NYC-WTC_000220142

NYC 9/11 Public Portal Document FEB-06-2002 17•■23 710 391 2385 718 391 2385 P.05/06

Summary ofAsbestos Sampling Results Page 2 of 3 Adless; 70 Battery Place Date sampled: November J9, 2001

fiber count is then compared to the asbestos standard, If the levels had been elevated using the PCM methodology, additional analysis would have been performed to detennine whether any of the fibers were asbestos.

Results of Phase Contrast Microscopy QPCM) testing of air at 70 Battery Place, Nov. 19,2001 Area Sampled Outside Common Residence 1 Residence!

Sample Numbers A-O-10 A-C-10 A-Rl-10 A-R2-10

Concentration of Fibers 0.001 0.002 0,001 0.001 (£/cc)*«70 Battery Pl.

Concentration of Fibers <0.001 to 0.001 <0.001 to 0.002 <0.001 to 0.003 <0.001 to 0.003 (f/cc) in comparison locations

NYC Re-occupancy 0.01 0.01 0.01 0.01 Standard (f/cc) * fZoc is fibers in each cubic centimeter (cc) of air. This is calculated hum the number of fibers seen on the air filter and the volume of air pulled through the filter measured in cubic centimeters of air.

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 re^latory purposes for dust samples.

While a low level of asbestos was Reeled in some of the dust samples from your building, this was only from the dust samples outside and in a small area of the lobby. Low levels of asbestos (less than 1%) were found in one visible dust outdoor sample. Sli^tly higher levels were found (1,5%) in a vacuum dust in the lobby, although no visible dust was observed. However, since there is variability in laboratory analyses, the sample with 1.5% asbestos was reanalyzed and upon reanalysis, levels were <1% asbestos. No asbestos fibers were found in the dust samples from the two residences. Aj. V Fibrous materials in dust found by PLM analysis: Polarized Light Microscopy identifies fibers by shape and optical characteristics. Other fibers such as fabric (synthetics), paper

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