NYC 9/11 Public Portal Document
0.0009 s/cc. No additional cleaning is required for asbestos. All of the areas met the primary
clearance level for asbestos.
Lead — Thirty pre-cleaning wipe samples were collected and analyzed for lead at a detection limit of 20
µg/ft2. Thirteen samples were above 25 µg/ft2 and represent apartments on the 10`s floor (2 of 3 above 25
µg/ft2), 9a' floor (2 of 3 above 25 µg/ft2), 7`h floor (1 of 3 above 25 µg/ft2), 5th floor (2 of 3 above 25
µg/ft2), 4th floor (2 of 3 above 25 µg/ft), 3 floor (1 of .3 above 25 µg/ft), and 11`x' floor (3 of 6 above 25
µg/f)•
Thirty post-first cleaning wipe samples were collected from each floor and analyzed for lead at a
detection limit of 9 µg/ft2. All of the sample results were below 25 µg/ft2. Post-cleaning concentrations
from areas that had pre-cleaning concentrations above 25 µg/ft2 were all below the primary clearance
value. No additional cleaning required for lead. All of the areas met the primary clearance level for
lead.
Dioxin — Thirty pre-cleaning wipe samples collected and analyzed for dioxin. The maximum Toxicity
Equivalents (TEQ) Estimated Maximum Potential Concentration (EMPC) with non-detects equal to %2 Of
the detection limit (ND=1/2) value was 0.951 ng/m2. This sample and the remaining 29 samples were all
below the primary clearance value of 4 ng/m2. Based on the pre-cleaning samples, no additional cleaning
required for dioxin.
Thirty post-cleaning wipe samples collected and analyzed for dioxin. The maximum TEQ EMPC
(ND=1/2) value was 0.837 ng/m2. This sample and the remaining 29 samples were all below the primary
clearance value of 4 ng/m2. Based on the post-cleaning samples, no additional cleaning required for
dioxin. All of the areas met the primary clearance level for dioxin.
PAHs — Thirty pre-cleaning wipe samples collected and analyzed for PAHs at a detection limit of 1µg.
All or the results were below the detection limit and the calculated Toxicity Equivalent Factors (TEFs) for
each sample was 116 µg/m2, which is below the primary clearance level of 300 µg/m2. Based on the pre-
cleaning samples, no additional cleaning is required for PAHs.
Thirty post-cleaning wipe samples collected and analyzed for PAHs at a detection limit of 1µg. All or
the results were below the detection limit and the calculatedTEFs for each sample was 116 µg/m2, which
is below the primary clearance level of 300 µg/m2. Based on the pre-cleaning samples, no additional
cleaning is required for PAHs. All of the areas met the primary clearance level for PAHs.
Fibrous glass — Sixty-five air samples were collected and analyzed for fibrous glass. All of the samples
were below the secondary clearance level of 0.01 f/cc. In addition, all of the PCM analyses were below
the 0.01 f/cc. PCM analysis results provide another data set that can be used to assess fibrous glass, with
the assumption that all detected fibers are fibrous glass, and the PCM data set for 114 Liberty indicates
that even if all the fibers from the PCM analysis were fibrous glass, all samples would be below the
secondary clearance level of 0.01 f/cc. All of the areas met the secondary clearance level for fibrous
glass.
Silica — Eleven-air samples were collected and analyzed for crystalline silica at a detection limit of
11J.Lg/m3. Seven samples were below the detection limit and four samples were above the detection limit,
with values of 17.2, 19.6, 22.1, and 22.1 µg/m3. The numeric criterion that USEPA has proposed in the
1 This conclusion does not include the area that contains the pizza shop. As discussed in the letter and the summary
of the data, the pizza shop contains asbestos-containing material (ACM) that is in poor condition. The ACM will be
addressed through an asbestos abatement project.
NYC-WTC 000102523
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