How Alberta wildfires are causing poor air quality in the Midwest

CNN
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Residents of the central United States experienced poor air quality and smoke over the weekend. The potentially dangerous air has a distant source: Canada’s raging wildfires.

The fires have ravaged western Canada, with more than 10,500 people evacuated from communities in Alberta.

The effects of the fires extend far beyond Canada, with poor air quality appearing in states as far apart as Missouri and New York. Here’s what you need to know about how the smoke may continue to affect parts of the United States.

While all fires produce smoke, the bigger the fire, the more smoke it can produce. As this spring’s Canadian wildfires burn bigger and hotter, the heat from the fire is causing smoke to travel further into the atmosphere, where it is picked up by winds and weather.

The higher the smoke rises in the atmosphere, the further the smoke can spread. Winds in the upper layers of the atmosphere can spread smoke hundreds or even thousands of miles away, which can lead to hazy skies and poor air quality in towns far from where fires occur.

Wildfire smoke was measured to rise up to 1 to 2 miles above the surface during the 2018 California Campfire, according to NASA. As the smoke moves away from its heat source, the air eventually cools and the smoke can sink, keeping it in the troposphere, the layer of the atmosphere closest to the surface of the earth. Earth.

The troposphere is where the daily weather patterns that we generally experience occur. High and low pressure systems can cause all kinds of weather, from strong winds and thunderstorms, to hail and snow. The troposphere can extend anywhere from 4 to 12 miles above the Earth’s surface, according to the National Weather Service.

Several states, including Nebraska, Washington, Montana and Wisconsin, announced air quality alerts early Friday. The National Weather Service in Omaha tweeted the smoke would continue to create red colored sunsets and sunrises. Service in Tacoma reported the smoke would be “pushed east in time for the weekend”.

On Sunday afternoon, the U.S. Environmental Protection Agency’s Air Quality Index reported “unhealthy” air quality levels in parts of Montana and North Dakota and from South.

Sunday morning, the National Weather Service office in Grand Forks, North Dakota confirmed the “high level smoke” would continue throughout the day.

Similarly, the weather service in Sioux Falls, South Dakota, reported “thick smoke well above the surface layer” would move through the area on Sunday. Poor air quality caused by smoke would primarily affect those “who are particularly sensitive to particulate pollution”, they said.

Smoke from wildfires can affect the health of people living far from where the fires started. A 2021 study by epidemiologists at Colorado State University found that long-term exposure to wildfire smoke results in about 6,300 additional deaths each year, with the highest numbers seen in the most heavily populated states. populated.

Wildfire smoke carries fine particulate matter, or PM 2.5, a tiny but dangerous pollutant, as CNN has previously reported.

When inhaled, the particles penetrate deep into lung tissue, where they can enter the bloodstream. PM 2.5, which comes from sources such as smoke, fossil fuel power plants and cars, is linked to a number of health complications, including asthma, heart disease, chronic bronchitis and other respiratory diseases.