Document 2Rggrb4GkrvdNQObjwV9wNZ7r

Research on Health Effects of Asbestos Asbestos as a curious material was known several centuries B.C., especially for its ability to withstand flame. The physical and chemical properties of asbestos combined with its fibrous structure recommended it as a unique material with a wide range of potential industrial appli- cation. It was not until the end of the lase century, however, chat it gained importance as an industrial resource. The subsequent use of asbestos in a number of technological areas and its contribution to haw products made it the precursor of the special science of -Industrial . mineral fiber technology. Asbestos is essential in today's industrial technology including national defense, aerospace, and civilian consumer use. Asbestos is a general term applied to a group of fibrous crystal line hydrated silicate minerals. Although a number of different types : of asbestos minerals exist^. only four or five are of cotsaercial. import ance. Each differs somewhat from the others in chemical composition, * physical properties such as ability ta withstand heat and chemical erosion, crystalline structure, end' in fiber dimension and degree of harshness and brittleness.. The worldwide production of asbestos has greatly expanded since the* turn of the century, the overall consumption In this country level ing off for the period 1958-63 at around 750,000 short tons annually. Of this tonnage, approximately 937. was chrysotile, 3.5Z crocidolite. 2.5Z ambsite, and 1Z anthophyi1ite and tremolite. j BB 0020561 l 2054 -2- Even chough asbestos has been in industrial use for well over SO years, nuch is unknown regarding its health effects and safe levels of exposure. It was known in the early 1900's that excessive exposure to asbestos gave rise to the disabling pulmonary disease "asbestosis." More recently, evidence has been developed that Che incidence of respiratory tract and other malignancies may be excessive in asbestos workers. A major problem in studying the health effects of asbestos Is the long latent period of 20 to 25 years and over from initial exposure to the onset of disease. Also in the mid-1930's and earlier, there was little dust control so Chat the workers were often exposed during this period to massive levels of dust from asbestos and ocher ! 'i if associated materials in the manufacture of asbestos products. Thus the causative agents of the resultant disease are essentially unknown. - iJ- r Included in these potential sources of causative agents, either alone or in combination, are the one or more types of asbestos fibers tthen^ selves, materials associated with the fibers in the ores such as trace minerals and polycyclic aromatic oils, materials which might be added r F. 4 .* during processing such as metals, tars and pitches, and concomitant external exposures such as smoking or other air pollutants. A salient point is that in subsequent years when heavy dust exposures were reduced, disease also diminished. This definitely indicates that with sufficient knowledge of the agent(s) responsible for the disease, along with dose-response data, safe levels of exposure m can be established. "['SB 00 20562_J THIS DOCUMENT WAS NOT A RECORD OH PPG INDUSTRIES, INC. DID NOT COME FROM **ITrS~TTLES' AND CANNOT BE AUTHENTICAXED--------------BY PPG INDUSTRIES,-INC. 2055 - 3- Studies Co elucidate the importance of the asbestos minerals as hazards Co health fall into two broad categories: first, chose efforts needed to insure answers to urgent questions involving public policy and control efforts;, and second, chose needed to broaden ehe long-term base of information on the physical and chemical factors of fibrous materials as related eo th'eir Interaction with animals and man so that efforts to maintain safa working and living environments can be constantly revaluated and improved. In Che first category, for example, coma programs aimed at clarifying reporta of asbestos bodies being present, to some extent in the lungs of a third or more of our population. Are these truly responses to asbestos fibers or are other fibers also involved? Where do these fibers come from, and what is chair potential significanca in terms of health? Is there, an increasing incidence of mesothelial tumors in our population and is this in any way related to asbestos minerals? Do fibrous minerals play a major or minor role in the causation of lung cancer? Are certain forms of asbestos or ocher fibers more important in chase relationships, and what co-factors are important? K: rJ3 Concurrent with answers to these pressing questions, there, is s -V , .u need for a strongly supported program aimed at answers over the longer ' term regarding the pathogenesis of asbestosis and tha other effaces that appear associated with the inhalation of asbestos dust* Better Information on the physical and chemical characteristics of the asbestos minerals which lead to their being inhaled and retained in the body, in their carrying with them other chemicals, in their migration, may open up- i |I I 2056 ; .. ... ./ unsuspected avenues of biological research. Answers are needed to the following questions in safeguarding Che workers' health, yet permitting the benefit- of asbestos in today's industrial technology. The information gained will also have direct application toward the safe use of the many new synthetic fibers being introduced into industry in the rapidly expanding science of industrial fiber technology. 