Document dnNQV4p14jYOr31NwVMK9DGg9

PLA IN TIFFS EX H IB IT WCD-395 Talc: A Possible Occupational and Environmental Carcinogen Hector P. Blejer, M.D., D.I.H. and Robert Arloo, Pbarm .D. T a lc is mineralogically closely related to three of the five major asbestos.-group .m inerals..speoifically, the . serpentine Chrysotile, as w e|l as the first : two of the amphiboles Anthophyilite, Trem olite, Amosite and Crocidoiite. In certain toxicological aspects, talc and asbestos are also dosefy related: They are silicates which produce fibrosis of . the lung and other tissues. Talcs and the asbestos minerals cited are hydrous magnesium silicates difficult to dif fe re n tiate -- excep t w ith " sp e c ia l techniques, such as electron microscopy ' w ith selected area diffraction--and ' w hich form in the same as w ell as sim ilar geological processes. Con sequently, many talc deposits contain asbestos minerals, so that in industrial and comm ercial use, such talcs always ' contain varying amounts, of asbestos fibers. Because o f this asbestos con tamination o f talcs, w e reviewed data ont (1) The composition of talc and related asbestos m inerals; (2) The toxic effects of both substances; (3 ) The general environmental exposures to talc; and (4) Its common uses, including those involving ingestion o ft e le ' co n tainin g foods and drugs. A d -, ditionally,, (5) M ineral residues from lalc-coated'jtee washings were analyzed for asbestos. Then we re-evaluated such data, together w ith new findings on the asbestos contamination of lalc-coated polished white rice. A s a resuit, w e Or. EJr[pr it M edical O fficer and Head. Qc- Cvpalional Health. Southern California Bureau of O c ' eupatinrul Hea th and tnvironm enljl Ep irirm in ltfiv. S a le of Caltlnania Defunm enl nI Public Health, Lot A njeles. and Antclam C lin iral Pm leuor of M edicine, : School of M erleirre, U nivm tty of Srtuhem C alifw - n ia. lo t A n sel. Or. Artnn it from K a iw Foundation H otptlalt, 1m Anselm , Reprint Trqncctt In 1A49 Temple -51, Su ilr TOfi, Lot Anselm SOtHh (D r. B leier). . Pierenled in part at the 15th annual W fM rm In- tlu vn al Health Cnnlerence, San Francttcn, O rliS rer 1. 71. .... . 92 present some new conclusions about related possible health' risks arising from occupational and -environmental ex posures to asbestos contaminated talcs. Definitions and Composition of. Talc ` Pure talc and the three .related asbestos group minerals are hydrous magnesium silicates whose theoretical chem ical formulae are; ; . ".. Tree Talc ' Mgs Sii Oao (OH)a Anthophyilite Asbestos.. Mgr Sis Ojz (OH) 2 Chrysotile Asbestos Mgs Sis Oio (OH)a TremoHtiTAsbestos Caz Mgs Sis 0 :2 (OH) 2 M ineralogically, there are two forms of talc: Nonasbestiform, also called platy or nonfibrous, and Fibrous, also called tre m o litic . As used co m m ercially, however, the term "talc" connotes cer tain desired physical properties rather than a mineral species: It includes all gradations, from the pure mineral to im pure. massive falcose- rocks, such as soapstone. In fact, some com m ercial tafe deposits can contain .a very sm all talc content w ith varying amounts of many accessory m inerals, such as asbestos, quartz, and other "im p urities." In the United States, for exam ple, the Saint Lawrence County, New York State com m ercial talc deposits contain 30% or less of m ineralogically pure talc. The remain der consists partly of: (1) Serpentine, the host mineral of chrysotile, antigorite and liza rd ite ; (2 ) T re m o lite ; and Anthophyllile, w hich can convert naturally to talc. Although m ineralogical "im purities," the asbestos minerals are con sidered in many cases as an integral, part of such commercial talc, whereas other m in eralo g ical im p u ritie s, such as hematite and pyrite, are commercially unacceptable:*, An example is that talcs f - Tabla 1. -- Observed anil Eipectei Deaths, B j Cinte , fcnonj 632 Asbestos Insulation Workers Observait iresperteely - L .. 