Document GmN38QMREL0mkN2n6bzeoZyxx

CorporatOeccupationMaeldicine 3M CenterB,uildin2g20-3W-05 St.PaulM,N 55144-1000 65''Lt34,230Telephone 6517339066Fax 1.HealthStatusofPlantWorkers ExposedtoFluorochemical-sa Preliminary Report Thispublishepdaperby Ube]etal(Am IndHyg AssocJ 1980;41:384-38p9r)ovideasn overview of fluorochemicalindustriahlygiene,medicalsurveillancaend epidemiology researchdata collectedinthe late1970'satthe Chemolite (CottageGrove, Nlinnesota) facilityT.he authorsconcludedthattotalorganicfluorinewas found intheblood of workers exposed to industriaflluorochemicals.Medical examinationof exposed workers and a briefsummary ofthe initiarletrospectiveepidemiologicmortalitystudy(seestudy # 2) ofthe plantemployees indicatedthattherewere no illhealtheffectsattributablteo fluorochemicalexposure. Iq;ghar than no rrnaIIeve Isof org anicfluorinewere found inthe blood ofworkers exposed to fluorochomica Isinan indus Iti&Ienv ironme nt. No ilhlen ltheliectsettribualbIstOeXpQ3UTStOfluoroc hemical3 war@ lound among those rkers.The ambient airinthe Process operationareas inthe plantvvestound to contain Measurable amounts 01 &nic Iluorins.Through conain rnodilics?iomisnthe Process 3tePS and improvements inengineering controls.a 0-stantial reduction in the airborneiluarachomical levelswithin the plant was achieved. Health status of plantworkers exposed to fIuorochemica a preliminajy report F.A.USEL. M.D..S.0,SORENSON. M.P.H.and0.E.ROACH, M.D. 3M MedicalDepartrnen2t2.0-2E3M CenterS,t.Paul.Minnesota55144 Is- iow(Titi1t7 W Code). introduction This report provides interimresultsofan ongoing PrOgT21n which CVaIU3tCSthe healthstatusofa group ofproduction workers exposed to fluorochemicals. itwas recognized as earlyas 1956 thatnormal human, evaluatethe overallimpact a[ exposure of rluorochcm'cal,,' on the health Of workers. In addition, we have 1a1l30 undertaken toxicologicaland metabolic@studies in experimentalaniinsis. animal and avian blood containssmall Amounts of fluorine."I't was recentlyrtpontd thathuman blood contains two forms or nuarinc, "erchangeable" and I.nonexchii7gra6le"."Tjhis findingwas corroborated by 2norher study which described"ionic"and "noo7ionic" nuorinc fractionsinthe b)ood.43E'ssentiallyi,neitherstudy -nc form ran be regardedasinotg2cifcluoridaend theother ovalentlybound organicfluorine. We believethatitis*now appropriateto reportin a preliminaryway on blood organicfluorinelevcisand the healthstatusof a group of chemicalproduction workers at one chemical plant which Produces ammonium pcrfluorooct3no3Atse.theprogramprogresseasndas oihrr investigationasrc completed.it is expected that more detailedpaper5 and more dcrinitivceonclusionswillbe fonhcorning. a(cry littloerganicfluorine-as foundinthebloodseraof 5evcralspeciesof anirnals,-hen thesamples were processed by an open ashing proccdure.(4H1owever, when thesamples rnelhods and investigations were analy2edfollowingconfinedcombustion inan oxygen delerminaiion ij7 blood itrum: The bomb, the COnCCntr2tiCn3of organicfluorinefound insome concentrationof organicfluorineinblood was determined bovine scra were comparable to those found in human by subtractingthe inorganicfluorideconcentrationfrom sera."'No clearcut relationshibpetween thetwo forr:uof tots]fluorineconcentrationT.he littcwras de't'crminebdy fluorineIn a given sample could be demonstrated.""' gas chromatography."))followingcombustion of the The precisenature of the orgar@cfluorinefractioninthe blood is stillspeculativeand could be very complex, containingmore than one organicfluorinecompound and from more than one source,includingthe diet.Organic sample by a modiried oxygen bomb i.echnique.til Perflucrooctanoic acid was also dettrmin@@edby gas chromatography followingitsextractionfro'm"serum and conversionto itsmethyl esterusing diazomethant.""' fluorinecompounds such as fluoroacet3taend fluorocitrate have been identifiedin lettuce,foragecrops,soybean and b. Fluorine rneo.Tuerneniinair-fampirs.A,ir samples were tea.when thegrowing plantsor singleccliculturesof plants obtained by using midget impingers containing were exposed to high levelsof inorganicfiuoride.