Determination of Firefighter Exposure to Polycyclic Aromatic Hydrocarbons and Benzene During Fire Fighting Using Measurement of Biological Indicators

Abstract

In accomplishing their duties, firefighters are potentially exposed to a vast array of toxic combustion and pyrolysis products such as benzene, carbon monoxide, acrolein, nitrogen dioxide, and polycyclic aromatic hydrocarbons. Exposure to PAH and benzene was assessed by means of urinary measurements of 1-hydroxypyrene and t,t-muconic acid, respectively. All urine samples were collected from 43 firefighters during a period extending for 20 h following the end of exposure during a fire. A control sample was also obtained from each participant after at least four days without involvement in fire fighting activities. Only one control 1-hydroxypyrene measurement exceeded the value of 0.32 micromol/mol creatinine considered as the 95th percentile of a normal reference population in this study. Following exposure, 38 percent of the maximum values of all samples collected from each firefighter exceeded this reference value. The highest single value observed in this study was 3.6 micromol/mol creatinine. None of the control samples had a t,t-muconic acid concentration above the limit of detection. A large number (81%) of post-fire samples also had nonquantifiable concentrations of this metabolite. Among 43 firefighters in this study, 17 had measurable excretion of this metabolite in any of the urine samples after fire fighting and, of the latter group, only 6 had t,t-muconic acid concentrations exceeding 1.1 mmol/mol creatinine, a value considered to correspond to a benzene-air concentration of approximately 1 ppm according to the literature. There is clear evidence that fire fighting activities are associated with exposure to PAH above environmental background, as assessed by 1-hydroxypyrene measurements, despite the use of protective equipment. However, in comparison with observations made in other cohorts of industrial workers with known polycyclic aromatic hydrocarbons exposure, firefighters' exposure in this study was low. Similarly, based on t,t-muconic acid determinations, exposure to benzene was rather low in this study. For both contaminants, observation of low exposure could be due to either low concentrations of the contaminant during fire fighting or to the efficiency of protective equipment worn.

Evaluation of dermal exposure to polycyclic aromatic hydrocarbons in fire fighters.

“…Our findings are similar to the findings in other studies where investigators measured biomarkers of PAHs and benzene in fire fighters who wore SCBA most of the time during controlled [Laitinen et al 2009] and uncontrolled fires [Caux et al 2002]. Caux et al [2002] found that the largest increase in urinary excretion of 1-hydroxypyrene (a PAH metabolite) occurred between 4 and 8 hours after the exposure period, but were unable to identify the peak excretion of muconic acid (a benzene metabolite).…”

“…Post-exposure urine levels of 1-hydroxypyrene (metabolite of PAHs), 1-naphthol (metabolite of PAHs), and muconic acid (metabolite of benzene) were higher than pre-exposure levels, and PAHs were found on the fire fighters' hands [Laitinen et al 2009]. In a similar study involving fire fighters under field conditions, post-exposure urine levels of 1-hydroxypyrene were elevated but muconic acid was not [Caux et al 2002]. Dermal exposure was not measured in this study.…”

“…Dermal exposure was not measured in this study. Laitenen et al [2009] and Caux et al [2002] did not have strict control over when SCBA was removed. Furthermore, the turnout gear, hood, and gloves had not been laundered in either study.…”

Biological monitoring of smoke exposure among wildland firefighters: A pilot study comparing urinary methoxyphenols with personal exposures to carbon monoxide, particular matter, and levoglucosan

“…While previous studies with urban firefighters have shown post-shift increases in several biomarkers (Caux et al, 2002), the current study is the first report in which biological measurements of woodsmoke-derived chemicals have been directly linked to personal measurements of woodsmoke exposure in wildland firefighters. We found that individual and summed creatinine-adjusted guaiacol urinary MPs were highly associated with CO (and, to a lesser degree, LG) exposure levels, even though the relationships between exposure levels and urinary MPs in the subsets of data available were somewhat unstable due to the small sample size of the study.…”

Fruit and vegetable intake influences the association between exposure to polycyclic aromatic hydrocarbons and a marker of oxidative stress in pregnant women

“…PAHs can induce the production of reactive oxygen species by forming quinone metabolites (Flowers et al, 1997;Bolton et al, 2000;Singh et al, 2007) and cause oxidative stress by raising malondialdehyde (MDA) levels in the blood (Caux et al, 2002) and urine (Pan et al, 2008;Bae et al, 2010;Liu et al, 2010). There is some evidence that oxidative stress can be ameliorated by sufficient intake of fruit and vegetables, which are rich in vitamin C and other antioxidative nutrients (Barber and Harris, 1994;Collins, 2005), through their antioxidant defense mechanism.…”