Lung function measures following simulated wildland firefighter exposures.

Area of Science:

• Environmental Health
• Occupational Health
• Toxicology

Background:

• Biomass smoke, particularly wood smoke from wildland fires, is a significant air pollutant in the western U.S.
• Wildland firefighters face prolonged exposure to elevated fine particulate matter (PM_2.5) during physical exertion.
• Epidemiological studies on wood smoke health effects in firefighters are challenged by field conditions.

Purpose of the Study:

• To investigate the health impacts of simulated wood smoke exposure on wildland firefighters in a controlled environment.
• To establish a wood smoke inhalation facility for reproducible occupational exposure research.
• To assess pulmonary function changes following controlled exposure to wood smoke PM_2.5.

Main Methods:

• A randomized crossover trial involving 10 participants in a wood smoke inhalation facility.
• Exposure to clean air, 250 µg/m³, and 500 µg/m³ wood smoke PM_2.5 during 1.5-hour simulated firefighting exercise.
• Continuous monitoring of PM_2.5, CO₂, CO, and relative humidity; pulmonary function testing pre- and post-exposure.

Main Results:

• Participants were exposed to PM_2.5, CO₂, CO, and humidity levels representative of occupational settings.
• Spirometry testing indicated some minor reductions in Forced Vital Capacity (FVC) and Forced Expiratory Volume in 1 second (FEV₁).
• No statistically significant changes in overall lung function were observed immediately or 1 hour post-exposure.

Conclusions:

• The simulated exposure study did not reveal significant adverse lung function changes in wildland firefighters under the tested conditions.
• The developed wood smoke inhalation facility provides a valuable platform for future research on biomass smoke and firefighter health.
• Further research is warranted to fully understand the long-term and nuanced health effects of occupational wood smoke exposure.