Heavy Metal Contamination in Urban Surface Soil of Klang District (Malaysia)

This study aimed to determine bioavailability of heavy metal concentrations (Al, Fe, Zn, Cu, Co, Cd, Pb and Cr) in 76 urban surface soil samples of Klang district (Malaysia). This study also aimed to determine health risks posed by bioavailability of heavy metals in urban soil on adults and children. For bioavailability of heavy metal concentrations, a physiologically bioavailability extraction test in vitro digestion model was used. Mean values of bioavailability heavy metal concentrations for this study were found to be the highest in Al (25.44 mg/kg) and lowest in Cr (0.10 mg/kg). Results of Spearman correlation coefficient (r) values showed significant correlations were observed for Al-Fe (r = 0.681), Cd-Co (r = 0.495), Cu-Zn (r = 0.232), Fe-Pb (r = 0.260), Fe-Zn (r = 0.239). For cluster analysis, output showed that these heavy metals could be classified into four clusters: Cluster 1 consisted of Cd, Cr, Co, and Pb; Cluster 2 consisted of Zn and Cu; Cluster 3 consisted of Fe; and Cluster 4 consisted of Al. For Clusters 1 and 2, anthropogenic sources were believed to be the sources, while for Clusters 3 and 4 the heavy metals originated from natural sources. Health risks were determined in adults and children through health risk assessment. For adults, Hazard Quotient (HQ) value was <1, indicating no non-carcinogenic risk, while for children, the HQ value was >1, indicating a non-carcinogenic risk. Meanwhile, for carcinogenic risk, heavy metal contamination in the Klang district might not pose a carcinogenic risk to adults while it may pose a carcinogenic risk to children because TR values in this study were >1.0E-04 for children. Output has identified the general health risk in the Klang district. Moreover, this study's findings will contribute to fill in the gap of knowledge on heavy metals' impacts on human health and urban development in the Klang District.     

Heavy Metals in Agricultural Soils of the Mouriki-Thiva Area (Central Greece) and Environmental Impact Implications

The heavy metal content of 51 surface soil samples from the agricultural region of Mouriki-Thiva (central Greece) was investigated by a combination of mineralogical (X-ray diffraction and scanning electron microscopy) and geochemical (aqua regia and 0.5 M HCl extractions) methods in order to determine the levels of contamination, as well as the origin, distribution and mobility of selected metals. The geology of the area includes ultrabasic rocks, and consequently the soils have anomalous values in Ni (621-2639 mg/kg) and Cr (134-856 mg/kg). Whereas Cr is mainly hosted in the crystal structure of chromite, Ni is primarily mobilized from olivine and serpentine. Nickel, and to a lesser extent Cr, were also found to be absorbed in Fe oxides. The results of a single 0.5 HCl leach revealed significant differences in the mobility and potential bioavailability of Ni and Cr in representative soil samples; Nickel is substantially more labile, and as a result a potential amount of this metal is readily available to the plants. The whole area is heavily contaminated by Ni and Cr and consequently the monitoring of the agricultural products of the region for their heavy metal content is strongly recommended.     

Environmental Monitoring of Heavy Metal Status and Human Health Risk Assessment in the Agricultural Soils of the Jinxi River Area,China

Soil contamination with heavy metals is one of the main environmental concerns in China, mainly owing to rapid industrialization and mining activities in certain areas. The current study aimed at monitoring the levels of heavy metals in soils of the industrial areas along the Jinxi River and surrounding Lake Qingshan. In addition, a health risk assessment for humans in contact with these soils was also conducted. The results revealed that the soils of the studied areas were contaminated with Cr, Cu, As, Se, Cd, Pb, and Zn and that the industrial activities were the main source of soil contamination therein. Furthermore, soils of the sites adjacent to Lin’an city exhibited higher levels of heavy metals than the upstream and Lake Qingshan sites. Most of the studied heavy metals tended to concentrate in the fine soil fractions (PM100, PM10, and PM2.5). Calculation of the hazard index (HI) revealed that humans, especially children, have potential health risks. Moreover, As was found to contribute to more magnitude of cancer risks. Thus, we concluded that the unmanaged development negatively affects the Chinese environment and human health. Furthermore, fine fractions of soil particles should be considered for risk assessment.     

