In Situ Sampling Tool for Assessing Bioavailability and Toxicity of Sediments

摘要 本计画提出一种新的策略来测定沉积物污染物的生物可利用性 具有广泛的化学结构、性质和物理化学行为。项目 解决了超级基金利益相关者的迫切需要，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（IS 2B）工具是一种新型的、正在申请专利的设备， 在迄今无法达到的低水平下同时测定散装水和孔隙水中的污染物水平 方法检测限（MDLs）。当部署时，管状IS 2B装置的一半被埋在沉积物中， 另一个暴露于大量的水。集成的多通道泵同时抽取大量水， 将孔隙水沉积到主动采样装置中，并分别以高和低的期望流量将其推动 速率通过一系列过滤器和吸附介质。水样可以储存在设备中， 随意排入水中。由于在部署过程中可以不受限制地进入孔隙和大量水， IS 2B工具为广泛的污染物提供超低的MDLs，范围从完全水溶性到 高吸附性和疏水性。此功能将设备与目前可用的无源设备区分开来 抽样策略 利用以前三个SRP项目的专门知识来测试IS 2B 技术可用于可靠地（i）在低于ng/L的范围内对大量和孔隙水污染物进行取样分析，（ii） 提供关于沉积物污染物的生物利用率和生物活性的信息，（三）提供关于人类接触的信息， （a）监测鱼类消费的相关健康风险;（b）监测沉积物补救活动的进展情况。 实验室和实地研究将进行污染的沉积物从阿波普卡湖，家庭之一， 佛罗里达的各种超级基金网站。为了说明IS 2B应用的广度，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）。因为通过模拟预测的生物累积性与 将评估污染物的采样数据和实际生物累积性、生物利用度和生物累积性， 通过测定水体，对新鲜加标和长期老化的污染沉积物进行实验室实验 在两种试验生物中的负荷：杂色蚓和黑头呆鱼。生物反应 还将使用DNA微阵列分析来测量鱼类的污染物暴露，以评估可能 不能仅仅根据母体化合物的体内负荷来预测。之间的数学关系 将根据理论和实验室数据制定散装水、孔隙水、蠕虫和鱼类中的污染物浓度， 并将其应用于IS 2B衍生数据，以预测风险并跟踪两种补救方法的有效性， 颗粒活性炭（GAC）改良和污染底泥的深翻。

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.