Health effects of Hiroshima and Nagasaki atomic bombings still carefully tracked

More than 70 years have passed since the bombings of Hiroshima and Nagasaki, and the long-term health effects of nuclear radiation are still not fully known. But American and Japanese scientists have been studying survivors since the end of the war, and are uncovering valuable information about how to fight and prevent the bombs’ atomic consequences. Science correspondent Miles O’Brien reports.