HL Deb 14 July 1960 vol 225 cc319-33

4.30 p.m.

LORD TAYLOR rose to ask Her Majesty's Government whether the consumption of milk among schoolchildren has been adversely affected by publicity given to the effects of radioactive fallout. The noble Lord said: My Lords, I beg to ask Her Majesty's Government the Question standing in my name on the Order Paper. We now pass from the complexities of the law to the complexities of nature, which are sometimes even greater, and this is a very good example of them. Every one of your Lordships who has watched the children of this country over the past fifteen or twenty years cannot but have been struck by the amazing improvement in their health and their physique. This is very largely due, or is, at least, in substantial measure due, to the increase in consumption of milk which has taken place since before the war. This is partly due to the free and cheap milk schemes for expectant mothers, nursing mothers and young children, and partly to the milk-in-schools scheme. The net effect of it all is that between 1939 and the present time the total consumption of liquid milk in this country has approximately doubled.

When this excellent process was beginning, milk was by no means an entirely safe fluid. It was, in fact, still liable to carry tuberculosis germs; and only with the virtual universal extension of pasteurisation did milk become completely safe. Yet it was a balance of advantages, and it was on that balance that the decision was made to do everything possible to increase the consumption of milk by young children, by expectant mothers and by growing children—and the results brilliantly justified that decision. I was going round the ward of a children's hospital last week, and there were fifteen out of twenty beds vacant. That is a situation largely due to the improved nutrition of the children, in which milk has played a very large part.

It would be a thousand pities, therefore, if there were any decrease in the consumption of milk because people were unjustifiably frightened that the milk would harm their children in some way. People have been asking, as a result of all the publicity which has been given to Strontium 90 fall-out, whether children's milk should be cut. They ask, "Is it really safe to give our children as much milk as they want, and should condensed milk be substituted for ordinary fresh, liquid milk?" In some of the newspapers, Strontium 90 has been referred to as "death dust", and it is natural that people should be anxious of it, particularly in areas where they have heard that the fall-out from Strontium 90 has been very heavy.

In fact, radiation has been with mankind since the beginning of time. In the United Kingdom, four-fifths of the radiation to which we are subjected, and have always been subjected, comes from cosmic rays, and one-fifth comes from diagnostic radiology—that is to say, the taking of X-ray pictures. The amount that comes from diagnostic radiology has, of course, been going steadily up as many new medical processes have been introduced; and the figure of one-fifth is substantially higher in the United States. The amount of cosmic radiation to which people are subjected varies in different parts of the country. It is twice the average in Aberdeen, because the Aberdeen granite is comparatively highly radioactive. It is high in Cornwall, and it is high in Leeds, for some mysterious reason. In Stockholm, it is twice as high as our average English figure, again because the main building materials are radioactive. If one goes up a hill to a height of 400 feet, the amount of radiation is substantially increased. I say "substantially", but the increases are actually very small; nevertheless they are appreciable. If one goes down a coal mine, the amount of radiation to which a person is subjected gets less. If we all lived in coal mines, therefore, presumably we should escape radiation altogether, although whether that would be biologically desirable in the long run nobody knows.

Now Strontium 90 is something that is quite new. It is a new element which has appeared as a result of atomic explosions; and the measurement of the amount of radiation produced by this is also something quite new. It makes, as yet, a very small contribution to the total radiation to which human beings are subjected. In 1956, it was about 1 per cent. of the total background radiation; in 1958–59, it was 2 per cent. of the total background radiation to which we are exposed. It is detected in two ways: first, by sampling milk—and it needs a great deal of milk to be examined for us to get hold of any Strontium 90, and is a highly technical and difficult job; and, secondly, by sampling infant bones—the bones of little infants who have died and who may have ingested this milk or absorbed it from their mothers before birth. So small is the amount of Strontium 90 that the biggest bone in the body has to be used—namely, the femur—and it requires, an entire femur to make it possible to detect any Strontium 90.

