With wildfires raging out of control across Canada, experts warn the United States may be facing a summer of intense heat and hazardous smoke. But just how dangerous is this smoke to our health, and when should we be masking up outdoors?
“If you are healthy, you’re usually not at major risk from short-term exposure to smoke,” said Dr. Thomas Kilkenny, a pulmonary and critical care specialist at New York’s Northwell Staten Island University Hospital. “Still, it’s wise to avoid breathing smoke when possible.”
What Exactly Is the Air Quality Index?
When there’s wildfire smoke reported for your area, it’s important to monitor the U.S. Air Quality Index (AQI), Dr. Kilkenny said.“This is a measurement of the amount of particulate matter (PM) in the air that is of the dangerous type, noted as PM 2.5 and PM 10,” he added. “These values both relate to the size of the particles in the air.”
In addition to the fine particulate matter with a diameter of 2.5 or 10 micrometers, AQI quantifies the levels of ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide.
The AQI typically ranges from zero to 500, with lower values indicating better air quality and higher values indicating worse air quality. The AQI is color-coded and categorized into different levels, each corresponding to a different level of health concern.
Health Risks of Inhaling Wildfire Smoke and Who Is Most at Risk
Wildfire smoke poses health hazards like lung damage, but some people face much bigger risks of severe health problems.Most Vulnerable Populations
- Children: Their airways are still developing, making irritation, inflammation, and other health issues more likely. Their faster breathing rate also exposes them to more smoke.
- Older people: They often have chronic health issues that smoke can exacerbate. Their immune systems may also be weaker, and their lungs less able to handle lung irritation.
- Pregnant women: Smoke exposure can affect the development of the fetus and pregnancy health. The woman’s elevated breathing rate also means more inhalation. One study found that wildfire smoke can cause preterm birth and affect how a fetus develops.
- People with preexisting conditions: People with preexisting conditions like asthma, chronic obstructive pulmonary disease (COPD), heart disease, etc., already have compromised respiratory and cardiovascular systems that smoke can further damage.
- Outdoor workers: They have higher exposure to smoke for extended periods, which increases risk, especially with physical exertion.
Health Hazards of Wildfire Smoke
- Eye, nose, and throat irritation: Smoke can cause stinging eyes, runny nose, scratchy throat, and headaches.
- Worsening of respiratory conditions: The fine particles in smoke can worsen chronic lung diseases like asthma, COPD, and cystic fibrosis. It can make breathing more difficult.
- Increased risk of respiratory infections: The particles compromise the lungs’ immune defenses, making one more prone to getting respiratory infections.
- Heart problems: Smoke from wildfires can increase blood pressure and chest pain and reduce heart rate variability, which indicates stress on the cardiovascular system.
- Mental health effects: Exposure to smoke has been linked in some studies to increased anxiety, depression, and post-traumatic stress disorder symptoms.
- Fatigue and difficulty concentrating: The smoke can reduce oxygen delivery in the body and lead to fatigue and impaired concentration (pdf).
Can Masks Help?
The AQI is a scale, ranging from “good” to “hazardous.” When the AQI is elevated, wearing specific types of masks called respirators can be helpful.The appropriate mask is determined by particle size, with small particles (PM 2.5) easily passing through protections like scarves, bandanas, or even surgical masks and dust masks found at large hardware stores, according to Dr. Kilkenny. “These masks would offer little help,” he added.
Using a mask with lower efficiency than an N95 will not effectively prevent dangerous smoke particles from reaching your lungs, Dr. Kilkenny said.
The decision to wear a mask depends on a person’s susceptibility. “If the person has chronic lung issues, they should start wearing the mask when the AQI is elevated into the orange range, which is noted as being ‘unhealthy for certain groups,’” Dr. Kilkenny said. When the AQI is elevated beyond that, “even healthy individuals should consider wearing a device.”
People should use their common sense, Dr. Kilkenny added. If it looks smoky outside or the AQI is elevated, “it’s probably not a good time to go outside and go for a run,” and children should avoid playing outdoors as well.
How Long Could This Last?
As bad as the Canadian wildfires have been so far, the odds are that the smoke will likely continue, or even worsen, in the near future. Even one major forest fire can prove daunting to control, and Canada isn’t trying to put out just one fire. Firefighters from around the world are gathering in our northern neighbor to help fight what has become Canada’s worst wildfire season on record.As we approach the dog days of summer, there is a high possibility of many more air-quality alert days due to the ongoing wildfires, along with hot and dry conditions that could exacerbate the impact of wind-driven wildfire smoke.
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