Document rxbLxeq59MxOJnKNVZEzn95Xv

Silks ii-r Sf/ifgnjfcer-Ocfaker, l<n;, *s section of this manual. Shmulyakovskii, Ya. E., art ~nsknya: Application of Inf-.. --osfopy to the Determination ' Aromatic Hydrocarbons. 7- htroskopjrii. A lad. .Vaul SR. 2: 367 (1963;. 7651h (19651. Ishida. K - nf Mixtures of C.c-o Aromaer oans by Infrared Spertrop!;... tnko Kenkyu 9: 27-40 < IPuo T.-tr. 57: 13808g (1962A j 1 { j infrared spectrophotometr. D., Y. Matsumoto. and K analysis of Mixtures of Orenr.:: - ds bv the Method of Inversion _a) Spectrophotometry in tr, Koru Tam. J-f: 434 (1962 -str. Cl: 38a (1964). magnetic resonance. Takcuri.i. _.l. Yamazaki: The Ptecision o: -.Ti'tative Analysis of Toluene nr.;;' mzene Mixtures by High Rev!-;. J.R. Spectroscopy. 67: 13T Shem. Ab>tr. 62: 8373h (1963 T-fCtrophotomctrv. Knsitnov. R. . Agaeva, and O. 1. D/hal'aim: ^nnksjs Ol DlCtlmDchvdrogrnation Produrtc.'ftim. '7.h~ 1966: 101. Cher: r: 18387b (19661. . 1 i ; | ) _i.ee of the ethylbenzene niuntie.. . "rinitroctliylbcn/cnc. Krivorue::- : Detci mmah.on of Some ".ances Which Occur in _i_g Styi ene-Butadienc. Butyl, and ?nc Rubbeis. .\ovor c Obhi-:. -in. AitaHza. (Raboty po Pioti:- illum.'1 19G2; 101-12. Cl-r. : I8!6g (19631. ; J { j j * J _r.ee of the reaction ptodur: ") nitropi u-s:d.' in conccmi a'-' ; acid. Dimitrov. D. 1". Ei.u.v j _novn. and M. Bratkova; Sou;-' actions of Ajomatic C'vn: sfuntil- 'C' ('.dot Reaction of ''on.:!. _^sidc \Mth Ainm.iiic C'oir.nini: J: Khitn.-'J ,'Ui)i,d Jed. 'J: - _ , 'hem. Ah dr. 62: 1 1 ! 33;,, , !'RA Monitoring Exposures to Vinyl Chloride Vapor: Breath Analysis and Continuous Air Sampling EDWARD D. BARETTA.* RICHARD D. STEWART, M.D.,* nd JOHN E. MUTCHLERt Department of Environmental Medicine. Marquette School of Medicine. hfilwaukee, Wiseonsin, and Environmental Health Section, biochemical Research Laboratory, 7~he Dow Chemical Company, Midland, Michigan ^ An environmental survey was conducted to determine the utne-wcightcd average exposure (TkNA) of a group of chemical plani workers to vinyl chloride (VCI) vapor. This survey featured continuous multipoint air sampling and analysis using an infrared spectrophotometer. The inhalation exposure data were digitized and record ed or paper tape for subsequent computer analysis and derivation of daily TWA values for each worker. A breath sampling program was conducted concurrently wills the environmental survey, and a series of breath decay curves relating post exposure breath concentration to vapor exposure were derived from the data. To validate the breath curves derived from on-the-job data, postexposure breath curses were also constructed from breath data obtained following experimental hiuran exposures to carefully controlled concentrations of VCI sapor. The close agreement between postexposure breath cone mirations at the corresponding TWA's obtai ted by each of the methods suggests that either continuous air monitoiing or bre.di k valid for estimating the worker's individual daily exposure to 'k Cl, . nd -- -..JJ-- f.,.1>x Wrp*.i]\ jirinl -ci< is \iveful industrial livciene teen.a^ue for evaluating vapor exposure. Introduction THE QUESTION THAT MAY ARISE following an environmental sutvey is whether the chemical vapor concentrations measured ate truly representative of the ex posure being experienced by the workmen. Evaluation of the ranges of atmospheric con centrations and estimates of time-weighted average coneenti ation (TWA' arc all too often based on a feu spot samples obtained under conditions which ate not rcpteseniati\C of all phases of a given optimum. A more exact iiie.asmeiuent of vapor expuxiue would base to hi- based on ermtirmou;, moni toring of an in the uotkinans breathing /one during his entiie work slut: Obviously tills ta.sk is made dilhcull and often impossible 'll:.' rJ|`.r -.1- a' ll"- Ai'in.i., Im.1ii-i: i il I Is ,.in,r U,,,krrn. r S> I ..... -.in. \|.,, MIT. I'Wi. \fjriyartf^ i*.f M- lir'/i.