Document pRaYKVowoKy2JkZR3ZYD5rVw

FILE NAME Allied Signal Bendix ASB DATE 1973 May 21 DOC ASB052 DOCUMENT DESCRIPTION Unpublished Conference Presentation by Dr. Selikoff on Asbestos at AIH Conference with Cover Memo Castleman File Allied Bendix w = with cover letter or memo If DATE = 0 undated ROM Docum#en abt ex 52 published article from journal DATE 1973 published presentation from conference published government report government inspection results unpublished or internal report _ flunpublished presentation from conference of Selikoff| | with wmemo memo newspaper article letter memorandum industry warning labels industry sales literature industry recommended practices agenda minutes attendee list ____ legal filing of defense legal filing of plaintiff legal deposition __ legal testimony of z Internal : Memorandum Date August 21 1973 / Distribution Letter No. Gendis + 1 - Research Laboratorios From W. M. Spurgeon Subject PRESENTATION AND CORRESPONDENCE ON ASBESTOS CUS SF ES NS SES ESSE eT ene ot Attached are copies of documents received on August 17 from the Friction Materials Standards Institute On first reading it appears that the experts are not in agreement The fact that ingested or inhaled asbestos is harmful to health is not questioned What Drs Selikoff and Lewinsohn are both saying in effect is that the safe exposure levels if any are not known The various parties differ in the rigor and hence the cost of the protective measures to be adopted To sone Dr. Selikoff appears to be an overzealous crusader In fairness to him it should be realized that an epidemiologist has to be a crusader in order to be effective in his work Further it is not a tenable position to advocate that rigorous control methods should be postponed until safe exposure levels are established It is not possible to establish them since designed experiments on human subjects are both impermissible and impractical in this matter : . In such a situation it is better to err on the safe side pushing ahead with our programs for control of asbestos in our factories ensee for labeling our aftermarket friction materials and our search for aA new fibrous reinforcing materials os Ona fan WMS Distribution . ACSG Troy ; ACSG South Bend J. W. Armstrong D. Bitondo B. B. Burton G. T. Burton .- A. Capsalis L. D. Ferguson M. G. Jacko R. S. Kiwak T. Liu C. E. Miller S. K. Rhee L. B. Taplin A. B. Van Rennes F. W. Aldrich C. N. Menz J. R. Farron B. W. Klein J. J. Lukas E. T. Pyles E. A. Sheridan Aa oe , tf FRICTION MATERIALS STANDARDS INSTITUTE INC C. 210 ROUTE 4 PARAMUS 11.J.07575 oMATe ERIALS MATERIALS AUC 17 1973 W. M. SPURGEON August 14 1973 TO MEMBERS OF ASBESTOS STUDY COMIATTEE SUBJECT DR SELIKOFF PRESENTATION TO MERICA INDUSTRIAL HYGIENE ASSOCIATION Your Chairman Mr. I. H. Weaver has sent the enclosed papers for distribution to the Committee 1 Presentation Dr. I. J. Selikoff to the American Industrial Hygiene Association on May 21 1973 Includes Question & Answer Session 2. Letter from il C. Levinsohn and S. Holmes of Turner Brothers Asbestos of July 12 1973 to Dr. Selikoff 3 Letter from 11. Swetonic Asbestos Information Association N.A. to J. 1. Stender of OS dated July 24 1973. Forwarding Dr. Selikoff's allegations and the comments of Lewinsohn and Holmes 4. Letter from G. F. Scannell OSHA of July 31 1973 to M. Suetonic acknowledging receipt and advising on distribution of enclosures 5. Mr. Swetonic letter of August 3 1973 covering distribution of correspondence to members of AIA Mr. Swetonic's letter of August 3 1973 to the AIA Membership summarizes the presentation and review of a talk Dr. Selikoff gave to the American Industrial Hygiene Conference in Boston Massachusetts on May 21 1973. In essence Dr. Selikoff is attacking the 2 fiber asbestos exposure level in the work place as being too loose This is the 2 fiber limit that goes in effect in - 1976 not the 5 fiber limit now in effect For your information EWD 11z Enc E. U. Drislane Executive Director . SRN TOE TOTS 23 rroran =s ri ewe sisi Nee ve TEE ORE ie eR eee sm etme Se le Presentation on Asbestos . by Dr. Irving J. Selikoff at American Industrial Hygiene Conference Boston Massachusetts May 21 1973 This year 1973 marks 50 years since the examination of the first case of death due to asbestosis Dr. Cooke in Leeds wel . . described this fatal disease in 1924. He might well have been asked the question which points a dilemma in which westill are ad If he had been asked what exposure of this asbestos textile worker resulted in her fatal pulmonary fibrosis he would have had to say I don't know Because 20 years ago when she began work in this textile factory no dust counts were done Now the dilemma that he faced is still very much with us at this time because the disease that we are now seeing is the result of ex- posures at a time when we were not alerted and environmental measurements were not made We find this agreat difficulty in . 