It’s hazy out there. The health consequences of wildfires in Canada are being felt across the United States this summer. Poor air quality from wildfire smoke and other pollutants is harmful to everyone, even those with no known preexisting conditions. Knowing how to protect yourself is crucial.

Symptoms can show within just days of wildfire smoke exposure. Prolonged exposure can damage the lungs and heart, or even weaken your immune system. The following are some of the symptoms and health risks that may result from wildfire smoke and pollutants, as well as prevention best practices.

General symptoms

• Eye irritation
• Fatigue
• Sneezing
• Coughing and/or wheezing
• Shortness of breath

Respiratory effects

• Inflammation
• Bronchitis
• Impaired lung function
• Worsening asthma
• Higher lung cancer risk

Cardiovascular effects

• Heart failure
• Heart attack
• Stroke
• Atrial fibrillation

Wildfire smoke is especially dangerous because of the fine particles it produces. With a diameter 30 times smaller than a piece of hair, these particles easily enter the nose and throat before traveling to the lungs and bloodstream. Compared to pollution particles the same size, wildfire smoke is up to 10 times more harmful.

Other harmful air pollutants

In addition to wildfire smoke, other harmful pollutants also lower air quality. These exist both indoors and outdoors, with the most common sources being:

Indoor

• Fuel-burning appliances
• Building materials and furnishings
• Household cleaning products
• Excess moisture

Outdoor

• Electric utilities
• Burning fuel
• Transportation vehicles/equipment
• Manufacturing processes

While our bodies have defense systems against some pollutants, too much exposure can overwhelm these defenses and render them less effective. Plus, tiny particles from wildfire smoke quickly bypass our natural defenses, like nose hair.

Risk factors

The exposure to daily pollutants and ongoing wildfires is a global health concern. Certain risk factors increase the likelihood of negative health effects:

• Asthma
• Lung cancer
• Chronic obstructive pulmonary disease (COPD)
• Heart disease
• Allergies
• Age (children and adults older than 65)
• Pregnancy
• Compromised immune system