An air quality advisory is in effect for the Comox Valley due to high concentrations of fine particulate matter and officials are warning those with chronic underlying medical conditions to stay indoors.
On Dec. 2, the Ministry of Environment and Climate Change Strategy in collaboration with Island Health issued the advisory which will remain in place until weather conditions change.
As of Dec. 1 at 2 p.m., the PM2.5 (fine particulate matter of airborne solid or liquid droplets with diameters of 2.5 mircometres or less) was 28.7 in Courtenay.
According to the ministry, PM2.5 can easily penetrate indoors because of its small size. Sources of PM2.5 contributing to the air quality include wood smoke (wood stoves and open burning) as well as emissions from commercial and transportation sources such as vehicles and marine traffic.
Earle Plain, air quality meteorologist with the ministry said air quality advisories are not unique to the Comox Valley (they also happen frequently in Port Alberni and the Cowichan Valley), but the topography of the area shows multiple low points where air can settle in the area.
“With the lower sun angle (this time of the year), things cool off quickly at the surface and you end up with colder air lower down. Add in the sources (of particulate matter) and this triggers the problem.”
Meanwhile, an air quality advisory in Port Alberni has been lifted, barely 24 hours after it was first issued.
The advisory was issued for Port Alberni on Sunday, Dec. 1 because of “high concentrations of fine particulates,” according to the Ministry of Environment and Climate Change Strategy in collaboration with Island Health.
Fine particulate concentrations averaged over 24 hours were 27 micrograms per cubic metre as of 10 a.m. on Sunday, which exceeds the provincial air quality objective of 25 micrograms per cubic metre.
The air quality advisory ended on Monday, Dec. 2, but more advisories can be expected in the coming months as the cold winter weather sets in.
“There’s a real correlation between when air quality advisories occur and the time of year,” explained Anna Lewis, chair of the Air Quality Council.
In the summertime, advisories are often the result of wildfire smoke. But as the weather gets colder, thermal inversions trap harmful smoke particulate in the Valley and woodstove use adds to the amount of smoke entering the atmosphere.
“We can definitely expect more [advisories] this winter,” Lewis added.
The ministry noted exposure is particularly a concern for pregnant women and infants, the elderly and those who have diabetes and lung or heart disease.
For those with medical conditions, it is recommended residents with asthma or other illnesses should activate their asthma or personal care plan, stay indoors, keep windows and doors closed and reduce indoor sources of pollution such as smoking, vacuuming and use of wood stoves.
Plain explained because the last couple of weeks have been unusually cold, cold dense air drags with it any particulates from higher elevations over residential areas of the Comox Valley to the ocean from west to east.
To reduce health risks, the ministry and Island Health suggest avoiding roads with heavy vehicle traffic and areas with wood smoke; use common sense regarding outdoor physical activity and continue to manage medical conditions.
Elevated PM2.5 concentrations build up in the Valley under calm wind conditions. Fine particulate concentrations are expected to be higher during the evening, overnight and early morning hours and should improve during the mid-afternoon hours.
The air monitoring station in the Comox Valley is located at Courtenay Elementary School. For real-time air quality observations, visit https://bit.ly/2LhqfAr
— with a file from Elena Rardon