灌河口海域沉积物中有机氯农药的空间分布、来源解析与风险评估

2011年4月通过GC定量检测和210Pb测年对灌河口海域表层和柱状沉积物中OCPs (Organochlorine Pesticides)的空间分布、来源解析进行了研究。结果表明:灌河口海域表层沉积物中OCPs的浓度在nd~58.310-9 (干重)之间,河口海域O,P'-DDT浓度明显高于潮间带和入海河段,3个区域浓度排序为:潮间带河口海域入海河段。DDTs和HCHs浓度均处于国内中等水平。柱状沉积物中OCPs浓度在(2.0~850.0)10-9之间、平均值210.010-9,90年代初期OCPs浓度有所下降,2000年后又在波动中升高。来源解析及柱状样中OCPs浓度变化、转化情况均表明该海域沉积物有新的DDTs源输入。参照加拿大颁布的沉积物质量标准对灌河口沉积物进行风险评估,结果表明灌河口海域以DDT和DDD为主的毒性已处于频繁效应,需深入开展沉积物的环境风险评估研究,确认开展OCPs底质修复方案及区域。

A study on OCPs distribution,sources and risk in the sediment from Guanhe Estuary

In this study,OCPs (Organochlorine Pesticides) in surface and column sediments from Guanhe Estuary(taken in April,2011) were analyzed by GC-ECD and 210Pb methods.The results showed that OCPs concentrations in surface sediments ranged from nd (Not Detected) to 58.310-9 (dry weight),and the concentrations range among three sampled regions are,from highest to the lowest,intertidal zone,estuary area and Guanhe River.However,concentrations of O,P'-DDT were highest in the sediment from estuary area,compare to those from interidal zone or Guanhe River.Based on the studies in other areas in China,DDTs and HCHs concentrations around Guanhe estuary were average.OCPs concentrations in column sediments ranged from 2.010-9 to 850.010-9,with an average of 210.010-9,and the results also indicated that the OCPs were relatively low in 1990s and increased in 2000.These results were validated by the studies around the area,that there were new inputs of DDTs sources in this region during the study period.Meanwhile,the ecological risks were also evaluated according to Sediment Quality Guidelines (SQCs) applied in Canada.According to SQCs,the adverse effects of OCPs in this area mainly originated from contaminations of DDD and DDT,which could occur frequently.The study suggested that more research on risk assessment of OCPs need to be conducted in this area,and feasible solutions to restore sediment environments need to be formulated for Guanhe estuary.