Novel exposure metrics for assessing the effects of ultrafine and fine particulate matter on asthma in children

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Project Summary Particulate matter (PM) air pollution is known to exacerbate asthma symptoms in children; however, it is still unclear which metric (particle size, morphology or chemical composition) of PM is most relevant to respiratory health. The broad objective of this work is to determine which potentially modifiable factors of fine PM, including ultrafine particles (UFP), microenvironment, and peak exposure, are associated with respiratory effects in inner-city children with asthma. A second, related objective is to evaluate the effects of these fine PM factors on overweight children with asthma, a susceptible population recently identified by our Center. To accomplish these objectives, we will examine the effects of PNC and peak PM exposure in a panel study of 50 children with asthma, each of whom will be followed for 7 days with 4 days of continuous monitoring of PNC and PM2.5 mass, geographic location, biomarkers, and asthma outcomes. In Aim 1 we will evaluate the relationship between UFP and fine particles and asthma symptoms, lung function and inflammatory biomarkers. We will use the location information to apportion exposure into the microenvironments in which children spend time (e.g. home, school, transit) and evaluate the relationships between these microenvironmental exposures, as well as longer-term measures of exposure, on asthma outcomes. In Aim 2 we will develop an automated peak detection algorithm and evaluate the contribution of peak exposures to cumulative exposure and estimate the effects of peak exposures on children with asthma. Finally, in Aim 3, we will evaluate the role of weight as a susceptibility factor for the impact of UFP, microenvironmental, and peak exposures on asthma outcomes. We expect that this study design, taking advantage of recent technological advancements, will provide unprecedented ability to assess the importance of fine PM factors on asthma outcomes in children. Such evidence will allow for individualized environmental intervention strategies that target susceptible populations.