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This study quantified the concentrations of trace and heavy elements, including Al, K, Ca, Mg, Zr, Ti, La, Ce, Mn, Cr, Zn, and Nd, in soil samples from Tukwikwi. It also assesses the potential human health risks posed by exposure to these metals through ingestion, inhalation, and dermal absorption for both children and adults. The study area lies in Hadejia flood plain between latitudes 12°10′ N to 13°0′ N and longitudes 10°15′ E to 11°30′ E. The result showed that the mean concentrations of Al (47,140 mg/kg), K (23,110 mg/kg), Fe (18,020 mg/kg), Mg (7810 mg/kg), Zr (404 mg/kg), and La (64 mg/kg) exceeded the crustal values of Al (25,000 mg/kg), K (10,700 mg/kg), Fe (9800 mg/kg), Mg (7000 mg/kg), Zr (220 mg/kg), and La (30 mg/kg). By contrast, the concentrations of Ca, Cr, Ce, Mn, Ti, Zn, and Nd were lower than the crustal values. These crustal values were used, as there were no regional values that could be used for comparison. The result of the noncarcinogenic health risk assessment showed that Al exhibited the highest value ranging from 5.52×10−1$5.52 \times {{10}^{ - 1}}$ to 7.51×10−1$7.51 \times {{10}^{ - 1}}$ for children and 7.3×10−1$7.3 \times {{10}^{ - 1}}$ to 9.9×10−1$9.9 \times {{10}^{ - 1}}$ for adults. The results also revealed that adults have a higher potential risk than children. The results for the carcinogenic risk (CR) showed that the total CR (TCR) values for Cr ranged from 0 to 3.20×10−4$3.20 \times {{10}^{ - 4}}$ for children and 0 to 4.29×10−4$4.29 \times {{10}^{ - 4}}$ for adults, which are higher than the acceptable limit of 1×10−4$1 \times {{10}^{ - 4}}$. These suggest that there are health concerns for adults and children in the research area. This necessitates the need for monitoring the soil in the study area to reduce potential environmental issues. [ABSTRACT FROM AUTHOR]

The hydrosphere becomes contaminated secondarily by accumulated heavy metals in sediments which may be released into the aquatic environment, thereby increasing the risks to human health. To evaluate the pollution characteristics of heavy metals in surface water sediments of Ifite Ogwari, nine sediment samples were collected from surface water sources used by the residents for drinking and other household activities. The concentrations of eight heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), Iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) were analyzed using Atomic Absorption Spectroscopy (AAS). Enrichment Factor (EF), Contamination Factor (CF), Geoaccumulation index (Igeo), Potential Ecological Risk Index (PERI) and Risk Assessment Code (RAC) were conducted. Results of heavy metal concentration indicated that Cu < Cr < Ni < Pb < Cd < Zn < Mn < Fe based on the average metal concentration. Human health assessment showed high cancer risk for children and adults in a ratio of 1 in 10000 population. PERI indicated that sediment samples from Iyiutu and Ahala streams have low potential ecological risk while samples from Ube, Tabasi and Ogbu showed moderate ecological risk whereas samples from Isiachala, Nabaloku and Atammele streams as well as Omambala river sediments were high. RAC shows no ecological risk by Zn, Pb, Ni, Cu and Mn but in Omambala river, Cr and Cd contributed to ecological risk while Fe contributed to ecological risk in all the samples. Consequently, there is need for proper monitoring from health base evaluation and conscious effort to live in a clean environment devoid of any kind of exposure. [ABSTRACT FROM AUTHOR]

Rainwater is usually harvested through catchment systems such as roofs or directly from the sky for storage in different vessels for eventual use due to water scarcity which is as a result of increased in water demand, rapid industrialization, increasing pollution, global warming and climate change. This study was carried out to assess the effects of galvanized iron and PVC tanks, thatched roof and industrial activity on harvested rainwater quality by investigating physico-chemical properties, heavy metals, coliform level and metal composition of the storage vessels. Seven-two harvested rainwater samples were collected from four locations in the urban and rural areas of Delta and Enugu States, Nigeria between the months of April-July, 2018. Rainwater samples stored for 1 month to a year in storage vessels were considered. The results were compared with water quality standards (USEPA, WHO, NAFDAC and NSDWQ) and Water Quality Index ratings. Heavy metals (Pb, Fe, Cr, Zn and Al) were analyzed using Flame-AAS; other parameters were determined using standard methods. The WQI ratings were calculated using the weighted arithmetic method. The results were analysed using descriptive and two-way ANOVA statistical analysis. Results obtained in both areas of the States showed mean values ranging from 5.60 ± 0.28 to 7.60 ± 0.20 for pH, E.coli (0.00 ± 0.00–1.00 ± 0.00 cfu/mL), EC (7.00 ± 1.41–108.70 ± 8.62 µs/cm), colour (0.44 ± 0.01–12.86 ± 0.17 TCU) and heavy metals (mg/L) gave 0.00 ± 0.00–1.52 ± 0.13 for Fe, Pb (0.00 ± 0.00–0.29 ± 0.02), Cr (0.00 ± 0.00–0.30 ± 0.05), Zn (0.00 ± 0.00–0.05 ± 0.02) and Al (0.00 ± 0.00–4.65 ± 2.24). The results of the harvested rainwater samples analyzed showed that, the mean values of all the parameters analyzed were below and within the water quality set standard with the exception of a few in both areas in each of the States and were significantly different at (p < 0.05). The results of WQI ratings showed that, harvested rainwater qualities in both States were rated from excellent to unfit for drinking water quality. Generally, harvested rainwater stored in PVC tanks rated better than rainwater stored in galvanized iron tanks though not free of contamination. The storage duration for harvested rainwater is very important for its water quality, hence, harvested rainwater whether it is stored or not should be subjected to treatment before being use for potable usages. [ABSTRACT FROM AUTHOR]

This study examined heavy metals in some aquatic organisms [crabs (Callinectes amnicola), periwinkles (Tympanotonus fuscatus) and oysters (Crassostrea gasar)] from Eyaa Creek, Onne, in southern Nigeria. Samples were collected from four stations monthly for three months. Characterization of the environment was via physico-chemical properties, while heavy metal analysis was by Atomic Absorption Spectrometry. Physico-chemistry results indicated: temperature; 30.2 - 30.7oC; pH: 6.7 - 6.8; dissolved oxygen: 6.1 - 6.3 mg/l; electrical conductivity: 18.8 - 20. 8 mS/cm; total dissolved solids: 4698.5 - 6212.0 mg/l; salinity: 11.1 - 12.4 PSU and turbidity: 3.7 - 4.7 NTU. ANOVA showed insignificant difference (p>0.05) between stations indicating homogeneity of the area assessed. Mean metal concentrations (mg/kg) in the organisms were cadmium: 0.18 ± 0.09 - 0.60 ± 0.08; chromium: 0.41 ± 0.14 - 0.78 ± 0.08; iron: 12.1 ± 6.9 - 20.2 ± 7.7; lead: 0.31 ± 0.2 - 0.91 ± 0.05. Chromium and lead values were above permissible values of FAO/WHO and EU but cadmium fell within and above the limits. Principal component analysis did not show a clear pattern with organisms' feeding habit but discriminated based on metal concentrations. In conclusion metal concentration in periwinkles>crabs>oysters which was related to their feeding habits in terms of sediment and pelagic affiliations. [ABSTRACT FROM AUTHOR]

Heavy metal concentrations were determined in four different locations: market, abattoir, mechanic village and farmland in Obollo–Afor and its environs. The samples were digested and subsequently analysed using Atomic Absorption Spectrophotometer (AAS). The mean concentration of metals in the soil samples were in the order Fe > Zn > Mn > Cr > Pb > Cu > Ni > Cd. The mean concentration of metals in the effluent samples were in the order Fe > Cr > Ni > Pb > Zn > Mn > Cd > Cd. The mean concentration of the metals in meat samples were in the order Fe > Zn > Cu > Ni > Mn > Cd > Cr > Pb. The mean concentration of metals in the plant samples were in the order Fe > Mn > Zn > Cu > Ni > Cr > Pb > Cd. Cadmium, zinc, chromium and lead were higher than the World Health Organization (WHO) standard for soil while cadmium, copper and zinc were higher than the WHO standard for plant. Iron, zinc, copper, nickel and chromium were higher than the WHO standard for meat while lead, nickel, iron, were higher than the WHO standard for water. Heavy metal pollution index (HPI) and heavy metal evaluation index (HEI) showed low risk for all locations while degree of contamination (Cdeg) revealed medium to high values for all locations except AB7. Consequently, the environment is not safe due to high concentration of these toxic metals. The multivariate analyses unraveled anthropogenic and geogenic sources of the contamination. With this trend of findings from the forensics entropy analysis, it can be said that Obollo Afor is the epicentre of these contaminants and attenuates towards the farmland area. The study therefore recommends effective and efficient environmental management strategy measures to curb this menace. [ABSTRACT FROM AUTHOR]