-, VI ...vU r VV j-r.m.uk, 1'llif 11.... ( li.-mir.ll (<>m|i.iiis. M'. I...:.il. by the large number and variety of tasks per formed by today's modern chemical plant worker. Recent improvements in automatic moni toring and data processing equipment have provided a means for a more satisfactory so lution. Sequential samplers and automatic nnulv/crs and iccorders ran now be used to continuously moniloi several locations or opetatinns to provide more valid data on which to luw estimates of chemical exposure. Computers tun be mi't/H to manage the large volume of data yemiated bv euii'inu<ms monnoi iijc 1 Meanu bile a t'.-clmique ha- been under de velopment which nuue preiwlv delines the level of individual exposing I in- reah-utio;: that the total bodv butden of a volatile chem ical is directk ielated to its romenir.itiun it: expiietl air letl io the development <'l teehni<pies for <ul!'xt;ut' ami unalv/ine biee.ili samples mefnl in exhuming the tnore intii- RSV 0008754 538 NovrtnbtT-Dccrmb,-,. r vidualized exposure experience of each work man. Studies by Stewart >t al. '* have shown that the excretion or "decay*' of vapor in the breath can be used to characterize the ex posure. breath decay curves constructed for several chemical solvents have proved clin ically useful as an index to chemical expo sure. These breath decay curves, for the most part, were constructed from postexposurc breath data obtained from experimental hu man exposures to carefully controlled and relatively constant vapor concentrations. Howcvet, breath decay curves have recently been constructed from breath data collected from workers whose work environment was being continuously monitored^ In this study of human exposure to vinyl chloride (YCl! vapor, breath decay curves constructed from data obtained during ex perimental exposures to the relatively uni form concentration within an exposure cham ber .verc compared with those derived at the theoretical'; o^uul, bui uroaaiy fluctuating, concentrations en,'0"n,ereri in a chemical plan atmosphere. A measure of the validity of continuous monitoring data and the use fulness of breath analysis in assessing timeweighted average exposure was reflected by a c'ose similarity between the two sets of breath decay curves. c WORK ARE A i STATION J 9 I STATION i 19 OUTSIOE Aifll ? 1STATION I | STATION Z !STATION 4 I' STATION E ? J9 |i > A o A A ~ INfAK0 SPECTROMETER | --.0 IITIZER Procedures Monitoring the Plant Almosphetr The chemical installation surveyed closed structure housing several chemical processing operations. Fijvt, ,i v survey was conducted for each of font i classifications to determine the wotk .n, frequented by the. workmen and tlie time i;.. spent in each area. Ebr each job cla'sihc.m... five sampling probes were strategically p!.,, in the work area. A sixth probe was pl.i, outside the building, and charcoal and -.hi. . gel filters were placed in the sampling i:: to assure a clean air reference. The sauqi.probes were 5/16-inch I.D. Saian tui.in through which air samples were drawn L\ ,i vacuum pump at a rate of 17.5 liters, me, to a centrally located infrared spectrophotom eter. The spectrophotometer was equip;'-.! with a lO-mcter path-length gas cell sui>.tive to 5 ppm of VC1 at a wavelen' tli <; 10.63 microns. The VC1 concentration w.ilineariv related to absorbance up to .vppmv. iinaieiy 1000 ppm. A schematic diagram of the sampling -v-. tem is shown in Figure 1. Sampling w is rv ecuted sequentially with a set of six two-u.n solenoid valves controlled by a timer wln>ii advanced the sampling location every t tw:iutes. A visual account of transmittance wurecorded on a strip chart recorder. Mem. while the data were recorded in digital foim on paper tape by a tape punch and tligiii/'-i programmed to record three equally sp.w- >; transmittances during the last half of i\i< a 5-ininuie sampling period. The ti an'inittance data ftn ni'iu d hy li.