Heavy Metal Contamination Status Research Articles

Heavy Metal Content and Pollution Assessment in Typical Check Dam Sediment in a Watershed of Loess Plateau, China

To understand historical trends and assess the ecological risk associated with heavy metal pollution, the concentration of eight species of heavy metals (vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), copper (Cu), and arsenic (As)) in typical silt dam sediments on the Loess Plateau were analyzed. The radionuclide 137Cs was used to quantify rates of erosion, deposition, and heavy metal contamination in the soils of a watershed that supplies a check dam. The sediment record revealed three time periods distinguished by trends in erosion and pollutant accumulation (1960–1967, 1968–1981, and 1985–1991). Heavy metal concentrations were highest but exhibited significant fluctuation in the first two periods (1960–1967 and 1968–1981). From 1985 to 1991, heavy metal pollution showed a downward trend and tended to be stable. The potential risks of heavy metals in silt dam sediments were explored by applying the geo-accumulation index and the potential ecological risk index. The results indicated medium risk associated with Cu and As accumulation, especially in 1963, 1971, and 1986 when the assessed values increased significantly from previous levels. Agricultural practices and high rates of slope erosion may be responsible for the enrichment of As and Cu in soil and the accompanying increase in risk. Land use optimization and the careful use of fertilizers could be used to control or intercept heavy metal pollutants in dammed lands. The results provide the basis for evaluating the current status and ecological risk of heavy metal contamination in dam sediments and for predicting possible heavy metal pollution in the future.

Evaluation of Contamination Status, Ecological and Human Health Risks of Heavy Metals in Sediments North of Safaga Bay along the Red Sea, Egypt

Evaluation of Contamination Status, Ecological and Human Health Risks of Heavy Metals in Sediments North of Safaga Bay along the Red Sea, Egypt

Contaminant Characteristics and Influencing Factors of Heavy Metals in Seawater and Sediments in a Typical Mariculture Bay in South China

Heavy metal pollution in the mariculture areas is of considerable attention due to its potential ecological effects and public concern for seafood safety. A better understanding of the current contamination status and historical trend of heavy metals in the ecosystems of mariculture areas has an important implication for the sustainable development of marine ecosystems and for public health concerns. To assess the impact of human activities on heavy metal pollution in the mariculture area, seven metals (Cu, Pb, Zn, Cd, Hg, As, and Cr) and the environmental parameters were seasonally investigated in the surface seawater and sediments in Qinzhou Bay, a typical mariculture bay in South China. Seasonal variations in the concentration of heavy metals were found in both seawater and sediment, which are mainly influenced by seasonal hydrological change, biological activity, and human influence. The concentration of heavy metals in the seawater was at a relatively higher level than that of other mariculture areas in China, while a lower level was found in the sediment. The concentration of Cu increased in both seawater and sediment for the past decades (by nearly 2 times), which is mainly influenced by the mariculture and shipping activities. The concentration of Hg decreased significantly in the seawater for the past 40 years (decreased by 13 times) due to the decrease in production and usage of Hg. However, the concentrations of Pb, Zn, and Cd in seawater showed an increasing trend in the mariculture bay, while the concentrations of Pb, Zn, As, and Cr decreased in the sediment over the past decades. The decrease in pH value (decreasing by 4.7% for the past 20 years) was responsible for the different trend of those metals between seawater and sediment because the decrease in pH could re-release metals from sediments into the water column. Hg and As are the main ecological risk factors in the mariculture bay. This study suggests that environmental changes, such as ocean acidification, affect the distribution of metals in seawater and sediments, which we should be more vigilant and concerned about under the global climate change.