6 our own work and perhaps it may be well demonstrated by the first | slide which I will read to you in view of the circumstances This is a slide of the ray results in 1,000 employee workers in the New York area examined by us and it demonstrates that out of 725 people with less than 20 years from onset of exposure most had normal rays When they were abnormal they tended to be be mininally mininally mininally mininally st . On the other hand more than 20 years from onset of exposure of the over 300 men so examined few had formal rays and when they were abnormal not infrequently . the fibrosis was extensive So the 20 year rule which was found in 1924 is present with us today 1935 and subsequently of pleural The description of lung mesothelioma in 1954 and cancer after- wards in 1955 of peritoneal mesothelioma and subsequently of other tumors has done nothing to resolve this question because they too have had this difficulty which we still face We have found it so in our studies~ at For example in the New York area : - we have been following 632 % cers workers workers workers will see and 1948 the the Asbestos Workers Union these are the insulation who who rolls January who were were were on the union on 1 1945. You in this slide that for the first 10 years from 1943 to to 1952 the total number of deaths was almost exactly 1947 what was expected It was not until after this 10 year period had passed that we began to see the extraordinary mortality patterns that are still with us We found for example that after 20 years wherein there should have been 6 or7 deaths of cancer in the lungs and pleural mesothelioma there were 45. There should have been 9 or 10 deaths of cancer of the stomach colon and rectum There were three times as many 29 and of course there were 12 deaths of asbestosis where none had been expected Yet as we go longer ithith this this this this group group group group group - we have followed them now through December 31 119971 179711 and and thaia thaia are are unpublished unpublished unpublished data data might find I thought you might find whe ee ee. ee wa oe AD e 7 a nem nem interesting ~ we have found that of the survivors of this 343 group there should have been another 85 deaths but 168 ave occurred There should have been 4 or 5 deaths of lung ancer There were esothelioma which 42. There should have almost never occurs in beenno deaths of the general population there were 25. There was the small increase 3 or 4 times increase In intestinal cancer and the asbestosis deaths so that the longewre go from onset of exposure the more evident the risk appears 3 have in order to further study this question undertaken a second study and these are the first reports of this second not yet published - . On January 1 1967 we registered every single union insulation worker in the United States There were 17,800 members of this union on that date and Dr. Hammond and I have followed them from January 1 1967 through December 31 1971. These are the results found in that study Whereas there should have been 805 deaths among them given their ages there actually were almost 1,100 And once again the lung cancer death rate was extraordinarily increased Whereas there should have been 44 expected 213 bronchogenic carcinomas tually occurred There should have been no deaths of mesothalions there were 77. There should have been a small number of gastro- gastro- intestinal deaths there were 3 times as many as expected s. e: a And of course there should have been no deaths of asbestosis which doesn't occur in the general population and there were 78 When we analyze these deaths by duration from onset of work among these 17,800 men we found that in the group less than 15 years from onset of exposure there was no significant increase in either lung cancer or mesothelioma We did see one mesothelioma in less than 15 years from onseotf work although we were observing almost 10,000 men in this category On the other hand of expected once the 15 to observed years passed deaths was 5 1 we found that the ratio 6 and 7 times now the mesothelioma deaths began to be seen We have also looked to see whether this was in an asbestos products factory making insulation and many other products -- study this we made a list of every single production worker in this plant on January 1 1959 who had on that date worked at least 20 years We have followed this group 689 people through December 31 1971. And once again we have found that whereas there should have been 8 or 9 deaths of respiratory cancer there were 35 of these 27 were lung cancers 8 were pleural mesothe- liomas 7 were peritoneal mesotheliomas and the same increase a modest increase in intestinal cancer and asbestosis Finally to try to get some sense out of the duration from onset versus the actual