Document Y9gjXRoxd5p492wgRD1LGneJD

September 16* 1968 ASBESTOS AND THE GENERAL PUBLIC People of virtually every nation in the world benefit from the many uses of the mineral, asbestos. Asbestos helps to build safety and durability into schools, houses, ships, aircraft and public buildings. ' ` With the increasing use of this mineral fiber, the question has been raised as to whether asbestos, especially when suspended in city air, poses any health risk to the general public. The same question is being asked about many other materials in general use in our modern society. Medical and scientific research is being conducted to find answers. For asbestos, some of the answers are already in. t To the extent that any asbestos fibers are in the general air -- and there are literally hundreds of different animal, vegetable and mineral fibers in the dust of the air -- there is nothing to show that these are a health hazard for the public. To see why this is so requires understanding of how and why asbestos is used, of some of the scientific research that has been conducted, and of the meaning of this research with regard . specifically to those with occupational exposures in contrast to the general public. ' CHEV BB modern uses grow out of atc;hot totowlesge 2 The word .asbestos is from the Greek; it means "unquenched" or "incombustible." The peculiar properties of asbestos have fascinated people ever since the mineral was discovered more than 4,500 years ago. Although in the raw state it is as dense and compact as the rock which encases it, asbestos can be separated into light, silky fibers. These fibers have many uses. They can be woven into non-combustible fabrics for such things as fire curtains for theaters or protective garments for firefighters. They can be added to other materials to produce floor and ceiling tile, roofing shingles, siding, asbestos-cement pipe and many other useful products.- The earliest known use of asbestos goes back 45 centuries. Objects unearthed by archeologists in Finland indicate that it was used to hold together pieces of pottery before the clay was baked. ' According to legend, the Emperor Charlemagne owned a "magic" asbestos table cloth which his stewards cleaned after royal banquets by throwing it into a fire, then retrieving it intact. Marco Polo found asbestos cloth on his journey to Asia and was told that it was woven from a salamander skin, but he later learned its true origin. (More) 3HEVBB tnnmQQ MINERAL PROVIDES SAFETY AND DURABILITY 3 * In the twentieth century, asbestos has become an increasingly essential material of an improved way of life and an expanding industrial economy. Asbestos has many vital functions in constructios m transportation and industrial processes. It provides built-in protection against fire and deterioration in scores of common products in daily use. Through the years it has saved countless lives and billions of dollars in property damage by preventing or checking the spread of fires. Electrical installations are safer because of asbestos insulation. When used as packings and gaskets, asbestos promotes the efficient operation of industrial machines and pumps. * In transportation, the brakes on vehicles -- cars, trucks, buses and trains -- are dependable because asbestos is a chief component in brake linings. OCCUPATIONAL RISKS AND STEPS TO PROTECT WORKERS To meet the increasing demand for this invaluable fiber, a worldwide asbestos mining and processing industry came into being. As in many other mineral and materials industries, the need developed to protect employees'against occupational health hazards. (More) CHEVBB 4 It was found that some workers exposed to excessive asbestos dust over a period of years developed a non-malignant lung disease called "asbestosis." As with many similar conditions, asbestosis is dose-and-time related -- that is, it develops only after inhalation of excessive concentrations of asbestos dust over a period that averages 17 years. Some medical studies have reported an association between the disease "asbestosis" and an increased risk of a certain type of lung cancer (bronchogenic). Even though the number of lung cancer cases among workers heavily exposed to asbestos fiber is only a small fraction of the total employed, the industry considers the problem serious. Zt is the subject of considerable Scientific research through statistical, clinical and pathological studies of exposed workers; through experimental studies with laboratory animals, and through studies of the physical and chemical nature of asbestos and associated minerals. In the recent past, the asbestos industry has invested millions of dollars in equipment and techniques to prevent the inhalation of asbestos dust by workers in the mining and milling of asbestos and in the manufacture of asbestos-containing products. A program of education and training is conducted for asbestos fabricators and applicators to provide them with a thorough under standing of potential risks and'to eicourage general adherence to sound industrial hygiene practices. CHEVBB 5 * Studies in asbestos-using industries in England and the United States indicate that where dust control measures have been taken, the