, it was not possible to assess the willingness of students to engage in remediation activities, which could have improved the understanding on motivational factors. Second, the number of participants in some initiatives was relatively small, potentially affecting the generalizability of the findings. Moreover, the survey response rate was notably low in some countries, largely due to limited computer access, which may have introduced sampling bias and limited cross-country comparisons.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eExcept in the CS projects with schools, the engagement of younger participants more adept at using technology was generally missing, as most citizens involved were elderly persons. Targeting younger generations through educational efforts could enhance data collection and analysis. Maintaining participant engagement over time is an additional challenge and often, the participants whose measurements indicated low radon levels lost motivation and disengaged from the project. In some CS projects, authorities were involved from the outset, while in others, their collaboration came later. Nevertheless, cooperation with authorities was essential for providing tools and support to citizens and for ensuring that project outcomes were integrated into national radon awareness campaigns.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur findings confirm that while increasing awareness of radon is important, it is insufficient on its own to drive behavioural change or risk mitigation, as proved in different studies (Perko et al. 2024; Davis et al. 2018; Duckworth et al. 2002 Khan \u0026amp; Chreim, 2019). Future efforts should prioritize actionable engagement strategies that empower citizens to participate in the different stages of the research process. Authorities at national, regional and local levels should support CS as a complementary approach to testing campaigns by providing funding, infrastructure and technical support for these initiatives. Collaboration with schools, local non-governmental organizations and municipalities can enhance both participation and the societal relevance of the outcomes. Integrating CS into national radon action plans and radiation protection policies can strengthen monitoring capacity, increase risk communication and enhance the coproduction of knowledge between scientists, authorities and the public. \u0026nbsp; \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e[1] https://radonbehaviouratlas.wixstudio.com/radonorm\u003c/p\u003e"},{"header":"6. Conclusions","content":"\u003cp\u003eThis study addresses the gap between awareness of radon-related health risks and the adoption of protective measures by evaluating the impact and effectiveness of CS projects, with attention to both participant outcomes and project-level contributions. Through a mixed-methods approach, including computer-assisted web interviews with 231 citizen scientists, interviews with seven researchers, and group discussions with ten CS coordinators and the CS evaluation method developed by Hoedoafia et al (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2024\u003c/span\u003e), this paper has shown through empirical evidence that participation in CS projects on radon can significantly increase participants\u0026rsquo; awareness, knowledge, risk perception and willingness to engage in protection behaviours related to radon exposure. We have assessed both the individual-level benefits of CS projects (e.g., knowledge gain and behaviour change) as well as the broader scientific and social outcomes, including the challenges encountered during project implementation.\u003c/p\u003e\u003cp\u003eFuture research should investigate what motivates citizens to engage at deeper levels and over extended periods. In addition, further investigation is needed into how CS influences descriptive and social norms as well as the broader social environment in which participants operate. Understanding these dynamics can contribute to the design of more resilient and socially embedded CS projects.