Document zdXb5DRD3eDy77GQbEBXmd92g

-t _ . /L ,co ? PLAINTIFF'S EXHIBIT S T O O !1647 NOTES TAKEN AT FIBROUS DUST SEMINAR AT MELLON INSTITUTE, PITTSBURGH, PENNSYLVANIA ON 22 NOVEMBER 1$58 SPONSORED BY INDUSTRIAL HYGIENE FOUNDATION AND MELLON INSTITUTE Part I - FIBROUS GLASS HEALTH RESEARCH Opening Remarks by W. Clark Cooper, M.D., School of Public Health, University of California Airborne glass fibers are not known to be a medical hazard at this-time. There is a suspicion that airborne glass fibers may be a medical hazard. More time may be needed to study the airborne glass fiber problem to permit a decision to be made whether or not these fibers are hazardous. Statistical Studies of Health of Fibrous Glass Workers by Industrial Hygiene Foundation - H. Michael D. Utidjian, M.D., Department of Epidemiology, University Of Pittsburgh The Industrial Hygiene Foundation made a statistical study of the health of employees of a glass fiber manufacturing plant operated by the Owens-Coming Fiberglas Corporation at Newark, Ohio. The plant has been in operation for 30 years. More than 2,000 workers are employed at the plant. The study was made in the period from August through October 1968. Employees were classified with regard to degree of exposure to airborne glass fibers. The exposure classifications used are - high, inter mediate, low. Also, the employees were classified by age. The age classifications used are - under 30 years, 30 to 49 years, 50 years and over. A sample of 232 employees was used in the study. Employees were subjected to answering a questionnaire with regard to health. Employees also were subjected to spirometry tests to determine the breathing capacity of their lungs. In addition, chest X-rays of the employees were studied. The purpose of the questionnaire was to determine gross effects of exposure to airborne glass fibers on the health of employees of the glass fiber manufacturing plant. A study of the questionnaires indicates that there is no clear relationship between the degree of exposure to airborne glass fibers and the health of persons exposed. Only age seemed to have an effect upon the health of the employees. Coughing - this increases with age but there is no increase due to high exposures to airborne glass fibers. Bronchitis - there is no clear pattern of relationship between bronchitis and degree of exposure to airborne glass fibers and there is no relationship between bronchitis and age. Breathlessness - results are the same as for bronchitis. Chest illness in last 3 years - results are the same as for bronchitis. Total history of chest illness during life - there is a slight increase in chest illness with age. The results of the spirometry tests indicate that there is a slight decrease in the breathing capacity with age but there is no relationship between breathing capacity and degree of exposure to airborne asbestos fibers. Smokers were found to have a greater decrease in breathing capacity than non-smokers. ST0011647 S T O O !1648 2- - The study of the chest X-rays showed that there was nothing unusual in the X-rays to suggest a radiologic lung pattern that could be associated with exposure to airborne glass fibers. It is conlcuded that there is no definite relationship between the health of a worker and his degree of exposure to airborne glass fibers. The study showed that health deterioration increased only with age. A question was asked if any workers in the plant wore dust respirators. Dr. C. S. Bishop, physician at the plant who was present, stated that only workers in a batch house used dust respirators. Statistical Studies of Health of Fibrous Glass Workers by National Insulation Manufacturers Association - L. J. Cralley, Ph. D. of U. ~S. Public Health Service A study is now being made of the health profile of glass insulation workers and glass textile workers. The health records of 20 to 25 thousand workers are being studied. A substantial number of these workers have had long periods of exposure to airborne glass fibers. In addition, a study is being made of the concentrations of airborne glass fibers for various operations in the glass insulation and glass textile fields. Workers are exposed to much lower concentrations of airborne glass fiberthan concentrations of airborne asbestos fibers. Glass fibers generally are much larger in size than asbestos fibers. Glass insulation employs glass fibers having diameters 6 microns and greater. Glass fibers used in glass textiles are smaller than glass fibers used in glass insulation. Recently, micro-fine glass fibers having diameters less than 1 micron have been introduced for use in the manufacture of glass textiles. Pathological Studies of Respirable Fibrous Glass Dust with and without Phenol-Formaldehyde and Textile Binders- Paul Gross, M.D., IndustriaT Hygiene Foundation Finely ground flake glass of respirable size deposited in the lungs of animals was found to behave like inert dust particles. In the study, rats and hamsters were exposed to uncoated glass fibers, glass fibers coated with phenol-formaldehyde resin, and glass fibers coated with a textile binder (starch). Thirty rats and thirty hamsters were used in each phase of the study. Glass batt material was used to generate the aerosol used in the study. The glass utilized had a diameter of 1 micron. The batts were cut into pieces and ball milled. The material from the ball mill was in the form of a finely divided powder. 