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Rapid urbanization a major factor affecting heavy metal contamination on suburban agricultural soils. In order to assess the dynamic contamination of heavy metals in soil from agricultural land bordering a rapidly urbanizing area and the transfer of human health risks from contaminants in this process, 186 and 293 soil samples from agricultural land in suburban Chengdu were collected in September 2008 and September 2017, respectively. Several indicators, such as the integrated pollution index (PI) and the potential ecological risk index (RI), were employed for analyzing the heavy metal contamination levels, and the APCS-MLR receptor model were applied for analyzing the heavy metal sources. As a result, mean concentrations for five elements did not exceed the national soil pollution risk screening values in the two periods mentioned above. Nemerow's composite contamination index revealed an increase in soil contamination of arable land after 10 years of urbanization, with 3.75 and 1.02% of light and moderate sample plots, respectively, by 2017. The assessment for potential ecological risk indicated an increased level of eco-risk to high for most of the sample plots. Based on the APCS-MLR model, the origin and contribution to the five elements varied considerably between the two periods mentioned above. Among them, soil Pb changed from "industrial source" to "transportation source," soil Cr changed from "natural source" to "transportation source," and As and Hg changed from "industrial source" to "transportation source." As and Hg were associated with agricultural activities in both periods, and Cd was derived from industrial activities in both periods. The study suggests that inhalation has become a major contributor to non-cancer health risks in urbanization, unlike intake routes in previous periods, and that the increase in cancer risk is mainly due to children's consumption of agricultural products with As residues. The change in the main source of As to "transportation" also indicates a decrease in air quality during urbanization and the development of the transportation industry. This study provides a reference for the governments of rapidly urbanizing cities to formulate relevant highway and agricultural policies to safeguard the health of the people based on the current situation.

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Background: Accelerated modern industrial processes, extensive use of pesticides and fertilizers and remaining issues of wastewater irrigation have led to an increasingly severe composite pollution of heavy metals in arable land. Soil contamination can cause significant damage to ecological environments and human health. Mineral resource mining can result in varying degrees of heavy metal pollution in surrounding water systems and soil. As a plateau lake, Hongfeng Lake has a fragile watershed ecosystem. Coupled with the rapid development of the current socio-economy and the ongoing activities of mining, urbanization and agricultural development, the water and soil environment of the lake and arable land are facing serious heavy metal pollution. Therefore, the situation warrants attention. Methods: This study focused on characterizing soil types and conducted sampling and laboratory testing on the farmland soil in Hongfeng Lake. The integrated Nemero comprehensive pollution assessment and potential ecological pollution assessment methods were used to evaluate the heavy metal pollution status. The APCS-MLR model was employed to explore the sources of heavy metal pollution. In addition, the human health risk model was used to analyze the association between heavy metal content in cultivated land and human health risks. Results: The single-factor pollution of each element was ranked in descending order: Hg > As > Pb > Cr > Cd, with Hg being the main pollutant factor. The entire area was subjected to mild pollution according to the pollution index. Pollution source analysis indicated two main pollution sources. Hg, As, Pb and Cr pollution mainly resulted from Source 1 (industrial and natural activities), accounting for 71.99%, 51.57%, 67.39% and 68.36%, respectively. Cd pollution was mainly attributed to Source 2 (agricultural pollution source), contributing 84.12%. The health risk assessment model shows that heavy metals posed acceptable carcinogenic risks to humans rather than non-carcinogenic risks. As was the main non-carcinogenic risk factor, while Cr was the main carcinogenic risk factor, with higher risks in children than adults. Conclusion: Our study identified the heavy metal pollution in farmland soil in Hongfeng Lake, evaluated and analyzed the pollution sources and identified the heavy metal elements in cultivated lands that have the greatest impact on human health risks. The aim of this study is to provide a scientific basis for soil heavy metal pollution control.

