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

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

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.