'L JiBiury IS 4 3 -- 30 Jnne XS7I* . V . - .. .......... ' Baiai " . v - ;-`Z> ' * * ,, ' Curt flf Onte ` *` .. *' ' Tutti, i l i Causa , flambw Observed Fapeetad I i 6 Olietted te E i;c M Perceflt * ObSiFM - 419 . ; . 2SJJ . ; . ; .. t,s : 100.0 -,, ; rotai Ciacer' <Alt Sto) 1 187 Cantar et ttia Lunf. Pltun TtaUtia, Branrhui ' Limi Cinar. , .. * . \ -. B ' ,. j S picufil otti elicmi Pititanu] Mcrttfieliom \ , ' - Caneer nf Slomirt. Cala, Renna ' Canai ni RII ber Slln ! _ . . - ' ' - "*-, , . .. , t . Stintali i: 1 41 " 1S ` _- df* - - : " ' - All Otber Canata | '. . ... t :: e . . 51.5 -- . l.S ' . \ u t .3 1.7 ' ___ ' . ; * .11.4 M ' 11.1 U - t i --' UI ., - 0.1 4 - . ' 22.0 . 10.1 1J - ' l.S ' . 94 . M ' . , ' v` 47. . ' 5; ;'. - Source: riiloil et il.t r t os data art am ila!, but l:|u it tiuuld be oulf llish U j In s tbu 11,1. * US dala aol ita m e la , but ih m a it t u t M u m oi death in lb geaeral puputatlae. Goodhue WCD 000184 Tib) t . -- Deaths tnd Eipcclcd Morii lily liom Ch im i ol tho U n j ini) Pleuu imf Gaslioinltstimt Trini tnd PtrHarwm Scialtd lo Agi In Tale Horkeri" reviewed recently and succinctly by Wagner. ,. ' In addition, inhaled asbestos particles - itin Tram ' Proportion! M ortality* ` 1 M a lijiu n l G iu s t i 1l i r . j I n a M u r i G H end Perrlonturti retained in lung tissues can be covered w ith a protelnaceous-iron coating w hich produces a type of ferruginous body Group T a lli Lufif tn d .G W and commonly termed "asbestos body." O n to rruri Peritoneum ' O b ito r i T fiw retia f O isrrted T h ttru U til T alc. -- As shown .in Table 2 , Klein TtU l L s Itlan 40 59 ' 0 '. 80 in d Q v ir ' 91 19 . j 2 C' b 38 i ! . . t ; - -, t j : l-.l:- 4 0 J. 11 - 3.2 . il 0 - ' * 5.3 s s t - ; S I 17 . ' ! .5 ' . 0. -, '25 : . S .3 5. 5t , . m Y tfter Kielirleld e ltl.i '' ' -- , - , . +Hambei 1 deiUii in I iioiio diiided by tolil deaths in urns roup t 100.' . - ., +Gulwlfl'estinal tract, ; ^/ _ -' t Dineiein-not llllrsliully jjgnll^art. 11 ' - --- - ' 1 Dillnr.itr itatiilially sitnilicjut (p = <0.01), ` .' " r _ I SlillslEnl inilysii not doni due to snrall mwnler in irniip. ' . feld et at9 demonstrated that tal.c miners and m illers in Northern New. York State have 3.4 times an excess mortality from lung and !pleural carcinom as. Such exj cess was' shown to be statistically significant and appeared 20 years later than among asbestos insulation workers. The New York investigators ascribed this difference, in part, to talc being less car cinogen jc than asbestos,' w itho ut'co n sidering the fact that talc deposits in-the for m illing are often chosen preferen- sulation workers, of the, 418 deaths ob- tia lly ' on the basis of how much "im : `served from January 1, 1943, to June 30, purity" is present, apparently because 1971, 20% were due to bronchogenic talc w ilh larger, purer grains is more dif- carcinom a, 10% to cancer of the ficult to m ill. 'Also of note .is that the stom ach, colon, arid rectum, and 6% to most recent revision of the US P/iar- pleural and peritoneal mesothelioma. macopefa2 does not specifically exclude The asbestos forms used ,in the past by asbestos as an im purity in its definition . these workers w ere mostly chrysotile of pharmaceutical grade talc. The World and am osite, w jth possibly sm all Health Organization1 in its 1971 ner amounts of cro cid o lite,.. . evaluation o f food additives noted that As % group, the same asbestos in asbestos is a contaminant in some talcs. sulation-workers show about eight times A ll of these are factors which make it im- an excess mortality from bronchogenic perative to ascertain the mineralogical carcin o m a. M oreover, asbestos in- . type and purity of talcs in assessing their sulation workers w ho smoke have a 92- potential, health effects. ' fold risk o f dying from bronchogenic car- ' ' cinom a, as compared with men w ho neither smoke nor work