Many heavy metals, including cadmium, chromium, copper, lead, and zinc, are produced during cement-making. Even in low quantities, most of the heavy metals released are known to be harmful to plants and animals. The objective of this study was to isolate, identify and characterize heavy metal-resistant bacteria from soil samples collected at Benue Cement Company, Nigeria. Soil samples taken near the Gboko facility of Nigerian cement manufacturer Benue Cement Plc were tested for heavy metal-resistant bacteria. Results from the study revealed that compared to other metals (Pb, Cr, and Cd), the concentration of copper and zinc was consistently quite high across all sites. The levels of all components examined were determined to be higher than the limits allowed by the World Health Organization In this study, Cd, Zn, Cr, Cu, and Pb were found in soil samples taken from the Benue cement industry, according to the analysis of heavy metals. The results obtained from this study further revealed that out of 20 isolates only five (5) bacterial isolates, namely Staphylococcus aureus, Escherichia coli, Proteus sp., Bacillus cereus, and Lactobacillus which showed high levels of heavy metal resistance were selected for further studies in secondary screening. Based on the biochemical tests, S. aureus reacted positively to catalase and coagulase test. They were also seen to ferment lactose, sucrose and glucose. The E. coli reacted negatively to citrate, catalase, coagulase tests, and did not ferment sucrose. However, the bacteria fermented lactose and glucose. Lactobacillus reacted positively to only citrate but fermented the three sugars. Proteus sp. fermented glucose and sucrose and also reacted positively to citrate, catalase and urea tests. The B. cereus fermented glucose and sucrose. The bacteria also reacted positively to only citrate and catalase tests. Results of showed that S. aureus had MIC values between 12 and 16 mg/L, E. coli between 20 and 50 mg/L, Proteus species between 15 and 64 mg/L, and B. cereus between 10 and 18 mg/L, all against various metals. The B. cereus showed the lowest resistance to several heavy metals, while E. coli showed the highest resistance. Additionally, E. coli demonstrated a significant resistance level to all ten antibiotics examined. Antibiotic resistance was highest in E. coli and lowest in Proteus species. The findings of this study revealed that the four isolates that showed high tolerance to heavy metals could be used as inoculants to bioremediate cement sites that polluted by heavy metals. [ABSTRACT FROM AUTHOR]

This study assessed soil pollution and index properties in Okpulor through geochemical, geotechnical, and geoenvironmental analyses. Twenty samples, comprising 14 surface and 6 shallow subsurface ones, underwent geochemical analysis for heavy metals (Fe, Cr, Cu, Zn, Ni, and Pb). Five geochemical indices, including the Geoaccumulation Index (Igeo), Enrichment Factor (EF), Contamination Factor (CF), Metal Pollution Index (MPI), and Potential Ecological Risk Index (PERI), were utilized. Simultaneously, six subsurface samples underwent geotechnical analysis for Natural Moisture, Grain Size, Specific Gravity, Bulk Density, and Atterberg Limits, following Unified Soil Classification System (USCS) and American Association of State Highway and Transportation Officials (AASHTO) guidelines. The Igeo highlighted significant heavy metal contamination in Okpulor soils, particularly Cd. EF values exceeding 1.5 underscored a strong anthropogenic influence, with CF indicating Cd's substantial contribution to overall contamination. PERI underscored the ecological risks associated with Cd contamination. Natural moisture content, ranging from 18.21% to 21.45%, indicated a notable presence of water in the soil during the dry season, potentially leading to increased leaching and migration of water-soluble contaminants. Bulk density values suggested moderate to lightly packed soils, impacting porosity and permeability, and influencing contaminant movement. Atterberg limits indicated low soil plasticity, impacting moisture retention and contaminant behaviour. Grain size analysis revealed poorly graded soils with a close sand-to-clay ratio, affecting water drainage. These geotechnical properties and heavy metal contamination reveal the intricate interplay between soil characteristics and contamination risks in the Okpulor area, emphasizing the need for targeted interventions to safeguard the environment. [ABSTRACT FROM AUTHOR]

Studies have emphasized that the presence of heavy metals in freshwater fish represents a global public health issue. Nigeria, being a developing nation with less emphasis on the quality of seafood consumed by the residents, ranks this study very vital. The policy implication of this study is the advancement of a healthy population in contemporary Nigeria. Hence, this study assessed heavy metal concentration in two fish species, Clarias gariepinus (Catfish) and Oreochromis niloticus (Nile Tilapia), in the Anambra River. The sample included twenty fishes, of which eighteen were collected from the three sampling locations (the fish ports of Anambra River), namely Otu-nsugbe, Otuocha, and Ikemivite) while two control samples were collected from a pond about 200 m away from the river. The levels of heavy metals were determined using Varian AA 240 atomic absorption spectrophotometer (AAS). The results showed that the concentrations of heavy metals (cadmium and arsenic) in the sampled fishes from Anambra River exceeded the joint World Health Organization and Food and Agriculture Organization (FAO/WHO) standard for fish and fish product consumption, while the concentration of chromium, mercury, and lead are within the permissible limit. The study also showed the distribution of the heavy metals in the fish organ varies among fish species. Heavy metals occur higher in Clarias garepinus than in Oreochromis niloticus, while tissue preference for heavy metal accumulation is in the order of gill > liver > muscle. It was recorded from this study that the heavy metal concentration in the fish from the pond is generally higher than the fish from the river for some metals. The high level of heavy metals in the sampled fish was attributed to heavy metals contamination of the river as a result of various anthropogenic activities such as mining, burning of fossil fuel and emission from the exhaust of boats/vehicles, overuse of fertilizers and pesticides, discharge of effluent, sewage, and hospital waste. This study concluded that long-term consumption of fish from the river may pose health risks to the consumers due to the possible bioaccumulation of heavy metals, especially cadmium and arsenic. It was recommended that continuous monitoring of heavy metal levels in the fish and water, public awareness, and appropriate legislative provisions should be put in place to ensure that harvested fish and fish products may be safe for human consumption. [ABSTRACT FROM AUTHOR]

Nigeria is facing the problem of soil degradation as a result of continuous deposition of spent oil in the soil. The physiochemical properties, including heavy metals concentrations, of spent oil contaminated soils and adjacent control soils were investigated at 0–15 and 15–30 cm depths at Ladipo and Berger auto-mobile Markets in Lagos, southwest Nigeria. The soils were collected in triplicate and analyzed in a 2 (location) * 2 (study site) * 2 (soil depth) factorial experiment. The results showed a uniform soil texture in both study sites and at both soil depths, with loamy sand at Ladipo and sandy loam at Berger. Bulk density was significantly decreased, while the total porosity (46.44%), organic C (21.79 g kg− 1), available P (16.48 mg kg− 1), Na+ (0.72 cmolc kg− 1) and K+ (0.81 cmolc kg− 1) increased in the contaminated site compared to the control site. Soil pH was higher at Ladipo (8.4) than at Berger (7.4). However, the soil pH and available P concentration decreased in the contaminated soil compared to the control at both locations, resulting in a decrease in available P concentration of more than 300% and 100% at Ladipo and Berger, respectively. At the Ladipo location, the concentration of Ca2+ was higher in the control than in the contaminated counterpart, while the opposite was true at the Berger location. The concentrations of the heavy metals Pb and Zn in the contaminated soils were low, while the Cu concentration was high. Although the concentrations of these heavy metals were below the standards for potential environmental risks, the high Cu concentration at both locations poses a potential ecological risk and may affect soil and human health as Cu accumulates in critical levels in the soil due to the continued irresponsible disposal of spent oil on the ground. [ABSTRACT FROM AUTHOR]

The water qualities of the table, municipal and groundwater sources in some parts of Enugu State, Nigeria, were examined to determine their suitability for drinking. A total of 12 physicochemical properties (PCPs) and 9 heavy metal (HM) concentrations, distributions, source analysis, health, and ecological risks were evaluated. The water samples were collected in triplicate from 28 sampling locations from December 2021 to February 2022. The HMs were quantified using Flame Atomic Absorption Spectroscopy and titrimetric analysis. The mean HM values ranged within 0.0286 ± 0.0324–13.6067 ± 35.582, 0.0268 ± 0.0370–2.7450 ± 1.8666, and 0.0097 ± 0.0157–0.7718 ± 0.5080 mg/L in table, municipal and groundwater, respectively. Mean concentrations of Fe, Cd, Pb, and Ni were above recommended WHO/NIS standards in all water samples. For PCPs, the mean turbidity values for table and groundwater and all mean pH values of groundwater were above safe limits. The Hazard Quotient (HQ) and the Hazard Index (HI) for oral exposures in adults and children to HM were < 1. However, all HQ and HI for Cd dermal exposure in children for all drinking water sources were > 1. Source analysis and ecological risk assessments confirmed that HM pollution was of both geogenic and anthropogenic origins. Ecological assessments also revealed that pollution levels ranged from low risk of Ni concentrations in table water to very severe risk for Cd levels in groundwater. [ABSTRACT FROM AUTHOR]

Groundwater resource plays a central role in every sector of life globally. Unfortunately, the roles of groundwater are often unappreciated in many parts of the world, especially in developing nations. The paper applied a combined geo-electrical method and hydrochemical analysis alongside physical surveys to investigate aquifer promising zones, the quality and the source of water supply in the selected regions. The geo-electric resistivity data were used to select the most aquifer-promising zone for groundwater development with a key interest in groundwater potential and aquifer overburden protective capacity overlying the water-bearing unit. Seventeen (17) vertical electrical sounding (VES) acquired in four regions reveals that the regional weathered/fractured unit which constitutes the aquifer unity extends from 13.4 m to 41.3 m in depth with the subsurface resistivity value varying between 53 Ωm–1013 Ωm in terms of resistivity values. The overburdened thickness (protective soil layers) stretches from 2.5 m to 13 m with a resistive layer of resistivity values ranging from 111 Ωm to 2877 Ωm, which could provide high aquifer protective cover for the regional groundwater systems. The computed aquifer transmissivity and hydraulic conductivity range from 0.54 m 2 / h –15.85 m 2 / h , and 0.95 m/day–9.19 m/day, respectively. The estimated average longitudinal conductance (0.2 moh) reveals that the regional groundwater systems are moderately protective against surface contaminants. In addition, the physicochemical water analysis was examined, which exposes the level of heavy metals (HMs) compositions in the regional groundwater systems and the possible public health risks compared to WHO permissible drinking water limits. The sample water from the Rivers had the highest concentration of HMs (0.089 mg/I–2.012 mg/l), followed by the hand-dug wells (HWDs) (0.033 mg/l–1.555 mg/l) and the lowest in the borehole (0.011 mg/l–0.511 mg/l). In contrast, the borehole water sample shows a moderation where the HMs presence falls within the WHO standard for drinking water. The outcomes of the study show that 63% of the investigated region consumed water with a high concentration of HMs above the WHO permissible standard allowance for drinking water, while only 37% took water that falls within the WHO permissible standard. In conclusion, the study showed significant impacts of anthropogenic activities on the regional water quality, which provides vital information about the regional groundwater systems and the quality of water supply for adequate groundwater development and sustainability. [ABSTRACT FROM AUTHOR]

