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Asbestos Cancers to the Director of the International Agency for Research on Cancer. In 1964 the Geographical Pathology Committee of the International Union against Cancer C UlCCl set up a working group on asbestos and cancer and later issued a Report and Recom mendations (1965). A further meeting was held at the International Agency for Research on Cancer (IARC), Lyon, France, on 5 and 6 October 1972. This was organized jointly with the Medical Research Council Pneumoconiosis Research Unit. The report and recommenda tions given here will also be published by IARC in 1973, together with the complete pro ceedings of the meeting. The Committee consisted of three panels--Epidemiology, Pathology, and Physics and Chemistry. The panels met in separate sessions and at the final session (Chairman Dr. J. C. Gilson) prepared this report to the Director of the International Agency for Research on Cancer. Terms of reference 1. The Committee was to report on the present evidence relating exposure to asbestos dust to cancers, especially that obtained since the meeting of the UICC Working Group on Asbestos Cancers in 1964. 2. The Committee was to make recommendations for further research and indicate priorities for work of immediate and long-term value. in several countries. The Agency has done this as pan of their wider programme of investigating environmental carcinogens. Common memberships between the UICC sub-committee and the com mittee advising the IARC ensured continuity of policy. In October 1972 the IARC held an international conference with 137 participants from 20 countries to review all the evidence relating asbestos to cancers. Subsequently the Advisory Committee prepared-its report which is divided into two sections, first, a general review in the form of answers to a number of important general questions about the relation of asbestos to cancers of different sites and, secondly, recommendations for further research. Co-ordination of international co-operation Following the meeting of the UICC Working General review Group on Asbestos and Cancers in 1964, a sub I. Are all major commercial types of asbestos able committee of the UICC Commission on Geo to cause lung carcinoma? graphical Pathology and Environmental Carcino Yes. Since 1964 the evidence of a causal rela gens (Chairman Dr. J. Higginson) was formed to tionship has been increased by epidemiological co-ordinate work required to achieve the recom studies showing exposure-response relations for the mendations. incidence of lung carcinomas. The production of In April 1970 agreements between the UICC and lung carcinomas in certain animals by ail types of the IARC led to the winding up of the UICC asbestos supports this conclusion. The epidemio- sub-committee and the IARC taking on respon logicaLsxidence in man, however, shows that there sibility for the sub-committee's work and extending are clear differences in risk with type-of .fibre-and it by supporting certain projects on asbestos cunceyjgyiuture jjf exposure. --'2 - JSO The evider based in part on the type an excess lun the occupati' occupational much greater pollution. 3. Since 19t to asbesi The evide further pro studies in m;. asbestos. Thof asbestos e Evidence fo different occ has increase less with ami With amosii higher risk i milling. The studies that have no kno> 4. Is there theiiai i. asbestos general There is e tumours wit crocidolite r asbestos fibditions man excess risk pollution wf chrysotile a differences < urban and r been cstabii: general pub 5. Since 1 importa smokin; tributor The evide (I) Cieareenhancing exposed wo workers hav smoking to been demot jnesothffiior. --(2) J5uma =. the import: ~icer .ncer tomarch with ndaprology. done this as investigating nemberships d the com- iuity of international 20 countries to cancers, prepared its ions, first, a a number of : relation of td, secondly. asbestos able causal relademiological .tions for the roduction of all types of le epidemioas that there of fibre and Report of the Advisory Committee on Asbestos Cancers 181 2. Is there evidence of an increased risk of lung carcinoma at low levels of exposure to asbestos, such as have been encountered by the general population in urban areas? . The evidence of an exposure-response relationship based in part on past dust measurements and in part on the type of job within the industry suggests that an excess lung carcinoma risk is not detectable when the occupational exposure has been low. These low occupational exposures have almost certainly been much greater than that to the public from general air pollution. 