-'pectrophototnotet was convened to abM'd-a nee and t educed to conrcimution acrotchu. to Heel's law: EXPOSURE SUMMARY TIME-WtlOHtCO ML AN EXPOSURE 0 0! 1. Whf'i C, $*eion i jr (art gl i,mr ,-*M oi lecdlo* , I'lUt'Kt. 1. Si ht'in.ilir (I r re (.1111 i >! the inframl rent imi. nt in.'iiili'ime s'-km v. hete A -V, X' X, i A' L09'(X;-X") = ohsni bailee -- base-line t ripon-e. -- response at total absm ptinn = response at location i. - 2. X -1, :*). 6. RSV oooa?5* A. -mrbrr-Decembrr, /<*,', American Industrial Hygiene Association Journal 539 Finally, Atmosphere C= KA -lation surveyed was a _sing several separate w ht-re =>eracions. First, a j<,|, K = a proportionality constant. for each of four jol, C ~ concentration TTnine the work area- The taped data were processed by a Bur -=nen and the time tla ' roughs 5500 computer at The Dow Chemi- each job classification, -ere strategically placet! j ial Company Computation Research Laboramrv. The computer was used to calculate TCth probe was placetl _nd charcoal and silic.i in the sampling line e/erence. The sample h l.D. Saran tubing iDles were drawn by a a:e of 17.5 liters/itiin nirared spectrophotom* reneter was equipped the mean and standard deviation of concen trations at each location for each 8-hour 0* *.1 tl ( I 1 10 JQ *3 13 illlMi ^ ^ rc f* eoh6ii**fi9 (fctioie t-*i work shift. Finally, time-weighted average concentrations were calculated for each job classification using the time-location data Figcre 2. Exposure profiler expressed as VC1 vapor concentration versus the exposure frequency distribution for the four job classifications. I obtained from the job surveys. As described i elsewhere,1 the weighted percentage of time cap glass vial (Figure 4). The overall length ^ during which concentrations exceeded sev of the pipet was about 9 incites, so it could -.rngth gas cel] send- eral prechosen levels was also computed for be convenientlv and inconspicuously trans . at a wavelength oi use in establishing exposure profiles. ported to and from work in a lunch bucket. "Cl concentration wa- Figure 2 describes the exposure profiles The plastic caps were lined with six layers irbance up to appro.x- (frequency distributions) for the four job o.` Saran film identical to that used for the classifications studied during this survey. construction of Saran ait sampling bags. A _u of the samolin? svs- 1. Samnlimr u.it <-v- a set of six iwo-wa\ _rd by a timer which ioeation every 5 minof transmittance wa< __art recorder. Meancorded in dicital f<nm puncli and digiti/vithree equally spaced _ae last half of each ad. _ata furnished l>y the These profiles show the percentage nf time that concern! exceeded the levels shown. Tut.) 9ummaiv `.zt.z zl the.: ands of individually measured concentra tions and reduce them to single curves. Fig ure 3 shows the corrective trend brought about by actions undertaken to reduce the atmospheric concentration-of VCl over the 7-momh period during which the study was conducted. Only two job classifications war ranted extensive study, but men in all four classifications were asked to participate in the breath sampling program. 3/32-inch ho!'.