Almost 46 percent of the nation’s public housing units for the poor are located within one mile of factories that emit toxic pollution, according to a study conducted by the Dallas Morning News and the University of Texas-Dallas. “It is an American tragedy. But we sweep it under the rug and forget about it,” said Henry Cisneros, former secretary of housing and urban development (HUD). Some of the people living in federally subsidized housing, mostly minorities, have complained that pollution in their communities causes health problems, including cancer, birth defects, respiratory illnesses, and developmental delays in children.