Pollution Status Of Heavy Metals Research Articles

Environmental Pollution Assessment of Heavy Metals in Soils and Crops in Xinping Area of Yunnan Province, China

With the development of the economy and society, the environmental problems caused by heavy metals have always been the focus of attention. Strong concern has been recently shown for the heavy metal pollution of soils in southwestern China. The heavy metals of surface soils in the Xinping area of Yunnan province, China are surveyed along with some crop samples. There are 3312 surface soils and 95 crop samples collected in about 370 square kilometers. Heavy metals including As, Cd, Cr, Hg, and Pb and pH are analyzed. New single and integrated pollution indices of heavy metals for soils (PI and PIn) and crops (PIc and PInc) based on Chinese criteria (GB15618-2018 and GB2762-2022) are described and presented here and used to assess the pollution status of heavy metals. The results indicate that the background level of surface soils is about 62.1%, the screening level is about 33.4%, and the intervention level is about 4.5%, which is mainly a result from Cr and spatially coincides with the peridotite rock, indicating a geogenic pollution source. Most crop samples are not contaminated with heavy metals. Comparing the results of the two integrated pollution indices between soils and crops, two inconsistent assessments are observed. One is that some contaminated crops are growing in unpolluted areas (or Type I) and the other is that some uncontaminated crops are growing in polluted areas (or Type II). This indicates a new challenge between the assessment criteria on soils and crops.

Soil heavy metal pollution from waste electrical and electronic equipment of repair and junk shops in southern Thailand and their ecological risk

The waste electrical and electronic equipment (WEEE) stream in Thailand shifted from exporting WEEE to recycling them in domestic enterprises after China's import restrictions on e-waste in 2018. This study aims to investigate the pollution status, pollution sources, and ecological risk of heavy metals from manual WEEE dismantling facilities (12 repair shops and 8 junk shops) in the Nakhon Si Thammarat province of southern Thailand by examining the concentrations of As, Cd, Ni, and Pb in the topsoil (0–15 cm) during the wet and dry seasons. The results revealed that the mean concentrations of all heavy metals were higher during the dry season than in the wet season. The concentrations of analyzed soil heavy metals decreased as the intensity of e-waste dismantling activities increased, with recycling sites > repair sites > control sites (no e-waste recycling activities). Only 10% of WEEE processing workshops (junk shops) had soil Pb and As concentrations that exceeded Thailand's residential soil quality standards. However, ecological indexing models based on the geo-accumulation index found that 75% of electric repair shops were contaminated with the analyzed heavy metals, particularly Pb. Moreover, the Nemerow integrated pollution index indicated that 16.7% of electric repair shops were on the pollution warning line. Our findings suggest that policymakers should promote ecological risk assessment as a method for mitigating the negative environmental impact of electronic repair businesses, which are widely dispersed in residential areas and tend to dominate the WEEE stream because of the circular economy concept of “right to repair”, and highlight the decline of junk shops and e-waste dismantling villages for waste export resulting from China's ban.

Spatial Distribution, Speciation, and Ecological Risk Assessment of Heavy Metals in Surface Sediments of Dongjiang Lake, Hunan Province

To understand the heavy metal pollution status of Dongjiang Lake, the contents and species of heavy metals in the surface sediments were investigated during September 2021, and the heavy metal pollution level and potential ecological risk were evaluated. The results showed that Cd, Pb, As, Cu, Zn, Ni, and Cr contents were in the range of 0.40-34.1, 14.8-1688, 6.99-1155, 6.89-280, 26.2-1739, 6.29-55.4, and 23.3-44.8 mg·kg-1, respectively, with extremely uneven spatial distributions. The highest contents of Cd, Pb, As, Zn, Cu, and Ni were found in the site adjacent to Yaogangxian tungsten ore. The proportion of metal species with bioavailability was high, in which Cd in acid-soluble species was 46.7%-71.5% and Pb in reducible species was 46.8%-67.0%. The bioavailable species of Cu, Zn, Ni, and Cr were 35%-68%, 42%-72%, 26%-51%, and 6%-30%, respectively, although they primarily existed in residual species. According to the geo-accumulation index (Igeo), there was a moderate or extreme pollution status of Cd in all sites, moderate or extreme pollution status of Pb in 90% of sites, and moderate pollution status of As, Cu, and Zn in 30% of sites. The ecological risk factor (Eri) of Cd showed high potential ecological risk in all sites with significantly high potential ecological risk in 80% of sites. Moreover, As and Pb had significantly high potential ecological risk, and Cu had moderate potential ecological risk in S7, which was adjacent to Yaogangxian tungsten ore. There was a high total potential ecological risk in all sites and significantly high potential ecological risk in 50% of sites. Therefore, the surface sediments of Dongjiang Lake were under the combined pollution of Cd, Pb, As, Zn, and Cu with high bioavailability and high total potential ecological risk.

