Background: Evidence concerning the effects of different chemical components of particulate matter with an aerodynamic diameter of 2.5 μm or less (PM2.5) on asthma is limited, and the methodology to compare the relative importance of different PM2.5 components is lacking. Objective: Our aim was to examine the associations between PM2.5 components and asthma and investigate which constituent of PM2.5 possessed the most harmful effect on asthma. Methods: A total of 45,690 subjects in 6 countries were surveyed from 2007 to 2010. We geocoded the residential community addresses of the participants and used satellite remote sensing and chemical transport modeling to estimate their annual average concentrations of PM2.5 constituents. Mixed-effects generalized additive models were utilized to examine the associations between PM2.5 constituents and prevalence of asthma. We further used counterfactual analyses to determine the potential number of asthma cases. Results: We identified 6178 patients with asthma among the participants, producing an asthma prevalence of 13.5%. The odds ratio for asthma associated with per-SD increment was 1.12 for PM2.5 mass, 1.12 for organic carbon, 1.18 for black carbon, 1.19 for sulfate, 1.28 for ammonium, and 1.21 for nitrate after controlling for potential confounders. Our counterfactual analyses suggested that ammonium was responsible for a substantial decline in asthma cases (by 1382 cases, corresponding to 22.37% of overall cases) if the concentration was reduced to the 5th percentile of the current level. Conclusions: Our study suggests that some chemical components of PM2.5 (including black carbon, organic carbon, sulfate, ammonium, and nitrate) might be hazardous constituents contributing to the prevalence of asthma; among them, ammonium might be responsible for a substantial proportion of asthma cases if reduced to a certain level.
|Journal||Journal of Allergy and Clinical Immunology|
|Publication status||Published - 2022 Jul|
Bibliographical noteFunding Information:
Supported by the National Natural Science Foundation of China (grant 82041021) and the Guangdong Basic and Applied Basic Research Foundation (grant 2019A1515110003).
Supported by the National Natural Science Foundation of China (grant 82041021 ) and the Guangdong Basic and Applied Basic Research Foundation (grant 2019A1515110003 ).
© 2021 American Academy of Allergy, Asthma & Immunology
All Science Journal Classification (ASJC) codes
- Immunology and Allergy