Document mpo0XVX2yOKDxEwzkLjoowBgB

Electromotive Phenomenon in Metal and Mineral Particulate Exposure*: Relevance to Exposure to Asbestos and Occurrence of Cancer * LEWIS J. OULLEY, PU.U.' US. Drparimrut >/ Health, t>luratia, and Wel/are, Public Health Sriviif, Health Snvitn aud Mental Itrullh Admunitltalim, Sahtmal luthlulr /or Occupational Safety ami Health, I0H Urvaduay. Cincinnati, Ohia 4f2ul ST0095270 Espawm lo wltUk pwliriihin) ImlitMiwtUy ami iti alloys aloiiK with mineral partkalatm may riw rac to an rtnlmiMlic plnuaiinrimn wtsrrrtu laijtla level* ol biologically active rainma an produced at localised tissue rites Tbe relative position at ihe involved metal* In Use electromotive mica alooa witb Uw naiorc of Use associated mclaia anal odicr minerala will influence Uac uaUuc ami concculraiiou at the cations Tbi* phetteanmnn luay accottnl (or otherwise uneapiaiuctl exacerbations at 'loeairs acutillralian reactloua, carcioogenicity, latency periods and ads reapmnet Tbe potential Mir of Ihia pitenontcnoti in cxpaauit lo metak in mbcatua ia rteojpurrU, and supporting data are presented. Introduceion ample, the interaction of metal manganese LITTLE .VITENTION ha* been given on a nickel compound may be depicted: to the biologic eiTecu of exposure* to Ni++ + Mu* -- Ni + Mn+ + meui paniculate* other titan to their direct acute and chronic toxicity. Although in- T)ie tame phenomenon may relate to the creased attention it being given to the interaction of two dissimilar metals. The dTccts of metal cations on proteins and en degree of reactivity will depend on thedif zymes in the study of mcdianism* of bio ferences in the jsotcntials of the metals, sur logic rcsjxjnse and injury, these seldom face areas of the |>articulalcs, nature of the relate to the potential influence of metal solutes, etc. The phenomenon will continue particulates on the biologic response to until the more active metals have dissolved. multiple minerals and metals through con Generally, die greater the difference in elec current or separate and intermittent ex- trode |>oirniial between the two metals, the jsurcs. more active is the displacement reaction. The electromotive projicnics of metals Table 1 lists a tumilrcr of metals, iu descend are well established. Metals going into solu ing order, in the electrochemical (electro tion undergo reaction wherein metal cations motive) series, their reactions, and their arc formed and electrons arc released. If an standard reduction values. Although the electrolyte of a metal lower in the electro metals lower in the electromotive scries ami motive series is present, the released elec their compounds will have a tendency to go trons will migrate to the metal cations of into solution and ionize, the concent ration this electrolyte, causing their dtangc to an of cations front litis source will be decreased elemental and un ionized metal. At an ex by the reaction on them of electrons from the more active metals continuing to go into * Prrtrttic4 n AihmU Mcrttiw, AnrrkM *!>* AmmUmtm, ltotrau* MkSkgM* May 1979, solution. The immediate effect will be in- 6S ST009527I 654 October, 1971 Tabu I Electrochemical Stria* (Stamlard Rc-dueium Potentials) HraiiMC taml1*1 (yti M" -C-SrSiMi He" -1-Sr 5* Sc M** + V At Ti" -t-SsS'l i V t 3rt V \\n*+ 4. > 9 Urn /n* + 4!if* -- >srO Jr *ir?f If *!* 4 2r?-<4l <n * ri \t** ^ s. Ml'* 2V ^ on Ml- * 4* Ml i u<* 4> ;v 4 ( h --i.tTma -1,700 -1.** -1.2 -l.api -,-<if*i -iMDStt --a w -41.21 -0.11A4 'Mt.M.'O Vjlun iiLn from M<WM of Ciwlilw smf I'hyiin. Flu fd-. Thr Cacoskal HySScr Cigwr. Oswlsiyt Ohio (IV.OTIl. tion of the several dissolved metals and minerals ai well as the concentration of metal cations at any one period in time. A schema depicting the influence of the electromotive phenomenon on the interac tions of metals ami minerals and their bio chemical activity is presented in Figure I. A hypothesis is tlcvelojjcd with sup|jorting data relating the biological activity associ ated witlt asbestos liber* to the electromo tive interaction of the metals and minerals present. Relevant e of this phenomenon to other exposures to metals and minerals is discussed. creased levels of cations of the higher met* als. The lesser reactive metals will subse quently go into solution ami form cations as the electromotive influence of higher metals decreases. The concentration of cat ions during any phase of the interaction will depend on the dynamics of the system including the electrode potentials of s|x.tiftc metals involved and of the minerals in the electrolyte. This electromotive phenomenon may thus effect a change in the concentra Metals Associated with Asbestos Fibers Several investigations have shown that biologically active metals and minerals are associated with asbestos fibers. The minerals and metals arc derived both from the min eralogy in the formation of the filers and from the abrasive action of the fibers on the alloy metals of the equipment in w-hiclt they are processed.'