Measurement of urban environmental exposure to Extremely Low Frequency Magnetic Fields in several Spanish regions

Measurement of urban environmental exposure to Extremely Low Frequency Magnetic Fields in several Spanish regions | 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 Measurement of urban environmental exposure to Extremely Low Frequency Magnetic Fields in several Spanish regions Aránzazu Sanchis-Otero, Raquel Ramirez-Vazquez, Jesús M. Paniagua, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7363662/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Jan, 2026 Read the published version in Environmental Science and Pollution Research → Version 1 posted 5 You are reading this latest preprint version Abstract This is an observational descriptive study carried out in three Spanish regions to identify typical environmental levels of extremely low frequency magnetic fields (ELF-MF) in diverse population settings as well as in the proximity to various electrical infrastructures. To achieve this, measurement protocols were previously established considering national and international reference standards. To describe the public exposure to ELF-MF, both immission and emission levels have been quantified in public spaces and close to the main infrastructure related to the transportation and distribution of electricity, but also to those related to electrified transport. Based on the collected data, the average environmental ELF-MF exposure level in public spaces is 0.095 µT, while it is 1.303 µT in the vicinity of emission sources. The observed levels of exposure to ELF-MF in Spain are very similar to those in other European countries, with values significantly below the maximum exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection in 2010, which for the public are set for 50 Hz at 200 µT. This study, as a preliminary step, paves the way for further research that may encompass more Spanish’ regions and provide a data collection for future epidemiological studies, as well as a useful reference for the public. It could provide a foundation for establishing national regulatory frameworks on this matter, given the current absence of specific legislation in Spain. Extremely low frequency magnetic fields (ELF-MF) exposure assessment outdoor exposure public spaces ELF-MF emission sources exposure assessment Figures Figure 1 Figure 2 Figure 3 Figure 4 Highlights - Typical ambient ELF-MF levels in Spain were identified. - Immission and emission levels in public areas and from diverse sources evaluated. - The low ELF-EMF levels found in Spain are like those in developed countries. - The mean outdoor immission value is 0.1 µT and the mean emissions level 1.3 µT. 1. Introduction Residential exposure to magnetic fields (MF) in the extremely low frequency range (1 Hz to 100 kHz) has raised some public concern due to the hypothetical relationship between low levels of MF of 50 Hz/60 Hz and childhood leukemia (CL). Since 1979, this possible association has been observed for years in epidemiological studies (Wertheimer and Leeper 1979; Ahlbom et al. 2000 ; Greenland et al. 2000 ; Malagoli et al. 2023 ) (Kheifets, Ahlbom, et al. 2010 ) (Kheifets et al. 2016 ), and other health effects, such as cancer and neurodegenerative diseases in adults, have also been studied in connection to this environmental physical agent(Kheifets et al. 2016 )(Seomun 2021 ; Gervasi et al. 2019 ; Huss et al. 2009 ). The regulation to limit the exposure to ELF-MF for public protection relies, in Europe, on the recommendation for health protection against exposure to electromagnetic fields throughout the frequency range (0 Hz to 300 GHz), the EU Council Recommendation ((BOE) 1999). This is based on the guidelines published by ICNIRP in 1998, in light of established evidence on the acute effects (short-term) of exposure to electromagnetic fields (Matthes et al. 1998 ). Concerning ELF-MF, the primary objective is to prevent effects on the nervous system resulting from the induction of electric currents within the body, as well as any perception and annoyance occurring at high ELF-MF levels. Following the establishment of various safety factors, ICNIRP recommended as a basic restriction to limit the induced electric current density in the head and trunk to 2 mA/m 2 . Then, theoretically calculated reference levels for the 50 Hz magnetic field were set at 100 µT. In 2002, the International Agency for Research on Cancer (IARC) classified the ELF-MF in Group 2B as possibly carcinogenic to humans. The scientific literature evaluation made by the IARC led to this classification due to limited and inadequate evidence in humans regarding CL and other cancers, respectively, and to inadequate evidence in experimental animals. Specifically, the classification responded to those epidemiological studies reporting a statistical relationship between acute lymphoblastic leukemia (ALL) and prolonged average exposure during childhood to ELF magnetic field levels of 0.3–0.4 µT (IARC 2002), in which random, biased, or confounding factors could not be ruled out. Later, the health risk assessment of exposure to ELF electric and magnetic fields addressed by the World Health Organization (WHO), and published in 2007, concluded that “new human, animal and in vitro studies, published since the 2002 IARC monograph, do not change the overall classification of ELF magnetic fields as a possible human carcinogen” (Organization 2007 ). Then, in 2010, ICNIRP reviewed the 1998 guidelines regarding electric and magnetic fields at ELF, establishing a new limit of 200 µT for the magnetic field of 50 Hz (Matthes et al. 1998 ). These updated guidelines were based solely on the scientific evidence available at the time, excluding as a criterion the observed increased risk of childhood leukaemia due to the lack of a causal relationship with the chronic exposure to ELF-MF. Conclusions from consecutive scientific reports by national and international agencies and committees (European Commission 2015 ; National Agency for Food, Environmental and Occupational Health and Safety (ANSES) 2019; Swedish Radiation Safety Authority’s Scientific Council on Electromagnetic Fields 2024 ) are consistent with previous findings that, to date, any potential health effect from chronic exposure to ELF-MF do not meet sufficient criteria to be deemed causal, and further research is needed (ICNIRP 2015 ). This is generally supported by international bodies, such as the UK Health Security Agency, the German Federal Office for Radiation Protection (BfS), the Irish Environmental Protection Agency (EPA), the Dutch National Institute for Public Health and the Environment (RIVM) or the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Besides, the relative risk over time in epidemiological studies has shown a slight decrease, i.e., a weaker association between childhood leukaemia and ELF-MF, but without fully understanding the possible causes of this trend (Kheifets, Ahlbom, et al. 2010 ) (Swanson, Kheifets, and Vergara 2019 ; Crespi et al. 2020 ) (Crespi et al. 2020 ) (Swanson, Kheifets, and Vergara 2019 ) (Kheifets, Ahlbom, et al. 2010 ). In a recent study, the diverse meta-analysis addressed considering the different approaches for assessing the magnetic field exposure, such as direct ELF-MF measurements, distances between dwelling and high-voltage power lines (HVPL) and wire coding configurations, pointed to a reduced risk found when studies were based on magnetic field measurements (Brabant et al. 2021 ). Also, a pooled analysis of individual data from 24,994 cases and 30,769 controls, obtained from four recent studies on ELF-MF and CL, concluded that there is no increased risk at exposure levels above 0.4 µT compared to levels below 0.1 µT (Amoon et al. 2022 ) unlike previous studies. According to the authors, methodological issues, chance or a true finding of disappearance of the association could respond to these new observations. However, the data collected by the International Agency for Research on Cancer (IARC) shows a worldwide increase in the incidence rate of childhood leukaemia from the 1980’s to the end of the 2000s, that might only in part be explained by an improvement in diagnosis and registration (Steliarova-foucher et al. 2017 ). Therefore, all these observations indicate that more multidisciplinary investigations are still needed to clarify the potential role of ELF-MF on CL and other suggested health effects, especially, experimental and mechanistic but also epidemiologic studies, all of them supported by improved exposure assessments of this environmental agent (ICNIRP 2015 ; Schmidt, Hornhardt, and Erdmann 2021). Despite the international effort made in the last years for an improvement in the assessment of the ELF-MF exposure (Bonato et al. 2023 ; Gajšek et al. 2016 ), in Spain there are still few studies devoted to this issue. Some relevant data about personal indoor and outdoor exposure to ELF-MF by children and pregnant women were registered in two Spanish provinces, Granada (south) and Guipuzcoa (north), from the INMA project population cohort (Calvente et al. 2014 ; Gallastegi 2017 ). Other studies of ELF-MF environmental characterization were addressed in different towns from the western region of Extremadura to estimate the outdoor exposure levels of their inhabitants (Paniagua et al. 2004 ). Thus, one of the main objectives of this preliminary study is to provide new information about the ELF-MF environmental exposure in the general Spanish population, defining in advance a measurement protocol, considering both immission (magnetic field reaching a location) levels in public spaces (outdoor and indoor) and emission levels in proximity to electrical infrastructure. Through this study quality data and procedures will be provided for addressing future measurement campaigns and epidemiological analysis, but also relevant information will be reported for national regulator agents and other stake holders for risk perception management. Besides, this study, initiated by the Spanish Ministry of Health, addresses key objectives outlined in the "Strategic Plan for Health and Environment 2022–2026" (PESMA). It serves as a crucial first step towards a comprehensive national assessment of ELF-MF exposure levels in Spain. As a first approach, three Spanish regions were considered (Albacete, Cáceres, and Community of Madrid), and diverse public places and ELF-MF emission sources included. Measurements were performed following previously established protocol based on international and national standards. The immission ELF-MF levels in outdoor and indoor public spaces were measured. The ELF-MF emission levels were assessed in proximity to primarily infrastructure related to the transportation and distribution of electricity, but also to electrified modes of transport. Moreover, in order to analyze the consistency of this environmental assessment with other countries, the ELF-MF levels measured near the HVPL have been compared to those obtained from a recent French study (Deshayes-Pinçon et al. 2023 ). 2. Materials and methods 2.1. Measurement equipment and test inter-comparison All measurements were carried out using identical electromagnetic field meters SMP2 from WAVECONTROL which allow selective -up to 400 kHz- and broadband measurements. All systems were equipped with the WP400 probe (frequency range of 1 Hz to 400 kHz and a resolution of < 0.1 nT (at 50 Hz)) and GPS for geo-referencing the recorded data. The devices calibrated at the manufacturer were subjected to an inter-calibration process, carried out at the Institute of Applied Magnetism of the Complutense University of Madrid (IMA-UCM), before the measurement campaign. An Kepco BOP 2050 MG power supply and Helmholtz coils were used to generate various levels of magnetic field (in the supplementary material we can see an image showing the Kepco BOP 2050 MG power supply and the Helmholtz coils used to generate various levels of magnetic field). The coils were fed with four different current intensities − 0.1 A; 0.15 A; 0.2 A and 1 A - and a background measurement was also made. SMP2 equipment was configured to measure in the frequency range of 10 Hz to 400 kHz, and the magnetic field levels were recorded during six minutes. All results obtained for each intensity and equipment, were quite similar. Differences among them were evaluated through the dimensionless z-score parameter, defined as follows (1): $$\:z=\frac{x-{x}_{a}}{{\sigma\:}_{p}}$$ 1 in accordance with the G-ENAC-14 guide (National Accreditation Entity (ENAC) 2008 ) where x is the measurement of each equipment, x a is the average of the results obtained by the different equipment, and σ p is the target or appropriate standard deviation. Since the objective of this project is the measurement of environmental magnetic fields, the average of the relative standard deviations of the outdoor measurements corresponds to σ p , taking a value of 12.3%. All the z -score obtained for the different equipment were satisfactory (| z |< 2). 2.2. Measurement Locations Across the three Spanish provinces involved, Albacete (Castilla-La Mancha), Cáceres (Extremadura) and Madrid, specific locations were selected within two distinct categories: public spaces (group A) and emission sources (group B). Thus, on the one hand, we will measure the ELF-MF immission levels in public spaces considering the following environments: A.1) streets in urban and single-family residential areas, A.2) parks and gardens, A.3) public buildings, A.4) public buildings (interior), A.5) public transport stations and A.6) underground. And, on the other, the emission levels were measured in proximity to ELF-MF infrastructure, which may present higher magnetic field values, considering the following sources: B.1) overhead 220 kV high-voltage power lines (HVPL), B.2) overhead 400 kV HVPL, B.3) underground 220 kV HVPL, B.4) electrical substations, B.5) transformer stations, B.6) electrical service entrances of buildings, B.7) photovoltaic solar panel installations, and B.8) electric vehicle charging points. Based on the information provided by the Spanish company responsible for electricity transportation, Red Eléctrica de España (REE), a preliminary selection of locations was conducted on-site regarding the corresponding infrastructure. 2.3. Measurement protocol The measurement protocol was established in accordance with both international and national standards concerning the measurement of magnetic fields at industrial frequency in relation to human exposure (IEC 62110, n.d.; IEC 2014 ; Spanish standard UNE 215001 2004 ). In addition, the technical document TR 170 from Australian Radiation Protection and Nuclear Safety Agency was considered (ARPANSA (Australian Radiation Protection and Nuclear Safety Agency) 2023 ). A brief description of the protocol followed at each location is detailed below. Configuration parameters used in all SMP2 devices for measurements in the project are the following: unit of measurement: Micro-Teslas (µT), filter applied (High Pass Filter): 10 Hz, measurement range: 10 Hz a 400 kHz, sampling frequency: 0.5 seconds. 2.3.1. High-Voltage Power Lines (HVPL) Both longitudinal and transversal profiles of the ELF-MF were registered for each HVPL selected. All measurements were recorded 1 m above the ground, georeferenced, and for 1 minute. Once located the maximum magnetic field intensity, B max , under the HVPL axis line between two pylons, or along the path located perpendicularly above the underground line, longitudinal measurements were taken at least at 5 equidistant points, following the lateral lines (or above the line in underground lines). If the HVPL had three lines, the central one was disregarded. For the transversal characterization of the line, from the B max point and moving in the normal direction and outward from each of the two lateral lines, the field was recorded at the minimum recommended intervals: 0 m, 5 m, 10 m, 15 m, 20 m and 30 m, if no obstacle prevents it. In the supplementary material, we can see a photograph of the SMP2 equipment located under a 400 kV high voltage-power line in the city of Trujillo (Cáceres). 