Berdan Nehri Yüzey Sedimanlarında Ekolojik ve Sağlık Riski Değerlendirmesi (Mersin-Türkiye)

Berdan River (Tarsus-Mersin) is one of the major rivers flowing into the coastal region of Northeastern (NE) Mediterranean Sea. Determination of water and sediment quality is of great importance for the sustainable management of streams and rivers. In this study, it was aimed to determine heavy metal pollution status and health risk assessment of sediments in Berdan River caused by human activities. Study findings showed that while nickel and cadmium pollution were determined at all sampling points of the Berdan River Basin, there was a regional pollution of lead and zinc caused by anthropogenic pressures due to industrial and agricultural activities as well as domestic wastewater and atmospheric inputs into the Berdan River. Furthermore, the potential health risk assessment of sediments indicated significant health hazards for the children and adults living in the study area from the carcinogenic lead, chromium and nickel.

Dissolved and particulate heavy metal pollution status in seawater and sedimentary heavy metals of the Bohai Bay

Heavy metal contamination has been the focus of many studies owing to its potential risk on the health of coastal ecosystems. The Bohai Bay (BHB) is the second largest bay of Bohai Sea and subjected to serious anthropogenic perturbations. The aim of this study was to evaluate the distribution and pollution status of toxic heavy metals in seawater with two fractions (dissolved and suspended particulate phases) and surface sediments of this coastal system. Therefore, several hydrochemical parameters and concentration of seawater metals and sediment metals were measured at two cruises of 2020 summer and autumn. The spatial distribution and potential ecological risks were examined and their inter-element relationships were analyzed to identify potential geochemical processes. By comparing historical data since 1978, we find declining trends in contents of most trace metals in seawater and sediments, suggesting that recent pollution control in BHB have an effect on diminishing metal pollution. Dissolved metals showed no significant dependence on their particulate phase. The seawater posed a moderate to high level of ecological risk. The hydrochemical factors mainly had a greater impact on dissolved metals during summer, whereas they influenced suspended metals more significantly during autumn. These results provide fundamental information to support environmental quality management and ecological protection in coastal systems.

Distribution, source, and contamination assessment of heavy metals in surface sediments of the Old Yellow River Estuary in China

To assess the sources and pollution status of heavy metals, surface sediments from the Old Yellow River estuary were systematically sampled and analyzed to determine the concentrations of seven heavy metals. The Pearson's correlation coefficient, enrichment factor, geoaccumulation index, and principal component analysis were used to distinguish the sources and assess the pollution risk of heavy metals. The results showed that the distributions of Al, Fe, Cu, Pb, Zn, Cr, and As were similar and mainly dominated by fine-grained sediments, whereas the distributions of Cd and Hg were irregular. Al was strongly correlated with Fe, Cu, Pb, Zn, As, and Mz, and positively correlated with Cr. Except for Cr, Cd, and Hg, all the other elements were positively correlated with Mz. Multiple indicators indicated that Cu, Pb, Zn, Cr, and As were mainly derived from natural sources, whereas Hg and Cd were derived from anthropogenic sources.

Pollution Characteristics, Source Analysis, and Risk Assessment of Heavy Metals in the Surrounding Farmlands of Manganese Mining Area

In order to understand the status of heavy metal pollution and the resulting ecological risk of farmland soil surrounding the manganese mining area, 174 soil samples were collected, and the heavy metals(Cu, Zn, Pb, Cr, Ni, Mn, As, and Hg) were analyzed. Principal component analysis (PCA) and the positive matrix factorization (PMF) model were used to determine the source of heavy metals in the soils. The single-factor pollution index method, geo-accumulation index method, potential ecological risk assessment method, and US EPA health risk assessment model were used to evaluate the ecological environment risk of heavy metals. The results showed that the average values of Cu, Zn, Cr, Ni, Mn, and Hg exceeded the background value of Guizhou. 100% of Zn samples and 38.86% of Cu samples exceeded the risk screening value for agricultural land soil pollution. Source analysis revealed that the main sources of soil heavy metals were mining emission, mixed agricultural activity and transportation, nature, and agricultural activities. The risk evaluation showed that Ni, Cr, Pb, and As belonged to the clean level, Hg and Cu were in a light pollution stage, Zn fell into the category of moderate contamination, and Mn reached the heavy pollution level. Cu, Zn, Pb, Cr, Ni, Mn, As, and Cd posed low potential ecological risk, while Hg caused a considerable potential ecological risk. In total, the integrated potential ecological risk of heavy metals was ranked "strong", eight types of heavy metals had carcinogenic risks and non-carcinogenic risks for children aged 0-5 years, and the main contributing factors were Cr and Mn, respectively.

