Site identification record, 74-90 Church Street, Oct 2001

NYC 9/11 Public Portal Document

Mr. Shaun Hession New York City Housing Authority O EMTEQUE November 12, 2001 Page 5

TABLE 2 POLYCYCLIC AROMATIC HYDROCARBONS Sample #/Location Compound(s) Concentration TAGM (ppm) Standard (ppm) PNA-5-02 Chrysene 0.7 0.4 5th Floor — South wall toward SW corner (3 offices from end)

Four samples were obtained from each floor with the exception of the 8th floor where EMTEQUE obtained five samples. A total of 33 samples were obtained. Based upon EMTEQUE's initial assumption that contamination would be localized to the southwest quadrant, sampling was broken down with four samples from the dirtiest area (southwest comer — one sample), cleanest area (usually the northwest — one sample), and the tapering off areas (two samples).

Detectable levels of silica were observed within all 33 samples. Sample results ranged from 1.1 to 12.0 percent quartz by weight.

Dioxins

Only bulk samples were obtained for analysis for dioxins. Analysis for dioxin was conducted by PSC. One sample was obtained from each of the subject floors that did •

not have fire damage. One sample was obtained from the eighth floor, two samples from the fifth floor and three samples were taken from the sixth floor. A total of 11 samples were obtained.

All 11 samples obtained revealed detectable levels of dioxin compounds. In order to review the data, EMTEQUE utilized the World Health Organization (WHO) dioxin equivalency factors (1997). These factors are intended to allow correlation from a level of each dioxin compound to the concentration of 2,3,7,8-C14-Dibenzo-p-dioxin (TCDD). 2,3,7,8-TODD is considered the most hazardous of the dioxin compounds and each of 2,3,7,8- the other dioxin compounds are compared to this toxicity. After correlation with total equivalent concentration. This level was TCDD, the levels are added to generate a 600 parts per trillion (ppt). Sample results from then compared to the TAGM standard of5th 6th the fire damaged floors, specifically the and floors were higher in concentration than the levels from the other floors. One sample from each of the fifth and sixth floors completely were above the TAGM standard. Observed concentrations did not appear consistent with the locations of the fires since much higher levels were identified in the the fire location. two samples away from the fire on the 6th floor rather than the sample at The two samples from the 5th floor away from the fire location appeared consistent with 6th TAGM the samples away from the fire on the floor. A summary of samples above the standard is listed in Table 3.

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NYC-WTC 000124618