Heavy Metal Contamination and Cancer Risk Assessment in Groundwater Near Dumpsites: Health Implications for Vulnerable Populations in Nigeria

Heavy Metal Contamination and Cancer Risk Assessment in Groundwater Near Dumpsites: Health Implications for Vulnerable Populations in Nigeria | 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 Heavy Metal Contamination and Cancer Risk Assessment in Groundwater Near Dumpsites: Health Implications for Vulnerable Populations in Nigeria Charming Osaro Asemota, Alex Enuneku, Isioma Tongo, Lawrence Ikechuchukwu Ezemonye This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5753074/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 14 You are reading this latest preprint version Abstract Nigeria is experiencing a growing threat of groundwater pollution due to insufficient waste management practices. This study aimed to assess the levels of heavy metal contamination in groundwater near the Ikhueniro and Otofure dumpsites in Benin City, Edo State, Nigeria, and to evaluate the associated health risks. Water samples were collected from boreholes in residential areas surrounding both dumpsites during both the rainy and dry seasons, yielding 144 samples. These were analyzed for concentrations of lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), iron (Fe), nickel (Ni), and copper (Cu) using standard protocols. The results indicated that Fe, Cu, Zn, and Ni were the most prevalent metals, with Fe showing the highest concentrations at both sites. The hazard index (HI) and cancer risk (CR) calculations highlighted serious health risks, particularly for children and infants. Specifically, the cumulative cancer risk for Pb, Cr, and Ni exceeded internationally recognized safety limits, indicating a significant potential for long-term health impacts. The study concluded that the proximity to these dumpsites significantly deteriorates groundwater quality, emphasizing the need for stricter environmental controls and public health interventions. Groundwater Contamination Heavy Metals Water Quality Dumpsite Pollution Health Risk Assessment. Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Groundwater is a vital resource globally, providing drinking water to millions of people, particularly in regions with limited access to surface water (Carrard et al., 2019 ). However, its quality is increasingly under threat from various human activities such as industrialization, urbanization, and inadequate waste disposal systems (Abanyie et al., 2023 ). These processes have introduced contaminants, including heavy metals like lead (Pb), chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), and iron (Fe), into groundwater systems, raising significant public health concerns (Adeyemi and Ojekunle, 2021 ). Heavy metal contamination is especially concerning due to the toxic nature of these elements, even at trace levels (Briffa et al., 2020 ), and the long-term health risks associated with their ingestion (Mitra et al., 2022 ). According to Mitra et al., 2022 , the ingestion of heavy metals over prolonged periods can lead to severe health issues, including neurotoxicity, developmental delays in children, and increased cancer risks. This global concern is even more pressing in developing countries, where the rapid pace of urban growth often outstrips the capacity of existing infrastructure to manage waste effectively (Abubakar, et al., 2022 ). Regions such as Sub-Saharan Africa, including Nigeria, are particularly vulnerable (Orhorhoro, and Oghoghorie, 2019 ). Inadequate waste management practices, such as the unregulated dumping of waste near residential areas, have led to the leaching of heavy metals into groundwater supplies that serve local populations (Kolawole, et al., 2023 ). In these contexts, where groundwater is often the sole source of drinking water, contamination poses severe and immediate health risks. As Aigberua et al. (2021) highlight, this is further compounded by the lack of resources and institutional frameworks to monitor and mitigate these environmental hazards. The contamination of groundwater with heavy metals has been linked to numerous adverse health effects. Lead (Pb), for example, is known for causing cognitive impairments and developmental delays in children, even at low exposure levels (Pan et al., 2018 ). Children and infants are particularly vulnerable to the effects of heavy metals due to their smaller body mass and higher intake of water relative to their body weight (Ojekunle et al., 2022 ). Chromium (Cr), in its hexavalent form, is recognized as a carcinogen associated with lung and stomach cancers (Wise et al., 2022 )., while nickel (Ni) exposure has been linked to dermatitis, respiratory issues, and elevated cancer risks (Anyachor et al., 2022 ). Metals like copper (Cu), zinc (Zn), and iron (Fe), while essential to human health in trace amounts, can become toxic at higher concentrations, resulting in gastrointestinal distress, liver and kidney damage, and other severe health issues (Witkowska et al., 2021 ). In Nigeria, the situation is particularly dire, with a rapidly growing population and a significant lag in waste management infrastructure. Many urban centers, such as Benin City in Edo State, are experiencing the harmful effects of inadequate waste disposal systems. The Ikhueniro and Otofure dumpsites in Benin City are prime examples of this, as both are located in proximity to residential areas, where boreholes and wells serve as the primary sources of drinking water for local inhabitants. Previous studies, such as those by Ugwu et al. ( 2022 ) and Ojekunle et al. ( 2022 ), have documented elevated levels of heavy metals in groundwater near dumpsites across Nigeria, highlighting the urgent need for intervention. Aigberua and Tarawali (2021) specifically examined the heavy metal content in groundwater near dumpsites in Port Harcourt, Nigeria, and found that concentrations of lead, chromium, and nickel exceeded the World Health Organization (WHO) guidelines for safe drinking water. The Ikhueniro and Otofure dumpsites have long been sources of concern for environmental and public health experts, as leachates from these sites are suspected of infiltrating the surrounding groundwater, compromising the safety of the local water supply. The current study aimed to assess the concentrations of heavy metals in groundwater near the Ikhueniro and Otofure dumpsites and evaluate the potential health risks for local populations. Materials and methods Study area Benin City is the capital of Edo State and is situated in Nigeria's south-south geopolitical zone; it has a total area of roughly 500 square kilometers and is bordered by latitudes 6 o 12' 38’’ N and 6 o 27' 25’’N and longitudes 5 o 29' 46’’ E and 5 o 45' 0.41’’ E. It is located in the tropical equatorial zone, where the dry season runs from December to March and the wet season from April to November (Cirella et al., 2019 ). Sedimentary formation underlies the city (Akujieze and Oteze, 2007 ). Reddish clayey sand makes up the top layer of the formation, which caps vastly porous fresh water bearing loose pebbly sands, and sandstone with local thin clays and shale interbeds which are considered to be of braided stream origin. Sand that is loose and brownish blankets the formation; it is virtually entirely water-bearing with a water level range of between 20 m to 52 m. It is largely believed to be highly porous and abundant in water yield. Sampling Stations Satiation One The Otofure dumpsite, which has been in operation for over 20 years, is situated in a neighborhood of Benin City, in the Ovia North East Local Government Area of Edo State (Oboshenure and Airen, 2021 ). Its coordinates are 6.027759°N, 5.035861°E, and it is managed by the Edo State government. This sizable dumpsite serves as a major disposal site for waste generated across Benin City, with authorized agencies transporting waste from residences, offices, businesses, marketplaces, and hospitals. The waste deposited at the site is highly heterogeneous, consisting of organic and inorganic materials. Groundwater sampling in the Otofure area was carried out at 12 active private boreholes located at varying distances from the dumpsite. This was done to evaluate potential groundwater contamination due to waste disposal activities. The distances of these boreholes from the dumpsite ranged from 0.10 km to 0.33 km, enabling a comprehensive spatial analysis of contamination levels. The closest borehole, OTF 12, was situated just 0.10 km from the dumpsite, while other nearby boreholes included OTF 11, located 0.15 km away, and OTF 1 and OTF 2, both positioned 0.14 km from the site. Farther from the dumpsite, boreholes OTF 10 and OTF 9 were located 0.20 km and 0.27 km away, respectively. Additional boreholes—OTF 5 (0.29 km), OTF 3, OTF 4, and OTF 6 (each 0.31 km), and OTF 7 and OTF 8 (each 0.33 km)—were also included to provide a gradient of distances for the analysis. This distribution of sampling points facilitated the assessment of how proximity to the dumpsite potentially influenced groundwater quality. Station Two The Ikhueniro dumpsite, which has been in operation for more than 30 years, is situated alongside the Benin-Lagos Bypass in the Uhunmwonde Local Government Area of Edo State (Idugboe et al., 2014). Its coordinates are 6.32668°N, 5.74605°E, and it is managed by the Edo State Waste Management Board (EDSMA). The dumpsite covers a footprint of approximately 150 meters and serves as the primary disposal site for waste generated across Benin City. The waste deposited here is heterogeneous, comprising building materials, household refuse, market debris, agricultural byproducts, hospital waste, and industrial waste. The surrounding areas are primarily residential, commercial, and industrial, making the dumpsite an important area for assessing environmental impacts. Various forms of waste, including organic, inorganic, hazardous, and non-hazardous materials, are carelessly dumped here by Private Sector Partnership (PSP) collection trucks, which transport waste from different parts of the city. Groundwater sampling in the Ikhueniro area was conducted at 12 active private boreholes located at various distances from the dumpsite to evaluate the potential contamination of groundwater from waste disposal. The distances of these boreholes from the dumpsite ranged from 0.10 km to 0.33 km, allowing for a detailed spatial analysis of contamination levels. The closest boreholes, IKH 12 and IKH 11, were located just 0.10 km and 0.15 km from the dumpsite, respectively, while the farthest points, IKH 7 and IKH 8, were situated 0.33 km away. Additional boreholes were positioned at varying distances: IKH 1 and IKH 2 were 0.14 km away, IKH 3, IKH 4, and IKH 6 were each 0.31 km away, IKH 5 was 0.29 km away, and IKH 10 was located 0.20 km from the dumpsite. This systematic distribution of sampling points was designed to assess how proximity to the dumpsite influenced groundwater quality. Sample Collection and Analytical Procedure Groundwater sample collection, storage, transport, and analysis followed standardized protocols outlined by the American Public Health Association (APHA, 2005 ). A total of 144 groundwater samples were collected from 12 active private boreholes located near two waste dumpsites: Otofure (Station 1) and Ikhueniro (Station 2). A total of 77 samples were obtained from each site during two distinct seasons—wet season (July to September 2019) and dry season (December 2019 to February 2021). This seasonal approach ensured a comprehensive analysis of groundwater quality under varying environmental conditions. To minimize contamination during sampling, all bottles were thoroughly rinsed multiple times with deionized water and preconditioned by rinsing three times with the sampled groundwater. Before sample collection, a 10-minute pump-out of the borehole was conducted to remove stagnant water. Groundwater samples were then collected in 2.5 L sterile polyethylene bottles, each clearly labeled with site codes. To preserve sample integrity and prevent ion precipitation or reactions with the container walls, 2 mL of concentrated HNO₃ was added to each sample immediately after collection. The samples were maintained at 4°C using ice packs during transport to the Laboratory for Ecotoxicology and Environmental Forensics at the University of Benin for further analysis. In the laboratory, the samples were analyzed for heavy metals (HMs) including iron (Fe), chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn). Heavy metal concentrations were measured using an atomic absorption spectrophotometer (Buck Scientific, Model 210 VGP), with a detection limit of 0.0001 mg/L and a quantification limit of 0.0003 mg/L. The analytical procedures adhered to APHA ( 2005 ) guidelines, ensuring the reliability and precision of the results. All chemical reagents used in the analysis were of analytical grade. Statistical Analysis All statistical analyses were conducted using IBM SPSS Statistics, Version 20. Descriptive statistics were applied to summarize the collected data and provide insights into the distribution of measured parameters. To assess spatial and temporal variations in groundwater quality between the two sampling stations (Otofure and Ikhueniro) and across the wet and dry seasons, a one-way analysis of variance (ANOVA) was performed. Statistical significance was set at p < 0.05 to determine whether there were significant differences among the parameters measured across the different sites and seasons. For post-hoc analysis, Duncan’s Multiple Range Test was applied to identify where significant differences occurred between specific groups. Human Health Risk Assessment To evaluate potential health risks posed by exposure to heavy metals in groundwater, a comprehensive human health risk assessment was conducted. This assessment considered both carcinogenic and non-carcinogenic risks, based on individual exposure to contaminated groundwater across three distinct population groups: infants, children, and adults. The methodologies followed the guidelines provided by the U.S. Environmental Protection Agency (USEPA, 2001 , 2011 ), focusing on the calculation of the Average Daily Dose (ADD), Hazard Quotient (HQ), Hazard Index (HI), and Cancer Risk (CR) for each population group. The ADD was calculated based on exposure routes, including ingestion of contaminated water. The Hazard Quotient (HQ) was derived by comparing the ADD to the reference dose (RfD) for each metal, with HQ > 1 indicating a potential non-carcinogenic health risk. The cumulative non-carcinogenic risk for each individual was evaluated using the Hazard Index (HI), calculated as the sum of HQs for all metals. An HI greater than 1 suggests that adverse health effects may occur. Additionally, the lifetime cancer risk (CR) was estimated for metals with carcinogenic potential, using the established cancer slope factor (CSF). A CR value within the range of 1 × 10⁻⁶ to 1 × 10⁻⁴ was considered acceptable, whereas values above this range indicated a heightened risk of cancer due to metal exposure. (1) $$\:\begin{array}{ccc}\text{A}\text{D}\text{D}&\:=&\:\frac{\text{C}\:\times\:\text{I}\text{R}\:\times\:\text{E}\text{D}\:\times\:\text{E}\text{F}}{\text{B}\text{W}\:\times\:\text{A}\text{T}}\end{array}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\text{E}\text{q}.\:1$$ In this study, the Average Daily Dose (ADD) of heavy metals through contaminated groundwater was calculated using the following parameters: ADD is expressed in micrograms of metals per kilogram per day (µg kg⁻¹ day⁻¹). C represents the mean concentration of the examined metals in water samples, measured in micrograms per liter (µg L⁻¹). IR denotes the intake rate, which varies by age group: 2 L per day for adults, 1 L per day for children, and 0.75 L per day for infants. ED refers to the duration of exposure, set at 30 years for adults, 6 years for children, and 1 year for infants (USEPA, 2001 ). The exposure frequency (EF) was assumed to be 365 days per year. BW signifies the average body weight, which is 60 kg for adults, 10 kg for children, and 5 kg for infants. AT (exposure time) was calculated as 30 years for adults, 6 years for children, and 1 year for infants, multiplied by 365 days per year. The Non-Carcinogenic Index, resulting from the ingestion of contaminated groundwater, was determined using Eq. 2: (2). \(\:\begin{array}{ccc}\text{H}\text{a}\text{z}\text{a}\text{r}\text{d}\:\text{q}\text{u}\text{o}\text{t}\text{i}\text{e}\text{n}\text{t}\:\left(\text{H}\text{Q}\right)&\:=&\:\frac{\text{A}\text{D}\text{D}}{\text{R}\text{f}\text{D}}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\text{E}\text{q}.\:\:\:\:2\end{array}\) where RfD stands for the reference dose in mg kg⁻¹ day⁻¹. An HQ greater than 1 indicates the potential for non-carcinogenic adverse health effects. Furthermore, the Hazard Index (HI) was calculated to assess the cumulative risk posed by the combined effects of all metals present in the drinking water evaluated in this study: health. \(\:\begin{array}{ccc}\text{H}\text{a}\text{z}\text{a}\text{r}\text{d}\:\text{i}\text{n}\text{d}\text{e}\text{x}\:\left(\text{H}\text{I}\right)&\:=&\:\sum\:_{\text{i}=1}^{\text{n}}\text{H}\text{Q}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\text{E}\text{q}.