All 32 exceedances of national air quality standards in Iowa so far this year have been recorded in Muscatine.
The National Ambient Air Quality Standards (NAAQS) are levels of pollution considered "harmful to public health and environment," and include air pollutants ozone, sulfur dioxide, carbon monoxide, nitrogen oxide, lead and particulate matter.
As of Nov. 9, the air quality standard for sulfur dioxide (SO2) in Muscatine was exceeded 30 times and twice for particulate matter of less than 2.5 microns (PM2.5).