Abstract:
Photochemical pollutants, with ozone (O3) as a primary constituent, have been shown in several studies to have adverse effects on the lung function of exposed individuals. Based on these reports, ventilatory function was measured once daily on 105 children (54 males, 51 females) aged 8-11 years, on at least 4 days for each child during a 3-week period in Jult and August, 1992, at an Eastern Washington YMCA summer camp. The highest 1-hr O3, 24-hr particulate matter (PM10), and 12-hr acid aerosol (H+) concentrations were 72 ppb, 55.76 ug/m3, and 4.07x10-5 nmol/m3, respectively, while the highest temperature reached 96.2 F. Regressions of change in forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) with varying concentrations of O3, PM10, H+, and temperature were calculated for the study population as a whole, as well as for a subset of 10 children with asthma who attended the camp. For all 105 campers, no significant correlations were found between pulmonary function and O3, PM10, or H+, although a significant positive association was found between FVC and temperature (p<0.01). In the children with asthma, a significant decline in FVC was seens with increasing O3 concentrations (p<0.05), while both FVC and FEV1 showed a significant decrease with increasing PM10 concentrations (p<0.05). Ozone and PM10 levels below the current National Ambient Air Quality Standards (NAAQS) of 120 ppb and 150 ug/m3, respectively, may protect healthy individuals, while susceptible populations are still at risk.