Knowledge of the impact of chronic occupational exposures to irritants on asthma and its symptoms remains scarce.

We studied the associations between occupational exposures to irritants including disinfectants/cleaning products (DCP) and solvents and asthma and its symptoms. Adults from the French CONSTANCES population-based cohort completed questionnaires at baseline (2012-2021). Current asthma was defined by lifetime asthma with symptoms, attacks or medication in the past 12 months, and the asthma symptom score as the sum of 5 symptoms in the past 12 months. Occupational exposures were assessed by the Occupational Asthma-specific Job-Exposure Matrix. We used logistic and negative binomial models stratified by sex and adjusted for age, smoking status, body mass index.

Analyses included 115,540 adults (55% women, mean age 43 years, 10% current asthma, 40% ever exposed to irritants). Modest associations were observed between current asthma and ever exposure to irritants (odds ratio: 1.05, 95%CI 1.00-1.11), DCP (1.06, 1.00-1.12) and solvents (1.06, 0.98-1.14) in women. In men, only ever exposure to DCP (1.10, 1.01-1.20) was associated with current asthma. Ever exposure to irritants was associated with increased asthma symptom score both in women (mean score ratio: 1.08, 95%CI 1.05-1.11) and men (1.11, 1.07-1.15), especially for DCP (women: 1.09, 1.06-1.13, men: 1.21, 1.15-1.27) and solvents (women: 1.14, 1.10-1.19, men: 1.10, 1.05-1.15). For both current asthma and asthma score, smaller or inverse associations were observed with current exposures.

Lifetime occupational exposures to irritants were associated with current asthma and asthma symptoms. These exposures should be carefully considered in asthma management.