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To assess the health risk status and pollution sources of heavy metals in the atmosphere of ecologically vulnerable areas, the surrounding area of Dahekou Reservoir in Xilingol League was selected as the study area. From 2021 to 2022, 12 monitoring points for atmospheric dust fall were collected for a period of one year. A total of 144 samples were collected to determine the contents of eight types of heavy metals, namely Cr, Ni, Pb, Cu, Zn, Mn, As, and Cd. The potential ecological index (Eri) and health risk assessment model were used to assess the risk level of atmospheric heavy metals on ecological security and human health. The analysis of enrichment factors, principal components, and the model of absolute principal component multiple linear regression (APCS-MLR) receptor were used to analyze the sources of heavy metal pollution qualitatively in the atmosphere of the study area. The results showed that:① the mean value of the comprehensive potential ecological risk of heavy metals in the annual atmospheric dust fall in the study area was at a high ecological risk, and only the Cd value was at a very high risk level among the heavy metals, whereas the remaining were at a slight risk. ② The results of the health risk showed that intake by hand, mouth, and skin contact were the main exposure routes, which led to non-carcinogenic and carcinogenic risks. Children were under non-carcinogenic and acceptable carcinogenic risks in different months. During those months, the main source of the risks was As. ③ Through enrichment factor analysis, principal component analysis, and APCS-MLR receptor model calculation, the results revealed that the proportion of wind-blown sources was the largest, accounting for 37.82%, and the contribution rates of coal combustion and traffic sources to Cu, Cd, Pb, and Zn were 73.01%, 40.22%, 70.31%, and 32.82%, respectively. The contribution rate of mining activities to As was 42.59%, while that of industrial sources of Cd was 22.01%; the contributions of other human activity sources of Cd, As, Pb, and Zn were 21.12%, 34.40%, 23.04%, and 32.15%, respectively.

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To identify the characteristics and sources of heavy metal pollution in the surrounding soil of a typical pyrite concentrated mining area in Anhui Province, the pH value and the concentrations of Zn, Cu, Cd, Pb, Cr, Ni, Hg, and As in 42 surface soil samples and 16 soil samples from two vertical sections in the study area were collected and measured. The distribution characteristics, pollution assessment, and source analysis of heavy metal elements were conducted using the ArcGis inverse distance weight interpolation method, Nemero comprehensive index method, principal component analysis method, and absolute factor score-multiple linear regression (APCS-MLR) receptor model. The results showed that the average concentration of the eight heavy metals was 1.03-13.14 times the background value in the Tongling area. The local enrichment of Zn, Cu, Cd, Pb, Hg, and As was obvious, and the spatial distribution was basically consistent with the location of man-made mining activities. The single-factor pollution index evaluation showed that Zn, Cu, Cd, Pb, and As had different degrees of pollution risk, and the pollution degree of Cd and Cu was the most serious, accounting for 47.62% and 42.86% of moderate pollution, respectively. The Nemerow comprehensive pollution index evaluation showed that 61.90% of the soil samples in the study area were moderately polluted. The ground accumulation index evaluation showed that the pollution degree of Zn, Cu, Cd, Pb, Hg, and As in the study area was mainly from light pollution to strong pollution. In the vertical soil profile variation, heavy metals were easily enriched in the surface layer of the soil but migrated slowly to the deep layer, with concentrations mainly above 1 m. The results of source analysis showed that the high geological background and mining contribution rates of Zn, Pb, and As were 37.82%, 43.49%, and 46.63%, respectively. The natural contribution rates of weathering of parent material were 34.02%, 40.88%, and 38.52%, respectively. The sources of Cr and Ni were mainly natural sources of weathering of the parent material, with contribution rates of 91.95% and 73.68%, respectively. Geological high background and mining activities contributed 41.91% of the Cu sources, and atmospheric sedimentation and agricultural comprehensive sources contributed 41.30%. There were many sources of Hg. The natural source of weathering of soil parent material contributed 35.60%, geological high background and mining activities contributed 29.87%, and unknown sources contributed 34.05%. The main source of Cd was atmospheric sedimentation and agricultural comprehensive sources, contributing 81.81%.

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Heavy metals (HMs) are the toxic pollutants in urban environment, and their sources are complex. Dust might be a good carrier of HMs into ecosystem and human. In this study, 48 dust samples were collected in Nanjing, an industrial city and transportation hub in the Yangtze River Delta, China. The concentrations, spatial distribution, sources and risks of heavy metals (Cr, Ni, Cu, Zn, Cd and Pb) in dust were determined and analyzed. The results showed that although the health risks of some HMs had decreased, Cr, Zn, and Cd had high concentrations and high risks on ecosystem/human. And thus, the total risks of the target HMs were higher than the threshold of non-risks. Especially, children may face the highest possible risks due to the frequent hand-oral ingestion when children play. The hot spot regions of the HMs were mainly in the industrial district in the north, urban, and rural region in south, relating with the industrial, traffic, and agricultural sources, respectively. The analysis for the risks of individual sources further confirmed these sources should be further controlled. The results in this study will provide information on the priority of HMs' monitoring and source management.

