NYC-WTC_000199062

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 1, 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. 234M ATC Project No. 15-19125-0279

Dear Mr. Orlan:

ATC Associates, Inc. (ATC) is pleased to provide this report of air sampling for metals in airborne dust on February 19, 2002, at the referenced school. The New York City Board of Education (BOE) requested this sampling at the recommendation of Environ Corp., the consultant retained by the parents association.

Scope of Work

ATC collected four (4) 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 inside the building and two (2) were collected outdoors. One blank sample was also submitted. The samples were sent to PSC Analytical Services, Inc., an American Industrial Hygiene Association-accredited laboratory in Reading, PA. Analysis was performed by NIOSH Methods 7300M. Each sample was analyzed for a panel of eleven .(11) metals. The metals were aluminum (Al), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni) and zinc (Zn). A copy of the analytical report is attached.

The sampling locations were the Main Entrance Lobby, 1“ floor Hallway, the west Playground and the Roof.

Tenzin Namgyal and Wagdi Abdelshahid, Industrial Hygienists from ATC’s New York City office, conducted the sampling.

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. The Environmental Protection Agency (EPA) has set a screening level for hexavalent chromium (the more toxic form) in air of 0.6 ug/m\ this assumes a continuous exposure for one year. These samples were analyzed for total chromium (trivalent and hexavalent). The results represent conditions at the time the samples were collected.

CITY_21MC100_003031041

NYC-WTC_000199062