Chronic productive cough and inhalant occupational exposure-a study of the general population.

Purpose: Occupational inhalant exposures have been linked with a higher occurrence of chronic productive cough, but recent studies question the association.

Methods: We included participants from two general population studies, the Copenhagen City General Population Study and the Copenhagen City Heart Study, to assess contemporary (year 2003-2017) and historical (1976-1983) occupational inhalant hazards. Job titles one year prior to study inclusion and an airborne chemical job-exposure matrix (ACE JEM) were used to estimate occupational exposure. The association between occupational exposures and self-reported chronic productive cough was studied using generalized estimating equations stratified by smoking status and cohort.

Results: The population consisted of 5210 working individuals aged 20-65 from 1976 to 1983 and 64,279 from 2003 to 2017. In smokers, exposure to high levels of mineral dust, biological dust, gases & fumes and the composite variable vapours, gases, dusts or fumes (VGDF) were associated with chronic productive cough in both cohorts with odds ratios in the range of 1.2 (95% confidence interval, 1.0;1.4) to 1.6 (1.2;2.1). High levels of biological dust were only associated with an increased risk of a chronic productive cough in the 2003-2017 cohort (OR 1.5 (1.1;2.0)). In non-smokers, high levels of VGDF (OR 1.5 (1.0;2.3)) and low levels of mineral dust (OR 1.7 (1.1;2.4)) were associated with chronic productive cough in the 1976-1983 cohort, while no associations were seen in non-smokers in the 2003-2017 cohort.

Conclusion: Occupational inhalant exposure remains associated with a modestly increased risk of a chronic productive cough in smokers, despite declining exposure levels during the past four decades.