She is on the faculty Brooklyn College, the CUNY School of Public Health at Hunter College (SPH), and the CUNY Doctoral Program in Earth and Environmental Sciences. She coordinates the Environmental and Occupational Health Doctoral Program at the SPH. Prior to coming to CUNY, she worked within the Molecular Epidemiology Program at NIEHS and the Environmental Science Program at Columbia University. In 1994, Grassman was selected as an AAAS Science and Engineering Fellow and served within the EPA in Washington, DC.