There are dangerous particles in the smoke we’re breathing: ‘It doesn’t seem like any part of the body is safe’

As the skies fill with haze and wildfire smoke turns the moon red, prompting poor air quality warnings over large chunks of Ontario and Quebec, experts are warning that, barring any major climate-change mitigating factors, we may have to get used to this.

And that means getting used to the increased risk of lung disease, heart disease, cancer and the resultant strain on already taxed health-care resources that comes along with it.

As of Tuesday, most of southern and eastern Ontario and a large swath of Quebec were under Special Air Quality Statements largely thanks to Quebec wildfires burning out of control.

Those statements get issued when the Air Quality Health Index — an amalgamation of measurements of the concentrations of pollutants and forecast weather conditions — reaches seven on a scale that goes to 10+.

Residents of portions of the Rockies west of Jasper, northern Alberta and B.C. as well as southern N.W.T. found themselves in similar situations due to fires in those areas.

“This region is being impacted or is likely to be impacted by wildfire smoke over the next 24-48 hours,” said those advisories.

“Wildfire smoke can be harmful to everyone’s health even at low concentrations. Continue to take actions to protect your health and reduce exposure to smoke.”

An extraordinary start to the spring fire season has seen wildfires burning — unusually — from coast to coast, goosed by dry, hot and windy conditions.

And as climate changes progress unabated, we can expect to see more of those conditions and consequently more frequent and severe wildfires.

With those fires come smoke — lots of it — and with that come health hazards for millions of Canadians. And as wildfires become more common and more severe, continued exposure to that smoke will begin to affect the full breadth of the population: not just the elderly and children and those with pre-existing health conditions, but the young and the healthy as well.

The culprit is known — in the lexicon of the country’s Air Quality Health Index — as PM2.5. It’s one of three pollutants measured by the AQHI, the others being ozone and nitrogen dioxide.

PM2.5 is the by-product of the smoke emitted by wildfires — fine particles of matter with a size of 2.5 microns or less. You could fit about 30 of them across the width of a hair.

At this size, PM2.5 can easily sift down through air passages to the depths of the lungs. At that size, it can also pass into the blood, causing a system-wide inflammation that can exacerbate heart conditions and potentially cause cancers.

Those particles are capable of infiltrating almost every organ in the body, said Matt Adams, director of the Centre for Urban Environments at the University of Toronto.

“As the science evolves and our ability to detect them increases, we keep finding them more and more places,” he said. “We found them on the other side of the placental barrier in babies. We found these particles in the brain, for example.

“It doesn’t seem like any part of the body is safe.”

Once they’re in the body, one of the problems of assessing the damage potentially caused by PM2.5s is that we don’t really know enough about them or how badly they might hurt us.

“Because it’s so complex, we don’t know what is in them,” said Arthur Chan, associate professor of chemical engineering and applied chemistry at U of T.

“There are just thousands of different compounds. There are many different research groups that are studying what is in them and what might be the most toxic components.”

We do know that one of its components are PAHs — short for polycyclic aromatic hydrocarbons — primarily caused by incomplete combustion of organic materials, like wood, said Chan. And we do know that PAHs are carcinogenic — they’ve been linked to lung cancer and other forms of cancer — and mutagenic, meaning they can make changes in the DNA, which can also lead to cancers.

So, the danger exists, though we don’t yet know the full extent.

That’s why advisories are issued based on the Air Quality Health Index — to some extent, a measure of who needed treatment the last time similar conditions existed.

“These air quality advisories are based largely off of hospitalization increases following the days of an air pollution event,” said Adams. “Over a few years they take the data — number of people who are ending up in the hospital — and they link that to the air quality in the days preceding.”

In short-term, isolated incidents, that poor air quality generally affects a portion of the population.

Asthma sufferers might need to treat themselves with their puffers; the elderly, or children, whose lungs are still developing might need a visit to the doctor or the hospital. People with heart issues might find those conditions aggravated by even a short exposure.

Generally speaking, for most people, in an isolated incident, where the source of the smoke stops, the symptoms from that smoke irritation clear up after a few days.

But when the exposure to wildfire smoke goes on for extended periods — as seems likely in the near future — those whose systems are compromised suffer even more, and even the young and healthy will begin to develop chronic long-term lung and heart conditions and possibly cancers as well.

“Chronic or repeated exposure to wildfire smoke might have impacts on long-term development of the airways in children,” said Michael Schwandt, medical health officer for Vancouver Coastal Health. “There’s potential for the incidence of asthma or the worsening of asthma over time. There seems to be a risk of impaired lung development or respiratory illness early in life for developing infants whose mothers were exposed to wildfire smoke.

“This is research in early stages … but we’re seeing more and more of these wildfire events and sadly, more and more evidence is gathering of some of those impacts.”

Those impacts mean a higher strain on an a health-care system. All the research thus far points to existing conditions being exacerbated and an increase in people experiencing symptoms for the first time after prolonged exposure to wildfire smoke, he said. And that exposure is bound to increase as the frequency and severity of wildfires increase.

“It’s definitely a potential surge in demand on the health system at a time when most systems definitely don’t need to be further taxed.”

And though our bodies show some ability to adapt to protracted heat exposure, we have no ability to withstand prolonged exposure to smoke over time. “If anything, repeated, exposures seem to make people more vulnerable to future smoke exposures.”

That means that coping with predicted increased exposure to wildfire smoke means there will have to be some behavioural adaptations on our part, said Schwandt.

The big picture is to find ways of hitting at the root of the problem — mitigating climate change.

But we can also change some of the ways we live, he said. Prioritizing things like developing houses with filters to provide clean air indoors when the air quality is bad, and making sure neighbourhoods have clean airspaces like libraries and community centres for people is a step in the right direction.

In the meantime, when wildfire smoke fills the sky, the best bet is to limit exposure to it, said Adams. Stay inside, find a clean airspace and avoid strenuous activities.

“The best resource we have really is to understand when it’s a risky day and change those behaviours.”