Document 71kbwQM5xK8GpMMeGmLRyLYG6

c .V!'i! I Minutes; Air Hygiene and Manufacturing Committee June 3, 19^5 1-Scrtol LeProvence Thetford Mines, P. Q. Canada 10:30 A.ii. to 3:00 F.l-i. t ' .4 ' Attending: Members: L. C. lilliams, Chairman U. C. Atkinson D. T. Austin, Jr, C. L. Sheckler R. B. Smith A. C. Link T. C. i-icCluskey, Jr. K. Nelson Raybestos-Manhattan, Inc. Johnsville-Mauville Corp. United States Rubber Johns--flanville Corp. Raybestos-Manhattan, Inc. United States Rusher Tal,lman-t-nCluskey Fabrics Co. American Smelting & Refining Co. Guests: Dr. K. Smith Dr. L. J. Cralley Dr. J. H. Wolfsie Dr. P. Cartier Maurice Lachance Jerry Idtchell Johns-Manville Corp. U.S. Public Health Service Medical Director-U.S.Rubber Thetfcrd lines Clinic Q.A.M.A. British Belting & Asbestos Ltd. Absent: H. Walter A. P. Gouyeia American Asbestos Textile H. K. Porter Co., Inc. Public Health Service Survey Dr. Lewis J. Cralley Scientist Director. Assistant Chief Dr. Cralley presented a paper (draft copy) prepared by Jeremiah B. Lynch of the Department of Health, Education and welfare titled "Asbestos Study -- Procedures and Findings0. Particular attention was given to Table 1. This table shows the improvement industry control programs have had cn dust concentrations. Table 1 Dust Concentrations - Asbestos Textile Surveys SIEVE! Penna. FHS 1938 Public Health Service 1934 Without With 1964 T'fCilZ---- Control Control ^oncentraxxon xn roucx Range of F 67-0 concentration) t 3*a 36.0 to 7.1 2.6 t 1.2 2.6 to 1.2 THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICAi ED BY PPG INDUSTRIES, INC. 3455 NOTE: TH!0 r r\ f\ v-tmt Hi NOT COME; r-. Page 2 Two (2) charts were also presented. The'first showing Average Dust Concentration by Plant and Operation in department Fibre Preparation, Carding, Spinning, Twisting and leaving. The second chart was on Dust Concentration by Operation. The chart bars were identified as IMPHHER xlO, MF Total Fibers, MF Fibers r- 5t-h MF Fiber rlOH and show the Fibres/ce when using the IMPHEER xlO vs the membrane filters counted at U30 X Phase Contrast. All indications point to good dust control in the Textile Plants. Dr. Cralley cautioned us not to become complacent as it is ia>pertant to keep improving systems at every opportunity and further, we do not know at this time what the data means with respect to health. Dr. Cralley distributed another paper titled "Relationship of Xmpinger Counts to Fibre Concentration by Membrane Filters in Asbestos Textile Plants" prepared by H. E. Ayer, G. H. Edwards, J. H. Fanney, Cr., J. R. Lynch, U. S. Department of Health, Education and Welfare. The committee will review this paper and will discuss same at the next meeting. When bath these papers arc finalised, they will be published. Tha Textile phase of environmental studies will be completed by fall of 1965 and all data published will be af interest to the member ship; Dr. Cralley is meeting with the groups doing field studies. Also, with Insurance - Air Hygiene Groups, Seminar at the Universities of Texas, Oklahoma and Pittsburgh, Scientific and Medical Groups and at the International meeting, 1966 in Vienna, Switzerland. During the discussion period several points were made: 1. There is a 25$ error in dust counting. 2. Where there is a 5000 total count the fibre count is considerably lower around 1000. 3. Plants should make all data pertinent to this program available. A* Dr. Cralley* s group has completed 10 plants surveys. There are 2 remaining. Portable Vacuum Cleaners Two (2) units, 1) Suction Apparatus and 2) Compressed ------~~ Air Unit were tried. Beth units do a satisfactory cleaning l -------------------- -of easy to reach areas but In' equipment and close areas, the&'*~* are not adequate. The committee has agreed that for the present this investigation is complete and we do not know of any available vacuum unit r that will replace air hose cleaning method used by most of us. We would request any member to report any new units as they be come available so we can investigate their possible use. We are all very interested in retiring the air hose method at the earliest possible date. THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FIL-ES AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 3456 Direct Dust Counter NOTE: THIS OC'E" ' in NOT C0?iEf;iC..,*i Information received by Ken Nelson states Bausch and Lomb are developing a new Direct Dust Counter light and a photo electric cell to count all dust particles in the air. l<hen this unit is developed it nay eliminate much of the manual counting presently being done. Three main factors mice a unit such as this desirable: 1. EBimtnate the human factor. 