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis project has received funding from the Euratom research and training programme 2019\u0026ndash;2020 RadoNorm under grant agreement No 900009 and from PIANOFORTE Euratom research and innovation program under the 101061037 grant agreement.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to express their sincere gratitude to Mabel Akosua Hoedoafia, postdoctoral researcher at SCK CEN, for their dedicated contribution to the RadoNorm project. Over the course of 18 months, she worked exclusively on RadoNorm, playing a key role in data collection and helping to lay the groundwork for this study. Mabel\u0026rsquo;s efforts and commitment are deeply appreciated.\u003c/p\u003e\n\u003cp\u003eWe would like to express our sincere thanks to the coordinators of the citizen science projects. Our heartfelt gratitude also goes to the interviewees who took the time to share their insights with us. All these contributions were invaluable to the success of this project.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAmbrosino, F., La Verde, G., Colucci, M., Fanti, V., Barrale, D., Caciolli, A., Hemmer, S., De Giorgi, M. L., Ventura, A., Imm., J., Pagano, A., Budinich, M., Vascotto, M., Montalbano, V., Capua, M., Tucci, R., Chiosso, M., Visca, L., Groppi, F., \u0026amp; Pugliese, M. (2024). RadioLab project: Knowledge of radon gas in Italy. Scientific Reports, 14(1), 1224. https://doi.org/10.1038/s41598-023-45809-6\u003c/li\u003e\n\u003cli\u003eAndresz, S., Marchand-Moury, A., Goyette-Pernot, J., Rivi.re, A. L., \u0026amp; Schieber, C. (2023). When citizen science meets radon building diagnosis: Synthesis of a French pilot project developed in the framework of the European RadoNorm research project. Open Res Eur, 3, 106. https://doi.org/10.12688/openreseurope.15968.2\u003c/li\u003e\n\u003cli\u003eBonney, R., Phillips, T.B., Ballard, H.L., Enck, J.W. Can citizen science enhance public understanding of science? Public Underst Sci. 2016 Jan;25(1):2-16. doi: 10.1177/0963662515607406.\u003c/li\u003e\n\u003cli\u003eBouder, F., Perko, T., Lofstedt, R., Renn, O., Rossmann, C., Hevey, D., Siegrist, M., Ringer, W., P.lzl-Viol, C., Dowdall, A., Fojt.kov., I., Barazza, F., Hoffmann, B., Lutz, A., Hurst, S., \u0026amp; Reifenh.user, C. (2019). The Potsdam radon communication manifesto. Journal of Risk Research, 24(7), 909-912. https://doi.org/10. 1080/13669877.2019.1691858\u003c/li\u003e\n\u003cli\u003eDe Cicco, F., Balzano, E., Limata, B. N., Masullo, M. R., Quarto, M., Roca, V., Sabbarese, C., \u0026amp; Pugliese, M. (2017). Radon measurement laboratories: An educational experience based on school and university cooperation. Physics Education, 52(6), 065003. https://doi.org/10.1088/1361-6552/aa811e\u003c/li\u003e\n\u003cli\u003eEuropean Environment Agency. (2022). Radon. Retrieved 11 July 2025.\u003c/li\u003e\n\u003cli\u003eMurray, C. J. L., Aravkin, A. Y., Zheng, P., Abbafati, C., Abbas, K. M., Abbasi-Kangevari, M., Abd-Allah, F., Abdelalim, A., Abdollahi, M., Abdollahpour, I., Abegaz, K. H., Abolhassani, H., Aboyans, V., Abreu, L.G., Abrigo, M. R. M., Abualhasan, A., Abu-Raddad, L. J., Abushouk, A. I., Adabi, M., . . . Lim, S. S. (2020). 