Special Investigative Audit #14 Draft, WTC Site, Nov 2001

NYC 9/11 Public Portal Document

Indoor Air Samples:

Between September 14th and 23rd, twenty-five (25) indoor air samples were collected at various locations in Lower Manhattan and analyzed by PCM.. Detectable fibers were reported from 16 of the samples with 4 concentrations greater than 0.01 f/cc. The highest reported result, 0.044 f/cc, was collected on September 18th at 225 Rector St. The indoor air results for the 25 samples analyzed are tabulated in Table 8. Too few data points are available to perform trend assessment.

Bulk Dust Samples:

A total of three hundred eight (308) bulk dust samples were collected in the Work Zone, Disposal Zone, and various Lower Manhattan locations between September 11th and October 14t''. These include 171 in the Work Zone, 68 in the Disposal Zone, and 59 at various Lower Manhattan locations. In the Work Zone, 133 samples, or 78 % of the samples collected, were reported to contain detectable amounts of asbestos. Of these, eight (8) samples were reported to contain Amosite in amounts less than 1%, 115 samples were reported to contain Chrysotile in amounts ranging from trace (<1%) to 40%, and 10 samples were reported as detected with no asbestos class identified. The highest asbestos levels reported were 38% Chrysotile from Ground Zero (Sample WTC919-1B2) collected on September 19t'' and 40% Chrysotile from Building 6 (Sample 03819B) collected on October 10th, respectively. In the Disposal Zone, 10 of 68 bulk dust samples collected were reported to contain detectable amounts of asbestos. Of these, nine (9) samples were reported to contain Chrysotile at amounts ranging from trace (<1%) to 2.7 %, and one sample was reported to contain trace amounts (<1%) of Amosite. The highest asbestos level, 2.7% Chrysotile, was reported from a sample collected at the Bulk Steel Pile (Sample 03825B) on October l0t''. Of the 59 samples collected from Lower Manhattan, 34 were reported to contain detectable amounts of asbestos fibers; 30 samples were reported to contain Chrysotile from trace amounts (<1%) to 4%, and 4 samples were reported to contain Amosite at trace amounts (<1%). The highest result, 4.5% Chrysotile, was reported from a sample collected at Murray Street and West Side Highway (Sample 111979) on September 11t''. Bulk dust sample results greater than 1% asbestos are tabulated in Table 9. Too few data points are available to determine possible trends.

Conclusions:

With the available data, several conclusions concerning asbestos may be drawn:

• Ambient air sample results indicate a decrease in both total fibers (f/cc) and asbestos fibers (S/mm2) in the Lower Manhattan area from September 18t'' to November 2nd •

• Ambient air sample results indicate an increase in both total fibers (f/cc) and asbestos fibers (S/mm2) at the Fresh Kills Landfill from September 14t'' to November 2 1 .

• It appears from the PAM sample data provided that the level of total fiber (f/cc) exposure to personnel in the Work Zone, Perimeter, and Nearby Neighborhoods has steadily decreased from September 11t'' to September 23rd

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