福建近岸海域表层沉积物重金属、PCBs潜在生态风险评价

Potential ecological risk assessment of heavy metals and PCBs in surface sediments at Fujian coastal sea area

  • 摘要: 对福建近岸海域38个表层沉积物样进行测试分析,探讨了沉积物中重金属(Hg、Cd、Cr、Pb、Cu、Zn、As)和多氯联苯(PCBs)的空间分布特征及其可能的来源,并采用Hakanson潜在生态风险指数法进行了污染评价。结果表明:(1)三沙湾和闽江口—妈祖海域的重金属富集较为严重,罗源湾及湾口外海域沉积物污染程度较低;(2)沉积物中PCBs没有新的来源,重金属主要来自岩石自然风化和侵蚀、工业排污、生活污水以及船只油品泄漏;(3)三沙湾具有中等偏高的潜在生态风险;闽江口—妈祖海域整体接近、局部已达中等潜在生态风险;罗源湾及湾口外海域均属低潜在生态风险。Cd和Hg是主要的生态风险贡献因子,各元素的平均生态风险指数由大到小依次为:Cd> Hg> As> Cu> PCBs> Pb> Cr> Zn。

     

    Abstract: In order to understand the pollution characteristics and sources of heavy metals and polychlorinated biphenyls (PCBs) in surface sediments of Fujian coastal sea area, 38 sampling sites of surface sediments were collected and concentration of 7 heavy metals (Hg、Cd、Cr、Pb、Cu、Zn、As) and PCBs were analyzed.The ecological risk regarding pollutants was assessed by using Hakanson Potential Ecological Risk Assessment Method.The results showed that:(1) The heavy metals were highly enriched in the Sansha bay and Minjiang estuary-Mazu sea area, pollution levels of sediments were low in the Luoyuan bay and estuary.(2) No new sources of PCBs input.Natural weathering and erosion of rocks, industrial and domestic wastewater discharge and vessels oil spill were the main sources of heavy metals.(3) The ecological risk assessment indicated that Luoyuan bay and estuary were at low ecological risk level, the whole Minjiang estuary-Mazu sea area approached medium level, while Sansha bay was at little higher than medium level.The sequence of potential ecological risk of these elements was Cd> Hg> As> Cu> PCBs> Pb> Cr> Zn, Cd and Hg were the main ecological risk factors in the Fujian coastal sea area.

     

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