\:3\end{array}\) An HI value greater than 1 suggests a potential for negative impacts on human health. Potential carcinogenic risks were evaluated using Eq. 4, following the methodology outlined by Giri and Singh ( 2015 ). This equation provides a cumulative estimate of the likelihood that an individual will experience carcinogenic exposure throughout their lifetime and may develop cancer: $$\:\begin{array}{ccc}\text{C}\text{a}\text{n}\text{c}\text{e}\text{r}\:\text{r}\text{i}\text{s}\text{k}\:\left(\text{C}\text{R}\right)&\:=&\:\text{A}\text{D}\text{D}\:\times\:\text{C}\text{S}\text{F}\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\text{E}\text{q}\:4\end{array}$$ In this context, CSF denotes the cancer slope factor. A CR value greater than 1.0 × 10⁻⁴ signifies a potential for carcinogenic effects. Result and discussion Measured Heavy Metal Levels in Groundwater Surrounding Ikhueniro and Otofure Groundwater contamination by heavy metals is a growing concern in many parts of the world, particularly in areas close to waste disposal sites (Li et al ., 2021). These contaminants, often carried by leachates from decomposing waste, can infiltrate groundwater (Magda et al ., 2015), posing significant health risks to local populations who rely on this resource for drinking, cooking, and farming (Ewim et al., 2023 ). This study provides an in-depth analysis of heavy metal concentrations in groundwater in residential areas near the Ikhueniro and Otofure dumpsites, two major waste disposal sites in Edo State, Nigeria. Data were collected during both the dry and wet seasons to examine the seasonal variability in contamination levels, which is crucial for understanding the temporal dynamics of groundwater pollution in tropical regions (Ayotunde et al ., 2014). The investigation focused on key heavy metals—lead (Pb), zinc (Zn), chromium (Cr), iron (Fe), nickel (Ni), and copper (Cu)—which are known to pose health and environmental risks when present in concentrations above permissible limits (Xie, et al., 2023 : Singh, et al., 2022 ; Bai, et al ., 2022). These metals are often introduced into the environment through various anthropogenic activities, such as improper waste disposal (Kumar, et al., 2023 ). At both Ikhueniro and Otofure, groundwater samples were analyzed to determine the mean concentrations of these heavy metals and assess their potential risks to human health. The results revealed a range of heavy metal concentrations, with significant variations between the two dumpsites and across seasons (Table 1 ). At Ikhueniro, Pb concentrations varied between 0.0077 and 0.0363 mg/L, with a mean value of 0.0206 ± 0.0061 mg/L. In contrast, Otofure recorded Pb levels ranging from 0.002 to 0.020 mg/L, with a mean of 0.007 ± 0.0029 mg/L. Notably, the highest concentrations of Pb were observed during the rainy season at both sites, likely due to increased leaching of metals from the dumpsites into the groundwater system as a result of heavy rainfall and the subsequent percolation of surface water. The elevated Pb levels are concerning, as lead is a known neurotoxin and carcinogen (Collin et al., 2022 ), with the ability to cause severe health problems, especially in children, who are more susceptible to its toxic effects. (Ara and Usmani, 2015) Similarly, zinc (Zn) concentrations at Ikhueniro ranged from 0.147 to 1.2567 mg/L, with an average of 0.0206 ± 0.0061 mg/L, while at Otofure, Zn values were between 0.02167 and 0.2800 mg/L, with an average of 0.0071 ± 0.0029 mg/L. Though zinc is an essential micronutrient required for various physiological functions (Saper and Rash, 2009 ), excessive exposure to Zn through contaminated water can lead to adverse health effects, such as nausea, vomiting, and immune system dysfunction, especially when coupled with the intake of other heavy metals. (Jaishankar et al., 2014 ) Chromium (Cr) levels presented a more complex picture, with Ikhueniro showing concentrations between 0.0147 and 0.0823 mg/L, while Otofure recorded a broader range of 0.013 to 0.467 mg/L. Chromium, especially in its hexavalent form (Cr (VI)), is classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC) (Wise et al., 2022 ). Prolonged exposure to Cr(VI) can result in severe health effects, including lung cancer, skin ulcers, and reproductive harm (Ellen et al. , 2022). In this study, the Cr concentrations at Otofure exceeded the World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ) permissible limit of 0.05 mg/L, highlighting a pressing need for intervention in the affected areas. Iron (Fe) concentrations were also notably high at Ikhueniro, ranging from 0.6253 to 1.7437 mg/L, with a mean of 1.0504 ± 0.1869 mg/L, compared to lower levels at Otofure, where concentrations varied between 0.0253 and 0.6195 mg/L. The mean Fe concentration at Ikhueniro significantly exceeded the NSDWQ permissible limit of 0.3 mg/L for drinking water. While iron is a vital element for human health, playing a key role in oxygen transport and enzyme function (Abbaspour et al., 2014 ), excessive iron intake can lead to iron overload disorders, such as hemochromatosis, which can cause organ damage (Abbaspour et al., 2014 ). Moreover, elevated iron levels in water may promote the growth of iron-oxidizing bacteria, leading to the clogging of wells and pipes, further complicating access to clean water. (Beimeng et al., 2015 ) Nickel (Ni) concentrations, though lower compared to other metals, were still of concern, particularly at Ikhueniro, where levels ranged from 0.0117 to 0.09867 mg/L. Otofure recorded lower Ni levels, ranging from 0.01533 to 0.039 mg/L. Nickel exposure, even at low levels, has been associated with respiratory problems (Wenchao et al. , 2024), skin irritations, and in some cases, cancer. Additionally, recent studies have linked nickel to reproductive and developmental toxicity, (Genchi, et al., 2020 ). further underscoring the risks posed by nickel-contaminated groundwater. Copper (Cu) levels were generally within permissible limits, with Ikhueniro showing a range of 0.016 to 0.6587 mg/L and Otofure recording values between 0.0137 and 0.12067 mg/L. However, prolonged exposure to copper-contaminated water, even at levels within regulatory limits, can lead to gastrointestinal distress, liver damage, and anemia, especially in populations with preexisting health conditions. (National Research Council (US) 2000) Statistical analysis of the data revealed significant differences in Pb and Fe concentrations between the two dumpsites, with Ikhueniro showing higher levels of contamination compared to Otofure (P < 0.05). This suggests that the Ikhueniro dumpsite may be contributing more heavily to groundwater contamination, potentially due to differences in waste composition, volume, or management practices at the two sites. Comparisons with other studies support this finding; for instance, Saheed et al. ( 2020 ) reported Pb levels between 0.01 and 0.02 mg/L near refuse dumps in Ibadan, while Ogunrinola et al. ( 2021 ) observed much higher Pb concentrations (0.08–1.20 mg/L) in groundwater near the Igando dumpsite in Lagos. The elevated Pb levels reported in this study, though lower than those found in some other regions, still pose significant health risks to residents, particularly children, who are more vulnerable to lead exposure due to higher absorption rates. (Collin et al., 2022 ) In addition to lead, iron concentrations at Ikhueniro were significantly above the permissible limits, a finding consistent with previous studies in the region. Uroupa and Ogbeibu ( 2020 ) reported similar elevated Fe levels in groundwater near dumpsites in Benin City, while even more extreme Fe concentrations (10.885–25.612 mg/L) have been recorded at the Kumasi dumpsite in Ghana (Boateng et al., 2019 ). The presence of iron in such high concentrations not only raises concerns about iron toxicity but also indicates the potential for broader contamination, as iron is often associated with other heavy metals in polluted groundwater. For instance, studies in Pakistan have demonstrated that groundwater contaminated with iron often contains elevated levels of other harmful metals like arsenic and lead, raising significant concerns for human health and environmental safety​ (Ullah et al., 2022 ) The health implications of heavy metal contamination in groundwater are profound (Kwakye et al., 2024 ). Lead exposure has been linked to a wide range of health problems, including carcinogenic effects, cognitive impairments, and developmental delays in children (Olufemi et al., 2022 ). In adults, lead can cause hypertension, kidney damage, and reduced fertility (Maslekar et al., 2022 ). Iron toxicity, though less common, can lead to gastrointestinal issues and developmental problems, particularly in children Eid et al., 2017 ). The presence of chromium, a known carcinogen, in concentrations exceeding safe limits is particularly alarming, as prolonged exposure to Cr(VI) can increase the risk of cancer and other serious health conditions (Shin et al., 2023 ). The elevated levels of heavy metals in groundwater near the Ikhueniro and Otofure dumpsites can largely be attributed to leachates from the waste, which carry contaminants from the dumpsites into the surrounding environment. Anthropogenic activities, including industrial waste disposal and the use of heavy metal-containing products, further contribute to groundwater pollution. The seasonal variation in contamination levels observed in this study suggests that rainfall plays a significant role in the mobilization and transport of contaminants from the dumpsites into the groundwater system. Table 1 Heavy metal concentrations (mg/L) in groundwater samples from Ikhueniro and Otofure Parameters Locations Season N Mean SD Max Min NSDWQ boundary Pb Ikhueniro Wet 12 0.021 a 0.008 0.030 0.008 0.01* Ikhueniro Dry 12 0.020 a 0.007 0.036 0.013 0.01* Otofure Wet 12 0.007 b 0.004 0.018 0.002 0.01 Otofure Dry 12 0.007 b 0.005 0.020 0.003 0.01 Zn Ikhueniro Wet 12 0.300 a 0.096 0.491 0.147 3.0 Ikhueniro Dry 12 0.665 b 0.384 1.257 0.254 3.0 Otofure Wet 12 0.106 a 0.049 0.189 0.023 3.0 Otofure Dry 12 0.192 a 0.051 0.280 0.134 3.0 Cd Ikhueniro Wet 12 BDL BDL BDL BDL 0.003 Ikhueniro Dry 12 BDL BDL BDL BDL 0.003 Otofure Wet 12 BDL BDL BDL BDL 0.003 Otofure Dry 12 BDL BDL BDL BDL 0.003 Cr Ikhueniro Wet 12 0.029 a 0.023 0.082 0.016 0.05 Ikhueniro Dry 12 0.024 a 0.015 0.071 0.015 0.05 Otofure Wet 12 0.058 a 0.129 0.467 0.014 0.05* Otofure Dry 12 0.044 a 0.035 0.101 0.013 0.05 Fe Ikhueniro Wet 12 1.065 a 0.340 1.744 0.625 0.3* Ikhueniro Dry 12 1.036 a 0.137 1.230 0.763 0.3* Otofure Wet 12 0.486 b 0.161 0.619 0.025 0.3* Otofure Dry 12 0.536 b 0.045 0.595 0.473 0.3* Ni Ikhueniro Wet 12 0.028 a 0.023 0.099 0.015 0.02* Ikhueniro Dry 12 0.019 a 0.005 0.028 0.012 0.02 Otofure Wet 12 0.027 a 0.006 0.039 0.015 0.02* Otofure Dry 12 0.024 a 0.003 0.029 0.020 0.02* Cu Ikhueniro Wet 12 0.532 c 0.055 0.659 0.460 1.0 Ikhueniro Dry 12 0.334 b 0.219 0.534 0.016 1.0 Otofure Wet 12 0.031 a 0.029 0.121 0.016 1.0 Otofure Dry 12 0.020 a 0.003 0.024 0.014 1.0 SD – Standard deviation, Min – Minimum, Max – Maximum, NSDWQ – Nigerian Standard for Drinking Water Quality. Superscript with the same letter down the column are not significantly different (p < 0.05). * Indicates levels higher than the permissible limit Average Daily Dose (ADD) Calculation and Exposure Risk The Average Daily Dose (ADD) were calculated for different age groups (adults, children, and infants) across the Ikhueniro and Otofure dumpsites (Table 2 ). These estimations allow for an understanding of the level of exposure to heavy metals such as Fe, Zn, and Cu. In Ikhueniro, the ADD values calculated for adults with an assumed body weight of 60 kg showed that prolonged exposure to Fe, Zn, and Cu via ingestion resulted in average daily doses of 3.50E-02, 1.61E-02, and 1.44E-02 mg-1kg-1day-1 bodyweight, respectively. In comparison, children weighing 10 kg exposed to the same concentrations over a six-year period had significantly higher exposure doses of 1.05E-01, 4.83E-02, and 4.33E-02 mg-1kg-1day-1, while infants showed the highest exposure dose, with values reaching 1.58E-01, 7.25E-02, and 6.49E-02 mg-1kg-1day-1 for Fe, Zn, and Cu, respectively. This pattern of elevated exposure doses in children and infants compared to adults is consistent with findings in similar studies globally. For instance, in Iran, Alidadi et al. ( 2019 ) conducted a comprehensive study in northeast Iran, where children were found to have three times higher exposure to heavy metals from drinking water compared to adults. This disparity was largely attributed to children's smaller body sizes and higher consumption of water relative to their body weight. These results align with the findings in the present study, which show a significantly higher hazard quotient (HQ) and average daily dose (ADD) for children and infants at both dumpsites. Similarly, in Uganda, Bamuwamye et al. ( 2017 ) reported that children were twice as exposed to heavy metals through the ingestion of contaminated water as adults. Their research demonstrated that younger populations in regions with inadequate waste management and poor water quality face heightened risks of heavy metal toxicity, particularly from metals like lead and copper. The Ugandan context reflects the situation observed in this study, where higher HQ and ADD values for children were noted across both the Ikhueniro and Otofure sites. In China, Khandare et al. ( 2020 ) found that the risk for children from heavy metal exposure through groundwater consumption was twice as high as for adults. The study emphasized that developing countries often experience groundwater contamination as a result of industrial and domestic waste, creating disproportionate health risks for younger populations. This mirrors the pattern observed in the current study, where children and infants are at greater risk, particularly from Fe, Zn, and Cu. Additionally, India has reported similar findings. Ji et al. (2020) noted that children’s exposure to hazardous metals, such as lead and chromium, was 2.5 times higher than that of adults, mainly due to their increased water consumption in proportion to their body mass. The cumulative exposure to heavy metals in drinking water, leading to chronic health effects, was a key concern in the Indian study, reinforcing the global relevance of the present research’s conclusions. Lastly, a Nigerian study by Ojekunle et al. ( 2022 ) in Ogun State found that children exposed to groundwater near poorly managed dumpsites were three times more likely to ingest dangerous levels of heavy metals than adults. This is consistent with the findings in both Ikhueniro and Otofure, where the calculated health risks were substantially higher for younger populations, particularly infants. Non-Carcinogenic Health Risk Assessment (HQ and HI) To assess the non-carcinogenic health risk, Hazard Quotients (HQ) and Hazard Index (HI) values were calculated for the heavy metals found in groundwater samples from both sites (Fig. 3 ). For each age group, exposure to metals through ingestion was analyzed, and results showed concerning HQ values for certain metals, particularly in younger age groups. At the Ikhueniro site, HQ values for Cu (1.08 and 1.62) in children and adults, and Cr (1.31) in infants exceeded the acceptable threshold of 1.0, indicating significant non-carcinogenic health risks. Similarly, at the Otofure site, HQ for Cr was elevated in children (1.69) and infants (2.12), further indicating a risk of adverse health effects for these age groups. The metals Zn, Fe, and Pb, however, recorded HQ values less than 1, signifying a lower risk of non-carcinogenic harm. Comparatively, the findings align with Custodio et al. ( 2020 ), who demonstrated heightened vulnerability of children to the non-carcinogenic effects of heavy metals. This vulnerability is supported by similar investigations, such as Bello et al. ( 2019 ), which found higher HQ values in children compared to adults in their study on groundwater contamination in Nigeria. Furthermore, the HI values computed for cumulative exposure to multiple metals in children and infants exceeded 1, pointing to a compounding non-carcinogenic risk in these vulnerable groups. This is consistent with studies by Ojekunle et al. ( 2022 ), where HI values were significantly higher in children, indicating a potential for adverse health effects from multi-metal exposure. Table 2 The Non-carcinogenic values in groundwater at Ikhueniro and Otofure dumpsite area. Metal (mg/L) Mean RFD (Mg/kg/day) Sf ADD Adult ADD Children ADD Infant Ikhueniro Copper 0.0257 0.04 - 1.44E-02 4.33E-02 6.49E-02 Iron 0.5110 0.7 - 3.50E-02 1.05E-01 1.58E-01 Zinc 0.1491 0.3 - 1.61E-02 