The Institute of Occupational Medicine and its research publications: 1969-2005
A Commentary by Anthony Seaton, Director 1978-1990
- Part 1: Origins of the Institute
- Part 2: Origins of the Institute (cont.)
- Part 3: Expansion
- Part 4: The European dimension
- Part 5: Outcomes of the PFR
- Part 6: Measurement of dust and Ergonomics
- Part 7: Fibre research
- Part 8: Other research and Independence
Origins of the Institute and its pneumoconiosis research
The Institute of Occupational Medicine (IOM) was founded in 1969 by the then National Coal Board (NCB) as an independent charity, but with staff employed by the NCB. From the beginning its research was overseen by a Council of Management with representatives of the NCB, the mining trade unions and independent scientists, the first of whom was Sir John Brotherston of Edinburgh University.
The initiative for IOM's foundation came from Dr John Rogan, an Edinburgh medical graduate, who after service in the Royal Army Medical Corps during the war and a period working for the Medical Research Council, had been appointed Chief Medical Officer of the NCB. Dr Rogan had initiated the NCB's Pneumoconiosis Field Research (PFR) and had persuaded the then Chairman, Lord Robens, to seek NCB approval to fund a scientific institute to take over the running of this research.
The early history of the IOM's research is inextricably bound up with the NCB and the PFR. Dr Rogan became the first Director of the IOM, combining this post with that of Chief Medical Officer. His knowledge of coalworkers' pneumoconiosis derived from his time at the Medical Research Council, whose Pneumoconiosis Unit in Cardiff had started to investigate the epidemiology of a disease which at that time afflicted many thousands of miners annually, when coal was the fuel on which Britain’s post-war industrial and social recovery depended.
The PFR started in the early 1950s with the objective of determining how much and what types of coal caused pneumoconiosis and what dust levels should be attained in order to prevent miners from becoming disabled by the air they breathed. These ambitious and clear objectives were remarkably ahead of their time, implying a requirement to measure both exposure and outcome in a large cohort of miners over a prolonged period, and to use these quantitative data to set protective health standards in the industry.
At the time of the enunciation of the objectives, it is doubtful if the computing power or statistical methods to handle and analyse the data were available anywhere. Nevertheless, the researchers recruited some 50,000 coalminers from a representative 25 collieries across Britain, from Kent to Wales to Scotland, and started a programme of airborne coal dust measurement in all the pits, combined with 5-yearly assessments of the miners by occupational and symptom questionnaires, lung function testing and chest radiography. The collieries were chosen to represent the range of mining and geological conditions in the country. Thus started the largest occupational epidemiological study ever carried out.
Back to topThe PFR was unique not only in its size but also in the detailed estimates made of individual exposures of the 50,000 participants. Initially these required retrospective estimates of exposure prior to the start of formal measurements, but after the research had started prospective determinations were made from regular surveys at the various pits and detailed occupational histories from the miners.
Chest X-Ray of PVC worker with pneumoconiosis.
Many of the TMs (eg the earliest such as TM70/04, TM70/05-09 and TM71/01-03) record the dust conditions at these pits and the results of the radiological surveys throughout the 25 years of the research.
The early work involving estimates of dust exposure was dependant on particle counts and early NCB standards were based on particle counts. A substantial advance was achieved when it the conversion from number to mass concentrations became possible following side by side trials. This enabled the old data to be used effectively in the research and encouraged the adoption of mass concentration standards by the NCB.
The MRE 13a respirable sampler was another significant advance. It was invented specifically for the research by Henry Walton (later deputy director of IOM) and Robert Hamilton, two distinguished physicists working for the NCB at the Mining Research Establishment.
This instrument, which is referred to in TM/77/08, sampled air at a pre-determined flow rate through a horizontal elutriator, collecting on a filter for weighing dust representative of that sampled by the gas exchanging part of the human lung. It was the invention of this instrument, accurately representing the size fraction of dust inhaled to the part of the lung where pneumoconiosis occurs,that gave the PFR its edge over all other previous and current research into mineral dust diseases.
This requirement to measure the environment as well as the outcome in humans also involved a wide range of scientists in the research, notably physicists, statisticians, physicians, mining engineers and physiologists. And it was this multi-disciplinary combination that was grouped together to form the core of the original IOM in 1969.
IOM's foundation coincided with the receipt of a large database, a landline link to the NCBs mainframe computer in England and a headquarter building in Edinburgh with satellite laboratories in England and Wales.
