Source apportionment and health risk quantification for heavy metal sources in soils near aluminum-plastic manufacturing facilities in northeast China

Abstract

Identifying the source effect on heavy metals to human health risk is essential for devising and implementing restoration policies for polluted soils. For this purpose, eight heavy metals (As, Cd, Hg, Cr, Cu, Ni, Pb, and Zn) in soil profile samples (0–10, 10–20, 20–30, and 30–40?cm) collected in the area around aluminum-plastic manufacturing facilities (APMF) were determined. An absolute principal component score multiple linear regression (APCS-MLR) model supported by a health risk assessment (HRA) model was developed to determine the source apportionment of soil heavy metals and contribution rate of pollution sources to human health risk. Results showed significant accumulations of eight metals in the topsoil (0–20?cm), parent material, transportation, APMF, and agricultural practices were the four major contributing sources for heavy metals in soils, with average contribution percentages of 21.69%, 24.99%, 29.60%, and 14.25%, respectively. Carcinogenic risk factors for adults (1.23E-04) and children (1.32E-04) were found to be above the acceptable level (1E-06 to 1E-04). The health risk quantification results indicated that parent material, APMF, transportation, agricultural practices, and unidentified factors accounted for 55.76%, 14.48%, 12.09%, 10.13%, and 7.54% of the carcinogenic risk for children and adults. The adverse impacts of Cd, Zn, and Pb accumulations in soil coming from APMF activities were significant and need to receive more attention.     

Chemical speciation distribution characteristics and ecological risk assessment of heavy metals in soil from Sunan mining area,Anhui Province,China

In this study, the content characteristics, comprehensive pollution assessment, and morphological distribution characteristics of heavy metals (Mn, Cd, Cr, Pb, Ni, Zn, and Cu) were researched based on the processes of field investigation, sample collection, and experimental analysis. Results showed that the mean concentrations of Mn, Pb, Cr, Cu, Cd, Zn, and Ni in surface soils were 522.77, 22.56, 55.10, 25.41, 0.25, 57.02, and 48.47 mg kg^?1, respectively. The surface soil from Sunan mining area was contaminated by Cu, Cd, and Ni in different degrees, and high CV values of Cd, Zn, Pb, and Ni were influenced by local human activities possibly. The evaluation results suggested that the mean I_geo values were in the sequence of Cd (0.657) > Ni (0.052) > Cu (?0.293) > Mn (?0.626) > Zn (?0.761) > Cr (?0.884) > Pb (?0.899). Besides, Cd was the most significant potential risk factor among all elements. Nevertheless, the Cd of bioavailable speciations with higher proportion had stronger migration and toxicity, and was more easier to be absorbed and enriched than other elements by some crops (e.g., vegetables, rice), and being at a relatively higher potential ecological risk in soil.     

Source apportionment and health risk assessment of heavy metals in agricultural soils in Xinglonggang,Northeastern China

Heavy metals in soil can affect human health through the exposure pathways of oral ingestion, dermal contact, and inhalation. In this study, to assess the health risk of heavy metals in the agricultural area of Xinglonggang, 52 soil samples were collected and tested to obtain the concentrations of As, Cd, Cr, Cu, Ni, Pb, V, and Zn in the soil. The enrichment factor indicated that the heavy metals of the agricultural soils were enriched, but the degree of enrichment was mild for all of the heavy metals. Coefficient analysis and principal component analysis indicated that V, Cr, Ni, and Pb were mainly from natural sources, As was from irrigation, Cu and Cd tended to be from chemical fertilizers and pesticides, and Zn was from mixed sources including irrigation, chemical fertilizers, and pesticides. A human-health risk assessment indicated that the residents in the study area face high risk from carcinogens and low risk from noncarcinogens; As and Cr are the major heavy metals affecting human health. This study provides a reference and a basis for formulating effective measures to prevent and control heavy metal enrichment in agricultural soils.     

