Health Effects of Wildfires-April 2022

Wildfires are occuring more frequently in the United States and in many parts of the world. In 2020 in Colorado, three fires were the largest ones on record. As temperature and rain amounts change, the numbers of wildfires are expected to increase.
There is consistent evidence that wildfire smoke exposure in the general population can cause eye and respiratory irritation, as well as exacerbations of asthma and chronic obstructive pulmonary disease. Wildfire smoke contains many air pollutants of concern for public health, such as carbon monoxide (CO), nitrogen dioxide, ozone, fine particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds. PM2.5 is the primary air pollutant of concern in wildfire smoke. Protections and controls include staying indoors, limiting physical activity, air filtration, and wearing respiratory protection devices. Indoor infiltration can be reduced by closing doors and windows and the use of portable air filters, central air filters, or air conditioners in recirculation mode may also be effective in reducing exposure.
Outdoor workers, such as agricultural workers, grounds maintenance workers, and construction laborers, masons, painters, and roofers, spend most of their working hours outside, and therefore are at increased risk for inhaling wildfire smoke  Those with underlying lung disease are most at risk. In 2019, Cal OSHA proposed that employers use the local air quality index (AQI) or a direct-reading PM monitor to determine smoke levels and offer respirators to workers expecting exposure to harmful levels of smoke. The AQI reflects federal health standards of five air pollutants identified in the Clean Air Act, including PM2.5. The AQI ranges from 0 to 500. The EPA’s “Air Now” website “Air Now” gives a 24-hour forecast of the AQI.
Recent research has suggested that long-term exposure to wildfire smoke may have negative health effects in fire fighters. The scientific community does not fully understand how long-term, repeated exposures, or exposures to high concentrations of wildfire smoke may affect a worker’s health. More studies are needed on both the short-term and long-term effects of wildfire smoke. However, there is sufficient evidence for employers to protect their workers whether they are fire fighters, outdoor workers, or are working indoors during a wildfire event

OccuSafe Industrial Hygiene & Safety, Inc. provides skills and expertise to recognize, evaluate and control hazards and injuries in the areas of industrial hygiene, occupational safety and health. OccuSafe services companies of all sizes in a range of industries.

For more information on this topic and to discuss your company’s safety and industrial hygiene needs call OccuSafe at (214) 662-6005 or visit us at

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