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V PLAINTIFF'S * EXHIBIT S/l-33; Asbestos Exposure During Naval Vessel Overhaul WILLIAM T. MARR Medical Department, Long Beach Naval Shipyard, Long Beach, California A study among insulation workers in a shipyard has revealed several men on disability compensation and one death due to asbestosis. Exposures occur during the fabrication and installation of asbestos insulations and during removal of insula tion for repairs or overhaul of ships. X-ray examinations are not adequate for con trol as cases usually take a minimum of seven years to develop. Problem iron, nickel, manganese, or aluminum often THE LONG BEACH Naval Shipyard in sulation shop has 60 to 80 employees replacing part of the magnesium. The fibrous form of amphibole has four principal vari working primarily aboard ship applying ine ties, amosite, anthophyllite, tremolite, and sulation containing asbestos to the steam crocidolite. These four are various silicates power plants. Five employees, averaging 15 of iron, calcium, magnesium, and sodium. years exposure, have retired on disability The replacement of one element by anoth compensation due to asbestosis. One em er in varying proportions is a unique charac ployee, after 10 years employment as a pipe- teristic of asbestos causing a change in its coverer and insulator, received disability physical properties. For example, machinery compensation for seven years prior to his crushes chrysotile into fine soft silky-feeling death in 1962. Extensive physical examina fibers which are strong, flexible and can be tions and autopsy reports leave no doubt his woven into cloth. Amosite, which comes death was due to asbestosis. He worked most from South Africa, has long coarse fibers ly on farms and in restaurants before his suitable for a blanket-type of insulation ma employment in the shipyard and denied any terial. Amosite has been used in large quan previous employment in a dusty trade. tities on naval ships since before World War Breathing asbestos fibers, usually over a II. Other than amosite, the amphibole min period exceeding 10 years, causes this insidi ous industrial disease.1-2,3 A non-productive cough and progressive shortness of breath eral type of asbestos is weak and brittle. Most authorities believe that all types of asbestos can cause asbestosis.7 Medical sci that can lead to disability are the most strik ence has not conducted sufficient research to ing symptoms.4-5 determine the possible different effects of This report covers: (a) material used, (b) the mineral or which variety is the most working environment, (c) fiber counts, (d) hazardous. x-ray findings, (e) discussion, and (f) sum Employees in the insulation trade also use mary. fiberglass, magnesia, diatomaceous earth, and Material other inert substances that can complicate air sampling and the exposure hazard. Ship Asbestos is a commercial name applied board insulators use about ten different types to several varieties of fibrous minerals. These of insulation material containing different varieties are two distinct mineral groups, ser varieties and a varying quantity of asbestos. pentine and amphibole, that differ consid Table I gives a list of material used in ship erably in composition and physical proper board insulation and its composition. The ties.6 Chrysotile, the fibrous form of ser table also shows the percentage of time the pentine, comes from Canada and constitutes employee works with the material and his about 95% of the total world production of exposure in millions of particles per cubic asbestos. It is a magnesium silicate with foot. 264 Industrial Hygiene Journal Table I Materials and Exposures in Shipboard Insulation Jobs Material (Used aboard ship by pipecoverers and insulators) 1. 100% Amosite asbestos blanket Installing Removing Percentage of working time aboard ship (with each rarely 3.0 Exposure Concentrations (length of exposure time varies from minutes to hours) particle range in microns fiber range in 2-5 mppcf 5-10 mppcf 3-60 mppcf 1.4-3.0 Installed damp 1.6-2.0 0.5-8.0 2. 85% Magnesia and 15% amosite asbestos blocks and pipe sections Installing Removing 38.0 1.5 1.4-6.0 0.8-10 0.1-0.4 0.7-2.0 0.1-1.8 tr.-l-2 3. Calcium silicate and 10% amosite asbestos blocks and pipe sections Installing Removing 42.0 2.0 0.9-2.8 0.4-1.7 0.2-3.0 0.4-0.9 trace trace 4. 