Document OE8qKzQaVJY3vOQeYBj7VyKOp

FILE NAME: Avondale (AVD) DATE: 197D DOC#: AVD DOCUMENT DESCRIPTION: ZWZZ ZWZ MD-006371 ).-~ I ~ ~- / Rebert B. ?iaidner and Howard. E~ Ayer lfact:;to~1al. lmstitu.te far- Oceupatiotu.i.:::. SafGty n.nd Health tr..s,.. D<~pa.rt:m.en-t of liea.J~tr.1 .aa.1ic-i;..ti.t.m, al'.l..d. \~&.lfau:.~ C:mcu1n:ati, Oh.ic 45202 -INXRO_D.U..C..T.I.O..N_ .lm:l'wS:tmi is a generic term. applied to a number cf' f'ihro.us er,rst.alline ffii:iU.<1~.ii.e. mi:a.c.rals. ilthough chemically they are grouped a.s hydrated. a::r.J.:.1:cn.--t.a~ t;J~-=Y var:r g.l"'aa..tl;r in degree o-f hydrat"ion, c.omplex compoa:ti;-t-;,m:i.. of t:he s-i:licat-:: 2 and physical l]ro.perties o,f the crystal.line fil1~ .cm.w.. ~.r-tn.:c tu.re.. IlefP,:l."ance, w,:?.S, me.de to 2.Sbe.stos as early as several centuries B.C. J.::t;.. wan. xm,t e2:tabJi..cthed as a mineral. of" industl."ial importance, howsvr~r ,: until arc".!l'lCl. the end of the last century. Asbestos has a w:i:.'i.fo -mriety of usee in rn:odem ind:ust:,;ial. technology because of its o:a~.~dm_;. p::-cpe:rties of cbe~i cal resi~ta..TJ.ce, fibrous str'li.ct-1.1re and in.combi..:s'tiai.lityQ It is use.d in the manufacture of textiles, felts y rapea, brake linings, clutch facings, roofing and flooring 1;.7:,.ti:.u~.fo.J.s r, asba!:l=tos--o.&.o.~:c.t pl."Qd.u.cts, g~ke.ts, insu.1tation materials, s-p;cr(;;bl. pe_~E:r'.3r :filters, and plastic products.. These are used in pr.r..<:-ti~ti.JJ.Jt e,rer:r ma.,jcr in.dustr.:r. S~;,TLi.:::: tics fro;n the Bureau: cf f.1ines "Mi.n-?.rs.l Facts and Problems, .Eu1.J.et1.n 6~0 ... 197.0t indica:te tnat" the Ucl ted States is the woxld 's la:r{.{est cori.:J!..!l."'ler of asbestos, usi.i."lg inor~ than one-fifth of the 3. 5 milllcm Ghort tens of rJorld. pradu.ction.. ?.1ost of the asbestos prochn:rt...iL.l'.>. is ch.rysocile asbestos, but e.pproxima.tely 200,000 t<ms of the. world rs pro4,xctic~ each year consists of a.mosi te and crocidolite. Itr. J:968 the United S-tates e.o.nsumed about 23% of the total world produ.c..tian .A'i:;ber_; tos worlce.rs, have be.en the subject of numerous studies a.'l'l.d re~i,wi r::.rcicles since aabestosi!S tr!as first recognized as an occupation.n.l d.ise~.se in the. la:te 192os; howevei, many questions remained 1u1.r:-:::r~.::::wgrf.d conc-e.rnin,g 'lih.G.- clinical. aspec-r;s of the disease ru1d its e:t.ic.logy.. Inf::n.--matio.n on the prevalence and clinical characteristics of' asb.!;sto:::is had. be~n derived prima.rily from me,lical studies of acti\n~ly em:9lcyed a.sb:::s.tos norkers. These were supplemented by s--ra-c:ieJ. c:!.i.1:dcal studies and autopsy data. Little defiv.itiYe data negar.tling the nature 1?.nd magnitu.de of concurrent e?lvironmental expc.sures had been obtained. ~'van t...'11.ough an es ti.mated 3. 5 million workers are exposed annually to uubestoa, this may represent only a part of a much_ larger eme-:"ging b.ace :c-csul.ti.ng from advancements in industrial technology anc.t aff~cting a far greater population, the r~pidl.y expancling field o! ind1.>_str-lal fibet tech.no.logy.. There is evidence that respirable fi- ber::; t whether they- are of nat-i.u-al :t:inera.l, vegetable or sY1?-thetJ.C ar.i-gi.ll,, mux- b&have quite di:ft'1rently in the luneo thrui po.rticulates a:.t i.h.e san1e c..b.emica1 c..amposi tion. l -104- A comprehensive study was staried in order to obtain data which could be utilized to accomplish the following objectives: I l. Po determine the health status of the asbestos workers in this industry with special attention to diseases of the respiratory tract. 2. To determine the relationship between occupational exposure and cause of death of asbestos workers. t 1 3. To develop medical and environmental criteria and procedures for the control of health risks identified by the study. l I l 4. To determine which environmental factors have an achrerse effect 1 upon the health of asbestos workers in the asbestos-products industry. ; The National Institute for Occupational Safety and Health (NIOSH) (formerly Division of Occupational Health} in-the u.s. Public Health t Service has been conducting an epidemiological study of the asbestos proces~ing industry since 1964. This paper will confine itself to 1 ~ the environmental phase of this study which was designed to define the working environ.men!, of the various plants. Particular emphasis j ~as placed on levels and nature of exposure to asbestos dust. ' ]?RESENT 'EPIDEl'v:iIOLOG IC STUDY I I The present epidemiologic study of tha asbestos produ.cts in9ustry I was started for the following reasons: I j i. The subs'tantial changes in the size and technology of the indus- I try have created new exposure situations in need of evaluation. 2. Over-all reductions in asbestos dust l~vels now make it possible to examine tho relatioll. of asbestos to asbestosis in workers with I long-term lower level exposures. 