2.3.2. Electrical substations First, the highest field B max is searched walking around the perimeter of the substation, measuring at 1 m height with the SMP2. From the B max point, at 0.2 m from the adjacent wall, the field is measured at 0.5 m, 1 m, and 1.5 m heights and the resulting mean value will correspond to the exposure level at that point. Again, from the same B max point, the field levels are measured at 1 m height and 1 m, 5 m, 10 m, and 20 m away from the wall. In the supplementary material, we can see a photograph of the SMP2 equipment placed in front of the entrance to La Pinilla substation in the city of Albacete (Spain). 2.3.3. Streets On streets, field levels are recorded georeferenced by walking between two selected points in the center of the sidewalk, for 6 to 20 minutes, keeping the SMP2 at 1m height and avoiding sudden movements. At the beginning and end of the route, the field level was statically recorded for one minute as reference values to validate the dynamic registration. The possible magnetic field peaks that appear during the journey (number of them, magnitude and location) are identified and noted for further analysis. 2.3.4. Inside and outside public buildings The community sensitive spaces or public buildings (kindergartens, schools, nursing homes, health centers, among others) were inspected to identify the emitting sources. To begin, we positioned ourselves at the entrance of the building to be measured, noting down the location. Outside the entrance, we set up the equipment (SMP2) to record in "continuous" mode. Next, we started walking around the building, aiming to avoid sudden movements with the equipment, and keeping it consistently at a height of one meter. During this tour, we identified the location where the peak of the magnetic field was highest. Once the peak was identified, we conducted at least three “static” measurements (spot measurement) on the equipment positioned one meter high, without any movement, for 1 minute each. In some buildings where access was allowed, additional measurements were carried out. This same procedure was applied to the measurements conducted within the train and bus station building. With respect to the measurements in public buildings, the field levels are also recorded georeferenced while walking, keeping the SMP2 at 1m height and avoiding sudden movements. Where a magnetic field peak is identified, one to three additional measurements are recorded at that point for 1 minute. The measurements carry out in public transport stations follow the same procedure. 3. Results The environmental average levels of ELF-MF obtained from the total data collected in both public spaces - immission levels - and in proximity to the selected field-generating sources - emission levels - are graphically represented in Fig. 1 . Specifically, in total, throughout the three Spanish regions, 39 different locations were measured as public spaces, meanwhile for emission sources 46 items were considered. The averaged time for data registration was around 20 min, resulting in around 2,400 recordings of the magnetic field per site. 3.1. Public spaces Average of the total ELF-MF records carried out in the so-called public spaces (A) resulting a mean value of 0.095 µT for the magnetic field B , with a median of 0.068 µT. The distribution of magnetic field levels found is represented in the histogram of Fig. 2 . Subsequently, results are broken down and shown in Table 1 , categorized as previously mentioned. For each type of public area, the number of different locations sampled is as follows: A.1) 10 urban areas, A.2) 4 parks and gardens, A.3) 17 surroundings of public buildings, A.4) inside of 5 public buildings, A.5) 5 public transport stations, and, finally, A.6) 3 records in the underground (urban transport). Table 1 ELF-MF (µT) values recorded in total at streets in urban and single-family residential areas, parks and gardens, public buildings, interior of public buildings, public transport stations and underground (metro). Mean Median Minimum Maximum % of the limit value (200uT) A.1 Streets in urban & single-family residential areas 0.083 0.062 0.010 1.430 0.042% A.2 Parks and gardens 0.078 0.058 0.012 0.906 0.039% A.3 Public buildings 0.096 0.065 0.001 11.700 0.048% A.4 Public buildings (interior) 0.129 0.086 0.011 0.870 0.065% A.5 Public transport stations 0.089 0.071 0.001 0.460 0.044% A.6 Underground 0.152 0.096 0.041 3.514 0.076% * Magnetic field units: microTeslas 3.2. Emission sources The quantification of ELF-MF environmental emission levels near various sources has shown, as expected, higher values than those in public spaces. The average values of ELF-MF in the vicinity of the so-called emission sources, derived from all recordings across the various locations analyzed in the study, resulted in a mean value of 1.303 µT, with a median of 1.154 µT. The corresponding histogram of these values is depicted in Fig. 3 . Table 2 shows the results of the ELF-MF measurements carried out, according to the diverse types of sources studied: B.1) 5 overhead HVPL of 220 kV and B.2) 6 HVPL of 400 kV, B.3) an underground HVPL, B.4) three electrical substations, B.5) 11 transformation centers B.6) 5 building electrical connections, B.7) 3 solar panel installations, and B.8) 2 electric vehicle charging installations. In the supplementary material we can see an image showing an aerial view of the route (on foot) followed during measurements at two different locations. On the left, in the city of Galapagar (Cercado Redondo street, Community of Madrid, Spain). And on the right, in the vicinity of the electrical substation in the city of Cáceres (Spain). In the latter, a color code can be observed (with red indicating higher MF measurements and blue indicating lower MF measurements). Mean Median Minimun Maximun % of the limit value (200uT) B.1 Overhead 220 kV hifh-voltage power lines 0.733 0.674 0.065 3.334 0.366% B.2 Overhead 400 kV 2.140 2.298 0.130 6.700 1.070% B.3 Underground 220 kV 1.069 0.954 0.245 2.751 0.535% B.4 Electrical substations 0.669 0.522 0.019 8.995 0.335% B.5 Transformer stations 2.083 1.294 0.001 13.452 1.042% B.6 Electrical service entrances of buildings 3.284 3.097 0.104 6.540 1.642% B.7 Photovoltaic solar panel installations 0.066 0.060 0.042 0.180 0.033% B.8 Electric vehicle charging points 0.382 0.331 0.207 0.615 0.191% * Magnetic field units: microTeslas Table 2 . ELF-MF (µT) values recorded in overhead 220 kV high-voltage power lines, overhead 400 kV, underground 220 kV, electrical substations, transformer stations, electrical service entrances of buildings, photovoltaic solar panel installations and electric vehicle charging points. 3.3. Statistical Analysis Several statistical analyses are presented below, including hypothesis testing for group comparison, percentile calculation, variability analysis of the records, and confidence interval calculation. 3.3.1. Statistical comparison between groups Based on the two exposure scenarios, namely public spaces and emission sources, considering that both data groups do not follow a normal distribution, a non-parametric (Mann-Whitney test) for two samples was conducted with a significance level of 5%. The probability p value obtained for the hypothesis test was 1.81 x 10 − 5 , and therefore, the null hypothesis can be rejected, indicating that both groups of values are statistically different. The mean field value in public spaces is 0.095 µT compared to 1.303 µT in proximity to ELF-MF emission sources. Nevertheless, as previously mentioned, this highest average value resulting from the contribution of all emission sources represents 0.65% of the recommended 200 µT reference level. 3.3.2. Percentile calculation In all the cases presented, the average value of the measured magnetic field, resulting from the emission sources, corresponds to the highest values, which represents 0.65% of the limit recommended by the ICNIRP (200 µT). . It is noteworthy that 95% of the recorded values are below 0.17 µT in public spaces and 4.12 µT for emission sources. This exposure level represents only 2% of the recommended 200 µT reference level. 3.3.3. Variability of the recorded data and confidence Intervals for the means The variability of the measured field levels is described by the standard deviation calculated for both groups. In public spaces, the standard deviation is 43%, whereas for emission sources it is 149%. Consequently, it is evident that there is a greater dispersion of values among the ELF-MF records in the emission source group. By definition, the confidence interval for the mean provides both a maximum and a minimum value within which the population mean is estimated to lie, with a certain margin of error. Calculated at 95% confidence level, the confidence interval for each of the two data groups turns out to be [0.072 µT- 0.10 µT] for public spaces and [0.73 µT − 1.71 µT] for emission sources. As expected, the wider dispersion of the data collected around the emission sources results in a significantly broader range of values for the mean of this group. 3.3.4. Analysis focused on emission sources When initially categorizing the data into public spaces and emission sources, it was assumed that the ELF-MF sources were consistently distant from the public areas. However, upon recognizing that three types of emission sources – electrical transformation centers, building electrical connections, and electric vehicle charging points – can be present in public spaces, data have been reorganized. Then, the field levels recorded for these three sources were included in the group of public spaces and excluded from the emission sources, and the comparative study was carried out again. Both data subsets follow a normal distribution and exhibit equal variances, as indicated by Snedecor's Test ( p = 0.67). The analysis of exposure levels in public spaces now includes electric transformation centers, building electrical connections, and electric vehicle charging points, comprising a total amount of 48 locations, while the emission sources group has been reduced to 28 locations. Subsequently, a t-test for two samples with equal variances was conducted once again (alpha = 5%), yielding a probability p value of 0.06 for the hypothesis test. Given that p > 0.05, we conclude that both sets of values are not statistically different. Therefore, significant disparities between the field values measured in public spaces and those recorded in the proximity to emission sources are no longer evident. 3.4. Study of the magnetic field around HVPL The results obtained during the environmental characterization of ELF-MF levels near the HVPL outline the cross-sectional profile of magnetic field that decreases with distance from the midpoint of the line, as shown in Fig. 4 (a and b) for voltages of 220 kV and 400 kV, respectively. Extrapolating values obtained through an exponential function (with equation: \(\:y=1.24{exp}^{-0.045x}\) and R 2 -value: 0.98, for 220 kV, and equation: \(\:y=2.44{exp}^{-0.053x}\) and R 2 -value: 0.99, for 400 kV), as observed from the solid lines in both graphs (Fig. 4 ), the magnetic field values at 50 m distance from the power lines are like the average ELF-MF values in any of the public spaces within the urban environment, nearing 0.1 µT. A recently published study evaluating the French population's exposure to ELF-MF from HVPL (Deshayes-Pinçon et al. 2023 ) follows a similar protocol for measuring the magnetic field and analyses the records from 731 HVPL sites of 225 kV and 306 of 400 kV, characterized longitudinally and transversally. Despite the different sample sizes, considering the similarities with the present study, a comparison has been made between both studies. Figure 4 (c and d) shows the ELF-MF levels on the transverse axis of the HVPL in France and Spain. 4. Discussion and conclusions From the present study, based on the ELF-MF data recorded at the different locations in Albacete, Cáceres, and Madrid, with over 85 sites and more than 28 hours of total measurement, several conclusions can be drawn. Firstly, upon analyzing the categorized groups of public spaces and emission sources, it is observed that 95% of the environmental ELF-MF recorded in public spaces are below 0.17 µT, while in proximity to the emission sources, 95% of the measured emission levels are lower than 4.12 µT, constituting this higher value a mere 2% of the recommended limit value of 200 µT. Secondly, statistically comparing public spaces and emission sources or, respectively, immission and emission levels, the resulting average magnetic fields from public spaces, 0.095 µT, is significantly lower than those from the so-called emission sources, 1.303 µT. However, considering that some of these emission sources may be within public spaces contributing to immission levels, as occurs with transformation centers, building electrical connections and electric vehicle charging points, then, in this case, the conclusion is that there would be no significant differences between the environmental ELF-MF values in public spaces and in proximity to emission sources. Specifically, in relation to the ELF-MF immission levels in public spaces, the median value of 0.068 µT is around 30% lower than the mean value of this same group. Since the median is a much more robust parameter to extreme values than the mean, it can be considered that 0.068 µT better reflects the environmental magnetic field level in public spaces. Furthermore, comparing the ELF-MF levels observed in streets of denser urban centers to those in streets of residential areas -single-family homes-, the average field value in less populated residential areas is around 25% lower. Another aspect to highlight is the difference found between the magnetic field levels in the vicinity of public buildings, 0.096 µT, and the levels inside them, 0.129 µT, with the latter being approximately 26% higher. This discrepancy may be due, among other reasons, to the significant contribution from electrical installations inside the buildings. Among all the data in public spaces, the highest magnetic field value of 11.69 µT was recorded in the vicinity of a shopping center, probably due to proximity to some unnoticed internal transformer station in the building. It is followed by the maximum of 3.51 µT recorded during the journeys made in the underground, in any case representing less than the 6% of the reference level. In relation to the emission sources, three subgroups contribute to higher ELF-MF exposure levels: 400 kV HVPL, averaging 2.14 µT, transformer stations, with an average of 2.08 µT, and building electrical connections, averaging 3.28 µT. Among these subgroups, building electrical connections exhibit the highest emission levels and could, therefore, strongly contribute to the residential exposure levels as do interior transformer rooms in buildings (Röösli et al. 2011 ; Okokon 2014 ; Navarro-camba 2018 ). They should be then considered for future exposure assessment in residential settings. Regarding HVPL, the decreasing transverse profile of the magnetic field with the distance to the central point of the axis line was verified. Extrapolating the obtained values, it is noteworthy that the contribution of overhead HVPL to the ELF-MF exposure levels at 50 m distance from the axis line, approximating 0.1 µT, is like the field levels found in a typical urban environment, away from this electrical infrastructure. With respect to the installations of photovoltaic panels, more and more used for energy supply of diverse public services like electric bikes stations, and the electric vehicle charging points, the lowest values were registered as expected far from transformer devices and due to safety design of charging infrastructure networks. As the main conclusion of the present study, with the data available to date, the ambient ELF-MF levels of the population in Spain are very similar to those in other developed countries (Bonato et al. 2023 ; Gajšek et al. 2016 ), remaining well below the 200 µT limit recommended by ICNIRP. The exposure levels in public spaces are within a range of 0.05 to 0.2 µT, with values of few µT in proximity to the emission sources, which in any case represent only the 1.64% of the ICNIRP reference level, in the worst-case scenario near the building electrical connections. Present study has several limitations that should be acknowledged. First, the observational and descriptive nature of the research precludes the establishment of causal relationships between electromagnetic field exposure levels and potential health effects. Second, the geographic scope was limited to specific regions, which may not be representative of exposure patterns in other urban or rural settings, thereby limiting the generalizability