What to know
- Toronto was ranked as having the worst air quality in the world by IQAir as heavy wildfire smoke blanketed the city.
- Environment Canada issued an air quality warning, with the Air Quality Health Index reaching 8 and forecast to climb to 10+ overnight.
- Officials warn that wildfire smoke can cause respiratory symptoms and poses the greatest risk to seniors, children, pregnant people and those with underlying health conditions.
- A heat warning is also in effect, with temperatures near 30 C and humidex values in the upper 30s expected to further impact air quality.
Toronto is waking up to some of the worst air quality on the planet as heavy wildfire smoke blankets the city, prompting Environment Canada to issue a special air quality warning.
As of publication, air monitoring service IQAir ranked Toronto as having the worst air quality in the world, as thick smoke from forest fires burning in northwestern Ontario continues to pour into the region.
Wildfire smoke prompts air quality warning
Environment Canada issued an orange air quality warning Wednesday morning, saying smoke from the ongoing wildfires is causing poor air quality and reduced visibility across the Greater Toronto Area.
Much of the city is waking up to hazy skies as a dense blanket of smoke settles over the region.
According to the Air Quality Health Index (AQHI), Toronto’s air quality sits at 8, placing it in the high-risk category. Conditions are expected to worsen overnight, with the index potentially reaching 10+, the highest “very high risk” category.
Health risks increase as smoke lingers
Environment Canada warns that exposure to heavy wildfire smoke can affect everyone’s health, though some people are at greater risk.
Common symptoms include eye, nose and throat irritation, headaches and a mild cough. More serious, though less common, symptoms can include wheezing, chest pain and a severe cough.
Those most vulnerable to wildfire smoke include adults aged 65 and older, pregnant people, infants and young children, and anyone with an existing illness or chronic health condition.
People who work outdoors are encouraged to reduce or avoid strenuous outdoor activity where possible and seek medical attention if they experience concerning symptoms.
Residents are also advised to keep windows and doors closed to limit smoke from entering their homes.
Heat warning remains in effect
The poor air quality comes as Environment Canada has also issued a yellow heat warning for Toronto amid an ongoing stretch of hot, humid weather.
Temperatures are expected to reach around 30 C on Wednesday, with humidex values climbing into the upper 30s.
The weather agency notes that hot and humid conditions can further degrade air quality, causing the Air Quality Health Index to rise into higher-risk categories.
Wildfire smoke has affected Toronto several times in recent summers as large fires have burned across northern Ontario and other parts of Canada. Smoke can travel hundreds or even thousands of kilometres, reducing visibility and affecting air quality far from the fires themselves.
The Air Quality Health Index measures the health risk from outdoor air pollution on a scale of one to 10+, with higher numbers indicating greater health concerns. Public health officials recommend limiting strenuous outdoor activity when the index reaches high or very high risk levels.