Behavior of Enzyme Activities Exposed to Contamination by Heavy Metals and Dissolved Organic Carbon in Calcareous Agricultural Soils

To investigate the relevance of biochemical parameters in biogeochemical mechanisms of the soil, it is important to gather data related to different soil types under different pedogeoclimatic conditions. In this study, we investigated on the calcareous agricultural soils in the Saiss plain (North Morocco). Four agricultural soils exposed to multi-metal (Cr, Cu, Zn, and Ni) and organic matter (OM) contamination as a result of irrigation with Oued Fez and Oued Sebou waters that are affected by urban and industrial activities around the city of Fez were studied and compared to a reference site irrigated with uncontaminated water. The study concerned soil physicochemical properties and the activity of a range of enzymes [phosphatase (PHOS), arylsulfatase (SULF), urease (UREA), arylamidase (AMID), β-galactosidase (GALA), glucosidase (GLUC), and laccase (LACA)] related to nutrients cycles. Pearson's correlations between these parameters showed that soil enzymatic activities (PHOS, SULF, UREA, GALA, GLUC, and LACA) were correlated positively with heavy metals (Cu, Zn, and Cr) concentrations in the soil and also with dissolved organic carbon (DOC), and negatively with the aromaticity (AROM) of these compounds. Interestingly, analysis of intra-site correlations showed strong relationships among enzyme activities in the reference soil, while in contaminated soils, these activities were largely unrelated to each other. It was concluded that soil irrigation with heavy-metal- and OM-contaminated watercourses over decades has resulted in soils with high enzymatic activities function and nutrient turnover but altered relationships among geochemical cycles.     

湘南某矿区蔬菜中Pb、Cd污染状况及健康风险评估

通过采集湘南某矿区周边农田中种植的蔬菜和对应耕作层土壤样品,探究了农田蔬菜Pb、Cd的污染状况,蔬菜和土壤重金属含量之间的相关性,蔬菜中重金属对人体的健康风险。结果表明:(1)污染区土壤重金属污染非常严重,叶菜类蔬菜重金属超出了食品卫生标准限值,但是果菜类蔬菜中重金属没有超出食品卫生标准限值。(2)不同蔬菜不同器官所含Pb、Cd有明显差异;不同种类蔬菜Pb、Cd含量不同,一般是叶菜类果菜类;同种蔬菜不同部位重金属含量的顺序也不同,一般为根茎叶果,或根叶茎果。(3)二类蔬菜中重金属Pb、Cd的富集系数顺序为叶菜类果菜类。(4)蔬菜中Pb、Cd含量与土壤中相对应元素含量均无显著相关性。(5)就农产品安全性而言,果菜类蔬菜比叶菜类蔬菜更适合在此矿区栽培。     

Health Risks Assessment of Heavy Metal Pollution in the Soil-Crop System from an E-Waste Dismantling Area

Soil is an essential resource for agricultural production. In order to investigate the pollution situation of heavy metals in the soil-crop system in the e-waste dismantling area, the crop and soil samples (226 pairs, including leaf vegetables, solanaceous vegetables, root vegetables, and fruits) around the e-waste dismantling area in southeastern Zhejiang Province were collected. The concentrations of Cd, Cu, Pb, and Cr were determined. The average concentrations of Cd, Cu, Pb, and Cr in soils were 0.94, 107.79, 80.28, and 78.14 mg kg^-1, respectively, and their corresponding concentrations in crops were 0.024, 0.7, 0.041, and 0.06 mg kg^-1, respectively. The transfer capacity of leaf vegetables was significantly higher than that of non-leaf vegetables, and the accumulation of four heavy metals in crops tended to be Cd > Cu > Cr/Pb. The pollution index’s results revealed that the soil pollution degree under different land uses ranked as root vegetables soil > leaf vegetables soil > solanaceous vegetables soil > fruit soil. The carcinogenic and non-carcinogenic risks of heavy metal exposure were ranked as food intake > accidental ingestion > dermal contact > inhalation. The comprehensive non-carcinogenic risk was ranked as Cr > Cd > Pb/Cu. Our results could be used to provide useful information for further crop cultivation layout in the study area, which can guarantee the local residents’ health and food safety.

