HC Deb 31 May 1960 vol 624 cc1402-12

Motion made, and Question proposed, That this House do now adjourn.—[Mr. J. E. B. Hill.]

2.6 a.m.

Mr. John Morris (Aberavon)

This is a late hour to start a debate on what I consider to be a very important subject, namely, the Second Report of the Agricultural Research Council on the amount of Strontium 90 in milk and other agricultural products in the United Kingdom. I am conscious of the fact that there are two interests at stake here. First, there is the interest of the producers, which is not to have too much publicity on this matter and, secondly, the interest of the consumers. I am also conscious that all producers are consumers, and although publicity now might affect their interests, in the long run it is of vital importance that the public—my constituents and those of all other hon. Members—should be aware of the dangers that have arisen as a result of the nuclear testing which has gone on all over the world. We should be told what the dangers are—or, if it is said that there are no dangers or hazards, we should he given a proper assurance on the matter by the Government.

Strontium 90 is a radioactive substance given off by nuclear explosions. It is most harmful. Before the series of nuclear tests took place it did not exist anywhere in the world, at least in its present radioactive form. Today, each one of us is absorbing Strontium 90 in our bones, through our diet. I do not intend to adopt an hysterical tone, but the public want reassurances.

No one anticipated such a rapid increase in the amount of contamination in our food, the soil, and in human and animal bones. The unit of measurement adopted in connection with this complicated and scientific matter is the ratio of Strontium 90 to calcium. In 1954, when the measurements were first taken, the ratio in milk was 0.5; today the average throughout the United Kingdom is 9.6. Indeed, there are wide local variations, from 7.3 in south-east England to the highest average for any area in the country, of 14.89 in west Cornwall Wales is not far behind, with 14.39. There are tremendous local variations within areas. In Cardiganshire, where I was born and bred, the figure is three times the national average. It is also high in Cumberland, with 23 units.

I now turn to the contamination of another part of our diet—drinking water. In this case the measurement is taken on another basis. Cardiff, with 1.7 units, has today four times more Strontium 90 than in 1957; Birmingham has three times more; Liverpool has doubled, and Manchester has increased by three times. The ratios for Cardiff and Birmingham, respectively, are four and five times higher than that for Oxford. It is of interest to the inhabitants of these towns that they draw their water supplies from the Welsh hills.

I will not go in detail into the amounts of Strontium 90 in the bones of young children who have been tested in recent years. In 1956 the average in the United Kingdom was .55 units. Now the average child in the United Kingdom has 2.7 units. The maximum recorded has been in a child in Manchester with 6.9 units. There are several in Glamorgan, part of which I have the honour to represent, with between 3.5 and 3. 6 units. The importance of these figures lies in the fact that there has been a startling increase in a few years, but no one anticipated when the tests were first taken that the increase would have been as startling as it is today.

Over 100 samples have been taken from the bones of young children, but few have been taken from the far West. Generally the incidence of contamination has been higher in the West than in other parts of the country. I should like to know if the Parliamentary Secretary considers that there has been sufficient testing of the bones of young children in the counties in the West, which are the most affected by contamination today.

Those are the facts. It may be asked why milk is of such importance. The answer is that milk is in everyone's diet. It is easy to test. It is produced all the year round, and it plays a considerable part in the diet of young children who are most affected by it. They partake of milk in the most important period of their lives, in the bone-formative years. It is known that Strontium 90 is ten times more effective in giving young children cancer than in the case of adults.

I submit that the key part of the Report is found on page ix which states: It appears that the 12-month mean of contamination of milk for England, Wales and Scotland increased by 40 per cent. between December, 1958, and June, 1959. The values rose relatively steadily, during the intervening period, but such information as is available from samples collected after June, 1959, shows the values have since decreased. While, on the one hand, we have had a startling increase, the samples available show that there has been some decrease. The samples last available were taken in June, 1959. Since this is a matter of vital importance, I wonder whether the Parliamentary Secretary can say what is the position today. Have later samples borne fruit along the same lines? Has the increase been continued since June, 1959, and what is the position to date?

We know that the increase of 40 per cent. in the relevant months was caused by the testing of nuclear weapons in the northern latitude between November, 1958, and May, 1959. As we know, there has been a cessation of those tests, and I wonder if the Parliamentary Secretary could assure us of the present situation.