The original senior members of staff, under John Rogan, were Henry Walton, Deputy Director and head of Dust Physics, Dr Michael Jacobsen, head of statistics and Dr David Muir, head of Medical Branch. The initial objective was to analyse the data from the PFR with a view to determining the relationships between exposure to coal dust and risk of pneumoconiosis.
This first analysis was reported in R/72/01 and in the first important IOM paper, published in Nature. At the same time TM72/02 reported an association between the miners’ exposure to dust and their lung function, the first in a long series of reports and publications that ultimately led to recognition of bronchitis and emphysema as diseases of coal miners.
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Expansion: ergonomics, mechanisms of lung disease and asbestos
Very early in the history of IOM, the NCB recognised the importance of ergonomic research to the coal industry, in protection of men from adverse environments and in the design of mining equipment. This resulted in the ergonomics group, based in the Mining Research Establishment at Bretby, being transferred to the staff of IOM and to the recruitment of Tom Leamon as head of the branch. The earliest reports on this subject (TM70/01 and TM70/03) recorded studies of protective clothing and equipment needing to be carried by miners.
A 1970 report from the Dust Physics Branch dealt with release of asbestos fibres from removal of boiler lagging. This presaged a most important development of the IOM, when in 1971 Dr John MG Davies was recruited from Cambridge University to head a new Pathology Branch and to continue the research into asbestos-related diseases that he had been involved in at that university.
This work was supported by the Asbestosis Research Council, a body funded by the main companies involved in asbestos in UK and overseen by a committee including some independent scientists. This extensive programme of research on asbestos and, later, other fibres was reported in the peer-reviewed literature and no restrictions were placed on such publication.
Analysis of asbestos fibres Tby ransmission Electron Microscope
John Davies broadened the research base of the IOM, allowing an expansion in two directions - into the pathological examination of lungs of coal miners and into mechanistic studies of the causation of dust-related lung diseases.
By 1973, Dr Rogan had passed the directorship of IOM to Dr David Muir and Dr James Burns took over as head of Medical Branch. Over the period 1972 to 1977 most TMs simply reported the data gathered in the PFR. A few however indicated early stirrings of research that was to make major impacts in other areas. In particular, TM74/15 and TM75/10 reported the first of many studies of the characteristics of dust sampling instruments while TM75/14 and TM75/15 reported the earliest ergonomic studies of mining machines.
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The European dimension and the road to independence
1973 saw the accession of the UK into the European Community and this opened up the opportunity of research funding through the European Coal and Steel Community. From then on, a major impetus to analyses of the data from the PFR and mechanistic studies derived from it came from European and NCB joint funding.
The first report of an EU project was TM76/23, a study of influences of exposure underground to oxides of nitrogen on the lung function of miners. This focused on methodology and included preliminary results from underground measurements of NOx in coalmines. In the same programme, TM76/24 reported a detailed investigation of sources of dust in relation to different mining conditions, a theme followed up in TM77/02 in which airborne dust concentration at coal faces were investigated. The final report in the series which showed negative results was published as TM/81/03.
TM77/08 reported an investigation into the influences of different compositions of coal dust on risks of pneumoconiosis, pointing in particular to increased influences of high levels of quartz and of high rank (high carbon, anthracite-like) coals. These proved important subjects for further investigation.
In 1976, Dr David Muir left IOM for an academic post in Canada and was succeeded in 1979 by Dr Anthony Seaton, a chest physician in Cardiff who had worked in the US Appalachian Laboratory for Occupational Respiratory Diseases earlier in his career and was editor of Thorax. Henry Walton acted as Director in the interim and continued for a year as deputy.
In 1979 Dr Colin Soutar, an academic chest physician who had qualified in London but was then working in Chicago, was recruited as head of Medical Branch while James Dodgson was appointed the new head of Environmental Branch in succession to Henry Walton. Dr Jim Vincent from Strathclyde University was recruited as head of a new Physics Branch.
These changes coincided with a change to a Conservative Government under Mrs Thatcher and a new policy of downsizing in the coal industry, called British Coal (BC) from 1986.
A practical outcome of these political changes was that the coal research budget was reduced annually and it became necessary to seek funding increasingly from other sources. Part of this strategy was to increase the recognition of the IOM by the wider scientific community outwith those interested specifically in coal mining diseases; another was to maximise the value of the research done on behalf of BC. This is reflected in the increasing numbers of publications in the scientific literature and the higher proportion of coal-related TMs funded in part by the EC. From a strategic point of view, it was recognised that the long-term future of the IOM lay either in independence or in an alliance with a university or a Government Department.
