§ Q13. Mr. Dribergasked the Prime Minister if, bearing in mind his assurance of 31st October, 1961, that nuclear tests would if possible be made underground where there is no danger of pollution, he will, before authorising any further British tests in Nevada, consult the United States authorities on the possibility that leakage from underground testing in Nevada has been a contributory cause of relatively high concentrations of iodine-131 in milk in the United States, as disclosed by Dr. E. A. Martell of the Cambridge Air Force Research Centre before the Joint Committee on Atomic Energy on 5th June, 1962.
§ Mr. R. A. ButlerI have been asked to reply.
It is true that in a very few cases underground tests have resulted in the venting of small quantities of radioactive material into the atmosphere; but the United States Atomic Energy Commission investigated Dr. Martell's hypothesis and were able to satisfy themselves that the high level of short lived radioactivity in parts of the United States at certain times since September 1961, was due, not to underground tests in Nevada, but to atmospheric tests much further away.