Fine particle pollution in Minnesota is much lower than many areas of the world. Across the United States, the highest levels of fine particle pollution are typically measured in the industrial Midwest and Eastern states. While fine particle pollution in the U.S. has decreased since the Clean Air Act went into effect, some areas of the country continue to experience unhealthy levels of fine particle pollution. In Minnesota, annual average fine particle concentrations are below levels of health concern, but fine particle pollution can reach unhealthy levels several days each year.
Fine particle pollution is lowest in the northern areas of the state, while the highest fine particle levels are measured in the most densely populated areas such as the Twin Cities and Rochester.
Overview of fine particle pollution and information about fine particle pollution in Minnesota. (June 2013)
Minneapolis and St. Paul
Annual differences in weather conditions influence the number of unhealthy days each year, but on average fewer than 1% of all days are unhealthy for fine particle pollution.
Monitoring results indicate that fine particle levels are very similar across monitoring sites in St. Paul. Compared to other metro sites, fine particle concentrations are slightly higher in St. Paul.
Twin Cities suburbs
Fine particle levels in suburban locations are generally lower than pollution levels measured in the urban core cities of Minneapolis and St. Paul. Across suburban sites, annual average fine particle pollution levels are very similar. However, on a daily basis, suburban air pollution levels are sensitive to prominent wind directions. When a location is downwind of the urban core cities of Minneapolis and St. Paul, fine particle concentrations in the downwind area are more likely to increase.