of our findings. Third, measurement conditions were subject to inherent variability, including temporal fluctuations, time-of-day variations in emission sources, and spatial heterogeneity. Finally, the measurements represent environmental exposure levels rather than personal exposure, and no correlation was established between the recorded electromagnetic field levels and individual exposure patterns or health outcomes. Future research should address these limitations through longitudinal designs, personal dosimetry, and integration with epidemiological health data to better characterize the relationship between electromagnetic field exposure and potential biological effects. Overall, the results of this study in Spain can guide to address a broader evaluation of environmental exposure to ELF-MF through an established protocol, bringing relevant data for future epidemiological studies, as well as useful tool for management of risk communication to the Spanish population. The identified ambient levels of ELF-MF can be also relevant information for the implementation of the requested national regulation to limit the exposure levels to this range of magnetic fields. It is a first steppingstone, bridging the gap between scientific inquiry and practical policy implementation in the realm of ELF-MF regulation. Glossary - Extremely low frequency magnetic fields (ELF-MF) : Magnetic fields with frequencies below 300 Hz, typically associated with power lines and electrical appliances. - Electrical infrastructures : Systems and facilities for the generation, transmission, and distribution of electrical power. - Emission (magnetic fields) : Refers to the generation or release of magnetic fields from a source. It is the process by which a device or infrastructure produces and radiates magnetic fields into the surrounding environment. - Immission (magnetic fields) : Refers to the presence and intensity of magnetic fields at a specific location. It is the result of emissions from one or more sources after they have propagated through the environment. - International Commission on Non-Ionizing Radiation Protection (ICNIRP) : An independent organization that provides scientific advice and guidance on health and environmental effects of non-ionizing radiation. - Induced electric current density : The amount of electric current flowing through a unit area of a conductor, induced by a changing magnetic field. - International Agency for Research on Cancer (IARC) : An intergovernmental agency part of the World Health Organization, focusing on cancer research. - High-voltage power lines ( HVPL) : Electrical transmission lines that carry high voltages (typically above 100 kV) over long distances. - G-ENAC-14 guide : Spanish technical guide issued by the National Accreditation Entity (ENAC) - Z-score : A statistical measure that indicates how many standard deviations an element is from the mean of a data set. - Georeferenced measurements : Measurements or data associated with specific geographic locations or coordinates. - Median value : The middle value in a sorted list of numbers, separating the higher half from the lower half of a data set. Declarations Acknowledgements We would like to express our sincere gratitude to Rodrigo San Millán and Enrique López from Redeia’ company, for their invaluable assistance and support in conducting this study. Their contributions were instrumental in the successful completion of our research. We are also deeply indebted to Dr. Miguel Ángel Cobos from the Institute of Applied Magnetism (UCM) for his selfless help in carrying out the measurements in the Community of Madrid. The authors gratefully acknowledge the support of all those who contributed to this research. Funding Funding: This work was partially supported by the Environmental Department of the company Redeia (Spain). RR-V and EA gratefully acknowledge financial support from the Junta de Comunidades de Castilla-La Mancha of Spain (Project SBPLY/23/180225/00089) and from University of Castilla-La Mancha grant number 2022-GRIN-34356. Authors’ contributions - Sanchis-Otero, Aránzazu: Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Writing – original draft and Writing – review and editing. - Ramírez-Vázquez, Raquel: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Supervision, Validation, Visualization and Writing – review. - Paniagua, Jesús M.: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Supervision, Validation, Visualization and Writing – review. - Bajo, Ricardo: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing – original draft and Writing – review and editing. - Arribas, Enrique: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, and Writing – review. - Giacomone, Fernando: Conceptualization, Data curation, Investigation, Methodology, Validation. - Ramis, Rebeca: Conceptualization, Formal analysis, Investigation, Methodology, Resources, Supervision and Writing – review. - Marín Palacios, Pilar: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, and Writing – review. - Vargas Marcos, Francisco: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, and Writing – review. Ethical Approval* (Missing) This is not applicable Consent to Participate* (Missing) This is not applicable Consent to Publish* (Missing) This is not applicable Competing Interests No competing interests Data availability statements All data corresponding to the present study are available in the following free repository (GitHub): https://github.com/Ric-count/Spain-ELF-MF-data- Clinical trial number: not applicable References (BOE), Official State Gazette. 1999. “RECOMMENDATION OF THE EUROPEAN COUNCIL of July 12, 1999 on the Exposure of the General Public to Electromagnetic Fields (0 Hz to 300 GHz) (1999/519/EC).” Diario Oficial de Las Comunidades Europeas . Vol. 1999/519/C. Ahlbom, A, N Day, M Feychting, E Roman, J Skinner, J Dockerty, and M Linet. 2000. “A Pooled Analysis of Magnetic Fields and Childhood Leukaemia.” British Journal of Cancer 83 (5): 692–98. https://doi.org/10.1054/bjoc.2000.1376. Amoon, AT, J Swanson, C Magnani, C Johansen, and L Kheifets. 2022. “Pooled Analysis of Recent Studies of Magnetic Fields and Childhood Leukemia.” Environmental Research 204: 111993. https://doi.org/10.1016/j.envres.2021.111993. ARPANSA (Australian Radiation Protection and Nuclear Safety Agency). 2023. “Https://Www.Arpansa.Gov.Au/Understanding-Radiation/What-Is-Radiation/Non-Ionising-Radiation/Low-Frequency-Electric-Magnetic-Fields.” 2023. Bonato, Marta, Emma Chiaramello, Marta Parazzini, Peter Gajšek, and Paolo Ravazzani. 2023. “Extremely Low Frequency Electric and Magnetic Fields Exposure : Survey of Recent Findings.” IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology 7 (3): 216–28. https://doi.org/10.1109/JERM.2023.3268555. Brabant, Christian, Anton Geerinck, Charlotte Beaudart, Ezio Tirelli, Christophe Geuzaine, and Olivier Bruyere. 2021. “Exposure to Magnetic Fields and Childhood Leukemia: A Systematic Review and Meta-Analysis of Case-Control and Cohort Studies.” Rev Environ Health . 10.1515/reveh-2021-0112. Calvente, Irene, Cristina Dávila-Arias, Olga Ocón-Hernández, Rocío Pérez-Lobato, Rosa Ramos, Francisco Artacho-Cordón, Nicolás Olea, María Isabel Núñez, and Mariana F Fernández. 2014. “Characterization of Indoor Extremely Low Frequency and Low Frequency Electromagnetic Fields in the INMA-Granada Cohort.” PLOS ONE 9 (9): e106666. https://doi.org/10.1371/journal.pone.0106666. Crespi, Catherine M, John Swanson, Ximena P Vergara, Leeka Kheifets, Los Angeles, Environment Sector, Drive South, and Los Angeles. 2020. “Childhood Leukemia Risk in the California Power Line Study: Magnetic Fields versus Distance from Power Lines,” 530–35. https://doi.org/10.1016/j.envres.2019.01.022.Childhood. Deshayes-Pinçon, Fanny, Fabrice Morlais, Olivia Roth-Delgado, Olivier Merckel, Brigitte Lacour, Guy Launoy, Ludivine Launay, and Olivier Dejardin. 2023. “Estimation of the General Population and Children under Five Years of Age in France Exposed to Magnetic Field from High or Very High Voltage Power Line Using Geographic Information System and Extrapolated Field Data.” Environmental Research 232 (September): 116425. https://doi.org/10.1016/j.envres.2023.116425. European Commission. 2015. Scientific Committee on Emerging and Newly Identified Health Risks SCENIHR Opinion on Potential Health Effects of Exposure to Electromagnetic Fields . https://doi.org/10.2772/75635. Gajšek, Peter, Paolo Ravazzani, James Grellier, Theodoros Samaras, and József Bakos. 2016. “Review of Studies Concerning Electromagnetic Field ( EMF ) Exposure Assessment in Europe : Low Frequency Fields ( 50 Hz – 100 KHz ).” Int. J. Environ. Res. Public Health , 1–14. https://doi.org/10.3390/ijerph13090875. Gallastegi, Mara. 2017. “Exposure to Extremely Low and Intermediate-Frequency Magnetic and Electric Fields among Children from the INMA-Gipuzkoa Cohort.” Environmental Research . https://doi.org/https://doi.org/10.1016/j.envres.2017.05.027. Gervasi, Federico, Rossella Murtas, Adriano Decarli, and Antonio Russo. 2019. “Residential Distance from High-Voltage Overhead Power Lines and Risk of Alzheimer’s Dementia and Parkinson’s Disease: A Population-Based Case-Control Study in a Metropolitan Area of Northern Italy,” no. July: 1949–57. https://doi.org/10.1093/ije/dyz139. Greenland, S, A R Sheppard, W T Kaune, C Poole, and M A Kelsh. 2000. “A Pooled Analysis of Magnetic Fields, Wire Codes, and Childhood Leukemia. Childhood Leukemia-EMF Study Group.” Epidemiology (Cambridge, Mass.) 11 (6): 624–34. https://doi.org/10.1097/00001648-200011000-00003. Huss, Anke, Adrian Spoerri, Matthias Egger, and Martin Ro. 2009. “Original Contribution Residence Near Power Lines and Mortality From Neurodegenerative Diseases : Longitudinal Study of the Swiss Population” 169 (2): 167–75. https://doi.org/10.1093/aje/kwn297. IARC. 2002. “MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS.” IARC . ICNIRP. 2015. “ICNIRP Statement Gaps in Knowledge Relevant to the ‘ ICNIRP Guidelines for Limiting Exposure to Time-Varying Electric , Magnetic and Electromagnetic Fields ( 100 KHz TO 300 GHz ) ,’” no. Who 2014. https://doi.org/10.1097/HP.0000000000001944. IEC. 2014. “Measurement of DC Magnetic, AC Magnetic and AC Electric Fields from 1 Hz to 100 KHz with Regard to Exposure of Human Beings - Part 2: Basic Standard for Measurements.” https://standards.iteh.ai/catalog/standards/iec/81e72401-d6d7-43ca-ac5f-3e14588a12bb/iec-61786-2-2014. IEC 62110. n.d. “Electric and Magnetic Field Levels Generated by AC Power Systems - Measurement Procedures with Regard to Public Exposure.” Kheifets, Leeka, A Ahlbom, C M Crespi, G Draper, J Hagihara, R M Lowenthal, and G Mezei. 2010. “Pooled Analysis of Recent Studies on Magnetic Fields and Childhood Leukaemia.” British Journal of Cancer 103 (7): 1128–35. https://doi.org/10.1038/sj.bjc.6605838. Kheifets, Leeka, Los Angeles, Anders Ahlbom, Karolinska Institutet, and Catherine M Crespi. 2010. “Pooled Analysis of Recent Studies of Magnetic Fields and Childhood Leukemia Pooled Analysis of Recent Studies on Magnetic Fields and Childhood Leukaemia,” no. May 2014. https://doi.org/10.1038/sj.bjc.6605838. Kheifets, Leeka, Catherine Crespi, Chris Hooper, Sona Oksuzyan, Myles Cockburn, Thomas Ly, and Gabor Meze. 2016. “Epidemiologic Study of Residential Proximity to Transmission Lines and Childhood Cancer in California: Description of Design, Epidemiologic Methods and Study Population.” J Expo Sci Environ Epidemiol 25 (1): 45–52. https://doi.org/10.1038/jes.2013.48.Epidemiologic. Malagoli, Carlotta, Marcella Malavolti, Lauren A Wise, Erica Balboni, Sara Fabbi, Sergio Teggi, Giovanni Palazzi, Monica Cellini, Maurizio Poli, Paolo Zanichelli, Barbara Notari, Andrea Cherubini, Marco Vinceti, Tommaso Filippini. 2023. “Residential Exposure to Magnetic Fields from High-Voltage Power Lines and Risk of Childhood Leukemia.” Environmental Research 232 (June): 116320. https://doi.org/10.1016/j.envres.2023.116320. Matthes, Rüdiger., Jürgen H. Bernhardt, Alastair F. McKinlay, and International Commission on Non-Ionizing Radiation Protection. 1998. Guidelines on Limiting Exposure to Non-Ionizing Radiation : A Reference Book Based on the Guidelines on Limiting Exposure to Non-Ionizing Radiation and Statements on Special Applications . Health Physics Society . Vol. 74. National Accreditation Entity (ENAC). 2008. “Guide to Participation in Intercomparison Programs.” National Agency for Food, Environmental and Occupational Health and Safety (ANSES), France. 2019. “Health Effects Associated with Exposure to Low-Frequency Electromagnetic Fields.” Navarro-camba, Enrique A. 2018. “Exposure to 50 Hz Magnetic Fields in Homes and Areas Surrounding Urban Transformer Stations in Silla ( Spain ): Environmental Impact Assessment,” 1–11. https://doi.org/10.3390/su10082641. Okokon, Enembe Oku. 2014. “Indoor Transformer Stations and ELF Magnetic Field Exposure : Use of Transformer Structural Characteristics to Improve Exposure Assessment,” no. September 2013: 100–104. https://doi.org/10.1038/jes.2013.54. Organization, World Health. 2007. “2007 WHO Research Agenda for Extremely Low Frequency Fields,” 1–8. Paniagua, Jesús M., Antonio Jiménez, Montaña Rufo, and Alicia Antolin. 2004. “Exposure Assessment of ELF Magnetic Fields in Urban Environments in Extremadura (Spain).” Bioelectromagnetics 25 (1): 58–62. https://doi.org/10.1002/bem.10147. Röösli, Martin, Daniela Jenni, Leeka Kheifets, and Gabor Mezei. 2011. “Science of the Total Environment Extremely Low Frequency Magnetic Fi Eld Measurements in Buildings with Transformer Stations in Switzerland.” Science of the Total Environment, The 409 (18): 3364–69. https://doi.org/10.1016/j.scitotenv.2011.05.041. Schmidt, Janine-alison, Sabine Hornhardt, and Friederike Erdmann. 2021. “Risk Factors for Childhood Leukemia : Radiation and Beyond.” Front. Public Health 9 (December). https://doi.org/10.3389/fpubh.2021.805757. Seomun, Gyeongae. 2021. “Exposure to Extremely Low-Frequency Magnetic Fields and Childhood Cancer : A Systematic Review and Meta-Analysis” 10: 1–21. https://doi.org/10.1371/journal.pone.0251628. Spanish standard UNE 215001. 2004. “Standardized Procedures for the Measurement of Industrial Frequency Electric and Magnetic Fields Produced by High Voltage Power Lines.” Steliarova-foucher, Eva, Murielle Colombet, Lynn A G Ries, Florencia Moreno, Anastasia Dolya, Freddie Bray, Peter Hesseling, and Hee Young Shin. 2017. “Articles International Incidence of Childhood Cancer , 2001 – 10 : A Population-Based Registry Study.” Lancet Oncology , 719–31. https://doi.org/10.1016/S1470-2045(17)30186-9. Swanson, J., L. Kheifets, and X. Vergara. 2019. “Changes over Time in the Reported Risk for Childhood Leukaemia and Magnetic Fields.” Journal of Radiological Protection 39 (2): 470–88. https://doi.org/10.1088/1361-6498/ab0586. Swedish Radiation Safety Authority’s Scientific Council on Electromagnetic Fields. 2024. “Recent Research on EMF and Health Risk , Seventeenth Report from SSM ’ s Scientific Council on Electromagnetic.” Wertheimer, N, and E Leeper. 