The amount of radiation given by Strontium 90 is far less than the amount of radiation to which workers in our factories are subjected—for example, those doing X-ray crystal work, X-ray work on castings, and X-ray work on wings of aeroplanes. There, they take all precautions. There is what is called a maximum permitted concentration, and that maximum is very seldom reached in industry. The total effect of Strontium 90 is far below the sort of exposures to which people are subjected in industry, and even further below the amount of radiation to which workers in X-ray departments—radiologists, and so on—are subjected. A Strontium unit, by which the stuff is measured, is in fact one-5,000th of the maximum permissible dust for workers in factories. It is one million-millionth of a curie: but it is dangerous, and it is dangerous because it tends to be picked up by the human body and deposited in the bones, and because it has got a very long half-life —namely, 28 years—and, therefore, even though present in very minute quantities, does go on acting for a very long time.

In 1958 we began to get reports coming through of an increase of Strontium 90 in the diet, particularly in the milk of this country and in the bones of newborn children. The increase was higher in places of very heavy rainfall, for obvious reasons. It appeared to be coming from the radioactive fall-out, and it was brought down with the rain. On some of the hill farms, it was as much as four times as high as in the rest of the country. I think I am right in saying, although the noble Viscount will correct me if I am not, that the peak was reached between March and June of last year, almost certainly as a result of the fall-out from the large series of Russian atom tests in 1958, just before the ban on atom bomb testing. There appears to be a six months' time lag between the explosion of an atom bomb and the rise in Strontium 90. I believe I am right in saying—again I hope that the noble Viscount, will give us the latest information—that the figures are now starting to fall.

The important thing is to keep this matter in proportion. The danger has increased but it is still a very small danger, so far as I am able to estimate; but it is enough to make a strong argument for continuing the ban on atomic bombs. The danger of not taking milk, I consider, is far greater than the danger of doing so. It is a pity that there has been a good deal of publicity in the West Country, mainly by a gentleman (whose name happens to be the same as mine, who is also a member of the medical profession and was a member of the Liberal Party—though I gather that that is no longer so) who went around making alarming speeches about the effect of Strontium 90 on children, with the result that people in the areas he visited were perturbed about whether they should go on giving their children milk. I think, and I hope the noble Viscount will confirm, that there is virtually no risk in continuing to take milk—indeed, that it would be criminal not to give children milk.

However, there has been one point which has worried me a great deal; and I think it has worried serious medical scientists, and not alarmists—that is, the steady increase over the past 20 or 30 years in the disease of leukæmia, particularly the extraordinary increase which has occurred in certain counties in Wales and in Cumberland. We all know now that leukæmia is a disease which can be produced by radiation. It was produced in a very dramatic way among the victims of the atom bombs in Japan, and the incidence of leukæmia went up steadily as the epicentre, the point at which the bomb went off, was approached. Fully 100 cases are known which are directly attributable to the atom bomb explosions.

We know that leukæmia is associated with industrial radiations. It is more common in doctors than in the general population, and it is most common in radiologists, who are the most radiated doctors. There has been a five-fold increase in 1euk æmia in the last 30 years. Even so, the figures are very small. But a five-fold increase of a fatal disease is a very serious matter, and it-now causes in this country about five deaths per 100,000 of the population every year, mainly in infants and old people. It is one of those diseases which appear to go up with the rise in the standard of living. It is like poliomyelitis in this respect, but it appears to be for different reasons. One of the main reasons is that, as the standard of living goes up, the length of life goes up, and more people are living into the leukæmia age, as it were, and more people are exposed to diagnostic radiology.