4.83E-02 7.25E-02 Lead 0.0071 0.0035 0.085 6.85E-04 2.06E-03 3.08E-03 Chromium 0.0508 0.003 0.50 8.70E-04 2.61E-03 3.92E-03 Nickel 0.0254 0.02 0.91 7.84E-04 2.35E-03 3.53E-03 Otofure Copper 0.0257 0.04 - 8.55E-04 1.03E-03 3.21E-03 Iron 0.5110 0.7 - 1.70E-02 2.04E-02 6.39E-02 Zinc 0.1491 0.3 - 4.97E-03 5.96E-03 1.86E-02 Lead 0.0071 0.0035 0.085 2.37E-04 2.84E-04 8.89E-04 Chromium 0.0508 0.003 0.50 1.69E-03 2.03E-03 6.35E-03 Nickel 0.0254 0.02 0.91 8.47E-04 1.02E-03 3.18E-03 Cancer Risk (CR) Estimates for Pb, Ni, and Cr The cancer risk (CR) associated with the ingestion of Pb, Ni, and Cr was evaluated for all age groups (Fig. 4 ). The results showed elevated risks, particularly for children and infants, which surpass the USEPA’s accepted risk threshold of 1.0 x 10 − 4 for lifetime cancer risk. At Ikhueniro, the CR for Pb exposure in infants was particularly alarming at 2.62 x 10 − 4 , significantly exceeding the permissible limit. Similarly, the CR values for Cr and Ni across all age groups were also high, with infants showing the greatest risk—Cr at 1.96 x 10 − 3 and Ni at 3.21 x 10 − 3 . The Otofure site mirrored this trend, with CR values for Cr and Ni for infants surpassing the threshold at 2.67 x 10 − 3 and 2.89 x 10 − 3 , respectively. These findings are supported by similar studies conducted in other regions of Nigeria. Ugwu et al. ( 2022 ), in their study on groundwater contamination in Southeast Nigeria, observed similarly high cancer risk values. Raman and Haruna (2019) also reported elevated CR values for heavy metals in North-Central Nigeria, reinforcing the conclusions drawn from the current study that certain populations, especially children and infants, are at heightened risk. The primary contributor to the cancer risk in this study was found to be Ni, accounting for 62% and 52% of the total CR in Ikhueniro and Otofure, respectively. This highlights the urgent need for mitigation strategies to reduce nickel contamination in groundwater, particularly near vulnerable populations. Conclusion This study has brought to light significant insights on groundwater contamination near the Ikhueniro and Otofure dumpsites in Edo State, Nigeria, showing just how much heavy metal pollution in water sources can impact nearby communities. By testing groundwater samples from these areas, both in the dry and rainy seasons, we found concerningly high levels of metals like lead (Pb), zinc (Zn), chromium (Cr), iron (Fe), nickel (Ni), and copper (Cu). The results often surpassed recommended safety limits, revealing how seasonal changes, especially during the rains, can increase the risk of contaminants seeping into groundwater. One particularly worrisome finding is the high lead levels, especially during the rainy season, as lead is known to be especially harmful to children, affecting cognitive development and overall health. This aligns with broader research that shows how waste sites often leak metals into water sources (e.g., Li et al., 2021; Ewim et al., 2023 ). Besides lead, we observed notable amounts of zinc and chromium, both of which have been linked to immune and reproductive health risks (Saper and Rash, 2009 ). Iron levels in particular stood out at Ikhueniro, with the average concentrations much higher than recommended by the World Health Organization (WHO). Although iron is essential for health, too much of it can damage organs, causing long-term health problems and even clogging water systems over time (Abbaspour et al., 2014 ). These findings are a clear call to action. To protect these communities, local and national governments need to improve waste management practices, monitor water quality more closely, and ensure residents have access to safe water sources. Immediate action and robust policies could help prevent further contamination, especially since communities near these sites heavily rely on groundwater for daily use. Declarations Declaration of competing interest The authors declare no known competing interest Funding Not applicable Author Contributions: Osaro Charming Asemota: Conceptualization, data collection, manuscript drafting. Alex Enuneku: Laboratory analysis, data interpretation, manuscript review. Isioma Tongo: Literature review, manuscript preparation. Lawrence Ikechuchukwu Ezemonye: Supervision, project funding, final manuscript approval. Data availability All data generated or analyzed during this study are included in this published article and its supplementary information files Acknowledgement We gratefully acknowledge the Laboratory for Ecotoxicology and Environmental Forensics at the University of Benin, Benin City, for providing the facilities and resources that were essential for our analyses. We extend our sincere appreciation to Mr. Timothy Agho, the technologist, for his invaluable technical support and assistance in sample processing. We are especially grateful for the generous provision of laboratory services at no cost, which greatly facilitated this research. References Abanyie, S.K., Apea, O.B., Abagale, S.A., Yahans E.B., Amuah, E.E.Y and Sunkari, E.D. (2023) Sources and factors influencing groundwater quality and associated health implications: A review, Emerging Contaminants , 9:(2)1-12 Abbaspour, N., Hurrell, R. and Kelishadi R. (2014). Review on iron and its importance for human health. J Res Med Sci ., 19(2):164-74. Abbaspour, N., Hurrell, R. and Kelishadi, R. (2014). Review on iron and its importance for human health. Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences, 19(2), 164–174. Abubakar, I. R., Maniruzzaman, K. M., Dano, U. L., AlShihri, F. S., AlShammari, M. S., Ahmed, S. M. S., Al-Gehlani, W. A. G., and Alrawaf, T. I. (2022). Environmental Sustainability Impacts of Solid Waste Management Practices in the Global South. International journal of environmental research and public health , 19(19):1-26 Adeyemi, A and Ojekunle, Z.O (2021) Concentrations and health risk assessment of industrial heavy metals pollution in groundwater in Ogun state, Nigeria Scientific African 11:1-11 Agency for Toxic Substances and Disease Registry (2012) Toxi Heavy metal pollution in the environment and their toxicological effects on humans cological profile for Chromium. Agency for Toxic Substances and Disease Registry Division of Toxicology and Human Health Sciences (proposed) Environmental Toxicology Branch (proposed) 1600 Clifton Road NE Mailstop F-62 Atlanta, Georgia 30333 Akujieze, C.N and Oteze, G.E (2007). Deteriorating Quality of Groundwater in Benin City, Edo State, Nigeria. Journal of Nigeria Association of Hydrogeologists, 1: 192-196 Alidadi, H., Belin, S., Sany, T., Zarif, B., Oftadeh, G., Mohamad, T., Shamszade, H. and Fakhari, M. (2019) Health risk assessments of arsenic and toxic heavy metal exposure in drinking water in northeast Iran Environmental Health and Preventive Medicine, 24:(59)1-17 Anyachor, C.P., Dooka, D.B., Orish, C.N., Amadi, C.N., Bocca, B., Ruggieri, F., Frazzoli, C.F and Orisakwe, O.E. (2022) Mechanistic considerations and biomarkers level in nickel-induced neurodegenerative diseases: An updated systematic review, IBRO Neuroscience Reports , 13:136-146, APHA (2005). Standard Methods for the Examination of Water and Wastewater. 21st Edition, American Public Health Association/American Water Works Association/Water Environment Federation, Washington Wani, A.L., Ara, A. and Usmani, J.A. (2015). Lead toxicity: a review. Interdiscip Toxicol. 8(2):55-64 Etchie, A.T., Etchie, T.O., Adewuyi, G.O., Kannan, K., Wate, S.R., Sivanesan, S. and Chukwu A.U. (2014). Influence of seasonal variation on water quality in tropical water distribution system: is the disease burden significant? Water Research , 49:186-196, ISSN 0043-1354, Xu, Z., Shi, M., Yu, X., and Liu, M. (2022). Heavy Metal Pollution and Health Risk Assessment of Vegetable-Soil Systems of Facilities Irrigated with Wastewater in Northern China. International journal of environmental research and public health , 19(16):1-15. https://doi.org/10.3390/ Balogun, T.F. and Onokerhoraya, A.G (2017). Spatio-Temporal Growth of Benin City, Nigeria, and Its Implications for Access to Infrastructure. Journal of Geography and Geology , 9(2):11-23 Bamuwamye, M., Ogwok, P., Tumuhairwe, V., Eragu, R., Nakisozi, H. and Ogwang, P.E. (2017) Human Health Risk Assessment of Heavy Metals in Kampala (Uganda) Drinking Water. Journal of Food Research , 6:(4)6-16 Beimeng, Q.I., Chongwei, C. and Yixing, Y. (2015) Effects of iron bacteria on cast iron pipe corrosion and water quality in water distribution systems. International Journal of Electrochemical Science . 10:545–558. Bello, S., Nasiru, R., Garba, N.N. and Adeyemo, D.J. (2019) Carcinogenic and non-carcinogenic health risk assessment of heavy metals exposure from Shanono and Bagwai artisanal gold mines, Kano state, Nigeria. Scientific African , 6:1-6 Boateng, T.K., Opoku, F. and Akoto, O. (2019) Heavy metal contamination assessment of groundwater quality: a case study of Oti landfill site, Kumasi. Applied Water Science 9:(33)1-15 Bodrud-Doza, M.D., Didar-Ul Islam, S.M., Rume, T., Quraishi, S.B., Rahman, M.S. and Bhuiyan M.A. (2020) Groundwater quality and human health risk assessment for safe and sustainable water supply of Dhaka City dwellers in Bangladesh. Groundwater for Sustainable Development, 10(3):1-12 Briffa, J., Sinagra, E. and Blundell, R. (2020). Heavy metal pollution in the environment and their toxicological effects on humans, Heliyon , 6(9):1-26. Carrard, N., Foster, T., Willetts, J. (2019). Groundwater as a Source of Drinking Water in Southeast Asia and the Pacific: A Multi-Country Review of Current Reliance and Resource Concerns. Water, 11(8):1605. https://doi.org/10.3390/w11081605 Cirella, G. T., Iyalomhe, F. O. and Adekola, P. O. (2019). Determinants of flooding and strategies for mitigation: Two-year case study of Benin city. Geosciences , 9(3), 136. Collin, M.S., Venkatraman, S.K., Vijayakumar, N., Kanimozhi, V., Arbaaz, S. M., Sibiya, S. R. G., Anusha, J., Choudhary, R., Lvov, V., Tovar, G.I., Senatov, F., Koppala, S. and Swamiappan, S. (2022) Bioaccumulation of lead (Pb) and its effects on human: A review, Journal of Hazardous Materials Advances, 7:2772-4166. Collin, M.S., Venkatraman, S.K. Vijayakumar, N., Kanimozhi, V., Arbaaz, S.M., Sibiya, R.G, Anusha, J., Choudhary, R., Lvov, V., Tovar, G.I, Senatov, F., Koppala, S. and Swamiappan, S. (2022) Bioaccumulation of lead (Pb) and its effects on human: A review, Journal of Hazardous Materials Advances, 7:2772-4166, Custodio, M., Cuadrado, W., and Penaloza R. (2020). Human Risk from Exposure to Heavy Metals and Arsenic in Water from Rivers with Mining Influence in the Central Andes of Peru. Water . 12(7):1946. Eid, R., Arab, N. T., and Greenwood, M. T. (2017). Iron mediated toxicity and programmed cell death: A review and a re-examination of existing paradigms. Biochimica et biophysica acta. Molecular cell research, 1864(2), 399–430. https://doi.org/10.1016/j.bbamcr.2016.12.002 Hessel, E. V. S., Staal, Y. C. M., Piersma, A. H., den Braver-Sewradj, S. P., and Ezendam, J. (2021). Occupational exposure to hexavalent chromium. Part I. Hazard assessment of non-cancer health effects. Regulatory toxicology and pharmacology : RTP, 126, 105048. https://doi.org/10.1016/j.yrtph.2021.105048 Eni, D.V., J.Obiefuna., C. Oko., and I. Ekwok. (2011). Impact of urbanization on sub-surface water quality in Calabar municipalty, Nigeria. International Journal of Humanities and Social Sciences , 1(10):167-172. Enitan, I.T., Enitan, A.M., Odiyo, J.O. and Alhassan, M.M (2018) Human Health Risk Assessment of Trace Metals in Surface Water Due to Leachate from the Municipal Dumpsite by Pollution Index: A Case Study from Ndawuse River, Abuja, Nigeria. Chem ., 16: 214–227 Ewim, D.R.E., Orikpete, O.F., Scott, T.O. (2023). Survey of wastewater issues due to oil spills and pollution in the Niger Delta area of Nigeria: a secondary data analysis. Bull. Nat. Res. Cent . 47, 116 (2023). https://doi.org/10.1186/s42269-023-01090-1 Genchi, G., Carocci, A., Lauria, G., Sinicropi, M. S. and Catalano, A. (2020). Nickel: Human Health and Environmental Toxicology. International journal of environmental research and public health , 17(3), 679. https://doi.org/10.3390/ijerph17030679 Giri, S. and Singh, A.K. (2015). Human health risk assessment via drinking water pathway due to metal contamination in the groundwater of Subarnarekha River Basin, India. Environ. Monit. Assess. 187:(63) Idugboe, S.O., Tawari-Fufeyin, P. (2014) Soil pollution in two auto-mechanic villages in Benin City, Nigeria. Journal of Environmental Science, Toxicology and Food Technology 8(1): 9-14. Jaishankar, M., Tseten, T., Anbalagan, N., Mathew, B. B. and Beeregowda, K. N. (2014). Toxicity, mechanism and health effects of some heavy metals. Interdisciplinary toxicology, 7(2), 60–72. https://doi.org/10.2478/intox-2014-0009 Khandare, A.L., Validandi, V., Rajendran, A., Singh, T.G., Thingnganing, L., Kurella, S., Nagaraju, R., Dheeravath, S., Vaddi, N., Kommu, S. and Maddela, Y. (2020). Health risk assessment of heavy metals and strontium in groundwater used for drinking and cooking in 58 villages of Prakasam district, Andhra Pradesh, India Environ Geochem Health 42 , 3675–3701 Kolawole, T.O., Iyiola, O., Ibrahim, H., and Isibor, R.A. (2023) Contamination, ecological and health risk assessments of potentially toxic elements in soil around a municipal solid waste disposal facility in Southwestern Nigeria, Journal of Trace Elements and Minerals , 5:1-9 Kumar, V., Kumar, S. T., Kumar, K and Parmar, R.S. (2023) Heavy Metal-Induced Pollution in the Environment through Waste Disposal. International Journal of Research Publication and Reviews , 4(7):1205-1210 ff Kwakye, S.O., Amuah, E.B.Y., Ankoma, K.A., Agyemang, E.B. and Owusu, B. (2024). Understanding the performance and challenges of solid waste management in an emerging megacity: Insights from the developing world, Environmental Challenges , 14:1-9, Li, H., Chen, Q., Li, S., Yao, W., Li, L., Shi, X., Wang, L., Castranova, V., Vallyathan, V. and Ernst, E. (2001). Effect of Cr (VI) Exposure on Sperm Quality: Human and Animal Studies. Ann. Occup. Hyg . 45:505–511. Abd El-Salam M.M. and Abu-Zuid G.S. (2015). Impact of landfill leachate on the groundwater quality: A case study in Egypt, Journal of Advanced Research , 6(4)579-586, Maslekar, A., Kumar, A., Krishnamurthy, V., Kulkarni, A. and Reddy, M. (2022). Association Between Blood Lead Levels and Hypertension in a South Indian Population: A Case-Control Study. Cureus . 16;14(2):e22277. doi: 10.7759/cureus.22277. PMID: 35350484; PMCID: PMC8932219. Mitra, S., Chakraborty, A.J., Tareq, A.M., Emran, T.B., Nainu, F., Khusro, K., Idris, A.M., Khandaker, M.U., Osman, H., Alhumaydhi, F.A. and Simal-Gandara, J. (2022). Impact of heavy metals on the environment and human health: Novel therapeutic insights to counter the toxicity, Journal of King Saud University - Science , 34(3):1.21 NSDWQ, (2007). Nigerian Standard for Drinking Water Quality. Nigerian Industrial Standard NIS 554, Standard Organization of Nigeria, Pp30. Oboshenure, K. K. and Airen, O.J. (2021). Aquifer vulnerability assessment using Dar-Zarrouk parameter: A case study of Otofure and Ikhueniro dumpsites, Benin-city, South-South Nigeria. Australian Journal of Science and Technology. 5:((1):422-433 Ogunrinola, O., Joshua, O. and Elemo, B. (2021). Heavy Metals Concentration in Underground Water and its Environmental Health Effects: A Case Study of Solous Dumpsite, Igando, Lagos. Journal of Research and Review in Science, 8(1): 40-46. Ojekunle, O.Z., Rasaki, A., Taiwo, A.M., Adegoke, K.A., Balogun, M.A., Ojekunle, O.O., Anumah, A.O., Ibrahim, A.O. and Adeyemi, A.A., (2022) Health risk assessment of heavy metals in drinking water leaching through improperly managed dumpsite waste in Kurata, Ijoko, Sango area of Ogun State, Nigeria. Groundwater for Sustainable Development . doi: https://doi.org/10.1016/ Olufemi, A.C., Mji, A. and Mukhola M.S. (2022). Potential Health Risks of Lead Exposure from Early Life through Later Life: Implications for Public Health Education. Int. J. Environ. Res. Public. Health. 30:19(23):16006. doi: 10.3390/ijerph192316006. PMID: 36498077; PMCID: PMC9741093. Orhorhoro, EK and Oghoghorie, O (2019). Review on Solid Waste Generation and Management in Sub-Saharan Africa: A Case Study of Nigeria. J. Appl. Sci. Environ. Manage. 23(9):1729-1737 Pan, S., Lin, L., Zeng, F., Zhang, J., Dong, G., Yang, B., Jing, Y., Chen, S., Zhang, G., Yu, Z., Sheng, G., and Ma, H. (2018). Effects of lead, cadmium, arsenic, and mercury co-exposure on children’s intelligence quotient in an industrialized area of southern China, Environ. Pollut. 235:47–54. Saheed, I.O., Azeez, A.A., Jimoh, A.A., Obaro, V.A., Adepoju, S.A. (2020). Assessment of some heavy metals concentrations in soil and groundwater around refuse dumpsite in Ibadan metropolis, Nigeria. Nig. J. Technol . 