NYC-WTC_000195194

NYC 9/11 Public Portal Document

w Post 2^ Cleaning Samples - Two air samples were collected after the second cleaning. w The results indicate that both samples were below the detection limit.

Tridymite w' Before Cleaning Samples - Pre-cleaning air samples were not collected.

Post J^‘ Cleaning Samples - Two air samples were collected after the first cleaning. All of the samples were below the detection limit.

Post 2*^ Cleaning Samples - Two air samples were collected after the second cleaning. The results indicate that both samples were below the detection limit.

MMVF * Before Cleaning Samples - Three pre-cleaning wipe samples were collected. All three sample results indicate that MMVF was present above the detection limit. W Post P' Cleaning Samples - Three air samples and five wipe samples were collected after the first cleaning. The results for the three air samples indicate that MMVF was present; however, both samples were below the primary clearance criterion of 10 S/L. The results of the five wipe samples indicate that four of the samples were below the detection limit and one sample was at the detection limit. The MMVF concentrations after the first cleaning were lower than those in the pre-cleaning samples. There is not a clearance criterion for MMVF in settled dust. Since the air samples were below the primary clearance criterion and the MMVF in settled dust was greatly reduced after the first cleaning, no additional samples were collected for analysis of MMVF.

* PAH Before Cleaning Samples - Three pre-cleaning wipe samples were collected. All three samples were below the detection limit and the TEF for each sample was below the primary clearance criterion.

Post P‘ Cleaning Samples - Four wipe samples were collected after the first cleaning. All * of the samples were below the detection limit. The TEF for each sample was below the primary clearance criterion of 300 pg/m^. Since all of the samples were below the detection limit and the primary clearance criterion after the first cleaning, no additional samples were collected for analysis of PAH.

Unit 4B - This unit is located on the fourth floor. It is a 968 sq. ft. loft with four bedrooms facing Cedar Street. No windows were blown in and there was minimal dust accumulation in the w dwelling with the exception of the baseboard heating units, which contained visible dust. The unit W has hardwood floors and all of the tenant’s personal items were cleaned and sealed in bags prior to the cleanup.

Cleaning Method- This unit was cleaned using Test 2B. a Ridgid® shop vacuum and Hoover® upright vacuum with a HEPA filter for vacuuming the floors and other surfaces. An AFD was used during the cleaning process. In addition, all horizontal surfaces were wet wiped. This

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