Geochemical speciation and ecological risk assessment of heavy metals in surface soils collected from the Yellow River Delta National Nature Reserve,China

In this study, a comprehensive assessment of soil heavy metal (HMs) pollution in the Yellow River Delta National Nature Reserve (YRDNNR) was conducted. Spatial distributions, chemical fractions, and sources of eight HMs (Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni) in 46 soil samples in the studied region were analyzed. In addition, the potential risks of the HMs were evaluated. The results showed that the mean concentrations of Cu, Zn, Pb, Cr, Cd, Fe, Mn, and Ni were 19.4, 65.2, 38.4, 55.9, 0.078, 41546.5, 510.3, and 27.5 mg kg^?1, respectively. It indicates that the concentrations of most HMs, with exception of Pb and Fe, in samples were similar to the background value of soil in China. Principal component analysis results showed that the HMs originated mainly from natural sources, but Pb pollution in the studied area was significantly caused by anthropogenic activities. In addition, Ecological risk assessment statistical analysis indicates that the HM contamination level in YRDNNR ranged from low to moderately polluted, however, the environmental risk due to Mn and Pb contamination was high.     

Source identification and availability of heavy metals in peri-urban vegetable soils: A case study from China

The purpose of this study was to investigate the total and available concentrations of Pb, Cr, Cu, Ni, and Zn in the vegetable soils from the outskirts of a heavy industry city, Northeast China, and to assess the sources of heavy metals and their availability. The average concentrations of Pb, Cu, and Zn were significantly higher than their background values of Changchun topsoil. Principal component analysis, cluster analysis, and geostatistical analysis results suggested that Pb, Cu, and Zn were consistently from anthropogenic sources, while Cr and Ni were from natural sources with low concentrations. Kriging results showed that several hotspots of high metal concentration were identified by the geochemical maps and caused by different environmental factors. Although the available (ethylene-diamine-tetraacetic acid-extractable) fractions showed much lower values than total concentrations of metals, Pb and Cu had relatively high AR^a (average availability ratio of metals) values. Our findings show that most of the studied metals had accumulated to some extent in vegetable soils and several hotspots of high metal concentration appeared at the peri-urban of Changchun. The concentrations of some metals in peri-urban vegetable soils have been largely affected by anthropogenic activities. Appropriate measures should be taken to effectively control heavy metal levels in vegetable soils and thus protect human health.     

Heavy metal contamination in surface soils of the industrial district of Wuhan,China

The Qingshan district of Wuhan City is a typical Chinese industrial area. An increase in heavy metal pollution in the region's soil, due to industrialization and urbanization, has become a serious environmental problem. Surface soil samples from 155 sites were collected and analyzed. The median concentrations of cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) in soil were 2.3, 46.2, 24.3, 28.2, and 86.8 mg/kg, respectively. Principal component analysis coupled with hierarchical cluster analysis showed that (1) in residential and industrial areas, Pb, Cu, and Zn concentrations were mainly affected by industrial emissions and traffic emissions, whereas in agricultural areas Cu and Zn were less affected by industrial emission and traffic emission, whereas Pb was affected by agricultural activities; and (2) Cd originated from a combination of sources, including industrial activities, traffic emission, and hypergene geochemical characteristics. The integrated pollution index varied from 1.1 to 16.6 with a mean of 3.9, and 70.6% of the area is extremely contaminated, 28.1% is heavily contaminated, and the remainder is moderately contaminated.     

Site-specific risk assessment and integrated management decision-making: A case study of a typical heavy metal contaminated site,Middle China

A typical contaminated land was spatially investigated and assessed based on Chinese guidelines to establish remediation strategy for exploring the shortcomings of the current guidelines to suggest improvements. Results showed that Cr, As, Pb, and Cd should be regarded as the priority pollutants under sensitive land use, while Cr and As should be regarded as the priority pollutants under insensitive land use. Ingestion of soil for each studied metal appeared to be the main exposure pathway under both the land uses. The calculated screening values of the priority metals were conservative to certain extent—even some were lower than their background values. Therefore, an integrated risk management strategy was suggested and the hierarchic clean-up values were proposed considering the health risk, local background value, land remediation cases, current remediation technology, and financial cost. Consequently, it was suggested the clean-up values of Cr(VI), Cr, As, Pb, and Cd, under future sensitive land use, should be 7.5, 1000, 30, 250, and 1.4 mg/kg in the first class control layer, respectively. For future insensitive land use, the clean-up values of Cr(VI), Cr, As, Pb, and Cd should be 20.4, 8000, 60, 580, and 4.3 mg/kg in the first class control layer, respectively.     

