贵州草海耕地土壤与农作物中DDTs和HCHs残留及污染特征

Residue and Pollution Characteristics of HCHs and DDTs in Crops and Soils in Caohai Watershed in Guizhou

采集草海流域周边成熟期整株农作物及土壤样品，分析测试其中DDTs和HCHs的含量，对比研究了土壤和作物中DDTs和HCHs污染水平及其在作物中富集能力。结果表明：研究区域土壤中HCHs和DDTs残留检出率均为100％，残留范围分别为0．06～16．66μg·kg^-1和0．08-39．77μg·kg^-1，土壤中HCHs和DDTs的残留量均小于国家土壤环境质量一级标准；三种农作物中DDTs、HCHs及∑（DDTs，HCHs）残留量差异显著，HCHs含量最高的是玉米，DDTs和（DDTs，HCHs）最高的是马铃薯；三种农作物中HCHs和DDTs残留的风险系数均为1．1，属于低度风险，农作物中DDTs、HCHs及∑（DDTs，HCHs）的安全指数IFSc均小于1，DDTs和HCHs残留量对三种农作物安全影响的风险是可以接受的。

We collected whole crop plants at their maturity stage and soils in the watershed of Caohai, measured concentrations of DDTs and HCHs in both crops and soils, and then determined their enrichments in crops. The detection rates of both HCHs and DDTs in soils were 100%, and their residues ranged 0.06-16.66μg·kg^-1 and 0.08-39.77μg·kg^-1, respectively. The concentrations of HCHs and DDTs in soils were below the first class levels of the National Soil Environmental Quality. The residues of DDTs, HCHs and E （DDTs, HCHs） were sig- nificantly different among three crops, with the highest HCHs in corn, and greatest DDTs and E（DDTs, HCHs ） in potato. The risk factors of HCHs and DDTs were 1.1 for three crops, belonging to low risk. The Security Index （IFSc） of DDTs, HCHs and E （DDTs, HCHs ） were all less than 1 in three crops. Therefore, the risks of HCHs and DDTs in three crops were acceptable.