The quality of freshwater sources is a key factor in sustainable development. This study investigated the water quality suitability of Ossiomo River for human consumption and the implications for public health. Water samples were collected and analysed from October 2021 to March 2022. Results indicated that the water physico-chemical parameters from sampled locations were within their respective National Environmental Standards and Regulation Enforcement Agency (NESRA) permissible limits except for pH (< 6.5), dissolved oxygen (< 6.0mg L−1), cadmium (> 0.005m /L−1), manganese (> 0.05mg L−1) and total hydrocarbon content (>10mg L−1). Comprehensive pollution index (0.4–1.0) and water quality index (251.57–765.37) values indicate that the water body was slightly polluted and unsuitable for human consumption (WQI > 50). Health risk assessment showed that children and adults were predisposed to non-carcinogenic risk (HIoral > 1) and carcinogenic risk (ICR: 1.21E-02 and 2.84E-03) from heavy metals through oral exposure. Natural run-off and anthropogenic activities were identified sources of heavy metals and hydrocarbons within the catchment. The study has provided data for water resource quality monitoring and raised concerns as to the need for immediate action to safeguard the public health of communities surrounding the Ossiomo River, through the provision of alternative sources of potable water. [ABSTRACT FROM AUTHOR]

This study assessed the physicochemical properties of soils and their levels of heavy metal contents in soils along the Enyigba mining site in Ikwo, Ebonyi State, Nigeria. A total of 96 samples of soil were taken at depths of 0 to 20 cm using a soil auger and core sampler at a horizontal spacing of 100 m between each location and examined using standard laboratory techniques. The control soil samples were taken from the Alex Ekwueme Federal University Experimental and Research Farm in Ebonyi State, at a distance of 50 m from each spot at a depth of 0 to 20 cm. The results obtained from this study showed significant variations in the physicochemical properties and heavy metal levels of the soil from the Enyigba mining site, indicating that the mining activities have contaminated the soil. The result also indicated that mining operations may be responsible for the increase in sand and the decrease in silt and clay particles. The mining site's pH was typically low, indicating that the soil is naturally acidic. The contamination indices showed that lead recorded very high contamination factor of 27.068, while iron, nickel and zinc were low. The observed high concentration factor of lead had an impact on the soil's bulk density, saturated hydraulic conductivity, total porosity, calcium, potassium ion, magnesium ion, total nitrogen, organic carbon, cation exchange capacity, phosphorus and base saturation contents. It is recommended that the government's Ministry of Environment, at all levels, take a proactive stance in managing the excessive and subpar mining operations in the study area. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa) is an important source of human internal exposure to radionuclides and heavy metals because, worldwide, a large fraction of the population consume rice as their daily basic diet. In this study, the levels and correlation of natural radioactivity (232Th, 226Ra and 40K) and heavy metals (Pb, Ni and Cd) in local rice sold in Enugu urban markets, a southeastern part of Nigeria, were examined. Possible health implications were also evaluated. The mean activity concentrations were estimated to be 235.81 ± 12.93, 54.29 ± 8.08 and 63.70 ± 3.93 Bqkg−1 for 40K, 226Ra and 232Th respectively. Obtained values were higher than values reported in the literature for rice in other locations. The estimated committed effective doses for 226Ra and 232Th exceeded the global ingestion dose average of 0.12 mSvy,–1 whereas that of 40K is below the 0.17 global average. The average concentrations of the metals were estimated to be 0.41, 3.70, and 0.02 mgkg–1 for Pb, Cd and Ni, respectively, with only Ni having an average concentration below the threshold food safety limit of FOA/WHO. Only the concentrations of Cd were of significant levels with their health risk indices exceeding the tolerable reference levels for both children and adult. Only the pairs, 232Th-Ni and Pd-Cd, correlated significantly (p < 0.05) which implies common sources. Multivariate principal component analysis indicated common natural sources for 226Ra, 232Th and Ni in local rice, possibly of lithogenic and paedogenic in nature. It is believed that the results of this study will be valuable to the radiological and toxicological food safety and policy framework of WHO/FAO in Nigeria and the rest of the world. [ABSTRACT FROM AUTHOR]

Anthropogenic impacts and the accumulation of heavy metals in water bodies have increased significantly as a result of increased urbanisation, endangering both aquatic biota and human health. The pace of urbanisation and its attendant freshwater ecosystem pollution in Nigeria is so fast that there are concerns for the nation's freshwater biota. To this end, six heavy metals were investigated in the water column, sediment, and tissues of macroinvertebrate functional feeding guilds (FFGs) of a Nigerian stream. Three heavy metals that are non-essential (As, Cd, and Pb) exceeded their WHO permissible limits for surface fresh waters. According to the geo-accumulation index (Igeo) and contamination factor (CF) used to assess heavy metal pollution, there was a high level of Cd contamination among all heavy metals found in the sediment. These heavy metals were all biomagnified (>1), especially among the predators. The study concluded that Opa Stream was moderately impacted based on the concentrations of heavy metals in the stream's water column, sediment, and macroinvertebrate tissues. Future research works can consider the remediation of heavy metals that are non-essential in freshwater systems to ensure the sustainability of freshwater biodiversity and human health. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the degree of contamination and intake rates, as well as the risk of Lithium (Li), Arsenic (As), Cadmium (Cd), Mercury (Hg), and Lead (Pb) contained in wild species of King Tuber Mushroom (P. tuber-regium) collected pre-, post- and during the COVID-19 lockdown which is widely consumed in northwestern Nigeria; and to also assess their potential to accumulate some heavy metals, which comprises the linked consumer health hazards by assessing the risks to children, adolescents, and adults from cancer-causing and non-cancer-causing substances based on estimated weekly intake (EWI). After mineralization with acid, the concentrations were determined using Optical Emission Spectrometry with Inductively Coupled Plasma (OES-ICP), and Mercury (Hg) using Cold Vapor Atomic Fluorescence Spectrophotometer (CV-AFS). Moreover, the health risk assessment due to the ingestion of these elements through the consumption of P. tuberregium was estimated. The findings showed that concentrations of As, Pb, Cd, Li and Hg varied greatly within between 2018 and 2022, with levels higher in pre- and post- COVID-19, and lower during the COVID-19 lockdown. In descending order, the average content of these substrates and metals, was As > Pb > Cd > Li > Hg. Children, adolescents, and adults all had EWI values below the mushroom’s provisional tolerable weekly intake (PTWIs). The consumption of P. tuber-regium harvested from the areas investigated, therefore, poses no toxicological or health risks to the inhabitants. [ABSTRACT FROM AUTHOR]

This study investigates heavy metal concentrations and surface sediment characteristics in the Ozomu Lake, located in southern region of Nigeria. Sediment samples were systematically collected across three stations, over six months, spanning from March to August. This period encompasses the transition from the late dry season to the early wet season, offering valuable insights into the seasonal variations of heavy metal distribution and sediment properties. The concentrations of heavy metals in the sediment were determined using standard methods, along with the analysis of particle size distribution and organic content (% organic carbon and % organic matter). Essential findings reveal significant values. Iron (Fe) averaged 1194.86 mg/kg, zinc (Zn) 30.71 mg/kg, copper (Cu) 14.80 mg/kg, manganese (Mn) 17.43 mg/kg, lead (Pb) 1.17 mg/kg, and cadmium (Cd) 0.18 mg/kg. Enrichment factor (EF) assessments indicate notable enrichment in Fe, Zn, Cu, Mn, and Cd. Key sediment properties include total organic carbon (%TOC) at 4.46%, total organic matter (%TOM) at 7.72%, and particle size distribution with clay at 8.99%, silt at 6.24%, and sand at 84.77%. Principal component analysis (PCA) uncovers intricate relationships among heavy metals, shedding light on their sources and distribution. Geoaccumulation indices (Igeo) reveal moderate pollution levels in Fe and Cd, suggesting potential ecological risks. Conversely, Zn, Cu, Mn, and Pb remain within unpolluted ranges. The study enhances our understanding of heavy metal contamination in Ozomu Lake, emphasizing the need for tailored management and conservation strategies. Future research should explore seasonal variations and specific pollution sources in the lake’s catchment area. This study contributes valuable insights into Ozomu Lake’s environmental dynamics and underscores the importance of sustainable management for its long-term health and ecological integrity. [ABSTRACT FROM AUTHOR]