Analyzing topsoil heavy metal pollution sources and ecological risks around antimony mine waste sites by a joint methodology

Studies on soil contamination caused by waste sites near antimony mining areas are scarce. For environmental protection, it is critical to investigate the contamination levels, spatial distribution, and ecological risk assessment of heavy metals (HMs) in the surface soils of different land use types around waste sites and to identify related potential sources. In this study, the pollution status, spatial distribution, sources and ecological risks of Hg, Pb, Cd, Cr, As and Sb in the surface soils of built-up areas, woodlands and croplands around the waste sites of antimony mining areas were resolved for the first time by combining self-organizing maps (SOM), K-means clustering, geographic information systems (GIS) and positive matrix factorization (PMF). According to the analysis results of soil samples, the average abundance order of HMs is: Sb > As > Cd > Pb > Cr > Hg. The cumulative geological index defines Sb as a severe pollution level. The pollution index shows that Sb and Cd in all samples are above the severe pollution level. The pollution load index shows that 67.7% of soil samples are heavily polluted. SOM and K-means divided the studied elements into three clusters and were combined with GIS analysis to from Cd as cluster 1, Sb and As as cluster 2, and Pb, Hg and Cr as cluster 3. The PMF analysis yielded three potential sources of heavy metals: natural sources dominated by Hg, Pb and Cr (48.6%), direct sources caused by the accumulation of waste sites represented by Sb and As (32.9%) and mixed sources caused by human activities and transportation represented by Cd (18.5%). Ecological risk shows that the risk of construction area is prominent, and Sb is the main contribution element of high risk. This study combines multiple methods to investigate the current status of heavy metal pollution in the soil environment around antimony mine slag sites, providing a theoretical basis for better research on the pollution of heavy metals in the soil around antimony mine slag sites and source control, and contributing to the scarcity of antimony mine slag site pollution research.

Seasonal variation, contamination and ecological risk assessment of heavy metals in sediments of coastal wetlands along the Bay of Bengal

Functioning of coastal wetland habitats is essential for the ecosystem integrity and sustainability of coastal development that enables human progress along transitional waterways. However, these habitats are continuously being affected by a variety of pollutants including metallic elements. In this study, seasonal variation, pollution status and ecological risks of heavy metals (Cr, Mn, Co, Ni, As, Cu, Zn and Pb) in surface sediment of the several types of coastal wetlands (estuaries, mudflats, sandy beaches, mangroves, and saltmarshes) were detected by using X-ray fluorescence (EDXRF) spectrometry. The results showed that the mean concentration level of metals in the surficial sediment samples followed the order of Cu (84.06 ± 8.60 μg/g) > Zn (51.00 ± 8.97 μg/g) > Mn (38.25 ± 11.34 μg/g) > Cr (3.52 ± 0.91 μg/g) > Pb (0.27 ± 0.13 μg/g) > Co (0.24 ± 0.13 μg/g) > As (0.21 ± 0.12 μg/g) > Ni (0.16 ± 0.08 μg/g). In comparison to the pre-monsoon period, the post-monsoon season had higher concentrations of heavy metals while the overall accumulation level of metals in the wetlands exhibited a pattern of estuarine wetland (28.47 ± 31.35 μg/g) > mangrove (22.23 ± 30.79 μg/g) > mudflat (21.79 ± 29.71 μg/g) > sandy beach (21.47 ± 28.15 μg/g) > saltmarsh (21.28 ± 30.02 μg/g). Although, the pollution assessment indices e.g., contamination factor (CF), degree of contamination (CD), geoaccumulation index (Igeo) and pollution load index (PLI) showed minimal levels of contamination in the studied sites, enrichment factor (EF) suggested greater enrichment of the metals in the pre-monsoon season but with the lowest ecological risk (RI < 40) in both seasons. Cluster analysis, principal component analysis (PCA), and Pearson's correlation were performed to determine the sources of heavy metals in collected samples which specified that Pb, As, Co and Ni predominantly came from natural sources whereas Cu, Mn, Zn and Cr emerged from anthropogenic sources such as industrial effluents, domestic wastewater, fertilizer or pesticide consumption on farmland along the riverbank, vessel emissions, and the confluence of tributary rivers.

