Investigating Biogeochemical Controls on Metal Mixture Toxicity Using Stable Isot

描述(由申请人提供)：评估特定地点的生物可用性是确定和有效解决受金属污染的废物地点造成的危害的重要考虑因素。该应用程序满足了NIEHS超级基金研究计划对基础研究的需求，以提高对生物地球化学相互作用对污染物生物利用度影响的理解。由于金属在许多污染地点以混合物形式存在，而不是以单一污染物的形式存在，因此对金属暴露及其对人类和生态系统的影响的准确评估必须考虑到混合效应，它可以是相加的，也可以是少于相加的，也可以是多于相加的。然而，目前的水质法规和管理做法通常针对单个金属，因为目前还没有足够的工具来预测金属混合物的生物利用度和毒性。我们的长期目标是检测、表征和评估受污染的金属混合物带来的风险。为了实现这一目标，我们需要开发和/或改进用于检测、评估和评估金属生物有效性的先进技术。这些技术将包括环境分子诊断和稳定同位素分析。在这项拟议的研究中，我们在受控条件下开发的方法将在科罗拉多州中部的北福克清溪超级基金遗址的一条金属污染的溪流中进行现场实况调查。为该地点开发的方法和工具将提供适用于其他元污染地点的物质和智力决策基础设施。在该项目中，将开发和应用生物体和社区一级的反应研究(项目1)、生物体对多种金属暴露反应的基因组生物测定(项目2)以及生物可利用水柱金属和组织金属残留物的测量(项目3)。我们将了解生物/化学/地质界面之间的通量，因为它与生物有效性和修复效果有关。此外，我们还将阐明影响生物吸收的地球化学因素(例如，向食物链的运输)。我们还将在被金属污染的溪流中进行“自然实验”，检查在安装水处理系统之前、期间和之后的反应，该系统将降低金属的浓度。利用在项目头两年开发和测试的方法，我们将能够在项目的最后几年模拟和观察补救工作的效果。最后，我们制定了一项“研究转化”计划，包括在整个赠款期限内吸引最终用户(例如，监管机构、金属行业代表和毒性建模人员)。虽然拟议的研究重点是一个单一的超级基金地点，但方法和结果将适用于许多接收水域的金属混合物，无论污染源是什么。

DESCRIPTION (provided by applicant): Assessing site-specific bioavailability is an important consideration in determining and affectively addressing hazards posed by metals-contaminated waste sites. This application addresses the NIEHS Superfund Research Program's needs for fundamental research that improves the understanding of the effects of biogeochemical interactions on contaminant bioavailability. Because metals occur in mixtures rather than as single contaminants at many contaminated sites, accurate assessment of metal exposure and effects to humans and ecosystems must account for mixture effects, which could be additive, less than additive, or more than additive. However, current water quality regulations and management practices usually address individual metals, because adequate tools are not yet available for predicting bioavailability and toxicity of metal mixtures. Our long-term objective isto detect, characterize, and assess the risks posed by contaminant metal mixtures. To accomplish that goal, we need to develop and/or refine advanced techniques for the detection, assessment, and evaluation of metal bioavailability. Those techniques will include environmental molecular diagnostics and stable isotope assays. In the proposed research, the methods we develop under controlled conditions will be "field-truthed" in a metals-contaminated stream at the North Fork Clear Creek Superfund site in central Colorado. The approaches and tools developed for that site will provide a physical and intellectual decision infrastructure applicable to other meta-contaminated sites. In this project a combination of organism- and community-level response studies (Project 1); genomic bioassays of organism response to multiple-metals exposure (Project 2); and measurements of bioavailable water-column metals and tissue-metal residues (Project 3) will be developed and applied. We will gain an understanding of the flux between biological/chemical/geological interfaces as it relates to bioavailability and remediation effectiveness. Furthermore, we will elucidate the geochemical factors affecting biological uptake (e.g., transport into the food chain). We will also conduct a "natural experiment" in the metal-contaminated stream in which we will examine responses before, during, and after installation of a water-treatment system that will decrease concentrations of the metals. Using the methods developed and tested during the first two years of the project, we will be able to model and observe the effectiveness of the remediation efforts during the later years of the project. Finally we have delineated a plan for "research translation", including engaging end-users (e.g., regulatory agencies, metals-industry representatives, and toxicity modelers) throughout the duration of the grant. Although the focus of the proposed research is a single Superfund site, the methodology and results will be applicable to metal mixtures in many receiving waters, regardless of the contamination source.