-' These arc primarily the metals ami compounds of nickel, chromium. Mu, Xu, Cr, Co. Ft, Ni Mn, /n, Cr, Co, Fe, Ni /it. Cr. Fe. Co. Ni Oxklalkxi reaction: valence change Incu-aieil metal lolubilily laicaliml calioii linuc flooding rile* i Imtcascsl concentration ol mvlal cation* Altered wi um protein Alimrl cell enzymes Stmi in wium and cell metal lulaucc Keducatioii reaction; valence change Increased mineral solubility Temporary reduction of metal cation* lower in rleclromotite SCI IS Shill of taruli in minerals from combined to elemental stale Concentration of elemental metals lower in the rivet tumot i* e series on associated particulate* Subsequent tissue- flooding effect of cations u( metals suppressed from soIuikhi liy those higher in electishimiIise series Souiics: Metal, nlkiy particu late* in IkxI* tuauci 11iint iim!tisiriaI. cowituuiiiy ami pviKinal lialiit actisitic*; metals tii);)icT ill liie ekclioitiulise ncius leading on metal tatiom lower iii thr seiies .Sources; Mineral particulate* in body tissues from en vironmental exposures; iimit-ruls in stabilized loim in body tissues; metals present in serum amt cell clcctrolWc* Sources: Transfuimaiion of metals in minerals and elect ml*les fium comliimi! to ekinetital state Fill sc ]. .Sclicfiia: Kh-slroiiioiivc plicnoinenoii anil bioilieitiieal activity o( metals ami miiieiats. jlniriiiun huluxlHut Hygprne AwiHiution Joiinml ST0095272 manganese, and iron, though a number o( minerals go into solution in du- serum as others such as vanadium, zinc, cobalt, and electrolytes and into ionic cquililuium. In oi|i|kt are picscut in smaller and leu uni- the absence of significant amounts of ele form amotmts. mental metals higher in the electromoiivc The biologic rule o( these metals anti series, stub as manganese, the minerals con minerals in uslicslin exjmsure is confused, taining nitkel, chromium. cobalt, etc., will since auy dose-response l';u tor extrapolated go into Milutiutt and into an ionic equilib from |>3st rvsearelt is obscure. The amounts rium between the mineral molecules and and solubility in serum of these metals and their caiUm-auiou components. The con- their compounds vary widely from one type ccmration of such metal cations will dc- of asbestos to another and within ilte same liettil on the nature and amount of die type of asbestos.Yet, it is known that minerals present, their surface area, solubil some metals**1* associated with asbestos ity, etc. The metal cations will be comjieti- have carcinogenic properties, and evi- livc, dt-|iciu!ing on their relative reactivity dence'11* indicates a doc-rcs]>onsc relation and their affinity for biomolccular matctials for some types of asbestos to both nbrusis present. and rarcinogenit ity; that is, a lowering of The presence of reactive metals in the mi worker exposure to the asbestos results in a lieu of the asbestos fibers, liowcsx-r, will liavc corresponding lowering of associated asbet- a profound influence on the concentration tosis and cancer. Most of the past research of cations from the dissolved minerals and on aslnctos, however, lias not licen designed other metals lower in the elect romoiivc to relate to the associated biologically active series that may be associated with the as metals and minerals present, and no ratio bestos. These metals include, in descending nale or model lias been presented upon order of activity, manganese, chromium, which to design such research so that tire iron, and nickel, though other metals such data would relate to worker exposure. The as zinc and vanadium, which are also con hypothesis presented could account for the tained in processing alloys, may also be in differing biological responses observed in volved. The metals from the alloy partic past epidemiologic and animal research on ulates or other sources which are associated asbestos exposure. widt the fibers set up a myriad of miniature galvanic electrolytic cells. Through die en Hypothesis suing oxidation action, the metals from the. alloy particulates dissolve, but the cations The biologic response of asbestos is gov of the lesser active metals are precipitated . erned appreciably by die metal and mineral on the more active metal particulate sur contaminants associated with die inhaled faces and thus arc prevented from reacting filler im'Tcacting in body fluids at tissue with die biomolccular