Document 5k2a4KpRDRJ2B795b9ZO0XBk4

<3n?5HDC2 TO: R.M. yinlng FROM: " H.A. Eschenbach DATE:' June. 5, 1972 SUBJECT: Asbestos Update CC: H.A. Brown T.L. Lyall H.C. Duecker O.M. Favorito R.E. Schneider R.A. Kulberg PERSONAL & CONFIDENTIAL During the past two months, we have been reorganizing our dust and mineral fiber sampling program and developing the capability of evaluating the results ourselves. Our early discovery that one can usually differentiate between chrysotile and tremolite at the standard fiber counting magnification (430X) led Frank Serafin of CPD Labs to obtain samples of several types of asbestos to compare them with chrysotile and tremolite. One observation of interest is that Libby tremolite and South African crocidolite appear to be identical within the limits of our phase contrast microscope. Both are monoclinic amphoboles, although their chemical formulae differ somewhat and perhaps this similarity is to be expected. During the week of Hay 15, I attended the annual Conference of the American .Industrial, Hygiene Association. Many of the papers presented there concerned asbestos. \ Also, the monthly.-American Medical Association oaa aptor ". une paper indicated that crocidolite Is 5-10 more carcenogenlc than chrysotile. No one has had anything to say about tremolite and apparently no one is particularly interested at this time. However, the 430X similarity of crocidolite and tremolite is bound to eventually be of interest to someone and the obvious superficial conclusions could be less than desirable from our viewpoint. Unfortunately, there is little information available to refute any such allegation. At the AIHA meeting, Selikoff simply updated his study of 18,000 asbestos and continued to conclude that chrysotile is a prime cause of several cancers as well as asbestosis. J.C. McDonald's study of asbestos miners and mill workers in Canada indicates to him that chrysotile is not as serious a problem as others would lead one to believe and points b^it that his subjects were exposed only to chrysotile while those in other studies may have also had exposure to crocidolite and amosite. A great deal more work will be needed to reconcile these divergent opinions. JUN 61972 15 16 28 59 R.M. Vining `-'.Tv ` -- - 2- - 03625903 June 5, 1972 There Is considerable controversy and disagreement concerning almost all aspects of the asbestos problem. Most agree, however, that health problems are exposure related with the general rule of thumb that under 20 years of exposure, problems are minimal; 20-30 years - somewhat greater; over 30 years - serious. It is also noted that as one goes back from the present, one enters periods when people worked in unbelievably high concentrations. However, the issue has become emotional that decisions concerning the TLV, etc. are not based rationally upon knowledge. It is a foregone conclusion that the TLV will be 2 fibers (greater than 5 microns) per ml and some unions and researchers (Selikoff) pushing for 1 or 0 fiber levels. Lack of significant reliable information to oppose this type of regulation will allow the "panic button set" to do pretty much as they wish. I believe that we had better start building up a bank of knowledge on tremollte, its properties, etc. as well as the medical data to show that Libby has no significant problems. Failure to do so could result in a total lack of defense if someone decides to make allegations concerning "tremollte asbestos". Recently, NI0SH, which is the research arm of 0SHA, let it be known that it is going to place a contract for the development of criteria for a new TLV for fiber glass. Many studies over the .past several years, including one in which Selikoff was involved, found no reason to consider fiber glass other than a nuisance dust. However, this situation should - H.A. Eschenbach HAE:mh P.S. If anyone has interest in the asbestos related articles and published papers, please contact me and we will arrange to circulate them in the future. 15 162860 L . .V ? ; r . . - ' -: -'V - _W. o. Gracs -& Co. ----Tll K tTRCCT.-N.W. WASHINGTON, D. C. 0 y'. nil> ,362j903 ' "^tpy-i^y. February 11, 1972 Presiding Officer Hazardous Emission Standards Hearing Environmental Protection Agency Parklawn Building Room 17-70 5600 Fishers Lane Rockville, Maryland 20852 Attention: Mr. Edward B. Reich Advisor to Director, Division of Stationary Source Enforcement Gentlemen: You were advised by telegram on January 28, 1972, that W. R. Grace & Co. requested permission to make a statement at the Public Hearing concerning National Emission Standards for Hazardous Air Pollutants on February 15, 1972, at the U. S. Court House, Los Angeles, California. In your, proposed Rule Making, published in the ,i&j'i FEDERAL-REGISTER on December 16, 1971, you requested that persons desiring to make a statement should ^^$^llil-fiYe'copies with yc u 10 days prior to the* Hearing-date In our discussion with Mr. Edward B. Reich on February 8, 1972, he advised us that we could delay filing until February 11, 1972. Enclosed are five copies of the statement that we propose to offer at the forthcoming Hearing. 2 ? -VVV> Jv Sincerely yours, JNT/ck Enclosures^) o Favorito ; ;y. - - . ....... V ^ 15162661