MRI: Acquisition of Tekran mercury speciation system for mercury biotransformation and ecotoxicology research and training at UT Tyler

该合同将允许获得一个汞物种形成系统，该系统将通过使PI和co-PI能够分析环境样品、微生物培养物、水生和鸟类生物中不同化学形式的汞，从而推进他们的研究领域。燃煤电厂的排放物是造成鱼类和野生动物汞污染的主要原因，尤其是在德克萨斯州。德州东部有四个火力发电厂，在2009年位列全国六大大气汞排放点源之列。汞污染在德克萨斯州东部的鱼类中广泛存在，在墨西哥湾北部的东部褐鹈鹕中也发现了相当高的水平。尽管对鱼类和野生动物物种以及人类健康产生了这些影响，但目前还没有MeHg分析仪器可用于开展必要的研究，以解决这些地区的问题。获得汞物种形成系统的资金将促进对汞物种形成系统和共同物种形成系统的研究，以解决汞的微生物转化机制、物种形成和命运、生物利用度和生态毒理学方面的知识空白，这将有助于开发潜在的汞减排和修复应用，以创建更健康的水生生态系统，支持对人类和野生动物安全食用的鱼类。汞的生物地球化学命运分析对生物汞甲基化和甲基汞降解机制的研究至关重要。该仪器系统的研究项目将有助于揭示受工业汞源直接影响的淡水湖产甲烷菌及其合流中汞甲基化的新机制。有机碳贫湖和有机碳富湖之间微生物汞甲基化机制的比较将有可能得出汞甲基化微生物与沉积物有机碳的相互作用模式。其他受益于该系统的研究包括假单胞菌的甲基汞降解途径，稻田中的汞生物转化，棕鹈鹕鸟类中的汞残留物和德克萨斯州南部海岸繁殖地面沉积物中的汞甲基化源，金矿开采和汞污染对南美洲鱼类和食物网的影响。研究结果可协助联邦和各州环境监管部门制定大气中汞污染监测方案，为制定大气中汞污染控制策略提供科学依据，以解决区域和全国的汞污染问题。项目负责人和共同项目负责人将在多达七门与环境科学有关的课程的教学和实验室训练活动中使用这一仪器系统。从研究中获得的知识将传播给高中生，鼓励他们接受STEM领域的大学教育和职业，并有助于教育公众有关汞污染的问题，大气汞排放与气候变化之间的关系，有毒金属食物链转移引起的食品安全问题以及环境管理。该奖项反映了美国国家科学基金会的法定使命，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。

This award will permit the acquisition of a Mercury Speciation System that would advance the research fields of the PI and co-PIs by enabling them to analyze different chemical forms of Hg in environmental samples, microbial cultures, and aquatic and avian organisms. Emissions from coal-fired power plants are the leading cause of Hg contamination in fish and wildlife especially in Texas. East Texas is home to four coal-fired power plants that are ranked in the nation's top six point sources of atmospheric Hg emissions in 2009. Hg contamination is widespread in fishes in East Texas and found at significantly high levels in eastern brown pelican in the northern Gulf of Mexico. Despite these impacts to fish and wildlife species and human health, no MeHg analysis instrument has been available for conducting needed research to address the problem in these regions. Funding of the acquisition of the Mercury Speciation System would facilitate research of the PI and co-PIs that addresses the gaps in knowledge about the microbial transformation mechanisms, speciation and fate, bioavailability and ecotoxicology of Hg that would help develop potential Hg abatement and remediation applications to create healthier aquatic ecosystems that support fish that are safe for human and wildlife consumption. Biogeochemical fate analyses of Hg are crucial for the studies on microbial Hg methylation and MeHg degradation mechanisms in the PI’s lab. The research programs enabled by this instrument system will help unravel new Hg methylation mechanisms in methanogens and their syntrophy in freshwater lakes which are impacted directly by industrial source of Hg. The comparison of microbial Hg methylation mechanisms between the organic carbon poor and organic rich-lakes will likely derive the interaction patterns of the Hg methylating microbes with sediment organic carbon. Other studies which benefit from this system include MeHg degradation pathways by Pseudomonas spp., Hg biotransformation in rice paddies, Hg residues in brown pelican birds and Hg methylation source in their breeding ground sediments along south Texas coasts, effects of gold mining and Hg contamination on fish and food webs in South America from the PI and co-PI’s labs. Results of the research conducted could assist federal and state environmental regulators in developing Hg contamination monitoring program from air emission and in the lakes, and provide the scientific basis for establishing air Hg emission control strategies to address Hg contamination regionally and nationally. The PI and co-PIs would use this instrument system in the teaching and lab training activities of up to seven environmental sciences-related courses. Knowledge gained from the studies will be disseminated to high school students to encourage them to acquire college education and careers in STEM fields, and will help educate the public about the problems associated with Hg contamination, the relationship between atmospheric Hg emission and climate change, food safety concerns from toxic metal food chain transfer, and environmental stewardship.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.