2. Take more readings in a shorter period of time. * 3. Cost of unit estimated at 3300.00. Ken Nelson will folio* up with Bausch and Lcmb, and if a unit is ready by the October meeting, a request will be made to have it demonstrated at that time. Consultant Industrial Hygiene Program A suggestion has been received to discuss and in/estigate the possibility of Asbestos Textile Manufacturers retaining a consultant to supervise a uniform industrial hygiene program and to conduct periodic surveys of plants. Generally, the consultant would check dust concentrations and noise levels in plants. He would then be available to give his findings as an outside report. This would be an aid to the industry whenever they are confronted with compensation cases, as he would have facts and history on actual in-plant conditions. The committee is aware that more cases are going to be filed as time goes on and with this fact it was agreed all members will consider this suggestion and report their wishes at the next meeting. When reviewing, keep in mind 1. Hearing cases - k in New Jersey 1 in Quebec 1 ease cost 38,000 at age of 69-1/2 years. 2. Cost of Consultant approximately vl50 to $200 per day plus expenses. Automatic Loom Cl earring Parks-Cramer have developed a new unit called Weave Cleaner- Trsvel Vac which has much higher velocity air -- cooperating vacuum. They claim the unit is more effective than the compressed air hose and the broom without their disadvantages. Any member interested in further information should contact Parks-Cramer Company, Fitchburg, Hass ./Charlotte, N. C./Atlanta, Ga- ___________ 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. 345? NOTE: T.'-:"' r; - Page 4 6 Published Pamphlet - "Method for Determining Asbestos Dust Concentration11___________________ Since otar meeting in Piaehurst last February we have disposed of 27 copies of subject pamphlet. These went to: American Asbestos Textile Corp. * Asbestos Magazine Asten-Hill iifg. Co. Zonolite (Div. of I .S. Grace Co., Libby, Montana) Alta Friccbn S.A., Mexico North American Asbestos Corp., Chicago Central Asbestos Co., Ltd., London, Eng. lines Dept., iiinistry of Commerce 4 Industry Nicosia, Cyprus 5 copies 9 4 1 1 5 1 1 Total Balance on hand, approximately 859 copies. 2? Each member is requested to help to distribute the pamphlet whenever there is any interest. The pamphlets that have been distributed meet the needs of the receivers as we have never received any suggestions for revision of any part. In order to generate more interest by covering a larger part of industry an advertisement is being placed in the Journal of Industrial Hygiene. General * The ccusaittee and guests wish to express their sincere thanks to the liners for a very educational and pleasant meeting at Thetfard Hines, F. Q., Canada. Respectfully submitted. L. C. Williams, Chairman Air * hygiene 4 Hfg. Como. f %HIS DOCUMENT WAS NOT A RECORD 01 PPG INDUSTRIES, INC. DID NO I' COME FRO!\ IT'S FILES AND CANNOT BE AUTHENTICATE! BY PPG INDUSTRIES. INC. _^ 3458 I % I i*Ii ) 5t i ( J 1 P- U~-3 --P* ,, I C" _g o ASBESTOS STUDY - PROCEDURES AMD FINDINGS : . m-25 SEPTEfSER 1965 I J \ U 5. DEPART!.FY.7 CF HEALTii, EDUCATION. and WELU.:r r^tlie Health S;rviCf pivi: i v* <*< Oc:.: i t1 Bp* * I*1 .THIS DOCUMENT WAS NOT A RECORD OF >PG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHEN fiCA, LrD BT- PPG INDUSTRIES* INC. | BB 0020967 J 3459 ASBESTOS STUDY - PROCEDURES AND FINDINGS NOTE: tr:*; - CIO,' NOT COMcfEGiVi TrU FILES Jeremiah R. Lynch <* Oceupational Health Research and Training Facility. 