Heavy Metals, Phosphorus and Some Other Elements in Urban Soils of Hangzhou City, China

Health implications of inhaling and/or ingesting dust particles with high concentrations of heavy metals from urban soils are a subject of intense concern. Understanding the geochemistry of these metals is key to their effective management. Total concentrations of heavy metals,phosphorus (P) and 8 other elements from topsoil samples collected at 82 locations in Hangzhou City were measured to:a) assess their distribution in urban environments; and b) understand their differentiation as related to land use. Metal mobility was also studied using a three-step sequential chemical fractionation procedure. About 8.5%,1.2%,3.6%,11.0% and 30.3% of the soil samples had Cd,Cr,Cu,Pb,and Zn concentrations,respectively,above their allowable limits for public and private green areas and residential use. However,in commercial and industrial areas,most samples had metal concentrations below their allowable limits. Statistical analyses revealed that the 16 measured elements in urban soils could be divided into four groups based on natural or anthropic sources using a hierarchical cluster analysis. Additionally,Cu,Pb,and P showed similar spatial distributions with significant pollution in commercial zones,suggesting vehicle traffic or commercial activities as dominant pollutant sources. Also,Cd,Co,Cr,Ni,Zn,Mn and Fe had the highest concentrations in industrial locations,signifying that industrial activities were the main sources of these seven metals. Moreover,the data highlighted land-use as a major influence on heavy metal concentrations and forms found in topsoils with large proportions of soil Cd,Co,Cr,and Ni found in residual fractions and soil Cu,Pb and Zn mainly as extractable fractions.

Heavy metal contamination of urban topsoil in a petrochemical industrial city in Xinjiang, China

Heavy metal pollution is a widespread phenomenon in many countries of the world. In this study, we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi, a district of Karamay city in Xinjiang, China. A total of 56 soil samples in the topsoil layer of 0-15 cm were collected within the urban area and seven elements （Cu, Zn, Cd, Pb, Cr, As and Ni） were analyzed. The mean concentrations of these metals were all higher than their corresponding background values of soils in Xinjiang. We used the pollution index and ecological risk index to assess the degree of heavy metal pollution and the potential ecological risk of urban soils. The pollution index values of Cu, Zn, Cd, Pb, Cr, As and Ni were 1.81, 1.35, 4.64, 1.27, 1.80, 1.39 and 1.22, respectively; and the potential ecological risk index values for them were 12.03, 1.79, 185.05, 8.39, 4.78, 18.44 and 1.79, respectively. These results indicated that urban soils in Dushanzi were polluted by heavy metals to some extent and demonstrated a high ecological risk, as influenced by industrial activities. Cd was the key element for the metal pollution of urban soils in the study area. Correlation analyses, principal component analysis coupled with the spatial distribution maps of element concentrations further soils can be mainly attributed to petrochemical commercial activities. revealed that heavy metal pollution of urban ndustry, coal chemical industry, traffic and

Heavy Metal Contaminations in Urban Soil within Baghdad City, Iraq

Soil samples were collected from three land use types within Baghdad urban areas. The samples analyzed for Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn indicated higher concentration of Cd, Cr, Cu, Fe, Ni, Pb and Zn in the industrial area, while higher concentration of Mn was observed in the residential areas. However, the concentration of Cd, Ni and Pb was higher than the calculated worldwide mean of unpolluted soil. For both roadside and open areas soils, industrial area exhibited high values of Cd, Ni and Pb. The highest Single Element Pollution Index (SEPI) for Cd, Ni and Pb in the industrial soils seems therefore to be that this type of soil is the most polluted in the city of Baghdad. The calculated Combined Pollution Index (CPI) for Cd, Ni and Pb ranged from 0.98 to 2.15 with a mean of 1.28 for the entire urban soil samples, with the highest values in the industrial area which suggest multi-element contamination and in some cases are recommended for treatment. Furthermore, significant to extremely high values of enrichment factors were recorded confirming an important role of anthropogenic pollution.

