C2H2 EAGER: Gadolinium Contamination in the Middle Rio Grande Valley: Understanding Environmental Fate and Human Exposure

气候变化的影响日益加剧，对全球淡水供应构成前所未有的挑战，特别是在新墨西哥州等已经面临水资源压力的地区。该提案解决了与医疗废物污染水资源有关的紧迫问题，特别是钆（Gd），一种有毒元素，是磁共振成像中使用的造影剂的重要组成部分。本文通过对新墨西哥州中部大河谷的河流、溪流和地下水的分析，探讨了人为钆在干旱至半干旱地区地表水和地下水资源中的命运及其对生态和人类健康的影响。这项研究包括实地观察、河流和地下水取样以及实验室实验工作。重点将是检查和追踪天然水体中Gd的来源，并确定其在环境中的分布。将研究钆对水处理设施的影响，并最终通过接受核磁共振成像的人的尿液进入环境，并通过人体消化/胃液的暴露和毒理学研究确定其对人类健康的影响。这项研究的更广泛影响包括增进对医疗废物对水质和公众健康的影响的了解。这项工作将为缓解计划提供急需的数据，并为促进环境可持续性和公共福利的国家利益服务。该项目还将吸引当地的高中生（其中许多来自该地区的印第安部落）参与水项目，以培养对这个已经面临严重水资源压力的地区的兴趣，并加深对水问题的了解。拟议的研究将解决有关Gd污染的命运，分布和毒性的关键研究问题，这些污染来自含有元素钆（Gd）的对比增强磁共振成像（MRI）液体的医疗废物，这是一种对人类有毒的元素。在MRI液体中，Gd被螯合成一种化合物，使其对人体无害。然而，这种液体在成像后通过尿液排出体外，并通过污水和污水处理厂进入地表水和地下水系统。然后，Gd水性物种被释放到自然环境中，在那里它们与自然物质和过程相互作用，可以改变物种形态，使其成为生物可利用的。本研究提供了新墨西哥州里约热内卢格兰德河谷地表水和地下水中Gd分布和物种形成的研究，并解决了低浓度Gd自然样品物种形成的分析挑战。它包括胃肠道液体对钆形成及其毒性的影响的研究。主要成果包括：(1)确定了天然水体（地表水和地下水）以及阿尔伯克基和象丘之间里约热内卢Grande沿岸沉积物中Gd的浓度和种类；(2)评估了通过饮用水源摄入Gd的人类暴露途径和潜在健康风险；(3)提高了对以胃肠道为重点的Gd暴露毒理学影响及其对人类健康的影响的理解。这项工作将大大有助于我们了解Gd医疗废物对环境造成的风险。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。

The escalating impacts of climate change pose unprecedented challenges to freshwater supplies globally, particularly in areas already experiencing water stress, such as New Mexico. This proposal addresses a pressing concern related to the contamination of water resources by medical waste, specifically gadolinium (Gd), a toxic element that is an important component of contrast agents used in magnetic resonance imaging. This research focuses on the analysis of river, stream, and groundwater of the Middle Rio Grande Valley in New Mexico to investigate the fate of anthropogenic Gadolinium in surface and subsurface water resources of understudied arid to semiarid areas and its impact on ecologocal and human health. The research involves field observations and sampling of river and groundwaters and laboratory experimental work. A focus will be to examine and trace the sources of Gd in natural waters and determine its distribution in the environment. The impact of Gadolinium, released to water treatment facilities and ultimately to the environment via the urine of those who have under gone MRI, will be studied and its impact on human health will be determined through exposure and toxicological studies of human digestive/gastric fluids. Broader impacts of the reserach include improved understanding the consequences of medical waste on water quality and public health. The work will provide much needed data for mitigation plans and serve the national interest in promoting environmental sustainability and public welfare. It will also engage local high school students, many from Native American tribes in the area, in water projects to foster interest and to increase understanding of water issues in a region already experiencing significant water stress.The proposed research will address critical research questions regarding the fate, distribution, and toxicity of Gd contamination stemming from medical waste from contrast enhancing magnetic resonance imaging (MRI) fluids containing the element Gadolinium (Gd), a toxic element to humans. In MRI fluids, Gd is chelated into a compound that renders it harmless to humans. However, this fluid is excreted from the body in urine, post imaging, and enters surface and groundwater systems through sewars and sweage treatment plants. Gd aqueous species are then released into the natural environment where they experience interactions with natural materials and processes that can change the speciation allowing it to become bioavailable. This resaerch provides a study of the Gd distribution and speciation in New Mexico Rio Grande Valley surface and ground waters and addresses analytical challenges of speciating natural samples with low-concentrations of Gd. It includes investigation into the effects of gastrointestinal fluids on speciation of Gadolinium and its toxicity. Key outcomes include (1) characterizing the concentrations and species of Gd in natural waters (surface water and groundwater) and sediments along the Rio Grande between Albuquerque and Elephant Butte, (2) an assessment of human exposure pathways and potential health risks associated with Gd ingestion through drinking water sources, and (3) improved understanding of the toxicological implications of Gd exposure focusing on the gastrointestinal tract and its effects on human health. The work will contribute significantly to our understanding of the risks posed by Gd medical waste in the environment.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.