HC Deb 19 March 1953 vol 513 cc333-50

Motion made, and Question proposed, "That this House do now adjourn."— [Sir H. Butcher.]

9.37 p.m.

Mr. H. Hynd (Accrington)

My purpose in raising this subject tonight is to call attention to a matter which is causing grave concern to many of our constituents and to try to get some authoritative ruling from the Ministry of Health as to the alleged connection between smoking and cancer.

As a layman, I naturally approach this subject with every reserve, but we are faced with the fact, as stated in a recent television broadcast, that the total amount of tobacco smoked in this country is working out in terms of cigarettes to about 2,000 cigarettes for every person in the country every year. We are also faced with the recent statement by medical men that deaths known to be caused by cancer of the lung are 15 times more frequent now than they were 15 years ago. Making full allowance for improved methods of diagnosis, I suggest that this is a matter serious enough to warrant very grave public concern.

No hon. Member of this House will be so naive as to jump to the conclusion that because two things happen at the same time they are necessarily related, but I am afraid it goes much beyond that. More than six years ago the Medical Research Council called a conference to consider whether, on the facts as they had been revealed then by the Registrar-General's statistics, they were justified in having an inquiry. That was in 1947, and two doctors, Dr. Richard Doll and Professor A. Bradford Hill, started an important medical inquiry.

These doctors selected some 1,500 patients suffering from cancer of the lung and another 1,500 patients suffering from other diseases, and they made comparisons along lines into which I need not go in detail. It was on a scientific basis, as anyone can see who reads their reports. The first and preliminary report, published in 1950, was based on observations taken mainly in London and the surrounding counties.

Their broad conclusion was that smoking was a factor in the production of carcinoma of the lung. That was their interim conclusion. Since then the position has been getting steadily worse. In 1921 there were only 550 deaths from cancer of the lung, but in 1951, for the first time in our history, the deaths from cancer of the lung in England and Wales exceeded deaths from respiratory T.B. In 1947, the number of deaths from respiratory T.B. was 19,753. That dropped steadily until it reached 12,036 in 1951. In 1947 the figure for deaths from cancer of the lung was 9,535, and that has risen steadily until in 1951 it was 13,233.

It is interesting to note that of those 13,000 there were roughly 11,000 men, of whom only 56 were non-smokers, and 2,000 women. Immediately we are faced with the question, do more men die from this cause because men generally smoke more than women? There has, in fact, been an annual increase of roughly 1,000 in the number of deaths from this cause. Dr. Horace Joules, the medical director of the Central Middlesex Hospital, writing in the "British Medical Journal," has stated that by 1965, if this rate of increase goes on and unless something is done, the number of deaths per annum will reach 25,000. We cannot ignore figures of that kind.

The two doctors I mentioned issued their second report in December, 1952. It was published in the "British Medical Journal" for 13th December and was based on more extensive investigations in London and many other parts of the country. They said that among 1,357 men with cancer of the lung only seven, that is, about half of 1 per cent., were non-smokers as compared with 61, or 4.5 per cent., among other people with whom they were being compared, who suffered from other diseases.

At the other end of the scale 25 per cent. of men suffering from cancer of the lung smoked 25 or more cigarettes a day, or the equivalent in pipe tobacco, as compared with 13.4 per cent. of the controlled cases. Of the women with cancer of the lung, 37 per cent. were non-smokers, compared with 54.6 per cent. of the women with other diseases, and 11.1 per cent. of the cancer sufferers among women smoked 25 or more cigarettes a day, compared with 0.9 per cent. of the heavy smokers suffering from other diseases.

The doctors say: These results are essentially the same as those recorded in the 1950 Report. They support our conclusion that there is an association between smoking and cancer of the lung. They quote from the 1950 report, and go on: We therefore conclude that smoking is a factor and an important factor in the production of cancer of the lung. They add this: The present analysis of nearly 1,500 cases, or more than double the number dealt with in our preliminary report, supports the conclusion then reached, 'The association between smoking and carcinoma of the lung is real'. They tell us that smoking a pipe, although also related to cancer of the lung, appears to carry a smaller risk than smoking cigarettes, if that is any comfort to hon. Members.

