In Situ Sampling Tool for Assessing Bioavailability and Toxicity of Sediments

描述(申请人提供)：本项目介绍了一种测定沉积物中污染物生物利用度的新方法，该方法具有广泛的化学结构、性质和物理化学行为。该项目满足了超级基金利益攸关方的迫切需要，即以方便和可靠的方式确定受污染沉积物对人类健康的风险以及所实施的补救战略的有效性。原位采样/生物利用度测定(IS2B)工具是一种正在申请专利的新型设备，能够以迄今无法达到的低方法检测限(MDL)同时测定散装水和孔隙水中的污染物水平。在部署时，管状IS2B装置的一半埋在沉积物中，另一半暴露在散装水中。集成的多通道泵同时将散装水和沉积物孔隙水吸入主动采样装置，并分别以高和低所需的流速推动其通过一系列过滤器和吸附介质。水样既可以储存在装置中，也可以随意排入散装水中。由于在部署期间不受限制地获取孔隙水和散装水，IS2B工具为从完全水溶性到高度吸附和疏水的各种污染物提供了超低MDL。这一功能使该设备有别于目前可用的被动采样策略。正在利用前三个SRP项目的专门知识来检验工作假设，即IS2B技术可用于可靠地(I)采样散装和孔隙水污染物以供在亚ng/L范围内进行分析，(Ii)提供沉积物污染物的生物有效性和生物活性的信息，(Iii)提供有关人类暴露于鱼类消费的相关健康风险的信息，以及(Iv)跟踪沉积物修复活动的进展情况。实验室和实地研究将对来自阿波普卡湖的受污染沉积物进行，阿波普卡湖是佛罗里达州各种超级基金地点之一的所在地。为了说明IS2B的适用范围，本项目集中于两种传统的和三种新出现的沉积物污染物(p，p‘-DDE、狄氏剂与氟虫腈、三氯生、三氯卡班)。由于通过采样器数据建模预测的生物累积与实际生物累积之间可能存在差异，因此将在实验室实验中通过测定两种试验生物的身体负荷来评估污染物的生物有效性和生物累积。还将使用DNA微阵列分析来测量鱼类对污染物暴露的生物反应，以评估可能无法仅基于母体化合物的身体负担预测的影响。将根据理论和实验室数据建立散装水、孔隙水、蠕虫和鱼类中污染物浓度之间的数学关系，并将其应用于IS2B导出的数据，以预测风险并跟踪两种修复方法的有效性，即颗粒活性碳(GAC)修正和对受污染沉积物的深耕。 公共卫生相关性：项目说明本研究项目通过引入现场采样/生物有效性测定(IS2B)方法，解决了更好地监测受污染沉积物中毒物生物有效性的迫切需要。所提出的装置和数学模型将为超级基金和其他危险废物场地的环境管理提供风险评估信息。

DESCRIPTION (provided by applicant): ABSTRACT This project introduces a novel strategy for bioavailability determination of sediment-borne contaminants featuring a wide range of chemical structures, properties and physical-chemical behaviors. The project addresses the pressing need of Superfund stakeholders to determine in a convenient and reliable fashion both human health risks from contaminated sediments and the effectiveness of implemented remediation strategies. The in situ sampling/bioavailability determination (IS2B) tool is a novel, patent-pending device enabling simultaneous determination of contaminant levels in bulk water and pore water at hitherto unattainably low method detection limits (MDLs). When deployed, one half of the tubular IS2B device is buried in sediment and the other is exposed to bulk water. Integrated multi-channel pumps simultaneously draw bulk water and sediment pore water into the active sampling device and push it at, respectively, high and low desirable flow rates through an array of filters and adsorption media. Water samples either can be stored in the device or expelled into the bulk water at will. Due to unlimited access to pore and bulk water during deployment, the IS2B tool provides ultra-low MDLs for a broad spectrum of contaminants, ranging from fully water-soluble to highly sorptive and hydrophobic. This functionality distinguishes the device from presently available passive sampling strategies. Know-how from three previous SRP projects is being leveraged to test the working hypothesis that the IS2B technology can serve to reliably (i) sample bulk and pore water pollutants for analysis in the sub-ng/L range, (ii) inform on the bioavailability and bioactivity of sediment contaminants, (iii) inform on human exposures and associated health risks from fish consumption, and (iv) track the progress of sediment remediation activities. Laboratory and field studies will be conducted with contaminated sediments from Lake Apopka, home to one of Florida's various Superfund sites. To illustrate the breadth of IS2B applicability, this project concentrates on two traditional and three emerging sediment contaminants (p,p'-DDE, dieldrin versus fipronil, triclosan, triclocarban). Because there may be discrepancies between the bioaccumulation predicted via modeling from sampler data and actual bioaccumulation, bioavailability and bioaccumulation of pollutants will be assessed in lab experiments with freshly spiked and long-term aged contaminated sediments via determination of body burdens in two test organisms: Lumbriculus variegatus and Pimephales promelas. Biological responses to contaminant exposure will also be measured in fish using DNA microarray analysis to evaluate effects that may not be predicted solely based on body burden of parent compounds. Mathematical relationships between pollutant concentrations in bulk water, pore water, worms and fish will be formulated from theory and lab data, and applied to IS2B-derived data to predict risk and track the effectiveness of two remediation approaches, granular activated carbon (GAC) amendment and deep tilling of contaminated sediment. PUBLIC HEALTH RELEVANCE: Project Narrative This research project addresses the pressing need for better monitoring of toxicant bioavailability in contaminated sediments by introducing the in situ sampling/bioavailability determination (IS2B) approach. The proposed device and mathematical model will inform risk assessment for environmental management for Superfund and other hazardous waste sites.