Document Rj001BkKORYY3DkrYoEEgLaOz

PLAINTIFF'S EXHIBIT Li. No. I Industnal Hygiene beccion Industrial Medi lagrc 5 A group "nlrn'1's `s exposed to each time .nim'fli concentration level point. After the ait.- ;r.-is ii.-.vc been observed for a month or six weeks exposure a mortality table is established. The Air Sampling of Asbestos Dust -- Comparison oj I m plnr/cr and Electrostatic l`rrciplititor A/cthods'*-- arc then plotted on log-log scale as used by .Sayers and Yant.1 We haVc made one exception ;iiis method. We piot uvo curves: one represents J. Wm. Feiinzl, Chemist, Industrial Hygiene Laboratory, ;i,e lowest concentration level--shortest time :n- Metropolitan Life Insurance Company, n rval tvnere all animals die; the other represent-- Sew York ir.^ the highest concentration level--longest-time .r.'.crvai at which ail animals survive. This chart ~ \ URING the past 10 years the Industrial ^.ves a cicar picture of the acute toxicity of the j Health Section of the Metropolitan Life vapor studied. ----- ' Insurance Company has been studying the effect of the inhalation of asbestos dust by em Chronic Vapor Toxicity ployees in plants in the United States and the SOME reasonable period of exposure had to be Province of Quebec engaged in mining asbestos chosen in extended chronic studies. A period fiber and manufacturing asbestos products. nf eight hours exposure and an interval of 16 hours In 1929, the American asbestos industry was between exposures has been arbitrarily chosen. practically uninformed of the health hazard asso Smith and Smyth: used the same interval. It has ciated with asbestos dust, although a few British .-orr.c reasonable basis in our standard work day. articles had been published describing cases of These eight hours per day exposures are continued with week end intervals of rest for a period up to six months. Occasionally a longer total than six months is used but this is our standard. There is no doubt that a different period of exposure or a different interval of rest between exposures would change the results profoundly. Studies of the effect of interval variation would be most illumi nating when time permits. Several different species of animal should be tested in order to avoid the individual vagaries of any one species. We asbestosis contracted in English plants. In 1927, Cooke and Hill* and McDonald1 gave the first de tailed description of what are known as "asbestosis bodies." Asbestos fibers as long as 360 microns were described as occurring in the lung tissue of asbestos workers. We, therefore, made an effort to distinguish as bestos fibers in our collected air samples and, while we used the impinger method of sampling for the determination of dust counts or concentra tions, we also collected a large number of samples have, however, used the rat as preferable for a standard animal. At intervals during the six months, exposed ani mals arc removed for complete histological study with the electric precipitator1 for examination of physical structure and determination of particle sizes. We were, however, unsuccessful in finding much fibrous material in the air-borne dust anti and at the conclusion of any scries of exposures all ti:c remaining animals are so examined. Other im portant studies made during chronic exposures arc blood examinations, tissue analysis, urine an very few of a length greater than 50 microns and practically none of the 360 micron size. Wc found that 50% of the dust was less than 2.5 microns in the longest diameters while 97% was less than 10 alysis. and function tests where such are indicated. Such complete toxicological studies on the chronic vapor toxicity of even our common chemi cals are lew and far between. They are, however, the basis upon which the industrial hygienist and safety engineer must base his work. Nearly any material m;v be handled in industry without seri ous hazard if its properties including its physio logical effect are clearly understood and intelli gently used. microns. These particles are of the same dimen sional sizes as those encountered generally in in dustrial plants. Later Fulton* and his associates reported that not more than 