1979. “Electrical Wiring Configurations and Childhood Cancer.” American Journal of Epidemiology 109 (3): 273–84. https://doi.org/10.1093/oxfordjournals.aje.a112681. Supplementary Files SupplementaryMaterial.docx Cite Share Download PDF Status: Published Journal Publication published 03 Jan, 2026 Read the published version in Environmental Science and Pollution Research → Version 1 posted Reviewers agreed at journal 31 Oct, 2025 Reviewers invited by journal 30 Oct, 2025 Editor invited by journal 30 Oct, 2025 First submitted to journal 28 Oct, 2025 Editorial decision: Minor Revision 29 Sep, 2025 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-7363662","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":537531181,"identity":"1c3c720b-2b51-42c4-8a43-eda496eaff06","order_by":0,"name":"Aránzazu Sanchis-Otero","email":"","orcid":"","institution":"Non-ionizing Radiation Unit, Radioprotection Area, National Centre of Environmental Health, Institute of Health Carlos III. Majadahonda, Madrid","correspondingAuthor":false,"prefix":"","firstName":"Aránzazu","middleName":"","lastName":"Sanchis-Otero","suffix":""},{"id":537531182,"identity":"0f1bf1c6-82d2-4f2d-9efc-948025160493","order_by":1,"name":"Raquel Ramirez-Vazquez","email":"","orcid":"","institution":"University of Castilla-La Mancha, Department of Physics, Polytechnic School of Cuenca, University Campus, 16071 Cuenca, Spain","correspondingAuthor":false,"prefix":"","firstName":"Raquel","middleName":"","lastName":"Ramirez-Vazquez","suffix":""},{"id":537531183,"identity":"b3e57942-2dfd-4184-8f94-49476bf91b8b","order_by":2,"name":"Jesús M. Paniagua","email":"","orcid":"","institution":"GRNIIU Research Group, University of Extremadura, 10003 Cáceres, Spain","correspondingAuthor":false,"prefix":"","firstName":"Jesús","middleName":"M.","lastName":"Paniagua","suffix":""},{"id":537531184,"identity":"96d20f62-ccda-48d7-9f7b-e51744ab2af7","order_by":3,"name":"Ricardo Bajo","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAq0lEQVRIiWNgGAWjYDACCR4IzU+ilgQGBskGkrUYHCBWh/ns3mMfPv6wyTO+kfx0A0NFHWEtMnfOJc+ckZBWbHYjzewGw5nDRLhLIseYmSfhcOK2GzlsNxjbiHAeWMsfoJbNM0Ba/hHhMLAWBqCWDRIgLQ3MRGiROZfM2JOWljjjzDOzGwnHiPGLdO9hhh82Non97cnPbnyoIcJhqCCBVA2jYBSMglEwCrADAG0TORALXqzRAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-0646-2962","institution":"Institute of Applied Magnetism, Complutense University of Madrid, Madrid, Spain \u0026 Faculty of Science and technology, Valencia International University (VIU), Valencia, Spain","correspondingAuthor":true,"prefix":"","firstName":"Ricardo","middleName":"","lastName":"Bajo","suffix":""},{"id":537531185,"identity":"3d0c1d1c-9183-4bb9-84b6-c55e01e848f8","order_by":4,"name":"Enrique Arribas","email":"","orcid":"","institution":"MORFEO Research Group, University of Castilla-La Mancha, Albacete, Spain","correspondingAuthor":false,"prefix":"","firstName":"Enrique","middleName":"","lastName":"Arribas","suffix":""},{"id":537531186,"identity":"5603466a-e2b0-4b52-8f79-3a1bae673b8b","order_by":5,"name":"Fernando Giacomone","email":"","orcid":"","institution":"Institute of Applied Magnetism, Complutense University of Madrid, Madrid, Spain","correspondingAuthor":false,"prefix":"","firstName":"Fernando","middleName":"","lastName":"Giacomone","suffix":""},{"id":537531187,"identity":"aa439711-d4a1-4c00-860f-5d78a3712a57","order_by":6,"name":"Rebeca Ramis","email":"","orcid":"","institution":"Cancer and Environmental Epidemiology Unit. Chronic Diseases Deparment, National Centre for Epidemiology, Institute of Health, Spain Carlos III (ISCIII), Madrid, Spain","correspondingAuthor":false,"prefix":"","firstName":"Rebeca","middleName":"","lastName":"Ramis","suffix":""},{"id":537531188,"identity":"f0662083-4934-4c9b-b1f5-20b7629ceef2","order_by":7,"name":"Pilar Marín Palacios","email":"","orcid":"","institution":"Institute of Applied Magnetism, Complutense University of Madrid, Madrid, Spain","correspondingAuthor":false,"prefix":"","firstName":"Pilar","middleName":"Marín","lastName":"Palacios","suffix":""},{"id":537531189,"identity":"dc222d1c-6629-4ca6-86d1-65cc1cef6bd1","order_by":8,"name":"Francisco Vargas Marcos","email":"","orcid":"","institution":"Ministry of Health, General Directorate of Public Health, Deputy Direction of Environmental Health and Occupational Health, Madrid, Spain","correspondingAuthor":false,"prefix":"","firstName":"Francisco","middleName":"Vargas","lastName":"Marcos","suffix":""}],"badges":[],"createdAt":"2025-08-13 10:02:24","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7363662/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7363662/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11356-025-37318-y","type":"published","date":"2026-01-03T15:57:26+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":94867005,"identity":"9aa80616-0f67-4f9e-9e2d-3ab2e14ab765","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"tif","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":4033708,"visible":true,"origin":"","legend":"","description":"","filename":"Figure1.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/24c4dbc885853e53b9970992.tif"},{"id":94986687,"identity":"08afb8bf-770b-4f6c-816a-d5be8565dc20","added_by":"auto","created_at":"2025-11-03 07:00:37","extension":"tif","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":112166,"visible":true,"origin":"","legend":"","description":"","filename":"Figure2.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/b90f27f532008630cbb949f7.tif"},{"id":94867004,"identity":"98639e8b-d3f1-45a0-be78-3256319e6032","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"tif","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":117358,"visible":true,"origin":"","legend":"","description":"","filename":"Figure3.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/499f3831b1e7f3d948ecd24f.tif"},{"id":94867019,"identity":"51415712-ff02-4e39-85ab-93475ac63e0d","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"tif","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2222462,"visible":true,"origin":"","legend":"","description":"","filename":"Figure4.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/94873a93dd7f317087a18c79.tif"},{"id":94985354,"identity":"dfb43ac3-51ec-4d67-86f1-dd9076d6726a","added_by":"auto","created_at":"2025-11-03 06:58:00","extension":"xml","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14778,"visible":true,"origin":"","legend":"","description":"","filename":"esprESPRD2505857.xml","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/157fa612a4d7a9ada8d05053.xml"},{"id":94867026,"identity":"c3af5ee9-2a0b-40d9-abee-ad0fc82f8f09","added_by":"auto","created_at":"2025-10-31 14:07:44","extension":"xml","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1349,"visible":true,"origin":"","legend":"","description":"","filename":"ESPRD2505857504331.go.xml","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/393dec657db4f6f8dea59342.xml"},{"id":94867009,"identity":"50ea814f-e3b2-4199-99fb-fb87c2b0e303","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"xml","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":930,"visible":true,"origin":"","legend":"","description":"","filename":"ESPRD2505857Import.xml","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/7ac36709f0771f4f0b4b1c60.xml"},{"id":94867025,"identity":"2b1dde00-f5f1-4ab3-9465-8e0f278570bc","added_by":"auto","created_at":"2025-10-31 14:07:44","extension":"xml","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":121958,"visible":true,"origin":"","legend":"","description":"","filename":"ESPRD25058571enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/86e0357271bc9147f14cdea8.xml"},{"id":94867030,"identity":"27154985-a115-4a6c-a995-7c80b792266b","added_by":"auto","created_at":"2025-10-31 14:07:45","extension":"tif","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":4033708,"visible":true,"origin":"","legend":"","description":"","filename":"Figure1.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/fd0d8a3cb056018995ace7ff.tif"},{"id":94986303,"identity":"a8fdd97a-0e4b-44f8-877f-95c1efcbaf3d","added_by":"auto","created_at":"2025-11-03 07:00:10","extension":"tif","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":112166,"visible":true,"origin":"","legend":"","description":"","filename":"Figure2.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/6a9c4ccd784fe9f2c476321c.tif"},{"id":94986653,"identity":"0ca9b500-cb49-4eb0-8b64-510927f7628b","added_by":"auto","created_at":"2025-11-03 07:00:32","extension":"tif","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":117358,"visible":true,"origin":"","legend":"","description":"","filename":"Figure3.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/e34a51ff17302d04143b7a19.tif"},{"id":94986414,"identity":"9d50f9e6-4bce-48ee-85f5-2fad93e7c360","added_by":"auto","created_at":"2025-11-03 07:00:17","extension":"tif","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2222462,"visible":true,"origin":"","legend":"","description":"","filename":"Figure4.tif","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/7ff91a7a4b9cc710f1a98a63.tif"},{"id":94867015,"identity":"3ef4bc4e-4a8e-4021-93df-f0d29de353b0","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"jpeg","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":152818,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/2b4fe6c33e53716f569fca67.jpeg"},{"id":94867012,"identity":"dbaf72e8-5aaa-4dc7-995b-6d70468bcde5","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"jpeg","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":132690,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/ecf15d38801cece919d2af2c.jpeg"},{"id":94986759,"identity":"06424c17-e079-4f48-8c7b-6d421dbaeac7","added_by":"auto","created_at":"2025-11-03 07:00:44","extension":"jpeg","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":155397,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/7ca17cec52f2b6e15d82b25a.jpeg"},{"id":94867016,"identity":"b3a1f208-33dd-4c5d-b82e-adce65919b0b","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"jpeg","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":355005,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/b5032aa6bc4556e1bcf89dec.jpeg"},{"id":94986252,"identity":"87bd00fb-27d6-47b8-865a-78a231183330","added_by":"auto","created_at":"2025-11-03 07:00:07","extension":"png","order_by":21,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":35310,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/fbf986413949cdc3e87e6923.png"},{"id":94867024,"identity":"a07e23de-a9df-4bff-8f8e-1441f29c40c4","added_by":"auto","created_at":"2025-10-31 14:07:44","extension":"png","order_by":22,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":15935,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/5abe1c4b0723b5b1020cc510.png"},{"id":94867011,"identity":"47eaad1a-af93-494b-b040-c70c2126f8e7","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"png","order_by":23,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":17539,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure3.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/70e717a993275afe37e5120b.png"},{"id":94867008,"identity":"35f19480-2d10-4030-9717-451bf43bd240","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"png","order_by":24,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":189448,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure4.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/62723be6421e4b8fbdc1417a.png"},{"id":94985455,"identity":"02dcb82b-479d-4c25-8144-3170099fb655","added_by":"auto","created_at":"2025-11-03 06:58:12","extension":"png","order_by":25,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":25269,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/80a9ea0e5753ae57da610485.png"},{"id":94867017,"identity":"59b75dd0-9e43-4b00-b9d4-3132f91b8a4c","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"png","order_by":26,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":21092,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/12730fa484aef0640abf8e56.png"},{"id":94867021,"identity":"d83c7273-b365-4ad3-a8c5-5ccd4cf7b218","added_by":"auto","created_at":"2025-10-31 14:07:44","extension":"png","order_by":27,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":27131,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/66c6db2f382cedf2fb4c5b83.png"},{"id":94867013,"identity":"50e8323f-52f9-4fd4-ab1a-41d6a132ea48","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"png","order_by":28,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":48194,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/3f2b86ed1a4b8191232861b3.png"},{"id":94867022,"identity":"62077e77-25d8-4156-be61-bfb1f36d90d2","added_by":"auto","created_at":"2025-10-31 14:07:44","extension":"xml","order_by":29,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":121164,"visible":true,"origin":"","legend":"","description":"","filename":"ESPRD25058571structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/d8612e1f7490663fa3307a3f.xml"},{"id":94867027,"identity":"8c6cb4af-7956-43b8-8a8c-015961595087","added_by":"auto","created_at":"2025-10-31 14:07:44","extension":"html","order_by":30,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":134547,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/991b4be994b3461c32efc81f.html"},{"id":94867033,"identity":"6fe552e5-d74a-4a40-8992-74cd65a230ab","added_by":"auto","created_at":"2025-10-31 14:07:46","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":136137,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eAverage environmental levels of magnetic field (ELF-MF), both in public spaces (black) and in vicinity of emission sources (gray), based on the total data. In total, n = 39 locations were measured as public spaces, and n = 46 for emission sources. Magnetic fields were measured in microTeslas (µT).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/87773fe380796e68e6395774.png"},{"id":94985480,"identity":"91ad851e-f97a-4932-ab45-9e90bc8d5dae","added_by":"auto","created_at":"2025-11-03 06:58:16","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":46145,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eBar plot of the average ELF-MF values in public spaces. Magnetic fields were measured in microTeslas (µT).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/a3e6a50d7a5e3ce76840da95.png"},{"id":94867001,"identity":"a789c58b-0ba2-44de-b28b-419a549cf634","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":57593,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eBar plot of the average magnetic field values recorded at the 46 locations around ELF-MF emission sources. Magnetic fields were measured in microTeslas (µT).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/2dd55b8f31d0bc38e31cc96a.png"},{"id":94867002,"identity":"6d6926aa-0344-408e-b7c5-24ec3d2c6a4e","added_by":"auto","created_at":"2025-10-31 14:07:43","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":193327,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eRepresentation (in a and b) of the transverse profile of the magnetic field with the distance from the axis of the line, resulting from the average values recorded in the environment of 220 \u003c/em\u003ekV\u003cem\u003e and 400 \u003c/em\u003ekV \u003cem\u003ehigh-voltage lines, and values obtained through extrapolation (blue line). Comparison (c and d) of the transverse profile of the ELF-MF obtained in proximity to 225 \u003c/em\u003ekV\u003cem\u003e and 220 \u003c/em\u003ekV\u003cem\u003eHVPL in France and Spain, respectively, and in 400 \u003c/em\u003ekV \u003cem\u003elines, along with the result of the extrapolation in each case (blue and red lines). Magnetic fields were measured in microTeslas (µT).\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/08519efd8469e88ba7d14a5a.png"},{"id":99545635,"identity":"a73a53a7-a5ef-461d-a8b2-15d257345e16","added_by":"auto","created_at":"2026-01-05 16:09:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1660041,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/df0c484c-29d1-4bd3-b8a0-f374097b8d0d.pdf"},{"id":94985509,"identity":"ee895951-20e6-4ebf-a85b-a7d8998b8257","added_by":"auto","created_at":"2025-11-03 06:58:18","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2000582,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterial.docx","url":"https://assets-eu.researchsquare.com/files/rs-7363662/v1/005e58d65cf58272a72e8960.docx"}],"financialInterests":"","formattedTitle":"Measurement of urban environmental exposure to Extremely Low Frequency Magnetic Fields in several Spanish regions","fulltext":[{"header":"Highlights","content":"\u003cp\u003e- Typical ambient ELF-MF levels in Spain were identified.\u003c/p\u003e\u003cp\u003e- Immission and emission levels in public areas and from diverse sources evaluated.\u003c/p\u003e\u003cp\u003e- The low ELF-EMF levels found in Spain are like those in developed countries.\u003c/p\u003e\u003cp\u003e- The mean outdoor immission value is 0.1 \u0026micro;T and the mean emissions level 1.3 \u0026micro;T.