3. Tlle relationship between types and .magnitudes of exposures and I the occurrence of lung cancer needs to be defined. SAMPLING METHODS ~e types of samples co11ected in the environmental phase can be divided into four categories: 1. Bulk sar~ples - Several pounds of each of tbe different'types of crude fiber, bag house waste, and treating and lubricating o:i).s used were collected at each plant. 2, Long period gravimetric samples - Several instruments for obtaining mass samples of total and respirable dust were run simulta.neously in the representative area in the midst of each operation. These instrumenta included a high volume sampler, a Hsx~t modified to take a membrane filter, and a set of four membrane filter field monitors with and without 10 millimeter cyclone pres~L'Tlplers, a.."'1.d a membrane filter field uoni tor with a horizontal ;~ 1_: ~ trici i;) r ~-,_,~; trear11. 3, Simultaneous impin3er-filter samples - Breathing zone sam.ples taken with an impinger and a membrane filter s~multaneously were used to obtain a comparison of these methods of dust ~n:mieration. Th~s_method of sampling was used because the in~ti~l expos1:r~ l1mits were based on samples evaluated \Vi th the ~mp~nger a.nn it was hoped that a correlation existed betv,een the methods so that a meaningful use could be made of all the past data collected. Other sets of .simultaneous impingerfilter sanples, with and without horizontal elutriator preaamplers, wera taken in general room air near specific operations. 4. Personal Samplers~ Only the personal samples collectea using membrane filte!'s v1ill be B.isoussed because it gives a better index of airborne fiber concentration. Lynch, et all found that tr1e impinger method. of sampling v,as very inefficient with relation to capturing fibers to be counted later. The lack of fibers in the iillpinger samples was not due to the absence of fibers in the air. The impingez, an impaction device, has a collection efficiency related to the aerodynamic size of particles and is not efficient for particles with falling speeds I less than that of one micrometer, unit density spheres. Further, the lOX objective, light field, counting technique 'U,Bed does not resolve particles much smaller than one micrometer (m). Laboratory experiments showed tha~ the irnpinger passed fibers and from field s&~pling it is estimated that only about one out of one l'iundred fibers in the air as seen in elect1on micro- grap...lJ.$ was seen in the impinger samples. l Since it i~ important ~hat a."'.JY method used be able to measure that factor in the environment that is most relevant to the diseasecausing mechanism arii will, therefore, yield a significant correlation between health and exposure, it was determined that the mem- brane filter method met this criteria. Fibers have long been implicated as the causative agent in asbestosis and may be significant in cancer. Timbrell's2 work showed that because of the peculiar aerodynamic :properties of fibers (i.e., that their fallirlg speed is dependent on diameter only when aspect ratios are greater than 10) it is possible for much larger objects {longer and heavier) to penetrate deep into the lung in the shape of fibers than in the shape of grains. This appears to be a most significant biologic property considering that the parent minerals involved (amphibole ar1d serpentine) are not considered biologically active. I Based on methods developed in Great Britain3, a methoa oi collec~ing , and counting fibers on membrane :filters was developed These 'fil- ters have pore sizes of o.8 pm but are almost 1000; ef~icient down D t to several hundre-d.ths of a micrometer because of surf2.ce effects. They are dissolved by means of a mounting medium which i~ prepared by dissolving 0.05 g of membrane filter per ml of 1 to l mixture I of diethyl oxalate and dimethyl phthalate and has an index of re- rraction {ND) cqunl to 1.47. The samples are counted with a_4_mru ~ objective (430X) under nhase contrast illumination. By examining a suitable number of fields, it is posr;ible to count e11ough l'J.bers to make a statistically useful estimate of fib1ous dust concentra- I tion. In order to collect a sample representative of airborne dust -106- which ia likel,y to enter the subject's respiratory system, it is necessary to position a collection apparatus near the nose and mouth of the subject (i.e., in his "breathing zone"). An exploded view of the ~ampler is shown in Figure 1. The sample is collected on a 37 mm millipore type AA filter mounted in a.n open-face field monitor. The monitor is fastened to the worker's lapel a'l'ld air is drawn through the filter by means of the battery powered pe~onal sampler pump, similar to those approved by NIOSH \lllder the provisions of 30 CFR 74. A support pad is placed between the :field monitor and the membrane filter which aids in controlling the distribution of air through the filter. Flow rate of the personal sampler pump was 1naintained at 1.7 liters per minute (1pm). Sample time varied fro'lll 15 minutes up to 4 hours. The majority of the samples ware collected between l 1/2 to 2 1/2 hours. Actual sampling time depended upon many variables {e.g., concentration of fibers, types of operation, amount of background material present, etc.). GENERAL CHARACTERISTICS OF PARTICUL.l\.TES IN ASBESTOS PLANTS l The sources of airborne particulates in an asbestos processing plant may be classified as follows: 1. Fibrous asbestos 2. Asbestos type minerals (serpentine, antigorite, eto.) ). Non-asbestos type mineraL~ occurring with asbestos (magnetite, periodotile, chromite, 11ickel, quartz). 