Document xdvpykZKzz3ME53k2aLJ8DazG

o;i; ietgy-of federal tnWN - fk/T owner fTiiW V 4 IK r<> 2 *v< &'. t'V;v:".-- vC ; TM,,^V'^^A->VINVLSCntOKIDr.^>AKT 5* MMlinAGILMCm IN* M W . f.ttS.CV] A.lfic .... ' JiirteeilJiVuttJcK accepted that somatic mutation i\ was the mo-a iinpu:jnt vv,tii respect in n>b ca<cg->iy. llte grejiesl si.iiistieallv sigmtieanl mxicase in tmth mm.11 and maim ihimimsmiic afvnormalilies iKCiined m aniiKiave ojvraiors eleancfs (17 men in M?'-' '* lS genetic`jcxaniinali>n l' one means of evaluating Iliis aallll)l SSmmaalllleerr min--ute-aas-eess imn oonnee ionr mrnooiiec notf tthhee ll>>|iK*s ! *$!$$!$;$' :/Ti aspect i^lhe monomers biological profile. alci ration wcie minninnlv seen wiih oilier |h Calx'- Ufltljjwornlly. studies of this type have given ci|tn- ,, goncs. Ihe aei.nl.ive o|n-taiors n subject In avci- ' vocal r<gfults, the i.ceppoorrtls'iiJdeennitiftyimngg a_ VC. -ass, o.vi.iicil ' ape v(` c'c1' *'! 4,|l,ppm f**< the decade iup to gj-l.'.T'Iv.1- %7.J"- / '' IIinI.cTr,e--IaIUwfemi~chlllrioiimli.lovs.ioinm'ial l iatnb`errrrialitnioinii- 11b.e1i1n.g Kb-aiflanced I'i.h1. (oMuil ihet' leevwelks h.andl fKrve-cnn iciluecvi ilno I1S5 npnpm by V-L \> '* ., /,L f hy tho$5).howing no eflcct. Several of the jwiwrive jnul,|*>,'.7 and in *> ppm hy I`z75 Hlmid samples lm Tgbf* sy-d:- ' S^br- .'. . . jj;; studjeslixf <4 limited value, involving* oniv-xniall ami **1':'?? 7* j llicrefo^p [*ossib|y non-representative groups of chromo>a|ia| .malvsis were taken lit nad-IV'4 I Jeig X. 'I Iness if ", 1 u;\ Mftl pi's. ;n, 557l com vvorkorlj|j)ncat man ft at. IMutatum Rft. 1975, 31. pared lymphocyte cultures limit leu workers exposed WW-: .vV^, c-1;-7.1f.*. , 163k follexample. examined lymphocyte euliures from to VC (bill sbowig no symptoms 01 VC diveasci wnh 11 VCroEpovcd workers. Kuferova ft til. iibiJ J079, those Irom 2<i maieheil tmexposeil control- Iherc 67. `>7Jdrdiii nine ami FuMcs-Cravioio ft til. 11.,meet were no sl.tii-iisallv sigmlicani ilitleicnees helween 1975,12|j59l Irom seven. Ihe two group- However a significant!) higher mei- The experiment of Leonard rt til (J. totuol emir. denee id abenaimns was lound in a group of ill `''"'ii -x Milt IQ??,'2. 1135k in which . lymphocyte eulimes v,vrelilpin. from Irn "control" individuals, seven men who liui) worked in ihe ljhoralory of a VC plant and workers sullenng from various symptoms of VC dis ease Ilian in the control group of id individuals, the. control incidence ol aK-irations o! 5 5",, including |Plr$?J' i'ft,- l who were subjected 10 onlv limned VC exposure and gaps and 2 1".. excluding gaps being raised 10 11-2 and j , ,i. '* workers in a VC pivlvnieri/alion plain, is open 10 5 2",, rc'|vx`clivelv I unhermme, a 16 6",. incidence of j the sanie crilicism While Ihese authors found lli.il ihc chromovim.il abviratums C ,V',, ex-lndiiig gapsl was f ineideiu.'e.of chromosomal aberrations, such as eliro- ineasuicd in a 4t-vi-old pjtieni. who had developed malid gaps and breaks and chromosome gaps,`were an angiosarcoma alter working in ihe I'VC industry : comparable in all groups, more severe abnormalities, for l.tyr. Ills es[sisurv to VC in the past lew years. such as dicentrics, fragments, translocations and tings, ICxtilimg Irom the cleaning of .lUt.'elavcs. wa> esli- were observed in ten of the 11 workers front