Ecological Risk Assessment of Combined Pollution of Heavy Metals and Pesticides in Urban Soils

Urban soil is the main component of urban ecological systems and the key risk receptor from urbanization. Heavy metal and green pesticide pollutions in urban soils have been widely reported with the expanding of urbanization. Since urban soil pollution comes from various resources, application of integrated thinking and methods is needed in ecological risk assessment of urban soil pollution. This paper synthetically reviewed the combined pollution of heavy metals and pesticide, and ecological risk assessment, and then proposed some research trends and areas in the future that are required to carry out intensively according to the present situation of environmental pollution and international research fronts.

Current Situation of Heavy Metal Pollution in Soil and Dustfall in Some Cities of China

Because of human activities, urban dustfall and soil in China have been polluted by heavy metals in different degrees. However, the type and pollution degree of heavy metal hazard are different among cities. Based on data about the heavy metal pollution of urban soil and dustfall as well as related information inves- tigated, the present situation of heavy metal pollution in soil and dustfall in 23 regions of China were summarized, and some suggestions were put forward accord- ing to the existing problems of research on heavy metal pollution, aiming to provide reference for government decision-making and related research in future.

Assessment of pollution levels and human health risk of heavy metals in dust deposited on Yerevan＇s tree leaves (Armenia)

The total concentrations of Cd,As,Pb,Cr,Ni,Co,Zn,Cu,Ag,Hg,and Mo were determined in the atmospheric dust of the city of Yerevan by atomic absorption spectrometry(AAnalyst PE 800).Heavy metal pollution levels were evaluated by calculating geo-accumulation(I_(geo)) and summary pollution(Z_c) indices.Potential human health risk was assessed using the United States Environmental Protection agency's human health risk assessment model.The results show that mean contents of all elements tested except Ni and Cr were substantially higher than local geochemical background values.According to the I_(geo),Yerevan territory is strongly-to-extremely polluted by As,Ag,Hg,Mo,and Cd.The Z_c assessment indicated that very high pollution was detected in 36%of samples,high in 32%,average in 12%,and low in 20%.The health risk assessment revealed a noncarcinogenic risk(HI >1) for children at 13 samplings sites and for adults at one sampling site.For children the risk was due to elevated levels of Mo,Cd,Co,and As,while for adults,only Mo.Carcinogenic risk(>1:1,000,000) of As and Cr via ingestion pathway was observed in 25 and 14 samples,respectively.This study,therefore,is the base for further detailed investigations to organize problematic site remediation and risk reduction measures.

城市内湖底泥特性及资源化利用分析

当前园林绿化用土是城市内湖底泥资源化利用的主要途径之一,但资源化利用过程中可能存在的环境污染风险问题不容忽视,因此了解底泥特性是指导其资源化利用途径的基础。以江西省九江市甘棠湖、南门湖疏浚底泥为研究对象,检测疏浚底泥的基本理化性质、营养肥力指标、重金属含量及多环芳烃含量,系统分析其底泥特性并探究其资源化利用方式的匹配性。结果表明:内湖疏浚底泥的有机质平均含量为45.5 g/kg,pH为5.7,水解性氮平均含量为130.7 mg/kg,有效磷平均含量为62.6 mg/kg,速效钾平均含量为248.7 mg/kg,基本理化性质及营养肥力指标均满足CJ/T340-2016《绿化种植土壤》要求,同时重金属、多环芳烃等典型污染因子在CJ/T340-2016《绿化种植土壤》、GB36600-2018《土壤环境质量建设用地土壤污染风险管控标准》要求范围内。相比采购种植土,利用疏浚底泥制备绿化种植土用于绿化工程的成本,显著降低30.5%。综上所述,针对养分含量高、重金属污染程度低的城市内湖底泥,经进一步处理后可用于园林绿化及种植土制备,其资源化利用潜力较大。研究成果可为城市内湖底泥处理处置去向及城市建设用土选择提供数据支撑和参考。