Commenting on this important report, the "British Medical Journal" said in a leading article: Tobacco has been incriminated as the vehicle conveying an agent responsible for a large proportion of the cases. Out of any random sample of 400 men now aged about 55, at least 10 must be expected to die of cancer of the lung within the next 20 years. Intensive research on the chemical constituents of tobacco and tobacco smoke is now needed. That is bad enough, but I gather that similar investigations in Germany and in the United States of America have led to similar conclusions. One doctor in Chicago, for example, has been able to prove by experiment that he can induce cancer of the lung in mice by subjecting them to cigarette smoke. We are also told that in Iceland, where there has been an exceptionally low rate of deaths from cancer of the lung, the amount of tobacco smoked is also exceptionally low, amounting to not more than one quarter of what we smoke in this country.

Medicine is not one of the exact sciences—it has to proceed largely by trial and error—but I suggest that we have reached a stage, having regard to important reports of that kind, when the medical profession must make up their minds about the cause of this dread disease and whether it is really related to smoking. I also suggest that it is part of the responsibility of the Ministry of Health to guide us in these matters. Something ought to be done about it.

Following the report that I have quoted, there was a television programme called "Matters of Medicine" on 12th January this year in which a Dr. Walker, a pharmacologist from Oxford, gave an analysis of cigarette smoke. He told us that it contained pyridine, ammonia, acridine— which was tried out as a gas in the First World War—nicotine and carbon monoxide. He told us that in one cigar there is an amount of nicotine which would be lethal if it were all absorbed, but fortunately much of it escapes into the atmosphere or is retained in the butt of the cigar, or else we should probably not have our present Prime Minister.

In the same programme, Dr. Scadding produced charts showing how the average amount of tobacco smoked per person since the beginning of the century has increased and how cancer of the lung has increased during the same period. He made the same point that I made a moment ago, that there is no proof that the two things are necessarily related, just because they happened over the same period. He agreed with the conclusion of Dr. Hill and Dr. Doll, and gave it as his opinion that, although smoking cannot be called the cause of lung cancer since non-smokers also get the disease, the increase in tobacco consumption, especially of cigarettes, may explain part at any rate of the increase in the death rate from cancer of the lung and may also explain the fact that the death rate from cancer of the lung is lower in women than in men since women smoke less than men.

He also said that heavy smoking predisposes to lung cancer. His conclusion was that many people who smoke remain quite well, but the risk to health and even to life is nevertheless very real and quite definite and that we must each decide for ourselves whether the pleasure that we get from smoking is worth the risk that we take.

In that connection, amongst the letters which I have received since this subject was announced was one which came this morning, and which read as follows: I do not think that smoking or anything in the tobacco way has anything to do with the cause of cancer, as my father, grandfather and uncles have been smokers and chewers all their lives. My father dropped dead at the age of 81, and his brother lived to be 101, but my wife's father and mother died in their 40's and all their families were non-smokers. I myself have been a smoker nearly all my life and I am 76, and my brother is 82 and still likes his pipe. I give that for what it is worth. There have been other efforts to put the other side of the case, and I think I ought to refer to them, because I hold no brief for either side, but am merely asking for information.

The "Evening Standard" of 6th February criticised the television programme to which I have referred, and thought that it was unnecessarily scaring the public. In its leading article, it denied that cigarette smoking had been proved to be a potent cause of cancer of the lung, and it pointed out that the consumption of tobacco in the United States of America was twice as heavy as in this country, while cancer of the lung was only half as prevalent as here.

Professor Massey, of Leeds University, taking part in the correspondence in the medical Press, told us that, in the early part of the present century, it was taught in the students' textbooks that breast cancer might be related to the bone and metal supports in corsets in Edwardian days, but in the intervening 45 years the incidence of this kind of cancer has not fallen, and he suggested that that assumption had proved to be a false one. He also told us that, in the early 30's in the present century, it was the fashion to ascribe cancer of the lung to the tarring of the roads and the exhaust fumes from motor vehicles, and that that hypothesis has also been abandoned. We have had further statements from the chairmen of the two largest tobacco companies, but I do not think we need spend too much time quoting them, because they might not be regarded as entirely independent witnesses.

