NYC-WTC_000199617

NYC 9/11 Public Portal Document

Summary ofAsbestos Sampling Results Page 2 of 3 Address: 88 Greenwich Street Date sampled: November J9, 2001

have been present, such as textiles or fiberglass, are counted along with the asbestos fibers, and the total fiber count is then compared to the asbestos standard. If the results were above 0.003 ficc using the PCM methodology, additional analysis was performed to determine whether any of the fibers were asbestos. In this building, additional analysis was not warranted since the air sampling results were not greater than 0.003 fZcc.

Results of Phase Contrast Microscopy (PCM) testing of air at 88 Greenwich St., Nov. 19, 2001 Area Sampled Outside Common Residence 1 Residence 2

Sample Numbers A-0-9 A-C-9 A-Rl-9 A-R2-9 A-C-X-9* Concentration of Fibers in Air <0.001 0.001 0.001 0.003 at this location (f/cc) ** 0.001* Concentration of Fibers (fZcc in <0.001 to 0.001 <0.001 to 0.002 <0.001 to 0.003 <0.001 to 0.003 air at comparison locations NYC Re-occupancy (f/cc)*** 0.01 0.01 0.01 0.01 * Denotes a second air sample taken in the same location for quality control purposes. ** f/cc is fibers in each cubic centimeter (cc) of air. This is calculated from the number of fibers seen on the air filter and the volume of air pulled through the filter measured in cubic centimeters of air. *** New York City Department of Environmental Protection asbestos clearance criteria for post-abatement work (Rules of the City of New York, Title 15, Chapter 1)

ASBESTOS DUST TEST RESULTS The dust and debris samples were examined by two different laboratory methods for asbestos fibers. Polarized Light Microscopy (PLM) and Transmission Electron Microscopy (TEM). PLM is used to define asbestos containing material in dust and debris. A material is considered to be asbestos containing material if it contains more than 1% asbestos using the PLM method. The PLM method only counts the larger asbestos fibers. Therefore, if results by PLM were not greater than 1% asbestos, the sample was then analyzed by the TEM method that does count the smaller fibers. However, TEM analysis is not used for regulatory purposes for dust samples.

No asbestos fibers were found in the dust samples from the lobby or in the two residences by the PLM laboratory method. Not enough dust was found outdoors, so a sample was not collected. Further analysis by the TEM method detected asbestos at levels of less than 1% in the residences, but no asbestos was detected in the lobby.

Fibrous materials in dust found by PLM analysis: Polarized Light Microscopy identifies asbestos fibers by shape and optical characteristics. Other fibers such as fabric (synthetics), paper (cellulose) and fiberglass may be identified in the analysis. The laboratory analyst counts the fibers present to give an estimate of fiber content. PLM is used for regulatory purposes for dust samples.

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NYC-WTC_000199618