60% of the product was fibrous while 40% was non-fibrous. The fibrous material was chiefly 5 to 10 micron in length. The material from the ball mill was fed continuously by means of a screw type feeder into an air stream which passed through a blower having a squirrel cage type impeller and then into the animal inhalation exposure chamber. The concentration airborne matter in the animal inhalation exposure chamber was 100 milligrams of matter per cubic meter of air. The animals were exposed to the airborne glass matter for 6 hours per day, 5 days per week, for a period of 1 year. ST0011648 STOO!!6 49 3- - A gross examination of the lungs of animals killed after 1 year exposure to the airborne glass matter showed that the lungs were normal. Microscopic examination of lung tissue of the animals exposed to the airborne glass matter for 1 year indicates that none of the 3 types of glass (uncoated, coated with phenol-formaldehyde resin, coated with textile binder) had any distinguishing effect upon the lungs. An increase in connective tissue in the lungs usually is due to irritation there was no increase in the connective tissue in the lungs of the exposed animals. The glass matter was found to have penetrated through the alveoli walls. Air spaces in the lungs were not affected by the glass matter. Collections of glass were found in the lymph nodes in the lungs and in cells of lung tissue - this collected glass seemed to have caused no effects in the lungs. Reactions in the lungs of the exposed animals were similar to that of inert soot or coal dust. - It is concluded that exposure to airborne glass matter results in reactions similar to that of inert dust. Coatings on glass fibers of phenol-formaldehyde resin or textile binder (starch) do not alter the benign characteristics of glass. Examination of the lungs of animals exposed to the airborne glass matter for a 2-year period showed that neoplasms were not formed. A study of the effects on animal lung tissue of an aluminum silicate fiber made by the Carborundum Corporation showed that this fiber produces lung effects like those of the glass fiber. It is known that animals exposed to airborne asbestos fibers for less than 6 months develop a fibrosis in the lungs. Some people have said that this is due to the fibrous nature of asbestos. Since animals exposed to airborne glass fibers do not develop a fibrosis in the lungs, we must conclude that the fibrous shape is not a significant factor in causing adverse physiological effects in the lungs. Physiological Studies of Health of Fibrous Glass Workers - Benjamin J. Lambiotte, M.D., Industrial Hygiene Foundation Pneumoconiosis is a diagnosable disease of the lungs produced by dust. Let us propose the following hypothesis: Inhalation of airborne glass fibers will cause significant effects on lung tissue. The hypothesis would be proven to be true if it is found that long term workers exposed to high concentrations of airborne glass fibers have significant deterioration of their lung functions. The hypothesis would be proven to be untrue if it is found that long term workers exposed to high concentrations of airborne glass fibers do not have significant deterioration of their lung functions. The Industrial Hygiene Foundation is making a study of the effects of inhalation of airborne glass fibers on lung tissue to prove or disprove the mentioned hypothesis. Effects of inhalation of airborne glass fibers on the mechanical function of the lungs is to be determined by spirometry tests on workers who have been exposed to airborne glass fibers. The effects of inhalation of airborne class fibers on the membrane walls RTOO11649 4- - of the alveoli of the lungs will be determined by measuring the diffusion of carbon monoxide gas through the alveoli membrane walls of workers who have been exposed to airborne glass fibers. The study involves both older workers who have been exposed to high concentrations of airborne glass fibers for many years and younger workers who have been exposed to low concentrations of airborne glass fibers for only a few years. The results of this study will be available for use by the Threshold Limits Committee of the American Conference of Governmental Industrial Hygienists in 1969. Radiological Studies of Health of Fibrous Glass Workers - Jon L. Konzen, M.D. Owens-Corning Fiberglas Corporation The chest X-rays of the sample of workers in the glass fiber manufacturing plant used in the study reported today by Dr. H. Michael D. Utidjian were reviewed to determine if the lungs of these workers showed micronodulation or a diffuse fibrosis pattern. STOO!1650 The chest X-rays showed that 33 micronodulation in their lungs. minimal micronodulation was due fibers. of the 232 workers had a minimal of It could be explained that this to matters other than that of glass Micronodulation in Lungs Number of Cases Found Age of Workers Exposed to Glass Fibers Workers with Low Exposures to Glass Fibers Workers with Intermediate Exposure to Glass Fibers Workers with High Exposures to Glass Fibers Under 30 years 3 2 6 30-49 years 4 3 4 50 & more years 4 4 3 The table pertaining to