基于PCA-PMF模型的城市土壤中重金属空间分布及健康评价

通过主成分分析(Principal Components Analysis,PCA)和正定矩阵因子分析(Positive Matrix Factorization,PMF)模型,研究城市土壤中重金属的空间分布及其污染源。相较于背景值,大部分元素的平均含量偏高。通过PCA识别出人为活动和自然母质为两个主要污染源,通过PMF进一步细化为交通活动、工业活动和自然来源3个污染因子。健康风险评估表明,虽然儿童面临更高的致癌风险,但是所有评估的重金属致癌风险均未超过可接受水平,表明该地区土壤中的重金属对公众的致癌风险是可接受的。

Evaluation of soil pollution situation in urban industrial wasteland:A case study

Urban industrial wasteland might have been affected by toxic and hazardous substances emitted by the original production activities. Consequently, pollution survey analysis and environmental risk assessment should have been conducted before redevelopment. In the paper, by surveying soil sample from waste dump, tailing pond and surrounding area in Lead-Zinc Mine, fuzzy mathematics method was adopted to establish Fuzzy Comprehensive Evaluation model as to analyze conditions of soil pollution by heavy metal and soil nutrient. It would provide important scientific basis for pollution control and ecological restoration in the mining area and thus carry out comprehensive ecological restoration in Lead-Zinc Mine. Fuzzy Comprehensive Evaluation results indicated that soil pollution by heavy metal were severe. It could give priority to develop forestry. Most deficient soil nutrient elements were available P and N. Due to the lack of nitrogen and phosphorus, it was necessary to improve the soil before phytoremediation.

Urban Soil Microbial Features and Their Environmental Significance as Exemplified by Aberdeen City, UK

Urban soil research has invoked great interest in recent years. Previous studies were mainly focused on urban soil physics and chemistry, and soil geography to constrain the source, distribution, transport and deposition of pollutants such as heavy metals and health\|hazardous organic matter, but little has been done on soil microbiology. In this paper, the authors reported the variation of microbial features in urban soils compared with those from adjacent rural areas. The results show great changes in basal respiration rates, microbial biomass and ecophysiological parameters have taken place in urban environment because of the anthropogenic stress, thus activating the microorganisms. As a result, much more energy carbon is consumed at a low utilization efficiency. So microbial biosensors can be used to indicate urban environmental pollution effectively.

Application of City Wetland Park on Protection of Urban Rivers

With the rapid development of urbanization and the lack of sustainable regulation policies,large cities have become a critical pollution source to urban rivers.To elucidate the pollution status of the Nanming River,an urban river in Guiyang City,SW China,water samples were collected along the river from the upstream(through the urbanization area)to the downstream locations.Pollution levels of heavy metals,NH4+and total phosphorus(TP)were investigated,and dissolved organic matter(DOM)was analyzed with fluorescence spectrophotometer.The results reveal that Huangjindadao,a local famous scenic spot,is a notable pollution source to the Nanming River,and the Huaxi National City Wetland Park plays an important role in protection of the water quality of this river.Analysis of 3DEEM characteristics of DOM indicated that the main pollution sources of DOM in this water body was municipal waste water.Protein-like compounds and humic acid with high molecular weight was the main components of DOM in this river.Organic compounds with low molecular weight represented a very small portion of the DOM in water of the Nanming River,especially in the downstream part of this river.

长江流域洞庭湖片区典型城市水环境问题解析与治理对策

为解析洞庭湖片区城市对洞庭湖及长江流域造成的水环境污染问题并提出相应的治理对策,以洞庭湖片区6个城市为研究对象,对该区域城市国控断面水质变化情况、水资源特征和重金属污染问题进行梳理,对工业源、城市生活源和城市面源的污染负荷进行核算。结果表明,片区内6个城市排放的COD、氨氮、TN和TP负荷量分别为14.07万、1.21万、2.45万和0.14万t/a,主要污染源来自城市生活源,其次分别为工业源和城市面源,影响片区城市水质的主要因子分别为氨氮和TP。对该片区城市水环境问题进行剖析,发现管网建设不完善是引起城市水体水质恶化的重要原因之一,工业规模扩大和工业历史遗留问题导致工业废水排放和重金属污染,并基于上述分析提出相应的城市水环境问题整治建议。