4. Other process materials (cotton, rayon, gla.Bs fiber, etc,) 5. Non-process materials (air pollution). An air sample from an asbestos plant -taken by any efficient sampling device and examined microscopically reveals that most particles do not appear fibrous. They resemble, in fact, the particles common in air samples from virtually any operation producing mineral dust. If such a sample is magnified several thousand diameters by electron microscopy many particles less than 0.5 micrometers (m) in diameter are also visible. These small "air pollution" particles occur in any air sample, indoor or outdoor, and the number varies depending on time, season, oommuni ty heating fuel, location of plant air inlets relative to nearby smokestacks, and general atmospheric cor.ditions. Air pollution particles bear little if any relationship to the dust generated from asbestos processing. However, many fibers including rayon and cotton which are identifiable by their large diameters a.re also observed in such an air '3ample. The presence of asbestos fibers is the unique characteristic of the sample. Figure 2 is a typical electron micrograph of_dust from asbestos textile processing. Figure 3 is an electron micrograph at a higher magnification of extreme~ clean bulk asbestos treated to open the fibers. Both Dreesen5 and Fulton6 reported that the usual diameter of airborne O/,her>tr,.;:; fiberr~ was lr1ss t!'",an O. 5;1!n, Ele::-t:1.-,:,~1. mi. c:r~:~~_-_-,_;:,h:.r --~- c , :!::IB :-: 'j. ~ -_ - ~ .,.-:) ._' .; ;;~ ,\ !"',.,. '.. .,_ f "' ._ ; ..__I , .- .: .!. .._ ' ' . t" . ; !- '' l o:.l:._11l di.am~~-e~. I:f a.. f:i:t>.er. i~_ d_eri~~d: aa_ having an aspect ratio gT:Ca'ter th~-- three to-. OP,?, ~o;.:, t-=- of the fi.bers, by number, are 4shomr.t...;. me!l.;i,_@_ l~!+gt1+s. f:r-om'- e1.c.c. -tr--0.n- m. i-c-.r.o-g.r.a.phs are betv,een l and O'.ORRENT STAND,\IlDS ... I I .,, Aab.f:f3':t-Ps b~- b.~ l:i.:s-ted as one. o.f.. the fj,.ve target health hazards bY,: the2 Qc.c..upa,t;i.:Ma~. s_~f:t.:tY al?-~. Hea-lth Administration of the U.S. Deyar.tment: oJ_ ~or_. .t\9_ o-f'. ~~:ey~_p_" 7 ~.--~9-71, an emergency stan- ~d~ f-..o.r ~))_estp~ w~ ~~Y.o,ked by the. fe_deral gove~ent under the sa-u_ot-a-Pt..e:i.:..ac-:e::.~ Qf. th~. O ccu-p-ati-ona l- Sa---:-fe-ty: a-n-a- lf-e- a lth Act. The standard '''tbi:=t 8-,.rum~ t~19~e-.:i,ghted ave.rage ai.~borne concentration Q-:f 8$-b.es.tQB dust_ tQ. w~1.ic~ eynployees are exposed shall not ~Ae~4. ~:i;v:e.- f'ibe_rs_ per-milliliter- gre.atel' than five mi- I ctrons :i.:1'-. :t.,e.ngth, ~- -~etem:faied by the membrane filter method at 4.00-450X mag11if~~ation 14.niillimeter objective) phase cmnt:r;-aat illumination. Co11centJ.ation above five fibers per mil..l..ili t.ei--~ut ~-- ri,~t t_o E:p~~~e:a.. ten fibers per milliliter, of may- ~e pe~mitted up to a total 15.minutes in an hour I t.or up. -ftq.. :ftv.-~ h. o. .~-- . i-~n 'a..r..i'..~. h. o... u. r d'.ay~" The National J.m~ti ~u:t_e :f~r 09oupational Safety and Health (lUOSH) in its "C.riteriPr for ~ Re}~_-ommended -Standard~ Occupational. I Exposv.re to A~_Qef;"ltO~ ~ u ;"'~~Offi!ll~~ds ~ - . - . l ttQccupatio:p,al. ex.posure to airborne ash1Btos dust shall be eo:p.trq:J._led i;;q tb:at no v:~orke!:'S shall be ~x::_:iosed to j mo.re tha.'1. 2~0 ~bf#~tos :q.bers per cubic centj.meter (cc) l o.f air b~~d on~ col.!nt of fibers greater tha..~ five f m.i.c~Q~et~r~ (>5 ~) in length (determined by th~ mem- at brane :filter ~e-thod 400~4':iQX magnification (4 milli- meter c,b je.~tivc) phase contrast illumination, ] , determi~ed ?S? t~m~~eighted ~verage '(TWA) exposure I for an 8~hQu.r work ~a.y, ?~~~o peak concentration of ewl>eatos te which w<:>rkers ar.e exposed shall exceed lO.O fi~er~/cc- greater thw1 5 J.mi"as-d~termined by a minimum {?11lp:J_in~ -;;i;!Jl~ ~f ~? ~!lut~n ~ '' I RESULTS OF ENVIRONt,'iEI-JTAL SAJ/IPLING ., raps Although~ ~itf~r~nt ~yp~~af somples have been collected only "hl:1e reeults of the membrane filter method will be discussed because this is the metho~-~~umeiated-~n te ~~istingFcderal Standard on asbestoa. All of the data iisted a~e the values of fibers greater than 5 micrometers in leneth~ All concentrations a.1'e listed as the num- ber or ttbers greater than 5 micrometors in len6th per cubic centi- anete:r .ot air ~a.r.1p_led (p.