100% Chrysotile asbestos filler and binder Installing Removing 1.6 0.5 mixed as cement and applied wet 0.9-4.9 0.9-1.6 trace 5.15% Chrysotile and 85% rock wool filler and binder Installing Removing 1.5 0.5 mixed as cemeni and applied wet 0.8-4.7 0.7-1.7 trace 6. 80-95% Chrysotile asbestos cloth , Installing Removing 8.0 0.6 0.8-1.8 0.2-1.9 0.2-1.4 0.5-2.0 trace trace 7. Fiberglass Installing Removing 1.0 rarely 265 Working Environment These employees, known as pipecoverers and insulators, face a potential exposure to asbestos fibers in the insulation shop and on board ship. Employees in the shop make pads shaped like small pillows for easy installation and removal from shipboard fittings, control valves, and pipe joints. A bolt of asbestos cloth is on a roller at the end of the layout and cutting table. Directly over the bolt a water spray system allows water to dampen the cloth as an employee draws it on the table. The employee measures and marks the material into appropriate sizes and cuts it with a rotary electric hand cutter. An other worker then stitches the cloth on a power sewing machine and passes it to an other table where fiberglass is cut to size and stuffed into the opening. Finally, an employee closes the pad by sewing, trims it with a pow er cutter, and attaches rings to aid in the installation aboard ship. The cloth remains damp during the work process making dust control methods relatively easy in the shop. General exhaust ventilation operates contin ually, assisted by large doors and windows allowing for cross-ventilation. Aboard ship pipecoverers and insulators perform a great variety of installations in most compartments, especially in the firerooms and enginerooms. Several of these tasks are shown in Figures 1. 2 and 3. These men wire insulation block and insulation pipe sections in position around machinery and pipe. They make the surface smooth first by mudding with 85% magnesia plaster and then wrapping with asbestos cloth glued in position with a fire retarding waterproof ad hesive. The amosite blanket, rarely used now, was generally used rather than preformed blocks and pipe sections until 1962. Em ployees apply rock wool mud to this amosite blanket followed by portland cement and 266 May-June, 1964 Figure I. Removing insulation during over haul. asbestos cloth to form a smooth finish. They apply glass sheets to ventilation ducts and wrap it with fiberglass or asbestos cloth. These men wrap fiberglass around fittings, control valves, and pipe joints, then attach the pads from the shop into position. During ship overhaul, repair, and remod ernization, pipecoverers and insulators re move all the various types of insulation they have applied. As shown in Table I, this small portion of time spent in removing ex cessively dry insulation gives a high exposure to asbestos dust. Adequate ventilation for pipecovers and insulators is rarely possible with our present ventilating system, which consists of 3,600 cfm exhaust fans with connections for four 3-inch flexible ducts. These portable exhaust fans are usually placed on the main deck and the ducts routed into the work area. The flow at each exhaust-duct entrance varies from 800 to 1500 Ifm depending on the dis tance from the exhaust fan to the work process. This present exhaust system designed especially for welding and burning work is not adequate for our pipecoverers and insu lators because their work processes and work positions vary. Dust control by use of water during ship board work appears to be practical only dur ing application of amosite, a material seldom applied in our shipyard because of the ex cessive dust it causes during removal. The best protection for these employees is to avoid careless creation of dusty conditions by the use of damp material when possible, and the wearing of dust respirators constantly. Figure 2. Applying filler and binder. Figure 3. Sawing pipe sections. fIndustrial Hygiene Jou l'- >1 :A Figure 4. Photomi< taken during insulation rc i 20 microns. [Fiber Counts There are no establi lunum allowable con' gfibers in pipe covering ^duration massive expo fa textile mill in 1938 gbestosis where the cc ^field was below 5 mp kthe recommended m; |centration.s An asbesjlhas had no new cases |Vhere the particle o rfor dust below 10 m dustry uses 5 mppcf 1 mppcf above 10 n Pathologists find f crons in lungs durim fibers do not settle in j cal particles. They ; in thickness and thei. them to stand on ei the lungs. The Saranac Lai animal exposure to j| asbestosis is a mei chemical action.12 ~ sidered fibers great' H most harmful. This recent studies in Sot ties consider fibers most harmful.13 Dust counts, tak' Lomb Dust Countei low counts on san fct.gwe an adequate Industrial Hygiene Journal 267 A, . * -* y H.' . ;r .