NYC-WTC_000208370

NYC 9/11 Public Portal Document

Page J of 3 Summary of Asbestos Sampling Results 130 Water Street, New York, N.Y., 10005 Date sampled: November 30, 2001

Four locations were sampled at your building: inside two private residences, an indoor common area (e.g., a lobby or hallway), and a nearby outdoor area (see tables below for sampling results). One air and one dust sample was collected in each of the four locations. An additional air sample was collected in one of the residences for quality control purposes.

Air samples were collected using vacuum pumps to draw air past a filter that was suspended at the height of a person’s breathing level. Outdoor dust and debris samples were collected by placing visible material in a container. Indoor dust and debris samples were collected on a filter by vacuuming surfaces. The collected material was weighed, viewed under a microscope, and/or chemically processed to determine the types and quantities of substances present. The materials are being analyzed for fibers such as asbestos, fiberglass, synthetics (e.g. man-made materials such as nylon and polyester), cellulose (e.g. cotton, paper), silica, and for other minerals and small particles.

ASBESTOS AIR TEST RESULTS The air samples tested from directly outside, in the building lobby, and in the apartments were taken during normal daily activity. All air samples were examined in a laboratory for fibers using the Phase Contrast Microscopy (PCM) method.

Fibers were detected in all of the air samples by PCM analysis; the highest of these was at a level of 0.005 free. For comparison, in the homes above 59*^ Street, level of fibers found in the air ranged from less than 0.001 free to 0.003 free. Since the PCM air analysis includes non-asbestos fibers, the two highest samples were re-examined by a second laboratoiy' method, transmission electron microscopy (TEM), to determine if any of those fibers were asbestos. No asbestos fibers were found in these two samples by TEM.

Airborne fibers as determined by PCM analysis: An air sample is collected by pulling air through a filter. The filter catches fibers and is sent to a laboratory to determine the number of fibers in the air. Phase contrast microscopy identifies fibers based on size and shape, but not the specific type of fiber. Therefore, the fibers seen by PCM include asbestos fibers as well as other fibers, such as textiles, fiberglass, and cellulose, which might be present in your home. The PCM analysis assumes that all fibers present were asbestos. Therefore, less hazardous fibers that may 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 free using the PCM methodology, additional analysis was performed to determine whether any of the fibers were asbestos. This additional analysis was done for the air sample in one residence since the air sampling results were greater than 0.003 free.

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NYC-WTC_000208370