NYC-WTC_000215006

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 17, 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: Wipe Samples for Dioxins P. S. 150M ATC Project No. 15-19125-0289

Dear Mr. Orlan;

ATC Associates Inc. (ATC) is pleased to provide this report of the results of the wipe-samples for polychlorinated dibenzo-p-dioxins (PCDDs)and dibenzofurans (PCDFs) collected on March 8, 2002, at the referenced location. The New York City Board of Education (BOE) requested these samples to evaluate possible contamination in the school building per the recommendation of Environ Corp., consultant to the parents association..

SCOPE OF WORK

The samples were collected using gauze pads and hexane as a solvent. The pads and solvent were provided and samples were analyzed by Pace Analytical Services, Inc. (Pace) of Minneapolis, MN, a laboratory experienced in dioxin analysis. The analysis was performed by modified EPA Method 8290 using combined capillary column gas chromatography/high resolution mass spectrometry.

ATC’s findings and conclusions are based on the laboratory samples results and the conditions present in the school at the time of the assessment.

Wagdi Abdelshahid, Industrial Hygienist of ATC’s New York City office, collected the samples. consistent with generally accepted industrial hygiene practices. There were inherent limitations created by constraints of time, operational and work practice variability, variations in contaminant concentrations, and sampling and analytical accuracy. The results of the sampling represent conditions found on the date the samples were collected.

RESULTS

ATC submitted one wipe sample for PCDDs/PCDFs to Pace for analysis. The sample area was one square meter (1 m^). The location sampled was the Main Entrance - Lobby.

CITY_21MC100_002871450

NYC-WTC_000215006