8292123 Cumulative occupational exposure to wood dust and interstitial lung disease: a Norwegian cohort study

<h3>Objective</h3> To investigate the association between cumulative wood dust exposure and risk of interstitial lung disease (ILD) in the Norwegian working population. <h3>Material and Methods</h3> The Nor-Work cohort was utilised in this prospective, register-based cohort study. The study population was comprised of 1,864,416 men and 1,720,597 women with at least one year of registered employment between 1970 and 2020. Cumulative exposure to wood dust was calculated using a job exposure matrix (Wood-JEM) connected to registered occupation. Incident cases of silicosis (ICD-10 code J62), hypersensititvity pneumonitis (J67), radiation-induced ILD (J70.1), drug-induced ILD (J70.2-J70.4), idiopathic fibrotic ILD (J84), and connective-tissue ILD (J99) were identified in the Norwegian Patient Registry in the period 2010-2020. Prevalent cases in 2008 and 2009 were excluded. Discrete time hazard models were used to calculate incidence risk ratios (IRR) according to cumulative exposure group (0 years (ref), 1-5 years, 6-10 years, &gt;10 years). Analyses were stratified by gender and adjusted for age at baseline, calendar year, history of connective tissue disease, and educational level. <h3>Results</h3> A dose-response association was observed for men with less than 10 years of exposure to wood dust (1-5 years: IRR 1.28, 95% CI 1.13-1.46; 6-10 years: IRR 1.73, 95% CI 1.46-2.04), but not for men with over 10 years of cumulative exposure (IRR 1.49, 95% CI 1.24-1.79). No association was found between cumulative exposure and ILD incidence among women. <h3>Conclusion</h3> This is the first register-based Norwegian study to investigate the association between wood dust exposure and ILDs. Cumulative exposure to wood dust was associated with an increased risk of ILDs among men in the Norwegian working population. Further research is planned to investigate if there are differences between subtypes of ILD along with other respiratory conditions. <h3>Funding</h3> This study received financial support from the IA industry program for the building and construction industry.