NYC 9/11 Public Portal Document
Post Cleaning Sconpies - Two air samples were collected after the first cleaning. All
samples were below the detection limit.
Cdcite
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post Cleaning Samples - Two air samples were collected after the first cleaning. All of
the samples were below the detection limit. Because all of the samples were below the
detection limit after the first cleaning, no additional samples were collected for analysis of
calcite.
Cristobalite
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post f Cleaning Samples - Two air samples were collected after the first cleaning. All of
the samples were below the detection limit. Because all of the samples were below the
detection limit after the first cleaning, no additional samples were collected for analysis of
cristobalite.
Tridymite
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post P‘ Cleaning Samples - Two air samples were collected after the first cleaning. All of
the samples were below the detection limit. Because all of the samples were below the
detection limit after the first cleaning, no additional samples were collected for analysis of
tridymite.
MMVF
Before Cleaning Sconpies - Four pre-cleaning wipe samples were collected. The four
wipe samples had MMVF detected in concentrations from 228.93 S/cm^ to 1259.09
S/cm^. This indicates that MMVF was present prior to cleaning.
Post Cleaning Samples - Three air samples and five wipe samples were collected after
the first cleaning. All of the air sample results indicate that MMVF was present but at
levels below the primary clearance criterion of 10 S/L. All of the wipe sample results were
at or below the detection limit of22.89 S/cm^. This indicates that the cleaning method
was able to reduce the pre-cleaning concentration of MMVF.
PAH
Before Cleaning Samples - Four pre-cleaning wipe samples were collected. Three of the
four samples were below the detection limit and below the primary clearance criterion.
The fourth sample had two PAH compounds detected; the calculated TEF was below the
primary clearance criterion.
Post P‘ Cleaning Samples - Four post-cleaning wipe samples were collected. All four
samples were below the detection limit, and each sample was below the primary clearance
criterion of 300 pg/m^.
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NYC-WTC_000145754
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