Dr Jacobsen was appointed Deputy Director in 1980, continuing as Head of Statistics Branch. His interest in mortality studies had led to the publication in his PhD thesis of the association between mortality from lung diseases and respirable dust exposure in coal miners but the absence of an association with lung cancer. This was probably the first publication that recognised the association between dust exposure and stomach cancer, something that remains unexplained. In contrast, in TM77/13, with Fintan Hurley, he showed an increased mortality from lung cancer among coal carbonisation and tar workers and in TM78/01 his Branch reported an increased risk of lung cancer among coke oven workers in the steel industry.
Back to topThe outcomes of the Pneumoconiosis Field Research
The original results of the PFR, which had shown relations between respirable dust exposure and risks of pneumoconiosis of different degrees, attracted international attention; they were used immediately in the formulation of UK and United States coalmine dust standards and later influenced such standards world-wide.
However, many questions about coal mine dust diseases remained unanswered: what would have been the influence of migration out of the PFR population of ill and disabled workers; did coal dust exposure cause other lung disease such as emphysema, how representative of individual exposure was measurement of dust concentrations in the air in the return airway on a long-wall coalface, what were the influences of different geological conditions and different dust compositions in different mines? All these and other questions formed the basis of the programme of research into coalmine dust diseases over the following decade and the results can be found in the TMs published from 1979 onwards.
Tracer study of air flow
Some of the research was methodological. For example, TM78/04 and TM79/15 [ 9Mb, 23mins/38secs] reported respectively on the reliability of lung function tests in epidemiological studies and on the deposition of dust in human lungs, while TM80/06 reported the validity of using trained non-medical personnel as readers of epidemiological radiographs, using the ILO classification of pneumoconiosis. These “lay readers” contributed to the radiological classification of films in many subsequent research projects.
TM78/03, TM79/12, TM81/05 [ 7Mb, 17mins/29secs] and TM82/12 reported investigations of the cellular mechanisms of pneumoconiosis, a line of research that expanded under the influence of Dr John Davis, Pat Gormley, Dr Rob Bolton and, in the late 1980s, Dr Kenneth Donaldson, who had come to IOM as a technician, was awarded an NCB scholarship to study for a degree at Stirling University and subsequently obtained an Edinburgh PhD and DSc. It is worth noting, in passing, that four other technicians who started work in this era in Pathology Branch also subsequently obtained PhDs.
TM84/02 [ 5Mb, 13mins/22secs] showed the association of risk of massive fibrosis with different types of dust exposure, while TM84/05 [ 9Mb, 23mins/39secs] was the first to examine different quartz contents of coal dust in relation to observed epidemiological risks of pneumoconiosis.
TM82/22 [ 5Mb, 13mins/22secs] was the first to report on in vitro studies of mechanisms of inflammation induced by dusts, a theme that was taken further with funding by the newly founded Colt Foundation (TM86/09) and EC funded studies of in vivo effects of different dusts (TM88/01 [ 4Mb, 11mins/18secs] ); this work was to become of international importance as the IOM developed.
Further studies of the risks of pneumoconiosis were carried out on behalf of the US National Institute of Safety and Health (TM87/09) and on reasons for rapid progression of pneumoconiosis (TM87/11 [ 5Mb, 13mins/22secs] ).
The important issue of the effect on epidemiological results of migration of ill workers from the PFR population was addressed in TM82/05 and TM88/06, which showed that the risks were higher when ex-miners were included in the surveys.
Finally, in TM90/01 [ 5Mb, 12mins/20secs] it was shown that the definition of pneumoconiosis needed to be expanded to include small irregular radiological shadows, hitherto ignored by radiologists but which were related to dust exposure.
The combination of pathology and epidemiology was another unique strength of the PFR. Almost from its initiation, attempts had been made to obtain post mortem lungs from deceased miners who had participated in the research in life. Dr Anne Ruckley led this research and was able to show relationships between different pathological and radiological types of pneumoconiosis, dust exposure during life and dust content of the lungs (TM81/18 [ 9Mb, 22mins/37secs] ).
Later, in TM89/05 [ 5Mb, 13mins/22secs] , an important association between risk of pathological emphysema and dust exposure was demonstrated, leading ultimately to recognition of this disease as an industrial hazard of coal miners.
Studies of rats in vivo also gave support to the hypothesis that coal dust was capable of causing release of proteases as part of a defensive lung reaction, pointing to a mechanism of emphysema (TM88/07).
Back to topMeasurement of dust
Jim Dodgson developed and introduced interference microscopy to quantify quartz in coal mine dust. The two Dodgson and Whitaker papers on IR analysis (published in 1973 in the Annals of Occupational Hygiene) were influential in the coal industry and the methods were the basis of the analysis used in PFR in general and the Lady Victoria study in particular.
