Document G525Yo1Lvdvk6dyBw5G3aDpvV

INTERNAL CORRESPONDENCE UNION CARBIDE CORPORATION 270 PARK AVENUE, NEW YORK, NEW YORK 10017 rofNom.j om,iob location Mr. John A. Riddle Chemicals & Plastics p. o. Box K King City* California 93930 oaf* January 19 * 1968 Originating Onpt. Me d IC al Antwnring Ititir data Zapf to $vbjact Dear John: The relation between crocidolite and mesothelioma seems to be pretty strongly established by experience in South Africa and elsewhere. The relation between chrysotile and mesothelioma is not clear. If it exists* it apparently is much less prounced than that shown by crocidolite. The limit of 5 MPPCF that we observe in our operations is still recognized in the United States as satisfactory for chryso tile* but there is strong feeling that it is much too high for crocidolite. I wouldn't be at all surprised to see supplied-air respirators recommended for handling the latter. In our own operations with chrysotile* I feel that we should try to control the dust to levels as far below 5 MPPCF as reason ably possible. That is, I don't believe we should be content with control that just maintains the level at 5 MPPCF. Actually* this figure is known a3 a threshold guide and not a level that strictly defines safe and unsafe conditions. There is some thought that metals associated with asbestos either from the ore or from milling machines* etc.* may be part of the problem. Investigation is underway to evaluate this potential; and as soon as I hear more about it* I'll let you know. FWM:dmf DISTRIBUTION J. A. Ridcile L. F. Crow^v^7 R, O. Marwgn Q W, E. Hfi;apple Q A. A. Andrade Q G. C. Erice Q Sniffers (~J J. L. Myers K. A. Wood D S. Kamens Q G . jUssels 0 K. West Q fl/e Very truly yours. '' 1 . O'* ------ > Paul W. McDaniel Industrial Hygiene Engineer RECEIVED JAN -2 1358 U.C.C. " C-HEM*.*'a PLASTICS cr ' UCC 023540 ^CEIVEO 1V< -JAR -. 1060 Ft3 b '"' .any havo boon ,,,,ing candidates for O.C-C- ^ ^ ' _,v boards have been. '' ' jstaclcs to return should be ..mulish the rate of emigration in ..icnts for career guidance of trainees j-ved and that more opportunities should .or academic careers. The Minister of Health . studying these recommendations. . ne loss of 300 doctors a year is indeed serious, but should be seen in proportion to the numbers Britain .' in <m of Urn. -view mU-d now null, gains from other countries. Last year almost 2,000 doctors from the Commonwealth alone applied to enter Britain. In 1!X>5, the most recent year for which figures arc available, there were G,000 doctors working in National Health hospitals who had been bom abroad--about 30 per cent of the total. Of general practitioners 2,G00, or 12 per cent of the total, were born abroad. If every doctor were to practise in the ill of -or-- rittsh country of iiis birth, Britain would not bo tho gainer. But this is not to decry any efforts that tho ministry may now make to cncourago tho return of expatriates, and to allay the discontent of those who would follow will them. goad ; its ie to <! to .-itain podictcrs been .i ta in More on Asbestosis That there arc risks associated with asbestos is not now disputed. A review of the problem os it occurs in Britain has just been published as a memorandum by the Advisory Panel on Problems Arising from the Use of Asbestos {HMSQ, 3s. 9d.). Tho advisory panel, sot up in 1965 by HM Factory Inspectorate, is respon sible for considering the use of asbestos in relation to iv of the health of those directly or indirectly exposed to id its asbestos in their occupations. Over the whole country had tho panel estimates that about 20,000 persons are :i for exposed to asbestos in the uso or handling of the fibres. loing Hie figure is probably higher than this; people can i the easily be put at risk by working near to where asbestos ria.ee is handled. The present Asbestos Industry Regulations, .sons ^ 1931, arc applied to some 300 registered factories, but posts the report saj's that there arc many other factories y of which use asbestos products and which do not come that "yithin the regulations. The Ministry of Labour is at .irciy present drawing up new regulations to cover a wider ar.d range of factories. . --ato It was in tho 1920s that it was first clearly recognized i the that asbestosis, a fibrotio condition of the lungs, is etnic caused by occupational exposure to asbestos. Within itelv a few yearn it was suggested that tho disease might be complicated by tho development of carcinoma of the io:n,c lung, but an association was not generally accepted the until the 1950s. Recently, there has been concern over i a:: the occurrence of mesothelial tumours of the pleura with or peritoneum which appear to be causally related to ie is asbestos exposure in many eases. Since 19G6 meso fects thelioma lias been a scheduled