Associations of current and life-course smoking and indoor environmental exposures with lung function level in early adulthood.

Background: Lung function, expressed as forced expiratory volume in 1 second (FEV Methods: Using data from 858 participants of the Dutch PIAMA birth cohort (mean age: 25.7 years), we investigated associations between smoking, second-hand smoke (SHS), dampness or mold, furry pets, and gas cooking exposure with maximal lung function. Exposure data were collected via questionnaires from pregnancy through early adulthood, and life-course exposure trajectories were derived using latent class growth modeling. We assessed associations with FEV Results: Pre- and post-bronchodilator spirometry was available for 846 and 806 participants, respectively. We found no associations between exposure to dampness or mold, furry pets, or gas cooking and lung function. Current and life-course active smoking was associated with higher post-bronchodilator FEV Conclusion: No associations were found between indoor environmental exposures and maximal lung function in early adulthood. The observed positive associations with active smoking likely reflect bias arising from a selective uptake of smoking by individuals with higher pre-existing lung function, rather than a true physiological effect.