With the imminent industrial growth and population increase, Nigeria will continue to experience significant shifts in the quality of water, with a rise in emerging contaminants. This will increase the irregularity and complexity of the water quality information. Therefore, using the PRISMA meta-analysis approach, this review systematically identified the commonly used water quality assessment techniques in Nigeria, the drawback in the application of these techniques as well as the gaps in the area of water quality assessment and monitoring from 2003 to 2023. Recommendations were also made based on the evaluation of a new research direction; through the review of the effectiveness of advanced techniques for monitoring water quality in Nigeria. Sixty-eight published articles were chosen for the meta-analysis while the VOSviewer program was used to perform bibliographic coupling and visualization. The review revealed that the application of machine learning in water quality prediction has not been well explored in Nigeria. This is attributed to limited data availability and poor funding by the government. It was found that southwestern Nigeria has a greater amount of research on groundwater quality monitoring and evaluation than other regions. The variability was explained by variations in the underlying geology, aquifer features; variability in anthropogenic activities, and level of literacy among various geopolitical zones. Further studies should focus on the application of soft-computing and integrated biomonitoring techniques for effective prediction and monitoring of emerging contaminants for improved water quality. Effective collaboration between environmental stakeholders and government agencies is recommended for effective water resource sustainability. [ABSTRACT FROM AUTHOR]

Pesticide residues and heavy metal content of cassava, yam, cocoyam, potato, water yam and carrot were evaluated by gas chromatography-mass spectrometry and atomic absorption spectroscopy. The detected pesticide residues in the samples were 2,4-dichlorophenoxyacetic acid, glyphosate, hexachlorobenzene (HCB), dichlorobiphenyl, aldrin, endosulfan, profenofos, g-chlordane, carbofuran, biphenyl, heptachlor, lindane and t-Nonachlor. The concentration of HCB ranged between 0.0799 ± 0.06 mg/kg and 0.1596 ± 0.00 mg/kg, which was greater than the permitted maximum limit of 0.5 mg/kg established by the US Environmental Protection Agency. The concentration of aldrin and profenofos detected was lower than the predetermined maximum allowed limits. Endosulfan concentrations in cocoyam (0.2500 mg/kg) and potato (0.3265 mg/kg) were higher than the limits allowed by the Canadian Department of Industrial Research. The heavy metals detected in these samples include cobalt, nickel, lead, manganese, chromium, arsenic and mercury in at least one of the samples evaluated. There was not much difference between the concentration of cobalt in yam (0.036 mg/kg) and the maximum allowed concentration (0.043 mg/kg). Lead was detected in potatoes and carrots but was below detectable concentration in cassava, yam, cocoyam and water yam. Similarly, cocoyam was found to have a significant mercury content (0.658 mg/kg), but mercury content was below detectable concentrations in cassava, yam and water yam. [ABSTRACT FROM AUTHOR]

The present study assesses the pollution load of groundwater with reference to the trace and rare earth elements (REEs) and the potential health risk by its consumption for the residents of three distinct geological areas underlain by rocks of Quaternary (area 1), Cretaceous (area 2), and Precambrian, areas 3A and 3B in southeastern (SEN) and northcentral (NCN) Nigeria respectively. For this, 75 groundwater samples were collected and analyzed for physical parameters including hydrogen ion concentration (pH), electrical conductivity (EC), and total dissolved solids (TDS), trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn), and REEs. The pH varied from acidic to alkaline, with EC (6–1270 μS/cm) and TDS (8–922 mg/l) below guideline values. Concentration of Al (16.78–3716 μg/l), Ba (7.83–730.8 μg/l), Fe (33.72–1192.5 μg/l), and Mn (3.58–1192.0 μg/l) in some locations were higher than their respective guideline values. REEs (0.05–26.42 μg/l) PAAS normalized values showed negative Ce and positive Eu patterns with minor variations to positive Ce and flat patterns. Geochemical analysis of the groundwater samples showed that areas 1, 2, and 3A were severely contaminated with Al, while area 3B was contaminated with Fe. Multivariate analysis indicated that elements in groundwater were contaminated mainly through natural (Al, As, Ba, Fe, Mn, Ni, REE) as well as anthropogenic (As, Cd, Cu, Cr, Pb, V, and Zn) sources, degree of contamination (Cd), trace element pollution index (TEPI), and trace element evaluation index (TEEI) for the different areas for most groundwater samples were below critical values, indicating low pollution. However, rare earth element evaluation index (REEEI) showed various level of pollution in the different areas, in the order 3A > 1 > 2 > 3B. For the majority of groundwater samples across the different areas, non-carcinogenic health risk was not observed as the hazard quotient (HQ) values were less than unity, except for Al. The hazard index (HI) values were higher than unity for all areas and age groups (1.60–754.61) due to Al, indicating unacceptable non-carcinogenic health risk. The total carcinogenic risk (CRTOTAL) values were ranged 1.10E-04 to 6.21E-03 for all areas and age groups, suggesting that the CRTOTAL values were at unacceptable level of 1.00E-04 for sum of all PHEs. The order was Cd > Ni > As > Cr > Pb. In all cases, higher values of HI and CR were obtained for children compared to adults and infants in the entire study area, which means that children are more susceptible to health impairment. [ABSTRACT FROM AUTHOR]

Medicinal plants have played an undeniable role in treating diseases in mankind. However, these plants may be contaminated by toxic substances like heavy metals. Therefore, this study aimed to determine the contamination and health risks (carcinogenic and non-carcinogenic) of heavy metals in economically important medicinal plants mostly in Northern Nigeria. A total of 72 samples from 12 medical plants were purchased and analyzed for heavy metal (Pb, Cr, As, Cd, Zn, Cu, Ni and Fe) contamination using Atomic Absorption Spectrometry (AAS) after wet digestion. The concentrations of the heavy metals (mg·kg−1) were in the range of 1.71–9.01 for Pb, 0.23–2.08 for Cr, 0.00–0.05 for As, 0.00–0.51 for Cd, 5.08–23.67 for Zn, 1.28–13.45 for Cu, 0.96–1.95 for Ni and 20.58–108.50 for Fe. The results revealed that the plant under study contained unsafe levels of Cr and Cd being higher than the World Health Organization (WHO) permissible limits. The hazard index (HI) was < 1, suggesting a probable non-carcinogenic effect. Similarly, the cancer risk (CR) for children and adults was below the (1.0 × 10–4) acceptable limit, indicating non-probable cancer development for consumers. Based on the studied results, the samples may not pose a carcinogenic health risk. However, there is a need for the regulatory agency to continuously monitor medicine plants available in the markets for the safety of consumers. [ABSTRACT FROM AUTHOR]

The release of wastes generated from the activities at automobile workshops leads to heavy metals' contamination of such soils which can be harmful to human health considering Sustainable Development Goal (SDG) number 3 of good health and well-being in mind. The study is aimed at investigating the physiochemical and heavy metal contamination of soils from three automobile workshops at Super, Jankara and Kola areas located at Alimosho, Ifako-Ijaiye and Agege Local Government areas of Lagos state. Twenty (20) samples were collected from residential houses near the automobile workshops, at 20–35 cm depth, and taken to the Federal Institute of Industrial Research (FIIRO) laboratory at Oshodi, Lagos. Electrical conductivity (EC), pH, temperature and total dissolved solids (TDS) with mean values 28.45 μs/cm, 6.5, 33.37 and 0.014 mg/L respectively were measured onsite using a 107 model pH metre. The samples were analysed for lead, magnesium, manganese, cadmium, arsenic, chromium and mercury using atomic absorption spectroscopy (Perkin Elmer Model Analyst 3000). Samples at the Super area gave the highest mean concentrations of lead (28.42 mg/kg), cadmium (0.65 mg/kg), arsenic (0.54 mg/kg) and chromium (11.70 mg/kg) while the highest mean concentrations of manganese (1.7282 mg/kg) and cadmium (0.4451 mg/kg) were high in the Kola area. The mean concentrations of metals in the soil samples were in the order Mn > Pb > Cr > Cd > As (AAS). The soil contamination degree was determined from the calculated values of the contamination factor and geo-accumulation index. The outcome of this research shows that heavy metals' concentration in the soil existed within tolerable limits of all the standards compared with as summarised by the pollution load index. However, if the contamination continues, the concentration of the heavy metals will surpass the tolerable limits, and this could make it toxic to plants and humans. [ABSTRACT FROM AUTHOR]

In Nigeria, almost all industries produce waste, which is typically disposed of with often little consideration given to environmentally friendly procedures. This study assessed the potential impact of pollution by slaughterhouse wastes on specific soil particle distribution, texture, physicochemical properties, and heavy metal concentrations in Ebonyi State, Nigeria. Samples of soil were taken at depths of 0–20 cm, and were examined using standard laboratory techniques. The results obtained from the determination of soil particle size distribution and textures were found to indicate a categorization of sandy loam in all the locations studied. The results indicate that slaughterhouse wastes decreased soil bulk density while increasing soil total porosity and gravimetric moisture contents in all the slaughterhouse soils compared to soils of the control locality. The mean soil pH values around the slaughterhouse (5.70–5.78, 5.13–5.25, and 5.47–5.59) were observed to be lower than the mean pH values (6.08–6.09) of soils of the control site, which indicated that the slaughterhouse soils are acidic in nature. Soils located around the slaughterhouse had higher exchangeable sodium (Na) and the lowest levels of exchangeable calcium (Ca) than soils of the control areas. The highest amounts of heavy metal contents were recorded in soils around the slaughterhouses, indicating that the presence of slaughterhouse wastes correlated with the soil's accumulation of heavy metals. Based on the foregoing results, it is submitted that slaughterhouse wastes should be treated using anaerobic digestion before being released into the environment, since they have a significant potential for pollution. [ABSTRACT FROM AUTHOR]

