Document wqKd7JDJNdLbdyGJznvZ3axno

SM.32 1-S7) SHELL OIL COMPAN . ilate - Initial PRIVATE & CONFIDENTIAL date NOVEMBER 22, 1965 _V^LTW /^SL _____WAB-----4- ___ .RRS----- _____ MLR. 1 REFINERY MANAGERS , ANACORTES HOUSTON MARTINEZ NORCO WII2GNGTON WOOD RIVER ODESSA/CINIZA from MANAGER - MANUFACTURING _ENGINEERING DEPARTMENT HEAD OFFICE subject HEALTH HAZARDS FROM ASBESTOS _____ .AGS. .TJV. There has "been considerable discussion in medical circles in recent y------ 5---years concerning the possibility of harmful effects to insulators from long-term -^^T^^xposure to asbestos. This matter has been a recent subject of eui investigation rfgy the API Central Committee on Medicine and Health. Attached is a report vhich summarizes the current status of the study vhich vas presented at the mid-year API meeting of the Central Committee. It includes a summary of the findings from a recent survey of workers in the petroleum industry to determine if there were any potential problems from exposure to asbestos. We thought you should be informed concerning this matter since vork in progress by the U.S. Public Health Service and the medical profession is apt to focus increased attention on the health of vorkmen engaged in insulation activities. You will note from the conclusions in the attached report that the data obtained to date is considered inadequate to resolve the question as to the degree of hazard posed to refinery insulators. For this reason, ve see no cause for alarm at this time. However, you may wish to review the potential exposure to insulators from asbestos dust to determine if there are any situations where some additional precautions appear desirable. Subsequent to review of this report by the Committee on Industrial Hygiene of the Central Committee on Medicine and Health it was decided that, although the data so far accumulated waa insufficient to draw any conclusions, a task force should be established to continue the review and make recommendations for future action. We will keep you advised if anything significant develops. WCB:JC Attachment H. M. Karr LAM 024228 ABS-007407 / e-6 Attachment III THE HEALTH OF EE73XERIMEN APPLHJIG ASBESTOS INSULATION (a Preliminary Audit) Recent reports describing a high incidence of pulmonary neoplasms among aobostoa vorkors has focused attention on the health of refinery craftsmen engaged in insulation activities. To obtain information relative to the exper ience of. petroleum companioo with the health of their insulatoro, members of the Medical and Health Committee were polled, inviting them to contribute personal information on this subject to a common pool. Assurances were offered that the identity of the donor and source of information would not be revealed to preserve their confidentiality. Before presenting an analysis of the available information on petroleum company experience, a brief history of asbestos as an industrial health hazard is appropriate. Historical - For 50 years or longer asbestosis has been recognized in the United States as a form of pneumonoconioois resulting from exposure to asbestos dust. However, it -was not until joint medical and environmental studies wore con ducted by official health agencies in the mills of Pennsylvania and North Carolina about 30 years ago that the relationship between dust concentration, particle size, years of exposure and definitive chest x-ray markings was established. The lung field markings were also shown to correlate veil with certain subjective reactions related to pulmonary function. Important facts concerning the physical character of the dusts associated with asbestosis were revealed in these studies* Although asbestos fibers, ranging in median length from 7-16 minrona, were found in the air, these long fibers were relatively few in number. The bulk of suspended dust ranged from about 0.5-3 microns in length and varied in concentration from_as little as 1 or 2 million particles per cubic foot of air (mppcf) to 20 or more mppcf, depending on the mechanical operation involved. The correlations also showed that after 15 or more years of exposure the disease reached about the same degree of advancement, as evidenced by chest x-ray markings, regardless of dust intensity. In these studies there seemed to be no evidence of pulmonary or other thoracic neoplasms and no suggestion of such findings. Subsequently, reports of the occurrence of lung cancer and other malignancies associated with asbestos employment began to appear In the literature. Although the number of such cases appearod large, some investigators felt that the observations did not establish an increased incidence of cancer end that the association was unproved. Many LAM 024229 ABS-007408 E-7 Attachment III valid uaaknecsos wore show to ccdst in tho roporto claiming lung cancer as a specific industrial hazard of asbestos workers, however, in 1963 a report pub lished by SclHooff, Churg and -Hammond . (tho latter of the cigarette fame) described a significant incidence of lung cancer and other pleural tumors as well as cancers of the stomach, colon and rectum among asbestos insulators in the construction industry. - These insulators wore exposed, to a varioty of materials including fibrous glass, cork and hair felts which contain no asbestos; othor insulating materials, such as magnesia, calcium silicate insulating block and insulation - cement3 containing 10-15 percent asbestos. No free silica was present and asbestos appears to be the only biologically active material in the exposure. This report seamed to be free of tho statistical weaknesses and othor valid criticisms of the earlier reports. Sinco tho date of that report at least 3 additional publications by other investigators confirm in part, if not all, the findings of Selikoff