All I am saying is that these facts of which we have been made aware are disturbing, and there ought to be some guidance offered to us who are laymen in this matter and do not possess the medical knowledge with which to assess these things as we ought to be able to do. The Minister of Health ought to be able to put his experts on the job in order to tell us how much value should be placed on these reports, and, if they do feel that some action is necessary, it is then up to the Ministry to take it.

One of my hon. Friends asked a Question on 28th January, when the Minister replied that the whole question was before the Standing Advisory Committee on Cancer and Radiotherapy, which was to meet on 5th February, and that he was waiting for their observations. If that was so, I am hopeful that the Parliamentary Secretary will be able to give us further news tonight, and I hope that the news that she will give us will be such as will reassure the public on this particular question.

9.54 p.m.

Mr. Harmar Nicholls (Peterborough)

The hon. Member for Accrington (Mr. H. Hynd) initiated this debate in order to obtain some guidance from the Minister of Health on this important problem, and from that point of view he has used this Adjournment debate to very good purpose. I should like to suggest to the House, however, that we should not panic on this matter.

I think it is vital that we should recognise that the fear of cancer is perhaps more dangerous in some homes than cancer itself. We all have experience of friends or constituents who have gone through fears and torment because they felt that they had contracted this horrible disease, and if it is the case that, by raising matters here or on television programmes or anywhere else, we are adding to this fear and bringing into the homes of the people this dread, which may be ill-founded, we shall not be doing the people of this country a very good service.

I agree, however, with the hon. Gentleman that the medical profession must make up their minds. I have no doubt that the Ministry, recognising the importance of the fear of this dread disease, will try to help in giving the guidance which the hon. Gentleman wants, but I must say that the report to which he referred is more a report of statisticians than a medical report, and that the figures he quoted from a good source show one thing only. They show that there is a relationship between cigarette smoking and cancer, but they certainly do not show that smoking causes cancer or necessarily plays any big part in aggravating it. It may well be that it is not the tobacco which aggravates it, but the paper round the tobacco. We do not know.

I agree that the sooner we know the answer to some of these questions the better, but I think that while we, as laymen, must take a proper interest in this subject, we must not be parties to encouraging panic. We have been told that in addition to the statisticians' report, about which we have heard tonight, there are other committees inquiring into the subject. I, like the hon. Member for Accrington, sincerely hope that we shall have the reports of these committees quickly, and that their members will be able to come to conclusions that will be helpful and will put people's minds at rest.

But until we get those reports, and until we get the result of medical research into the subject, I feel that in our capacity as Members of Parliament we must try to restrain this panic, which if overemphasised will grow, concerning the relationship between cigarette smoking and this dread disease.

Mr. H. Hynd

I hope that the hon. Gentleman is not suggesting that I am trying to panic anybody. I tried to put the matter very moderately. I think it is our duty to get the facts.

Mr. Nicholls

As I said in my opening words, I think that the hon. Gentleman has done a great service in bringing this matter forward, and indeed in the words he used.

I feel we can rest assured that if the message to be deduced from the figures quoted was as clear as that which some deduced from the television programme, the medical profession would have given us clear guidance before now. If there was a clear relationship between cancer and cigarette smoking, then it would have been the duty of the medical profession to have given such guidance.

We must not panic, and I know that the hon. Member for Accrington neither intended to give that impression nor, in fact, did give that impression. We must make it clear that as yet there is no actual evidence which proves that people who smoke are necessarily encouraging cancer. We must also make it plain to the Parliamentary Secretary that it is the wish of hon. Members on both sides of the House that if her Department has any power at all to speed up the decisions of the committees studying the matter it should do so. In the meantime, however, we should impress upon people that there is no need to worry themselves to death and that they are not bound to get this dread disease just because they smoke.

9.59 p.m.

Mrs. E. M. Braddock (Liverpool, Exchange)

Chiefly because of the comments made by the hon. Member for Peterborough (Mr. H. Nicholls) I think it necessary to let the public know that every possible method of investigation into the matter is taking place. There is no doubt that cancer of the lung is increasing in this country. There must be a reason for it; indeed, there may be two or three reasons for it. There are branches of voluntary organisations and research organisations who are making all sorts of inquiries and investigations to find out whether it is possible to reach one or even more than one conclusion—

It being Ten o'Clock, the Motion for the adjournment of the House lapsed, without Question put.

