Ozone Pollution and Acute Exacerbation of Asthma in Residents of China: An Ecological Study.

Purpose: The evidence for a causal relationship between high-level ozone (O) exposure and acute exacerbation of asthma among adults is limited, and the conclusions are less definitive.

Patients And Methods: Here we collected the daily data on asthma cases, O exposure, and meteorological factors from 2010 to 2016 in Shijiazhuang, China. We investigated the risk of asthma exacerbation associated with high-level ozone exposure using a polynomial distributed lag model (PDLM). Using a generalized additive model (GAM), we estimated the interactive effects between O and other pollutants as well as meteorological factors on asthma exacerbation.

Results: A total of 7270 patients with asthma were enrolled from 22 governmental hospitals in 13 counties. Each 10 μg/m increase in O concentration on the exacerbation of asthma was associated with a 1.92% (95% CI = 0.80-3.03%) higher risk of asthma exacerbation on day lag 7. The cumulative risk of O on asthma exacerbation increased by 18.9% (95% CI = 12.8-25.4%) on the 14th day. High consecutive levels of O increase the risk of asthma exacerbation, and the interactive effect of O and sulfur dioxide (SO) appears before the exacerbation onset.

Conclusion: These findings suggested that O should be an important risk factor for asthma exacerbation, and health benefits in reducing asthma exacerbation risk would be gained with continued efforts to improve the air quality in China.