(?-"') spectrogrademethanol through which the airwas drawn Perfluorooctanoicacid (C.,F,,COIH) or a similar with a portable battery-opcratedsampling pump. compound of industriaOlriginwas believedto be presentin a plasma fluorinefractionisolatedfrom a largepool of ParticuLatesampling was done using Nuclcpore a 0.8 turn pore sized filterisn 37 mm plasticcassettes.Samples so human plasma samples."" collectedwere analyzed forpernuorooctanoate ion by the Since some 3m plant workers are exposed to industrial fluorochemicals.we considered it important to (2) determinethefluorocherniclaelvelisnthebloodafthcplant workcm, (b) monitor the fluorochcrnicallevelsin the ambient air in the nuorocherr@calplants.(c) minimize rker exposure to fluOrOchcmicals(.d) conduct special 0-dicsi ciaminationof scjcctc%dworkersand (c)institutae retrospectiveepidemiologicalinvestigationin order to method described abovc.1161 . c. Hcalth evaluation:Evaluationof the hcalthof tht employees was based on a ca fulstudy of"theclinica history,a review of the multiprilcaeboratorytests&ad i physicalexamination by a physician(Table 1).Subsequen annual scrccningsincluded he same qUt$LionnaireaT clinicalhistoryand the laboratorytestsw.hileexamination by the physician were conducted on employees selectedat C---O-. IW. A-. A* I". If,$.Atint j (41) iger P. 0:3 TABLE I Medical Examination 1. Clinicalhistorvand chy3icalexamination 2. Height. wetgki. bloodpressure 3, Elecircearatogrern 4. Che.1 caamination.forced vitalcapacity.foresdexpiratoryvolume per secone. 5. Vision 6. Audiagrams 7. Complete blood count:Hemoglobin. ABC. WBC. Differentiaclount.Cellindices a. Urine analysis 9. Blood chemistry-. Glucose Urea Cholesterol Uric acid Calcium Phosphorus I cis)pratein Albumin Globulin A/G ratio B;Iirubin Alkalinephospholose Lactate dehydrager%ast (SLDMI G lularnic-cialoscitatteranssminest JSGOT] Glutarmic-pyruwaisir3ngaminese (SGPT) Gamma-olutamyl transferise(SCGT) the bzsis of test results.Routine clinicallaboratory determinations were carried out according to standard procedures by in outside contract laboratory. d. Epidemiological iriveiiirations:These investigations were structured after the principlesof relativesurvivaland proporional mortality analysis described recently.""The overall analysis essentiallyconvcrEc5 on a comparison ofthc observed to expected death rates 5peciricfor cause, age, time. 5cx and race. f(e, Oiher tupportive siudirs.-In vitro mut2genicity test mes) and animal toxicity studiesrelatedto ammonium pey-fluorooctancate were conducted by contract laboratories under 3M spon3or3hip. The studies included acute cral toxicity,primary skin irtitatione,ye irritation, one hour inhalation effects,two 28-day oral toxicitystudies in rau and MICC and 90-day ORRI toxicitystudiesinratsand monkevs. results and discussion i;.Fjuorine kveis ip:bloodrepum: The firssteriesofworkers was chosen on the basis of their estimated degree of exposure to iluorochernicairGroup A, 3M controls, who are never directlyexposed to flucrochemicals; Group B, laboratory personnel who roulinely handle fluarochcmicals an a laboratory scaleduring theirresearch and development work and Group C, selected employees in a chemical plant where fluorochemicals have been produced over approximately 30 years and where the potential for the exposure to fluorochemic2is is the greatest. The results of fluorine a'nalysis Of 3trUm