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NYC 9/11 Public Portal Document

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EMSL Analytical, Inc. 107 Haddon Ave., Westmont, NJ 08108

EMSL Order TD:040305286 Attn: Andrew/ M.N. Khan Customer ID: jnLx;c5O JLC Environmental Consultants, Inc. Customer PO: 200 Park Ave South, Suite 1001 Date Received: 04/05/03 12:23 AM New York, NY 10003 Fax: 212-420-6092 EMSL Order: 040305286 Project: #03-2744/NYCDEP—114 Liberty ST EMSL Project ED: Report Date: 04/14/03 Date Analyzed: 04/14/03

Silica, Crystalline Analysis Performed X-Ray Diffraction (XRD) Modified NIOSH Method 7500, Issue 3,1/15/98

1 Respirable Dust Airborne Silica Sample Sample Silica SiUca % Analytical Sample ID Identification Particle Volume Weight Cone. Weight Cone. SiUca Sensitivity ID (L) (Jng) (mg/m^ (n«) (mg/m'^ (mg/m*)

3RDFLR APARTMENT MB13687-10 KITCHEN Quartz 408 0.143 03505 <0.0045 <0.0110 3.1 0.0110

Disclaimer: The laboratory can only verity the concentration of silica on the filter and not the final concentration due to data obtained by non-laboratory personneL In the absence of a bulk dust sample, neither the specific forms of crystalline silica nor the interfering species can be fully determined. Hence, the amount for each phase, if anticipated, will be analyzed based on primary, secondary, and/or tortiary peak data with comparison to calibration curves of known standards. It should be noted that air samples are meant for only quantifying silica (or a mineral phase) which must first be identified from a bulk dust sample. “<" means less than the stated value. The lowest reportable value is equivalent to the Analytical Sensitivity that is calculated from the lowest reproducible amount of specific mineral detectable by the instrument.

Anant Samudra, Ph.D. Analyst Stephen Siegel, CIH- La^Manager Or other approved signatory

AIHA Accredited - Laboratory ID 11100194 Page 2 of3

NYC-WTC_000155056