As officials in Japan agonize over what constitutes a safe radiation dose for people who live near the Fukushima Daiichi nuclear reactors, the state of the science has been a daunting problem. Studies on the effects of exposure are based mostly on large doses delivered quickly by atomic bombs, while radiation from the Fukushima disaster would more likely result in small doses delivered over many years.
So far the debate in Japan has centered on the risks to children. Government guidelines set after the disaster allowed schoolchildren in Fukushima Prefecture to be exposed to 20 times the radiation dose previously permitted. The new level is equal to the international standard for adult workers at nuclear power plants.
After a huge outcry from parents, the government promised that it would lower the permissible level and that it would pay to remove contaminated topsoil from school grounds.
Continue reading at Radiation’s Unknowns Weigh