大连湾和杭州湾表层沉积物中多氯联苯和有机氯农药及风险评价

Distribution and ecological risk assessment of polychlorinated biphenyls and organochlorine pesticides in marine sediments of Dalian Bay and Hangzhou Bay

对大连湾与杭州湾沉积物样品中多氯联苯（Polychlorinated Biphenyls, PCBs）和有机氯农药（Organochlorine Pesticides, OCPs）进行了分析测定。结果表明,大连湾和杭州湾沉积物中PCBs的含量为0.72~14.87 ng/g和0.76~3.86 ng/g,其中3、4、5氯联苯比例较高,其和超过总含量的70%； OCPs的含量为2.98~32.23 ng/g和1.61~4.71 ng/g,其中主要成分为六六六（Hexachlorocyclohexanes, HCHs）和滴滴涕（Dichlorodiphenyldichloroethylenes, DDTs）。大连湾和杭州湾表层沉积物中HCHs主要来自农业使用,而且大连湾有新的DDTs输入,杭州湾表层沉积物中的DDTs则主要来自历史残留。生态风险评价的结果表明, PCBs几乎不会对研究区域产生生态风险, OCPs对杭州湾也不会造成潜在的生态风险,但大连湾的OCPs处于中等风险水平,应当引起关注。

Congeners of Polychlorinated biphenyls （PCBs） and organchlorine pesticides （OCPs） in sediment samples collected from the Dalian Bay and Hangzhou Bay were analyzed using gas chromatography in order to depict their spatial distribution pattern, reveal their sources and assess their risk levels. The PCB concentrations inDalian Bay and Hangzhou Bay ranged from 0.723 to 14.869 ng/g and 0.762~3.861 ng/g based on dry weight （dw）, respectively. The predominated components were 3-, 4- and 5-chlorinated PCBs, accounting for more than 70% of the total. The OCPs concentrations in Dalian Bay and Hangzhou Bay ranged from 7.757 to 69.597 ng/g and from 3.823 to 23.029 ng/g, dw, respectively. Hexachlorocyclohexanes（HCHs） and Dichlorodiphenyldichloroethylenes （DDTs）were the main forms in OCPs. The method of toxic equivalency quantity （TEQ） was used to assess the ecological risk levels. The TEQ values suggested that the PCBs had no ecological risks at the present in Dalian Bay and Hangzhou Bay. OCPs in the surface sediments of Hangzhou Bay might have minor influence to the environment, while the Dalian Bay should bepaidmore specific attention due to its medium risk level.