Document D4N7XojLdqaEbGBZQ5330YKn

C-I4S-3 INTERNAL CORRESPONDENCE UNION CARBIDE CORPORATION 270 park avenue, new york, new york 10017 To (Nan,*) Dirition location Mt. John A. Riddle Chemicals & Plastics P 0 SOX K King City, California 93930 oau January 19, 1968 Originating D*pt Medical Antwring ItHtr datn Copy fo S`,b/c, 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 as 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. DISTRIBUTION J. A. Riddle L. F. Crew s-* R. O. Marwn^ W. E.Kf!;apple Q A. A. Andrade G. C. Brice Shifters J. L. Myers K. A. Wood D S. Kamens C . 'essels K. West File Very truly yours. _ Paul W. McDaniel Industrial Hygiene Engineer RECEIVED JAN 22 1969 U.C"C. CHEM. & PLA>ScTICS RECEIVED 1-S+YN 1063 I Ft 3 ' iii- ..uiy havo been ,, .?Tlfe -.mg candidates for U.c.c. boards have been. " ' '-stacks to return should be ...ninish the rate of emigration in ..cuts for career guidance of trainees -ved and that more opportunities should or academic careers. The Minister of Health studying these recommendations. - ne loss of :iOO doctors a year is indeed serious, but should be seen in proportion to the numbers Britain .' in ini of turn, view : :it cd now mat, gains from other countries. Last year almost 2,000 doctors from the Commonwealth alono applied to enter Britain. In 1903, tho most recent year for which figures arc available, there were 6,000 doctors working in Nat.io'nal Health hospitals who had been born abroad--about 30 per cent of the total. Of general practitioners 2,600, or 12 per cent of tho total, were born abroad. If every doctor were to practise in the n of ar-- :'itish country of his birth, Britain would not bo tho gainer. But this is not to decry any efforts that tho ministry may now make to encourage the return of expatriates, anti to allay the discontent of those who would follow wiil them. goad i its to d to .itain pedi'CtCCS oeen .itain More on Asbestosis That there are risks associated with asbestos is not now disputed. A review of tho problem as it occurs in Britain has just been published os a memorandum by the Advisory Panel on Problems Arising from the Use of Asbestos (HMSO, 3s. 9<f.). The advisory panel, set up in 1965 by HM Factory Inspectorate, is respon sible for considering the use of asbestos in relation to tho health of those directly or indirectly exposed, to ;d its asbestos in their occupations. Over tho whole country had the panel estimates that about 20,000 persons are :i for exposed to asbestos in the use or handling of the fibres. loing Tho Sgure is probably higher than this; people can ; the easily be put at risk by working near to where asbestos riato is handled. The present Asbestos Industry Regulations, .sons < 1931, are applied to some 300 registered factories, but posts tho report says that there are many other factories .V Of which use asbestos products and which do not come that >jthin the regulations. Tho Ministry of Labour is at a rely present drawing up new regulations to cover a wider ar.u range of factories. --a to It was in tho 1920s that it was first clearly recognized i the that asbestosis, a fibrotic condition of the lungs, is etr.ic caused by occupational exposure to asbestos. Within itelv a few year: it was suggested that tho disease might be complicated by tho development of carcinoma of the io:u,c lung, but an association was not generally accepted the until the 1950s. Recently, there has been concern over i an the occurrence of mesothelial tumours of tho pleura witii or peritoneum which appear to be causally related to io is asbestos exposure in many eases. Since 1966 meso foots 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: The tnnr.t likely explanation for tin's inrreuRri in t]ii> Mi greater u-e of'iisne.-.to* and the greater numbers of ro.'S, people employed in the industry over the past 20 the years. But the panel says that "there is no evidence 'ted that tho overall attack rate has decreased in ti.o indus fiod try over this period, although it has in somo textile mills1 in which the dust conditions have boon greatly NATURE. VOL. 217. JANUARY 13. 1363 *.YJ I { j improved". It appears that if the rcgtdai ions are more widely and more stringently applied than at presi .v. tjjp number of cases should inevitably fall. Tho panel indicates that crocidoiile has a special^ significance in relation to mesothelial tumours. 1' recommends that other types of fibre should he stitutedTor croeidolitc wherever possible, and, where this is impossible, special precautions should he n to reduce tho risks of inhaling the material!" TIT- panel atThutslhat at'thd'mbmcnt't he level of exp>osu.-''': below which the risk may be negligible is not known. The quantity of croeidolitc (blue asbestos) import'd into the country is much less than the other varieties of asbestos, and it has remained at about 7 ,<'//> tor.- per year for the last few yearn. But time may show that other fibres are also implicated in the development of mosothclial tumours. Finally, the report suggests that action should taken to control the discharge of dust-laden air from asbestos factories and the dispersal of dust from wa.-u- dumpB. It cmphasi7.cs, however, that the problem of mesothelioma in association with asbestos exposure should be kept in a proper perspective. Even though tho incidence is increasing, the total number of ca.-os of mesothelioma in Britain over several years is very small when compared with the annual total of deaths irom cancers of the trach'ca. bronchus ami lung. CJCG&eme'j P* Recording Weather ks automatic weather recording station which ca.u operato unmanned for af least three months has arer. produced by the Plessey Company Ltd. Tin's station, which can make and record more than 62,560 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 develop 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 mcteorplogists to provide accurate data day by day. Professionals cos: money, and so there should be a real market for autema::: stations which can do the job reliably for long periods without attention. The Plessey station is virtually self-contained and can monitor parameters such as rainfall, humidity, wind speed and direction, air, soil and water tempera tures, barometric pressure, pH, solar radiation and water level and flow. The basic design was evolved in co-operation with the 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 fan:;";.