Smoke lingering over much of British Columbia from Siberian wildfires has pushed ozone levels in parts of the province to never-before-seen numbers.
By Monday, ozone levels reached 84 parts per billion in the central Interior region, about three times the average for July. B.C.
Ministry of Environment air-quality meteorologist Eric Taylor said that on Sunday and Monday, levels were above 82 parts per billion, causing concerns because of potential health effects for people with respiratory problems, for example. He said that in the past seven years, levels have only exceeded 82 parts per billion for a total of three hours.
"It appears that in this smoke there must have been a lot of other pollutants — natural pollutants — that come from forest fires, so much that it has generated ozone to a much higher extent than normal," Taylor said. "I have never seen ozone levels at the ground in the central Interior as high as I've seen them in the last couple of days."
He said levels in the area had dropped by Tuesday and were sitting at about 62 parts per billion. But, relief is literally on the horizon as a cold front has helped clear out the haze in the central Interior and normal air turbulence is expected to force out much of the remaining smoke, Taylor said.
The situation in Vancouver is a bit different according to Ken Reid of the regional district of Metro Vancouver. Reid said it's a little harder to tell when Vancouver's skies will begin to clear up and pointed out the haze isn't only from international fires.
"There's certainly some particulate matter which is due to all of our local activity here," he said, in reference to exhaust levels from vehicles. "But on top of that we have the smoke coming across the Pacific."
B.C.'s government-run Air Quality Health Index showed Vancouver was rated at about three out of 10 on Tuesday, meaning there are no health risks.
Reid said though visibility is compromised, the air isn't as bad as it looks.
"You can have very few particulate matter in the air and still get a very dramatic visibility reduction," he said. "So, we're seeing particulate matter concentrations that are maybe only five micrograms per cubic metre higher than normal, it's even less than double, so it's not a dramatic increase but certainly the haze is dramatic."
The thick smoke from the Siberian fires is travelling south over the Pacific Ocean before making an upswing to approach B.C. from the southwest.
The infernos have consumed thousands of hectares in southern Siberia as hundreds of firefighters battle the flames. Last month, eight firefighters were killed parachuting into the affected area after the wind shifted and carried them off course.
Taylor said ozone is one of the largest parts of the air quality health index and those with pre-existing conditions should consult the index before taking part in strenuous activities.
But the opaque air hasn't been a total disappointment. Taylor said the microscopic particles in the haze have a red and brown hue, which help create stunning sunsets.