Spatial distribution, pollution assessment, and source identification of heavy metals in the Yellow River

The discharge of pollutants into the Yellow River has been strictly controlled since 2013 due to the severe pollution. Thus, the overall water quality of the Yellow River has been becoming better year by year. However, the contamination status and source identification of heavy metals from the entire Yellow River remains unclear. Our results demonstrated that heavy metal contents in sediments showed little changes over time, whereas significant alleviation was observed in surface water compared to the reported metal concentrations before 2013. No heavy metal contamination was observed in surface water, and the distribution of all heavy metals in surface water fluctuated along the mainstream without a significant spatial difference. Heavy metals in sediments were assessed as low to moderate contamination degree. The majority of heavy metal concentrations were higher in the upstream and midstream than that in the downstream. Besides anthropogenic activities, the natural contribution from soil erosion of the Loess Plateau was also an important source of heavy metals in the Yellow River sediments. Our results highlight that control of anthropogenic activities and soil erosion of the Loess Plateau are necessary measures to reduce heavy metals in the Yellow River.

Analysis of the status and ecological risks of heavy metals contamination in artisanal and small-scale gold mine-spoils at the Atewa Forest Landscape, Ghana

The study analysed the contamination status and potential ecological risk of heavy metals (Fe, Cu, Mn, Zn, Pb, Cd, As and Hg) in soils from un-reclaimed illegal artisanal and small-scale gold mine (‘galamsey’) sites at the Atewa forest landscape. Composite soil samples (48) were collected from topsoil (0–20 cm) and subsoil (20–50 cm) across eight communities in four districts. Samples were analyzed using FAAS in the laboratory, and the results were evaluated using the geoaccumulation index (Igeo) and potential ecological risk index (PERI). The results based on the I geo values showed that the contamination status from the heavy metals in the topsoil and subsoil were: Hg>Cd>As>Pb>Mn>Cu>Zn>Fe and Hg>Cd>As>Pb>Cu>Mn>Zn>Fe respectively. These suggest strong Hg pollution in both topsoil (4.01) and subsoil (4.45), moderate Cd contamination in topsoil (1.04) and subsoil (1.48) and moderate As (0.54) contamination in subsoil only. The PERI from the heavy metals in both topsoil and subsoil were: Hg>Cd>As>Pb>Cu>Mn>Zn>Fe. Overall, Hg (PERI > 964) posed very severe ecological risk, with the greatest contribution to potential ecological toxicity; followed by Cd (PERI > 92) and As (PERI > 16) in the soils. Multivariate statistical analysis revealed that the elements Fe, Cu, Mn were consistently naturally occurring in the soil minerals while As, Pb and Hg were of anthropogenic origin, notably galamsey’ activities with Cd and Zn originating from both sources. This outcome highlights the need for prompt action towards the restoration of soil quality in the study area to protect human and ecological health and enhance post-mine forest restoration.

Level, distribution, ecological, and human health risk assessment of heavy metals in soils and stream sediments around a used-automobile spare part market in Nigeria.

The aim of this research was to assess the distribution, sources, contamination status, ecological risk, and human health risk of heavy metals (HMs) in soil and sediments of a used-automobile spare part market in Nigeria. Forty-three (43) soil samples were collected within a spare part market section (SPMS-17 samples), market-residential section (MRES-10 samples), traffic section (TRAS-10 samples), and non-market residential section (NMRS- 6 samples). Fifteen (15) stream sediments were collected within and around SPMS. Based on average concentrations, HMs (As, Cd, Cr, Cu, Fe, Mo, Pb, and Zn) had their highest values in SPMS, and their minimum values were observed in NMRS. The high concentration was as a result of contributions from anthropogenic activities such as the direct discharge of used-lubricant oil, scrap metals, tire wear, and traffic emission in the environment. However, Al, Co, and Mn were derived from the geology of the area. The same trend was observed in the stream sediment section (STSS), except that in addition to Al, Co and Mn in soils, Cr was also sourced from geogenic activity. There were moderate to high enrichment/contamination factors of the anthropogenically sourced HMs, especially in the soil of SPMS, MRES, TRAS and stream sediments (STSS). Similarly, high potential ecological risk (Eri) and ecological risks (RI) were observed for As, Pb, and Cd in SPMS and STSS, while these were moderate in MRES and TRAS. Assessment of health risks was within acceptable limit for most of the HMs in the different sections for both adults and children, except As, Cd, and Pb in SPMS and STSS, which were beyond the acceptable limit for children. The carcinogenic risk was within the acceptable limit.