w ith asbestos.7 . T o xic Effects Thus, this type of occupational asbestos Asbestos. -- Different forms of inhalation exposure points to another ef- asbestos appear to have different feet of asbestos, that of a cocarcinogea .. biological effects. These differences are The asbestos group.m inerals have the still too incom pletely understood and added toxic effect of fibrogenicity w hich ' complex to be discussed here, except as results in ; Asbcstosis, the well-known mentioned briefly below . Nevertheless, it o ccup atio nal lung fibrosis due to can- be staled that carcinogenicity is ihe chronic inhalation overexposure; Pleural most serious toxic effect of the various plaques and calcifications; as w ell as the asbestos group m inerals..In the last few lass w ell-know n asbestos ' corns or decades in particular, these substances, "w arts" of the skin among workers especially some types of cro cid d ile, handling such materials. - have . been occupationally associated As mentioned, toxicological effects of With greatly excessive incidence of different forms of asbestos appear to be pleural and peritoneal mesotheliomas, different. For example, as compared with previously extremely infrequent cancers chrysotile, exposure to the amphiboles is in humans. Moreover, a number of generally m ore lik e ly to produce northern part of that state contain much asbestos, as w e noted above. No significant difference was found be tween the observed and expected mor tality from carcinom a of the gastroin testinal tract, and peritoneum among- these talc workers. A w e ll-k n o w n e ffe ct o f ta lc s , especially the fibrous variety, is talcosis, another o f the many occupational lung fibroses. Other toxic effects are the production o f granulomas in wounds and scars, and intense m esothelial irritation, w ith fibrosis and adhesion in the pleural and peritonea! cavities. These occurred often in the past, due to the operated tissues being contaminated w ith the talc used as'dusting powder for and shed from surgical gloves-- a use no ; longer recommended.10 Likely.for sim ilar reasons, the Kaiser Foundation Hospital in Los Angeles discontinued the use of "talcum " powders for any inpatient use. A bizarre, new and serious talc effect is th at o f p u lm o n ary in tra v a sc u la r granulomas w ith vascular thrombosis and sclerosis leading to pulmonary hypertension, due to intravenous in jection of talc-containing oral tablets and talc-adulterated substances in drug m isyse.*' .. inhaled fibrous talc particles can also toe changed by cells in the lung into another type of ferruginous body which seme call "ta lc bodies." researchers have experimentally induced asbcstosis and bronchogenic carcinoma, . pleural mesolheliomas after intrapleural A lso , in h alatio n of cro cid o lite-- es- injeclion of various forms of asbestos and demonstrated:the neoplastic nature of those tum ors.' As shown in Table 1, Selikoff et al* recently reported lhal among a cohort of 632 asbestos in- pecially of some types w ith shorier, finer Hygienic Work Standards lib e rs as m easured- by e je c tio n ' ..-. A sbestos. -- For 1972, the Committee m icroscopy--appears to produce more . on Threshold Lim it Values for Airborne mesotheliomas than other amphiboles Contaminants o f the American Conand ch ry so tile . T h is su b ject w as feeence of G overnm ental Industrial Journal of Occupational Medicine/Vol, 15, No. i/Fcbruary 1373 Goodhue WCD 000185  I lyglenjits (ACG1M) tas proposed a time-weighted, average lim it value (for an fi-Jirjur workday, 40 hour workweek) for all forms of asbestos of 5 fibers per m illiliter longer than 5 i in length, as determined by the membrane fille r , method at 430-tim es- m agnification phase-contrast illu m in a tio n ,15 This Threshold Limit Value [TLV) has been developed as the air concentration of asbestos fibers which" (1) should afford protection against asbeslOsis, and (2) reduce to