Chemical Pathway (IMAGE) University of Washington Caption Sulfur dioxide from power plants (red) and nitrogen oxides from both power plants and cars (blue) follow various paths to form hazardous sulfate and nitrate particulates. The multiphase path becomes more important in winter, resulting in a weaker response of sulfate and nitrate to emissions reductions. Credit Viral Shah/University of Washington Usage Restrictions With credit 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.