Project 6: Geochemical Controls on the Sorption, Bioavailability, Formation

项目 6：吸附、生物利用度、形成的地球化学控制

• 批准号: 8564242
• 负责人: Stephen A. Boyd
• 金额: $ 34.34万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8564242
• 关键词: Accounting; Affect; Amendment; Animal Feed; Attenuated; Bacteria; Binding; Biological Availability; Characteristics; Charge; Chemistry; Chlorophenols; Collaborations; Dioxins; Economics; Elements; Exposure to; Funding; Furans; Generic Drugs; Goals; Health; Human; Immune response; In Situ; In Vitro; Individual; Instruction; Knowledge; Ligands; Liquid substance; Measures; Methods; Minerals; Modeling; Movement; Mus; Phase; Prevalence; Process; Reaction; Research; Resistance; Risk; Risk Assessment; Role; Salvelinus; Site; Soil; Source; Surface; Technology; Testing; Tissues; Toxic effect; Water; Work; base; clay; feeding; functional genomics; in vivo; microbial; particle; remediation; research study; response; water solubility

PROJECT SUMMARY (See instructions): Due to their exceptionally low water solubilities polychlorinated dibenzodioxins and furans (PCDD/Fs) are strongly and extensively bound to soil and sediment particles. Sorbed PCDD/Fs are distributed among the primary component geosorbents, namely char-like carbonaceous materials, amorphous organic matter, and clays, and the fractional distribution among these geosorbents is hypothesized to change with the total PCDD/F load. Since PCDD/Fs are also highly resistant to decomposition, sorption is a primary determinant of their environmental fates and impacts. Importantly, sorption to soil/sediment particles may modify the bioavailabilities and toxicities of PCDD/Fs in unknown ways, and bioavailability is expected to be geosorbent-specific. The major goals are: (1) to advance fundamental understanding of PCDD/F sorption by these dominant geosorbents comprising soils/sediments, especially at very low environmentally relevant (pptppb) concentrations where carbonaceous materials (e.g. chars) are hypothesized to control soil-water distribution, (2) to determine the differential bioaccessibilities/bioavailabilities of PCDD/Fs sorbed to each key geosorbent type using physiologically based extraction fluid, and mammalian models, (3) to test the hypothesis that mechanistic knowledge of sorption/desorption reactions for PCDD/Fs with individual component geosorbents can be extrapolated to predict site-specific bioaccessibilites and bioavailabilities for contaminated whole soils/sediments, and (4) to evaluate the clay-facilitated formation of PCDD/Fs, and corresponding predioxins/furans, from precursor chlorophenols, and elucidate the underlying mechanistic basis for these reactions. Estimates of PCDD/F bioavailability in soils/sediments are few and inconsistent, hence most risk assessment models for exposure to environmental PCDD/Fs make generic assumptions of 100% bioavailability, irrespective of soil/sediment characteristics. The results of the proposed research will provide the basis for (1) a more mechanistic understanding of the relationship between soil/sediment composition and the human and ecological risks posed by a given total PCDD/F load in soil/sediment, and (2) understanding the prevalence of clay-facilitated PCDD/F formation as an on-going in-situ process leading to unexpected PCDD/F accumulations that threaten human health. Further, it would be of great economic and environmental benefit if certain chars, such as those produced as intentional by-products of biofuels/Csequestration technologies, were shown to be effective as soil/sediment amendments to diminish bioavailability of PCDD/Fs.

项目摘要（请参阅说明）： 由于它们异常低的水溶性，多氯联苯和呋喃（PCDD/fs）与土壤和沉积物颗粒强烈而广泛地结合。吸附的PCDD/FS分布在主要成分的地质吸附剂中，即类似炭的碳质材料，无定形有机物和粘土，并且这些地质吸附剂之间的分数分布被认为随着PCDD/F负载的总体而变化。由于PCDD/FS也对分解具有高度抗性，因此吸附是其环境命运和影响的主要决定因素。重要的是，对土壤/沉积物颗粒的吸附可能会以未知的方式修饰PCDD/FS的生物可利用性和毒性，并且预计生物利用度将是特定于地球吸附剂的。主要目标是：（1）提高这些主要的地质吸附剂对PCDD/f吸附的基本了解，包括土壤/沉积物，尤其是在非常低的环境相关（PPTPPB）浓度下，碳质材料（例如，炭）（例如，炭化）被指定以控制土壤水分分布（2）（2）（2）（2）（2）（2）（2）（2）（2） geosorbent type using physiologically based extraction fluid, and mammalian models, (3) to test the hypothesis that mechanistic knowledge of sorption/desorption reactions for PCDD/Fs with individual component geosorbents can be extrapolated to predict site-specific bioaccessibilites and bioavailabilities for contaminated whole soils/sediments, and (4) to evaluate the clay-facilitated formation来自前体氯苯酚的PCDD/FS以及相应的前毒素/Furans，并阐明了这些反应的基本机械基础。土壤/沉积物中PCDD/F的生物利用度的估计很少且不一致，因此，大多数风险评估模型暴露于环境PCDD/FS/FS中，无论土壤/沉积物特征如何，都可以使100％生物利用度的通用假设。拟议研究的结果将为（1）提供对土壤/沉积物组成与人类和生态风险之间的关系的基础，这是由给定的总PCDD/F负载在土壤/沉积物中带来的，以及（2）理解粘土核能的PCDD/F形成的普遍性，因为它是一种正在进行中的人为越来越多的人类F PCDD/FTRACTINT PCDD/FTRACTINS，从而导致了人为累积。此外，如果某些Chars（例如生物燃料/C序列技术的故意副产品）被证明作为土壤/沉积物修订以减少PCDD/FS的生物利用度是有效的，那么这将是巨大的经济和环境利益。