The Influence of Short-Term Weather Parameters and Air Pollution on Adolescent Airway Inflammation.

Fraction of exhaled Nitric Oxide (FeNO) is a marker of airway inflammation. We examined the main effects and interactions of relative humidity (RH) and air pollution on adolescents' FeNO. Two thousand and forty-two participants from the 15-year follow-up of the German GINIplus and LISA birth cohorts were included. Daily meteorological (maximum [Tmax], minimum [Tmin] and mean [Tmean] temperatures and RH) and air pollution [Ozone (O 3 ), nitrogen dioxide (NO 2 ) and particulate matter < 2.5 µm (PM 2.5 )] were assessed. Linear models were fitted with Ln(FeNO) as the outcome. Increases in FeNO indicate an increase in lung inflammation. Increased FeNO was associated with an increase in temperature, PM 2.5 , O 3 and NO 2 . A 5% increase in RH was associated with a decrease in FeNO. Interactions between RH and high ( p = 0.007) and medium ( p = 0.050) NO 2 were associated with increases in FeNO; while interactions between RH and high ( p = 0.042) and medium ( p = 0.040) O 3 were associated with decreases in FeNO. Adverse effects were present for male participants, participants with low SES, participants with chronic respiratory disease, and participants from Wesel. Short-term weather and air pollution have an effect on lung inflammation in German adolescents. Future research should focus on further assessing the short-term effect of multiple exposures on lung inflammation in adolescents.