Crack epidemic in Brazil

A social worker, center, holds up a piece of metal siding as a suspected drug user crawls under a fence to a waiting van near the Parque Uniao slum in Rio de Janeiro, Brazil, Oct. 17, 2012.

The South American country began experiencing a public health emergency in recent years as demand for crack boomed and open-air "cracolandias" -- or crack lands -- popped up in the sprawling urban centers of Rio and Sao Paulo, with hundreds of users gathering to smoke the drug.

Credit: AP Photo/Felipe Dana