UNDATED - The quality of the air we breath isn't as clean as it used to be.

The American Lung Association released their annual "State of the Air Report" today (Wednesday).  They say Stearns County received a grade of a "C" this year, after getting a "B" grade last year.

The score is based on the particulate pollution, which comes from emissions from coal-fired power plants and diesel exhaust.

A total of 18 Minnesota counties were graded, four other counties also received a declining score.

The report is based on data collected by the U.S. Environmental Protection Agency.