Toxic compounds such as redox-sensitive metals usually contaminate the soil. They are implicated in the causation of oxidative stress, a precursor of human diseases and ecological extinction. Having uncontaminated soil serves as the link between plant and animal health quality, and a sustainable ecosystem. Geological accumulation and spatial distribution of redox-sensitive metals in agricultural land can significantly hinder soil fertility, ecological health, food safety, and food security. This study used the soil samples from farmlands near the Lafarge industrial area at Mfamosing, Akamkpa local government area of Cross River State, Nigeria, to assess eight redox-sensitive metals (Cadmium, Chromium, Copper, Nickel, Lead, Arsenic, Cobalt, and Zinc), their spatial distribution, and geo-accumulation. The redox-sensitive metals were screened with an atomic absorption spectrophotometer connected with mass spectroscopy. A geographic information system (GIS) and ArcMap version 10:8:2 was used to infer the risk of the industrial area regarding geoaccumulation, and spatial distribution of redox-sensitive metals in the farmlands. The result shows Cd, Cr, Cu, Ni, Pb, As, Co and Zn have different concentrations among the samples. Three samples - MS2, MS3, and MS8, had the highest arsenic concentration, while samples Ms1, Ms2, Ms5, and Ms8, had the second-highest concentrations of Cadmium, Lead, and Chromium, respectively. The polluted area was moderately contaminated and distributed with other metals - Cu, Ni, and Co, respectively. Comparing these results with those of non-industrial areas, one can infer that the Lafarge industrial area is more contaminated with redox-sensitive metal. To advance this investigation, some microorganisms within the area can be used to verify a metal-hazard impact on the ecosystem and monitor the rise in redox-sensitive metals to predict the risk. [ABSTRACT FROM AUTHOR]

This study examined the levels and health threat assessment of organochlorine pesticides (OCPs) and heavy metal (HM) residues in five selected foodstuffs--sorghum, maize, rice, garri (processed fried cassava), and beans--randomly collected from three markets within the Abeokuta metropolis in southwestern Nigeria. Gas chromatography-mass spectrometry (GC-MS) and atomic absorption spectrometry (AAS) methods were used to analyze the foodstuffs for OCPs and HMs, respectively. The collected data were analyzed using simple descriptive and inferential statistics. Health risk indices, including non-carcinogenic and carcinogenic effects, were estimated for organochlorine pesticides (OCPs) and heavy metals (HMs) in food samples. The findings revealed that the concentrations of OCPs and HMs in many food samples exceeded the recommended dietary allowances. The risk index values of OCPs and estimated HMs in each foodstuff exceed the permissible limit of 1.0, indicating potential negative health impacts, although not cancer-causing. Dieldrin was the largest contributor to adverse health effects, ranging from 10 to 98%, while Pb had the highest contribution, with values between 43 and 54%. The combined cancer risk of OCPs and HMs was above the allowable limit of 1 x 10-4, suggesting a potential risk for cancer development. The data on OCPs and HMs in the analyzed foodstuffs represent direct threats to public health. [ABSTRACT FROM AUTHOR]

In this study, a new cumulative ecological risk index (CRI) was proposed to assess the ecological risk of groups of trace metals that simultaneously pollute an environment. Trace metals in the subsurface soils of the Gboko district, Nigeria were analyzed to evaluate the impact of agricultural, industrial, and urbanization on soil pollution. Twenty-five soil samples were collected and analyzed for potentially toxic trace metals. The cumulative ecological risk assessment revealed two groups of metals (Group 1-Cu + Cr + Ni + As) and (Group 2-Pb + Zn + Hg) that simultaneously accumulate and pollute the soils of the Gboko area. The CRI of the Group 1 metals ranged from 6 to 64 with a mean value of 15 and the Group 2 metals ranged from 6 to 1773 with a mean value of 162. For the Cu + Cr + Ni + As group of trace metals, 72% of the soil samples belong to very low and low ecological risk, and 28% belong to moderate to very high ecological risk. In the case of the Pb + Zn + Hg group of trace metals, 80% have a very low to low ecological risk and 20% have a moderate to very high ecological risk. [ABSTRACT FROM AUTHOR]

This study investigated heavy metal contamination around an industrial district in Obajana, Southwest Nigeria. The study region lies between latitudes 7°54'N to 7°56'N and longitudes 6°24'E to 6°27'E. Thirty samples each for groundwater and soil and twelve plant samples were collected from the study area. All samples were collected in triplicate. The physical and chemical parameters of the groundwater, soil, and plant samples were measured. The average pH level of the groundwater samples is 7.2 which falls within the Nigerian Standards for Drinking Water Quality (NSDWQ). The ranges of the other physical parameters such as electrical conductivity (EC), total dissolved solids TDS) and total hardness (TH) are also within the acceptable limits. The mean concentrations of heavy metals in groundwater samples for Mn 0.020 mg/L), Zn (0.010 mg/L), Ni (0.010 mg/L), Cr (0.130 mg/L), Cu 0.020 mg/L), and Fe (0.090 mg/L) are within the allowable limit, with the exception of Pb (0.090 mg/L) that is above the recommended level. According to the index of geo-accumulation (Igeo), the soil and plant samples are not polluted with respect to the heavy metals tested. The analysis of the human risk assessment reveals that the values for the carcinogenic risk are within acceptable bounds; however, the values for the non-carcinogenic risk are substantially above the acceptable bounds. This demonstrates that non-carcinogenic health impacts are a threat to the broader population. This study suggests continuous monitoring of groundwater, soil, and plant in the study area. [ABSTRACT FROM AUTHOR]

Environmental geochemistry examines the presence, dispersion, and movement of elements on the Earth's surface. This research explores the environmental geochemistry of the Idofian area in Kwara State, Nigeria, with a particular emphasis on water and stream sediments. The heavy metals were ascertained using X-ray diffraction (XRD) and atomic absorption spectrometer (AAS). The study revealed the presence of marble, diorite, gneiss, pegmatite and amphibolite in the Idofian area. Furthermore, the XRD analysis provided information about the mineral composition including quartz, micas, lepidolite, laumontite, orthoclase, plagioclase, dolomite and anthophyllite. The findings revealed the absence of sediment contamination, while highlighting substantial contamination in the study area's water. This contamination, attributed to a combination of geogenic and anthropogenic factors, underscores the crucial necessity for implementing sustainable management practices in the region. [ABSTRACT FROM AUTHOR]

This study conducts a comparative assessment of two dumpsites (abandoned and active dumpsite) around Osogbo metropolis Osun State Nigeria. Ten selected heavy metals (HMs) such as arsenic, copper, cobalt, cadmium, chromium, iron, nickel, manganese, lead and zinc were determined. The soil samples were collected, at strategic points to revealed variation in samples. The concentrations of HMs were quantitatively determined using atomic absorption spectroscopy. The results indicated that all the HMs determined were found between below detection limit (bdl) to 0.611 mg/kg and bdl –0.880 mg/kg for abandoned and active dumpsites, respectively. The concentration factor and geo-accumulation intensity revealed no contamination to strong contamination and from uncontaminated to strong contamination intensity, respectively. The concentrations for some of the HMs were below the tolerable recommendation level by National Environmental Standards and Regulation Enforcement Agency and Food and Agriculture Organization/World Health Organization in soil samples. This study recommends periodic monitoring and that possible decontamination of the dumpsite are crucial because these dumpsites were currently in use for crops cultivation such as maize, vegetable bananas, and some other arable plants. Also, HM concentrations in crops should be investigated and monitored at these dumpsites regularly in order to avert detrimental effects of HM pollution, which could manifest many years after exposure, as they are recalcitrant in the environment. [ABSTRACT FROM AUTHOR]

Background: The contribution of the processes involved and waste generated during gold mining to the increment of heavy metals concentration in the environment has been well established. While certain heavy metals are required for the normal functioning of an organism, certain heavy metals have been identified for their deleterious effects on the ecosystem and non-physiological roles in organisms. Hence, efforts aimed at reducing their concentration level are crucial. To this end, soil and water samples were collected from Ilesha gold mining, Osun State, Nigeria, and they were subjected to various analyses aimed at evaluating their various physicochemical parameters, heavy metal concentration, heavy metal-resistant bacteria isolation, and other analyses which culminated in the molecular characterization of heavy metal-resistant bacteria. Results: Notably, the results obtained from this study revealed that the concentration of heavy metal in the water samples around the mining site was in the order Co > Zn > Cd > Pb > Hg while that of the soil samples was in the order Co > Cd > Pb > Hg > Zn. A minimum inhibitory concentration test performed on the bacteria isolates from the samples revealed some of the isolates could resist as high as 800 ppm of Co, Cd, and Zn, 400 ppm, and 100 ppm of Pb and Hg respectively. Molecular characterization of the isolates revealed them as Priestia aryabhattai and Enterobacter cloacae. Conclusion: Further analysis revealed the presence of heavy metal-resistant genes (HMRGs) including merA, cnrA, and pocC in the isolated Enterobacter cloacae. Ultimately, the bacteria identified in this study are good candidates for bioremediation and merit further investigation in efforts to bioremediate heavy metals in gold mining sites. [ABSTRACT FROM AUTHOR]

Ground, surface and mine water samples of the Ijero-Ekiti mining area of Nigeria were assessed for their quality. Also, the ecological and human health risks associated with potentially toxic metals in them were also considered. Sixty samples (30 groundwater, 20 surface water and 10 mine water) were collected during the dry and wet seasons of year 2017. The concentrations of metals in the waters were determined using High-Performance Liquid Chromatography Inductively Coupled Plasma-Mass Spectrometry (HPLC-ICP-MS). Hydrogeochemistry, weathering indices and mineral speciation were used to assess the quality. Indices such as geo-accumulation and contamination factors were used to determine the extent of contamination by metals. Risk assessments were carried out using internationally acceptable methods. Results revealed that the average concentrations of Co Ni, Cr, Cu, Zn, As, Cd, Ba, Pb and Sb in groundwater were 0.04 mg/l, 0.04 mg/l, 0.03 mg/l, 2.94 mg/l, 0.19 mg/l, 0.02 mg/l, 1.93 mg/l, 0.13 mg/l and 0.006 mg/l, while for wet season, it was 0.03 mg/l, 1.03 mg/l, 0.02 mg/l, 1.99 mg/l, 0.83 mg/l, 0.02 mg/l, 0.04 mg/l, 0.59 mg/l, 0.86 mg/l and 0.002 mg/l, respectively. Plagioclase and silicate weathering contributes significantly to the amount of metals in the waters. Waters from this area are moderately to extremely polluted by heavy metals. Ecological risk revealed that metals in water of the area pose medium to high ecological risk aggravated by Cd, Zn and Ni. Hazard index (HI) for both carcinogenic (>1E-4) and non-carcinogenic health (>1) risks were above the recommended limits of USEPA. Oral ingestion and dermal contact with contaminated water are major pathways for non-carcinogenic health risks. Carcinogenic health risks of water from the area were aggravated by Pb. We suggest that mining activities in the area should be properly monitored to avoid an endemic. [ABSTRACT FROM AUTHOR]

