March 15, 2011
Immediate health risks for people living near Japan's Fukushima Daiichi nuclear plant appeared minimal Saturday, but experts cautioned that radioactive vapors could cause long-term problems ranging from birth defects to cancer if the situation worsens.
Based on a widely used definition of average normal exposure for humans —360 millirems per year of radiation from rocks, cosmic rays and manmade sources—even those levels would be safe for humans, said Ron Chesser, director of the Center for Environmental Radiation Studies at Texas Tech University. Radiation doses would have to rise 250,000 times beyond those background levels to cause damage to human cells, he said.
Still, Dr. Chesser said that "there is no doubt that there is a serious health situation there" because of how quickly problems could escalate. "Every precaution needs to be taken."