Document zdLYE64B9QoQd25n9x2vGzYn6

;iew York Telephone Asbestos Analysis. Case 48106-3 fftr. DeSfCn^ Bell Laboratories 600 Mountain Avenue Murray Hili, New Jersey 07974 Phone(201)582-3000 October 4, 1978 Mr. J. J. Preis Kev York. Telephone 1095 Avenue of Americas New York, N. Y. 10036 Dear Jack: The four filter casettes from 3110 Thomson Avenue and 45th Avenue, have been analyzed by phase-contrast optical microscopy using the method recommended by the National Institute of Occupational Safety and Health (NIOSH) for asbestos. The results were: Sample Air Volume Sampled (Liters) # Fibers Counted* Air Concentration (fibers/cm^) 280-A 281-A Outside Blank Blank 200 200 - 2 Less than .01 3 .01 4 3 The two bulk samples of insulation were analyzed by optical microscopy and x-ray diffraction. Although the sample labelled "L&P Building" was found to contain some fibrous particles, no evidence of asbestos was noted on the x-ray diffraction scan of the material. The major minerals noted in this sample were gypsum and mica. 100 Microscope fields were counted. The field area was .011 mm2. The area of the filter was 855 mm2. CONFIDENTIAL 003814 Mr. J. J. Preis - 2 The sample labelled "Lobby of LaGuardia Cnl." contained the minerals calcite, mica, and gypsum. Once again nc asbestos was seen. Optical examination revealed that fibrous glass particles were also present. If you have any questions about this analysis please let me know. Sincerelv. Copy to W. J. Schreibeis G. M. Wilkening R. L. Beach - AT&T" N. J. DeCapua - AT&T R. W. Stone, MD -- AT&T C. H. Steinmetz - NYT C. P. Lichtenwalner 003815