Samples (IMAGE) American Society of Agronomy Caption These laboratory-constructed soil samples contain various concentrations of petroleum hydrocarbons. Credit: David Weindorf Credit David Weindorf Usage Restrictions For use with this story only 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.