39: 301–305. Saper, R. B. and Rash, R. (2009). Zinc: an essential micronutrient. American family physician , 79(9), 768–772 Shin, D. Y., Lee, S. M., Jang, Y., Lee, J., Lee, C. M., Cho, E. M. and Seo, Y. R. (2023). Adverse Human Health Effects of Chromium by Exposure Route: A Comprehensive Review Based on Toxicogenomic Approach. International journal of molecular sciences , 24(4), 3410. https://doi.org/10.3390/ijms24043410 Singh, M., Singh, S. and Kumar, V. (2022). Heavy metal contamination and its hazardous impacts on soil, plant, human health, and aquifers: A review. Environmental Quality Management , 32(1), 97-108. Tan, B.L., Norhaizan, M.E., Liew, W.P. and Rahman H.S. (2018) Antioxidant and Oxidative Stress: A Mutual Interplay in Age-Related Diseases. Front Pharmacol. 16;9:1162. doi: 10.3389/fphar.2018.01162. PMID: 30405405; PMCID: PMC6204759. Ugwu, C.E., Maduka, I.C., Suru, S.M. and Anakwuo, I.A. (2022). Human health risk assessment of heavy metals in drinking water sources in three senatorial districts of Anambra State, Nigeria. Toxicology Reports , 9:869-875, ISSN 2214-7500 Ullah, Z., Rashid, A., Ghani, J., Nawab, J., Zeng, X.C., Shah, M., Alrefaei, A.F., Kamel, M., Aleya, L., Abdel-Daim, M.M. and Iqbal, J. (2022). Groundwater contamination through potentially harmful metals and its implications in groundwater management. Front. Environ. Sci. 10:1021596. doi: 10.3389/fenvs.2022.1021596 Uroupa, R. E. and Ogbeibu, E. A. (2020) Impact of Solid Waste Dump-Sites on Groundwater Quality in Benin City, Nigeria. African Journal of Health, Safety and Environment , 1 (1): 38-63 USEPA (1989). Risk assessment guidance for superfund. Volume I. Human health evaluation manual EPA/540/1-89/002. Ofce of solid waste and emergency response USEPA (2001) Baseline human health risk assessment Vasquez Boulevard and I-70 Superfund Site. Denver CO. U.S. Environmental Protection Agency. Assessed from http://www.epa.gov/region8/ uperfund/sites/VB-170-Risk.pdf USEPA (2004) Risk assessment guidance for superfund volume I: human health evaluation manual (part E). U.S. Environmental Protection Agency. http://www.epa.gov/oswer/riskassessment/ragse/pdf/introduction.pdf. USEPA (2011) United States Environmental Protection Agency’s risk assessment guidance for superfund. In: Part A: human health evaluation manual; part E, supplemental guidance for dermal risk assessment; part F, supplemental guidance for inhalation risk assessment, volume II. http://www.epa.gov/ oswer/ riskassessment /humanhealthexposure.htm USEPA, (1999). Risk assessment for multi way exposure spread sheet calculation tool. United States Environmental Protection Agency, Washington, DC Li, W., Zhou, J., Boon, D., Fan, T., Anneser, E., Goodman, J.E., and Prueitt, R.L. (2024). Nickel in ambient particulate matter and respiratory or cardiovascular outcomes: A critical review, Environmental Pollution, 347: 123442, ISSN 0269-7491, WHO. (2017). The cost of a polluted environment: 1.7 million child deaths a year, says WHO. Geneva: WHO. World Health Organization scs.2017.01.005. Wise, J. P., Jr, Young, J. L., Cai, J. and Cai, L. (2022). Current understanding of hexavalent chromium [Cr(VI)] neurotoxicity and new perspectives. Environment international , 158, 106877. https://doi.org/10.1016/j.envint.2021.106877 Witkowska, D., Słowik, J., and Chilicka, K. (2021). Heavy Metals and Human Health: Possible Exposure Pathways and the Competition for Protein Binding Sites. Molecules (Basel, Switzerland), 26(19), 6060. https://doi.org/10.3390/molecules26196060 Xie, Y., Wu, X. and Guo, F. (2023). Health risk assessment of heavy metal exposure in drinking water in mining areas of southwest China. Environmental Science and Pollution Research, 30(4), 4690-4701. Additional Declarations No competing interests reported. Supplementary Files DATAFORDESCRIPTIVESTATISTICS.xlsx calculaionforhumanhealthriskassessmnt.xlsx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 28 Jan, 2025 Reviews received at journal 26 Jan, 2025 Reviews received at journal 22 Jan, 2025 Reviewers agreed at journal 22 Jan, 2025 Reviewers agreed at journal 21 Jan, 2025 Reviewers agreed at journal 21 Jan, 2025 Reviewers agreed at journal 21 Jan, 2025 Reviewers agreed at journal 20 Jan, 2025 Reviewers agreed at journal 20 Jan, 2025 Reviewers agreed at journal 20 Jan, 2025 Reviewers invited by journal 20 Jan, 2025 Editor assigned by journal 14 Jan, 2025 Submission checks completed at journal 13 Jan, 2025 First submitted to journal 02 Jan, 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-5753074","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":401825492,"identity":"7d0c45c2-d723-4fe1-8733-b51ec86d023e","order_by":0,"name":"Charming Osaro Asemota","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA+klEQVRIiWNgGAWjYPCDCgYGNgkwi5ko9YwNDGdI1sLYBqQIaeHnP/zswwcGO3t+scPHH/ycdziPT7r52AOGCuvEBhxaJGekGc+cwZCcOHN2WmJj77bDxWwyx9INGM6k49RicIPBmJmHgTnB4HaOYQPvtsOJbRI5ZhKMbYdxazl//DNQS729PVBL4985IC353yQY/+HRciAHZMthxg3SOYbNvA1gW9gkGBtwa5GckVPMOMPgeOKM22mJs4HeSGyTOWYmkXAs3RiXFn7+45sZPlRU2/PPTj7w8U2NdeL82c3PJD7UWMvi0gJ1HrpAAl7lo2AUjIJRMAoIAQDjeFYXD2M9uwAAAABJRU5ErkJggg==","orcid":"","institution":"University of Benin","correspondingAuthor":true,"prefix":"","firstName":"Charming","middleName":"Osaro","lastName":"Asemota","suffix":""},{"id":401825493,"identity":"cabd5f7b-4d4d-4154-9656-fcd0d87c7417","order_by":1,"name":"Alex Enuneku","email":"","orcid":"","institution":"University of Benin","correspondingAuthor":false,"prefix":"","firstName":"Alex","middleName":"","lastName":"Enuneku","suffix":""},{"id":401825494,"identity":"544fe5ff-186e-48f8-bace-9b1e94c5a4ad","order_by":2,"name":"Isioma Tongo","email":"","orcid":"","institution":"University of Benin","correspondingAuthor":false,"prefix":"","firstName":"Isioma","middleName":"","lastName":"Tongo","suffix":""},{"id":401825495,"identity":"689dcabe-9127-4711-807d-c9543870232e","order_by":3,"name":"Lawrence Ikechuchukwu Ezemonye","email":"","orcid":"","institution":"University of Benin","correspondingAuthor":false,"prefix":"","firstName":"Lawrence","middleName":"Ikechuchukwu","lastName":"Ezemonye","suffix":""}],"badges":[],"createdAt":"2025-01-02 16:08:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5753074/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5753074/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":73871822,"identity":"9890dfca-753d-41ff-8b48-d8bb6b9cd886","added_by":"auto","created_at":"2025-01-15 12:25:49","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":868384,"visible":true,"origin":"","legend":"\u003cp\u003eMap showing the study location at Ikhueniro Edo State, Benin City. (Source: This study)\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/b1d48624fed006520218ed44.png"},{"id":73871837,"identity":"67e9d311-9c6d-47ff-931b-f16c868509b1","added_by":"auto","created_at":"2025-01-15 12:25:49","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":506305,"visible":true,"origin":"","legend":"\u003cp\u003eMap showing the study location at Otofure Edo State, Benin City. (Source: This study)\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/06a1ec0f4ecd72d610a3deff.png"},{"id":73871838,"identity":"06852a2f-67c7-4818-b28c-4dc15d6f66c7","added_by":"auto","created_at":"2025-01-15 12:25:49","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":21416,"visible":true,"origin":"","legend":"\u003cp\u003eThe estimated HQ values of the heavy metals for the adults, children and infants at (A) Ikhueniro, (B) Otofure and the HI at (C) Ikhueniro and Otofure\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/0cdc76d1da6820e298aaf781.png"},{"id":73872983,"identity":"9a250524-81f9-4699-8dda-24274170b89f","added_by":"auto","created_at":"2025-01-15 12:33:49","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":43830,"visible":true,"origin":"","legend":"\u003cp\u003eCancer risk estimated for heavy metals in (A) Ikhueniro and (B) Otofure for adults, children, and infants and the Percentage contributions of Pb, Cr, and Ni to the overall cancer risk at Ikhueniro (4C) and Otofure (4D)\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/1b131f7367824009d6d5112a.png"},{"id":73874124,"identity":"5bc2e9f1-961a-4774-ba41-2f08b359d523","added_by":"auto","created_at":"2025-01-15 12:41:50","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2797793,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/77df6f8f-b4b2-45f2-9625-10dfa2ee3f9e.pdf"},{"id":73871825,"identity":"bf793f63-316f-4f86-a957-271de4c051c8","added_by":"auto","created_at":"2025-01-15 12:25:49","extension":"xlsx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":73005,"visible":true,"origin":"","legend":"","description":"","filename":"DATAFORDESCRIPTIVESTATISTICS.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/fef87dd58943994e5d8bad10.xlsx"},{"id":73871824,"identity":"2a500f37-97e0-4625-bfa0-7638ad288197","added_by":"auto","created_at":"2025-01-15 12:25:49","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":62407,"visible":true,"origin":"","legend":"","description":"","filename":"calculaionforhumanhealthriskassessmnt.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5753074/v1/2aa8451aab44216de3f33f93.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Heavy Metal Contamination and Cancer Risk Assessment in Groundwater Near Dumpsites: Health Implications for Vulnerable Populations in Nigeria","fulltext":[{"header":"Introduction","content":"\u003cp\u003eGroundwater is a vital resource globally, providing drinking water to millions of people, particularly in regions with limited access to surface water (Carrard et al., \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). However, its quality is increasingly under threat from various human activities such as industrialization, urbanization, and inadequate waste disposal systems (Abanyie et al., \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). These processes have introduced contaminants, including heavy metals like lead (Pb), chromium (Cr), nickel (Ni), copper (Cu), zinc (Zn), and iron (Fe), into groundwater systems, raising significant public health concerns (Adeyemi and Ojekunle, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Heavy metal contamination is especially concerning due to the toxic nature of these elements, even at trace levels (Briffa et al., \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), and the long-term health risks associated with their ingestion (Mitra et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). According to Mitra et al., \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2022\u003c/span\u003e, the ingestion of heavy metals over prolonged periods can lead to severe health issues, including neurotoxicity, developmental delays in children, and increased cancer risks.\u003c/p\u003e \u003cp\u003eThis global concern is even more pressing in developing countries, where the rapid pace of urban growth often outstrips the capacity of existing infrastructure to manage waste effectively (Abubakar, et al., \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Regions such as Sub-Saharan Africa, including Nigeria, are particularly vulnerable (Orhorhoro, and Oghoghorie, \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Inadequate waste management practices, such as the unregulated dumping of waste near residential areas, have led to the leaching of heavy metals into groundwater supplies that serve local populations (Kolawole, et al., \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In these contexts, where groundwater is often the sole source of drinking water, contamination poses severe and immediate health risks. As Aigberua \u003cem\u003eet al.\u003c/em\u003e (2021) highlight, this is further compounded by the lack of resources and institutional frameworks to monitor and mitigate these environmental hazards.\u003c/p\u003e \u003cp\u003eThe contamination of groundwater with heavy metals has been linked to numerous adverse health effects. Lead (Pb), for example, is known for causing cognitive impairments and developmental delays in children, even at low exposure levels (Pan et al., \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Children and infants are particularly vulnerable to the effects of heavy metals due to their smaller body mass and higher intake of water relative to their body weight (Ojekunle et al., \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Chromium (Cr), in its hexavalent form, is recognized as a carcinogen associated with lung and stomach cancers (Wise et al., \u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2022\u003c/span\u003e)., while nickel (Ni) exposure has been linked to dermatitis, respiratory issues, and elevated cancer risks (Anyachor et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Metals like copper (Cu), zinc (Zn), and iron (Fe), while essential to human health in trace amounts, can become toxic at higher concentrations, resulting in gastrointestinal distress, liver and kidney damage, and other severe health issues (Witkowska et al., \u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn Nigeria, the situation is particularly dire, with a rapidly growing population and a significant lag in waste management infrastructure. Many urban centers, such as Benin City in Edo State, are experiencing the harmful effects of inadequate waste disposal systems. The Ikhueniro and Otofure dumpsites in Benin City are prime examples of this, as both are located in proximity to residential areas, where boreholes and wells serve as the primary sources of drinking water for local inhabitants. Previous studies, such as those by Ugwu et al. (\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) and Ojekunle et al. (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), have documented elevated levels of heavy metals in groundwater near dumpsites across Nigeria, highlighting the urgent need for intervention. Aigberua and Tarawali (2021) specifically examined the heavy metal content in groundwater near dumpsites in Port Harcourt, Nigeria, and found that concentrations of lead, chromium, and nickel exceeded the World Health Organization (WHO) guidelines for safe drinking water. The Ikhueniro and Otofure dumpsites have long been sources of concern for environmental and public health experts, as leachates from these sites are suspected of infiltrating the surrounding groundwater, compromising the safety of the local water supply.\u003c/p\u003e \u003cp\u003eThe current study aimed to assess the concentrations of heavy metals in groundwater near the Ikhueniro and Otofure dumpsites and evaluate the potential health risks for local populations.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy area\u003c/h2\u003e \u003cp\u003eBenin City is the capital of Edo State and is situated in Nigeria's south-south geopolitical zone; it has a total area of roughly 500 square kilometers and is bordered by latitudes 6\u003csup\u003eo\u003c/sup\u003e 12' 38\u0026rsquo;\u0026rsquo; N and 6\u003csup\u003eo\u003c/sup\u003e 27' 25\u0026rsquo;\u0026rsquo;N and longitudes 5\u003csup\u003eo\u003c/sup\u003e 29' 46\u0026rsquo;\u0026rsquo; E and 5\u003csup\u003eo\u003c/sup\u003e 45' 0.41\u0026rsquo;\u0026rsquo; E. It is located in the tropical equatorial zone, where the dry season runs from December to March and the wet season from April to November (Cirella et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Sedimentary formation underlies the city (Akujieze and Oteze, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). Reddish clayey sand makes up the top layer of the formation, which caps vastly porous fresh water bearing loose pebbly sands, and sandstone with local thin clays and shale interbeds which are considered to be of braided stream origin. Sand that is loose and brownish blankets the formation; it is virtually entirely water-bearing with a water level range of between 20 m to 52 m. It is largely believed to be highly porous and abundant in water yield.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSampling Stations\u003c/h3\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eSatiation One\u003c/h2\u003e \u003cp\u003eThe Otofure dumpsite, which has been in operation for over 20 years, is situated in a neighborhood of Benin City, in the Ovia North East Local Government Area of Edo State (Oboshenure and Airen, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Its coordinates are 6.027759\u0026deg;N, 5.035861\u0026deg;E, and it is managed by the Edo State government. This sizable dumpsite serves as a major disposal site for waste generated across Benin City, with authorized agencies transporting waste from residences, offices, businesses, marketplaces, and hospitals. The waste deposited at the site is highly heterogeneous, consisting of organic and inorganic materials.