NYC-WTC_000194874

NYC 9/11 Public Portal Document

104 East 25th St,, 10th F New York, New York 1( www.atc- enviro. 212,353£ Fax 212.353 / ASSOCIATES INC.

July 3, 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 Metals P. S. 150M ATC Project No. 15-19125-0289

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this report of air sampling for metals in airborne dust on June 3, 10, and 17, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling as part of a program to determine the indoor air quality prior to reoccupancy.

On each day, ATC collected three (3) air samples for metals at specified locations. Samples were collected for a minimum of eight (8) hours using 37 mm mixed cellulose ester filters connected to battery-powered sampling pumps at a flow rate of 2 liters per minute. Pumps were calibrated before and after each sampling period. Two (2) samples were collected outside the building and one (1) was collected indoors. ATC also submitted two (2) field blanks. The additional blank was included to confirm the levels of any trace contaminants in the filters. The samples were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association-accredited laboratory in Reading, PA. Analysis was performed by NIOSH Method 73OOM. Each sample was analyzed for a panel of twelve (12) metals. The metals were aluminum (Al), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni) and zinc (Zn). 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.

The sampling locations were as follows;

• Outdoors-Plaza, • Main Lobby, and • Roof.

The established regulatory values for metals are intended for industrial workplace exposures and are not generally applicable to office/school settings. There are no standards for these metals in indoor air in non-industrial situations.

CITY_21MC100_004152407

NYC-WTC_000194874