Historical trends and pollution assessment of heavy metals in core sediments from the Jiangsu offshore area, China

To assess the historical changes and pollution status of heavy metals, core sediments from the Jiangsu offshore area of China were systematically sampled and analyzed to determine the concentrations of Cu, Pb, Zn, Cr, Cd, As, Hg, Li, Ni, and Co. The stratigraphic framework of the SYS-1501 core was identified based on sedimentary structures, sedimentary facies, grain size, and comparison with seismic reflections and other well-studied cores from adjacent areas. The Pearson’s correlation coefficient, enrichment factor (EF), geoaccumulation index (Igeo), and principal component analysis (PCA) were used to distinguish the sources and assess the pollution risk of heavy metals. The results showed no elemental enrichment or contamination in the core sediments, and the high EF and Igeo values of Pb, As, Hg, and Li may be related to the selected background values of these metals. Except for Mn, all other metals and TOC exhibited similar vertical distribution patterns that were closely related to the mean grain size (Mz). Almost all the heavy metals were positively correlated with Al, Fe, and Mz, and all had high loadings on PC1, indicating that they are naturally sourced. Manganese (Mn) had a high loading on PC2, mainly representing the effect of marine authigenic elements on the sediments. Historical changes in the heavy metals in the core sediments were predominantly related to the sedimentary environment, sediment sources, and Mz.

Assessment of heavy metal pollution in the soil of a construction and demolition waste landfill

Construction industry has a significant effect on the environment and human health. In developing countries including Iran, the waste generated through construction and demolition is disposed in landfills, posing further harms to the environment by increasing the amounts of heavy metals (HMs). In order to tackle the mentioned issue, the first step is to assess the landfill soil’s contamination and risk. To date, no study has examined the status of heavy metal pollution and risk assessment of construction and demolition waste (CDW) landfills in Shiraz, Iran, although a large amount of CDW is disposed in this city. In order to fulfil the mentioned gap within the body of knowledge, a novel study was conducted in which a case study CDW landfill within Shiraz, Iran, was investigated carefully. 420 samples were collected, which was followed by various types of assessment techniques including geo-accumulation index, pollution load index, enrichment factor, and potential ecological risk assessment. The results obtained from pollution assessment methods illustrated considerable levels of contamination within the landfill, with Cd as the main contaminant (PLI value of 14.15, and significant enrichment for 92.7% of the collected samples). Risk assessment also showed a high-level risk of HMs for 84.16% of the samples extracted from the landfill soil, and the most prominent contributors were Cd and Pb with average ecological risks of 712.2 and 57, respectively. The results of this study can have a great impact on future policies and strategies regarding the disposal of CDW in Shiraz, Iran.

Heavy metal content and microbial characteristics of soil plant system in Dabaoshan mining area, Guangdong Province.

The disordered mining of Dabaoshan lead-zinc mineral resources in Shaoguan has brought serious harm to the regional ecological environment. In order to investigate the heavy metal pollution status and microbial characteristics of soil plant system in mining area, The distribution of heavy metals in the soil, the activity of soil microorganisms and the accumulation characteristics of heavy metals in the dominant plant Miscanthus floridulus were studied. The results indicated that metal element contents of Miscanthus floridulus in sequence were: Zn>Pb>Cu> Cd. This study demonstrated that the elemental content of the Miscanthus floridulus plant showed Zn>Pb>Cu>Cd, with Zn being the most significantly correlated with soil elements, followed by Pb. Compared with the control group, the Miscanthus floridulus-soil system possessed obviously different soil microbial features: intensiver in microbial basal respiration strength, and higher microbial eco-physiological parameters Cmic/Corg and qCO2, but lower in soil microbial biomass. The results showed the soil enzymatic activities decreased significantly with increase of contamination of heavy metals, especially dehydrogenase and urease activities. With the increase of the content of heavy metals in the mining area soil, the intensity of soil biochemical action in the mining area (Q1, Q2) soil decreased significantly, and the biochemical action showed a significant negative correlation with the content of heavy metals in the soil. Compared with the non mining area (Q8) soil, the intensity of soil ammonification, nitrification, N fixation and cellulose decomposition decreased by 43.2%~71.1%, 70.1%~92.1%, 58.7%~87.8% and 55.3%~79.8% respectively. The decrease of soil microbial activity weakened the circulation rate and energy flow of C and N nutrients in the soil of the mining area.