sampits are presented as ranges of values obtained and the number of sample$ involved per group (Table 11). The inorganicfluoridelevelsin thecast of allgroups are within generally reported normal ranges. The levelsoforganic fluorinein blood serum in Group A. 3M controls (0.01to 0.09 ppm) are similarto those reported in the literaturefor normal human plasma/scrum (0.01 tiD 0.13 ppm).'Z"-%"6-1"The concentrations oforganic fluorine in Group B. laboratory personnel (0.04 lo 2.0 ppm) are somewhat higher than those of Group A and the conctntr:tions of organic fluorine in Group C, plant TABLE 11 Levels of Inorganic Flworide and Organic Fluorine in Blood Sere of Selected Groups of Employees Group Normal human sere (fcconco in publishedligtraturs). Number of Samples Ansly2ed inorgsnlc Fluoride PPM Organic Fluorine PPM 0.01 -0.17 0.01 0.13 A. 3M Controls, 4 8. Laboratory personmel, over 20 years exposu(e. C. Chernical Plant workers. 0.04-0.08 0.01 .0.07 0.01 .0.09 0.01 0.06 0.04- 2.00 1.00. 71.00 AftriKisnoloottmryigamle AUK.SlioJnOUPINAL Il1i)8/80 TABLE III Levels of Organic Fivaririsin Blood Serum and Urim4018 Wcrksy Removed frorn Exposure to Fluarochemicals Durationof No Exposure to Fluotochern;cals Organic Fiwoline in Blood Saturn. PPM Perllucrooctamcoto Excretedin Vr;na. jig/24hra. I %vook 66 387 7 weeks 71 218 2 enanths 128 3 rnonths 17S 5 rnanihs 59 160 a months 4S- 220 11 r"onlmz A7 110 14 rhonths 44 so IE rmcmlns *60% of the organifcluorinwea3 perlluoroccianoiaotne. ,A-orkers(.1.0-71.0ppm), are higherthanthose in the other group$. The highest lcvcl5were found in workers with the longest work historyin fluorocherr@calproduction.The majorityof the va)ucs have Yernaincd at about the same levelduring monitoring over a two and one-haltyear period. Throughout the year$ of service,theseplantemployers were in situationswith a potentialfor multiplechemiw exposures. There was considerablemobility of workers within the chemical plantitselfa,s well2S IT2nsferto and .rom other non-fluorochemir-alproduction areas on the 0-amc site.These circumstancesmake itdifficultto define preciselythe duration of mposure of the subject to f)uorochernicals. One group of 15 employees had a range of J.D-10.3ppm organic fluorinein serum when theirserum samples were - analyzed before changing to a job involvingpackaging the dry nucrochemical powder. In seven months, 11 of the L.mploycts had an increasein serum organic fluorine concentration to a range of 2.2 to 18.1ppm. These levels were approximately the same or somewhat lowera-hen their scra were again analyzed three months later, The majority of scruznsamples were analyzed solelyfor organic fluorineand inorganic fluoride.When a mctbod became available.a selectednumber of rcrum samplc5 from the workers engaged in the production of Ammonium perfluorooctanoate*crc analyzed for perfluoroocisrioic acid.About 90% of the organicI)uorintin theseserum samples was composed of the periluorooctanoatc anion. In the cast of one worker, the organic nuorinc in blood, which was about 40 ppfn over R one year period,sy Idenly rose to 70 ppm for no apparent reason.The worker w&s then moved to a plantlocationfreeof fluorochemical exposure and his blood and urinesamples wcrc periodicallyanalyzed for organic f)uorineand p@enluorooctanoate over 'several months. The resultsprescntedin Table IIIindicatesgradual ut slow returnof theserum organic nuorine levelstoward 0.1 he earlierlevel.Eighty percentoforlanic fluorincinthe Efth month serum sample was found to be ptrfluorooctanoste ion. These blood and urine values suggest that sorne fluorochemicaisare very slowly eliminated in humans. b. Fluorine levelsin air somple-1:There has been an industrialhygiene program at the plant for a number of years.When itwas recognized