Professor Greg Evans and Dr. Cheol-Heon Jeong, University of Toronto (image) University of Toronto Faculty of Applied Science & Engineering Share Print E-Mail Caption Professor Greg Evans and Dr. Cheol-Heon Jeong studied levels of black carbon and ultrafine particles inside the cars of commuter trains. They found that passengers were exposed to high levels of these potentially carcinogenic fumes, especially when sitting directly behind the locomotive. Credit Tyler Irving Usage Restrictions None Share Print E-Mail 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.