If one takes the counties of England and Wales, as was done by Dr. Phillips, medical officer of South Carnarvonshire, in an interesting article in the Lancet, one finds that there has been a 50 per cent. increase in the incidence of leukæmia in the four hill counties in Wales and in Cumberland. In fact, what has happened is that these counties, which formerly had a low rate of leukæmia, have now come up to the level of the South of England—that is, they have come up to about 5 or 6 per 100,000 per annum. It is tempting to conclude that there is some relationship between this increase in leukæmia and the increase in Strontium 90 fall-out in these areas. Yet the more I look at the problem, the more I become convinced that this cannot be so, for the quantity of Strontium 90 involved is so utterly minute that it is not enough to produce this effect.

There must be a reason for it. It is very easy in medicine to argue falsely in this sort of way. If I may illustrate it from my own personal experience, I can show how one can go wrong. When I first heard of the increase in leukæmia in this country it occurred to me that it might be due to radiation from television tubes. Millions of people were putting what were, in fact, X-ray tubes into their own drawing rooms, which seemed to me a hazardous thing to do. So I made a "spot" map of television stations in the United States and obtained from the United States Embassy figures of the death rate from leukæmia, by areas and States, and superimposed it on the "spat" map of television stations. They coincided perfectly, and I thought we had proved that leukæmia was due to television. There was, however, one discrepancy: Minnesota showed an incidence ten times higher than any other State. The reason was that the Mayo Clinic was there and was collecting cases on leukæmia from all over the place A further analysis showed how foolish I was. I soon discovered that the incidence of leukæmia was different among coloured people and white people, and the high distribution of television stations was directly proportionate to the number of white people and the higher standard of living. And I was "up a gum tree!" Then I made tests on my own, and other people's, televisions, and I found that there was no appreciable radiation from them and no danger whatsoever. So one might very easily be misled. Indeed, I think the writer in the Lancet is misled in thinking that the increase of leukæmia in Wales and Cumberland had something to do with Strontium 90.

Yet why have the leukæmia rates in rural Wales and Cumberland gone up? I am prepared to hazard a guess. I think the much more likely cause is increased diagnostic radiology—for a very simple reason. In 1925 Mr. Ellis Stuart, at Oxford, showed that if X-rays of the child in the womb are taken, as may very properly be done, there is a slightly increased risk of leukæmia. As a result we have now cut down greatly on this type of examination land X-ray mothers only where it is essential from the medical point of view that this should be done. Since the coming of the National Health Service there has been a tremendous improvement in X-ray services throughout the country. With the Ministry of Health paying for them, the distribution of X-ray sets has gone up. In fact, if you want to buy a secondhand set, you can get one for £5. Recently I bought three, one at £5 and the others nearly as cheap. They are a drug on the market. I think that it is much more likely that increased diagnostic radiology in these backwoods or backward counties is explaining the increase in leukæmia, because they are now corning up to the level of the more forward counties in the South of England. I think that is the explanation, and I do not think it has got anything to do with Strontium 90. I quote that only to show how easy it is to be misled in interpreting geographical statistics, unless one is very stern with oneself.

All I have said is not to suggest that we should be complacent about Strontium 90, but merely that we should see it in proportion. In my view—and I hope that we shall hear from the noble Viscount whether he agrees or not—it is far less important than diagnostic radiology as a source of radiation, and it would be far more important to be extremely stringent in regard to unnecessary X-rays than in the consumption of milk: indeed, it would be a great tragedy if the consumption of milk were to be curtailed unnecessarily. I sincerely hope that the experience of the noble Viscount and his scientific advisers will confirm what I have said and answer in the kind of way that I hope it will. Nevertheless, it is clear that if atomic explosions went on, the stuff could slowly accumulate and could do serious harm. But in deciding what is right in such a matter we have to be good scientists and have to put away our emotional feelings about atomic bombs; we even have to put away our emotional feelings about X-ray machines, which are generally looked upon as rather beneficent. X-rays are often insisted on in the courts of law. That, I am afraid, is why a great many unnecessary X-rays are taken by doctors, and I think we shall have to revise our views there. Finally, I return to the subject of milk and ask whether the noble Viscount will give us an up-to-date picture of the situation with regard to Strontium 90 in milk; and I hope it will be reassuring rather than alarming.