典型城市单元的土壤重金属溯源方法与实证研究

随着城市化进程的不断深入,土壤中重金属污染现状及其治理情况越来越受到重视,而查明污染源是有效治理污染的前提。源解析技术目前已广泛的应用于环境受体重金属来源解析实践中,总结了近年来土壤重金属成因分析的常用方法及原理,并提出了一种将多种方法相配合使用的方法体系。选取珠三角某市城郊农田作为研究对象,结果表明,Cd、Pb、Cu、Zn、As存在含量超过国家农用地筛选值的情况,其中Cd超标率高达60.1%。农业活动、工业生产、交通源和自然母质均对研究区土壤重金属的累积产生一定的贡献。正定矩阵因子分析法(PMF,Positive Matrix Factorization)模型模拟的Cd、Ni、Zn和Hg预测值与实测值线性拟合r~2均大于90%,其余元素r~2均大于60%,呈现出很好的相关性,满足研究需要。PMF模型和铅同位素比值法计算得到的交通及农业对土壤Pb累积的贡献率之和分别为86.0%和84.8%,PMF模型和物质流分析法计算得到的农业对土壤Cd的贡献率分别为86.7%和79.7%,结果均比较接近。结果表明正定矩阵因子法、同位素比值分析法,物质流分析法能很好的联用应用于土壤重金属源解析研究。     

Phytoremediation potential of some agricultural plants on heavy metal contaminated mine waste soils,salem district,tamilnadu

The Pot culture experiment performed for phytoextraction potential of selected agricultural plants [millet (Eleusine coracana), mustard (Brassica juncea), jowar (Sorghum bicolor), black gram (Vigna mungo), pumpkin (Telfairia occidentalis)] grown in metal contaminated soils around the Salem region, Tamilnadu, India. Physiochemical characterization of soils, reported as low to medium level of N, P, K was found in test soils. The Cr content higher in mine soils than control and the values are 0.176 mg/L in Dalmia soil and 0.049 mg/L in Burn &; Co soil. The germination rate low in mine soil than control soils (25 to 85%). The content of chlorophyll, carotenoid, carbohydrate and protein decreased in mine soils than control. The morphological parameters and biomass values decreased in experimental plants due to metal accumulation. Proline content increased in test plants and ranged from 0.113 mg g^?1 to 0.858 mg g^?1 which indicate the stress condition due to toxicity of metals. Sorghum and black gram plants reported as metal tolerant capacity. Among the plants, Sorghum produced good results (both biomass and biochemical parameters) which equal to control plant and suggests Sorghum plant is an ideal for remediation of metal contaminated soils.     

华南地区典型燃煤电厂周边土壤重金属分布、风险评估及来源分析

为了解华南地区典型燃煤电厂周边表层土壤重金属空间分布特征,对韶关市燃煤电厂周边20处农田表层土壤中7种重金属(镍(Ni)、铜(Cu)、锌(Zn)、镉(Cd)、铅(Pb)、铬(Cr)及砷(As))的总量进行检测,并分析了其相应的空间分布规律,同时评估了周边土壤重金属的生态风险并分析其来源。结果表明:该燃煤电厂周边土壤中重金属Ni、Cu、Zn、Cd、Pb、Cr及As的平均含量分别是17.79、19.59、159.08、3.14、111.01、96.61 mg/kg和21.48 mg/kg,Cd、Pb污染情况突出,重金属Zn、Cd、Pb、Cr的分布与盛行风向密切相关。综合污染指数法表明,Cd、Pb及Zn处于重污染状态;潜在生态风险指数法表明,Cd处于严重潜在生态风险状态;地累积指数法表明,Ni、Cu整体处于无污染状态,Cd整体处于高污染状态。多种统计方法表明,Zn、Cd、Pb及Cr受燃煤电厂影响明显,Cu、As的来源不仅受燃煤电厂等工业的影响,还与该地区农业灌溉用水密切相关,Ni的分布最为均匀,受自然因素影响明显。     