The other part of the Report to which I would like briefly to refer is that which states It may therefore be assumed that no further increases in the level of Strontium 90 in milk are to be expected if weapon trials are not resumed and the rate of fall-out consequently continues to decrease. That is a reassuring statement, and I hope that in view of the importance of this Report, the Parliamentary Secretary, through the Minister of Science, will bring it to the notice of the Prime Minister, to show how vitally important it is to the ordinary people of the country that every pressure possible is brought to bear on the necessity to cease these tests.

Another question is whether the key factor to the contamination of milk and other products is recent deposition or accumulative deposition. What is the key factor? The Report contains a long discussion on the subject and does not come down firmly either way. The Report suggests that the evidence tends to the view that it is recent evidence, but there is a lack of complete evidence, and the Report states that the Committee has not the whole answer and would like more evidence on the point. Will the Parliamentary Secretary assure me that all possible research is undertaken in this subject in order that we may discover whether recent deposition or accumulative deposition will be the cause of contamination in the future?

Will the Government explain what is the significance of these figures? Are they at present a hazard? One school of thought suggests that any contamination is dangerous. It says that the relationship is linear and that the number of cancers increases directly with the amount of Strontium 90, even when it is present in small amounts. There is a second school of thought which says there is a threshold of safety. The Medical Research Council states that this is 100 units, that this level must not be exceeded and that if it rises much above ten units it should be a matter of immediate consideration.

I hope that the Parliamentary Secretary will tell us what is the correct view. I hope that there is a threshhold of safety. It would be a great reassurance to the public if it could be scientifically established that there is a threshhold of safety. Or is that merely a pious hope of the Medical Research Council? As I understand it, the Council intends very shortly to produce a White Paper on the spread of the hazard and its possible effects. The hon. Lady may be able to indicate when the Medical Research Council intends to issue that White Paper.

Will the Parliamentary Secretary tell me how much money is being spent on research into this very important subject? In recent months in the House we have heard reports of millions of pounds being spent on armaments and on missiles which will never be used and, indeed, which are never completed. It may be that this morning the Parliamentary Secretary will tell us that an insignificant sum is being spent on the research which is being carried out into this vital question. We should like to know exactly how much is being spent in order that we can compare it with the expenditure on weapons.

If there are any handicaps, other than finance, such as the shortage of scientists—and I am the first to concede that in this matter we need scientists of the highest calibre—we ought to be told why there is a shortage and what steps the Government are taking to eliminate it.

I am told that 40 per cent. of this country's milk is tested in accordance with the arrangements of the Agricultural Research Council and that this is taken from 200 milk depôts. Is there a very high rate of testing of milk from depôts in the west of the country? What is the method of testing in those depôts? The milk for some depôts, as I know well, comes from a wide area. When it is stated that a sample is taken from a certain depôt, is it taken from the bulk of the milk exported from that depôt? When there is such a wide variation in the sources of milk, including both highland and lowland areas, is there any differentiation between the places from where the milk comes? It might have come from an area of high density or an area of low density. We should like to know the exact significance of the sampling from these 200 milk depôts.

Local authorities in Wales have made a strong plea for special machinery to be set up in Wales to test the amount of Strontium 90 in food and other products. Several arguments have been advanced. I do not intend to go into them now, for they are apparent to all of us. Medical officers of health have certain statutory duties to carry out. The question I wish to ask is whether they have the facilities for carrying out these statutory duties as regards the contamination of food. If the local authority is not in one of the special areas where testing is carried out according to the Agricultural Research Council then it means that it is unable to discover whether food is contaminated or not.

There are certain areas not in the designated areas, which might be called the fringe areas. How are they catered for? Is the Parliamentary Secretary satisfied that sufficient attention is given in this field and have the local authorities done anything at all about the setting up of a special laboratory in the West?

The last remaining point I wish to make is that there are considerable references in the Report, into which I will not go at the moment, as to the effect of lime on pastures and whether lime does result in the diminishing of the amount of contamination of the soil and of the products from the soil. My hon. Friend the Member for Brecon and Radnor (Mr. Watkins) put that point to the Parliamentary Secretary to the Ministry of Agriculture in the debate on the lime subsidies. Has sufficient research been made in this respect with regard to the effect of lime on pastures which are contaminated?

