Work: The Continuing Experiment in Health and Safety
THE PRESIDENT, THE EARL OF HALSBURY, in opening the proceedings said:
"We are met this evening, and it is my pleasant task to welcome you, to hear the Paget Memorial Lecture for 1976 which is going to be delivered by Dr. Robert Murray who is a most interesting person as a medical practitioner, because he comes of a coal-mining family in Scotland. While he was a student he used to work in the coal mines as a vacational occupation and I think he must be one of the very few qualified medical practitioners who have snared the daily dangers and discomforts of life underground in a coal mine (Many doctors have proved heroic in contexts of accident or mine-disaster but it is not their daily occupation). And it is therefore not surprising that he was Medical Adviser to the Trades Union Congress. Dr. Murray qualified inGlasgowin 1939 and during the War he served in West Africa andIndiaandBurma. He was mentioned in dispatches and afterwards he became an Inspector of Factories in the Ministry of Labour until 1956. He then spent 5 years as a Councillor in the Occupational Safety of Health Commission in the International Labour Organisation. In 1968 he was President of the British Occupational Hygiene Society and in 1970-71 was President of the Society of Occupational Medicine. He was Medical Adviser to the Trades Union Congress from 1962-74, a span of 12 years and then elected Secretary-Treasurer of the Permanent Commission and International Association of Occupational Health in 1975. At present he is a senior partner in an occupational health and hygiene consultancy practice, Robert Murray Associates. I am now going to call upon him to deliver the Stephen Paget Memorial Lecture".
Work: The Continuing Experiment in Health and Safety
By Dr. ROBERT MURRAY, B.Sc, F.R.C.P.(Glas.), D.P.H., D.I.H.
I am honoured to have been invited to present this 45th Stephen Paget Memorial Lecture. In the long series of lectures dating back to 1927 this is the first to have been devoted exclusively to the problems of work though many previous lecturers have drawn their illustrations from the work situation.
Stephen Paget was much concerned about educating the public on the work and achievements of scientific research and with the increasing interest in the working environment, not only in this country but world wide, I am sure he would have approved of the topic, if not of the choice of lecturer.
My claims to this distinction are minimal. I am not an academic nor am I the head of a research laboratory. I carry out no experiments. My only pretension to individuality is that I have spent some 30 years observing workers in their unnatural habitat from the viewpoint of a government servant, an international functionnaire, a medical adviser to trade unions and in the last two years as a consultant to private industry, insurance companies, trade unions, and international organisations. Thus I have spent my professional life at the interface of science and industry and have had a unique opportunity of observing the effect of one upon the other. I hope that this attempt to distil the myriad impressions deriving from this experience will be as interesting to you as it has been salutary for me.
Man as the Victim of his own Ingenuity
The genius of Man in adapting his environment to his own comfort and convenience, which is a simple if comprehensive definition of work, may be regarded as a continuing human experiment, not as uncontrolled as the experiments of Nature but left to the whim of individuals to determine the conditions of the experiment according to the pressures of time and circumstance as they have varied through the centuries and as they continue to vary ever more rapidly now and in the future. Some people have suffered from their own ingenuity but, particularly since the Industrial Revolution, many more have been victims of the ingenuity of others. These have been human sacrifices to the energy gods of stone, metal, coal, oil and nuclear energy as well as the consumer gods of textiles and motor transport. The propitiation of deities is no longer part of a well organised scientific experiment but the gods of work have exacted their toll just as much as the gods of faith. In the search for the greatest good of the greatest number there has often been concealed the fate of the few.
One of the difficulties is that the conditions of the experiment are constantly changing. Work is no longer the application of muscle power to bend an unwilling Nature to our desires. It is now a highly sophisticated activity carried out with a bewildering range of tools, machines, chemicals and social organisations. Health is no longer the absence of disease but, according to the World Health Organisation, "a state of complete, physical mental and social wellbeing", which, however impossible, people are conditioned to expect. Safety has equally absolute and impossible connotations, beyond the wit or capacity of man to achieve. As our increasing sophistication provides earlier diagnosis and epidemiological techniques bring to the surface long buried hazards so our threshold of response or alarm is lowered. The hazard remains the same: it is the recognition and the response that change. Can we ensure that we have all the advantages of scientific and technological innovation without the attendant penalties? Or does scientific discovery merely extend our horizons and increase our expectations so that the Utopia which we seek moves further and further away as we approach it? To what extent are risks to health and safety acceptable and who makes the decision about acceptability? Let us look at a few examples.
