NYC-WTC_000208202

NYC 9/11 Public Portal Document

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

February 28, 2002

Mr. Bernard P. Orlan Director, Environmental Health 8& Safety New York City Board of Education 28-11 Queens Plaza North Long Island City, NY 11101-4008

Re; Respirable Particulate Monitoring Various School Locations ATC Project No. 15-19125-0314

Dear Mr. Orlan:

ATC Associates Inc. (ATC) is pleased to provide this report of the results of real­ time air monitoring of respirable particulates conducted on February 27, 2002, at numerous locations. The New York City Board of Education (BOE) requested this monitoring to obtain comparison data for lower Manhattan schools.

SCOPE OF WORK

John Scarcella, Environmental Technician, from ATC’s, New York City office, conducted the monitoring. ATC’s findings are based on real-time environmental measurements. Real-time readings of respirable particulates PM2 5) were collected from outdoors and limited indoor locations.

ATC recorded concentrations of respirable particulates with a Dust Trak® Aerosol Monitor Model 8520, manufactured by TSI, Inc.

The assessment was performed consistent with generally accepted 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 air quality parameters, and sampling and analytical. accuracy. The results of the sampling represent conditions found on the date of the survey and may not represent conditions found at other times.

EVALUATION CRITERIA

The target guidelines for the parameter that ATC evaluated during this investigation are shown in the following table.

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NYC-WTC_000208202