Sedimentation of metals in Sundarban mangrove ecosystem: Dominant drivers and environmental risks.

Metal contamination from upstream river water is a threat to coastal and estuarine ecosystem. The present study was undertaken to unveil sedimentation processes and patterns of heavy metal deposition along the salinity gradient of a tropical estuary and its mangrove ecosystem. Sediment columns from three representative sites of differential salinity, anthropogenic interference, and sediment deposition pattern were sampled and analyzed for grain size distribution and metal concentrations as a function of depth. Sediments were dominantly of silty-medium sand texture. A suite of fluvial and alluvial processes, and marine depositional forcing control the sediment deposition and associated heavy metal loading in this estuary. The depth profile revealed a gradual increase in heavy metal accumulation in recent top layer sediments and smaller fractions (silt + clay), irrespective of tidal regimes. Alluvial processes and long tidal retention favor accumulation of heavy metals. Enrichment factor (0.52-15), geo-accumulation index (1.4-5.8), and average pollution load index (PLI = 2.0) indicated moderate to higher heavy metal contamination status of this estuary. This study showed that alluvial processes acted as dominant drivers for the accumulation of metals in sediments, which prevailed over the influence of marine processes. Longer tidal retention of the water column favored more accumulation of heavy metals. Metal accumulation in the sediments entails a potential risk of bioaccumulation and biomagnification through the food web, and may increasingly impact estuarine ecology, economy, and ultimately human health.

Inputs and sources of Pb and other metals in urban area in the post leaded gasoline era

The contamination status of heavy metals in urban environment changes frequently with the industrial structure adjustment, energy conservation and emission reduction and thus requires timely investigation. Based on enrichment factor, multivariate statistical analysis and isotope fingerprinting, we assessed comprehensively the inputs and sources of heavy metals in different samples from an urban area that was less impacted by leaded gasoline exhaust. The road dust contained relatively high levels of Cr, Pb and Zn (with enrichment factor >2) that originated from both exhaust and non-exhaust traffic emissions, while the moss plants could accumulate high levels of Pb and Zn from the deposition of traffic exhaust emission. This suggest that the traffic emission is still an important source of metals in the urban area although gasoline is currently lead free. On the contrary, the occurrences of metals in the urban soils were controlled by natural sources and non-traffic anthropogenic emission. These findings revealed that different samples would receive different inputs of metals from different sources in the urban area, and the responsiveness and sensitiveness of these urban samples to metal inputs can be ranked as moss ≥ dust > soil. Taken together, our results suggested that in order to avoid generalizing and get detail source information, multi-samples and multi-measures must be adopted in the assessment of integrated urban environmental quality.

Pollution evaluation and health risk assessment of heavy metals in the surface water of a remote island Nijhum Dweep, northern Bay of Bengal

