Document g2RvO6nXvw14ZZdeZ4BEmBG5N

C2LDR CGBPCKi-C.V p. o. box 7027I buffalo, new york 14240 715-827-4500 August 13, 1982 Robert C. Barnard, Esq. Cleary, Gottlieb, Steen & Hamilton 1250 Connecticut Avenue, N.W. Washington, D.C. 20036 Dear Bob*. In response to your memorandum of July 22, 1982 on Dick Wilson's risk decision model based on LD^q values, I offer the following comments. 1. When one uses NCI data for justification, it must be kept in mind that the selection of chemicals by NCI was based on prior high level of suspicion of carcinogenicity and * that "toxic" chemicals frequently are hepatotoxic in rodents which are thus prone to late hepatocellular carcinoma. The high (?1 correlations (.lower 95% C.L. of r2 for the Oaborne-Mendel rat * ca. - 0.75? lower 95% C.L. of r2 for Fischer 344 rat ca. - 0.11? lower 95% C.L. r2 for B6C3F1 mouse -- ca. - 0.58) may largely reflect the wellknown susceptibility of rodents to hepatotoxins. Thus the independent variable may be the potency and the dependent variable is the LD5Q in this analysis. 2. It seems to me that a mutagenicity battery, including some dose-response data on mammalian cells is not much more costly than a well-done accurate LD5Q, and the correlation with CA. potency is likely to be better than using LDjq data. 3. The question of thresholds at low dose is prejudged by selecting a risk model which reduces to linear through zero at low dose. If systemie toxicity is correlated with CA. potency, then the correlation should persist using LD^q or LD^i0 data. I doubt if such is the case. 4. The theoretical biological basis of the correlation is weak and I need not expand on this point except that it is not surprising a priori that highly toxic chemicals may be more potent carcinogens than relatively inocuous ones inasmuch as such properties as reaction kinetics, partition coefficients, detoxication mechanisms and bodily distribution are common factors in any biological model of systemic toxicity or carcinogenicity. - cont. - saeuMv* d talms oMe* zrmgaf'W -rountatn HMZ v-ttroarerao* >** rmrsay ."*** 20i-38'->'CO nrHr30C--331-Otrf 1 AP00051373 ( 2- - 5. I suspect that if one made an economic analysis of the cost of proceeding & la Wilson vs. proceeding on the basis of a scientific panel consensus, it would be shown that more useful positive and negative carcinogen icity data would ensue via the process of peer scientific judgement. 6. It would be interesting to have Perry Gehring's analysis of Wilson's ideas. Bob, if the eminence of the authors is going to be important in the future use of this ID50 approach, I suggest that some good biostatisticians look the paper over for 1) built-in biases. 2) correlations using other than NCI bioassays 3) correlations involving target organs other than the rodent liver 4) potency adjusted for time-to-tumor. In short, I don't like the idea of substituting computers for either common sense or scientific evaluation of all the evidence. I smell a rat. Best regards, KHF:dt cc: 0. Hughes A. J. tenBraafc (BCC) Kelvin a. Ferber AP00051374 S' ^M- CT.O-rA6</ti&& etU L MUCO& J.// ^ '*r . 1\ , top shett o nly INTEROFFICE^^ W APR 151974 nm&mhe***1* -------------- prArTSgpr.--------- MEMORA* N**D--UM X^0W^ ^^inbject OSHA - Emergency Temporary Standard ^HWS/VUZ^ fcr Exp08ur t0 V*"?1 Chloride To Distribution From H. W. Smith cc: E. Blades -W. 11. Smith J. Novak H. Watson MTbU| UH...V #SqAyft4tm^r..x(LleAUrItI9oAw, OlnfM,Ul?tlO.,,n,,,f D<P4rlffllM) __ 1 V P ^tern3 T. Carey R* Fleming H. Spurlock M<i..OecCdli0oAA., OOrragainiuuuiKnoafnt., aottt0pa/lrnnt) R. He Hlllan J. Coat $ He Olnnla C. Woman 4Al Hs 6 Attached is a copy of the Federal Emergency Temporary Standard for * Aj Exposure to Vinyl Chloride as Issued in the April 5, 1974, edition of * .<* the Federal Register. Please revlev this document and provide for its Immediate application in all vinyl chloride processing areas exclusive of those areas con~ cemed with fabricated products. %Z. dhd enclosure uXew . S&cucfi. U heao&eoL itfc VC'a jne in thtfom 0 SabricsuUol protiuct^. MAt, Mc'o one ^rt^exL u^i-o Ws -jeetW tstiM AP00051403 richard M- pairbahkb,3B HENNT UDIAMONO ABSENT J. ttEVCmeOEtlS OARY H.BA1BE A.JAMES BARMCB HAROLD HIMMELMAH CHRISTOPHER H.BUCKLEY, JR. JONATHAN Z.CANNON ANDREW C, MISHKIN CHARLES A. PATRIZIA SCOTT W. BOWEN CATHERINE M.DUNLAP law prices Beveridge, Fairbanks & Diamond One Farraout Square South Waihinoton, D. C 20000 TELEPHONE (102) SSS-TSOO 3 July 1978 CARL CAROLEY CLUOTT OOLOBTCIN OP COUNSEL 'INDLAW* Joseph E. Hadley, Jr., Esquire Keller & Heckman Suite 1000 1150 17 Street N.W. Washington, D.C. 20036 Dear Joe: Enclosed Is an article from the June 30 Issue of the Houston Chronicle. Please note the assertions made by Jim Tarr of Toxcon Engineering