~r~inaf~e!, as f'ib~rs/ccJ. The results list~d are b~.e9- 9_'!). !lPP-.r~_~im~:t!J.Y ~p,900 ~l-1Ilple5 that were collected and ~ounte~. ~ab1e l :l.ists ~he a-r-i~hmetic means of ~he over-all asbestos concen1.-rat:ions by ty-pe_s or' pl.ants for -:those .that' were: in the cohor~ In :s,om.e ~-ases the-re -we-re -three m.u!'_Veys .conduc.ted, for example, in the -teJ.--:t.i"le and' f,riction ulants A JDini.zm.un-of two surveys was conducted :in -each .pl~t:. i.rhc -cy,cle on ~hci"resurvoys was approximai;ely every -108- 2 1./2 years. This table provides an overview of the various types I of plants and allows onl,y general conclusions to be made. It can be seen that there is a definite difference in exposure level.a t among the various types of plants. On the surface it would appear that the insulation plants have the high.est exposures, followed by I the textile, friction, construction materials and cement pipe plants. The values for the insulation plants are high because two of the ' plants had vecy high value3 as shovm in ~abl9 No. 2. This table i shows the asbestos concentratione by variouz operations within the f l insulation plants. The plants are arranged according to the over- all individual :Plant average fo-r all surveys conducted there. The l wide variation between the highest plants and lowest plants can be l attributed to the amom1t of controls that each plant has~ It is evident that regardless of the over-all plant average the mixing i ' ope.ations have the highest exposure of all operations in all the i plants and the inepection and packing operations the lowest. If these values are compared wi~h the emergency standard of 5,0 fibers/ cc ( T\'/A) and 10.0 fibers/cc (peak), it can be seen that all meana for all operations at the two highest plants not only exceed the '!!NA value but the peak value as well. Whereas the plant average for the lowest plant for all operations was equal to or less thar1 the proposed standard of 2.0 fibere7cc. . Listed in Table No. 3 are the asbestos concentrations for the insu- lation plants by operations broken down accordi..11g to the over-all means by survey conducted. The over-all values at each opgration are l1igh as a result of' the very high values from two of the plants. There was very little difference between the results of the two surveys conducted except at the mixing operations. All other operations had similar values for both sUTV'eys. The mixing o:perat.ions had the highest exposures. Table No. 4 lists the textile plants by individual plants according to their over-all plant average for all surveys conducted. It ap- pears that a plant which has a high over-all average ~ill generally have a high average for each of the various operations. 51hat is not to say that the highest averaged plant over-all will. have the highest average for each and every operation, but it is true most of the time. If their values are compared with the emergency standard of 5 fibers/cc, then neither of the two highest averaged plants have any operations where the mean value is below it. Th~ secund iowest-averaged plant has two operations which fall below the emer- gency standard, Whereas the lowest-averaged plant has virtually every operation below the emergency standard. The various asbestos concentrations by operations within the textile plants for each survey conducted are shown in Table No, 5. The fi- ber preparation, carding, spinning and twisting operations all appear to be problem areas based on the present emergency standard. Only the winding and weaving operations appear to be near the standard. The average concentrations for the friction plants are listed by the over-all individual pla.nt average in Table -No. 6. When comiiderine; the mea.'"l values of the various operations with respect tr, V: -~ ,:,~~ gency .s C[;,tJ<lard of fi ~,e fih~:rs/cc, it is aI1;::-n--~1t th.i., : Wn~~ plant. hu.:m t uny ope1'ationti wnieh g;r-g b~l-9W t.lJ.~ !?:t~~~rd, fp.~ ~?C:- on~ hie,:hest averaged p.l(l.Tlt h~!;i f~r pp~;r~t;i.9,n~ whig}} ?-F~ _j~-~ slie...ht~y above the emorgency ~t~Q.;Jrc:l MY. ~9 9p,gr~t.iPn.11 whf&h ~re below 1 t. . The two low~~1; ~v~~~g~g. fl. ~t:;J h,~v~ m~~ -Y.1-~-~- ~9!' ?,,:l.i the operation~ balow the im@~e@nPy t?.-~4~~~, ~~p~rt~~ iP.~~~ two planto usin~ the p~op.oo~~ ~~~~~r~ pf -w,9 liP.~F~ p~~ &9, ~t can be seen that the aeoond lowe~i pl~t ~ twp ~P~~gt~9n~ w~~?~ have mean v-alu.cs below and =t;wp pp~~-ti1-~n$ wbi~)~ f~ ~MP!J.!iPJ.Y close to the propoeed ~te.nd&rd, w}lJ1~~s, th l9W~s-~ fiL'V~.r~ge!l 'ptant has four operation$ w~~cn b~VP m@M v~lM~ ~~}9w '!ifl~ PT9PP~~~ standard m1d two of wh;icb ~J'!3 J'!H~9.l~P)..Y 9.l-9.se t9 i:t: . Ta"?le.No. 7 has the aritl'mleti11 m?@~ PY ~P~1'~ti.9~~ fsW ~:lJ. :Ph- f:1ct1on pla.~ts survey~d ac~ord!.ms i9 {h~-:t..~~?