Heavy metal contamination and health risk assessment in soil-rice system near Xinqiao mine in Tongling city,Anhui province,China

In this study, paddy soil and rice grain samples were collected from the vicinity around the Xinqiao mine in Tongling, China to test for the presence of heavy metals (Cd, Ni, Cr, Cu, Zn, and Pb) in soil-rice system. Results indicated that the soil samples were primarily contaminated with Cd and Cu and followed with Zn and Pb. In rice grains, Cd, Cu, and Cr concentrations exceeded recommended guidelines. However, the regional distribution of heavy metals in rice grains and soil was inconsistent. The bioaccumulation factor of heavy metals in rice grains decreased in the order of Cd > Zn > Cu > Ni > Cr > Pb. The BAF was significantly positively correlated with TCLP-extractable metals and significantly negatively correlated with soil pH. However, the relationship between soil organic matter and the BAF in rice grains was complex. Health risk assessment through rice intake showed that hazard quotients of Cu and Cd were greater than 1 and could pose a considerable non-cancer health risk to adults and children; meanwhile, Cr, Ni, and Cd could pose an unacceptable cancer risk. The results indicated that the government must take measures to reduce heavy metal contents in paddy soil and rice.     

Assessment of potential ecological disruption based on heavy metal toxicity, accumulation and distribution in media of the Lagos Lagoon

Toxicity evaluations of heavy metals against three benthic animals, Tympanotonus fuscatus, Clibanarius africanus and Sesarma huzardi of the Lagos Lagoon were carried out under laboratory conditions. On the basis of the 96hLC₅₀ values, Cd was found to be the most toxic metal tested followed by Cu, Zn and Pb, in a descending order of toxicity against T. fuscatus and S. huzardi; however, against C. africanus, Cu was the most toxic followed by Cd, Zn and Pb (least toxic). The determination of the metal concentrations in the water column and sediment of the Lagos Lagoon revealed that these media of the lagoon contained measurable concentrations of heavy metals but the levels were still several folds lower than the concentrations that will cause 50% mortality of exposed animals under laboratory conditions. The significance of the observed differences between the 96hLC₅₀ values of the test metals, the concentration of heavy metals detected in tissues of field animals and ambient levels of the metals in the Lagos lagoon were discussed in relation to the protection of aquatic lives and potential public health risks. The need to verify the possibilities of synergistic interactions between the constituent metals when acting jointly against the exposed animals was recommended.     

A human health risk assessment of heavy metals in agricultural soils of Yanqi Basin,Silk Road Economic Belt,China

A total of 195 farmland soil samples were collected in Yanqi Basin, Xinjiang, northwest China, and the concentrations of As, Cd, Cr, Cu, Ni, Pb, and Zn were analyzed for their concentrations and pollution levels using the Nemerow comprehensive index. The health risk assessment model introduced by USEPA was utilized to evaluate the human health risks of heavy metals. Results indicated that the average concentrations of these seven metals were lower than the allowed soil environmental quality standards of China, while the average concentrations of Cd, Cr, Ni, Pb and Zn exceeded the background values of irrigation soils in Xinjiang. The average contamination factor (CF) for Pb indicated the heavy pollution, whereas the CF for Cd, Zn, Ni, Cu and Cr indicated the moderate pollution. The average PLI of heavy metals indicated the low pollution. The non-carcinogenic hazard index were below the threshold values, and the total carcinogenic risks due to As and Cr were within the acceptable range for both children and adults. As and Pb were the main non-carcinogenic factors, while As was the main carcinogenic factor in the study area. Special attentions should be paid to these priority control metals in order to target the lowest threats to human health.     