3. Since 1964 has the evidence relating past exposure to asbestos and mesotheliomas changed? The evidence has been greatly strengthened by further prospective and retrospective mortality studies in many countries of populations exposed to asbestos. There is evidence that all commercial types of asbestos except anthophyllite may be responsible. Evidence for an important difference in risk in different occupations and with the type of asbestos has increased. The risk is greatest with crocidolite, less with amosite, and apparently less with chrysotile. With amosite and chrysotile there appears to be a higher risk in manufacturing than in mining and milling. There is also evidence from population studies that a proportion of cases of mesothelioma have no known association with exposure to asbestos. 4. Is there evidence of an increased risk of meso- thelial cancers at low levels of exposure to asbestos, such as have been encountered by the general population in urban areas? There is evidence of an association of mesothelia! tumours with air pollution in the neighbourhood of crocidolite mines and of factories using mixtures of asbestos fibre types. The evidence relates to con ditions many years ago. There is evidence of no excess risk of mesotheliomas from asbestos air pollution which has existed in the neighbourhood of chrysotile and amosite mines. There are reported differences on incidence of mesothelioma between urban and rural areas, the causes of which have not been established. There is no evidence of a risk to the general public at present. 5. Since 1964 has the evidence changed on the importance of other factors such as cigarette smoking, waxes, oils, and trace elements as con tributory factors to the cancer risk ? The evidence has accumulated indicating: (1) Cigarette smoking is an important factor enhancing the lung carcinoma risk in asbestosexposed workers, in both men and women. Asbestos workers have specially strong grounds for giving up smoking to protect their health. No association has been demonstrated between cigarette smoking and mesotheliomas. (2) Animal experiments designed thus far to test the importance of waxes and oils as contributory factors in the production of mesothelioma have shown that these contaminants are unlikely to be relevant. .13) From animal experiments there are no good clues suggesting that trace elements are likely to be a major factor in the production of asbestos cancers. 6. What other types ofcancer are related to exposure to asbestos? Prospective surveys of occupational groups exposed to asbestos have in general shown a small excess risk of some other types of cancers {in addition to bronchial and mesothelia)), especially those of the gastrointestinal tract. The excess of these tumours is relatively small compared with that for bronchial cancer. Evidence for an association with ovarian tumours has not been supported by the first large mortality survey of women previously exposed to asbestos. 7. Is there evidence of an increased risk of cancer resulting from asbestos fibres present in water, beverages, food or in the fluids used for the ad ministration of drugs? 1 Such'evidence as there is does not indicate any risk. 8. Is there evidence of a risk of lung fibrosis from low levels of exposure to asbestos such as have been encountered by the general population in urban areas? There is at present no evidence of lung damage by asbestos to the general public. The amount of asbestos in the lungs of members of the general public is very small compared with the lungs of those occupationally exposed. It is greatest where asbestos is mined or worked and lowest in rural areas. 9. Has the relationship between asbestos exposure and the development of pleural plaques been established? Pleural plaques have been associated with past exposure to all commercial types of asbestos. But additional factors, other than asbestos itself, are involved. The plaques may remain fibrous or become calcified. Not all pleural plaques are associated with asbestos. Recommendations for further research Projects which the panels rated high in priority are marked ; those which will require close co-opera tion between the Panels are marked *. Epidemiology The panel agreed that asbestos-related cancers occur in several sites in the body. The incidence of the different cancers varies with a number of definable factors and for other reasons, such as competing causes of death. Epidemiological studies w ill usually 