\u003c/p\u003e"},{"header":"1. Introduction","content":"\u003cp\u003eResidential exposure to magnetic fields (MF) in the extremely low frequency range (1 Hz to 100 kHz) has raised some public concern due to the hypothetical relationship between low levels of MF of 50 Hz/60 Hz and childhood leukemia (CL). Since 1979, this possible association has been observed for years in epidemiological studies (Wertheimer and Leeper 1979; Ahlbom et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Greenland et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Malagoli et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) (Kheifets, Ahlbom, et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) (Kheifets et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), and other health effects, such as cancer and neurodegenerative diseases in adults, have also been studied in connection to this environmental physical agent(Kheifets et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2016\u003c/span\u003e)(Seomun \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Gervasi et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Huss et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe regulation to limit the exposure to ELF-MF for public protection relies, in Europe, on the recommendation for health protection against exposure to electromagnetic fields throughout the frequency range (0 Hz to 300 GHz), the EU Council Recommendation ((BOE) 1999). This is based on the guidelines published by ICNIRP in 1998, in light of established evidence on the acute effects (short-term) of exposure to electromagnetic fields (Matthes et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e1998\u003c/span\u003e). Concerning ELF-MF, the primary objective is to prevent effects on the nervous system resulting from the induction of electric currents within the body, as well as any perception and annoyance occurring at high ELF-MF levels. Following the establishment of various safety factors, ICNIRP recommended as a basic restriction to limit the induced electric current density in the head and trunk to 2 mA/m\u003csup\u003e2\u003c/sup\u003e. Then, theoretically calculated reference levels for the 50 Hz magnetic field were set at 100 \u0026micro;T.\u003c/p\u003e\u003cp\u003eIn 2002, the International Agency for Research on Cancer (IARC) classified the ELF-MF in Group 2B as possibly carcinogenic to humans. The scientific literature evaluation made by the IARC led to this classification due to limited and inadequate evidence in humans regarding CL and other cancers, respectively, and to inadequate evidence in experimental animals. Specifically, the classification responded to those epidemiological studies reporting a statistical relationship between acute lymphoblastic leukemia (ALL) and prolonged average exposure during childhood to ELF magnetic field levels of 0.3\u0026ndash;0.4 \u0026micro;T (IARC 2002), in which random, biased, or confounding factors could not be ruled out. Later, the health risk assessment of exposure to ELF electric and magnetic fields addressed by the World Health Organization (WHO), and published in 2007, concluded that \u0026ldquo;new human, animal and in vitro studies, published since the 2002 IARC monograph, do not change the overall classification of ELF magnetic fields as a possible human carcinogen\u0026rdquo; (Organization \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). Then, in 2010, ICNIRP reviewed the 1998 guidelines regarding electric and magnetic fields at ELF, establishing a new limit of 200 \u0026micro;T for the magnetic field of 50 Hz (Matthes et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e1998\u003c/span\u003e). These updated guidelines were based solely on the scientific evidence available at the time, excluding as a criterion the observed increased risk of childhood leukaemia due to the lack of a causal relationship with the chronic exposure to ELF-MF.\u003c/p\u003e\u003cp\u003eConclusions from consecutive scientific reports by national and international agencies and committees (European Commission \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; National Agency for Food, Environmental and Occupational Health and Safety (ANSES) 2019; Swedish Radiation Safety Authority\u0026rsquo;s Scientific Council on Electromagnetic Fields \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) are consistent with previous findings that, to date, any potential health effect from chronic exposure to ELF-MF do not meet sufficient criteria to be deemed causal, and further research is needed (ICNIRP \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). This is generally supported by international bodies, such as the UK Health Security Agency, the German Federal Office for Radiation Protection (BfS), the Irish Environmental Protection Agency (EPA), the Dutch National Institute for Public Health and the Environment (RIVM) or the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Besides, the relative risk over time in epidemiological studies has shown a slight decrease, i.e., a weaker association between childhood leukaemia and ELF-MF, but without fully understanding the possible causes of this trend (Kheifets, Ahlbom, et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) (Swanson, Kheifets, and Vergara \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Crespi et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) (Crespi et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) (Swanson, Kheifets, and Vergara \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) (Kheifets, Ahlbom, et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). In a recent study, the diverse meta-analysis addressed considering the different approaches for assessing the magnetic field exposure, such as direct ELF-MF measurements, distances between dwelling and high-voltage power lines (HVPL) and wire coding configurations, pointed to a reduced risk found when studies were based on magnetic field measurements (Brabant et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Also, a pooled analysis of individual data from 24,994 cases and 30,769 controls, obtained from four recent studies on ELF-MF and CL, concluded that there is no increased risk at exposure levels above 0.4 \u0026micro;T compared to levels below 0.1 \u0026micro;T (Amoon et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) unlike previous studies. According to the authors, methodological issues, chance or a true finding of disappearance of the association could respond to these new observations.\u003c/p\u003e\u003cp\u003eHowever, the data collected by the International Agency for Research on Cancer (IARC) shows a worldwide increase in the incidence rate of childhood leukaemia from the 1980\u0026rsquo;s to the end of the 2000s, that might only in part be explained by an improvement in diagnosis and registration (Steliarova-foucher et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Therefore, all these observations indicate that more multidisciplinary investigations are still needed to clarify the potential role of ELF-MF on CL and other suggested health effects, especially, experimental and mechanistic but also epidemiologic studies, all of them supported by improved exposure assessments of this environmental agent (ICNIRP \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Schmidt, Hornhardt, and Erdmann 2021).\u003c/p\u003e\u003cp\u003eDespite the international effort made in the last years for an improvement in the assessment of the ELF-MF exposure (Bonato et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Gajšek et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), in Spain there are still few studies devoted to this issue. Some relevant data about personal indoor and outdoor exposure to ELF-MF by children and pregnant women were registered in two Spanish provinces, Granada (south) and Guipuzcoa (north), from the INMA project population cohort (Calvente et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Gallastegi \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Other studies of ELF-MF environmental characterization were addressed in different towns from the western region of Extremadura to estimate the outdoor exposure levels of their inhabitants (Paniagua et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). Thus, one of the main objectives of this preliminary study is to provide new information about the ELF-MF environmental exposure in the general Spanish population, defining in advance a measurement protocol, considering both immission (magnetic field reaching a location) levels in public spaces (outdoor and indoor) and emission levels in proximity to electrical infrastructure. Through this study quality data and procedures will be provided for addressing future measurement campaigns and epidemiological analysis, but also relevant information will be reported for national regulator agents and other stake holders for risk perception management. Besides, this study, initiated by the Spanish Ministry of Health, addresses key objectives outlined in the \"Strategic Plan for Health and Environment 2022\u0026ndash;2026\" (PESMA). It serves as a crucial first step towards a comprehensive national assessment of ELF-MF exposure levels in Spain.\u003c/p\u003e\u003cp\u003eAs a first approach, three Spanish regions were considered (Albacete, C\u0026aacute;ceres, and Community of Madrid), and diverse public places and ELF-MF emission sources included. Measurements were performed following previously established protocol based on international and national standards. The immission ELF-MF levels in outdoor and indoor public spaces were measured. The ELF-MF emission levels were assessed in proximity to primarily infrastructure related to the transportation and distribution of electricity, but also to electrified modes of transport. Moreover, in order to analyze the consistency of this environmental assessment with other countries, the ELF-MF levels measured near the HVPL have been compared to those obtained from a recent French study (Deshayes-Pin\u0026ccedil;on et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e"},{"header":"2. Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1. Measurement equipment and test inter-comparison\u003c/h2\u003e\u003cp\u003eAll measurements were carried out using identical electromagnetic field meters SMP2 from WAVECONTROL which allow selective -up to 400 kHz- and broadband measurements. All systems were equipped with the WP400 probe (frequency range of 1 Hz to 400 kHz and a resolution of \u0026lt;\u0026thinsp;0.1 nT (at 50 Hz)) and GPS for geo-referencing the recorded data. The devices calibrated at the manufacturer were subjected to an inter-calibration process, carried out at the Institute of Applied Magnetism of the Complutense University of Madrid (IMA-UCM), before the measurement campaign.\u003c/p\u003e\u003cp\u003eAn Kepco BOP 2050 MG power supply and Helmholtz coils were used to generate various levels of magnetic field (in the supplementary material we can see an image showing the Kepco BOP 2050 MG power supply and the Helmholtz coils used to generate various levels of magnetic field). The coils were fed with four different current intensities \u0026minus;\u0026thinsp;0.1 A; 0.15 A; 0.2 A and 1 A - and a background measurement was also made. SMP2 equipment was configured to measure in the frequency range of 10 Hz to 400 kHz, and the magnetic field levels were recorded during six minutes. All results obtained for each intensity and equipment, were quite similar. Differences among them were evaluated through the dimensionless z-score parameter, defined as follows (1):\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:z=\\frac{x-{x}_{a}}{{\\sigma\\:}_{p}}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003ein accordance with the G-ENAC-14 guide (National Accreditation Entity (ENAC) \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) where \u003cem\u003ex\u003c/em\u003e is the measurement of each equipment, \u003cem\u003ex\u003c/em\u003e\u003csub\u003e\u003cem\u003ea\u003c/em\u003e\u003c/sub\u003e is the average of the results obtained by the different equipment, and \u003cem\u003eσ\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e is the target or appropriate standard deviation. Since the objective of this project is the measurement of environmental magnetic fields, the average of the relative standard deviations of the outdoor measurements corresponds to \u003cem\u003eσ\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e, taking a value of 12.3%. All the \u003cem\u003ez\u003c/em\u003e-score obtained for the different equipment were satisfactory (|\u003cem\u003ez\u003c/em\u003e|\u0026lt; 2).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2. Measurement Locations\u003c/h2\u003e\u003cp\u003eAcross the three Spanish provinces involved, Albacete (Castilla-La Mancha), C\u0026aacute;ceres (Extremadura) and Madrid, specific locations were selected within two distinct categories: public spaces (group A) and emission sources (group B). Thus, on the one hand, we will measure the ELF-MF immission levels in public spaces considering the following environments: A.1) streets in urban and single-family residential areas, A.2) parks and gardens, A.3) public buildings, A.4) public buildings (interior), A.5) public transport stations and A.6) underground. And, on the other, the emission levels were measured in proximity to ELF-MF infrastructure, which may present higher magnetic field values, considering the following sources: B.1) overhead 220 kV high-voltage power lines (HVPL), B.2) overhead 400 kV HVPL, B.3) underground 220 kV HVPL, B.4) electrical substations, B.5) transformer stations, B.6) electrical service entrances of buildings, B.7) photovoltaic solar panel installations, and B.8) electric vehicle charging points. Based on the information provided by the Spanish company responsible for electricity transportation, Red El\u0026eacute;ctrica de Espa\u0026ntilde;a (REE), a preliminary selection of locations was conducted on-site regarding the corresponding infrastructure.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3. Measurement protocol\u003c/h2\u003e\u003cp\u003eThe measurement protocol was established in accordance with both international and national standards concerning the measurement of magnetic fields at industrial frequency in relation to human exposure (IEC 62110, n.d.; IEC \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Spanish standard UNE 215001 \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). In addition, the technical document TR 170 from Australian Radiation Protection and Nuclear Safety Agency was considered (ARPANSA (Australian Radiation Protection and Nuclear Safety Agency) \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). A brief description of the protocol followed at each location is detailed below.\u003c/p\u003e\u003cp\u003eConfiguration parameters used in all SMP2 devices for measurements in the project are the following: unit of measurement: Micro-Teslas (\u0026micro;T), filter applied (High Pass Filter): 10 Hz, measurement range: 10 Hz a 400 kHz, sampling frequency: 0.5 seconds.\u003c/p\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003e2.3.1. High-Voltage Power Lines (HVPL)\u003c/h2\u003e\u003cp\u003eBoth longitudinal and transversal profiles of the ELF-MF were registered for each HVPL selected. All measurements were recorded 1 m above the ground, georeferenced, and for 1 minute. Once located the maximum magnetic field intensity, \u003cem\u003eB\u003c/em\u003e\u003csub\u003e\u003cem\u003emax\u003c/em\u003e\u003c/sub\u003e, under the HVPL axis line between two pylons, or along the path located perpendicularly above the underground line, longitudinal measurements were taken at least at 5 equidistant points, following the lateral lines (or above the line in underground lines). If the HVPL had three lines, the central one was disregarded. For the transversal characterization of the line, from the \u003cem\u003eB\u003c/em\u003e\u003csub\u003e\u003cem\u003emax\u003c/em\u003e\u003c/sub\u003e point and moving in the normal direction and outward from each of the two lateral lines, the field was recorded at the minimum recommended intervals: 0 m, 5 m, 10 m, 15 m, 20 m and 30 m, if no obstacle prevents it. In the supplementary material, we can see a photograph of the SMP2 equipment located under a 400 kV high voltage-power line in the city of Trujillo (C\u0026aacute;ceres).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\u003ch2\u003e2.3.2. Electrical substations\u003c/h2\u003e\u003cp\u003eFirst, the highest field \u003cem\u003eB\u003c/em\u003e\u003csub\u003e\u003cem\u003emax\u003c/em\u003e\u003c/sub\u003e is searched walking around the perimeter of the substation, measuring at 1 m height with the SMP2. From the \u003cem\u003eB\u003c/em\u003e\u003csub\u003e\u003cem\u003emax\u003c/em\u003e\u003c/sub\u003e point, at 0.2 m from the adjacent wall, the field is measured at 0.5 m, 1 m, and 1.5 m heights and the resulting mean value will correspond to the exposure level at that point. Again, from the same \u003cem\u003eB\u003c/em\u003e\u003csub\u003e\u003cem\u003emax\u003c/em\u003e\u003c/sub\u003e point, the field levels are measured at 1 m height and 1 m, 5 m, 10 m, and 20 m away from the wall. In the supplementary material, we can see a photograph of the SMP2 equipment placed in front of the entrance to La Pinilla substation in the city of Albacete (Spain).