While the Japanese tsunami of March 2011 was devastating in its own right, the long term health consequences because of the damage to the nuclear reactor at Fukushima Daiichi are also of serious concern.There are a number of factors that have to be considered when assessing the health effects of radiation exposure: for example land decontamination efforts, size of evacuation area, shielding by buildings and terrain and consumption of contaminated food.Jan Beyea, from the US expert consulting service Consulting in the Public Interest, together with fellow colleagues has been analysing previous calculations of the subsequent nuclear accident in Japan, and...