Particulate readings 25 per cent higher on some winter days
By Sheila Pratt, Edmonton Journal
On bad days, Edmonton had higher levels of a harmful air pollutant than Toronto, a city with five times the population and more industry, says a new analysis from an advocacy group.
On some winter days, the level of fine particulate matter — invisible particles that cause serious heart and lung problems — was 25 per cent higher in Edmonton than levels in Toronto on that city’s worst air days a few years ago, said Dr. Joe Vipond, with the Canadian Association of Physicians for the Environment.
The group used Alberta government figures, released in January, showing pollution from particulate matter exceeded legal limits of 30 micrograms per cubic metre at two city monitoring stations on several winter days in 2010 through 2012.
Toronto’s level of particulate matter pollution has steadily declined to just under 20 micrograms per cubic metre in 2013, well below Edmonton’s level, the study shows.
“That’s not what we expected to find, given how much bigger Toronto is,” Vipond said.
The closing of coal-fired electricity plants in that province has improved air quality, he said.
Edmonton needs to address this major health concern, he said. “There is no safe level of particulate matter for human health, but for some reason this issue is under the radar.”
The impact of Edmonton’s bad air days is felt quickly in city hospitals, said Dr. Brian Rowe, an emergency physician with a Canada research chair at the University of Alberta.
“After a couple of days of bad air quality, visits to the emergency rooms go up, we’ve seen it many times,” Rowe said.
“While we’re mostly concerned with respiratory disease, particulate matter also gets into the blood stream and causes inflammation, heart problems and can cause heart attacks.
“There is no safe level of exposure and we should be trying to reduce this pollutant as much as possible.”
Vipond said there are many sources contributing to the high levels of fine particulate matter in Edmonton, including a growing number of vehicles on the road that pump the pollutant directly into the air.
But the science also shows that emissions from coal-fired electricity plants west of the city are the major contributor as their emissions combine with other pollutants to form particulate matter, he said.
Alberta Environment’s website says fine particulates are tiny particles smaller than 2.5 microns. A strand of human hair is about 70 microns in width. Fine particulates in this size range are referred to as PM2.5.
“Edmonton’s PM2.5 problem is mainly due to secondary formation — chemical reactions in the atmosphere between pollutants, particularly from nitrates and, to a lesser extent, sulphates,” says the report from the Canadian Association of Physicians for the Environment.
“The largest emitter of these pollutants in the capital region is the coal-fired electricity.”
It’s also possible the problem is getting worse as two older coal-fired electricity units were brought back on stream on 2013, Vipond said.
Air quality expert Andrew Read of the Pembina Institute, an environmental think-tank, said pollution from coal plants is a big factor, but not the only source of this pollution.
There’s some urgency to reduce those levels of particulate matter because the federal government is bringing in even tighter standards due to health concerns, Read said.
Next year the allowable limit for particulate matter will be reduced to 28 micrograms per cubic metre from 30 parts and reduced to 27 parts the following year.
The province continues to investigate pollution sources. No action plan is ready.
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