Passive sampling of atmospheric polycyclic aromatic hydrocarbons by silicone wristbands during wildland fires

Abstract

Wildland fires, including both wildfires and prescribed burns, emit large quantities of smoke containing hazardous air pollutants such as polycyclic aromatic hydrocarbons (PAHs). Understanding PAHs concentrations in these smoke-filled environments is key to developing effective mitigation strategies to protect public health and safety. However, conventional measurement strategies are not always feasible in the highly dynamic and logistically complex settings of wildfire events. As a result, alternative approaches are needed, such as the use of silicone wristbands (SWBs) as passive air samplers. In this study, PAHs were analyzed in SWBs worn by firefighters during prescribed burns and wildfires. After deployment, extraction, and GC-MS/MS analysis, PAH air concentrations were calculated using a compound-specific kinetic uptake model. Personal exposure to PAHs was task-specific: wildfire operators and torchers, who ignite the fires, experienced the highest concentrations (mean sum of PAHs ≈ 5000 ng/m³), followed by liners, who manage fire boundaries (≈2000 ng/m³), while truck drivers exhibited the lowest exposure concentrations (≈100 ng/m³), likely due to their roles keeping them farther from the smoke-dense areas. Additionally, to evaluate the SWBs’ ability to capture particle-bound PAHs, PAH air concentrations measured in SWBs were compared with those obtained from PM_2.5 filter sampling. The findings highlight the utility of passive air sampling with SWBs in detecting PAHs and underscore their potential for monitoring exposure concentrations in complex atmospheric environments.