Long Term Impact of Occupational Exposure to Fine Particulate Matter on the Incidence of Rare Histological Subtypes of Lung Cancer

Chronic occupational exposure to fine particulate matter (PM2.5) has been linked to an elevated risk of respiratory diseases, but the association between this exposure and the incidence of rare histological types of lung cancer has not yet been sufficiently studied. The current retrospective cohort study assesses the association between cumulative occupational exposure to PM2.5 and the incidence of rare lung cancer subtypes among industrial workers. Information on occupational health, occupational exposure measurements, and regional cancer registry data obtained in 2006-2023 have been used for the analysis. This study covers 6,500 employees of mining, construction, and metalworking industries. Exposures of individuals were determined from PM₂.₅ measurements in the workplace and the use of job-exposure matrices. Rare lung cancer events were documented from histopathology reports and categorized based on standardized tumor classification. Over a median follow-up of 13.4 years, 226 lung cancer events were documented, with 39 rare histology types (17.3%). The highest PM₂.₅ exposure group had an increased risk of rare lung cancer compared to the lowest PM₂.₅ exposure group (HR = 1.79; 95%CI: 1.18–2.71; p = 0.004). From the continuous exposure model, there was increased risk for each 10 µg/m³ increase in cumulative exposure to PM₂.₅. It can be concluded that long-term exposure to PM₂.₅ at workplaces increases the incidence of rare lung cancer subtypes.