NYC-WTC_000199183

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.

March 7, 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. 234M 292 Greenwich Street New York, New York 10007 ATC Project No. 15-19125-0279

Dear Mr. Orlan:

ATC Associates Inc. (ATC) is pleased to provide this report of indoor air quality (lAQ) measurements collected on March 6, 2002, at the referenced school. The New York City Board of Education (BOE) requested these measurements as part of a program to determine if acceptable indoor air quality is being maintained.

SCOPE OF WORK

ATC conducted this evaluation to assess the basic parameters of temperature, relative humidity, carbon dioxide (CO2) and carbon monoxide (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, Industrial Hygienist of ATC’s New York City office, conducted the assessment.

ATC’s findings 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.

CITY_21MC100_003032131

NYC-WTC_000199183