Toxicology study of emissions from a burn pit simulator

烧坑模拟器排放物的毒理学研究

• 批准号: 10339413
• 负责人: Nathan RAVI
• 金额: --
• 依托单位: ST. LOUIS VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-10-01 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10339413
• 关键词: Acute; Address; Aerosols; Afghanistan; Air Pollution; Apoptosis; Area; Aromatic Polycyclic Hydrocarbons; Asphyxia; Binding Sites; Biomass; Cancer Etiology; Cancerous; Carbon; Carcinogens; Cell Culture Techniques; Cell Death; Cell Line; Cell Survival; Cell physiology; Cell-Matrix Junction; Cells; Cessation of life; Charge; Chemicals; Chemiluminescence assay; Chinese Hamster Ovary Cell; Chronic; Chronic Disease; Cohort Studies; Cornea; Culture Media; DNA; DNA Damage; Data; Deposition; Development; Dioxins; Disease; Electrodes; Endocrine; Endocrine system; Engineering; Ensure; Environment; Epithelial; Ethylenes; Event; Exhibits; Exposure to; Foundations; Functional disorder; Furans; Gases; Generations; Genes; Genome; Genomics; Goals; Gold; Gulf War; Gulf War veteran; Human; Human Cell Line; Hydrophobicity; Impairment; In Vitro; Institute of Medicine (U.S.); Iraq; Lead; Light; Mammalian Cell; Measurement; Measures; Medical; Medicine; Methodology; Military Personnel; Minerals; Molecular; Monitor; Nature; Nitrogen; Onset of illness; Outcome; Oxidative Stress; Oxygen; Particulate Matter; Pathway interactions; Persian Gulf Syndrome; Phase; Preventive; Proliferating; Property; Publishing; RNA; Reactive Oxygen Species; Recommendation; Reporting; Research Design; Retina; Retrospective Studies; Review Literature; Sampling; Sedimentation process; Shapes; Soldier; Soot; Stream; Structure; Surface; Syndrome; System; Technology; Temperature; Testing; Therapeutic; Time; Toxic effect; Toxicology; Toxin; United States National Academy of Sciences; Universities; Veterans; War; Washington; Wildfire; Work; World Health Organization; acute toxicity; airway inflammation; base; biomaterial compatibility; burn pit; carcinogenicity; cell type; chemical property; combustion product; cost; culture plates; cytotoxicity; design; electric impedance; experimental study; irritation; lens; lung injury; metallicity; nanoGold; nephelometry; non-genomic; operation; physical property; response; tissue culture; tool; toxicant; transcriptome sequencing; volatile organic compound; wasting; zeta potential

Carbonaceous (i.e., carbon-containing) particulate matter (PM) emitted by the combustion of waste in military burn pits is associated with post-deployment sudden illnesses, such as the Gulf War Illness (GWI). GWI is a syndrome where otherwise healthy soldiers return with debilitating conditions ranging from acute respiratory inflammations to chronic impaired endocrine function. The nature by which it develops is unknown. To shed light over the effect of military burn pit emissions contributing to GWI, we propose to evaluate the combustion envi- ronments within, using a simulator we built, and understand how these are conducive to toxicant formation. To identify underlying mechanisms, our immediate goal is to modify and calibrate the simulator. Then, we will syn- thesize carbonaceous PM representative of burn pit emissions and expose it to mammalian cell lines. The simulator operates on the bench scale and, to the best of our knowledge, is the only one of its kind within the VA system capable of reliably reproducing carbonaceous PM (and gases) emitted by military burn pits. The simulator’s design allows modulation of the feed (fuel, oxygen, and nitrogen) in the respective inlet streams. The ability to modulate these three independent variables offers tight control over the structure and temperature of the flame that precedes PM synthesis. As a result, the physical and chemical properties of the PM can be predicted. We will generate a statistically designed full-factorial experiments for mixtures. In this approach, we will characterize the PM for size, shape, charge, and surface area-to-volume ratio as well as polycyclic aromatic hydrocarbon (PAH) content, and plot these responses as a function of the independent variables. The response surface methodology (RSM) is a statistical tool, used commonly in engineering, which will allow us to explore the relationship between the three independent factors (that regulate the flame structure and temperature) and the properties of the PM using the least number of experiments. While several PAH molecules that exist in the gas-phase are toxic, the known carcinogens are larger hydrophobic molecules adsorbed on or deposited within the PM. To separate the toxicological effect of PM from the gaseous species, we will collect PM on filters. We will sterilize and disperse the PM samples in cell culture media. To ensure the dispersions are stable, we will record their sizes and zeta potentials using dynamic light scattering (DLS) measurements, and sedimen- tation rates. Cell viability will be monitored by electric cell-substrate impedance sensing (ECIS). ECIS measures the total electrical impedance across two gold electrodes at the bottom of the tissue culture plates, so cell viability is determined by the area of the gold electrodes covered by cell attachment. Biocompatibility will be monitored by apoptosis (cell death) and reactive oxygen species (ROS) generation using chemiluminescence measure- ments. ROS measurements are an indication of oxidative stress to the cells; an environment adverse for healthy cell function. Finally, to determine the chemical pathways initiated by the PM at the molecular level, we will perform RNA sequencing. Before the cells show signs of death or detachment from the electrode, we will extract the total RNA. The RNA will then be analyzed in the Genome Technology Access Center (GTAC) at Washington University. Through GTAC we will determine which genes are under- or over-expressed in each cell line com- pared to control cell lines. We anticipate this data will illustrate the effects of carbonaceous PM on the cells. By initially excluding other types of PM encountered by military personnel (e.g., metallic, halogenated, heterocyclic, or mineral) we will be able to pinpoint PAH-initiated pathways that we believe are significantly re- sponsible for GWI. This will serve as a foundation to direct efforts on how studies (using real material) are to be undertaken. After identifying how real carbonaceous PM causes disease, we will explore therapeutic options.