Motion made, and Question proposed, "That this House do now adjourn."— [Mr. Redmayne.]

Mrs. Braddock

In Liverpool it is thought that smoke may have something to do with it, because the increase in cancer is not evenly distributed all over the country. The rate of increase is much larger, for instance, on urban Merseyside than in rural North Wales. It is almost certain that people smoke just as much in North Wales as on Merseyside, so there must be some factor or factors in addition to tobacco smoking which may be concerned in this increase.

It is clear from the statistics that there are about 2,000 cases a year that can definitely not be attributed to tobacco smoke. The fullest possible information should be given and the fullest investigation should be made. It would appear that the smokiness of the atmosphere or some other related factors are involved in the causation of lung cancer, since it has been shown that the incidence of cancer is greater on Merseyside and in Manchester than it is in towns where the atmospheric pollution is less. If I remember the figure rightly, the percentage of tar in smoke, particularly household smoke, is about 27, and some irritant may be responsible for lung cancer.

The British Empire Cancer Campaign are making detailed investigations on Merseyside into atmospheric pollution and its possible relationship to lung cancer, but it is not sufficient for an organisation of that kind to undertake an investigation without some serious and detailed help from the Ministry of Health, who are the responsible authority.

The Ministry of Health should accept the responsibility and take some definite steps towards making further inquiries into this subject, and particularly into the relationship between atmospheric conditions and the incidence of lung cancer. In areas where there is a large housing estate and coal fires are chiefly used for heating and cooking, the tar content in the atmosphere is very much greater than it is in areas where there are factories which have to treat smoke before it is allowed to be emitted into the atmosphere.

I believe that the Ministry of Health have been rather backward in instigating and taking responsibility for investigations of this kind. I believe that generally speaking there is at the backs of the minds of the medical profession, and particularly pf medical officers of health in areas where there is very heavy smoke pollution, a belief that that factor may have some responsibility for the greater incidence of lung cancer in industrial areas than in rural areas where there is plenty of space and smoke is not concentrated to the same extent.

There are two sides to the question of panic. If people do not know anything about it or feel that no one is investigating it at all, the effect upon them is much worse psychologically than if they know that by every possible means the Ministry of Health and those responsible in the local areas are doing something to try to discover the cause or causes of the increase in lung cancer.

The fact that it is being diagnosed more quickly and correctly may have something to do with the increase. We have to discover what are the irritants which cause the onset of lung cancer. The Report of the General Register Office on the Regional and Local Differences in Cancer Death Rates was published in 1947. Anybody who is particularly interested in the statistics will find that the death rate and the incidence rate of lung cancer differ very greatly in different parts of the country.

In view of the fact that cigarette and pipe smoking goes on all over the coun- try, it is folly to say that it is the main cause of lung cancer. There must be a cause; there may be one or two; but the Ministry should be very insistent and should take a much more detailed interest in the investigations which are now going on in Liverpool and Manchester on the question of smoke pollution and the degree of irritant in the smoke over big housing estates and areas where nothing is done to treat the smoke before it is emitted from chimneys.

Every possible avenue should be explored because there is no doubt—as the hon. Member for Peterborough said—that this subject scares people, and some of them are worried to death about it. The only way to ease that worry is to let them know that every possible avenue concerning the initial cause of lung cancer is being investigated, and that those organisations that are doing something about it are having the active and fullest support of the Ministry of Health in their endeavours to solve this very difficult problem.

10.7 p.m.

Mr. Richard Fort (Clitheroe)

I want to follow up the plea of the hon. Member for Liverpool, Exchange (Mrs. Braddock), who has drawn on her very extensive knowledge of the hospital services in Liverpool and other parts of England, and who has such a clear mastery of the facts which have been published on this vexed subject. It is clear that we have a duty to put before the Ministry and also the medical profession—and in particular the research organisations—the very widespread anxiety about the increase of lung cancer. I think that this anxiety has been stirred up by sensational newspaper articles, which have reported in a popular form what have been rather technical statistical analyses.

