Synergistic Effects of Ozone Reaction Products and Fine Particulate Matter on Pulmonary Physiology in Children with Asthma
Exposure to ozone (O3) reaction products has been linked to adverse pulmonary health effects. These reaction products may be carried by fine particulate matter (PM2.5) that can deposit in the deep lung. In a panel of 43 asthmatic children, we measured indoor and outdoor O3 concentrations and used the difference, termed “O3 loss”, as a proxy of exposure to O3 reaction products. Biomarkers of pulmonary physiology were assessed 4 times for each participant over 8 weeks. Our findings revealed significant and adverse associations between O3 loss and these biomarkers, but only when PM2.5 levels were above the mean value measured during the study. Similarly, PM2.5 exposure had stronger adverse effects on some biomarkers when O3 loss levels were above the mean value. These results support the hypothesis of synergistic effects between O3 reaction products and PM2.5 on pulmonary health.