成都市三岔湖表层沉积物重金属地球化学特征及生态风险评价

三岔湖是成都市第二大城市湖泊,为查明三岔湖沉积物重金属空间分布特征、城镇演化与人类活动的关系和生态风险评价。本文以表层沉积物和周边土壤为研究对象,对重金属元素含量变化、空间分布和富集特征进行调查,利用改进的BCR形态提取法进行形态分布特征提取,并对沉积物进行生态风险评价。结果表明,沉积物中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn元素平均含量分别为9.61、1.26、87.2、37.8、0.069、42.7、33.9、116 mg/kg;土壤各重金属平均含量均低于沉积物重金属。在空间分布方面,Cd、Pb、Zn、Cu、Hg变化规律表现为主要旅游区与历史高密度网箱养鱼区平均含量要高于历史中、低密度网箱养鱼区,而As、Ni、Cr的平均含量在历史中、低密度网箱养鱼区要略微高于历史高密度网箱养鱼区。As、Cu、Ni和Pb在沉积物中以残渣态为主,稳定性好;Cd以弱酸提取态为主,稳定性差。潜在生态风险评价与次生相富集系数法评估显示,三岔湖沉积物整体来说较为清洁,只有沉积物中Cd受人为因素影响较大,其E_(r)^(i)平均值为40.4(7.07~288),有个别点位达到了很强危害。相关性、沉积物重金属分布与人类活动的关系表明Cu、Pb、Zn、Cd、Hg主要与网箱养鱼、交通运输和城镇建设密切相关,Ni、Cr、As主要源于农业活动和岩土风化。

基于田块尺度的冀北山区矿区周边农田土壤重金属污染特征及安全利用修复策略研究

为探究矿区周边农田土壤、农作物的重金属污染状况,同时为矿区农田土壤修复提供参考,选取冀北山区某矿区内农田作为研究对象,采集土壤样品65个,农作物样品(可食用部分)21个,地下水和地表水样品各3个。分析测定Cd、Pb、Cu、Cr等重金属含量,研究该区域土壤、农作物籽粒重金属含量特征,并对重金属风险进行了初步评价。结果表明,农田所有样点4种重金属均超出风险筛选值,其中Cd、Pb污染相对显著,部分高粱、谷子存在Cd、Pb超标情况;重金属元素空间分布上存在明显差异,北部高于南部;单项潜在生态风险系数依次为Cd>Pb>Cu>Cr;综合潜在生态风险主要为轻微风险,总体污染相对较轻,Cd是农田土壤风险的主要贡献因子;从健康风险评价结果来看,虽然存在Cd含量超标情况,但未对人体健康构成风险。建议采取钝化修复技术,降低土壤重金属活性。同时选择种植重金属低累计植物,阻止重金属向食物链中迁移,降低其生物可利用性,从而降低土壤重金属含量、减少对人类健康的伤害。

工业厂区的植被筛选与利用研究——以成都电力金具厂为例

随着城市发展从向外扩张转向向内更新,城市中心许多灰空间开始被重视,以城市灰空间中的棕地为例,针对棕地再利用问题,立足于可持续视角,梳理了重金属污染类棕地修复的方法,提出了从植物角度解决场地污染的路径。为此,调研了场地现状自生植物通过计算场地生物多样性指数等数据分析选出场地自生植物优势种同时对场地土壤进行重金属污染物检测、计算了其污染风险指数,将二者相耦合,比对了不同区域不同污染程度自生植物生长发育状况,筛选出对Zn元素和Cu元素等重金属抗性强和景观效果佳的自生植物,为重金属污染棕地修复提供可持续的生态路径。

Spatial distribution and pollution assessment of heavy metals in urban soils from southwest China