Distribution,speciation, and ecological risk assessment of heavy metals in surface sediments of Jiaozhou Bay,China

This paper analyzed the distribution and speciation of seven heavy metals in sediments in Jiaozhou Bay. The ecological risk was assessed using three index approaches (i.e., risk assessment code (RAC), contamination factor (CF), and potential ecological risk index (PERI)) and by a comparison with sediment quality guidelines (Chinese Marine Sediment Quality Standards (CMSQS), and threshold effect level (TEL) and probable effect level (PEL) from the USEPA). Pb, Cr, As, Cu, Zn, and Hg contents at most sites were above the corresponding TEL and Class I criteria (CMSQS) value. Particularly, high contents of Cu, detected at sites S₇ (124.5 mg kg^?1) and S₈ (118.3 mg kg^?1), exceeded the respective PEL value, indicating that harmful biological effects might occur. Speciation analysis, individual CF, and RAC calculations suggested that Cd had the highest bioavailable fraction and thus posed a very high risk to aquatic ecosystem; Cu and Zn showed a medium–high risk. Both global CF and PERI analysis indicated a high pollution risk at sites S₇, S₁, S₃, and S₂, but the assessments of specific sites were different. The incomplete consistency suggested that it is necessary to consider both total contents and chemical speciation for providing a more realistic appraisal for the risk of heavy metals in sediments.     

Spatial variability characteristics and environmental effects of heavy metals in surface riparian soils and surface sediments of Qinggeda Lake

Abstract

One hundred and twenty topsoil (0–20?cm layer) samples and 45 surface sediment samples were collected from the riparian area and bottom of Qinggeda Lake. The content of Pb, Cu, Cr, Ni, Zn, Mn, V, and As were determined to reveal the distribution characteristics and explore the spatial dependency relationship between environmental factors (pH, conductivity, and organic matter) and heavy metals using Kriging interpolation and the geographical weighted regression model. Results showed as follows: (1) The average contents of Pb, Cu, Cr, Ni, Zn, V, and As did not exceed the Standard of National Soil Environmental Quality. However, Cu, Cr, and V were higher than the Xinjiang soil background. (2) The target elements in the surface sediments of the lake showed a decreasing trend from the center of the lake to the shore. Also, the heavy metal concentrations in the eastern part of the lake shore were significantly higher than those in other areas, and the highest concentrations appeared in the paddy field. (3) The effects of the eight heavy metals on pH, conductivity, and organic matter displayed significant spatial nonstationary characteristics. Cr, As, Cu, and Zn are the primary factors that affect environmental characteristics such as pH, conductivity, and organic matter content.     

Pollution and ecological risk assessment of antimony and other heavy metals in soils from the world's largest antimony mine area,China

Xikuangshan is located in Lengshuijiang City, Hunan province, China. With intensive mining and metallurgical activities, large amounts of tailing containing heavy metals (in this study, the term “heavy metals” is used for both metals and metalloids) were introduced to the soils around the mine area. Those heavy metals including antimony and other heavy metals would pose huge risk to human health and ecological environment. With a view to providing information on the extent of contamination and potential ecological risk of heavy metals in the soils of this mine area, the total contents of antimony (Sb), manganese (Mn), zinc (Zn), arsenic (As), cadmium (Cd), and lead (Pb) in the soils were examined. The results revealed that the predominant pollutants in this area were Sb, Cd, and Zn with mean concentrations being 356.58, 9.98, and 486.42 mg kg^?1, 119.66, 117.41, and 5.17 times of the corresponding background values respectively. The pollution indices (Ps) indicated that the pollution levels of all sampling zones were serious including the control zones. The ecological risk levels of all heavy metals were very high on all the sampling zones except sampling zone 7 (as considerable), and Sb, Cd, and As were regarded as making great contribution to the risk indices (RI).     

