Figure 1 (IMAGE) McGill University Caption Annual and 24-hour PM2.5 ambient air quality standards versus PM2.5 air pollution around the world. Credit Yevgen Nazarenko 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.