Document gD7eRaRJ0MNzXnqZmdGM1NdgN

c.w. gobs c.i. ams Bepeotmmt @f mi Smith mi IiestAtum of Oms^oMmsl. Smith and Safety* Hb&M Odmesteji, Omit Batata, Matt Saiat-Bilaira, P.Q., Canada mmmsanm Stoss is iraeraaaias mUbks due fibre shapei ewd arts* play m imgas&mtit cote in the pgsdeeciaa edhealsA offset related *& mftmmm. 'Stas*, fmrumetmm Smms&as pepaqratlna and depeslelaiu ia tin respiratory qsM, iatl--iro tacareepties la tbe mepigatosy adnata and afliaet da ability of aarnpbey ~ 60 eagalf os vemm SSsm dapedsei is t&e lane. fepersaatcal tntfcw t& mtimmlm tmm mmrn tW dan ie tapoc^ taat is driraaliatm the jfeULity of furai o pcatase pamdbpnl jeSmhm wnriaa 0MsP>t 1 fasdw, W5) aad eo tatasas pleccal wsBbrtlflta ohm placed on Cte plowTM {Stamfcoa lt 1977). %MesipXs^fcl. acedlea bam indicated eba* optaue to different fibre type eta gtwe rism to different rialca foe aanofbniiosn ffdlaaM A XeOeaal&T 19?#) mi pesatMy fof attar health effects (tart-late, 1976). Utile Seem and attar fatctora bam not been adequately dafiaad, tteaa dlffeteoces is beaUb dal wy be taplicsMe la barfe. pore by diffegeaees is the dinsiaw of istoled fdues. Ite dimaaims of fjfccaa to abfccb mrtera ate exposed ham been described to eely a United amtsnt (G3Ma a Bntng, 1975). Sic present capon. eanaxises saw titnervafteas os the HmtiBM of airborne eaaeita, eroeidolite and chrysotilat la selected pxoesaaas in shis-h only eon fibre type uaa aaomtsnd!. A note coaplete description of aettads and fibre dKwtroloos will be repotted elsodtere. "wy" 1 j I i ` HWBUI0007257 70 cms mm MttBODO Sawples of sixtome hast were collected ep Heelopoi* mtS MSMgoSm sabtane filters to wotldag areas of stoes and Mils frostectog acesidoUte (Cape fturtoee, Sooth Africa), smite (Xmvmal, Smth Afrlcs) end ebtysoclto (Omebee, Canada). Samples collected! se MUlUpore filters were eawissd try trenswtoaioa electros m& light optical kw seoyy, sod selected tn-mplm collected oe KtcJeofxne filters acre saasetned by seaming electron acLcsoscopy. Use dlaeostoas of fibres weed neesoxed ostog photograph* of mate fields. fibres acre tteftaed as hgsiag aspect cation > 3:1. ?<mr pataaeters ware aeaeszed far each ffbra; CD tree disaster was toe aserage wMtt of the cwtui pwrtloa of the fibre, sppestfag a a pfestogrsph; fli) true lagM* u toe length mgoaared slow tbs centre line of tte fibre; fill} coil dtowefccz was the inside disaster of aa imgt~ aaxy cylinder throng Add toe iftas oocld jeac peas tasgitwdlaally; sod (to) coil length wan the logtii of dn toagtanuzy cylinder into which tbs fibre would fit. The ass of each fibre as cslcalsted fraw toe weasared diwastons <MnMitog toe fibres to be dreuLsr to cross section. mass Fibre Umsftk # Hat dtotritoxlnas of airborne fibres by tree lagto as maxed by optical and rcenantoelnn election wfcxneoopy axe tow be figare 1. fbe length dtorrUmtions of toe fibres visible electro ataroscophcally and optically were slightly different is atotog and is hugging arms. Hie diffetances fcetoaa toe length disarUsetlros of toe entries! fibre types sere sere &stas3 muHm Ieegtos of cxocidolixs, mma&tm ss& etaysotile to too wine sere 0.95. 