天津渤海湾近岸海域沉积物中4种常见重金属的分布及其风险分析

重金属是近岸海域常见污染物之一，本文以天津渤海湾近岸海域为研究区域，对沉积物中4种常见重金属铜（Cu）、镉（Cd）、铅（Pb）和锌（Zn）的污染特征及其潜在生态风险进行调查分析。结果显示沉积物中Cu、Cd、Pb和Zn的浓度范围分别为（4.61~39.74）×10-6、（0.08~1.76）×10-6、（5.49~26.22）×10-6、（17.94~147.10）×10-6，平均值分别为27.07×10-6、0.52×10-6、21.88×10-6、86.84×10-6。根据《海洋沉积物质量标准》（GB18668-2002），4种重金属基本达到Ⅰ或Ⅱ类水平。为避免生态风险评价结果的片面性，分别采用国际公认的加拿大魁北克沉积物质量基准法、Hakanson潜在生态风险指数法和地累积指数法对4种重金属的生态风险进行评价，结果表明3种方法的评价结果基本一致，都发现研究区域内Cd污染最严重，在部分站位为中度污染，对海洋生物可能会产生一定的危害，应引起相关部门的重视。与之相比，其它3种重金属的生态风险几乎可以忽略不计。

Distribution and ecological risk assessment of four common metals in coastal sediment of Bohai bay along Tianjin city,China

Heavy metals have been the common contaminations in coastal area.Here 4 most common metals including Cu, Cd, Pb and Zn in coastal sediment of Bohai bay along Tianjin city, China were determined, and their ecological risk was assessed.The results showed that Cu, Cd, Pb and Zn varied between (4.61~39.74)×10-6, (0.08~1.76)×10-6, (5.49~26.22)×10-6 and (17.94~147.10)×10-6, respectively.The average values were 27.07×10-6, 0.52×10-6, 21.88×10-6 and 86.84×10-6, respectively.According to the National Marine Sediment Quality Standard of China, the 4 metals attained theⅠand Ⅱlevel.In order to scientifically assess the ecological risk in study area, 3 internationally recognized methods including sediment quality guidelines (SQGs) in Quebec, Hakanson index of potential ecological risk and Geoaccumulation index(Igeo) were used simultaneously.The assessment results using the 3 methods showed that Cd pollution was the most serious, and the risk level in some stations was moderate.The adverse effects caused by Cd on marine organisms might have occurred, that should be paid more attentions.In contrast, the ecological risk of the other 3 metals could almost be ignored.