thatorganic fluorineCould be round in theemployces' blood,the levelof industrialhygiene activitywas incteased. Air sampling was- conducted at points throughout the Various process steps.The Samples were collectedin the opcratoes breathingzone (OBZ samples) or in work areas while the panicular stepwas in progress(areasamples).The latierwas considered representativeof an operator's exposure while in the area. Many of the samples were collectedduring charging and draining stepswhen exposure levelswere likelyto be highest. Table IV shows the four main st&Eesand the process steps in the production of ammonium perfluorooctanoatc.the concentrationsof perflucrooetancieacid or itzarnmonium saltin area samples and inOBZ samples and the time span of sample collections.Stage I involves preparation and isolationof perflucroocianoicacid and itsconversion to an zmrnonium salislurry,Stage 11 involvesconversion of the s;Llstlurryto a saltcake, Stage IIIinvolvesdrying the cake and Stage IV involves further processing and finai t)BCk22ineof the ammonium salt. Phase A in Tab)c IV refersto the circumstances as the, existed when the present studieswere initiatedD.urin Ph&3c3 B and C. new measures wcrc introduced instages 11 111, and IV to minimize the levels of.,exposurt c fluorochtmicals.No changes were made in Stage 1. Phase A: The concentrationsof nuorocheinicalsinarc samplc-sand OBZ samples in Stage I wereo.03 toO.5 mg/r. and the concentrations inOBZ samples in Stage 11 wcrcO.1 to 1.04 mg/ m@. However, the nucrochemical levelsin OBZ:s'amplcs wt relativelyhigher,3.90 mg/m i, during drying in the ov (Stage 111)and 3.27 rng/m3, during fur-gherp'rocessinga packaging (Stage IV). These operations entaileda I en closed procedure with more opportunity@ for exposi than in the previous stages. Phase B. Because of the higher levels,attention focused on minimizing ihe exposures in Stages IIIand By making Appropriate modirication33UCh,&$.(&)replac Am W4 otyAlssocJfoi) Amov%L C:cncentraticns Stage and ProccaD Steps j,qproducloon liel lAoLt IV Of Ps rilwareaciancic Acicland ItsAmmonium Salt in Air During Various Stages Of Production Phase A flness a Phase C sample rime Mina, Conc. 'Im; mg Somple rorne Ming. Cone. mgim' Samole Time Min*. Cont. R%g/rn' A IPL) 13 0.5 1 A 75 0.05 A 21 <0.07 A 60 -Co.05 A 48 <0.07 A 30 <0.05 A 60 <0.03 A average: 0.05 A 40 0.01 A 37 0.02 A Es 0.68 A 55 0.03 A is 0,14 A 27 O.D4 A average: 0.05, oaz 12 oaz 5 ooz 5 average: 0.34 0.50 0.17 0.34 ooz ooz 6 <0.01 5 0.25 average: 0.13 A 30 0.04 A 23 0.05 A 46 0.07 average: 0.06 002 2e 0.16 ooz 26 0.03- average. 0.10 ills) (DI C, IV oaz 30 <0.03 osz 20 0.21 0111 18 1 OBZ 59 3.90 OBZ 2aS 3.27 A Area Samole PL Peak Level * elcluding iMe 55 min. value of 0.68 iml/ml OBZ - cp*ralors btosihtmg land sample A so 1.10 A 32S 1.$0 oaz 30 <0.03 0111 21 0,40 OBZ 20 0.18 oaz 11 0.42 coz 250 082 3,LO 082 129 082 212 osz 120 oaz 223 ooz as OOZ 199 OBZ 370 082 ISO oaz 123 DOZ 45 1.12 1.18 2.30 0.30 0.07 2.Ss 7.60 0.04 0.33 0.95 0.40 0.019 overage: 1.49 A 60 0.06 A 60 O.OS p 11 0.20 oaz As 0.30 oaz 49 o.s7 oaz 30 0.54 average: 0.47 the tray drying in the ovcn withclosedsystem drying,from which point the saltcould be Pas-sedthrough a grinder, directly into the packaging drums and (b) improying the ocal exhaustsys(cm, thC flucrOchcrniCal ICVcis in Stages ]I) Amemion incolutamtyloent)4sociabJoOnURRAL (41)8180 and IV were reduced from 3.9 and 3.27 ml/ml inPhase A to 0.42 and 1.49 Mg/rn3 in Phase B. rcspectivcly. Phase C.