Document 93OBz99xB4zkvX285YaQo31ND

Or. a. Holssa Mr. W.f. Howard, sit Ltd., Maoehaatar. *>l Copft AM/Off VfH BSL Canoar fro* Aabaatoa UthMif, 1976. fir. S.C. Lawinaobn baa aada a Busbar of aharjoa to tha ioou--at fomrdsd with four not# of 6th May Bo baa alaoa dlaciuaoad tha ohancaa with so and obtains* -mr agrtasaot to thas. I aoaloat aur propoaad mmdad vamloo barawlth. 0. jfelssa. toe. THE ASBESTOS INFORMATION COMMITTEE Memo toi AIC Sub Conalttee cc. sh/hcl from Hr V P Howard l0flA?l9% Thursday 6th May 1976 I enclose herewith the draft of sons questions and answers which Mr Cross proposes should be produced by the AIC. I shall be grateful for your consents. V P HOVAJtD SECRETARY vph/jg 037625 CANCER FROM ASBESTOS? ' Does asbestos give you cancer? It is extremely unlikely. If you are a heavy smoker end have developed asbestosis after working vith asbestos for a number of years in very dusty conditions before the Asbestos Regulations 1969 came into effect you may develop lung cancer. In reeent years there have been about 80 such ease.s reported each year, compared with 30.000 a year due to smoking cigarettes. There is another type of cancer, also very rare, called mesothelioma, for vhich, since IpG&t asbestos has been believed to be one of the causes wW*? Vbat is mesothelioma? It is a* malignant tumour vhich affects the pleura, the lining of the chest vail, or the peritoneum, the lining of the abdominal cavity vhere the stomach lies. Bov rare is this mesothelioma? Dr Greenberg, of the EMAS, has estimated that there are about 200 cases a year at present, of vhich i> are in the pleura and about % in the peritoneum. These compare/ vith deaths from cancer from all causes reported annually in the U.2C. Included in EMAS survey are listed as "possibly" due to casual, public, exposure. ? 'j Vhy is asbestos thought :to be a cause of mesothelioma? In 1&&6, Dr Vagner reported an untypical group of this rare cancer in the Cape Province of South Africa* Looking for some common circumstance vhich might have contributed, he observed that these cases had occurred in an asbestos mining area. Xnovlng of the risks of asbestosis. Dr Vagner investigated further and found that all the persons concerned had either worked with asbestos or otherwise inhaled asbestos dust ever a number of years in that arid climate. Subsequent studies in other places shoved that more cases of mesothelioma than would normally be expected had occurred in situations vhers a high possibility of inhaling asbestos fibres had existed for some years - that is, in and around asbestos factories and in places, such as ship building and repair yards vhere unusually high use of asbestos materials had been used in very dusty conditions. -2- Q How do you account for tho reported cases of mesothelioma in people with very 'slight contact with asbestos? /*--> \ A Zt la accepted by the neat expert j6t independent researchers that mesothelioma murt be caused by other factors than asbestos* since for many years cases have been reported where there is no possibility of asbestos being involved* In all investigations t there are found to be A large proportion of recorded cases where there is a clear history of exposure to asbestos dust. There is always a group (varying from 10# to 30#) where it is clear that asbestos was not present. In between these two groups there Is an area where a "possible" (though not probable) opportunity of inhaling asbestos fibres has been suggested, such as in "home handyman" work saving asbestos boards or even being related to an asbestos worker. Q Shouldn't such a possibility be taken seriously? A Of course. That is why so much effort has gone into endeavouring to establish Just what connection can be proved between asbestos and the reported cases. Every possible connection, however conjectural, is sought out. Unfortunately, in such cases the information available is very subjective and unreliable, first, is is acknowledged that diagnosis of mesothelioma is very ' difficult. In the U.K. this difficulty is now appreciated, and the medical profession tries to reduce the possibility of wrong diagnosis by relying on the assessment of post mortem material by a panel of five pathologists with specialised expertise. Only if a majority of these experts confirms it la the case concerned accepted as a 1 mesothelioma, and where there is not unanimity, the ' "benefit of the doubt" is given in favour of the me s o thelloma Zn those confirmed cases of mesothelioma, except in those where well established occupational exposure is known to have occurred, evidence of possible exposure is hard to : 1 establish. Zt is usually possible to obtain only the briefest and most tentative information of the occupational history over the life time of the deceased from friends or relatives. It is veil known hov uncertain a person's own memory can be - few of us possess the capacity for detailed total recall over a life time (the relevant period for a damaging exposure to have occurred is 13 to 30 years ago). Q Even so, does not