It is extremely difficult to link radiation from a nuclear accident to cancer. Part of the problem is that there is no way to determine what level of radiation exposure an accident survivor received. Typically it takes 4 to 6 years for their to be any detectable symptoms, excluding people who had very high doses. Further complications include for childhood thyroid cancer (the most common type of nuclear fallout cancer) are not screened for in the population in general at the same rate as it is for accident survivors, so we find more cancers because we are looking harder.
All this said, the latest news from testing done on 370,000 children from the Fukushima area looks quite distressing. Ultrasound tests have found 137 of these children have developed thyroid cancer. This is 20 to 50 times higher than the national rate in Japan. Some medical experts are saying that it is too soon to tell. Others claim the increase is due to increased testing. Still others are claiming it is not the same type of thyroid cancer we saw at Chernobyl and thus it is not likely from Fukushima’s triple meltdown.
What we know from Chernobyl is that there is a huge range of estimated premature deaths. The WHO/IAEA study estimates 4,000. The NY Academy of Science published report estimates nearly 1 million. And the protection of children, both in terms of evacuation and screening of food in Japan has been much better than in the Ukraine.
What we do know is that renewable energy is cheaper than nuclear and we sill continue to build reactors because a certain group of powerful people make a lot of money from it. And perhaps this (and the associated health toll) is the greatest crime of all.