碳质（即含碳）颗粒物（PM）由军事中的废物组合散发出来 烧伤坑与病后突然疾病有关，例如海湾战争疾病（GWI）。 GWI是一个 综合征在其他健康士兵的情况下，由于急性呼吸系统恢复了衰弱的状况 慢性内分泌功能的炎症。它发展的性质是未知的。散发光 在对GWI促成的军事燃烧坑排放的影响之上，我们建议评估组合的环境 使用我们构建的模拟器内部的隆起，并了解它们如何导电到有毒形成。到 确定基本机制，我们的近期目标是修改和校准模拟器。然后，我们将综合 将碳质PM的碳酸盐PM表示，代表燃烧坑的排放并将其暴露于哺乳动物细胞系。 模拟器以基准尺度运行，据我们所知，模拟器是唯一同类的一个 在VA系统中，能够可靠地再现由军事燃烧坑发出的碳质PM（和气体）。 模拟器的设计允许调节相应入口流中的进料（燃料，氧和氮）。 调节这三个独立变量的能力可以严格控制结构和温度 PM合成之前的火焰。结果，PM的物理和化学特性可以是 预测。我们将生成用于混合物的统计设计的全因素实验。在这种方法中，我们 将表征PM的大小，形状，电荷和表面积与体积比以及多环芳族 烃（PAH）含量，并将这些响应绘制为自变量的函数。反应 表面方法（RSM）是一种统计工具，通常用于工程，这将使我们能够探索 三个独立因素（调节火焰结构和温度）和 PM的性质使用实验数量最少。虽然存在于 气相是有毒的，已知的致癌物是疏水分子，被吸附或沉积在 下午。为了将PM的毒理作用与气态物种分开，我们将在过滤器上收集PM。 我们将在细胞培养基中刻板印象并分散PM样品。为了确保分散体稳定， 我们将使用动态光散射（DLS）测量以及sedimen-将记录它们的尺寸和Zeta电位 率率。电细胞基底阻抗感应（ECI）将监测细胞活力。 ECIS测量 在组织培养板底部的两个金电子上的总电阻抗，因此细胞活力 由细胞附着覆盖的金电子的面积确定。生物相容性将受到监测 通过化学发光测量 - 通过凋亡（细胞死亡）和活性氧（ROS）生成 - ments。 ROS测量是对细胞氧化应激的指示。不利的环境 细胞功能。最后，为了确定PM在分子水平上引发的化学途径，我们将 执行RNA测序。在细胞显示死亡或与电极脱离的迹象之前，我们将提取 总RNA。然后，将在华盛顿的基因组技术访问中心（GTAC）中分析RNA 大学。通过GTAC，我们将确定哪些基因在每个细胞系中都不足或过表达 汇编以控制细胞系。我们预计这些数据将说明碳质PM对细胞的影响。 最初排除军事人员遇到的其他类型的PM（例如金属，卤素， 杂环或矿物质）我们将能够确定PAH引起的途径，我们认为这是显着重复的 赞助GWI。这将是指导研究（使用真实材料）如何成为的基础 进行。在确定了真正的碳质PM如何引起疾病之后，我们将探索热选择。