David Lerner, University of Sheffield (IMAGE) University of Sheffield Caption Professor Lerner is testing for sewage pollution in a stream in Sheffield, UK, using a conductivity and temperature meter -- a more expensive but less effective method than using tampons and UV lighting. Credit University of Sheffield 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.