\u003c/p\u003e \u003cp\u003eGroundwater sampling in the Otofure area was carried out at 12 active private boreholes located at varying distances from the dumpsite. This was done to evaluate potential groundwater contamination due to waste disposal activities. The distances of these boreholes from the dumpsite ranged from 0.10 km to 0.33 km, enabling a comprehensive spatial analysis of contamination levels. The closest borehole, OTF 12, was situated just 0.10 km from the dumpsite, while other nearby boreholes included OTF 11, located 0.15 km away, and OTF 1 and OTF 2, both positioned 0.14 km from the site. Farther from the dumpsite, boreholes OTF 10 and OTF 9 were located 0.20 km and 0.27 km away, respectively. Additional boreholes\u0026mdash;OTF 5 (0.29 km), OTF 3, OTF 4, and OTF 6 (each 0.31 km), and OTF 7 and OTF 8 (each 0.33 km)\u0026mdash;were also included to provide a gradient of distances for the analysis. This distribution of sampling points facilitated the assessment of how proximity to the dumpsite potentially influenced groundwater quality.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eStation Two\u003c/h3\u003e\n\u003cp\u003eThe Ikhueniro dumpsite, which has been in operation for more than 30 years, is situated alongside the Benin-Lagos Bypass in the Uhunmwonde Local Government Area of Edo State (Idugboe et al., 2014). Its coordinates are 6.32668\u0026deg;N, 5.74605\u0026deg;E, and it is managed by the Edo State Waste Management Board (EDSMA). The dumpsite covers a footprint of approximately 150 meters and serves as the primary disposal site for waste generated across Benin City. The waste deposited here is heterogeneous, comprising building materials, household refuse, market debris, agricultural byproducts, hospital waste, and industrial waste. The surrounding areas are primarily residential, commercial, and industrial, making the dumpsite an important area for assessing environmental impacts. Various forms of waste, including organic, inorganic, hazardous, and non-hazardous materials, are carelessly dumped here by Private Sector Partnership (PSP) collection trucks, which transport waste from different parts of the city.\u003c/p\u003e \u003cp\u003eGroundwater sampling in the Ikhueniro area was conducted at 12 active private boreholes located at various distances from the dumpsite to evaluate the potential contamination of groundwater from waste disposal. The distances of these boreholes from the dumpsite ranged from 0.10 km to 0.33 km, allowing for a detailed spatial analysis of contamination levels. The closest boreholes, IKH 12 and IKH 11, were located just 0.10 km and 0.15 km from the dumpsite, respectively, while the farthest points, IKH 7 and IKH 8, were situated 0.33 km away. Additional boreholes were positioned at varying distances: IKH 1 and IKH 2 were 0.14 km away, IKH 3, IKH 4, and IKH 6 were each 0.31 km away, IKH 5 was 0.29 km away, and IKH 10 was located 0.20 km from the dumpsite. This systematic distribution of sampling points was designed to assess how proximity to the dumpsite influenced groundwater quality.\u003c/p\u003e\n\u003ch3\u003eSample Collection and Analytical Procedure\u003c/h3\u003e\n\u003cp\u003eGroundwater sample collection, storage, transport, and analysis followed standardized protocols outlined by the American Public Health Association (APHA, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). A total of 144 groundwater samples were collected from 12 active private boreholes located near two waste dumpsites: Otofure (Station 1) and Ikhueniro (Station 2). A total of 77 samples were obtained from each site during two distinct seasons\u0026mdash;wet season (July to September 2019) and dry season (December 2019 to February 2021). This seasonal approach ensured a comprehensive analysis of groundwater quality under varying environmental conditions.\u003c/p\u003e \u003cp\u003eTo minimize contamination during sampling, all bottles were thoroughly rinsed multiple times with deionized water and preconditioned by rinsing three times with the sampled groundwater. Before sample collection, a 10-minute pump-out of the borehole was conducted to remove stagnant water. Groundwater samples were then collected in 2.5 L sterile polyethylene bottles, each clearly labeled with site codes. To preserve sample integrity and prevent ion precipitation or reactions with the container walls, 2 mL of concentrated HNO₃ was added to each sample immediately after collection. The samples were maintained at 4\u0026deg;C using ice packs during transport to the Laboratory for Ecotoxicology and Environmental Forensics at the University of Benin for further analysis.\u003c/p\u003e \u003cp\u003eIn the laboratory, the samples were analyzed for heavy metals (HMs) including iron (Fe), chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn). Heavy metal concentrations were measured using an atomic absorption spectrophotometer (Buck Scientific, Model 210 VGP), with a detection limit of 0.0001 mg/L and a quantification limit of 0.0003 mg/L. The analytical procedures adhered to APHA (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2005\u003c/span\u003e) guidelines, ensuring the reliability and precision of the results. All chemical reagents used in the analysis were of analytical grade.\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003eAll statistical analyses were conducted using IBM SPSS Statistics, Version 20. Descriptive statistics were applied to summarize the collected data and provide insights into the distribution of measured parameters. To assess spatial and temporal variations in groundwater quality between the two sampling stations (Otofure and Ikhueniro) and across the wet and dry seasons, a one-way analysis of variance (ANOVA) was performed. Statistical significance was set at \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05 to determine whether there were significant differences among the parameters measured across the different sites and seasons. For post-hoc analysis, Duncan\u0026rsquo;s Multiple Range Test was applied to identify where significant differences occurred between specific groups.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eHuman Health Risk Assessment\u003c/h3\u003e\n\u003cp\u003eTo evaluate potential health risks posed by exposure to heavy metals in groundwater, a comprehensive human health risk assessment was conducted. This assessment considered both carcinogenic and non-carcinogenic risks, based on individual exposure to contaminated groundwater across three distinct population groups: infants, children, and adults. The methodologies followed the guidelines provided by the U.S. Environmental Protection Agency (USEPA, \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e2001\u003c/span\u003e, \u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e2011\u003c/span\u003e), focusing on the calculation of the Average Daily Dose (ADD), Hazard Quotient (HQ), Hazard Index (HI), and Cancer Risk (CR) for each population group.\u003c/p\u003e \u003cp\u003eThe ADD was calculated based on exposure routes, including ingestion of contaminated water. The Hazard Quotient (HQ) was derived by comparing the ADD to the reference dose (RfD) for each metal, with HQ\u0026thinsp;\u0026gt;\u0026thinsp;1 indicating a potential non-carcinogenic health risk. The cumulative non-carcinogenic risk for each individual was evaluated using the Hazard Index (HI), calculated as the sum of HQs for all metals. An HI greater than 1 suggests that adverse health effects may occur. Additionally, the lifetime cancer risk (CR) was estimated for metals with carcinogenic potential, using the established cancer slope factor (CSF). A CR value within the range of 1 \u0026times; 10⁻⁶ to 1 \u0026times; 10⁻⁴ was considered acceptable, whereas values above this range indicated a heightened risk of cancer due to metal exposure.\u003c/p\u003e\n\u003ch3\u003e(1)\u003c/h3\u003e\n\u003cp\u003e \u003c/p\u003e\u003cdiv id=\"Equa\" class=\"Equation\"\u003e \u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:\\begin{array}{ccc}\\text{A}\\text{D}\\text{D}\u0026amp;\\:=\u0026amp;\\:\\frac{\\text{C}\\:\\times\\:\\text{I}\\text{R}\\:\\times\\:\\text{E}\\text{D}\\:\\times\\:\\text{E}\\text{F}}{\\text{B}\\text{W}\\:\\times\\:\\text{A}\\text{T}}\\end{array}\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\text{E}\\text{q}.\\:1$$\u003c/div\u003e \u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eIn this study, the Average Daily Dose (ADD) of heavy metals through contaminated groundwater was calculated using the following parameters:\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cul\u003e \u003cli\u003e \u003cp\u003eADD is expressed in micrograms of metals per kilogram per day (µg kg⁻¹ day⁻¹).\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eC represents the mean concentration of the examined metals in water samples, measured in micrograms per liter (µg L⁻¹).\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eIR denotes the intake rate, which varies by age group: 2 L per day for adults, 1 L per day for children, and 0.75 L per day for infants.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eED refers to the duration of exposure, set at 30 years for adults, 6 years for children, and 1 year for infants (USEPA, \u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e2001\u003c/span\u003e).\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe exposure frequency (EF) was assumed to be 365 days per year.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eBW signifies the average body weight, which is 60 kg for adults, 10 kg for children, and 5 kg for infants.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAT (exposure time) was calculated as 30 years for adults, 6 years for children, and 1 year for infants, multiplied by 365 days per year.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eThe Non-Carcinogenic Index, resulting from the ingestion of contaminated groundwater, was determined using Eq.\u0026nbsp;2: (2).\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\begin{array}{ccc}\\text{H}\\text{a}\\text{z}\\text{a}\\text{r}\\text{d}\\:\\text{q}\\text{u}\\text{o}\\text{t}\\text{i}\\text{e}\\text{n}\\text{t}\\:\\left(\\text{H}\\text{Q}\\right)\u0026amp;\\:=\u0026amp;\\:\\frac{\\text{A}\\text{D}\\text{D}}{\\text{R}\\text{f}\\text{D}}\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\text{E}\\text{q}.\\:\\:\\:\\:2\\end{array}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003ewhere RfD stands for the reference dose in mg kg⁻¹ day⁻¹. An HQ greater than 1 indicates the potential for non-carcinogenic adverse health effects.\u003c/p\u003e \u003cp\u003eFurthermore, the Hazard Index (HI) was calculated to assess the cumulative risk posed by the combined effects of all metals present in the drinking water evaluated in this study: health.\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\begin{array}{ccc}\\text{H}\\text{a}\\text{z}\\text{a}\\text{r}\\text{d}\\:\\text{i}\\text{n}\\text{d}\\text{e}\\text{x}\\:\\left(\\text{H}\\text{I}\\right)\u0026amp;\\:=\u0026amp;\\:\\sum\\:_{\\text{i}=1}^{\\text{n}}\\text{H}\\text{Q}\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\text{E}\\text{q}.\\:3\\end{array}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003eAn HI value greater than 1 suggests a potential for negative impacts on human health.\u003c/p\u003e \u003cp\u003ePotential carcinogenic risks were evaluated using Eq.\u0026nbsp;4, following the methodology outlined by Giri and Singh (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). This equation provides a cumulative estimate of the likelihood that an individual will experience carcinogenic exposure throughout their lifetime and may develop cancer:\u003c/p\u003e\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$\\:\\begin{array}{ccc}\\text{C}\\text{a}\\text{n}\\text{c}\\text{e}\\text{r}\\:\\text{r}\\text{i}\\text{s}\\text{k}\\:\\left(\\text{C}\\text{R}\\right)\u0026amp;\\:=\u0026amp;\\:\\text{A}\\text{D}\\text{D}\\:\\times\\:\\text{C}\\text{S}\\text{F}\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\text{E}\\text{q}\\:4\\end{array}$$\u003c/div\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e \u003cp\u003eIn this context, CSF denotes the cancer slope factor. A CR value greater than 1.0 × 10⁻⁴ signifies a potential for carcinogenic effects.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Result and discussion","content":"\u003ch2\u003eMeasured Heavy Metal Levels in Groundwater Surrounding Ikhueniro and Otofure\u003c/h2\u003e\u003cp\u003eGroundwater contamination by heavy metals is a growing concern in many parts of the world, particularly in areas close to waste disposal sites (Li \u003cem\u003eet al\u003c/em\u003e., 2021). These contaminants, often carried by leachates from decomposing waste, can infiltrate groundwater (Magda \u003cem\u003eet al\u003c/em\u003e., 2015), posing significant health risks to local populations who rely on this resource for drinking, cooking, and farming (Ewim et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). This study provides an in-depth analysis of heavy metal concentrations in groundwater in residential areas near the Ikhueniro and Otofure dumpsites, two major waste disposal sites in Edo State, Nigeria. Data were collected during both the dry and wet seasons to examine the seasonal variability in contamination levels, which is crucial for understanding the temporal dynamics of groundwater pollution in tropical regions (Ayotunde \u003cem\u003eet al\u003c/em\u003e., 2014). The investigation focused on key heavy metals—lead (Pb), zinc (Zn), chromium (Cr), iron (Fe), nickel (Ni), and copper (Cu)—which are known to pose health and environmental risks when present in concentrations above permissible limits (Xie, et al., \u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e2023\u003c/span\u003e: Singh, et al., \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2022\u003c/span\u003e; Bai, \u003cem\u003eet al\u003c/em\u003e., 2022). These metals are often introduced into the environment through various anthropogenic activities, such as improper waste disposal (Kumar, et al., \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). At both Ikhueniro and Otofure, groundwater samples were analyzed to determine the mean concentrations of these heavy metals and assess their potential risks to human health.\u003c/p\u003e\u003cp\u003eThe results revealed a range of heavy metal concentrations, with significant variations between the two dumpsites and across seasons (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). At Ikhueniro, Pb concentrations varied between 0.0077 and 0.0363 mg/L, with a mean value of 0.0206 ± 0.0061 mg/L. In contrast, Otofure recorded Pb levels ranging from 0.002 to 0.020 mg/L, with a mean of 0.007 ± 0.0029 mg/L. Notably, the highest concentrations of Pb were observed during the rainy season at both sites, likely due to increased leaching of metals from the dumpsites into the groundwater system as a result of heavy rainfall and the subsequent percolation of surface water. The elevated Pb levels are concerning, as lead is a known neurotoxin and carcinogen (Collin et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), with the ability to cause severe health problems, especially in children, who are more susceptible to its toxic effects. (Ara and Usmani, 2015)\u003c/p\u003e\u003cp\u003eSimilarly, zinc (Zn) concentrations at Ikhueniro ranged from 0.147 to 1.2567 mg/L, with an average of 0.0206 ± 0.0061 mg/L, while at Otofure, Zn values were between 0.02167 and 0.2800 mg/L, with an average of 0.0071 ± 0.0029 mg/L. Though zinc is an essential micronutrient required for various physiological functions (Saper and Rash, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2009\u003c/span\u003e), excessive exposure to Zn through contaminated water can lead to adverse health effects, such as nausea, vomiting, and immune system dysfunction, especially when coupled with the intake of other heavy metals. (Jaishankar et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2014\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eChromium (Cr) levels presented a more complex picture, with Ikhueniro showing concentrations between 0.0147 and 0.0823 mg/L, while Otofure recorded a broader range of 0.013 to 0.467 mg/L. Chromium, especially in its hexavalent form (Cr (VI)), is classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC) (Wise et al., \u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Prolonged exposure to Cr(VI) can result in severe health effects, including lung cancer, skin ulcers, and reproductive harm (Ellen \u003cem\u003eet al.\u003c/em\u003e, 2022). In this study, the Cr concentrations at Otofure exceeded the World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ) permissible limit of 0.05 mg/L, highlighting a pressing need for intervention in the affected areas.