1014 Broadway Cincimat i, Ohio * I TR-25 September 196S 1 BB 00 20969~7 U. S. Department of Health, Education, and Welfare Public Health'Service Division of Occupational Health THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED 0Y PPG INDUSTRIES, INC- 3460  NOTE:THiSDO-r - ; NOT COME fHOiVl PrG riL'c.3 ASBESTOS STUDY - PROCEDURES AND FINDINGS INTRODUCTION In the early 1900's massive exposures in the dusty trades were common and the situation in American asbestos processing plants was no exception. The ability of asbestos dust to cause pneumoconiosis had been recognized for some years and a series of studies sought to define the dose-response relat ionship. In .1934 the Department of Labor and Industry of the State of Pennsylvania undertook an investigat ion of asbestos fabricating plants but was unable to establish the maximum safe. concent rat ion of asbestos dust in the air.(^) In 193S the U. S. Public Health Service related dust concentrations to incidence of disease and recommended that S million particles per cubic foot, as measured by the impingcr method, be regarded tentatively as the threshold value for asbestos dust until better data were available.^) This "tentative" standard has been used for 28 years. These investigations were one-time studies of actively employed asb stos workers. However,-due to the long period of. time between exposur to asbestos dust and onset of disease, a-prospective study which follows the workers for a period of years, during and after the exposure, is re? quired to define adequately the safe level of exposure. In addition to this lack of sufficient information upon which to base a standard for the prevention of asbestosis, a number of investigators have reported an association between exposure to asbestos and the occurrence of certain malignancies. Consequently, the U. S. Public Health Service has under taken an occupational health study of the asbestos products industry. OBJECTIVES .' The objectives of this present study arc as follows:^) *1. To determine the health status of the asbestos workers in this industry with special attention to disenses of the respiratory tract. * 2. To determine which environmental factors have an adverse effect . upon the health of asbestos workers in the asbestos-products industry. . r3. To determine the relationship between occupational exposure cod cause ot death of asbestos workers. 4. To develop medieql and environmental criteria and procedures rfn- ------ th control of health risks identified by the studies." ___ --- * ilJS------------ THIS DOCUMENT WAS NOT -A RECORD OR PPG INDUSTRIES, INC. DID NOT COM,t FROM ' IT'S FILES. AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES, INC. 0461 ASBESTOS STUDY . METHODS The over-a 11 study is divided into three semi'independent phases: bionet ric, medical and environmental. The hinmrtric phase of the study uses data obtained from the Bureau of Old Age and Survivors Insurance (BOASI) to calculate the aortality among asbestos workers..These mortality rates .are compared to these of similar unexposed occupational groups to indi cate those diseases for which there appears to be an excess risk related to occupation. Later, as BOASX reports the filing of death claims on embers of the groups of workers identified in the environmental phase, death certificates and autopsy data, alien availab le, _ i 11 be collected t determine the. causes of deaths among these groups. The medical phase of the study will consist of base line and routine follow-up examinations on a part of each group of workers included in the environmental phase. Appropriate tests and examination procedures are being devised. In the environmental phase of the study the hazards to which the markers ar exposed are measured by surveys of asbestos processing plants. Between January 1964 and April 1965. eight textile plants, three fricticn^ product plants, and one plant producing hydraulic packing'were surveyed. Additional measurements will be made in these plants st intervals of s y ar-or more as part of this