NYC-WTC_000208128

NYC 9/11 Public Portal Document

104 East 25th St. 10th Foor M J New York, New York 10010 www.atc- envi ro .com 212.353.8280 Fax 212.353.8306 r ASSOCIATES INC.

June 19, 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 P.S. 150M ATC Project No. 15-19125-0289

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this letter report of air sampling for silica-containing dust conducted on April 22 and 29, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling at the recommendation of Environ Corp., the consultant to the parents association.

SCOPE OF WORK

On each day, ATC collected four (4) 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 four samples were collected indoors. The samples, plus one blank filter per day, 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. Copies of the analytical laboratory reports are attached.

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

RESULTS

Samples were obtained in the Main Lobby, Multipurpose Room and Classroom 403. Classroom 402 was sampled on April 22 and Classroom 401 on April 29.

Silica was not present above the limit of detection (<10 micrograms per sample) in any of the four samples.

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NYC-WTC_000208128