an acceptably low risk the t / development of neoplasms. This TLV - \dces not ssre complete elim ination of . : d b e' carcinogenic risk because of in complete understanding of dose-effect relationships: Moreover, even though - different forms of asbestos apirear to , have different toxic effects, a single TLV .was established for all forms because of incomplete information about these dif ferences.1.5 . .. . ' In. June 1972, a sim ilarly documented but lo w er Tim e-W eighted Average (TW A) of two such fibers---proposed earlier in the year by the National In and illustrated in the figure. stitute for Occupational Sjfoty and Talc. -- For 1972, tire ACCIH has a Health, Public Health Service; US De TLV for each form of talc:15 partment of Health, Education, and (a) bkirusbmihirm Tafc: 20 m illion par- W elfare--was adopted for all forms xif -liclcs per cubic Toot of air (m p pcf), asbestos, effective July 1, 197f>, by the- based on the Light-field dust count Occupational Safely and H e a lth 'A d (b) Fibrous Tula The sam e1TLV of S ministration (O SH A ), US Department of- fibers discussed above. , Labor. Until that effective date, the 5- The Documentation for these TLV's takes fiber TWA discussed, above applies as into account, the different biological ef- ! the- US standard for alt forms of. fects of'the (w o forms of talc and of the asbestos.14 ' need to determ ine "their ty p e . arid , It should be noted that all these stand purity,15 ards are based oh the identification and i The revised Table G-3--Mineral Dusts quantification of all forms and types of I in the sam e'OSHA standards cited" lists asbestos fiber by phase-contrast (op only one hygienic work standard of 20 tical) m icroscopy. Although evidence mppcf for talc. This is an error w hich about their toxic effects is still not w ell should be.'rectified. O therwise, the 20 u n d e rsto o d , ce rta in ' -ch ry so tile , mppcf applies as the US Federal Stand? croddoftte, and other asbestos fibers are ard for both ptaty and fibrous talc. - - too short and/or fine to be detected ex cept by electron m icroscopy: Essentially the same can be said of-chrysotile Environmental Exposures to Tate fibrils-- ultram icroscopic morphological T a lc is e c o lo g ic a lly v irtu a lly units of a chrysotile fiber mentioned in ubiquitous through its many uses in the section on Environmental Exposures modern living. O nly very recently has Electraeptiotqmicroeraphs ol particles eititcled from talc-coated tic. Lett Talc (T) and Amphibole asbestos (A) libers. Right Talc fiber (T) with Chiyiotile asbestos fibril (C). Identification confirmed with selected area dif fraction. [Election microscopic studies by Dr. A. H. Lanier, Hew York. Original mapiificatieii If 45,ODD.) ' ' 94 Talc: A Possible Occupational and Environmental Carcinogen/Blejer and Arloii Goodhue WCD 000186 there been some indication o f its widespread environm ental inhalation and other exposures to humans. As '' '. , Tible 3. -- Tale PiiUtlei Found In Slice od "Homei'1 .. . . and Cincero Fomite Reproductive fu n * . ' reported in 1972, Unger el a llft set out through electron microscopy to Identify asbestos materials .-in the lungs of 28 ': . "' SpKlrnen * . Humber - Talt found* ' Humber tn u l consecutive autopsy cases nf New York City residents.. Asbestos bodies were found in only three cases, whereas chrysotile fibers were present in 24. tumor Geary ' Ctii ' Endonttriirfft , ' ' D ' 21 -. 1 23 .. 10 ' .i 66 77 17 . too Moreover, chiysotile fibrils were found in all 28 cases. In addition, clay and/or talc particles w ere identified- in the lungs. * ,V of 18'of'these 28 decedents, all of whom \\ had been long-timeresidents of that city. -Secondiry Tumor Qieiyt . , - MHrnL*r Ova17 from Patient Willi Bruit Center ' - 1 : ' 0\ ' .1 ; : 0. 12 * S ... 