NYC-WTC_000208394

NYC 9/11 Public Portal Document

Summary ofAsbestos Sampling Results Page 2 of 3 Address: 161 East 88"' Street Date sampled: December 8, 2001

Results of Phase Contrast Microscopy (PCM) testing of air at 161 East 88*^ Street, Dec. 8, 2001 Area Sampled Outside Common Residence 1

Sample Numbers A-0-32 A-C-32 A-Rl-32 A-Rl-X-32 * Concentration of Fibers at 161 East <0.001 <0.001 0.002 88* Street (^cc)** 0.001* Concentration of Fibers in air at all <0.001 to 0.001 <0.001 to 0.002 <0.001 to 0.003 background locations (f/cc)

NYC Re-occupancy Standard 0.01 0.01 0.01 (f/cc)*** * Denotes a second air sample taken in the same location. ** 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. *** 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

In general, 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 common area or in the residence by the PLM laboratory method. TEM analysis also did not detect any asbestos in the indoor dust. Not enough visible dust and debris was available for collection in the outdoor area.

Fibrous materials in dust found by Polarized Light Microscopy (PLM) Analysis: PLM 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 will count the fibers present to give an estimate of fiber content.

CITY_21MC100_010212846

NYC-WTC_000208395