On Guard At Border
An undocumented migrant attempts to cross the New River near the U.S- Mexico border as white toxic foams created from the river pollution float on the surface in Calexico, Calif., Sunday, June 4, 2006. The river is known as one of the most polluted rivers in North America. Public health officials along the border worry about this toxic, infested river and the people who use it as a route into the United States.
Author: CBS News Staff
Credit: AP Photo/Jae C. Hong