micronodulation in the lungs of workers exposed to airborne glass fibers shows no pattern of relationship of micronodu lation to either degree of exposure or to age. The chest X-rays did not show any cases of a diffuse fibrosis pattern in the lungs of workers exposed to airborne glass fibers. Expert radiologists stated that all the chest X-rays of the workers, including those with the minimal of micronodulation in the lungs, are normal for the general population. Even those showing the minimal of micronodulation are normal for such micronodulation is found in normal chest X-rays of the general population. ST0011650 STOO!1651 5- - Summarv of Portion of Seminar Pertaining to Fibrous Glass Health Research by W. Clark. Cooper, M.D., School of Public Health, University of California The serious effects of asbestos fibers on the health of humans undoubtedly may result in an increase in the use of glass fibers. Many people are asking questions about the effects of inhalation of airborne glass fibers on the health of people exposed to these glass fibers. Studies carried out up until the present of the possible effects of inhalation of airborne glass fibers on the health of people indicate that glass fibers do not have adverse effects on the health of people. Perhaps we have not had a chance exposed to airborne glass fibers decision on the effects of glass to them. to study a sufficient number of people for long periods of time to make a fibers on the health of people exposed Almost all reports on the effects of airborne glass fibers on the health of people are negative - that is, these reports indicate that glass fibers do not have any adverse effects upon the health of people exposed to them. Many medical research people find it difficult to accept these negative findings. We must realize that airborne glass fibers vary widely in size. We should examine the lungs of people exposed to airborne glass fibers to determine the size of glass fibers deposited in the lungs. Undoubtedly, we will hear more about the possible effects of airborne glass fibers on the health of people exposed to them in the years to come. Industry must continue to monitor the work environment with regard to airborne glass fibers and industry must continue to monitor the health of workers exposed to airborne glass fibers. PART II - FIBROUS ASBESTOS HEALTH RESEARCH Opening Remarks by Lewis J. Cralley, Ph.D,, U, S. Public Health Service The asbestos fiber industry is much older than the glass fiber industry. Asbestos differs from glass chemically. Even different types of asbestos differ chemically. In addition, oils and metals are attached to asbestos fibers during processing of these fibers. The exposure parameters of concentration and fiber size differ for airborne asbestos fibers and airborne glass fibers. We wish to learn how to use a very valuable material, asbestos, safely. Asbestos Exposure in the U. S. Textile Industry from 1930 to Date Joseph L. Goodman, M.D., Raybestos-Manhattan, Ind. Chrvsotile is the type of asbestos chiefly used in the United States. The history of the use of fibrous asbestos in the United States is about 60 years in time. ST0011651 6- - During the 1920's, asbestos textile plants used only very crude methods to eliminate asbestos dust. An exhaust opening in the ceiling of the building generally was the means used to liminate asbestos dust. Asbestos textile plants were extremely dusty during the 1920's. During the 1930's and 1940's, asbestos textile plants used floor exhaust systems to eliminate asbestos dust. The floor exhausts were connected by ducts to sack type cloth filters located in a dust room <>:. dust house. Workers often had to crawl through the ducts using brushes to clean the ducts. Currently, local exhaust hoods and vents are connected by ducts to wheelabrator type tubular-shaped cloth bag filters located in a dust room or dust house. The tubular-shaped cloth filters are suspended with open ends attached to an inlet manifold either at top or bottom of the filter housing. A lower manifold also serves as a receiving hopper for the dust. As air enters the filter unit, it impinges on a baffle plate causing larger dust particles to fall into the hopper. The air then passes through the tubular-shaped cloth filters and the dust particles are deposited on the inner surfaces of the cloth. Since the accumulation of deposited dust on the cloth surfaces gradually increases the resistance offered by the cloth to air flow, it is necessary to vibrate the tubular-shaped filters at intervals to detach deposited dust par ticles. A shaking device is used for this purpose. Local exhaust hoods are used on carding machines. Overhead exhaust vents and hoods are used on weaving machines. Also, aprons in front of weaving machines are used to direct airborne asbestos dust particles to the exhaust vents and hoods. Many people in an asbestos textile plant wear dust respirators. Wet weaving is being tried as a means of reducing the amount of asbestos dust. Also, spraying of water sometimes is used to wet airborne asbestos dust particles - the wetted asbestos dust particles fall to the floor. Measurement of asbestos dust concentrations in most asbestos textile plants show that these concentrations are below the present TL.V for airborne asbestos. The