Pollution Event Example (IMAGE) University of Utah Caption The evolution of PM 2.5 concentrations throughout Salt Lake County during a pollution event (not included in the study). Dark purple indicates low PM 2.5 particle concentrations, blue indicates higher PM 2.5 concentrations. The west side of the county has persistently higher concentrations under all scenarios. Credit Air Quality and U: https://aqandu.org Usage Restrictions Non commercial with attribution License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.