VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

uniformly in October and November. This was perhaps a time period of most rigorous unloading. Of the 50 readings above 70 S/mm^, 36 occurred during these two months. The highest level of 275.56 S/mm^ was observed on November 5, 2001.

The Trends Report (EPA, 2002a) summarizes the results of 12,674 ambient samples measured for PCM, of which 8870 were also measured for TEM. Figures 29 - 32 show the directional analysis results for PCM. It is noted that all samples were less than 0.1 fi'cc. The trend observed above for TEM, that most high readings were found in the early readings in September, holds as well for PCM. The range of these higher measurements is about 0.04 to 0.08 fi'cc, and only 7 measurements in this range are seen in Figures 29 - 32. As noted above, PCM analyses identify the presence of fibers, including fibers of materials other than asbestos. By December, the maximum 2-week readings were all at apparent background for the area. With a few isolated exceptions, levels ranging from non detect to about 0.003 fZcc had been observed from lower Manhattan sampling sites since February, 2002 (EPA, 2002a). This backgroimd is consistent with the background measurements in other locations summarized above.

Chatfield and Kominsky (2001) describe the sampling of two apartments one week after September 11, on September 18. In addition to sampling of indoor air and dust (described in Section V), and some outdoor dust, two samples of outdoor air were also sampled. One was at a residential dwelling characterized as “high”, so named due to the expectation that higher concentrations would be measured within it. It was in an apartment building located on 250 South End Avenue, close to and southwest of Ground Zero. Apartment lOD, on the east side of this building and which had sustained window damage, was selected for sampling. Heavy dust deposits were in the apartment. One air sample at this site was taken by positioning the sampler outside a sliding window. The concentration of chrysotile asbestos (S > 0.5 pm) was 548 S/mm^, which is the highest outdoor air measurement found. However, it is likely this high reading was influenced by the air quality on the inside of the apartment, which showed exceedingly high asbestos concentrations (>10,000 S/mm'’; see the discussion on this study in Section VI. Data on Occupational and Indoor Exposures), and was likely not representative of outdoor concentrations. The “low” location was located four blocks north on 45 Warren Street. The apartment building did not appear to sustain any external damage. Apartments on the second and fifth floors were sampled. A sample taken on the roof above the fifth floor apartment showed a reading of 6.5 S/mm^ chrysotile asbestos.

IV.e.5. Human Health Evaluation of Asbestos Air Measurements Only 22 of 8870 TEM measurements in lower Manhattan from EPA’s WTC data base exceeded the AHERA standard of 70 S/mm\ and one additional sample (of two taken) from an independent study exceeded the standard. The 12 exceedences, which occurred in September, were all at sites bordering Ground Zero: 250 South End Ave., Barclay & West Broadway, Albany & Greenwich, Liberty & South End, Vesey & West, and Albany & West. These sites were still in the restricted zone during September. The same general trend can be seen with the PCM data. Measurements near to or greater than 0.04 ficc occurred mostly in September (6 of 7 samples during September, with 1 high sample during the first two weeks in October) and at sites bordering Ground Zero: Broadway & Liberty, Rector & South End, Albany & West, West Broadway & Barclay, Wall & Broadway, Albany & Greenwich, and Liberty & South End. It is

DRAFT-DO NOT QUOTE OR CITE 92 October 2002

NYC-WTC_000149036