1. What Is the nature and pattern of disease in workers exposed o -to to Che different forms of asbestos fibers and how do they O JLi relate to the magnitude and duration of exposure? The answer to the above is basic to understanding related health problems and setting up research on a rational basis for their solution. It will provide evidence bearing on the etiologic factors involved and their Inter-relationship, give information on Che dose-response relation ship of the agent(s) to the disease, provide criteria far setting up sefe levels of exposure and give the basis for establishing, medical and environmental surveillance procedures where asbestos is encountered and handled. It will also provide useful information for evaluating possible risks from inhaled fibers in chose not occupationally exposed. | i 2- Row ere the diseases- and other manifestations observed in workers exposed to asbestiforts fibers characterized clinically ~ and pathologically, and do they differ when exposure involves one form of asbestos or another? | BB 0020564^2 THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC- DIO NOT COME FROM TriTHLES AND CANNOT OD'AUTHfrHTlCArT&Q BY PPG INDUSTRIES, INC. 3057 I -5- Far more information is needed on the pathogenesis of asbestos is and on other responses to asbestos fibers in man, based on careful serial studies and correlations of clinical, physiologic, radiographic and histological changes. Results of these studies would relate to the 'prevention of asbestos-related disease as well as give useful informs- tion on the biological response to ocher respirable fibers. The findings would supplement current criteria for diagnosis, prognosis and manage ment of disease, continued employability, fair adjudication of campensa- <3 C/9 Cion claims and effective rehabilitation. They would also provide information important in establishing surveillance program for asbestos workers and in effecting control measures. .* 3. What are the factors involved in the pathogenesis of the ^ ,' diseases associated with the Inhalation of asbestos minerals and what are the primary etiologlc factors involved? i* With few exceptions, asbestos is generally formulated with other fjp. a.,- ..... i !i I T') materials In the preparation of aabestos products, chough in many ' instances the asbestos may be a predominant Ingredient. Even in Che mining and milling of asbestos, recent studies have shown that these peretlons are associated with exposures to potentially Injurious agents such as trace minerals of nickel, cobalt, manganese, zirconium, titanium, etc., ab" well as polycyclic aromatic compounds in some ores, ... . . and potentially from metals abraded from processing equipment due to the harshness of the fibers. These same contaminants msy be carried in degrees in the milled fiber and subsequently added to as processiP i. l- I k I1 ; ; of the fiber continues. Thus the etiologlc agents resulting in the THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM 1T.S-EILES. ANDXAJMQJ BE -AlilHENTICATEO BY PPG INDUSTRIES, INC. 3058 -6- diseases observed In past studies are generally unknown. They may have been one or more of the fibrous forms of asbestos, trace minerals in the ore, polycyclic aromatic compounds associated with the. ore, additives in processing, such as metals, coal tars and pitch, eec., smoking, other air pollutants, or some combination of these factors. Studies in the past a have generally.related resulting disease to fiber exposure only. This requires a further look into both the clinical and animal research of the past, as well as current research, to further`define related agcnes in-light of this more recent Information. The above information will, also be most useful in pinpointing' . preventive measures, not only in terms of inhaled fibers, but in terms of other associated co-factors. What chemical and physical characteristics of asbestos fibers relate to their respirability, mobility, clearance j and itrmobiliration in the body and how do the types of asbestos differ In these respects? Most of the