251 Global burden of 87 risk factors in 204 countries and territories, 1990\u0026ndash;2019: A systematic analysis for the Global Burden of Disease Study 2019. The Lancet, 396(10258), 1223-1249. https://doi.org/10.1016/S0140-6736(20)30752-2\u003c/li\u003e\n\u003cli\u003eHahn, E. J., Wilmhoff, C., Rayens, M. K., Conley, N. B., Morris, E., Larck, A., Allen, T., \u0026amp; Pinney, S. M. (2020). High school students as citizen scientists to decrease radon exposure. International Journal of Environmental Research and Public Health, 17(24), 9178. https://doi.org/10.3390/ijerph17249178\u003c/li\u003e\n\u003cli\u003eHaklay, M. (2013) Citizen science and volunteered geographic information \u0026ndash; overview and typology of participation. In: Sui, D, Z., Elwood, S., Goodchild , M.F. (Eds.), Crowdsourcing Geographic Knowledge: Volunteered Geographic Information (VGI) in Theory and Practice. Springer, Berlin, pp. 105- 122 . https://doi .org/10.1007 /978 -94 -007 -4587 -2_7.\u003c/li\u003e\n\u003cli\u003eHevey, D., Perko, T., Martell, M., Bradley, G., Apers, S., \u0026amp; Rovensk., K. N. (2023). A psycho-social-environmental lens on radon air pollutant: Authorities\u0026rsquo;, mitigation contractors\u0026rsquo;, and residents\u0026rsquo; perceptions of barriers and facilitators to domestic radon mitigation [Original Research]. Frontiers in Public Health, 11. https://doi.org/10.3389/fpubh.2023.1252804\u003c/li\u003e\n\u003cli\u003eHoedoafia MA, Martell M and Perko T (2024) Evaluating citizen science projects: insights from radon research. Front. Environ. Sci. 12:1436283. doi: 10.3389/fenvs.2024.1436283 \u003c/li\u003e\n\u003cli\u003eLevontin, L., Gilad, Z., Shuster, B., Chako, S., Land-Zandstra, A., Lavie-Alon, N., Shwartz, A., 2022. Standardizing the Assessment of Citizen Scientists\u0026rsquo; Motivations: A Motivational Goal-Based Approach 7, 25. https://doi.org/10.5334/cstp.459\u003c/li\u003e\n\u003cli\u003eMartell, M., Perko, T., Andresz, S., Schieber, C., Tomkiv, Y., Dowdall, A., McKittrick, L., \u0026amp; Groma, V. O. (2024). Radon and citizen science. In J. Sixto-Garcia, S. P.rez-Seijo, \u0026amp; B. Garcia-Orosa (Eds.), Communicating Public Health Risk: The Case of Radon Gas. Routledge. https://doi.org/10.4324/9781032618180\u003c/li\u003e\n\u003cli\u003eMartell, M., Perko, T., Tomkiv, Y., Long, S., Dowdall, A., \u0026amp; Kenens, J. (2021). Evaluation of citizen science contributions to radon research. Journal of Environmental Radioactivity, 237, 106685. https://doi.org/10.1016/j.jenvrad.2021.106685\u003c/li\u003e\n\u003cli\u003ePerko T. (2025): RadoNorm European Radon Behavioural Atlas: Portugal, H2020 project RadoNorm, No 900009 https://www.radonorm.eu/ , DOI:10.20348/STOREDB/1179/1306\u003c/li\u003e\n\u003cli\u003ePerko, T., Thijssen, P., Hevey, D., Turcanu, C., \u0026amp; Muric, M. (2024). Measuring societal attitudes and behaviours towards radon indoors: A case study of Slovenia. \u003cem\u003eJournal of Environmental Radioactivity, 272\u003c/em\u003e, 107355. https://doi.org/10.1016/j.jenvrad.2023.107355\u003c/li\u003e\n\u003cli\u003ePerko, T., Martell, M., Rovenska, K., Fojtikova, I., Paridaens, J., \u0026amp; Geysmans, R. (2023). Review and evaluation of national radon action plans in EU Member States according to the requirements of Council Directive 2013/59/Euratom. (199). Luxembourg: European Commission\u003c/li\u003e\n\u003cli\u003ePerko, T., Turcanu, C., Hoti, F., Thijssen, P., \u0026amp; Muric, M. (2021) RadoNorm pilot study report from public opinion survey, Belgium 2020-2021. Development of a modular questionnaire for investigating societal aspects of radon and NORM.\u003c/li\u003e\n\u003cli\u003eStanifer, S., Hoover, A. G., Rademacher, K., Rayens, M. K., Haneberg, W., \u0026amp; Hahn, E. J. (2022). Citizen science approach to home radon testing, environmental health literacy and efficacy. Citiz Sci, 7(1). https://doi.org/10.5334/cstp.472\u003c/li\u003e\n\u003cli\u003eTsapalov, A., \u0026amp; Kovler, K. (2021). Studying temporal variations of indoor radon as a vital step towards rational and harmonized international regulation. Environmental Challenges, 4, 100204. https://doi.org/10.1016/j.envc.2021.100204\u003c/li\u003e\n\u003cli\u003eCronin, C., Trush, M., Bellamy, W., Russell, J., \u0026amp; Locke, P. (2020). An examination of radon