*.. * > tr/V/ *, * i ' > 9 * - 'V k * , * Tf 4 r*mi --`4 - ** >. Jc '** sLL m K' l * 7" -vk * * * ;>>v * F* v\* pC: ' V V 0 r% I** y* ' . : V' J . . --m ---r Figure 4. Photomicrograph of dust sample taken during insulation removal. Small squares are 20 microns. t4 H J ** V. , , ** vv. i 1^ _ ; m2 p'h j u V. d-S. * "+'?i J. m \. 4 ' -Jte. * \ ft ** ` Figure 5. Photomicrograph of dust sample tak en during application of insulation blocks. Fiber Counts There are no established figures for a max* imum allowable concentration of asbestos fibers in pipe covering operations or for short duration massive exposures. Because study in a textile mill in 1938 found no cases of asbestosis where the count by impinger light field was below 5 mppcf, this figure became the recommended maximum allowable con centration. An asbestos operation in Canada has had no new cases of asbestosis in 15 years where the particle count is below 1 mppcf for dust below 10 microns.9 One U. S. in dustry uses 5 mppcf below 10 microns and 1 mppcf above 10 microns as their MAC.10 Pathologists find fibers exceeding 400 mi crons in lungs during autopsy.11 These long fibers do not settle in air as rapidly as spheri cal particles. They are less than one micron in thickness and their needle-like form allows them to stand on end and work down into the lungs. The Saranac Laboratory experiments by animal exposure to asbestos indicated that asbestosis is a mechanical rather than a chemical action.12 The researchers also con sidered fibers greater than 10 microns the most harmful. This is not in agreement with recent studies in South Africa where authori ties consider fibers less than 5 microns the most harmful.13 Dust counts, taken with the Bausch and Lomb Dust Counter, appear in Table I. The low counts on sampling do not appear to give an adequate indication of the actual hazard. During sawing of blocks and pipe sections and removal of old insulation, the work environment appears extremely dusty. Respirator filters often clog after an hour's work removing insulation. Fibers from 3 to 60 microns in length re ceived special attention during this study (Figures 4 and 5). If fibers were present but count revealed less than one mppcf, they ap pear in Table I as a trace. X-Ray Findings It is common practice for industrial hy gienists to use information from periodic physicals to assure themselves that exposure controls are adequate. X-ray examinations on new employees in asbestos are not of value for this assurance; on the contrary, this in formation can be extremely misleading as it usually takes a minimum of seven years ex posure for cases of asbestosis to develop.14'15-16 It also appears that some people are suscepti ble while others escape harm during the same exposure.11 A medical team surveyed five shipyards in 1945 to investigate the health hazard due to insulation work.18 Only three cases of as bestosis appeared in 1074 x-ray examinations. These three employees had worked in as bestos material for more than 20 years. In sulation material and work methods have re mained essentially the same since that study. The greatest change, starting right after the war, is the removal of insulation during over haul and repair. Many of our employees 268 May-June, 1964 now have over 20 years in the insulation trade in contrast to the survey in 1945 where only 51 of the 1074 employees had over 10 years experience in insulation work. Discussion The world's consumption of asbestos has increased from 500.000 tons in 1942 to 2,~ 400.000 tons in 1961.20 Recent studies recog nize asbestosis as a serious health haz ard.2(,-2t-22 Asbestos exposure during shipboard insula tion differs from exposure in mining and manufacturing processes of this material. In these industries employees usually continue at one job with the same material and their exposure is relatively constant. This is not true for shipboard insulation