How wildfire smoke affects your health

Air quality plummeted across large parts of the United States and Canada again at the end of June as hundreds of wildfires continue to rage out of control north of the border.

Air quality ranged from “unhealthy” to “very unhealthy” in the Midwest with Chicago ranking number one in worst air quality in the world on Tuesday. By Friday, New York City’s air quality had dropped to unhealthy levels as the smoke shifted east.

So far, the smoke is yet to reach levels seen earlier this month when plumes darkened skies and made it difficult to breathe in at least 20 states and large parts of Canada.

On 7 June, New York City shot above 400 on the Air Quality Index (which runs from 0-500) – a “hazardous” level of pollution that bathed the city in an eerie orange haze. Public health officials advised all people to stay indoors and wear masks outside to limit their smoke inhalation.

Canadian officials have warned that this could be the country’s worst wildfire season on record and smoke would be a problem “all summer”.

Wildfires are increasing in frequency, size and severity globally due to hot and dry conditions being driven by the climate crisis. Fire seasons have become roughly 20 per cent longer around the world in the last 40 years, the World Health Organisation reports, and are expected to escalate as the global temperature rises.

Wildfire smoke can have serious health implications, particularly for vulnerable populations like young children, the pregnant, the elderly and those with underlying medical conditions.

The biggest health threat from smoke is its fine, airborne particulate matter, some smaller than a human hair, which can lodge deep inside the lungs and enter the bloodstream.

Even relatively healthy people need to be concerned if the AQI is high enough, Dr Joe Alton and Amy Alton, a nurse practitioner, told The Independent, via email.

AQI of 200 is considered very unhealthy and 300 or greater hazardous, even to those without respiratory or cardiovascular disease.

“Generally speaking, however, most healthy persons will experience minor effects such as eye irritation, sore throat, headache, fatigue, and sinus congestion,” they noted.

Particle pollution can have more serious impacts and trigger asthma attacks, heart attacks and strokes, the American Lung Association reports.

If people are exposed to smoke over long periods, it can increase their risk of chronic conditions such as cancer, lung disease, and cardiovascular disease, NY Health Department warns.

Outdoor air pollution is estimated to have caused 4.2 million premature deaths worldwide in 2019, according to WHO.

The Altons, founders of medical preparedness site doomandbloom.net and authors of The Survival Medicine Handbook, recommend a number of precautions against wildfire smoke.

To start, keep an eye on local air quality reports and any health warnings relating to smoke, they said.

“If warnings are in effect, you’re safer if you avoid spending your time outdoors. If you’re told to stay inside, keep doors and windows shut.

“In hot weather, run the air conditioner, but close the fresh-air intake. Use fresh HEPA air filters throughout your air circulation system, including air purifiers.”

Don’t add to air pollution by lighting fireplaces or candles, they noted.

“Believe it or not, vacuuming the floors is also a bad idea: It stirs up particles into the air, worsening its already poor quality. Of course, avoid smoking tobacco or other products.”

Outdoors, they recommend using N95 masks against wildfire smoke as standard surgical masks may not be sufficient protection against tiny particles.

This article was updated on Friday, 30 June