The first evidence of Man's ingenuity was the manufacture of flint tools (and sadly, in this as in other examples of his skill, weapons). If you go to Grimes Graves inNorfolkyou can see in the well preserved flint mines there the conditions under which our palaeolithic ancestors dug out from the chalk the flints that were best suited for their purpose. In the nearby town ofBrandoninSuffolkthese were fashioned into spear heads, axes, knives and arrow heads with a skill that has survived the centuries. The local pub is the Flint Knappers Arms and behind it until a few years ago there was the workshop of the world's last flint knapper. Herbert Edwards, whose dexterity with a knapping hammer evoked a healthy respect for those of our ancestors who regarded it as we might regard driving a motor car, a skill which is used by only part of the mind while the remainder stays alive to the more immediate problems of the environment or the news on Radio 4.
Out of this skill however came disease, for flint is pure silica and as each fragment of flint is split from the parent stone a small puff of fine dust is given off so that according to the intensity of his work the flint knapper was exposed to dangerous amounts of this fibrogenic dust. How many of our distant ancestors died of silicosis is not known—there were other more immediate hazards at the time—but certainly in the last century, Brandon flint knappers were dying of the disease.
The replacement of stone tools by those of metal did not eliminate the hazard of flint for the early potters used it as a bedding medium for fine china. It is only within the last thirty years that flint as a bedding medium has been replaced by alumina and finally the pot kiln with its saggars of chinaware has been replaced by the tunnel kiln. Even now flint is still used in the earthenware and dust tile industry, though modern wet methods of dust control and effective exhaust ventilation of towing hoods have reduced the hazard to near zero. Any relaxation of the high standards we have now achieved would raise once again the spectre of "potters rot". As with many other hazards the price of safety is eternal vigilance—monitoring of the environment and maintenance of the ventilation equipment. The role of the British Ceramic Research Association in this respect has been of the greatest importance.
The first casualties of ionising radiations were the silver miners of Joachimstaal and Schneeberg in Bohemiawhose fate, though not the reasons for it, were recounted by Agricola in his De Re Metallica in 1556. The death rate among miners was so high from lung disease that some of the women in the area had as many as seven husbands. The cause of their death has only been elucidated within the last thirty years. The mines are not only a source of silver and cobalt but of pitchblende and the cause of death was cancer of the lung from the inhalation of radioactive dust and gas just as it is in uranium mines at the present time.
The development of the use of ionising radiations stems from the discovery of X-rays by Roentgen in1895 and of radium by Becquerel in 1896. In spite of the advantages which they have represented in terms of diagnosis and therapy their use has not been an unmixed blessing. Cancer of the skin among the early radiographers and radiologists was followed by sarcoma of the bones in luminous dial painters during the first war. When I first looked at the conditions of work of luminisers in 1947 the permissible dose of radiation was 1 R per week. Now as the result of the development of nuclear energy and the work of the International Commission on Radiological Protection the permissible level for "classified workers" is 5 R per year. There is no hope or possibility of achieving zero exposure in view of the natural background of 10 R as a lifetime dose and its doubling as a result of medical procedures and the fall out from atomic bombs, but we can by the efforts of health physicists and our own National Radiological Protection Board provide systems and standards within what we believe to be acceptable limits, though there are many people who criticise them.
Poisoning by lead was known to Hippocrates and was the first metallic poison to be recognised. The extent of its use and the severity of its effects on the blood and nervous system was noted by Bernardino Ramazzini in his classic pioneer work De morbis artificum diatriba published in 1700. Ramazzini was ostracised by his colleagues because he thought no shame to associate with common workmen, but it was by this very association that he learned about the hazards of work, just as we do today.
Lead poisoning was known to Charles Turner Thackrah, another pariah of his professional colleagues, who wrote The Effects of the Arts Trades and Professions on Health and Longevity in 1832, and to Charles Dickens in Hard Times, but the man who made the greatest impact on the prevention of the disease was Sir Thomas Legge who as the first medical inspector of factories in 1898 investigated the notified cases of the disease and devised regulations for their control. He resigned his government post when the Government of the day refused to ratify the ILO White Lead Convention of 1921. Under his tutelage the incidence of the disease declined though other men, notably Lane in this country and Kehoe in theUnited States, continued to investigate the problem in the battery industry and the manufacture of tetra-ethyl lead respectively.
