汞是剧毒重金属元素之一，而我国是汞生产、消费和排放大国。探索预防和降低汞对人体健康影响的可能途径具有重要社会意义。硒是机体必需元素，纳米硒具有生物利用度高、毒性低及小尺寸效应等优点。本项目以大鼠为模式动物，研究纳米硒对汞中毒的预防与解毒作用与机理。项目首先研究纳米硒在大鼠体内的吸收、分布、转化与排出行为。通过同时灌胃给予大鼠不同剂量纳米硒和氯化汞或氯化甲基汞，研究纳米硒对汞中毒的预防作用；通过先建立大鼠亚急性汞中毒模型，然后灌胃给予不同剂量的纳米硒，研究纳米硒对汞中毒大鼠的解毒作用。考察的指标包括体重、生物学行为及脏器系数，汞、硒含量与形态，生化指标的变化等。项目将充分利用基于大科学装置的同步辐射XAS、XRF、XRD及SAXS研究大鼠体内汞、硒的分布、转化与代谢；胡须中汞、硒分布及胡须中衍射峰的变化，从而揭示纳米硒对汞中毒的预防与解毒机制。本研究可为涉汞人员健康防护与治疗提供依据。

China is one of the biggest producers, consumers and emitters of mercury, which is extremely toxic. It is important to prevent and decrease the adverse effects of mercury to human being. Selenium is an essential trace element. Nano-sized selenium (nanoSe) is more bioavailable with lower toxicity than other selenium forms. Besides, it also has the peculiar effects of nanomaterial itself, like the small-size effect. In this proposal, we will study the prevention and detoxification effects of nanoSe on mercury (including inorganic mercury and organic mercury) poisoned rats and the underlying mechanism. We will first study the absorption, distribution, metabolism and excretion behavior of nanoSe at different doses in rats. To study the prevention effect, the rats will be given both nanoSe and mercury simultaneously through gavage; To study the detoxification effect, the rats will be given mercury to reach a sub-acute status, then be given nanoSe. The body weight, biological behaviors, organ coefficients, the elemental level and speciation, the biochemical indexes will be checked. Furthermore, we will use the synchrotron radiation-based technologies, including XAS, XRF, XRD and SAXS to study the distribution, transformation and metabolism of mercury and selenium in rats. Through all these effects, the underlying mechanism of nanoSe on the prevention and detoxification of mercury poisoning will be revealed. This will shed lights on the health protection of mercury-exposed people and the detoxification in mercury poisoned people.