Air pollution and rhinitis in the Constances cohort

The prevalence of rhinitis has increased in the past decades. We aim to study the effect of air pollution, as one of the environmental factors that may explain the increase of rhinitis prevalence. A total of 21507 (80%); of the 26737 participants included until December 2013 in Constances, a large French population-based cohort, answered standardized questions on rhinitis in 2014. Ever rhinitis was defined by a positive response to “Have you ever had a problem with sneezing or a runny or a blocked nose when you did not have a cold or the flu?”. Current rhinitis was defined among those reporting ever rhinitis and nasal symptoms in the past 12 months. Annual exposure to nitrogen dioxide (NO2), particulate matter ≤2.5 µm (PM2.5) and black carbon (BC) was estimated at the participants' residential address by extrapolating European land-use regression models for 2010 to year 2014. Associations between annual exposure to air pollution and rhinitis were estimated using a logistic model adjusted for age, gender, smoking and education level. After exclusions, 18506 participants were included (mean age: 52, 45% men, 13% ever asthma). Ever and current prevalence of rhinitis were 58% and 41% respectively. Significant and positive associations were found between each pollutant and current rhinitis. Adjusted ORs were 1.26 [1.16-1.36] per 15 µg.m-3 increase in NO2, 1.28 [1.17-1.41] per 5 µg.m-3 increase in PM2.5, and 1.36 [1.22-1.51] per 10-5.m-1 increase in BC. Results were similar for non-smoking participants and those whose address had not changed since inclusion. Exposure to air pollution is associated with current rhinitis in adults in the general population. In view of the high prevalence of rhinitis and its costs, these findings have an important public health impact and reinforce the need to reduce the population's exposure to air pollution. Key messages Exposure to air pollution is associated with current rhinitis in adults in general population. These results contribute to a better understanding of health effects of air pollution.