The Ministry of Health have a duty here. Of course they do not carry out research themselves but they have unique facilities for making known the results of the investigations as they go on. As the hon. Lady said, it is not only that people want to know generally that work is going on, but that they require an authorised statement from those who can collect the available information and make, as it were, progress reports.

Members of this House and the newspapers have a common duty in not raising false hopes. The investigation of these matters is very complicated. As the hon. Member for Liverpool, Exchange and the hon. Member for Accrington (Mr. H. Hynd) said, there are many factors which may influence the increased incidence of lung cancer, and in any scientific investigation it is always very difficult to disentangle the effect of one factor from that of another. If that is true—and it is true in all scientific investigations—it is particularly true in the field of cancer research.

Despite all the millions of pounds which have been spent in this and other countries on cancer research, one of the reasons we are still only feeling our way so much is that what those who are researching into this field are investigating is the living cell. They are trying to answer the question why a certain cell in our body suddenly begins to behave like an anarchist—which is a term we can use on either side of the House; why, instead of behaving as it normally does, in a healthy way, it suddenly begins, regardless of the other cells surrounding it, to increase its activity. Its behaviour, whether in normal or abnormal conditions, is very complicated indeed. Therefore, it is inevitable that research will be slow.

So I think that while we have the job here of reminding those who are concerned with the matter about public anxiety, and reminding the Minister of Health that it is his duty to give a progress report whenever definite information is available, we have also the duty of not raising false hopes by suggesting that if research were concentrated on this particular form of cancer, or the sums of money being spent on cancer research were doubled, we should in a short time get a much more complete answer to the problem than we have now. It is inevitably a slow line of investigation.

However, with those provisos let us from time to time ask—and press, indeed, if need be—the Minister of Health to let us know how the work is going on, and whether anything new has been discovered which will, in the first place, relieve those who may be suffering, or assist in the diagnosis of the disease; and, in the second place, show that we are making progress in this difficult, complicated medical field.

10.12 p.m.

Mr. C. R. Hobson (Keighley)

I shall detain the House for only a few moments to make two points. I think that the Minister will agree, as certainly the bulk of medical opinion agrees, that one of the causes of cancer is an irritant. It does so happen that in the manufacture of tobacco, and particularly of cigarette tobacco, a considerable amount of saltpetre is used, and saltpetre is known to be an irritant. I should like to know whether the Minister is examining that aspect of this problem.

I come to the second point, which was raised by my hon. Friend the Member for Liverpool Exchange (Mrs. Braddock) and commented upon by the hon. Member for Clitheroe (Mr. Fort), and that is the question of the incidence of atmospheric pollution. A tremendous number of new power stations have been built in this country—38 since the war. They burn a tremendous amount of coal. Between five and eight tons of coal are burned in each boiler per hour, and there is a tremendous amount of smoke coming through the vents.

There is public objection to the black smoke, and black smoke has to be treated. There are two ways of treating it. One can get beautiful white smoke by simply adding water. That often happens. I speak from many years' experience in this connection. One can put a floodlight on the chimneys of a power station, and people will say, "Look, the smoke washing plant is working to perfection," whereas in fact the case is that from the combustion there is saltpetre, and water is added, and we have the simple chemical formula H2SO4, which is sulphuric acid.

The residents of Chelsea and Battersea very often complain about the black smoke from Battersea Power Station. It has the effect of rotting their curtains. Indeed, we can find examples in the Committee Rooms of this House. It is also what has taken place in the Borough of Willesden. I know that power station engineers say, "We can neutralise that with ammonia." That is perfectly true, but these plants are very complicated and frightfully expensive, and care has to be taken to avoid breakdowns. I feel that the increased amount of atmospheric pollution that is taking place as a result of this great fuel consumption by the power stations which are being built may have some relation to the increase in cancer, particularly cancer of the lung.

That is true not only of Great Britain but also of the United States of America, particularly in the industrial areas on the eastern seaboard and in Pennsylvania. It is interesting to note from the American statistics that it is in these large industrial agglomerations, where there are vast power stations with their tremendous kilowatt capacity, that there is a high incidence of cancer. I am not saying that there is any relationship between those two facts. I do not know. I am not an expert. What I do know is that in the opinion of the medical profession an irritant is a cause of cancer, and it would be just as well if the Parliamentary Secretary could give us some information with regard to the pollution of the atmosphere through sulphur, and on the minor point I raised at the commencement of my remarks about saltpetre, a known irritant, being used in tobacco blending.