~ ~P.l~Y~ ~9_n~,9~?d a~ these plants~ There A.ppears -t9 pe P- ~~:ft:9,:i_i:i !3:J.!19i:J.t p_f :f1,.911a- t1on ainong the va:rios o;Per~t;i.o_n.s f_9r. ~a.9l;l g,'J);rVJPJ, -,wj.-~h -~~~ P-Y!!.r- t all ~eans being highest .in th~ mi~mg, g:r,-j.1.1,Q.i.IJ.g M.9 ~~:~xig., ~9- t I cutt1ng and drillJ.ng o_pe~ation~. ' - ' - i I The concentTations by ope:r,~tj.9::ey~ :fpp t,_}_l.~ B-~l]..~:tJ'.U.c:t::ts>l'.1 :~a~.~.I'.:i-::!- ! plants are listed accordi-ng to ~Ve1'....!:!-ll i:1:1~.ivJg.u.~J :pJ.~t ~ve:r!lg~ in Table No.. 8,. '.!'he :r.a;nge .o:f -v~J..-U?s .i.s ~.m:a:1:1.. ~!i :r~.!:iSO_l}. :t~~--:t I ! I the value o.:f 'the ().Ver~ge ~f a.l,l ~_emp:l~~ :fP:r j;p~ .~i:~J.ng op~:rat:i9n is higher th2:n either vA:l~e :l-iet~i i~ th~1; ;~er~ .w~ ~9th~.r ~~ant l in the cohort wh;i.ch .ha~ .a .l.J..ig~ Y!..i~~- .~J:i.a-~ p:l_ant .\~~ -~9t Jist~~ because it .bad low -ve.l:ues :fo:l' th~ :fOl".l'\l.i-ng ~~ f-in:::)..~h:.\~g op_~rp.:t:ions which brougrrt th~ .PVJ:J.r-.aJ.l _PJ?-":lt -~v~r~~e P~.:~.pw :t;hp Jl.iJ;_h.es:t p).llt . ~here were o:n1y -:two .sui"'Veys condu9-:ted in Jhe ,pons~:ro.c-~ion materials -pJ.&nts (Table .No. 9),. '.,l'here -w~s ~ _c;lec_:r.E3a13e :l,n .me!:Ul v_al_ues _in all operations beiween. the .o_rig:i.,~~.:r ;f3~IT_ey ~d :the :r_e.~_~rvey. Pl;lly -the mixing .Op0T'.ations d):J;r.:i.;ng tn~ prj.,gi:na,l ;S;}~v~y ~:r,.~~~~d 'J}?.~ e.mcrgeney t:aridard of :fiY~ .f.ib~r_s/p_c . R-e.milts :for- the s:ement p_ipe p'l~n:ts :f:ll:I'~ :iD- _T_9>l_e N9,. :19. _Q~~ ~~e o.f -the arithmet.i9 means if the .as.be.-s:tos -~onc.e~~ra:t_;i._ons _by op~ra- -tions :exceeds :th.e .eme.rgen~y s-t~d0;r.!i o_f _f_iy_e ::tJbers/c_c ...: :t:a_t., jn ICOJJ.plin_g finishing.. .Thi~ .a.iig~1 ;!~-~ v:alue -i:~ ~th.e :r~sul:t, _of ~~-e :ern.;np.le with .an ,ei::tr.eme.ly :.w.gh .PnP.e.n:t.r:a:ti.Q~. .~_;i.nc_e -.~:P.~re w_n.s J'l_o :li.:mnie.d.iat.e appar.ent .:r.e.as~o.:,;i :fo_r ~~.13W~:t.ing -~~:t ;;Lt ,V~:9. _:ot _a :1(?,;];~d :s:a.mple,, .ii.ti .w.a-s .included,.. :l!0\7.ev_e_;r-t :;i.:t :sho.uJ.d ,b.e po~:i;it~_d ~ut -:tih.at :all >the.r :ope-.rati.ons -at :tihat P.l&l:t ~d a,11 ,9_p_e_r:a:t_i_Ql'.),tj _at -~p.e o~h_er plants .:have .c.anc~ntrati-~.ltl..S :tha t t'.~ r.~la~;i.y~_~y .low.. ~~s_ed .on. ~~-e :p:ropo.s.e:d :standa:r.d i>.f :tw,o ~:i,bfJJ::s/~.9., -:t;p_e~e iwJ~.fJ -*:P:1:-Y QJ;1.e .:0pe~~~1~:;1, :mixing., :in the :two .l.o.w_e_s:t .av_~I~g~,d -JJ)._an:t;~ ,,w._.l;lj.,_q.p. ~~~s:.o:e.c\ed .tnat :s-tandar.d.. - .Table No. 11 1ists the asbes.tos concentrations by operations for the :cement pipe plari.ts .~c_c_ordj.ng -:t:0 -:the .s.urv~ys .con_dw~ted _at ~~c;h .p].an:t.. .There ,were ~only -j;y,1_0 :-S.uI-v~y.s -:c.o~d.ucted .~t _e~_qtl PJ..~t ~ ,A~l. ime.an :v:alue:::; f-or -:the .resurvey w~re .below th_o_::;_e _-from -the ~r1e1nal <.S:u.rv.~y.. .All :o-_pn_ra:tions _:i;n ,CJ}mQnt pipe plan:t !ho.ve -mean VJ1lu_e_s twL:i.ch $U~ ibe.l:ow ;the -~m.v.l:6v.U.~Y .~.~l~~~~ \o.f _5 :i'J..~~x:s./4,Rc,. -110- SAMPLING METHODS EVALUATION A opecial study was conducted to evaluate the possible variations between:. 1) different oampling positions, and 2} repeatability betv,een adJacent samples. In the past, it was standard operating procedure to ascertain whether a worker was right-handed or left-handed and then the field monitor would be hung ~rom his left lapel and t rieht lapel, respectively. The first phase of this study consisted of having a worker simultaneously wear two samplers with one field monitor positioned at his left lapel, a.nd one at his right lapel (left-right paired samples). The pumps v,ere hung on the worker's belt and the hoses put over his shoulders and attached to the field monitors on each lapel. 1 Table No. 12 lists -the results of the left-right pa.ired samples that were collected sirnulta.."11.eously on each worker. There were a total of 23 pairs of samples collected ( 46 total sa-rnples). The results I were tabulated according to which side had the higher concentration; no matter how small. The total number of samples listed on this table is 22 rather than the 23 pairs which were collected since I one pair of srunples had the same concentration. The fact that an equal number of ::;amples ha.cl higher concentrations on each side does I not of itself tell the complete story, sinqe it doesn't show the variability :i.n the differences. A more complete evaluation can be realized if a range of differences is calculated. This was accom- plished by subtracting the lower concentration value from the higher concentration va.lue. Where the right side had the higher concentra- I tion, the ran&e of differences was from less tha.