title: Systemic exposure to PAHs and benzene in firefighters suppressing controlled structure fires.
abstract: Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters' bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants.
authors.affiliation: 1.Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA kfent@cdc.gov.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Fent
authors.affiliation: 1.Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA.
authors.forename: Judith
authors.initials: J
authors.lastname: Eisenberg
authors.affiliation: 2.Division of Applied Research and Technology, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA.
authors.forename: John
authors.initials: J
authors.lastname: Snawder
authors.affiliation: 2.Division of Applied Research and Technology, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Sammons
authors.affiliation: 3.Human Exposure and Atmospheric Sciences Division, U.S. Environmental Protection Agency, 109 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
authors.forename: Joachim D
authors.initials: JD
authors.lastname: Pleil
authors.affiliation: 4.Oak Ridge Institute for Science and Education/U.S. Environmental Protection Agency Research Fellow, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Stiegel
authors.affiliation: 1.Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Mueller
authors.affiliation: 5.Illinois Fire Service Institute, University of Illinois-Urbana/Champaign, 11 Gerty Drive, Champaign, IL 61820, USA.
authors.forename: Gavin P
authors.initials: GP
authors.lastname: Horn
authors.affiliation: 6.Research and Development Section, Training Division, Chicago Fire Department, 558 West DeKoven Street, Chicago, IL 60607, USA.
authors.forename: James
authors.initials: J
authors.lastname: Dalton
mesh_terms: D000395:Air Pollutants, Occupational / Q000032:analysis; D001554:Benzene / Q000032:analysis* / Q000633:toxicity; D015415:Biomarkers / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D061388:Firefighters; D005390:Fires; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000633:toxicity; D011481:Protective Clothing; D012869:Skin Absorption
chemical_list: D000395:Air Pollutants, Occupational; D015415:Biomarkers; D011084:Polycyclic Aromatic Hydrocarbons; D001554:Benzene
keywords: PAHs; aromatic hydrocarbons; benzene; biomarkers; dermal exposure; exhaled breath; firefighters; urine