prospective study. Detailed interviews arc . also being conducted to obtain identifying information, occupational, histories and.smoking histories on each worker included in'the'groups or "cohorts" of workers on whom exposure measurements have been collected. A field team consisting of three industrial hygiene engineers and s dust counting technician,augmented by State industrial hygiene personnel when available, performs the environmental survey of each plant. After aieeting with management and union representat ivea to explain details-jof the operat ion, the team collects samples throughout the plant following the production route. All of the impingcr samples taken are counted within 36 hours at a field laboratory set up convenient to the planti All ther samples arc returned to the Division of Occupational Health laboratories in Cincinnati for later counting or analysis. Jn addition to sampling, local and general exhaust ventilation systems are studied and pertain other information, such as machine speed, is obtained. NOTE: Ti !H||n' c\ NOT P : ASBESTOS STUDY The types of samples collected can be divided into four categories. 1. Bulk samples. Several pounds each of the different types of crude fiber, bag house waste and treating and lubricating oils used are collected at each plant. These samples are subjected to such analyses as x-ray diffraction for minerals including free silica, mass spectroscopy for such metals as nickel and chromium and other analyses for polycyclic aromatic hydrocarbons and natural radioactivi ty* II. Long period gravimetric samples. Several instruments for obtain* ing mass samples of total and respirable dust are run simultaneously in a repr s ntative area in the midst of each operation. These instruments include a high volume sampler, a Hexhlet modified to take a membrane filter, a coni cycle, an electrostatic precipitator and a set of four membrane filter field monitors with and without IQ mm cyclone presamplers. . An additional high volume sampler is set up outside the plant to sample the makeup air being'used. Certain of these samples are sn. red for the same constituents as the bulk samples. Other methods of m.' es are being developed to estimate the respirable mass of asbestos. III. Simultaneous impinger-fiIter samples. Breathing zone samples taken with an impinger and a membrane filter simultaneously are used to >btain a comparison of these methods of dust enumeration. Other sets of .mpinger-fi1ter simultaneous samples, with and without horizontal tlutriator pre-samplers, are taken in the general room air near apecific perations. c IV. Personal samples. Membrane filter field monitors connected to ersonal sampler pumps are worn by workers with the monitor attached to heir collars. These samples are collected for one to two hours at a te of 1.5 .or 2.0 1pm. In the large plants personal Samplers are worn y about half the workers while in the small plants almost all the brk rs wear them. npinger samples are counted in a Bunn cell using a 16 mm {10X) light ield objective, 10.\ ocular with a porton eyepiece reticle and Kohler llumination.- Membrane filters are rendered transparent with a mixture r dimethyl phthalate and diethyl oxylatc and counted with a 4 mm phase >ntrast objective and 10X ocular. ** THIS DOCUMENT **^0* cS'fWM PPG INDUSTRIES INa DID nu .ai eD Irs FILES AND CANNOT BEAU. gy ppG INDUSTRIES, iNC. .j 3463 ASBESTOS STUDY RESULTS All of the data presented here represent optical dust counts on impinger and filter samples taken in asbestos textile plants. The average results for impingers (Figures 1 and 2) are presented by plant and operation so as to permit comparison of the effectiveness of dust controls. Asbestos enters the textile will in 100 lb. poetran f i cal 1 v packed bags of pened fiber. The first operation, fiber preparation, includes the picking" of the fiber to loosen and further open the material, followed by blending. Usually cotton, rayon or other fibers are mixed with the new filter and in some cases, bag house waste and rendered yarn are added. Each ingredient is weighed, mixed and sent by