§ 45. Dr. Strossasked the Prime Minister whether he can now state whether there is a threshhold below which the ingestion of radiostrontium will not cause disease of blood or bones.
§ The Prime Minister (Mr. Harold Macmillan)I would refer the hon. Member to the Answer I gave to the right hon. Gentleman the Member for Ebbw Vale (Mr. Bevan) on Tuesday, 2nd June, to a similar Question on this matter.
§ Dr. StrossIs it the view of the Prime Minister, however, that this particular cancer-producing agent is merely like every other—and there are many others 809 —and that there is a difference in the sensitivity of different people to them and that, like all other cancer-producing agents, its action is irreversible? Will lie not, therefore, accept and say quite frankly that the right view to take is the pessimistic one, namely, that some people are bound to be affected by even the very smallest dose?
§ The Prime MinisterWhat I said the other day was that it was at present impossible with certainty to say whether there was a threshhold dose. I added that the estimates of maximum permissible concentration of strontium 90 in the bone which the Medical Research Council have accepted had never been based on the concept of a threshhold dose. Those estimates are intended to apply to the population as a whole. Naturally, it is possible that any addition, however small, to the radiation in the environment—which we cannot avoid—whether from nuclear tests or, to a much greater extent, from a variety of other man-made causes, might have a damaging effect in a particular case. However, at the present rate, the contribution to such disease from strontium 90 would in this case be very small. While I agree that there is obviously a difference between individual reactions to this or any other natural effects, yet it is the broad picture which I have tried to give to the House.
§ Mr. BevanIs it not a fact that what that really means is that if there is an increase in man-made radioactivity from any cause whatsoever there will be an increase in cancer in particular persons?
§ The Prime MinisterIt means that any increase in man-made radioactivity has its dangers. In trying to see how to deal with it, we must have regard to the fact that in America man-made radioactivity is about 100 compared to 100 from natural background radiation, while here it is about 22 compared to 100 natural. As the nuclear fall-out is something between 1 and 2, it throws particular emphasis on the study by Lord Adrian's Committee as to what regulations ought to be made for the control of various forms of man-made radiation
§ Mr. BevanDoes not that mean that we ought frankly to state that if there was an increase in strontium 90, some 810 individuals—and it is not possible to estimate how many—would be adversely affected by it and, therefore, any increase in radioactivity caused by man-made activity would result in a number of victims which we cannot at the moment estimate?
§ The Prime MinisterAny increase in man-made radioactivity, for whatever purpose and by whatever means, has its dangers. What has to be measured against that is its advantages. In a great deal of medical radioactivity it would be absurd to say there were not many advantages. Many of us in this House are alive today because of the advantages from medical radio methods, but I agree with the right hon. Gentleman that every addition has its dangers which have to be balanced. That is why we are working so hard at the Geneva Conference in the hope of reaching an international agreement to remove this particular addition, small as it may be.
§ 46. Mr. Hector Hughesasked the Prime Minister if he will give the latest figures showing fall-out of strontium 90 on Scotland, indicating the degrees of fall-out on the east, west, north and south of Scotland, respectively.
§ The Prime MinisterI refer the hon. and learned Gentleman to the reply I gave on 7th May to the hon. Gentlemen the Members for Dundee, East (Mr. G. M. Thomson) and for Cleveland (Mr. Palmer).
§ Mr. HughesThat statement was made on 7th May and this is now the 9th June. Would the Prime Minister state what effect this fall-out has on open-air workers such as fishermen and farmers, and on the quality of the fish they catch and the food they produce?
§ The Prime MinisterI gave a fairly comprehensive reply then, and I have nothing to add today.
§ 47. Mr. Hastingsasked the Prime Minister whether he is aware that the percentage of strontium 90 found in the bones of sheep reared on Welsh mountains with little calcium in the soil is greatly in excess of that in the bones of similar sheep living on the plains; and to what extent similar differences have been noted in the bones of human beings.
§ The Prime MinisterI am aware that the levels of strontium 90 in the bones of sheep reared on the Welsh mountains may be many times the levels in similar sheep living on the plains. No such differences occur in the bones of human beings because the levels in the bones of human beings are dependent on the amounts of strontium 90 and calcium in the diet and not on the amount of fall-out locally.
§ Mr. HastingsIs the Prime Minister aware that while X-rays have been in use for approximately sixty years, we are only now learning some of the dangers of such rays? May not the same apply to radiations produced from strontium 90 and other substances?
§ The Prime MinisterThe hon. Gentleman's observation is very true. These studies have been mainly the result of one set of problems, but we have learnt a great deal more about others.
§ 48. Mr. Hastingsasked the Prime Minister whether the figures given as one or at most two of the amount of radiation resulting from nuclear tests compared with 100 from natural sources assumes an even distribution over the whole world; to what extent this assumption has been confirmed; and what variations are met with in different parts of Great Britain and the Commonwealth.
§ The Prime MinisterThe report of the United Nations Scientific Committee explained that the world-wide fall-out rate is uneven, and is, in general, higher in the northern than in the southern hemisphere. The figure of between 1 and 2 per cent. of natural background radiation, which I have quoted as applying to the possible effects of radiation from fall-out, is based on measurements made in this country.
As I have explained to the House, fall-out varies from place to place in the United Kingdom as the result of variations in rainfall, and there are, of course, variations in the natural background.
§ Mr. HastingsWould not the Prime Minister agree that whilst, as far as we know, the average is safe, the amount received in some areas may be really dangerous?
§ The Prime MinisterI do not think so because, as I was pointing out, what matters as regards the incidence of bone cancer is the diet and not the particular fall-out in a particular locality.
§ Mr. BevanWould it be possible for the Prime Minister to ask the Medical Research Council to give us a little more information about this to find out the incidence of bone cancer and blood leukaemia in people living at different altitudes? We might then find out to what extent they have adapted themselves to the different levels of radioactivity at different altitudes.
§ The Prime MinisterIf the right hon. Gentleman puts down a Question I will do my best to get the answer.
§ 51. Mr. Frank Allaunasked the Prime Minister, in view of the fact that radioactivity in West German rainwater in January was sixty times the maximum permissible concentration for drinking water, what examinations have been made in Great Britain after June, 1958: and what they revealed.
§ The Prime MinisterSince June, 1958, determinations of strontium 90 and other isotopes have been continued on samples of rainwater collected at regular intervals at fixed stations in the United Kingdom.
As to what these examinations have revealed, I would refer the hon. Member to my Answer to his Question on 11th May and to the Answer given by my right hon. Friend the Minister of Housing and Local Government to the hon. Member for Newcastle-under-Lyme (Mr. Swingler) on 2nd June. The concentration in rainwater of strontium 90, which is the most important single index of radiological hazard, has continued to be well below a level which would give cause for concern.
§ Mr. AllaunAs we live in the same latitude as Germany, is it not rather strange that something similar has not occurred in this country? Since these monitorings take place regularly, should not the figures be published regularly? When will they be published?
§ The Prime MinisterThe figures are published from time to time. I do not think it is of much use publishing them except at reasonable intervals of six 813 months or so. With regard to the figures from other countries which have been quoted, we are not responsible for them. I understand that there has been some confusion about all the radioactivity being thought to be due to strontium 90 whereas in fact strontium 90 is known to constitute only a very small part of the radioactive content of the water.