杭州湾北岸金山岸段滩涂沉积物中持久性有机污染物污染特征及潜在风险评价

Pollution characteristics and potential health risk of persistent organic pollutants in mudflat sediments at the north coast of Hangzhou Bay in Jinshan section

目的 分析测定杭州湾北岸金山岸段滩涂沉积物中持久性有机污染物(persistent organic pollutants,POPs)的组成,评估其健康风险水平。方法 沿杭州湾北岸集中饮水上游金山岸段滩涂选取4个采样点(S1、S2、S3、S4),应用气相色谱质谱联用技术分析滩涂沉积物中多环芳烃(polycyclic aromatic hydrocarbons,PAHs)和多氯联苯(polychlorinated biphenyls,PCBs)的组成。采用效应区间中值法对沉积物中POPs进行风险评价。结果 4个采样点16种PAHs的浓度范围为2.39~249.40 ng/g,S1平均值为44.3 ng/g,S2平均值为38.2 ng/g,S3平均值为36.7 ng/g,S4平均值为39.5 ng/g,其中检出率最高的是苯并(b)荧蒽(60%)。在所有样品中,PAHs总量最高值为249.40 ng/g,出现在S1点的42~44 cm深度。18种PCBs的浓度范围为1.12~34.90 ng/g。S1平均值为10.6 ng/g,S2平均值为11.3ng/g,S3平均值为9.2 ng/g,S4平均值为12.4 ng/g,其中检出率较高的是PCB153(97.5%)、PCB180(92.5%)。在所有样品中,PCBs总量最高值为34.90 ng/g,出现在S2点的14~16 cm深度。结论 杭州湾北岸金山岸段滩涂沉积物中POPs污染程度较低,PCBs潜在风险较小,PAHs潜在风险极低,但是仍然存在一定的残留和累积,应该持续关注。

Objective To analyze the composition of persistent organic pollutants(POPs)in the intertidal sediments at the north shore of Hangzhou Bay in the Jinshan section and to assess their potential health risk.Methods Four sampling sites(S1,S2,S3,and S4)were selected along the intertidal zone of the north shore of Hangzhou Bay in the Jinshan section,which is upstream of the centralized drinking water source.The gas chromatography-mass spectrometry technique was used to analyze the composition of polycyclic aromatic hydrocarbons(PAHs)and polychlorinated biphenyls(PCBs)in the intertidal sediments.The effect range-low method(ERL)and the effect range-median method(ERM)were used to evaluate the potential risk of POPs in sediments.Results The concentration range of 16 PAHs at 4 sampling sites was 2.39-249.40 ng/g,with an average value of 44.3 ng/g at S1,38.2 ng/g at S2,36.7 ng/g at S3,and 39.5 ng/g at S4,respectively.Among these,benzo(b)fluoranthene had the highest detection rate(60%).In all samples,the highest total PAH concentration was 249.40 ng/g,which was found at the depth of 42-44 cm of the S1 site.The concentration range of 18 PCBs was 1.12-34.90 ng/g,with an average value of 10.6 ng/g at S1,11.3 ng/g at S2,9.2 ng/g at S3,and 12.4 ng/g at S4,respectively.Among these,PCB153(97.5%)and PCB180(92.5%)had higher detection rates,and the highest total PCB concentration was 34.90 ng/g,found at a depth of 14-16 cm of the S2 site.Conclusions The POP pollution level in the intertidal sediments at the north shore of Hangzhou Bay in the Jinshan section was low,with a small potential risk for PCBs and a very low potential risk for PAHs.However,the residual and accumulation should still be continuously monitored.