exposure because most of the men in the three s - we ones cohorts that I have just reported to you had worked continuously and in one group we were able to find a very significant differ- ence in the amounts of work This was a factory which opened in June 1941 to make insulation for the U. S. Navy Nine hundred thirty men were employed for the first fime for '41 to '45 The factory closed in 1954. Some 11 men worked for only 1 day They didn't like it Some worked until the plant closed in '54 Following this group - they got their Navy of 933 people E we have it is a darn found that in good plant these 933 men there should have been 300 deaths actually were And once again - by the end of '71 there it's almost monotonous - ; same 7 times increase in lung cancer pleural mesothelioma peritoneal mesothelioma intestinal cancer and asbestosis But of these men approximatelyapproximately third worked for less than 3 months third worked from 3 to 11 months and third worked for more than a year We have found that although the group with more than a year of exposure had a very significantly greater ratio of expected to observed deaths 11 times as many lung cancerass expected still even less than 3 months of work was enough to give a 3 or 4 times increase in bronchogenic carci- noma provided they lived long enough - 30 years later Now all of these data provided indicate you looked at them that what we are seeing now the current mortality experience is the result of the inadequately controlled exposures of the past However the ence vee problem is with this long latent period how you find out what the exposures of the past were to relate them to the epidemio- logical evidence of disease at the present time Unfortunately in the United States we are at a loss for this There are no sets of dust counts and resulting disease observations from the first case reported in the United States in 1930 to permit judgment here of acceptable levels There are two approaches Both have been used First of all if there were measured dust levels 20 years ago and if we could identify the population exposed to those levels 20 years ago we could make some corre- lations One of course would be asbestosis . * ad The other approach approach has been to take dust measurements now and get some sense of how these measurementmseasurements now relate to what existed in practice 20 30 and 40 years ago This has been done but there are significant differences with this technique First of all in the past very few dust counts were done The current techniques membrane filter methods phase microscopy etc. were not used at oe whe . Dressen that time For example the , study Also at that time all particles were counted rather than only fibers and as we try to convert particles per cubic foot to fibers per cc the results are unfortunately uncertain We have on the other hand had some . | measurements of what exists today in the construction industry with the use of insulation material and we have found in using fibers per cc that in general somewhere around 5 to 10 fibers . te per cc exists in these environments We don't really know whether this was true 20 years ago There are 4 studies that provide evidence First there is the original study of Dr. Fleischer and his colleagues in the U. S. Navy shipyards published in '46 and done in '44 and '45 A different instrument was used and a time weighted average of 25 fibers per cc could be obtained but other glass fibers and so forth were included Murphy and Ferris " and their colleagues have looked at shipyard data published in '63 and '71 and they came to somewhere around 10 fibers per cc Balzer and Cooper in San Francisco insulation workers have come to round 6 fibers per cc An in od ur laboratories looking at con- struction work in shipyards throughout the United States we have found exactly what Balzer and Cooper have found somewhere around 6 fibers per cc But this is reconstruction And we don't really know that this existed 20 years ago While this is the dilemma that we faced we thought that 6 fibers per cc somewhere around that 10 fibers per cc existed in the past but we weren't sure We know what the disease is I've just shown it to you Therefore we were all very much impressed and grateful when the British Occupational Hygiene Society gave us the answer . . . bd ; In 1968 the British Occupational Hygiene Society published a report stating that 4 fibers per cc or 2 fibers per cc would likely be safe The basis for their report was the report of their sub- committee on asbestos published in the Annals of Occupational Hygiene . 