Alaska’s vast tundra paints the landscape with brush and towering stands of black spruce – a picturesque setting for remote hikes and fishing expeditions. These lush forests and tundra have also provided fuel for devastating wildfire complexes which have fouled air quality from Fairbanks to Anchorage because of lightning strikes starting May 31, 2022.

Even as firefighters extinguished one nearly 251,000 acre fire in southwestern Alaska on Friday, June 25, an even larger complex of fires spanning millions of acres was driven forward by high winds over the same weekend (1)(2). On Monday morning, June 27, Fairbanks’ skies were deluged by wildfire smoke from the complex and from a tundra fire closer to home.

Alaska’s severe wildfires left Fairbanks and residents across the state breathing some of the worst air quality in the country. The air quality index for most of Fairbanks ranged from unhealthy to very unhealthy, with one air quality monitoring station reaching as high as 282 in one Fairbanks neighborhood.

Where are the wildfires in Alaska?

Heavy rains are a welcome site during a drought. But when combined with tinder-like ground cover and thunderstorm lightning strikes as occurred earlier in June, storms can also spark wildfires like the infernos racing across the Alaska tundra.

As of June 27, most of western and central Alaska was experiencing short-term abnormally dry to severe drought (3). Drought conditions created an abundance of dry grass and bushes to feed the fires.

The largest challenge facing firefighters is the Lime Complex, the largest of the Alaska wildfires. A fire complex is two or more individual fires that are burning near one another; firefighters work under a unified command to tackle those blazes. The Lime Complex represents about 20 different fires which have consumed 560,725 acres over 21 million acres.

That acreage is mostly roadless, only accessible by river and air. That’s hampered efforts to control the fires since most were ignited by lightning strikes earlier in June.

A fire closer to Fairbanks is adding to the poor air quality mix. The Clear fire, also caused by a lightning strike on June 21, has burned 9,555 acres and was only 7 percent contained on Monday morning (4). Situated near Anderson, Alaska between Denali National Park and Fairbanks, smoke from the Clear fire and the Lime Complex fires was blown into the heart of the city.

The East Fork fire in southwest Alaska was 100% contained as of June 25. Prior to containment, smoke from the 250,725 acre fire also impacted city air quality.

There were and continue to be numerous smaller wildfires burning across the state. Because of this, Alaska joins New Mexico, Arizona, New Jersey and other U.S. states experiencing early and significant wildfire seasons.

Alaska cities severely polluted by smoke

Heavy smoke resulted in air quality monitors measuring concentrations of unhealthy to very unhealthy air quality in central Alaska.

Five Alaska cities were among the top ten most polluted American cities on June 27, including Fairbanks and its neighboring communities Ester, College, Farmers Loop, and North Pole.

Pictured: Live air quality index city rankings for the United States showed five Alaska cities among the top six most polluted cities in the country on the morning of June 27.

Pictured: Air quality monitors in Fairbanks, Alaska measure unhealthy (red) and very unhealthy (purple) air quality.

Though air quality in Anchorage has sometimes been poor since the fires began June, it was good on June 27 thanks to prevailing winds.

PM2.5: Wildfire smoke’s main danger

The most abundant pollutant present in wildfire smoke is particulate matter, with the PM2.5 constituent representing about 90% of the total particulate mass present. PM2.5 (insert definition here) and is the wildfire smoke pollutant that presents the greatest health risk.

When inhaled into the lungs, PM2.5 is so small that it can enter the bloodstream and impact all bodily organs. PM2.5 exposure has been linked to heart failure, bronchitis, lung and heart disease, worsened asthma, and premature death.

To better understand the danger of PM2.5 exposure, compare the World Health Organization’s (WHO) recommended guideline for annual PM2.5 exposure to the air quality measured in Fairbanks.

WHO’s annual recommended guideline is 5 micrograms per cubic meter of air (µg/m3) or less. Fairbank’s PM2.5 on June 27 was 177 µg/m3 – 35 times the WHO guideline.

Fairbanks’ average annual PM2.5 concentration for 2021 was 5 µg/m3. In June 2021, the city’s average PM2.5 concentration was only 4 µg/m3.

The takeaway

Hotter days make for a drier planet and much more fuel for wildfires. While Fairbanks is hundreds of miles from the Lime Complex fires, wind can carry smoke over oceans and continents into any home. Even remote wildfire smoke in Alaska can be anyone's health concern..

The best protection against wildfire smoke is to have a plan of action for poor air quality days.

• Try to stay indoors when air quality is very poor.
• Shut windows and doors to keep smoke out of buildings.
• Know your community’s air quality by installing a low-cost outdoor air quality monitor and downloading an air quality app.
• Run an air purifier with proven filtration.