     

Assessment of Human Health Risk for an Area Impacted by a Large-Scale Metallurgical Refinery Complex in Hunan,China

Due to accelerated urbanization and reform of industrial structure in China, polluting industries in major cities have been closed or relocated. Consequently, large numbers of industrial sites were generated and the contaminated soils on and around these sites may pose risks to humans. This case study presents an estimation of human health risks for an area that is mainly impacted through air dispersion and deposition from a large-scale metallurgical refinery complex in Zhuzhou city, Hunan Province, China. Carcinogenic and non-carcinogenic risks posed by the contaminants were estimated under future industrial and residential land use scenarios. The result shows that adverse health effects may occur primarily through ingestion of soils contaminated with As, Cd, and Pb. The total carcinogenic risks of multiple contaminants for a large area exceed the acceptable risk level of 1 × 10^?5, and several localized hotspots, where the total hazard index exceeds 1 were identified. Soils in the Tongda site pose the highest carcinogenic risks and non-carcinogenic hazards. It is concluded that potential human health risks exist under the proposed redevelopment scenarios, and development of risk-based remediation strategies is recommended.     

Heavy metals' contamination in sediments of Wadi Al-Aqiq water reservoir dam at Al-Baha region,KSA: Their identification and assessment

Sediments are the ultimate sump for heavy metal pollutants. The main purpose was to investigate the ecological and health risk assessment of heavy metals in the sediments of Wadi Al-Aqiq water reservoir. The metals detected were arranged in decreasing order Fe > Mn > Cr > Cu > Zn > Ni > Co > Pb. Pearson correlation analysis indicated strong positive association and significant linear relation between various pairs of metals. Different evaluation indices used indicated that source of contamination from lithogenic sources and sediments can be classified as low polluted quality. A comparison of the concentrations of metals with International Sediment Quality Guidelines criteria showed that only Cu and Ni concentrations above the ERL and below the ERM guideline values suggest possible adverse effects. On comparing with US Environmental Protection Agency prepared sediment quality criteria it indicated that Pb and Zn have concentrations below the non-polluted criteria, Fe, Mn, and Ni lies in the range of moderately polluted criteria, and Co and Cu are within the heavily polluted criteria. Non-carcinogenic risk quantification indicated health concern from ingestion route and no health effects for dermal exposure. On considering additive effect, the dermal exposure may cause health harm. The carcinogenic risk assessment for lead and chromium showed an acceptable risk to human health.     

Evaluation of Heavy Metals and Associated Health Risks in a Metropolitan Wastewater Treatment Plant's Sludge for Its Land Application

The objectives of this study are to monitor the heavy metal concentrations in sludge samples collected from the Ankara Central Wastewater Treatment Plant (ACWWTP) in Turkey, check if these concentrations comply with the Turkish Regulation (Regulation Regarding the Use of Domestic and Urban Sludges on Soil), and evaluate possible health risks of heavy metals in sludge due to ingestion of sludge by a child. Monthly sludge samples were collected from the ACWWTP during 2012 and analyzed for seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn). According to the results from the study, heavy metal concentrations showed no common seasonal trend. All heavy metal concentrations, except for one sample in which Zn was found to be at the limit value, are below the Turkish Regulation limits. In addition, health risks calculations for the “child ingesting biosolids” pathway, which is one of the most critical pathways identified by the U.S. Environmental Protection Agency (USEPA) for land application, were carried out. Among the seven heavy metals, Pb contributed the most to the cumulative non-cancer health risks throughout 2012. Nevertheless, the results showed that cumulative non-cancer health risks associated with this pathway are within the acceptable non-cancer health risk level suggested by USEPA.     

Heavy metal contamination and health risk assessment in drinking water of Sistan and Baluchistan,Southeastern Iran

Access to safe and clean drinking water is an essential element of healthy life also known as the primary human needs. The present study was conducted to investigate heavy metal (HM) concentrations of drinking water. Excess health risk of HM (Cr, Pb, and Cd) intake is related to the drinking water consumption in local population. HMs concentrations were analyzed by using graphite furnace atomic absorption spectrometer and were compared with permissible limits regulated by country and World Health Organization (WHO). The hazard quotient (HQ) and Excess Lifetime Cancer Risk (ELCR) were determined to show the carcinogenic and non-carcinogenic effects of HMs, respectively. HQs were found in the order of Pb > Cd > Cr and subsequently HI index was also estimated for all HM in two age groups (children and adults). The comparisons indicate no possibility of non-carcinogenic effects to the local population. The values for ELCR were found in the order of Cr > Cd > Pb. The ELCR index was found above acceptable risk levels for chromium and cadmium in both children and adults groups. Furthermore, intermetal correlation results revealed that heavy metals have common sources resulting from geogenic and anthropogenic activities and these are major sources of water contamination in Sistan and Baluchestan province.     