- predrilled through one of the caps provided an access for withdiawina sam-pkl The Sarar. hr.;:: provided ar. tl Jective gas barrier so that vapor losses were held to less than 10/< for a holding period cf 3 days. When collecting a sample the subject was c-sked to remove the caps, place the pipet to his lips, and breathe normally in thiongh his nose and exhale through the pipet three tonveitrcl to alwoth- Ori-thr-Job lircath Sanijilino r.cenlintion accoidinj Three separate hicnili sampling progianw were conducted concuucntiv uiiii the emit* x,-- X00) xf-xw) rspotw. - total al)M>i pnon . : location i. 6. uiimental plant suiwv, designated b\ the boxed portions in Figure 3. Each woikei j collected three breath samples tl.viU--the first on ftis arrival home 1'iom work, tfit* second ' to 10 hours latci, and a I'm.Vi sample bi- forc returning to work the following d.w The samples were colleited in nipeis ronMiucied hum short lengths of -O inrn .nt; c'l.fw tubing to wlueh had been welded at each etui the threaded portion at a 2-tham fft-mh mu-w- Kh.vki !V Wrcklv iiu-.m v a j >c'r rvimsuii* r *ru rn- iraiioiis iiiramp'il ilnrmi; ihe mrw'y. IVriuJs dorinc I'tiuii l*n'. 11 '.implmc n.is i"iuliKU-iJ .ire repicm uiiii by the buxcil-iii jic.w. I ftSV 0008756 540 Novcmbcr-Dcccmbi*, p, Fioi'xi Glass pipet (50 rnl) used tor collect ing breath samples. One cap has a predrillcd hole for gas sampling. Both raps have Saran liners which seal (he pipei chamber- times. After expelling the fourth breath he quickly caps the tube, trapping a portion of alveolar air. The importance of writing the name, date, exact time of sampling, and the worksliift most recently completed, on the label attached to each pipet. was stressed. Aliquots were drawn from the pipets with a 1-ml Hamilton gas-tight syringe and ana lyzed in an Aerograph A-600B gas chromato graph using X; carrier gas and a hydrogen flame detector. Separations were made with a 6-foot, !4-inch ID. stainlcss-stccl column packed with Caibowax 20M alkaline on Chromosnrh W 60/80 mesh acid-washcd. pOSiii J s- . - v>t i ^yt. I Ul 10/1 Three experimental human exposures to VCl were conducted at nominal vapor con centrations of 50, 250, and 500 ppm. The expos jrc chamber was a room measuring 41 feet ly 6 feet wide by 7.3 feet high. The room had a continuous positive air supply and exhaust system capable of maintaining a slight negative pressure within the cham ber. Continuous distribution of the cham ber air was achieved by recirculating the air with a squirrel cage fan through a series of inlet and outlet cluci< spanning the length of the chamber. The YG1 was moteied into the duct carrying aii exhausted by the squirrel cage fan and entered the mom ainio-phcic via the recirculation sM-tetn at ,i i.itr sufhrieni to maintain the desited aimosphei ic toncentrntion. 'I'he vapors ru initndured fioin a pressurized stoi.ige i \ l incl i r tinough 6 feet of ha-iurii 1.1). sl.iiiiir"--teel tubing into a rot nine ter prim to rniei mg i he 111 r ui .u mg a: r dm t A healing t.ipe flapped .iiouml the 'la in less-o.erl mbing pi r\ rniei! rni ulema lion of tlu` \ Cl and stabilized the flow of the vapor. 'I'he tnnit-n11,i11,.11 of VCi in iii.- ehambei was constantly mmnimed with a Pei k in-fh- mcr infrared spectrophotometer equip- with a 10-inctcr path-length gas cell. pling probe, consisting of 5/16-inch l.h. s ran tubing, was centrally located during ; exposure to represent the breathing . all subjects within the chamber. Tin- was moved about' prior to each exposm,- detect imbalance of vapor conccntr.iti,.-, within the chamber so that ncccssar\ ,... rcctions in the recirculating system enuiq made. Air samples collected pvriodu.,;: within the chamber throughout the expnMi:. day were analyzed by gas chromatographs t. added assurance of analytical accuiavy. ik>:i. the infrared spectrophotometer and the g,, chromatograph were calibrated before e.i,:. experiment and at intervals thioughout i!, exposure day. Each 7.5-hour exposure day included ,i 0.5-hour lunch period in an uncomami-i.u-d area outside the exposure chamber, IL TWA concentration was calculated on :I,, basis of / .5 hours ot cxnosurp Clinical and Laboratory Procedures Each subject had been under careful pu-ii. cal surveillance by the medical dep.u tua-te for a nuinbei of years, and each was gi-,in i complete jncdical examination a few d.nprior to tlie VCI exposures. Included uma complete urinalysis and 24-hour uiiiir !' urobilinogen, complete blood count with vi!imemntion rate, leticuiocyte count. hO.