Update: This has been upgraded to a health alert still active until midnight Wednesday. 

If you have a sensitive respiratory system or plan to go big during that midweek run, take note that ozone levels in the Mendota Heights area might be working against you through Wednesday night.

The Minnesota Pollution Control Agency (MPCA) issued an air pollution health advisory Tuesday afternoon due to expected increases in ozone pollution for the Twin Cities metro and Rochester.

The health advisory runs until midnight Wednesday, June 27.

The advisory indicates that ozone levels are expected to be near a level that is considered unhealthy for sensitive groups, including those with preexisting respiratory conditions, the elderly, children, and individuals who participate in outdoor activities requiring extended or heavy exertion.

High levels of ozone can aggravate preexisting health conditions in these individuals.

The MPCA encourages people in these groups to postpone or reduce vigorous outdoor activity, or schedule outdoor activity in the morning, when ozone levels are lower.

Elevated levels of ozone can also affect people that are not considered vulnerable.

Symptoms include:

• Difficulty breathing deeply and vigorously
• Shortness of breath
• Breathing discomfort
• Coughing
• A sore or scratchy throat
• The MPCA recommends contacting your physician if you are affected by these symptoms. 

Ozone is produced on hot, sunny days by a chemical reaction that occurs most often during fuel combustion. Residents are asked to “postpone or reduce vehicle trips; engine idling and refueling; the use of gasoline-powered equipment; working with paints and solvents; and burning wood,” during this advisory.

For hourly air quality updates, visit the MPCA AQI webpage. you can also sign up for daily air quality forecasts and air pollution health alerts by email or text message.

Source: MPCA