Mitt Romney, then the president of the 2002 Salt Lake Organizing Committee, greets attendees at the opening ceremony of the Winter Olympics in Utah. Roberto Schmidt /AFP/Getty Images hide caption

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At the opening ceremony of the 2002 Winter Olympics in Salt Lake City, Mitt Romney (left) stands with President George W. Bush (center) and International Olympic Committee President Jacques Rogge (right) in front of the American flag that flew at the World Trade Center before the Sept. 11 terrorist attacks. George Frey/AFP/Getty Images hide caption

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West Virginia State Police direct traffic at the entrance to Massey Energy's Upper Big Branch coal mine in Montcoal, W.Va., after an explosion April 5, 2010. Twenty-nine miners were killed in the blast. Jeff Gentner/AP hide caption

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A haze can be seen at night hovering over the Asarco copper smelter, which turns copper ore into nearly pure copper bars. Emma Schwartz/Center for Public Integrity hide caption

itoggle caption Emma Schwartz/Center for Public Integrity

Jeff Galemore leans on his pickup truck near the Ash Grove Cement plant in Chanute, Kan. He and his family are concerned about the toxic emissions and are fighting for independent testing downwind. David Gilkey/NPR hide caption

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The Continental Carbon plant sits on the southern outskirts of Ponca City, Okla. Residents blamed the plant, which produces a black dust known as carbon black, for polluting their city. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR