Abstract
BACKGROUND: Few studies have compared the associations between long-term exposures to particulate matters (aerodynamic diameter ≤1, ≤2.5 and ≤10 µm: PM(1), PM(2.5) and PM(10), respectively) and asthma and asthma-related respiratory symptoms. The objective of the present study was to compare the strength of the aforementioned associations in middle-aged and elderly adults. METHODS: We calculated the mean 722-day personal exposure estimates of PM(1), PM(2.5) and PM(10) at 1 km×1 km spatial resolution between 2013 and 2019 at individual levels from China High Air Pollutants (CHAP) datasets. Using logistic regression models, we presented the associations as odds ratios and 95% confidence intervals, for each interquartile range (IQR) increase in PM(1)/PM(2.5)/PM(10) concentration. Asthma denoted a self-reported history of physician-diagnosed asthma or wheezing in the preceding 12 months. RESULTS: We included 7371 participants in COPD surveillance from Guangdong, China. Each IQR increase in PM(1), PM(2.5) and PM(10) was associated with a greater odds (OR (95% CI)) of asthma (PM(1): 1.22 (1.02-1.45); PM(2.5): 1.24 (1.04-1.48); PM(10): 1.30 (1.07-1.57)), wheeze (PM(1): 1.27 (1.11-1.44); PM(2.5): 1.30 (1.14-1.48); PM(10): 1.34 (1.17-1.55)), persistent cough (PM(1): 1.33 (1.06-1.66); PM(2.5): 1.36 (1.09-1.71); PM(10): 1.31 (1.02-1.68)) and dyspnoea (PM(1): 2.10 (1.84-2.41); PM(2.5): 2.17 (1.90-2.48); PM(10): 2.29 (1.96-2.66)). Sensitivity analysis results were robust after excluding individuals with a family history of allergy. Associations of PM(1), PM(2.5) and PM(10) with asthma and asthma-related respiratory symptoms were slightly stronger in males. CONCLUSION: Long-term exposure to PM is associated with increased risks of asthma and asthma-related respiratory symptoms.