4.52 p.m.

THE LORD PRIVY SEAL AND MINISTER FOR SCIENCE (VISCOUNT HAILSHAM)

My Lords, before I formally answer the Question on the Order Paper which the noble Lord has put down, I should like to make one or two comments of my own. My first words I should wish to be of sincere gratitude to the noble Lord for raising this subject and for doing so in such an illuminating and helpful way. I agree with, I think, everything he said, although I am not in a position to give an explanation of the rise of leukæmia in the particular counties which he mentioned. I had asked the question myself but got no very conclusive answer. I did receive the comment, from those who are wiser than I in this matter, that the absolute figures concerned are so small that the increase, although the percentage rate seems large, could really be without final significance. But I am not specially armed on this occasion to deal with this question, and this I say only because the same subject had happened to interest me.

I have been trying for some time to secure a calm and deliberate Parliamentary occasion to discuss these matters, and therefore I am doubly grateful to the noble Lord. I have tried without much success, primarily, I think, for two reasons. The subject of fall-out had become, until the happy and I hope permanent cessation of tests of nuclear weapons, emotionally connected with the warmly-felt opinions about weapons of war involving nuclear explosions. I think that serious-minded people who wished to discuss this matter dispassionately, and to enlighten the public, have been to some extent reluctant to embark on what often developed into an emotional and political discussion. Also, of course, it is extremely difficult for someone like myself, without a strict scientific training, to express about such matters opinions which will both mean something to the ordinary man and woman and will also be true, without qualification, when examined by the far stricter standards of the scientist. A chance in a million might in ordinary language accurately be described as nothing at all; but the scientist would not so regard it, and in the context of a world population of 3,000 million he would clearly be right. The result has been—much to my dismay —that, as the noble Lord rightly said, the field for two or three years has been largely left to people without any real right to speak with authority on these matters, and who have in fact spoken (and I must say this) without any due sense of responsibility to their fellow men.

I absolutely agree with the noble Lord what a disastrous thing it would be, and how criminal it would be, if anyone paid the slightest attention to warnings that milk was not an absolutely essential item of diet for children. I speak under advice of my Department in this matter, but I speak also as the father of young children—and I only add, because I think strictly I should, that as a matter of fact I have an interest in this matter as a farmer, and therefore I should disclose the fact that I am, through my cows, a producer of milk; but I hope I have not allowed this circumstance to influence my judgment in the matter in the least. Milk is an essential item of diet and, as the noble Lord, Lord Taylor, has said, there is absolutely no reason why the parents of this country should feel the slightest anxiety about giving it to their children. I entirely agree with the noble Lord that one of the main reasons, perhaps, for the remarkable improvement in children's health in recent years has been the access of children to reasonable supplies of fresh liquid milk.

I should like to take the opportunity of declaring what has been, at any rate for three years while I have been more or less responsible for some part of this, the policy of the Government in this matter. Our policy is to give all the reliable information we can upon this topic, and we think that by far the most important thing we can do is to enlighten and instruct public opinion about it. We have published everything that we have had available to us; we have suppresed absolutely nothing; and we have not sought to influence the scientists in any way in the advice which they have given and which we have published. I emphasise this, because part of the misfortune to which both the noble Lord and I have referred, of leaving the field to rather irresponsible comment, has been that some of these people have actually gone so far as to suggest that reports coming from the Medical Research Council's panel in this matter have in some way been influenced by the Government. If there were any one member of the Government who could have influenced this, it would have been I; and I can categorically assure the House that my one anxiety in this matter has been to produce as much reliable information for the benefit of the country as possible, and to secure that nothing whatever was done except to give it the fullest publicity in the form in which the scientists have produced it themselves.

