Air Pollution and Allergic Rhinitis: Findings from a Prospective Cohort Study.

To investigate the association of long-term exposure to ambient air pollution with the risk of allergic rhinitis (AR), we performed a longitudinal analysis of 379,488 participants (47.4% women) free of AR at baseline in the UK Biobank. The annual average concentrations of PM 2.5 , PM coarse , PM 10 , NO 2 , and NO x were estimated by land use regression models. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). A weighted polygenic risk score was constructed. During a median follow-up period of 12.5 years, 3095 AR cases were identified. We observed significant associations between the risk of AR and PM 2.5 (HR: 1.51, 95% CI: 1.27-1.79, per 5 μg/m 3 ), PM coarse (HR: 1.28, 95% CI: 1.06-1.55, per 5 μg/m 3 ), PM 10 (HR: 1.45, 95% CI: 1.20-1.74, per 10 μg/m 3 ), NO 2 (HR: 1.14, 95% CI: 1.09-1.19, per 10 μg/m 3 ), and NO x (HR: 1.10, 95% CI: 1.05-1.15, per 20 μg/m 3 ). Moreover, participants with high air pollution combined with high genetic risk showed the highest risk of AR, although no multiplicative or additive interaction was observed. In conclusion, long-term exposure to air pollutants was associated with an elevated risk of AR, particularly in high-genetic-risk populations, emphasizing the urgent need to improve air quality.