1966. It read The results of recent work the study of thn F. Knox and Steven Holmes have been made available to the ommittee by the asbestos industry and it is on these recent esults that the new standard is primarily based What they ame to is that it would be safe to have 100 fiber years such = 2 fibers per cc for 50 years or 4 fibers per cc for 25 years work Dr. he of Knox and Dr. Holmes they were both members of This committee was valid Dr. Knox was Chief Medical Officer of Turner Brothers Asbestos Company in Rochdale and Dr. Holmes as their Industrial Hygiene Scientist . . = bases for these data were then published by the British Occupational Hygiene Society Dr. Know had xrayed all production workers at Turner Brothers Asbestos Company in Rochdale as of . June 30 1966. There were 931 workers in this plant of whom a large number had been more than 10 years in their employ They had done dust counts very good dust counts from 1951 on and therefore we had a population for the first time where dust counts could be related to clinical evidence of disease In the departments where the dust counts were 10 to 15 fibers per cc of the large number of workers there employed 7 showed some ray abnormality which could have been asbestosis On the other hand . of 70 or 80 people working at 3 to 4 fibers per cc only one was ported to have which itself did an abnormal ray This being so the subcommittee not review the data but reviewed the numbers i * 8 OR ee ee .* " submitted to it then reviewed the data given it and decided that since fibers per only one worker exposed for 20 years or more at 4 cc showed evidence of asbestosis that half that level 2 fibers per cc would be prudent and safe And if I weroe n that committee I would have come to exactly the same conclusion When these data this conclusion and this recommendation reached the United States it did as I say impress all of us So much so that on February 28 1969 Howard Ayer sent a letter containing this statement to departments From 28 asbestos companies these standards that and is 50 state health the British Occupational ygiene Society recommended standards one would gather that concentration below 2 fibers per cc are probably safe A fair statement Indeed when the criteria document was submitted by NIOSH last year 1972 it stated The development of a standard for asbestos dust in Great Britain and the evaluation made by the British Occupational Hygiene Society Subcommittee on Hygiene Standards for Asbestos which considered data to reduce the risk " of asbestosis was given weight in the development of this asbestos standard That is the origin of the 2 fiber per ce standard Two fibers cc per obviously is 2 million fibers per somewhere cubic meter A working man inhales around 8 to 10 cubic , meters of air in an eight working day which means that we have told him that he can safely inhale with an uncertain unmeasured retention somewhere around 20 million fibers longer than 5 microns in eight day As Mr. Dement has just told us anywhere from 20 to 99 of fibers are smaller than 5 microns and therefore . the total numbeorf fibers of all sizes is somewhere around 20 to 40 billion * : Now some new data has recently appeared which I thought might be of interest to you In 1968 Dr. Knox retired as Chief Medical Officer of Turner Brothers and was replaced by a young South African Dr. Hilton Lewinsohn Dr. Lewinsohn has rayed all of the workers at Rochdale in December The populations however were not entirely identical however Knox Dr. had examined only she men in the scheduled - areas that is the production areas 913 - all including whereas Dr. Lewinsohn included employees | the office a a personnel and therefore had a larger number To some extent you could say that this diluted the population but I think it was a wise thing to do Also some of the . people working there in 1966 were some were no longer employed obviously they had retired or died and large new workers had been added The very majority of course in both surveys Dr. Lewinsohn reported the results of his December 1970 ray of the Rochdale personnel in the Royal Society of Health Journals in 1972. slide Dr. Lewinschn's data are on this It demonstrates that of those with let's let's say from onset of exposure of 114 rayed 51 had 20 to 29 abnormal years x rays All together total abnormalitiesabnormalities were 55 of all people who had . . i i i reached 20 to 29 years from fibrosis was seen in 21 out ~ 2 onset and of these actual pulmonary of 114. Of those who had reached 30 to 39 years from onset 78 had abnormal rays and 17 out of the 42 had actual pulmonary fibrosis Of those 40 to 49 years there was too small a number to show When we put these two sets of data together can find that as of 400 fiber years Dr. Knox had found in reading the films that somewhere around 7 or % had abnormal rays whereas in the same population a different film reader had found that somewhere between 40 to 50 % had abnormal rays There is obviously a considerable iscrepancy in the two sets of film readings Now when these dis- epancies were discussed with our British colleagues last October in Lyon