安徽省某市农田土壤与农产品重金属污染评价

为评价安徽省某市农田土壤与农产品重金属污染水平，在研究区内共布设1933个点位，采集土壤样品并在污染农田中采集43个农产品样品，对其与土壤进行一对一检测，分析研究Cr、Pb、Cd、As和Hg 5种重金属含量，对研究区农田土壤重金属含量水平、空间分布特征以及农产品重金属含量与土壤性质的关系进行分析。结果表明：研究区农田土壤中Cr、Pb、Cd、As和Hg的平均含量分别为62.5、32.6、0.209、8.85、0.080 mg·kg^-1，点位超标率分别为0.05%、0、14.59%、0.67%和1.97%。根据单因子污染指数法评价研究区农田土壤污染情况，5种元素污染程度Cd > Hg > As > Pb > Cr，从内梅罗综合污染指数来看，所有点位中清洁的占78.58%，综合生态风险指数法评价结果显示研究区基本处于轻微生态危害水平。农产品中Cr、Pb、Cd和As 4种重金属元素都是在偏酸性的土壤上富集系数较大，而Hg在偏碱性土壤上富集能力较强。

Evaluation of heavy metal pollution of farmland soil and agricultural products in a city of Anhui Province, China

To explore the relationship between soil and agricultural products of heavy metals, total 1933 soil samples and 43 samples of agricultural products were collected from contaminated farmland in a city of Anhui Province. Heavy metal contents of Cr, Pb, Cd, Hg and As, spatial distribution characteristics and the relation between heavy metal contents of agricultural products and the properties of soil were analyzed. The results showed that the contents of Cr, Pb, Cd, As and Hg in farmland were 62.5, 32.6, 0.209, 8.85, 0.080 mg·kg^-1, respectively, 0.05%, 0, 14.59%, 0.67% and 1.97% higher than the standards. According to the single factor pollution index assessment, farmland soil was contaminated in the order of Cd > Hg > As > Pb > Cr. From the Nemero comprehensive pollution index, 78.58% of all samples was in the clean state. The whole study area was basically at the level of slight ecological risk with the evaluation method of the comprehensive ecological risk index. The enrichment coefficients of Cr, Pb, Cd and As were higher in the agricultural products on the acid soil, while Hg had stronger enrichment ability on the alkaline soil.