0 0, 47 None had been asbestos workers nor, from our review of the published data, talc workers. Recently, Henderson et a l'r * Source: tfendeiun. et el." t Particle et rincer 1000 A = S'oiti fix e plient' drew, attention to the dose association of talc and asbestos minerals when, searching for asbestos through special electron microscopic techniques, they unexpectedly identified talc particles whether the presence of talc was ad deeply imbedded within the tissue of ventitious or causative. . A different study reported in'mid-1971 primary ovarian, endometrial and cer vical carcinom as. Table 3 summarizes these data and also shows that no talc - by the En viro n m e n ta l Scien ces Lab o rato ry, M t. S in a i School of particles w ere found in the one secon dary ovarian carcinoma thus Studied. M edicine, The C ity University of New York, revealed that significant amounts A dditio nally, the same investigators of asbestos were present in. two brands of com m ercial, household-use fibrous found talc particles also ovarian tissues removed in "norm al" from patients talc dusting resu lt,-th e ("talcu m ") powder. As a US Food and Drug Ad with breast cancer. They made no com ministration announced that' if such ment, however, as to how the-talc par ticles reached the , ovaries and other results w ere to be corroborated by an in reproductive tissues in w hich the talc dependent expert panel, it would ask the was found; nor did they comment as to manufacturers to recall such "talcum " powders. It Is of interest that in dependent geologists informed the FDA that talc and asbestos can appear in the Table 4. -- Talc Used in the United Steles* - end Sold or Used in California ' 1933 1963 Ateret same m ines, and that contamination could be caused at that source.1" 19 U ses o f T a lc G e n e ra l. -- T a lc is found, in cosmetics; spray and dusting powder, including "talcum "; .chalks, and crayons; ceram ics; electric and heating insulating materials; roofing materials; Insecticides; foundry facings; textiles; white ' shoe polishes and glove cleaners. Talc is also used as pigment in paints, varnishes, and ruhber; filler for asphalt, paper, rubber, plastic, and soap; dusting powder in rubber m anufacturing, and products such as inflatable toy ballons, prophylac t i c co n d o m s, and co n trace p tive diaphragms.1. w ' ' . . In Foods and Drugs. -- Talc also en ters into food processing' and phar m aceuticals. It Is used as ap. excipient and filter for pills and tablets; for dusting tablet m olds; in clarifyin g . liquids by Phterl Du 'V, ' Total Ceramics Paints Rubber ' ' loteeficrdn Fapir ' Sowflnt Tflll PftpraiOfi 1tali ta Jlspfiill fjJUr ffiund^ facinis Reitaetorrei . Rict Coaling Crayons. Other Uses tfniW States Califon IDO 3S . 21 5' .4 4 3 3 3 2 .t * 4 .* IS too . to 21 1 2 -- 2 4 Z --. 1 * 1963 11$ wntumplioe: 13 i 10? etieit tun t Seul Welle.1 . 4 leu Uiee 1 ptreeet ' . Table S. -- Aje-Siairdardiied Deith tatel lor Malignant Heopfesms . of the Slomech, bp Sex, Japan end Varioui Ethnic Groups In California ' Urea antf Ethnic troop Japin' Ciliterniat Iiaelt nisei) Slid White ... .. - :` , ,. / , . .' . ' .* ` .aft ' * - ItT H4 , am fw ili* 35.5 11^ 11.3 4,9. 4.0 . Mataifftrrili - . 1,9 2.1 1.0 1.0 2.0 19B439S, Storce Sep et el. ' 1 11574314 let tuei end Hietl; 195MHI Iei Had endW ife fanta: Dunn and Both. 4 Fereifl let tapieeie. ( uS-bem jieetieu.' - journal of Occupational Medicine/Vol, 15, No. 2/February 1973 95 Goodhue WCD 000187 filtration; in salam i dusting; candy uncooked and washed, cooked rice molding; in peanut polishing; and in the samples. Sim ilar -analyses revealed that coaling of polished rice.' 10 Table ,4 all samples were contaminated with presents quantitative data on many of much Am phibole asbestos (A , M. these, uses in the United 5taics and , Langer, personal com m unications, Feb, California. . M ar, Apr 1972). Sim ilar work done, at the School of Public Health, University of California, Berkeley, revealed essen T alc-C o a te d P o lish e d R ice tially identical results, even after