Beijing Smog (IMAGE) U.S. National Science Foundation Caption Thick smog often obscures the sky over Beijing and nearby regions. Residents are frequently warned to spend as little time as possible outdoors, due to the air pollution. Credit NASA 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.