182 Report of the Advisory Committee on Asbestos Cancers provide-information on more than one type ofcancer. Research directed at only a single type may. on occasions, be useful, but in general the inevitable uncertainties, in some cases in the differential manufacturing and applicarion sections of the industry than in the mining and milling of this type of fibre. What are the important factors in this reported difference? diagnosis of, for example, peripheral lung car (c) Crocidolite Further studies are required in cinomas and pleural mesotheliomas, and between occupational groups exposed only to crocidolite or peritoneal mesotheliomas and other intra-abdominal amosite or chrysotile in manufacturing and applica cancers, will require that more than one type is tion parts of the industry to establish more clearly studied at the same time. differences in risks due to different fibres. The panel recognized that some of the epidemio logical projects could be pursued only if there was dose co-operation between epidemiologists, patholo gists, physicists and chemists, and others, because their success will depend upon the development of improved techniques, some of which are referred to in the recommendations of the other two panels. (4) * * Studies of the amount and type of asbestos in the lungs of cases of mesothelioma (if possible by cell type) in (a) a national survey of mesotheliomas, and lb) representative samples of cases arising in groups with a definable past exposure. (5) * Studies of secular changes in the incidence of pleural and peritoneal mesotheliomas nationally and internationally. Projects (1) Further development of objective methods for early detection and surveillance of effects caused by asbestos: Topics for particular study include (6) * Epidemiological studies to investigate the association between past exposure to asbestos and cancer of sites other than lung, pleura, and peri toneum. (a) immunological techniques for screening for (7) Studies of secular trends in the asbestos content fibrosis and neoplasia. of the lungs in the general population. (b) functional tests of changes in the peripheral (8) ** Studies to relate amount and type of asbestos airways, in the lung and estimates of past dust exposure and (c) detection of pleural thickening, interval since last exposure. (d) assessment of the specificity ofsmall irregular (9) Experimental and epidemiological studies to opacities in the chest radiograph as defined in investigate possible differences ofeffect ofcontinuous ILO U/C Classification, 1971, low and intermittent high exposure to asbestos. (e) tests of the usefulness of different tech niques of chest radiography, including the use of 100 mm films, (f) development* of statistical procedures for analysis and presentation of serial observations. (10) Opportunities afforded by intercuiTent deaths should be used to interrelate radiographic appearan ces, lung pathology, respiratory function, and dust content and type in asbestos workers. Standardized techniques and classification recommended by the (2) t Evaluation of the usefulness of early detectum panels should be used. in the prevention of progressive fibrosis and asbestos cancers, also in the identification of hazardous conditions. Routine health surveillance of industrial populations should be designed to assist epidemio logical studies and should include measurement and recording of environmental dust levels. Surveillance of new entrants could be particularly valuable. Arrangements should be made to register workers so that their morbidity and mortality experience can be studied even after cessation of exposure to asbes tos. (3) * Assessment of excess cancer risks following exposure to only one type of fibre: (11) Investigation ofthe prognostic significance and aetiological factors in the development of calcified and uncala'fied pleural plaques in different environ ments. (12) Investigation of talc-exposed groups in mining and manufacturing to establish any dif ferences in morbidity 'or mortality which might be related to the amount and shape of the fine respirable panicles. ; (13) Devcioptfient of cost/benefit analyses to study the health, safety, social, and economic interrelations of the use of asbestos. la) Chrysolite The much higher cancer risk reported for chrysotile textile workers compared Pathology and experimental pathology with mine and mill workers requires explanation. The panel reviewed the progress made on the 1964 How much is explicable by differences in size of airborne fibres and past dustiness? There