\u003c/p\u003e\u003cp\u003eIron (Fe) concentrations were also notably high at Ikhueniro, ranging from 0.6253 to 1.7437 mg/L, with a mean of 1.0504 ± 0.1869 mg/L, compared to lower levels at Otofure, where concentrations varied between 0.0253 and 0.6195 mg/L. The mean Fe concentration at Ikhueniro significantly exceeded the NSDWQ permissible limit of 0.3 mg/L for drinking water. While iron is a vital element for human health, playing a key role in oxygen transport and enzyme function (Abbaspour et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), excessive iron intake can lead to iron overload disorders, such as hemochromatosis, which can cause organ damage (Abbaspour et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Moreover, elevated iron levels in water may promote the growth of iron-oxidizing bacteria, leading to the clogging of wells and pipes, further complicating access to clean water. (Beimeng et al., \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2015\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eNickel (Ni) concentrations, though lower compared to other metals, were still of concern, particularly at Ikhueniro, where levels ranged from 0.0117 to 0.09867 mg/L. Otofure recorded lower Ni levels, ranging from 0.01533 to 0.039 mg/L. Nickel exposure, even at low levels, has been associated with respiratory problems (Wenchao \u003cem\u003eet al.\u003c/em\u003e, 2024), skin irritations, and in some cases, cancer. Additionally, recent studies have linked nickel to reproductive and developmental toxicity, (Genchi, et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). further underscoring the risks posed by nickel-contaminated groundwater.\u003c/p\u003e\u003cp\u003eCopper (Cu) levels were generally within permissible limits, with Ikhueniro showing a range of 0.016 to 0.6587 mg/L and Otofure recording values between 0.0137 and 0.12067 mg/L. However, prolonged exposure to copper-contaminated water, even at levels within regulatory limits, can lead to gastrointestinal distress, liver damage, and anemia, especially in populations with preexisting health conditions. (National Research Council (US) 2000)\u003c/p\u003e\u003cp\u003eStatistical analysis of the data revealed significant differences in Pb and Fe concentrations between the two dumpsites, with Ikhueniro showing higher levels of contamination compared to Otofure (P \u0026lt; 0.05). This suggests that the Ikhueniro dumpsite may be contributing more heavily to groundwater contamination, potentially due to differences in waste composition, volume, or management practices at the two sites. Comparisons with other studies support this finding; for instance, Saheed et al. (\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) reported Pb levels between 0.01 and 0.02 mg/L near refuse dumps in Ibadan, while Ogunrinola et al. (\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) observed much higher Pb concentrations (0.08–1.20 mg/L) in groundwater near the Igando dumpsite in Lagos. The elevated Pb levels reported in this study, though lower than those found in some other regions, still pose significant health risks to residents, particularly children, who are more vulnerable to lead exposure due to higher absorption rates. (Collin et al., \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2022\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eIn addition to lead, iron concentrations at Ikhueniro were significantly above the permissible limits, a finding consistent with previous studies in the region. Uroupa and Ogbeibu (\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) reported similar elevated Fe levels in groundwater near dumpsites in Benin City, while even more extreme Fe concentrations (10.885–25.612 mg/L) have been recorded at the Kumasi dumpsite in Ghana (Boateng et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). The presence of iron in such high concentrations not only raises concerns about iron toxicity but also indicates the potential for broader contamination, as iron is often associated with other heavy metals in polluted groundwater. For instance, studies in Pakistan have demonstrated that groundwater contaminated with iron often contains elevated levels of other harmful metals like arsenic and lead, raising significant concerns for human health and environmental safety​ (Ullah et al., \u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e2022\u003c/span\u003e)\u003c/p\u003e\u003cp\u003eThe health implications of heavy metal contamination in groundwater are profound (Kwakye et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Lead exposure has been linked to a wide range of health problems, including carcinogenic effects, cognitive impairments, and developmental delays in children (Olufemi et al., \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). In adults, lead can cause hypertension, kidney damage, and reduced fertility (Maslekar et al., \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Iron toxicity, though less common, can lead to gastrointestinal issues and developmental problems, particularly in children Eid et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). The presence of chromium, a known carcinogen, in concentrations exceeding safe limits is particularly alarming, as prolonged exposure to Cr(VI) can increase the risk of cancer and other serious health conditions (Shin et al., \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe elevated levels of heavy metals in groundwater near the Ikhueniro and Otofure dumpsites can largely be attributed to leachates from the waste, which carry contaminants from the dumpsites into the surrounding environment. Anthropogenic activities, including industrial waste disposal and the use of heavy metal-containing products, further contribute to groundwater pollution. The seasonal variation in contamination levels observed in this study suggests that rainfall plays a significant role in the mobilization and transport of contaminants from the dumpsites into the groundwater system.\u003c/p\u003e\u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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=\"char\" char=\".\" 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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\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\u003eHeavy metal concentrations (mg/L) in groundwater samples from Ikhueniro and Otofure\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"9\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eParameters\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLocations\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSeason\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSD\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMax\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eMin\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eNSDWQ boundary\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePb\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.021\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.030\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.01*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.020\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.036\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.01*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.007\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.018\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.007\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.020\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZn\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.300\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.096\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.491\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.147\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.665\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.384\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.257\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.254\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.106\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.049\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.189\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.023\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.192\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.051\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.280\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.134\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e3.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCd\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eBDL\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCr\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.029\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.023\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.082\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.024\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.071\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.058\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.129\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.467\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.05*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.044\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.035\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.101\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFe\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.065\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.340\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.744\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.625\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.3*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.036\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.137\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.230\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.763\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.3*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.486\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.161\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.619\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.025\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.3*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.536\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.595\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.473\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.3*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNi\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.028\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.023\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.099\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.02*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.019\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.028\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.012\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.027\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.039\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.02*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.024\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.029\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.020\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.02*\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCu\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.532\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.055\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.659\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.460\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.334\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.219\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.534\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWet\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.031\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.029\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.121\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.020\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1.0\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"9\"\u003eSD – Standard deviation, Min – Minimum, Max – Maximum, NSDWQ – Nigerian Standard for Drinking Water Quality. Superscript with the same letter down the column are not significantly different (p \u0026lt; 0.05). * Indicates levels higher than the permissible limit\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003ch2\u003eAverage Daily Dose (ADD) Calculation and Exposure Risk\u003c/h2\u003e\u003cp\u003eThe Average Daily Dose (ADD) were calculated for different age groups (adults, children, and infants) across the Ikhueniro and Otofure dumpsites (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). These estimations allow for an understanding of the level of exposure to heavy metals such as Fe, Zn, and Cu. In Ikhueniro, the ADD values calculated for adults with an assumed body weight of 60 kg showed that prolonged exposure to Fe, Zn, and Cu via ingestion resulted in average daily doses of 3.50E-02, 1.61E-02, and 1.44E-02 mg-1kg-1day-1 bodyweight, respectively. In comparison, children weighing 10 kg exposed to the same concentrations over a six-year period had significantly higher exposure doses of 1.05E-01, 4.83E-02, and 4.33E-02 mg-1kg-1day-1, while infants showed the highest exposure dose, with values reaching 1.58E-01, 7.25E-02, and 6.49E-02 mg-1kg-1day-1 for Fe, Zn, and Cu, respectively.\u003c/p\u003e\u003cp\u003eThis pattern of elevated exposure doses in children and infants compared to adults is consistent with findings in similar studies globally. For instance, in Iran, Alidadi et al. (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) conducted a comprehensive study in northeast Iran, where children were found to have three times higher exposure to heavy metals from drinking water compared to adults. This disparity was largely attributed to children's smaller body sizes and higher consumption of water relative to their body weight. These results align with the findings in the present study, which show a significantly higher hazard quotient (HQ) and average daily dose (ADD) for children and infants at both dumpsites. Similarly, in Uganda, Bamuwamye et al. (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) reported that children were twice as exposed to heavy metals through the ingestion of contaminated water as adults. Their research demonstrated that younger populations in regions with inadequate waste management and poor water quality face heightened risks of heavy metal toxicity, particularly from metals like lead and copper. The Ugandan context reflects the situation observed in this study, where higher HQ and ADD values for children were noted across both the Ikhueniro and Otofure sites. In China, Khandare et al. (\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) found that the risk for children from heavy metal exposure through groundwater consumption was twice as high as for adults. The study emphasized that developing countries often experience groundwater contamination as a result of industrial and domestic waste, creating disproportionate health risks for younger populations. This mirrors the pattern observed in the current study, where children and infants are at greater risk, particularly from Fe, Zn, and Cu. Additionally, India has reported similar findings. Ji et al. (2020) noted that children’s exposure to hazardous metals, such as lead and chromium, was 2.5 times higher than that of adults, mainly due to their increased water consumption in proportion to their body mass. The cumulative exposure to heavy metals in drinking water, leading to chronic health effects, was a key concern in the Indian study, reinforcing the global relevance of the present research’s conclusions. Lastly, a Nigerian study by Ojekunle et al. (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) in Ogun State found that children exposed to groundwater near poorly managed dumpsites were three times more likely to ingest dangerous levels of heavy metals than adults. This is consistent with the findings in both Ikhueniro and Otofure, where the calculated health risks were substantially higher for younger populations, particularly infants.\u003c/p\u003e\u003ch2\u003eNon-Carcinogenic Health Risk Assessment (HQ and HI)\u003c/h2\u003e\u003cp\u003eTo assess the non-carcinogenic health risk, Hazard Quotients (HQ) and Hazard Index (HI) values were calculated for the heavy metals found in groundwater samples from both sites (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). For each age group, exposure to metals through ingestion was analyzed, and results showed concerning HQ values for certain metals, particularly in younger age groups. At the Ikhueniro site, HQ values for Cu (1.08 and 1.62) in children and adults, and Cr (1.31) in infants exceeded the acceptable threshold of 1.0, indicating significant non-carcinogenic health risks. Similarly, at the Otofure site, HQ for Cr was elevated in children (1.69) and infants (2.12), further indicating a risk of adverse health effects for these age groups. The metals Zn, Fe, and Pb, however, recorded HQ values less than 1, signifying a lower risk of non-carcinogenic harm. Comparatively, the findings align with Custodio et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2020\u003c/span\u003e), who demonstrated heightened vulnerability of children to the non-carcinogenic effects of heavy metals. This vulnerability is supported by similar investigations, such as Bello et al. (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), which found higher HQ values in children compared to adults in their study on groundwater contamination in Nigeria. Furthermore, the HI values computed for cumulative exposure to multiple metals in children and infants exceeded 1, pointing to a compounding non-carcinogenic risk in these vulnerable groups. This is consistent with studies by Ojekunle et al. (\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), where HI values were significantly higher in children, indicating a potential for adverse health effects from multi-metal exposure.