Seasonal Variation Characteristics and Pollution Assessment of Heavy Metals in Water and Sediment of Taipu River

Taipu River is a river spanning two provinces and one city in a demonstration area in the Yangtze River Delta on an ecologically friendly developmentand an important water source in the upper reaches of the Huangpu River in Shanghai. To understand the multi-media distribution characteristics, pollution status, and ecological risk of heavy metals in the Taipu River, the contents of heavy metals (As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, and Zn) in the sediments of Taipu River were analyzed, and the pollution status and potential ecological risk were evaluated using the Nemerow comprehensive pollution index, geo-accumulation index, and potential ecological risk index methods. In addition, the health risk assessment model was used to assess the health risk of heavy metals in surface water of Taipu River. The results showed that the concentrations of Cd, Cr, Mn, and Ni in the surface water of Taipu River exceeded the class Ⅲ water limit at the upstream point in spring; the concentrations of Sb exceeded the class Ⅲ water limit at all points in winter; the average value of As exceeded the class Ⅲ water limit in overlying water during the wet season; and the average values of As and Cd exceeded the class Ⅲ water limit in pore water during the wet season. The health risk assessment of surface water implied that both adults and children had higher health risk in spring and lower health risk in other seasons. The health risk of children was significantly higher than that of adults, and it mainly came from chemical carcinogenic heavy metal elements As, Cd, and Cr. The average contents of Co, Mn, Sb, and Zn in Taipu River sediments in the four seasons all exceeded the Shanghai soil baseline; the average contents of As, Cr, and Cu in summer, autumn, and winter exceeded the Shanghai soil baseline; and the average contents of Cd, Ni, and Pb in summer and winter exceeded the Shanghai soil baseline. The evaluation results of the Nemerow comprehensive pollution index and geo-accumulation index showed that the pollution degree of the middle reaches of Taipu River was higher than that of the upper and lower reaches, and the Sb pollution was more serious. The potential ecological risk index method revealed that the Taipu River sediment was at a low risk. Cd had a high contribution in both the wet and dry seasons and could be regarded as the main heavy metal of potential ecological risk in the Taipu River sediment.

Trophic transfer of heavy metals in a wetland food web from an abandoned e-waste recycling site in South China

In order to understand the pollution status and trophic transfer of heavy metals across wetland food web organisms, four invertebrate species, six fish species, one snake species, and one bird species were collected from an abandoned e-waste site in South China for analysis of toxic elements (Ni, Zn, Cu, Cr, Cd, and Pb). The concentrations of Ni, Zn, Cu, Cr, Cd, and Pb were 0.16–15.6, 24.9–850, 1.49–645, 0.11–64.6, 0.01–4.53 and 0.41–40.4 mg/kg dry weight, respectively. The results demonstrated that the concentrations of six studied heavy metals decreased throughout the whole food web, but Cu and Zn concentrations increased along the bird and reptile food chains, respectively. The trophic transfer of metals for the key species should be of special attention, as the trophic biomagnification factor (TMF) in a food web may overlook the ecological risks of metals for certain species, especially those at high trophic levels. The estimated daily intake (EDI) and the target hazard quotient (THQ) results showed that Cu, Cd, and Pb posed the main risks on human health, especially through the consumption of snail and crab species.

Levels of heavy metal in soil and vegetable and associated health risk in peri-urban areas across China