where the pipecoverers and insulators work location, work position, and material constantly change. Un der these conditions it is impossible to de termine the exposure of the employee without spending hours in observation and sampling. Samples taken as in Table I are only bases for discussion concerning their exposure. We do not know whether our cases of as bestosis came from massive exposure during removal of old insulation or from many years of exposure by susceptible individuals during all types of insulation work. Summary The Long Beach Naval Shipyard has sev eral men on disability compensation and one death due to asbestosis. Many of these em ployees have more than 20 years' experience as pipecoverers and insulators working pri marily aboard ship. Asbestos exposure during ship overhaul and repair varies extensively giving an entirely different problem from exposure in mining and manufacturing operations. The maxi mum allowable concentration for pipe cov ering operations or for short duration mas sive exposures is unknown. There still re mains a difference of opinion among medi cal authorities on a MAC and the effects of long-fiber and short-fiber asbestos. Chest x-ray examinations of employees exposed to asbestos can be misleading as it usually takes a minimum of seven years for cases of as bestosis to develop. Shipboard pipecoverino and insulating during overhaul and repair is a hazardous trade. Employees in this trade should wear respirators when exposed to dry insulation material containing asbestos. References 1. Smith, Kenneth Vi.-. Pulmonary Disability in As bestos Workers. AMA Arch. Ini. Health. 12: 2'C (August 1955). 2. Maxcv. K. F.: Rosenau Preventive Medicine and Hx- girne. ?th Ed-, p. 1052, Appleton-Centurv-Crofts. !nc.. New York (1951). ' 3. Lanza, A. J.; Silicosis and Asbestosis, p. 58. Oxford University Press, New York (1938). 4. Lanza. p. 59. 5. Hunter, Donald: The Disease of Occupations, p. 878. The English Universities Press Limited. London f|953;. 6. Bowles. Oliver; The Asbestos Industry, p. 2. U. S. Bureau of Mines, Bulletin 552 (1955). 7. Convention Proceedings: The Asbestos Worker. V'i>1. 15. No. 1, p. 8, November 1962. 8. Lanza, p. 59. 9. Personal Correspondence, Paul Cartier, M.D.. Thetford Mines, Quebec. 10. Personal Correspondence. H. M. Jackson. Medical Department, Jonns-Manville Corporation, New York. 11. DallaValle, J. M.: The Industrial Environment and Its Control, p. 39. Pitman Publishing Corp., New York (1957). 12. Vorwald, A. J.. T. M- Ddrkan. and C. Pratt; Ex perimental Studies of Asbestosis, AMA Arch. Ind. Hxeand Occ. Med. 3: 4 (Jan. 1951). 13. Personal Correspondence, C.G.D.. Cowling. Penge As bestos Mines. South Africa. 14. Lanza, p. 175. 15. Hunter, p. 879. 16. Johnstone, R. T.: Occupational Medicine and Indu<trial Hygiene. p. 372. The C. V. Motbv Company. SiLouis. Mo. (1948). 17. Lvsck. K. N'.: Pathology of Asbestosis. AMA Arch. Ind. Health. 2: 185 (March 1955). 18. Fleischer, W. E.. F- J. Vilf.s. R, L- Gass, and Philip Drinker: A Health Survey of Pipccoverinz Operations in Constructing Naval Vessels. J. Ind. Hyl and Tox. 2d: 9 (January 1946). 19. Thomson. J. G.-. Exposure to Asbestos Dust and Dif fuse Pleura! Mesotheliomas. Brit. Med. J.. p. 123 (January 12. 1963). 20. Thomson, p. 123. 21. Smither. W. J.: Mesotheliomas and Asbestos Du>iBrit. Med. }., p. 494 (November 3. 1962). 22. McCaughev. W. T. E.: Exposure- to Asbestos Dust and Diffuse Pleural Mesotheliomas, Brit. Med. }., p. !39i (November 24. (962). Asbestos Exposure During Naval Vessel Overhaul WILLIAM T. MARR Medical Department, Long Beach Naval Shipyard, Long Beach, California (5J A study among insulation workers in a shipyard has revealed several men on disability 'compensation and one death due to asbestosis. Exposures occur during the fahricationiand installation of asbestos insulations and during removal of insula tion for repairs1 or overhaul of ships. X-ray examinations are not adequate for con trol as cases usually take a minimum of seven years to develop. Problem O'1 HE LONG BEACH Naval Shipyard'in^ sulalion shop lias 60 to 80 employees working primarily aboard ship applying in sulation containing asbestos to the steam power plants. Five employees, averaging 15 years exposure, have retired on disability compensation due to asbestosis. One em ployee, after 10 years employment