this indicate that some people may get cancer by slight exposure? A The eases of mesothelioma where unquestionably exposure to asbestos is a contributory factor relate to conditions in factories many years ago, or usually 30 to bO years ago, or more recently from people engaged in such occupations as lagging or spraying, before control methods were effectively developed or the Asbestos Regulations 1969 required precautions to be taken in those occupations. continued.... O CO cr ro 7 Even under these conditions, where regular occupational exposure to dust levels many times higher than those stipulated as safe today must have occurred, the percentage of people developing mesothelioma is small. The great majority have not been affected. If such is the ease when such relatively high exposure has been experienced, common sense suggests that the extremely small amounts of dust, often almost undetectable, which might be encountered by the general public in its nerval use of asbestos products in the home or daily life, is unlikely to be a danger. Vhy is it suggested that blue asbestos is particularly haxvful? Dr Vagner*s original reports referred to eases in a mining area where the type of asbestos mined was blue (erocidolite). A similar incidence of mesothelioma has not been found in other mining areas, including those in Transvaal, where erocidolite has also been mined for over 50 years. Subsequent attempts to determine if mesothelioma occurs with exposure to blue asbestos in manufacture or use has been made^ difficult because in almost all asbestos factories, more than one type of asbestos is used. In a majority of 'the reported cases where asbestos is believed to have been a elear cause, blue asbestos has been.present, but it is also significant that in all of these cases, the exposure levels have been very heavy. By its nature, blue asbestos has been very suitable for insulation products, which have tended to be in such a fora as to be dusty in manufacture and use -- for example, textile manufacturing, insulation mattresses, sprayed asbestos Insulation. In use and manufacture of asbestos cement products, which today, other than in the UK, represents the main use for blue asbestos, there is evidence of an increased risk of mesothelioma. Vhy then are special precautions necessary? Whether special precautions are necessary is possibly a matter for debate - experts in some other countries, notably the U.S.A, do not accept this -- but the Asbestos Regulations 1969 in the UX do specify certain extra precautions where blue (erocidolite) asbestos is concerned, and so the law must be observed.Some other European countries have followed the British form of regulation in this as they have in all ether aspects of asbestos control. The reason the UK authorities made these special provisions was that, at the time the new Regulations were being formulated, the recognition of mesothelioma had been mainly in association with the blue mining areas, and erocidolite use in this country was relatively insignificant and eonfined to particularly dusty operations not easy to control. Accordingly, in view of the uncertainty, extremely stringent requirements were proposed and the UK asbestos industry, (which had no need for technical reasons for erocidolite for asbestos cement manufacture) saw no particular problem in accepting these. continued J continued... J .| ' -k - In the light of knowledge obtained in the last ten years, there is no doubt that a very different view would be taken if such additional or selective measures were proposed during the foraulation of regulations. Q Zs the present standard of 2 fibres per ailllleter adequate for the prevention of mesothelioma? A Since the undisputed cases of mesothelioma appear to have related to exposure to much higher levels, and only a small proportion of people exposed to such high levels hare 'developed this tumour, it is believed that it is a safe standard. As stated earlier, it takes 25 to 40 years for harmful exposure to produce this effect. The effect of the improved controls under the 1951 Asbestos Industry Regulations has already resulted is clear improvement in prevention of all asbestos related disease, and the greatly improved control standards, including the establishment of a standard for dust concentrations and methods of measurement are to be expected, as Dr M Nevhouse predicted at tih International Occupational Health Conference in Brighton in September 1975, to eliminate mesothelioma as far as it is possible to forcast a total result, when sufficient time has elapsed to exclude all those not subject to such improved regulations. More work is naturally involved in controlling dust to the 2 f/ml level when the operations concerned are dry or otherwise "dust conducive", and it is in this direction that greater effort is required rather than in the setting of tighter levels, based on arbitrary judgments unrelated to the scientific data available. (VPH comment i Dr Nevhouse must be asked to comment on this answer) O CO cn ro co r