3%, of the air-borne plant dust was greater than 10 microns in the longest diameter which agrees with our findings, although he had surveyed only one of the dozen plants and mines studied by us. Recently the U. S. Public Health Service1 issued a comprehensive report on the as The procedures and apparatus just discussed bestos textile industry covering one of the plants arc for the purpose of furnishing in so far as wc had previously surveyed, but also many others it is possible the toxicological data by which an intelligent engineer can design or control an industrial plant for the manufacture or use of es sential chemicals with the minimum of hazard. References: in other geographical locations. In their survey they took impinger samples for dust counts in or der to evaluate the degree of exposure of em ployees engaged at various operations. On page 23 of this report the following statement is made; "The relatively low percentage of fibers in sus t- S aYens. R. R.. Yant. \V. P.. Thomas. B. G. H., and ilimr.r.i;. I.. U.: Phyjioiocicnl response attending exposure lo vapors nf methy] bromide, methyl chloride, ethyl bro mide and cihyl chloride. U. S. Pub. Health Service Bull. No. 10J. 1020. pended dust explains the small-number of fibers observed while making dust counts of impinger samples." They determined the percentage of ffoeis by means of samples collected with the Owens w'. 2' Smyth. H. F.. Smyth. H. F.. J*., and Carpunter, C. ? : The chronic toxicity of carbon tetrachloride; animal exposures and field studies. J. Ini. Him Toy is- CS.'.G). dust counter, while Fulton made his fiber e.ctcr- * IVoemrri at ihr Tr\ntf.Fi*Mrk Antiv.il Mertiuc *wi nf Imlitwna* and wih -iirpaumiai tikI lligmv, ( ihr Am> ................ a. i .. . mirations on electric precipitator collected sam ples. Recent work published by Gardner' indicates that chrysotilc fibers less than 3 microns is no more active than the silicate serpentine which has the same chemical composition but which is massive" rather than fibrous in structure. He states that by inhalation, chrysotile, ground to such fineness that its fibrous structure is no longer recognizable, has produced no fibrosis in guinea pigs after a year's exposure. All his observations suggest a mechanical rather than chemical form of irrita tion, also that the reaction to asbestos la restricted to the lungs because only these organs possess the proper structure and physiological activity to per mit friction with a stiff fibrous foreign body. Recently, t'nc electrostatic dust collector has been placed on the market. This device employs a combination of ionization and electric precipita tion in entrapping dust. It is highly efficient in entrapping fine dusts and fumes. It was, there fore, considered advisable to study its efficiency, as compared with the impingcr, in determining as bestos dust with the object of distinguishing fibers. While cotton is used in the manufacture of as bestos textiles, no attempt was made to differen tiate between cotton and asbestos fibers. The U. S. Public Healui SerViee' in their study were unsuc cessful in distinguishing individual types of fibers. In our study the standard impinger method of Taile I. Preparation Department Impingcr Sampling M.P.C.F. Electrostatic Precipitator Sampling M.P.C.F. Sample Cu. Ft. Total Fibers % Fibers No. Air Sampled Dust 1 ...... ..... . 38 .......... ..... 8 ... ................40 ... .............. 5.0 2 ..... ........ 4G .......... ..... 5 ... ..... ........ 2.0 3 ...... ........ 45 ..... .. ..... 3 ... .............. 3.0 4 . .. 5G ...... ................4 ... ........... .. 10.0 5 ...... ......... 44 ......... 2 .... .......... 03 ... __ _____ 2.0 5 56 ....... ..... 5 ................07 ................. 1.0 7 ...... ........ 38 ...... .. ..... 3 ... .... ........... 20 ................. 7.0 r. ...... _____ 36 .......... ..... 3 ... ................70 ........... . 21.0 Average ____ 47 .......... ..... 4 ... ....... ... .30 .. .............. 6.0 Cu. Ft. Total Fibers % Fibers Air Sampled Dust 180 .................. .......... ... .40 ......... ..... 10.0 144 .................. .......... 4 ... ......... ... .30 ..._.... ..... 