Vernon, B.C. is once again under a dust advisory due to a high concentration of particulate matter in the air.
The advisory was issued Monday morning, by provincial health and environment officials after the concentration of dust in the air over the last 24 hours was noted to be 73 micrograms per cubic metre, well above the provincial air quality objective of 50 micrograms per cubic metre.
“The current dusty conditions are caused by road traffic stirring up winter traction materials that have accumulated on roadways over the past winter,” a provincial statement on the dust advisory said.
These types of dust advisories have become an annual problem in Vernon after the yearly spring melt until winter traction material can be cleared away.
In the last couple of years, the city says it has taken several steps to try and address the issue including adding new sweeping equipment, sweeping more in the winter months, improving training about how much sand to apply, and changing the type of traction material it uses.
Read more: Dust stirred up in Vernon, prompts advisory
However, city staff told council last month it is not possible to eliminate all dust in the spring.
“Road grit is pulverized into smaller particles on heavily used roadways; dirt and debris is deposited onto roads and parking areas from the under carriages of vehicles; and periods of dry spring weather result in airborne particulate that can be trapped in our valley due to our surrounding topography and localized weather inversions,” the February city staff report said.
City staff also believes that the poor air quality readings may, in part, be due to where the measurements are being taken.
The province’s air quality monitoring station is on the Okanagan Science Centre near both Highway 6 and Highway 97.
The city says the province has now installed another temporary monitor at Vernon’s airport which should show how conditions vary around the community.
During Vernon’s current dust advisory, officials are advising people with chronic conditions to put off or reduce strenuous exercise.
On Monday afternoon, the air quality health index for the North Okanagan showed a low health risk in the area, but the health risk was scheduled to rise to moderate overnight.