John Giesy, University of Saskatchewan (IMAGE) University of Saskatchewan Caption Professor John Giesy inspects a sample in his lab at the USask Toxicology Centre. Credit Daniel Hallen/USask Usage Restrictions Only to be used in conjunction with this news release, and with the appropriate caption and credit accompanying it. 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.