Prolonged acute exposure to 0.16 ppm ozone induces eosinophilic airway inflammation in asthmatic subjects with allergies

Background: Increased ambient ozone levels have been associated with increased asthma morbidity in epidemiologic studies. Given that asthma is characterized by airway inflammation and increased sensitivity to airway irritants, it has been suggested that asthmatic subjects may be particularly sensitive to the effect of ozone. Objective: The objective of this study was to determine whether exposure to 0.16 ppm ozone induces eosinophilic inflammation in the lower airways of asthmatic subjects. Methods: Eight asthmatic subjects sensitive to mites were exposed to 0.16 ppm ozone and clean air on separate occasions no less than 4 weeks apart in a double-blind, randomized fashion followed by bronchoscopy 18 hours later. Bronchoalveolar lavage fluid and bronchial lavage fluid were examined for eosinophils. Results: Ozone induced significant increases in airway eosinophils, especially in bronchial lavage fluid. Conclusions: Ozone exposure results in increased eosinophilic inflammation in the lower airways of asthmatic subjects with allergies.