Document EvgOQwBYopNmnJpD5x5erVQGx

506NBS SPECIAL PUBLICATION U.S. DEPARTMENT OF COMMERCE / National Bureau of Standardsj Workshop on Asbestos: Definitions and Measurement Methods SCF-ALLF-06620 . ' ASBESTOS WORKSHOP IN REVIEW JULY 18-20. 1077 NATIONAL BUREAU OF STANDARDS . ATTACHMENT 1 -Pag^-1 of 2 The workshop was organized to discuss a definition of asbestos and suitable measurement methods for regulating against asbestos health hazards, prior to the issuanoe of a standard. Four hundred persons from the mining industry, ' asbestos manufacturing, U.S. and Canadian health agencies, and medical and research facilities attended the workshop. The National Bureau of Standards concluded in May from analysis of 80 industrial samples that OSHA's present techniques for analyzing for asbestos in Industrial talc is useful only for determining fiber content and not asbestos content. This and other unresolved issues were discussed at the workshop. Divergence of opinion was expressed in two camps: U.S. Government Agencies and Medical represent atives v.b. Industry and the U.S. Geological Survey. The Bureau will consider these viewpoints in making its final report to OSHA. '' * ' 4 Significant segments of the proceedings include the following: Mearl Stanton. National Canoer Institute Cancer-oausing danger of fibrous materials is related to fiber dimension. Greatest carcinogenicity came from fibers with dimensions that were equal to or less-than .25 M- hy more than 8 Smaller fibers were controlled by phagocytes* in the body. Knowledge on why long fibers are carcinogenic is presently inadequate. Continued effort must be done on inhalation studies to allow extrapolation to human experience in understanding the effects of asbestos. Paul Kotin. Johns-Manvllle Corporation. Denver Exposure to Asbestos under the present standard level does not result inevitably in lung cancer, mesothelioma or asbestosis. There is no such thing as a single threshold for a carcinogen but a series of thres holds can be identified. Nothing rules out a dose-response relationship for asbestos. ', William Nicholson. Arthur Laneer. Mt. Slnal/Hospltal- N.Y. Thresholds exceed present scientific capability. Excesses of lung cancer and mesothelioma from mortality studies were cited from job related asbestos exposure. In one study spouses, children and other family members of workers in an amosite asbestos factory were studied for asbestos related disease. Out of 626 persons, approximately one-third were found to have abnormal luna fc-rays. ' ' ' ., ' * phagocyte - white blood corpuscles that ingest and destroys organisms--- - - or particulates that result in disease. .- HFM - 004231 8002 i5S 8 Afibeatos Workshop in Review ATTACHMENT 1 Page 2 _p 2 Malcolm Roas. U.S. Geological Survey - According to the preBent OSHA definition for asbestos, rocks from Maine to Georgia could be viewed aB containing asbestos and be considered unsuita ble for quarrying for crushed stone. Evidence is lacking on any environ mental health threat from such operations. Canadian mining studies with higher concentrations of chrysotile asbestos indicate no adverse health effeots. The 1976 NIOSH (National Institute for Occupational Safety and Health) can be oriticized on the basis there is no safe level of exposure to asbestos and questions the safety of the crust of the earth. Paul Gross. Medical University of S. Carolina Animal studies which have produced tumors by inhalation have not been cited. The conference concluded with presentations on the advantages and limitations of available analytical methods and counting techniques for detection and measurement of the workplace oontaminants. Studies have been done using x-ray diffraction, (TIM) transmission electron microseopy, thermo-analysis, phase contrast and optical microseopy. Proceedings will be published and sent to all those who attended. Addtional oopies may be ordered through the National Bureau of Standards. HFM - 004232 C. B. Zelek Vehicle Materials Engineering August, 1977 1589