1.83 and 0.34 ps, xaspaetiwely, raid, in toe bagging sees 1.16, 2.53, 0.55 m* wapectlswly. bssmlts showed tbst^processing tends to reduce toe ptopsttieo of shorter fibrns present to air for ell fibre types, and especially tor eaoslte. Airborne waosite fibres were laager than chase of toryaotUe or erocidolire (Table 1). ' Fibre diaseter the dlseribwtioas of true fibre dtoseteTS are sheen to Tiguxw 2. For both sitting sod bagging operations, chrysotll* and croddollte dis played stowed oatoodal dtotritmtlons. with median mines tanging fxoa 0.05-0.06 m and iron 0.07-0.03 to, respectively. Anssite had flatter bat apparently nalttoads! dtotrUmtiaa, with aedtoa disasters of 0.200.26 pa, depodtog on the process. So airborne fare bad dimeters OINSNSIONS OF AIRBORNE ASEBTO5 FIBRES 71 FIG, 1. LENGTH DISIMBUTIWI AS OE0WB M WKMISSIM ELECTRON mcKtsoopr cm) and tiaw oral, mawam (lor) ftfntng: 1 - crocldoTfte; 2 - anslt**. 3 - et**sMl<s Nillfni (bogfhig): 1 - crocfdollte; f - msfte; 3 - chrymtlle HWBUI0007258 . mjNitaSitiii n :I5 MM s Table 1. Total length dtstrfbatfem (*) of various laves of airborne film as seen b? coiMivei light optical and tranatlssfoa electron satcrmwp# Lmtb Crocldolltc Jtasfte ObrysoWle Wring Baling Wring Baggios Wring Baggios <1.00 1.01- 2.00 2.01- 3.00 3.01- 4.00 4.01- 5.00 fe 5,00) 5.01- 7.50 7.51-10.00 10.01-20.00 2i.01-3O.OO 30.01-40.00 4Q.01-5O.OO 50.01-100.00 100* (5.91-lOOt) 52.430 x,m 10.330 4.710 2.450 (95.970) 2.490 0.570 0.(00 0.070 O.OQ5 0.005 0.008 0.010 (4.118) 43.340 31.800 27.080 21.940 11.540 17.210 5.730 10.100 3.430 .510 (92.920) {87.660} 4.460 7.357 1.710 3.117 o.w 1.746 0.004 0.160 0.006 0.108 0.008 0.036 0.033 : 0.018 0.006 . 0.072 (7.111) (12.664) IS.520 21.970 15.890 11.760 7.320 (75.460) 10.706 6.311 6.349 0.714 0.376 i*0.QS8 0.087 0.944 m.m} 85.950 7.890 2.690 1.500 0.700 (98.730) 0.926 0.176 0.176 0.006 0.002 9.002 0.001 0.001 (1-290) 70.620 16.410 5.420 2.040 1.410 (95.900) 2.255 0.787 0.919 0.131 0.042 0.013 0.024 0.015 (4.196) OTMBMSKW5 OF AIRBOME ASaESWB FHAES 73 FIS. 2. TO DIMETER aiSTMltffMB ASOBSSWIP 8V WWSMISSIOS ELECTOR MICROSCOPT A - Mining: 1 - croefOolite: 2 - awKite; 3 - chrysotlla B - Millino (bajgtng): T - crocltolttx; 2 - amsfte; 3 - chrysotile greater than 3 vm hence* on OianCar sa.'rtfcM&wwO. mttlemtat criteria alatm, all ftores *ou2d be capable of panetzacing duply into that Img. AKactaest of ftarctdes to tafMfcole fibres and tba aarling of cfarysstile fibres cd increase the csoss-eacttoaal area n indi-vidaal fibre*. Hie aedlas coil diaaetere* oben curliness and adhering particles were eonsidered, ver approximately twice the Eros dlanacteirs- Coil tad erne lengths of durysotile fibres in tanlap; (0.34 tad 0.36} tad fcatacfaijr (0.53 and 0.5$} were stellar. TMs eaggtots that as for as airborne fibres in the werfeplaoe are oonceraed, cnrJdaess is nor a ufor factor in explainlag differences in the pesettoilset of asgthibolt and eferysecile fibres into the long. It ahoaM be noted, fanuvex* that ttzis ebaervetinffl is