Air quality advisory remains in place
An air quality advisory for the city will continue into at least a third day.
Gail Roth, an air quality meteorologist with B.C.’s Ministry of Environment, had hoped to see the advisory lifted by sometime Thursday, but a weather pattern that has been trapping particulate matter failed to budge.
The advisory will remain in place until at least Friday morning.
“I was hoping to start seeing the improvement tomorrow,” Roth said. “I was hoping to actually see it start this afternoon but obviously that’s not happening yet.”
The advisory was put into effect Wednesday morning after concentrations of fine particulate matter exceeded the threshold of 25 micrograms per cubic metre. It had actually dropped slightly below that level by Thursday morning but it was decided to err on the side of caution and to keep the advisory in place.
As it turned out, Roth said concentrations subsequently rose back above the threshold.
She attributed the situation to a highpressure system settling over the area and trapping pollutants that otherwise would disperse into the air.
There is no more particulate being emitted than usual, Roth emphasized. But she also noted that under the city’s clean air bylaw people shouldn’t be burning wood if they have other ways to keep warm.
Added to the woe, a mixture of snow and ice pellets was in the Environment Canada forecast for Thursday night and for Friday.
Environment Canada meteorologist Lisa West said the ice pellets are a result of a lowpressure system bringing in warm and wet air from the ocean but rather than displacing the high-pressure pattern and the cold that’s come with it, it will ride over top.
“What you get is this above-freezing level well above the earth’s surface and as precipi- tation falls, it first starts out as snow and then it descends into that warm air and melts and turns into rain droplets,” West said.
“And then depending on the depth of the below-freezing level beneath that, and how cold it is as well, determines whether that rain freezes back into ice pellets or freezing rain.”
While conditions should improve somewhat over the weekend, West is not as optimistic as Roth.
“The poor air quality could continue right through until at least early next week before we finally see the advisory lifted,” she said.
People with chronic underlying health issues should remain cautious and avoid strenuous exercise for the time being.
“Staying indoors and in air conditioned spaces helps to reduce fine particulate exposure,” officials said in the advisory. “Exposure is particularly a concern for infants, the elderly and those who have diabetes, and lung or heart disease.”