Media contact: Mark Sulzbach 651-296-7768
Technical contact: David Thornton 651-296-7265
St. Paul, Minn. -- How good is the air quality in Minnesota? The Minnesota Pollution Control Agency (MPCA) has just released two reports that help answer complex questions about the state's air quality.
The "Air Quality Index (AQI) Summary for 2004" provides an overview of data collected during the past year. The 2005 report to the legislature titled, "Air Quality in Minnesota - Progress and Priorities," offers a comprehensive look at state air pollution trends and work being done to reduce emissions.
The reports are timely. Minnesota's recent air alert beginning on January 29th, lasted six days and was the most severe alert since the MPCA began monitoring fine particle pollution in 1999. AQI levels were above 150 (unhealthy for all groups) for fine particles on three days.
Fine particles from the combustion of fossil fuels have emerged as a major health concern. They are associated with increased hospitalizations and deaths due to respiratory and heart disease and can worsen the symptoms of asthma. Ozone (smog) is the other pollutant that activates air alerts. It is linked to respiratory problems including asthma attacks.
Still, the overall air quality in Minnesota is within federal standards and the vast majority of the time the AQI is in the good to moderate range. The legislative report shows that total state emissions of key pollutants have decreased 15 percent since 1985, despite a population increase of 21 percent that has spawned even greater surges in energy use and vehicle fuel consumption.
The question of clean air becomes complex because many pollutants and factors are part of the evaluation. Weather is a significant factor in air quality. Hotter weather tends to bring more ozone (smog) alerts but the cool summer of 2004 produced few alerts due to high ozone levels. Air pollution also knows no boundaries, so wind often plays a big role. It can disperse pollution or bring bad air into Minnesota from as far away as Missouri or Texas. When additional pollution blows into Minnesota followed by a temperature inversion and low winds, bad air can be trapped as if under a blanket across much of the state.
So even if the overall average emissions for key pollutants is trending lower in Minnesota and the state meets all federal air quality standards, there can still be a number of days when the AQI reaches 100 or higher and becomes unhealthy. These alerts show that Minnesota must continue its efforts to find cost-effective ways to reduce emissions that contribute to ozone and fine particle formation.
On the plus side, a variety of local projects mentioned in the MPCA's legislative report will help clear the air. The Metropolitan Emissions Reduction Project will reduce sulfur dioxide and nitrogen dioxide emissions from three power plants by 95 percent. Other efforts include volunteer emission reduction efforts by a coalition of private, public and non-profits organizations called Clean Air Minnesota, vapor controls on fuel tanks for all Twin Cities area gas stations, and the Metropolitan Council's purchase and use of ultra low sulfur diesel fuel in 400 transit buses. All show good promise to improve air quality in the Twin Cities.
To help assess the air in Minnesota, the MPCA has been expanding its network of air monitors. Currently, the Twin Cities, Duluth, Brainerd, Rochester and St. Cloud have both ozone and fine particulate monitors. This spring the MPCA will add new ozone and fine particle monitors in Marshall and Detroit Lakes. Ely will also gain an ozone monitor this spring. Each monitor adds a snapshot of the air quality in that region and gives a more complete picture of the state's air quality.
The legislative report also describes federal programs to reduce emissions from power plants, motor vehicles, heavy-duty diesel trucks and off-road diesel vehicles that are phasing in and will reduce pollution in Minnesota and in states whose air pollution can blow into Minnesota.
The MPCA's AQI summary is available at/publications/reports/aqi-summary2004.pdf The air quality legislative report is at/publications/reports/lr-airqualityreport-2005.html