广东吴川近岸海域表层海水重金属含量及生态风险分析

为了解广东吴川近岸海域重金属含量现状及其潜在风险，以便有针对性地对重金属污染进行防控，于2020年10月采集了吴川海域41个站位的表层海水样，运用综合指数法、HAKANSON潜在生态风险指数法和相关性分析法评价了其重金属污染程度和潜在生态风险。结果表明：Cu含量范围为0.48～14.1 μg/L，平均含量为1.75 μg/L；Pb含量范围为0.07～7.79 μg/L，平均含量为0.44 μg/L；Zn含量范围为3.98～65.8 μg/L，平均含量为9.22 μg/L；Cd含量范围为0.03～0.17 μg/L，平均含量为0.05 μg/L；Cr含量范围为0.62～2.69 μg/L，平均含量为1.92 μg/L；Hg含量范围为0～0.039 μg/L，平均含量为0.021 μg/L；As含量范围为0.39～1.42 μg/L，平均含量为0.93 μg/L。吴川海域各重金属元素平均含量均未超过中国海水水质一类标准。通过与国内外其他海域表层重金属含量的比较，吴川海域表层海水重金属含量整体处于中低水平。按其相关性可将吴川海域重金属元素分为3类：第1类为Cu-Pb-Zn-Cd组合，第2类为Cr-As组合，第3类为Hg元素。第1类重金属元素主要来源可能为海域内来往船舶及其燃烧尾气的大气沉降，第2类重金属元素可能主要来源于沿岸养殖场排放的养殖废水和溶解于海水的农药、化肥等农业活动用品。吴川近岸海域综合污染指数（WQI）平均值为0.31，整体污染程度为清洁。单项潜在生态风险指数（Eri）介于0.2～38.95，综合潜在生态风险指数（RI）介于6.65～65.32，整体生态危害等级为轻微。

Analysis of heavy metal content and ecological risk in surface seawater of Wuchuan coastal area,Guangdong Province

To understand the status and potential risks of heavy metal content in the coastal waters of Wuchuan, Guangdong Province, surface seawater samples were collected from 41 stations in October 2020, and the degree of heavy metal pollution and potential ecological risks were evaluated by comprehensive index method, Hakanson potential ecological risk index method, and correlation analysis method. The results show that the content of Cu ranged 0.48-14.1 μg/L (1.75 μg/L on average), Pb 0.07-7.79 μg/L (0.44 μg/L), Zn 3.98-65.8 μg/L (9.22 μg/L), Cu 0.48-14.1 μg/L (1.75 μg/L), Cd 0.03-0.17 μg/L (0.05 μg/L), Cr 0.62-2.69 μg/L (1.92 μg/L), Hg 0-0.039 μg/L (0.021 μg/L), As 0.39-1.42 μg/L (0.93 μg/L). The average content of heavy metal elements in Wuchuan sea area did not exceed the first-class benchmark of China’s national marine water quality criteria. By comparing the contents of heavy metals in the surface waters of other sea areas in China and the world, the contents of heavy metals in the surface waters of Wuchuan sea area are generally at a medium or low level. According to their correlation, the heavy metal elements in Wuchuan sea area were divided into three types: Cu-Pb-Zn-Cd assemblage, Cr-Hg-As assemblage, and Hg element. The main source of the first type may be the atmospheric deposition from marine vessel emission in the sea area, and the second type may be mainly from aquaculture wastewater from coastal farms and agricultural activities using pesticides and fertilizers. The average comprehensive pollution index of the Wuchuan coastal waters was 0.31, indicating an overall clean state of pollution. The single potential ecological risk index ranged from 0.2 to 38.95, and the overall potential ecological risk index ranged from 0.59 to 87.38, showing that the overall ecological hazard scale was low.