我国海洋食用贝类重金属污染特征及其健康风险

目的探讨我国海洋食用贝类重金属累积水平及人体健康风险。方法基于已报道的数据,分析我国海洋食用贝类中Cu、Pb、Cd、Cr、As和Hg污染统计特征,采用美国国家环境保护局(US EPA)提出的靶器官危害系数(THQs)方法评估贝类重金属污染的人体健康风险。结果我国海洋食用贝类中各重金属含量呈非正态分布。Pb、Cd、Cr、As和Hg的平均含量均未超过食品中污染物限量。牡蛎、菲律宾蛤仔、缢蛏及贻贝4类典型食用贝类中,As、Cu和Cd的含量均差异有统计学意义(P0.05),牡蛎中Cu和Cd含量最高,缢蛏中As含量最高;4类贝类中其他重金属含量均差异无统计学意义(P0.05)。珠江口、福建沿海、长江口-浙江沿海、山东沿海、渤海湾海域食用贝类中Cu、Pb、Cr、Hg的人体健康风险较低,但山东沿海、渤海湾和福建沿海部分贝类中Cd以及福建海域部分贝类中As的风险超出了可接受水平;除山东沿海、渤海湾和福建沿海贝类重金属污染对儿童的风险值大于1.0外,其他海域贝类6种金属的总风险均可接受;Cd和As是我国贝类重金属污染健康风险的主要贡献者。结论我国海洋食用贝类中Cu、Cd和Cr含量存在超标现象,部分海域一些贝类Cd和As污染的健康风险超出了可接受水平。总体上,海洋贝类重金属污染不严重,但重金属复合污染的健康风险需引起重视。

Accumulation and health risks of heavy metals in edible marine shellfishes from China

To investigate the contamination and health risks of heavy metals in edible marine shellfishes from China.Methods Statistical characteristics of the concentrations of six metals, i.e., Cu, Pb, Cd, Cr, As and Hg, in the edible shellfishes from China offshore waters were investigated, and their health risks were assessed using the target hazard quotient model recommended by US EPA, based on the available information regarding the metal concentrations reported in published literatures. Results The Kolmogorov-Smirnov test indicated that all the six metals had skewed concentration distributions. The average contents of Pb, Cd, Cr, As and Hg did not exceed the food standards. In this study, several independent samples tests showed that the concentrations of As, Cu and Cd were significantly different (P>0.05) among oyster, short necked clam, razor clam and mussel. In these four shellfishes, oyster had the highest levels of Cu and Cd, and razor clam had the highest level of As. No significant differences were observed for other three metals. In the Pearl River Estuary, Fujian coastal waters, the Yangtze River estuary-Zhejiang coastal waters, Shandong coastal waters and Bohai Bay, the non-carcinogenic risk levels from exposure to individual shellfish metal (including Cu, Pb, Cr, and Hg) were separately acceptable. However, the health risks from exposure to Cd in some shellfishes from Fujian coastal waters, Shandong coastal waters and Bohai Bay, and from exposure to As in some shellfishes from Fujian coastal waters, exceeded the acceptable levels. Although the health risk levels from exposure to multiple metals in shellfishes from Fujian coastal waters, Shandong coastal waters and Bohai Bay were unacceptable for children, the non-carcinogenic risks from six metals in other waters were within the safe level. The findings suggested that Cd and As were the key contributors to health risk from exposure to shellfish metals.Conclusion In China coastal waters, the concentrations of Cu, Cd and Cr in some shellfishes exceeded the food standard. The health risks from Cd and As were unacceptable in some shellfishes in some area, respectively. In this study, no serious heavy metal pollutions were found in the edible marine shellfishes, but the risk of multiple metals exposure in the shellfishes should be of concern.