restricted to fibres observed by erta*as*lea tlactm sdexo- copy- i HWBUI0007259 J** eras twc CrocMollee bad ceoslseeaCly larger of me length os tree dlanefe* (JJ..7 nad 0.2} than eftfaer a--gtcr CB.4 and 8.8> or etoyjwgfie (6.2 and 8.0) Ear nriailnB md huggiag, respaeeiaatly. Mtss The mediae masse of individual fibres (fa 10r*'I8) far ararfjfolite, oaosite and eferyeetll In adnlag sere 0.01*3, 0.1956 and 0.0818, respect" iyely, sad in tte bagging * 0.0231, 0.52*0 mad 0.8039, respectively. The data illustrate clearly that Cor a given anus of the three fibre* tvpes la alx thera srtll be a mastdersMy wllrr ssaaber of aaosite fibres la tb* Won dost than of ereeifcUte or ehrysoeUe. For the same aaas a airbeXM creeldollte aad ebryaoella.. me efatyeotile fibres aoaM be pnacet Ssk tie airborne dost than erseMoUte. Sere ass a greater sum f fibre (as jMsed If dn --Kan) in adding than is bagging for all fUwe types. Lmgtk-dimmtsm nettngw the inter sateless, based an iiiiini inrrninnnmt by a--IsdoB elects-- adcxosospy, axe stem la Sable 2.- ' Xhs mjacify of (be fibres of <rroeMl (3* .092 red 36.90S) and cteymeeila (60,732 sad 31-6SZ) had lengths lea* than 2.5 tat and rn.Mmm.mm loss thaa 0.06 its, -Aemtum text (< 2.3 M) --asim fibre* bad at--- becmMaa 0.101 aod 0.200 pa CU.OsTwtf 17.2XZ). da lagA isaaM she aashcr of fibre* la cells aa a peneascage-of die bocal fibre popdaftStm dtdfiwascd, bat certaha diffairacas tat-- fibre types ben-- erlAcut. Wax {Stans greater thaa 2.5 pa is length, mmt cwddtllts fibres Sa eaefa sell bad dtaanrere betreao 0.101 and 0.209 was; for etepnetHs. the ngjerttf of fibres witMe a given Isageh range varied bst a--gsd w--nda diameters gxeataer tbea 0.3 pa; this tread au even ante eeidset So% amite. Box lamgthai oE S.0-SSO pa, (be percentage* of fibre* < 0.200 m la dimeter la croeidoLite mining and bagging sere 2.9 and sT3; the aqoivalre* . .figures for aaaslte were 2.2 sad 3.6, sad those for cbryswtil, 0.3 and 20 / jxmdmathxt of crocldolite fibres tren Haclaopance miflu by bcamming electron microscopy iadlcsted that the ataaber of fibres arttli a diameter of less thaa 0.2 pa (not seen by light optical methods) ajr be aadexasthteted by cransniasloe electron Ktccaaeopy teeatose of the reateietieos <m length aannMiia biased by specanaat grid saeginfi. This does not affeet the e--parisasa gtn above. DMNSIGNS OF AMBSWe AS8EST0S. FIBRES Table 2. lm/gis&ime&@r mtrism 75 Olaaetar ftustte Crocfdaltte 9tfSag Sagging 1 bnhi length! < 2.50 g 0.06 14.84 0.061 - 0.109 8.9S o.in - ojw 19.45 0.201 - 0.300 11.47 0.3K * 9.09 2,59 S.97 17.21 12.55 11.31 34.08 27.01 19.96 3.31 0.90 26.90 24.74 22.81 2.60 0.72 g 0.06 0.25 H.0C1 * 0.100 0.62 0.W1 - 0.80 4.99 %m - o.3@o 6.7* 0.300 + 12 M OjOC 0.061 - 0.100 8. Ml - 0.200 o.m - 0.300 0.300 * 0.12 \M 1.75 3.06 Lcegtma 3.51 - $.09 - . 2.16 1.68 0.75 2.70 3.92 4.63 3.99 6.29 5.79 1.04 1.83 14.68 0.M 1.27 Lengths 5.91 - 7.50 - 0.25 0.22 0.12 0.66 0.61 1.00 0.66 2.48 2.93 9.43 0.83 6.75 9.30 0.34 < 0.06 - 0.061 - 0.100 * 0.101 - 0.200 0.37 0.201 -0.300 0.87 0.360 + 1.86 <0.06 0.061 - 0.100 - 0.101 - 0.209 0.12 0.201 - 0.300 0.62 0.390 0.99 LtmgtAS 7.51 19.Q0 - 0.09 0.13 0.00 0.07 0.39 0.98 0.43 0.77 1-01 0.11 o.ts 4.33 - 0.23 length* 10.01 - 20.90 - 0.67 - - 0.07 0.17 0.71 0.54 0.50 0.86 0.04 0.22 4.77 0.11 - Ghrysetfle Mat BbWlrH 60.71 . 