~ 0.1 fibers/cc up to 1.0 fibers/cc, with a mean difference equal to 0.3 fibers/cc. Where the left side had the higher concentrations, the range ot" differences was from J.ess than O.l fibers/cc up ta 1.1 fibers/cc, with a mean difference equal to 0.5 fibers/cc. Thus, it is evident that even the differences (which are minimal) are reasonably uniforra regardless of which side had the higher value. The second phase of this study was conducted similar to the first phase ~a that two samples were collected simultaneously from an individual worker. Instead .of hanging the field monitors one on each lapel, the field monitors were hung side-by-side on the same lapel. The results of the side-by-side paired samples that were collected simultaneously are lis~ed on Table No. 13. For identification purposes the field monitor located closer to the center of the worker was called the inside sample, and conversely, the other was-referred to as the outside sample. There were a total of 85 paired samples collected for this pha~e of the study. The total number of samples shown on Table No. 13 is 84. This is the result of one oair of samples having the same concentration for each sample. The di~tribution on these s~p~es s~ows t!1at 38 of the samples had higher conc~ntrations on th~ ins;de filter, whereas, 46 had higher concentra:hons on the outside filter. The binomial probability test was applied to the data and the_rc-:suJ.ts indicated that this distribution of 38 and 46, for the insJ.de ~md outsirlo B;ur.ples 1 res:pectivP.ly, could have easily occurred by "'" "' 0 I .. L, - chance. There is no significance in the number of samples on the outside which had higher concentrations as compared with those on the inside. A check of the range of differences for the samples that had a higher co11centration on the inside filter woul.d reveal values of less than 0.1 fiber/cc up to 1.5 fibers/cc. The mean of these differences was 0.4 fibers/cc. Where the 46 outside samples had higher concentrations than the inside, the range 0 differences varied from less tha..~ O.l fibers/cc to 4.9 ibers/cc. The variation between the 'high values of each side, 1.5 to 4.9, appears to be relatively large. This is the result of one pair of samples. The mean of the differences is only 0.6 fibers/cc ror the outside sa.mplco in contrast to 0.4 fibers/cc for the inside samples. The difference here is not significant. This phase of ~he study, the side-by-side pa.ired samples, was also instituted to determine what the variation in the sampling procedure was for samples that had values close to the proposed stan~a.rd of 2.0 fibers/cc. The side-by-side paired samples were arbitrarily broken down into three separate groups: 1. -Samples with mean concentra~ions less than l.5 fibers/cc, i 2. Samples yfi th mean concentrations between 1.5 and 2.5 t fibers/cc; and ' 3. Samples with mean concentrations greater than 2.5 fibers/cc. \ The results of the Iirst group (samples with mean concentrations less than l.5 fibers/cc) are shown in Table No. l4. There was an I i even distribution in the number of samples that had higher concentrations on either side, 28 and 27. The range of differences l is the same, 0.2 fibers/cc, which is la% of the proposed stan- dard of 2.0 fibers/coo ~e breakdown for -the mean concent:rations for these samples which had values between 1.-5 and 2.5 fibers/cc is shown in Table l'lo. 15. There were 11 samples collected on the outside which had higher concentrations as compared with 5 samples collected on the inside. The outside samples had a higher range value, 1.6 fibers/cc, than did the inside samples, 0.9 :fibers/cc.. The mean of the differences was the same for both types of samples - 0.6 fibel'S/cc. Table No. 16 ~resents the data for -those samples with mean con- centrat1ons greater than 2.5 ~ibers/cc. The inside samples to- taled 6, with a range of differences between 0.1 and 1.5 fibers/cc. !l'he outside samples, of which there were 7, had a range of differences between O.l and 4.9 fibers/cc. Since this group includes all samples wbose mean concentrations are greate1 than 2.5 ~ibcrs/c~ it would be exi,ected that a wider vs.riaticn woal.d occur between ranges of" di:ff'erence and .means o:f di1.fe1ences because of the larger values invo1vea.. T.he "bigh" vuJ.ue of 1..5 :fibers/cc i'or the inside samples was the resu.1t of a sample whose mean concentration was 4. 7 .fibers/cc. Whereas the 0 .h;i.gh11 value of 4.9 fibers/cc for the -, ~- outside samples resulted from a sample with a mean concentration of 12.3 fibers7cc. The mean of differencea for the inside samples was o.7 fibers/cc, whereas the outside srunple9 had a value of 2.0 fibers/ cc. Once aeain, these values are influenced by several high sample concentrations which, a:.1 expected, had hj_gher differer1ces between paired samples. S1Wffi1ARY There is a wide variation among types of plants as well as a.