materials present. sites. The metals and minerals associated The lesser reactive metal cations will con with the fibers set up an electromotive reac tinue to l>c converted to the cleim ni.il met tion whereby cations of biologically active als and precipitated and concentrated on metals are formed and become available to the fibers and associated particulates until react widt cell enzymes and scrum proteins. die intlucncc of die more reactive metals A dircc-component system is involved: (1) has ceased. Thus the metals manganese, asbestos fibers, (2) minerals associated with zinc, chromium, iron, cobalt, and nickel, in the fillers during dteir formation, and (S) descending order, on going into solution metallic alloys associated with die fibers and through electron transfer, will alfoct a during their formation or arising from die change in die cations derived front the met abrasive action of the asbestos on the alloy als lower in flic series and their minerals, processing equipment. transforming them into an elemental state In die lungs or other tissue sites to which with subdued solubility. These lesser rcac- the fiber may translocate, die associated live metals remaining at die tissue sites will 656 Oclo'trT, 1971 ST0095273 subsequently go into solution, and the period it involved. It is known that past cation* will exist at higher concentration dust cxjroture* have been heavy and that level* than when they were pretent and in equipment replacement in the industiy was ionic equilibrium as mineral electrolytes. more frequent than at the present time. The galvanic action will govern tlte solubil Present data oil exposure to metals and ity of the metal* and minerals, increase the minerals in the asbestos industry are impor concentration of metal rations near the tant, though, since they will give some liber, and ci up a localized Hooding effect paramelets on which to base past exposures. on a serial basis. This phenomenon will ac McDonald cl at.'* in a study of clirssotile cordingly increase appreciably lioth the resi mine and mill workers in <_>ucl>cc n-ported dence time and the relative biulogic re a threefold diUeietne in tespiratory cancer sponse of inetafs such as nickel. Asbestos between workers maximally ami minimally fiber will behave dilferently biologically cx]xjsed. VigUani'-'" in a study ol workers according to the milieu of metals ami min milling and milling clirssotile in Italy re- erals associated with the fibers. Mixtures of liorlcd in preliminary data (hat $M"l of the dillcTent iy|>cs of usltcslos may have biologi workers wlio died had cancer of the lung. cal responses quite different from those of Gilson2' in an investigation of chrysolite any of the individual lyjscw alone. Since the mine and mill workers in Cyprus, wltere the asbestos fiber may translocate and become work force was stable and had worked for fixed in a tissue, the potential lor the cat many years in the mine and in which the ions to build up prolonged and high local- only exposure to asbestos was chrysotile, re- iced concentrations and to react with ]>orted that available medical evidence indi enzymes and proteins is greatly enhanced. cated tltat the incidence of respiratory- The following data arc presented to sup disease of any type related to cxjwsure to port the above hypothesis. asliestos was likely to lie low or very low. In each of tlte altove studies, much of the Del* Supporting Hypofhotis exposure of the workers to chrysotile in the past twenty years ami earlier had Isecu Epidemiologic data on tlte prevalence of iteavy to massive, though definitive quanti cancer in workers exposed to specific anti tative data during this |icri<xl were not predominantly single type* of aslrcstos in available. In a rccau study of trace metal which some tnctal exposure parameters arc cx|>osiircs of workers mining and milling known relate predominantly to the milling asbestos ill Cuclx-t, Giblss / i/.*J showed and milling of chrysotile in Canada, Italy, average mill airliomc this! concentrations and Cyprus; to die chrysotile textile indus for total nickel ranging from 15.7 to -II.f> try in England, Italy, ami the United .States; pg/in', total chromium ranging from 3.H to and to the mining and milling of crocidnlitc 53.1 |tg/nv\ total colsalt ranging from 1.6 to in the Transvaal and North Ca|>c regions of 2.5|tg/ni*, and total manganese ranging South Africa. In the studies from which the from 1.7 to 23.7 mg/m'. Exjsosurc* prior to data are drawn, the author had the priv ilege of securing samples of the related as bestos for determining ^nctal analyses on the respirable fraction not only of the 1!'50 were estimated at four to ten time* as high as those rcjxmed. Although no infor mation could Ik- obtained on the relative source of these metals--that is. minerals inilleil aslx'stos but also of the unojwned present in the asliestos versus abrasion of ft Ixt, material from the adjacent zones of the alloy metals in processing--observations contact, and country rock. A major problem as well as management rx|x.