Characterization of Firefighter Smoke Exposure

A study of firefighter exposure was undertaken as part of a larger smoke exposure study. Teams of Chicago Fire Department firefighters were issued equipment for monitoring exposure conditions during structural fire suppression activity (knockdown and overhaul) and search and rescue operations. Potential inhalation exposure was characterized by outfitting firefighters with direct-reading gas meters and personal cascade impactors. The gas meters used electrochemical sensors to detect six gases of interest: carbon monoxide (CO), hydrogen sulfide (H₂S), sulfur dioxide (SO₂), ammonia (NH₃), nitrogen dioxide (NO₂) and hydrogen cyanide (HCN). The personal cascade impactors were four stage units with 9.8 μm, 3.5 μm, 0.93 μm and 0.52 μm particle size cut points. Size-segregated particles collected on the impactor plates were analyzed for smoke particle weight distribution and for inorganic element content by inductively coupled plasma-mass spectroscopy (ICP-MS). Gloves and hoods were issued to teams of firefighters as part of their standard turnout ensemble and collected at regular intervals for chemical evaluation of accumulated combustion residue. Sections of the hoods and gloves were analyzed for inorganic element content by ICP-MS, mercury by cold vapor atomic absorption spectroscopy (CVAAS), and polynuclear aromatic hydrocarbons (PAHs) and other organic compounds by gas chromatography-mass spectroscopy (GC–MS). Findings indicated that firefighters are exposed to: