NYC 9/11 Public Portal Document
Alpha-Quartz
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post f Cleaning Samples - Two air samples were collected after the first cleaning. All
samples were below the detection limit.
Calcite
Before Cleaning Samples - Pre-cleaning air samples were not coUected.
Post Cleaning Samples - Two air samples were collected after the first cleaning. AU of
the samples were below the detection limit.
Cristobalite
Before Cleaning Samples - Pre-cleaning air samples were not coUected.
Post Cleaning Samples - Two air samples were collected after the first cleaning. All of
the samples were below the detection limit.
Tridymite
Before deeming Samples - Pre-cleaning air samples were not coUected.
Post 1" Cleaning Samples - Two air samples were coUected after the first cleaning. All
were below the detection limit.
MMVF
Before Cleaning Samples - Two pre-cleaning air samples and three pre-cleaning wipe
samples were coUected. The two air samples had MMVF detected, but were below the
primary clearance criterion. The three wipe samples had MMVF detected in
concentrations from 57.23 S/cm^ to 801.24 S/cm\
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 at levels
below the primary clearance criterion of 10 S/L. All of the wipe sample results were
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 - Three pre-cleaning wipe samples were coUected. All three
were below the detection limit. The TEF for each sample was below the primary
clearance criterion.
Post Cleaning Samples - Four post-cleaning wipe samples were coUected. AU four
were below the detection limit. The TEF for each sample was below the primary
clearance criterion of300 pg/m^.
47
NYC-WTC_000145745
OCR can misread numbers and units. Confirm readings against the page image before using them.