Application of indexical models in assessing ecological-health risk and heavy metal pollution in Enyigba-Ameka, Nigeria

Heavy metals affect the suitability of aquatic environment for all purposes; hence, this study evaluated heavy metal contamination in Agodi Reservoir Oyo State, Nigeria. Atomic Absorption Spectrophotometry was used to determine heavy metal concentrations. Heavy Metal Pollution Index (HPI), Water Quality Index (WQI), Pollution Index (PI), Comprehensive Pollution Index (CPI), Contamination Index (CI), Single-Factor Pollution Index (SFPI), Heavy metal Evaluation Index (HEI), and Human Health Risk Assessments (HRA) were used to determine the extent of heavy metal pollution and their impact on the aquatic environment. The order of heavy metal concentrations in both wet and dry seasons was Fe > Mn > Zn > Cu > Cd > Ni > Cr > Pb > Co and Mn > Fe > Zn > Cu > Co > Ni > Cd > Cr > Pb, respectively. WQI for both wet (3182.6) and dry (3649.5) seasons classified the reservoir as "unsuitable for aquatic life." Also, the CPI rated the reservoir to be "severely polluted" in both dry (311.2) and wet (268.7) seasons. Similarly, HEI (951.3 and 2059.7) and Cd (942.3 and 2050.7) rated the reservoir as "highly polluted" in wet and dry seasons, respectively. The Hazard Quotient (HQ ingestion) was in the order of Mn > Cu > Cd > Zn > Fe > Co > Ni > Cr > Pb in the dry season while the order was Cu > Mn > Cd > Fe > Zn > Ni > Pb > Co > Cr in the wet season. The HQ ingestion revealed that Cr (0.00), Ni (0.33; 022), and Pb (0.00; 0.06) were the only metals with HQ values lesser than 1 (HQ < 1) while the values of HQ (dermal) were less 1 (HQ < 1) indicating that there was no health risk in association with the domestic use of the water. The pollution level of the reservoir means that urgent attention is needed from different agencies for the conservation, management, and sustainable development of the reservoir.

The investigation of water quality is crucial for the protection of health. This study assesses water quality, using pollution indices, within the coastline communities of southern Nigeria by examining a total of 48 samples of domestic water sources from 12 communities in Eastern Obolo for one year from November, 2017 to October, 2018. GPS was used to identify the sampling points and Geostatistical technique was used to visualize the risky communities. Water pollution status of the coastline communities was determined using three pollution indices: Water Quality Index (WQI), Heavy metal Evaluation Index (HEI) and Heavy metal Pollution Index (HPI). Result revealed a 66.7% acidification of the sampled domestic water sources with seasonal variation. High Turbidity in 66.67% of surface water during the wet season. Domestic water sources were generally low in Dissolved Oxygen with the highest mean value of 2.13 ± 0.45mg/L for surface water. The mean concentration of Lead (Pb), Iron (Fe) and Cadmium (Cd) were as high as 0.240.06 mg/L, 1. 400.46 mg/L and 0.680.08mg/L, respectively in some water sample. Greater than 50% of the sampled water was not safe for drinking based on water quality index. Water quality was poorer in the wet season than the dry season. Quality rating based on HEI showed that 91.7% of the sampled water had low heavy metal pollution and 8.3% was moderately polluted with heavy metals in both seasons. The total heavy metal pollution index revealed highly polluted domestic water sources. The spatial pollution distribution maps showed a more polluted urban and semi- urban communities than the remote rural communities, demonstrating the influence of urbanization and industrialization on water pollution.