Lastly, we are discussing—though we are few in number at this very late hour—what I consider to be one of the most important subjects that have been discussed for a long while in the House. Of course, it may be that while on the one hand science has managed to push back death, on the other hand it has crept up. It may be that not we ourselves or our children will be affected, but that generations unborn will be affected by the amount of contamination in the soil and in the products of it.

2.22 a.m.

The Parliamentary Secretary to the Ministry of Health (Miss Edith Pitt)

I welcome this debate, even though it is taking place at a late hour, because it gives an opportunity to dispel any idea that milk, whether it comes from Wales or any other part of Great Britain, is dangerous. I can well understand the anxiety which rumours or stories can cause, particularly to mothers.

Milk is an essential part of every child's nutrition, and we are proud of our Welfare Foods Service which provides a pint of milk every day, cheap or free, for the expectant mother and the child under five. Then the School Milk Service takes over and provides free milk for every child throughout its school life.

These benefits have played no small part in the health and growth of the children of this country. Nor is the value of milk confined to childhood. I can appreciate the concern that the wholesome quality of milk should be maintained. We have overcome the danger, which was once so common, of tuberculosis being caused by infected milk. It would be terrible indeed if this risk were to be replaced by another in the form of Strontium 90.

For this reason, I can assure the hon. Gentleman, we take this matter seriously. The experts, however, are emphatic that the present levels of Strontium 90 in milk are no cause for alarm or concern. I would stress that there is no complacency on the part of the Government on the dangers of fall-out. We have an effective monitoring programme which is planned and supervised by an expert sub-committee of the Agricultural and Medical Research Councils and the Development Commission.

The results of the programme are published from time to time in reports on rain, drinking water, the human diet and human bone. The efficacy of the programme depends on careful statistical design which ensures that samples are truly representative, and on the accurate measurement of small amounts of radioactivity. Statistical design is particularly important in the monitoring of food, which contains over 90 per cent. of the Strontium 90 which enters the human body in the United Kingdom.

The hon. Gentleman has suggested that the Welsh local authorities would themselves like to take samples and, having received a report on them from a Welsh laboratory, assess the results independently of the Government. Such an argument is understandable even though it overlooks the independent authoritative nature of the research councils from which the Government get advice. There are arguments against it which I will not develop fully. Surveys should cover the pattern of production and consumption of food so that statistically valid sampling schemes can be designed. It is much cheaper in time and effort for data covering the whole country to be considered together. Experience gained in one locality can then be applied, with suitable modifications for local conditions, to sampling elsewhere.

Elaborate analytical procedures are necessary to detect Strontium 90 in the minute quantities at present found in the human diet. It is much more efficient and economical to do the work in relatively large laboratories where the skilled directing staff can be properly used. The present organisation of survey work co-ordinates results so that the general situation can be assessed by the Medical Research Council. This overall assessment would be much less easy if part of the work were carried out on a regional basis, as the hon. Gentleman has in mind. If there were to be separate centres for Wales, it would be in addition to the present effort. It would be expensive and the results, being random ones, would at best add little to the value of the main programme and at worst might confuse the picture. This is not a purely financial objection; the new centre would create a further demand on the limited scientific manpower available for nuclear health and safety work.

The hon. Member has said that the present scheme involves fortnightly samples from over 200 depôts which handle over 40 per cent. of the milk produced in the United Kingdom. In answer to his point about what he called the fringe areas, I would say that this is reinforced by samples from special areas which, from geographical location, may be expected to yield the highest figures, and during 1959 over 900 samples of potatoes, green vegetables, eggs, flour and other foods were obtained.

In international discussions the British plan has been held up as a model for all nations to copy because of its excellent statistical design. We feel that there is no call for a special expense in monitoring, neither do I think it can be argued that Welsh sources fail to get a fair share of the fall-out monitoring programme.

The hon. Gentleman asked some questions and I should like to thank him for his courtesy in informing me of them in advance so that I might be advised on what he called a very technical and scientific subject. One was about the amount of money spent on research. I am not able to give the total figure to the hon. Gentleman, because the research is done in many spheres and we cannot currently calculate what is spent not only through the various councils but through other bodies engaged in nuclear research. But I can tell him that the work is going on at a number of centres and that finance is not an obstacle. On the adequacy of scientists, about which he also asked, I am advised that scientists are being recruited and trained as needed for the development of the programme.

