National Radiological Protection Board

This study investigated methods of providing summary statistics for measurements of radioactive contamination in food when the available measurements are incomplete. Several techniques to calculate e.g. the mean when the amount of contamination, in a significant number of samples, is less than the minimum level reported by measurements are discussed. To support the estimation of summary statistics the study identifies physical processes that give rise to observed distributions, e.g. lognormal, of radioactive contamination. The improved estimates possible by application of the methods reviewed will allow the Food Standards Agency to gain a better understanding of the levels of radioactivity in the environment and if required direct effort to minimising the most significant uncertainties in these estimates. This study was funded by the Ministry of Agriculture, Fisheries and Food, Radiological Safety and Nutrition Division (now part of the Food Standards Agency), under contract RP0342. This work was carried out under the EADERG quality management system which is approved t