Yet when I came into the field of occupational health thirty years ago I was still seeing cases of frank lead poisoning and the conditions which produced them. At that time laboratory methods for estimating lead in blood and urine were in their infancy and the criteria of lead damage were in clinical signs of poisoning, though I was using punctate basophilia as evidence of preclinical poisoning.
Since the last war there has been an explosion of monitoring techniques so that now the criteria of lead absorption is the number of micrograms of lead in 100 millilitres of blood, a biological threshold value. For some time 80 μg was regarded as a threshold but a recent meeting in Amsterdam has suggested 60 μg. The elucidation of the synthesis of haem and the role of lead in blocking that synthesis has given us other parameters of lead intoxication. Delta amino-laevulinic acid in the urine, reduction of the activity of amino-laevulinic acid dehydratase in the blood, increase of free erythrocyte protoporphyrin and slowing of nerve conduction time are all indicators of the damage done by lead and given the necessary laboratory facilities and personnel any or all of these procedures can be performed on lead workers. To what extent they are all desirable or necessary is a matter for continuing debate. Already they threaten to overwhelm our laboratory resources. Public opinion would rise up in wrath at one death from lead poisoning while it accepts, and indeed connives at, 7,000 deaths a year from motor transport which depends heavily on lead for accumulators and anti-knock agents.
Asbestos has been much in the news of late. This mineral fibre had been used in antiquity as a fireproof shroud in which the body of the dead chief was burned but it first came into modern industry in the 1880's as a fireproofing and insulating material and as the primary constituent of brake linings. Its dangerous properties were not recognised until 1901 when Dr. Montague Murray recognised the now characteristic signs of pulmonary fibrosis in a cardroom worker from theCapeAsbestosfactory in Barking. Wider recognition was by modern standards slow (though one must remember the overwhelming contribution of the tubercle bacillus to chest disease in the first 50 years of this century) and it was not until 1929 that Dr. E. R. A. Merewether made a survey of the asbestos industry and recognised the scale of the damage it had caused. Regulations were made for the industry in 1931 and the application of these regulations reduced considerably the incidence and severity of the disease among the workers in "scheduled processes".
By the time I became associated with the industry I was attending regularly post mortems on asbestos workers most of whom had worked in the pre-regulation days. At the instigation of Dr. Merewether I made a survey of the proximate cause of death in these cases and discovered to my surprise that some 25 % of them had died of bronchogenic cancer. This was in marked contrast to the potters and miners who also died of chest disease but among whom bronchial carcinoma was at a rate of 2-3 %. At the same time I became aware that the problem of asbestos was not confined to the asbestos industry as such but extended into the users of asbestos, notably the thermal and fire insulation industry in ships, power stations and even domestic installations.
In 1960 Dr. Wagner inSouth Africadescribed mesothelioma of the pleura and peritoneum in people (not only workers) exposed to crocidolite or "blue asbestos". Almost immediately cases began to be found all over the world, notably in centres of the shipbuilding industry where crocidolite had been extensively used particularly for vessels of the Royal Navy. Cases also arose among women who had been employed in making filters of crocidolite asbestos for civilian duty respirators. The sinister feature of crocidolite as compared with chrysotile and amosite asbestos is that the mesothelioma can arise many years after exposure without any signs of asbestosis in the lung.
In the early years asbestosis could be diagnosed by means of radiography of the lungs. The appearances were characteristic and different from fibrogenic disease arising from other causes. Today it is recognised that radiological diagnosis can only be made at a stage when the condition is already significantly advanced. There is no way of removing the asbestos fibres from the lungs or reversing the process of fibrosis. The only treatment is prevention. But at what level can the disease be prevented?
The British Occupational Hygiene Society published in 1968 its standard for chrysotile asbestos. This was based on data derived from the asbestos industry where environmental and personal monitoring had been carried out for many years. The level derived from these data was that exposure to 2 fibres/cc over a lifetime of work 8 hours a day and 5 days a week would result in 1 % of workers being minimally affected. This was felt to be within the area of acceptable risk and to be within the capacity of any industry using asbestos.