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In order to identify the source of heavy metals in the soil around a mining area and provide effective suggestions for the prevention and control of regional soil pollution, 118 topsoil samples (0-20 cm) were collected in the northern part of Wuli Township, Qianjiang District, Chongqing. The heavy metal (Cd, Hg, Pb, As, Cr, Cu, Zn, and Ni) contents in the soil and soil pH were analyzed, and the spatial distribution and sources of heavy metals in the soil were studied using the geostatistical method and APCS-MLR receptor model. The results showed that the content of heavy metals in the soil was significantly higher than the background value in Chongqing; there was obvious surface accumulation; and Hg, Pb, Cd, As, and Zn showed strong variation. The proportions of soil Cd, Hg, Pb, As, and Zn exceeding the risk screening values were 47.11%, 6.61%, 4.96%, 5.79%, and 7.44%, respectively, and the proportions of soil Cd, Hg, Pb, and As exceeding the risk control values were 0.83%, 4.13%, 0.83%, and 0.83%; thus, the problem of excessive heavy metals in the soil was significant. Soil Cd, As, Cr, Cu, and Ni were mainly affected by soil parent materials, and their contribution rates to the total soil elements were 77.65%, 68.55%, 71.98%, 90.83%, and 82.19%, respectively. Soil Hg, Pb, and Zn were mainly affected by the mining of mercury mines and lead-zinc mines, with the contribution rates of 86.59%, 88.06%, and 91.34%, respectively. In addition, agricultural activities also affected soil Cd and As contents. It is recommended to strengthen the safety monitoring of agricultural products and agricultural inputs, plant varieties with a low accumulation of heavy metals, reduce the use of livestock manure, and grow non-edible agricultural products in areas that exceed the control value of heavy metal pollution risk.

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Human activities often increase the content of heavy metals in surface soils, thus affecting the precise quantification and evaluation of heavy metals in regional soils. In order to systematically study the spatial distribution characteristics and contribution rate of heavy metal pollution sources in typical farmland soil around stone coal mines in western Zhejiang Province, heavy metals such as Cd, Hg, As, Cu, Zn, and Ni in topsoil samples of arable land and agricultural products were collected and analyzed, with an emphasis on the geochemical characteristics of each element and ecological risk assessment of agricultural products. Correlation analysis, principal component analysis (PCA), and the absolute principal component score-multiple linear regression receptor model (APCS-MLR) were used to discuss the source and source contribution rate of soil heavy metal pollution in this area. Meanwhile, the spatial distribution characteristics of the contribution rate of Cd and As pollution sources of the soil in the study area were also expounded in detail by the geostatistical analysis method. The results showed that the contents of six heavy metal elements including Cd, Hg, As, Cu, Zn, and Ni in the study area all exceeded the risk screening value. Among them, two elements exceeded the risk control value, Cd and As, and the point-exceeding rates were 36.11% and 0.69%, respectively. The Cd in agricultural products was also seriously exceeded. According to the analysis, there were two main sources of heavy metal pollution in the soil in the study area. Source one (Cd, Cu, Zn, and Ni) was coming from mining activities and natural sources, and the contribution rates to Cd, Cu, Zn, and Ni were 78.53%, 84.41%, 87%, and 89.13%. Source two (Hg and As) was mainly an industrial source, and the contribution rates to As and Hg were 82.41% and 83.22%, respectively. Cd was the heavy metal with the greatest pollution risk in the study area, and measures should be taken to reduce the pollution risk. There was an abandoned stone coal mine rich in elements such as Cd, Cu, Zn, and Ni. Located in the northeastern part of the study area under the action of atmospheric deposition, the confluence of mine wastewater into irrigation water and farmland sediment was one of the important factors for forming the source of farmland pollution. The settled fly ash was the main pollution source of As and Hg, which was also closely related to agricultural production. The above research can provide technical support for the precise implementation of ecological and environmental management policies.

