Environment Canada issued a smog warning for the Montreal and Laval areas, Thursday, warning of high concentrations of pollutants in the air. It remains in effect Friday.
More broadly, the warning covers the area from the south of the Laurentians, extending past Quebec City and into the Chaudière-Appalaches region.
The department says the air quality will be poorest in metropolitan areas where there are higher levels of pollution.
Air quality in the Montreal and Quebec City areas is considered “high risk” as of Friday morning. Environment Canada forecasts the risk level will reduce to “low” by Saturday night.
Children with asthma as well as people with respiratory ailments or heart disease are being encouraged to avoid intense physical activity outdoors until the warning is lifted.
Environment Canada says wood heating is the main source of particles that contribute to smog in the winter, surpassing industrial activities and transportation.
On Friday, Quebec City issued an indefinite temporary ban on the use of solid fuel-burning appliances in response to the warning. Owners of such appliances are required to declare them via a municipal website.
In Montreal, it’s prohibited to use a wood or solid-fuel burning appliance unless it emits fewer than 2.5 grams of particles per hour.
It’s prohibited to use even certified wood stoves or solid fuel appliances during smog warnings, and those who disregard the rule can be fined.