What caused the worst air quality in the world? Questions and answers about the recent haze

It's been over a week since smoke from Canadian wildfires blanketed the area with some of the worst air quality in the world.

Here are answers to some lasting questions about the hazy event, like how much of it was due to climate change, why the wildfires have been burning for so long and why poor air quality is dangerous.

Q: Is this climate change?

A: Though it is difficult to determine whether specific events like the current wildfires are a direct result of climate change, experts say the unprecedented impact of the blazes is in line with the science - which says extreme weather events are likely to occur more frequently as the planet warms.

Most recently, Environment Canada meteorologist Steven Flisfeder predicted that Canadian wildfires will be "more probable" in the future due to higher than normal temperatures and the drying nature of climate change.

"The likelihood of forest fires becoming a bigger concern in coming decades is something that is consistent with climate change," Flisfeder told Canadian media outlet Global News last week.

Since 1959, Canada has experienced a significant rise in the number of large fires and area burned, according to a 2018 study published in the Canadian Journal of Forest Research. The study reported that the country's fire season is starting approximately one week earlier and ending one week later than in the past.

"Over the past decade or so, we've seen a lot more years where we're getting above-average area burned," said Richard Carr, a fire research analyst with the Canadian Forest Service. "This year is an outlier, but still we're seeing more and more of those years with really a considerable area burned so I think climate warming is definitely playing a part."

A 2021 report from scientists at the Intergovernmental Panel on Climate Change further found that fire weather - dry, hot, windy conditions - has become more probable in many parts of the world and likely will become more common across the globe if warming worsens.

Q: Why have the fires been burning for so long?

A: While wildfires are common in Canada and are often part of a forest's natural cycle of regrowth, this year's fires have been fueled by unusually hot and dry weather.

"Some of these big, intense fires, you get a certain intensity and there's nothing manmade that can really stop them," Carr said.

The country experienced a drought late last summer that intensified through the fall and winter. Since then, the drought has spread to nearly every province or territory and has played a huge part in fueling the fires.

The country has been at what's called "national preparedness level 5" since early May, meaning it has committed all national resources to fight the fires. International firefighters are also flying in, including more than 600 from the U.S.

Carr said while it's not unusual for Canada to reach Level 5, the status typically lasts for shorter periods and doesn't start until mid to late summer. Canada also has had to expand its sourcing of international firefighters to more countries.

"We've pretty much exhausted the supply from the countries that we have the agreements with," Carr said. "We have agreements with the United States, Mexico, Australia, New Zealand, Costa Rica and South Africa. Those would be our usual sources of international firefighters. This year we've also brought in people from France, Spain, Portugal, European Union and even South Korea. We've got people from every continent on Earth except Antarctica."

How long will the fires last?

Projections show a continued potential for higher-than-normal fire activity across the majority of the country for the rest of the fire season, according to the most recent update from the Canadian government, released Thursday.

"This is due to long-range forecasts for warm temperatures and ongoing drought, which are affecting parts of all provinces and territories and intensifying in some regions," according to the update. "For July, warm and dry conditions will increase wildfire risk from British Columbia and Yukon through to western Labrador. During August, the area at risk will stretch from British Columbia through western Quebec."

Q: Why doesn't the smoke from wildfires in western states like California ever make it to Chicago?

A: Smoke from those fires does reach us, but it's higher in the atmosphere and has less of a noticeable effect. While the smoke typically creates a red, hazy sunset, the particulates don't reach the ground or affect our air quality.

The wildfire smoke from the much closer areas of Ontario and Quebec reached Chicago by riding on an unusual atmospheric flow pattern.

"It is rare that we get extended periods of northeasterly flow - the northeast to southwest flow - in the summertime," state climatologist Trent Ford said. "The main reason why we haven't seen wildfire smoke like this before with air quality is because that part of Canada doesn't burn nearly as often and we don't get this kind of flow in the summertime when those fires are burning very often. We've gotten both."

Q: What's in the air and why is it dangerous?

A: The particulate matter in wildfire smoke contains particles so small that they can bypass a lot of the filters in the human body, reaching the lungs and even the bloodstream.

Urban areas like Chicago have an existing issue with air pollution due to ozone pollution, often referred to as smog, said Brian Urbaszewski, environmental health director for the Respiratory Health Association in Chicago.

"When you have forest fires, not only are you getting the smoke particles, but you're getting all the other organic fuels that are just like the ingredients from industrial air pollution that will also cook in the sky and make ozone," Urbaszewski said. "The forest fires are accelerating the existing urban metropolitan area air pollution homegrown problem we already have."

Ozone occurs when sunlight reacts with organic chemicals or nitrogen oxides in the air. The process thrives in high temperatures, making ozone pollution a greater concern in the summer.

As climate change worsens, the likelihood of increasingly low air quality persists, Urbaszewski added.

Q: Do masks help? What else can I do to protect myself against poor air quality?

A: Masks like KN95 masks are the best at filtering out particulate matter. Cloth or surgical masks won't be as effective as they don't provide a tight fit.

When air quality is low, the best strategy is simply "to avoid it as best you can," Urbaszewski said. Older adults, people with heart or lung disease, pregnant women, children and teenagers especially should strenuous activities, keep outdoor activities short and consider moving physical activities indoors or rescheduling them.

You can further ensure better indoor air quality by upgrading your air filters and installing home HEPA filter, which can remove over 99% of small, airborne particles.

When driving, turning on the recirculation mode in your car and checking that your air filter is up to date also are a good idea, ​​Jonny Straczek, owner of CBA Barrington said.

Q: How can I check the air quality in my community?

A: Current air quality can be found at airnow.gov. Information on how to subscribe to regular email or text updates when the quality dips below a certain level can be found at enviroflash.info.

Both websites are run by the U.S. Environmental Protection Agency.

• Jenny Whidden is a climate change and environment writer working with the Daily Herald through a partnership with Report For America supported by The Nature Conservancy. To help support her work with a tax-deductible donation, see dailyherald.com/rfa.