The use of post-Chernobyl human data for caesium: model validation and intake estimation

The data from routine monitoring of persons working in French nuclear power stations was used to study the retention and urinary excretion of 137Cs in various regions of France over the three year period following the Chernobyl accident. In order to minimise interference from less than detectable values, true means of the monthly measurements were preferred to arithmetic means. We were thus able to deduce an equivalent biological half-time very close to that recommended by the ICRP and confirm that uptake and intake of caesium were very similar, bring out the persistence of differences between regions, and even within regions, in terms of measured activity, over a period of two years following the accident, show that intake during the second year represents one third of total intake, confirming that the resulting internal exposure of the French population has been extremely low. (author)