Air pollution in the Copenhagen Metro (IMAGE) Aarhus University Caption New studies show high levels of particulate pollution in the air in the Copenhagen Metro. (Note: Masks worn in photo are due to Covid-19 restrictions). Credit Niklas Kappelt Usage Restrictions None License Original 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.