research relating to Che respifabillty and recention,'< mobility, and clearance of materials from the lungs has been done on- Fibers, however, having a much greater length-to-diaaeter ratio, have direction and orientation in their .movement and may-behave quite dlffer- ently than particulates. Fibers that are harsh and rigid may haver tissue penetration potential. Through this mechanism they may, as carriers, transport toxic agents from the lungs to other organ sites and. thus h^*** a causal relationship heretofore not understood. It is important to 0020566 X. PPG 1NDUSTR1 ES^ I NC> 2059 - 7- have an understanding of the behaviour of fibers In. lungs and other tissues and to relate this Co the respective physical and chemical characteristics of fibers so that patterns of response can be under* stood and predicted. 5*. How can asbestos fibers In vivo and vitro be differen tiated as to type and how can they be distinguished from non-asbestos fibers? Respirable fibers are ubiquitous. They may be either natural or synthetic and from animal, vegetable or mineral origin. Moderntechnology is introducing increasing numbers of synthetic fibers into industrial use. It has been known for some time chat asbestos fibers is the lungs give rise to asbestos bodies. The findings of similartype bodies in the lungs of a large percentage of individuals coming to autopsy in general urban hospitals, even though the number in any individual may be relatively small,' has given concern as to their meaning as well as to the indentlfication of the associated fibers and their environmental source. Methods must be developed for isolating, identifying, and quantitating fibrous msterials in thelungs and other tissues and in the associated ferrunglnous bodies.. - 6. What levels of exposure to the etlologic agents associated witth~isbestos-related diseases can be regarded* as safa? This is a prime objective of the research. When information on safe levels becomes available, environmental and other controls can be devised to keep exposures within the recoraended limits. O CO DOCUMENT WAS NOT A RECORD "oF if,INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. rsrsss^u. 2060 - rS -8- 7. How can exposures be prevented? The aerodynamic properties of fibers will differ somewhat depending upon the specific physical and chemical properties of the fibers. Their behavior in air is much less understood than that of particulates spherical in shape. Information is needed on the a behavior of.fibers for the design of ventilation control equipment and the design of process equipment to minimire the dispersion of fibers into the air. 8. What environmental and medical surveillance procedures - .... . % are recommended where asbestos fibers are encountered, or handled? o ca Surveillance of the working population at risk is an essential part of any occupational health program in industry to detect early changes before damages to health have occurred. Environmental monitoring of exposure levels as well as continuing information on the health status of the working forpt are important segments of a surveillance program. The development and application of surveil- lance procedures will assure the use of asbestos with miniown risk to health. The answers to the- above- questions can come only from widely- baaed interrelated research directed to the health responsa of the worker and his specific environment. The research, although directed rather specifically to Che asbestos worker and his environment, has application in the understanding of a wide range of 3llied occupational diseases, especially those relating to fiber exposures. This research THIS DOCUMENT WAS NOT A RECORD OF. PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES-AND CANNOT GFACJTFTERTICATED'---------BY PPG INDUSTRIES, INC. ij?--8 0-0-2--0-S-6-8-~7 3061 I should encompass: Epidemiologic (a) Longitudinal studies of groups of workers in different employ ment categories with contrasting exposures to different types of asbestos fibers by magnitude and duration, singly and In combination with other associated materials capable of producing injury or eliciting a synergistic response to establish inter-relationships between health patterns of the workers and environmental exposures. (b) Studies of the relation beeween exposure to asbestos minerals py UJ and clinical symptoms, pulmonary changes demonstrable by pulmonary function and work tasts, and chest roentgenographic shadows suggestive of asbestosis.y . (c) Records studies of morbidity and mortality patterns and trends in groups of workers with contrasting exposures to asbeseos and oeher associated materials; also a search for common genetic or hereditary patterns relating to the disease. (d) Analysis of selected post-mortem tissues of workers