Long-term associations of PM₁vs. PM_2.5and PM₁₀with asthma and asthma-related respiratory symptoms in middle-aged and elderly population

BackgroundFew studies have compared the associations between long-term exposures to particulate matters (aerodynamic diameter ≤1, 2.5 and 10 µm: PM1, PM2.5and PM10) and asthma and asthma-related respiratory symptoms.ObjectiveTo compare the strength of the above-mentioned associations in middle-aged and elderly adults.MethodsWe calculated the mean 722-day personal exposure estimates of PM1, PM2.5and PM10at 1 km×1 km spatial resolution between 2012 and 2019 at individual levels fromChina High Air Pollutantsdatasets. Using logistic regression model, we presented the associations as odds ratios (ORs) and 95% confidence intervals (95%CIs), for each interquartile range (IQR) increase in PM1/PM2.5/PM10concentration. Asthma denoted a self-reported history of physician-diagnosed asthma, or wheezing in the preceding 12 months.ResultsWe included 7371 participants inChronic Obstructive Pulmonary Diseases Surveillancefrom Guangdong, China. Each IQR increase in PM1, PM2.5and PM10was associated with a greater odds [OR (95%CI)] of asthma [PM1: 1.22 (1.02, 1.45); PM2.5: 1.24 (1.04, 1.48); PM10: 1.30 (1.07, 1.57)], wheeze [PM1: 1.27 (1.11, 1.44); PM2.5: 1.30 (1.14, 1.48); PM10: 1.34 (1.17, 1.55)], persistent cough [PM1: 1.33 (1.06, 1.66); PM2.5: 1.36 (1.09, 1.71); PM10: 1.31 (1.02, 1.68)] and dyspnea [PM1: 2.10 (1.84, 2.41); PM2.5: 2.17 (1.90, 2.48); PM10: 2.29 (1.96, 2.66)]. Sensitivity analysis results were robust after excluding individuals with a family history of allergy. Associations of PM1, PM2.5and PM10with asthma and asthma-related respiratory symptoms were slightly stronger in males.ConclusionsLong-term exposure to PM is associated with increased risks of asthma and asthma-related respiratory symptoms.