is need to make more use ef past dust records for relating to UICC recommendations. It was agreed that con siderable progress had been made on the majority of the recommendations. Some require further study. indices of disease. or modinguion of previous methods of investigation: (h) Amosite The excess lung carcinoma and these arc included in jhc list of recommendations mesothelioma risk i> apparently much greater in thejg^that follows. The recommendations artrdiyided-injo three categori clinical rescan Mt Projects 1. Asbestosis (1)* Further methods for structural fea committee sh the Physics : accelerate woi (2) The me' asbestosis sh different obse 2. Carcinom (1)*? An in asbestos expc asbestosis als was considere (2) A comp occupational! exposed, inch smokers, in r< tumours and be of value. 3. Mesothel (1) The Int< National Pa meeting5 hav mended that and membei extended. Tl ensure unifor of histologic. Iaborativc s; Panels is re thelioma can pleural fluid, competent c (2) To imp: urgent need liomas or, al section on n WHO Mor Criteria for description should be in 'The Internal (USA). Profe (Finland). Pro H. Oito (FR Roiu<ch Kil Wohler (Siu real 'Ujrij Nlclhcrjand>- -- 4 i of the 'type this quired in idolite or 1 applicare dearly sbestosin tssible by heliomas, arising in :idence of mally and igate the estos and and peri ls content f asbestos asure and .tudies to antinuous :stos. :nt deaths appearanand dust dized --w oy the cance and f calcified t-environ- roups in any difmight be respirable s to study rrrelations >gy t the 1964 that conlajority of aer study, .-stigation; icndations vided into Report of the Ad' hory Committee on -Uhestos Crntrer* jrx three categories: morbid anatomy and histology, Clinical research clinical research, and experimental studies. (1) ** Monitoring by immunological methods of populations exposed to asbestos should be in Morbid anatomy and histology vestigated to ascertain whether it is possible to Projects recognize those who are developing, or will develop, 1. Asbestosis tumours. (1) * Further consideration should be given to (2) The use of chromatographic methods for the methods for determining the amounts, types, and study of mucopolysaccharides and other tumour- structural features of asbestos in tissue. A sub associated substances in pleural fluids should be committee should be established with members of explored. Sensitive methods might be developed and the Physics and Chemistry Panel and others to applied to identify secretory products of meso accelerate work on this problem. theliomas in blood and urine. (2) The methods for assessing the severity of asbestosis should be tested for consistency by Experimental studies different observers. (1) * Information is required about the role of fine 2. Carcinoma panicles, especially the influence of fibre size, in the (1) V An investigation. of whether reduction of induction of tumours. These studies should be asbestos exposure to levels below those producing extended to include fibres other than asbestos. A asbestosis also abolishes excess risk of carcinoma was considered important. (2) A comparison of lung carcinomas in persons occupationally exposed to asbestos and those not so sub-committee should be established to review the need for. and arrange the distribution of. standard samples of asbestos and other fibres in addition to the UICC reference samples. exposed, including both cigarette smokers and non- (2) *. The fate of inhaled panicles of various sizes, smokers. in respect of sites of origin and cytology of shapes, and chemical compositions should be studied tumours and presence or absence ofasbestosis, would to determine more precisely the quantities and sites be of value. 3. .Mesothelioma (1) The Internationa) Panel of Pathologists' and National Panels established following the 1964 meeting' have served a useful purpose. It is recom mended that panels be established in-other countries and membership of the Internationa! Panel be extended. The main purpose of these panels is to ensure uniformity of diagnostic criteria and recording of histological types of diffuse mesothelioma. Col laborative study of histology slides in National Panels is recommended. The diagnosis of meso thelioma can be made by exfoliative cytology of the pleural fluid. If the cytological diagnosis is made by a competent cytologist. biopsy may be unnecessary. (2) To improve consistency of diagnosis there is an urgent need for a comprehensive atlas on mesothe liomas or, alternatively, for inclusion of an enlarged section on