If you thought this past summer was a bit hazier than usual, you’d be right.
The summer of 2017 saw an unprecedented number of air quality advisories.
“It was a summer where we actually issued five separate air quality advisories and they were in place for 19 days,” said Roger Quan, director of air quality and climate change for Metro Vancouver. “It’s actually the most air quality advisory days that we’ve ever had in a single year.”
The next highest was 2015, which saw 10 days of air advisories.
“In both cases the main reason for the advisory was smoke from wildfires that were burning outside the Metro Vancouver region but with the smoke being transported into our region because of certain weather conditions that tended to bring smoke towards us,” Quan said.
The fires that burned across the province this spring and summer were also a big story over the past year. Environment Canada called it “the longest and most destructive fire season in the province’s history,” and named it number one on its top 10 weather stories for 2017.
“The occurrence of wildfires increased by 66 per cent, and they consumed four times the usual area.”
The smoke brings with it fine particulate matter, airborne solid or liquid droplets with a diameter of 2.5 micrometres or less. Inhaling fine particles of smoke has been known to aggravate pre-existing respiratory and cardiovascular conditions.
Quan said Metro Vancouver has a benchmark of 25 micrograms per cubic metre of fine particles, based on a 24-hour rolling average. If the amount of fine particulate matter in the air exceeds that number, an air quality advisory is issued.
“We have air quality standards and objectives which essentially are benchmarks of what constitutes acceptable air quality in the region and if we are able to predict that those air quality levels are going to exceed those benchmarks that is when we’d be calling in an advisory,” Quan said.
“For example, with the advisory issued for Aug. 1, which lasted 12 days, we had models that were able to predict that we were going to see this influx of smoke from fires in the B.C. interior as well as Harrison Lake and those models were telling us that we were certainly going to exceed that 25mg per cubic meter,” Quan said. “In that case the models helped us to pre-emptively issue an advisory; we actually called the advisory on July 31 to be effective Aug. 1. That actually shows the importance of having models that can predict with some accuracy what we can expect in the next day or two.”
Metro Vancouver’s advisory service is comprised of a network of 29 air quality monitoring stations that are located across the region from Horseshoe Bay to Hope. Those stations are keeping tabs on the area’s air quality 24 hours a day, seven days a week.
Data from the stations is available to then public in real time at airmap.ca.
Metro Vancouver has been managing the region’s air quality since the 1970s, Quan said, and since then things have changed.
In the 1980s and ’90s, most of the air quality advisories were due to ground level ozone, which is created when contaminates in the air, such as volatile organic compounds (emitted from solvents) and nitrogen oxides (pollutants emitted when fuels are burned), react with sunlight. Higher levels of ground level ozone are typically seen in the mid-afternoon and early evening in the summer and leads to smoggy conditions.
“Our programs have really led to improvements there,” Quan said. “We haven’t had the kinds of advisories for ground level ozone that we had perhaps a couple of decades ago but we have seen this shift to fine particulate advisories due to wildfires from outside of the region.”
Summers like 2017 and 2015 used to be thought of as anomalies.
“It hasn’t been uncommon in the last decade for us to have summers… where there have been zero advisory days and that’s obviously what we aspire to,” Quan said.
“Two of the last three summers we’ve been significantly impacted by wildfire smoke and we’re concerned that this is the new normal and I think that’s a phrase that a lot of people are using right now,” he said. “If this is the new normal we have to be ready to respond to it.”
Quan said Metro Vancouver is already in discussions with a number of other agencies — Environment Canada, the B.C. Ministry of Environment, Vancouver Coastal Health Authority, Fraser Health Authority — in an effort to prepare for the summer of 2018.
“And we don’t know what 2018 is going to bring but if it is another summer like 2017 we want to be sure we’re dealing with the situation a little bit better, not that we’ve done poorly with it but we want to get the message out for better preparation in terms of information to the public,” he said.
The region is looking at how to better get out information to the public about air quality levels, managing exposure to low air quality, as well as looking at better preventing human-caused wildfires.
“We generally do have very good air quality in Metro Vancouver… but we have run into the situation where this year was an unprecedented year of not being compliant with those objectives and standards so we’re definitely making sure that our programs respond to this new challenge,” Quan said.