Assessment of potential health risk of heavy metals in soils from a rapidly developing region of China

Soil heavy metal contamination is a major environmental concern, and health risk associated with heavy metals is not fully explored. A combination of spatial analysis and Monte Carlo simulation was successfully used to identify the possible sources and health risk of cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), chromium (Cr), and copper (Cu) in soils collected from a rapidly developing region of China. It was found that mean concentrations of Cd (0.17 mg/kg ), As (8.74 mg/kg ), Hg (0.15 mg/kg ), Pb (27.28 mg/kg ), and Cu (33.32 mg/kg ) were greater than the soil background values. Accumulation and spatial variability of heavy metals were significantly affected by anthropogenic activities and soil properties. The risk assessment indicated that non-carcinogenic risk was not significant. However, 95% of the total cumulative carcinogenic risk of children was greater than 1E-05, implying high potential carcinogenic risk with As and Pb representing the major contributors. Ingestion of heavy metals in the soils was the main exposure pathway compared with the inhalation and the dermal exposure. Concentration of heavy metals in the soils, particulate emission factor, and dermal exposure ratio were the major parameters affecting health risk. This study highlights the importance of assessment of soil direct exposure health risk in studying heavy metal exposures.     

Distribution and risk assessment of heavy metals in river surface sediments of middle reach of Xijiang River basin,China

Xijiang River is the main surface water source in Guangxi province, South China. This study was carried out to investigate the distribution and potential ecological risks of seven heavy metals (Cu, Pb, Zn, As, Cd, Ni, and Cr) in surface sediments in Xijiang River basin. The results illustrated that the average concentrations of Zn, Pb, Cd, Cu, As, Ni, and Cr were 483.9, 207.5, 13.35, 23.50, 312.1, 28.75, and 50.62 mg/kg, respectively. Among them, Zn, Pb, Cd, and As were the major heave metals with concentration exceeding Class 3 threshold value of Chinese national standard. The result also showed samples with high ecological risk were mainly located in the upstream of Xijiang River basin as Diaojiang River, Hongshui River, Jincheng River, and Dahuan River. Based on the pollution risk assessment, the area manifested composite pollution of heavy metals in the sediments, signifying As, Pb, and Cd as the dominant heavy metals, and there were high ecological risk in sediments for these metals. According to correlation matrix and factor analysis (FA), the seven heavy metals were divided into three types/classes, Cd, as and Zn attributed by anthropogenic sources, natural sources corresponds for Ni and Cr while both natural and anthropogenic sources were attributed to Cu.     

鄱阳湖地区多尺度流域水体重金属输送特征及其污染风险评价

鄱阳湖流域的生态健康是维系长江下游区域生态安全的重要保障,而流域内丰富的重金属矿排放的工业废水会对流域生态健康产生巨大威胁。通过对不同级别河流水体中8种重金属（As、Cr、Fe、Mn、Mo、Pb、Se和V）的浓度进行监测,分析和探讨鄱阳湖流域河流重金属污染状况、来源及迁移输出特征,评估通江河流重金属迁移运输对鄱阳湖流域生态健康的影响。研究结果表明：鄱阳湖流域内梅罗综合污染指数平均值为2.67,属于中度污染,丰水期污染情况较为严重,污染指数在4.14-4.74之间,处于重度污染水平,水体主要污染元素是V和Se,V的最大浓度达331.90 μg/L,超过国家水质标准（50 μg/L）6.64倍。重金属浓度和由季节差异造成的水文特征变化是控制流域重金属输出通量的主要原因,而小流域的重金属输出通量对丰枯水期的响应更为敏感。香溪对架竹河、架竹河对赣江以及赣江对鄱阳湖的重金属输出通量分别为7.30 kg/km²、4.06 kg/km²和28.10 kg/km²。不同尺度流域对下游的重金属输出贡献率与径流量相关,丰水期,香溪流域对下游架竹河流域重金属输出的贡献率为1.10%,架竹河对赣江的贡献率为0.02%,而在枯水期,上述贡献率分别为1.61%和0.02%。主成分分析表明鄱阳湖流域水体溶解态重金属的主要污染来源为工业采矿,因此,在预防和治理鄱阳湖流域水体重金属污染问题时,应重点控制工业污染来源。