mesotheliomas in the new edition of the WHO Monograph on Tumours of the Lung. Criteria for diagnosis by exfoliative cytology and a description of the fine structure of mesotheliomas should be included. of initial deposition, change within the body, and later retention. The feasibility of increasing fibre elimination by various methods should be explored. Studies should be made of means of reducing the fibrogeniciiv and carcinogenicity of fibres already retained in the lungs. (3) The use of cell and organ culture, including mesoiheliat tissue from man and other species, should be further investigated with a view to develop ing methods of screening dusts for fibrogenic and carcinogenic properties. (4) Further studies should be carried out to determine the nature of the combined effect of tumour induction when animals are exposed to asbestos dust and cigarette smoke, metals or other chemical carcinogens, including those which act systemically, such as nitrosamines. (5) Inhalation experiments should be extended to test various types of fibre; of special interest are forms of chrysotile and crocidolitc. including the finer grade materials. (6) It was felt that studies of the pathological effects of asbestos on species other than rodents would be of value. 'The International Panel conusts of: Dr. M. Kanncrstein (USA). Professor D. Magner tCanada). Dr. L. Meunnan (Finland). Professor W_ T. H. McCauthey (Eire). Professor H. Ouo (FRGl Dr. H. Planuydt (Netherlands). Dr. E. Roitzsch tGDR). Professor L. Sami (Italy). Professor I. (7) The effect of long-term ingestion of fibres of various, sizes, shapes, and chemical compositions should be studied. (8) Effects of fibres and associated metals on metab olism ofTarget organs should be investigated. Webster (South Africa!, and Dr. J. C. Wagner (UK) as Secretary. :Greal Britain. South Africa. United States. Canada. Netherlands. Physics and chemistry The panel reviewed the progress made on the S' 184 Report of the Advisory Committee on Asbestos Cancers UICC Recommendations. The proposals for the have a marked influence on their carcinogenicity, preparation and characterization of the UICC reference samples of asbestos had been satisfactorily implemented, and the panel recommended that a list of references to papers featuring the samples should be distributed to investigators in this field. Considerable progress had been made on methods of identifying the type of fibre in tissues but a quan titative method when several types of fibres were present had yet to be developed. The panel discussed the further contribution that physical and chemical studies can make to research on the biological _ effects of asbestos and other fibrous materials. Of especial interest are the effects of fibre size and shape on the retention of.material in the lungs, the site of deposition, the migration of fibres within the body, and their carcinogenic or other biological activity. The following recom methods arc required for quantifying dispersion. W) Inhalation studies require precise control of the characteristics of the dust clouds. Improved methods of dispensing fibrous dusts in such investigations need to be developed. (e) Methods are available for collecting the impor-. tant size fractions of dust clouds in inhalation studies when the panicles are of compact shape. Similar methods must be developed for fibrous panicles. (/) The present membrane filler methods of measuring the levels of airborne asbestos dust require standardization. This should be done by interlaboratory trials on a continuing basis. Particle counting by electron microscopy should also be developed. Gravimetric assessment methods and the automation of panicle counting should be explored. Dr. M. Beck Dr. H. Bohl Dr. N. Day Professor P. Dr. J. C. Gi D. J. Lepou Professor J. Mr. C. E. R Dr. H. Saka Dr. I. J. Seli mendations were made: 3. Inhalation studies* Dr. G. K. S' Projects 1. Materials for experimental work" (a) Supplies of asbestos from relevant sources should be obtained where there is evidence of varia tion in geological form, trace element content or significant biological findings. (h) Small samples of various fibrous materials should be prepared for studies on the influence of fibre size and shape on carcinogenicity. For this purpose the samples should be milled to different degrees of fineness. (c) For investigations on the influence of particle shape and size, on the inhalation and subsequent fate of asbestos fibres a chrysotile and an amphibole of fibre length greater than the UICC samples should be prepared. 