Document K6njerm7dJ52pLwVRpox3RXqX

UNIT* STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON. O.e. 104S0 October 29, 1984 Mr. Jack K. Unt Assistant Administrator for Water CW1-336] 0. S. Environaeacal Fretacelon Agency 401 H sertoe, sv Washington, D.C. 2Q4&0 Da? Hr. Seven: On July 24, 1984, eha Environmental Health Cemttea (IK) of EIA's Selaaeo Advisory Board rovleved a paper praparad by eha Crltaria aod Standards Division is eho Offlea of Drinking Weter (OOH) aad aaelelad `Major Issues Associated with laaleh Effaces of Asbastoe la Drinking Water (Carcinogenesis of lageetad Asbe sees Fibers).* Two sclaatists dio are amperes on the subject of asbestos assisted tbs eoanittec: Dr. Brooks T. Kossesn free Che Oalvetslcy of Texmoat aad Dr. J. Corbitt HeDonald from McGill University. The aeisatlflc issues presented to eha Coaaleeee for les review were carefully fraaed. The docuaeae with les supporting aaearlal was wellfocused aad reached eha Coaaieeae la a timely say. Dallka the clarity with which your staff presented eha kay scientific Issaes, to data 11 tele of eha relevant evidence Is anaaablo to elaar--eat scientific Interpretation. Isperdlng caperlasntal aslael evidates, ODD staff drew attention to raceme seady from the National Toxicology Program (RTF), which has noe yet beaa pser-revlewed or published. The NTT bloaseay aey contain evidsoea in fever of eueerlgeoeeia by asbestos ingested by experimental anlaala, a result which has see beaa reported la ocher bloaaseyo. The Conmietae la preperod to revisit the Issues that this evidence eaa be aora widely evaluated. Zc undarstaada that ODV staff have transmitted a cepy of tha bloaooay to XTA'o Cardnogon Aaoasoeent Creep for thalr ovaluatlon. Other wise, the ESC agrees with ODW'a essssseeat that the salami toxicologic evidence sheuld be eeaeldered negetlve with respect to aay association between ingested asbestos fibers aad gsacrolatestlaal cancer. Thus, peer-reviewed txparlmantal analyoaa of hasard does not support, at this time, as association between asbastoe exposure sad gastrointestinal ceacar, whether by diet or by auco-cillary elsereset of inhaled fibers. OUT 0908952 DU 028811 ta eontraat, eha tpldsmlolaglc record ia eablgusus. As compared to eh* thirteen (13)^studi*s reviewed by ODV staff, Dt. McDonald cited ten* thirty (30) atudlbs, of which eighteen (13) suggest eh* possibility ot m positive eaaocUtloB. So** food reasons axiae for tha inconsistency of eh* evidence. Thas* lncludat * la aoaa lastaaeaa It la ooc clear what vaa eh* nature of tha asbastlfor* aaearlal that waa eh* soure* of eh* exposure*. * the teudlas were eoaiuetad vlth saall populaeioaa ae high expoa ora to a putatively low risk aaearlal. * tuaor elea aay be recorded e*bl|uoualy (for exeapla, lower sad upper gastrointestinal tract aitas aay or aay aoe have baaa eaalysad saparaealy). * eh* assoclaeloa rseeable* thee aoaa with other Materials that esc aa confounding factors rsehar ehaa as causaelva afeues. Twelve (12) of eh* thlreaoa (13) epldaalologlc seudles reviewed la ehe ODH docuaaae reveal to apparent exceaa rlek. Tha seas thlrteae acudlee were ehe aabjece of a critical review of health affects caused by eabeaeos lngeaeloa that was coaalaalonad by ETA through lea Caaeer for Esrlroanaeeal Zpldaalology ee eh* University of Pittsburgh.* The critical review concluded chat each scudy had aathodologlc weaknass** aad llaltatIons, aad that no individual study or ijiriticlsi of aeudloa coaid aatablieh risk lavala. Hhllo eh* agreeaeat betweaa sale aad ftaala population* within tha studios as low, tha association of caacars of tha esophagus, seoaach, prostaea, aad pancreas with asbestos lagostloa was aot likely eo result frea chaace alone. although a poor quality risk taelaace will result fro* sach data, tbs population risk will ba low, and soaa eciaatltta prafar to work with each a risk tselaaea# Aabigulty anises la tha epidemiologic record, end eh* draft report by tha National icadeay of Sciences Coraittee o* Naa-Occupacieael laaileh tlaka of Aaboatlfoc* fibers,' foaad that existing data do aoe provide * eciaatifio basis e* deesrain* vUecber ow aac chore is aa association boewata Ingested asbestos fibers sad gastrointestinal caaear. Sivaa ehe positiva signal isaa la soaa epldaalologlc seadlos, plus vall-docuasatad avldaae* for the association batwaaa aabastss fiber inhalation aad laag caaear, it ia hard for eh* Coaalttae eo feel coafortebl* ia lladulai eha peeslbillty of aa iasraaaad risk of gaaerolnteseinal cancer la ham exposad es asbeetos fibers fra* drinking water. lowvnr, eha Coniteas eaanasa* is chat curraae paar-ravlawad avldaaea for hraaaa aad aniaala daea aac support tha view that aabastss Ingested la water causes organ-specific caacars. Cary X. Marsh, 'Critical Ievlev of epldaalologlc Studies Related eo Ingested dabaato*,* Eaviroarantil health Perspectives. 53 (1933), 49-56. ^National Acadaay of Scteneas. Cosmictee oa Mott-Occupational Health tiska ef Aabestlfora fibers. Aebeatlfora fiber*: Nea-Occupatlocal Health Ileka, Naeioaal Acadaay Prase, Washington, D.C., 19**. DUP 0908953 DU 028812 \' Mon daesUatf eaetaleal coaaaaea fTea individual IK Mabara Hava baa cfunicata diractlr to Dr. Cotnrro. Va graatl^ ippnelitt both eha opportunity to tarlaw tha papar and to aekaovladaa cba ehouaheful coaaldaradoa at tho Ccaaiteaa'a claa. cc: Alvin L. Ala tA--1011 Joaaph Cotravo [Wl-550] Viceor J. Kim [W-550] tarry F. Toala fA"l0l} l/\ iaJ~vD l/(^ Norton Ralaoa, Zaacatlva Coaalttaa ft OUf 09089S4 P\] 028813