51.65 23.79 73.99 8.59 12.38 1.23 1.38 0.97 0.74 9.S7 0.66 0.66 0.31 1.19 0.62 1.41 2.04 0.79 0.08 0.13 0.33 0.13 0.S1 0.16 0.3) 0.6E 0.16 9.88 0.04 0.12 0.3O 0.10 0.20 0.06 o. 0.04 0.13 0.63 0.0} 0.36 0.16 0:33 I { | I HWBUI0007260 76 GIBBS * mvc DISOBSM the ramies home ebm due. Ix is easestial to oatiiitt optical muS lT3rmm!LsmUm mleetcoe aleroaenpiK utanitiw, end probably. t include scaaoiag electros vicxoecepe or arimnlng-eronastasleB electreo wlcrocope nethofa Co describe nwplecely Che Botel size dlstrifcottaa of airbanrae fibres. Mftoeeat dteaslota of airborne fibres ere associated with differ ent processes, bet these ate less Shan tins differences betwees fibre types- the significant difference la tbs iii'Mnn boss of airborne fibres is of great laportsme is eoasiderlntt whether health effects are related to ss or marine. faperlaeatsl wife teo relate health effects to fibre dimasleas deasmds at--erwasnt of does bath by rows and ember. Is practice, the majority of fibres no hMch porker# ere exprowd are shore and narrow, and eron the boager fibres lane dianeters of ow i.tally less than 1.0 fie. Farther amelysa are accessary to facerate Us txne order of aogaitafa f dUemes is exposure of different eooupotioaal groups to different fibre dhaeasiess, as theae nay be iepoctaat is explainlag dfffareneaa is health daks, especially for mesothelfona, for diffesast gxeepa ef wders. Fibre dfeasBaiana also fane fspUcfaiMS fax the settisg of standards.. If it is wnwamad that the fibres etoeeeed by pfamsa oamtragt nteuwoopy ace those >J (!* lamgtb and WM2 Mi--Wj> 9.3 m, tbe percentage of the oetal eta-boro fibre stsgsed faximg tie h*iHt<*tg of treeldollte wold be O.dS,-Cor aaoslee, 16.9* mas foe dtcygetUs, 1.61, If the conceetxat&oe vena 2 fibree/ai (F/aOJ, as **rwstf by optical micro scopy, the total Fibre ooecaatxatloea eoaM be Ml /ml for crocidoUts, 12 f/al for mmmite and 12$ f/ail for cfacysotile. If fibres with a diaaetar of loan than 0.3 fro sag a laagxh of > S.O ps proved to b those that predate biological effects, da eaaoancxadoins of fibras in tu size range, for esaantradon of 2 f/mt an rousnred by phnse-oontxast nicroecopy, vocld be apprwrfufly 23 f/ml far crocldolite, 0.9 f/ml for anoslte and 3 /al for Uxxysotile. {HWNSHMS OP MOE ASBESTOS FIBRES 77 far hanaifa. So aixbonro fibres had n dimeter greater thaai 3 pet. and all mold therefore be capable of raadhtag the pdf--sty alveoli. It as sboaa Chet for the mmm airborne ants of the ddfSercnt razlsdse of wheats*, fsasr awosfte fibres; Wald be peanut than otocifaUte or cfexyeedle fibtss. hast of the fibres tas which mottoes see asqpooed axn abort and (Ms. It me also shows that the choice snftlytlcai method and the Unites of fibre diemsloa that can be ebnervwl axe critical, ffeas, fibre* > $ pa efedch ora visible ist tim. light