The objective of this paper is to assess heavy metal concentrations and pollution indices of surface water in Enerhen River, Warri South, Delta State, Nigeria using appropriate standard method. Data obtained show that the result indicated the concentration of Zinc 0.065mg/l - 0.190mg/l, Pb (0.003mg/l -0.142mg/l), Cu (0.081mg/l - 0.213mg/l), Cd (0.02mg/l - 0.282mg/l, Cr (0.041mg/l - 0.171mg/l), Fe (0.162mg/l - 0.278mg/l) and Ni (0.104mg/l - 0.762mg/l) comparison with WHO 2012 permissible limit the probed water sample falls within the allowable concentration of the standard except the concentration of lead (Pb) in SW1, SW2, SW4 and SW5 which is a concern because it exceeded the allowable limit, lead is considered toxic to human at higher concentrations . The computed indices for the maximum admissible concentration upper permissible values buttress as follows Zn 0.3MAC, Pb 0.01MAC, Cu 2MAC, Cd 0.01MAC, Cr 0.05MAC, Fe, 0.3MAC and Ni 0.02MAC. Also, the interpretation of the assessment of pollution indices with connotations as heavy metal pollution indices (HPI), Heavy metal evaluation index (HEI) and Degree of contamination as CD. The values from the analysed sample locations are as follows SS1 for HPI value gives (3869.928), HEI (103.0056) and CD ( 96.00583). For SS2 HPI value gives as (6157.674), HEI (100.4356) and CD (93.4353). SS3 HPI (5394.674), HEI (102.2192) and CD (95.21933), SS4 HPI (507.0053), HEI (20.39265), CD (13.39267) and SS5 HPI (568.5303), HEI (25.9153) and CD (18.9154) .The HPI indicated values &gt;150 which expresses high concentration of heavy metal pollution. Similarly the HEI also indicated values &gt; 20 which again buttress high heavy metal evaluation index and the degree of contamination also gives values &gt; 3 which indicate a higher level of contamination in the samples. The River water is recommended for treatment before use due to the higher concentration of Nickel, Pb and Cadmium especially lead (Pb) which is deleterious to human health.

Heavy metals in drinking water, even in low concentrations, can be very injurious to humans. Groundwater, spring and stream waters for public consumption in Umunya district were analyzed to understand the extent of heavy metal (Fe, Zn, Mn, Pb, Cr, and Ni) pollution. Several indexical and statistical tools were integrated to achieve the research objectives. The utilized indexical tools for pollution assessment (e.g., pollution index, Nemerow’s integrated pollution index, geoaccumulation index, heavy metal evaluation index, heavy metal pollution index, and modified heavy metal pollution index) showed that at least 40% of the analyzed water samples were loaded with heavy metals. Similarly, the overall index of pollution and synthetic pollution index, which were used for drinking water quality evaluation, confirmed that at least 40% of the water supplies are unsuitable for human consumption. Moreover, similar results were obtained from an ecological risk assessment performed on the samples. Overall, Pb and Ni were the most predominant pollutants that greatly impacted the quality of the water resources for human consumption. The performance and interrelationships of the utilized models were also evaluated. Strong correlations were observed among the models. Furthermore, multivariate statistical tools, such as correlation analysis and factor analysis, were used for the pollution source apportionment. The results showed that anthropogenic inputs are more important factors that influence the heavy metal pollution in the waters. Therefore, efforts should be made to treat the polluted water supplies before human consumption and more awareness campaigns should be encouraged to protect the water resources from further deterioration in quality.

In this work, the quality of River Benue water at Makurdi was assessed for its heavy metal load alongside seven other physico-chemical parameters using water quality index (WQI) and multivariate statistical tools. A total of 45 samples from three (3) different points along the River course were collected for five months (October 2018–May, 2019) spanning the dry and wet seasons. Samples were analysed in accordance with standard methods. Most of the parameters evaluated were found to fall in the allowable limits of the World Health Organization (WHO) among others, except for colour, turbidity, total suspended solids, nickel, lead and cadmium. WQI analysis using the BISWQI, OWQI and CCMEWQI indicated that all indexing methods were suitable for estimating the WQI of River Benue as they all showed that the water corresponded to the classification as “poor water”. Heavy metal index of the river ranged from13.40–6080.00 and from 47.07–7240.00 for the dry and wet seasons, respectively, and was majorly influenced by high cadmium and lead pollution levels. Principal component analysis (PCA) revealed three rotated factor with respective communality levels for both the dry and wet seasons. Factor 1 was positively loaded with nine parameters which accounted for 32.3% of the total variance during the dry season, while it was positively loaded with 10 parameters in the wet season accounting for 25.9% of total variance. Hierarchical cluster analysis (HCA) revealed that the river was zoned into four clusters each for both dry and wet seasons. Sampling points 2 and 3 were the most polluted during the dry season, while sampling point 1 was found to be the most polluted in the wet season. It was concluded that the increasing and diverse nature of anthropogenic activities on the river course was responsible for the deteriorating quality of the water. The study recommended continuous pollution monitoring and local regulations to reduce the entrance of both diffuse and point source pollution into the river.