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Elevated levels of pharmaceuticals, steroid hormones and xenoestrogens (PSHXEs) in the aquatic environment pose a serious threat to the ecological balance. The endocrine disrupting PSHXEs in aquatic systems are linked to several adverse effects like reproductive health impairment, feminization, high mortality rate, decreased biodiversity etc. This study, therefore, sought to investigate the occurrence and the ecological risks posed by some selected PSHXEs and also conduct source apportionment of the PSHXEs in the Ghanaian aquatic environments. A total of 48 samples comprising 24 sediments and water each were taken from six waterbodies in Ghana. The samples were extracted using SPE cartridges for water and QuEChERS-dSPE for sediments. The analyses were done using Shimadzu Prominence UFLC 20A series. Ecological risk assessments were also conducted with the aid of USEPA T.E.S.T., whereas source apportionments were conducted using the APCS-MLR receptor model. Elevated mean total levels of PSHXEs ranging between 12,187 and 52,117 ng/L and 2,022-6,047 ng/g for water and sediment samples respectively were found. The risk quotients (RQ > 1) suggested a high risk posed by PSHXEs in water to organisms at the three trophic levels and also to benthic organisms in sediments of the Ghanaian aquatic environments for a short-term period. The APCS-MLR receptor model suggested three statistically significant sources (p < 0.05) designated by signature PSHXEs as domestic (major), mix hospital and industrial and agricultural waste sources. The source apportionment suggested increased use of steroid estrogens and anabolic drugs among the Ghana populace.

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With the rapid economic development, potentially toxic elements (PTEs) are continuously migrating, transforming, and enriching in farmland through atmospheric deposition and other media, posing threats to food security and human health. At present, there are few quantitative studies on the health risks of PTEs sources in farmland. In this study, absolute principal component score-multiple linear regression (APCS-MLR) receptor model was used to quantify the pollution sources of PTEs in farmland in Suzhou of Yangtze River Delta Economic Zone, China. Combined with geoaccumulation index (Igeo) and health risk assessment model, the source risk of PTEs was further quantified. The results show that Cd has reached the level of unpolluted to moderate polluted (0 < Igeo < 1); the total hazard index (THI) and total carcinogenic risk (TCR) index of PTEs are acceptable for adults, but not for children (THI > 1, TCR > 1 × 10-4). The results of APCS-MLR source apportionment were industrial sources (25.65%), agricultural sources (20.00%), traffic sources (16.81%), and domestic pollution sources (9.71%). The Igeo values of all pollution sources were less than 0, and no ecological risk was caused. The contribution patterns of pollution sources to THI and TCR in adults and children are similar. Industrial pollution sources pose the greatest non-carcinogenic risk to humans, accounting for 47.35% and 47.26% of adults and children, respectively; for carcinogenic risks, domestic pollution sources contribute the most among all identified pollution sources, accounting for 27.71% and 27.73% of adults and children, respectively. In general, this study emphasizes the need to strengthen the supervision of industrial pollution sources and domestic pollution sources in the study area to reduce the health risks to children.

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Spatial distribution and source apportionment of heavy metals in the surface soil of the Qinghai-Tibet Plateau was investigated to gain an understanding of the pollution characteristics. The surface soil (0-20 cm) samples were collected from the northeast to the southwest in the study area. The total amount of 13 heavy metals (Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sc, and Zn) was determined. The potential sources of heavy metals were preliminarily apportioned and identified by the principal component analysis-absolute principal component score-multiple linear regression (PCA-APCS-MLR) receptor model. Results show that the average contents of Cd and Sb significantly exceed the environment standard, and they were 2.13 and 1.52 higher than the soil background values of the Qinghai-Tibet Plateau in the 1970s, respectively. The enrichment factor (EF), geo-accumulation index (Igeo), and Nemero synthesis index (PN) were used to evaluate the surface soil heavy metal contamination, which indicated that Cd and Sb also were pollutants in the Qinghai-Tibet Plateau with a limited pollution level. Various levels of pollution were presented at the central, southeastern, and northeastern regions of the Qinghai-Tibet Plateau, while the central and southeastern areas exhibited relatively severe pollution levels. The PCA-APCS-MLR levels revealed that three main sources of heavy metals in the soil of the Qinghai-Tibet Plateau were the natural source, traffic activities, and the mining industry, in that order. Cobalt, Cr, Cu, Fe, Mn, Ni, and Sc, were largely affected by natural sources, while Ba, Cd, Mo, and Pb were mainly affected by traffic activities. Specifically, Zn gave priority to natural and traffic sources, and Sb was jointly affected by natural sources, traffic activities, and the mining industry. Therefore, Sb and Cd pollution from traffic activities and the mining industry should be noted in control plans for the heavy metal pollution in soil of the Qinghai-Tibet Plateau.