Document Rj4dRz67j6a88yO3KLznwn2ek

V \.j ji*i.il hiilMilriKV. nwtl *'. 'gu t$f hne.Mitmum .*\C,m,|i, liu . ?4?0 l 11*1*111* <m ihi' Ihr Kittuntum tout iiii: irul aiuiiy*'*. it icrram, in lo;h (he JUlhor or to a 90.U7. = > mftnmu nt t'icv. ;*i7(i \ i 4. |ij. 12* 12*. i*iiiticU in tircii Hnuin JNII.RNAL KIJI.IVIION .SI'l.Cl KOSCOI'Y AIMM.ILD TO AIR POLLUTION I kANk M. Nkiman and Binmmin Linsxv I Vl'ni liiienl til I iv[t 1 .iiitinccfiiiu. West Viruinm lItiivrrvilv. Mnrganlowti, Wvvi Viiitmu t / vl rrrrhri/2'i Muv IVfiV; ntuf in finalform J Auyu.f I '>f'V>) AlNtrct--Five internationally standardized samples of types of asbestos were identified by miilnivlL' internal reflectance spectroscopy in the infra-red region between fSO cm'* and 4000 tin Previously. identification ofasbestos types hat regtiircd personal visual recognition Ihrougn light microscopy, electron microscopy, or electron microprobe techniques The type of samples used in this invettigaiion were undiluted, uncomaminated masses of large sired asbestos fibres less than 200 aim in length, similar to refined production material. The ability in identify lhiv material in bulls, rcjdiiy, can be expected to be useful when relating atmospheric asbestos fibre samples to specific sources and types. The lower limits of resolution as to mass, fiber length, and dilution with other air pollutants will next be determined, along with methods of atmospheric samples preparation, such as a slow ashing method. . . t . I NT RODDCTION Si'ttfAO spoiling. including soiling, of materials by paniculate and gaseous air pollu tants is a recognized undesirable effect encountered almost daily in our environment. One type of paniculate pollutant, asbestos, seems to have more than just a surface soiling effect. .Asbestos fibers arc generally characterized and identified by visual or electron nticroscopv methods requiring skilled visual observers. V different class of instrumental technique that mas be useful in identifying parti culate pollutants and pollutant effects is known variously as multiple internal reflection spectroscopy and attenuated reflectance spectroscopy. Pollutants may be chemically identified using this technique determining the infra-red absorption characteristics of the collected pollutant or its effects on some materials in the 4000 cm* '-650 cm* 1 region of the spectrum. 2. EXPERIMENTAL ' Internal reflection spectroscopy was used to characterize 5 standard reference sam ples of asbestos obtained from the International Union Against Cancer as described by Timbrvll. Gilson and Webster (1969). These sample consisted of Amosite. Anthophvllitc. Crocidolitc, Chrysotilt "A", and Chrysotile "B". These samples were assembled and distributed by the Pneumoconiosis Research Unit of the International I in ion Against Cancer primarily for biological tests of the effects of asbestos in animal experiments. The asbestos samples are fibrous in nature and approximately 200 pm in length. The Ampliibole samples (Amosite, Amhophyllitc and Crocidolitc) fibers are coiled. The 5 standard reference samples of asbestos were all Grade IV on the Cana dian scale or the nearest equivalent in order to have materials of relatively short fiber that together now' account for 98 per cent of all commercially used asbestos. 125 PLAINTIFF'S KXllllllT l'TS-234 0000 I $ ?llli SCF-FA-6313 PRODUCED HV FtTPn : v^ < 136 Fxane M. Noonan and Benjamin Linsky . . The ftsbtttos samples were deposited onto both sides of a KRS-5 reflector plate approximately 50 x 20x2 mm with a 45 degree angle face (hat yielded approximately 25 reflections. Approximately one third to one half of the KRS-5 reflector plate surface area was covered with the asbestos sample supported in a Wilks M1R-2 steel holder. Pressure was applied to achieve efficient intimate contact of the asbestos wiih the reflector plate. Internal reflectance measurements were made by means of the Wilks Scientific Model 9 Single Beam Internal reflectance attachment, including a Wilks Model 2 sample holder, on a Perkins Elmer Model 137B. Infra-red Spectrophotometer with sodium chloride optics. A Wilks M1R-I1 beam attenuator was used to attenuate the reference beam. The optical efficiency of the Wilks Model 9 attachment with no sample present