Gravimetric, morphological, and chemical characterization of fine and ultrafine particulate matter inside fire stations

Poor air quality inside buildings has direct implications for human health. The activity of firefighters causes cancer and promotes the development/aggravation of cardio-respiratory diseases. The indoor air quality inside fire stations remains poorly characterized. This work assesses firefighters’ daily exposure to fine (PM2.5, PM156nm) and ultrafine (PM50.4nm, PM30.8nm) particulate matter (PM) inside three microenvironments of fire stations, and, for the first time, characterizes the morphology and elemental content of collected PM. Fine PM fractions were predominant in all microenvironments. Fine and ultrafine PM concentrations were increased in the personal protective equipment (PPE) storage room than in the common area and garage [11.84–103.5 μg/m3 versus 18.67–51.89 μg/m3 and 22.57–70.69 μg/m3; p > 0.05 and 4.78–46.02 μg/m3 versus 3.03–40.99 μg/m3 and 5.55–23.30 μg/m3; p > 0.05]; values were below the guideline proposed for occupational exposure to respirable dust (5.0 mg/m3). The morphological analysis revealed the presence of organic matter, microorganisms, crystals, minerals, metals, and other unidentified substances in fine/ultrafine PM. Exposure to total PM-bound metals was increased in the garage comparatively to the common area and the PPE storage room (2765.0–46586.0 pg/m3 versus 2414.2–4568.6 pg/m3; p > 0.5). Cu, Zn, and Cr were the predominant PM-bound metals while Sb, Cd, and Tl were the less abundant. Exposure to PM-bound possible/probable carcinogenic metals (Ni, Cd, Sb, and Pb) accounted for 7.81–10.72% and 0.342–13.07% of fine and ultrafine PM, respectively. The data generated can support regulatory agencies in proposing air quality guidelines that promote occupational safety and health.