The standard has come under considerable criticism, first of all that it does not represent absolute safety and secondly that it is based on the fibrogenic effect and not on the carcinogenic effect of chrysotile. The difficulty is that there is no known threshold of carcinogenic effect and the principal cause of lung cancer is cigarette smoking. The evidence is quite clear that the combination of smoking and asbestos exposure is multiplicative in effect and the inference is that asbestos exposure should be reduced to near zero even though cigarette smoking cannot. I am not an apologist for the asbestos industry but its elimination, while possible in some circumstances, cannot be complete if only in the matter of brake linings. The judgment of the hazard of asbestos must therefore take into account its advantages to society. Some thought must be given to its replacement by alternative materials. The most obvious candidate, mineral wool, is itself under suspicion.
I first became aware of polyvinyl chloride in the late 1940's when it was introduced as a replacement for nitro-cellulose leathercloth which up to that time had been the main fabric for motor car and other upholstery. I was aware of the narcotic properties of the monomer but no such hazard was attached to the polymer and considering that I had seen several cases of chronic benzene poisoning in the manufacture of nitrocellulose leathercloth I welcomed the new material.
No cloud appeared on the horizon until 1966 when I saw an article on acro-osteolysis in a Belgian medical journal. This described an unusual condition occurring in p.v.c. autoclave workers, so bizarre that I took the trouble to make an English translation which I circulated to my friends. I was not so curious as Dr. Viola of the Montedison company inNorthern Italywho tried to reproduce the lesion in experimental animals. He failed but his animals developed unexpected cancers. The experiments were repeated under carefully controlled conditions by Professor Maltoni of Bologna who described the occurrence of a rare cancer, angiosarcoma of the liver, among his experimental animals exposed to various concentrations of vinyl chloride monomer down to a level of 50 parts per million.
A short time later Dr. Johnson of the B. F. Goodrich Company inLouisvilleKentuckydescribed four cases of human angiosarcoma among autoclave cleaners. This started a world wide search which has now revealed some 56 cases of the disease in this occupational group.
There was an enormous outcry all over the world and demands came from many quarters for the abolition of p.v.c. This presented a considerable economic and technical problem. The world production of p.v.c. was of the order of 10 m. tons and it was used in endless applications from floor coverings to gramophone records. There was no immediate substitute and its abolition would have created economic chaos.
In this country a tripartite committee was set up with representatives from employers, unions and government. This committee with commendable speed produced a Code of Practice recommending a permissible level of 25 ppm. The industry responded magnificently. Within a year multiple point infra red analysers had been installed in all the six factories engaged in the manufacture of p.v.c. and it was possible to reduce the permissible limit to 10 ppm. If this is not an absolute guarantee of safety it certainly reduces the chances of angiosarcoma near to the level of its natural, if rare, occurrence in the population.
These examples have illustrated that there is no such thing as absolute safety short of abolition of the offending materials or agents. This has been done in a number of cases. Phossy jaw, a necrosis of the mandible and maxilla in workers engaged in the manufacture of lucifer matches, declined after 1906 when the Berne Convention of that year outlawed the manufacture and importation of matches made with white phosphorus. Miners' nystagmus has disappeared from our coal mines with the introduction of the electric cap lamp. The Carcinogenic Substances Regulations have prohibited the manufacture and import of the substances mainly incriminated as causing cancer of the bladder in dyestuffs, rubber and cable workers—benzidine, beta-naphthylamine, 4-amino-diphenyl and 4-nitro-diphenyl.
Such conditions can only be eliminated if there is an alternative which serves the same purpose and this has already been in some cases a successful challenge to scientific ingenuity. But where no such alternative exists the agonising decision has to be made concerning at what level of exposure the agent is least likely to exert its malevolent effect. In the absence of any guarantee of absolute safety there remains only the acceptance of risk. Who shall decide and on what evidence what level of risk is acceptable? Conversely who shall decide about the benefits of lead or asbestos or radiations or p.v.c. to the community at large and draw up the human balance sheet of profit and loss?
