ST. PAUL -- Minnesotans may like warm weather that has been unusual in this polar vortex winter, but it is adding to an air pollution problem in western and southern Minnesota.
The Minnesota Pollution Control Agency issues an air pollution alert for the western and southern parts of the state, lasting through noon Friday.
"Air quality monitors indicate that fine particle pollution is increasing across the central plain states..." the pollution agency reported. "A strong temperature inversion, snowmelt and morning fog are trapping fine particle pollution near the surface, causing fine particle concentrations to reach a level considered unhealthy for sensitive groups."
The agency reported that the situation will be particularly bad for groups such as people cardiovascular or respiratory disease, the elderly, children and individuals who participate in activities requiring extended or heavy exertion.