< \ 1 . SGPT. LDH. alkaline phosphatase. Ill Y creatinine, and bilirubin. Each :-it ivceitecl a repeat pins,, i. (s.1iii!ii:!t;nn I liour heluie entering the is polite chamber This examination im'iue'b measure] i .-;i t ol lempr: .nutc. blond ]iii"ii' .ind piil-e jute, a iiviiiulugical exanimate and enlleilion of blood and hie.nil s.ntipl'A quest inn na ire noting the pieseniv nl .u ' s\ ni.ilunis ol illness {fin ( xauqile. liead.u * nausea, sirs' tluoaii (minih'led the pre-evpiisiire inetiuai evaluatinn. After the subjet t entered the ch.uuh. : tui.il espaid bieath samples new rnlhi'a, cviiy linui by has ing him bieatlm out tin nii"' a Yuan tube leading m a Saian pl.isue <' leelinu l... _ Inland iml-iile tile i 11. U111' t Tidal relume and total expiiatme capaml' RSV 0006757 -ber-DecernbxT, /ftdo ^mfrican Industrial Hygiene Association Journal Ml riotometcr cqnij)j>.-il gas cell. A <um- lz. 5/i6inch I.D. S.i. -i- located durin~ _ne breathing /one <s chamber. The pro!*.' to each exposure i,, vapor conccntratii-T!. that necessary vm-edng system could !. fleeted periodiraDv - nugbout the CNprwiui- chromatography for vtical accuracy, both -rometer and the c.u .eJibrated before each crvals throughout the vjre day included .1 za an uneontammau-d :->ure chamber. The --zls calculated on tlie .-closure. t% Ii r 4 ert under caicful im-di- medical department and each was given a cmination a few dm: sures. Included wne j_nd 24-hour urine for blood count with <-cl_locytc count. SGOI . - phosphatase. HUN, _n. cd a repeat ph\I fore enicvin" the 1 -\exrmunaiicn inchuh >! . -atme, blood pi c."in>. rologiral ex ami mu r-!. '1 and bccruh r.uwplm r tin- presence >! am r example, lie.iil.udie. : omph'ted tin' piv-rxion. -nteri'd t!ic clnmlu-t. -tuple- were m!!.-, ted :m breathe out tin ou.:ii :< a Saran p!.i-.u ><T uiside tlie eh.mil.ei. .il expii,n<MV r.ipuei" I were measured in the morning and again late Table l * in the afternoon exposure periods. Experimental Human Exposure to Vinyl Chloride Subjective and neurological rcs|>onses were measured before the subject entered the Chamber Concentration chamber, 15 minutes after entrance, and at (Pt>n) X S.D. 1-hour intervals thereafter. Flannagan Co 59 ordination and Crawford Manual Dexterity 201 2 B , Tests were conducted at midmorning and r? 491 7 5 Range (ppm) 05- 53 289-243 518-471 52S-475 TWA' (pfn) 48 248 45i> 491* Number o( Sub|itu 6 4 4 7 j acain in the afternoon. Breath sampling be gan immediate))- after the subject left the `Time-weighted average concentration based on 7.5 hour* including; a. 0,5-hour lunch period in an unconiuninated J exposure chamber. A 24-hour postexposure area. urine sample was collected and a blood satn- kContinueus exposure for 3.5 hour*. j pic was drawn the following morning for SGPT, LDH. alkaline phosphatase, BUN, Table I shows the analyzed concentration creatinine, and bilirubin determinations. to which the subjects were exposed. Calcu ) Analysis of Breath Data lations of the mean and standard deviation of exposure concentration arc based on chart Tlie decay curves for the breath vinyl chlo readings from tlie infrared spectrophotometer ride concentrations were constructed by step taken at 5-ntinutc intervals over the two 3-5- wise multiple regression using a digital com hour exposure