March 4, 2010
The Minnesota Pollution Control Agency (MPCA) has upgraded the air pollution health advisory issued yesterday for Rochester and the Twin Cities to an air pollution health alert for Thursday, March 4, through Friday, March 5. An air pollution health advisory will remain in effect for these areas on Saturday, March 6.
An air pollution health advisory is issued when the Air Quality Index (AQI) is expected to exceed 90. The MPCA issues an air pollution health alert when the AQI exceeds or is expected to exceed 101, the level considered unhealthy for sensitive groups.
A high pressure system located over central Iowa, and the associated air stagnation, are encouraging fine particle levels to build across much of Minnesota, Iowa, Illinois and Missouri. Locally, overnight fog and mist have led to enhanced particle production, and calm early morning winds have further limited pollutant dispersion. In addition, light southeasterly winds this afternoon will gradually transport moisture and additional pollutants into the Twin Cities, enhancing particle production.
As a result of these conditions, AQI levels will be unhealthy for sensitive groups in the Twin Cities and Rochester. AQI levels are expected to remain in the unhealthy-for-sensitive-groups category into Friday, and they should fall to the high-moderate AQI range on Saturday. Air quality conditions are expected to continue to improve on Sunday, and should return to good conditions by Monday, March 8, as wind speeds increase and become more northwesterly.
Those with respiratory or cardiovascular problems, young children, the elderly and individuals who participate in activities that require heavy exertion are the most sensitive to elevated levels of air pollution. Since fine particles can be drawn deeply into the lungs, it is a good idea to reduce or postpone activities that lead to deep or accelerated breathing. Exposure to high levels of fine particles may cause chest pain, shortness of breath, coughing and fatigue, even after air quality has improved. If you experience these symptoms, contact your physician. Even individuals that are otherwise healthy may experience health effects when air pollution increases.
Everyone can help reduce local air pollution. Reducing motor vehicle emissions by carpooling, combining trips, avoiding idling, and using alternate transportation all help. Avoiding burning wood and reducing energy consumption will also help.
For hourly air quality updates, visit the MPCA AQI Web site at http://aqi.pca.state.mn.us/. Sign up at http://mn.enviroflash.info to receive daily air quality forecasts and air pollution health alerts by email or text message.
