This paper examines the relationship between the location of environmental risks and federally assisted public housing (Housing and Urban Development [HUD] Section 8) in a sample of eight medium-sized United States metropolitan areas. Using four U.S. Environmental Protection Agency databases, locational and potential risk exposure surfaces were constructed for each study area using a GIS-based methodology. Families living in HUD housing had a greater risk potential from hazardous facilities based on proximity and the reported releases from them. Minority populations (defined as percentage non-White) had significantly greater locational exposure than nonminority populations in all but one metropolitan area, Albuquerque. Minority populations also had higher risk burdens than nonminority residents. The historical evolution of the patterns of social and industrial change illustrates the unique localized processes of residential and industrial development. Explanations based solely on race and income show little consistency in cause and effect through time, but there is some emerging evidence that industrial host tracts are becoming poorer and home to more minority residents in at least half of our cities. [Key words: environmental justice, HUD housing, GIS.]