Jim Dodgson also developed a micro IR technique wjich enabled all the old STP slides to be analysed for quartz by IR. This achieved sub-microgram detection limits in the 1970s and maximised the value of the early dust measurements.
Henry Walton, as mentioned above, had contributed to the design of the MRE113a respirable dust sampler, and in 1977 with Steve Beckett published details of the eyepiece graticule that became the standard microscope device for counting asbestos and other airborne fibres.
Two other physicists, Dr Trevor Ogden and Len Birkett started work on a sampler that collected dust representative of all the air inhaled into the lung beyond the larynx, publishing their first papers in 1977/8.
Henry Walton's successor, Jim Vincent, continued an innovative research programme in the design of new sampling instruments. The effects of wind conditions on personal samplers were reported in TM79/18 and the development of a portable dust spectrometer capable of measuring dusts of different size fractions in an aerosol was described in TM82/15 [ 7Mb, 17mins/28secs] and TM87/07 [ 4Mb, 11mins/18secs] .
Sampling instruments designed or tested by the Institute
The work on wind effects on samplers led to an instrument capable of measuring total inhalable dust in the sort of conditions occurring in coal mines (TM83/15 [ 5Mb, 13mins/21secs] ) and Jim Vincent played an important international role in defining the size fractions of dust relevant to human lung disease.
A culmination of this work was the development of an inhalable dust sampler, the IOM sampler, which has become established as the standard method for measuring all dust in an aerosol that penetrates beyond the larynx (TM90/06).
A concurrent programme led by Dr Nigel Crawford followed up the work of Walton and Beckett in examining the measurement of fibrous aerosols such as asbestos. This raised important issues in comparability of counts by different laboratories (TM82/23, TM82/24, TM85/07 and TM87/19). This led to the establishment at IOM of quality control schemes for asbestos, being nominated by the Health and Safety Executive as the Central Reference Laboratory for asbestos counting in 1979, and by the World Health Organisation for man-made mineral fibre counting in 1980 (TM89/08).
Ergonomics
Over the decade 1980 to 1990, the credibility of IOM with British Coal depended largely on the ergonomic research under the Branch Head, Tom Leamon, since this had the virtue of not only making for greater safety of those in the industry but also increasing efficiency and saving costs. Its greatest contribution undoubtedly was in the areas of machine and system design, work that was passed to the machinery manufacturers and contributed to the then success of this industry.
The emphasis was on design with the operator and the maintenance engineer in mind. Examples are TMs80/10 - 80/10C, TM82/07 and TM85/12 [ 5Mb, 12mins/20secs] . Other important research included studies of heat (TM80/09, TM86/07 [ 6Mb, 14mins/24secs] ), noise (TM84/01 [ 6Mb, 15mins/26secs] and TM89/09) and lighting conditions (TM80/08 [ 5Mb, 11mins/19secs] ) in mines, safety issues arising from poor design of control rooms (TM85/06 [ 7Mb, 17mins/29secs] ), and management stress (TM87/04, an issue of no little importance at that time of pit closures).
Later, as the IOM moved towards independence, the ergonomists with a physiological interest moved to the Edinburgh headquarters while those more interested in machine design transferred to the Mining Research Establishment.
Back to topFibre research
The combination of expertise in fibre counting, aerosol science and pathology established IOM at the forefront of asbestos/fibre research worldwide. Relatively little of this appears in TM format, being published directly in the peer-reviewed literature. TM82/23, TM82/24, TM84/04 and TM85/10 record studies of different methods of counting asbestos and in TM87/01 the value of electron microscopy was explored.
John Davis and Ken Donaldson continued important studies of the toxicology of fibres, showing inter alia that persistence of fibres in the lung as a result of their insolubility was an important determinant of carcinogenicity and fibrogenicity, and that fibre length was also a critically important factor (TM87/08).
The relevance of fibre type was investigated and the differences in toxicity of different forms of asbestos were summarised by John Davis in TM80/04. An important outcome of this research, which expanded to consider fibres and other materials introduced as substitutes for asbestos, such as calcium silicate (TM83/01 [ 5Mb, 12mins/20secs] )and aramid fibres (TM87/12), was the foundation at IOM in 1990 of the Colt Fibre Research programme.
A further consequence was the involvement of IOM in a major European epidemiological study of the carcinogenicity of man-made mineral fibres, with responsibility for the assessment of workers’ exposures led initially by James Dodgson and subsequently taken over by Dr John Cherrie, on behalf of the International Agency for Cancer Research. The first publication leading to this was a study of historical exposures in the 13 factories across Europe (TM85/09 [ 5Mb, 13mins/22secs] ).