mlexeecope represent only a anall proportion of the total flhte ooone, sod tEsmamiaelm electros microscopic nathods can lead to under-repottkag of long films. tom satewrs eet systfaatlgrasww* aesuxd lev dteenslena do fibres da eeocifalite, d'snosfte et. de cbrysotUs oboervfes dhsa l'fr to ndaes st d'mtiflss. has &&miS23zm& cot 4tS reeneiUis roar fHexes 1 aror- brsste et earoMiin an vdsreeeopia opsiepn ea gtemcppSe dlaccraalRae 5 txsaacfssion at & halayage. la.proportion des fibran eanrtes s'aet svMe dlafiwor v*a le degrf 4a. tzaftanat, pssr I'anelts ea fnrtles- lisr. Iss fibres v&ticaldes par 1`oir a'ayast Jamals na dirodtrm sspdriaer ft 3 pn, ll*s poorxaiamt toste* attsXa&e Ins slsiolea polao- sixea. Lea tears oat nootxS *&mr pout on* aDae maase dams I'mir 4m diff&natna wmldcfie d'antece. In nohbra das fares d'adaiM strait iafkxisar 1 cdloi dam fibre da aroeidB31ee no fa dtexyaotM** is plapert fas faros iniu^miillni las exmvaillnar* amtt ea^nsSs moat eourtes et mdtmeea. Oh Hfl--nr aantre qoe la <six fa Is afahpfa d'analysc et 1# Unites ofaenahlss das dimensions fas fibres sent d'ame Hgper- taaom capitals. Cast atel qm las Bbraa fa plus fa S m visible ea a&exoecopl* optiqoe oa ropxfaentsst qn^nae faihle prpportlOB fa la totalitf, et qwe la aiaeoaespie dlwctroniqoe A tcaawaleaion pew ebootir 6 ane smio-faalaatlOB fa naobxe dan fibres leagnes. SOWRIK Systematic naasormacBts were Safa of the dtessims of fibres frond in the air is aloes and sills for craddolits, asoeite and cfarysotile. Samples were collected on madwraae filters and examined is light, txaasmission electron and scanting elaetron niexoseopas. She proportion of abort fibres was shorn to decrease with octeot of processing, especially 78 t II cries a hm We acloHHrlalge wi th {tanks the assistance presided bf Dr &.S.J. Beloit3 fe made stamgsmstts for us to irteit aloes sad sSUj la SsmSA Africa, sad to the atoieg eaapsais la Smelt Africa and Qaskec ujbo praaittod ns ce take airborne staples ia (Mr vorkplacaa. We slao acknowlnd&e tbc laatteat* of Geeapnfctonal aad 8n*lreaBeatal Stealth o tits Qssboc Asbaataa Wimls* Aaooeinclan for ftoanafet support of tids Priiminarch. I l i I i t i Bacfclafca, M.R. 0976); State of cte arts wbmaa gfatad dints--m of die Isa* sa& s&m. osgnst. <wlr egMaadoiagy and dnpUcaciess Is* clinical ptacttoe. . JSsu Bm. reap. Pf*., IM W7-2Z7 >&, C.W. A tat, CUT. (1975) HqwlcaL fMiiaama. of airborne asbestos fibres is vssfsea wo*k awrlxaaHao - pNUafosqr ftndtags. tte. -fad. dpf, J., Jff 4S9-466 KcOonsM, A.D. a McDonald, J.C. <1978) HmtVIlw after exocldoUte exposure faring gim iiiilr aanafacctace. 346 6u. Jk., 27, 340- Stanton, K.T., layerd, K., April, A., Killer, E., Ksy, H. X Kent, E. (1977) Carcinogeni&ie^ of fibrous glass: platral response la the rat la rslatloa to filter dlaansioa. ' <7. unit Cemasrp last., 58, 587-603 Drlpt, 6-H. t Xasebaer, H. (197S) Tha jaffmimra of ossyina ftbss lengths 9f glass mi aahsstxm fibres an tornm response ia gameopigs. tat MUno. V.B., ed.,, Saboted tasrHeles 17, Vol. 2, Oxford, Pezgassn Press, pp. 435-474 HWBUI0007262