The current study aimed to evaluate the distribution and status of heavy metal contamination of surface water in the Nijhum Dweep, northern Bay of Bengal. Ten surface water samples were collected to determine the heavy metals and the associated human health risk. Themean concentrations of heavy metals were ranked in descending order ofFe (3.412 mg/L) > Mn (0.3911 mg/L) > Pb (0.3 mg/L) > Co (0.2918 mg/L) > Zn (0.230 mg/L) > Ni (0.1943 mg/L) > Cu (0.167 mg/L) > Cd (0.11 mg/L) > Cr (0.077 mg/L). All the metals except Cd, Pb, and Ni were found uncontaminated, and these three metals influenced the values of heavy metal pollution indices. Heavy metal evaluation index (HEI), heavy metal pollution index (HPI), and Nemerow pollution index (NI) revealed that the surface water of Nijhum Dweep is low to moderately contaminated by these selected heavy metals. The calculated potential ecological risk for the surface water of Nijhum Dweep ranged from 0.88 to 382.93 with a mean value of 189.71, which falls in the moderate ecological risk category. Hazard quotient (HQ) and hazard index (HI) for adults and children showed no non-carcinogenic risk of heavy metals from dermal exposure pathways except station 4 at the south of the Nijhum Dweep due to high Mn concentration. No possible carcinogenic risk was found from the analyzed metals. Several local sources of heavy metals were found during the field investigation, such as small-scale metallurgical activities, oil spills from ships, and fishing trawlers. Again, industrial effluents and agrochemicals from upstream regions also contribute to heavy metal pollution in downstream coastal regions of Bangladesh. Even though the surface water pollution level is low to moderate in the study area, the authority should take proper management and monitoring strategy for future sustainability.

The application of machine learning methods for prediction of metal immobilization remediation by biochar amendment in soil

Biochar has been used widely in heavy metal contaminated sites as a soil remediation agent. However, due to the diversity of soils, biochars, and heavy metal contamination status, the remediation efficiency is difficult to measure, owing to a variety of parameters such as soil, biochar properties, and remediation procedure. Thus, an appropriate method to predict the remediation results and to select the appropriate biochar for the remediation is required. We initially created a database on soil remediation by biochars, which has 930 datasets with 74 biochars and 43 soils in it, based on collecting and organizing data from published literatures. Then, using data from the database, we modeled the remediation of five heavy metals and metalloids (lead, cadmium, arsenic, copper, and zinc) by biochars using machine learning (ML) methods such as artificial neural network (ANN) and random forest (RF) to predict remediation efficiency based on biochar characteristics, soil physiochemical properties, incubation conditions (e.g., water holding capacity and remediation time), and the initial state of heavy metal. The ANN and RF models outperform the lineal model in terms of accuracy and predictive performance (R2 > 0.84). Meanwhile, model tolerance of the missing data and reliability of the interpolation were studied by the predicted outputs of the models. The results showed that both ANN and RF have excellent performances, with the RF model having a higher tolerance for missing data. Finally, through the interpretability of ML models, the contribution of factors used in the model were analyzed and the findings revealed that the most influential elements of remediation were the type of heavy metals, the pH value of biochar, and the dosage and remediation time. The relative importance of variables could provide the right direction for better remediation of heavy metals in soil.

Pollution Assessment and Source Apportionment of Soil Heavy Metals in a Coastal Industrial City, Zhejiang, Southeastern China.

In this research, Ningbo City, a typical industrial city in southeastern China, was selected as the study area, and the concentrations of 12 heavy metals (Cd, Cr, Ni, Pb, Zn, Cu, Hg, As, Co, V, Se, and Mn) were measured at 248 sampling points. Pollution index methods were used to assess the status of soil heavy metal contamination, and the Positive Matrix Factorization (PMF) model and Unmix model were integrated to identify and apportion the sources of heavy metal contamination. The results indicated that nearly 70% of the study area was polluted by heavy metals, and that Ni, Cr, and Zn were the main enriched heavy metals. The five sources identified using the PMF model were a geological source, an atmospheric deposition source, a transportation emissions source, a mixed source of agriculture and industry, and a mixed source of geology and industry. The four sources identified using the Unmix model were a mixed source of geology, agriculture, and industry (14.27%); a transportation emissions source (4.76%); a geological source (14.7%); and a mixed source of geology and industry (66.28%). These results have practical significance, as they can help to carry out pollution source risk assessment and give priority to the management of pollution source control.

