官厅水库沉积物表层中的有机氯农药分布特征及风险评价

采用气相色谱法对北京市官厅水库沉积物表层中持久性有机氯农药(OCPs)的残留状况进行了调查,并对有机氯农药污染水平和生态风险作出评价。结果表明:沉积物中有机氯农药总含量为8.48 ng/g～24.40 ng/g,其中HCHs和DDTs的含量较高,分别为1.11 ng/g～7.73 ng/g和2.97 ng/g～10.52 ng/g,其组分特征为来自环境的残留。与沉积物风险评估低值(ERL)和风险评估中值(ERM)对比评价沉积物中有机污染物的风险程度,官厅水库沉积物表层中的有机氯农药存在一定的生态风险。

Distribution of Organochlorine Pesticides in Surface Sediments from Guanting Reservoir and Its Risk Evaluation

The contents of organochlorine pesticides （OCPs） in sediment samples collected from 6 sites of Guanting Reservoir were analyzed by using gas chromatography. The contamination level and risk were assessed. The results showed that the concentration of total OCPs ranged from 8.48 ng/g to 24.40 ng/g. The contentra- tions of HCHs and DDTs were higher than that of other compounds and ranged from 1.11 ng/g to 7.73 ng/g and from 2.97 ng/g to 10.52 ng/g respectively. Their composition characters indicated that the pesticides came from environmental residues. Comparing the effects range-low （ERL） values and effects range-median （ERM） values from the risk evaluation, OCPs in surface sediments from the middle and lower reaches of the Guanting Reservoir had a risk to consumers of bottom feeders.