2. Methods'* (a) There is an urgent need for the quantitative assessment, size analysis, and characterization of particles and fibres in the lungs and other organs. Details of available methods should be circulated, international comparisons undertaken, methods standardized, and new techniques developed. ib) No methods are at present available for the preparation of fibres in narrow ranges of diameter and length in sufficient quantities for inoculation experiments. Techniques for these purposes are urgently required, especially in view of the advantages such graded samples could provide for investigating Considerable information is now available on the deposition, retention, and migration of panicles of compact shape. Recently developed methods, especially radioactive tracer techniques, should be used to obtain similar knowledge for fibrous par ticles. This information is needed to identify the biologically important size fraction and to help inter pretation ofepidemiological and pathological studies. 4. Occupational and environmental studies The use of both fibre counts and gravimetric methods for assessing asbestos dust concentrations should be encouraged. Data collected over an extended period will be particularly valuable in identifying the parameters of the dust which can be correlated with epidemiological evidence on the health hazard. 5. Physics and chemistry panel It is recommended that an international panel be established to assist in implementing these recom mendations. The panel would periodically review requirements for materials for experimental work, provide guidance on physical and chemical prob lems. and arrange' national and international standardization trials. References ILO U;C International Classification of Radiographs of Pneumoconioses 1971. Occupational Safety anti Health Series. International Labour Office. Genera. 1972. I Dr. W. Smit i Dr. G. Wrig Dr. A. C. A Mr. G. BenDr. P. Bogo Dr. M. Kar Professor \\ Professor D Professor H Dr. H. T. P Dr. M. Star Dr. J. C. VV J Professor S. i Professor 1. the influence of these physical factors on the carcino genicity of fibres'of deferent materials. (c) Since the degree of dispersion of fibres (es pecially chrysolite) u>ej in inoculation studies may Report and Recommendations of the Working Group on Asbestos and Cancer consencd under the auspices of the Geographical Pathology Committee of the International Union against Cancer I U'ICCi i I9f>5). Brithh Journal of. tiuliiiirinl Mrtlicinr. 22. W'5-I7l. Dr. L. Lc B Mr. G. W. Dr. S. Holn UnattCjo a t 4 i- iceeniciiy. i. u..of the d methods rstigations the imporinhalation act shape, or fibrous :ihods of .stos dust done by is. Panicle d also be ds and the : explored. Me on the >anic!e$ of methods, should be brous parlentify the help intercal studies. s travimetric rcntrations 1 over an "ble in an be ce on the 1 panel be ese recomllly review ntal work. iica.1 probtemational l-.ocrjphs of ar.d Health . :972. c Group on ispices of the .International r Journal oi Report of the Advisory Committee on Asbestos Cancers 185 Dr. M. Becklake Dr. H. Bohlig Dr. N. Day Professor P. C. Himes Dr. 1. C. Gilson D. J. Lepoutre Professor J. C. McDonald Mr. C. E. Rossitcr Dr. H. Sakabe Dr. 1. J. SelikofP Dr. G. K. Sluis-Cremer Dr. \V r-fnither Dr. G. right Dr. A. C. Allison Mr. G. Berry Dr. P. Bogovski Dr. M. Kannerstein Professor W. T. E. McCaughey Professor D. Magner Professor H. Otto Dr. H. T. Plameydt Dr. M. Stanton Dr. J. C. Wagner Professor S. Waianabe Professor 1. Webster Dr. L. Le Bouffant Mr. G. W. Gibbs Dr. S. Holmes Epidemiology panel McGill University. Department of Epidemiology and Health. 3775 University Street, Montreal 110. Quebec. Canada Municipal Hospital Ludenschetd. 588 Ludenscheid. Germany International Agency for Research on Cancer. Unit of Epidemiology and Biostatistics, 150 Cours Albert Thomas. Lyon 69003. France Queen's University of Belfast, Department of Therapeutics and Pharmacology. Institute of Clinical Science. Grosvenor Road. Belfast BTI2 6BJ. Northern Ireland. UK Medical Research Council, Pneumoconiosis Unit. Llandough Hospital, Penarth. Glamorgan. Wales. UK (Chairman) Sj\. Etemtt. Medical Department. 2920 Kapelle-op-den-Bos. Belgium McGill University. Department of Epidemiology and Health. 3775 University Street. Montreal 110. Quebec, Canada Medical Research Council. Pneumoconiosis Unit. Llandough Hospital, Penarth. Glamorgan, Wales. UK Ministry of Labour. .Department of Industrial Physiology'. National Institute of industrial Health. 