Polar Bear (image) Aarhus University Caption Scientists have been monitoring the polar bear for contaminants in East Greenland over the past 30 years. They are worried by the findings of bioaccumulated perfluoroalkyl substances (PFASs) in the brain. Credit Photo: Rune Dietz, Aarhus University. Usage Restrictions None 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.