*ncmc in the in evaluating past ex]osures Is the lack of replacement of worn processing parts indi definitive data on the magnitude of these cated that there was only minimal to mod exjeosures and the comjcosiliou of the alloy erate abrasion of equipment and that most in the processing equipment in the HKMVs of the metals apparently come trom the and earlier, as a 25- to 30-ycar latency minerals associated with the asbestos. ST0095ZT* .tuii-ii.au !ni!n\ti ini //vgrcm- /I\uiriiiliou Journal G57 In contrast i<i iIn- lower rate of iancer of 2Xfi mg llie In11in woikcrs milling .'mil milling passing hi. In contrast, the- fiat I ion ..a a I9-ii mesh sieve ol three 11 ita Mil i le. Dull-1 \lmweil 11till in a ;.;mmi]i i if samples ol milk'd crncidnlite from the i 1u\ senile textile workers ill Kngland, deaths Northern (kijK- atra averaged, per gram of limn i.inier ol (lie lime were nlioul ten fdier. 270 jig of nickel, 155 ug ol chiomiuin, times tin1 iiuhiIkt e\|ie(leil. Vi"Ii.mi-" re- K5 jcg of cobalt, 1X51 ug ol inatiganc-se, and imiteil tien iif the dentil', in 223 male "tifi mg of iron. The most significant differ- te\ti!e ;ind ftictiutt product woikcrs com- i-nc c* was the ",-foItl inc rease of manganese in | iis.iteil for .istK'Mosjs in Italy wete ranted the Northern (lape over the Transvaal l.y cancer of the lung, a hvefohl increase cI'ocidciliie.sJl was cihsc'ived that the rock over those Winking in asliestos mining. surrounding the Northern ('.ape filter is As in cluysotile mining, exposures of workers to chrysolite in the asliestos textile inilnstrv ilnrilij; the past twenty ye.its mill earlier were also generally heavy to massive. much harder than ilii rock surrounding I lie Tiansvaal fiber and recpiiies harsher neaiinriil in luring the filler. I hat the inc reased manganese content is from the Northern In a study hy (Irallcy rt a!.% in a rhrysodlc <!ape ore passing through die high-speed textile I'lniit where operations simulated hammer mill is further attested in data th.ise of the 1930's. the airlmme dust con from a s]crial lest which showed a 7-folil in centration of nickel was higher hy 3-fold, crease of manganese in the fine dust of the chromium hy 3-fold, and manganese by 2.3- crcicicloliie leaving the' hammer mill over fold over that in the filler entering the the nnojieiicel rrocidolite and country rock carder. (.'orrcsjionding increases were ob entering the hammer mill. The need for re served at filler jirejmradon and spinning placing tiie hammers in the mills at the end o[ieratioiis, with lesser increases at twisting of the sliilt rellc't is the abrasive effects of the and weaving o|icrafions. The increased ore on the mills. The electromotive influ metal content arose from the abrasive action ence of the excess elemental manganese in of the .isIkmos on the alloy processing the respirable dust of the North Cape cm- equipment. cidolite over dial in the respirable dust of Data on rite occurrence of mesotheliomas die T iansvaal ctocidolite could account for in aslKMos mine workers are most interest the unusual biologic artivitv of the former. ing. Webster14 rqiortcd that, of 179 cases of laboratory riwrmrb ilula of die past have mesothelioma rcrogi/'rd up to the end of generally not related the metal content of 1WS. 51 uerc from miners working in cm- the asliestos to biologic rcsjion.se. Some data, cidoiite mines in the Northern (Tape area, 3 however, are available cm this nsjiect. Smith were from workers is amosite mines, 21 were rl a!.* introduced ecjual doses bv weight of from unikers in asliestos and manganese soft chrysolite, harsh chrysenile, and amosite mines, and 2 were front workers in manga intraplcur.dly and intratrachcallv into ham nese mines only. None were from workers in sters in testing the relatis-c carcinogenicity the rrocidolite mines in the Transvaal area, of these agents. In groups of 15 hamsters The author suggested that anotlirr mineral given single intrajileural injections of 25 mg such as manganese or iron may play a part of each tyjic of asliestos. pleural mesotheli in the carcinogenic agc-nt(s) involved. Sam omas developed in 3 receiving die amosite, ples of the adjoining country rock, tutojiencd fdier, and milled rrocidolite fillers from IhiiIi the Northern Cajic and Trans vaal areas were analyzed