Outdoor air pollution and health effects in urban children with moderate to severe asthma

Abstract

Particulate matter less than 2.5 μm in diameter (PM2.5) is associated with asthma morbidity. Recent studies have begun examining the role of various constituents of PM2.5, their potential sources, and their effects on health. We examine their role in asthmatic children. Thirty-six children 6–14 years with moderate/severe asthma from inner city areas in New York City were studied for 2-week periods (summer and winter) using diaries and lung function. Outdoor data, including PM10, PM2.5, elements, elemental/organic carbon, and criteria gases (NO2, SO2, and O3) were collected at two sites. Odds ratios (ORs) relating daily pollutant concentrations to asthma indicators were calculated. During summer significant ORs>1 for symptom severity were obtained (O3, PM10, PM2.5, and S); after adjustment for O3, the ORs were no longer significant. During winter, Cu, Fe, Si, and Zn were significantly but negatively (ORs 1) on symptoms (As, K, Pb, and V). Albuterol use increased during summer (O3, PM10, PM2.5, Na, and S); after adjustment for O3, only Na and S remained significant. Reduced pulmonary function was significantly associated with O3 and Cl. Components of PM2.5 are associated with asthma exacerbation in asthmatic children. Same-day pollutant associations with symptoms are seen in summer. In winter, our analysis suggests delayed adverse associations of PM2.5 components.