with work histories in industries having contrasting ccposures to diffarene forms of* asbestos and other associated materials during and after periods of massive dust exposure. Also, studies must be conducted on workers in , these categories-who died from an exposure associated disease as well- as those who showed no obvious indication of associated disease. I (e) Sputum study of asbestos workers to correlate and quantitate magnitude and duration of exposures with the occurrence of asbestos bodies. --. (f) Study of contrasting papulation groups with respect to RK0RD F iJiLOO 20 56 9 3062 - 10 - geographical areas, air pollution, employment patterns, etc., for presence of pulmonary ferruginous bodies; determine if these correlate with disease patterns observed. (g) Study of ecological factors that may have a bearing on either the disease or be inter-related with causative"agents. including community exposures Clinical and human pathology (a) Comprehensive study of selected individuals with different patterns and progression of disease with respect to: (1) impaired pulmonary vascular circulation, both by tests of function and by angio graphy, (2) pleural thickening in reducing function, producing physical ' ** signs, altering roentgenograph!c patterns, and being a precursor of L pleural tumors, (3) impact of viral infections on persons with asbestos exposures, (4) sites of pulmonary fiber depositions and injury. I' (5) immunochemical changes, (6) the nature of emphysema so often associated with asbestos is, . (7) the role of chronic bronchitis and other causes,, and ' of pulmonary obstructive disease in altering the prognosis of asbestosis, (8) correlation between roentgenograph!c evidence of disease and the capacity of the cardiopulmonary system to fulfill its required function. (b) Eatablishjnent of a mesothelioma case registery including uniform critarfa* for diagnosis; epidemiologic follow up of reported cases. ~ (c) Development of a uniform classification for reading chest roentgenograms of persons exposed to asbestos and ocher fibers; correlate ' roentgenologic patterns with clinical, physiologic and histological changes. THIS DOCUMENT WAS NOT A RFrnon PPG INnilCTDire ________ A RECORD Br fPG INDUSTRIES, INC. | BB 0020570 J 3063 11 (d) Study to detect individuals who tray be hypersusceptible, either on an acquired or a genetic basis. Animal and tissue culture (a) Determination of resplrablllcy, sites of retention, mobility, penetration and migration to other tissue, and clearance of pulmonary fibers in relation to their chemical and physical properties. (b) Study of mechanism of formation and meaning of ferruginous bodies arising from respired pulmonary fibers from different sources. (c) Study of the chemical and physical characteristics of various types of asbestos fibers, singly and in combination with ocher associated .. .. 4 injurious materials and thatr capacity to give rise to different forms r- ,-j- Wj t---' - j a * V j-m --^ L*a i.i, t 1* ' of cancer; evaluate additive,enchancing, or inhibiting action of fibers ' and carcinogens from cigarette smoke and other sources. (d) Study of potential of pulmonary fibars as carriers of carcinogenic and other agents from lungs to ocher tissue sites. 1 (*) Development of dose-response data as an aid to developing safe exposure levels. - () Investigation into the effects of asbestos and ocher fibers, and of associacad injurious materials, on cellular physiology, enzyme suppression, and genetic pattern. (g) Study-of innunochetnical changes, biochemical tests, etc., that, may further characterize the exposure-response pattern and serve- as predlcitlve tests. THIS DOCUMENT WAS NOT A RECORO OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES. AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, tNC. _ 7~BB~002057TM ------------------- ---------- . '' " 2064 - 12 - Chemical and physical (a) Study of Che positive 'identification of individual fibers, both in vivo and vitro; Che nature and quantity of ocher contaminants such as minerals, meCals, and oils associated with the fibers including mechanism of association, (b) SCudy of-solubility of'fibers and associated contaminants ^ In Cissua fluids; relate Co blood and urine levels of associated -. materials. - > (c) Study of sources and identification of respirable fibers responsible for ferruginous bodies seen in lungs and general population of non-asbestos workers. v I- - .\ ( u *r 1V f DRAFTr Lewis J. Cralley, Ph.D. William S. Lainhart, M.D. U. S. Dpartment_Health~Education, and Welfare Public Health Service National Center for Urban & Induatrial Health Occupational Health Program 1014 Broadway, Cincinnati, Ohio . March 8, 1967. THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. | BB 00 20 572 I . 3065