PAH exposure and associated health risks can be high at a fire site both during fire and long after the fire is extinguished

The International Agency for Research on Cancer has recently classified occupational exposure as a firefighter as carcinogenic (group 1A). Even though the occupation of firefighter is associated with high exposure to pollutants, it is challenging to carry out exposure studies to assess health risks due to the extreme conditions associated with firefighting. Routine monitoring of occupational exposure to polycyclic aromatic hydrocarbons (PAHs) via active sampling of air is thus not feasible; however, polyurethane foam (PUF) passive air samplers are robust enough to enable monitoring of PAH in occupations such as firefighting. Two measurement campaigns were carried out at a firefighter training facility in Sweden. In the first, PAH concentrations in air were measured for firefighters, observers, and post-fire workers during fire extinguishing exercises. A wide range of PAH exposures were found; firefighters' exposures were highest (8,300 to 760,000 ng m-3), followed by those of observers (1,600 to 11,000 ng m-3) and post-fire workers (120 to 3,600 ng m-3). In the second, PAH concentrations in air were measured inside 2 burned out sheds for 38 d, starting 3 h after the end of the fire extinguishing exercise. Gas-phase PAH concentrations inside the shed after the fire was extinguished subsided rapidly initially but were high even a week after the fire (3,000 ng m-3) and were 15 to 20 times higher than ambient air levels after more than a month. Mechanical agitation or stirring ashes during post-firework may lead to elevated exposure to the more carcinogenic PAHs, which have higher molecular weights. The results indicate that PAH exposure can be high at a fire site both during the fire and for weeks after the fire is extinguished. Simple preventive measures such as postponing investigation of a fire site for at least a week and wearing respiratory protection can decrease occupational exposure to PAHs.