Science: Too Much Radiation?

Of the sources of the radioactivity that batters man, fallout from nuclear weapons testing is the least. At current levels, it is less than 5% of radiation from natural sources. But this is small comfort: the total of all radiation, largely from rocks, body chemicals, cosmic rays and X rays, may already be at a dangerous level. So warned a 15-country United Nations scientific committee last week, after studying world radiation for 2½ years. Shunning politics, the experts voted against urging a ban on nuclear tests. As top scientists, they voiced a sobering opinion: "Even the smallest amounts of radiation...