10.17 p.m.

The Parliamentary Secretary to the Ministry of Health (Miss Patricia Hornsby-Smith)

I am grateful to the hon. Member for Accrington (Mr. H. Hynd) for the moderation with which he raised this very important subject which, as many hon. Members have already said, is of the gravest possible public concern because of the rise in the number of cases of cancer of the lung. This is recognised by the Ministry as an important cause of death which demands attention in its own right. In his 1950 Report the Chief Medical Officer of the Ministry said: Cancer, and especially cancer of the lung, remains the greatest problem of medicine. I think that the figures given by the hon. Member for Accrington of the rise in the number of cases of cancer of the lung, from 2,281 in 1931 to 13,247 in 1951, must be qualified. It is only fair to qualify them, rather than that people should accept them in all their horror. It must be appreciated that much of this rise is accounted for by vastly improved diagnosis, by the universal use of X-rays in diagnosis which 20 years ago were very much less than they are today, and by the increased education of practitioners on cancer work so that they are now better able to diagnose cancer than they were hitherto.

Many of the deaths in 1931 diagnosed as due to bronchitis might today be diagnosed as deaths from cancer. So, while I do not for a moment suggest that there has not been a grave rise in the number of deaths from cancer of the lung, it is not fair to suggest that they are as horrific as the statistics of 20 years ago and now would lead one to believe.

In view of the gravity of the statistical evidence the Ministry and the Medical Research Council are not only examinng very carefully what lines of research into the problems of incidence and possible causative factors are most promising and should be encouraged, but they have also taken the initiative in stimulating new lines of research into this disease.

To deal with the report which was the basis of the hon. Member's speech tonight —the very important and valuable report by Dr. Doll and Professor Bradford Hill, in which investigation they considered the connection between smoking and cancer—I must emphasise to the House that this report must not be considered in isolation from all the other statistical and experimental work which is taking place at the present time.

Dr. Doll and Professor Hill undertook an examination, by statistical methods, of possible causative factors in lung cancer. As a result of their inquiries into the smoking habits of a number of patients, some of whom had and some of whom had not contracted the disease, they came to the conclusion that the association between tobacco smoking and lung cancer was a real one, the effect varying with the amount smoked. In the language of the statisticians, they endeavoured to show that the results were more than could be accounted by pure chance. That, I believe, is accepted by everybody.

A similar kind of investigation has been carried out in America with the same conclusion, and I would emphasise that the information we have so far received from the Medical Research Council shows that they do not regard this Report as wholly conclusive, and whilst they accept that re- search has shown a statistical relationship between tobacco smoking and lung cancer, they do not necessarily accept that that statistical relationship means a causal relationship.

Even if causal relationship could be shown clearly, tobacco smoking cannot be the only cause, because, as we know, there are many thousands of people who die from cancer who have never smoked in their lives. It is important that this point should be emphasised, as the hon. Lady said. To say that A is associated with B does not mean that A causes B.

It would be helpful if I gave the House a brief outline of the very widespread research into the various aspects of this disease which is being conducted at the present time, because I do not think that it is generally realised the extent of research which is being conducted, directly and indirectly, in medical, surgical and scientific studies throughout the country. New lines of research are being followed and perhaps I will take as an example the new experiments in nuclear physics. Only a few days ago my right hon. Friend was present when the new Cobalt 60 beam unit, a great gift from Canada, was accepted by the British Empire Cancer Council. My right hon. Friend said that we are harnessing atomic energy towards peace instead of towards war. That is merely one aspect of the battle which is going on at the present time to find a cure for this disease.

At the same time the Medical Research Council are promoting and co-ordinating the research of all the voluntary bodies mentioned by the hon. Lady. I want to emphasise again, as I did on a previous occasion in an Adjournment debate, that the total sum spent by the Medical Research Council is only a fraction of the sums which are being spent on cancer research throughout the country, because every patient in every one of the hospital units and specialised cancer units are part and parcel of the research and investigation which is being done to try to find a cure for this disease.

