• Environment Canada has issued a smog warning for Montreal and the surrounding areas.
• Exposure to smog can have adverse health effects, especially for people with breathing problems and heart disease.
• Visit MTLBlog for more headlines.

Environment Canada has issued a smog warning for much of the Montreal metropolitan area as a thick haze covers the city. "High concentration of pollutants are expected and will result in poor air quality, especially in urban areas where pollutant emissions are higher," the agency states in its alert. "Fine particulate concentrations are high over the Greater Montreal area and will remain that way overnight and possibly into Sunday. Poor air quality may extend into other regions."

The affected areas include:

• the Châteauguay – La Prairie area;

• the Laval area;

• the Longueuil – Varennes area;

• and Montreal Island area.

Smog can result in adverse health effects for children with asthma and people with heart conditions. "It is therefore recommended that these individuals avoid intense physical activity outdoors until the smog warning is lifted."

A high volume of car traffic contributes to the accumulation of smog. Montrealers can help better the air quality by opting for public transit.

"In Quebec," however, "wood heating is the main source of fine particles that contribute to smog during winter. This activity generates the largest number of these particulates, more than industrial activities and transportation," says Environment Canada.

On Twitter, the City of Montreal reminded residents that the use of appliances and fireplaces, including wood and pellet stoves, that "make use of solid fuel" is forbidden during smog warnings.

"Smog can cause damage to your heart and lungs — even when you can't see or smell it in the air around you," according to Health Canada.

"Smog can irritate your eyes, nose and throat. Or it can worsen existing heart and lung problems or perhaps cause lung cancer with regular long-term exposure."

[rebelmouse-image 26887046 photo_credit="Environment Canada" expand=1 original_size="480x432"] Environment Canada

"It also results in early death. Studies on ozone show that once it gets into your lungs, it can continue to cause damage even when you feel fine."

More information about the health effects of poor air quality is available on the websites of the government of Canada and Quebec.

The complete, current smog warning is visible on the Environment Canada website.