The urban rivers of developing countries like Bangladesh have been severely affected by toxic heavy metal pollution, posing serious ecological and human health risks. This study aimed to investigate the concentrations, spatiotemporal discrepancies, and associated risks of five alarming toxic metals (Pb, Cd, Cr, Cu and Mn) in the surface water of urban Shitalakhya River around Narayanganj port, one of the biggest and most important river ports in Bangladesh. Water samples were collected for three prevailing seasons i.e., pre-monsoon, monsoon, and post-monsoon from five selected sites. Physicochemical properties (color, odor, temperature, DO, pH, EC and TDS) of river water were also assessed, while heavy metal pollution index (HPI), heavy metal evaluation index (HEI) and degree of contamination (CD) were calculated to evaluate the risks associated with toxic metal pollution in river water. The findings revealed that several physicochemical parameters, especially DO, EC and TDS, were not within the standards. The hierarchy of mean heavy metal concentrations in Shitalakhya River water was found as Mn&gt;Cr&gt;Cu&gt;Cd&gt;Pb during pre-monsoon, Mn&gt;Cu&gt;Cr&gt;Cd&gt;Pb during monsoon, and Mn&gt;Cr&gt;Cu&gt;Pb&gt;Cd during post-monsoon season. The metal concentrations were found to be higher in pre-monsoon and post-monsoon seasons, whereas the concentrations of all the heavy metals excluding Mn were within the standards recommended for domestic use, surface water, fisheries and irrigation purposes. The comparative analysis exhibited that the water quality of Shitalakhya River is deteriorating day by day at an alarming rate. HPI showed a critical pollution index value (drinking) for all three seasons, whereas HEI revealed low heavy metal contamination for all sampling stations. The values of CD indicated a high level of contamination in pre-monsoon and post-monsoon but monsoon season. The results confirmed the spatiotemporal discrepancies in toxic metal concentrations and associated ecological and human health risks, possibly resulting from the hydrological and anthropogenic interventions not only associated with port activities. Hence, urgent collective effort and proper monitoring are of utmost importance to safeguard the public health and this urban riverine ecosystem. Int. J. Agril. Res. Innov. Tech. 14(2): 74-84, December 2024

Rapid urbanization, population growth, agricultural practices, and industrial activities have led to widespread groundwater contamination. This study evaluated heavy metal contamination in residential drinking water in Shiraz, Iran (2021). The analysis involved 80 groundwater samples collected across wet and dry seasons. Water quality was comprehensively assessed using several indices, including the heavy metals evaluation index (HEI), heavy metal pollution index (HPI), contamination degree (CD), and metal index (MI). Carcinogenic and non-carcinogenic risk assessments were conducted using deterministic and probabilistic approaches for exposed populations. In the non-carcinogenic risk assessment, the chronic daily intake (CDI), hazard quotient (HQ), and hazard index (HI) are employed. The precision of risk assessment was bolstered through the utilization of Monte Carlo simulation, executed using the R software platform. Based on the results, in both wet and dry seasons, Zinc (Zn) consistently demonstrates the highest mean concentration, followed by Manganese (Mn) and Chromium (Cr). During the wet and dry seasons, 25% and 40% of the regions exhibited high CD, respectively. According to non-carcinogenic risk assessment, Cr presents the highest CDI and HQ in children and adults, followed by Mn, As and HI values, indicating elevated risk for children. The highest carcinogenic risk was for Cr in adults, while the lowest was for Cd in children. The sensitivity analysis found that heavy metal concentration and ingestion rate significantly impact both carcinogenic and non-carcinogenic risks. These findings provide critical insights for shaping policy and allocating resources towards effectively managing heavy metal contamination in residential drinking water.