m ultiple a As stated above, talcs are used In a washings of the rice {ji C M urchio, per . multitude of ways which can lead lo sonal com m unications, Feb, Jul 1972). ' widespread inhalation, ingestion, and 1 .other exposures. O ne siich major use in . ' ; .yolving ingestion is that of talc-coating Discussion of New Findings :: h i polished {w hite} rice.. - Regarding the asbestos contamination . '\ t n . lhe United States, and especially in of California-processed talc-coated rice, . California,15 a significant portion of the our findings and those of others cited . polished rice is coated w ith glufose and above appea ta be important for a num '-.ta lc . This process, w hich imparts to ber of reasons. Firstly, talcs have no - white rice a pearly, esthetically more at nutritional valu e.15 31 Thus, agricultural tractive appearance and may also researchers have tried unsuccessfuliy to . .. prolong its sh e lf-life , has to our ' convince the rice-processing industry to knowledge, never berin. traditionally substitute talc for other substances with used in the O rient. Currently irt Califor- some nutritional valu t-- even though, to nia food stores it is common to see sacks' our knowledge, these researchers did not of rice displaying the mandatory warning know that talcs could be contaminated ...- ; label that the rice contains added talc with asbestos. Secondly, the "Delaney and glucose and that it should be Amendment" to the US Food Additives . washed before cooking. Consequently, Act essentially prohibits the use of any w e set out to determine whether the talc used in such . coated rice ' contained asbestos and, if so, whether a related food additive substance known to be carcinogenic to -man *'or any anim al. Thirdly, the H aw aiian, Italian, Latin asbestos-ingestion exposure existed. A m erican ,: O kin aw an , and Spanish New Findings. -- In this regard, early peoples currently prefer the smooth and in 1971, u sin g , p h ase-co n trast shiny taic-coated type o f w hite rice, such microscopy w e could not identify any as the one processed in California.- In asbestos in the residue obtained from fact, the Associated Commonwealth of . w ashing s of -uncooked C a lifo rn ia -, Puerto Rico buys much o f this Type of processed taic-co ated rice . Later, rice, and requires that all rice sold there however, electron microscopic studies be both enriched and talc-coated, using selected area diffraction w ere done Some of the nations cited, as w ell as to analyze sim ilar samples of talc-coated others in the Orient where w hite nee has rice bought at neaFby stores in small been a staple for centuries, continue to quantities (eg, 85 gm for 4 cents) e xp e rie n ce w id e ly d iffe re n t age- scooped out of . large rice Sacks' and standardized gastric cancer rates, and handed over the the clerk in a plain, none higher than Japan. Moreover, in brawn paper bag. Amphibole asbestos some European and other nations where fibers and Chrysotile fibrils were iden rice is nol a: staple, the pertinent gastric tified in .the mineral residue, as shown in cancer rates are almost as high as in the Figure. Sim ilar w ork done by another Japan.1111W orld-wide, such high gastric program of the California State Depart cancer experience can, therefore, be ment of Public Health in Berkeley also , ascribed specifically neither to just a identified asbestos in samples of talc- habitually large inlake of urtcoated w hile coated rice sold locally. At essentially the sam e tim e the Environm ental Science Laboratory, M L Sinai School of rice nor lo a habitually large intake of asbestos-contaminated talc-coated rice, as one report in Science did recently.M .M edicine, the C ity University of New Thus far, the one common denominator York, extracted the minerals from several in gastric cancer throughout the w orld samples of laic-coated rice marketed in appears to be a gross nutritional im the WesT Coast of