for metals. The 2 receiving the harsh rhrvsciiilr. and none receiving Ihc soft chry.sotilc. No tumors had apjicarctl in the hamsters rereiving the in tratracheal injections of the three iy|ie\ of fraction passing through a 10-p mesh .sieve of three samples of milled rrocidolite from the `1 ransvaal arcr. averaged, per gram of fiber, 342 |jg of nickel, 99 fig of chromium, SI jig of cobalt, G33pg of manganese, and asliestos. An analysis of the soft and harsh ruiysoiilc showed diat in the cutting and romminmion of the fillers using the rotat ing knives of a blender, the fraction passing through a 10-p mesh sieve of the harsh duy- v ST0095275 053 October, 1971 wile has a several-fold increase of nickel, time of tire nickel and chromium at the chromium, manganese, and iron over that local tissue site with respect to the different of die soft liter: soft chrysolite--Upg/gm forms of oslrestos. This is reflected in the in of nickel, 157 ug/gm of chromium, and 230 duction periods observed. ug/gm of manganese; harsh chrysoiile--230 Serum solubility tliun clearly reflect the pg/gm of nickel. Ill tiR/gm of thrnniiiim, electromotive inllticncc of one metal on the ami INIpg/gin of manganese. Although (he solubility in serum of another metal or min amosiie was not analysed, this phenomenon eral. Itt the following table, limited rlata are would be expected to occur, since it is a presented to show the effects on solubility of harsh filler rnnt|>arcd to clnysotilc. designated amounts of paniculate materials (iross rt al.,it in ex|>osing rats hy inhala that were introduced into 15 ml of bovine 1 tion to asbestos dust, rqioricd that 35% of .serum and held for 31 days. l the 72 rats surviving Mi months or more of the dust exposure develojietl lung cancer. The chrysolite in tlie exjHistirc chandler had l>een coinminmcd to the desired si/e hy re nding through a hammer mill. An analysis of the comminuted asltcsios showed that the original fillers had picked tip an increase of f<2% nickel, H5% cohalt, anti 31% chro mium from the hammer mill, Wagner ft a!introduced 20 mg of atnosite, cltrysotilc. and crocidolitc intraplctrrallv into rats to contrast the percent age of rats developing mesotheliomas. Of DO rats in each group. 317,', of those inoculated with amosiie, 01% inoculated with chrv*otilc. and 0H% inoculated with crocidolitc develojied ntCMiiliclitimns. The induction Material Mtnuwv metal NUkrl metal VfiWtifieie meta! \Mke| metal AfttmlnHiq metal Marutaiirv metal metal (ihrmliif fOrprin) Mjneanrtr tmrah t Itrrmitsim (imall Vukrl 'total* Mjoonete ftntah f 'Knmiiim \isk.l fnoN tfjne.inrv* Mkmtrrama of Fariioifefe Material Imrtaliiffd int*i Serum a#Ki tWt 1 <M*f* i;w "no 1 t*i l?KI '2 f,2 1 tit o ; r?i Perreot of Part lr iflate Material (rt Vrum lk.O f>7.0 HO 0 \r vi o *IA JWO 2.* 32 k K> f jieriotl--tliat is, the time from iutMiilatiou to development of mesotheliomas--was Nm Multpil, di-st-dependent. The ituhutiott jtetiod was shortest for the chrysolite, intermediate for the crocidolitc, and longest lor the atnosite. An analuis of the samples shosved the 21mg doses to contain the following: chrvsot'h'--33.3 ug of nickel. 21.N ug of chromium, In another test 5 mg of nickel chloride in solution and 5 mg of meta! manganese were added to 15 ml of bovine scrum. After hold ing for 4 'lays, IS tig of nickel wn< recovered on the particulate manganese. 1.1 ug of roliah, S.5 ug of manganese: cm- cidolite--n.:l ug of nickel. Of, ,fg of chtoiniimi. 11..' ug of niatiganese; amosife--1,1 Discussion tig of niikfl. 1.1 ug of i Imnuium, S'1.2 ug of uianganese. \o infniuiatluii was availahlc on the pro(ise forms in which these metals existed in the almvc different samples ,,f asltcsios. The higlier levels of elctnenia] marigaii' se in the crocidolite and amosite resulting from abra sion dining processing would, though, have an o.'f-st ring influence on the higher met d conv-nt of the chrssotile in relation to toe In the past ' has licen generally assumed that the aslicsfos filter per sc was the causa tive agent for both the asbestosis am! the cancer ubset ved in asljesfos workers. It was not until dilleremes were noted in the prev alent e ,,,,](ci among workers in dilleicnt ashestos industries with ptolongid ;.iul heavy expusutes u> rhe same tvpe ol ashesins that other agents appeared to lie insohed and that the asbestos filter was metal ratlin rt'iuctiti.itiutis and ivsidem.v iinjificatcd as a jxissjble (artier of these i .Imi'iiifin iihliKlnnt / / V; icuc .'limct/iC/mi loimiitl <>:/> STGQ95276 .i ;<ms |> v.niims tissue sill's. This is Imii iu1 tnriiis, in the respiiafde lilieis and ariotnfill lis i'll1 ifl.oiM'h loss' lull* ol brmu