- Jn Stage 11, Phjasc3 A and B. two successive filtration steps were involved. Under Phase C. the rtrst %1) fitrationstep -as replacedby a more rapidlj)tration process,which was also amenable toa betterlocalexhaust system. As a result,itwas Possibleto shortenthe exposure irneduring the firstriltratiofnrom 6.9hoursto 1-2hours I*. nd also to reduce the levelof nuorochemicalsinthe area ,ampic@ from to 0.05-0.06mg/m'. Furiher,in Stage IV. Phase C, ETindinEwas eliminated TCSUltint ina lowermean concenir2tiO0n..41mi/m, inthe OBZ airsamples compared to mean concentrationsof3.27 and 1.49mg/ M' in Ph2ses A and B. respectivelTyh.e period of exposure during STIEC IV was also reduced from 6-8 hours in Phases A and B to 1-2 hours in Phase C. Careful cxarnination of the data in Table IV TC%-eals sporadic high valuesrelativteo othervaluesinthesame set of samples (Phase B, Stage 1.0.68 mg/m3, rS min. area sample; Phase B. Stage IV, 7.60 mgirn),65 min. OBZ sampic). However. the overallresultsdo show a dccrea5cin levelsof exposure to fluorochemicalsas a resultof the rrostdifficultto tvaluale.In a few instances.through episodesunrelatedto plantwork. theelevatedSGGT levels %L,crteraceableto alcohol consumption, A consultant hcpatologiswtho examined 'hesubjectsconcurred with out conclusionthatthtscminor deviationsfrom the normal in the liverfunctiontestswcrc most likelyunrelatedto pla,t work and arc compatible with the individuals' predispositiotnoward alcohol.Further a review Of the resultosflaboratorytestsperformed on other plantworkers and on a largenumber Of man2gemcnt personnel shows the same generaldcgrctof variations(Tom the normal valuesas in the case of flucrochemicalproductionarea employees. During the course of thisthreeyear monitoringprogram therehasbeen 3 generaldeclineinthenumber ofindividuals With .2.bnormal' laboratoryrindings.This is possibly attributablteo the implementation ofa concertedprogratn of medical concern and personalhealthcarecounsellingand to improved personalhabitsof the employees* process modificationsdescribed. No relationshiwpas observed between the few testresult in additionto exposure by inhalatione,xposure by dermal absorption has been consideredand measures havc deviations(from normal) and the blood levelsof organic fluorinc. been taken to reduce thistype of exposure. Additional modificationand processchanqes arc under As was mentioned earlierw,e have not dttcctcdany diseasepatternattributabloer relatedto fluorochemiw continualreview.The objectiveosf thesechangesarcbetter exposure.Fumhei-rnorca review of absenteeism and illnt%3 containment of flucrochernicalasnd reduced reliancean patternsin these employees doc3 not suggestany work personalprotectivedevices.Until complete controlof the relatedproblerms. fluarochemicaldust is achieved,the personalprotection program consi3tingof a dust respirato(r3M Brand No. d. Epidemiological studlei: A retrospectivecohort 9900),d&Uy cleanoverallsand rubber gloveswillcontinueto mortalitystudy of employccz at thisplantsite,coveringa )cenforced. I* C. HealrhevaluationB:eginningin late1976,speciahlealth period ofthe past30 years(1949-78),was conducted by an independent group under 3M sponsorship'The main objectivewas to determine(a) whether the mortabty scrcer@ngexaminations were offeredon a voluntarybasisto experienceof employees at the plant was significantly ctnpiOYCCi3nthechefnir-palant.About 300cmployceshave been examined yearly over the three year period. differenftrom thatexpectedin a population group of the 'same demographic composition and (b) whether the Approximately 90% Of thePlantworkers panicipatedinthe mortalityexperienceof thechemical workers of the plant prog7am each year,although only 5OTo of the employees was significantldyifferenftrom thatexpected. took part for three coaseculivcyears.The examination resultswere given to the employees and, it theirrequest, were sentto a physicianof theirchoice. Records of 42 18 employees at theplantsitewere screened and a comprehensive mortalitystudywas carriedout on the 3688 employees