the United States. balance w ith an Intake high in car Such extracts w ere prepared from both bohydrate, tow In fat and certain vitam ins, as w ell as, in some cases, high in spicy and/or salty additives. For exam ple, Ihe Japanese ingest targe amounts of w hite rice and salty- sauces;35 they also have, as a nation, the highest age- standardized gastric cancer m ortality and- morbidity rales.11' 1J , ,' Lastly, for a variety of environmental factors which are not clear but w hich point lojdietary changes, Ihe foreign and US-born Japanese in California are at a much reduced risk from gastric cancer than the Japanese in Japan.311This change is quite evident from the data in Table 5. In the last few years these Californians of Japanese extraction have begun to.show a new and marked preference for short- grain, talc-coaled rice.TM Apparently, ex cept for the talc-coating, this is .the same rice traditionally and habitually eaten in Japan, since most o f the California- produced rice is of the japnica variety of Oryza sativa, 21 Given the possibility that the ingestion of enough asbestos- contaminated talc were to be car cinogenic, the question arises, therefore,- ; whether the Japanese-Americans might not be adding to their risk of gastric and other gastrointestinal cancers36 From their new and increasing ingestion of enough, asbestos-contaminated talc-coated rice, thereby counteracting the gastric cancer- reducing factors in th eir new en vironment? Sim ilarly, might other cited nations , and peoples who now also prefer talc-coaled rice be at a sim ilarly grea.er risk? If this were so, and con sidering the long lapse-time for the car cinogenic effects of asbestos to become manifest, it would take years, maybe decades, to find conclusive answers. Ir* any case, talc has no known nutritional value, As such, its use as a food and drug additive is questionable, at least, and unwarranted if these talcs are con- laminated with asbestos. G e n e ra l C o n clu sio n s an d Su m m ary Talcs can. be contaminated w ith asbestos m inerals. Both talc and asbestos produce various . fibrosing conditions. Asbestos as w e ll a s . asbestos-con taminated talc are known to . be oc cupationally associated w ith excess mor tality from various cancers. Talc enters into o u r. lives through everyday-use item s. Ing estio n , in h a la tio n , sk in , vaginal, and other routes of talc ex posure and absorption might, therefore, be associated w ith increased en- 96 Talc: A Possible Occupational and EnvironmenUI Carcinogen/Blejer and Arlen Goodhue WCD 000188 vironmenUl and consumer health risks. Environm entally produced deposition and retention of talc particles'in human lungs appear to be widespread. Also, talc particles have been (ound in some normal ovaries, as .in the core of primary cancers of the ovary, endometrium, and cervix of nonoccupationally talc- or asbestos-exposed wom en in Britain. Nevertheless, the presence of talc in ihese tissues cannot presently be said to be more th.an adventitious, and a finding w hose sig n ifica n c e m ust i w a j l corroboration by well-controlled studies, preferably from, diverse geographical areas. Moreover, many talc dusting ("talcu m ") powders and Californiaprocessed talc-coatecf -rices recently tested Were found to contain significant amounts, of asbestos. Such .findings raisequestions of possible w orld-w ide in creased health rjsks to humans, arising from occupational and environmental exposures to those every-day use cosm etics, , foods, drugs, and other products w hich contain talcs signifi cantly contaminated w ith asbestos. ' It is not the intent here to im ply that all forms of talc pose an occupational or en viro nm en tal ca rcin o g e n ic risk , although there are obvious instances in which certain, talcs can.be a source of asbestos exposure. The data presented here indicate that whenever talc ex posures are expected to occur, adequate analyses be