This study aimed to determine the levels of some heavy metals in the Koche River and the potential health risks. A replica of water samples was taken from 12 sampling sites purposely selected in the dry season. Heavy metal levels were determined using a flame atomic absorption spectrophotometer following the APHA (1998) procedure. Heavy metal pollution index (HPI), heavy metal evaluation index (HEI), chronic daily intake (CDI), hazard quotient (HQ), hazard index (HI), total hazard index (THI), and incremental lifetime cancer risk were calculated on the basis of the results. The heavy metals detected were Fe > Mn > Cu > Zn > Cr. The Cr, Fe, Mn, and Cu contents were above the maximum allowed limit of WHO for drinking and irrigation water at most of the sampling sites. The HPI and HEI values also surpassed the maximum limit of the study sites. The highest HPI and HEI values were found at the Yam1site. Oral ingestion represented 99.55% and 97.85% of CDItotal (CDIingestion + CDIdermal contact) in adults and children, respectively. The mean CDItotal and the noncarcinogenic risk values were found in the order of Fe > Mn > Cu > Zn > Cr in both ages. CDI, HQ, HI, and THI scores were higher in children. The HIoral and THI values were also higher than 1 in both ages except in DK 2, Sour 1, and Sour 2 sites. However, the HQdermal level was higher than 1 only for Cr in children. The ELCR obtained also indicated a high carcinogenic risk of Cr (0.75 ± 0.44 and 1.15 ± 0.66 in adults and children, respectively). In general, most of the study sites had heavy metal pollution levels that exceeded the maximum allowed limit. Therefore, effective management of sources of pollution and continuous monitoring of river quality to minimize health risks are very important.

Appraisal of heavy metal pollution in alluvial aquifers. Study case on the protected area of Ronișoara Forest, Romania

Heavy metal pollution in groundwater is a substantial environmental risk for Bangladesh. The Meghna Ghat industrial area in Bangladesh becomes a promising site for installing various industries for few decades. It was necessary to assess the heavy metal level in the groundwater of this area, and current study took the initiative. We collected 20 groundwater samples and tested pH, DO, TDS, EC, turbidity, COD, and DOC as well as four heavy metals (Cr, Cd, Pb, and Ni) to calculate four water quality indices, i.e., water quality index (WQI), degree of contamination (DC), heavy metal evaluation index (HEI), and heavy metal pollution index (HPI). Ni was too low to detect by the instrument, whereas the mean concentrations of Cr, Cd, and Pb were 0.07, 0.007, and 0.18 mg/L which exceeded the drinking water standards set by Bangladesh. According to the water quality indices, only 10% samples were good according to WQI; 30% and 15% samples were subjected to low level of pollution considering DC and HEI, respectively. Although according to HPI 35% samples were unsuitable for drinking, rest of the values were very close to characterize as unsuitable. Finally, we proposed two best-fitted models that can represent relationships between the metals and water quality indices. Water quality was comparatively better near the open spaces of the study area. The area needed to be under continuous monitoring for checking further pollution distribution.

This study appraise the heavy metal contamination in twenty drinking water sources of Dehradun, Uttarakhand, India using water quality indices viz., heavy metal pollution index and heavy metal evaluation index. A total of six heavy metals (Cu, Mn, Pb, Zn, Cr, & Fe) were analysed by atomic absorption spectroscopic (AAS) method during pre-monsoon and post-monsoon seasons. In accordance to BIS: 10500:2012, the monitored values of heavy metals have been used to evaluate heavy metal pollution index and heavy metal evaluation index in association with correlation coefficient. The results revealed the assessment of overall water quality with respect to heavy metal pollution. Heavy metal pollution index as well as heavy metal evaluation index of the water sources of Dehradun were found below the critical values of 100 and 20, respectively, which showed that there is no serious threat to human consumption with respect to studied heavy metals from sources analysed.

