Chemical Pollution in Rivers (image) Helmholtz Centre for Environmental Research - UFZ Caption Agriculture is responsible for the major part of the input of chemicals into streams and rivers. Pesticides dominate the chemical burden of freshwater ecosystems. Credit Photo: André Künzelmann, UFZ Usage Restrictions None 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.