Company. The 36 percent of vinyl chloride emissions In Texas not being controlled is an Intriguing figure. I have no Idea where he came up with this figure and 1 am curious If anyone on the Manufacturing Technology Committee has an Idea. Furthermore, I would suggest that we attempt to obtain a copy of the paper Mr. Tarr presented at the Air Pollution Control Asso ciation Convention. Someone from our Committee may want to reply to the assertions made by Mr. Tarr In a letter to the editor of the Houston Chronicle. If you have any questions, please advise. enclosure i AP00051435 w >. FVMay,jMne3Mf7l HwMQwiKie Secttel,^, Vinyl chloride regulations calledvweak 36% of. Texas emissions sad free of control under EPA rules BY CARLOS BYAMS CWaaMeSekoce Writer Federal air pollution regulation da not Tarr aaU the amount of vinyl chloride nun ana to area, m Hit The higher adequately protect the public from the hazards tl vinyl chloride, a substancebe lieved to cause cancer, two potation con trol specialists said here. Jim Tair of Tncn Engineering CO., Hoston. said the primary weakness of the regulations is that they donet place a ceiling on vinyl chloride emiaafana. instead, the rule* Until the amount of permissible vinyl chloride In exhaust gases or liquids and apply only to certain types of processes with others not being controlled. This means thatpeople tiring downwind of a targe plant get-more exposure to the dangerous material than those living downwindof a smaller plant, Tarr said. released Into the air hat been aafcriaatially reduced since 1V74 but the potalic Still is being regularly expemri ta smai amounts ofthe material. It h difficult if not impossible to fix a safe limit lor chemical carcinogens and medical science cannot say any exposure is without risk, be said. The amount of vinyl chloride found In Ihe air is small, he said, "but h does not follow that those concentrations are insignificant. "Given present knowledge, about all that can be said is that members of the public who live and work in the vicinity of plants which manufacture or utUue vinyl / concentrations are in South and Central Texas.. , _____ _ so* waptiauP or mM 0MVTQV I Some South Texas Ugflite plants release upin four times the amountofradioactivi -radiation that people swallow hi food c ; water. ty permitted for nuclear plants. Cooper 1 Control etpjiprant specified by lb said, ddi%thatthe potential health haz federal Clean Air Act for controlling sul ard from radioactivity could be worse : fur andfiyosh Iron now power plants**! thanfrom ottwt power plantpottoUmU. ' control modof the radioactivity and evei ' permit Hs recovery hrwe asnuclear fee Cooper saidthe San Miguel powerpiwit, . m some cases, he said. under construction about sa miles south of I Some of the equipment converts sulfur San Antonio by the Braaoo Electric Power ` pollution from exhaust gooes to sulfuric Cooperative, will exceed federal guide I arid that can be wed in recovering the lines for radiation unless its pollution aranhMU from theflyash. cantrol equipment is extremelyefficient, i It also means that X percent of the chloride in large quantities are at im. * A spokesman for the cooperative. W. B. vinyl chloride emissions in Texas are not The magnitude of that risk appears lobe Townsend, manager of engineering at controlled at all by US. Environmental smalt.'* ( Vaco. soldhefa notawareofaqrndtoac- ProtectionAgency regulations, he said. Tarr. a former engineer with the Texas Air Control Board, was joined in prepay ing the paper by Or. flamy McMurry. an environmental health rpcdriiri with the air board's Beltaire oflice. Their peper was presented Thursday at In another presentation, Hal Cooper, asaociate professor at dvfi eagtoeering f the University of Texas at Audio, said a yearlong study shows substantial amounts of radionetivity arereturned assomecool laburned in powerplants tivftyinttwfael ataB... Tte plant is scheduled far lestoperation in December 1979 and will have control equipment fliat the supplier guarantees will meet poRutten standards, Townsend odd.' . a technical sessioa of the Air Pdhitton i Some coal beds contain uranium and Cooper contrasted tbli plant to asm Central Association canveatlen at Abort Jboritan. both radioactive elements. The heir* built near Fairfield by Texas UtiB-. Thomas Convention Center. |mwd of uranium and thariam varies **< ties that wtM use North Texas lignite. He In 1974. vinyl chloride was found to be -= the came of a rare liver cancer In some - i * .. ,, -- said its emisriom would be below the plant workers. It alsohasbeententatively linked ta other caocen. btrth defects and chromofnmedamage. Polyvinyl chloride, uaed in the manu* ladore ofdwusmds of ptootfc products, is made fromvinyl chloride. n i * AP00051436 -U >'