8.0 180 ............... ......... .30 ......... ..... 10.0 I4<* ............... .......... 4 .... ... .30 v.-T..... .. .. 8 0 129 ................. .......... 5 .... ... .40 ..n...... 225 .................. .......... 6 .. .. .50 S0 135 ................... ... .50 .......... ..... 8.0 135 .................. ..... 4 .... ......... ... .50 .......... ...... 12.0 159 ...... ........... .......... 5 .... -- ... .40 .......... ..... 9.0 Carding Room Impinger Sampling M.P.C.F. Electrostatic Precipitator Sampling M.P.C.F. Sample Cu. Ft. Total Fibers' % Fibers No. Air Sampled Dust 1 ...... ......... 42 .......... ..... 2 ... ................1 .............. 5.0 2 ...... ........ 42 .......... - 2 ....................1 ... .............. 5.0 3 ...... _____ 44 .......... ...... 2 ....... ...........2 ... ..... ........ 10.0 4 ...... ........ 42 ......... ...... 3 ... ................i ... .............. 3.0 5 ...... ........ 44 ......... ..... 3 ... ........ . .1 ................. 3.0 s ...... .......... 44 ................ 2 ... .............. 15.0 .......... 44 .......... ..... 2 ................... I .............. 5.0 3 ..... ____ 37 ...... .. A .............j ... .............. 10.0 0 ...... .......... 36 ...... ..... ..... 2 ... ............ 1 .... ......... 5.0 io ..... 22 .... . i __ _____ 10.0 u ............... 45 .......... ___ 3 ... .......... .3 ,,.............. 10.0 Average ........ 43 ........ . ...... 2 ... .... ........... 2 .. .............. 7.0 Cu. Ft. Total Air Sampled Dust 135 .................. .......... 2 .... 135 .................. .... . 2 .... 135 .................. .......... 4 .... 135 .................. .......... 3 .... 135 ................. .......... 2 .... 135 .... ............. .......... 3 .... 135 ............................. 4 .... 114 .------------ .......... 3 .... 114 .................. ..........3 .... 162 ................. -------- 2 ... 135 .................. 4 134 .... ............. .......... 3 .... Fibers' % Tiber* ... .1 . .1 ... .3 .. .1 ... A .. .3 ... A _ .2 ... .2 3 /... 5 0 . . ion ......... ..... 10.0 ...... no .......... ..... n.n ao .......... .... 13.0 7.0 ......... ..... 10.0 an ..... 9.0 .Mule Spinning Impingcr Sampling M.P.C.F. Electrostatic Precipitator Sampling M.P.C.F. Sample Cu. Ft- Total Fibers' % Fibers No. jgAtr Sampled Dust i ...... .. ..... 20 ......... .._... 3 ...... ........1 .... ...... .. 3.0 2 ......... ..... 34 .... .. .... - 3 ................... 2 .... 3 ...... ..... 34 .... _.. ....... 3 ................ J .... ............ 7.0 Average ....... 22 ................ 3 ................. .2 ......._...... 0.0 Cu. Ft. Total Fibers Fiber* Air Sampled Dust 00 ............................ 4 .. ................. 5 ........- .... 1.1,0 No sample 93 ............................ 4 .,..................fi .......... .... i.vn 02 ............................ 4 . ..................o i -t.o 1 "34 2 3 36 Average ......... 38 44 3 ........... .1 3 ..... ....... .1 2 ............. .1 3 _______, .1 Spooling. Twistikc fc Winding ----------- 3.0 135 ... _____ 2.0 ..... ....... 3.0 135 ... ..... ............. 6 ... .......... 2.0 ............. 5.0 135 .... ................. 4 ... .............4 ............. 4.0 135 ....................... 5 ... .......... 1.5 .._...... . ri.o .......... ... 33.0 .......... ... 100 ....... ... 23.0 Weaving Impincer Sampling M.P.C.F. Sample Cu. Ft. Total Fibers % Fibers Vo. A ir Sampled Dust 1 .... .... 44 ...... .____ 3 _... , .... 3.0 2 .... 34 ........ ____ 1 ..... ............. i , . . .... 10.0 3 ..... 5 .... 6 ... .... <4 ........ ............. I ........... .... 3.0 .... 40 ....... -.... 3 ...... .......... .4 ........... .... 13.0 ..... 44 ................ 1 ...... _____ .1 ........... Average .... 35 ........ ............. 1 .......... ..... 5.0 Electrostatic Precipitator Sampling M.P.C.F. Cu. Ft. Total Fibers Air Sampled Dust 135 ...... ......... .3 135 ................ ............ 3 ... 135 ............ ............ 4 .... 135 ................ * ...... .. 135 ............................ 1 .... ..............2 ...... 135 ................ ...... . 2 .... ............ .3 . r.'r Fibers f. n :n n io a : a (t :o o : i.o