Source Determination and Health Risk Assessment of Heavy Metals in Groundwater of Guangzhou

Increasing attention has been paid to the heavy metal pollution in groundwater. The source analysis and risk assessment of heavy metals will provide data and method support for the targeted control of heavy metal pollution in groundwater. In this study, 20 sampling sites were selected in Shijiazhuang City. The APCS-MLR model and health risk model were applied to analyze and evaluate the pollution sources and health risks of 10 types of heavy metals in the groundwater of Shijiazhuang. The results showed that ① the mean concentration of heavy metals in groundwater followed the order of Fe>Zn>Mn>Cu>Al>Pb>Cr>As>Cd>Hg, and the mean ρ(Fe) and ρ(Pb) were 260.3 μg·L-1 and 10.01 μg·L-1, respectively. According to the results of the single factor and Nemerow index, Pb, Fe, and Cd primarily contributed to the heavy metal pollution in the groundwater. ② The concentration of heavy metals ranged from 47.30 to 2560 μg·L-1. In terms of spatial distribution, the highest concentration appeared at S3 (2560 μg·L-1), whereas the lowest concentration was at S9 (47.30 μg·L-1). ③ Source analysis results showed that industrial and agricultural activities, transportation emission, and geological background were the major heavy metal sources, among which the contribution of industrial and agricultural activities was the highest (47.83%). ④ The industrial-agricultural activities posed a potential threat to adults (HI>1); however, the non-cancer and the cancer risks of other sources for both adults and children were at an acceptable level (HI<1) and potential threat level, respectively; industrial-agricultural activities were the major source of non-cancer (adults:52.46%, children:52.45%) and cancer risks (adults:65.22%, children:65.69%), among which Cd and As showed high cancer risk. Therefore, to ensure the safety of the groundwater environment, strictly controlling the pollution sources and further strengthening the risk control of heavy metal pollution in groundwater are necessary.

Heavy metal pollution in groundwater is a serious threat to ecological security and human health. High arsenic, iron, and manganese groundwaters are widely distributed in the Poyang Lake Plain in the middle reaches of the Yangtze River. Urbanization and anthropogenic activities have further aggravated heavy metal pollution in groundwater. Source analysis and health risk assessment of heavy metals will provide a scientific basis for the precise prevention and control of heavy metal pollution in groundwater and the health management of residents in this area. In this study, the northeast of Nanchang City,the central city of Poyang Lake Plain,was selected as the study area,and 94 groundwater samples were collected. The PMF and health risk assessment models were used to analyze and evaluate the pollution sources and health risks of heavy metals in groundwater in the study area. The results showed that：① The mean concentration of heavy metals in groundwater followed the order of Mn&gt;Fe&gt;As&gt;Zn&gt;Al&gt;Cd&gt;Pb&gt;Cu&gt;Hg； the average concentrations of Mn, Fe, and As exceeded the corresponding standard limits； and the spatial distributions of the heavy metals were quite different. ② Source analysis results showed that the mixture of natural and agricultural sources, transportation emissions, waste incineration, and mineral dissolution were the major heavy metal sources, among which the contributing rate of the mixture of natural and agricultural sources was the highest （80.1%）. ③ The health risk assessment showed that the risk of the drinking water pathway was much higher than that of the skin infiltration pathway. The non-carcinogenic health risk （HI） was mainly caused by As through the drinking water pathway, and the non-carcinogenic HI to both children and adults in the study area was higher than the safety level （HI&gt;1）. The carcinogenic risk （CR） caused by As in adults through the two pathways and in children through the drinking water pathway, and the carcinogenic risk caused by Cd in children through the drinking water pathway were all higher than the maximum acceptable risk level （1E-04）. For drinking water safety, the concentrations of As and Cd should be controlled before drinking.

Heavy metal pollution in groundwater has become a widespread issue worldwide. However, information on heavy metal pollution in groundwater of inland river basins in NW China remains limited. This study evaluated pollution and ecological health risks of heavy metals in groundwater of the Zhangye Basin, which is a typical inland river basin in NW China. The concentrations of heavy metals in groundwater were relatively low. Heavy metals in groundwater of the northeastern edge and western regions of the study area showed a higher concentration than those of the remaining parts. Iron was the dominant heavy metal in groundwater with a maximum concentration of 1270 μg L −1 . Results of heavy metal pollution index calculations showed that approximately 3.5% of groundwater samples are classified into moderate or high pollution levels. The ecological risks of heavy metals in groundwater were relatively low with several metal(loid)s including As, Ni and Cd serving as the dominant risk contributors. The ingestion pathway contributed to 97.2%/93.6% of non-cancer risks and 97.5%/97.5% of cancer risks for children/adults, respectively. Ingestion was the main health risk contributor. Total hazard quotients and cancer risks for children were 3.5 and 9.7 times higher than those for adults, suggesting that children are much more susceptible to potential harm caused by heavy metals in groundwater. Therefore, more effective control strategies should be taken in the study area as soon as possible. Supplementary material: Spatial distribution of health risks of heavy metals is available at https://doi.org/10.6084/m9.figshare.c.4967510