as a pipecovercr and insulator, received disability compensation for seven years prior to his death in 1962. Extensive physical examina tions and autopsy reports leave no doubt his death was due to asbestosis. He worked most ly on farms and in restaurants before his employment in the shipyard and denied any previous employment in a dusty trade. Breathing asbestos fibers, usually over a period exceeding 10 years, causes this insidi ous industrial disease.'1,2,3 A non-productive cough and progressive shortness of breath that can lead to disability are the most strik ing symptoms.4,5 This report covers: (a) material used, (b) working environment, (c) fiber counts, (d) x-ray findings, (e) discussion, and (f) sum mary. Material Asbestos is a commercial name applied to several varieties of fibrous minerals. These ,varieties arc two distinct mineral groups, ser pentine and amphibolc, that differ consid erably in composition and physical proper ties." Chrysolile, (he fibrous form of ser pentine. mines from Canada and constitutes about 95% of the total world production of asbestos. It is a magnesium silicate with iron, nickel, manganese, or aluminum often replacing part of the magnesium. The fibrous form of amphibolc has four principal vari eties, amositc, anthopliyllitc, tremolitc. and crocidolitc. These four arc various silicates of iron, calcium, magnesium, and sodium. The replacement of one element by anoth er in varying proportions is a unique charac teristic of asbestos causing a change in its physical properties. For example, machinery crushes chrysotile into fine soft silky-feeling fibers which are strong, flexible and can be woven into cloth. Amositc. which comes from South Africa, has long coaisc fibers suitable for a blanket-type of insulation ma terial. Amosile has been vised in large quan tities on naval ships since before World War II. Other than amositc, the amphibole min eral type of asbestos is weak and brittle. Most authorities believe that all types of asbestos can cause asbestosis.' Medical sci ence has not conducted sufficient research in determine the possible different effects of the mineral or which variety is the most hazardous. Employees in the insulation trade also use fiberglass, magnesia, diatoinaccous earth, and other inert substances that can complicate air sampling and the exposure hazard. Ship board insulators use about ten different types of insulation material containing different varieties and a varying quantity of asbestos. Table I gives a list of material used in ship board insulation and its composition. The table also shows the percentage of time the employee works with the material and his exposure in millions of particles per cubic foot. * srhaul 'nlifornin -i vcral men on * occur during loval of insula - quale for con- or aluminum often :.jcnesium. The fibrous four principal varihyliitc, tremolite, and : arc various silicates ii-sium, and sodium, one element by anothus is a unique charac* using a change in its i example, machinery fine soft silky-feeling flexible and can be \mr*'te, which comes i;i g coarse fibers , insulation ma i' used in large quanuce before World War the amphibole minv\eak and brittle, lii've that all types of .estosis/ Medical scid sufficient research to v different effects of ! variety is the most ''illation trade also use ;.itomaccous earth, and ' that can complicate xposure hazard. Ship'out ten different types I containing different quantity of asbestos, material used in shipits composition. The luTcentagc of time the the material and his of particles per cubic Industrial Hygiene Journal Table I Materials and Exposures in Shipboard Insulation Jobs Material (Used aboard ship by pipecoverers and Insulators) 1. 100%-Amosile asbestos blanket Installing Removi ng 2. 85% Magnesia and 1S% amositc asbestos blocks and pipe sections Installing Removing 3. Calcium silicate and 10% amositc asbestos blocks and pipe sections Installing Removing 4. 100% Chrysotile asbestos filler and binder Installing Removing S. 15% Chrysotile and 85% rock wool filler and binder Installing Removing 6. 80-95% Chrysotile asbestos cloth Installing Removing 7. Fiberglass ' Installing Removing Percentage of working lime aboard ship (with each material) rarely 3.0 Exposure Concentrations (length of exposure time varies from minutes to hours) particle range in microns fiber range in 2-5 5-10 3-60 mppcf mppcf mppcf 1.4-3.0 Installed damp 1.6-2.0 0.5-8.0 38.0 1.6 - -- 42.0 2.0 1.4-6.0 0.8-10 0.9-2.8 0.4-1.7 0.1-0.4 0.7-2.0 - 0.2-3.0 0.4-0.9 0.1-1.8 U.