Wildfire smoke can harm your lungs, your heart, and maybe even your mental health: research

30 May 2019

Published by https://globalnews.ca/

USA – Wildfire season has sparked to life in Alberta, destroying homes, putting others at risk and forcing evacuation orders throughout the province’s north.

The effects of the wildfire won’t just be felt in the province, however. Modelling projects that smoke from the wildfires could drift all over Canada in the coming days, reaching as far east as Newfoundland and as far south as Kansas.

With smoky conditions come health warnings that advise people to check air quality, stay inside and clean the air in their homes.

But what exactly happens when people breathe in smoke? How does it upset the lungs, the heart and the body overall?

In Canada, air quality and smoke concentration is often calculated by measuring PM2.5, or particulate matter measuring 2.5 micrometres in diameter or less.

Such measurements allow for smoke forecasts like the one displayed below — the darker areas represent higher PM2.5 concentrations:

Visualization by Firesmoke.ca shows a forecast for concentrations of PM2.5 across Canada on May 31, 2019.



PM2.5 can be made up of any matter; it depends entirely on where the emissions come from.

Where wildfires are concerned, particulate matter is often made up of soot from burning trees.

The soot can become little “spitballs” that stick together to make bigger particles, explained Sarah Henderson, senior scientist in environmental health services at the BC Centre for Disease Control (BC CDC).

“Mostly they’re going to be made of carbon in various forms, but there can be other stuff in there as well,” she told Global News.

“Anything that was in the source material that was burning, in this case the trees, can wind up in the particles, so there will be trace amounts of heavy metals.

“But mostly what’s happened is the organic matter, the hydrocarbon has been combusted down to just the carbon.”

Health risks can arise when people breathe in these particles, provoking an immunological response in the body, Henderson said.

“These particles can’t be filtered out by your nose or mucus because they’re too small,” she said.

“So they pass right through those systems and they go straight into the lungs. And the smaller they are, the more deeply they can penetrate.”

The body treats these particles like “foreign invaders,” provoking an immunological response, and defending itself in a way it might against a virus or bacteria.

PM2.5, however, can’t be killed like viruses can, so the body remains in a state of systemic inflammation, Henderson explained.

The body experiences inflammation in response to bacteria and other phenomena, causing swelling by having blood vessels leak fluid into certain tissues, according to the U.S. National Library of Medicine.

The inflammation can mean harm to several parts of your body when you breathe in smoke.

Exercise, Henderson said, can increase the intake of smoke because you’re breathing in 10 times more air than you would be at rest.

“So you’re more exposed to whatever’s out there,” she said.

Health warnings linked to wildfires largely focus on areas such as the respiratory system and the heart.


Medical study has determined a close link between wildfire smoke and asthma.

Studies have shown more visits to the doctor, as well as the emergency room, and hospitalization for asthma linked to wildfire smoke exposure, according to a 2016 literature review led out of the Harvard Center for Population and Development Studies.

Some studies have found “no significant acute changes in lung function among people with asthma” related to particulate matter.

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