done beforehand to deter mine that m ineral's type and purity, as w ell as the related need for proper 'oc cupational and environm ental controls. This approach is warranted because, in our experience, many exposed em ployees and consumers at large consider working w ith o r using talc-containing materials essentially safe, which has not been the universal occupational ex perience, Although there is no scientific evidence of any carcinogen icily of talc per.se, We would bo remiss if w e did not suggest a need for feasible, properly con trolled experimental anim al exposure studies to ascertain any possible car cinogenicity of pure talc. . ' The author*. Lhank D rt A . M. U nger and f. .S e lik flif, M l. Sinai School of M rdirino. New Yoric, for their constjuclivp comment* a ix} iAsislancv; Ms, M arilyn Hunter and ihn CummimicaMon Service Cen ter., California Department of Public Health, Berkeley, for their pal m uting work on manustript pTeparallpn: the Reference Staff. Public Health lib rary. University of California, Berkeley, and M r. E. Hughes, Medical Librarian; Kaiser foundation Hospital, Los Angle], for their indispensible hefp in researching1 the literature. References 1. W ells lit: Talc, so lp slo n e , and pyrophyllile, in Mineral Facts a n d Problems, 1965 ed. US Bureau of M ines. US Govern ment Printing Office, 1965, pp 919-927. 2. 7he United States Pharmacopeia, IBIh revision. U S Pharmacopeial Convention, tnc, 196.5, . p. 705. . ' . 3. W orld Health Organization technical Report Senes, No. 462: valuation of fbod Additives: Geneva, 1971, p 16. . 4. Wagner |C, Sleggs CA, M archand P: Dif fuse pleural mesolbclionta and asbestos ex posure in the North Western Cap e Province. Brit ) Industr Med 17 260-271, 1960. 5, Smith W E, Milter L, Churg J, el. al: Mesotheliomas fn hamsters following in trapleural injection of asbestos. J Mount Sinai Hasp NY 22:1-0, 1%5. , 6 , -Selikoff l|, Hammond EC. Churg I: Mor tality experience of asbestos insulation workers, 1912-1971. Presented at the IV. In ternational Conference on Pneumoncontosis, Bucharest, 5ept 29, 1971. , . . 7, Selikoff !|, Ham m ord EC. Churg |:' Asbestos exposure, smoking, and neoplasia IAMA 204:106-112; 1968.. 0, Wagner |C: Current opinions on Ihe asbestos cancer problem. Ann O c cu p H fg 15.61-64, 1972. '. 9. Kleinfeld M, Messite I, Kooyman O , et al: Mortality among talc miners and millers In New York State. Arch Environ Health 14:663 667, 1967, 10. Merck Index, ed 8, 1968, p -1011, 11. Hopkins GB, Taylor C D ; Pulmonary talc granulomatosis. Arnnr Rev fiw p DA 101:104, 1970. ` , .' 12. American Conference of Governmental v Industrial Hygienists: Threshold Limit Values of Airborne Contaminants amf Physical . /Agents with Intenrled Changes Adopted hy ACCIH b t T972. Cincinnati, 1972. ` , 13. American Conference of Governmental Industrial tlygienlsls: Documentation of the Threshold Limit Values for Substances in Workroom Air, etl 3.. Cincinnati. 1971, " 14. U S O ffice of Ihe Federal Register; O c cupational safety'and health standards. Title 29 -- Labor, Chap XVII, Section 1910.93a; as of lune 7, 1972, p 11230. 15. US O ffice of Ihe Federal Register: Table .G-3 -- Mineral Ousts, Section 1910.93, 1972.. p 11230. -' - '' 16. U n g er AM. Selikoff . 1|, Saslre A: Chrysatile asbestos in the lungs of persons in New York City. Arch Environ Health 22:348 361, 1971, . 17. Henderson W |, loslin CAF, Turnbull A C , el al: Talc and carcinoma o f the ovary and cervix. 1 Ohs ret Cyn aec Brit Comm 78:266 272, 1971. ,' 18, Trade and government memos, in F-J>C . Reports 33:1, f u ly '12, 1971. : . 19. Trade and government memos, in F-D-C Reports 33:12, |uly 19,. 1971. 20/ Ferrel RE,- Kohler G O , Mickus RR: New ' rice coating materials. Rice J 69:11, 1966. 21. Houston -D F, Kohler. G O : Nutritional Properties of Rice, W ashington, National Academy of Sciences, 1970. . 22. 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