industrial disease. d to The advisory panel concludes that there is an inch increasing incidence of asbestosis in the country; "!i: TV moat likely explanation for this ihermsti is fchu 'Out greater use of"asi>entos and the greater numbers of re.'S, people employed in the industry over the past 20 the years. But the panel says that "there is no evidence 'ited that the overall attack rate has decreased in tnc indus ded try over this period, although it has in soma textile ~ mills-in which the dust conditions have boon greatly i! | NATURE. VOL. 217. JANUARY 13. I 963 improved . Jt appears that if tun reguiat ions are more widely and more stringently applied than at pre.v .v. tbp number of cases should inevitably fall. Tho panel indicates that crocidoiilo has a special_ significance in relation to mesothelial tumours. irecommends that other types of fibre should be stituted tor crocidolitc wherever nossiblc. and, where \ this is impossible, special precautions should be :; to reduce the risks of inhaling the matr-rialT Tl. panel admits "Ihat at tho moment"tho level of expos;;.-, /? below which the risk may be negligible is r.ot known. The quantity of crocidolitc (blue asbestos) import'-:; into tho country is much Irss than the other varieties of asbestos, and it lias remained at about 7,000 tons per year for the last few years. But time may show that other fibres are also implicated in the cievclopmenr of mosotheiial tumours, Finally, tho report suggests that action rimu.'i .;\token to control the discharge of dust-laden, air from asbestos factories anti the dispersal of dust from wo.-:'dumps. It emphasizes, however, that the problem of mesothelioma in assoeiation with asbestos exposure should bo kept in a proper perspective. Even thou.'h the incidence is increasing, the total number of cases of mesothelioma in Britain over several years is very small when compared with the annual total of death; Irom cancers of the trachea, bronchus and lung. CjcA/Sstt&'j y* Recording Weather Ax automatic weather recording station which can operate unmanned for af least three months has beer, produced by the Plessey Company Ltd. This station, which can make and record more than 62,500 measure ments in a three month period, is available from the ' Marine Systems Division of the Plessey Electronics Group at Ilford. The value of automatic weather stations was recognized by a recent report from the World Meteorological Organization (Nature, 215, 1324; 1967), They are important because modem dcvelop- ments in weather forecasting require information about climate from all over the world--sometimes from un inhabited areas--and it is becoming increasingly . hard to persuade amateur metnorplogists to provide accurate data day by day. Professionals cost money, and so there should be a real market for automatic stations which can do the job reliably for long periods without attention. '~ The Plessoy station-is virtually self-contained and can monitor parameters such as rainfall, humidity. . wind speed and direction, air, soil and water temper-.- turca, barometric pressure, pH, solar radiation ar.d water lcveFand flow. The basic design was evolved in co-operation with tho British Water Resources Board, tho Meteorological Office and the National Physical Laboratory. By adding various instruments to the basic design, it has been possible to produce a family of stations including hydrometeorological, climoro- logical, water level, water quality and rt-cr.rding rainfall stations. Kadi can be arranged for jolfimatir n: tl^H, and tho recorded data can bo sent by rvioriieiry to a control ccntro on demand. ' I Each station is supplied as a complete system vri:h l sensors, recorder, power supply, `Stevenson' screens j and a stayed aluminium mast which support- the .w,- . . .... sors..JTlio memory of the sU-lion sample* up-u.eight ~ sensors in turn, recording their outputs in ten-bi: I UCC 023541 i* )ri rvss iu limiting lu Msiesfos Dust Called a Hazard \ f\ To at Le^st One-Fourth of U. 5.1 Hy .TANT3 B. IU10DY I Asbestos -List, which has al struction workers and their ready been connected with families. the development of fatal can According to the findings of cer in onc-half of asbestos three recent limited studies, the workers, may be a ' potential dangers might extend to the health hazard for one-quarter general population. The studies, of the population or more. It which involved autopsies on was reported yesterday. 