\u003c/p\u003e\u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\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\u003eThe Non-carcinogenic values in groundwater at Ikhueniro and Otofure dumpsite area.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetal (mg/L)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRFD\u003c/p\u003e \u003cp\u003e(Mg/kg/day)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eSf\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eADD\u003c/p\u003e \u003cp\u003eAdult\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eADD\u003c/p\u003e \u003cp\u003eChildren\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eADD\u003c/p\u003e \u003cp\u003eInfant\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cp\u003eIkhueniro\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCopper\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0257\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.44E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.33E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6.49E-02\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIron\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.5110\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.50E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.05E-01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.58E-01\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZinc\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.1491\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.61E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.83E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.25E-02\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLead\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0071\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0035\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.085\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.85E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.06E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.08E-03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChromium\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0508\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.70E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.61E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.92E-03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNickel\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0254\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.84E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.35E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.53E-03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"7\" nameend=\"c7\" namest=\"c1\"\u003e \u003cp\u003eOtofure\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCopper\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0257\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.55E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.03E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.21E-03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIron\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.5110\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.70E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.04E-02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6.39E-02\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZinc\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.1491\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.97E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.96E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.86E-02\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLead\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0071\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.0035\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.085\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.37E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.84E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8.89E-04\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChromium\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0508\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.69E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.03E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6.35E-03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNickel\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.0254\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.47E-04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.02E-03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.18E-03\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e\u003ch2\u003eCancer Risk (CR) Estimates for Pb, Ni, and Cr\u003c/h2\u003e\u003cp\u003eThe cancer risk (CR) associated with the ingestion of Pb, Ni, and Cr was evaluated for all age groups (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). The results showed elevated risks, particularly for children and infants, which surpass the USEPA’s accepted risk threshold of 1.0 x 10\u003csup\u003e− 4\u003c/sup\u003e for lifetime cancer risk. At Ikhueniro, the CR for Pb exposure in infants was particularly alarming at 2.62 x 10\u003csup\u003e− 4\u003c/sup\u003e, significantly exceeding the permissible limit. Similarly, the CR values for Cr and Ni across all age groups were also high, with infants showing the greatest risk—Cr at 1.96 x 10\u003csup\u003e− 3\u003c/sup\u003e and Ni at 3.21 x 10\u003csup\u003e− 3\u003c/sup\u003e. The Otofure site mirrored this trend, with CR values for Cr and Ni for infants surpassing the threshold at 2.67 x 10\u003csup\u003e− 3\u003c/sup\u003e and 2.89 x 10\u003csup\u003e− 3\u003c/sup\u003e, respectively. These findings are supported by similar studies conducted in other regions of Nigeria. Ugwu et al. (\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2022\u003c/span\u003e), in their study on groundwater contamination in Southeast Nigeria, observed similarly high cancer risk values. Raman and Haruna (2019) also reported elevated CR values for heavy metals in North-Central Nigeria, reinforcing the conclusions drawn from the current study that certain populations, especially children and infants, are at heightened risk. The primary contributor to the cancer risk in this study was found to be Ni, accounting for 62% and 52% of the total CR in Ikhueniro and Otofure, respectively. This highlights the urgent need for mitigation strategies to reduce nickel contamination in groundwater, particularly near vulnerable populations.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study has brought to light significant insights on groundwater contamination near the Ikhueniro and Otofure dumpsites in Edo State, Nigeria, showing just how much heavy metal pollution in water sources can impact nearby communities. By testing groundwater samples from these areas, both in the dry and rainy seasons, we found concerningly high levels of metals like lead (Pb), zinc (Zn), chromium (Cr), iron (Fe), nickel (Ni), and copper (Cu). The results often surpassed recommended safety limits, revealing how seasonal changes, especially during the rains, can increase the risk of contaminants seeping into groundwater.\u003c/p\u003e \u003cp\u003eOne particularly worrisome finding is the high lead levels, especially during the rainy season, as lead is known to be especially harmful to children, affecting cognitive development and overall health. This aligns with broader research that shows how waste sites often leak metals into water sources (e.g., Li et al., 2021; Ewim et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Besides lead, we observed notable amounts of zinc and chromium, both of which have been linked to immune and reproductive health risks (Saper and Rash, \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Iron levels in particular stood out at Ikhueniro, with the average concentrations much higher than recommended by the World Health Organization (WHO). Although iron is essential for health, too much of it can damage organs, causing long-term health problems and even clogging water systems over time (Abbaspour et al., \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThese findings are a clear call to action. To protect these communities, local and national governments need to improve waste management practices, monitor water quality more closely, and ensure residents have access to safe water sources. Immediate action and robust policies could help prevent further contamination, especially since communities near these sites heavily rely on groundwater for daily use.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eDeclaration of competing interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no known competing interest\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOsaro Charming Asemota: Conceptualization, data collection, manuscript drafting. Alex Enuneku: Laboratory analysis, data interpretation, manuscript review. Isioma Tongo: Literature review, manuscript preparation. Lawrence Ikechuchukwu Ezemonye: Supervision, project funding, final manuscript approval.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data generated or analyzed during this study are included in this published article and its supplementary information files\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWe gratefully acknowledge the Laboratory for Ecotoxicology and Environmental Forensics at the University of Benin, Benin City, for providing the facilities and resources that were essential for our analyses. We extend our sincere appreciation to Mr. Timothy Agho, the technologist, for his invaluable technical support and assistance in sample processing. We are especially grateful for the generous provision of laboratory services at no cost, which greatly facilitated this research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAbanyie, S.K., Apea, O.B., Abagale, S.A., Yahans E.B., Amuah, E.E.Y and Sunkari, E.D. (2023) Sources and factors influencing groundwater quality and associated health implications: A review, \u003cem\u003eEmerging Contaminants\u003c/em\u003e, 9:(2)1-12\u003c/li\u003e\n\u003cli\u003eAbbaspour, N., Hurrell, R. and Kelishadi R. (2014). Review on iron and its importance for human health. \u003cem\u003eJ Res Med Sci\u003c/em\u003e., 19(2):164-74.\u003c/li\u003e\n\u003cli\u003eAbbaspour, N., Hurrell, R. and Kelishadi, R. (2014). Review on iron and its importance for human health. \u003cem\u003eJournal of research in medical sciences\u003c/em\u003e: the official journal of Isfahan University of Medical Sciences, 19(2), 164\u0026ndash;174.\u003c/li\u003e\n\u003cli\u003eAbubakar, I. R., Maniruzzaman, K. M., Dano, U. L., AlShihri, F. S., AlShammari, M. S., Ahmed, S. M. S., Al-Gehlani, W. A. G., and Alrawaf, T. I. (2022). Environmental Sustainability Impacts of Solid Waste Management Practices in the Global South. \u003cem\u003eInternational journal of environmental research and public health\u003c/em\u003e, 19(19):1-26\u003c/li\u003e\n\u003cli\u003eAdeyemi, A and Ojekunle, Z.O (2021) Concentrations and health risk assessment of industrial heavy metals pollution in groundwater in Ogun state, \u003cem\u003eNigeria Scientific African\u003c/em\u003e 11:1-11\u003c/li\u003e\n\u003cli\u003eAgency for Toxic Substances and Disease Registry (2012) Toxi Heavy metal pollution in the environment and their toxicological effects on humans cological profile for Chromium. Agency for Toxic Substances and Disease Registry Division of Toxicology and Human Health Sciences (proposed) Environmental Toxicology Branch (proposed) 1600 Clifton Road NE Mailstop F-62 Atlanta, Georgia 30333\u003c/li\u003e\n\u003cli\u003eAkujieze, C.N and Oteze, G.E (2007). Deteriorating Quality of Groundwater in Benin City, Edo State, Nigeria. \u003cem\u003eJournal of Nigeria Association of Hydrogeologists,\u003c/em\u003e 1: 192-196\u003c/li\u003e\n\u003cli\u003eAlidadi, H., Belin, S., Sany, T., Zarif, B., Oftadeh, G., Mohamad, T., Shamszade, H. and Fakhari, M. (2019) Health risk assessments of arsenic and toxic heavy metal exposure in drinking water in northeast Iran \u003cem\u003eEnvironmental Health and Preventive Medicine, \u003c/em\u003e24:(59)1-17\u003c/li\u003e\n\u003cli\u003eAnyachor, C.P., Dooka, D.B., Orish, C.N., Amadi, C.N., Bocca, B., Ruggieri, F., Frazzoli, C.F and Orisakwe, O.E. (2022) Mechanistic considerations and biomarkers level in nickel-induced neurodegenerative diseases: An updated systematic review, \u003cem\u003eIBRO Neuroscience Reports\u003c/em\u003e, 13:136-146,\u003c/li\u003e\n\u003cli\u003eAPHA (2005). Standard Methods for the Examination of Water and Wastewater. 21st Edition, American Public Health Association/American Water Works Association/Water Environment Federation, Washington\u003c/li\u003e\n\u003cli\u003eWani, A.L., Ara, A. and Usmani, J.A. (2015). Lead toxicity: a review. \u003cem\u003eInterdiscip Toxicol.\u003c/em\u003e 8(2):55-64\u003c/li\u003e\n\u003cli\u003eEtchie, A.T., Etchie, T.O., Adewuyi, G.O., Kannan, K., Wate, S.R., Sivanesan, S. and Chukwu A.U. (2014). Influence of seasonal variation on water quality in tropical water distribution system: is the disease burden significant? \u003cem\u003eWater Research\u003c/em\u003e, 49:186-196, ISSN 0043-1354,\u003c/li\u003e\n\u003cli\u003eXu, Z., Shi, M., Yu, X., and Liu, M. (2022). Heavy Metal Pollution and Health Risk Assessment of Vegetable-Soil Systems of Facilities Irrigated with Wastewater in Northern China. \u003cem\u003eInternational journal of environmental research and public health\u003c/em\u003e, 19(16):1-15. https://doi.org/10.3390/\u003c/li\u003e\n\u003cli\u003eBalogun, T.F. and Onokerhoraya, A.G (2017). Spatio-Temporal Growth of Benin City, Nigeria, and Its Implications for Access to Infrastructure. \u003cem\u003eJournal of Geography and Geology\u003c/em\u003e, 9(2):11-23\u003c/li\u003e\n\u003cli\u003eBamuwamye, M., Ogwok, P., Tumuhairwe, V., Eragu, R., Nakisozi, H. and Ogwang, P.E. (2017) Human Health Risk Assessment of Heavy Metals in Kampala (Uganda) Drinking Water. \u003cem\u003eJournal of Food Research\u003c/em\u003e, 6:(4)6-16\u003c/li\u003e\n\u003cli\u003eBeimeng, Q.I., Chongwei, C. and Yixing, Y. (2015) Effects of iron bacteria on cast iron pipe corrosion and water quality in water distribution systems. \u003cem\u003eInternational Journal of Electrochemical Science\u003c/em\u003e. 10:545\u0026ndash;558.\u003c/li\u003e\n\u003cli\u003eBello, S., Nasiru, R., Garba, N.N. and Adeyemo, D.J. (2019) Carcinogenic and non-carcinogenic health risk assessment of heavy metals exposure from Shanono and Bagwai artisanal gold mines, Kano state, Nigeria. \u003cem\u003eScientific African\u003c/em\u003e, 6:1-6\u003c/li\u003e\n\u003cli\u003eBoateng, T.K., Opoku, F. and Akoto, O. (2019) Heavy metal contamination assessment of groundwater quality: a case study of Oti landfill site, Kumasi. \u003cem\u003eApplied Water Science\u003c/em\u003e 9:(33)1-15\u003c/li\u003e\n\u003cli\u003eBodrud-Doza, M.D., Didar-Ul Islam, S.M., Rume, T., Quraishi, S.B., Rahman, M.S. and Bhuiyan M.A. (2020) Groundwater quality and human health risk assessment for safe and sustainable water supply of Dhaka City dwellers in Bangladesh. \u003cem\u003eGroundwater for Sustainable Development,\u003c/em\u003e 10(3):1-12\u003c/li\u003e\n\u003cli\u003eBriffa, J., Sinagra, E. and Blundell, R. (2020). Heavy metal pollution in the environment and their toxicological effects on humans, \u003cem\u003eHeliyon\u003c/em\u003e, 6(9):1-26. \u003c/li\u003e\n\u003cli\u003eCarrard, N., Foster, T., Willetts, J. (2019). Groundwater as a Source of Drinking Water in Southeast Asia and the Pacific: A Multi-Country Review of Current Reliance and Resource Concerns. \u003cem\u003eWater,\u003c/em\u003e 11(8):1605. https://doi.org/10.3390/w11081605\u003c/li\u003e\n\u003cli\u003eCirella, G. T., Iyalomhe, F. O. and Adekola, P. O. (2019). Determinants of flooding and strategies for mitigation: Two-year case study of Benin city. \u003cem\u003eGeosciences\u003c/em\u003e, 9(3), 136.\u003c/li\u003e\n\u003cli\u003eCollin, M.S., Venkatraman, S.K., Vijayakumar, N., Kanimozhi, V., Arbaaz, S. M., Sibiya, S. R. G., Anusha, J., Choudhary, R., Lvov, V., Tovar, G.I., Senatov, F., Koppala, S. and Swamiappan, S. (2022) Bioaccumulation of lead (Pb) and its effects on human: A review, \u003cem\u003eJournal of Hazardous Materials Advances, \u003c/em\u003e7:2772-4166.