Peri-urban vegetable field plays an essential role in providing vegetables for local residents. Because of its particularity, it is affected by both industrial and agricultural activities which have led to the accumulations of heavy metal in soil. So far, information on heavy metal pollution status, spatial features, and human health risks in peri-urban vegetable areas across China is still scarce. To fill this gap, we systematically compiled soil and vegetable data collected from 123 articles published between 2010 and 2022 at a national level. The pollution status of heavy metals (i.e., cadmium (Cd), mercury (Hg), arsenic (As), lead (Pb), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn)) in peri-urban vegetable soils and vegetables were investigated. To evaluate the levels of heavy metal pollution in soil and human health risks, the geoaccumulation index (Igeo) and target hazard quotient (HQ) were calculated. The results showed that mean concentrations of Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn in peri-urban vegetable soils were 0.50, 0.53, 12.03, 41.97, 55.56, 37.69, 28.55, and 75.38 mg kg−1, respectively. The main pollutants in peri-urban vegetable soil were Cd and Hg, and 85.25% and 92.86% of the soil samples had Igeo > 1, respectively. The mean Igeo values of this regions followed the order of northwest > central > south > north > east > southwest > northeast for Cd and northeast > northwest > north > southwest > east > central > south for Hg. The mean Cd, Hg, As, Pb, Cr, Cu, Ni, and Zn concentrations in vegetables were 0.30, 0.26, 0.37, 0.54, 1.17, 6.17, 1.96, and 18.56 mg kg−1, respectively. Approximately 87.01% (Cd), 71.43% (Hg), 20% (As), 65.15% (Pb), 27.08% (Cr) of the vegetable samples exceeded the safety requirement values. The vegetables grown in central, northwest, and northern China accumulated much more heavy metals than those grown in other regions. As the HQ values for adults, 53.25% (Cd), 71.43% (Hg), 84.00% (As), and 58.33% (Cr) of the sampled vegetables were higher than 1. For children, the HQ values were higher than 1 for 66.23% (Cd), 73.81% (Hg), 86.00% (As), and 87.50% (Cr) of the sampled vegetables. The findings of this study demonstrate that the situation of heavy metal pollution in peri-urban vegetable areas across China are not optimistic and residents who consume the vegetables are at high risk of health issues. To ensure soil quality and human health, strategies should be taken to guide vegetable production and remedy soil pollution in peri-urban areas with the rapidly urbanizing China.

Assessment of heavy metal pollution in Nigerian surface freshwaters and sediment: A meta-analysis using ecological and human health risk indices

Heavy metal pollution in surface freshwaters is prevalent globally and is an environmental issue of concern. Many studies have described sources, concentrations in selected waterbodies and toxic effects in biological systems. The purpose of the present study was to assess the status of heavy metal pollution in Nigerian surface freshwaters as well as the ecological and public health risks associated with current levels of pollution. A literature review of studies which assessed concentrations of heavy metals in named freshwater bodies around the country was done to gather relevant data. These waterbodies included rivers, lagoons, and creeks. The data gathered was subjected to a meta-analysis using referenced heavy metal pollution indices, sediment quality guidelines, ecological risk indices and non-carcinogenic and carcinogenic human health risk indices. The result obtained showed that concentrations of Cd, Cr, Mn, Ni and Pb in Nigerian surface freshwaters are higher than the maximum recommended levels in drinking water. The heavy metal pollution indices calculated using drinking water quality criteria by the World Health Organization and the US Environmental Protection Agency, were also significantly higher than the threshold value of 100 (13,672.74 and 1890.65 respectively). These results indicate that the surface waters are unsafe for drinking purposes. The enrichment factor, contamination factor and ecological risk factor indices for cadmium (684.62, 41.73 and 1251.90 respectively) were all higher than the maximum threshold for each index (40, 6, 320 respectively). These results indicate that cadmium contributes significantly to the ecological risk associated with pollution in Nigerian surface waters. In terms of public health risk, the current levels of heavy metal pollution in Nigerian surface waters pose both non-carcinogenic and carcinogenic risks to children and adults who are exposed through ingestion and dermal routes as shown by results from the present study. Nigeria is blessed with abundant surface freshwater resources and many coastal indigenous populations use the water resources for drinking and domestic purposes. Many of them are also commercial fish farmers earning their daily living from fisheries resources. Heavy metal pollution must be regulated to levels below which end users and aquatic life are protected from adverse impacts of pollution.

