Residents of eastern Canada and the United States shared unhealthy air quality as hundreds of northern wildfires burn. On June 7, unhealthy to hazardous air advisories were issued for the capital cities of Ottawa, Ontario, and Washington, D.C., and for populations along the smoke paths.
The Fire and Smoke Map from AirNow offers an interactive map-based tool with local precautions. For Ottawa on June 7, AirNow sensors identified a hazardous air quality index (AQI) in the 400s for PM 2.5 (particulate matter that is 2.5 micrometers or smaller; the average human hair is 30 times larger than the largest of PM 2.5 particulates). Due to the hazard of such a PM 2.5 loading, an advisory was issued to avoid all outdoor physical activity.
In Washington, the AQI was unhealthy on June 7, with advisories to keep outdoor activities short and light, and to go indoors if you have symptoms. Sensitive groups should consider moving all activities indoors.
By the evening of June 8, the plume of unhealthiest air had shifted predominantly to the Northeast coast. In New York City, producers cited the effects of smoke when cancelling two Broadway shows and a Shakespeare in the Park performance. On June 6, New York City Mayor Eric Adams cancelled outdoor school activities. “We are taking precautions out of an abundance of caution to protect New Yorkers’ health until we are able to get a better sense of future air quality reports,” he said. “We recommend all New Yorkers limit outdoor activity to the greatest extent possible. Those with preexisting respiratory problems, like heart or breathing problems, as well as children and older adults may be especially sensitive and should stay indoors at this time.”
To track smoke risk, the IQAir Earth Map and the associated World AQI Ranking offer another set of monitoring tools, based on their IQAir network. As of June 7, their World AQI Ranking listed New York City as #2 and Detroit, Michigan as #5 as global cities with the worst air, with Toronto as #15. By the evening of June 8, New York City had dropped to #6, Toronto to #10, and Detroit to #24.
in an article for The Conversation, Christopher T. Migliaccio, a research associate professor in toxicology at the University of Montana, wrote on smoke toxicity and precautions to consider when exposed to smoke:
If there is smoke in the air, you want to decrease your exposure.
Can you completely avoid the smoke? Not unless you’re in a hermetically sealed home. The PM levels aren’t much different indoors and out unless you have a really good HVAC system, such as those with MERV 15 or better filters. But going inside decreases your activity, so your breathing rate is slower and the amount of smoke you’re inhaling is likely lower.
We also tend to advise people that if you’re in a susceptible group, such as those with asthma, create a safe space at home and in the office with a high-level stand-alone air filtration system to create a space with cleaner air.
Some masks can help. It doesn’t hurt to have a high-quality N95 mask. Just wearing a cloth mask won’t do much, though.
The BlueSky Canada smoke forecast for June 8 through June 10 offers a specific two-day outlook that doesn’t promise an end to smoke, but indicates that the thickest production may alternate with lighter periods of smoke. By June 10, something like clear skies may appear over Detroit, and the thickest fingers of smoke, from the Quebec fires through Ottawa to New York City, will become more intermittent. A look at the timing of the heaviest smoke may help to plan outside activities during the hours of clearer air.
The BlueSky Canada forecast also shows continued fire and smoke in western Canada and Alberta.