pneumatic conveyor to n "condenser" which separates the asbestos from the air. The dust ccncentralions for fil>er preparation reflect the degree of enclosure used at the different plants. Plants 2 and 4 used almost totally enclosed systems such that the asbestos did not emerge until it- dropped out* of the con denser. In the pther plants manual handling was involved in moving the fiber from one step to the next and dumping into hoppers. The carts of blended fiber are moved into carding and the fiber is man ually transferred to the card hoppers. The card combs the fibers into a web which is separated into strands to form a "roving" wound on spools at the end of the machine. All cards were enclosed since it would be impossible to operate a cord without almost complete enclosure and stay tsxjcr the TLV. The dust concentrations in carding were inversely related to the volume of air exhausted and the tightness of enclosure. All.air volumes were above the 800 cfm per card recomncndcd by the Committee on Industrial Ventilation of the American Conference of Governmental Indus trial Rygienists(^) end some were over twice that figure. However, none were as high ns the 2200 c-fm per card used in one English asbestos textile mill.(5) The spinning machine imparts a twist to the parallel fibers in the strand of roving to produce a yarn. Plant-2 had no exhaust on-the spin frames and tlx? exhaust in Plant 1 was ineffective due to a plugged duer. Plants 4 and 5 both had good down-draft 1ocal-exhaust systems with baffles in front of the xt>oals to limit the open area to the top where the roving entered. Plnnt 2 had no local exhaust but a very large general exhaust system removing 120,000 cfm from a room of approximately 450,000 cubic .feet containing 60 spinning and twisting frames. *. * _ . The yarn produced by the spinning frame is next plyed wi th some other r . ? yarn and possibly nyIon.__i:lnss or metnl threads on a twisting suichine. " The hi.' - THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM IT'S FILES AND CANNOT BE AUTHENTICATED ' BY .PPG INDUSTRIES, JNC. | SB 0020972 J S4S4 ASBESTOS STUDY NOTE:-THIS DT-WM 5 ' . NOT COOL rr.dA MM ! * t-r,TT2 TOY -. - concent rat's ons were partly- related to higher machine speeds, which ranged over 3000 BFM as opposed to less than 2000 RPM in spinning. Another contributing factor was the practice of unwinding a spool on the high speed shaft to locate a broken wire. This resulted in beating the twisted yarn against the frame and occasionally produced dust-levels in excess of the TLV. The average concentration in twisting in Plant 3 exceeded the TLV and probably resulted from the use of dusty raw fiber, which created generally higher dust concentrations in this plant. Plant 4 used .a "speeder" or "slubber" twister instead of a ring twister. This machine enclosed the yarn on its way to the spool and.thus produced less dust. w* The twisted asbestos yarn, synthetic fibers and wire rare then-woven into cl th or tape. Tape weaving was less dusty than cloth weaving. Plant 1, f r example, wove only tape and had Jow concentrations at the weaving operation in spite of generally higher concentrations at other opera tions. ' Most plants wet either the .warp or the filling or both to reduce the dust. This was very effective in Plant 4 where a water spray thoroughly doused the warp. Plant 3 also used wet control by submerging the filling in a bucket of- water before loading into the shuttl . Apparently not enough water penetrated the tightly wound cop and con siderable dust emanated from the unventi1ated machine. Plant 2 wov cl th entirely dry, due to customer. requirements, but had a well designed canopy hood with side and partial front baffles which was successful in removing the dust. Apparently, either wet weaving or good local exhaust is ffeetive in maintaining dust concentrations below the TLV*. * * *" These results showed that average dust concentrations in asbestos mills were generally below the threshold limit value and in some cases very much below this limit. Tremendous progress has been made over the past -30 