France Dr. Holmes made the following statement Thus the information although the best available at the time was to say the least scanty for the purpose And some of us who were associated with it have become increasingly concerned with the authority with which it has become invested in the international field meaning the United States The time has therefore probably arrived for an date reappraisal of the original data I have communicated with Dr. Lewinsohn the last three weeks and am informed that there are definite plans to undertake this review in the future It has not yet been done conclusion then as a result of these new data from Turner Brothers Asbestos Company we can say that if the 1972 report of the Chief Medical Officer of Turner Brothers Asbestos Company correctly represents the disease incidence associated with prior levels of asbestos exposure in the company then the asbestos standard of the Department of Labor places U. S. asbestos workers at serious risk of irreversible often fatal disease opinion it should immediately be reconsidered and in my Unfortunately then I feel that we are in the same dilemma still - after 50 years - that Dr. Cooke found himselifn 1923 Thank you , R very much es . a an wy oe ate ove - E : 4 i e P vee Nell Pratt - ae we : ~ a . . Pras Dew! tp sh asravaarcerenermminnanmfiasahl aah: bytenty thepneanpuseembaomaret CIvEEY sear the jvannizem alien ~ ~ 2 a et pec eate conten Een menese. va Porm la " aaa et:Ta mae on S ~macg eimetee ot mee: TO TE Te ee te me patitee een ee , - * a 2 een pet@sa fi .0 r- AFFECTED AFFECTED wee AFFECTED AFFECTED AFFECTED AFFECTED INDIVIDUALS INDIVIDUALS - INDIVIDUALS INDIVIDUALS * INDIVIDUALS INDIVIDUALS INDIVIDUALS INDIVIDUALS INDIVIDUALS INDIVIDUALS e sr ee eee wee wa he fete * 330 0 : . OF PERCENTAGE PERCENTAGE PERCENTAGE PERCENTAGE PERCENTAGE PERCENTAGE YEARS YEARS YEARS . . - 1 10-19 10-19 oe See YEARS 10 0-9 oe eee 0-9 o 3 4 , ole . ie | :y. ie . | wee 7 . 0 a 0 SSP es MPwa omed wth. mt ~ . _ ar 109 na CUMULATIVE 200 300 400 oti! CUMULATIVE 300YEARS EXPOSURE EXPOSURE X FIBERS . ee ates Oe emery gh se rameter. ee, -wereenn o Aru ew avegee gaees _ QUESTION AND ANSWER SESSION FOLLOWING DR SELIKOFF'S PRESENTATION os Q. In the asbestos products factory in which men employed for only three months were found to have a significant increase in lung cancer were smoking histories obtained Dr. Selikoff A. The answer is Yes and those data are now being analyzed but I would be amazed if we found any lung cancers or any more than a trivial number among those who did not smoke cigarettes We have failed to see any significant increase in the incidence of lung cancer among asbestos workers who do not smoke cigarettes We have been following 2,066 non- smoking insulation workers from January 1967 through 1971 and we have only seen two lung cancers among them On the other hand of 9,590 cigarette smoking insulation workers i we have found 145 lung cancers whereas only some 30 were expected Bronchogenic carcinoma is almost limited to ciga- probably rette smoking asbestos workers This is not true of peritoneal. mesotheliomiat is not true of asbestosis and it is although our data is too scant yet to be sure it is probably lung not true of pleural mesothelioma Eut of is no question - this will not occur by and cancer - large among workers who do not smoke cigarettes there - asbestoassbestos . ~ I would like to ask Dr. Selikoff if he thinks the new standard should include both a total dust count - if there is a new standard - both total dust count and a per cent fiber count At least in our experience we seem to vary comparatively A other could standard set on one rather than the . leading ; be quite mis- . vA Murphy embarrassing A. Ray has askemde a very question He asked me to give an opinion where I can't give it even on fiber counts He now asked me whether I would do it on total counts rather 4 than just fibers The answer is I don't know But I'm Holiday | not very impressed if I can upstage Duncan a bitwho is going to review this tomorrow morning - we're not very with asbestos standards which rely upon dust counts impressed being done May I asbesto if you think these standard came into give you some data Very depressing data are depressing On June 7 1972 the asbesto effect And it said that every company using asbestos had to do at least one dust count one dust count in insulation the next 7 did a six months survey of That is by December 6. We on December workers in the United States and we now have some 5,000 odd replies Each man was asked about : t Os > .? "% the dust counts that he personally had seen in the six months when every company was supposed to do a dust count In the United States insulation industry fewer than % of the in- sulation workers saw even one dust count done from June 7 to December 6 1972. Obviously then dependence upon