periods. The TWA is based puter. An empirical relationship of tine form on the total 7.5 hours which included a 0.5- Concentration = f (TWA, time) was select h.our lunch period in an uncomaminat ;d ed from a choice of several terms, each based tvea. on TWA and/nr time. The resulting regres The final breath decay curves intended or sion cijtw.i.ii, repreter'' ,ni' ntdiued re use ss an index to VCl exposures were ad lationship between breath vinyl chloride con justed to TWA concentrations or au, *->0, centration, time-weisrhted average exposures, and pcste.xposure time. 1 Each breath decay curve has an associated standard error of regression wliich can be used to compute the confidence hand for any chosen level of significance. The 95fr con fidence band for the mean of a group of ob servations w as chosen in this case 10 describe ibe statistical cnor as'-ociated with the breath data and the [egression technique. Results /wperimrnta' /heath C.o-res A iota! of 1" men participated in the three experimental c ham hen exposures at nominal concentrations of 50, 250. and apO ppm pro ducin': a iota! of lf>0 v.vid lircmh d.ain points. Five of the six subjects exposed to 50 ppm weir le-exposcd at 500 ppm 2 class later. There was no measurable residual \iml chloride detected on the breaths of the sub jects prim to the second exposure. Serial btcatli sampling was initiated immedkuch after the subjects left the exposure clumber and continued up to 20 hours following the exposures. I'kii kc. 5. Breath decay ouwj i'.ivti un experi- "ii'ni.il human ev;i<iturr tu j", J ill. ,mil jOf? (i|>ru uf VCl [7 5-fvnir TWA), RSV 0000758 542 Hovcmbcr-Dcccmbcr, lOG't DAILY VARIATION IN EXPOSURE TO VCL VAPOR (0 hr. TWA) with confidence bands only slightlv widet than ifiosc from controlled human expertments, The close similarity between these curves and those constructed from controlled exposure data are further illustrated in Fig ure 8. ! j j ] Human Responses , Fioi'xr. 6. Variation in VCI vapor exposure for three shifts. and 500 ppm (Figure 5). A 100-ppm decay curve was interpolated from the available data using regression analysis. These curves arc presented with the calculated 9bc,c con fidence bands for the mean of a group of ob servations. On-thc-Jol Breath Curves Ten workmen iiviir'p?.'.ed in the on-thejob breath s-irpll..^ ^lugiam, piouucing a total of 91 usable sets of data. Ten percent of the breath samples collected were discard ed because nf piper leakage or poor sampling techniques. Absolute breath levels ranged front about 20 ppm in tne sample taken less than 1 hour after an 8-hour TWA of 250 ppm. to barely detectable let els (<0.05 ppm' in samples taken after exposures at TW.Vs below 50 PPJThe extremely broad vatiation in the TWA's experienced bs woihmen during one of the periods in which breath samplin'.' was being conducted i> demunm rued for thiee shins of men bearing the job classification "rnngiilaior operator" .'Figure fit Minute, hmirlv, atul daily liueuintions in the concen tration of a coutanunam are most deecripth ely reseated bv umtinuous tnoniioi mg. ! Ins tnetliod of sampling quickly points out the fallacy of judging TU.\ and peak expo-tue fonrenti at ions on iln- b.isi- of <pot sampling Oi penotVu sni\o\s nf `lirief dut.i;i,>n The rem.ii k.ible cm i 1 a t ion between lucath concotitiatimi and cm ic-poiuhve.: T'V.\ val ues made it possible to const! net tin' sera-* ol bieatli decay cuitcs shown m Figure 7. From a subjective standpoint no significant untoward affects were noted at any of the exposure concentrations. The only complaints were those of two subjects who reported mill! headache and some dryness of their eves ami nose during the 500-ppm exposure expeiiments. No odor was detected by anvonc entering the exposuie chamber at 50 ppm. At 250 ppm all four subjects entering the chamber initially repot tec! that they could delect a very slight odor of the chemical. Five of the sever subjects entering tlte exposure chain- ber at 500 ppm were able to detect the odm of YCL hiu - --.ir.v.'