risk of lung diseases among the workers has been greatly reduced. . yo ris:<s to general puultc ssphs is studies 3ecause of the occupational health hazards associated with asbestos, some people who are concerned about general air pollution have raised the question of whether there is asbestos dust in the air in sufficient quantities to constitute a health risk to the general public. . Studies of asbestos exposure and human health of the general public have produced no evidence of any health hazard to the genera public from the use of finished asbestos products. "Asbestosis" does not occur among the general population? it occurs only among those with long-time,heavy occupational exposures. There is no evidence that anyone has ever contracted any disease from exposure to the wearing or weathering of brake linings, floor tile, roofing, or other products containing asbestos. 3rake linings in particular were the subject of a 1968 United States Public Health Service report. Jeremiah Lynch of the National Center for Urban and Industrial Health, U. S.Public Health Service, conducted the tests. He concluded that any asbestos that might come from brake lining wear was "an inconsequential health CHEVBB 6. factor in urban air pollution." The study provided scientific evidence refuting much recent unsupported speculation that the wear of brake linings might be releasing many asbestos fibers into the air: "Except in all but the most extreme driving conditions, only a very small fraction of the 30 to 50% asbestos present in a brake lining escapes into the atmosphere as free fiber ... the remainder is converted into some other mineral as a result of the extreme temperatures generated at small spots on the lining surface. Thus, although urban air contains a few free fibers as a result . of brake lining wear, they represent a very small pro portion of the total asbestos used in the manufacture of brakes. Many sources of respirable fibers not associated with asbestos products have been identified, and the free fibers from brake lining wear appear to be an inconsequential health factor in urban air pollution." Other medical and scientific reports show that the' occupational health risks from, asbestos dust exposure do not extend to the public. 4 In 1967 Drs. P. E.Enterline and M. A. Kendrick reported on the reduction of asbestosis among workers in asbestos fabricat- in industries where protective measures have been taken. They pointed out that the small amount of asbestos to vhich people in general may be exposed is of "little importance:" '*...................... if very low-level exposures of populations to asbestos dust play any part in the pathogenesis (development) of disease i-t must be very small indeed .... Asbestos dust at levels to which general populations are exposed probably is of little importance in the etiology (caustion) of disease." (More^ :hev bb 7 en-rar.r.'PO "ASBESTOS BODIES" KOT RELATED TO DISEASE In the mid-1960's the question of public: exposure was ' discussed in studies that reported finding so-called "asbestos bodies" in the autopsied lungs of some city dwellers who were not known to have been exposed directly to asbestos dust. The studies emphasized that these so-called "asbestos bodies" had no relation with either the cause of death or with any history or symptoms of pulmonary disease. . The authors of one such study, Drs. J. G. Thomson and W. M. Graves, noted that it would have taken a tremendous increase in the number of "asbestos bodies" found in the autopsied lungs to constitute even a'"minimal" case of asbestosis. They said in their 1966 reports ' "It should be stressed that in spite of .frequent asbestos bodies in the lung bases none of this group had pulmonary disability and all died from other causes .... to convert the scanty or very scanty bodies which we have demonstrated to be present in so many urban dwellers to the frequency present in a minimal basal asbestosis would require an increase by hundredfolds and to get a more diffuse classical asbestosis with pulmonary disability the multiplying factor might well be in many millions." ./ In a similar study the same year, Drs. L. Anjilvel and w. M, Thurlbeck noted that there is no risk of cancer to the general population from asbestos exposure. These researchers said: * - "In our series there seemed to be no particular association between malignancy and the presence of asbestos bodies ... asbestos bodies are not more common in patients with malignant disease in the autopsy populations we have CHEV BB 8. studied, and thus casual exposure to asbestos is not an important cause o malignancy in the general . population." . Other authors have raised the question of the real identity of these so-called "asbestos bodies." The term has for years been , applied loosely to describe a tiny body of tissue in the lung containing a core of some inhaled particle -- asbestos, talc, man-made fiber, or certain other common substances. The name "asbestos body" is misleading if the core substance has not been positively identified. Thus, it is not necessarily so that the finding of such "bodies" in city dwellers' lungs means that these people inhaled asbestos. ' Because the cores of such "bodies" do not always contain asbestos, and because the over-growth tissue contains some identifiable iron. Dr. Paul Gross, who has studied the problem extensively, has suggested that a more accurate name would be "ferruginous (iron-like) bodies." Other specialists have now begun to refer to "ferruginous bodies" in their papers. Dr. J. M. G. Davis, in 1967, deplored the "current furor over asbestos bodies------which recently appeared in the professional literature and was widely reported in the news media with varying degrees of sensationalism." He commented specifically: # "..............the basic assumption that asbestos-like bodies can only be produced from asbestos has proved incorrect and this casts considerable doubt on the theory that has been the chief basis of the asbestos 'scare'." CHEVBB MACT THINGS 9SSI55S AS3EST0S MAY CAITS5 FI3R0US "BODIES" Much research work is going on to develop ways of identifying the particles that may be the core of these "bodies." It has been shown that a number of substances can cause "bodies"in both humans and experimental animals. L. J. Cralley and associates in the U. S. Public Health Service have discussed the great number of substances which might produce "bodies" in human lungs. Publishing in 1968, they saids . "On the premise that the fibrous bodies observed in the lungs of persons at autopsy are all "asbestos bodies" and that coated fibrous bodies are a specific reaction to asbestos fibers, sorre investigators have concluded that asbestos fibers are significant air contaminants ... Respirable fibers may be mineral, vegetable or animal in origin and may come from both natural and synthetic sources. There are.well over a hundred different natural minerals with some degree of fibrous structure .... Respirable fibers of vegetable orgin may be from both live.and dead plant tissues .... Animal fibrous materials include animal hair and scale, insect hair ... Synthetic fibers include the newer ceramic fibers ... as well as a wide range of established and emerg ing organic types used in textiles, fillers, containers, filaments, structural materials, etc." Whatever their origin, the "bodies" that have been reported have not been connected with any disease, or with the cause of death, in the subjects studied. Even if some asbestos is among the variety of fibers in the air breathed by the public there is no evidence that it has any health significance. SUMMARY *>r> throughout +,v,r* vor1 d benef.it from the many .......... r. * CHEV BB 10. asbestos -- in schools, houses, theaters, ships, aircraft, offices and other public buildings, furnances, boilers, firefighting equipment and in a myriad of everyday products. With the 20th century growth in the use of asbestos has come recognition of the need to cope with occupational hazards associated with excessive inhalation of asbestos dust. Much progress has been and is being made in protecting workers who handle asbestos fibers in mines, mills, factories _and in some building and insulation trades. Medical scientists studying the occupational health har ..M: of asbestos see no evidence that asbestos poses any risk to the general public. Asbestos dust is not present in the general air in amounts of any significance to human health. . PERSPECTIVE It is important to view in its proper perspective the expressed concern of some people that asbestos in the ambient air is a health risk to the general public. Asbestos is by no means alone in having the finger pointed toward it as a possible health hazard. Literally hundreds of substances -- as common and everyday as fuel oil,charcoal broiled steaks, iron rust and egg yolks -- are known orsuspected of being cancer causing agents under certain experimental conditions. :hev bb 11. The point is that nearly everything we use and create in our increasingly complex society has been suspected, by someone, of being a potential hazard. To forego the many benefits of these products of modem technology -- simply on the basis of suspicions that are un supported by medical evidence, would be a great and unwarranted disservice to the American public. # ## # CHEV BB 0003098 Anjilvel, L. and Thurlbeck, W.M., "The Incidence of Asbestos Bodies in the Lungs at Random Necropsies in Montreal" -- CANADIAN MEDICAL ASSOCIATION JOURNAL. December 3. 1966. Cralley.L. J., Keenan, R. G., Lynch, J. R., and Lainhart, W. S. "Sources and Identification of Respirable Fibers." AMERICAN INDUSTRIAL HYGIENE JOURNAL, March/April, 1968. Davis, J.M.G., "Asbestos Bodies and Bioeffects -- A Detective Story" presented at the meeting of the Industrial Hygiene Foundation, Pittsburgh, Pa., October 1967. Enterline, P. E., and Kendrick, M. A., "Asbestos Dust Exposures at Various Levels and Mortality" - ARCHIVES OF ENVIRONMENTAL HEALTH, August 1967. Gross, P., Cralley, L.J., and de Treville, R.T.P., "Asbestos Bodies: Their Nonspecificity." AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL, November/December, 1967. Lynch, J., "Brake Lining Decomposition Products." Meeting American Conference of Governmental Industrial Hygienists, St. Louis, May, 1968. Thomson, J.G., and Graves, W.M., "Asbestos as an Urban Air Contaminant." ARCHIVES OF PATHOLOGY, May 1966. ## CHEV BB