崇明岛东北部表层土壤及近地表大气中HCHs DDTs污染及土-气交换

The Pollution and Environmental Behaviors of HCHs, DDTs at Air/Soil Interface in Chongming Island

通过对崇明岛东北部表层土壤和大气中HCHs和DDTs两类有机氯农药的测定,对其残留现状和环境行为进行了研究。结果表明,土壤中HCHs浓度为0.40～20.0ng·g-1,DDTs浓度为0.78～163.2ng·g-1,绝大部分地区未超过国家土壤环境质量标准规定,近期没有新的HCHs和DDTs污染源输入;近地面大气中气相HCHs和DDTs的浓度范围分别为0.38～2.26ng·m-3和0.17～0.98ng·m-3。研究表明大气长距离传输对该区域的有机氯农药污染有较为明显的影响。初步运用逸度概念模型对该区域进行分析,发现HCHs和DDTs的逸出方向绝大部分地区为从土壤向大气挥发。

The concentrations of HCHs and DDTs in the surface soil and air in north-eastern part of Chongming Island were determined to study the residual levels and environmental behaviors of these compounds. In the surface soils, HCHs concentrations were in the range of 0.40～20.0 ng·g^-1, and DDTs were 0.78～163.2 ng·g^-1. In most sampling site, HCHs and DDTs in the soils did not exceed the limits of the national environment quality standards for soil. The pollutions in most sites were not caused by new pollution sources recently and the long range atmospheric transport of the organochlorine pesticides may play a significant role in the pollution. HCHs and DDTs in the vapor phase were in the range of 0.38～2.26 ng·m^-3 and 0.17～0.98 ng·m^-3 respectively. The fugacity model was used to study the environmental behaviors of HCHs and DDTs. The escaping tendency of HCHs and DDTs from soil to ambient air was found in most place of the studied area.