Much has been done in this direction. The Government first intervened in the hitherto haphazard experiment in 1802 after an epidemic of typhus in the cotton mills belonging to the family of Sir Robert Peel. During the Industrial Revolution of the XIXth Century government intervention intensified but so did the nature and appreciation of the hazards. The process has continued into our own times with the establishment of the Health and Safety Commission and Executive under the Health and Safety at Work Act (1974). The attitude of employers at the beginning and during the last century was equivocal. There were many good employers but many more who resented the interference of government in the laissez-faire operation of a free market. Dickens lampooned them as the Association for the Mangling of Operatives. Workers attitudes were no more creditable. While some mute inglorious workers may have complained about death and disease arising from work there was greater attention until recently and even now on compensation for industrial accident and injury.
The new legislation gives a place on its policy making body to employers and trade unions and in one respect may be regarded as a triumph for tripartitism which is essential for the resolution of any industrial problem. But 1 am convinced that representation, however desirable, is no substitute for expertise. Unless expert evidence is put into the balance the representatives have nothing to discuss except emotion. The Health and Safety Executive includes a number of experts in health and safety but it is not a police force to control every potentially dangerous situation in industry. The trade unions are almost completely lacking in expertise. Regulations are being introduced to deal with the role of workers' safety representatives but I have considerable reservations about their capacity to deal with potential hazards unless they are supported by an adequate number of experts, at least one to each union. Without adequate support they will tend to be interested in absolute health and safety and so be at the mercy of the media and the multitude of politically motivated false prophets who point to the dangers of work and produce titles such as Peril on the Job, Health Hazards and How to Fight Them and, my favourite, Work is Dangerous to your Health. All of these publications have an underlying element of truth but they lack balance and they seek for perfection where none is to be found.
Having rid ourselves of plague and the dark Satanic mills we now have the luxury to worry about subtle hazards to such an extent that it has become almost a neurosis.
Any reputable scientist, even one as low down the scale of professional competence as I, is careful in his conclusions to the extent of leaning over backwards to admit the validity of some of the most outrageous statements made by the media and the false prophets I have mentioned. Work can be dangerous to health and safer/ but it is also advantageous to many more people than it damages.
The horizons of danger are continually extending. Today we are concerned, not only with those factors at work which may shorten the lives of workers but those—not just ionising radiations— whose effects like thalidomide may be teratogenic to the workers children or mutagenic to subsequent generations. At the same time the expectation of life and even the quality of life is constantly improving. Technological development has reduced our vulnerability to the hazards of nature. The only unchanging factor in the experiment is man himself who has the same anatomical physiological and psychological equipment as he had when he was painting the walls of the caves of Lascaux andAltamira20,000 years ago.
It is therefore necessary to consider who are the best people to strike the balance and to give the guidance that is needed to doctors, engineers, lawyers, unions, employers and governments. I believe it should be that group of people to which I am proud to belong, scientists, technologists, doctors, safety engineers, occupational hygienists, psychologists and ergonomists, mortal and fallible as they are and no matter whether they are employed by government, management, union or university, whose duty and vocation it is to reduce to the irreducible minimum the dangers of an experiment where success is not measurable but where every advance that is made is a yardstick for measuring failures. It is time for us to be more courageous in our statements of cost benefit. Adult workers recognise that there are risks in every human activity from romance to finance and they need positive guidance to help them make up their minds. I believe we should be less tentative, even if not purely scientific, accepting the inevitable result that sometimes with the best of intentions, we may be wrong.
The President thanked Dr. Murray for his interesting and informative lecture and called upon Dr. Tom Stuttaford a member of the Council of the Research Defence Society to propose the Vote of Thanks to Dr. Murray on behalf of the Membership of the Society.
"Mr. President" Dr. Stuttaford said "in proposing a vote of thanks to Dr. Murray for coming here to deliver the Stephen Paget Lecture tonight I would like to remind you of what he said—that his life in occupational health has been only successful and possible because of eternal vigilance. I think it is very appropriate, really, because he has had to display the eternal vigilance in occupational health to deal with such diverse complaints as potters rot, lead colic, and, rather more sophisticated, the diseases occasioned by P.V.C. or asbestos. And in view of medical science he has to show eternal vigilance in order to protect the general public from the unexpected hazards which are occasioned by modern pharmaceutical medicine. It is only by displaying equal eternal vigilance that the general public is indeed protected. We in the RDS like to think we help to protect you from the onslaught of those who are misinformed or mischievous. So I think that Stephen Paget would have appreciated your lecture—not only because it was informative and entertaining and also because it was stimulating, and because it showed that medical experiment is not dead, never will be dead, and will have to be preserved by effort. Thank you very much.