洪湖湿地水鸟肝脏中有机氯农药的分布

Distribution of organochlorine pesticides in the liver of waterbirds from Honghu wetland, Central China

对我国中部地区洪湖湿地6种水鸟肝脏中20种有机氯农药进行了测量．发现DDTs是最主要的OCPs，约占总OCPs的38．3％---93．0％，其平均含量范围为2．74---121．72ng／g湿重．HCHs和DDTs的富集形态说明洪湖湿地这些有机氯农药主要来源于历史残留．不同水鸟肝脏中YOCPs含量差异显著（P〈0．01），表现为自鹭和池鹭体内OCPs含量（37．91～137．22ng／g湿重）要远高于其他水鸟（5．00--21．49ng／g湿重）这种差异的产生主要与其饮食习性有关．大多数水鸟HCHs性别间基本无差异；但白鹭、池鹭雄性水鸟中总OCPs平均含量（白鹭：136．90ng／g湿重；池鹭：52．41ng／g湿重）高于雌性水鸟（白鹭：126．60ng／g湿重；池鹭：49．78ng／g湿重）．与已有研究相比，洪湖湿地水鸟体内OCPs含量处于较低水平．风险评价结果表明研究区水鸟肝脏中OCPs含量不会对该地区水鸟种群产生不利效应．

Twenty organochlorine pesticides （OCPs） were measured in the liver of six waterbird species from Honghu wetland. Among OCPs, DDTs were the most prevalent compounds （38.3%-93.0%）, with average concentration ranging from 2.74 to 121.72ng/g wet weight. The accumulation profiles of HCHs and DDTs suggested that these OCPs in the Honghu wetland were largely derived from historical usage. Significant interspecific differences were observed in the levels of sum OCPs in the liver of all waterbirds （P〈0.01）. Concentrations of total OCPs in little egrets （Egretta garzetta） and chinese-pond herons （Ardeola bacchus） （37.91-137.22ng/g wet weight） were higher than those in the other birds （5.00-21.49ng/g wet weight）, which might be attributed to their different dietary habits. Higher average concentrations of OCPs were observed in males （little egrets： 136.90ng/g wet weight; chinese-pond herons： 52.41ng/g wet weight） than in females （little egrets： 126.60ng/g wet weight; chinese-pond herons： 49.78ng/g wet weight） for little egrets and chinese-pond herons. Compared with other regions worldwide, concentrations of OCPs in waterbirds from Honghu wetland were at low levels. The analysis of risk assessment indicated that the concentrations of OCPs detected in the present study were not expected to pose any hazard to waterbird populations.