The Adada River is among the essential rivers in Enugu State which rural dwellers depend on water supply and agriculture farmlands situated beside its channels. Current research was undertaken to ascertain the extent of lethal metals (Co, Zn, Cd, Ni, Pb, As and Fe) pollution in soils from the Adada River bank. Fifteen topsoil (0 cm), subsoil (5 cm) and deep-soil (10 cm) samples were gathered from the downstream, midstream and upstream of the river. The results revealed that the average values of the metals in the three different depths declined in the pattern of As>Pb>Zn>Co>Ni>Fe>Cd. Adada River bank soils possess moderate to critical enrichment for Pb, moderate enrichment for As and Cd, as well as no enrichment for Co, Zn and Ni. The results of the contamination factor (CF) revealed that Cd and As are responsible for the high contamination. The Pollution Load Index (PLI) for some of the sample stations demonstrates that, with the exception of the Amagu and Ogbosu locations, the sampling locations were largely unpolluted. To delineate the different origins of the metals, multivariate tools like correlation matrix and cluster analysis were used. The results indicated that the soil samples obtained from the upstream of the river possess lesser metal values, whereas soils in the downstream of the river had higher metal values as a result of intensive rice farming in the downstream part of Adada River. Our observations can also be beneficial as baseline data for regulatory agencies to implement appropriate action in the future on issues relating to heavy metal contamination in the Adada River. [ABSTRACT FROM AUTHOR]

In the Okurumutet-Iyamitet Mine area, mining is done by the open-cast method, without environmental impact assessment, thereby exposing the environment and its inhabitants to risks. This study aimed to assess the toxicological processes that control the plants' heavy metal uptake into their tissues, the suitability for human consumption, and the possible sources of heavy metals using an integrated approach. The concentration of selected trace metals in plant samples was analysed by the microwave digestion method using 1 mL and 6 mL of concentrated perchloric acid and nitric acid respectively. The concentration of heavy metals in soil samples was analysed by extraction and centrifugation following standard procedures. The extracts collected were analysed by placing them into the flame of the PerkinElmer Analyst 200 atomic absorption spectrophotometer and graphite furnace atomic absorption spectrophotometer for soil and plants respectively. The concentration of heavy metals decreased in the order: Fe > Zn > Mn > Ba > Pb > Cd and Fe > Zn > Ba > Mn > Pb > Cd for the soil and cassava plants respectively. When compared with the Food and Agricultural Organisation/World health organisation and soil quality guideline, Cd recorded values in soils above the required standards. Numerical models revealed a moderate to high extent of heavy metal pollution in soil with Cd and Fe posing the highest contamination level across all the samples. The translocation factor revealed that heavy metals are more accumulated in the leaves than tubers. Similarly, the bioconcentration factor (BCF) showed that the inhabitants are exposed to heavy metal contamination from the consumption of cassava tubers, as the BCF values were >1.00. Chemometric analyses identified anthropogenic activities as the major influence on the accumulation and bioavailability of heavy metals. Hence, emphasis should be placed on Cd and Fe to mitigate further heavy metal pollution in the area. [ABSTRACT FROM AUTHOR]

Pollution by heavy metals is a threat to public health because of the adverse effects on multiple organ systems including the brain. Here, we used the African giant rat (AGR) as a novel sentinel host to assess the effect of heavy metal accumulation and consequential neuropathology upon the brain. For this study, AGR were collected from distinct geographical regions of Nigeria: the rain forest region of south-west Nigeria (Ibadan), the central north of Nigeria (Abuja), and in oil-polluted areas of south Nigeria (Port-Harcourt). We found that zinc, copper, and iron were the major heavy metals that accumulated in the brain and serum of sentinel AGR, with the level of iron highest in animals from Port-Harcourt and least in animals from Abuja. Brain pathology, determined by immunohistochemistry markers of inflammation and oxidative stress, was most severe in animals from Port Harcourt followed by those from Abuja and those from Ibadan were the least affected. The brain pathologies were characterized by elevated brain advanced oxidation protein product (AOPP) levels, neuronal depletion in the prefrontal cortex, severe reactive astrogliosis in the hippocampus and cerebellar white matter, demyelination in the subcortical white matter and cerebellar white matter, and tauopathies. Selective vulnerabilities of different brain regions to heavy metal pollution in the AGR collected from the different regions of the country were evident. In conclusion, we propose that neuropathologies associated with redox dyshomeostasis because of environmental pollution may be localized and contextual, even in a heavily polluted environment. This novel study also highlights African giant rats as suitable epidemiological sentinels for use in ecotoxicological studies. [ABSTRACT FROM AUTHOR]

The concentrations of Cu, Zn, Fe, Cd, Co, Cr, and Mn and their seasonal variations in water samples from the Wupa River, Abuja, Nigeria, were studied through the atomic absorption spectrophotometric method to determine the suitability of the water for domestic usage and identify potential sources of contamination. Sixty samples were collected during both dry and wet seasons. The respective metal concentrations (in mg/dm3) in the dry and wet seasons were as follows: Cu (0.023 ± 0.022, 0.023 ± 0.026), Zn (0.104 ± 0.039, 0.158 ± 0.085), Fe (0.350 ± 0.097, 0.3630.103), Cd (not detectable), Co (not detectable), Cr (0.003 ± 0.003, 0.004 ± 0.004), and Mn (0.120 ± 0.132, 0.110 ± 0.099). Among these metals, Cu, Zn, Cr, and Mn occurred in concentrations below the tolerable limits recommended by Nigeria Standard for Drinking Water Quality and WHO, whereas Fe exceeded these limits, and Cd and Co were not detectable. The calculated heavy metal pollution index values (68.22 in the dry season and 63.78 in the wet season) were lower than the critical value (100), indicating low pollution levels in both seasons. The metal index values for both seasons (1.50 for the dry season and 1.55 for the wet season) suggest that the water from the Wupa River was slightly affected by heavy metals. Moreover, no significant differences in metal concentrations existed between the dry and wet seasons. A strong positive correlation occurred between Zn and Fe only during the wet season. Water from the river was polluted with Fe and unsuitable for domestic use. Potential sources of contamination include agricultural areas, industrial effluents, and domestic waste in the wet season, and industrial and domestic sewage in the dry season. To make the river water safe for use, it should be treated and regularly monitored for metal contents, and sources of contamination should be managed appropriately. [ABSTRACT FROM AUTHOR]

Food safety has become a serious global concern because of the accumulation of potentially toxic metals (PTMs) in crops cultivated on contaminated agricultural soils. Amongst these toxic elements, arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) receive worldwide attention because of their ability to cause deleterious health effects. Thus, an assessment of these toxic metals in the soils, irrigation waters, and the most widely consumed vegetables in Nigeria; Spinach (Amaranthushybridus), and Cabbage (Brassica oleracea) was evaluated using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentration (measured in mg kg−1) of the PTMs in the soils was in the sequence Cr (81.77) > Pb(19.91) > As(13.23) > Cd(3.25), exceeding the WHO recommended values in all cases. This contamination was corroborated by the pollution evaluation indices. The concentrations (measured in mg l−1) of the PTMs in the irrigation water followed a similar pattern i.e. Cr(1.87) > Pb(1.65) > As(0.85) > Cd(0.20). All the PTMs being studied, were found in the vegetables with Cr (5.37 and 5.88) having the highest concentration, followed by Pb (3.57 and 4.33), and As (1.09 and 1.67), while Cd (0.48 and 1.04) had the lowest concentration (all measured in mg kg−1) for cabbage and spinach, respectively. The concentration of the toxic metals was higher in spinach than in cabbage, which may be due to the redistribution of the greater proportion of the metals above the ground tissue, caused by the bioavailability of metals in the aqueous phase. Expectedly, the hazard index (HI),and carcinogenic risk values of spinach were higher than that of cabbage. This implies that spinach poses potentially higher health risks. Similarly, the Monte Carlo simulation results reveal that the 5th percentile, 95th percentile, and 50th percentile of the cumulative probability of cancer risks due to the consumption of these vegetables exceeds the acceptable range of 1.00E−6 and 1.00E−4. Thus, the probable risk of a cancerous effect is high, and necessary remedial actions are recommended. [ABSTRACT FROM AUTHOR]

