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There’s a winter smog warning in effect for Gatineau, Ottawa and Renfrew County, and by the time the air clears late Friday we’ll be heading into a weekend mix of freezing rain, snow, and rain.
First, the smog, which is already here.
There are two parallel warnings. One from Environment Canada and the Quebec Ministries of Health and the Environment says air quality will be poor for Friday morning in and near Gatineau, improving in the afternoon. It calls for moderate air quality in the Ottawa region.
The second is from the Ontario Environment and Climate Change Ministry. It also calls for moderate air quality in and around Ottawa Friday morning, and also for the Renfrew County area. There are similar conditions across a large section of central Ontario from Niagara to Barrie.
The problem is microscopic air particles, which come largely from smoke from wood-burning stoves. Friday’s atmospheric conditions are preventing the particles from blowing away, and keeping them close to the ground.
The City of Gatineau says there are more than 30,000 wood stoves in Gatineau. A wood stove that isn’t burning efficiently can produce as much small-particle pollution in nine hours as a mid-sized car produces in 18,000 kilometres of driving, the city warns.
Summer smog is more common in this region, and it’s a combination of gases that react together in hot sunshine. Environment Canada says that winter smog is different: “Residential wood heating is responsible for almost 61 per cent of particles that contribute to smog during winter. This activity generates the largest number of these particles — more than industrial activities (22 per cent), the use of motorized vehicles (14 per cent) and other sources (three per cent).”
These particles are in the range of 2.5 microns in diameter. There are 1,000 microns in a millimetre. At that size they can lodge deep inside the lungs.
Meanwhile, the weekend forecast looks cleaner but sloppy and with its own set of problems.
The Ottawa weather offices is forecasting snow with a chance of freezing rain overnight Friday, then periods of snow Saturday changing to rain Saturday, but with more risk of freezing rain. The high Saturday is expected to reach 5 C.
tspears@ottawacitizen.com
twitter.com/TomSpears1
查看原文...
First, the smog, which is already here.
There are two parallel warnings. One from Environment Canada and the Quebec Ministries of Health and the Environment says air quality will be poor for Friday morning in and near Gatineau, improving in the afternoon. It calls for moderate air quality in the Ottawa region.
The second is from the Ontario Environment and Climate Change Ministry. It also calls for moderate air quality in and around Ottawa Friday morning, and also for the Renfrew County area. There are similar conditions across a large section of central Ontario from Niagara to Barrie.
The problem is microscopic air particles, which come largely from smoke from wood-burning stoves. Friday’s atmospheric conditions are preventing the particles from blowing away, and keeping them close to the ground.
The City of Gatineau says there are more than 30,000 wood stoves in Gatineau. A wood stove that isn’t burning efficiently can produce as much small-particle pollution in nine hours as a mid-sized car produces in 18,000 kilometres of driving, the city warns.
Summer smog is more common in this region, and it’s a combination of gases that react together in hot sunshine. Environment Canada says that winter smog is different: “Residential wood heating is responsible for almost 61 per cent of particles that contribute to smog during winter. This activity generates the largest number of these particles — more than industrial activities (22 per cent), the use of motorized vehicles (14 per cent) and other sources (three per cent).”
These particles are in the range of 2.5 microns in diameter. There are 1,000 microns in a millimetre. At that size they can lodge deep inside the lungs.
Meanwhile, the weekend forecast looks cleaner but sloppy and with its own set of problems.
The Ottawa weather offices is forecasting snow with a chance of freezing rain overnight Friday, then periods of snow Saturday changing to rain Saturday, but with more risk of freezing rain. The high Saturday is expected to reach 5 C.
tspears@ottawacitizen.com
twitter.com/TomSpears1
查看原文...
