Silica dust air sampling report, June 2002

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104 East 25th St., 10th Floor New York, New York 10010 www,atc-enviro.com 212,353,8280 Fax 212,353.8306 ASSOCIATES INC.

June 17,2002

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

Re: Air Sampling for Silica Dust Stuyvesant High School ATC Project No. 15-19125-0246

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this report of air sampling for silica-containing dust conducted on April 24, May 1, May 8 and May 15, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling at the recommendation of H. A. Bader, a consultant to the parents association.

Scope of Work

ATC collected twelve (12) samples on each day for respirable dust using pre-weighed 37mm PVC filters connected to size-selective cyclones to remove the larger (non-respirable) particles prior to deposition on the filters. Eleven (11) samples were collected inside the building and one sample was collected outdoors. The samples were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association accredited laboratory in Reading, PA, One blank filter was also submitted on each day. Analysis was performed by x-ray diffraction according to OSHA Method 142. Copies of the analytical laboratory reports are attached.

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

On all four days, the following locations were sampled: 1“ Floor Main Lobby, Auditorium, Pool, 2"*^ Floor Main Lobby, 3"* Floor Gym and Outdoors.

On April 24, the following locations were sampled: 5* floor hallway, 6* floor hallway. Room 801, Room 838 and Room 611.

On May 1, the following locations were sampled: 4* floor hallway, 6* floor hallway, Room 440, Room 505 and Room 601.

On May 8, the following locations were sampled: 4* floor hallway, 8* floor hallway, Room 515, Room 601 and Room 838.

CONFIDENTIAL, CITY_21MC100_003433155 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

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