Document nkMdOJV9yGM4j6RXM3YvNNN1a

PLAINTIFF'S EXHIBIT Bell Laboratories 600 Mountain Avenua Murray Hill. Naw jersey 07974 Phone (201)582-3000 April 22, 1980 Mr. Raymond E. Clark Manager - 0SHA New England Telephone Company 185 Franklin Street Boston, Massachusetts 02107 Dear Ray: The two bulk samples you mailed to me from the Topsfield Massachusetts Central Office, have been analyzed for asbestos. The two wipe samples were not analyzed. The analytical technique used was dispersion staining optical microscopy. X-ray diffraction was not performed because the sample volumes were small. Results are as follows: Plenum Chamber Sleeve This sample contains chrysotile asbestos. Using dispersion staining optical microscopy, birefringent fibers with the optical and morphological characteristics of chrysotile asbestos were seen. Dust From Inside Ductwork Birefringent fibers with the appearance of organic material were seen in this sample. No fibers having resemblance to asbestos were observed. The wipe samples were not analyzed because it is not possible to clearly identify individual fibers on a filter as being asbestos by optical light microscopy. To make this determination the preferred method of analysis is transmission electron microscopy (TQi) This analytical tool enables asbestos fibers to be differentiated positively from other fibrous materials. Per our telephone discussion the wipe samples were not sent out for TEM analysis pending further on site evaluation, i.e., air sampling to determine if airborne fiber counts are high. CONFIDENTIAL 003806 Hr. Raymond E. Clark - 2 If you have any questions about this analysis, please give me a call at (201) 582-7512. MH-8685-DR-vg Ref: Copy to J. D. Ludwig - NET R. E. Finn, M.D. R. L. Beach - AT&T R. W. Stone, M.D. W. J. Schreibeis G. M. Wilkening David Rainer Field Industrial Hygienist CONFIDENTIAL 003607