Evaluating the effect of long-term exposure to ozone on lung function by different metrics

Background: The majority of studies examining long-term exposure to ambient ozone have utilized averages as the exposure parameter. However, averaging ozone exposures may underestimate the impact of ozone peaks and seasonality. The current study aimed to examine the association between ozone exposure evaluated by different exposure metrics and lung function in healthy adolescents. Methods: We conducted a cross-sectional study among 665 healthy adolescent males living within a 2 km radius of an ozone monitoring station. Multiple ozone exposure metrics were evaluated, including two-year and peak-season averages, peaks, peak intensity, and the total excess of peak level. Lung function was measured using FEV₁, FVC, and FEV₁/FVC ratio. Results: The peak intensity during the ozone peak-season was associated with the largest decrease in the FEV₁/FVC ratio, -1.52% (95%CI: -2.55%, -0.49%) (p < 0.01). Concurrently, we did not observe a significant association between ozone exposure, assessed by different metrics, and either FEV₁ or FVC. Conclusions: The study findings suggest that when evaluating ambient ozone exposures, ozone peak intensity during peak-season should be considered, as it may predict greater adverse health effects than averages alone.