awareness, risk communication, and radon risk reduction in a Hispanic community. \u003cem\u003eInternational Journal of Radiation Biology, 96\u003c/em\u003e(6), 803\u0026ndash;813. Retrieved from \u0026lt;Go to ISI\u0026gt;://WOS:000517180600001\u003c/li\u003e\n\u003cli\u003eD\u0026apos;Antoni, D., Auyeung, V., Walton, H., Fuller, G. W., Grieve, A., \u0026amp; Weinman, J. (2019). The effect of evidence and theory-based health advice accompanying smartphone air quality alerts on adherence to preventative recommendations during poor air quality days: A randomised controlled trial. \u003cem\u003eEnviron Int, 124\u003c/em\u003e, 216\u0026ndash;235. doi:10.1016/j.envint.2019.01.002\u003c/li\u003e\n\u003cli\u003eDavis, S. F. J., J.D.; Magnusson, B.M.; Novilla, M.L.B.; Torgersen, B.K.; Schnell, A.J.; Crandall, A. (2018). Predictors of radon testing among Utah residents using a theory-based approach.\u003cem\u003e J. Environ. Health 80\u003c/em\u003e, 20\u0026ndash;27.\u003c/li\u003e\n\u003cli\u003eDesvousges, W. H., Smith, V. K., \u0026amp; Rink, H. H. (1992). COMMUNICATING RADON RISKS EFFECTIVELY - THE MARYLAND EXPERIENCE. \u003cem\u003eJournal of Public Policy \u0026amp; Marketing, 11\u003c/em\u003e(2), 68\u0026ndash;78. Retrieved from \u0026lt;Go to ISI\u0026gt;://WOS:A1992JW96500007\u003c/li\u003e\n\u003cli\u003eDiPofi, J. A., LaTour, M. S., \u0026amp; Henthorne, T. L. (2001). The new social marketing challenge to promote radon testing. \u003cem\u003eHealth Mark Q, 19\u003c/em\u003e(1), 79\u0026ndash;90. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/11727294\u003c/li\u003e\n\u003cli\u003eDragojevic, M., Bell, B., \u0026amp; M., M. (2014). Giving Radon Gas Life Through Language: Effects of Linguistic Agency Assignment in Health Messages About Inanimate Threats. \u003cem\u003eJournal of Language and Social Psychology, 33\u003c/em\u003e(1). doi:https://doi.org/10.1177/0261927X13495738\u003c/li\u003e\n\u003cli\u003eDuckworth, L. T., Frank-Stromborg, M., Oleckno, W. A., Duffy, P., \u0026amp; Burns, K. (2002). Relationship of perception of radon as a health risk and willingness to engage in radon testing and mitigation. \u003cem\u003eOncology Nursing Forum, 29\u003c/em\u003e(7), 1099\u0026ndash;1107. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036674504\u0026amp;doi=10.1188%2f02.ONF.1099-1107\u0026amp;partnerID=40\u0026amp;md5=08e99058c8ab0a2e47aeeae4ab3f49e5\u003c/li\u003e\n\u003cli\u003eEuropean Commission: Directorate-General for Energy, MERIENCE, SCK CEN, SURO, Perko, T. et al., \u003cem\u003eReview and evaluation of national radon action plans in EU Member States according to the requirements of Council Directive 2013/59/Euratom\u003c/em\u003e, Publications Office of the European Union, 2023, \u003cstrong\u003ehttps://data.europa.eu/doi/10.2833/531667\u003c/strong\u003e\u003c/li\u003e\n\u003cli\u003eGolding, D., Krimsky, S., \u0026amp; Plough, A. (1991). Evaluating risk communication: narrative vs. technical presentations of information about radon. \u003cem\u003eRisk Anal, 12\u003c/em\u003e(1), 27\u0026ndash;35. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1574615\u003c/li\u003e\n\u003cli\u003eHahn, E. J., Rayens, M. K., Kercsmar, S. E., Robertson, H., \u0026amp; Adkins, S. M. (2014). Results of a Test and Win Contest to Raise Radon Awareness in Urban and Rural Settings. \u003cem\u003eAmerican Journal of Health Education, 45\u003c/em\u003e(2), 112\u0026ndash;118. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-84897711978\u0026amp;doi=10.1080%2f19325037.2013.875960\u0026amp;partnerID=40\u0026amp;md5=8aa2d94e4366b40f4609cbc52d88a67a\u003c/li\u003e\n\u003cli\u003eHevey, D. (2017). Radon Risk and Remediation: A Psychological Perspective. \u003cem\u003eFrontiers in public health, 5\u003c/em\u003e, 63. doi:https://doi.org/10.3389/fpubh.2017.00063\u003c/li\u003e\n\u003cli\u003eKennedy, C. J., Probart, C. K., \u0026amp; Dorman, S. M. (1991). The relationship between radon knowledge, concern and behavior, and health values, health locus of control and preventive health behaviors. \u003cem\u003eHealth Educ Q, 18\u003c/em\u003e(3), 319\u0026ndash;329. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/1917508\u003c/li\u003e\n\u003cli\u003eKhan, S. M., \u0026amp; Chreim, S. (2019). Residents\u0026apos; perceptions of radon health risks: a qualitative study. \u003cem\u003eBMC Public Health, 19\u003c/em\u003e(1), 1114. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/31412828\u003c/li\u003e\n\u003cli\u003eNiemeyer, S., \u0026amp; Keller, B. (1999). Radon Publication Information: Impact on Readers\u0026rsquo; Knowledge, Attitudes and Intentions. \u003cem\u003eHousing and Society, 26\u003c/em\u003e(1-3), 54\u0026ndash;62. doi:10.1080/08882746.1999.11430435\u003c/li\u003e\n\u003cli\u003eNwako, P., \u0026amp; Cahill, T. (2020). Radon gas exposure knowledge among public health educators, health officers, nurses, and registered environmental health specialists: A cross-sectional study. \u003cem\u003eJournal of Environmental Health, 82\u003c/em\u003e(6), 22\u0026ndash;29. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078222393\u0026amp;partnerID=40\u0026amp;md5=ad67b4ee0b416f102a8810a6c14147fa\u003c/li\u003e\n\u003cli\u003ePerko, T., Thijssen, P., Hevey, D., Turcanu, C., \u0026amp; Muric, M. (2024). Measuring societal attitudes and behaviours towards radon indoors: A case study of Slovenia. \u003cem\u003eJournal of Environmental Radioactivity, 272\u003c/em\u003e, 107355. doi:https://doi.org/10.1016/j.jenvrad.2023.107355\u003c/li\u003e\n\u003cli\u003ePerko, T. and Hevey, D. (2024). Communicating radon risks: the impact ofdifferent risk formulations on risk perception andprotection intention. \u003cem\u003eJournal of Risk Research\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(4), 562-580. https://doi.org/10.1080/13669877.2024.2387346Peterson, E. W., \u0026amp; Howland, J. (1996). Predicting radon testing among university employees. \u003cem\u003eJournal of the Air \u0026amp; Waste Management Association, 46\u003c/em\u003e(1), 2\u0026ndash;11. Retrieved from \u0026lt;Go to ISI\u0026gt;://WOS:A1996TN47700001\u003c/li\u003e\n\u003cli\u003ePoortinga, W., Bronstering, K., \u0026amp; Lannon, S. (2011). Awareness and perceptions of the risks of exposure to indoor radon: a population-based approach to evaluate a radon awareness and testing campaign in England and Wales. \u003cem\u003eRisk Anal, 31\u003c/em\u003e(11), 1800\u0026ndash;1812. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/21477087\u003c/li\u003e\n\u003cli\u003eRyan, D., \u0026amp; Kelleher, C. C. (1998). A survey of householders\u0026apos; mitigation strategy - Response to raised radon levels. \u003cem\u003eEuropean Journal of Public Health, 9\u003c/em\u003e(1), 62\u0026ndash;64. Retrieved from \u0026lt;Go to ISI\u0026gt;://WOS:000079648300014\u003c/li\u003e\n\u003cli\u003eWeinstein, N. D., man, P. M., \u0026amp; Roberts, N. E. (1990). Determinants of Self‐Protective Behavior: Home Radon Testing. \u003cem\u003eJournal of Applied Social Psychology, 20\u003c/em\u003e(10), 783\u0026ndash;801. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-0000075296\u0026amp;doi=10.1111%2fj.1559-1816.1990.tb00379.x\u0026amp;partnerID=40\u0026amp;md5=20f23078cdac72adadbb7a453006b418\u003c/li\u003e\n\u003cli\u003eWeinstein, N. D., man, P. M., \u0026amp; Roberts, N. E. (1991). Perceived susceptibility and self-protective behavior: a field experiment to encourage home radon testing. \u003cem\u003eHealth Psychol, 10\u003c/em\u003e(1), 25\u0026ndash;33. