Health. Fires in Canada: Are the smoke that crossed the Atlantic dangerous to health?

As of Tuesday, June 10, 215 forest fires were still burning in Canada, an early occurrence at the start of the wildfire season. 109 of them remain uncontrolled, while 106 are contained or under control. The immense plumes of smoke crossed the Atlantic and clouded the skies over Western Europe this Whitsun weekend.

"Smoke from wildfires in the Canadian provinces of Manitoba and Saskatchewan has crossed the Atlantic, reaching Europe in recent days, and forecasts predict further smoke transport this week," the European Union's Copernicus Atmosphere Monitoring System (CAMS) announced seven days ago. Thus, across France and elsewhere in Europe, the sky is milky because of the smoke obscuring the sun.

What's in wildfire smoke?

Wildfire smoke contains fine particles, including submicron particles – particles smaller than one micron. It also contains carbon monoxide and many other chemicals; volatile organic compounds, including acrolein, formaldehyde, and benzene; semi-volatile compounds including polycyclic aromatic hydrocarbons (PAHs), heavy metals, and nitrogen oxides (NOx).

Short-term inhalation of fumes causes respiratory effects, primarily respiratory irritation symptoms. "It can lead to emergency room visits or hospitalizations for respiratory illnesses such as asthma or other chronic lung diseases, or even cause changes in lung function," explains ANSES. Cardiovascular effects can also be observed.

Should we be concerned about the health effects of the fumes circulating in the French sky?

The Copernicus agency is reassuring : "According to CAMS forecasts, the expected smoke transport should not have a significant impact on surface air quality, as such episodes tend to occur at high altitudes." Initially predicted at an altitude of 9,000 meters, the smoke is said to be much lower.

This was the case in Bouches-du-Rhône on Monday, June 9, where smoke was present at an altitude of 4,000 meters. According to the website Meteo-Paris.com, on Tuesday, June 10, the smoke has been "mainly between 1,000 and 3,000 meters in altitude in recent days." However, it states that " at ground level, air quality remains good."

However, Atmosud, the air quality observatory in the South Provence-Alpes-Côte d'Azur region, issued a pollution alert on Tuesday, June 10.

"The plume of particles from the Canadian fires is expected to persist, with high concentrations of fine particles in the eastern Hautes-Alpes. A prefectural alert for persistence has been issued for this department," notes the air quality observatory. "Poor air quality is thus expected in the eastern Hautes-Alpes, Vaucluse, and most of Bouches-du-Rhône. Air quality will deteriorate in the rest of the region."

What precautions should be taken in the event of a pollution peak?

The alert is being issued for PM10 particles, which are particles with a diameter of less than 10 micrometers. These particles can penetrate deep into the lungs, causing inflammation and worsening the health of people with pulmonary heart disease. According to Ademe recommendations, in the event of a peak in fine particle pollution,

• continue to go out for walks but avoid going out near major roads during rush hour (7 a.m. - 10 a.m. and 5 p.m. - 8 p.m.);
• Avoid activities that may cause shortness of breath (i.e., breathing through your mouth).
• If you experience any respiratory or cardiac discomfort (shortness of breath, wheezing, palpitations, etc.), report it to your doctor;
• continue to air your home twice a day for 10 minutes, preferably at night;
• Above all, do not turn off the ventilation. Pollutants are being emitted into your home. If you no longer renew the air in your home, these pollutants will no longer be evacuated.

The situation could evolve rapidly across the country. For example, Marion Guitter, a research engineer at Air Pays de la Loire, told France 3 Pays-de-la-Loire on Monday: " What's burning right now in Canada could impact us in several days. So, we'll continue to monitor this. But there's nothing worrying, at least not for now."

Source: Meteo-Paris.com, Ademe, Copernicus, AtmoSud, Anses, Radio Canada