It is well known that deposition of Strontium 90 varies more or less with the local rainfall and that therefore the general level for Wales is above the national average. I am advised that the local variations in the deposition of Strontium 90 may therefore, at present levels, be ignored for all practical purposes. Perhaps the position may be summed up by the address given by Dr. R. Scott Russell to the National Farmers' Union at Beaumaris on 11th May in which he said: We could say that man's increased exposure to radiation from Strontium 90 was comparable to that which, unknowingly, many people had accepted down the ages by moving from one district to another. On the question of the acceptable levels in bone, the proportion of Strontium to calcium which is transferred from diet to human bone is only about one-quarter of the proportion of Strontium to calcium in the diet. This is a fact which I ought to emphasise, because it is not adequately realised. In 1956 the Medical Research Council expressed the view that the level of Strontium 90 in the bones of the general population should not exceed 100 Strontium units, to which the hon. Gentleman referred when he asked me about the hazards. The Council said that, if the level showed signs of rising greatly beyond one-tenth of this value, namely, 10 Strontium units, it would be desirable to give immediate consideration to the situation. The most recently published measurements indicate that the average levels of Strontium 90 in human bone are well below these figures.

The hon. Gentleman suggested that only one or two of the samples of children's bones were taken from the West. I take it that he means the west of the Principality. Again, I have had an opportunity to make inquiries about this. I am advised that scientists try to get these bones, but so few are available from that area—very happily, as the hon. Gentleman will agree—that it is difficult to obtain samples.

A report has already been published giving a simplified account of the role of calcium and Strontium in the body. The Medical Research Council is at present undertaking a further comprehensive assessment of the significance of all the available evidence on the exposure of man to ionizing radiations, which will include an appraisal of the effects of radioactive contamination of food by fall-out.

The hon. Gentleman specifically asked me if I could give the latest figures. I am happy to be able to tell him that the report for the second half of 1959 is at present in preparation, and I hope that it will be available within the next month or two.

On the question whether contamination is caused by cumulative effect of Strontium 90 or by recent falls, I am advised that it is predominantly by recent falls. The latest figures are not yet published, but they show that the trend is downward and this is expected to continue.

Liming is really a question for my right hon. Friend the Minister of Agriculture, and no doubt the hon. Gentleman will have an opportunity to pursue this matter in the more civilised hours of this morning. While it is recognised that liming can in certain areas reduce the uptake of Strontium 90 from the soil, an extensive liming programme in the remote hill areas which show the highest levels is scarcely a practical proposition. At present levels local variations can be ignored.

I should like to make one further point on the question of the elimination of milk from the diet, because I regard this as the most important point arising from the debate. The most recently available figures give no indication that any alteration should be made to the diet of children in this country on account of contamination of milk from radioactive fall-out. Although milk is the main source in the diet of Strontium 90 from world wide fall-out, the suggestion that, for this reason, it presents a special hazard is incorrect. Hazard is best measured in terms of the ratio of Strontium 90 to calcium in the diet as a whole, and if milk were removed from the diet the calcium which it provides would have to be obtained from some other source, unless the diet was to be seriously impaired. The resulting ratio of Strontium 90 to calcium in the diet would be unlikely to be greatly changed.

Finally, while this matter is one which should be and is being carefully watched, there is no reason to be alarmed about any current levels in milk so far recorded. The simple truth is that the level is still so low that there is no ground for immediate consideration; that the trend is downward and should continue so unless air tests are resumed; that it is so small that local variations—for example, between Wales and East Anglia, and Cumberland—can, for practical purposes—though not for scientific analysis—be ignored.

Far from being complacent, the Government have a system of monitoring that is as comprehensive as any in the world, they make a practice of publishing all monitoring reports, and they have a panel of assessors of the best available scientific opinion whose periodic assessments have been published and are available in this country.

I hope that, seriously though one takes the matter, this discussion will have removed some of the concern—the unjustified concern—about the risk in milk. For that reason, I am very happy that the hon. Gentleman has raised the matter on the Adjournment.

Question put and agreed to.

Adjourned accordingly at twenty-five minutes to Three o'clock.