who had worked atthep'laniforatleastsix No health problems related to exposure to months. fluorochcmicalswere encountered among these examined. Inany largescaleclinicallaboratorytestinpgrogram such In thisgroup, a totalof 190 deathswere identifie(d159 males and 21 females)and death ceriif*icatfeosr 177 of these as the presentoDc, difficultiiensvariablyariseinassessing caseswere traced.Alleffortstolocatetheremaining 3 death the weight to be plarcd on those laboratorytestresults certificatewstre unsuccessful.The numbcr of deathsamong which show minor excursionsfrom thenormal values.This femaleswas too few to permit Statisticeavlaluation.Results isespecialltyruein the absence of clinicaelvidenceof any of mortality analysts for the maic3 itidicatedno healthimp&irment as isthe case now. All deviationsfrom the normal valuesin the laboratorytestresultswem criticalslcyrutinizeduring our clinicaalssessment.and disagreement between the observed mort&Uty and that expected.This was trueof ailthcvariouscau3c3of death and 21SO of variousspecificcausesof death due to cancer.In were &ISOevaluatedstatisticalwlhyen possible.Occasional variationsfrom the normal in isolatedliverenzyme tests addition,mortalityanalysesforthe chemical workers atthe plant rcvc2ied no disagreementsbetween observtd and %%.erencountered.Detailed historieswtrc again reviewed with theemployeesabout medication,alcoholconsumption expected monality for any cause of death. and otherpersonalhabits.Thi M03t frequentlyencountered e. Other supportive studies (dt)ails in o@irporate ver cnzyrneexceeding the normal range was the serum publication): Ammonium perfluorooctsnid&tc was amma.Siulamyl-irinsfera(sStOC;T) inc)udedforthefirst examined for mutagcnic activityin microbialassays time in our liverfunctionprorile.With itsexquisite employing Salmonella typhimurium strainsTA-98, TA- sensitivi1t0yalcoholconsumption,"""' the SGGT was the )C)O,TA-1535, TA-1537 and TA-1538 and Sa.cchatoinyces Am. M Mrs A3W J (4)) Awom 1910 c=revisist Str2in D4. The compounds *erctestedby two without livermicrosemalenzymc 13boratorieswith and A -. preparationsfrcm Aroclor - induced rats. Ammonium perfluoroocianoatr- was nOt rnutaL2cnicunder the test conditior,s. The toxiceffectsof ammonium pcrf)uorcoctanoate (LD3c: 540 rnjg/kg,rat) wcrc fairlyconsistentin rodents.The liver was the t2rgct organ. An apparent sex related differencein toxicity was also evident. The males developed hepatotoxic effects at lower treatment levelsthafi the females and at comparable trestment levelsthe males had more pronounced histopathologic effectsthan the females. Serum and liver concentrations of organic fluorinewere appreciably greater in inajc!sthan in femajes. These findings have been corrobornted in our laboratoriesby metabolism C;tperimcnU in rats involving he use of C"-Iabcllcd ammonium perflucrooCtanOatrIn the rhesus monkey, the major siteof toxicityappeared to be the reticuloendothelialsystem. The sex related difference in the concentrations oforgenic fluorinein serum and livernoted in the rodent studieswas not evident in the primate study. Such species and sex differences in the toxicityof ammonium perfluorooctanoate make extrapolation of results of these studies to the human diff-icult. conclusions C)rg;inic fluorine was found in the blood of workcrs exposed to industrialfluorochcmirals. The levelsof organic fluorine in blood appcar to be relatcd to the degree and duration of exposure. Although itis assumed that high organic fluorine levelsin the blood are a result of high concentration Of airborne flUCTOchernicals,the contribution from dermal absorption may also be signiric&nl Limited data from the study of one individual who was removed from CAP03ure to industrial flucrochemicals suggest that