-1-2 trace trace 1.5 mixed as cement and applied wet 0.5 0.9-4.9 0.9-1.6 ' trace 1.5 mixed as cement and applied wet 0.5 0.8-4.7 0.7-1.7 trace 8.0 0.5 1.0 rarely 0.3-1.8 0.2-1.9 0.2-1.4 0.5-2.0 trace trace 265 ii :i i1 Working Environment ,`:'y These employees, known as pipecoverers and insulators, face a potential exposure to asbestos fibers in the insulation shop and on board ship. 1'Vi Employees in the shop make pads shaped like small pillows for easy installation and removal from shipboard fittings, control %'alvcs, and. pipe joints. A bolt of asbestos cloth is on a roller at the end of the layout and cutting table. Directly over the bolt a water spray system allows water to dampen the cloth as an employee draws it on the table. The employee measures and marks the material into appropriate sizes and cuts it with a rotary electric hand cutter. An other worker then stitches the cloth on a pow'er sewing machine and passes it to an other table where fiberglass is cut to size and stuffed into the opening. Finally, an employee closes the pad by sewing, trims it with a pow er cutter, and attaches rings to aid in the I installation aboard ship. The cloth remains damp during the work process making dust control methods relatively easy in the shop. General exhaust ventilation operates contin ually, assisted by large doors and windows allowing for cross-ventilation. Aboard ship pipecoverers and insulators perform a great variety of installations in most compartments, especially in the fire- rooms and cngincroonis. Several of these tasks are shown in Figures 1, 2 and 3. These men wire insulation block and insulation pipe sections in position around machinery and pipe. They make the surface smooth first by mudding with 85% magnesia plaster and then wrapping with asbestos cloth glued in position with a fire retarding waterproof ad hesive. The amositc blanket, rarely used now, was generally used rather than preformed Vblocks and pipe sections until 1962. Em ployees apply rock wool mud to this amositc blanket followed by portland cement and .l:!* 266 Mny-Junc, 1964 asbestos doth to form a smooth finish. They apply glass sheets to ventilation ducts and wrap it with fiberglass or asbestos cloth. These men wrap fiberglass around fittings, control valves, and pipe joints, then attach the pads from the siiop into position. During ship overhaul, repair, and remod ernization, pipccovcrcrs and insulators re move all the various typos of insulation they have applied. As shown in 1 able I, this small pottinu of (ittw spent in removing exressiwlv dry insulation gives a high exposure to asbestos dust. Adequate ventilation for pipccovcrs and insulators is rarely possible with our present ventilating system, which consists of 3,600 cfm exhaust fans with connections for four 5-inch flexible ducts. These portable exhaust fans arc usually placed on the main deck and the ducts routed into the work area. The flow at each exhaust-duct entrance varies from 800 to 1500 Ifm depending on the dis tance from the exhaust fan to the work process. This present exhaust system designed especially for welding and burning .work is not adequate for our pipccovcrcrs and insu lators because their work processes and work [>ositions vary. Dust control by u<o of water during ship board work appears to be practical only dur ing application of amositc, a material seldom applied in our shipyard because of the ex cessive dust it causes during removal. The best protection for these employees is to avoid careless creation of dusty conditions hy the use of damp material when possible, and the wearing of dust respirators constantly. A oy*A une, 1964 removing exhigh exposure ^or pipecovcrs and with our present Tltich consists of 3,600 connections for four - These portable exhaust d on the main deck and to the work area. The st-duct entrance vanes hi depending on the dishaust fan to the work exhaust system designer! ig and burning work is pipecovcrcrs and insuwork processes and work of water during shipu be practical only dur'osite, a material seldom .ard because of the cx< during removal. The these employees is to >i of dusty conditions by -rial when possible, and respirators constantly. iJt pipe sections. :. i Fiber Counts '`i V:: /!