Hanspeter Witschi, associate director of the UC Systemwide Toxic Substances Research and Teaching Program based at UC Davis, has been appointed to three national positions. He has been named to two committees of the National Research Council, the Committee on Toxicology for the Commission on Life Sciences and, secondly, the Committee on Risk Assessment of Hazardous Air Pollutants for the Board of Environmental Studies and Toxicology. Earlier this year, Witschi was invited to become a consultant to the Science Advisory Board of the U.S. Environmental Protection Agency.