CAREER: Uncovering the Geochemical and Biomineralization Processes Responsible for Mercury-Selenium Antagonism in the Environment

研究人员和他在加州戴维斯大学的研究小组将研究汞和硒之间的相互作用如何影响汞在环境中的循环和生物积累。汞是一种普遍存在的全球污染物，对全世界的环境和人类健康都有影响。该项目的研究旨在填补我们对汞-硒相互作用的理解方面的关键知识空白，这将有助于改善对复杂淡水环境的管理，并准确评估汞对野生动物和人类的风险。除了研究之外，研究人员还将致力于通过美国国家公园的公民科学来扩大公众对金属污染物的兴趣，并利用项目数据开发新的本科课程。编写的教材将在公共数字图书馆上出版，供教育工作者使用。三个研究假设将寻求建立硒影响汞的甲基化，神经毒性甲基汞在食物网中的吸收，以及甲基汞的生物矿化为硒化汞的机制。含有确定的汞和硒投入的天然湖泊将用于实地取样和实验。将使用一套跨学科的原子和分子水平的技术，包括微生物基因组学，X射线吸收光谱和蛋白质纯化。这些方法将应用于沉积物，食物网的组成部分，并与纯化的蛋白质，以调查潜在的地球化学和生物矿化反应负责汞硒拮抗作用的环境。本科生、研究生和博士后研究人员将与大学内外的合作者进行交叉培训，在会议上共同召开会议，并共同开发基于问题的课堂学习活动和面向公众的教育材料。这些努力旨在培养一支多元化且具有全球竞争力的STEM工作队伍，以应对汞硒拮抗作用以外的未来环境挑战。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The investigator and his research group at the University of California Davis will study how interactions between mercury and selenium influence the cycling and bioaccumulation of mercury in the environment. Mercury is a prevalent global contaminant that impacts both environmental and human health worldwide. The research of this project aims to fill critical knowledge gaps in our understanding of mercury-selenium interactions, which will permit improved management of complex freshwater environments and accurate risk assessment of mercury to wildlife and humans. Beyond research, the investigator will work to broaden public interest in metal contaminants through citizen science at U.S. national parks and develop new undergraduate curriculum with project data. The educational materials developed will be published on a public digital library for educators. Three research hypotheses will be pursued to establish the mechanisms by which selenium influences the methylation of mercury, the uptake of neurotoxic methylmercury in food webs, and the biomineralization of methylmercury to mercury selenide. Natural lakes with defined inputs of mercury and selenium will be used for field sampling and experimentation. A suite of interdisciplinary atomic- and molecular-level techniques will be used, including microbial genomics, X-ray absorption spectroscopy, and protein purification. These methods will be applied on sediments, within components of food webs, and with purified protein to investigate the underlying geochemical and biomineralization reactions responsible for mercury-selenium antagonism in the environment. Undergraduate, graduate, and postdoctoral researchers will cross-train with collaborators within and outside the university, co-convene sessions at conferences, and co-develop problem-based learning activities for the classroom and educational materials for the public. These efforts aim to develop a diverse and globally competitive STEM workforce to address future environmental challenges beyond the topic of mercury-selenium antagonism.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.