The Effects of Wildfire Smoke

Wildfire smoke not only impacts the environment but poses significant risks to human health. It can reach far beyond fire-affected areas, impacting regions hundreds or even thousands of miles away.

The Effects of Wildfire Smoke

Wildfire smoke not only impacts the environment but poses significant risks to human health. It can reach far beyond fire-affected areas, impacting regions hundreds or even thousands of miles away.

Staying informed about the risks of wildfire smoke and how to minimize exposure are crucial to staying safe in conditions that are becoming more and more frequent. 

Geographical Impact

A screengrab of AirNow’s map on June 29th, 2023 shows how Canada wildfires are creating dangerous air quality conditions for the Midwest and East Coast.

Smoke inhalation, which is typically seen in people who have been in close proximity to a fire, especially those who’ve been trapped in a closed-space fire, can damage the respiratory system and is often times deadly. The direct heat from the fire can cause thermal damage, while the inhalation of toxic chemicals and lack of oxygen can cause respiratory damage and systemic toxicity. 

But what about those that are hundreds or even thousands of miles away from the blaze? AirNow’s Smoke and Air Quality Map demonstrates just how far-reaching and impactful wildfire smoke can be. Throughout the past several weeks, smoke from wildfires in Canada has billowed across the border and into the United States, impacting visibility and triggering air quality alerts in many parts of the country. On June 7th, NBCNews reported air quality levels in New York at a hazardous AQI of 342, officially the worst on the planet at the time. In late June, smoke from Canada had stretched its way east and hit Europe. 

The frequency and severity of wildfire smoke is likely only going to get worse. Since 2000, wildfires in the U.S. have burned an average of 7 million acres annually, more than double the 3.3 million average in the 1990s. The 21st century has also seen some of the largest wildfires on record, especially in recent years. For instance, eight of California’s largest wildfires in recorded history occurred in 2017 or later. 

Climate change has been attributed to the increased severity of wildfires in recent years. Moreover, large, superheated fires drive smoke higher into the atmosphere, which can reach people farther away, and dispel even more toxic byproducts from particles that have aged. These circumstances make it ever more critical for people to understand the effects of wildfire smoke and how they can mitigate their risk. 

Respiratory and Neurological Health Effects

It is known that individuals with chronic airway diseases like asthma and chronic obstructive pulmonary disease (COPD) are particularly vulnerable to the harmful effects of wildfire smoke. Pregnant women and children are also especially susceptible to the negative effects of smoke exposure, and permanent damage is more likely. It should come as no surprise that smoke can impact healthy individuals, as well. 

A study conducted by UC Davis Health in Sacramento during the 2020 wildfire season found that healthy individuals experienced elevated levels of inflammatory markers and the activation of immune cells called dendritic cells. The study indicated that these effects could potentially lead to “increased sensitization to allergens and could promote the development of lung disease.” 

New studies within the last 5 years or so are also emerging about the effects of smoke on the brain and its neurological functions. Studies have shown links between wildfire smoke and lower test scores, as well as cognitive performance decline. While more research is needed to fully understand the impacts of wildfire smoke on health, it is clear that wildfire smoke should not be taken lightly.  

Signs of Wildfire Smoke Effects

Exposure to wildfire smoke can have a range of detrimental effects on human health. It is important to be aware of the signs and symptoms associated with wildfire smoke exposure, as early detection can help in minimizing the impact on individuals. Here are some common signs to watch out for:

  • Respiratory issues: coughing, wheezing, shortness of breath, chest tightness
  • Eye irritation: burning, redness, itching, watering
  • Nasal and throat irritation: runny or stuffy nose, sneezing, sore throat, excessive phlegm production
  • Headaches and dizziness
  • Fatigue and weakness
  • Aggravation of existing health conditions like respiratory and heart conditions

How to Reduce Exposure to Wildfire Smoke

Reducing exposure to wildfire smoke is crucial for safeguarding your health, especially during periods of active wildfires. While it may not be possible to completely eliminate exposure, there are steps you can take to minimize your contact with smoke. Here are some effective strategies:

  • Stay informed about air quality conditions and wildfire information – check air quality alerts from the Environmental Protection Agency (EPA)
  • Create a clean indoor environment by keeping doors and windows closed
  • Use a CARB-certified air cleaner and run your AC on recirculate with a new filter
  • Limit outdoor activities, and if you must go outside, wear N95 or P100 respirator masks
  • Create a “clean” room in your home if your area is severely impacted – seal any gaps around doors, windows, and vents with duct tape
  • Or, consider temporarily leaving the area until air quality levels improve


A study on a smoke-driven air pollutant in the U.S. found that the number of people exposed to at least 1 day of smoke PM2.5  above 100 μg/m3  per year has increased 27-fold over the last decade. Most studies consider a 24-hour concentration of 35 μg/m3 or higher to be unhealthy and prolonged exposure to 50 μg/m3 or higher can cause serious health issues. 

If you haven’t yet experienced the effects of wildfire smoke, it seems like it’s only a matter of time until you do. If you have concerns about your health or worry about how wildfire smoke exposure has or will affect you, consider consulting a healthcare professional. By taking proactive measures and staying informed, you can help protect yourself and reduce the potential health risks associated with wildfire smoke.