To identify the concentrations and sources of heavy metals, and to assess soil environmental quality, 63 soil samples were collected in Yibin City, Sichuan Province, China. Mean concentrations of As, Pb, Zn, and Cu were 10.55, 61.23, 138.88 and 56.35 mg/kg, respectively. As concentrations were comparable to background values, while Pb, Zn, and Cu concentrations were higher than their corresponding background values. Industrial areas exhibited the highest concentrations of As, Pb, Zn, and Cu, while the lowest concentrations occurred in parks. Statistical analysis was performed and two cluster groups of metals were identified with Pb, Zn, and Cu in one group and As in the other. Spatial distribution maps indicated that Pb, Zn, and Cu were mainly controlled by anthropogenic activities, whereas As could be mainly accounted for by soil parent materials. Pollution index values of As, Pb, Zn, and Cu varied in the range of 0.24-1.93, 0.66-7.24, 0.42-4.19, and 0.62-5.25, with mean values of 0.86, 1.98, 1.61, and 1.78, respectively. The integrated pollution index （IPI） values of these metals varied from 0.82 to 3.54, with a mean of 1.6 and more than 90% of soil samples were moderately or highly contaminated with heavy metals. The spatial distribution of IPI showed that newer urban areas displayed relatively lower heavy metal contamination in comparison with older urban areas.

新疆绿洲城市地表灰尘重金属污染风险对比

为了解新疆绿洲城市地表灰尘中重金属污染风险的整体情况,从新疆工业化、城市化程度相对较高的典型绿洲城市采集地表灰尘样品,测定其中As、Cd、Cu、Hg和Pb等5种元素含量,采用污染负荷指数(PLI)和US EPA健康风险评估模型,对比分析各城市地表灰尘重金属污染及潜在风险。结果表明,乌鲁木齐、昌吉、克拉玛依与库尔勒地表灰尘中As、Cd、Cu、Hg和Pb等元素含量平均值均小于《土壤环境质量建设用地土壤污染风险管控标准(试行)》(GB 36600-2018)中第二类用地筛选值。各城市地表灰尘重金属PLI平均值从大到小依次为昌吉、乌鲁木齐、库尔勒、克拉玛依,其中昌吉市呈现中度污染,其他城市均呈现轻度污染。各城市地表灰尘中重金属元素潜在非致癌风险从大到小依次为克拉玛依、昌吉、库尔勒、乌鲁木齐,潜在致癌风险从大到小依次为克拉玛依、库尔勒、昌吉、乌鲁木齐。整体上,新疆各绿洲城市地表灰尘中As、Cd、Cu、Hg和Pb等5种元素不存在显著的非致癌健康风险,As和Cd元素产生的潜在致癌风险处于可接受风险值范围内。Hg元素是各绿洲城市地表灰尘中污染程度最高的元素,As元素是最主要的潜在非致癌与致癌健康风险元素。绿洲城市地表灰尘中As和Hg污染需要重点关注。

A meta-analysis of heavy metals pollution in farmland and urban soils in China over the past 20 years

A total of 713 research papers about field monitor experiments of heavy metals in farmland and urban soils in China,published from 2000 to 2019,were obtained.A meta-analysis was conducted to evaluate the level of China's heavy metal pollution in soils,mainly focusing on eight heavy metals.It was found that the average concentrations of cadmium(Cd),lead(Pb),zinc(Zn),copper(Cu),mercury(Hg),chromium(Cr),nickel(Ni),and arsenic(As)in China were 0.19,30.74,85.86,25.81,0.074,67.37,27.77 and 8.89 mg/kg,respectively.Compared with the background value(0.097 mg/kg),the Cd content showed a twofold(0.19 mg/kg)rise in farmland soils and a threefold(0.29 mg/kg)rise in urban soils.The decreasing order of the mean Igeo was Cd(1.77)>Pb(0.62)>Zn(0.60)>Cu(0.58)>Hg(0.57)>Cr(0.54)>Ni(0.47)>As(0.28).Nearly 33.54%and 44.65%of sites in farmland and urban soils were polluted with Cd.The average concentrations of eight heavy metals were not sensitive change in recent two decades in farmland and urban soils.The average P_n values for urban(2.52)and farmland(2.15)soils showed that heavy metal pollution in urban soils was more serious than that in farmland,and the middle Yangtze River regions,where industrial activity dominates,were the most polluted.The meta-analysis comprehensively evaluated the current pollution situation of soil heavy metal,and provided important basis for soil management and environment prevention in China.