§ 82. Mr. Frank Allaunasked the Secretary of State for Education and Science if he will state the average amount of strontium 90 found in babies' bones every six months since 1950, and the highest figure for any one child in each of those periods; and what are likely to be the average and the highest figures for the next 6, 12, 18 and 24 months, provided that there are no more nuclear explosions in the atmosphere within the next two years.
§ Mr. PrenticeI will, with permission, circulate the available data which begins in 1956 in the OFFICIAL REPORT. In the absence of further nuclear tests it is expected that over the next two years the countrywide average for children aged about one year will fall slowly from the present figure of nine pico-curies of strontium 90 per gram of calcium, but the rate of fall cannot be accurately predicted. There have been considerable variations—by as much as five to 10-fold between the concentrations observed in the bones of individual infants, but it is exceptional for an individual to exceed twice the average. I regret that it is not possible to predict future variations.
The information is as follows:
CONCENTRATION OF STRONTIUM-90 IN THE BONES OF CHILDREN AGED ABOUT ONE YEAR (PICOCURIES PER GRAM OF CALCIUM) Average Annual Concentrations 1956 1 1961 3 1957 2 1962 3 1958 2 1963 6 1959 4 1964 9 1960 4
Highest Observed Values (I=first six months; II=second six months) I II I II 1956 1 1 1961 7 3 1957 2 3 1962 4 5 1958 3 3 1963 10 16 1959 7 10 1964 18 21 1960 6 7