years as can be seen from Table r. The 1934 Pennsylvania survey occurred at a time when controls were relatively unknown and dust exp aur s were massive. By 1938, when the Public Health Service studied plants in.North Carolina, some controls were in use and concentrations were measured with and without controls. No control system had yet been devised for spinning and only.one twisting machine had local exhaust. Average dust levels reported here are well below the previous levels but about 10 per cent of the individual measurements are still over $ mppef. E/fect ive engineering dust control practices are available and appli cation of these methods would eliminate the occasional high dust con centrations. Dust concentrations on membrane filters counted with a 4 mm phase contrast~objective cannot be evaluated by the same TLV established for impingcr_samples counted with a 16 am light field objective. Comparison BB 0020973 THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM nys FILES. AND CANNOT BE AUTHENTICATED BY PPG INDUSTRIES-, INp. 34S5 ASBESTOS STUDY 6- - ' NOTE: THIS NOT CGixiE: fr !J i i i O j i \- f fiber concentrations on filters with total paftides by impinger do not yi-eld a high correlation since the two methods are not Measuring the same thing. However, an approximate equivalence has been derived by the methods described by Ayer, et al.C) The number of fibers per cc equivolent to one million particles per cubic foot arrived at hy these methods is: 10 total fibers or 6 fibers longer tlum 5 m or 3 filers longer tlum 10 m- * The results of over 600 membrane filter samples are summarized in Figure 3. Each of the bars represents the Average concentration of the samples taken in each operation in four plants. In order to compare impinger results, the average dust concentrations measured by impinger (see "1964" column. Table I) have been converted to equivalent total fiber concentrations using the above approximate relationship. These are shewn as circles on Figure 3. If the ratio of total fiber concentration by membrane filter to dust concentration by' impinger were the same for all operations, all the circles would'be expected to lie at the ends of the total fiber bars. However, in some operations significant differences can be noted. Fiber preparation is relatively dustier as measured by impinger, while the later operations of carding, twisting and weaving have relatively higher fiber concentrations on membrane filters. It may be that the granular dust which contributes the bulk of the impinger count disperses fran the asbestos early in processing while the fibers are dispersed more slowly. The ratios of concentrations of fibers of different lengths are not constant. For example, the total fiber concen tration for spinning is much lower than that, for twisting but the > 5 b-' fiber concentration is higher for spinning. This illustrates the diffi culties in attempting to characterize the exposure to all sizes of fibers by counting only fibers longer than a certain size. The total fibers show more variability from operation to operation indicating they may be a more sensitive measure of relative dustiness.' Some British asbestos textile mills use a concentration of 4 fibers per cc longer than 5 m as a goal in dust control. This is shown on Figure 3, by vertical lines. It would appear*from the results reported in this study that the British limits are exceeded, on the average, in all operations. However, their counts are mode with vertical illunination on colored membrane-filters while in this laboratory counts are made with transmitted light-phase contrast on cleared filters, and therefore the two stajidards may not be comparable. Further work is in progress to resolve-this question. . . :' 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. ` #X " 3466 -7* ASBESTOS STUDY CONCLUSION It should be emphasised that all of the data presented arc preliminary and that the results of more extensive studies both in textile and other asbestos processing plants will be reported in the literature as the studies progress. In general, dust