When we think of smog, most of us picture the muggy days of summer. But according to Environment Canada, smog actually occurs more frequently in winter because of the use of wood-burning heat — which produces smoke containing air pollutants.
The agency notes that in 2010, for example, there were 17 smog days in the winter compared to 7 in the summer on the island of Montreal.
Smog consists of air pollutants that form a yellow haze over cities, but it can also occur in suburban and rural areas. In the winter though, smog is generally a local phenomenon that is exacerbated by cold weather and occurs when the air is stable (little wind). Fine particles play a significant role in the formation of smog. While industrial activities and public transportation are the main sources in the summer, fireplaces and wood-burning stoves are responsible for more than 60% in the winter.
According to Environment Canada, fine particles (which are too small to be seen with the naked eye) can penetrate deep into the lungs. Children with asthma and those with cardiovascular or respiratory disease may be affected the most and experience aggravated symptoms of their illness.
So just because it’s chilly out don’t assume that smog isn’t an issue. That wood-burning fire (which we just love during the holidays!) is just one of smog’s contributing factors during these cold winter months.