A dozen people more than usual came into the clinics in Valemount and McBride last week complaining of shortness of breath and wheezing, during the five days smoke from forest fires clouded the region.
The smoke came from the central interior of the province, where massive fires continue to burn in one of B.C.’s worst wildfire seasons in years.
Dr. Ray Markham at the Valemount clinic says the impact of the pollution depends on what’s in the smoke and how long a person is exposed.
“The more volatile compounds can sometimes be associated with cancer,” he says. “I would expect that this short exposure isn’t going to do that.”
The smoke left an odour of campfire in the air for most of last week, blotting out surrounding mountains and the sun. Chemicals such as creosote, methyl mercury and formaldehyde are released when trees burn. Toxic gasses can stick to particles that are breathed in by people far away, when carried by the wind.
Bob Beeson, 96, has lived in the Valley 62 years.
“This is the smokiest I’ve seen it,.”
He said he wasn’t sure if the smoke was impacting his health. A condition requires Beeson to carry around an oxygen pack in order to breathe.
Beeson used to be a fire warden, organizing fire crews to battle fires near Lilloet and Merritt, among other regions.
No health advisory was issued for the Robson Valley area, though the smoke may have been as bad as Prince George where an advisory was issued, says Dennis Fudge, air quality meteorologist with the B.C. Ministry of Environment.
Valemount and McBride have no continuous air quality monitoring system, only a non-continuous monitor, which means samples are taken over 24 hours once every three days, and it takes a month for the results to be analyzed in a lab.
Fudge says for regions like the Robson Valley, they rely on weather data and images of the smoke through webcams to determine whether an advisory is necessary.
But he says sometimes levels are high and visibility isn’t that bad.
“That’s the hardest thing is getting the message out to the people,” he says. “Most people aren’t even aware there is an advisory in effect.”
An advisory was issued for Prince George Aug. 20, warning people not to exercise and for people with breathing conditions to remain indoors or in an area with filtered air conditioning.
The Chief Medical Health Officer for the Northern Health Authority also warned people suffering from asthma or other chronic illness should activate their asthma or personal care plan.
Thomas White, who manages water and air monitoring for the Ministry of Environment, says a monitor is not always needed to make an advisory. The Ministry’s new smoke forecasting system is one tool to figuring out where the air may become polluted. He also says people should be responsible for knowing what to do if they see the air outside is smokey.
The Ministry maintains 150 monitors throughout the province. Large-scale industrial operations are also required to install and maintain continuous monitors.
A continuous monitor costs roughly $10,000 to install. Results from the monitors are posted to the B.C. air quality website every hour.
Fudge says if more people contacted the ministry asking about getting a continuous monitor that would increase the chances of getting one. The size of the population and the consistency of a polluting source also determine which areas get continuous monitors.
In Valemount, the air quality committee is in limbo as the Village waits to hear back from the Regional District of Fraser-Fort George whether the district will take on the responsibility for air quality in the region. Village administrator Tom Dall says they expect to hear back within a week.
The smoke last week contained toxic dust and chemicals known as particulate matter (PM), which affects more people than any other pollutant, according to The World Health Organization. The major components of PM are sulfate, nitrates, ammonia, sodium chloride, carbon, mineral dust and water. It’s a complex mixture of solid and liquid particles of organic and inorganic substances suspended in the air.
PM10 are particles with an aerodynamic diameter smaller than 10 µm and PM2.5 have an aerodynamic diameter smaller than 2.5 µm. The latter are more dangerous since, when inhaled, they may reach the peripheral regions of the bronchioles, and interfere with gas exchange inside the lungs.
Last week, levels of PM10 and PM2.5 were far above the safe guidelines. The provincial air quality objective for coarse particles, PM10, is 50 micrograms per cubic metre, averaged over 24 hours. The average was three to four times that level in Prince George several days last week. The objective for fine particles, PM2.5, is 25 micrograms per cubic metre, averaged over 24 hours. On Friday, the average was 158 μg/m3 at the Plaza 400 downtown site and 180 μg/m3 at College Heights site.
“Asthmatics or elderly people would find that 50 should be lower,” Fudge says. “The higher the numbers, the worse it is.”
The World Health Organization targets are a maximum of three days a year with up to 150 micrograms of PM10 per cubic metre and 70 micrograms per cubic metre for long-term exposures to PM10.
The WHO reports that by reducing PM10 from 70 to 20 micrograms per cubic metres, air-quality related deaths would drop by about 15 per cent.
On a clear day the number of fine and coarse particles is close to zero.