香港周边海域野生鱼体内DDTs和PCBs的含量分布和食用风险评估

Spatial Distribution of DDTs and PCBs in Wild Fish from Hong Kong Coastal Areas and Potential Human Health Risk Assessment

为研究香港周边海域鱼体内持久性有机污染物的污染水平、分布特征及其对当地居民的健康风险评估,采集了香港周边海域中31种野生鱼,分析鱼体中两类典型持久性有机污染物,如滴滴涕(DDTs)和多氯联苯(PCBs).结果表明,香港周边海域野生鱼类DDTs和PCBs的含量范围分别为0.44~17 ng·g^(-1)和0.028~6.3 ng·g^(-1),与国内外其他地方相比处于中低水平.在空间分布上,大屿山西部的鱼体内DDTs含量最低,而吐露港鱼体中PCBs含量最低.鱼类的生活环境及食性影响其在鱼体内DDTs与PCBs的富集程度.来源分析显示野生鱼体内DDTs来源主要为历史残留,迁徙的鱼类可能受沿海岸河口DDTs污染影响.此外,健康风险评估结果表明,香港青少年和成年人长期食用香港周边海域的鱼类可能会存在潜在的终生致癌风险.因此,香港当地居民应尽量减少对其周边海岸野生鱼类的摄入.

To examine the distributional patterns of persistent organic pollutants in the wild fish of Hong Kong and assess the health risks associated with consuming them,two typical kinds of persistent organic pollutants,such as dichlorodiphenyltrichloroethane（ DDTs） and polychlorinated biphenyls（ PCBs）,were determined in 31 kinds of fishes caught from the coastal areas of Hong Kong.The results indicate that the concentrations of DDTs and PCBs in the wild fishes were in the ranges of 0. 44-17 ng·g^-1 and 0. 028-6. 3 ng·g^-1,respectively,which were at the low end of the global ranges. Spatially,the lowest concentrations of DDTs and PCBs were found in the fishes occurring in the west of Lantau Island and Tolo Harbor. Furthermore,the feeding habits and living environments of the fishes could have some influence on the accumulation of DDTs and PCBs in them. Source diagnostics indicated that DDTs in these fishes mainly originated from historical residues,but the fishes which migrate for relatively longer distances may be subject to DDT contamination in the estuaries. Finally,human health risk assessments suggested that the increased potential lifetime cancer risk of local adolescences and adults exposed to DDTs and PCBs via wild fish consumption was high. Therefore,the local residents in Hong Kong should reduce their daily intake of wild fish caught from the surrounding coastal regions.