Background: Toxic Heavy Metals (THMs) threaten food safety and result in human poisonings. It seems to be few studies on THMs contamination in food chain in developing countries. Current investigation determine the concentration and health risk of arsenic (As), cadmium (Cd), lead (Pb), as well as mercury (Hg) in fish and water at Nsukka, Metropolis, Enugu state, Nigeria. Methods: Forty eight samples; 24 (catfish and tilapia) fish and 24 (borehole, sachet, and bottled) water were randomly collected from two major markets and districts in Nsukka Metropolis and were evaluated for THMs using Atomic Absorption Spectrophotometer. The Estimated Daily Intake, Target Hazard Quotient, Hazard Index, and Cancer Risk (CR) were assessed as well. Results: THMs analaysis showed that As, Cd, and Hg were at 100% and Pb being at 16% in all the fish samples while 12.5% of fish of exceeded the Hg Maximum Permissible Limit (MPL) of 0.050 mg/kg, that not statistically significant (p>0.05). On the other hand, based on the analysis of all water samples, Hg and As were detected at 100% rate, Cd at 58.3% while Pb was not identified. The values above the MPL appeared to be 9 (37.5%), 2 (8.3%), and 3(12.5%) for Hg, As, and Cd, respectively in water while not statistically significant (p>0.05). The mean value of Hg (0.06425 mg/kg) in roasted fish as well as Cd (0.0065 and 0.0105) mg/ml in tap and bottled water respectively surpassed the MPL although not statistically significant (p>0.05). The Estimated Daily Intake of THMs except Cd in fish were proved to be within the Provisional Tolerable Daily Intake in contrast with As and Cd in water. CR is present both in children and adults with CR value >1. Conclusion: The finding of THMs in fish and water above the MPL is regarded as potential health risk for the consumers of such contaminated water and fish in the investigation scope. [ABSTRACT FROM AUTHOR]

The non-compliance of ballast water management is a global concern due to the environmental risks associated with the transfer of harmful organism and sediment contaminant in ballast water. This study examined the physicochemical parameters of ballast water samples collected from selected ships docked in the Onne river with the aim of investigating the ballast water compliance and heavy metal concentration content. The investigated parameters include, temperature, salinity, total suspended solids, hydrogen ions concentration, dissolved oxygen, and heavy metals. The result shows varying concentration of parameters and total concentration of heavy metals, in increasing order from ship 4 > ship 3 > ship 2 > ship 1 (27.897 > 20.941 > 16.636 > 16.586) and according to the distance from the loading ports to ships destination port. The highest concentration of heavy metals was recorded for Zinc (Zn) (S4 = 6.820, S = 5.080, S = 6.050 and S1 = 3.500) and lead (Pd) (S4 = 21.010, S3 = 15.800, S2 = 10.550, S1 = 12.500). The analytical results revealed a complex parameter, the salinity and dissolved oxygen were higher in samples collected from offshore vessels and general cargo ships but decreased substantially with other samples and traced to certain reasons. This study shows the need for policy makers and maritime regulators to constantly monitor the qualities of ballast water discharged in the Nigeria ports and developing management strategy towards achieving BWM compliance in ships dock in the port. [ABSTRACT FROM AUTHOR]

Environmental pollution arises from the myriad of chemicals in current and historic applications. In Nigeria, the fate of pollutants among other factors relies on water runoffs with pollution implications on the flooded environment. In addition, there is a need for applications of pesticides against disease vectors in a flood-prone environment, therefore increasing pollution complications in the environment. Literature information is missing regarding the levels and public health risk implications of contaminants such as heavy metals and organochlorine pesticide (OCP) residues in groundwater and residential soils within the selected flood-prone residential locations in Lagos, Nigeria. This study was hence targeted at examining the levels and health risks of heavy metals and OCP residues in residential soils and groundwater sources of the targeted environment. Seven heavy metals comprising Cd, Zn, Fe, Pb, Cu, Ni, and Co were detected in the water samples with high concentrations of iron (mean = 22,000 mg/kg) and Zn (mean = 810 mg/kg). Only Fe (mean = 5.8 µg/L) and Zn (mean = 2.6 µg/L) were detected in the groundwater samples. Fifteen OCP residues were observed in the soil samples within the concentration range of 7.9 to 13 (mean = 11) mg/kg while seven OCP residues were reported in the groundwater samples within the concentration range of 0.19 to 0.35 (mean = 0.24) mg/kg. There was a concern about high contamination of dieldrin and heptachlor epoxide in the groundwater sources with concentrations exceeding the WHO (2017) drinking water guideline. A significant Pearson correlation (< 0.05) was obtained for endrin and endosulfan I in water and soil samples indicating potential contamination of groundwater from soil sources. The diagnostic ratio indicated possible applications of endosulfan and some other OCP residues. Overall, our data indicated low health risk implications for all the targeted contaminants. We recommend continuous investigation of newly listed priority chemicals such as dicofol and more public engagement on the implication of environmental pollution and health impacts of regulated chemicals. [ABSTRACT FROM AUTHOR]

Automobile Mechanic Workshops (AMWs) in Low- and Middle-Income Countries (LMIC) contribute to the problem of soil contamination with petroleum hydrocarbons and toxic heavy metals as a result of indiscriminate disposal of spent engine oil (SEO). Such contaminated soil ecosystems can serve as reservoirs of bacteria harboring adaptive tolerance to metals and hydrocarbons as well as resistance to antibiotics. This study investigated the growth response of bacteria isolated from spent engine oil contaminated soils collected from AMWs in South-West, Nigeria to different concentrations of petroleum hydrocarbons, heavy metals (Cu, Zn, Pb and their mixture) and clinically relevant antibiotics. Sixty percent of the bacterial isolates (n = 192) from the hydrocarbon contaminated soil samples possess the unique ability to metabolize various hydrocarbons, tolerate heavy metals and resist at least one of the tested antibiotics. The isolates were identified as members of the Genera Pseudomonas, Bacillus, Enterobacter, Burkholderia, Micrococcus, Staphylococcus, Actinomycetes, Citrobacter and Serratia. Significant correlation (p <.05) was observed between hydrocarbon utilization and antibiotic resistance. Results showed SEO contamination plays a role in the development and spread of antibiotic resistance in the soil ecosystem. Thus, it is necessary to enforce stricter regulations on the disposal of SEO and other petroleum hydrocarbons to limit their human and environment associated hazards. [ABSTRACT FROM AUTHOR]

In this study, the concentration and risk of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in 9 composite samples around the vicinity of an Asphalt plant in North Central, Nigeria, was evaluated. Aqua-regia wet digestion was used for heavy metals extraction in the water samples while atomic absorption spectrometry was used quantification. For PAHs, liquid-liquid extraction was used for extraction while gas chromatography-mass spectrometry was used for quantification of PAHs in the extracts. The risk assessment was estimated using the hazard index (HI) and incremental lifetime cancer risk (ILCR) in all the samples studied. The results showed that Cd and Cr were present in concentrations higher than their permissible limits in water set by World Health Organization, while Pb was not detected. Total concentration of 14 PAHs ranged between 6.47-390 mg L-1 and were within the WHO permissible limits. High molecular weight PAHs were dominant (71.54%) relative to low molecular weight PAHs (28.46%). The risk assessment results revealed that 100% ILCRtotal values recorded for heavy metals were higher than the recommended limit. While 37.5% of ILCRtotal values recorded for PAHs were higher than the recommended values, implying that residents are exposed to health risks from both metals and PAHs. [ABSTRACT FROM AUTHOR]

This is aimed at assessing the effect of the analysed physico-chemical, microbial parameters and heavy metals on run-off in selected routes at Nsukka Urban. The major roads selected included campus gate (CG), Ikenga road (IR), Enugu road (ER) and Ikpa/Orba road (IKPR); with university market road serving as control location (C). Four run-off samples were collected from each of the selected roads; in October 2020. The heavy metals were analysed using the Atomic Absorption Spectrophotometer (AAS); other parameters were analysed using standard methods. The results revealed that the analysed metals concentrations ranges from (in ppm): Cd (0.00–0.09), As (0.23–1.58 mg/L), Fe (6.48–79.72), Hg (.00–3.00), Pb (0.25–0.75), Ni (0.21–0.92), Mn (0.10–0.21), and Cr (0.67– 01.33) indicating increase in the concentration of samples as against control showing anthropogenic influences. The results also unravelled that metal concentrations are above the permissible standards for potable water. Coliform ranged (0.00–1736.00 cfu/mL), Turbidity (22.50–52.80 NTU) and Organic matter (55–130 mg/l). All other parameters like pH, EC, K+, Mg2+, and Na+ are all within the permissible limit of WHO. Multivariate and Sorensen analyses were also employed to separate chemical variables into components which gave a clue to the different sources of contaminants within an area, based on the indicator parameter associations. This analysis unravels anthropogenic contamination from domestic solid and sewage wastes on the quality of surface run-off and should be mitigated. [ABSTRACT FROM AUTHOR]

The assessment of health risk associated with the consumption food crops grown in the Ishiagu mining area has been carried out. Mining activities in the area have consequently increased the concentration of heavy metals in the arable soils. Uptake by plants can lead to bioaccumulation which increases the health risk of inhabitants of the community. In this study, forty (40) samples of leaves of Musa paradisiaca, Carica papaya, Abelmoschus esculentus, Telfairia occidentalis, Phaseolus vulgaris, Manihot esculenta, Colocasia esculenta and tubers (Solanum tuberosum, Dioscorea alata, Dioscorea cayenensis, M. esculenta, Dioscorea rotundata and C. esculenta) were collected across the area and analysed for heavy metals using atomic absorption spectrophotometric method. Health risk indices were applied to evaluate the effect on humans. Result show that the metal accumulations follow Hg > Cd > Mn > Pb > Cu > Co > As > Cr > Zn > Mo and Hg > Cd > Pb > Mn > Co > Cu > Cr for leaves and root/tubers, respectively. The DIM, HRI and THQ were analysed for adult and children, respectively, where children were found to be more vulnerable to these associated risks. DIM, HRI and THQ data revealed Hg, Cd and Pb as the most potent contaminants in the area with risk quotient of following order Hg > Cd > Pb. Tubers showed higher frequency of the presence of these metals, whereas leaves accumulate higher quantity/concentration of them. Mo and Zn were BDL in the crops sampled in the study area except for leave of M. esculenta from LSI 1 with Zn 42.15 mg/kg. There are diverse degrees of health risk that could be incurred through consumption of these food crops resulting from Hg, Cd and Pb which has HRI and THQ > 1. [ABSTRACT FROM AUTHOR]