>. There are no established figures for a max imum allowable concentration of asbestos fibers in pipe covering operations or for short duration massive exposures. Because study in a textile mill in 1938 found no eases of asbestosis where the count by impinger light field was below 5 mppcf, this figure became the recommended maximum allowable con centration.8 An asbestos operation in Canada has had no new eases of asbestosis in 15 years where the particle count is below 1 mppcf for dust below 10 microns. One U. S. in dustry uses 5 mppcf below 10 microns and 1 mppcf above 10 microns as their MAC.10 Pathologists find.fibers exceeding 400 mi crons in lungs during autopsy.11 These long fibers do not settle in air as rapidly as spheri cal particles. They are less than one micron in thickness and their needle-like form allows them to stand on end and work down into the lungs. The Saranac Laboratory experiments by animal exposure to asbestos indicated that asbestosis is. a mechanical rather than a chemical action.12 The researchers also con sidered fibers greater than 10 microns the most harmful. This is not in agreement with recent studies in South Africa where authori ties consider fibers less than 5 microns the most harmful.18 Dust, counts, taken with the Bausch and I.omli f)ust Counter, appear in Table 1. The low counts on sampling do not appear to give an adequate indication of the actual t. m :<;iv.Uj' Tr i`.". V v./y. 2d; :* Bf X hazard. During sawing of blocks and pipe sections and removal of old insulation, the work environment appears extremely dusty. Respirator filters often clog after an hour's work removing insulation. Fibers from 3 to 60 microns in length re ceived special attention during this study (Figures 4 and 5). If fibers were present but count revealed less than one mppcf, they ap pear in Table I as a trace. X-Ray Findings It is common practice for industrial hy gienists to use information from periodic physicals to assure themselves that exposure controls arc adequate. X-ray examinations on new employees in asbestos arc not of value for this assurance; on the contrary, this in formation can be extremely misleading as it usually takes a minimum of seven years ex posure for eases of asbestosis to develop.1,,1V16 It also appears that some people are suscepti ble while others escape harm during the same' exposure-.1 ' ~ ---------- --------------------------------- - A medical team surveyed five shipyards in 1945 to investigate the health hazard due to insulation work.18 Only three cases of as bestosis appeared in 1074 x-ray examinations. These three employees had worked in as bestos material for more than 20 years. In sulation material and work methods have re mained essentially the same since that studv. The. greatest change, starting right after the war, is the removal of insulation during over haul and repair. Many of our employees A 26S . ' May-Junr, now have over 20 years in the insulation trade in contrast to the survey in If74.e) where only 51 of the 1074 employees had over 10 years experience in insulation work. Discussion The world's consumption of asbestos has increased from 500,000 tons irv 1942 to 2, 400,000 tons in 1961.20 Recent studies recog nize asbestosis as a serious health haz ard."-"*" Asbestos exposure during shipboard insula tion differs from exposure In mining and manufacturing processes of this material. In these industries employees visually continue at one job with the same material and their exposure is relatively constant. This is not true for shipboard insulation where the pipccovcrcrs and insulators work location, work position, and material constantly change. Un der these conditions it is impossible to de termine the exposure of the employee without spending hours in observation and sampling. Samples taken as in Table I are only bases for discussion concerning their exposure. We do not know whether our cases of as bestosis came from massive exposure during removal of old insulation or from many years of exposure by susceptible individuals during all types of insulation work. Summary The Long Reach Naval-Shipyard has sev eral men on disability compensation and one death chic to asbestosis. Many of these em ployees have more than 20 years' experience as pipccovcrcrs and