Measured human thyroid radioactivities in Britain arising from the Chernobyl disaster

Abstract

131I activities in thyroids taken at necropsy from more than 160 adults from 7 areas in Britain who died during the 9 weeks following the Chernobyl incident were measured. Peak mean specific activities in these areas varied from 2.5-5 Bq g-1 dry weight (i.e. by a factor of only 2) in spite of the reported enhanced deposition of radioactivity in N and W Britain. It is suggested that this reflects diets deriving from a wide area, including the pooling of milk. Activities decayed with effective half-lives 11-16 days, which is longer than expected if milk were the only main source. Mean thyroid doses in the areas fell within the range of 44-74 mu Sv with probably most adults in Britain receiving between 15-150 mu Sv and very few more than 200 mu Sv.