Document EvZvQEqg2mYxn9VQQ32VEQne0

FILE NAME: Union Carbide (UC) DATE: 1968 Jan 19 DOC#: UC165 DOCUMENT DESCRIPTION: Letter with Report - 'More on Asbestosis,' Newspaper Articles - 'Asbestos Dust Links to Cancer,' & Internal report - Asbestos Toxicology Report INTERNAL CORRESPONDENCE UNION CARBIDE CORPORATION 270 PARK AVENUE, NEW YORK, NEW YORK 10017 To(Namw) Division ocofion Copy to M r . John A. Riddle Chemicals & Plastics P . 0 . BOX K King City, California 93930 on* January I9, I968 Originating Dopt. M e d i c a l Antwaring lottor dato Svtyact 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 MFPCF that we observe in our operations i s 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. P W M :dmf Very^truly yours, D is t r ib u t io n V J. A. Riddle L. F. C re w s--- R. O . Martfr' W .E .K fh ap p le Q Paul W. McDaniel Industrial Hygiene Engineer A. A. Andrade G . C. orice Shifters J. L. M yers K. A. W ood D S. Kamens G , 'asseta K. West R ie UCC 020772 AQ7074 --- RECEIVED J A N 2 2 13SS U.C.C. CHM. . PLASTICS f 1c R E C E IV E D -J-AR .. 1363 NATURE. VOL. 217. JANUARY 13. 1303 Ft.3' 5 H ..my have boon -,,-A t rustics .i,ing candidates for UX.C. ! d. c vlF> *w boards iiavc boon. . - Stacies to return should be '...niiiish t-ho rate of emigration in ...icnts for career guidance of trainees -wed and t hat more opportunities should . or academic careers. The Minister of Health . .studying these recommendations. .* nt ml of turn, view ;uted now rruit, Ill oj(fi ar_ :ItisKh Ugnt- will - nu loss of 300 doctors a year is indeed serious, but 'should be seen in proportion to the numbers Britain gains from other countries. Last year almost 2,000 doctors from the Commonwealth alono applied to enter Britain. In 1965, tho most recent year for which figures arc available, there, were 6,000 doctors working in National Health hospitals who had been born abroad--about 30 per cent of the total. Of general practitioner 2,000, or 12 per cent of tho total, were born abroad. I f every doctor were to practiso in the country of his birth, Britain would not be tho gainer. Ihit this is not to decry any efforts that tho ministry may novv nia''C to encourugo the return of expatriates, and to allay the discontent of those who would follow them. . goad ; its to ci to itain pedictcrs been it ;t in tv of ;d its had n for loing 1 the riacc lions 4 f'GStS y of thattroiy ar.d -More on Asbestosis That there arc risks associated with asbestos is not now disputed. A review of the problem as it occurs in Britain has just been published as a memorandum by the Advisory Panel on Problems Arising from the Use of Asbestos (H.tlSO, Si. 9d,). The advisory panel, set up in 1965 by HM Factory Inspectorate, is respon sible for consicering the use of asbestos in relation to the health of those directly or indirectly exposed to sbestos in their occupations. Over tho whole country the panel estimates that about 20,000 persons are exposed to asbestos in tho use or handling of the fibres. Tho figure is probably higher than this; people can easily be put at risk by working near to where asbestos is handled. Tne present Asbestos Industry Regulations, 1931, are applied to some 300 registered factories, but the report says that there are many other factories which nsc asbestos products and which do not come yithin tire regulations. The Ministry of Labour is at present drawing up new regulations to cover a wider range of factories. ~ato i the etnic vtely iom , the an with ie is 'Vets. ci to iiieh UUIL; ri>s, the "'ted -dod It was in the 1920s that it was first clearly recognized that asbestosis, a fibrotio condition of the lungs, is caused by occupational exposure to asbestos. Within a. icw years it was suggested that the disease might be complicated by the development of carcinoma of the lung, out an association was not generally accoptcd until the 1950s. Recently, there has been concern over the occurrence of mesothelinl tumours of the pleura or peritoneum which appear to be causally related to asbestos exposure in many eases. Since 19C6 mesotndioma has been a scheduled industrial disease. . Tllc . advisory panel concludes that there is an increasing incidence of asbestosis in the country: fbe most likely explanation for this ihereiwri in tfm .cuter use or iKUe-nos and the greater numbers of people employed in tho industry over the past 20 years. But the panel says that "there is no evidence wint tae overall attack rate has decreased in tne indus- trv , - cr tMf* Period, although it lias in some textile m.iiifin wr.ich the dust conditions' have booh greatly'' improved . It appears that if (lie reguJat ions are more widc.y ami more stringently a;,;,lied than at pre.s.-v t-hp number of eases should inevitably fait. ' ' Tho panel indicates that crocidolile has a ^ c i - ' significance in relation to mesotheb'a! tumours ,,recommends t-h a ^ ifier type of fibre should be ^TT" sUtuted tor croeidojite: wherever possible, and, where . this ib impossible, .special precautions should be r.-.TT~i7 to reduce tho riks_ofjnhaling tho inatjmjaT T,v7~ panel fixHnTta lliat at tho rr.omcnfc tho level of exposur.*^ below which the risk may be negligible is not known. The quantity of crocidolitc (blue asbestos) imported into the country iTmuch im titar. the other varieties of asbestos, and it has remained at about 7,000 tons per year for the last few years. But time nir.v shr,-.-.- that other fibres are also implicated in the development of mosothclial tumours. Finally, the report suggests that action should d.