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\u003ch2\u003e2.3.3. Streets\u003c/h2\u003e\u003cp\u003eOn streets, field levels are recorded georeferenced by walking between two selected points in the center of the sidewalk, for 6 to 20 minutes, keeping the SMP2 at 1m height and avoiding sudden movements. At the beginning and end of the route, the field level was statically recorded for one minute as reference values to validate the dynamic registration. The possible magnetic field peaks that appear during the journey (number of them, magnitude and location) are identified and noted for further analysis.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\u003ch2\u003e2.3.4. Inside and outside public buildings\u003c/h2\u003e\u003cp\u003eThe community sensitive spaces or public buildings (kindergartens, schools, nursing homes, health centers, among others) were inspected to identify the emitting sources. To begin, we positioned ourselves at the entrance of the building to be measured, noting down the location. Outside the entrance, we set up the equipment (SMP2) to record in \"continuous\" mode. Next, we started walking around the building, aiming to avoid sudden movements with the equipment, and keeping it consistently at a height of one meter. During this tour, we identified the location where the peak of the magnetic field was highest. Once the peak was identified, we conducted at least three \u0026ldquo;static\u0026rdquo; measurements (spot measurement) on the equipment positioned one meter high, without any movement, for 1 minute each. In some buildings where access was allowed, additional measurements were carried out. This same procedure was applied to the measurements conducted within the train and bus station building.\u003c/p\u003e\u003cp\u003eWith respect to the measurements in public buildings, the field levels are also recorded georeferenced while walking, keeping the SMP2 at 1m height and avoiding sudden movements. Where a magnetic field peak is identified, one to three additional measurements are recorded at that point for 1 minute. The measurements carry out in public transport stations follow the same procedure.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"3. Results","content":"\u003cp\u003eThe environmental average levels of ELF-MF obtained from the total data collected in both public spaces - immission levels - and in proximity to the selected field-generating sources - emission levels - are graphically represented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Specifically, in total, throughout the three Spanish regions, 39 different locations were measured as public spaces, meanwhile for emission sources 46 items were considered. The averaged time for data registration was around 20 min, resulting in around 2,400 recordings of the magnetic field per site.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.1. Public spaces\u003c/h2\u003e\u003cp\u003eAverage of the total ELF-MF records carried out in the so-called public spaces (A) resulting a mean value of 0.095 \u0026micro;T for the magnetic field \u003cem\u003eB\u003c/em\u003e, with a median of 0.068 \u0026micro;T. The distribution of magnetic field levels found is represented in the histogram of Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Subsequently, results are broken down and shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, categorized as previously mentioned. For each type of public area, the number of different locations sampled is as follows: A.1) 10 urban areas, A.2) 4 parks and gardens, A.3) 17 surroundings of public buildings, A.4) inside of 5 public buildings, A.5) 5 public transport stations, and, finally, A.6) 3 records in the underground (urban transport).\u003c/p\u003e\u003cp\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\u003eELF-MF (\u0026micro;T) values recorded in total at streets in urban and single-family residential areas, parks and gardens, public buildings, interior of public buildings, public transport stations and underground (metro).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"8\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMedian\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMinimum\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMaximum\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e% of the limit value (200uT)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA.1 Streets in urban \u0026amp; single-family residential areas\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.083\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.062\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.010\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.430\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e0.042%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA.2 Parks and gardens\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.078\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.058\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.012\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.906\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e0.039%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA.3 Public buildings\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.096\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.065\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e11.700\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e0.048%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA.4 Public buildings (interior)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.129\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.086\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.011\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.870\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e0.065%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA.5 Public transport stations\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.089\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.071\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.460\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e0.044%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA.6 Underground\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.152\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.096\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.041\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.514\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e\u003cp\u003e0.076%\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c8\" namest=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e\u003cp\u003e\u003cem\u003e* Magnetic field units: microTeslas\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c8\" namest=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Emission sources\u003c/h2\u003e\u003cp\u003eThe quantification of ELF-MF environmental emission levels near various sources has shown, as expected, higher values than those in public spaces. The average values of ELF-MF in the vicinity of the so-called emission sources, derived from all recordings across the various locations analyzed in the study, resulted in a mean value of 1.303 \u0026micro;T, with a median of 1.154 \u0026micro;T. The corresponding histogram of these values is depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\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\u003eshows the results of the ELF-MF measurements carried out, according to the diverse types of sources studied: B.1) 5 overhead HVPL of 220 kV and B.2) 6 HVPL of 400 kV, B.3) an underground HVPL, B.4) three electrical substations, B.5) 11 transformation centers B.6) 5 building electrical connections, B.7) 3 solar panel installations, and B.8) 2 electric vehicle charging installations. In the supplementary material we can see an image showing an aerial view of the route (on foot) followed during measurements at two different locations. On the left, in the city of Galapagar (Cercado Redondo street, Community of Madrid, Spain). And on the right, in the vicinity of the electrical substation in the city of C\u0026aacute;ceres (Spain). In the latter, a color code can be observed (with red indicating higher MF measurements and blue indicating lower MF measurements).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\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\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMedian\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMinimun\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMaximun\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003e% of the limit value (200uT)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.1 Overhead 220 kV hifh-voltage power lines\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.733\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.674\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.065\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.334\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.366%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.2 Overhead 400 kV\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.140\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.298\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.130\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6.700\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.070%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.3 Underground 220 kV\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.069\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.954\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.245\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.751\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.535%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.4 Electrical substations\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.669\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.522\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.019\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e8.995\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.335%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.5 Transformer stations\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2.083\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.294\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e13.452\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.042%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.6 Electrical service entrances of buildings\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3.284\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.097\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.104\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e6.540\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e1.642%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.7 Photovoltaic solar panel installations\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.066\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.060\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.042\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.180\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.033%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB.8 Electric vehicle charging points\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.382\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.331\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.207\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.615\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.191%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e\u003cp\u003e\u003cem\u003e* Magnetic field units: microTeslas\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. \u003cem\u003eELF-MF (\u0026micro;T) values recorded in overhead 220\u003c/em\u003e kV \u003cem\u003ehigh-voltage power lines, overhead 400\u003c/em\u003e kV, \u003cem\u003eunderground 220\u003c/em\u003e kV, \u003cem\u003eelectrical substations, transformer stations, electrical service entrances of buildings, photovoltaic solar panel installations and electric vehicle charging points.\u003c/em\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.3. Statistical Analysis\u003c/h2\u003e\u003cp\u003eSeveral statistical analyses are presented below, including hypothesis testing for group comparison, percentile calculation, variability analysis of the records, and confidence interval calculation.\u003c/p\u003e\u003cdiv id=\"Sec14\" class=\"Section3\"\u003e\u003ch2\u003e3.3.1. Statistical comparison between groups\u003c/h2\u003e\u003cp\u003eBased on the two exposure scenarios, namely public spaces and emission sources, considering that both data groups do not follow a normal distribution, a non-parametric (Mann-Whitney test) for two samples was conducted with a significance level of 5%. The probability \u003cem\u003ep\u003c/em\u003e value obtained for the hypothesis test was 1.81 x 10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e, and therefore, the null hypothesis can be rejected, indicating that both groups of values are statistically different. The mean field value in public spaces is 0.095 \u0026micro;T compared to 1.303 \u0026micro;T in proximity to ELF-MF emission sources. Nevertheless, as previously mentioned, this highest average value resulting from the contribution of all emission sources represents 0.65% of the recommended 200 \u0026micro;T reference level.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section3\"\u003e\u003ch2\u003e3.3.2. Percentile calculation\u003c/h2\u003e\u003cp\u003eIn all the cases presented, the average value of the measured magnetic field, resulting from the emission sources, corresponds to the highest values, which represents 0.65% of the limit recommended by the ICNIRP (200 \u0026micro;T). .\u003c/p\u003e\u003cp\u003eIt is noteworthy that 95% of the recorded values are below 0.17 \u0026micro;T in public spaces and 4.12 \u0026micro;T for emission sources. This exposure level represents only 2% of the recommended 200 \u0026micro;T reference level.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\u003ch2\u003e3.3.3. Variability of the recorded data and confidence Intervals for the means\u003c/h2\u003e\u003cp\u003eThe variability of the measured field levels is described by the standard deviation calculated for both groups. In public spaces, the standard deviation is 43%, whereas for emission sources it is 149%. Consequently, it is evident that there is a greater dispersion of values among the ELF-MF records in the emission source group.\u003c/p\u003e\u003cp\u003eBy definition, the confidence interval for the mean provides both a maximum and a minimum value within which the population mean is estimated to lie, with a certain margin of error. Calculated at 95% confidence level, the confidence interval for each of the two data groups turns out to be [0.072 \u0026micro;T- 0.10 \u0026micro;T] for public spaces and [0.73 \u0026micro;T \u0026minus;\u0026thinsp;1.71 \u0026micro;T] for emission sources. As expected, the wider dispersion of the data collected around the emission sources results in a significantly broader range of values for the mean of this group.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section3\"\u003e\u003ch2\u003e3.3.4. \u003cem\u003eAnalysis focused on emission sources\u003c/em\u003e\u003c/h2\u003e\u003cp\u003eWhen initially categorizing the data into public spaces and emission sources, it was assumed that the ELF-MF sources were consistently distant from the public areas. However, upon recognizing that three types of emission sources \u0026ndash; electrical transformation centers, building electrical connections, and electric vehicle charging points \u0026ndash; can be present in public spaces, data have been reorganized. Then, the field levels recorded for these three sources were included in the group of public spaces and excluded from the emission sources, and the comparative study was carried out again. Both data subsets follow a normal distribution and exhibit equal variances, as indicated by Snedecor's Test (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.67). The analysis of exposure levels in public spaces now includes electric transformation centers, building electrical connections, and electric vehicle charging points, comprising a total amount of 48 locations, while the emission sources group has been reduced to 28 locations. Subsequently, a t-test for two samples with equal variances was conducted once again (alpha\u0026thinsp;=\u0026thinsp;5%), yielding a probability \u003cem\u003ep\u003c/em\u003e value of 0.06 for the hypothesis test. Given that \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.05, we conclude that both sets of values are not statistically different. Therefore, significant disparities between the field values measured in public spaces and those recorded in the proximity to emission sources are no longer evident.