There was a very interesting edition of Horizon on BBC2 last night. See write-up here http://news.bbc.co.uk/1/hi/sci/tech/5173310.stm
Looking at data from Chernobyl, the cases of cancer following the accident are far lower than expected. The suggested reason is that the predictions were based on data from the Hiroshima and Nagasaki nuclear bombs. Whilst these provided plenty of data for high doses of radiation, the effect of low doses was determined on a straight line graph, suggesting all levels of radiation have some risk. The basic premise of the Horizon program was that there is a minimum threshold, below which there is very little risk and in fact some data suggests it may be beneficial.
I had always naively assumed that when it was reported that 2,000 or 20,000 people had died prematurely as the result of Chernobyl, that this was based on medical data (i.e. the actual number of people that have died). It actually turns out that this was probably based on projected figures. A good example of where a projected figure is published, and over time it starts to be quoted as an actual result.
I have often wondered if we can get useful data from animals. They were not evacuated from region after the accident, and even today there are sheep in the UK that are considered too contaminated for human consumption. The program did follow this line of investigation, and claimed that there was no evidence that animalimal populations were suffering from the effects.
ossibly more harmful than the actual exposure.