\u003c/li\u003e\n\u003cli\u003eCollin, M.S., Venkatraman, S.K. Vijayakumar, N., Kanimozhi, V., Arbaaz, S.M., Sibiya, R.G, Anusha, J., Choudhary, R., Lvov, V., Tovar, G.I, Senatov, F., Koppala, S. and Swamiappan, S. (2022) Bioaccumulation of lead (Pb) and its effects on human: A review, Journal of Hazardous Materials Advances, 7:2772-4166,\u003c/li\u003e\n\u003cli\u003eCustodio, M., Cuadrado, W., and Penaloza R. (2020). Human Risk from Exposure to Heavy Metals and Arsenic in Water from Rivers with Mining Influence in the Central Andes of Peru. \u003cem\u003eWater\u003c/em\u003e. 12(7):1946.\u003c/li\u003e\n\u003cli\u003eEid, R., Arab, N. T., and Greenwood, M. T. (2017). Iron mediated toxicity and programmed cell death: A review and a re-examination of existing paradigms. Biochimica et biophysica acta. Molecular cell research, 1864(2), 399\u0026ndash;430. https://doi.org/10.1016/j.bbamcr.2016.12.002\u003c/li\u003e\n\u003cli\u003eHessel, E. V. S., Staal, Y. C. M., Piersma, A. H., den Braver-Sewradj, S. P., and Ezendam, J. (2021). Occupational exposure to hexavalent chromium. Part I. Hazard assessment of non-cancer health effects. \u003cem\u003eRegulatory toxicology and pharmacology\u003c/em\u003e: RTP, 126, 105048. https://doi.org/10.1016/j.yrtph.2021.105048\u003c/li\u003e\n\u003cli\u003eEni, D.V., J.Obiefuna., C. Oko., and I. Ekwok. (2011). Impact of urbanization on sub-surface water quality in Calabar municipalty, Nigeria. \u003cem\u003eInternational Journal of Humanities and Social Sciences\u003c/em\u003e, 1(10):167-172.\u003c/li\u003e\n\u003cli\u003eEnitan, I.T., Enitan, A.M., Odiyo, J.O. and Alhassan, M.M (2018) Human Health Risk Assessment of Trace Metals in Surface Water Due to Leachate from the Municipal Dumpsite by Pollution Index: A Case Study from Ndawuse River, Abuja, Nigeria. \u003cem\u003eChem\u003c/em\u003e., 16: 214\u0026ndash;227\u003c/li\u003e\n\u003cli\u003eEwim, D.R.E., Orikpete, O.F., Scott, T.O. (2023). Survey of wastewater issues due to oil spills and pollution in the Niger Delta area of Nigeria: a secondary data analysis. \u003cem\u003eBull. Nat. Res. Cent\u003c/em\u003e. 47, 116 (2023). https://doi.org/10.1186/s42269-023-01090-1\u003c/li\u003e\n\u003cli\u003eGenchi, G., Carocci, A., Lauria, G., Sinicropi, M. S. and Catalano, A. (2020). Nickel: Human Health and Environmental Toxicology. \u003cem\u003eInternational journal of environmental research and public health\u003c/em\u003e, 17(3), 679. https://doi.org/10.3390/ijerph17030679\u003c/li\u003e\n\u003cli\u003eGiri, S. and Singh, A.K. (2015). Human health risk assessment via drinking water pathway due to metal contamination in the groundwater of Subarnarekha River Basin, India. \u003cem\u003eEnviron. Monit. Assess.\u003c/em\u003e 187:(63)\u003c/li\u003e\n\u003cli\u003eIdugboe, S.O., Tawari-Fufeyin, P. (2014) Soil pollution in two auto-mechanic villages in Benin City, \u003cem\u003eNigeria. Journal of Environmental Science, Toxicology and Food Technology \u003c/em\u003e8(1): 9-14.\u003c/li\u003e\n\u003cli\u003eJaishankar, M., Tseten, T., Anbalagan, N., Mathew, B. B. and Beeregowda, K. N. (2014). Toxicity, mechanism and health effects of some heavy metals. Interdisciplinary toxicology, 7(2), 60\u0026ndash;72. https://doi.org/10.2478/intox-2014-0009\u003c/li\u003e\n\u003cli\u003eKhandare, A.L., Validandi, V., Rajendran, A., Singh, T.G., Thingnganing, L., Kurella, S., Nagaraju, R., Dheeravath, S., Vaddi, N., Kommu, S. and Maddela, Y. (2020). Health risk assessment of heavy metals and strontium in groundwater used for drinking and cooking in 58 villages of Prakasam district, Andhra Pradesh, India\u003cem\u003e Environ Geochem Health\u003c/em\u003e \u003cstrong\u003e42\u003c/strong\u003e, 3675\u0026ndash;3701\u003c/li\u003e\n\u003cli\u003eKolawole, T.O., Iyiola, O., Ibrahim, H., and Isibor, R.A. (2023) Contamination, ecological and health risk assessments of potentially toxic elements in soil around a municipal solid waste disposal facility in Southwestern Nigeria, \u003cem\u003eJournal of Trace Elements and Minerals\u003c/em\u003e, 5:1-9\u003c/li\u003e\n\u003cli\u003eKumar, V., Kumar, S. T., Kumar, K and Parmar, R.S. (2023) Heavy Metal-Induced Pollution in the Environment through Waste Disposal. \u003cem\u003eInternational Journal of Research Publication and Reviews\u003c/em\u003e, 4(7):1205-1210 ff\u003c/li\u003e\n\u003cli\u003eKwakye, S.O., Amuah, E.B.Y., Ankoma, K.A., Agyemang, E.B. and Owusu, B. (2024). Understanding the performance and challenges of solid waste management in an emerging megacity: Insights from the developing world, \u003cem\u003eEnvironmental Challenges\u003c/em\u003e, 14:1-9,\u003c/li\u003e\n\u003cli\u003eLi, H., Chen, Q., Li, S., Yao, W., Li, L., Shi, X., Wang, L., Castranova, V., Vallyathan, V. and Ernst, E. (2001). Effect of Cr (VI) Exposure on Sperm Quality: Human and Animal Studies. \u003cem\u003eAnn. Occup. Hyg\u003c/em\u003e. 45:505\u0026ndash;511.\u003c/li\u003e\n\u003cli\u003eAbd El-Salam M.M. and Abu-Zuid G.S. (2015). Impact of landfill leachate on the groundwater quality: A case study in Egypt, \u003cem\u003eJournal of Advanced Research\u003c/em\u003e, 6(4)579-586,\u003c/li\u003e\n\u003cli\u003eMaslekar, A., Kumar, A., Krishnamurthy, V., Kulkarni, A. and Reddy, M. (2022). Association Between Blood Lead Levels and Hypertension in a South Indian Population: A Case-Control Study. \u003cem\u003eCureus\u003c/em\u003e. 16;14(2):e22277. doi: 10.7759/cureus.22277. PMID: 35350484; PMCID: PMC8932219.\u003c/li\u003e\n\u003cli\u003eMitra, S., Chakraborty, A.J., Tareq, A.M., Emran, T.B., Nainu, F., Khusro, K., Idris, A.M., Khandaker, M.U., Osman, H., Alhumaydhi, F.A. and Simal-Gandara, J. (2022). Impact of heavy metals on the environment and human health: Novel therapeutic insights to counter the toxicity, \u003cem\u003eJournal of King Saud University - Science\u003c/em\u003e, 34(3):1.21\u003c/li\u003e\n\u003cli\u003eNSDWQ, (2007). Nigerian Standard for Drinking Water Quality. Nigerian Industrial Standard NIS 554, Standard Organization of Nigeria, Pp30.\u003c/li\u003e\n\u003cli\u003eOboshenure, K. K. and Airen, O.J. (2021). Aquifer vulnerability assessment using Dar-Zarrouk parameter: A case study of Otofure and Ikhueniro dumpsites, Benin-city, South-South Nigeria. \u003cem\u003eAustralian Journal of Science and Technology. \u003c/em\u003e5:((1):422-433\u003c/li\u003e\n\u003cli\u003eOgunrinola, O., Joshua, O. and Elemo, B. (2021). Heavy Metals Concentration in Underground Water and its Environmental Health Effects: A Case Study of Solous Dumpsite, Igando, Lagos. \u003cem\u003eJournal of Research and Review in Science,\u003c/em\u003e 8(1): 40-46.\u003c/li\u003e\n\u003cli\u003eOjekunle, O.Z., Rasaki, A., Taiwo, A.M., Adegoke, K.A., Balogun, M.A., Ojekunle, O.O., Anumah, A.O., Ibrahim, A.O. and Adeyemi, A.A., (2022) Health risk assessment of heavy metals in drinking water leaching through improperly managed dumpsite waste in Kurata, Ijoko, Sango area of Ogun State, Nigeria. \u003cem\u003eGroundwater for Sustainable Development\u003c/em\u003e. doi: https://doi.org/10.1016/\u003c/li\u003e\n\u003cli\u003eOlufemi, A.C., Mji, A. and Mukhola M.S. (2022). Potential Health Risks of Lead Exposure from Early Life through Later Life: Implications for Public Health Education. \u003cem\u003eInt. J. Environ. Res. Public. Health.\u003c/em\u003e 30:19(23):16006. doi: 10.3390/ijerph192316006. PMID: 36498077; PMCID: PMC9741093.\u003c/li\u003e\n\u003cli\u003eOrhorhoro, EK and Oghoghorie, O (2019). Review on Solid Waste Generation and Management in Sub-Saharan Africa: A Case Study of Nigeria. \u003cem\u003eJ. Appl. Sci. Environ. Manage. \u003c/em\u003e23(9):1729-1737 \u003c/li\u003e\n\u003cli\u003ePan, S., Lin, L., Zeng, F., Zhang, J., Dong, G., Yang, B., Jing, Y., Chen, S., Zhang, G., Yu, Z., Sheng, G., and Ma, H. (2018). Effects of lead, cadmium, arsenic, and mercury co-exposure on children\u0026rsquo;s intelligence quotient in an industrialized area of southern China, \u003cem\u003eEnviron. Pollut.\u003c/em\u003e 235:47\u0026ndash;54. \u003c/li\u003e\n\u003cli\u003eSaheed, I.O., Azeez, A.A., Jimoh, A.A., Obaro, V.A., Adepoju, S.A. (2020). Assessment of some heavy metals concentrations in soil and groundwater around refuse dumpsite in Ibadan metropolis, Nigeria. \u003cem\u003eNig. J. Technol\u003c/em\u003e. 39: 301\u0026ndash;305. \u003c/li\u003e\n\u003cli\u003eSaper, R. B. and Rash, R. (2009). Zinc: an essential micronutrient. \u003cem\u003eAmerican family physician\u003c/em\u003e, 79(9), 768\u0026ndash;772\u003c/li\u003e\n\u003cli\u003eShin, D. Y., Lee, S. M., Jang, Y., Lee, J., Lee, C. M., Cho, E. M. and Seo, Y. R. (2023). Adverse Human Health Effects of Chromium by Exposure Route: A Comprehensive Review Based on Toxicogenomic Approach. \u003cem\u003eInternational journal of molecular sciences\u003c/em\u003e, 24(4), 3410. https://doi.org/10.3390/ijms24043410\u003c/li\u003e\n\u003cli\u003eSingh, M., Singh, S. and Kumar, V. (2022). Heavy metal contamination and its hazardous impacts on soil, plant, human health, and aquifers: A review. \u003cem\u003eEnvironmental Quality Management\u003c/em\u003e, 32(1), 97-108.\u003c/li\u003e\n\u003cli\u003eTan, B.L., Norhaizan, M.E., Liew, W.P. and Rahman H.S. (2018) Antioxidant and Oxidative Stress: A Mutual Interplay in Age-Related Diseases. \u003cem\u003eFront Pharmacol.\u003c/em\u003e 16;9:1162. doi: 10.3389/fphar.2018.01162. PMID: 30405405; PMCID: PMC6204759.\u003c/li\u003e\n\u003cli\u003eUgwu, C.E., Maduka, I.C., Suru, S.M. and Anakwuo, I.A. (2022). Human health risk assessment of heavy metals in drinking water sources in three senatorial districts of Anambra State, Nigeria. \u003cem\u003eToxicology Reports\u003c/em\u003e, 9:869-875, ISSN 2214-7500\u003c/li\u003e\n\u003cli\u003eUllah, Z., Rashid, A., Ghani, J., Nawab, J., Zeng, X.C., Shah, M., Alrefaei, A.F., Kamel, M., Aleya, L., Abdel-Daim, M.M. and Iqbal, J. (2022). Groundwater contamination through potentially harmful metals and its implications in groundwater management. \u003cem\u003eFront. Environ. Sci.\u003c/em\u003e 10:1021596. doi: 10.3389/fenvs.2022.1021596\u003c/li\u003e\n\u003cli\u003eUroupa, R. E. and Ogbeibu, E. A. (2020) Impact of Solid Waste Dump-Sites on Groundwater Quality in Benin City, Nigeria. \u003cem\u003eAfrican Journal of Health, Safety and Environment\u003c/em\u003e, 1 (1): 38-63\u003c/li\u003e\n\u003cli\u003eUSEPA (1989). Risk assessment guidance for superfund. Volume I. Human health evaluation manual EPA/540/1-89/002. Ofce of solid waste and emergency response \u003c/li\u003e\n\u003cli\u003eUSEPA (2001) Baseline human health risk assessment Vasquez Boulevard and I-70 Superfund Site. Denver CO. U.S. Environmental Protection Agency. Assessed from http://www.epa.gov/region8/ uperfund/sites/VB-170-Risk.pdf\u003c/li\u003e\n\u003cli\u003eUSEPA (2004) Risk assessment guidance for superfund volume I: human health evaluation manual (part E). U.S. Environmental Protection Agency. http://www.epa.gov/oswer/riskassessment/ragse/pdf/introduction.pdf.\u003c/li\u003e\n\u003cli\u003eUSEPA (2011) United States Environmental Protection Agency\u0026rsquo;s risk assessment guidance for superfund. In: Part A: human health evaluation manual; part E, supplemental guidance for dermal risk assessment; part F, supplemental guidance for inhalation risk assessment, volume II. http://www.epa.gov/ oswer/ riskassessment /humanhealthexposure.htm\u003c/li\u003e\n\u003cli\u003eUSEPA, (1999). Risk assessment for multi way exposure spread sheet calculation tool. United States Environmental Protection Agency, Washington, DC\u003c/li\u003e\n\u003cli\u003eLi, W., Zhou, J., Boon, D., Fan, T., Anneser, E., Goodman, J.E., and Prueitt, R.L. (2024). Nickel in ambient particulate matter and respiratory or cardiovascular outcomes: A critical review, Environmental Pollution, 347: 123442, ISSN 0269-7491,\u003c/li\u003e\n\u003cli\u003eWHO. (2017). The cost of a polluted environment: 1.7 million child deaths a year, says WHO. Geneva: WHO. World Health Organization scs.2017.01.005.\u003c/li\u003e\n\u003cli\u003eWise, J. P., Jr, Young, J. L., Cai, J. and Cai, L. (2022). Current understanding of hexavalent chromium [Cr(VI)] neurotoxicity and new perspectives. \u003cem\u003eEnvironment international\u003c/em\u003e, 158, 106877. https://doi.org/10.1016/j.envint.2021.106877\u003c/li\u003e\n\u003cli\u003eWitkowska, D., Słowik, J., and Chilicka, K. (2021). Heavy Metals and Human Health: Possible Exposure Pathways and the Competition for Protein Binding Sites. Molecules (Basel, Switzerland), 26(19), 6060. https://doi.org/10.3390/molecules26196060\u003c/li\u003e\n\u003cli\u003eXie, Y., Wu, X. and Guo, F. (2023). Health risk assessment of heavy metal exposure in drinking water in mining areas of southwest China. Environmental Science and Pollution Research, 30(4), 4690-4701.\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":"discover-water","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"diwa","sideBox":"Learn more about [Discover Water](https://www.springer.com/43832)","snPcode":"","submissionUrl":"","title":"Discover Water","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Groundwater Contamination, Heavy Metals, Water Quality, Dumpsite Pollution, Health Risk Assessment.","lastPublishedDoi":"10.21203/rs.3.rs-5753074/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5753074/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eNigeria is experiencing a growing threat of groundwater pollution due to insufficient waste management practices. This study aimed to assess the levels of heavy metal contamination in groundwater near the Ikhueniro and Otofure dumpsites in Benin City, Edo State, Nigeria, and to evaluate the associated health risks. Water samples were collected from boreholes in residential areas surrounding both dumpsites during both the rainy and dry seasons, yielding 144 samples. These were analyzed for concentrations of lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), iron (Fe), nickel (Ni), and copper (Cu) using standard protocols. The results indicated that Fe, Cu, Zn, and Ni were the most prevalent metals, with Fe showing the highest concentrations at both sites. The hazard index (HI) and cancer risk (CR) calculations highlighted serious health risks, particularly for children and infants. Specifically, the cumulative cancer risk for Pb, Cr, and Ni exceeded internationally recognized safety limits, indicating a significant potential for long-term health impacts. The study concluded that the proximity to these dumpsites significantly deteriorates groundwater quality, emphasizing the need for stricter environmental controls and public health interventions.\u003c/p\u003e","manuscriptTitle":"Heavy Metal Contamination and Cancer Risk Assessment in Groundwater Near Dumpsites: Health Implications for Vulnerable Populations in Nigeria","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-01-15 12:25:44","doi":"10.21203/rs.3.rs-5753074/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-01-28T05:47:43+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-26T14:40:56+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-01-22T13:56:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"318428956283874666932657408075677578856","date":"2025-01-22T06:14:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"196291456684991390903947010907495227833","date":"2025-01-21T11:59:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"291399964646245698935464757218421171801","date":"2025-01-21T06:59:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"28027500422078460369708881505702332016","date":"2025-01-21T06:53:07+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"122089734553674289844768155969809886152","date":"2025-01-21T04:49:57+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"243467059819823426914544846344290441026","date":"2025-01-21T04:46:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"245370863094180841601528773107129344118","date":"2025-01-21T04:45:57+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-01-21T04:02:51+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-14T05:30:26+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-01-13T13:31:40+00:00","index":"","fulltext":""},{"type":"submitted","content":"Discover Water","date":"2025-01-02T15:53:30+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"discover-water","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"diwa","sideBox":"Learn more about [Discover Water](https://www.springer.com/43832)","snPcode":"","submissionUrl":"","title":"Discover Water","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Discover Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ceb3ca1f-38b8-4183-9b9c-759394c490c5","owner":[],"postedDate":"January 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-05-28T08:08:10+00:00","versionOfRecord":[],"versionCreatedAt":"2025-01-15 12:25:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5753074","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5753074","identity":"rs-5753074","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}