Residential Air Pollution and Associations with Wheeze and Shortness of Breath in Adults: A Combined Analysis of Cross-Sectional Data from Two Large European Cohorts

BACKGROUND: Research examining associations between air pollution exposure and respiratory symptoms in adults has generally been inconclusive. This may be related in part to sample size issues, which also preclude analysis in potentially vulnerable subgroups. OBJECTIVES: We estimated associations between air pollution exposures and the prevalence of wheeze and shortness of breath using harmonized baseline data from two very large European cohorts, Lifelines (2006–2013) and UK Biobank (2006–2010). Our aim was also to determine whether the relationship between air pollution and respiratory symptom prevalence differed between individuals with different characteristics. METHODS: Cross-sectional analyses explored associations between prevalence of self-reported wheeze and shortness of breath and annual mean particulate matter with aerodynamic diameter [Formula: see text] , [Formula: see text] , and [Formula: see text] ([Formula: see text] , [Formula: see text] , and [Formula: see text] , respectively) and nitrogen dioxide ([Formula: see text]) concentrations at place of residence using logistic regression. Subgroup analyses and tests for interaction were performed for age, sex, smoking status, household income, obesity status, and asthma status. RESULTS: All PM exposures were associated with respiratory symptoms based on single-pollutant models, with the largest associations seen for [Formula: see text] with prevalence of wheezing {odds ratio [Formula: see text] per [Formula: see text] [95% confidence interval (CI): 1.11, 1.21]} and shortness of breath [[Formula: see text] per [Formula: see text] (95% CI: 1.45, 1.78)]. The association between shortness of breath and a [Formula: see text] increment in [Formula: see text] was significantly higher for individuals from lower-[[Formula: see text] (95% CI: 1.52, 1.97)] versus higher-income households [[Formula: see text] (95% CI: 1.11, 1.55); [Formula: see text]), whereas the association between [Formula: see text] and wheeze was limited to lower-income participants [[Formula: see text] (95% CI: 1.22, 1.38) vs. [Formula: see text]; (95% CI: 0.96, 1.08); [Formula: see text]]. Exposure to [Formula: see text] also showed positive associations with wheeze and shortness of breath. CONCLUSION: Exposure to PM and [Formula: see text] air pollution was associated with the prevalence of wheeze and shortness of breath in this large study, with stronger associations between [Formula: see text] and both outcomes among lower- versus higher-income participants. https://doi.org/10.1289/EHP1353