The Office of Emergency Preparedness (OEP)of the United States Department of Health and Human Services has been contracting with the most heavily populated U.S.cities in an effort to improve those cities’ capabilities to respond to terrorism incidents on the scale of the September 11,2001 attacks on the World Trade Center and the Pentagon.The central focus of this effort,the Metropolitan Medical Response System(MMRS)program,has been on unfamiliar chemical and biological agents.