the poly* in.ited at between 5' and 150 ppm for aKiut 2<l 50hr : meri/ation plant but in none of the controls. Levels of a month. Surprisingly, there is no -|veitie mention of VC 111 thc.plant were less than 111 ppm at the time of Die X-.'ay expenenee ot ihe workers \tillering from VC the study., but had been us high as 5(0 ppm a few disease and tlte-e individual' are likely lo have been years earlier. The authors cid not consider that these Mibiccicsf lx) X-ray exammaoons. As lor the cancer lindingCinerinmiated VC as the causative factor. xicnm. ihe authors noted that cancer chenmiherapy Many oft he workers in tin- polymerization plant had had been received *> months before the lymphocyte cvidently^been given several X-rays of the hands and exantinalion J:- feel (ipfiirdcr lo check oh possible aero-osteolysis|. A siinly of a large number of PVC workers of Dow V while j^con'rol group;had no'similar exposure to Chemical USA, conducted by lVciano t-r til IJ oecup. MfJ. I*r77. 19. 527i. suggests that VC exposures below 15 ppm do not induce chromov>ma! aberra tions. When lymphocyte suliures taken from a group They thought that d suitably representative sample . of 2IW xvoikeis who had worked in the plant for /S VC.workers would be dillicult io identify because of periods ranging from I U> 552 month- (average 4x 3 g*.;7 the practice in the industry of monitoring the work- miinths) were compared with those from a control force ;regularly by various scanning techniques. group of 2`fS pre-employ mem examinees, no signifi Nevertheless, this is a fairly recent development and cant cytogenetic diilerences were ob-erxed. The m at least one of the earlier studios, that of Purchase workers had been exposed 10 maximum levels of frV y-' V^iEi.i-a-'Sb'.t.V el til, in'1975 ILtincft 1*775, II, 410k the test and con* ~ trol groups were said to be comparable in their ex- , posureUo'rudiation. In that stud.y, .lym.phocyte cu.l- 15 2 ppm VC before I960, 11 4 ppm from I960 lo 1972 arid S ' ppm between 1973 and 1974 I he two groups were not comparab.l.e.in age. the controls, averaging ; lures from-56 workers exposed to VC and from 24 25-1 yr. being some 14\r younger than the VC lOnirols wtVe cxammcil and u was found that VC- workers and apparently no attempt wa- made to e.xposure wa- associated with an increased incidence slandatdizc with re-peel lo X-ray exposure. Again of chromosomal aberrations including major chromo- there was no indication -4 any VC-a-vsiated changes , somal abnormalities. m ihe chromosomes whe- ihe data were analysed On further analysis of.essentially the same data (the with respect to monome- exposure, the 2H9 workers ex posed'group had been increased to 57 men L Pur being divided lo: tins purp.vs.- mio three sub-groups, 't-\ ' ' o'1' " ' 5V,.; -. chase fl tll. {Mutation Re*. 1978, 57, 325) lound an .association between chromosomal aberration and ,, four factors; job category, length of employment, c.x- those exposed on average le less than I ppm. 1 5 ppm and above 5 ppm VC. respectively. "Further support for VC j, the real cause of the perience of expiisure to short-term excursion levels of chromosomal damage some- front Ham-teen t-r til. VC. and-smoking habits (as ascertained m an lnter- I.Wuhirriai Ties, 1978. 51. 