Silica dust sampling report at School for Leadership, April 2002

NYC 9/11 Public Portal Document

104 East 25lh St., 10th Fioor New York, New York 10010 www.atc-enviro.com 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

April 5, 2002

Mr. Bernard P. Orlan Director, Environmental Health & Safety New York City Board of Education 28-11 Queens Plaza North Long Island City, NY 11101

Re: Air Sampling for Silica High School for Leadership and Public Service (M894) 90 Trinity Place New York, New York ATC Project No. 15-19125-0290

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this letter report of air sampling for silica-containing dust conducted on March 8, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling to assess the concentration of crystalline silica in the respirable particulates within the building.

Scope of Work

ATC collected three (3) samples for respirable particulates using pre-weighed 37mm PVC filters connected to size-selective cyclones to remove the larger (non-respirable) particles prior to deposition on the filters. All three samples were collected indoors. The samples, plus one blank filter, were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association accredited laboratory in Reading, PA. Analysis was performed by x-ray diffraction according to OSHA Method 142. A copy of the analytical report is attached.

Tenzin Namgyal and Wagdi Abdelshahid, Industrial Hygienists of ATC’s New York City office, collected the samples consistent with generally accepted industrial hygiene practices. The results of the sampling represent conditions found on the date the samples were collected.

Samples were obtained in the 1” Floor Main Lobby, the 5* Floor Hallway near the Elevator and the 10* Floor Hallway near the Elevator.

CONFIDENTIAL, CITY_21MC1OO_OO34318O7 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

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