Heavy Metal Contamination Status and Risk Assessment in Surface Sediments of Köyceğiz Lagoon Estuary System (KLES) (South-West Anatolia)

This study reports the presence of heavy metals (Cr, Ni, Cu, Cd, Pb) in the sediment and water column in the Köyceğiz Lagoon Estuary System (KLES) (South-West Anatolia). The mean heavy metal concentrations (µg L-1) in the water were found as Cr: 3.72-8.36, Ni: 6.51-9.48, Cu: 1.29-11.88, Cd: ND-0.08, Pb: ND-0.34. The heavy metal concentrations in water samples were found to be below the internationally acceptable limits. The mean heavy metal concentrations (mg kg-1) in the sediment were found as Cr: 1.75-4.25, Ni: 5.24-12.69, Cu: 0.25-0.51, Cd: <0.01, Pb: 0.04-0.13. As a result of the analyses conducted concerning contamination factor (CF), geo-accumulation index (Igeo), pollution load index (PLI), monomial potential ecological risk index (ER), and total potential ecological risk index (RI) for heavy metals in the sediment, it was deduced that there was not any pollution and moderate or high ecological risks.

Source analysis and source-oriented risk assessment of heavy metal pollution in agricultural soils of different cultivated land qualities

Heavy metal pollution in soil has received much attention in recent decades. Many studies have analyzed the contamination status, spatial distribution, and pollution sources of heavy metals. Little information is available on the interaction between cultivated land quality and soil heavy metal pollution. Combining soil quality information and intensive heavy metal sampling surveys, this study analyzed heavy metal contamination and the ecological and health risks of various soils with different quality levels. Additionally, through the PMF model and risk assessment techniques, the ecological and health risks of specific pollution sources and their interaction with soil quality were investigated. The results showed that the mean content of the studied elements followed the increasing order of Hg (0.12 mg/kg) < Cd (0.19 mg/kg) < As (6.98 mg/kg) < Pb (25.57 mg/kg) < Cr (72.02 mg/kg). In addition, with increasing soil quality, the concentrations of Pb, Cr and Hg as well as the overall ecological risk increased significantly. Regarding health risks, heavy metal pollution posed a higher risk to children than adults, and ingestion was the main exposure pathway. The total hazard index and carcinogenic risk also increased with increasing soil quality. The PMF analysis showed that Pb and Cr mainly came from industrial activities, As could be attributed to natural sources, Cd was mainly derived from agricultural activities, and Hg pollution was determined by coal combustion. Considering the risks of specific pollution sources, agricultural activities and coal combustion were the major reasons for high ecological risks, whereas industrial activities and coal combustion posed significantly higher risks in suburban high-quality soil. Industrial activities mainly determined the health risk, which contributed more than 50% to the total risk. There was an upward health risk trend with increasing soil quality. Industrial activities in high-quality suburban soil posed the highest health risk to both adults and children. Reasonable and effective policies should be formulated to control industrial pollution and improve the ecological environment in this area.

Source identification, contamination status and health risk assessment of heavy metals from road dusts in Dhaka, Bangladesh

In this study, concentrations of Cr, Mn, Ni, Cu, Zn, Cd and Pb were determined in road dusts collected from different locations in Dhaka to assess source, contamination status and health risk. Energy-dispersive X-ray fluorescence spectroscopy and energy-dispersive X-ray spectroscopy were used to determine Cr, Mn, Ni, Cu, Zn, Cd and Pb and their mean concentrations were 162.27 ± 29.46, 721.18 ± 180.14, 35.65 ± 12.55, 104.56 ± 128.33, 515.32 ± 321.90, BDL, and 342.82 ± 591.20 mg/kg, respectively. Among the heavy metals, highest concentrations of Cu, Zn and Pb were found at urban sites-7 (municipal waste dumping) and 8 (medical waste incineration). Highest concentration of Cr followed by Cu and Zn was found at site-5 (Tejgaon, urban). Principal component analysis revealed that anthropogenic activities are the potential sources for Cr, Ni, Cu, Zn and Pb while earth crust for Mn. Pollution index and pollution load index results suggested that all the sites were contaminated and/or degraded by Cr, Cu, Zn and Pb except sites-9 (urban), 10 (sub-urban), 11 (rural) while sites-7 and 8 (urban) were extremely degraded. For noncarcinogenic health risk, hazard quotient values for dermal were higher compared to that of inhalation/ingestion. Though hazard index values were less than 1 at all the sites, these were at least one order of magnitude higher for children group than that of adult group, thus the children group may face more noncarcinogenic health risk at sites-7 and 8. Values of incremental lifetime cancer risk were from 10−9 to 10−11 showed no carcinogenic health risk by road dusts contaminated with the heavy metals.