2711. In 1974 this group i-ean chromosome breakage ultures front a group of 39 - ,w. m :vV<| -7-i^K I II ml 1 'SS*1 19. R&S 024088 g&ettwl r?M-. M'&y. .^. , ;. . ;, v-,^- -. ... Sw pvc/il mtCflSl - rj ('fiwnif, r*f*Knl_ Vt) Jh '-'-saift l hijilicf mil), Aioupof4)5 pfWvmcn/^in*n Hnfkcr* Ipnmji) f ^il)c-16,Ciyrtlfpl)* <r?1/'*,,! JIiiwvlci'. . \C group* ujs ioinp.iu.1 with ju 4?tMiut*hi*U tmi- J^hcn^JSpf Uic^prifin-iI^^ ut>rkcr i*v<rt.*'t:*.mmn.\J in*l ^ttiup tip *'f i libber jn*l |*V<"- W&PiSff'dufui utiicti Ihc) li.itl onl) | f,ihi:,ion Vtoiki*r> iwiiii \cr> or no V(` ex- ? ^^ I^C lfC^liCncv of chromosome pmufcj; ihcvc numhciv fctliVicM pump p*uiu.ipjtMHj J^brcakape/vij>0oun 10 v`onirtl lc\clv '.u^jicsim^ iJut, fates of 62 77',, Age-a.busies! l,v;jl deaths per t^> J^Mwblc chromosomal changcsii!ay tellecl only recent , pi egituns'ies m (lie pt II11JIV V( gi.-ap ss s-r s (. 'i Indore *-^ff:;jSndu*lrial CXfSericnec ' and ] 5 S jllel Vf S' s ;s 'MilS'. s.>n:p.if Csj mill vofre- 'V ba bcnijihown that the frequency ami type of spsiiiding (octal Unto ol *.u s ', m the controls age primp. lability has al>o been observed tJIanstccii ei ul, Inc, nr), foetal loss after Vf exposure "as in'., compares) mill biological,implications of. somatic imitations are 5":. ill (tie controls. whereas Itic foet.il loss uivs*s'of SKlPifSa*' ^c* .un)n^>',,r',.bs' 2 time-scale of, chromosomal... men oser 30 yr oM was comparable in ihe esposesl ','ch.mgc is an area .particularly in need of further, and coniiol primps <13 and 12 ., rcspcstiirlsi A VC- v'ddud>"0althi>ughxuch changes may escniually prove '- assoeijied increase vsas -tilt appars'iu silien ssomen ssnil more than one abortion sseiv excluded troni the analysis.The lack ol details of flic meihivl of data collection and the agc-adiusimeni procedure used in ^.breakage frequency in tin's group's original study was this study were queried by Paddle ul>i,l I/'(,. |. ]<r7*>i |^;i.Mibsequentl>Tound to base cancer|. it is re.issuring. Responding with details ot their mierstew prose-hues ^Hvhowever, thar.on the present evidence workers and with a further explanation ol the age-adm-tincm exposed lo-VC'al levels up to the Tl.V of 5 ppm method. Infante ct ,il hhi,l I'r'r.. I. livn tentatively probably do hot develop visible eytogenetie changes suggested that llteir Imduigs lor the und-i-hi ugc the cells of.tbc peripheral blood. group might base letlested the placing oi newly.lurex) While somatic mutation is, expressed in exposed personnel in categories involving the "orsi levels of y;: ...individuals, alterations of, the genetic niaien.il in the VC exposure. . germ cells will not become apparent until the next These lindmgs m particular raise sioubis over Ihe generation and perhaps even later. One possible con- possible genetic risks ->f Vf More studies ol tins iyie sequence of a chromosomal aberration in germ cells is are badly needed. Ii is to be hoped that tuture slushes the induction of dominant lethal imitations, which in will include dneet information Kith on maiernal age many would be observed tts early foetal loss, A study', at conception and on occupatisma espv'sure levels w?.;by Infante c; aKiUmcct 1976.1, 734> ol the pregnancy! T I './si;; 2"outcome among wives of workers exposed to VC sug-' . `v`l' gests that, lhc>monomcr may, possess just such ae-: [J Hopkins ItlllKA] m oh i - . .. vi---r. - m jJsl. `v . '^ i'