records indicate that the highest concentrations of asbestos dust occurred during the 1930's and that the largest numbers of deaths of asbestos textile workers due to asbestosis and lung cancer occurred during the 1950's. The present trend in the asbestos textile field is a decrease in the number of deaths due to asbestosis and lung cancer with a decrease in the concentration of asbestos dust in the work area atmosphere. Statistical Studies of U. S. Asbestos Textile Workers - Philip E. Enterline, Ph.D., University of Pittsburgh A statistical study was made of men who were working in asbestos textile plants during the 1950's. The study involves a determination of what are the causes of death of these men. ST001165? S T 00I!652 STOO!!6 5 3 7- A review of asbestos dust concentrations show that plants producing asbestos textiles have higher asbestos dust concentrations than do plants producing asbestos friction materials and that the asbestos friction materials plants have higher asbestos dust concentrations than do plants producing asbestos building products. The incidence of lung cancer and asbestosis is found to be the greatest for workers in asbestos textile plants, next for workers in asbestos friction materials, and least for plants producing asbestos building products. The death rate due to lung cancer increases with the time period from the initial exposure to asbestos dust. The death rate due to asbestosis does not increase as rapidly with time from the initial exposure to asbestos dust as that due to lung cancer. The study indicates that if a person is exposed to a high concentration of airborne asbestos fibers for a short period of time, the risk of death due to lung cancer remains but the risk of death due to asbestosis does not remain. Studies of Pathogenicity of Synthetic and Natural Asbestos and Brake Drum Dust - Paul Gross, M.D., Industrial Hygiene Foundation Animals exposed to airborne synthetic chrysotile asbestos fibers do not develop adverse reactions in the lungs. An investigation was made of the effects of exposure of animals to airborne synthetic chrysotile asbestos fibers containing various additives. The additives used were compounds of certain metals. The results of the investigation were negative - that is, the animals did not develop adverse physiological effects. These results do not agree with those of investigations of the effects of exposure of animals to airborne natural chrysotile asbestos fibers. The difference in the results of the exposures of animals to airborne synthetic chrysotile asbestos and to airborne natural chrysotile asbestos may be due to the fact that natural chrysotile asbestos contains insoluble metal additives while the synthetic chrysotile contained soluble metal additives. Automotive brake linings contain asbestos fibers bonded together by plastic materials. There is a large amount of dust from brake linings in the urban atmosphere. The heat used in injecting asbestos fibers into the plastic materials of brake linings and the heat developed when brake linings are used results in causing the asbestos fibers to vlose water of hydration and thus this asbestos differs chemically from the original asbestos. The asbestos which has lost the water of hydration is amorphous while the original asbestos was crystalline. Rats and hamsters were exposed to dust from brake linings. A considerable amount of dust was found in the lungs of the animals. A microscopic examination of the lungs of these animals was made and adverse physio logical effects were difficult to find. The results for the exposure of animals to dust from automotive brake linings indicates that this dust produces reactions in the lungs which are similar to that produced by a biological inert dust. STOO11653 8- - Methodology Employed in Pathological Studies of Ferruginous Bodies H. Michael D. Utldjjan, M.D., University of Pittsburgh A ferruginous body has a central core or shaft of fibrous form with a coating, often segmented or beaded in appearance, which is probably composed of ferritin or a ferritin-like protein material. Ferruginous bodies are found in the lungs of most people studied in autopsies. The fibrous central core may be an asbestos fiber or other types of fibers such as glass, natural textile fibers, or synthetic fibers. Also, the fibrous central core may be an elongated or fibrous particle of various minerals. A ferruginous body having an asbestos fiber as the central core is called an asbestos body. Longitudinal lung sections were digested using domestic laundry bleach containing sodium hypochlorite. A gray sediment from the bleach solution is dissolved in a mixture of chloroform and ethanol and shaken with clean water in a separatory funnel. The lower layer of liquid in the separatory funnel contains the inorganic mineral residue from the digested lung tissue plus any ferruginous bodies that may have been in the lungs. The lower layer of liquid in the separatory funnel is run into an elongated glass tube, clean water is added, and the liquids are shaken. The material is then poured into a centrifuge tube and spun in a centrifuge. A dense material is deposited in the apex of the centrifuge tube. The liquid material is decanted from the centrifuge tube and discarded. The deposit in the apex of the