基于生物可给性的广东省居民主要消费海水鱼膳食暴露评估应用初探

Bioaccessibility of methylmercury from marine fish commonly consumed in Guangdong Province and its application in dietary exposure assessment

目的分析广东省居民主要消费海水鱼品种中甲基汞的生物可给性及其影响因素,探讨生物可给性对膳食海水鱼甲基汞暴露的影响。方法在广州某大型水产贸易市场采集12种海水鱼(共36份样品),经不烹调(生样)、油煎、烘烤或清蒸等4种烹调后,采用体外模型生理原理提取法测定甲基汞生物可给性,比较不同海水鱼、烹调方式之间甲基汞生物可给性差异,并分析生物可给性对甲基汞暴露状况的影响。结果 12种海水鱼生样中甲基汞生物可给性范围为26.5%(带鱼)~84.3%(龙利鱼)。烹调后海水鱼甲基汞生物可给性下降,油煎、烘烤后分别下降了29.0%和30.7%,差异均有统计学意义(P<0.05),清蒸后变化差异无统计学意义(P>0.05)。甲基汞生物可给性与甲基汞含量呈线性负相关,Pearson相关系数r=-0.442(P<0.001)。考虑生物可给性后,沿海地区居民海水鱼甲基汞每周暴露量均值下降48.3%;带鱼甲基汞暴露贡献率由13%降至7%,龙利鱼贡献率由8%上升至14%。结论海水鱼中甲基汞生物可给性因鱼种不同存在差异,烹调后生物可给性下降,在膳食甲基汞暴露风险评估中可综合考虑生物可给性的影响。

Objective To characterize methylmercury(MeHg) bioaccessibility from commonly consumed species of marine fish in Guangdong Province, and to investigate the effects of bioaccessibility on MeHg exposure of dietary marine fish. Methods A total of 36 samples of 12 species of marine fish were purchased from seafood trading market in Guangzhou City. The bioaccessibility of MeHg from raw, fried, grilled and steamed fish samples was determined by dual-phase in vitro gastrointestinal digestion based on the physiologically based extraction test. The bioavailability of MeHg in different sea fish and cooking method was compared, and bioaccessibility-corrected MeHg exposure assessment was conducted. Results The bioaccessibility of MeHg from raw fish ranged from 26.5%(Trichiurus lepturus) to 84.3%(Cynoglossus). Frying and grilling reduced MeHg bioaccessibility by 29.0% and 30.7%(P<0.05), respectively. There was no significant change after steaming(P>0.05). A significantly negative correlation was observed between initial MeHg concentration and MeHg bioaccessiblity(r=-0442, P<0.001). The average exposure of MeHg from marine fish was reduced by 48.3%. The contribution of Trichiurus lepturus dropped from 13% to 7%, and the contribution of Cynoglossus increased from 8% to 14%. Conclusion The MeHg bioaccessibility varied across different species of marine fish. Cooking process reduced the MeHg bioaccessibility from fish. The effects of bioaccessibility need to be considered on dietary MeHg risk assessment.