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e3.4. Study of the magnetic field around HVPL\u003c/h2\u003e\u003cp\u003eThe results obtained during the environmental characterization of ELF-MF levels near the HVPL outline the cross-sectional profile of magnetic field that decreases with distance from the midpoint of the line, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e (a and b) for voltages of 220 kV and 400 kV, respectively.\u003c/p\u003e\u003cp\u003eExtrapolating values obtained through an exponential function (with equation: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:y=1.24{exp}^{-0.045x}\\)\u003c/span\u003e\u003c/span\u003e and R\u003csup\u003e2\u003c/sup\u003e-value: 0.98, for 220 kV, and equation: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:y=2.44{exp}^{-0.053x}\\)\u003c/span\u003e\u003c/span\u003e and R\u003csup\u003e2\u003c/sup\u003e-value: 0.99, for 400 kV), as observed from the solid lines in both graphs (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e), the magnetic field values at 50 m distance from the power lines are like the average ELF-MF values in any of the public spaces within the urban environment, nearing 0.1 \u0026micro;T.\u003c/p\u003e\u003cp\u003eA recently published study evaluating the French population's exposure to ELF-MF from HVPL (Deshayes-Pin\u0026ccedil;on et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) follows a similar protocol for measuring the magnetic field and analyses the records from 731 HVPL sites of 225 kV and 306 of 400 kV, characterized longitudinally and transversally. Despite the different sample sizes, considering the similarities with the present study, a comparison has been made between both studies. Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e (c and d) shows the ELF-MF levels on the transverse axis of the HVPL in France and Spain.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Discussion and conclusions","content":"\u003cp\u003eFrom the present study, based on the ELF-MF data recorded at the different locations in Albacete, C\u0026aacute;ceres, and Madrid, with over 85 sites and more than 28 hours of total measurement, several conclusions can be drawn. Firstly, upon analyzing the categorized groups of public spaces and emission sources, it is observed that 95% of the environmental ELF-MF recorded in public spaces are below 0.17 \u0026micro;T, while in proximity to the emission sources, 95% of the measured emission levels are lower than 4.12 \u0026micro;T, constituting this higher value a mere 2% of the recommended limit value of 200 \u0026micro;T. Secondly, statistically comparing public spaces and emission sources or, respectively, immission and emission levels, the resulting average magnetic fields from public spaces, 0.095 \u0026micro;T, is significantly lower than those from the so-called emission sources, 1.303 \u0026micro;T. However, considering that some of these emission sources may be within public spaces contributing to immission levels, as occurs with transformation centers, building electrical connections and electric vehicle charging points, then, in this case, the conclusion is that there would be no significant differences between the environmental ELF-MF values in public spaces and in proximity to emission sources.\u003c/p\u003e\u003cp\u003eSpecifically, in relation to the ELF-MF immission levels in public spaces, the median value of 0.068 \u0026micro;T is around 30% lower than the mean value of this same group. Since the median is a much more robust parameter to extreme values than the mean, it can be considered that 0.068 \u0026micro;T better reflects the environmental magnetic field level in public spaces. Furthermore, comparing the ELF-MF levels observed in streets of denser urban centers to those in streets of residential areas -single-family homes-, the average field value in less populated residential areas is around 25% lower. Another aspect to highlight is the difference found between the magnetic field levels in the vicinity of public buildings, 0.096 \u0026micro;T, and the levels inside them, 0.129 \u0026micro;T, with the latter being approximately 26% higher. This discrepancy may be due, among other reasons, to the significant contribution from electrical installations inside the buildings. Among all the data in public spaces, the highest magnetic field value of 11.69 \u0026micro;T was recorded in the vicinity of a shopping center, probably due to proximity to some unnoticed internal transformer station in the building. It is followed by the maximum of 3.51 \u0026micro;T recorded during the journeys made in the underground, in any case representing less than the 6% of the reference level.\u003c/p\u003e\u003cp\u003eIn relation to the emission sources, three subgroups contribute to higher ELF-MF exposure levels: 400 kV HVPL, averaging 2.14 \u0026micro;T, transformer stations, with an average of 2.08 \u0026micro;T, and building electrical connections, averaging 3.28 \u0026micro;T. Among these subgroups, building electrical connections exhibit the highest emission levels and could, therefore, strongly contribute to the residential exposure levels as do interior transformer rooms in buildings (R\u0026ouml;\u0026ouml;sli et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Okokon \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Navarro-camba \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). They should be then considered for future exposure assessment in residential settings. Regarding HVPL, the decreasing transverse profile of the magnetic field with the distance to the central point of the axis line was verified. Extrapolating the obtained values, it is noteworthy that the contribution of overhead HVPL to the ELF-MF exposure levels at 50 m distance from the axis line, approximating 0.1 \u0026micro;T, is like the field levels found in a typical urban environment, away from this electrical infrastructure. With respect to the installations of photovoltaic panels, more and more used for energy supply of diverse public services like electric bikes stations, and the electric vehicle charging points, the lowest values were registered as expected far from transformer devices and due to safety design of charging infrastructure networks.\u003c/p\u003e\u003cp\u003eAs the main conclusion of the present study, with the data available to date, the ambient ELF-MF levels of the population in Spain are very similar to those in other developed countries (Bonato et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Gajšek et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), remaining well below the 200 \u0026micro;T limit recommended by ICNIRP. The exposure levels in public spaces are within a range of 0.05 to 0.2 \u0026micro;T, with values of few \u0026micro;T in proximity to the emission sources, which in any case represent only the 1.64% of the ICNIRP reference level, in the worst-case scenario near the building electrical connections.\u003c/p\u003e\u003cp\u003ePresent study has several limitations that should be acknowledged. First, the observational and descriptive nature of the research precludes the establishment of causal relationships between electromagnetic field exposure levels and potential health effects. Second, the geographic scope was limited to specific regions, which may not be representative of exposure patterns in other urban or rural settings, thereby limiting the generalizability of our findings. Third, measurement conditions were subject to inherent variability, including temporal fluctuations, time-of-day variations in emission sources, and spatial heterogeneity. Finally, the measurements represent environmental exposure levels rather than personal exposure, and no correlation was established between the recorded electromagnetic field levels and individual exposure patterns or health outcomes. Future research should address these limitations through longitudinal designs, personal dosimetry, and integration with epidemiological health data to better characterize the relationship between electromagnetic field exposure and potential biological effects.\u003c/p\u003e\u003cp\u003eOverall, the results of this study in Spain can guide to address a broader evaluation of environmental exposure to ELF-MF through an established protocol, bringing relevant data for future epidemiological studies, as well as useful tool for management of risk communication to the Spanish population. The identified ambient levels of ELF-MF can be also relevant information for the implementation of the requested national regulation to limit the exposure levels to this range of magnetic fields. It is a first steppingstone, bridging the gap between scientific inquiry and practical policy implementation in the realm of ELF-MF regulation.\u003c/p\u003e"},{"header":"Glossary","content":"\u003cp\u003e-\u0026nbsp;\u003cstrong\u003e\u003cem\u003eExtremely low frequency magnetic fields (ELF-MF)\u003c/em\u003e\u003c/strong\u003e:\u0026nbsp;Magnetic fields with frequencies below 300 Hz, typically associated with power lines and electrical appliances.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e- Electrical\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003e\u0026nbsp;infrastructures\u003c/em\u003e\u003c/strong\u003e: Systems and facilities for the generation, transmission, and distribution of electrical power.\u003c/p\u003e\n\u003cp\u003e- \u003cstrong\u003e\u003cem\u003eEmission (magnetic fields)\u003c/em\u003e\u003c/strong\u003e: Refers to the generation or release of magnetic fields from a source. It is the process by which a device or infrastructure produces and radiates magnetic fields into the surrounding environment.\u003c/p\u003e\n\u003cp\u003e- \u003cstrong\u003e\u003cem\u003eImmission (magnetic fields)\u003c/em\u003e\u003c/strong\u003e: Refers to the presence and intensity of magnetic fields at a specific location. It is the result of emissions from one or more sources after they have propagated through the environment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e- International Commission on Non-Ionizing Radiation Protection (ICNIRP)\u003c/em\u003e\u003c/strong\u003e: An independent organization that provides scientific advice and guidance on health and environmental effects of non-ionizing radiation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e- Induced electric current density\u003c/em\u003e\u003c/strong\u003e: The amount of electric current flowing through a unit area of a conductor, induced by a changing magnetic field.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e- International Agency for Research on Cancer (IARC)\u003c/em\u003e\u003c/strong\u003e: An intergovernmental agency part of the World Health Organization, focusing on cancer research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e- High-voltage power lines (\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003eHVPL)\u003c/em\u003e\u003c/strong\u003e: Electrical transmission lines that carry high voltages (typically above 100 kV) over long distances.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e-\u0026nbsp;\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u003cem\u003eG-ENAC-14 guide\u003c/em\u003e\u003c/strong\u003e: Spanish technical guide issued by the National Accreditation Entity (ENAC)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e- Z-score\u003c/em\u003e\u003c/strong\u003e: A statistical measure that indicates how many standard deviations an element is from the mean of a data set.\u003c/p\u003e\n\u003cp\u003e- \u003cstrong\u003e\u003cem\u003eGeoreferenced measurements\u003c/em\u003e\u003c/strong\u003e: Measurements or data associated with specific geographic locations or coordinates.\u003c/p\u003e\n\u003cp\u003e- \u003cstrong\u003e\u003cem\u003eMedian value\u003c/em\u003e\u003c/strong\u003e: The middle value in a sorted list of numbers, separating the higher half from the lower half of a data set.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to express our sincere gratitude to Rodrigo San Mill\u0026aacute;n and Enrique L\u0026oacute;pez from Redeia\u0026rsquo; company, for their invaluable assistance and support in conducting this study. Their contributions were instrumental in the successful completion of our research.\u003c/p\u003e\n\u003cp\u003eWe are also deeply indebted to Dr. Miguel \u0026Aacute;ngel Cobos from the Institute of Applied Magnetism (UCM) for his selfless help in carrying out the measurements in the Community of Madrid.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe authors gratefully acknowledge the support of all those who contributed to this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFunding: This work was partially supported by the Environmental Department of the company Redeia (Spain).\u003c/p\u003e\n\u003cp\u003eRR-V and EA \u0026nbsp;gratefully acknowledge financial support from the Junta de Comunidades de Castilla-La Mancha of Spain (Project SBPLY/23/180225/00089) and from University of Castilla-La Mancha grant number 2022-GRIN-34356.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e- Sanchis-Otero, Ar\u0026aacute;nzazu: Conceptualization, Formal analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Writing \u0026ndash; original draft and Writing \u0026ndash; review and editing.\u003c/p\u003e\n\u003cp\u003e- Ram\u0026iacute;rez-V\u0026aacute;zquez, Raquel: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Supervision, Validation, Visualization and Writing \u0026ndash; review.\u003c/p\u003e\n\u003cp\u003e- Paniagua, Jes\u0026uacute;s M.: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Supervision, Validation, Visualization and Writing \u0026ndash; review.\u003c/p\u003e\n\u003cp\u003e- Bajo, Ricardo: Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing \u0026ndash; original draft and Writing \u0026ndash; review and editing.\u003c/p\u003e\n\u003cp\u003e- Arribas, Enrique: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, and Writing \u0026ndash; review.\u003c/p\u003e\n\u003cp\u003e- Giacomone, Fernando: Conceptualization, Data curation, Investigation, Methodology, Validation.\u003c/p\u003e\n\u003cp\u003e- Ramis, Rebeca: Conceptualization, Formal analysis, Investigation, Methodology, Resources, Supervision and Writing \u0026ndash; review.\u003c/p\u003e\n\u003cp\u003e- Mar\u0026iacute;n Palacios, Pilar: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, and Writing \u0026ndash; review.\u003c/p\u003e\n\u003cp\u003e- Vargas Marcos, Francisco: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Supervision, and Writing \u0026ndash; review.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval* (Missing)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis is not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate* (Missing)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis is not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish* (Missing)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis is not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data corresponding to the present study are available in the following free repository (GitHub):\u003c/p\u003e\n\u003cp\u003e\u003cem\u003ehttps://github.com/Ric-count/Spain-ELF-MF-data-\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number: not applicable\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003e(BOE), Official State Gazette. 1999. \u0026ldquo;RECOMMENDATION OF THE EUROPEAN COUNCIL of July 12, 1999 on the Exposure of the General Public to Electromagnetic Fields (0 Hz to 300 GHz) (1999/519/EC).\u0026rdquo; \u003cem\u003eDiario Oficial de Las Comunidades Europeas\u003c/em\u003e. Vol. 1999/519/C.\u003c/li\u003e\n \u003cli\u003eAhlbom, A, N Day, M Feychting, E Roman, J Skinner, J Dockerty, and M Linet. 2000. \u0026ldquo;A Pooled Analysis of Magnetic Fields and Childhood Leukaemia.\u0026rdquo; \u003cem\u003eBritish Journal of Cancer\u003c/em\u003e 83 (5): 692\u0026ndash;98. https://doi.org/10.1054/bjoc.2000.1376.