We have carried out this policy, first by making and publishing the results of a monitoring service which is carried out mainly under the responsibility of the Agricultural Research Council, but with the assistance of experts from the Medical Research Council. I think I can say that this monitoring service is generally accepted in the world as being something which is probably better than any other nation has available, except, perhaps, the United States—indeed, I fancy even better than the United States. That has been the first thing we have done; and about twice a year the reports are published and are available to the public, although they are in technical form. One is more or less due now. It will in fact be published, as I shall shortly be saying, somewhere about September.

Secondly, we have taken and published the advice of a panel of experts, convened by the Medical Research Council, under the chairmanship of its Secretary, which has again commented upon the nature and extent of the hazards of ionising radiations from time to time. Speaking from memory, I think their last Report was in 1956, though there has certainly been some further work since then, and another Report is due again. I hope that it will be published about the same time as the next monitoring service report in September. The panel of experts consists of, I think, all the really authoritative experts on this subject in the country. Their reports have always been unanimous and I need hardly tell your Lordships that they are completely uninfluenced by any considerations of policy whatever, except to provide the scientific truth about a matter of importance to the community. Although it is, from my point of view, completely irrelevant, I am informed that the experts involved include scientists of quite different political opinions who are simply interested in the scientific aspects of the subject. Thirdly, of course, we participated, particularly through Dr. Pochin, in the United Nations Inquiry in 1958, which yielded an authoritative report upon the whole subject of fall-out as it affects the whole of the planet.

May I next deal with one or two specific issues? My task has been made much easier by the fact that the noble Lord has given such a lucid and admirable account of the matter. I think that in a sense it is a pity the course which discussion has taken has tended to select Strontium 90 as the only possible hazard. All ionising radiations are potentially harmful. Strontium 90 has attracted attention for three reasons: first, its long half-life, to which the noble Lord gave attention; secondly, the fact, which he also explained, that strontium has a chemical affinity to calcium, and therefore tends to be picked up and stored in the mechanism of one's body in the bone structure and therefore is concentrated in one place; and, thirdly, that Strontium 90 is not a substance known in nature, although natural Strontium is, and, therefore, any Strontium 90 which exists in the world is the result directly of the invention of the atomic bomb and other nuclear warlike devices.

But, of course, all radiation is potentially harmful. Of the various isotopes which are produced by fall-out, however, it is thought that whereas Strontium 90, by concentrating in the hones, could cause bone cancer or leukæmia, it could not, for instance, cause any genetic effects as compared with some of the other isotopes or possibly X-rays. The reason for this is that the radiations are of a type that have a very short length—possibly only one millimetre—and Strontium 90 does not, in practice, occur in the human body in the neighbourhood of the gonads and therefore it is thought quite impossible that it would cause a genetic effect.

It is, of course, picked up in rainfall and can be ingested into the body, either in drinking water or on vegetables or grain, and, of course, in milk where it has been passed through the cow who has got it from the same sources. It is measured, for the purposes of this question, in what are called Strontium units. As the noble Lord, Lord Taylor, explained, these are very tiny amounts—one micro-microcurie per gramme of calcium—that is to say, one millionth part of a millionth part of the radiation contained in a grain of radium for every grain of calcium in the bones. Sometimes when people use rather alarmist figures about the number of Strontium units which may exist on a Brussels sprout, I think they rather tend to forget both how very small those units may be, and also how very little of it will ever remain in the bones of anyone ingesting the Brussels sprout.

The noble Lord, Lord Taylor, is, broadly speaking, correct in his estimate of the effect of stopping tests. This will become apparent as and when the monitoring reports are published. The amounts involved are so small, and the tests conducted so varied, that they are nearly always about a year in arrears. The next report will tend to show the increase in fall-out due, in the main, to the Russian tests at the end of 1958 leading to a very rapidly increased fallout which reached its peak in March, 1959. Thereafter, and in the latter part of 1959, the reports will show (I cannot give the figures but, as I say, they will be published in September) a very rapid falling-off. That falling-off will, of course, continue unless the unhappy event occurs of someone letting off an-other of these things in the atmosphere when, of course, the figures will marginally increase again.