1,100 persons in three cities, This preliminary finding was showed that 23 per cent of the described by Dr. Irving j. Sell- people had asbestos lodged inj' koff in announedng the estab their lungs. ' |J lishment of an environmental Dr. "Seiikoff explained that health laboratory at Mount the studies had used a "crude 11 Sinai Hospital, The laboratory will further investigate the dingers to man of asbestos and other environmental contaminants. Dr. Seiikoff safd the link between cancer and asbestos had led him to suspect that technique" that disclosed only those asbestos fibers that had become coated by an irbn-richj material while lodged in the lungs. A more refined technique now shows that ma:persons harbor noncoated asbestos fi bers as well, he said. other mineral dusts that con Now Study Started taminate both urban and rural Dr. Seiikoff and his col air might create medical haz leagues at the new laboratory ards for the public. - have started a three-year study The new laboratory will be in which they will: headed by Pr. Seiikoff who, qExamine, with the de with Dr. J" ib Churg, found ceased's family's approval, the that asbesti workers eventu lung tissue of the from 3.000 to al] showed to seven times 4,000 persons expected to die in tl normal death, rate from lung the next two years at Mount cancer and three times the nor Sinai, Elmhurst Hospital and mal death rate from cancer of Veterans Hospital In the Bronx. the stomach, colon and rectum. The doctors will look for un Other Workers Affected coated as well as coated ashes Dr. Seiikoff noted that the tos fibers In the tissues. dangers of exnosure to asbestos qLook for correlations be- v dust were n mlted to tl >se tween the causes of dead) and who work directly with this the presence of asbestos fibers ubiquitous insulator and filler In lung tissue. material. The dangers, he said, <1Determine the occupational extend to workers la "contigu history of the deceased and their ous trades," such as other con relatives and other pertinent background information. Asbestos Is a fibrous mineral highly valued for its noncor rosive and long-wearing prop- p ertles. In addition to its common use as a fireproof material, Dr. Seiikoff said, asbestos makes up; about 30 per cent of asphalt h tile and Is used in dental cement, p brake linings, plastics, beer fil ters, gas masks and paper. Until last year, some schools usod asbestos dust instead of - sand for children to play In. I Study Links j Asbestos j ' To Cancer J| '. By Earl Ubell Science Editor I _ Scientists have known for j a long time that asbestos was bad for your lungs. Now [ 1 a study of New York City 1 workers, both roofers and I. .Insulation blowers, reveals ,, that exposure to the mineral -,' sends lung-cancer death I i. rates skyrocketing, j* The figures--gathered by j' . doctors at Mount Sinai Hos- j | pital--show that such work- / ers have eight times the lung- 1 cancer death rate as would . be expected In a non-exposed | , population. :: - More suprlslngly, the stud- . les reveal that such workers i I run four times the risk of j [' getting cancer in other parts j [ of the body, ylth cancer of 1 the colon particularly singled out. For all other diseases, the Insulation workers have the same death rate as the . ; rest of tide population. - These findings were em ' phaslzed yesterday by Dr. Irving J. Seiikoff, head of Mt Sinai's Division of Envi ronmental Medicine,' on the occasion of the establish ' 1 ment of an environmental , health laboratory in the hos: ` pitaL The laboratory has received grants totaling $324,, 000 from the United States ' Public Health Service and | the New York City Health i- Research Council. : Dr. Seiikoff also painted r out that cigarette smoking ' ' seems to heighten the effects * I of the asbestos. Among 130 : / men exposed to asbestos 20 . years or more who were non smokers, he found one lungcancer, death among 310 ; smokers, 31 such deaths. v / / UCC 023542 i UNION CARBIDE CORPORATION 270 PARK AVENUE, NEW YORK, N. Y. 10017 ASBESTOS TOXICOLOGY REPORT It has been known for many years that seme persons working in asbestos production were prone to develop a disabling lung disease. In time, this condition became known as asbestosis and was related to exposure to high concentrations of asbestos dust. With further experience, it was found that men could work with asbestos without development of lung disease if dust concentrations were kept below a certain level. It is now gen erally accepted that a man can work a 40-hour week for a lifetime without developing asbestosis if the asbestos dust particle count is kept at or below S million particles per cubic foot of air. This dust concentration of 5 million particles per cubic foot of air is the Threshold Limit Value for asbestos, and no cases of asbestosis are known to have occurred when exposures have been maintained at or below this level, despite large-scale utilization (now approaching one million tons per year in the U.S.A.). This concentration of dust is generally not visible in the average work area unless a beam of light causing a Tyndall effect is present. Usually the dust concentration must be from 8-10 