广东电子垃圾污染区水体底层鱼类对PCBs的富集效应

采用GC/MS分析方法测试了广东电子垃圾回收地水体沉积物中多氯联苯(PCBs)含量,并利用以前测定的底栖性鱼类(鲮鱼、鲫鱼和乌鳢)PCBs含量数据,计算了生物/沉积物富集因子(BSAF)和生物放大因子(BMF),研究底栖性鱼类对PCBs的富集能力及其影响因素.研究表明,沉积物中总PCBs含量达到24.5~38.6μg/g干重,证实当地环境已受到PCBs严重污染.鲮鱼、鲫鱼和乌鳢的BSAF范围分别为0.05~2.52、0.01~1.20和0.01~5.03.根据乌鳢/鲮鱼和乌鳢/鲫鱼食物关系计算的BMF范围分别为0.14~2.23和0.14~4.93, 其中大部分PCB同系物的BMF>1,表明乌鳢对PCBs具有生物放大作用.BSAF及BMF均与PCBs的KOW和氯原子取代数具有显著相关性,说明化合物的理化性质是控制其生物富集的主要因素.

Bioaccumulation Potentials of Polychlorinated biphenyls in bottom fishes from an e-waste recycling site in South China

The bioaccumulation potentials of polychlorinated biphenyls (PCBs) in bottom fishes from an e-waste recycling site in South China were investigated, and the biota-sediment accumulation factors (BSAFs) and biomagnification factors (BMFs) were determined based on the concentrations of PCBs in surfacial sediment samples and in three bottom fishes (i.e., mud carp, crucian carp, and northern snakehead). Concentrations of total PCBs in the sediments ranged from 24.5 to 38.6μg/g dry wet (or 279.2-338.5μg/g OC), showing severe contamination of PCBs in the aquatic environment. The calculated BSAFs ranged from 0.05 to 2.52, 0.01 to 1.20, and 0.01 to 5.03 for mud carp, crucian carp, and northern snakehead, respectively. The BMFs ranged from 0.14 to 2.23 and 0.14 to 4.93 for the northern snakehead/mud carp and northern snakehead/crucian carp coupling. For most PCB congeners, the observed BMFs were less than unit, indicating the biomagnification of these congeners in the food-chain. Both BSAFs and log BMF correlated significantly with log KOW and the chlorine numbers of PCBs, which suggested that the physiochemical properties of PCBs played an important role in their bioaccumulation.