Health risk assessment via consumption of Pb and Cd contaminated vegetables collected from fresh markets in the lower north of Thailand

This study aimed to investigate the Pb and Cd contamination and health risk assessment for population via consumption of vegetables sold in fresh markets around the lower north of Thailand. The concentrations of Pb and Cd in various vegetables such as root/tuber, stem, inflorescence, fruit, and leaf vegetables were analyzed using an atomic absorption spec-trophotometer. Human health risks of these metals in vegetables were assessed based on target hazard quotient (THQ). The results indicated that more than 80% of the Pb and Cd in almost all vegetable samples exceeded the maximum allowable concentration by National Food Institute criteria with an average range of 0.96–3.39 and 0.48–1.40 mg/kg, respectively. The estimated daily intakes (EDI) of Pb and Cd via dietary consumption of vegetables were between 0.001–0.010 and 0.002–0.008 mg/kg/d, respectively. All EDIs of Pb contaminated vegetables were higher than the reference dose recommended by the USEPA except for leaf edible vegetables, while all EDIs of Cd contaminated vegetables were higher than the reference dose recommended by the USEPA. THQ indicated that the consumption of Pb contaminated root/tuber, stem, inflorescence, and fruit edible vegetables and Cd contaminated leaf vegetable for the local population in the lower north of Thailand could be a severe health risk problem.     

Dietary Intakes and Health Risk of Toxic and Essential Heavy Metals through the Food Chain in Agricultural,Industrial, and Coal Mining Areas of Northern India

Minerals can enter the food chain through industrial and mining activities. Soil-to-vegetable transfer is higher than soil-to-cereal, but human consumption of metals is attributable to balanced diets containing both vegetables and cereals and drinking water. However, the impact of location on intakes of metals from predominantly cereal-based Indian diets is not clear. Hence, the present study was undertaken in selected Agricultural, Industrial, and Coal Mining Areas (AA, IA, CMA) around the Allahabad District in Northern India to compare transfer of toxic metals, Pb, Cd, Cr and essential metals, Fe, Zn, Cu, Co in soil and water to common crops: cereals (rice, wheat, maize) and vegetables (spinach, potato), and to assess Daily Intake of Metal (DIM) and consequent Health Risk Index (HRI). The overall content of all metals, except Cu, in water, soils, and crops followed the pattern CMA > IA > AA. Transfer factors (TFs) followed the sequence spinach > potato > cereals. Quantitatively, however, cereals contribute maximally to a balanced diet, so DIM and HRI were higher from cereals than vegetables. Even though spinach had the highest TFs, cereals contributed maximally to HRI. CMA had the highest metal content so locally grown cereals contributed significantly to intake of both toxic and essential metals.     

Bioavailability of Metals in Soil and Health Risk Assessment for Populations Near an Indian Chromite Mine Area

Soils contaminated with toxic metals may be environmental hazards and sources of exposure to human population. Soils in mining areas are among the most heavily contaminated by metals from the mining activity. This study was focused on metals of interest in bioavailability studies using single and sequential extraction methods. Results of geochemical fractionation suggest that changes in soil characteristics may enhance the mobilization of Cu, Cr, Zn, and Al. The observed metals’ availability pattern was Cr > Cu > Zn > Al. However, the pattern of total contents of metals in soils was Al > Cr > Zn > Cu. Risks to human adults and children from selected metals through soil ingestion was assessed in terms of incremental lifetime average daily dose (LADD), hazard quotient (HQ), and hazard index (HI). The estimated LADDs and HI were within acceptable reference doses and less than 1, respectively, indicating low risk to human populations from the studied metals through soil ingestion in the studied mine area. The generated data may be useful in remediation of contaminated soils with metals.     

Determination of the Heavy Metal Levels in Panax notoginseng and the Implications for Human Health Risk Assessment

ABSTRACT

High levels of heavy metals in Panax notoginseng (Sanchi), a valued traditional Chinese medicine, have drawn increasing concern regarding the safe usage of Sanchi preparations. Here, we measured the concentrations of six heavy metals in Sanchi samples from 20 major plantations, investigated the pharmaceutical processes and usages of Sanchi preparations, and assessed the associated potential health risks to consumers. The average concentrations of chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), lead (Pb), and arsenic (As) in the Sanchi samples were 2.7, 3.7, 6.2, 22.1, 2.0, and 1.4 mg/kg, respectively. The hazard quotients (HQs) for these six single metals and the hazard index (HI) of these metals’ combination were all far less than 1, indicating the absence of a non-carcinogenic health hazard to consumers. The carcinogenic risk of As was 2.1 × 10^?6, which is higher than the allowable level suggested by the U.S. Environmental Protection Agency but less than the level suggested by the World Health Organization (WHO). The probabilities of consumers’ exposure due to daily medicine consumption exceeding the allowable daily intakes from medicine (ADIs_drug, 1% of the ADI) suggested by the WHO were 0.0%, 0.1%, 0.1%, 0.0%, 1.6%, and 27.3% for Cr, Ni, Cu, Zn, Pb, and As, respectively.     

