Arctic wildfires are on the rise — but we still know very little about their health effects

A new study aims to fill in knowledge gaps about how wildfire smoke affects human health.

By Yereth Rosen - October 2, 2019
The setting sun is partially obscured by smoke from an out of control wildfire near Willow, Alaska in 2015. (Stefan Hinman / Matanuska-Susitna Borough)

On the heels of a fiery and smoky summer in Alaska’s forests, effects of wildfire smoke on human health are getting new scrutiny.

A three-year study funded by one of NASA’s Arctic research programs is examining the relationship between smoke from Alaska wildfires and serious impacts on respiratory and cardiovascular health.

The study, led by Tatiana Loboda, a geography professor at the University of Maryland, will examine wildfire-smoke patterns and hospitalization records in Alaska. Just getting launched this year, the study will compare outcomes in years of varying fire severity — 2005, which was a near-record year for Alaska wildfires, 2010, which was a moderate year, and 2006, which was a low-fire year.

While wildfire smoke emits a variety of pollutants that can compromise health, Loboda’s study is focusing on the pollutant considered the biggest hazard: fine particulates.

They are tiny. The diameter of an average human hair is 30 times the size of a particulate that measures 2.5 microns, according to the Environmental Protection Agency. And while bigger particles can be coughed out, the small particulates are more dangerous to those who breathe them in.

“Because they’re so fine, they penetrate the lung membrane and get into the bloodstream. Because of that, they actually have a much larger impact on the cardiovascular system than the respiratory system,” Loboda said.

Other ill effects, like low birth weight and exacerbation of diabetes problems, have been documented, and some research indicates that even very low levels of PM 2.5 exposure pose hazards.

Wildfire smoke is a health hazard everywhere it exists in the world, implicated in hundreds of thousands of deaths annually.

In the Far North, it presents some special challenges. In Alaska and other northern regions, especially in rural areas, residents are out doing necessary seasonal activities like fishing at the same time that smoky wildfires occur, Loboda noted. “The season for fire actually coincides with the season when people spend a lot of time outdoors,” she said. And people in Alaska and similar places that are exposed to smoke might have few options for relief; there is almost no air-conditioning, and those who are out doing food-gathering activities may be distant from any significant indoor shelters of any kind, she said.

There is excellent historic weather and fire information that makes it possible to do detailed reconstructions of past flows of smoke through the air, Loboda said. But information about health outcomes is more difficult to compile, she said, for a variety of reasons.

There are confidentiality rules that limit the availability of patient treatment and outcomes. Even when information is available, hospitals classify patients’ locations by zip codes, which may not match the locations where patients were exposed to smoke, Loboda said. And hospital records, even when available, don’t tell the full story. “If they don’t make it to the hospital, we don’t have access to the records,” she said.

Loboda’s study is one of several being conducted in NASA’s Arctic-Boreal Vulnerability Experiment, or ABoVE.

The examination of smoke impacts on Alaskans’ health is timely. Wildfires may be a natural part of the Alaska forest ecosystem, but climate change has skewed the fire cycle.

Big fire seasons are more frequent and last longer, scientists report. In Alaska, there was a 50 percent increase since 1990 in wildfire seasons with more than 1 million acres burned compared to the 1950-to-1989 period, said a newly released report from the University of Alaska Fairbanks’ International Arctic Research Center. There are dramatically more smoky days, too, the report said. Prior to 2004, Fairbanks had just one summer — 1954 — with more than three weeks of significant smoke, but since 2004, that three-week mark has been hit five times in Fairbanks, the report said.

The 2019 Alaska fire season, in which over 2.5 million acres burned, fits the trend. Of the 15 times in the past 80 years when more than 2 million acres burned in Alaska, six of those years have occurred since 2000, according to the Alaska Division of Forestry. The Alaska fire season has expanded, and state fire managers now mobilize for an April 1 start instead of the May 1 start used in past years. Fires can burn well past what used to be the normal end of the season, too; this year’s 167,164-acre Swan Lake Fire on the Kenai Peninsula south of Anchorage is expected to smolder for weeks and months to come, and final containment is not expected until December, wildfire managers said.

Accordingly, wildfire smoke has emerged as a climate-health risk. A 2018 Alaska state report on climate-change impacts on health counted increased wildfire smoke among the many risks. “As large wildfires increase, more poor air quality events may result, potentially leading to exacerbations of pre-existing respiratory and cardiovascular illnesses,” said the report, issued by the epidemiology section of the Alaska Division of Public Health.

Alaska dominates the U.S. statistics for extreme wildfire smoke. In a list of monitoring sites ranked by hours per year with significant smoke and compiled by UAF climatologist Brian Brettschneider, 12 of the top 20 are in Alaska, and the top four sites are all in interior Alaska in the record fire year of 2004, when more than 6.6 million acres burned. The list, which comes mostly from airports, uses statistics going back to 1980. Smoke from this year’s wildfires put Anchorage’s Elmendorf Air Force Base at 17th on the list, with 423 hours in 2019 with smoke so thick it significantly obscured visibility, according to the analysis by Brettschneider.

For Alaskans, the severity of this year’s fire season and the locations of the major fires produced dangerous levels of smoke in some of the most populous regions.

Anchorage had more smoky days this year — by far — than the city has had in any year on record, Brettschneider said. That led to disruptions in southcentral Alaska and other parts of the state.

Sports events, like school cross-country running meets and citizen races, were canceled. Roads were closed down or, if open, traffic flow reduced and slowed substantially. One fatal air crash, the wreck of a small plane on the Kenai Peninsula, was linked to smoky conditions from the Swan Lake Fire, which also limited visitor use of the Kenai National Wildlife Refuge and parts of the Chugach National Forest. In the North Slope village of Nuiqsut, heavy wildfire smoke drifting in from elsewhere in the north hindered fish-drying in the North Slope village of Nuiqsut, according to a community notice posted on the Local Environmental Observer Network operated by the Alaska Native Tribal Health Consortium.

Some health providers have worked to provide relief.

In Fairbanks, the largest hospital this summer set up a clean-air shelter, an air-conditioned room with 24-hour access. ANTHC’s air-quality program, in partnership with EPA and other organizations, has been conducting education campaigns to address wildfire smoke hazards in remote villages.

The tribal-run clinic in Fort Yukon, an Athabascan community on the Arctic Circle, has an innovative air-cleaning and cooling system to provide relief to villagers struggling with smoke and heat. It is one of the few clinics in Alaska that is equipped with an air-cooling system, an important feature in a far-inland community that has some of Alaska’s hottest summer temperatures, the Alaska Native Tribal Health Consortium said in a 2016 report on the Upper Yukon River region’s climate-change health concerns.

There are similar increases in wildfire and smoke problems elsewhere across the Arctic. Smoke from Siberia, where the wildfire season was extraordinarily fierce this year, reached Alaska, Canada and the Seattle area by the end of July, according to the National Oceanic and Atmospheric Administration. A prolonged fire season in Canada’s Yukon Territory produced smoke that prompted health warnings there and across the border in Alaska. Wildfire smoke in Greenland interfered with a reindeer hunt this summer, the CBC reported.

Wildfire smoke does not stop at national borders, and Loboda said one limitation of her study is its Alaska-only focus. In the future, smoke should get some broader geographic analysis, she said. “The smoke moves so much that at the next step, someone should really look at the impacts of the fires from other areas,” she said.