Wildfire smoke, air quality and your health: Health effects of wildfire smoke exposure

On this page

• Pollutants in wildfire smoke
• Symptoms and health effects of wildfire smoke exposure
• Who is most at risk of health effects of wildfire smoke exposure

Pollutants in wildfire smoke

Wildfire smoke is a mix of gases, particles and water vapour that contains:

• ozone
• methane
• sulphur dioxide
• nitrogen dioxide
• carbon monoxide
• volatile organic compounds
• fine particulate matter (PM_2.5)
• polycyclic aromatic hydrocarbons (PAHs)

Fine particles (PM_2.5) represent the main health risk from wildfire smoke. These particles aren't visible to the human eye and have been linked to a wide range of health effects. Air quality may be poor even if you can't see or smell smoke.

There's no known safe level of exposure for some of these pollutants. This means that wildfire smoke can impact your health even at very low levels. As smoke levels increase, your health risk increases. Spending more time exposed to smoke can also increase health risks.

Symptoms and health effects of wildfire smoke exposure

Wildfire smoke can cause a variety of symptoms or health effects that can range in severity. Some symptoms or health effects are more common than others.

Milder and more common symptoms of smoke exposure include:

• headaches
• a mild cough
• production of mucus
• nose, throat, eye and sinus irritation

In many cases, you can manage these symptoms without medical intervention.

More serious but less common symptoms of smoke exposure include:

• dizziness
• wheezing
• chest pains
• severe cough
• asthma attacks
• shortness of breath
• heart palpitations (irregular heart beat)

If you experience any of these symptoms, talk to a health care provider or seek urgent medical attention.

Less commonly, exposure to wildfire smoke can lead to:

• stroke
• heart attack
• premature death
• reproductive and developmental effects, such as low birth weight

If you think you are having a medical emergency, dial 9-1-1 and seek immediate medical care.

Who is most at risk of the health effects of wildfire smoke

During heavy smoke conditions, everyone is at risk regardless of their age or health.

Some people are more likely to experience symptoms or health effects when exposed to wildfire smoke because of their life stage, existing illness, or health conditions. Others are at higher risk because they are more likely to be frequently exposed to wildfire smoke.

In general, those who are most at risk of health effects of wildfire smoke are:

• people with an existing illness or chronic health conditions, such as lung or heart conditions
• people aged 65 and older
• infants and young children
• pregnant people
• people who are more likely to be exposed because of their location or occupation, such as people who:
  • live in rural and remote areas
  • exercise outdoors
  • work outdoors, including wildland firefighters

People living in situations of lower socioeconomic status are also at higher risk because they may have reduced ability to limit exposure. This includes people:

• with lower incomes
• with lower education
• experiencing housing insecurity
• experiencing uncertain employment