Document jaxm4oDdNby2aEwEZRgde9Ny

I. famorandum UH*\Rr\!tM OF I li'AI.Tl{, UHCATIO.X. AND WELFARE ft lil.tC lllALTII intAICL Consvcaor Protection and Environmental Health Service* Environmental Control Administration ro mow Director, Division of Criteria and Standards Development Assistant Director, Division of Epidemiology and Special Services date: July 14, 1959 SfBJtCT Ciimstnts cn "Proposed criteria and recommended interim standard for asbestos", draft of 6-12-69. NiifOtT;tf: *; i p. 3, para, 3; p. 10, para, 1 NO l COMt Fti0jVI pPi-'i;'io' The statement "adherence to this interim standard vill reduce to an insignificant risk the eccurrence of asbestosis, even among workers vho nay he exposed to asbestos dust for as long as 30 years" is not supported by available data. For example: "A * J: J kf * <rv*> ^S *J a. The Hygiene Standards for Chrysotile Asbestos of the British Occupational Hygiene Society estimates that 100(fiber/ce) - years vill result in 17. asbestosis. For 30 year exposure this would V give 3 fibers/at; not 12 fibers/ml. (see p. 15, this std) .* b. Dr. John Wells, U.S. Ilubber Company, Newman, Georgia state* (Ref. 1, p. 335) "When we got to a period of 50 to 60 million particles per cu. ft. - years, we began to find people with pul monary asbestosis". This would correspond roughly to the interim limit, but not to an "Insignifleant risk". e. Tn the only medical study done so far by the DESS, about 1 of 6 workers examined were positive for basal rales, and perhaps 1 of 10 workers were positive for asbestosis by X-ray findings. Current exposures are almost all within the interim limit. While it is quite possible, perhaps even likely, chat these findings are the results of previous, unrecorded higher exposures, such speculation ia far from firm scientific data. Thus, it Is hard to see. how ve can quote "its own. recent epidemiological Investigations" as a basis for the USF11S interim standard. ' 7^ P*'H lines 7 to 9. What is meant by the "occupational neighborhood"? ' The Job sices surrounding asbestos workers? The housing area near a factory processing asbestos? Could this be made more specific? \i 3. p. 11, lines 19 and 20. Should this be "nay contribute", until we have more data on the proportion of asbestotics dying from these causes? THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID NOT COME FROM 7"r00 21232_l IT'S FILES AND CANNOT BE AUTHENTICATED ( J|C n_r-snnrzBY PPG INDUSTRIES, INC. LTU5WI____HllP tllMINAft V*mAl1ut cCoOST liOUCTION MOCtAM 3724 ' N0TE:.Tf"? NOT COMB & t'r^j ri p. 15, pars. 2. This 30HS document is s Hygiene Standard, vhich includes a description of an epidemiologic study carried out in one British factory. The analysis of these data result in scateaencs chat "the concentration .giving a risk of 17. for a aan working for 50 years in the industry is estimated as 2.2 fibers per cc .... the uncertainty of the estimate of the concentration for 17. risk at 50 years is such chat the concentra tion for which one could state with 57. probability that the risk is less than 1" Is 1.0 fibers per cc." Elsewhere they state: 'Tor basal rales a 1Z risk is estimated for an exposure of 112 f/cc - years... At this concentration there is a reasonable chance that the risk is as high as 3Z..." (underlining nine) Similar analysis of the Dreesen study by the SOUS group results in a 50 year, IZ risk estimate at 0.7 mppef, with a 957. confidence limit for a 50 year, 17. risk i/ 0.17 nppef, corresponding approximately to 1 fiber per nl, as in the British factory. p. 23. The standard seems to digress to describe the PUS techniques es determined by equipment "on hand". For example, a rotating phase turret is not necessary for 4Q0X fiber count, and the ribbon filament illuminator is not used with the built-in illuminator as in our Leitx microscope, Nor are "total fiber" or >10|i fiber counts necessary for the interim standard method. .This section sight be revised to include as requirements only those things vhich we do because they oust be so done, with more general statements for the things we do because they are convenient for us. p. 35. Tliis section does not mention electron diffraction or electron mlcroprobe analyses vhich are used (by others) for single fiber analyses f fibers, including those from lung tissue. Should not this standard include all relevant techniques? p. 36, lines l to 3* What arc "the criteria"? The interim standard appears to have ignored the British epldeniologic data, the Bremen study had no 30 year (or even 20 year) exposures, and Veils says that ha finds people with asbestosis at a lavel equivalent to the interim standard. BOSH data support no level as yet. Neither the epidemiologic data nor the analytical methods Included in this document are necessarily "best". p. 36, lines 17 snd 18. There is no section giving "techniques utilized la control." General: * The Interim Standard can give no quantitative estimate aa to the proportion of workers who, if exposed at the Standard level, would eventually develop asbestosis or cancer. The available evidence suggests THIS DOCUMENT WAS wnr . PPG INDUSTPirc m,?S N0T A REC its ?ADL"`;or "a BVWSmouSTOB INC *UrhH' | BB 0021233_j 3725 3 that rhl-s proportion would not be "insignificant". Since the basis of this Standard is so tenuous, and its safety so questionable, it appears that i*-should be recomended (If at all) for no oore chan a three year oeriod. Exposures should be kept as far below this Interia Standard as possible. Howard E. Ayer THIS DOCUMENT WAS NOT A RECORD OF PPG INDUSTRIES, INC. DID M0r- COME FROM ITS FILES AND CANNOf BE BY PPG INDUSTRIES. INC -----2 2123 <T7 3726