§ 45. Mr. Woodburn
asked the Parliamentary Secretary for Science whether the fall-out consequences of the massive Russian atmospheric nuclear explosions have now been calculated; to what 27W extent the danger to the population from these tests has been over-estimated; and whether such experiments are now considered relatively harmless so far as genetic effects are concerned.
§ Mr. Denzil Freeth
I would refer the right hon. Member to my statement to the House on 23rd November, 1961.
Measurements of iodine 131 in milk supplies have shown that in no region of the country has more than 25 per cent. of the annually acceptable radiation dose from this source been exceeded and that present levels of iodine 131 in milk are negligible. In the case of strontium 90 the most recent evidence tends to confirm the prediction that the amounts of this isotope in human bone are unlikely, as a result of the recent Russian test series, to approach the level regarded as the maximum permissible.
The genetic effects which may result from the recent Russian tests are likely to be comparable to those incurred from the test explosions which had taken place up to the end of 1958. The Medical Research Council have concluded that these effects are likely to be very few by comparison with those arising in the population from other causes, but the occurrence of even a relatively small number of genetic effects in successive generations is bound to be a matter for concern.