The accumulation and retention of strontium-90 in human teeth in England and Wales—1959 to 1965

Abstract

The results of monitoring the accumulation of strontium-90 in human teeth in the United Kingdom are reported up to the end of 1965. Estimations are confined to clinically perfect teeth, viz premolars from persons 9–13 years old and third molars from persons 17–21 years old. Roots and crowns are divided, bulked according to age group and analysed separately. Continuous results are now available respecting over 11,000 teeth collected from all parts of the United Kingdom. The rate of fall-out was negligible before 1953 but between 1954 and 1964 world-wide deposition of strontium-90 increased from 0.10 to 11.58 MCi. This was reflected in the findings. Concentrations in the teeth (estimated in pCi/g Ca) steadily increased with the passage of time. At any given point it was highest in the teeth of the youngest groups since these were obtained in an active state of mineralization during a period when dietary levels were rising. Similarly, in any given age group, concentrations were higher in the roots than in the crowns because the roots were affected by recent uptake whereas the crowns had mineralized when dietary levels were relatively lower. Since the crowns related to previous uptake, it was possible to deduce the probable activity of 90Sr during mineralization for the years 1956/1959. When the results were related to longitudinal uptake in children of the same age, it was found that the ratio of strontium-90/calcium in the teeth of individuals has been steadily rising although not so steeply as with age-groups born in successive years.