Calls and visits to Minnesota medical clinics increased midweek as people inhaling historically bad air could no longer tolerate it.
"You breathe the stuff in yesterday, and today stuff is flaring," said Dr. Andrew Stiehm, a pulmonologist with Allina Health in St. Paul.
Air quality levels in the Twin Cities nudged into the "very unhealthy" range at one point on Wednesday as smoke from Canadian wildfires blew south.
Nick Witcraft, an air quality meteorologist with the MPCA, said Wednesday's smoke was the worst on record for the Twin Cities. At 6 p.m. Wednesday, St. Paul had the worst air quality in the United States, with a score of 256, according to AirNow.gov, the official U.S. air-quality index site. The air had cleared markedly by mid-day Thursday, with continued air quality alerts for southwestern Minnesota.
Clinicians expected a delayed effect as the dirty air took its toll on patients with asthma, COPD and other breathing-related conditions.
Hospital emergency rooms didn't see a dramatic increase, though more than 30 patients came to Allina's two Mercy hospital campuses in Coon Rapids and Fridley with breathing-related problems Wednesday.
Hennepin Health spokeswoman Christine Hill said she was "wheezing like crazy" but so far the downtown Minneapolis ER hadn't encountered a substantial increase in patients with conditions related to the air quality.
Organizations across Minnesota may have helped by taking the rare step of cancelling outdoor events in response to the air quality warnings. Youth soccer fields across the Twin Cities were deserted as teams and leagues cancelled practices and games.