As wildfire smoke blankets Metro Vancouver, Health Canada’s Air Quality Health Index (AQHI) has reached a 10+ rating as a warning of very high health risks and major concentrations of fine particulate matter in the air.
The 10+ rating has led health officials to recommend limiting strenuous outdoor activities, particularly for seniors or children, or if the individual exhibits symptoms of coughing or throat irritation.
A provincial state of emergency was issued on August 15, when there were 566 wildfires burning in British Columbia, with 29 evacuation orders affecting approximately 3,050 people. The state of emergency stays in effect for 14 days unless extended or rescinded.
“Public safety is always our first priority and, as wildfire activity is expected to increase, this is a progressive step in our wildfire response to make sure British Columbia has access to any and all resources necessary,” announced Mike Farnworth, Minister of Public Safety and Solicitor General. “Taking this step will further ensure we can protect the public, property and infrastructure, and assist with firefighting efforts,” he added.
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The AQHI takes live data from fine particulate matter, ground-level ozone and nitrogen dioxide, then calculates those levels through its reporting software program. According to the B.C. Centre for Disease Control, gases in wildfire smoke include carbon monoxide, nitrogen oxides and volatile organic compounds. Some of the compounds in wildfire smoke are known to be carcinogenic, such as polycyclic aromatic hydrocarbons (PAHs), benzene and free radicals.
Officials suggest that the AQHI is capped at a 10+ rating because it becomes more difficult to quantify additional increases to health risks beyond a certain point. While the index has reported numbers well beyond the 10 level in previous years, the program has since been modified to report that risks beyond 10, described as 10+, represent not only an unquantifiable risk, but also the limitations of the health advice that can be offered to those at risk.
Critics of the AQHI suggest that its real limitations are proven by the fact that it can only measure short-term risks, whereas long-term exposure has the more significant influence on human health.
Air emissions engineers in other provinces have reported plumes of B.C. smoke reaching across Canada, and even over the Atlantic Ocean into Ireland. The travelling plumes have led to special air quality statements from Environment Canada to be issued across the Maritimes.
“A plume of smoke from fires in Western Canada is moving at high altitude across the Maritimes, causing hazy skies and a reddish sun,” said a statement issued by Environment Canada last week.
Even the Canadian Mental Health Association has begun to weigh in on the B.C. wildfires. Association officials have warned of new anxiety over increased risks of climate change and potential social isolation from remaining indoors to avoid the effects of smoke.
B.C. has experienced four of the worst fire seasons on record in the past decade.