The activities of quarrying in Ebonyi State have resulted in the loss of soil nutrients and an increase in soil pollution. This paper examines the environmental impact of quarrying on soil quality in the three zones of Ebonyi State, south-eastern Nigeria. To achieve the main aim of the study, three objectives were set: access the environmental impact of quarrying on the soil quality of the three zones of Ebonyi district; examine the physico-chemical properties of the soil; and evaluate the environmental impact of quarrying on the heavy metal content of the soil. The auger and core samples were collected at a depth of 20 cm to obtain physicochemical soil properties and heavy metal content. The generated data were subjected to factor analysis, which consists of a correlation matrix, KMO and Bartlett's test, communalities, total variance, scree plot, and component matrix. The major results showed that quarrying has significantly negatively impacted the soils of the three zones of Ebonyi State, as it has led to distortions in soil quality. The results also proved that soil quality within 0–50 m of quarry sites was found to be poorer than in the control area. Positive correlation matrix studies between the quarry locations revealed a common origin of pollution and the negative impact of quarry activities on soil. Based on the results, the study strongly recommends that such soils not be used for agricultural production unless remediation methods are in place, such as bioremediation, soil washing, and thermal desorption. [ABSTRACT FROM AUTHOR]

The bioaccumulation of some heavy metals in coaster waters directly affects the ecosystem and human beings. Thus, the objectives of this study are to evaluate the interaction between fish and coastal water and assess the long-term implications of human consumption of some major organs obtained from Tilapia brevimanus and Euthynnus alletteratus. The study determined the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) in twenty coaster water samples collected from two points and in the muscle, gills, and intestine of ten pieces of Tilapia brevimanus and ten pieces of Euthynnus alletteratus using a Perkin Elmer Model 306 Atomic Absorption Spectrometer. Furthermore, the accumulation of these metals and the assessment of the long-term implications of human consumption of the designated organs of the two species types were performed. The statistical significance level of the obtained results was determined using the T-test analysis tool, which revealed that the distribution of the metals varies in different organs of the fish species. The levels of pollutants were higher in Tilapia brevimanus organs than in Euthynnus alletteratus. The contents of As, Cd, Cr, and Pb in the gills were higher than those in the muscle. Also, the metal pollution index in the organs followed the order of intestine > gills > muscle for both Tilapia brevimanus and Euthynnus alletteratus, posing serious health risks. [ABSTRACT FROM AUTHOR]

Introduction: The burden of cardiovascular disease (CVD) is huge due to its associated morbidity, mortality and adverse socio-economic impact. Environmental pollution as a risk factor contributes significantly to the burden of CVD, especially in the low and middle income countries. One of the effective strategies to reduce CVD burden is to prevent or detect cardiovascular risk factors early in at-risk population. This study determined some cardiovascular risk factors, kidney function, and their association with heavy metals among automobile mechanics. Method: This was a cross-sectional study involving 162 automobile mechanics and 81 age and sex matched controls. Serum levels of lead, cadmium and some cardiovascular risks were assessed and compared in the two groups. Associations between serum lead, cadmium and some cardiovascular risks were determined using correlation analysis. P value of <0.05 was taken as significant. Results: The mean ages of the automobile mechanics and controls were 47.27±9.99 years and 48.94±10.34 years, respectively. The prevalence of elevated serum cadmium was significantly higher in the automobile mechanics (25.9% vs 7.9%; p = <0.001). The significant cardiovascular risk factors in the automobile mechanics vs controls were elevated total cholesterol (32.1% vs 18.5%; p = 0.017), hyperuricemia (20.4% vs 1.2%; p = <0.001), elevated blood glucose (16.0% vs 4.9% p = 0.013); and alcohol use (55.1% vs 30.0%; p = 0.001). Among the automobile mechanics, there were significant positive correlations between serum cadmium, atherogenic index of plasma (AIP) (p = 0.024; r = 0.382) and triglyceride (p = 0.020; r = 0.391). Significant positive correlation was found between serum lead and neutrophil gelatinase associated lipocalin (NGAL) (p = <0.001; r = 0.329). There were significant positive correlation between serum cadmium level, AIP (p = 0.016; r = 0.373) and TG (p = 0.004; r = 0.439); between serum lead and NGAL in all the study participants (p = 0.005; r = 0.206). Conclusion: Automobile mechanics have notable exposure to heavy metals and a higher prevalence of some cardiovascular risk factors. Health education and sensitisation as well as policies that would regulate exposure of persons to heavy metals should be implemented in Nigeria. [ABSTRACT FROM AUTHOR]

This study evaluates human health, pollution, and radiological risk assessment of potentially toxic metals (PTMs) (Pb, Cd, Cr, Ni, and Zn), radioisotopes (238U, 232Th, and 40K) and its associated radiological indices from dumpsite soils in Ogun State, Nigeria, using a calibrated atomic absorption spectrophotometer (AAS) and highly shielded γ-ray spectrometry using NaI(TI) detector. Fourier transform infrared spectrometer (FTIR) complemented by X-ray diffraction (XRD) techniques were used to evaluate the mineralogical composition of the soils. Multivariate statistical analysis was used to apportion the source of PTMs and the radioisotopes. The mean concentration of Pb, Cd, Cr, Ni, and Zn obtained were 22.35, 17.95, 20.83, 19.02, and 75.88 mg kg−1, respectively. The activity concentrations of 238U, 232Th, and 40K ranged from 49.71 ± 16.3 − 314.15 ± 55.2, BDL − 87.54 ± 7.38, and BDL − 3721.3 ± 231.6 Bqkg−1, respectively. The values obtained were above the global average value in most of the samples. According to the four-pollution and ecological risk assessment model, the dumpsite soils are strongly to low polluted and enriched with toxic metals in the order Zn > Cr > Pb > Ni > Cd. The estimated carcinogenic risk of the three carcinogenic PTMs for children and adults were higher than the acceptable limit (1 × 10−6). The results of the PCA and HCA results are consistent with the correlation coefficient analysis which showed that mixed natural, anthropogenic and lithogenic sources mainly from aggregation of lead-containing materials in the waste on the dumpsite, vehicular emission and industrial discharges are the main sources of Pb, Ni, and Cd in the three studied dumpsites. Thus, dumpsite soil poses great threat to health, increased pollution and enhances the radiological risk to the general population via human multiple exposure routes. [ABSTRACT FROM AUTHOR]

In Nigeria, artisanal mining has become a serious issue. In the Nigerian mining region of Arufu Pb–Zn–F, this study assessed the level of pollution, ecological hazards, and health risks related to the presence of metals in the water. In the dry and rainy seasons, 36 water samples (20 from the ground, 10 from the surface, and six from the mine) were gathered. Samples were examined for the presence of heavy metals such as Cr, Co, Ni, Cu, Zn, As, Cd, and Pb. Other than Cu, Zn, As, Cd, Sb, and Cd (surface water, dry season), which were below the acceptable norm, all water samples had metals over the suggested limits. Heavy metals from nearby mining activities polluted the water, according to contamination evaluations utilizing the contamination factor (CF). Metals in the water may pose very significant ecological dangers, according to ecological risk assessments. The evaluation of human health risks revealed that both adults and children in the region are susceptible to carcinogenic and non-carcinogenic health hazards since the hazard index (HI) values for both indices were above 1* ( 10-5 and above 1, respectively. This report emphasizes the need for monitoring mining operations in the nation to safeguard public health [ABSTRACT FROM AUTHOR]

An integrated interpretation of the magnetic data and the analysis of physicochemical parameters and heavy metals from Lamurde hot spring has been done for the first time. The temperature of the hot spring was measured to be at 44 °C while the normal surface temperature is 25 °C. Three prominent magnetic anomalies were found at bottom depths of 11.379 ± 0.253 km, 13.015 ± 2.120 km and 9.161 ± 1.200 km suggesting that the Lamurde hot-spring is heated at deep mantle (13.015 ± 2.120 km) and issued to the surface through either local or regional fault system or both. The physicochemical analysis gave pH (7.93 ± 0.06), total chlorine (125.0 ± 2.89 µg/L), total dissolved solids TDS (202.0 ± 2 ppm), hardness (64 ± 1.73 µg/L), alkalinity (210 ± 4 µg/L) and nitrate (1.3 ± 0.3 µg/L). In comparison with that of WHO standards, the results indicated that all the physicochemical parameters studied except for alkalinity fall within the permissible limits. Heavy metals were identified and analyzed in the sampled water: lead (0.1501 ± 0.0007 mg/L), chromium (0.0729 ± 0.0007 mg/L), nickel (0.1987 ± 0.1476 mg/L), cadmium (0.0115 ± 0.0003 mg/L), copper (0.0442 ± 0.0008 mg/L), arsenic (0.0456 ± 0.0003 mg/L), iron (0.8016 ± 0.0005 mg/L), cobalt (0.0274 ± 0.0004 mg/L), selenium (undetectable), manganese (5.31 ± 0.0361 mg/L) and zinc (0.1629 ± 0.0004 mg/L). The concentrations of heavy metals observed in the area with the exception of Zn, Cu and Se are all above the standards for drinking water. Their concentrations are in the order of Mn > Fe > Ni > Zn > Pb > Cr > As > Cu > Co > Cd > Se. These results suggest that the Lamurde hot spring is a potential zone for Mn, Fe, Ni, Zn and Pb deposit. [ABSTRACT FROM AUTHOR]