and his associates. An important finding in theso reports is that these cancers are found coma 20-40 years after initial exposure to asbestos, frequently after retire ment from active employment. Stcrmary of Findings - Tho response to the poll of the Nodical and Health Committee members regarding this potential problem was nominal for this type of inquiry. Twelve replies representing nine companies were received. Of this number about 3 companies had made what appears to bo a careful examination of their health records and at least two other companies are engaged or are about to begin both environmental as well as medical surveys of asbestos insulators. A point' of special interest is that not all insulating materials used in a refinery consist of or contain asbestos. Considerable quantities of glass wool or rock wool, as wall as magnesiaj are also used as insulation. These materials <ire similar in composition to those reported by Solikoff and associates. One company reports that among a group"of about 40 insulators there was one case of bronchogenic carcinoma after come 16 years of exposure and one case of adenocarcinoma of tho rectum after some 20 years of exposure. Two other employees have had lung biopsies performed; one with 25 years of exposure show ing a single asbestos body in the specimen and the other with 20 years of service with fibrous thickening of the avoolar septa but no asbestos bodies in the specimen. There was no significant pathology in these specimens. In another company one plant reports a suspected case of asbestosis which occurred some 10 years ago, but the outcome of the case is lost to antiquity. At another plant of tho samo company one insulator had a lower lobectosgr and it was suspected that the fibrosis was caused by asbestos. A biopsy disproved this -2- LAM 024230 ABS-007409 e-8 Attachment III allegation. X-ray examinations of 7 additional insulators at this plant, each of whoa hnr. had IS or core yoars of Gxpbsuro,_revealed no significant findings. At still anothor plant roentgenography of fill the insulators rovoalod bronchovascular markings which was not apparent among other refinery people. No signifi cance v/as attached to these markings by the contributing physician. 1 A third company reported examination of insulators at all their plants. The majority have less than 15 years service and their chest x-ray films and ether . /- hosts appear normal. Two employees with more thatf 15 years service are reported to have a bronchitis. All other reporting companies state that their insulators appear healthy and that there have been no unusual iilnosoos among the group. No results of any dust surveys ware reportod although one or two companies state that the inhalation exposure to asbestos is insignificant. It is pertinent to point out that the so-called KAC for asbestos dust is 5 mppcf and that some investigators consider this value to be too high. It is equally important to point out that dust con centrations below about 5 mppcf of air are generally invisible to the naked eye even to that of the experienced observer. Conclusion - The data obtained to dato from tho Medical and Health Committee is inadequate to resolve the question as to the degree of hazard which ... asbestos poses to refinery insulators. This is so because the total number of refinery insulators (about 150) covered by the contributing companies' reports is insufficient for reliable statistical treatment and it is uncertain in every case that the morbidity and mortality records of retired refinery insulators ; or former refinery Insulators have been included in the reports. Since the usual / ' diagnostic examinations are frequently inadequate to detect certain cancers in thoir early stages, the disease may not be revealed until it has progressed to advanced stages late in life. To obtain an adequate population aample of refinery insulators for statistical reliability and comparison with published data, at least 5CO employees should be covered in the surrey. Since there are only a relatively few insulators of long tenure in any one *plant, the survey would require the full cooperation of at least 10 companies to obtain meaningful results. As a matter of interest, Salilcoff reports that the expected mortality from lung and plueral cancers over a 20 year period in a population of 500-600 persons is about 6 and for the same length of time, the expected mortality from neoplasms of the stomach, colon and rectum is about 9 for the same size population. -3 - LAM 024231 ABS-007410 / E-9 Attachment III oasca on some personal observations of insulating activities* it is my opinion that the Inhalation exposure to asbestos among refinery insulators is neither minimal nor insignificant and I~urgo the Kedical and Health Cosmittoe to continue studying this potential health problem. C \ LAM 024232 ABS-007411 E-10 Attachment III 1. "A Study of Aaboatosia la tho Asbestos Textile Industry" - Public Health Bulletin #241, August 1938, U.S. Government Printing Office. 2. Braun, i>.C. and Truan, T. D. - "An Epidemiological Study of Lung Cancer in ` Asbestos Minora" -- AMA Archives of Industrial Health, Vol. 17 (June) 1958. 3. Selikoff, Churg and Hammond - "Asbestos Exposure and Neoplasia" - JAMA' Vol. 188, No. 1, 1964. 4. Elwood, P.C. and Cochrane, A.L. - "A Follow-up Study of Workers from an Asbestos Factory" - British Journal of Industrial Medicine, Vol. 21, No. 4# 1964. 5. Dutra, T.B. and Carney, J.D. - "Asbestosls and Pulmonary Carcinoma" - Archives of Environmental Health - Vol. 10, No. 3> 1965* 6. Williams, W.F. - "Asbestosls and-Lung Cancer" - Archives of Environmental Health - Vol. 10, No. 1, 1965. 7. Asbestosls Symposium - Hew York Academy of Sciences - Summer of 1964* /* ./.r J *' LAM 024233 ABS-007412