The Minnesota Pollution Control Agency issued an air pollution health advisory for central and southern Minnesota, effective early this morning through the evening.

Air quality monitors indicate slowly-rising fine particle pollution values across the majority of the state of Minnesota.

Overnight Wednesday, a combination of low clouds and fog and light southeasterly to easterly winds were expected to cause fine particle pollution to approach a level considered unhealthy.

The peak was during the morning rush hour and continued into the late afternoon hours.

Much of central and southern Minnesota is impacted.

Conditions were expected to improve by late this afternoon or early evening when increased northwesterly winds begin to disperse pollutants, according to the Minnesota Pollution Control Agency.

An air pollution health advisory is issued when the air quality index approaches but is expected to remain below 101, a level considered unhealthy for sensitive groups. The MPCA issues an air pollution health alert when air quality is expected to reach and remain above that level.

According to the MPCA, populations at risk are those with pre-existing cardiovascular or respiratory disease, the elderly, children and people who participate in activities requiring extended or heavy exertion, both indoors and outdoors.

These people are encouraged to postpone or reduce vigorous activity and minimize exposure to things such as heavy-duty vehicle traffic, wood fires and candles.

The agency warns that even people who are otherwise healthy may experience health effects when pollution levels increase.

Fine particles may exacerbate pre-existing health conditions and may cause individuals to experience chest pain, shortness of breath, wheezing, coughing or fatigue. People are encouraged to contact their physician if they experience these symptoms.

During air quality alerts, residents are particularly encouraged to postpone or reduce vehicle trips and engine idling, the use of gasoline-powered equipment and burning wood.