Hookah Study (IMAGE) University of Cincinnati Caption University of Cincinnati assistant research professor Julio Landero Figueroa holds a piece of hookah charcoal that contains a nail. Researchers found heavy metals and other toxins in hookah charcoal sold at retail stores. Credit Joseph Fuqua II/UC Creative Services 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.