§ 45. Dr. Strossasked the Prime Minister to what extent individual variations in the sensitivity of human bone marrow will account for the increase of aplastic anaemia, leukaemia and bone cancer in those subjected to ingestion of radioactive strontium at levels considered safe for the population as a whole.
§ The Prime Minister (Mr. Harold Macmillan)There is no direct evidence that aplastic anaemia, leukaemia, or bone cancer have resulted from the ingestion of radioactive strontium at present levels, which are far below those regarded by the Medical Research Council as the upper limit for the general population.
§ Dr. StrossDoes not the Prime Minister agree that, long before we heard of any danger from fall-out, individual cases were found in people in different parts of the world of bone cancer, aplastic anaemia and leukaemia? Is it not because there are individual idiosyncrasies and weaknesses in different people that they have so suffered, and that we think ionising rays are the cause of it? If that be the case, does it not follow that threshold values are individual matters, not racial or group ones, and that every addition will pick up its selected victims?
§ The Prime MinisterThere are individual variations, but the International Commission on Radiological Protection regarded the maximum permissible level for workers in special occupations as 1,000 units, and the Medical Research Council here used this as the basis for the figure of 100. The highest level of strontium 90 in any one bone sample yet assayed in this country as the highest is, so far, three, which is far below those figures.
§ 46. Dr. Strossasked the Prime Minister whether he will state the proportion of the radiation affecting the organs of reproduction from the average intake of radioactive strontium as compared with the natural background and with the use of diagnostic X-ray apparatus.
§ The Prime MinisterI have already given the House the figures 100, 22 and between 1 and 2 as the proportions in this country between the radiation dose to the gonads from the natural background, from the diagnostic radiology 365 and from fall-out generally. The radiation dose to the gonads from radio strontium only is however far less than one on this scale since this material is predominantly deposited in the bones.
The figure of twenty-two for the dose from diagnostic radiology in the United Kingdom is subject to the findings of the Committee on Radiological Hazards to Patients whose final report is expected shortly. A considerably higher figure has been given for countries where more use is made of X-ray apparatus.
§ Dr. StrossDoes not this rather highlight the Question I put previously and the Answer which, with great respect, I think the Prime Minister gave in a somewhat unsatisfactory fashion? Is it not true that this tiny amount of stuff ingested into the bone marrow, with its radiation to bone marrow alone—not taking into account the genetic effect and not affecting the gonads—is probably responsible inevitably amongst certain people for future illness, which will show itself as cancer or leukemia or aplastic anaemia?
§ The Prime MinisterNo, Sir. I am trying to answer Question No. 46, which is about the diagnostic effects, and I think my Answer covers it.
§ Dr. SummerskillCan the Prime Minister tell the House how he relates the answers he has just given to the answer he gave on Tuesday, when he agreed that there was no known threshold dose below which there could be no danger?
§ The Prime MinisterI was assuming—indeed it had been put forward by all the bodies—that one could not say there was an absolute threshold of this or that kind for this particular thing. I was basing myself both upon the United Nations and the British Medical Research Council that, for practical purposes, some arrangement has to be made. They took 1,000 in certain cases and 100 for the general population as the point at which sonic danger might be considered.
§ 49. Mr. Beswickasked the Prime Minister what research has been done into the amount of radioactive fall-out which would be released by the operational use of tactical nuclear weapons; and what number of kiloton weapons it is estimated can be used before the atmosphere is polluted above the level defined by the 366 Medical Research Council as warranting immediate concern.
§ The Prime MinisterAs my right hon. Friend the Minister of Defence stated in a reply to the hon. Member for Oldham, West (Mr. Hale) on 11th February, the only difference between strategic and tactical nuclear weapons is the nature and location of the target. Thus, as regards the first part of the Question, my many previous statements on fall-out are of general application. If, however, the hon. Member's Question is meant to refer to low-yield kiloton weapons as contrasted with megaton yield weapons, then it is relevant that, in general, the fall-out from small yield weapons is of local rather than world-wide distribution.
So far as the second part of the Question is concerned the Medical Research Council has never attempted to define a danger level for the pollution of the atmosphere. What it has done is to quote a figure for the level of radioactivity in human bone which, if greatly exceeded, would warrant immediate concern. It would be unprofitable to attempt to calculate the number of kiloton weapons which might be used before this level was exceeded, since the answer would depend upon a number of assumptions, not only about the circumstances in which the weapons were used, but also, for example, about the possibility of avoiding food, especially milk, from the affected areas.
§ Mr. BeswickBut would not the Prime Minister agree that the whole concept of a limited nuclear war is that it would be possible to localise the consequences, and although in the United States, at any rate, a great deal of research has been done as regards blast effects into the practicability of using low yield nuclear weapons, are we not neglecting the radioactive consequences? Whatever there may be in the poisoning of the atmosphere from isolated test explosions, is it not obvious that, even from a limited war, we would succeed in poisoning the world's atmosphere?
§ The Prime MinisterI find it difficult to go into these speculations by question and answer, but I can say without hesitation—and I think the hon. Gentleman will agree with me—that all wars of all kinds are very destructive. We have seen two in my lifetime which have caused 367 terrible loss of life, limb and property, and the great purpose we must keep in mind is to avoid war.
§ 50. Captain Pilkingtonasked the Prime Minister what revision there has been in his estimate of man-made radiation.
§ The Prime MinisterAs the House will know, the contribution from the largest of the man-made sources, namely the medical use of ionising radiations, is at present being investigated by Lord Adrian's Committee. Until this report is received, the average figure for these medical uses of at least 22 per cent. of natural background in the United Kingdom is the most authoritative that is available. As regards the contribution from fall-out, I see no reason to alter the figure I have already given the House of between 1 and 2 per cent. of natural background radiation.
§ Captain PilkingtonDid my right hon. Friend see a recent article in theSunday Timeswhich seemed to suggest that the amount of man-made radiation is much greater than had been thought?
§ The Prime MinisterI read the article which, broadly speaking, put the position very well and fairly. Professor Waddington, however, fell into an important though understandable error. The estimate of 2 per cent. to 4 per cent. which he gave was the worst case considered by the United Nations Scientific Committee. That was based upon the continuation of weapon tests for some hundred years or so.
§ Dr. StrossHas the Prime Minister noted that the 22 per cent. for which diagnostic and curative techniques are responsible was based upon work done in one or two of the best teaching hospitals we have available, and that therefore it is fair to assume that if the figure is revised, it will have to be drastically upward?
§ The Prime MinisterWell, Sir, I think the best thing now is to wait for the report of Lord Adrian's Committee, which is bound to be very authoritative and very helpful.