India and Pakistan say they have stopped testing nuclear weapons for the moment after both countries' recent spate of underground detonations. The tests confirmed the rumored nuclear capabilities of these two rival nations, and rekindled a sense of nuclear peril that abated with the end of the cold war. These tests also bring back public health risks that were first unleashed by the U.S. and former Soviet Union. Underground nuclear bomb blasts are not very visible, but radiation can escape through vents or into ground water. Steve Curwood speaks with Dr. Arjun Makhijani, president of the Institute for Energy and Environmental Research in Takoma Park, Maryland. He says it's difficult to assess the effects of the tests as neither Pakistan or India have come forward with much data.