With more frequent and intense precipitation events across the globe due to a changing climate, there is a need to understand the relationship between precipitation and respiratory health. Precipitation may trigger asthma exacerbations, but little is known about how precipitation affects lung function and airway inflammation in early adolescents.
To determine if short-term precipitation exposure is associated with lung function and airway inflammation in early adolescents and if ever having a diagnosis of asthma modifies associations of precipitation with lung function and airway inflammation.
In a prospective prebirth cohort, Project Viva, that included 1,019 early adolescents born in the Northeastern United States, we evaluated associations of 1-, 2-, 3-, and 7-day moving averages of precipitation in the preceding week and FEV1, FVC, and FeNO using linear regression. We used log transformed FeNO with effect estimates presented as percent change. We adjusted for maternal education and household income at enrollment, any smoking in the home in early adolescence; child sex, race/ethnicity, ever asthma diagnosis, and age, height, weight, date, and season (as sine and cosine functions of visit date) at the early adolescent visit; and moving averages for mean daily temperature (same time-window as exposure).
In fully adjusted linear models, 3- and 7-day moving averages for precipitation were positively associated with FeNO but not lung function. Every 2mm increase in the 7-day moving average for precipitation was associated with a 4.0% (95% CI 1.1, 6.9) higher FeNO. There was evidence of effect modification by asthma status: precipitation was associated with lower FVC and higher FeNO among adolescents with asthma. We also found that outdoor aeroallergen sensitization (IgE against common ragweed, oak, ryegrass, or silver birch) modified associations of precipitation with FeNO, with higher FeNO in sensitized adolescents compared to nonsensitized adolescents. The associations of precipitation with FeNO were not explained by relative humidity or air pollution exposure.
We found that greater short-term precipitation may trigger airway inflammation in adolescents, particularly among those with asthma.