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/2026127\u003c/li\u003e\n\u003cli\u003eWeinstein, N. D., Roberts, N. E., \u0026amp; Pflugh, K. K. (1992). Evaluating Personalized Risk Messages. \u003cem\u003eEvaluation Review, 16\u003c/em\u003e(3), 235\u0026ndash;246. Retrieved from https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973744433\u0026amp;doi=10.1177%2f0193841X9201600302\u0026amp;partnerID=40\u0026amp;md5=65c3c25e30ef6ee55130337838452041\u003c/li\u003e\n\u003cli\u003eWitte, K., Berkowitz, J. M., Lillie, J. M., Cameron, K. A., Lapinski, M. K., \u0026amp; Liu, W. Y. (1998). Radon awareness and reduction campaigns for African Americans: A theoretically based evaluation. \u003cem\u003eHealth Education \u0026amp; Behavior, 25\u003c/em\u003e(3), 284\u0026ndash;303. doi:10.1177/109019819802500305\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[{"identity":"b4efcb40-ce5e-4be0-a0a5-25b6e4cbac04","identifier":"10.13039/100010687","name":"H2020 Euratom","awardNumber":"900009","order_by":0},{"identity":"3bc5ec1a-6efc-469e-a001-efda1badc982","identifier":"10.13039/100010687","name":"H2020 Euratom","awardNumber":"101061037","order_by":1}],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"citizen engagement, citizen science, radon awareness, crowdsourcing, radon mitigation ","lastPublishedDoi":"10.21203/rs.3.rs-7120379/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7120379/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eRadon exposure poses a significant public health risk, yet authorities often struggle to engage residents in high-risk areas to test and mitigate radon levels. Traditional top-down approaches have shown limited success in motivating citizen engagement in radon mitigation. This study aims to assess the effectiveness of citizen science (CS) approaches in enhancing radon measurement and mitigation efforts across Europe, with a focus on citizen engagement and impact of the RadoNorm CS incubator. To evaluate the impact of CS projects, a mixed-methods approach was used, including computer-assisted web interviews with 231 citizen scientists, interviews with seven researchers, and group discussions with ten CS coordinators. The CS evaluation method developed by Hoedoafia et al (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) has been used. The RadoNorm CS Incubator engaged over 800 citizens and 57 research organizations across the EU. Pilot CS projects related to radon in France, Hungary, Ireland, and Norway informed the design of an open call, resulting in the selection and funding of six CS projects related to radon in Italy, Poland, Portugal, Slovakia, Slovenia, and Spain. The results show that these projects employed diverse methodologies to address specific community needs and improve radon awareness, measurement and mitigation strategies. The study highlights the successful outcomes of these projects, including the development of new radon dosimeters, innovative mitigation techniques, increased public awareness, improved local policies, and expanded school curricula. The findings demonstrate the potential of CS to enhance public engagement, improve risk communication, address research and scientific gaps and contribute to more effective radon protection strategies.\u003c/p\u003e","manuscriptTitle":"Empowering communities: the impact of citizen science on radon measurement and mitigation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-17 06:28:41","doi":"10.21203/rs.3.rs-7120379/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a4f5dfcb-ed7e-440e-a56e-fe94ed661e77","owner":[],"postedDate":"July 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":51493393,"name":"Environmental Policy"},{"id":51493394,"name":"Sociology"},{"id":51493395,"name":"Health Policy"}],"tags":[],"updatedAt":"2025-07-17T06:28:41+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-17 06:28:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7120379","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7120379","identity":"rs-7120379","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}