dust counting as a means of control in this unusual industry has many deficiencies It is really one question in two parts perhaps The fibers at the Turner Asbestos Company Holmes study what were these and could you comment would you comment on the possible differences that you think may be between crocidolite and chrysotile and amosite a The fibers in Turner Brothers since it was textile operation operation were largely chrysotile We can give you no information on- cerning crocidolite because none of the workers studied by us had any crocidolite exposure They had chrysotile exposure . an * many of them had exposure Indeed in the plants in amosite the factory making the Navy insulation this was almost entirely apply amosite So our data only to amosite and to chrysotils and unfortunately I can give you no information the relative. hazard of crocidelite I would suggest however that if cro- cidolite is more dangerous than amositoer chrysotile it is going to be almost as bad as chloromethylether Laughter Q. Dr. Selikoff are you aware of a particular type of asbestos fiber mined in Ontario called Headman fibers which have been found to be relatively inert by Paul Gross and others I presume that you mean the fibers mined in Quebec not Ontario No mined in Headman Mine in Ontario No I do not know these ae comparatively particular fibers and I would be delighted to know of an asbestos | . fiber which is inert Q. . They claim - and Paul Gross and other's have done experimental work - and they have found that this particular fiber which is chrysotile has been Min experimental work found to be inert delighted A. Well I would be delighted to see those indeed I'd be delighted to see those in industrial use Thank you Dr. Selikoff . ? } . ror \. 4 silfe _ TURNER TV NEWVALL teers LIMITED IndustriIanldustrial * ECL 12.7.73 Professor Irving J.Selikoff _ Mount Sinai School of Medicine . Fifth Avenue and 110th Street NEW YORK NY 10029 U.S.A. Dear Professor Selikoff We have recently received a transcript of a tape recording of your address to the American Industrial : Hygiene Conference in Boston on 21st 1973 which was cent to us because of its references to our work If the is herewith copy enclosed a true representation of that address and the graph shown by you we must tell you that we find your assumptions and conclusions to be extremely misleading The cascaese made at the end of your paper appears to rest on the fact that the data which formed the basis of our Eygiene Standard was scanty the Figures in HCL's between original publication the original You then attempt to extract data from in order to show a discrepancy data and these Figures We are astonishei at your having communicated the contents of a private correspondence to the meeting which you addressed without having obtained our agreement We are also very displeased at the ranner in which you have used the information we provided in campaign order to launch what sees to us to be a politicaclampaign inin the USA aimed at discrediting our Evgiene StSandardtandard for asbestos We cannot accepttheimplication that the HCL publication allows on doubt to be cast onthe validity of the BOSS Standard and are is of the opinion that such a conclusion unwarranted Comparisons such as those you have rade between the Krox data and the ECL data are invalid for the following reasons := _+ 1. - + The paper by ECL was not intended to justify or verify the 2POHS Standard and no reference is made in this paper to environment duaslt measurements The results presented in ECL's paper were preliminary results and in the discussion section it was clearly stated . that from the information currently available only . tentative opinions can be expressed . We are T IndustriaPl roducts am P. A ....... -2- surprised therefore that you have been able to read far more into the incomplete picture presented than the author was able to do or even intended to do 2 The populations reported by Enox and HCL were not identical nor were the very large majority of asbestos workers common to both surveys as Office you suggested personnel were not included The population studied by ECL consisted of workers in the recognised asbestos areas together with maintenance quality control and research staff 3. Knox reported on 290 men not 913 as stated by you with at least 10 years exposure since lat January when the Asbestos Industry Regulations 1931 took effect and who were still in the Company's employ on the 30th 1966 ' ECL on the other hand has analysethde rays of a much larger population 1,297 as of November irrespective of date of first employment some were in fact first employed befor 1st January 4. Enox divided his population according to actual cumulative exposure whereas ECL's was divided decades by elapsed since of the actual sumber differences these basic differences first exposure irrespective