鱼类对汞（Hg，尤其是甲基汞）有较强的富集能力，Hg污染严重影响鱼肉及鱼类制品的质量安全，威胁着人类健康。鱼体内富集的Hg主要来源于食物，肠道是Hg进入鱼体的最重要途径。申请者的前期研究发现肠道不仅参与了Hg的吸收和排出，更是Hg的生物转化过程的重要位点。但目前，关于肠道对鱼体内Hg生物累积过程的影响鲜有报道。本项目拟通过室内暴露实验，探究Hg在不同海水鱼体内的分布动态，利用动力学模型比较Hg在肠道内的吸收、转化及排出过程的差异，并探明影响Hg在鱼体内积累及形态分布的关键动力学过程。研究假设如下：不同海水鱼的肠道动力学过程存在差异，且其中存在某个关键过程，导致了海水鱼积累Hg水平的高低；不同形态Hg的肠道动力学过程存在差异，并影响到Hg在鱼体内的形态分布。研究结果有助于更为全面地认识Hg在鱼体内迁移、代谢和积累的规律，并为探索控制鱼类Hg积累、降低鱼肉的Hg暴露风险的有效途径提供理论依据。

Mercury [Hg, especially methylmercury (MeHg)] is easily to be accumulated by fish. Hg contamination severely affects the quality of fish and fish products and poses a great threat to human health. Food is the predominant source for Hg accumulation and the digestive tract is the most important route for Hg uptake by fish. Our previous studies have shown that the gut not only participates in the absorption and elimination of Hg, but also plays an important role in Hg biotransformation in fish. However, the effects of intestine on Hg bioaccumulation in fish have not been thoroughly understood. This project plans to conduct laboratory exposure experiments to investigate the distribution of inorganic Hg and MeHg in different species of marine fish, with the aims to: 1. Compare the bioaccumulation processes of Hg in the gut of different fish species by developing kinetic model; 2. Explore the “key” kinetic process that affects the accumulation and species distribution of Hg within fish body. We hypothesize that: 1. The kinetic processes in the gut are varied in different fish species, and the Hg levels in fish could be independent on one “key” kinetic process. 2. There are also variations in the intestinal kinetic processes for different Hg species, and this may influence the species distribution of Hg within fish body. The study can help to develop a broader understanding of the disposition, metabolism and accumulation of Hg within fish body, and can provide potential solutions to control Hg accumulation by fish and diminish the exposure risk through fish consumption.