Association Between Lung Function and Exposure to Smoke Among Firefighters at Prescribed Burns

Abstract

We investigated the short-term effects of exposures to PM_3.5, acrolein, formaldehyde, and carbon monoxide on lung function in a group of firefighters performing prescribed burns. Spirometric measurements were made on 65 firefighters at the beginning, midpoint, and end of their work shift, while exposure was measured over the entire day. The interquartile range (IQR) of daily personal PM_3.5 exposures was 235 μg/m³ to 1317 μg/m³, with an average daily exposure of 882 μg/m³. Concentrations of acrolein (IQR: [0.002, 0.018] ppm), formaldehyde (IQR: [0.008, 0.085] ppm), and carbon monoxide (IQR: [2.10, 10.48] ppm) were similarly elevated. In this group of firefighters, FEV₁ changed by −0.125 L from preshift to postshift (p < .001). We examined the association between this cross-shift lung function decrement and smoke exposure. A 1000 μg/m³ increase in PM_3.5 was associated with a −0.030 L change in the cross-shift FEV₁ (95% CI [−0.087, 0.026]). Acrolein, formaldehyde, and carbon monoxide exposure were also not significantly associated with changes in FEV₁, FVC, or FEF_25–75. We concluded that while firefighters' lung function significantly decreased from preshift to postshift, firefighters exposed to greater concentrations of respiratory irritants did not experience greater lung function decrements. We could not establish a significant link to any of the individual toxic components of smoke we measured.

Keywords:

• respiratory disease
• particulate matter
• formaldehyde
• acrolein
• carbon monoxide

ACKNOWLEDGMENTS

This study was supported in part by grant PNW 91-0031 Forest Service, USDA, and in part by the EPA Northwest Research Center for Particulate Matter and Health, grant # R 827355.

We thank Christine Betchley for collection of the spirometry data and publication of a prior manuscript.

Notes

^A SD = standard deviation.

^A Adjusted for age, gender, and current smoking status.