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

Abstract

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.