太湖梅梁湾沉积物中多环芳烃的生态和健康风险

Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons in Sediments of Meiliang Bay, Taihu Lake

持久性有机物引起的水质安全性问题日益受到广泛的关注.利用生态和健康风险评价的原理和方法,对太湖梅梁湾水源地沉积物中的多环芳烃可能导致的负面效应进行了分析.首先采用商值法筛选出该地区沉积物中具有潜在风险的多环芳烃,再进一步用建立在暴露浓度分布和物种敏感度分布上的概率法定量表征风险.结果表明,太湖梅梁湾水源地沉积物的多环芳烃中,菲、荧蒽、芘、苯并[a]蒽、屈、苯并[a]芘、二苯并[a,h]蒽7种具有潜在风险;在保护95%的物种水平下,菲的风险最小,而荧蒽和芘风险较高,达20%.健康风险分析表明,美国EPA提出的7种具有遗传毒性的多环芳烃其致癌风险在梅梁湾沉积物中均在10-5水平以下.

Safety of water resources threatened by persistent organic pollutants is of great concern in all countries. A case study was carded out in Meiliang Bay, Taihu Lake. The quotient method served as screen level estimation of risk and it appeared that seven kinds of PAHs could pose potential adverse effects. Probabilistic method involved comparing distributions of exposure concentrations and species sensitivity to PAHs. Results showed that phenanthrene posed a negligible risk when 95 % species were not affected at 95 % confidential level. Fluoranthene and pyrene posed higher risk where the probability of the quotients exceeded unit would be near 20%. The cancer risk of seven kinds of PAHs presented by US EPA with genotoxicity was below 10^-5 in Meiliang Bay.