ho- panying pai lirulates obsimisly is nut a good nil i.iiiiit obwivcil .unmig ivmkris 11 si 11- index nl iIris iclaiimiship. Il is ipiiie evi in; .iml milliil;;. ( Iiissniilc in Canada. Il.ily. dent, also, tiiat the rpialitative and ipiauti- .uni (.spins in cnuti isi m the scsTral-fuld talive milieu of the aslteslos fillers to width im iiM>i' in Iniuu lingruii i .ini it among the workers svete ex|xsi'd varied gieaiiv ll ISsilllli' textile Ssnlklls ill l'.Uot:ll<l. Italy, auuiding to industry, l\|ie o( process, and .iml i!ii' I'niicd Sums liming |>i foriit ol filler and that these asbestos expo- juiniils of i-mili>\nu-i11 in llii' industry sines were often ipiite difTnent from tlie sslnn t'\|Misut'cs In .istirslns ill limit groujis asla'sius speiially jnejiarcd and Used iu lab- ssrir siiy heavy. Another example is Ilu; or.iti^ v ri st'ari It. i\]K'iii'iiu' in South Afina in the mining The (umi'jil of the role of metals through .iim( millin'; of urn iilnliu- where nil 1111- their electromotive projK'riies iu altering tiu'sntUcliniiui fK'nirs in ilie asbestos workers anil governing the solubility of minerals in llu- Xnrlli t I:.j>c :iri';i, in imilrast in none and metals and their cation i mu durations in tin- Transvaal area. at a given tissue site gives a raiimi.de front ft Although several ir|x>tts showed ilisiinrt which to interpret the meaning of their dilferenies in die various unal melals asset- preseme as well as the design of lalmratory 1 Mil'll Svilll .IslK'SWIS IS |K'S--tllill is, l Ill'S so- ami epidemiologic icsrarrii. Ksjieiially iui- i ill', i ins idolitc, aniosiii', ,<inl niuhophylliic |Hiiiatit in 111is ioiue]i| is the property if --il wasn't unlit ihe ri|iiisa'.eni tcspiial/c- melals higher in ihe elritrmuoiive si-ties io si/i- fractious were anals/cil lli.il those convcrl the metal rmtstiiuents, lower in the itilfereniTs were found in In' move pro- seties, of the minetals present to their ele noiimi'd than nas at iirst realized. Il lie- mental form anil thus imiieiuratc liiciu at a i .mic evident iliai these metals anil minerals Imal site. Thus, deluding on the metals were concentrated in the respiiahle frailinn ami minerals present, tho-c lower iu the ami appeared to relate tn the harshness ss'iih eleittummive seties will serially l>c rumen- ssliicli ilie fibers were ireated in llieir o]M'ii- trated with prolonged residency' lime at lo ing ami processing. The greater amount of calized tissue sites. The cations from the less certain metals in the aiihornc asheslns dust reactive metals stihsefjucnily going into in textile ojx'ratiuns in contrast to the solution will exist at a greater mitt filtra aslicstos being processed is cited. Also, there tion tlian when they were present and in is a great increase in certain metals in the ionic cijiiilibritim as mineral electrolyte's. In It;C'l milling of North C.ijtc crocidnlite svhere the ore is much harder and is treated more severely in hammer mills than iu the softer addition to a carcinogenic res|>mise this phenomenon mav telate to altered fihrogenic resjuMisf, tissue .sriisiii/aiion, forma Transvaal rrocidolitc. tion of feinigmotis Itodics. and ulliei bio The meaning of the present c of ihesc logic rranioni. metals and minerals was confusing hosvever, It is rational to conclude that, if the Itcrause most of the animal research data melals higher in the electromotive series do did not shosv a good correlation lietsveen influence the concentration of metals loss'cr the amount of ranrer olrserveil and the total in the scries and their residency time at amount of these metals involved either tissue sites and if the latter is of significance \ .Is individually or loinbincd. This svas not in the biologic response. it follows that the surprising, since the s|X'rific nature of the judicious selection of ntctals of less biologic associated minerals, the alloys in the cipiiji- activity and higher iu the electromoiivc incut, the respirulde particle sizes of the series may have application ill lltr lomrol metals and minerals, and their solubility of the eirccts of this phenomenon. svere essentially unknown. A single expo The hyjiothcsis on the electromotive in A'.l-, sure parameter expressed as total metals, fluence of metals on each other and on con cs<? including both elemental and combined currently present minerals has application fa ,11 Orlobrr, /V"/ ST0095277 lo <-limiir.it, minpr.il, nml oilier mei.il expo- Summary sutc situations even thoirjli fiber* sire not one of tlic parameters of exposure. Deposi tion in tlie lungs of elemental metal* anil alloys along with niinera's could set up an chitroumtivc reaction wherein high levels of hi.ilogirallv