Document page fragment, DEP Box 54, 2003

NYC 9/11 Public Portal Document 13/21E73 11:31 18568589551 EMSL ANALYTICAL PAGE 01

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

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• Order ID:040305206

Attn: Andrew/ M.N. Khan Customer ID: JLCC50 JLC Environmental Consultants, Inc. Customer PO: 200 Park Ave South, Suite 1001 Date Received: 04/05/03 1223 AM New York, NY 10003 Fax: 212-420-6092 EMSL Order: 040305286 Project #03-2744/NYCDEP-114 Liberty ST EMSL Project ID: 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

Resplrabie Dust Alrbonne Silica Sample Sample Silica Silica % Analytical Sample ID Identification Particle Volume Weight Conc. Weight Conc, Silica Sensitivity 1D (L) (mg) (mg/m') (mg) (mg/m') (mg/m')

MB13687-1 12TH FLR SOU'l14 Quartz 408 <0.002 N/A <0.0045 <0,0110 N/A 0.0110 MB13687.2 11TH FLR DINING Quartz 408 <0.002 N/A 0.0090 0.0221 N/A 0.0110 MB13687-3 I OTH FLR DINING Quartz 408 0.601 1.4730 0.0080 0.0196 1.3 0.0110 MB13687-4 9TH FLR DINING Quartz 408 0.014 0.0343 0.0090 0,0221 64.3 0.0110 13687-5 8TH FLLR DINING uartz 408 <0.002 N/A <0.0045 <0.0110 N/A 0.0110 13687-6 7TH FLR DINING Quartz 408 0.010 0.0245 <0.0045 <0.0110 45.0 0.0110 MB13687-7 6TH FLR DINING artz 408 0.090 0.2206 <0.0045 <0.0110 5.0 0.0110 M313687-8 5TH FLR DINING Quartz 408 <0.002 N/A <0.0045 <0.0110 N/A 0.0110 4Th FLR MB13687-9 KITCHEN artz 408 0.115 0.2819 <0.0045 <0.0110 3.9 0.0110

Disclaimer: The laboratory can only verify the concentration of silica on the filter and not the final concentration due to obtained by non-laboratory personnel. Jo the absence of a bulk dust sample, neither the specific forms of crystalline data 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 tertiary peak data with comparison to calibration curves of known standards. It should be acted that samples are meant for only quantifying silica (or a mineral phase) which must first be identified from a bulk dust air sample.. "<" ineans 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.

Aanant Samudra, Ph.D. Analyst Stephen Siegel, Cuff- Lab Manager Or other approved signatory

` l A..HA Accredited - Laboratory ID #100194 L ` Pagelof3 -

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