EPA evaluation summary of analytical data for 125 Cedar, Nov

NYC 9/11 Public Portal Document NOU-12-2002 16:46 FROM US EPA REGION 2 ORC .. TD 917185954544 P.03/05

Summary of the Analytical Results for the Cbemirah of Potential Concern

USEPA’s review of ihc analytical data for samples collected from 125 Cedar Street indicate that the areas sampled meet the numeric criteria established in the draft “World Trade Center Indoor Air Assessment: Selecting Contaminants of Potential Concern and Setting Health-Based Benchmarks” report (i e., COPC document). The COPC document was created by a committee with representation from federal, state, and city government and was designed to establish numeric criteria to be used in addressing potential contamination from dust and combustion by-products associated with the World Trade Center collapse and fire. This document is currently undergoing peer-review. The data which was evaluated consisted of pre-cleaning and post-cleaning samples for six chemicals, asbestos, polycyclic aromatic hydrocarbons (PAHs), dioxin, lead, fibrous glass, mercury and silica. For some chemicals all of the pre-cleaning samples were below the established numeric criteria, such as dioxin, hr addition, some of the post­ cleaning samples exceeded die numeric criteria for several chemicals, such as asbestos. These areas (i.e., an apartment or common space) required additional cleaning and subsequent re-testing. An area was not considered to be cleaned until all the numeric criteria for each chemical was met. All of the areas tested met the numeric criteria for each chemical prior to performing the walk through inspections that occurred on November 07 and 08,2002. Below is a summary of the analytical results for each chemical.

Asbestos - We reviewed approximately 143 asbestos analytical results that were analyzed using Transmission Electron Microscopy (TEM) perforihed using EPA 40 CFR Part 763 Final Rule (AHERA), which had a detection limit of either 0.0009 f/cc or 0.0008 f/cc for fibers greater than or equal to 5 fi. Based on these analytical results, eight samples in six units/spaces exceeded our clearance criteria of 0.0009 free. These units/spaces (5S, 5N, 3N, 9N, staircase between 7 & 8, and the 6* floor hallway) were recleaned and dien retested using the analytical method identified above. Several additional spaces (SS, 7N, 7S, 7* floor laundry room) were also recleaned and retested because asbestos was detected and the initial detection limit was set very close to the clearance criteria. Tt should be noted that these areas met the numeric criteria, however to provide additional confidence in the data, it was recommended that the 4 spaces be rccicancd and retested. The detection limit was lowered to 0.0004 f/cc for subsequent testing. All of the 43 samples collected during the retesting met the numeric criteria after the second cleaning. An additional set of data, 30 samples, was received for four units (2N, 9S, 8N, and 3S). This data indicated that two units met the numeric criteria (9S and 3S) and the remaining tw'o exceeded the numeric criteria. These two units were recleaned and retested. Apartment 8N met the numeric criteria after the second cleaning (5 Samples), however apartment 2N (5 Samples) did not, thus it was recleaned and retested. After the third cleaning, apartment 2N (5 Samples) met the numeric criteria. Thus, for asbestos, the data we reviewed indicates that asbestos is not a hazard at 125 Cedar Street.

(Note: Pie original 143 asbestos samples were analyzed a second time using a sligktly different method than EPA 40 CFR Part 763 Pinal Rule (AHERA). Although the results ofthe second analysis indicfited that onfy one sample exceeded the numeric criteria, this data was not used because it is not a standard practice to reatialyze afilter and use the second set ofdata. Thus, the original data that showed additional exceedances ofthe numeric criteria was used which resulted in additional units being recleaned and retested.)

PAHs - The analytical data for polycyclic aromatic hydrocarbons (PAHs) that was review^ consisted only of pre-cleaning samples. Post-cleaning samples were also collected, however the analytical results are not available at this date. When the analysis is completed for the post-cleaning samples, USEPA will review the data. We reviewed data for 66 wipe samples which were analyzed for a suite of 16 polycyclic aromatic hydrocarbons (PAHs). AU of the samples had reported results of non-detect which indicates that PAHs could not be detected above the limit of detection of 5 pg. Evaluation of PAH data is accomplished by using a method called toxic equivalency factors (TEFs). The TEF methodology uses die data from seven of the individual PAHs, which are summed after being adjusted to provide an estimate of the

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