* of stations including hydrometeorological, climar jlogical, water level, water quality and rev.r:lir.-j rainfall stations. Each can hri arranged f"r jibl.-imatir n; .. (Uni, ami tho rJCurdctl data e-an bo sent by tvieu'ieiry to a control ccntro on demand. Each station is supplied as a complete system \ri:'.; sensors, recorder, power supply, 'Stevenson' soroerj and a stayed aluminium mast which support- the ien- 6ore. sTho memory of the station samples up u.eight sensors in turn, recording their outputs in.:en-bi: 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 5 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 tests to assure continuation of a satisfactory condition. t 4 2- Pre-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 MEMORANDUM p =- > ' 15 \! TO: Messrs T. Dougherty R. A. Miller R. W. Stobaeus B. K. Barton T. R. van Fleet N. J. Setter R. T. Larkin 3. --* DATE: vtfarch 22^966 A. A. ri ' rw 1- rW-i` CC: L. S. O'Rourke SUBJECT: Asbestos - Toxicology T. J. Hall H. F. Relchard/R. 6. Woolery J. A. Riddle J. Derbecker P. R. Cheston T. F. Frangos 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. We 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. Dernehl's "Asbestos Toxicology Report." Additional copies are enclosed. Use these, and call particular attention to Dr. Dernehl'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 work'yet 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 -2- analyzing Random samples of our produce, and expece shortly to 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 * in ns<s lit iMuucing me w. n1 ===========----- ^Asbestos Dust Called a Hazard. '! To at Le^st One-Fourth ol US. ny JAND B. nnODY I Asbestos -ost, which has al structlon workers and their ready been connected with families. the development of fatal can- According to the findings of :er in one-half of asbestos three recent limited studies, the workers, may be a' potential dangers might extend to the iicalth 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. Seli- people had asbestos lodged in koff in announccing the estab their lungs. - 1 lishment of an environmental Dr. -Sellkoff explained that)1 health laboratory at Mount Sinai Hospital. The laboratory will further investigate the dingers to man of asbestos and 1-other environmental contain! Inants. Dr. Sellkoff said the link between cancer and asbestos had led him to suspect that the studies had used a "crude technique" that disclosed only those asbestos fibers that had become coated by an Irbn-rich material while lodged in the lungs. A more refined technique now shows that ma: j persons harbor noncoated asbestos fi bers as well, he said. 1 other mineral dusts that con Now Study Started taminate both urban and air might create medical rural haz Dr. Sclikoff leagues at the and his col new laboratory ards for the public. have started a three-year study The new laboratory will be in which they will: headed by Dr. Sellkoff who, ^Examine, with the de with Dr. J - >b Churg, found ceased's family's approval, the that asbesti workers eventu- lung tissue of the from 3,000 to all 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 ma] death rate from cancer of Veterans Hospital in the Bronx. the stomach, coloq and rectum. The doctors will look for un Other Workers Affected coated as well as coated asbes Dr. Sellkoff noted that the tos fibers in the tissues. dangers of exnosurc to asbestos <IIx>ok for correlations be dust were n mlted to tl >sc tween the causes of death and who work directly with this the presence of asbestos fibers ubiquitous Insulator and tiller in lung tissue. material. The dangers, he said, QDetcrmine the occupational extend to workers in "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 noncorrosive and long-wearing prop erties. In addition to its common use as a fireproof material. Dr. Sellkoff said, asbestos makes up about 50 per cent of asphalt tile and is used in dental cement, brake linings, plastics, beer fil ters, gas masks and paper. Until last year, some schools used asbestos dust Instead of sand for children to play In. j. Study Links Asbestos To Cancer By Earl Ubell Scianca Editor Scientists have known for a long time that asbestos was bad for your lungs. Now ' a study of New York City j workers, both roofers and l .Insulation blowers, reveals U that exposure to the mineral jv`. sends lung-cancer death i i. rates skyrocketing. The figures--gathered by doctors at Mount Sinai Hos- j | pltal--show that such work- ! ers have eight times the lung- * cancer death rate as would be expected In a non-exposed ; . population. More suprlslngly, the stud ies reveal that such workers i run four times the risk of i ' getting cancer In other parts ; of the body, ylth cancer of . ' the colon particularly singled ! out. For all other diseases, the Insulation workers have the same death rate as the . ; rest of the population. These findings were em- ' phaslzed yesterday by Dr. Irving J. Sellkoff, head ' of Mt. Sinai's Division of Envi ronmental Medicine,' on the j occasion of the establlsh- ! - ment of an environmental health laboratory In the hos pital. The laboratory has received grants totaling $324,- ; , 000 from the United States 'j Public Health Service and the New York City Health i- Research Council, i Dr. Sellkoff also pointed out that cigarette smoking seems to heighten the effects [ 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.