million particles per cubic foot before its presence is visible in average lighting conditions. Several years ago, it was reported that there was an Increase in the incidence of cancerous tumors, especially of the lung, associated with asbestosis. Recently there have been reports of some cancers occurring in individuals exposed to asbestos dust, but who have not developed clinical asbestosis. It is believed by most authorities that these cases have been associated with exposures significantly exceeding the Threshold Limit Value. A major manufacturer of asbestos products who also mines asbestos has not been able to show an increase in cancerous growths in men working where dust concentrations were maintained at the Threshold Limit Value. Control of asbestos dust exposure is therefore necessary. The control methods are the standard ones applicable to a variety of dusty operations. They include closed flow systems, wet processes where possible, and adequate exhaust ventilation where openings in the system are necessary. Pelletizing is sometimes used to improve the handling character istics of otherwise dusty materials. Where satisfactory containment to stay within the Threshold Limit Value is Impractical or impossible, efficient and reliable respirators are available for the protection of the employee. A program of environmental monitoring is highly desirable to determine that Threshold Limit Values are not being exceeded. In paper manufacturing, it would be desirable to know the dust concentrations where the asbestos is dumped from bags into the pulp slurry. Concentrations should also be determined where dusting occurs in finishing products. While initial dust determinations should be made at frequent intervals, once the level has been established as satisfactory, the frequency may be extended to occasional testa to assure continuation of a satisfactory condition. UCC 023543 2- Fre-employment and periodic physical examinations of workers are desirable. These should include chest X-rays to insure that the worker has no chest condition prior to work with asbestos and to determine that no lung changes are resulting from work with asbestos. It is believed that the addition of asbestos at the proposed levels during the manufacture of paper products would be harmless to the consumer. Total dusting would have to be well in excess of any levels acceptable to the consumer for the asbestos concentration to approach the Threshold Limit Value. In conclusion, while asbestos dust in excess of the Threshold Limit Value is potentially harmful, as are many other dusts encountered in industry, it is as readily controlled as other such dusts and it can be used safely with appropriate precautions. Carl U. Dernehl, M. D.. Director of Toxicology K. S. Lane, M. D. Assistant Director of Toxicology UCC 023544 k- K. '1 G. MEMORANDUM D. ft. ,1^ <tC| i V/ r Q i 't o. c. wetals OiV. TO: Messrs. T. Dougherty R. A. Miller R. W. Stobaeus B, X, Barton T. R. van Fleet N. J. Setter R, T. Larkin CC L. S. O'Rourke SUBJECT: Asbestos - Toxicology T. J. Hall H. F. Reichard/R. G. Woolery J. A. Riddle J. Derbecker P. R. Cheston T. F. Frangoa Gentlemen: Early in March the "New York Times" and the "Herald Tribune", reporting the establishment of a new environmental health laboratory at Mt. Sinai Hospital (New York City), revived some publicity (copy attached) in regard to Asbestos dust as a health hazard. He understand that a few newspapers in other cities picked it up. "Out of context" reporting leads to erroneous conclusions, and this is no exception. Nevertheless, we should reckon that such a commentary will recur, and all of us should use the tool we now have at our disposal to make certain our customers are acquainted with the facts: 1. You have copies of Dr. Demehl's "Asbestos Toxicology Report." Additional copies are enclosed. Use these, and call particular attention to Dr. Demehl's statements in regard to "Threshold Limit Value"fJr asbestos. Control of asbestos dust exposure is necessary, as is control of exposure to any of a variety of dusty operations. 2. Union Carbide pellets offer a clear-cut means of handling asbestos under exceptionally low dust conditions. 3. No work1yet conducted or published presents, nor pro fesses to present. Incontrovertible proof of a relationship between cancer and asbestos. Some publications have re ferred to the association of deleterious organic compounds, among them jute oils from jute sacking material, and 3,4 benzo(a) pyrene. We do not use jute bags. Further, we are UCC 023545 2analyzing Random samples of our produce, and expace shortly Co prove the absence of any polycyclic aromatics. Your pelleted asbestos affords customers the best means of avoiding dust hazards. Make this clear. Very truly yours, A.E.Pufahl/dh Enclosures UCC 023546