reactive selective metal ca tions eoitli! result with increased residency time at local tissue sites. Owing to dillerctires in removal and ini,''ration mecha nisms, these sites of reaction may differ from that when filters are involved. It should Ik- recognized, however, that other factors in addition lo the electromo tive phenomenon are undoubtedly involved in the interactions of metals and minerals that relate to their physical and chemical Itchavior in .serum and subsequent biologi cal rcsjKittsc. As an example, small amounts of metallic aluminum have Itcen shown to inhibit the solubility of silica through the conversion of the metal aluminum into hy drated aluminum oxide anil the subsequent coating of the quartz particle with an imjtcnnoablc gelatinous hydrated oxide of aluminum. The same may he true in in stances of other metals such as manganese, though the presence of metal manganese in the respirable dust did not show any pro tection against the mesotheliomas occurring in the workers mining anil milling rrocidolite in the North (iipo area of Sennit Africa, (loprcripitation oT re latively insoluble com pounds may likewise l>c involved in the behavior of mclals ami minerals in serum. A hypotheii* f* presented with support ing data which relates tlie carcinogenicity of asltestos to flic electromotive interactions of the alloy metals from the abrasive action of the filters on processing equipment and other metals and minerals already piesenr. The filter serves as a frarts|Ktrt mechanism for the translocation of the metals and min erals, The sultscquent electromotive- inter actions of these metals and minerals result itt carcinogenic metals lower in the series Iteing concentrated, along with tlu-ir resi dency time Iteing appreciably increased at IcK.-tli/cd tissue sites. The electromotive intcrac lions of metals and mineral* on biologic systems bus appli cation in other situations where exposures to metals and minerals exist though filters are not one of the explore parameters. In addition to carcinogenic response, the phe nomenon may relate to altered filtrogenic response and to tissue sensitization reaction and may account for otherwise unexplained exacerbations of diseases, latency periods, and unusual biological rcs|Ktttses. A Itelter understanding of the electromo tive phenomenon as it relates to cxjtosurcs and biologic resjxmsci to metals am! min erals is needed in the development of ra tional stanilaicls anil for the rontiol of cx|Ktsnres to these materials in the strategic metals and minerals industries and the con sumer use of iheir products. Thus the interactions of metals and min Research is currently underway further erals and their subsequent biologic response defining the elei ttomotive intcrac turns of in serum arc undoubtedly more complex metals and minerals in relation to their than can lie accounted for in a single phe carcinogenicity.* nomenon such as their electiomotive iiiiei- iic lions, though the l.titet Is helleved lo lie a very inqtoriant aspect. Acknowledgment* The in vitra test in which nickel in solu I acknowledge with appreciation the as tion in Ixivine sirinu was pieiipiiated oil sistance given by Messrs. Robert G. Kce particulate metal manganese confirmed the ll.i tit- and John V. Crablc in planning ami electromotive relation of manganese and executing ihc analytical as|>cets of this pro- nickel in sernm. Additional invesiigations need to he done, however, to establish the electromotive relation of metals in nino in serum along with their lespee live potential values. '(ittthiti I IlS-C-OtO^* r Mfr.r, tj!Mt 1m, \OirMm ( f*r'irw*r jiatmt*l*itMrni*.*ns!. ir\, K UtWari lr|4rtmrnf t*f N|tiam'w'rxrrmatannr?, Mrtf'he. htiirtsiM of Ittnnitium, S fwv*l f \frt*i<tff, M.tM'i*1.. i f. * W krrnAn n no* .nw* .ili'i* utth ('.micr V-tt.ihi, N*mhUr!l, Mulnc-tn, ST0095278 .1 i htilu\t\ i,tl Itx^n'ltr ,'l\\<h lotion Jl/Ullwt r.r.t |r< i .uni i>> Mrs. l'.itiiiia M. Quiim and Mr. Riih.ud I.. Ku(tcl in conducting the .iii.i 1 \ tit .i 1 work. aiui al-.ii ilic srrviics o( Mi., (aula II. Moore in (he preparation of liie samples. References l. 1'sm, Y. S.* ,4 Trslt*>k of >!!. \.t Y*l Jt*lm WiWv V ?. t'-ii<iv. 11 ` t %im Ihn'in. !*(* fin, Mihcic, r(>,,,.* i /(fj.-g.'i*'* , h .iiMalnt limn llx l.nm.iii lit k^lfOi 1 I Ih'iumaI JnMtf tUi., .TJ I Kill \\t., N. w \.tl <JN,U. 3. Vm ki i, I . It : 1 lx Otnuirmr nf Natitp NLlrllmn `m,iiiii!inm-i SPii|m*timiini'x, J Hn<*m. k.U<lH4^il.x'iVW A.' VT7 tm(1lrIVtlnl).n n( 4. I1\mm.ion. 1 V, 4iwl I'. I. C. Hot: Minim of <\ir. ln.m.c. tiAiPM.).k .i4*l.i.J\.IxVvmi.s t l*i%l.v*atMl lltcir NxmtaI Oil*. 