A critical review on various remediation approaches for heavy metal contaminants removal from contaminated soils

Heavy metal pollution remains a global environmental challenge that poses a significant threat to human life. Various methods have been explored to eliminate heavy metal pollutants from the environment. However, most methods are constrained by high expenses, processing duration, geological problems, and political issues. The immobilization of metals, phytoextraction, and biological methods have proven practical in treating metal contaminants from the soil. This review focuses on the general status of heavy metal contamination of soils, including the excessive heavy metal concentrations in crops. The assessment of the recent advanced technologies and future challenges were reviewed. Molecular and genetic mechanisms that allow microbes and plants to collect and tolerate heavy metals were elaborated. Tremendous efforts to remediate contaminated soils have generated several challenges, including the need for remediation methodologies, degrees of soil contamination, site conditions, widespread adoptions and various possibilities occurring at different stages of remediation are discussed in detail.

Geospatial analysis, source identification, contamination status, ecological and health risk assessment of heavy metals in agricultural soils from Qallin city, Egypt

Geospatial analysis, source identification, contamination status, ecological and health risk assessment of heavy metals in agricultural soils from Qallin city, Egypt

The effect of Typhoon Talim on the distribution of heavy metals on the inner shelf of the East China sea

Surface sediment and box core samples collected from the East China Sea (ECS) inner shelf mud area before and after Typhoon Talim (2017) were analyzed for grain size, chemical elements, and heavy metals (Cr, Ni, Cu, Zn, and Pb). By comparing the results of the survey in May with those in September, we distinguished the possible sources of heavy metals, assessed heavy metal contamination status, and elucidated the impacts of summer typhoons on the distribution of heavy metals. The results of the enrichment factor (EF) and geoaccumulation index (Igeo) showed that Cr, Ni, Zn and Pb were mainly derived from natural sources, while Cu was partly influenced by anthropogenic activities and showed minor to moderate pollution. The difference between the minimum and maximum values of heavy metals became larger after the typhoon. The distribution of heavy metals in surface sediments was positively correlated with grain sizes of 11–18 μm, while the distribution in box cores was positively correlated with grain sizes of 0.8–12 μm. Additionally, the correlation between heavy metals (except Cu in box cores) and specific grain sizes increased after the typhoon passage. The thickness of the storm layer caused by Typhoon Talim was 16 cm, and the erosion depth was 4 cm. The stations with high and low values of the enrichment factor of typhoons (EFt) were separated from each other, indicating that heavy metal pollution increased at some stations and decreased at others after Typhoon Talim. The impact of typhoons on heavy metal pollution is related to seabed erosion and deposition. Summer typhoons can play a great role in the redistribution and burial of heavy metals, which is significant in the marine environment of the ECS.

