Development of Stable Isotope Based Methods to Predict Bioavailability of Hydroph

开发基于稳定同位素的方法来预测 Hydroph 的生物利用度

• 批准号: 8335408
• 负责人: Jay Gan
• 金额: $ 27.46万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-20 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8335408
• 关键词: Adopted; Adsorption; Affect; Aging; Amendment; Area; Bioavailable; Biological Assay; Biological Availability; Calibration; California; Carbon; Chemicals; Consumption; Dependence; Deposition; Development; Dioxins; Effectiveness; Environment; Equilibrium; Exposure to; Fiber; Fishes; Halibut; Health; Human; In Situ; Isotopes; Isotropy; Label; Link; Los Angeles; Marine Sediment; Measurement; Measures; Methods; Monitor; Performance; Phase; Polychlorinated Biphenyls; Procedures; Property; Recovery; Sampling; Schedule; Shellfish; Silicon Dioxide; Site; Solid; Stable Isotope Labeling; System; Techniques; Testing; Time; Toxic effect; Trace Elements; absorption; abstracting; base; bioaccumulation; exposed human population; feeding; improved; instrument; novel; operation; organic contaminant; remediation; stable isotope; superfund site

Project Summary/Abstract Human exposure to sediment-borne contaminants is not directly related to chemical concentrations in the bulk sediment, but is instead controlled by the bioavailable concentration or bioavailability. Remediation practices, such as dredging, sand capping, sorbent amendment, and even monitored natural recovery (MNR) may all affect the bioavailability of sediment contaminants differently than the bulk sediment chemical concentration. In particular, bioavailability is a key to better assessing human exposure to hydrophobic organic contaminants (HOCs) such as DDT, PCBs, PAHs and dioxins through consumption of fish from contaminated areas. However, current methods for determining sediment HOC bioavailability suffer from method-specific limitations. Partial extraction techniques to estimate bioaccessibility are invariably influenced by types of extractants and extraction conditions selected. Passive samplers, including solid phase microextraction (SPME), must be used under equilibrium conditions that may take months to reach. In this project we exploit the wide availability of stable isotope labeled HOC compounds and GC-MS systems in two novel applications aiming to greatly improve the efficiency and accuracy of bioavailability measurement. The first approach uses the concept of isotope exchange (or dilution), similar to what has been done for trace elements, to derive the exchangeable concentration as an approximation of bioaccessible concentration. The fact that most HOCs are highly stable lends them the quality of being conservative and thus ideal for such an application. In the second approach, we incorporate stable isotope labeled HOCs with SPME by using the labeled HOCs as performance reference compounds so that SPME may be used under non-equilibrium conditions with short sampling time. The isotope exchange approach may be applied to ex situ assessment while the stable isotope- SPME method may be used for both ex situ and in situ measurements. We will carry out systematic studies to prove the underlying assumptions, develop and optimize the methods using spiked sediments, validate the methods through extensive bioaccumulation assays using a common fish prey (polychaete worm) and a deposit-feeding fish (California halibut), and then apply the methods for ex situ and in situ measurement of bioavailability of DDTs and PCBs at the Palos Verdes Shelf Superfund site off the coast of Los Angeles that has undergone pilot remediation trials and is scheduled for sand capping in 2012. At the end of this project, we expect to produce a range of rigorously tested methods that may be easily adopted for ex situ or in situ monitoring of sediment remediation sites to evaluate the effectiveness of remediation operations and predict changes in human exposure potential.

项目概要/摘要 人类接触沉积物污染物与沉积物中的化学浓度没有直接关系 大量沉积物，而是由生物可利用浓度或生物利用度控制。 补救措施，例如疏浚、沙盖、吸附剂修正，甚至监测 自然恢复（MNR）对沉积物污染物生物利用度的影响可能与自然恢复不同 大量沉积物化学浓度。特别是，生物利用度是更好地评估人类的关键 通过接触疏水性有机污染物 (HOC)，例如 DDT、PCB、PAH 和二恶英 食用来自受污染地区的鱼。然而，目前测定沉积物的方法 HOC 生物利用度受到方法特定的限制。部分提取技术进行估计 生物可及性总是受到提取剂类型和所选提取条件的影响。 被动进样器，包括固相微萃取 (SPME)，必须在平衡状态下使用 可能需要几个月才能达到的条件。 在这个项目中，我们利用稳定同位素标记的 HOC 化合物和 GC-MS 的广泛可用性 系统在两个新颖的应用中旨在大大提高效率和准确性 生物利用度测量。第一种方法使用同位素交换（或稀释）的概念， 与对微量元素所做的类似，导出可交换浓度作为 生物可接近浓度的近似值。大多数 HOC 都高度稳定，这一事实使它们 保守的品质，因此非常适合此类应用。在第二种方法中，我们 通过使用标记的 HOC 作为性能，将稳定同位素标记的 HOC 与 SPME 合并 参考化合物，以便 SPME 可以在非平衡条件下使用短采样 时间。同位素交换方法可用于异位评估，而稳定同位素方法可用于异位评估。 SPME 方法可用于异位和原位测量。我们将系统地进行 研究证明基本假设，开发和优化使用加标的方法 沉积物，通过使用常见鱼类猎物进行广泛的生物累积测定来验证方法 （多毛类蠕虫）和沉积物喂养鱼（加州大比目鱼），然后应用前的方法 帕洛斯维第斯陆架超级基金中滴滴涕和多氯联苯生物利用度的原位和原位测量 洛杉矶海岸附近的场地已经进行了试点修复试验，并计划进行沙土修复 2012 年达到上限。在该项目结束时，我们预计将产生一系列经过严格测试的方法 可以很容易地用于沉积物修复场地的异位或原位监测，以评估 修复操作的有效性并预测人类暴露潜力的变化。