The Role of Environmentally Persistent Free Radicals in the Chemistry of Airborne PM2.5

环境持久性自由基在空气中 PM2.5 化学中的作用

• 批准号: 1150761
• 负责人: Slawomir Lomnicki
• 金额: $ 43.17万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1150761&HistoricalAwards=false
• 关键词: Role; Environmentally; Persistent; Free; Radicals

The Environmental Chemical Sciences (ECS) program of the Division of Chemistry will support the research program of Prof. Barry Dellinger of Louisiana State University. Prof. Dellinger and his students will study the environmental impact of Environmentally Persistent Free Radicals (EPFRs) in airborne fine particles. Prof. Dellinger's group has detected organic free radicals associated with freshly sampled airborne particles that are less than 2.5 micrometers in diameter (PM2.5), which can persist in air for several days after collection. The chemical and toxicological characteristics of these radicals are similar to radicals associated with the tar in cigarette smoke, and detected in samples of combustion-generated PM. Since the radicals are both stable toward decomposition and resistant to reaction with air, they are referred to as environmentally persistent and may serve as effective reducing agents in aqueous solution. Using EPR spectroscopy, EPFRs formed from dosing samples of PM2.5 with suspected EPFR precursors, will be compared to EPFRs formed on controlled surrogate particles containing different transition metals. The decay and lifetimes of the observed EPFRs will be determined as a function of temperature, humidity, and solar irradiation. EPFR-induced formation of reactive oxygen species (ROS) under biological conditions will be determined. The potential for EPFRs to participate in selected atmospheric chemistry will be evaluated. Reactions with NO and O3 will be studied to determine if EPFRs result in depletion or formation of these pollutants as well as formation of nitro-/oxy-PAH, other oxygenated species, and secondary radicals.As part of this project, Dr. Dellinger and his students will present project and research summaries to science-affiliated clubs and undergraduate programs. Collaborative research and interdisciplinary training of graduate students in chemistry, combustion, and environmental health sciences research will be conducted through the LSU Superfund Research Center. The PI is committed to student presentations at national/international meetings and their participation in several high impact education and outreach groups and programs already established at LSU, including the Superfund Research Program seminars and exchange program with biomedical research collaborators.

化学系的环境化学科学（ECS）计划将支持路易斯安那州立大学Barry Dellinger教授的研究计划。 Dellinger教授和他的学生将研究空气中的细颗粒中环境持续的自由基（EPFR）的环境影响。 Dellinger教授的小组已经检测到与直径小于2.5微米的新鲜采样空气中颗粒相关的有机自由基（PM2.5），它们可以在收集后的几天内持续数天。 这些自由基的化学和毒理学特征类似于与香烟中的焦油有关的自由基，并在燃烧生成的PM样品中检测到。 由于自由基既稳定地分解，又对与空气的反应有抵抗力，因此它们在环境上被称为环境持久性，并且可以作为水溶液中的有效还原剂。使用EPR光谱法，将通过可疑的EPFR前体的PM2.5的给药样品形成的EPFR与在含有不同过渡金属的受控替代颗粒上形成的EPFR进行比较。观察到的EPFR的衰减和寿命将取决于温度，湿度和太阳照射的函数。 将确定在生物条件下EPFR诱导的活性氧（ROS）的形成。将评估EPFR参与选定的大气化学的潜力。 将研究与NO和O3的反应，以确定EPFR是否导致这些污染物的耗竭或形成，以及氮气/氧气-PAH的形成，其他氧化物种和次要激进。作为该项目的一部分，Dellinger博士和他的学生将向科学与科学的俱乐部俱乐部和不足的群体和研究生介绍。 将通过LSU超级基金研究中心进行化学，燃烧和环境健康科学研究研究生的合作研究和跨学科培训。 PI致力于在国家/国际会议上的学生演讲，并参与LSU已经建立的几个高影响力教育和外展小组和计划，包括与生物医学研究合作者的超级基金研究计划研讨会和交流计划。