牡蛎塭池中多环芳烃的分布、来源和生态风险评价

研究了长沙湾牡蛎塭池环境中多环芳烃的含量分布及其对养殖牡蛎质量安全的潜在风险。结果显示,牡蛎塭池水体、悬浮物、养殖牡蛎和沉积物中多环芳烃质量浓度分别为6.62~21.2 ng·L~(-1)(均值9.87 ng·L~(-1))、92.9~355μg·kg~(-1)(均值198μg·kg~(-1))、12.7~17.4μg·kg~(-1)(均值15.5μg·kg~(-1))和247~615μg·kg~(-1)(均值322μg·kg~(-1))。塭养区悬浮物平均含量高于塭养区外,但是差异不显著。塭养区水中多环芳烃平均含量与塭养区外相近,悬浮物中多环芳烃含量高于塭养区外,而沉积物中多环芳烃含量均值低于塭养区外。表层沉积物多环芳烃组成以3环为主,其次是4环。来源解析表明该区域多环芳烃主要源自化石燃料的燃烧,受养殖区周边燃煤发电工业的影响。风险评价结果显示,塭养区表层沉积物中多环芳烃含量低于效应区间低值,对养殖牡蛎安全潜在风险小,但是芴和蒽等同系物的含量介于效应区间低值和中值之间,可能会对塭养牡蛎养殖安全产生负面影响。

Distribution,sources and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in coastal waters in oyster pond

We explored the distribution of PAHs in pond waters in the Changsha Bay and assessed their ecological risk to the cultured oyster.It is indicated that the range of the 16 USEPA priority PAHs in water,suspended solids,oysters and surficial sediment from the oyster ponds were 6.62~21.2 ng·L-1 (average:9.87 ng·L-1),92.9~355 μg·kg-1(average:198μg·kg-1),12.7~17.4 μg·kg-1(average:15.5 μg·kg-1)and 247~615 μg·kg-1(average:322 μg·kg-1),respectively.Compositional analysis of the PAHs reveals that 3-ring PAHs were dominated in the sediments,followed by 4-ring compounds.The isomeric ratios of the PAHs in sediment show that the source of the PAHs in the oyster ponds were originated predominantly from high temperature pyrolytic inputs,which may be related with the thermal power plants around the culture zone.The Effects Range Low (ERL) and Effects Range Median (ERM) were applied to assess the ecological risk.It is indicated that the PAHs in the sediment were lower than the ERL values,which was rarely associated with adverse effects on oysters cultured in the ponds.However,attention must be paid to the compounds such as fluorine and anthracene due to their contents between ERL and ERM,which will cause adverse effects on the oyster.