西安城市居民区土壤重金属健康风险评价

城市化过程中各种人类活动的废弃物进入土壤生态系统后经由多种方式对城市居民健康产生威胁,城市居民区作为人类密集活动的场所,土壤重金属污染的健康风险更为值得关注。通过实验数据的分析可知西安市居民区土壤中Pb、Cu、As的污染相对较重而Ba、Co、Cr、Ni、Zn的污染相对较轻,这八种元素产生的健康风险均在可接受范围之内,但对成人与儿童的风险大小具有一定差异。多元统计分析与基于ARCGIS的地统计分析的结果表明Ba-Co-Zn的累积主要与交通、工业、居民区内部活动有关,其空间分布表现为西部高东部低的特征;Cu-Pb的累积主要受交通活动和垃圾堆放等活动影响,空间分布上在城市中心偏北存在两个极值中心;As-Ni累积主要受成土母质影响,叠加有轻微的化石燃料燃烧等人类活动,城市中心为其高值区;Cr的累积主要与交通活动相关,空间分布特征表现为西部低而东部、北部高。

Health Risk Assessment of Heavy Metal in the Urban Topsoil Collected from Residential Area in Xi'an City

The various wastes from human activities,which have been into the urban soil ecosystem,threatened the health of urban residents via many ways in the process of urbanization.The health risks of soil heavy metal contamination should be paid more attention in residential area with intensive activities.The analysis results of experimental data showed that soil Pb,Cu,As were more heavily polluted and Ba,Co,Cr,Ni,Zn were relatively light polluted in residential area,Xi'an City.For adults and children,the health risks of Pb,Cu,As,Ba,Co,Cr,Ni,Zn were within the acceptable range,but had many differences between them.The spatial distribution and sources were studied by multivariate analysis and geostatistics analysis.The accumulation of Ba-Co-Zn was mainly related with transportation,industrial,and residential activities and their spatial distribution characteristics tended to be lower in west region and higher in east region.The accumulation of Cu-Pb was mainly affected by the vehicles emission and garbage dumps and had two high-value region in the city center.The accumulation of As-Ni was mostly influenced by parent material and less by fossil fuel combustion emissions,and their spatial distribution performance for its high value area in the city center.The accumulation of Cr was mainly associated with traffic activities,which was higher in eastern and northern region and lower in western region.