insulators working pri marily aboard ship. Asbestos exposure during ship overhaul and repair varies extensively giving: an entirely different problem from exposure in mining and manufacturing operations. The maxi mum allowable concentration for pipe cov- <-iing operations or for short duration mas sive exposures is unknown. There still re mains a difference of opinion among medical authorities on a MAC and the effects of long-fiber and short-fiber asbestos. Chest. x-ray examinations of employees cxjiosed to asbestos can be misleading as it usually takes a minimum of seven years for eases of asbestosis to develop. Shipboard pipecovering and insulating during overhaul and repair is a hazardous trade. Employees in this trade should wear respirators when exposed to dry insulation material containing asbestos. ` i \ . . References - 1. Smith, Kfnnv.th \V.: Pulmonary Disability in Abtrn* VVllfv,n, AMA A'<rk. tad. Health. /?: 22 (AmptM I'l'iM. 2. Maxcy. K, F.: Rateaatt rf/iy[if/ Afrdj'rfne end /tv- gtenr. 7th F.d.. n. 1052. Anplcton-Ccnttirv-Ctedts Inc n.w Vmk u'tsn. 3. Lanza. A. J.: Si/rrnwt and A'bestosii, p. 58. Osford University \>w York (1938). 4. Lvnzs, i>. 59. 5. Jlt'OTi**, Dn.vtThe ITneoie nf Oeeufiatinnt. p. 878. The F.nslish t'niv'rsitifs Press Limited. London (1955). ft. Bmvrjvs. Oi (it* ; The Aibe/tar tnduitry. p. 2, U. S. ftiireau o( Mines. Bulletin 552 (1955). 7. OoNtr.NTtON* PaOCf.FfHsvss: The 15, No. 1. t>. 8. November 11182. 8. Lanza. p. 59. Atheifnt Warier. Vol. 9. Personal Corre-pondenro. Paui. Carth.r. M.D., Thet* (ord Stines. Quctvr. 10. Petsonal Correspondence. H. M. Jackson*. Medical Department. .{ohnt-Mans ifte Corporation. NVtv York. 11. Y ALIx. J. St.: The Induttricl Enidranrnent end /( Cnntrnt. p, 39. Pitman Publishing Cetrp.. Xnt Yeiek (1957). 12. Vo*tvMi>. A. J.. T. Sf. Dorkan*. and C Pusit: F.rtterimental Studiex c/ Atbetiatit. AMA Areh. Ind. Hv. and dee. iferf. .7.* 4 /.fan. 1931). 13. Personal Correspondence. C-G.D.. Cemlin*. Pens* As bestos Mines. South Africa. 14. Lanza. p. 175. J5. IIi'ntm. n. 859. 16. JoitNSTONf., R. T.: Occnp/f"a/ Medieine and Indu<- trial Hygiene. n. 372. The O. \'. Mnhv Companv. St. Louis. Mo. (1948). ' 17. Lynch. K. X.: Palboln^v of Asbestosis, AMA Areft, ltd. Health. 2: 185 (Match 1955). 18j Fi.fisciif.r, W. F... F. .1. Y`n.r.s. R. L. Gsnr.. and s---7 pitti.tr* tJatNKfs: A Health Survey o( Pioreosertn* Operations in (`.onslructii't Naval Vessels. /. Iad. Hif. and Tar. 28. 9 (January 1946). 19. Thomson. J. G : Fspetsure to Asbestos Duet and Dif fuse Pleural Mesotheliomas. /leit, hied. Jp. 123 (January 12. J963t. 20. Thomson, p. 12.3. 21. Smith!*. W. J.; Mesotheliomas and A'lystos Dust. flrlt. Med. /.. p. <04 (Xosrmlier 3. 1962). 22. McCmc.ihv. W. T. F..: F.xposurc (o Asbestos Oust and Diffuse Pleural Mesotheliomas. F'it. Md. } t>* 1397 (November 24. 1962). . of IS Introduct A PD1 rLX. dt, hearing lation, in the in exists the produced noisy situ the oxistt whirl) is ncccs<.ir\ a raised situation MiddU heat ing from cxi may nia damage duction pendv f auditor) prvtrd. also dc| The t fcrcnl t mediae) actorish 'r^Trchhi I'snos from f/ic Tht Sur* (Onimtt n AFFIDAVIT CITY OF RICHARDSON, TEXAS, TO WIT: BEFORE ME, A Notary Public in and for the State of Texas, personally appeared n _________________________, who stated under due oath of law as follows: i,______ c .....itgt am a librarian for The University of Texas at Dallas Eugene McDermott Library, Richardson, Texas 75083. The University of Texas at Dallas Eugene McDermott Library contains copies of the American Industrial Hygiene Journal. The pages attached hereto are true and correct copies from the American Industrial Hygiene Journal. May-June, 1964, pages 264-268, which is maintained in The University of Texas at Dallas Eugene McDermott Library. This document is in such condition as to raise no suspicion concerning its authenticity. This document was received by The University of Texas at Dallas Eugene McDermott Library and is maintained in The University of Texas at Dallas Eugene McDermott Library, Richardson, Texas 75083. C:\DOCS\LEGAL\MAR R.ART(S1S) Page 1 Tebruary 28, 1994 STATE OF TEXAS COUNTY OF DALLAS Fe liman first duly sworn, deposes and says: That the foregoing statements are true. Affiant, being of March, 1994 NOTARY PUBLIC a-- C:\DOCS\LEGAIAMARR.ART(S1S) Page 2 February 28, 1994