Changes in PM Concentrations Over China (IMAGE) NASA/Goddard Space Flight Center Caption Changes in PM 2.5 concentrations over China for February 2019 and 2020 derived from satellite observations. Credit NASA's Earth Observatory Usage Restrictions None 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.