- taken to control t he. discharge of dust-laden air from asbestos factories and t-hc dispersal of dust from ,:- dumps. It emphasizes, 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 cares o f mesotheiiorna. in Britain over several years' is ve~~~ small when compared with' the annual total of catty lroin cancers of tho trachea, bronchus and lu; n g . Fyecording Weather * -*. _ * j-Mt+k.atrtid^ , i Air automatic weather recording station which ear. operate unmanned for at"least three months has bf-f produced by the Plessey Company Ltd. This station' which can make and record, more than 82,500 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 weat'-.e* stations was recognized by a recent report from :U- World Meteorological Organization (Xahire, 215, 1324: 1967). _ They are important because modem devclco- ment8 in weather forecasting require information about climate from all over the world--sometimes from un inhabited areas---and it is becoming increa.=inr'lv hard to persuade amateur mctr.orplogists to provide accurate data day by day. Professionals cos: mcr.ev. and so there should be a real market for automat"c stations which can do the job reliablv for lone periods without attention. ' - The Plessey station-is virtually self-contained and can monitor parameters such as rainfall, humid;*v, wind speed and direction, air, soil and water temper'- turca, barometric pressure, pH, solar radiation ar.d water level and flow. The basic design was evolved ir. co-operation with the British Water Resources Board, tho Meteorological Office and the National Physical Laboratory. By adding various instruments :o the basic design, it has been possible to produce a famiiv of stations including hydrometeorological, c'imar-i. logical, water level, water'quality ar.d recording rainfall stations. Each can he arranged f>r mum-*.-.1ir a: - -.. tiait, and Ihe recorded d an can bo sent- bv tvhuh.urv to a control centre on demand. * ' Each station is supplied as a complete svston with sensors, recorder, power supply, `Stevenson' screens and a stayed aluminium mast which support' the sen- 60rs. .Tim memory of the station samples u:> re-eight sonsors in turn, recording their outputs in. ten-bit 0707b ", UCC 02{)773' * n | rvss Aii Muucmg cue -n1 -- i--- Asbestos Dust Called a Hazard 5 To at Le^st One-Fourth of U.S, n y ja n e el n n o n v I Asbestos ,,ust, which has al structlon workers and their ready been connected with families. the development of fatal can According to the findings of cer in one-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 onl' was reported yesterday. 1,100 persons in three cities, (, This preliminary finding was showed that 25 per cent of the described by Dr. Irving J. Sell- people had asbestos lodged In koff in announccing the estabr their lungs. 1 lishment o f ' an environmental ' Dr. Sellkoff explained that health laboratory a t Mount 0,0 studies had used a "crude Sinai Hospital. The laboratory technique" that disclosed those asbestos fibers that only had will further investigate dangers to man of asbestos the and become coated by an irbn-nch I other environmental 1 nants. contaml- material lungs. A while lodged in the more refined technique Dr. Selikoff said the link now shows that ms: j persons between cancer and asbestos harbor noncoated asbestos fi had led him to suspect that bers as well, he said. other mineral dusts . that con Now Study Started taminate both urban and rural Dr. Selikoff 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 Dr. Sellkoff who. ^Examine, with the de with Dr. J r >b 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 tt 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, coloq and rectum. The doctors will look for un- Other Workers Affected coatcd as well as coated asbes Dr. selikoff noted that the tos fibers In the tissues. dangers of exnosurc to asbestos JLook for correlations be dust were n .mlted to tl iso tween the causes of death and who work directly with this tiie presence of asbestos fibers ubiquitous insulator and filler in lung tissue. material. The dangers, he said, ^Determine 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 noncor rosive and long-wearing prop- p erties. In addition to its common t use as a fireproof material. Dr. t Selikoff said, asbestos makes up a about 50 per cent of asphalt h tile and Is used In dental cement, p brake linings, plastics, beer fit- g ters, gas masks and paper. Until 1 last .year, some schools used U asbestos dust instead of sand si for children to play in. wr Study Links Asbestos To Cancer . ! . By Earl Ubcll . Sclanca Editor . ` Scientists have known for / a long time th a t asbestos ' 'was bad for your lungs. Now : ` ' a study of Hew York City j workers, both roofers and I, .Insulation blowers, reveals .'/[ U th a t exposure to the mineral ; j v`. sends lung-cancer . J i !. rates skyrocketing. death : j* The figures--gathered by doctors a t Mount Sinai Hos- j pital--show th at such work- . . ers have eight times the lung- cancer death rate as would be expected in a non-exposed . j , population. . More suprislngly, the stud ' les reveal th at such workers I rim four times the risk of . jgetting cancer in other parts l' { of the body, with cancer of - j < the colon particularly singled ' out. For all other diseases, ' the insulation workers have t the same death rate as the : -rest of the population. These findings were em i phasized yesterday by Dr. - : Irving J. Sellkoff, head ' of 1 Mt. Sinai's Division of Envl- ; ronmental Medicine,' on the : occasion of the establish ! 'm ent of an environmental . , health laboratory in the hos- i ' 'pital. The laboratory has , . received grants: totaling $324, r 000 from the United States ' Public Health Service and . j the New York City Health I-' Research Council. _ j - Dr. Selikoff also pointed i . out th a t cigarette smoking ' 1seems to heighten the effects ; | of the asbestos. Among 130 i men exposed to asbestos 20 . years or more who were non- ` smokers, he found one lung : : cancer , death among 319 ; 'smokers, 21 such deaths. UCC 020774 A07076 y 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. UCC 020775 A0 7 0 7 7 f - 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 UCC 020776 A07078