This survey analysed 71 bottled water brands in Tehran, Iran. The laboratory analysis was investigated for ten physicochemical parameters and 16 elements, including heavy metals comprising (bicarbonate, fluoride, chloride, nitrate, nitrite, sulphate, pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), Na, Mg, Ca, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sr, Ba, and, Zn). Statistical analysis were performed with R software. The water quality index (WQI) approach was applied to investigate water quality, the carcinogen risk (CR) and hazard index (HI) methods were used for assessing the health risks, and the cumulative impacts of heavy metals were evaluated with contamination degree (Cd) and heavy metal evaluation index (HEI). The results showed that among the physicochemical parameters, EC, TDS, TH, and HCO3 and heavy metals like Sr > Zn > Cu > Ni had the Highest values. The WQI value in totals was 91.86 and had good quality class, and the order was good (60.56%), poor (35.21%), and very poor bottled water (4.22%). The correlation results demonstrated that WQI ~ Fe and Zn ~ Mn had significant correlation coefficients (r = 1). Moreover, there is a significant correlation between TH with Mg and Ca and also between HCO3 with EC, TH, and Ca, and then between SO4 with Na. Carcinogen risk for Cr in children and adults was 2 × 10−4 and 6 × 10−4, respectively. The responsible pollutants in non-carcinogen risk assessment were F and NO3, and their HI was greater than one in adult and child subgroups. The values of Cd and HEI were lower than critical limits. Also, Pb had a significant correlation with Cd and HEI (r = 1). This study revealed that bottled water contains minerals and may possess heavy metals, which pose significant human health risks, especially for children.

Groundwater quality in floodplain regions is increasingly compromised by combined geogenic and anthropogenic processes enriching potentially toxic elements (PTEs) in aquifers. This study assessed 18 groundwater samples from shallow tube wells in three zones of Chandina Upazila, Bangladesh, including industrial (Z1), semi-industrial (Z2), and residential-agricultural (Z3) areas, to evaluate water quality and health risks of As, Pb, Mn, and Fe. Physicochemical parameters and PTEs were analyzed following standard American Public Health Association (APHA) procedures. Drinking water suitability was assessed using the water quality index (WQI), heavy metal pollution index (HPI), and heavy metal evaluation index (HEI). Contamination sources were identified using Pearson correlation analysis and the absolute principal component scores-multiple linear regression (APCS-MLR) model. Deterministic and probabilistic (Monte Carlo simulation) risk assessment were applied to estimate health risks for children and adults. The mean WQI, HEI, and HPI values were 359.43, 12.66, and 363.93 in Z1; 267.00, 14.75, and 264.59 in Z2; and 203.10, 10.37, and 197.01 in Z3, respectively, suggesting that groundwater is 'strongly affected' and 'unsuitable for drinking'. Correlation analysis revealed significant relationships among physicochemical parameters and PTEs, while the APCS-MLR identified three contamination sources: geogenic (As and Fe), mixed (Mn), and industrial (Pb). Both deterministic and probabilistic health risk assessments revealed non-carcinogenic risk (NCR) and carcinogenic risk (CR) above threshold levels (HI > 1 and TCR > 1.0E-04), mainly due to As exposure. These findings highlight widespread groundwater contamination and underscore the need for groundwater management and public health surveillance to ensure safe drinking water.