Influence of coastal groundwater salinization on the distribution and risks of heavy metals

This paper mainly from the structural equation through conventional measurement and visual measurement model, analyzes the relationship between groundwater heavy metals and it, to establish the measurement model on the spatial distribution of groundwater heavy metals influencing factor model, analyzes the influence effect of various indicators on the spatial distribution of groundwater heavy metals, and their mutual influence effect. However, due to many characteristics of heavy metal groundwater, long-term use and management, it has become the research focus in the field of potential environmental protection, and has become an indispensable part of this study. Heavy metal pollution in groundwater not only endangers the safety of ecosystem, but also seriously damages the health of residents. A typical integration area between urban and rural areas is selected to understand the current situation of heavy metal pollution in groundwater, analyze the spatial distribution characteristics of heavy metal ions, and conduct qualitative and quantitative research on heavy metal pollution sources in groundwater, which has important theoretical and practical value for promoting urban sprawl, It also provides a scientific basis for the local government to formulate the strategy of protecting water resources. Of course, this problem also has a certain impact on leisure agricultural tourism, and leisure agricultural tourism is one of the important ways to promote the structural adjustment of agricultural sector and increase farmers' income, which is also an important practical process of developing multifunctional agriculture. In this paper, through structural equation analysis of underground heavy metal factor model, to understand its impact on leisure agricultural tourism, promote the development of leisure agricultural tourism.

This paper mainly from the structural equation through conventional measurement and visual measurement model, analyzes the relationship between groundwater heavy metals and it, to establish the measurement model on the spatial distribution of groundwater heavy metals influencing factor model, analyzes the influence effect of various indicators on the spatial distribution of groundwater heavy metals, and their mutual influence effect. However, due to many characteristics of heavy metal groundwater, long-term use and management, it has become the research focus in the field of potential environmental protection, and has become an indispensable part of this study. Heavy metal pollution in groundwater not only endangers the safety of ecosystem, but also seriously damages the health of residents. A typical integration area between urban and rural areas is selected to understand the current situation of heavy metal pollution in groundwater, analyze the spatial distribution characteristics of heavy metal ions, and conduct qualitative and quantitative research on heavy metal pollution sources in groundwater, which has important theoretical and practical value for promoting urban sprawl, It also provides a scientific basis for the local government to formulate the strategy of protecting water resources. Of course, this problem also has a certain impact on leisure agricultural tourism, and leisure agricultural tourism is one of the important ways to promote the structural adjustment of agricultural sector and increase farmers’ income, which is also an important practical process of developing multifunctional agriculture. In this paper, through structural equation analysis of underground heavy metal factor model, to understand its impact on leisure agricultural tourism, promote the development of leisure agricultural tourism.

Pollution of farmland by heavy metals threatens food security and human health. In addition, heavy metals in soil could infiltrate into groundwater to influence the water quality and safety of drinking water. However, the relationship between heavy metal pollution in soil and groundwater is still not clear. In this study, we investigated the soil and groundwater in the Guanzhong Plain region, which is a significant grain production base in China, and determined the spatial distributions, ecological risk, sources, and migration fates of heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn). The results showed that the mean values (0-20cm) in the soil were 19.57mgkg-1 for As, 0.71mgkg-1 for Cd, 69.65mgkg-1 for Cr, 21.97mgkg-1 for Cu, 28.67mgkg-1 for Ni, 17.54mgkg-1 for Pb, and 73.77mgkg-1 for Zn, and the corresponding mean values in groundwater were 1.2, 0.04, 4.69, 0.15, 0.07, 0.3, and 3.6μg L-1, respectively. The mean values for As, Cd, Cr, Pb, and Zn in soil exceeded the background values, and the mean values for As, Cd and Pb exceeded those in groundwater. Positive matrix factorization models identified five sources (fertilizers and organic fertilizers, natural sources, pesticides and herbicides, industrial activities, and sedimentation caused by transportation) for heavy metal pollution in soil and four sources (industry activity, atmospheric sedimentation caused by transportation, natural sources, and agriculture) for heavy metal pollution in groundwater. The soil particle composition and soil organic carbon content were important factors that affected the vertical distribution of heavy metals in the soil. The migration modes (convection and diffusion) were not found for all heavy metals. These results help to understand the relationships between heavy metals in soil and groundwater in farmland ecosystems regionally.

