Collaborative Research: Characterizing Sources and Sinks of the Oxidative Potential of Indoor Particulate Matter

在当今的现代世界中，人们大约90%的时间都在室内环境中度过，包括住宅、办公室/学校、商业、娱乐和娱乐设施。在室内环境中，人们可以接触到各种空气污染物，其中包括通常称为PM2.5的细颗粒物，PM2.5的定义是直径小于/等于（≤）2.5微米的细颗粒物。PM2.5等细颗粒物可以穿透人体肺部，通过产生活性氧（reactive oxygen species， ROS）对肺部生物组织造成损害。PM2.5产生活性氧的能力，也被称为氧化电位（OP），已经成为一种潜在的新指标，可能比单独的质量浓度更能捕捉它们对健康的影响。然而，迄今为止，对室内细颗粒物来源的OP研究非常有限。为了解决这一知识差距，该项目的主要研究者（pi）建议全面调查和表征室内PM2.5的源/汇，目的是提高对室内和室外来源的室内PM2.5的OP和反应性的基本认识。该项目的成功完成，将透过制定和实施研究和验证OP作为室内PM2.5对建筑环境（包括住宅和商业建筑）健康影响的新措施的框架，造福社会。通过学生教育和培训，包括伊利诺伊大学厄巴纳-香槟分校的一名研究生和伊利诺伊理工学院的一名研究生的指导，将为社会带来额外的好处。暴露于可吸入细颗粒物（PM2.5）可导致发病率和死亡率增加。然而，与室外浓度相比，个人PM2.5暴露与室内浓度的相关性要强得多，因为人们大部分时间都呆在室内，室内和室外的污染物都存在。此外，这些关联的因果机制尚不清楚，基于质量的PM2.5浓度测量并不能提供有关PM2.5固有毒性的信息。氧化电位（OP）被定义为PM2.5产生氧化剂的能力，是一种很有前途的空气污染健康指标，在流行病学研究中受到越来越多的关注。该项目的总体目标是建立对室内和环境源产生的室内PM2.5的OP和反应性的机制理解。该研究的具体目标是：1)通过开发测量源汇过程的新方法/分析方法，研究室内和环境源的OP和室内PM2.5的反应性的演变和动态；2)建立各种室内源排放PM2.5的OP值清单；3)对具有代表性的室内环境中测量PM2.5 OP源和汇（反应性损失）的方法/分析方法进行现场评估和验证。这项研究的成功完成将产生关于室内PM2.5的排放（源和汇）及其OP和反应性的新数据和基本知识，从而产生变革性的影响。为了实现该项目的教育和培训目标，首席研究员（pi）建议利用伊利诺伊大学厄巴纳-香槟分校（UIUC）和伊利诺伊理工学院（IIT）的现有项目，设计并实施一个夏令营，培训高中生进行环境空气质量监测，包括使用低成本的室内空气采样器。此外，专业人员计划将研究成果纳入伊利诺伊大学加州分校和印度理工学院现有的空气质量本科/研究生课程，以提高未来环境工程人员对室内空气质量重要性的认识，以及测量和控制室内空气质量所需的工具/技术，以保护公众健康。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In today’s modern world, people spend about 90% of their time in indoor environments including residential homes, offices/schools, and commercial, entertainment, and recreational facilities. In indoor environments, people can be exposed to various air pollutants including fine particles commonly referred to as PM2.5 , which is defined as fine particulate matter with diameter less/equal (≤) than 2.5 microns. Fine particles such PM2.5 can penetrate the human lungs and cause damage to lung biological tissues by generating reactive oxygen species (ROS). The ability of PM2.5 to generate ROS, also called its oxidative potential (OP), has emerged as a potential new metric that may better capture their health effects than their mass concentration alone. However, there are very limited studies of the OP of indoor sources of fine particles to date. To address this knowledge gap, the Principal Investigators (PIs) of this project propose to comprehensively investigate and characterize the sources/sinks of indoor PM2.5 with the goal of advancing the fundamental understanding of the OP and reactivity of indoor PM2.5 coming from both indoor and outdoor sources. The successful completion of this project will benefit society through the development and implementation of a framework for studying and validating the OP as a new measure of the health impact of indoor PM2.5 in the built environment including residential and commercial buildings. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student at the University of Illinois Urbana-Champaign and one graduate student at the Illinois Institute of Technology.Exposure to inhalable fine particulate matter (PM2.5) can lead to increased incidence of disease and mortality. However, personal exposure to PM2.5 is much more strongly correlated with indoor concentrations than outdoor concentrations because people spend most of their time indoors where pollutants of both indoor and outdoor origin are present. In addition, the causal mechanisms of these associations are still unclear, and mass-based measurements of PM2.5 concentrations do not provide information on the inherent toxicity of PM2.5. The oxidative potential (OP), defined as the capability of PM2.5 to generate oxidants, is a promising health metric of air pollution that is receiving increasing attention in epidemiological studies. The overarching goal of this project is to develop a mechanistic understanding of the OP and reactivity of indoor PM2.5 resulting from both indoor and ambient sources. The specific objectives of the research are to 1) investigate the evolution and dynamics of the OP and reactivity of indoor PM2.5 from indoor and ambient sources by developing new methods/assays to measure source and sink processes; 2) establish an inventory of the OP of PM2.5 emitted from various indoor sources; and 3) conduct field-evaluation and validation of the methods/assays to measure the sources and sinks (loss of reactivity) of PM2.5 OP in a representative indoor environment. The successful completion of this research has the potential for transformative impact through the generation of new data and fundamental knowledge on the emissions (sources and sinks) of indoor PM2.5 and their OP and reactivity. To implement the education and training goals of this project, the Principal Investigators (PIs) propose to leverage existing programs at the University of Illinois Urbana-Champaign (UIUC) and the Illinois Institute of Technology (IIT) to design and implement a summer camp to train high school students in environmental air quality monitoring including the use of low-cost indoor air samplers. In addition, the PIs plan to integrate the research findings into existing undergraduate/graduate courses on air quality at UIUC and IIT to increase the awareness of the future environmental engineering workforce of the importance of indoor air quality and the required tools/technologies to measure and control it for the protection of public health.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.