NYC 9/11 Public Portal Document
Asbestos
As of November 9`'', 22506 lines of data representing the analysis of 4176 samples for total
fiber concentration, asbestos fiber concentration, or percentage asbestos had been entered into the
NYC Response database. These samples, the majority of which were collected in Lower
Manhattan and the Fresh Kills Landfill, were analyzed by a combination of Phase Contrast
Microscopy (PCM), Transmission Electron Microscopy (TEM), and Polarized Light Microscopy
(PLM). Other sampling locations are located in New Jersey and Brooklyn, NY. Sample media
collected include bulk dust, ambient air, indoor air, and personal air monitoring (PAM) samples.
In general, ambient air, indoor air, and PAM samples were analyzed by PCM to determine total
fiber content in fibers per cubic centimeter (f/cc), and by TEM to determine the presence of
asbestos fibers in structures per millimeter squared (S/mm2). Bulk samples were analyzed by
PLM and are reported as percent asbestos (% Asbestos). It is important to note that PCM is a
determination of total detectable fibers and can not be used to differentiate between, or identify,
fiber type.
The following summaries and trend analyses, presented by media type, were developed from
data available in the NYC Response database on November 9`" and do not take into consideration
data entered since that time. The figures and tables in this report have been developed under the
assumption that all data points (analytical results) reported in the database have already been
adjusted for sample volume and other factors.
Ambient Air Samples:
Of the 4176 samples collected, 83%, or 3466, are ambient air samples collected in Lower
Manhattan, New Jersey, and the Fresh Kills Landfill Between September 12"' and November 2"d
One thousand six hundred two (1602) of these ambient air samples were collected in Lower
Manhattan (Locations A-V), 1301 were collected at the Fresh Kills Landfill, 190 were collected in
New Jersey, and 373 were collected at various other locations in Manhattan. All of the samples
were analyzed by PCM, with fibers detected at measurable concentrations in 891 samples from
Lower Manhattan, 308 samples from the Fresh Kills Landfill, 8 samples from New Jersey, and
184 samples from other various Manhattan locations. Of these 1391 detected results, 526 were
reported at concentrations greater than 0.01 f/cc and six (6) were reported at concentrations
greater than 0.1 f/cc. After review of the available PCM data, several locations in both Lower
Manhattan (Locations B, D, E & F) and the Fresh Kills Landfill (Location 09-A, 09-B & 12-A)
were selected for trend analysis. The selection of these locations was based on the ratio of
samples with reported detectable concentrations of fibers versus the total number of samples.
Those locations exhibiting higher ratios were selected. The date collected and reported
concentrations, along with the corresponding PM 2.5 results and average wind speed, are
tabulated in Table 4. For those dates in which more than one sample was collected and analyzed
for a given location, the higher of the reported results is used. PM 2.5 and average wind speed
data are included in Table 4 and were added to determine if they had any bearing on fiber
concentrations at the different locations. No correlating trends were observed. The highest results
on a given day for the Fresh Kill Landfill locations (09-A, 09-B & 12-A) and the highest results
on those days for the Lower Manhattan locations (B, D, E & F) were then plotted by date collected
(x-axis) and f/cc (y-axis). The attempt here was to eliminate site-specific factors and show
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