NYC-WTC_000199796

NYC 9/11 Public Portal Document

wtc settled dust—bldgl6,19,22,29 attach 1

Buildings with ND fibrous glass-all areas sampled

Results of Settled Dust Sampling in Building 29 (105 Duane Street)

On December 4, 2001, settled dust samples were collected from inside 2 residential units, 1 common area, and from 1 outdoor area close to your building. The dust was analyzed for fibers such as asbestos and fiberglass, and for silica (quartz) and other minerals. The results of the settled dust samples are the focus of this attachment. Air sample results collected at these same locations will be provided as soon as they are received from the laboratory and evaluated.

Settled dust samples were collected from indoor floors by using a specialized vacuum cleaner. The outdoor sample was collected by scraping visible settled material into a container. At the laboratory, samples were analyzed for fibrous glass using Polarized Light Microscopy (PLM). PLM can distinguish fibrous glass from fibers like asbestos by the appearance and the distinguishing color given off by each different type of fiber. X- Ray Diffraction (XRD) was used to analyze the samples for all of the mineral analytes (quartz, cristobalite, tridymite, calcite, port/lime, gypsum, mica, and halite). XRD analysis identifies crystalline materials by their unique fingerprint given off (a diffraction pattern) from a beam of X-Ray.

The results of your building along with the results of the indoor samples collected in comparison residential buildings above 59* Street are displayed in the table. No dust was available to collect in comparison building outdoor locations. Results of mineral analytes are comparable to those found inside homes above 59* Street. Fibrous glass was not detected in any of the dust samples collected inside or outside of your building.

Fibrous Building Quartz Cristobalite Tridymite Calcite Port/Lime Gypsum Mica Halite Glass Number Sample site [%] [%1 [%] [%] [%1 [%] [%] [%] [%1 29 Common Area 1.1 ND ND 0.09 0.06 2.1 ND ND ND 29 Outdoor 8 ND ND 3 2 1.5 0.3 0.07 ND 29 Residence 1 0.2 ND ND ND ND 1.3 ND ND ND 29 Residence 2 ND ND ND ND ND ND ND ND ND

Comparison Indoors ND-2.2 ND ND ND-0.9 ND-0.08 NDA,2 ND-0.08 ND-0.4 ND Buildings Outdoor NS NS NS NS NS NS NS NS NS ND = not detected NS = not sampled (not enough visible dust to sample)

CITY_21MC100_003051759

NYC-WTC_000199796