Back to topOther research
From 1978, a major objective of IOM was to obtain research work from funding bodies other than BC and the Asbestosis Research Council, both of which made annual reductions in their support. The Management Council was headed by a senior BC executive but importantly was joined by Sir Richard Doll of Oxford University and Dr Una Maclean of Edinburgh University, both of whom proved extremely helpful in the move towards independence.
Mortality studies led by Dr Michael Jacobsen, with Fintan Hurley and Dr Brian Miller were among the earliest moves away from the traditional coal research. An early study of mortality in coal carbonisation plants and tar workers (TM77/13, TM86/01) hinted at a lung cancer risk among some groups. A similar association was found among coke oven workers in a study of steel workers (TM79/14, TM82/06 [ 5Mb, 13mins/21secs] , TM90/07). Further studies on smokeless fuel workers also showed an increased risk of lung cancer (TM87/20).
The ability of IOM to deploy a multi-disciplinary team in investigating occupational health problems is well illustrated by three studies carried out over this period, in which medical, epidemiological, exposure assessment and pathological scientists were all involved.
First, after the discovery of an association between exposure to vinyl chloride and cancer of the liver, there was some anxiety that PVC production workers might be at risk of lung disease. A cross-sectional study of exposures, symptoms and lung function for ICI showed small changes in relation to high exposures, and this led to formulation of a science-based occupational exposure standard in this industry (TM79/02, TM81/08 and TM82/04).
Second, concern about the security of oil supplies in the early 1980s had led to consideration of the opening of a deep mined oil shale industry in the Rocky Mountains and, after an initial feasibility study (TM82/20), IOM was commissioned by the US Department of Energy to carry out a programme of research into the by then defunct Scottish oil shale industry, examining ex-workers and carrying out mortality and historical/sociological studies. This work, reported in TM85/02, TM85/03 [ 5Mb, 12mins/20secs] , TM85/04, TM90/02 [ 5Mb, 12mins/19secs] and TM90/03 [ 5Mb, 13mins/23secs] , confirmed risks of skin cancer and pneumoconiosis in some groups of workers but excluded a lung cancer risk, and was used by the US Governmentin its risk assessment for the industry.
Third, Trade Union concern about chest illness in wool workers led to that industry and the Health and Safety Executive commissioning research into the health of such workers. An association of wool exposure with respiratory symptoms was demonstrated for the first time, using a specially designed personal sampler (TM86/04 [ 5Mb, 12mins/20secs] ). This work also led to the formulation of an inhalable dust standard for this industry.
Occupational hygiene research was heavily promoted internally by Jim Dodgson when he became head of Environmental Branch and the agreement to proceed was the basis from which the MMMF studies, ECFIA, diffusive sampler work, dermal exposure research, exposure assessment work etc proceeded.
Independence
Over the decade leading up to 1990 the IOM succeeded in reducing its reliance on BC to the point that less than 30% of its income came from that source, and at this point BC consented to a plan for independence. This involved a donation equivalent to 3 years' funding at the current level and the gift of the premises in Edinburgh - £5 million.
At the same time, a large grant for fibre research was obtained by Anthony Seaton and John Davis from the Colt Foundation and a consortium of fibre manufacturers. John Davis and Michael Jacobsen retired and Anthony Seaton, Tom Leamon and Jim Vincent left for academic appointments. Colin Soutar succeeded as Chief Executive.
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Professor Anthony Seaton, CBE, MD (Cantab), FRCP (London), FRCP (Edinburgh), FFOM, FMedSci
Director of IOM 1978-1990
He is now emeritus professor in the Department of Environmental and Occupational Medicine, University of Aberdeen, and is an honorary senior consultant at the Edinburgh Institute of Occupational Medicine. He was editor of Thorax from 1976-82 and is presently an examiner for both the UK Royal Colleges of Physicians and Faculty of Occupational Medicine. Among many acheivements, he has served as chairman on the Department of the Environment's expert panel on air quality standards (EPAQS) from 1991until 2001; a member of the Department of Health's committee on medical aspects of air pollution from 1981-2003; and was the president of the British Thoracic Society in 1999. He is also a member of the Royal Academy of Engineering/Royal Society working group on nanoscience and nanotechnology.
His continuing research interests include environmental factors in the development of asthma, chemical neurotoxicity, the biological effects of air pollution and the interaction of environmental exposures and genetic factors in the causation of disease.