In the National Health Service hospitals there is most intensive research. It is going on in the Royal Cancer Hospital and Chester Beattie Institute, the Christie Hospital and Holt Radium Institute and the Hammersmith Hospital. Every patient is diagnosed and treated as part of this battle for a cure. In Hammersmith we have some of the latest and most modern equipment being used to find a new means by which we can diagnose and cure this disease. There are four linear accelerators for treatment and research in England and Wales already ordered and the rays from these very powerful instruments will be able to reach deep-seated tumours.

So far as research into cancer of the lung is concerned, at St. Bartholomew's Sir Ernest Kennaway is examining the ingredients of tobacco smoke for cancer-producing substances. That covers the point raised by the hon. Member for Keighley (Mr. Hobson) who asked about saltpetre. That is being used as one of the subjects of the research. This research is carried out under the sponsorship of the Medical Research Council, and an expert has been seconded to the Medical Research Council to aid Sir Ernest in this work.

Another field of research is the Pneumoconiosis Research Institute in Cardiff where the Medical Research Council are again carrying out experiments by a very ingenious device to see the effect on mice of living for long periods in a heavy atmosphere of tobacco smoke. The cancer research unit at the Royal Beatson Memorial Hospital, in Glasgow is carrying out further extensive research in cancer-producing agents, again related to cigarette smoke. Attention is being devoted to the possible carcinogeneity of alkaloids present in tobacco or in tobacco smoke. Research is going on in these units to establish conclusions and to find cures.

Similar research is being conducted in the United States of America. There is fortunately no iron curtain in research on this subject and the very best brains throughout the world are co-ordinating their researches in the matter. In regard to atmospheric pollution and its relation to mortality from cancer of the lung, a point in which the hon. Lady was particularly interested, study is being undertaken, again by the Medical Research Council and research is being conducted by Dr. Percy Stocks. He is devoting his time to this aspect of air pollution by sulphur fumes and the incidence of smokiness in the atmosphere and whether they contribute to producing cancer of the lung; and whether, alternatively, sunshine is a contributory factor in preventing it.

It is true to say that the difference between the incidence of cancer of the lung in rural areas and in densely populated industrial areas is very dramatic, and that is another wide field of research. A special study of the death rate of London where the density of population is great and the incidence of cancer is very high shows again evidence of greater incidence where the density of population is high and the atmospheric pollution fairly great.

So far as the arsenic content of certain tobaccos is concerned as a causation of lung cancer, all the evidence we have so far had shows that there is no support for this claim and that the amount is too small to be effective in carcinoma, I beg the House to remember that we cannot race research. All those concerned with this matter at the present time are doing their utmost to find a solution but we must see that nothing is done to panic the population while assuring them that everything is being done to find a cure for this disease One other matter mentioned and dismissed by the hon. Member who initiated the debate was research into exhaust gases of petrol and diesel engines. This has not been abandoned as a possible source contributing to cancer of the lung.

The Ministry's attitude is that we can only act on the best medical advice that we can get. The hon. Gentleman said he was a layman; we, too, are laymen in this matter. As to the Advisory Committee on cancer and radiotherapy they have not yet come to any conclusion or given us any advice going beyond the statement which I have made on the correlation between tobacco smoke and cancer of the lung. Therefore the Department can only be non-committal for the time being in this matter.

We have men of high standing on the Medical Research Council and the Standing Advisory Committee who are devoted to the cause of solving this problem as soon as they can. The House will realise that research is proceeding all the time. It is a long-term matter requiring careful sifting of results and highly complicated experimental work over a long period and the collection of vital statistical data.

The report we have had is important. It is one specific item of research which cannot be picked out in isolation or termed conclusive. Everyone in the health service shares our concern and I can assure hon. Members that the Medical Research Council will have no hesitation in carrying on further research into any particular line which shows promise and will do everything in their power to find a solution and a cure of this dread disease.

The Question having been proposed at Ten o'Clock, and the debate having continued for half an hour, Mr. SPEAKER adjourned the House without Question put, pursuant to the Standing Order.

Adjourned at Half-past Ten o'Clock.