~ong in- dividual plants within a given type. Thia is a result of many factors, including, but not limited to: different processing methods (e.g .. , f spinning and. weaving operations in textile plants as oppo::.ed to v:et processes in the cement pipe plants); use of different types of as- bestos (e.g., long fibers vs. short fibers); good ho1.wekeeping practices vs. bad housekeeping practices; properly designed and operated control systems; and modern machinery vs. antiquated machinery. Whereas a number of plants have mean concentrations at most operations which exceed not only the proposed standards but also the 13xisting emergency standard, there is a significant number of plants which have values for most operations that do meet -this criteria. There are a number of controlled plants as evidenced by their ability to meet the lower proposed standard. An evaluation of the special study based on all the samples collected would indicate that there isn't any appreciable difference between samples that were collected on either the right or left sides or be tween erunples that were collected side-by-side, especially for the samples that had low concentrations. As the concentrations got higher on ~he side-by-side samples, there might be a tendency for the outside sample to collect a higher concentration sarnple than the inside sample. When the proposed standard becomes law, the variation at tha higher concentrations becomES moot. CONCLUSIONS The results of environmental surveys of the various asbestos plants. reveal that dust concent1ation as measured by the membrane filter method are generally below the existing emergency standard. Due to the natural variability of the environment, catego.ries of signifi- cantly different dust measurements must be broad. There are currently available methods by which dust concentrations to asbestos du~t can i be maintained at or below the exi:::iting standard as evidenced by the l l number of controlled plants in this study. Bai.Jed on the limi tea number of samples collected e.nd analyzed during the spacial phaae of this study, l t would apr,e:'.i.r that position of the field monitor on the woiker has no il1.fluence on the resulting concentration. There is little variability between samples collected side-by-si_de, especiaJ.ly at the lower concentrations. . ~FSRENCES l. :r, Lynch, J. R. and H. E. Ayer, i'lleasurement of Asbestos "Sxpc~ure, Journal of Occupational Medicine, Vol. :@, no. l)G'S. -1U- 2. Timbrell, V, The Inhalation of Fibrouoc; Dusts, Ann. N. Y. Acad. Sci. 132: 1, 1965, 3. A.dd.ingle.y, c. G., Asbestos Dust and Its Measurement, 'Ann. Occupa. Hygiene, 9: 2, 196. ti ,;.; 4. Edwards, G. H. and J. R .liY'nch, The Method Used by the U.S. Public Health Service for Enumeration of Asbestos Dust on 1,iem- t hrane Filters, Ann. Occupa. Hygiene, IT: 1, 1967. f 5. Dreesen, w. c., J. M. Dalla. Valle, T. I. Edwards, J. W. Miller, I ! R. B. Sayers, H. F. Eason, and :M. :;:;. Trice, A Stu~ of Asbestos ' in the Asbestos Textile Indust!1[, Public HeaTih. B 1. 24!, Ig33. or 6 .. Fulton, W. B., A. Dooley, J. L. Matthews, and R. L. Hautz, Asbestosis Part II Tha Nature and Amount of Dust Encountered in Asbes-i;os i'=-.'br{cr..1;im~ r1:mts on the- Health of a Grouo Workers, PennsyJ.vaiuaDep.;. of Labor and Industry .Bui!. 32, 1935. -114- TABLE NO. l ASBESTOS CONCEHTRATIOllS BY TYPES 01!' PLANTS Arithmetic Means- (Fibers>5m in length per cc) Type of Plante Original Fi.:rst Survey Resurvey Second Resurvey Over-all Textile 4,4 9.6 9.0 7.6 Friction 4-9 2.4 4.9 4-3 Cem8nt Pipe - Construction Materials - I Insulation 2.6 4,0 13,9 l.7 1.3 12.9 2.2 3.2 i J 13,4 I TABLE NO. 2 ASBESTOS CONCENTRATIONS BY OPERATIONS l INSULATION PLANTS Arithmetic Means Operation (Fibers>5m in length per cc) Over-all Individual Plant Average Second Highest Highest Plant Plant Second Lowest Plant Lowest Plant Average of all Samples ntixing 58.9 25.3 11.2 2.0 26.0 Forming 23.2 2j.6 3,3 0.3 lJ.8 Finishing 34,9 27,l 5.1 0.8 16,0 Inspection & Packing 10.9 13.0 4.0 0.4 5.8 t Means 26.2 13.5 4.9 0.5 11.8 A.ESTOS T..A. B.Lf. ~- -.N~O- . . 3 CONCE.N.T.. R~ A.T.I...O.....N.. ...S.. -- B-Y- -..O-P-E...R. A---T. -IO-..N...S. : lNSULATION PLANTS ~ '> .. ; .. ' .... -- ...... ' - J\+!tt~e.t,~Q:; ~~!=gl~_ ((l~ib.~~>..5_p.m :i;_l}_ ~t~_ p. ~~- CP.d',i Q.)1erati ons. Mixing Forming Finishing lns.pe.-e.tion &. ~cmi.ns ...... s::sc:.__ Means _______ .. Resur.vey. - '-" .~ l lo., 1' ,_.....,__,__~............,. \. ~-.4: '..k~-.~ i~.. ~ 31~..~ 1-5.~...8... ~5-.~ ---- --- ~~~ ' ... \ ........ ------ . ____......,___ .. i T-ABLE NO. 4 'I L( ~ ....,% .I( ASBESTOS C~ ON<:.:ENTitAT!ONS. ...B-Y-~OPERATIONS -- -"'IP I !i'~XTILR PLAN'l'S Y,,,_ry__ . A~i~p.inetiQ M~~~ I (fibers~?pm ~n ~~~th p~~ f~~ I H~ghest f . ,. . l Qy~r..,13,ll ..l!l2_ividnal :PJant Av~ra~ Operation ~e~~na ~econd- Lowest Average Flii:t; H~tm~~~ !,~w~st :r.1w1:t b;f a.11 _ _ _ _ _ ___,........,,_~-=-,...,..,=-- flan ii ~~~ ~~ples ----- .. - w, ....... ..... _ .I l - . ~ .c:;.t ~ - .. ~ ...~. ,'l, .. ---...a:.- . .,., .........._.4t_ ..._ _ _ .... ~ .. . . . Fiber Preparation i~,t> g7r~ .~,, . :i ; 1., '-?- +2-1 .!.L - Carding Spinning Twisting }2,7 gg,~ 12,6 p, j.~.9 g.o . ~:~ 'i"'.' 3- ll.1 - . ... ir .1. ~. . . . ~-:J j-6~ f?>.1 '- 8.3 -3 ..-1 .1.1 Weaving :i~,., , i:~ .?f..), ~ .