Plan for an Integrated Human and Environmental Risk Assessment in the S. Domingos Mine Area (Portugal)

The need for the integration of the assessment of human and ecological risks in contaminated areas, such as derelict mines, widely increases. The risk assessment process is becoming a powerful tool to provide sound scientific bases for decision-making processes. In Portugal, the risk assessment process is in its early years and the lack of multidisciplinary teams of experts is frequently mentioned as the main obstacle to its implementation. Therefore, the majority of the reclamation actions are based on impact assessment studies that usually are characterized by few biological and toxicological considerations. In order to account for some of these constraints, the ecological risk assessment framework proposed by the U.S. Environmental Protection Agency was used to plan the assessment of human and ecological risks posed by the high concentrations of metals scattered in the vicinity of S. Domingos mine, a cuprous pyrite mine located in the Southeast Alentejo (Portugal). This study presents the problem formulation phase of the assessment. It includes all the scientific information available for the area, a conceptual model, and an analysis plan for the risk assessment process. Following a tiered approach, several tasks were planned in order to acquire chemical, toxicological, and ecological information, in order to compensate for the lack of toxicity data for site-specific species.     

Variation in Heavy Metal Accumulation and Genetic Diversity at a Regional Scale Among Metallicolous and Non-Metallicolous Populations of the Facultative Metallophyte Biscutella laevigata subsp. laevigata

Biscutella laevigata is a facultative metallophyte, with populations on non-metalliferous and metalliferous soils. Some of its metallicolous populations have been shown to hyperaccumulate thallium or lead in nature. Only Tl hyperaccumulation has been experimentally confirmed. We aimed to compare the patterns of metal (hyper)accumulation and genetic diversity among populations of B. laevigata subsp. laevigata in NE Italy.

None of the populations exhibited foliar hyperaccumulation of Cu, Zn, or Pb. The root-to-shoot accumulation rates for these metals were unchanged or decreased rather than enhanced in the metallicolous populations, in comparison with the non-metallicolous ones. Hyperaccumulation of Tl was confined to the population of the Cave del Predil mine. This population was genetically very distinct from the others, as demonstrated by AFLP-based cluster analysis. The two other mine populations did not surpass the threshold for Tl hyperaccumulation, but showed enhanced foliar Tl concentrations and root-to-shoot translocation rates, in comparison with the non-metallicolous populations. Genetic analysis suggested that adaptation to metalliferous soil must have been independently evolved in the metallicolous populations.     

卡拉麦里南部工业区梭梭和琵琶柴重金属空间分布及污染评价

对五彩湾工业区周边21个采样点的梭梭(Hadoxylon)和琵琶柴(Reaummuria soongorica)的Zn、Cu、Cr、Pb、As、Hg 6种重金属元素含量测定,运用统计学方法和地统计插值法分析其茎叶和根部重金属含量变化情况和空间分布特征,并综合评价其污染程度和潜在生态危害性。结果表明:梭梭和琵琶柴植株Hg含量的最大值和均值都超出新疆土壤背景值0.017 mg/kg,除梭梭根部的均值0.060 mg/kg未超出国家土壤背景值0.065 mg/kg,在二者其他部位的最大值和均值都已超出;琵琶柴整株中Cr最大值72.62 mg/kg和Zn最大值97.61 mg/kg均超出新疆土壤背景值49.3 mg/kg和国家土壤背景值61 mg/kg,Pb元素未被检出。插值精度方面,Hg、As的RMSE较小,分别为0.263和0.443,预测模型中Hg的R~2为0.72,Cu的R~2为0.67,能较好地估计预测样点的重金属含量,Zn的R~2为0.31,精度较低;插值结果,琵琶柴中的Zn、Cr、As、Hg含量较高的区域均在工业园区内部及周围,受人为扰动程度较大。梭梭和琵琶柴中Hg元素分别为中度污染和重度污染;Hg元素为中等潜在危害程度高于其他4种元素。