NYC-WTC_000195194

NYC 9/11 Public Portal Document

w w 3. Sampling Activities 3.1 Baseline Sampling

Prior to initiating cleanup activities, bulk composite samples were collected in each of the three units which had sufficient dust present to collect a bulk sample. These Units included 5C, and the two commercial units on the second floor (Mattress Store, Chiropractor’s Office). The bulk samples were analyzed for alpha-quartz, MMVF, lead, PAH, dioxins/furans, and asbestos. Due to «r insufficient volume, the sample collected from Unit 5C was not analyzed for PAH or dioxins/furans.

EPA's evaluation of the analytical data from the bulk composite sampling event was utilized in identifying COPC concentrations present in the settled dust, and assisted EPA in determining the applicability of regulatory standards and in identifying potential health and safety concerns. Analytical results of the bulk sampling are not included in this report.

In addition to the collection of bulk composite samples, baseline air samples were also collected. These samples were collected from the breathing level (5-6 ft.) and from the main living area of the units which, based upon visual observations, were both the least and the most impacted by the WTC disaster. Samples collected from the least impacted apartments (Units 3A and 3B) represented a best case test and were analyzed for asbestos and MMVF. Samples collected from * the most impacted areas (Mattress Store, Chiropractor’s Office) represented a worst case test and were analyzed for dioxin/furans, PAH, asbestos and MMVF.

EPA's evaluation of the baseline air sampling event determined that the airborne concentrations of PAH and dioxin/furans were not a health concern; therefore, the collection of additional air samples of these parameters was not necessary. This decision was based on the analysis of baseline bulk and air PAH and dioxin/furan samples which were collected from the most severely impacted units. As the air samples did not contain PAH or dioxin/furans at concentrations above the stringent primary clearance criterion as established in the COPCZBenchmarks Report", EPA determined that airborne PAH or dioxin/furans would also not be present in the other less impacted units. EPA's decision to eliminate PAH and dioxin/furan analyses for air samples was later confirmed through the collection of reference samples in Unit 4C. These samples were analyzed for PAH and the analytical result was found to be below the clearance criterion of 0.2 pg/m^

3.2 Pre-Cleaning Sampling

Prior to cleaning activities, wipe samples were collected from each of the thirteen residential units and the two commercial units included in the study (Chiropractor’s Office, Mattress Store). The wipe samples were collected from a 10 cm x 10 cm area using dedicated, disposable templates which were left in-place. One sample was collected from the surface of each of the following four non-porous locations within each unit; ceiling, wall, bare floor, and horizontal surface (e.g., counters, tables, dressers, window sills). All samples were analyzed for asbestos, MMVF, lead, PAH, dioxins/furans, and alpha-quartz. Exceptions to this were the ceiling samples which were

” U.S. Environmental Protection Agency. (September, 2002). H'orld Trade Center Jndoor Air Assessment: Selecting Contaminants of Concern and Setting Health-Based Benchmarks. 27

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