Document BRqNkYpmqg5jw3VEOpmZ6xyej

FILE NAME: Z< DATE: : DOC#:Z< DOCUMENT DESCRIPTION: /DZZE/K^,DZ ^ZZZ^ rn J~V' !\ gJ~,:A' Johns-ManviIle <:.J 0 i.OO q l InternaR Correspondence Paul Rotin, N. D. From! GQorgo W. wright, M. D. fiJ.~ & C Dale: JUly 2.3, 1975 l"E'1'ING Ol1Gl\NIZED BY DR. JOHN FIN1<LEJi OF NIOSn TO CONSIDER 1\ REPOR'r D'f DR. SELIKO::'::' AND HIS ASSOCIA'l'ES ON 'l'HEIR PPL!HINARY FINDI\~GS \'lITtl R~SPECT TO THE E~VIRON'Nl::;NT ;.1'1D THE HEALTH Ole \\!ORK~R$ EMPLOYED IN THE REPLliCEME1'1T OF BAAl<E LININGS. 'l'he H\(:leting was held in the afternoon of July 21 f :.:3 and those attending are indicated on the attached e)~ibi~. The agencld also a ttaoched. ' Dr. S0likoff opened the meeting by stating that their interest in the health of brake lining repair \vorker!:l arose bec~ll.tse of Cl report of several cuses of mesothelioma occurring in auto !'epair workers. Thoro \\las some confusion in my mind <it first as to whether this Vias solely frem the l~cw Yor]" art,., or a Inrger population. Tt. later oeveloped that there V-lcre 4, and possibly 5 cases that had come to his attcm:;i.on from workers in this throughout the United S!;;a\;!:-s. Hc estimated that at 1123St one million men might be 1;,hus emplo~ed and exposed to asbestos. He re- p.aated 50v(;'1:';:)1 times that in his judgement it vias not poss- ible at l:hi.s t:'loint in the develoomcnt at information to Uly whcth(~~' o}; f'.ot this !~epresented nn (lxcess :;.::'sk of. meso- !;b:l1oma iY..H~ Lh;.::: ~1e thought the observation me:::ited fur- t;lt.~r exploJ:\t.1.on. He also indicated that he had reviewed this problem '1ith appropriate people <:It the Ford ~10tor Corr:pany. I;) then asked ,Dr. I..ang!r to discL:.sS the nature of the mi'ltcrial found' in the dust that elcct.:ffiulatcs in brake : drums and \'I;)ich is by customary practice blown off the sur- face and into the s\lrr~unding air at: thf; time that worlt on the brake d~ums is being carried out. r.aflYY< opened his ,commel1ts by saying that otherz !ltid n''Jport:cd hid t 30 percent of the c!'>best(15 in brake lining ,-Lt;; C:911vcrb:,,! by hil]h heat eo Forst,eri l;c. He indicil tee. that "H;y\:l.i.f:1.(.')::': Ii prc;scn t preven ted the f otwi'd::i.on of 1;'0.).-!:t;':::l'i t.:;: finci he hClS round Forsterite in brake drum dust only in one instance. The only person I know of Vlho says that the asbestos ls converted to Forste:::itm iD Paul Gross. Others snv that it is converted to an amorDhous and essential!,y non-fibrous material. Dr. Langer' indicated that t:he residue \'1(15 not Pl:J sU.ne chrysotile fiber bllt ha did rot spa;:.;': about araorphou5 mo tttriaL La:; ~e c i.r. addi tian. ,saie ::110. t he ;1:1. ::Otirl, H. I), . ;~J t L') 1', '",-. P;J9C 'lt2 round pur!?, \.iQbcstos fibers. This too l!a~ been roport.ec hy otl:ieX'$ :tn quantities or Clnything f:rQJII l to :3 percent: cif the rns.Lul.wl dust. lIe then asked Dr. noh1 to discuss the fiber counts in the dust that Vias obtained. It ahmtl.d be indicntcd tha t brakc drum dust. w~s ohtained LrClw cars in taxi repair shops, municipa2. bus repair shop:, ,mo I belieVe fiome other similar l,1,'Orkplaces. D::. Hohl ir,dlcilted that studies of the H\iltorial blo'.~'n from. or obtainoci Lrom the brake drum conta;;.n~d fibers in large nuwbers and these were chrysotile. None of the tiere more t:han Cl. S microns long i:md the bulk v/ere under 0 . .3 microns. In diameter tl1CY varied from 250 to 500 angstroms. On the other hand', he reported thut the U::;er ~OUflt varied from 0.4 to 29.0 ioers per rnl at the VJ01::k(:lll: b::eathing ::.onc level \.jnere brakes '....ere being cl.eaned by air j(;t. It \<Iq;;; my t.mders-canding th;lt: these vlere :i1:;;;:;2':$ that \Vere countable under the OStIA regulations and therefore would be visible with the light ~icroscope and longer than 5 microns. It was not entirely clear to me ".,thether t:1ese optiCAlly recognizable fibets actually came :rom the brake drt:.lll dust or not. If thev did, I have a con:lict in reconciling his eLectron. micros~ope study .with his light microscope studies. Rohl also reported that in brushing tb2 brakc dn..uns rather than blowing Lf)crrl off the Cber count {OSI1A c:d.t';\J"ia} varied from 1 to 4 Del. ml, durina crinding the fibeJ.:' ,-ount varied betvJeen 1 and 5. Hos t important '.'i"?S the findIng that when men wore bevcllirg the brake linings by grinding the counts varied between 20 and 75 i;:;er5 per ml. !JurinU punching) riveting 'Or sWt::eping the fiber count '!aried betw(~("n 2 and 4. fibers per 1nl. It is my under:~t:anding tl!i":~: other kinds of. grinding of the brake lir:ing ooes on 1.n chc (ittin6 nrocess. Ed Fenner tells me that thQ~;' do S(llllv1t::hi'ng calied "arcing" and this involves direct grinding o[ the brake l;,ning and is Cl ve~y dusty lob. Robl ::\150 ShOW(,'cl d.l ta to indicnte t11a t tho:t() \-/:15 il VGt''.' l:.mid fiJll off in the level of count ilS one movGd awnv frorn~the source so that fiber co~nts 10 or 20 Eeet more aY/;:;}, ft'om , tIle sourcc of origin were lower than 1 fiber per rHl ilnd in general '_lOre in the neigh'borhood of 0 .2. On som0 question- ing it developed that these shops v/ero ,,,hat would be (:onf>icir.'rod to 110 very \'Jell run ?tnd thcrefOJ:<3 'l.;:ond to hav,~ lo.:er {?tl!~:..: <,!(.tml:~ !'h:lll Nould the average: 3wllller shop. In the pL:,,:u):es l h<i t Hero shown lmcl tJ:e COtnlOcn ts tha t wore? illude ~_:d?:::e v;as nu evidcr.cc to indiCi:n:e ,t:h<'lt ';.my SO!;t 0:: di.':.::t e~{l;i'1J:st (11- ,suppression systems were 1n use. I was sur- prised thi1L no direct rcferrence to C'xtclIsive data relative t:) brake drum Ju~l.:. bv r,Y'1ch, by Jacko t,:,t ill, by )\nderson c~ ",\It and by Jolln~l-Hc.mJille as v.ell as a ~~maJ..!. studv ef tile '.,;ark pldcc durj r~~; l1rakc trl8intC!1tlnCC by Uickish and~ l<n:'ghc WuS not In.':tdc by, either Langer or Rohl_