concentrations reported to date in this study are considerably below those found by previous investigators in 1934 and 1938. However, improvements in the dressing of crude asbestos may have increased the fiber to particle rotio .so that fiber concen trations may not have decreased as much as'particle concentrations. Additional data from many different types of plants will be requir d before the combination of epidemiological and dust concentration data may lead to a new standard of safe levels of exposure possibly based on a new method of evaluation.1 A RECORD of >r COME FROM irHENTICATED 1 BB 0020975 | 3457 C' J 8 REFERENCES NOTE: Thus oomvrv- | *t cow 'not rr * 1 :v IJ 1. Fulton, V. B. , A. Dooley. J. L. Matthews, and R. L. Houti (1935). Asbestos is. Pennsylvania Department of Labor and Industry Special - Bulletin 42. ` 2. Dreessen, W. C., J. M. Dalla Valle, T. I- Edwards, J. U. Miller, and R. R. Sayers (1938). A study of asbestosis in'the asbestos textile industry. Public Health Bui let in No. 241, U. S. Government Printing Office, Washington, D. C. . 3. - Objectives and General Plan for Occupational Health Study of the Asbestos Products Industry. Division of Occupational Health, Public Health Service, Department of Health, Education, and Welfare, August 21,-1962. '* 4. Industrial Ventilation - A Manual of Recommended Practice, 8th edition. Contnittee on Industrial Ventilation, American Conference of Governmental Industrial Hygienists, Lansing, Michigan. 1964. ,, ' " 5. Hamblin, W. P.: .Personal coenunicat ion. 6. Ayer, H. E., C. H. Edwards, J. H. Fanney, and J. S. Lynch. Relation ship of impinger counts to fiber concentrations by membrane filter in asbestos textile plants. Delivered at the annual meeting of the. American Industrial Hygiene Association, Houston, Texas, 1965. 1 THIS DOCUMENT WAS NOT A RECORD QF PPG INDUSTRIES> INC. DID NOT COME FROM IT'S FILES AND CANNOT EE AUTHENTICATED BY PPG INDUSTRIES, INC. . "bB~00 2097 6J_ j* 34SS i 9 * 'f ASBESTOS study HOI cowe from epui-itcb TABLE I DUST CONCENTRATIONS - ASBESTOS TEXTILE SURVEYS ~^^SUKVEY CFERATION^^ Fiber Preparation Carding Spinning Twisting Yeaving Pcnna. 1934 67.0 31.1 16.2 3.8 19.8 PHS 1938 without with control .control Public Health Service 1964 Mean Concentration in mppcf 36.0 6-0 35.7 3-3 7.1. n.i 14.0 2.1 'i 2.6 , 1*7 1.2 1.5. 1.2 **!?? WES, ^c` | BB 0020977 | 34S3 tn CD w 73 ^ ^ o 0SOo n 1 ^2n X- 7prn* . 'h23 o> 'W_'hfizzj ZO> O tf> o ra 5 a --! O -H > X O 3J rn O m X g0 --1 rn O CO > -n CO a n; O 0 O 2 -n PLANT ,* SWHiM il > IMI t I l,r.ll*.>. ftl. Ml^UUli ra_- . * ** TLV rIBER preparat;oi CARDING 1-- 1 11 1 I ! to I II ca II ,01 2 3 4 56 CO !I 0o 11 , mppcf I NJ | IOI t iO I AVERAGE DUST CONCENTRATIONS BY PLANT AND OPERATION Q I -J I II CD II I-- I IMPINGER SAMPLES COUNTED AT I00X *. Figure I 1 r !* i t Co r-a< r"j 2T) rX! _u -n *-- y> 2 FFn 5O Oo -- co ci n s >^s ?cco- rw2-j *r3nr rz|n -t O 01 <2 > *_ in 2 z< cn O > 2^O 0 y> 'O r>fnflZO?QH E5 OH ^> 3! O ML PLANT ISM" ;jr; myrrmmwrj fiteicZiiettftfttu&i MTTWI I > f rrPHIf'PtMWFW >>|imn \tgx*fAi . iakt ..*< --a<;*i,-*" r*- (ijitii TLV gg SPINNING TWISTING P$Ol WEAVING oo L1 I 2 345 6 fn^ncf AVERAGE DUST CONCENTR* ; 13 BY PLANT AND OPERATION IMPINGER SAMPLi . COUNTED AT IOOX * Fig re 2 lx*- * c:. DJ 3 T W < 00> I*DD X* C -n _ W t? -- 2'' F-l D^ wr|nInco 2no c > _j t_ hcCO; oa wran) 5=2 mco _^, y _or> c5o O Dm J^nZo i> 2 H -CH O"* > E*3"--Po<O? oarn =2^0* O>33, JO rDn OSoti i iwti> ntnimi --r----------- n--------------------- r .i|. FIBER PREPARATION lI CARDING sssBaMsaaa^^ iL - jf. >*.-.* -.I SPINNING J O wmirwii oy. ml' >imiiii. IWmIIHi, _, o O rl O\* \d* &> * \I oO 'v Wl . lI vJ Ii t5>\ \ . 1-- *. I; *.tj I o IMPINGER EQUIVALENT TWISTING 1 'T.Z.L"*' 1 I 111". *' * l 1 '-. 1 f T 11~ i.j..~-^tfc.rl.jfi ji> i .<> I O SB MF TOTAL FIBERS 3 MF FIBERS >5 \i ESI MF FIBERS >I0|I fFEVU'W*? . -T-C-4-* --V<L-j^- 1-LAl o O J 1 to 15 FIBERS/cc 1 20 * * 1 25 DUST CONCENTRATIONS BY OPERATION i** * t MEMBRANE FILTERS COUNTED AT 430X PHASE CONTRAST 2! s: Qo "H --i O rn C3 --j r:'T `Vj zv c: O 1 7* - ' ) 30 J ( Z:) -i n > o:ri ct, C2 FIGURE* 3