NYC-WTC_000222500

NYC 9/11 Public Portal Document

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

April 24, 2002

Mr. Bernard P. Orlan Director, Environmental Health & Safety New York City Board of Education 28-11 Queens Plaza North Long Island City, NY 11101-4008

Re; Indoor Air Quality Assessment P.S. 89M 201 Warren Street New York, New York 10282 ATC Project No. 15-19125-0297

Dear Mr. Orlan:

ATC Associates Inc. (ATC) is pleased to provide this report of indoor air quality (lAQ) measurements collected on April 23, 2002, at the referenced school. The New York City Board of Education (BOE) requested these measurements to evaluate air quality in the school building.

SCOPE OF WORK

ATC conducted this evaluation to assess the basic parameters of temperature, relative humidity, carbon dioxide (COj) and carbon monoxide (CO).

ATC measured temperature, relative humidity, COj and CO with a Q-Trak® Model 8551, manufactured by TSI, Inc.

ATC measured concentrations of respirable particulates (PM2.5) with a Dust-Trak® Aerosol Monitor Model 8520, manufactured by TSI, Inc.

ATC measured concentrations of Total Volatile Organic Compounds (TVOCs) using a RAE Systems, Inc. MiniRAE® photoionization detector (PID).

Mr. Jimmy Choy, Environmental Technician, of ATC’s New York City office, conducted the assessment.

ATC’s findings and conclusions are based on a visual inspection, real-time environmental measurements and conditions present in the school at the time of the assessment.

The assessment was performed consistent with generally accepted indoor air quality assessment practices. As with all such assessments, there were inherent limitations created by constraints of time, operational and work practice variability, variations in indoor air quality parameters and sampling and analytical accuracy. The results of the sampling represent conditions found on the dates of the survey and may not represent conditions found at other times. The information

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