Rapid land-use changes have significantly changed the occurrence of heavy metals (HMs) in tropical watershed systems. However, the influence of land-use patterns on the spatial and temporal distribution of HMs in tropical river systems remains poorly understood. This study aims to explore the relationship between land-use types and HM pollution in the China’s largest tropical watershed, the Nandu River. Eight heavy metals (Cd, Pb, Cr, Cu, Zn, As, Hg, and Sb) in the surface water were monitored across river, estuary, and nearshore zones during wet and dry seasons. Our findings show a higher total concentration of eight heavy metals (ΣHMs) in the wet season (30.52 μg/L) compared to the dry season (21.53 μg/L). In the wet season, ΣHM concentrations followed the order: estuary (70.96 μg/L) &gt; basin (31.03 μg/L) &gt; nearshore (8.07 μg/L). In the dry season, it was basin (31.56 μg/L) &gt; estuary (23.26 μg/L) &gt; nearshore (7.49 μg/L). Land-use patterns had higher interpretation rates for HM distribution in the dry season (65.8–73.0%) compared to the wet season (31.0–42.4%). The 2000 m buffer zone had a greater impact on HM distribution than the 500 m and 1000 m zones. Agricultural land and construction areas were the primary contributors to HM pollution in the dry and wet seasons, respectively. Noteworthy, in the river basin, chromium (Cr) presented carcinogenic risks to both children and adults through ingestion in both seasons and arsenic (As) posed a risk to children in the dry season. This study provides valuable insights for the sustainable management of land use and improving river water quality by highlighting the relationship between land use and HM contamination in tropical river ecosystems.

Aim: The aim of the study is to investigate the levels and risks associated with heavy metals in the soil samples collected during the dry and wet seasons around metal scrap recycling areas in Ogijo, Ogun State.&#x0D; Study Design: The soil samples were collected randomly within the industries and communities in the vicinity of the scrap metal recycling industries (SMRI) and analyzed with XRF.&#x0D; Place and Duration of Study: The study was carried out in Ogijo in Sagamu Local Government Area, Ogun State, located within Southwestern Nigeria. The soil samples were collected in dry and wet seasons (5th to 7th March and 24th to 25th September 2020 respectively.&#x0D; Methodology: Soil samples within the industries and communities in the vicinity of the SMR were collected randomly, dried, and then sieved through a 2mm mesh stainless sieve. The sieved sample was analyzed for heavy metal concentration by using S2 Ranger, and Bruker UKX-Ray Fluorescence Spectroscopy techniques (XRF).&#x0D; Results: The results of the analyzed soil showed that the range of concentrations of heavy metals in the soil samples collected during dry season were: Fe (40100 - 87300 mg/kg); Mn (400 - 3500 mg/kg); Zn (600 -1300 mg/kg); Pb (400 - 1000 mg/kg) and during wet season: Fe (26100 -82700); Mn (500- 4200) mg/kg. Zn (600 – 1300) mg/kg; and Pb were only detected in S3 sample (600mg/kg). The results of the heavy metals were found to exceed the WHO permissible limits of heavy metals. Contamination index, degree of contamination, and pollution load indices indicated slight contamination to excessive pollution, very high risk of the degree of contamination, and extremely polluted soils respectively. The geo-accumulation index was uncontaminated to moderate contamination (0&lt;Igeo≤1) with different metals at different locations that were not detected and with all the detected Zn concentrations (except at S1) to extreme contamination (Igeo≥5).Heavy metal enrichment during both dry and wet seasons ranged from background rank (EF ≤ 1) to moderate enrichment. Eri values ranged from low (Eri) &lt;40) to moderate ecological risk (Eri &gt; 80) with all the risk indices of the locations low (RI &lt;150). The cumulative non-carcinogenic, health index (HI) for ingestion and dermal for soil during the dry season were all above 1 indicating non - carcinogenic health concerns for the residents of the study areas as they recorded higher values. The CRI was far above the acceptable limit indicating that residents in S3 during the wet season and S2 and S9 during the dry season have the probability of contracting cancer through ingestion within the life time of 70 years.&#x0D; Conclusion: The results of pollution indices show that the quality of soil in the study entirely deteriorated with respect to the DPR background. This indicates that the soil could not be used for any agricultural or domestic purposes.