\u003c/li\u003e\n \u003cli\u003eAmoon, AT, J Swanson, C Magnani, C Johansen, and L Kheifets. 2022. \u0026ldquo;Pooled Analysis of Recent Studies of Magnetic Fields and Childhood Leukemia.\u0026rdquo; \u003cem\u003eEnvironmental Research\u003c/em\u003e 204: 111993. https://doi.org/10.1016/j.envres.2021.111993.\u003c/li\u003e\n \u003cli\u003eARPANSA (Australian Radiation Protection and Nuclear Safety Agency). 2023. \u0026ldquo;Https://Www.Arpansa.Gov.Au/Understanding-Radiation/What-Is-Radiation/Non-Ionising-Radiation/Low-Frequency-Electric-Magnetic-Fields.\u0026rdquo; 2023.\u003c/li\u003e\n \u003cli\u003eBonato, Marta, Emma Chiaramello, Marta Parazzini, Peter Gaj\u0026scaron;ek, and Paolo Ravazzani. 2023. \u0026ldquo;Extremely Low Frequency Electric and Magnetic Fields Exposure : Survey of Recent Findings.\u0026rdquo; \u003cem\u003eIEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology\u003c/em\u003e 7 (3): 216\u0026ndash;28. https://doi.org/10.1109/JERM.2023.3268555.\u003c/li\u003e\n \u003cli\u003eBrabant, Christian, Anton Geerinck, Charlotte Beaudart, Ezio Tirelli, Christophe Geuzaine, and Olivier Bruyere. 2021. \u0026ldquo;Exposure to Magnetic Fields and Childhood Leukemia: A Systematic Review and Meta-Analysis of Case-Control and Cohort Studies.\u0026rdquo;\u0026nbsp;\u003cem\u003eRev Environ Health\u003c/em\u003e. 10.1515/reveh-2021-0112.\u003c/li\u003e\n \u003cli\u003eCalvente, Irene, Cristina D\u0026aacute;vila-Arias, Olga Oc\u0026oacute;n-Hern\u0026aacute;ndez, Roc\u0026iacute;o P\u0026eacute;rez-Lobato, Rosa Ramos, Francisco Artacho-Cord\u0026oacute;n, Nicol\u0026aacute;s Olea, Mar\u0026iacute;a Isabel N\u0026uacute;\u0026ntilde;ez, and Mariana F Fern\u0026aacute;ndez. 2014. \u0026ldquo;Characterization of Indoor Extremely Low Frequency and Low Frequency Electromagnetic Fields in the INMA-Granada Cohort.\u0026rdquo; \u003cem\u003ePLOS ONE\u003c/em\u003e 9 (9): e106666. https://doi.org/10.1371/journal.pone.0106666.\u003c/li\u003e\n \u003cli\u003eCrespi, Catherine M, John Swanson, Ximena P Vergara, Leeka Kheifets, Los Angeles, Environment Sector, Drive South, and Los Angeles. 2020. \u0026ldquo;Childhood Leukemia Risk in the California Power Line Study: Magnetic Fields versus Distance from Power Lines,\u0026rdquo; 530\u0026ndash;35. https://doi.org/10.1016/j.envres.2019.01.022.Childhood.\u003c/li\u003e\n \u003cli\u003eDeshayes-Pin\u0026ccedil;on, Fanny, Fabrice Morlais, Olivia Roth-Delgado, Olivier Merckel, Brigitte Lacour, Guy Launoy, Ludivine Launay, and Olivier Dejardin. 2023. \u0026ldquo;Estimation of the General Population and Children under Five Years of Age in \u0026nbsp;France Exposed to Magnetic Field from High or Very High Voltage Power Line Using Geographic Information System and Extrapolated Field Data.\u0026rdquo; \u003cem\u003eEnvironmental Research\u003c/em\u003e 232 (September): 116425. https://doi.org/10.1016/j.envres.2023.116425.\u003c/li\u003e\n \u003cli\u003eEuropean Commission. 2015. \u003cem\u003eScientific Committee on Emerging and Newly Identified Health Risks SCENIHR Opinion on Potential Health Effects of Exposure to Electromagnetic Fields\u003c/em\u003e. https://doi.org/10.2772/75635.\u003c/li\u003e\n \u003cli\u003eGaj\u0026scaron;ek, Peter, Paolo Ravazzani, James Grellier, Theodoros Samaras, and J\u0026oacute;zsef Bakos. 2016. \u0026ldquo;Review of Studies Concerning Electromagnetic Field ( EMF ) Exposure Assessment in Europe : Low Frequency Fields ( 50 Hz \u0026ndash; 100 KHz ).\u0026rdquo; \u003cem\u003eInt. J. Environ. Res. Public Health\u003c/em\u003e, 1\u0026ndash;14. https://doi.org/10.3390/ijerph13090875.\u003c/li\u003e\n \u003cli\u003eGallastegi, Mara. 2017. \u0026ldquo;Exposure to Extremely Low and Intermediate-Frequency Magnetic and Electric Fields among Children from the INMA-Gipuzkoa Cohort.\u0026rdquo; \u003cem\u003eEnvironmental Research\u003c/em\u003e. https://doi.org/https://doi.org/10.1016/j.envres.2017.05.027.\u003c/li\u003e\n \u003cli\u003eGervasi, Federico, Rossella Murtas, Adriano Decarli, and Antonio Russo. 2019. \u0026ldquo;Residential Distance from High-Voltage Overhead Power Lines and Risk of Alzheimer\u0026rsquo;s Dementia and Parkinson\u0026rsquo;s Disease: A Population-Based Case-Control Study in a Metropolitan Area of Northern Italy,\u0026rdquo; no. July: 1949\u0026ndash;57. https://doi.org/10.1093/ije/dyz139.\u003c/li\u003e\n \u003cli\u003eGreenland, S, A R Sheppard, W T Kaune, C Poole, and M A Kelsh. 2000. \u0026ldquo;A Pooled Analysis of Magnetic Fields, Wire Codes, and Childhood Leukemia. \u0026nbsp; Childhood Leukemia-EMF Study Group.\u0026rdquo; \u003cem\u003eEpidemiology (Cambridge, Mass.)\u003c/em\u003e 11 (6): 624\u0026ndash;34. https://doi.org/10.1097/00001648-200011000-00003.\u003c/li\u003e\n \u003cli\u003eHuss, Anke, Adrian Spoerri, Matthias Egger, and Martin Ro. 2009. \u0026ldquo;Original Contribution Residence Near Power Lines and Mortality From Neurodegenerative Diseases : Longitudinal Study of the Swiss Population\u0026rdquo; 169 (2): 167\u0026ndash;75. https://doi.org/10.1093/aje/kwn297.\u003c/li\u003e\n \u003cli\u003eIARC. 2002. \u0026ldquo;MONOGRAPHS ON THE EVALUATION OF CARCINOGENIC RISKS TO HUMANS.\u0026rdquo; \u003cem\u003eIARC\u003c/em\u003e.\u003c/li\u003e\n \u003cli\u003eICNIRP. 2015. \u0026ldquo;ICNIRP Statement Gaps in Knowledge Relevant to the \u0026lsquo; ICNIRP Guidelines for Limiting Exposure to Time-Varying Electric , Magnetic and Electromagnetic Fields ( 100 KHz TO 300 GHz ) ,\u0026rsquo;\u0026rdquo; no. Who 2014. https://doi.org/10.1097/HP.0000000000001944.\u003c/li\u003e\n \u003cli\u003eIEC. 2014. \u0026ldquo;Measurement of DC Magnetic, AC Magnetic and AC Electric Fields from 1 Hz to 100 KHz with Regard to Exposure of Human Beings - Part 2: Basic Standard for Measurements.\u0026rdquo; https://standards.iteh.ai/catalog/standards/iec/81e72401-d6d7-43ca-ac5f-3e14588a12bb/iec-61786-2-2014.\u003c/li\u003e\n \u003cli\u003eIEC 62110. n.d. \u0026ldquo;Electric and Magnetic Field Levels Generated by AC Power Systems - Measurement Procedures with Regard to Public Exposure.\u0026rdquo;\u003c/li\u003e\n \u003cli\u003eKheifets, Leeka, A Ahlbom, C M Crespi, G Draper, J Hagihara, R M Lowenthal, and G Mezei. 2010. \u0026ldquo;Pooled Analysis of Recent Studies on Magnetic Fields and Childhood Leukaemia.\u0026rdquo; \u003cem\u003eBritish Journal of Cancer\u003c/em\u003e 103 (7): 1128\u0026ndash;35. https://doi.org/10.1038/sj.bjc.6605838.\u003c/li\u003e\n \u003cli\u003eKheifets, Leeka, Los Angeles, Anders Ahlbom, Karolinska Institutet, and Catherine M Crespi. 2010. \u0026ldquo;Pooled Analysis of Recent Studies of Magnetic Fields and Childhood Leukemia Pooled Analysis of Recent Studies on Magnetic Fields and Childhood Leukaemia,\u0026rdquo; no. May 2014. https://doi.org/10.1038/sj.bjc.6605838.\u003c/li\u003e\n \u003cli\u003eKheifets, Leeka, Catherine Crespi, Chris Hooper, Sona Oksuzyan, Myles Cockburn, Thomas Ly, and Gabor Meze. 2016. \u0026ldquo;Epidemiologic Study of Residential Proximity to Transmission Lines and Childhood Cancer in California: Description of Design, Epidemiologic Methods and Study Population.\u0026rdquo;\u0026nbsp;\u003cem\u003eJ Expo Sci Environ Epidemiol\u003c/em\u003e 25 (1): 45\u0026ndash;52. https://doi.org/10.1038/jes.2013.48.Epidemiologic.\u003c/li\u003e\n \u003cli\u003eMalagoli, Carlotta, Marcella Malavolti, Lauren A Wise, Erica Balboni, Sara Fabbi, Sergio Teggi, Giovanni Palazzi, Monica Cellini, Maurizio Poli, Paolo Zanichelli, Barbara Notari, Andrea Cherubini, Marco Vinceti, Tommaso Filippini. 2023. \u0026ldquo;Residential Exposure to Magnetic Fields from High-Voltage Power Lines and Risk of Childhood Leukemia.\u0026rdquo; \u003cem\u003eEnvironmental Research\u003c/em\u003e 232 (June): 116320. https://doi.org/10.1016/j.envres.2023.116320.\u003c/li\u003e\n \u003cli\u003eMatthes, Rüdiger., Jürgen H. Bernhardt, Alastair F. McKinlay, and International Commission on Non-Ionizing Radiation Protection. 1998. \u003cem\u003eGuidelines on Limiting Exposure to Non-Ionizing Radiation : A Reference Book Based on the Guidelines on Limiting Exposure to Non-Ionizing Radiation and Statements on Special Applications\u003c/em\u003e. \u003cem\u003eHealth Physics Society\u0026nbsp;\u003c/em\u003e. Vol. 74.\u003c/li\u003e\n \u003cli\u003eNational Accreditation Entity (ENAC). 2008. \u0026ldquo;Guide to Participation in Intercomparison Programs.\u0026rdquo;\u003c/li\u003e\n \u003cli\u003eNational Agency for Food, Environmental and Occupational Health and Safety (ANSES), France. 2019. \u0026ldquo;Health Effects Associated with Exposure to Low-Frequency Electromagnetic Fields.\u0026rdquo;\u003c/li\u003e\n \u003cli\u003eNavarro-camba, Enrique A. 2018. \u0026ldquo;Exposure to 50 Hz Magnetic Fields in Homes and Areas Surrounding Urban Transformer Stations in Silla ( Spain ): Environmental Impact Assessment,\u0026rdquo; 1\u0026ndash;11. https://doi.org/10.3390/su10082641.\u003c/li\u003e\n \u003cli\u003eOkokon, Enembe Oku. 2014. \u0026ldquo;Indoor Transformer Stations and ELF Magnetic Field Exposure : Use of Transformer Structural Characteristics to Improve Exposure Assessment,\u0026rdquo; no. September 2013: 100\u0026ndash;104. https://doi.org/10.1038/jes.2013.54.\u003c/li\u003e\n \u003cli\u003eOrganization, World Health. 2007. \u0026ldquo;2007 WHO Research Agenda for Extremely Low Frequency Fields,\u0026rdquo; 1\u0026ndash;8.\u003c/li\u003e\n \u003cli\u003ePaniagua, Jes\u0026uacute;s M., Antonio Jim\u0026eacute;nez, Monta\u0026ntilde;a Rufo, and Alicia Antolin. 2004. \u0026ldquo;Exposure Assessment of ELF Magnetic Fields in Urban Environments in Extremadura (Spain).\u0026rdquo; \u003cem\u003eBioelectromagnetics\u003c/em\u003e 25 (1): 58\u0026ndash;62. https://doi.org/10.1002/bem.10147.\u003c/li\u003e\n \u003cli\u003eR\u0026ouml;\u0026ouml;sli, Martin, Daniela Jenni, Leeka Kheifets, and Gabor Mezei. 2011. \u0026ldquo;Science of the Total Environment Extremely Low Frequency Magnetic Fi Eld Measurements in Buildings with Transformer Stations in Switzerland.\u0026rdquo; \u003cem\u003eScience of the Total Environment, The\u003c/em\u003e 409 (18): 3364\u0026ndash;69. https://doi.org/10.1016/j.scitotenv.2011.05.041.\u003c/li\u003e\n \u003cli\u003eSchmidt, Janine-alison, Sabine Hornhardt, and Friederike Erdmann. 2021. \u0026ldquo;Risk Factors for Childhood Leukemia : Radiation and Beyond.\u0026rdquo; \u003cem\u003eFront. Public Health\u003c/em\u003e 9 (December). https://doi.org/10.3389/fpubh.2021.805757.\u003c/li\u003e\n \u003cli\u003eSeomun, Gyeongae. 2021. \u0026ldquo;Exposure to Extremely Low-Frequency Magnetic Fields and Childhood Cancer : A Systematic Review and Meta-Analysis\u0026rdquo; 10: 1\u0026ndash;21. https://doi.org/10.1371/journal.pone.0251628.\u003c/li\u003e\n \u003cli\u003eSpanish standard UNE 215001. 2004. \u0026ldquo;Standardized Procedures for the Measurement of Industrial Frequency Electric and Magnetic Fields Produced by High Voltage Power Lines.\u0026rdquo;\u003c/li\u003e\n \u003cli\u003eSteliarova-foucher, Eva, Murielle Colombet, Lynn A G Ries, Florencia Moreno, Anastasia Dolya, Freddie Bray, Peter Hesseling, and Hee Young Shin. 2017. \u0026ldquo;Articles International Incidence of Childhood Cancer , 2001 \u0026ndash; 10 : A Population-Based Registry Study.\u0026rdquo; \u003cem\u003eLancet Oncology\u003c/em\u003e, 719\u0026ndash;31. https://doi.org/10.1016/S1470-2045(17)30186-9.\u003c/li\u003e\n \u003cli\u003eSwanson, J., L. Kheifets, and X. Vergara. 2019. \u0026ldquo;Changes over Time in the Reported Risk for Childhood Leukaemia and Magnetic Fields.\u0026rdquo; \u003cem\u003eJournal of Radiological Protection\u003c/em\u003e 39 (2): 470\u0026ndash;88. https://doi.org/10.1088/1361-6498/ab0586.\u003c/li\u003e\n \u003cli\u003eSwedish Radiation Safety Authority\u0026rsquo;s Scientific Council on Electromagnetic Fields. 2024. \u0026ldquo;Recent Research on EMF and Health Risk , Seventeenth Report from SSM \u0026rsquo; s Scientific Council on Electromagnetic.\u0026rdquo;\u003c/li\u003e\n \u003cli\u003eWertheimer, N, and E Leeper. 1979. \u0026ldquo;Electrical Wiring Configurations and Childhood Cancer.\u0026rdquo; \u003cem\u003eAmerican Journal of Epidemiology\u003c/em\u003e 109 (3): 273\u0026ndash;84. https://doi.org/10.1093/oxfordjournals.aje.a112681.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-science-and-pollution-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"espr","sideBox":"Learn more about [Environmental Science and Pollution Research](https://www.springer.com/journal/11356)","snPcode":"11356","submissionUrl":"https://submission.nature.com/new-submission/11356/3","title":"Environmental Science and Pollution Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Extremely low frequency magnetic fields (ELF-MF), exposure assessment, outdoor exposure, public spaces, ELF-MF emission sources, exposure assessment","lastPublishedDoi":"10.21203/rs.3.rs-7363662/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7363662/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis is an observational descriptive study carried out in three Spanish regions to identify typical environmental levels of extremely low frequency magnetic fields (ELF-MF) in diverse population settings as well as in the proximity to various electrical infrastructures. To achieve this, measurement protocols were previously established considering national and international reference standards. To describe the public exposure to ELF-MF, both immission and emission levels have been quantified in public spaces and close to the main infrastructure related to the transportation and distribution of electricity, but also to those related to electrified transport. Based on the collected data, the average environmental ELF-MF exposure level in public spaces is 0.095 \u0026micro;T, while it is 1.303 \u0026micro;T in the vicinity of emission sources. The observed levels of exposure to ELF-MF in Spain are very similar to those in other European countries, with values significantly below the maximum exposure limits recommended by the International Commission on Non-Ionizing Radiation Protection in 2010, which for the public are set for 50 Hz at 200 \u0026micro;T. This study, as a preliminary step, paves the way for further research that may encompass more Spanish\u0026rsquo; regions and provide a data collection for future epidemiological studies, as well as a useful reference for the public. It could provide a foundation for establishing national regulatory frameworks on this matter, given the current absence of specific legislation in Spain.\u003c/p\u003e","manuscriptTitle":"Measurement of urban environmental exposure to Extremely Low Frequency Magnetic Fields in several Spanish regions","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-31 14:07:38","doi":"10.21203/rs.3.rs-7363662/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-10-31T12:39:34+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-30T13:41:15+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Environmental Science and Pollution Research","date":"2025-10-30T05:10:34+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Science and Pollution Research","date":"2025-10-28T06:33:23+00:00","index":"","fulltext":""},{"type":"decision","content":"Minor Revision","date":"2025-09-29T04:16:13+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-science-and-pollution-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"espr","sideBox":"Learn more about [Environmental Science and Pollution Research](https://www.springer.com/journal/11356)","snPcode":"11356","submissionUrl":"https://submission.nature.com/new-submission/11356/3","title":"Environmental Science and Pollution Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"e3326e94-9698-4d5d-9096-d26be5f99f9c","owner":[],"postedDate":"October 31st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-01-05T16:07:26+00:00","versionOfRecord":{"articleIdentity":"rs-7363662","link":"https://doi.org/10.1007/s11356-025-37318-y","journal":{"identity":"environmental-science-and-pollution-research","isVorOnly":false,"title":"Environmental Science and Pollution Research"},"publishedOn":"2026-01-03 15:57:26","publishedOnDateReadable":"January 3rd, 2026"},"versionCreatedAt":"2025-10-31 14:07:38","video":"","vorDoi":"10.1007/s11356-025-37318-y","vorDoiUrl":"https://doi.org/10.1007/s11356-025-37318-y","workflowStages":[]},"version":"v1","identity":"rs-7363662","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7363662","identity":"rs-7363662","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}