5. ( iviuv, l. \,, R. 0*. Krrxw, ami l. R. tvsew: lvintf Jo Mrult in ilx MjmilaslMtc of A'Iipm** li'MiIr Timlmii. ,f"irr. imi. Uyc. A***+. /, 2*: 452 i'*.;. & IlniwM, \ . A. Moii.iv, ami F. J. 4immiiv ttrtfr- *'*iuJ**n >f < t.ohnfl, |t*n. .N'ifkrl and N-.MiWittm rn the lntr>naU,H4l I'nion nramW (.'anr* U7Ct. ,4*.hr\/,n krirtmr* S*mftlr% Hi .4iN- IkUN l mlauMlxd Rrjxtr A F KKK Vi 10 7. Uiumm, V. A. ami Y. ). n.iiK'O *! Imn, (.Ui*niiim. 0*lali. NmLvI, amt Van* <lrim m ilir*i fv Vnmnii Artitateon Analym. I"" tnl. five. (mx. J. )2: S (Mar hi*l>, A. VMHH. 'v 1.. L. Mmur, R. I m\iii, ami h. Iluarar: vIif.m\1*(*2:r Cu;iiinMcrnniti of Atlxvm. dun. <V-V. Arid. 4. MoiKouruo. F.: A Rnior of fit <Vriifa. lion.,I HraliU .Vjxiu. J. Ofrvf*. Mrti. 9 127 fl!*i7. Jd. hoi.i., R : Od-Mpaiinnat 2 tin* Onrrr: A Rnirw. fln'i. J. tn4. Afprf. /a. 1M| f|*Vn. II. Rn*, Y. J. C.. ami M. C l^srura: Naimal. M^allir ami Other Subwamrt, a* Carrinorpm. Mnlianivn* of I arrim4:pnp*; CHrmirjJ. rh>*ical and Vital. An(, M*d. /itd7. 2*t: |2<i I?. $h\nunv, F. H*., Jtu: Inhihitkm of ImltMtioM of llrjn*iMirne 1hiliMs\Ux l*v Niiirl f.arloivl. Ctntff /M. .7; *i'i fl'a*7|. IJ. sisi*ii\un, I. \V., ] . Nnlrl C.itl*onkl InhilHiion imiinHii1 Ii.iIih Inin t*l H. J..IM lui^oplian Pm* lax. r *ntrr /!* IVi'. (Irn.7i. 14. IlMfciiT, H. 1... and K W. m\wm*s\ !.: At*** i'dllMil.u:M Rr n Inm i \.lininr.l4HHi f Nnlrl Of |mi|. fitrh, A.nrimn. ttmlth *4.* Wil |l,47). 15. Ilnna. IV. f... ami \V. W. T*'n*: I \pi*iimmi... Vmhi* in >lal f-jMiJPniuo. Atfh. /ninmn. iOalfh >.' Il'i MMiJi. 1C. Ii\m. J. R.. ti. K. Iftui. n i k m mu'*. I- |. t*\uiA. and U. I. kiin.iM.iv- llx K*lf <( 'IfiMf Mn.iK in f.ix!iii..l (.jHinwin'M*:AvinMin (lamrr. I.anier rt. ; Hm.-I fl'i;t;. 17. Kv<\, J. R.. R. s. JHui. and I. 1 Ihir rol.**M o| I liim-M hi ImMlriHi* dHtom 1ii.nl l.ai* (itMttn.i in a I ivl'li1 A*.la,Mo I ai'mi. .Inn. N.l. AtM. Vi. IK: VJC (l/nmlx I'Ni'ij a**m- IN. Msmimi, T., ami A. A. I.i Aimh: Morialiiv 1`aOrtn in .i f-oUmi *r Wnikrtv- \ Miuly llaxil on I nipUiintriu Ia|hmimp. /. .'feu. f; M7 (IV7). 19. MiIm.vmo, 1. t.**u n. A. I> M'lh(\*m, ti. W. (.IMA, |. mi vmiiM, ami *' F. Ri*vmi: Mmialitv in ilx Clniwailp A'ln-'im Minm ami Mill* f (iixlxr. f,H<v<in, flrnlth 22: '<77 CI'*71*. 2ft. \'ii.iisni, F- A'IwaIin Fiiwmirp atnl In Hrviln in flail. /*Mi.ri/;iiifi uf U<* Omf'trntr on /'fif-NMti*roni<ut, _/y/ifln>ieihir*!, 19Oilwl L'niver* iir I'fev*. I.Mii'fon (MMili). 21. f;tlsiiv, 1. tltl'f'rf of f.i7 f* V.hry'nftl' Min*. (ibhhi. r.| OC. (iminiiMCf A'lxvm ami f'ailirr. |*rmiiiio<niiinsi* Knranh I nil, Llandonali |'in|u(al, rrnaiili, (..'jimircan. 22. fiitmi. O. \V.. J. O. <** K. Rwhtjb. F. C\im. and T. K. (.aiiMaa: QualMaJiir AijmJi Mf A*txin lni\i V\(MHurr in ilx Qim-Ixi Adxnna Mminc and Vdli;t.. finliixfiv. 7Uint /nfeinalinnaf Symposium >n /mhnlnl /`min/ei. / nniiim, /"'*. 2.1, hoi t, K.: Mmtaliir fi<*m l.mtc Caocrr In AthrMM Wmkrn. Aif. J. Inrf. .Vrd. 12: Rl (IV,5). 24. WiRMli, (.; AdxMm I'AfHnmr in -VwtU Afiirt. Tm* iw/iHC* from ln(*irmluHot i.onfr**m* on /*N/umo* oMiimu, JolmHnnhu*t, /Vf. OiltiH UjiiifTtiiir Prm, I i*<<Inti (Ifhi'iJ. 25. r.arm. P., H T. P. mTiuiij'. F.. R. Twill, M. W^n.uik. ami M. A. I\jxiimnwa1 Athmovv ,4r<!\. fnviion. tfmUA Jf: 3<5 (I9*i7). 26. IVacviR. J. C., C, firur, ami V. Trwaaru.: .Vrv* ilxlmma* in Rah. t*ro<ffdtnts of thr Intrmsiianot Cnn[rtrn<* nn tneumofoniom, fohonntikurg, t9*f. OmImmI I'nnriMiy Preu, I ornkni Knftvnl Siuih 30. 197). lm])roved Imulaiin^ Materials A report from NASA dcserilicj two multilayer foil and fabric insulators, us.ihlc to tcnijirraturcs of 2IHKrj' and -|0(K>K. These iii'id.iiors offer marked space savings in cfTiciem^ in nuclear power, plasma, liini'iietoliydrotlynarr.irs, and other hi^h-tcinpcrauirc operations. The lower temperature configuration consists of mnlylKlcnmn foil, 0.02'it nim illicit, wrapped with an interleaved layer of silica cloth around the object to lie insulated. When radially wrapped to a thickness of 1.17 cm around the combustion ch.milicr of a graphite rocket engine, the insulator withstood a tci]>cra!tiic of 2000F for a |>criod of 1000 seconds with only slight deterioration of the layers closest io the diamlier. A similar configuration of tantalum foil, 0.0251 mm thick, and carlxin cloth is usable at even higher tci]>erniurcs. W'rnpjicd to a thickness of 2.51 cm around the combustion chamber, this insulator withstood ,)000F. The inner layers of tantalum foil combined chemically with, the carbon cloth during the firing and formed a brittle tantalum carbide. The insulator retained its integrity despite this change. Requests for further information may lx: directed to Technology Utilization Oificcr, NASA Patcdcna Office, 4800 Oak Grove Drive, Pasedcna, California 91103. V