some fluorochemicals are very slowly clirr@n2tedfrom the body. . Mtdical examination of exposed workers and a retrospectivecpidemiologic mort2Jity study of the pla@t employees indicate that there are no ill health effects attributitblteo fljorochemical exposure. In vitro M'Ulagcnicity testing has shown that perfluorooctanoic acid is nonrnut3genic. Certain spccics and scx-relatcd differenceswere found in 2nimal toxicitystudies,which make extrapolation efresulls of such studiesto the humafi difFicii1tT.his observation emphasizes the irnporianec of the infcrmation on humans, such as that presented in ihispaper. cknowledgment T8he authors wish to thank R. A. Prokop and R.E.Oberfor reviewing the m2nuscripL,J. Belisleand-D. F. liagcn forthe analyses related to fluorochcmicab, and P. Vcnkatcswarlu for help with the manuscript preparation. references I. N;cU Ias. M.J.: Presence du F Iuarcans iaS ang compt. fenci. 43:885 (1E56). 2. Tevoi, C).Ft.E:vidence That There are Two forms of Fluctioe in Human Serum. Nature 217 ICSO-1051 lig6e). 3. VOM68le3wSflU, P. L. Sing'er and VV.D. Armstrong: Determination cf Ioniic(plusionizable)Fluoridein Siciogicai Fluids.Procedure Basee on Adsorption of Fluorice Ion on CalciumPhosphate.Anal.giechem. 42:350-359 (1971), 4. Teves. D.R.: Comparison Of "Organic" Fluoride in Human and Nonhuman Serums. .1.Dent.Res.50@783 (19711. S. Venksisswarlu, P.: Fluorineinserum and Other BiologicalMateriai3 by Oxygen Bomb and Reverse ExtractioTnorcmniquesA.naL Siochem. 68:Sl2-S21 (1975). 6. Guy. W.S.. D.R. 'tave3 and W.S. Brov: Biachomisfry Involving CJfbcn Flv*'iAt Bonds. pp. 117-134. ACS. Washington. DC 11976). 7. Wada, R.M.. J.M. Ross and H.M. Benedict: A Method for the Detection and isolationof Traces of Organic Fluorine Compounds in Plants.J. Chrormatop.14:37-45 11964). S. Lovelace. J., G.W. Miller and G.W. Walkis: The Accumulation of Fluccoaceintoand FlucrocitrateIn Forage Crops CollectedNcbr a Phosphate Plant.Atmos. Enriton. 2-.187-190 (19681. S. Cheng, J. Y-O.. M.H. Yu. G.W. M;Ilerand G.W. Welkin-, Fluoroori;st%iAccids in Sayt)esm Leaves Exposed to Fluoride. Environ.Sci.Technot 2;367-370 (19681. 10. Yu. M-M. and G.W. Mliler: Gas Ch?ornatographic . identification of Fluorcorgenic Acids. Environ. ScZ Teehnot 4:4,92-495 (1970). ii. Poiarz,R.A. end M. Shorthouss: Fluarocitrat-i6n Plantsand Food-sxvffzP.hyiochemistry 11:1337-1338 11972). 12. Palerm. R.A. and M. Shorlhowas: Formation of Monvilucrocarbon Compounds by Single Cell Cultures of GlycinL-Max Growing on inorganicFluoride.Phyrochomistry 11:1339 (1972). 13. Belisli,J. and D.F. Hagen: Method far the Determination of the Total FluorineContent by Whole Blood. Serum/Plaofne. and other BiologicalSamples. Ansk B;oehenL 87:SAS.SS@S 119781, 14. Belisle.J. and D.F. Kagan: A Me:had for the Determination of PerfluoroociancicAcid in Blood and Other Biological Samples. ANAL Biochem. 101:369-376 (1980). 15. Monson, R.A.: Analysis of Relative Survival and Proponional Mons lityC.omputers and D;cmed. Ats, 7;32S. 332 ilS7A@. 16. Cox. F.H. and 0. Beciter birks:The Determination of Fluariae in Blood Serurn. Cofies Res. 2:69-78 11968). 17, Frf36n, J.A.. F.M. Cox and M.J. Wirter.The Determination of Fluoride in Biological Materials by Means of Gas ChrorriatNrophy. Ph$fM. Woo*blad 103:909-914 (19661. le. Singer.L.one R.H. Ophoug-. Concentrationsof IonicT.otst. and Bound Fivorids in Plasms. Clin.CPiem. 25:523-525 (1979). 1S. Poliesen. J.G.. G. Pincherin iind D. Robinson: Serijm Gamma-glutemyl IrenzpcpttOose in Relation to Alcohol Consumption. Clin.Chim. Acro 39:7S-60 (1972). 20. Actalki. S.B. end D. Rau: Serum Go rnrna -glut@ myl Transpeptioass Aciiviry in Alcoholism, ClitL Cttitn.Acra 39:41-47 119721. somellup inovtitwlhvlwne kjwwlion SOL"INAL fd1) 01,80 Sol. TOTAL PAGE.08