centrifuge tube is removed from the tube and suspended in a few drops of distilled water to which is added a few drops of dimethyl sulphoxide as a preservative. This material is used to make smears on microscope slides for examination of ferruginous bodies. Instrumentation in Pathological Studies of Ferruginous Bodies - Martin N. Haller, Carnegie Mellon University The electron microscope can be used to obtain electron diffraction patterns of mineral fibers. Different types of mineral fibers will result in different electron diffraction patterns. Since different types of asbestos fibers have different mineral compositions, there may be a different type of electron diffraction pattern for each type of asbestos fiber. Unfortunately, the mineral composition of a specific type of fibrous asbestos varies depending upon the source of the asbestos. The minerals present in a specific type of asbestos have quantity ranges. Thus, different electron diffraction patterns may be obtained for asbestos fibers of the same type from different sources. Electron diffraction patterns of asbestos fibers may not be specific enough to use electron diffraction methods of analysis to determine the types asbestos fibers that may be present in ferruginous bodies. STOO11654 S T 00I!654 9- - Basic Considerations in Pathological Studies of Ferruginous Bodies John M.G. Davis, Ph.D., Department of Pathology, University of Cambridge, England Electron microscope studies of ferruginous bodies indicate that ferru ginous bodies are formed in the lungs by fibers being engulfed by cells. They are formed in gi'ant cells. Examination of ferruginous bodies using an electron microscope shows that the coatings of the fibrous core consists of granular materials. Study of the coatings of the fibrous core of ferruginous bodies using an electron microscope shows that most ferruginous bodies contain a single layer coating while some have a multitude of layers in the coating. An examination of the outside surface of the coating of a ferruginous body with the aid of an electron microscope shows the presence of fine filaments. Ferruginous bodies shorter in length than 5 microns are not present in the lungs. Fibers less than 5 microns are taken up by macrophages in the lungs. CD CD CD cn CJl It is obvious that ferruginous bodies are an exception. Less than 1% of the fibers that are deposited in the lungs are cotaed to become ferruginous bodies. Some fibers engulfed by giant cells get a coating to become ferruginous bodies but other fibers engulfed by giant cells do not get a coating and thus do not become ferruginous bodies. Examination by the electron microscope shows that many ferruginous bodies, but not all, present in giant cells contain a membrane separating them from the cytoplasm of the giant cells. Many fibers deposited in the lungs become coated with calcium. Whole areas in the lungs may become filled with calcified material. The environment of a fiber deposited in the lungs is a most important factor in determining the type of coating the fiber will get if any. It is thought that when a ferruginous body is formed, the fiber first becomes coated with acid polysaccharide and then colloidal iron attaches itself by impregnation of the acid polysaccharide coating. We would like to learn more about the special chemical environment that is necessary to permit a small percentage of fibers deposited in the lungs to become ferruginous bodies. Discussion of Papers Pertaining to Pathological Studies of Ferruginous Bodies - Paul Gross, M.D., Industrial Hygiene Foundation We desire evidence that the presence of ferruginous bodies in the lungs are not associated with diseases of the lungs. There is scanty evidence today that there is not any definite association between the presence of ferruginous bodies in the lungs and diseases of the lungs. ST0011655 ST 00 I 1656 -10Inasmuch as most of the asbestos used today is chrysotile, airborne asbestos fibers present in urban atmospheres should be chiefly chrysotile asbestos fibers. There is some evidence that the central cores of most ferruginous bodies may not be chrysotile asbestos fibers. Summary of Portion of Seminar Pertaining to Fibrous Asbestos Health Research - Lewis J. Cralley, U. S. Public Health Service There has been a great improvement in reducing the concentrations of airborne asbestos fibers in the atmosphere in asbestos textile plants and it is indicated that this is resulting in a reduction of deaths of asbestos textile workers caused by asbestosis and lung cancer. Much still remains to be done. The results of animal studies indicate that asbestos dust from automotive brake linings may not produce adverse physiological effects in the lungs. Ferruginous bodies are found to be present in the lungs of the majority of people. Much excellent work has been done with regard to identifying the central cores that make up the ferruginous bodies. However, much still remains to be done in making identifications of the central cores of ferruginous bodies. An excellent start has been made in determining how ferruginous bodies are formed in the lungs. There is an urgent need for more work to be done to determine the significance of ferruginous bodies in the lungs with regard to pathogenic effects, actual or potential. ST0011656