~...-.9. - I IS - A _ _ Z- - - - -.. - - - - - - - _ , , -116- Operation TABLE NO. 5 ASBESTOS CONCENTRATIONS BY OPERATIONS TEXTILE PLANTS [8) Arithmetic Means (Fibers>5m in length per co) Original Firot Survey Resurvey Second Resurvey- Over-all Fiber Preparation Carding Spinning Twisting Winding Weaving :Means 8.4 11.4 15.0 12.1 5.3 15,5 13.3 11.l 4.6 12.1 9.0 8.7 4.1 8.5 9.6 7.7 4.6 4.5 5-3 5.0 3.1 5.8 6.3 4.9 1 J 4-4 9.6 9.0 7,6 TABLE NO. 6 ASBESTOS CONCENTRATIONS BY OPERATIONS FRICTION PLANTS Arithmetic Means Operation (Fibers>~ in length per cc) Highest Plant Second Highest Plant Second Lowest Plant LoY1est Plant Average of all Sampleo Mixing ll.8 4.l 3 .. 7 1.4 5.3 Forming 1.1 5.5 1.4 2.5 3.6 Hot Pressing 8.7 2.5 l.3 1.4 3. 4 Grinding & Sanding 8.6 5.7 2.6 2.4 4.8 Cutting & Drilling 8.7 5.6 2.2 1.8 4.4 Inspection & "J:'.acking 1.1 5.8 3-4 1.7 3.8 Means l 8.5 4.5 2.1 1.7 4-.0 I ' TABLE NO. 7 AS-BE3TOS CONCFJiiTRATIONS BY OPERATIONS FBIC~ION PLANTS . ix;i,~E;1t!er ~~e~ (~~9~~~5~ !?. !~~~~~ p~~ ~i Qr;g;~al ~~~~, Fir.st ~~~\\~~Y- S~cond ~~~urvey 111.i~in~ J,4 f.'Q. ~ P . ~ ~-1 ..,,, I.,. f~? 2~..4 ttet l?:r~\:!~lJle; 4...9~ ..l..... 7 ~~7 ~r;S.pgi~g- ~ ~~d~- !'}g. ,P _3, .-5. !-6 Uu.tti~g- ~ Pr-~iit~1g~ ~,~ !~ 6., ,..3 p., LB ~ .!. , ,,,, .3, ..2 Over-all 3.4 4.8 4.4 3.8 i I l TABLE NO. 8 ASBESTOS CONCENTHA'l'IONS BY OPERATIONS l IIj fP.~~~~RU~~~-~~--.!~~J:~H-IA~~- ~~~TS. J1.F!t!WU~~} C ;~~!J ~f:J:p~~~>-,H!!:l .:!-.~ ~~~~-tif f'!J.r .gp_) Op~.r.~:tion ---- ,6iel~~-ai1 . . Pl~:.n:t A!nv.edir.avgedua.t-~~ --. --. Average of a-11 I J...6 'fUgheatPlan-t Low.est Plant 1111.J,.::;..,...._c._~--"'"".6,.,.-.-..-- ., ...-,, ___.. ......,._,,......_,,,., _,_,_,-,.-._.. ____ _ _ . - -- - - - ~.i.xing 4,6 - :FP~fl:g A-~ J .. :_l. Samples 5-9 2.2 - . fj.;}'.l_i.~h_:i,ng ~-- - - --...- --- _____________ - '.~JW:S .. --. ..... . - ~ } ----- -- - ---- ----- .!'VY -J.-!t --- ------- .,_.... 3.4 3.1 ~ _ ----------- .... """'--------------... __,.__ ... ,... .. - - - . -118- TABLE NO ;J ASBESTOS CONCENTRATIONS BY OPERATIONS CONSTRUCTION lVl.ATERIA:lli Arithmetic Means (Fibers~5m in length per oo) Operation Original Survey Resurvey Over-all Mixing 6.8 J.4 5.9 Forming 2.6 1.3 2.2 Finishing 4.8 0.9 3.4 Packing 2.6 0.2 1.9 Means 4.0 1.) J.2 TABLE NO. 10 ASBESTOS CONCENTRATIONS BY OPERATIONS CEI.filNT PIPE PLANTS Arithmetic Means. (Fibers>5m in length per cc) Operation Mixing Over-all Individual Plant Average I Second Highest Highest Plant Plar,t Second Lowest Plant Lowest :Plant I 4,9 3.5 4.2 1.6 Average of all Samples 3.4 Pipe Forming Pipe Finishing 2.0 1.4 0.5 1.1 1.9 2.9 3.2 o.a o.8 1.6 Coupling Fin:i.ahing 9.5 2.9 1.1 1.1 2.5 .Means 3.2 2.6 1.1 1.0 1.8 TABLE NO. 11 ASBE5TOS COi'lCEHTRAl'IONS B1 OPERATIONS CEMENT PIPE PLA.~TS Arithmetic Means (Fibers>5,-un in length per cc) Operation ltixing Pipe Forming Pipe Finishing Coupling Finishing Original Survey 4.4 2.0 1.7 3.3 Resurvey 2.2 l.6 1.4 l.7 Over-all 3-4 1.9 1.6 2.5 J,lecms 2.6 1.7 2.2 I l ~ABLE NO. l2 jj SAMPLING METHODS EVALUATION I I Left-Rig.lit Paired Samples Il Collected Simulta.~eously Side with Higher Concontrati;>r.1. Number Mean of of Dif~erences Samples Fibers>5m/cc Mean of Di:fferences Fibers:>5pm/cc Right Left ~ ~ 11 <O.l. 1.0 11 <O.l 1.1 . .... -1~0- TABLE NO. 13 SA:WtPLING METHODS EVALUATION Side by Side Paired Samples Collocted Simultaneously Position Ylith Higher Concentration Inside Outside Number of Samples 38 46 Range of Differences Fibers:>5:m/cc Low <0.1 ~ 1.5 ,0.1 4.9 raean of Differences Fibers>5m/cc o.4 o.6 ~rABLE NO. 14 SMU,LING ?r.ETHODS EVALUATION Side by Side Paired Samples Collected Simultar..eously Saraples with Mean Concentrations Less "h~1 l.. 5 FiberB>5pm in Lengt.h per cc I Position -.,iith Number Range of Mean of Higher of Differences Differences Coneentration Saraples Fibera>5m/cc Fibcrs:,-~.1:n/oc ' Inside 28 !figh 0.7 0.2 Outside 27 o.a 0.2 -'l'ABIE NO. 15 SAL!PLIHG l\1ETHODS EVJ1LUATlOH" Gide by Side Paired Samples Collected Simultaneously Samples with J\iean Concentrations Between 1. 5 and 2, 5 Fibers ~5m in Length per cc Pos'l.'"tion W::l. ti1 Higher Coricentration Inside Number TM of' Samples 5 Uange of Differences J11ibers ">5m/cc 1ifuy ~ <0.1 0.9 r~lean of Differences Fibers >5m/cc o.6 --O-ut-si-de----1-1 ---<-O.-l ---1.6-----0-.6--- -T-A..H..I.,I.~ l'TO......1..6 Side by Side Paired 5amples Collected Simultaneously s::!lnples w:i. th l.lean Concentrations Greater i;han 2. ~ Fibers ,-5.m in Length per cc !lean Position with -- }:uinoe"1~ of ,. Iileeno1~ HieJtcr of Differences Diffenmce:.; Coric ent_r_a_t_i_0_1_:1___S_a_.ni_p.._l_e_:._;;___F__i.b...e.._.:::~_,3-:,._.__.5~Lc..J'.Jl!..'?.!:? ;,- 58!.o/cc 1:.2! H_igh ln::'1-ide 6 0.1 1.5 0.1 ou~f,ide 7 0.1 4.9* 2.0 i<Sa.~iplc Concentration = 12.3 fibers ?>5m in Jr-mgth per cc ----.-----" ------------------- -122- FIGURE l -123FIGURE 2 -124- FIGURE 3 -122- ) j J FIGURE 1 -123FIGURE 2 -124- FIGURE 3