Figure 1. (IMAGE) Science China Press Caption Metal in PM2.5 exposure and difference in Heart rate in COPD and non-COPD participants. Credit ©Science China Press Usage Restrictions Use 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.