of years exposed In view of differences and others which we will point out in due course we fail to see how you derived the relationship between cumulative exposure affected and percentage of individuals . which you showed copy attached on the graph The heading on the Graph is obviously misleading asECL at no stage in his report equated the radiological changes with asbestosis 5. Decause it was possible to estimate dust exposures for the Knox population the BORS Committee were able to arrive at figures for curulative exposure expressed in fibre years No such exercise was ever attempted by HCL This is a further invalidation of the graph since you have attempted to relate radiological features we described by ECL to what exposure data can only regard as speculative| 6. Enox only recorded ray changes as being present which are possibly asbestotic after taking the whole clinical picture into consideration Radiological - changes considered significant included those of increased ' general opacity of the lower lobes blurring of the cardiac cutline pleural thickening and adhesions'.l adhesions'.l ..... poo po Poe ope ae -3- 6. ..... HCL on the other hand attempted to analyse his radiological findings according to the DICC classification an entirely diffezent set of criteria and took no account of the olinical picture as a whole . 7. The BOHS committee decided that basal rales were the key symptom since all the men with ray changes by the Knox criteriahad basal but rales changes.1 some with basal rales had no ray HCL points out in his paper that he has not yet attempted to correlate physical signs and ray changes a a. . : . st 8. We are obliged to point out that the use of the words pulmonary fibrosis by ECL in his paper may have misled you as they were used to describe . small opacities which prior to the advent of the UICC classification may have been regarded as consistent with fibrotic changes The use of this term does not allow for division into profusion the and type of opacity as is now possible with . DICC classification For simplicityin . . ; . showing presentation HCL grouped all cases evidence of these changes together imespective of severity Knox only included ray changes consistent with the elinical diagnosis of asbestosis It is not possible to say from the data that HCL has compiled how many persons would fulfil the criteria for a clinical diagnosis of asbestosis and to attempt to illustrate these two very different sets of data on the same _ graph is simply not permissible The clinical significance of theradiological changes observed cannot as yet be defined . You appear to have ignored completely the fact that . the number of cases of asbestosis in 1968 among 335 employees men and women exposed for 10 years or more since 1933 in Rochdale and still employed was 1.12 1.e. 4 cases as compared with Merewether's finding of 44.4 i.e. 59 cases among 133 workers 1929.3 exposed 10 years or more in the saze industry in 1929.3 This lower incidence has occurred in spite of the fact that the Freucoconiosis Medical Panels are better equipped to diagnose asbestosis than Merewether was In addition during the years immediately following 1933 there still was substantially greater exposure . in certain jobs than in more recent times | i y - 4 : j ..... wii 8. ..... | In view of your comments and our previous correspondence we should like to remind you that we are in the process of reviewing and bringing up to date the available data and hope to present it for publication in the near future Dr.Holmes Dr.Holmes remarks atat Lyon were never intended to ; suggestthat the E05Standard was not stringent enough years and The BOBS Standard is 100 fibre and therefore application of a 2 ce limit for periods of less than 50 years the effect of providing an apple safety margin The BOES committee of which we are both '+ members recently reviewed the Eygiene Standards for Chrysotile Asbestos in the light of the latest available recomended data and recomended time that no change be made at the present ue . : . . We are forwarding a copy of this letter to the President of the American Industrial Ergiene Association the Chairman of the ACCIR the Director of NICSH and also the Asbestos Information Association of North America in view of their interest important obrious interest in this subject i) Yours sincerely - . D.C. D.C. Lourishin Lourishin Lourishin ChiefH.C.LEWINSON Officer . . . . , a .- . . . a ~ S.HOLMES Physicist Chief Health ; Encl a . ae . 1. Hygiene Standards for Chrysotile Asbestos Dust - Annals of Occupational Hygien~ 1968 a | 2. The Medical Surveillance of Asbestos Workers = Royal Society of Health Journal April 1972 3. Report on effects of asbestos dust on the lungs and dust suppression in the asbestos industry - Merewether & Price HS0 1930 . ame 4. Annals of Occupational Hygiene Vol.16 1973 as