This study first presents the spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a nonferrous metal mine area in China. Unconfined groundwater was polluted by Pb, Zn, As, and Cu, in order, while confined karst water in the mines showed pollution in the following sequence: Zn, Cd, Cu, Pb, and As. Pollution by Pb was widespread, while Zn, As, Cu, and Cd were found to be high in the north-central industrial region and to decrease gradually with distance from smelters and tailings. Vertically, more Pb, Zn, Cu, and Cd have accumulated in shallow Quaternary groundwater, while more As have migrated into the deeper fracture groundwater in the local discharge area. Zn, Cd, and Cu concentrations in groundwater along the riverside diminished owing to reduced wastewater drainage since 1977, while samples in the confluence area were found to have increasing contents of Pb, Zn, As, Cu, and Cd since industrialization began in the 1990s. Sources of heavy metals in groundwater were of anthropogenic origin except for Cr. Pb originated primarily from airborne volatile particulates, wastewater, and waste residues and deposited continuously, while Zn, Cd, and Cu were derived from the wastewater of smelters and leakage of tailings, which corresponded to the related soil and surface residue researches. Elevated As values around factories might be the result of chemical reactions. Flow patterns in different hydrogeological units and adsorption capability of from Quaternary sediments restricted their cross-border diffusion.

Heavy metal contamination in groundwater has emerged as a significant environmental issue, driven by rapid industrialization and intensified human activities, particularly in southern China. Heavy metal pollution in groundwater often presents complex spatial patterns and multiple sources; understanding the spatial heterogeneity and controlling factors of heavy metals is crucial for pollution prevention and water resource management in industrial regions. This study applied spatial autocorrelation analysis and self-organizing maps (SOM) coupled with K-means clustering to investigate the spatial distribution and key influencing factors of nine heavy metals (Cr, Fe, Mn, Ni, Cu, Zn, As, Ba, and Pb) in a typical industrial area in southern China. Heavy metals show significant spatial heterogeneity in concentrations. Cr, Mn, Fe, and Cu form local hotspots near urban and peripheral zones; Ni and As present downstream enrichment along the river pathway with longitudinal increase trends; Zn, Ba, and Pb exhibit a fluctuating pattern from west to east in the piedmont region. Local Moran’s I analysis further revealed spatial clustering in the northwest, riverine zones, and coastal outlet areas, providing insight into potential source regions. SOM clustering identified three types of groundwater: Cluster 1 (characterized by Cr, Mn, Fe, and Ni) is primarily influenced by industrial pollution and present spatially scattered distribution; Cluster 2 (dominated by As, NO3−, Ca2+, and K+) is associated with domestic sewage and distributes following river flow; Cluster 3 (enriched in Zn, Ba, Pb, and NO3−) is shaped by agricultural activities and natural mineral dissolution, with a lateral distribution along the piedmont zone. The findings of this study provide a scientific foundation for groundwater pollution prevention and environmental management in industrialized areas.

地下水重金属污染问题已成为水资源和水环境领域的重点课题，严重影响人体健康和制约区域经济发展。本文综述了我国城镇、农村地区地下水中重金属污染现状，从水的自然循环和社会循环角度分析了地下水重金属污染的成因。研究了现阶段对于治理和控制地下水重金属污染的相关技术进展。原位修复技术由于其成本低、效果好、环境友好等优势，在治理地下水重金属污染中广泛应用。最后，结合我国地下水重金属污染实际，提出了防治地下水重金属污染的新思路。 Groundwater pollution of heavy metal has become a key issue in the field of water resource and water environment, seriously affecting human healthy and restricting regional economic devel-opment. This paper reviews the present situation of heavy metal pollution in groundwater of ur-ban and rural areas, and analyzes the causes of heavy metal pollution from the natural and social circulation of water. This paper introduces the relevant technology at present for the treatment of heavy metal pollution in groundwater. In-situ remediation technology is widely used in the treatment of heavy metal pollution in groundwater because of its economical, effective and environmental friendly. Finally, according to the Chinese reality of heavy metal pollution in groundwater, some new ideas of treatment of heavy metal pollution in groundwater are put forward.

