Abstract Oxidative potential (OP) of particulate matter measures the ability of particles to catalytically generate reactive oxygen species while simultaneously depleting antioxidants, leading to oxidative stress and, in turn, inflammation in the respiratory tract and cardiovascular system. OP measurements have been linked with adverse cardiorespiratory endpoints, such as asthma/wheezing, lung cancer, and ischemic heart disease. However, measurements of OP are limited, restricting the area over which epidemiologic analyses can be performed. In this work, a modeling approach is developed and evaluated that uses limited measurements of water-soluble OP and PM2.5 source impact analysis to estimate OP over a large spatial domain (eastern United States). The dithiothreitol (DTT) assay was used to measure daily OP of water-soluble PM2.5 from June 2012 to July 2013 across four sites in the southeastern United States. Daily PM2.5 source impacts were estimated using CMAQ-DDM during the same time period and related to OPDTT measurements via multivariate linear regression. This regression was then applied to spatial fields of daily CMAQ-DDM source impacts across the eastern United States to provide daily spatially-varying OPDTT estimates. Backward selection during regression development showed vehicle and biomass burning emissions to be significantly predictive of OPDTT, as observed in previous studies. The fire source impact was the largest contributor to OPDTT (29%) across the study domain during the study time period, and both spatial and seasonal variations were largely driven by fires. Vehicular impacts, especially diesel impacts, were more significant in urban areas. This CMAQ-DDM modeling approach provides a powerful tool for integrating OP measurements from multiple locations and times into a model that can provide spatio-temporal exposure fields of OPDTT across a wide spatial domain for use in health analyses, and the results offer insight into the large-scale spatial distribution of OPDTT driven by emission source impacts.

中文翻译：

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美国东部 PM2.5 氧化潜力时空趋势的源影响模型

摘要 颗粒物的氧化电位 (OP) 衡量颗粒催化产生活性氧物质同时消耗抗氧化剂的能力，从而导致氧化应激，进而导致呼吸道和心血管系统的炎症。OP 测量值与不良的心肺终点有关，例如哮喘/喘息、肺癌和缺血性心脏病。然而，OP 的测量是有限的，限制了可以进行流行病学分析的区域。在这项工作中，开发和评估了一种建模方法，该方法使用有限的水溶性 OP 测量和 PM2.5 源影响分析来估计大空间域（美国东部）的 OP。二硫苏糖醇 (DTT) 测定法用于测量水溶性 PM2.5 的每日 OP。5 从 2012 年 6 月到 2013 年 7 月，横跨美国东南部的四个站点。在同一时间段内使用 CMAQ-DDM 估计每日 PM2.5 源影响，并通过多元线性回归与 OPDTT 测量相关。然后将该回归应用于美国东部每日 CMAQ-DDM 源影响的空间场，以提供每日空间变化的 OPDTT 估计。正如之前的研究所观察到的那样，回归开发过程中的反向选择表明，车辆和生物质燃烧排放可以显着预测 OPDTT。在研究时间段内，火源影响是整个研究领域 OPDTT 的最大贡献者 (29%)，空间和季节变化主要由火灾驱动。车辆的影响，尤其是柴油的影响，在城市地区更为显着。