大气颗粒物氧化潜势的形成机制研究

Oxidative potential (OP), defined as the capacity of Particulate Matter (PM) to oxidise target molecules, has been newly proposed as a more health-relevant metric. Since the influence of particle size, chemical composition and emission source, the formation mechanism of PM oxidation potential still remains unclear. In the preliminary assessment, we studied the induction effect of transition metal ions, quinones and organic peroxide on PM oxidation potential by using the single-model method. It was found that the relative contribution of various chemical factors in the overall PM oxidative potential is not a simple summation. Therefore, we hypothesize that PM oxidation potential is caused by multiple factors. This project are designed to answer this scientific issue associated with PM oxidative potential by measuring DTT consumption and OH radical generation. In association with field observation and surrogate lung fluid simulation, we will systematically investigate: ① size distribution of PM oxidative potential, ② the behavior of PM oxidation potential before, during and after fog or haze episodes, ③ PM the influence of PM emission source on oxidative potential, ④ identification of redox-active components in PM humic-like substances (HULIS) and oxidative potential, ⑤ synergistic or antagonistic interactions among the PM components and antioxidants. The successful implementation of this project can not only further reveal the formation mechanism of PM oxidative potential, but also find the critical pathway of PM causing health endpoint.

氧化潜势是大气颗粒物（PM）氧化目标分子产生活性氧的能力，直接关联着健康效应。由于受到粒径、组成、来源等因素影响，PM氧化潜势的形成机制不详。我们前期曾利用单一模型法研究过渡金属离子、醌类与有机过氧化物等成分对PM氧化潜势的诱发效应，发现各因子对总PM氧化潜势的相对贡献不是简单的加和关系。因此推测PM氧化潜势是多物质联合作用的结果。本项目拟围绕这一主题，应用DTT分析法测量氧化潜势形成中的DTT消耗和OH自由基生成等指标，采取外场观测与人工肺流体模拟相结合的方案，系统研究①不同粒径大气PM氧化潜势的分布；②雾、霾污染前、后与过程中大气PM氧化潜势的变化行为；③不同贡献源对大气PM氧化潜势生成机制的影响；④PM类腐殖质的结构鉴定及氧化潜势；⑤活性组份与抗氧化剂之间的协同、拮抗效应。本项目的成功实施不仅能进一步揭示PM氧化潜势的生成机制，而且还可找出PM引发健康的前端路径。

本项目顺利完成大气颗粒物（PM）氧化潜势的生成机制研究。具体为：①在上海市完成采集PM样品，并对PM氧化潜势粒径分布特性进行分析；②利用源识别模型，探明了PM中氧化潜势的主要来源；③结合人工肺流体模拟方案，探究了活性组分对PM氧化潜势生成贡献及其相互作用方式；④通过比雾霾污染前后大气PM氧化潜势变化，实现了大气PM氧化潜势的特征行为研究；⑤利用MPPD模型，解析了PM氧化潜势呼吸道沉降及呼吸暴露风险，并提出了大气颗粒物氧化潜势形成过程中的预防方式，为如何降低PM对人体健康的影响研究提供了方向。.本项目按计划顺利执行，研究目标、研究/研制内容无变动。发表项目编号标注SCI论文19篇，其中含PNAS Nexus发表1篇，J. Geophys. Res. Atmos.发表4篇，Environ. Pollut.发表3篇，Atmos. Environ.发表1篇，Sci Total Environ.发表2篇等。通过本项目资助，研究生获得博士学位3人、硕士学位3人。