Air pollution alert issued for Twin Cities, Rochester

  • Article by: PAUL Walsh
  • Star Tribune
  • February 26, 2013 - 9:45 AM

An air pollution health alert was issued Tuesday for the Twin Cities area and Rochester, prompted in part by moisture in the air from melting snow.

The Minnesota Pollution Control Agency (MPCA) said its alert was prompted by “fine particle pollution” reaching unhealthy levels overnight for specific sensitive groups.

“As weather conditions become stagnant, as they have over the last few days, fine particle pollution will build up in the area,” said Cassie McMahon, an MPCA air quality research analyst. “The presence of snow melt adds extra humidity and fog, which act like a sponge to further trap the pollutants.”

McMahon also pointed to warmer weather of late, creating “more frequent early morning temperature inversions, which further trap pollutants near the surface.”

The agency’s alert said that “fine particle concentrations are expected to remain elevated through Tuesday morning. As wind speeds increase this afternoon, air quality conditions are expected to improve.”

Those groups most likely to be affected, the MPCA said, are those with cardiovascular or respiratory disease, the elderly, children and people whose activities require “extended or heavy exertion, both indoors and outdoors.”

The agency said these people should ease up or put off altogether their vigorous activity to minimize their exposure to the less-than-healthy air. Risks include chest pain, shortness of breath, wheezing, coughing or fatigue.

The alert will remain in effect throughout Tuesday. For the latest on air quality conditions in the state, visit


Paul Walsh • 612-673-4482

© 2018 Star Tribune