Exploring the Importance of Aging in Contaminant Bioavailability and Remediation

探索老化在污染物生物利用度和修复中的重要性

• 批准号: 8757606
• 负责人: Jay Gan
• 金额: $ 19.59万
• 依托单位: UNIVERSITY OF CALIFORNIA RIVERSIDE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-05 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8757606
• 关键词: Affect; Affinity; Age; Aging; Amendment; Area; Back; Biological Availability; Carbon; Carbon Black; Charcoal; Consumption; Coupling; Deposition; Dichlorodiphenyl Dichloroethylene; Diet; Dioxins; Effectiveness; Environmental Pollution; Equation; Evaluation; Event; Exposure to; Fishes; Food Chain; Goals; Health; Human; Immobilization; In Situ; Individual; Invertebrates; Knowledge; Laboratories; Location; Los Angeles; Measures; Methods; Modeling; Organism; Outcome; Phase; Polychlorinated Biphenyls; Process; Property; Relative (related person); Research; Risk; Risk Assessment; Role; Sampling; Simulate; Site; Soil; Stable Isotope Labeling; Surface; Testing; Time; age effect; aged; aqueous; base; bioaccumulation; exposed human population; hazard; improved; neglect; novel; organic contaminant; public health relevance; receptor; remediation; research study; risk mitigation; soil sampling; superfund site; uptake

DESCRIPTION (provided by applicant): Human exposure to many environmental contaminants such as DDT and metabolites (DDTs), PCBs, PAHs, and dioxins occurs primarily through food chain transfer and biomagnification. Due to their affinity for natural organic matter, these contaminants are distributed predominantly in the soil or sediment compartment. The initial trophic transfer involves uptake by sediment or soil-dwelling organisms, which dictates the ultimate human health risk of a contamination site. An often-neglected fact is that contamination at most Superfund sites is a result of historical events, and that contaminants at these sites have resided in the same media for many years or decades, a biogeochemical process loosely termed aging. Aging generally leads to lower contaminant bioavailability, i.e., a reduced potential for entering the food chain. However, at present, there lacks a good understanding of aging effects and its value is not used or exploited in current risk assessment and remediation practices. In this project, we will first develop a method to measure aging effects of DDTs and PCBs in field-aged sediments by quantifying their relative bioavailability. We will use concurrent bioaccumulation tests to validate the method. We will then apply the method to sediment samples collected as a function of depth (reflecting deposition at different historical times) and spatial location (reflecting different sediment properties) at the Palos Verdes (PV) Shelf Superfund site off the Los Angeles coast. The PV Shelf sediments contain high levels (up to 200 mg/kg) of DDTs (especially p,p'-DDE) and PCBs deposited from as far back as 60 years ago. Correlation analysis will reveal the relationship between age and bioavailability, and elucidate the influence of sediment properties. The aging-induced bioavailability changes will be incorporated into trophic food chain models to improve the estimation of hazards to ecological receptors and humans. Black carbon sorbents (e.g., activated carbon, charcoal, biochar) are increasingly used in remediation, as they immediately immobilize HOCs in soil or sediment. We will further carry out long-term laboratory incubation experiments to understand the effect of such amendment on contaminant aging or permanent sequestration. Through this project, we will obtain a holistic understanding of aging effects and its role in regulating contaminant bioavailability, and capture opportunities for their application to achieve improved risk assessment and mitigation.

描述（由申请人提供）：人类接触许多环境污染物，如滴滴涕和代谢物 (DDT)、多氯联苯、多环芳烃和二恶英，主要是通过食物链转移和生物放大发生的。由于它们对天然有机物的亲和力， 这些污染物主要分布在土壤或沉积物中。最初的营养转移涉及沉积物或土壤生物的吸收，这决定了 污染地点对人类健康的最终风险。一个经常被忽视的事实是，大多数超级基金地点的污染是历史事件的结果，并且这些地点的污染物已经在相同的介质中驻留了许多年或几十年，这一生物地球化学过程被笼统地称为老化。老化通常会导致污染物的生物利用度降低，即进入食物链的可能性降低。然而，目前人们对老化效应缺乏良好的理解，其价值在当前的风险评估和修复实践中没有得到利用或利用。在这个项目中，我们将首先开发一种方法，通过量化滴滴涕和多氯联苯的相对生物利用度来测量现场老化沉积物中滴滴涕和多氯联苯的老化影响。我们将使用并发生物累积测试来验证该方法。然后，我们将将该方法应用于在洛杉矶海岸附近的帕洛斯维迪斯 (PV) 陆架超级基金遗址收集的沉积物样本，这些样本是深度（反映不同历史时期的沉积）和空间位置（反映不同沉积物特性）的函数。光伏陆架沉积物含有高浓度（高达 200 毫克/千克）的 DDT（尤其是对，对'-DDE）和早在 60 年前就沉积的 PCB。相关分析将揭示年龄与生物利用度之间的关系，并阐明沉积物性质的影响。衰老引起的生物利用度变化将被纳入营养食物链模型，以改进对生态受体和人类危害的估计。黑碳吸附剂（例如活性炭、木炭、生物炭）越来越多地用于修复，因为它们可以立即将 HOC 固定在土壤或沉积物中。我们将进一步开展长期的实验室孵化实验，以了解此类修正对污染物老化或永久封存的影响。通过这个项目，我们将全面了解衰老效应及其在调节污染物生物利用度方面的作用，并抓住其应用机会，以实现改进的风险评估和缓解。