is about 50 per cent after reflection losses. Fine adjustments of the optical alignment were made without the reflectance unit to produce a recorder response of 98 per cent transmission at 2000 cm"1. The multiple internal reflection unit was inserted and produced a recorder response of 37 percent transmission at 2000 cm"1. The reference beam was then attenuated using a Wilks Model 1! beam attenuator such that the recorder pen response was 75 per ceiit transmission at 2000 cm '1 with no sample present. The infra-red interna) reflectance specira obtained for the asbestos samples arc shown in Figs. 1-5. WavtlwigOt, /I is FlC. I. Infra-ltd internal renectance specirui" f Amositc. 3. DISCUSSION No attempt was made to note band assignments since this part of the study has been directed only to detect instrumenlally measured differences between the various l.'iCC standard referenoe asbestos samples, Br.lj.AMV (lUfvt) lias miictl the region of transmission absorption area between 1100 cm 1and^OOem 1 tor silicate compounds. t.AUM a (Iv52) also shows u transmission spectrum of unlhophyllitc that was obtained from thill hints of powder asbestos (liber length of less than 2 /<mi Jcposiied on a sodium chloride plate. Launer indicates that the amphihols have a band near 709 cm "1 which is characteristic of the double-chain silicates Tlirir is u strong similarity between I lie- iibsm |>liin spcclinm obtained t ,| antin' pliyllitr by direct transmission measurements hy l.anner and tliai winch was ni.i.iineit B00U 0441 i' l' PRODUCED BY FORD t .. .#;*>, siirlaee lv holder. jggS&h '* Sociiiilu Model 3 neier with -nuaic (he no sample anee (mil muliipli. 7 pmvni : H ills lit'iMHi) Hi Ik. II a>|* |v 0||t|r>l III A| |*< >IJtiliin) 1:7 I : liifm-rs-a internal rchcsiancc apeclrum of AniSophyllilc. ias hecn various, gion of ounds. hlained d on u 'Km'1 antlnv 'laincd I Wovttoftfffh, pm 9000 044? PRODUCED BY FORD IM Frank M. Nuonan and Biniamin Linsav WsMlangth. pit* Fig. 5. Infra-red internal reflectance spectrum of Crocidolitc. in this investigation using internal reflectance spectroscopy on the UlCC standard reference sample. There appears to be a wavelength shift to the longer wavelength which may be expected as one changes from transmission to internal reflectance. The transmission absorption peak at 1639 cm'1 has been associated by Coblkstz (1906) in his early research on both water of crystallization and liquid water. When the sources of air pollutants in a community's atmosphere are being sought, or when an undesirable effect of air pollutants is being investigated, it is important to be able to determine the probable sources and types of the pollutants. Various types of asbestos have been implicated in vary ing degrees in human diseases. Heretofore, it was necessary to rely upon a highly skilled microseopist. visual or electronic, to distinguish between the major types of asbestos that arc used in pro duction at any one time. This investigation attempted to use an instrumental technique that might lend itself to a totally numerical, and. therefore, computerized, identification system for a larger number of samples with less manpower and lesser manpower skills. The continuing investigation is extending the technique to the characterization of air pollution soiled and otherwise spoiled surfaces and to extend the technique of asbestos idenliheation to smaller quantities above and in the presence of other pollu tants. Sample preparation techniques such as slow ashing will be investigated, together with spectrum signal peak amplification and masking. Afkm*wtrJtiement.\ Thu nivrlipntion wa* mjpfu tried hv I'uMiC Health .Service CtraiU Number x `11)1 AWOI AIR and Wr*l Virjiniu University I'ngincermg fisperitnent Stmum. ki l l kl'N( l s III 11 amt l,, }. (l**4) the tnfto nut Sheriff* #/ (imip/rr Moteiuilrs, p. VI .* Jitlin tA tlcv. Nc* 1 <k (`mi INI/. W. W. (I90h| tnretlk'o/ton.s of //, rt/ \/ii //<, I\it1% HI .*! IV. p. I.'K i uriiegts' IrHliiutc of J>.(' I AttNKa I1. ). (|V$2) Regularities iu the infra red ahynplum ipccti.t >I mIkoH- inihctiiW . Miner t7. 7*4 7*4. . V. / i and H'lMm I rf'^M Hit ( hi. *. W Ini. J I'unrrr ,t, 4(V 40H. 8000 04A3 PRODUCED BY FORD 8000 PRODUCED BY FOPn \^ v ie < r/j v J y 'H 4 & * x flf& tl