Chain of custody form for DEP environmental samples, 2001

NYC 9/11 Public Portal Document

4. Analytical Results Introduction This section reviews analytical results by building area and comparative results. The discussion of analytical results by building area mirrors to a large degree Attachment H, Synopsis of Cleaning Methods by Building Area and Fact Sheets, adding information relative to analytical results as they relate to the residential or commercial unit under review. Briefly summarizing the logistics of each unit, the cleaning methods employed, the number of times the unit was cleaned, and providing a narrative description of the analytical results for that unit, the narratives follow the tables in Attachment J, Keyfor Analytical Tables and Reporting ofAnalytical Results. Attachment J provides the analytical results for each sample that was collected and analyzed. Results reported in units of f/cc are associated with PCM analyses and results that are reported in units of 5>5u/cc are associated with PCMe analyses. A key at the beginning of Attachment J identifies the units associated with each result.

Analytical results are presented in alphabetical order, with details relative to samples that were collected before and after any cleaning event. If a compound is not present for a unit or if a sample type is not present for a compound, then it is not listed in the text. It is of note that in the case of asbestos wipe and micro vacuum samples, a certain number of structures needed to be detected to be reported as being detected above the detection limit. This number was in the range of 6-8 structures. Therefore, asbestos may be indicated as being present even though the sample result is reported as below the detection limit. Samples were analyzed for 23 PAH compounds.

The PAH results are reported as toxicity equivalency factors (TEF) values. These values are the sum of seven of the most toxic carcinogenic PAH^’, modified to reflect benzo[a]pyrene equivalents. The PAH analyses could potentially identify an additional 16 PAH compounds (23 total). These additional compounds are less toxic and in general are not carcinogenic, thus they are not included in the TEF calculations. Fifteen (15) samples that were analyzed for PAH detected at least one of these additional 16 less toxic compounds. These samples, along with the non-TEF modified concentrations detected, are reported in Table 8.0. The values in this table cannot be directly compared to the primary clearance value of300 ug/m^ because the primary clearance value represents a TEF value; however, the value listed for each PAH sample in Attachment J reflects the value that can be compared to the primaiy clearance value.

The dioxin results were modified using a toxicity equivalency method (TEQ), that takes into account the toxicity difference between the different congener groups, and the results are reported in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents. The TEQ value reported in the table represents the estimated maximum potential concentration (EMPC). The TEQ EMPC value used data that indicated the presence of a congener above zero but did not meet all of the QA/QC reporting level criteria. This value represents the highest potential concentration of dioxin that may be present.

’’These seven compounds were used to calculate the toxicity equivalence factor (TEF): benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, chrysene, dibenz[a,h]anthracene, indeno[ 1,2,3-cd]pyrene.

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