Portuguese wildland firefighters: assessing exposure and cytogenetic effects in non-fire settings during the pre-fire season

IARC has recently listed occupational exposure as a firefighter carcinogenic to humans. However, firefighter is among the least studied occupations. The goal of the present study was to assess the level of cytogenetic damage in buccal mucosa (first-contact exposure tissue) of Portuguese firefighters during the pre- wildland fire season, as well as, to evaluate firefighters ́ exposure to particulate matter (PM) on fire stations as a baseline for occupational exposure characterization. A group of 172 Portuguese wildland firefighters were enrolled in the study, relevant information was obtained through a questionnaire. The frequency of micronucleus and other endpoints were evaluated via buccal micronucleus cytome assay (BMCyt) along with the influence of potential risk factors (e.g., smoking habits). Estimated inhalation doses of PM10 and PM2.5 (indoor/outdoor) were estimated for a group of 80 firefighters. No significant associations were found between estimated inhaled doses and BMCyt endpoints. Some lifestyle/behavioural variables were shown to significantly decrease the levels of cytogenetic endpoints, whereas others were found to increase them. Firefighters of the Permanent Intervention Team also shown to have significantly higher levels of BMCyt endpoints compared to other firefighters. Fire seasons are getting longer and dangerous, and this trend will continue in a progressive warming world. Implementing effective mitigation strategies for firefighters’ occupational exposure is an urgent public health issue.