.tj v/f v.sposure those five v-.ere unable to detect it even wirh forced inspiiation. Three of the four subjects re entering the chamber after lunch were able Kici hi 7. lit < -i r i: bo'.W rmvf> tleiieril finlli I'M ,ir>i <1,11.1 ! 'Hi', red iioin wuikcrs ... me -n- i do j.i csp. ill c - |. \ ( .1 N - hmr 'l \\ A i i | ' j , j J i j j ! b i ti>i . the . I Inin nili. . i ii ib i cd d r\pi <.111! i\ OlSCU'. MUM'S ill.Illl kill- d one I' tr.ui.'i men! - nil a comb Vsjs compvalid : cxpo-i On <nnsii . mg i'1 agl ei ii < h.unb should I'll |o| Tii oils s!,. I II I'lII11 smd : mg |" lima II <; id - I. nt it \ i-i |i uj ii; -mil i > ' hill' I" \ noun h\ ird> in l. ( *< l| I ! I: ei 11. !\ mi nt i < RSV 0008759 "her, lQti't American Industrial Hygiene Association Journal 543 -ilv wiciu -in experiween these controlled -cd in Fig. to detect a faint odor of VC1. One subject could detect a faint odor on deep inspiration for approximately 15 minutes after entering the exposure chamber. The exposure had no noticeable effect on neurological responses, nor did it produce sig nificant changes in the results of mental, co ordination. or manual dexterity tests conduct ^ significant | ed during the exposure period. All clinical any <1/ the . laboratory studies performed in the post- -- complaints f exposure period were normal and not signifi "ported mild j cantly different from pre-exposure values. --ir eyes ami ^:ire expeii- | ' Discussion The object of the environmental health "T'ne entering survey is to identify the atmospheric contam "3m. At 250 | inant, determine the exposure level, and re ine chamber [ late this to the health hazard it presents. !f -Jd detect a * one is to judge hazard by ambient concen - Five of the ~-o$urc chant--ect 'bp odor tration measurements, then those measure ments must accurately describe the exposure on a continuing individual basis. A carefully ~ I conducted surrey combinin'.; continuous anal Fiour*. 8. Comparison of breath decay curves ^2 with forced ysts of the work 2vv>cnh<M-e with a drived from the on-the-job data and ifie expert- r subjects iv- comprehensive job scurfy will provide data Sira-*" exr>osurc data. were able valid for estimating time-weighted average exposure. limited by the number of sampling probes, On the oth t hand, breath decay curves and these probes are not always capable constructed fnm breath data collected dur of accurately measuring the individual's daily ing continuous plant monitoring are in close exposure experiences, especially should these agreement with those obtained from exposure involve unusual incidences such as chemical chamber experiments with VCl. These curves spills or exposures outside the monitored should therefore be useful as a second meth ai ea. od for assessing exposure to VCl vapor. The choice of whether one or both meth ods should be used depends on pre-lading circumstances and on the thoroughnc-s de sired. For example, data useful in describ Breath analysis has the advantage of in dividualizing each worker's integrated daily exposure. Breath decay Cones, as an index of expo-ure. offer a means of estimating the average d.iilv individual exposure on the basis u 16 t . HOOPS "'rs d'Tivrd fi.