Evaluation of health risk and heavy metal pollution status in the Bhima River water Kalaburagi, Karnataka, India

The current investigation aimed to examine the present status of pollution in the Bhima River using indices (degree of contamination, heavy metal evaluation index, &amp; heavy metal pollution index) and health risk assessment (non-carcinogenic &amp; carcinogenic) by choosing some heavy metals like copper (Cu), chromium (Cr), manganese (Mn), cadmium (Cd), nickel (Ni), lead (Pb), &amp; zinc (Zn). Eight samples of surface water were collected monthly from October 2021 to September 2022 and analyzed by an atomic absorption spectrometer. The absorptions of heavy metals into sequence Mn &gt; Zn &gt; Cu &gt; Pb &gt; Ni &gt; Cr &gt; Cd have been observed. Pb, Cd, and Ni concentrations were considerably higher in samples collected near sewage runoff and along bridges. The calculated pollution indices indicate that five of the eight sampling sites are extremely polluted. Carcinogenic &amp; Non-carcinogenic dangers were tabulated for adults, children, &amp; infants according to the quantity of heavy metal content in an average daily consumption of water. For adults, children, as well as infants, the estimated non-carcinogenic standards were 3, 5, and 2, respectively. The computed carcinogenic risk levels for Pb, Cd, and Ni exceed the 10-6-10-4 acceptable limit. Indices and risk assessment values suggest that river water is not acceptable for ingestion by all age groups. Additionally, principal component analysis and cluster analysis disclosed that agricultural runoff, lead battery usage, sewage sludge, and bridge construction were the foremost sources of water quality degradation in the study zone. The development of a public drinking water supply is advised by this research to lessen negative impacts of heavy metal poisoning upon human health. Before making the water available for use by the public, it needs also be treated.

Assessment of heavy metals pollution status of surface soil dusts at the Katima Mulilo urban motor park, Namibia

The aim of the study was to examine the pollution status of environmentally concerned heavy metals: lead, cadmium, chromium, arsenic, cobalt, nickel, copper, zinc, vanadium, and manganese in surface soil dusts at the Katima Mulilo urban motor park (KMUMP), Namibia. Composite surface soil dusts samples were randomly collected from three points at 10 m apart within the motor park, and a control site on a weekly basis over 8 weeks. Pooled sampled were homogenized and 20 sub-samples (<75 μm soil fraction) were taken from the large sieved sample and digested according to EPA method 3050B. The digestates were analyzed for concentrations of the heavy metals using ICP-OES (Perkin Elmer Optima 7000 DV). The results showed a wide range of heavy metals concentrations from 0.33 mg/kg Cd to 13.7 mg/kg Zn, and differed statistically between study locations (p < 0.05). The results were generally lower than their WHO’s maximum permissible concentrations in soils for the protection of ecosystem’s health. The ecological risk indexes of the heavy metals suggest that the surface soil dusts at KMUMP were not contaminated by the heavy metals at this point. However, this does not preclude exposure risks to travelers, especially vulnerable children due to heavy metals’ toxicity and bioaccumulation.

Heavy Metal Concentration and Pollution Status of Cross River in Afikpo Catchment Area, Ebonyi State, Nigeria

Heavy Metal Concentration and Pollution Status of Cross River in Afikpo Catchment Area, Ebonyi State, Nigeria

Spatial Distribution Characteristics and Source Analysis of Heavy Metals in Soil of a Lead Plant in Sanmenxia

At present, a large-scale relocation of industrial enterprises is taking place in major cities in China, and a large number of contaminated relocation sites are being generated, among which the heavy metal pollution is particularly serious. In order to analyze the pollution status, spatial distribution, and sources of heavy metals in the soil of a lead factory in Sanmenxia, the spatial variation and distribution characteristics of heavy metals in the soil were analyzed using geostatistics, and the main sources of heavy metals in the soil were analyzed using a PMF model. The results showed that the average values of As, Cd, Cu, Pb, Hg, and Ni in the soil far exceeded the background values of the soil environment in Henan province; the contents of As, Cd, Pb, and Hg exceeded the screening values of soil pollution risk; and the contents of As, Pb, and Hg exceeded the control values of soil pollution risk. The high-value area was located on the northern part of the slag yard; the Cr, Ni, and Cd high-value area was located in the north and south of the slag yard; the high-value As area was located in the slag yard between the southern area and the living quarters; the Cu and Pb high-value area was relatively scattered, mainly concentrated in the central part of the raw material storage area and furnace area; and Ni and Cd and Cu and Pb had the same spatial distribution characteristics. Based on the PMF model, it can be seen that there were three main sources of the seven heavy metals, and Cd was mainly from waste residue accumulation, with a contributing rate of 87.60%. Cu, Pb, and Hg were mainly soil parent material, with contribution rates of 92.50%, 75.20%, and 95.40%, respectively. Cr, Ni, and As were mainly raw material dust exhaust gas sources, with contribution rates of 80.80%, 83.30%, and 62.00%, respectively.