Groundwater is the most important natural resource required for drinking to many people. The study presents a case study of heavy metal pollution in groundwater at the Mitrovica region, Kosovo. A numerous heavy metals and their parameters were considered in the analysis. The aim of the study is monitoring the presence of heavy metals in groundwater by developing of spatial database and compilation of thematic maps through GIS technology. GIS is used to represent the spatial distribution of the heavy metals. In order to represent the spatial distribution are used two interpolation techniques such as IDW and Spline. As well as the study involves the comparison analysis between IDW and Spline interpolation techniques. The populated data in GIS such as spatial and non-spatial data are based in the field investigations and field surveying as well as in the office data processing and calculating. In order to monitor groundwater pollution are used two known indices in worldwide, known as Heavy Metal Pollution Index (HPI) and Metal Index (MI). The final datasets of the study will include a numerous raster maps of groundwater monitoring in Mitrovica. The groundwater monitoring maps produced, represent the situation of 2018 and will be used to support environmental management. The GIS based on monitoring of heavy metal in groundwater derived from this study, is an attempt for the first time in Kosovo to determine groundwater pollution and to identify places with high pollution within the study area.

Heavy metals pollution in groundwater and the resulting health risks have always been an environmental research hotspot. However, the available information regarding this topic and associated methods is still limited. This study collected 98 groundwater samples from a typical agricultural area of Songnen Plain in different seasons. The pollution status and sources of ten heavy metals (As, Ba, Cd, Co, Cr (VI), Cu, Fe, Mn, Ni, Pb, and Zn) were then analyzed and compared. In addition, the human health risks assessment (HHRA) model was used to calculate human health risks caused by heavy metals in groundwater. The results revealed that heavy metals were mainly distributed in the northwest of the study area and along the upper reaches of the Lalin river and that the concentrations of heavy metals were higher during the wet season than the dry season. Industrial and agricultural activities and natural leaching are the main sources, and each kind of heavy metal may have different sources. Fe and Mn are the primary pollutants, mainly caused by the native environment and agricultural activities. The exceeding standard rates are 71.74% and 61.54%, respectively based on the Class III of Quality Standard for Groundwater of China (GB/T 14848-2017). The maximum exceeding multiple are 91.45 and 32.05, respectively. The health risks of heavy metals borne by different groups of people were as follows: child > elder > young > adult. Carcinogenic heavy metals contribute to the main risks, and the largest risks sources are Cr and As. Therefore, the government should appropriately restrict the use of pesticides and fertilizers, strictly manage the discharge of enterprises, and control man-made heavy metals from the source. In addition, centralized water supply and treatment facilities shall be established to prevent the harm of native heavy metals.

This study presents heavy metal levels, including cadmium (Cd), copper (Cu), chromium (Cr), iron (Fe), manganese (Mn), zinc (Zn) and lead (Pb) in groundwater in the Hindon River basin, a region of high agricultural and industrial activity. These parameters were analyzed over different seasons, i.e. summer (April to June), Monsoon (July to September) and winter (October to December) during 2023. The results of this analysis are crucial for understanding the current state of groundwater quality in the Hindon River basin. Water samples were collected from the different sampling stations, strategically distributed across the Hindon River basin, to ensure a comprehensive understanding of the water quality in the region. Sampling was conducted thrice at each sampling point across different seasons. The stations encompass Sampling Site C (comprising sampling points C1 to C10). The Heavy Metal Pollution Index (HPI) was employed to evaluate water quality at specified sites. Mean HPI values were 132.05 in summer, 97.48 in the monsoon season, and 114.24 in winter. The average HPI suggests extreme contamination levels throughout the study area in all seasons. The correlation coefficient provides valuable insights into the complex relationships between different heavy metals in groundwater, supporting the assessment and understanding of sources of heavy metal pollution. The research findings underscore the situation's urgency, indicating that the water was unsafe for consumption without appropriate treatment. This highlights the critical need for ongoing groundwater monitoring to address heavy metal contamination, urging stakeholders to take immediate action.

The heavy metal pollution in groundwater, surface and spring water in phosphorite mining area of Tebessa (Algeria)

Heavy metal pollution in groundwater and the environment poses a serious threat to ecosystems and human health. In particular, heavy metal ions, such as copper (Cu), zinc (Zn) and manganese (Mn), in the leachate of metal mine tailings ponds have attracted much attention due to their high toxicity and bioaccumulation. In order to solve the problem of heavy metal pollution in groundwater caused by leachate from tailings pond of a polymetallic mine, carbon/hydroxyapatite (CHAP) prepared from animal bones was used as the medium material to systematically study its removal effect on heavy metal ions in water under static and dynamic conditions. The static experiment results showed that CHAP had excellent adsorption properties for copper, zinc, manganese and mixed ions, and the adsorption capacities were up to 80 mg/g, 67.86 mg/g and 49.29 mg/g, respectively. Dynamic experiments further confirmed the application potential of CHAP as a Permeable Reactive Barrier (PRB) medium material, which can effectively remove heavy metal ions from flowing water, having a long service life. This study provides a theoretical basis and experimental reference for the in situ remediation of heavy metal-contaminated groundwater and shows the application prospect of CHAP in the field of environmental remediation.