Wildfire Smoke & Health

Wildfires produce a range of harmful air pollutants, from known cancer-causing substances to tiny particles that can aggravate existing health problems and increase the risk of heart attack or stroke. Harmful ingredients include:

Particulate matter (PM): the principal pollutant of concern from wildfire smoke for the relatively short-term exposures (hours to weeks) typically experienced by the public. Particles from smoke tend to be very small (with diameters of 2.5 micrometers and smaller), and can be inhaled into the deepest recesses of the lung
Carbon monoxide (CO): a colorless, odorless gas, is at highest levels during a fire’s smoldering stages, especially very near the fire. CO is mainly a risk to people (like firefighters) who work near smoldering areas.

Larger and more frequent and intense wildfires are a growing public health problem, contributing to reduced air quality for people living near or downwind of fire. Health problems related to wildfire smoke exposure can be as mild as eye and respiratory tract irritation and as serious as worsening of heart and lung disease, including asthma, and even premature death.

While smoke from wildfires is a threat to health, there are many unknowns about the health effects of smoke from wildfires. However, one of the main components of smoke is particulate matter (PM2.5), which is a regulated air pollutant, and the association between PM2.5 and heart and lung health effects is well documented in the scientific literature.