The danger measured by fall-out—perhaps I should remind the House of what probably some noble Lords will already know—was described within very wide limits by the United Nations Report of 1958. The danger of any harm resulting from fall-out by the tests which have taken place so far is very small indeed. That does not mean to say that it is not a subject which ought to be taken extremely seriously. If the tests were continued indefinitely, the danger would increase, and if increased over fifty years it would still be very small indeed in relation to other forms of radiation and other forms of damage which could be avoided. But I do not think that that is the right way to look at it, and it is not the way in which the Government look at it. The Government wish to see an end of these tests, when the amount of fall-out will drop very quickly indeed. If there were an actual war in which these weapons were used, I think it would be impossible to estimate what damage would be done. Fortunately, or unfortunately, I think some of us would not be here to worry about it, because other effects would be even more damaging. But it would be a matter of serious concern to those who did remain.

The formal Answer, which I will now give, to the noble Lord's Question, is as follows. The noble Lord asked me whether the consumption of milk amongst schoolchildren has been adversely affected by publicity given to the effects of radioactive fall-out. I am happy to say that there is no evidence that this is the case. My right honourable friends, the Minister of Education and the Secretary of State for Scotland, have received no representations from any local education authorities that the publicity given to the effects of radioactive fall-out has caused any decrease in the amount of milk drunk by children at school. The returns received by the Ministry of Education and the Scottish Education Department for the years 1956 to 1959 show that there has been some slight fluctuation in the number of children taking milk. Any decrease is attributable to the increased numbers of children now in secondary schools, where the amount of milk drunk is normally lower than in the primary schools.

There is, of course, a very great deal which I could say about this topic. I should like to say once more that, so far as I am concerned, the rational and consistent discussion of this subject is something which I greatly welcome; and I repeat that I very much thank the noble Lord for raising it and raising it so well this afternoon. If there are any other questions the House desires to ask of me I will do my best to answer them.

5.13 p.m.

LORD SAYE AND SELF

My Lords, the noble Lord, Lord Taylor, referred to a gentleman of his own name, I think in Devonshire, who discouraged the drinking of milk, and Lord Taylor suggested that he was a Liberal. I think I can assure the House that he was not voicing any official Liberal policy in such an action.

Apart from that, I should like to ask the noble Viscount opposite a question. The subject of radioactivity is a question which very much concerns civil defence, though possibly indirectly. I would suggest that the Civil Defence Service might be assisted themselves, and also that the confidence of the public in the knowledge and action of Civil Defence throughout the country would be vastly increased, if they were used for disseminating information on such a subject as this. Apart from the "high politics" which the two noble Lords have been discussing this afternoon, it is a subject which is very near to the common man, and if the information could be put over in a common way through Civil Defence, who are common people, I think it would be a great help. While on the subject, should I be in order, in saying that Civil Defence gets left out on many occasions? We had a discussion not long ago on fires in Scotland and it was never suggested for one moment that fire-fighting in Scotland should be combined in any sort of way with the Civil Defence organisation. I was disappointed that that was not the case. I urge that Civil Defence should be brought in in any sort of way it can be brought in, because at present activity is very lacking throughout the country.

VISCOUNT HAILSHAM

My Lords, I should like to thank the noble Lord for his contribution. Anything that anybody can do to put forward sound information on this subject would be greatly welcomed. I certainly take note of the suggestion that the Civil Defence should be used, and I will draw it to the attention of my right honourable friend. I am also grateful to the noble Lord for his assurance with regard to the policy of his Party. I certainly did not intend myself to impute anything to them, although it was a misfortune that some of the remarks which were made, which were open to considerable criticism, misled a lot of innocent people, probably some in every Party.