205! Kizukisumiyosnicno. Kawasaki. Japan Mount Sinai School of Medicine. Environmental Sciences Laboratory. 100th Street and Fifth Avenue, New York, NY 10029. USA South African Medical Research Council. National Research Institute of Occupational Diseases, PO Box 47SS. Johannesburg. Soutn Africa British Asbestos Research Council, 114 Park Street. London WIY 4AB. England. UK Department of Medical Research. St Luke's Hospital. 11311 Shaker Boulevard. Cleveland, Ohio 44101, USA Pathology panel Medical Research Council. Clinical Research Centre. Watford Road. Harrow, Middlesex HA1 3UJ, England. UK Medical Research Council, Pneumoconiosis Unit. Llandough Hospital, Penarth. Glamorgan, Wales. UK International Agency for Research on Cancer, Unit of Environmental. Carcino gens, 150 Cours Albert Thomas, Lyon 69008, France Bamert Memorial Hospital Centre. Paiholoev Department, 680 Broadwav. Paterson. NJ 07514, USA Trinity College School of Pathology. University of Dublin. Dublin 2. Eire Canadian Tumour Reference Centre. Department of Pathology, University of Ottawa. Ottawa, Ontario, KIN 6NS. Canada Direktor des pathoiogischen Instituts der Stadt Krankenanstalten. Beurhausstrasse 40. 46 Dcrtmund, West Germany Stichting Streeklaboratorium "Zeeland", Noorpoortplein 2. Middleburg. The Netherlands National Institute of Health. Department of Health. Education and Welfare. Bcthesda. Md. 20014, USA Medical Research Council, Pneumoconiosis Unit. Llandough Hospital, Penarth. Glamorgan. Wales. UK (Chairman) National Cancer Centre, Research Institute, Department of Pathology, Tsukiji. 5-1-1 Chome. Chuo-ku, Tokyo, Japan Medical Research Council South Africa, National Research Institute for Occupa tional Diseases. PO Box 4788, Johannesburg. South Africa Physics and chemistry panel Centre d'Etudes et de Rechetches des Charbonnages de France, Vemeuit-enHallatte. B.P. No. 27. 60550 Crtal, France McGill University. Department of Epidemiology and Health. 3775 University Street, Montreal 110. Quebec, Canada Asbestosis Research Council, c/o Turner Bros. Asbestos Co. Ltd., PO Box 40. Rochdale. England. UK 'Unable to attend. 186 Report of the Advisory Committee on Asbestos Cancers Brit. J. itt. Mft-A. Morgan Dr. F. D. Pooley Or. S. Speil Dr. V. Timbrel! Dr. R. S. J. du Toil Mr. W. H. Walton Atomic Energy Research Establishment, Health Physics and Medical Division. Building 364, Harwell, Didcot, Berks, England, UK University College of South Wales and Monmouthshire, Department of Mineral Exploitation. Newport Road, Cardiff. Wales. UK A stJohns-Manville Research and Engineering Center, Greenwood Plaza, Denver, JColorado, USA Medical Research Council, Pneumoconiosis Unit, Llandough Hospital. Penarth, Glamorgan. Wales. UK i Government Mining Engineer's "Division. Department of Mines. PO Box 1132, Johannesburg. South Africa Institute of Occupational Medicine, Roxburgh Place. Edinburgh EH8 9SU, ii DAVIC Schoolc Scotland. UK (Chairman) The January (1973) Issue Morbidity of British coal miners in 1961-62 F. D. K. Liddell Mortality of British coal miners in 1961 F. D. K. Liddell A study of the acute and chronic changes in ventilatory capacity of workers in Lancashire cotton mills G. Berry. C. B. McKerrow, M. K. B. Molyneux, C. E. Rossiter, and J. B. L. Tombleson Use of radioisotopes in the study of textile workers with byssinosis and chronic lung damage L. S. Vaskov A survey of respiratory disease in cotton operatives. Part L Symptoms and ventilation test results A. J. Fox, J. B. L. Tombleson, A. Watt, and A. G. Wilkie A survey of respiratory' disease in cotton operatives. Part II. Symptoms, dust estimations, and the effect of smoking habit A. J. Fox, J. B. L. Tombleson, A. Watt, and A. G. Wilkie Computer simulation of industrial hazards E G. Knox Relationship between sickness absence and length of service S. J. Pocock Radiological changes in carpal and meracarpal boues and phalanges caused by chain saw vibration T. Kumlin, M. WllKERI, AND P. SUMARI Effect ofsilica on phospholipids in the rat lung M. Grunspan, H. Antweiler, and W. Dehnen Industrial ammonia gassing M. Walton ' Notes and miscellanea Safety and health at work: The Robens Report R. C. Browne Employment Medical Advisory Service Margaret Gracey Book reviews Information section A number of copies are still available and may be obtained from the Publishing Manager, -British Medical Association. Tavistock Square. London WClH~93TCpnce 1'25 (1'50 in countries-ovcrscas; "U:S.a: S3.60). J t F. oc w tf T w al te rr o> E rc 0 d (1 a c 1 h c F g P k P F c c il t F Claims t undertak being al extensive environn