Assessment of trace metal contamination by geochemical normalisation in sediments of two lagoons: A comparative study of the Kpeshie and Muni lagoons, Ghana

Heavy metal contamination status of bottom sediments of two lagoons was compared by the employment of Enrichment Factor (EF) analysis for Iron (Fe), Manganese (Mn), Cupper (Cu), Lead (Pb), Chromium (Cr), Nickel (Ni), Silver (Ag), Zinc (Zn) and Mercury (Hg). Kpeshie Lagoon recorded enrichment (EF ≥ 1) for Cd, Pb, Ag, Hg and Zn, whilst Muni Lagoon recorded enrichment for Cd, Mn, Ag, Hg and Zn as metals of anthropogenic influence. Kpeshie, situated in a highly urbanized area, has 75% spatial distribution of Pb enrichment. The assessment shows that Ag and Hg are the most enriched metals in the sediments of both Lagoons, reaching extremely severe levels. Only Mn showed statistically significant difference in mean concentration of metals for both Lagoons. Pearson correlation matrix indicated that Pb had a strong relation with Ag, Hg and Zn (r = 0.956; p &lt; 0.05) which is significant in Kpeshie. It also had a strong association with Ag and Hg but not with Zn (r = 0.240) in the Muni. The study clearly delineates Pb as a pollutant that designates the urban status of Kpeshie. Its associated metals; Ag, Hg and Zn which may be coming from a common source are from industrialized zones.

Assessing risk to human health for heavy metal contamination from public point utility through ground dust: a case study in Nantong, China.

Heavy metal contamination in ground dust presents potential environmental and human health threats. However, the heavy metal contamination status of ground dust in the vicinity of public point utilities remains poorly explored. Therefore, this study has been designed to analyze the heavy metal contaminations in the ground dust collected monthly near a public bronze sculpture in an urban campus of Nantong, China, using geo-accumulation indexes (Igeo), enrichment factors (EF), potential ecological risk indexes (RI), and health risks (noncarcinogenic risks (HI) and carcinogenic risks (CR)). This study revealed that the maximum Cr, Cu, Mn, Ni, Pb, and Zn concentrations in ground dust samples were 156.2, 708.8, 869.8, 140.8, 180.5, and 1089.7 mg kg-1, respectively, in which the mean Cu and Zn concentrations were 9 and 7 times higher than the background level in the soil. Temporally speaking, for the majority of heavy metals (with the exception of Ni), the high-concentration seasons tend to be mainly summer and autumn. It was observed that Cu and Zn exhibited significant enrichment (EF = 11.7 and 8.4, respectively), moderate-to-strong pollution (Igeo = 2.4 and 2.0, respectively), and moderate- and low-potential ecological risks ([Formula: see text] = 45.6 and 6.6, respectively). The noncarcinogenic risks which adults exposed to the heavy metal concentrations suffered were found to be insignificant. However, the carcinogenic risks related to Ni (1.3E-04) had exceeded the acceptable level. Based on principal component analysis (PCA) and correlation analysis, the heavy metal concentrations in the ground dust of urban campuses could be related to public point utilities, traffic-related exhaust sources, and industrial activities. This study's findings demonstrated that urban public utilities require more attention due to their significant enrichment, ecological risk factors, and the significant carcinogenic risks to the population.

Environmental contamination by heavy metals and associated human health risk assessment: a case study of surface water in Gomti River Basin, India.

The aim of the present study was to assess the status of heavy metal contamination and health risks associated withthe use of water from River Gomti by millions of people. The value of the degree of contamination (Cd) was found to be '11.93', signifying 'high' risk levels due to heavy metal contamination in River Gomti across an approximate stretch of 61 km including upstream, midstream, and downstream locations of Lucknow city. The potential sources of heavy metal pollution in River Gomti include both sewage and industrial effluents, being transported by drains which overflow into the river. The heavy metals were found to have low mobility owing to the 'near neutral' pH of river water. The findings from the human health risk assessment revealed that the hazard index associated with non-carcinogenic risks exceeded the permissible limits at all sampling stations. The highest health risk was found at Bharwara sewage treatment plant discharge point, downstream of Lucknow city signifying the elevated levels of heavy metal in the river water post treatment from Bharwara STP. The results of carcinogenic risk assessment suggested that children were more susceptible to health risks, and immediate remedial measures are required to control the elevated levels of heavy metals at all the sampling stations.