According to Montana Public Radio, hospital emergency department visits have surged this year as a result of respiratory conditions related to wildfire smoke since last summer.

This summer, Missoula County (Montana) had its worst wildfire smoke season on record. It’s unclear how exactly that impacted the health of county residents, both as the fires were burning and longer term, but researchers are starting to pull in some data.

Rachel Hinnenkamp is an epidemiologist with the state health department. She’s been tracking how many people went to emergency rooms complaining of respiratory-related symptoms during the 2017 wildfire season. And she found that this year, that number more than doubled for people who live in Missoula and Powell counties, compared to last year.

“The number of visits in 2016 was 163 and that increased to 378. That’s a statistically significant increase,” Hinnenkamp says.