Health officials dispute air quality report ranking Missoula among most polluted cities

Environmental officials in Missoula County are disputing a widely circulated report listing Missoula as one of the most polluted small metropolitan cities in the country when it comes to air quality.

Distributed by an auto insurance group as a tool to draw in customers, and citing EPA data, the report ranked Missoula as having the 12th worst air quality in the nation, just behind Decatur, Illinois, and San Luis Obispo, California.

While the city recorded 198 days with good air quality in 2018, according to the report, it recorded 166 days with moderate or unhealthy air for sensitive groups, and one day with hazardous air quality.

The problem is, the data isn't exclusive to Missoula. Rather, it draws from three air monitoring stations across the county, including Frenchtown and Seeley Lake.

“I had to go find source data and dig it out and make sure it lined out and made sense,” said Sarah Coefield with the Air Quality Program at the City-County Health Department. “Most of the days got lumped into the Missoula category are reflective of the air quality in Seeley Lake.”

Coefield said the data used to generate the values giving Missoula its lackluster standing isn't reflective of the city's actual air quality. Most of the days listed in the report as having moderate or hazardous air actually occurred in Seeley Lake.

The small mountain town northeast of Missoula has long struggled with air quality, Coefield said.

“2018 was actually a pretty good year in Seeley Lake, but they still do have significantly worse air quality than the city of Missoula, because they have such a density of wood stoves,” she said. “The majority of the days with moderate air quality the report identified were from Seeley Lake.”

While Missoula had a handful of days with moderate air quality, Seeley Lake had more, and it recorded the one day in 2018 when air quality was listed as hazardous. That occurred in August and was due to smoke from nearby wildfires.

“It's an area that really does struggle with air quality, though it's better than it used to be,” said Coefield. “We went in there and did a big wood stove change out in 2012 through 2014 to get cleaner devices, but it still does have degraded air quality compared to Missoula, and it's an area we're continuing to focus on.”

As health officials continue to focus on Seeley Lake, they're also looking to Missoula. The city's air quality has improved drastically from a few decades back, though Coefield said work remains.

“We've been holding pretty steady for the last six or seven years where I don't think Missoula's air quality has changed a whole lot,” she said. “Our winter air quality is where we need to come up with strategies for improvement.”

The summer of 2017 is still fresh in the memory of those who endured several weeks of throat burning, eye watering air. That summer, one of the worst recent seasons for wildfires, left much of western Montana stuck in a thick, smoky haze.

Coefield and other health and environmental experts believe such summers could become commonplace as climate change advances, leading to longer and more intense wildfires.

On top of it, the American Lung Association in its own data uses three-year averages, so 2017 is still in play when it comes to ranking Missoula's air quality.

“It's reflective of what people are exposed to when they come to Missoula,” Coefield said. “In the western part of the U.S. these days, wildfire smoke is a factor for air quality. Our Missoula air quality is doing OK, and it's certainly better than what that report suggested, but it's also something we can't rest on our laurels for.”

Other factors could become a greater contributor to degraded air quality in Missoula as the local population grows. According to one recent study prepared for the city, Missoula can expect to attract 12,600 new residents each decade.

As more people move in, auto emissions could play a bigger factor in the city's quality of air.

“The most recent study that looked at our primary sources of particulate matter still showed wood stoves and fireplaces as a bigger chunk than vehicles, but vehicle exhaust does contribute to worsening air quality,” said Coefield. “As we continue to see population growth, it's going to become more of a factor.”