中国近海海洋环境多氯联苯(PCBs)污染现状及影响因素

Status and Influencing Factors of Polychlorinated Biphenyls(PCBs) Pollution in the Coastal Areas in China

对中国近海海洋环境(水体、表层沉积物和生物体)中多氯联苯(PCBs)的空间分布、污染程度、来源及影响因素进行了总结,得出如下结果:①我国近海海域水体中,PCBs的含量水平呈现由北向南逐渐增加的趋势,以东部沿海工农业发达地区为最高,我国大部分近海海域水体中PCBs都超过美国EPA制定的30 ng·L-1的标准,污染比较严重;②我国近海海域表层沉积物中PCBs只有小部分超过ISQG(interim sediment quality guideline)和ERL(effects range-low)值,引起生物负效应的几率比较小,污染程度较轻;③生物体内富集的PCBs以4、5和6等高氯代联苯为主,其含量都低于《食品中污染物限量标准》2 000ng·g-1,不会对人类健康造成影响.④我国近海海洋环境中PCBs主要来源于周围大型工厂排放的废水以及电子垃圾拆解造成的PCBs泄漏,影响PCBs含量水平的主要因素有距离陆地的远近程度、水流交换情况、水量大小、季节的变化、沉积物颗粒大小、有机碳含量等等.

This review focused on the distribution,pollution status,sources and influencing factors of PCBs in the coastal areas（seawater,surface sediments and biota） in China.A few main points are listed as follows： ① For coastal seawater,concentrations of PCBs were increasing from the north to the south and the highest concentrations of PCBs were observed in the developed east coastal areas.The concentrations of PCBs in most coastal areas were higher than the seawater standard of U.S.EPA（30 ng·L-1）,indicating that there was a high potential risk.②Only a small part of surface sediments had PCBs concentrations higher than the ISQG（interim sediment quality guideline）and ERL（effects range-low） values,suggesting little probability of causing biological adverse effects and potential risk in surface sediments.③High-molecular-weight PCBs（4,5 and 6 chlorinated biphenyl） were bio-accumulated in marine biota.The concentrations of PCBs in organisms were generally lower than 2 000 ng·g-1,which may have negligible effects on human health.④ The main sources of PCBs were wastewater discharged from factories and the leakage of dismantling PCBs from electronic wastes.Factors influencing the concentrations and distribution of PCBs in the coastal areas included distance from land,flow exchange situation,water-carrying capacity,season,sediment particle size and total organic carbon content.