The Minnesota Pollution Control Agency has issued an air pollution alert for most of Minnesota. The alert will be in effect starting today until Friday, local media sources reported.

The alert came after the agency discovered elevated levels of fine airborne particles. The worst quality of air is expected in places like Rochester and the Twin Cities, the agency said.

The alert also includes Brainerd, Duluth and St. Cloud, but the pollution won’t be as severe in these places.

Northern and northwestern Minnesota were forecast to have fair air quality.

The particulates are the result of fossil fuel combustion from electricity generation, transportation and wood smoke, the Minnesota Pollution Control Agency reported. Stagnant air is helping to trap fine particles, so the quality index hit 103 this morning in Rochester and 92 in the Twin Cities, where it might climb to near 100 today.

The polluted air may be unhealthy for people suffering from respiratory and heart problems. Elderly, children and physically active adults are endangered as well. In addition, they should consider reducing or postponing heavy exertion during the advisory.

To contribute at reducing air pollution, the Minnesota Pollution Control Agency encourages people to drive less, reduce electricity use, avoid use of small engines and postpone outdoor fires.

People can find more information on http://aqi.pca.state.mn.u