Occupational inhaled exposures and risk of interstitial lung abnormalities in individuals with potential familial susceptibility to pulmonary fibrosis

INTRODUCTION: Interstitial lung abnormalities (ILAs) are early imaging markers of interstitial lung disease and pulmonary fibrosis. Occupational exposures to fumes and dusts are widespread and may especially impact individuals with familial susceptibility. We aimed to investigate the associations between occupational inhaled exposures and the risk of ILAs in individuals with potential familial susceptibility to pulmonary fibrosis. METHODS: We analysed data from 266 relatives of patients with familial or sporadic pulmonary fibrosis, enrolled in two cohorts: the Clinical Genetics and Screening for Pulmonary Fibrosis (n=184) and the Genetics of Pulmonary Fibrosis Study (n=82). Occupational exposures were determined through standardised questionnaires and categorised as vehicle fumes, non-vehicle fumes, mineral dusts, organic dusts, any fumes, any dusts or any dusts or fumes. Risk of ILAs was evaluated using modified Poisson models adjusted for age, sex and smoking status. RESULTS: The mean age of participants was 59.7 years and 23.7% had ILAs. Any occupational inhalational exposure was more common among participants with ILAs (27.0% for any fume) than among those without ILAs (16.7% for any fume). Exposure to any fumes, encompassing both vehicle and non-vehicle fumes, was associated with increased risk of ILAs (risk ratio (RR): 1.59, 95% CI 1.02 to 2.49). Similar positive but non-significant associations were observed for other exposures, including organic dusts, vehicle fumes, non-vehicle fumes and composite exposure. DISCUSSION: Occupational inhaled fume exposure is associated with higher risk of ILAs in individuals with potential familial susceptibility to pulmonary fibrosis. This highlights the potential value of considering occupational exposures in screening at-risk populations.