BTEX Emissions During Prescribed Burning in Function of Combustion Stage and Distance From Flame Front

Abstract

The authors investigated the volatile organic compound group benzene, toluene, ethylbenzene, and xylenes (BTEXs) produced during the combustion of forest fuel. The analytes were chosen because they have been identified in other forest fires. As a result, firelighters and the general population can be exposed to hazardous concentrations of BTEXs during prescribed burning. Firefighters were equipped with Tenax adsorbent tubes and the BTEX concentrations analyzed by Automated Thermal Desorption–Gas Chromatography/Mass Spectrometry (ATDGC/MS). Total BTEX concentrations were measured in function of the distance from the flame front (between 1 and 10 m, 30 and 50 m, and 100 and 150 m) and the combustion phase (flaming and smoldering). The major compounds detected were benzene and toluene. Significant differences were observed between the data collected. BTEX concentrations were higher close to the flame front and during the smoldering phase. The benzene concentration (0.093–18 mg·m⁻³) exceeded the Short-Term Exposure Limit (STEL, 16 mg·m⁻³) in samples collected during the smoldering phase at a distance of 1–10 m from the flame front. Statistical analyses were carried out to summarize the results.

Keywords:

• BTEXs
• Distance flame front
• Firefighter exposure
• Flaming and smoldering phases
• Prescribed burning smoke

ACKNOWLEDGEMENTS

This research is supported by the National Research Agency under contract N° NT05-2_44411.

Notes

Note. ^a,b,c  = significant difference according to the distance, Tukey test, p < .05, a > b > c; d = distance.

Note. *^,** = significant difference according the combustion phase, ANOVA, p < .05; d = distance.

Note. ^a Not statistically different, Tukey post hoc test, p > .05. d = distance.