In-situ Measurement of the Capacity of Airborne Particulate Matter to Generate Reactive Oxygen Species

空气颗粒物产生活性氧的能力的现场测量

• 批准号: 8904440
• 负责人: Arantzazu Eiguren Fernandez
• 金额: $ 14.93万
• 依托单位: AEROSOL DYNAMICS, INC.
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8904440
• 关键词: Address; Aerosols; Aging; Airborne Particulate Matter; Alzheimer' s Disease; Asthma; Binding; Biological Assay; Breathing; Caliber; Chemicals; Chronic Obstructive Airway Disease; Circadian Rhythms; Collection; Complement; Controlled Study; Coupled; Coupling; Deposition; Device or Instrument Development; Devices; Disease; Dithiothreitol; Environmental Exposure; Epidemiologic Studies; Exposure to; Generations; Goals; Growth; Health; Heating; Hour; Human; Human Biology; In Situ; In Vitro; Indoor Air Quality; Injury; Laboratories; Lead; Liquid substance; Lung diseases; Measurement; Measures; Molecular; Monitor; Morbidity - disease rate; Morphologic artifacts; National Institute of Environmental Health Sciences; Occupational; Online Systems; Oxidants; Oxidation-Reduction; Oxidative Stress; Particulate Matter; Physical condensation; Play; Process; Property; Public Health; Quinones; Reactive Oxygen Species; Risk Assessment; Sampling; Source; Staging; Suspension substance; Suspensions; Symptoms; System; Techniques; Technology; Testing; Time; Toxic effect; Transition Elements; Water; adverse outcome; ambient particle; anthropogenesis; base; biological adaptation to stress; chemical property; design and construction; environmental agent; in vitro Assay; in vivo; instrumentation; mortality; nervous system disorder; novel strategies; oxidative damage; particle; particle exposure; phase 1 study; portability; public health relevance; response; sample collection; screening; stressor; temporal measurement; vapor

 DESCRIPTION (provided by applicant): The oxidative capacity of airborne particulate matter has been correlated with the generation of oxidative stress both in-vitro and in-vivo. In recent years, epidemiological studies have associated damaged caused by cellular oxidative stress with several common diseases such as asthma, chronic obstructive pulmonary disease (COPD), Alzheimer's and other neurological diseases. However, these studies are based on daily exposure and averaged oxidative capacity of ambient particulate matter. Oxidative potential of the particles depends considerably on their chemical composition, more specifically on their redox active compounds, such as transition metals and quinones. It is well known that physical-chemical properties of ambient particles vary with emission sources and the extent of photochemical aging. Thus, we expect diurnal variations in the ability of particulate matter to generate reactive oxygen species and exert oxidative damage are expected. Currently, there are several chemical and in-vitro assays to determine the oxidative capacity of ambient particles. However, significant amounts of sample are needed to obtain a quantifiable response. Using the common collection devices, long sampling periods are needed, usually 24 to 48 hours. With these long collection periods, chemical properties of the particles may be altered and peak exposures hidden. Recent studies on the association between airborne particle exposures and adverse health effects identify short-term peaks in particulate matter exposures as important factors in health threat, especially in lung diseases. An epidemiological study of the effect of short-term exposure to peaks in particulate matter concentrations found that asthma symptoms were more highly associated with 1-h and 8-h maximum PM10 (particles with diameter <10µm) exposures than with 24-h mean PM10 exposures. Based on these results, the development of instruments capable of measuring exposure to peak concentrations of health stressors is of vital importance. In this project we propose a new approach for an on-line monitor of the oxidative capacity of aerosols (o- MOCA). The main objective is to develop a field-deployable system that allows in-situ, time-resolved assessment of the capacity of airborne particles to generate ROS. Our approach capitalizes on our firm's new particle growth technology that enables direct particle deposition into liquids, obtaining concentrated suspensions ready for chemical and in-vitro assays. The aerosol collector uses the water condensational growth technology which allows the collection of particles as small as 10 nm into concentrated water suspensions with efficiencies >90%. The oxidative potential of the collected particles will be measured using the chemical assays commonly known as the DTT assay (dithiothreitol assay). The o-MOCA approach has several advantages over the existing laboratory and on-line systems: i) it can efficiently collect PM2.5 directly into a small volume of water, increasing the particle concentration and thus reducing the time needed for collection; ii) with direct collection it avoids the most common artifacts associated with other particle collectio systems; iii) it allows for time-resolved collection and in-field direct analysis, allowing for a mre satisfactory daily characterization of the PM oxidative capacity. The ability to characterize the oxidative potential of aerosols in a time-resolved manner will provide more accurate results when assessing possible adverse outcomes related to oxidative stress responses resulting from PM exposure. Our goal will be achieved by completing the following specific aims: i) design, construction and off-line optimization of the chemical assay module; ii) interface the chemical module with the liquid collector; iii) conduct laboratory controlled studies to evaluate whether ou approach allows for near-real time measurements of the oxidative capacity of ambient PM.

 描述（申请人提供）：空气中颗粒物的氧化能力与体外和体内氧化应激的产生相关。近年来，流行病学研究将细胞氧化应激引起的损伤与几种常见疾病联系起来。例如哮喘、慢性阻塞性肺病（COPD）、阿尔茨海默病和其他神经系统疾病。然而，这些研究是基于环境颗粒物的每日暴露量和平均氧化能力。颗粒的氧化电位很大程度上取决于它们的化学成分，更具体地说取决于它们的氧化还原活性化合物，例如过渡金属和醌。众所周知，环境颗粒的物理化学性质随排放源和光化学程度的不同而变化。因此，我们预计颗粒物质产生活性氧和产生氧化损伤的能力会出现昼夜变化，目前有几种化学和体外测定方法可以确定环境颗粒的氧化能力。使用常见的收集设备需要大量的样品，通常需要 24 至 48 小时，因此可能会隐藏颗粒的化学性质和峰值暴露研究。空气颗粒物暴露与不良健康影响之间的关联将颗粒物暴露的短期峰值确定为健康威胁的重要因素，特别是在肺部疾病中。 短期暴露于颗粒物浓度峰值的影响发现，与 24 小时平均 PM10 暴露相比，哮喘症状与 1 小时和 8 小时最大 PM10（直径 <10μm 颗粒）暴露的相关性更高。结果表明，开发能够测量健康压力源峰值浓度的仪器至关重要。在这个项目中，我们提出了一种在线监测气溶胶氧化能力的新方法。 （o-MOCA）。我们的方法利用了我们公司的新颗粒生长技术，可以直接对空气中的颗粒进行时间分辨评估。颗粒沉积到液体中，获得浓缩的悬浮液，为化学和体外分析做好准备。气溶胶收集器使用水冷凝生长技术，可以将小至 10 nm 的颗粒收集到浓缩的水悬浮液中。效率 >90%。将使用通常称为 DTT 测定（二硫苏糖醇测定）的化学测定来测量 o-MOCA 方法与现有实验室和在线系统相比有几个优点：i)它可以高效地将PM2.5直接收集到小体积的 水，增加颗粒浓度，从而减少收集所需的时间；ii) 通过直接收集，可以避免与其他颗粒收集系统相关的最常见的伪影；iii) 它允许时间分辨收集和现场直接分析，从而允许在评估与氧化应激反应相关的可能不利结果时，以时间分辨方式表征气溶胶氧化潜力的能力将提供更准确的结果。我们的目标将通过完成以下具体目标来实现：i) 化学测定模块的设计、构建和离线优化；ii) 将化学模块与液体收集器连接；iii) 进行实验室控制研究以进行评估。该方法是否允许近实时测量环境 PM 的氧化能力。