-ni .'Us ..n fl-li-arr T\V \ . ing peak c\|>osui'C> arc obtained from con tinuous monitoring. Concurrend v. exposure trends and concentration gradients innv help identify plant operational inclliciem ie> and ecjuipmcni malfunctions by rescaling specific sources of emission. Collecting these ptuhlems not mils' restores a healthful uni* en vironment hut often U 'uhs in homi- s.n mgs fis tctluring iov-rs et ran materia! and prod uct. Continuous monitoung. however, is e\ttemelv ccwtlv both in time and in the equip1 ueiit rnpih eil. I he -cope of data ;n <|u 111 d t- of a few iueath sample- taken >ertulh in the [xwiexposuit* period. Consequently bivnth analxsis can he used to diagnose as well as quantitate an exposure winch has nlicndv occmied. It is a idatively inexpensive and simple method which ran be pm into opera tion without extensive and costly preliminary pieparatinns. lidurw;. |/mt exposing hii-ntb an ilv-w fines not pi o\ t< 1 e iulun 1 i.Uinn On tin- d.ulv !l 111 luations uf exposuio. initl the peak exp.wine nmcenitntinm are um made evident h\ Utrath data Fifiallv. breath anahris is mu applica- ftsv 0006760 l i y 544 Noiifinbcr-Dccnnbfr, !*,, blc to all chemicals, and breath decay curves established for one chemical are not useful as an index of exposure to any other chem ical. The decay curves presented here are in tended to serve as an index of exposure to vinyl chloride vapoi and arc based on an exposure duration of 7.5 hours for the experi mental exposures, and 8 hours for the on-thcjob study. The close agreement between the two sets of curves and the narrow confidence bands obtained in each case demonstrate the usefulness and accuracy of both methods for estimating TWA exposures and indicate the importance of breath analysis and the need for expanding its use in evaluating ex posures to ocher widely used volatile organic chemicals. References 1. Pit.**ojj, J. V... H. R. tEovlx, *nd E. J. sfll,,llj( The Application o( Computer Soencc to tml.i.irijl ti. jirnt. Amtt. !md. Hyg. A line. }. 27: ISO- l&j . M IU66). 2. SttwaHT, R. [).. H. If. Ctv, D. S. F.uev, c II,4. and A. W. Sciorfta. Human E^icn-orc u> Ttn.,' ...... rllivtoic \'a|Ktr: Krl.ition-hip of Expired Atr j,k| CnnctiHnlio'" to E^pwurt and Toxiriir. A>.* . WcaJiA 2: S16-512 {May-I960. 3. SrvscutT. R. D . H H. Gay, D S Ely, C t )).4, and J. E. I'tTMAOx: Ob*crv-inon> on the Om. rHii, of Trirhloroetlickno ia~ Wood and Evpircd \u mvAifiOHirt of Humana. ,4ncr. Jaf. ll)g Aunt J i 16?.ITU (April I9G2). 4. Stkwamt, K. D.. and V. K. Rotvr: Q,nn>r d'Eiudn *ur lr J.l.l-Trlehlarofthant. A'd. Ma-i.l,, fto/tu. 2H-. JW-201 11967). 3. R. D-, H. C. Dow, . D. btarirt. A. tV. Scutfrnt: Human Exposure to Sivr.nt Arch. Kmiron. Htaiih lb. No. 5 tMay Hn,6,. 6. Srewanr. R. D.. E. D. Bxnenv. If. C. On* ., . i T. R. ToaKHON: Exptrinifntal Human Lv*m' TeUachlorot'thylcne. .4.U.4 Areh. tm-iron. ihalllt fin print). ?. Stt.w cat, R. E>., H. C. Dodo, E. D. R**tTr\. A \v ScHiHia. and J E. Mt tciiu-r : Clirnmc Otririi,... to Bcnicne Vapor, Prc-rnicd at ili Sixth Amu.il V.r inf oi the Si'cicty ol Tuvicologv, March 2i-li. Ailanta. Ccorjij. Received Ms> 26. 1 Nolices and Deadlines It is the policy of the AIHA Journal 10 accept and publish notices and short items of import and interest to our renders subject to the limitations of available space. This is done as a service to our profession and no fee is charged for such announcements. Some notices are received too late to be carried to advantage in our jour nal. Persons supplying announcements to us should keep in mind the lime schedule of our publication. The Journal appears six times per vear with the copies being mailed about the aUih of February. April, func, August. October, and December. While emergem'v or urgent notices can bo inwited up to three or four weeks before the m.ii:ii:-_r date, mi.ii i.uinot brefuted. Xouuallv the announcements should be in the Editor:. hands at leu-i two months or moic before tltc issue in which vbes should appeal. Perhaps these guidelines will aid you announcement generators. ftSV 0008761