Document Rj9rw7x8Vd7ZboKDERvk2322a

for Asbestos Case 48106-3 Bell Laboratories 600 Mountain Avenue Murray Hill, New Jersey 07974 Phone (201)582-3000 July 6, 1979 P. A. Muller New York Telephone 140 West Street Room 2250 New York* New York 10007 Dear Pat: The five air filter samples and four bulk insulation samples which were collected at Two World Trade Center on the 9th, 10th, 11th and 12th floors have been analyzed for asbestos. The bulk insulation samples were analyzed by polarized light microscopy and X-ray diffraction. The results are given below. 2 WTC 9th Floor Sales Bulk Polarized light microscopy revealed the presence of mineral wool but no asbestiform fibers were seen. The major crystal line materials noted by X-ray diffraction were calcite and gypsum. No chrysotile or amphlbole forms of asbestos were seen. Therefore, this sample does not contain any asbestos. 2 WTC 10th Floor Hall The principal fibrous material seen in this sample was mineral wool. No asbestiform fibers were noted. No chrysotile or amphibole forms of asbestos were seen by X-ray diffraction. Therefore, this sample does not contain any asbestos. 2 WTC 11th Floor Carrier A small amount of chrysotile asbestos was observed by polarized light microscopy. The major crystalline materials 003801 present as noted by X-ray diffraction were chrysotile, calcite, and gycsu:.: The presence of fibers and the crys talline structure of chrysotile means that this sample contains asbestos. 2 WTC 12th Floor Frame Polarized light microscopy revealed the presence of mineral wool and a small amount of chrysotile. The major crystalline materials noted by X-ray diffraction were chrysotile, calcite, and a small amount of gypsum. The presence of asbestiform fibers and the crystalline structure of chrysotile means this sample contains asbestos. Air Filter Analysis The air filters were analyzed by counting all fibers greater than 5pm seen by phase contrast optical microscopy at 400x. This is the method recommended by the National Institute of Occupational Safety and Health (NIOSE). Based on the sampling data sheets and the optical microscopy counts the results were: Sample 2 WTC 9th FLR 2 WTC 10th FLR 2 WTC 11th FLR 2 WTC 12th FLR Blank Volume Air (L) 390 180 210 420 ___ Fibers Counted* 8 2 3 6 2 O Fibers/cm Blank Uncorrected Corrected .02 .01 * .01 <01 .01 <.01 .01 .01 ,,_ 2 * 100 Microscope Fields (.011 ram /field) were counted. The filter area was 855 mm*. ** < = less than CONFIDENTIAL 003802