Pollution Levels (IMAGE) Duke University Caption Six different photos taken of the same area of Beijing on different days experiencing different levels of air pollution. While the naked human eye can clearly tell that some days are more polluted than others, a new machine learning algorithm can make reasonably accurate estimates air pollution at ground level. Credit Tongshu Zheng, Duke University 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.