Associations between short-term exposure to fine particulate matter and acute exacerbation of asthma in Yancheng, China

Scarce evidence existed on the association between short-term exposure to fine particulate matter (PM2.5) and asthma in China. In this study, we aimed to explore the relationship of PM2.5 with acute asthma exacerbation in a coastal city of China. Cases of acute asthma exacerbation were identified from hospital outpatient visits in Yancheng, China, from 2015 to 2018. We utilized the generalized additive model linked by a quasi-Poisson distribution to assess the association between PM2.5 and daily acute asthma exacerbation. Different lag structures were built, and we conducted stratification analyses by gender, age, and season. Two-pollutant models were fitted, and concentration-response (C-R) curves were pooled. A total of 3,520 cases of acute asthma exacerbation were recorded, with a daily average of 3. We observed positive and significant associations of PM2.5 on lag 1, 2, lag 02, and lag 03 day. For each 10-mu g/m(3) increase in PM2.5 (lag 02), the associated increment in asthma was 3.15% (95% CI: 0.99%, 5.31%). The association remained after adjusting for gaseous co-pollutants. We observed significant PM2.5-asthma associations in males, patients <= 64 years, and during cold seasons. The C-R curves were positive and almost linear for total and strata-specific associations. In conclusion, this study provided robust evidence on the association of PM2.5 with acute asthma exacerbation, which may benefit future prevention strategy and policy making. (C) 2019 Elsevier Ltd. All rights reserved.