NYC 9/11 Public Portal Document
Post P' Cleaning Samples (Test 3B) - Two air samples, two micro vacuum samples, and
four wipe samples were collected after the first cleaning. The two air samples were below
the primary clearance criterion of 1.0 pg/m’. The results of the micro vacuum and wipe
samples show that all samples met the comparison value or primary clearance criterion for
lead.
Alpha-Quartz
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post P‘ Cleaning Samples - Two air samples were collected after the first cleaning. Both
were below the detection limit.
Calcite
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post P‘ Cleaning Samples - Two air samples were collected after the first cleaning. Both
were below the detection limit.
Cristobalite
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post 1“ Cleaning Scmtples - Two air samples were collected after the first cleaning. Both
were below the detection limit.
Tridymite
Before Cleaning Samples - Pre-cleaning air samples were not collected.
Post f Cleaning Samples - Two air samples were collected after the first cleaning. Both
were below the detection limit.
MMVF
Before Cleaning Samples - Four wipe samples were collected. The four wipe samples
evidenced MMVF above the detection limit, which indicates that MMVF was present
prior to cleaning.
Post Cleaning Scmiples - 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
in the range of 114.46 S/cm^ to 228.93 S/cm^. This indicates that the cleaning method
was able to reduce the pre-cleaning concentration of MMVF.
PAH
Before Cleaning Samples - Four wipe samples were collected. All four samples were
below the detection limit, and the TEF of 300 pg/m^.
Post f Cleaning Samples - Four wipe samples were collected. All four samples were
below the detection limit; the TEF value was below the primary clearance criterion of
78
NYC-WTC_000145776
OCR can misread numbers and units. Confirm readings against the page image before using them.