NYC-WTC_000187693

NYC 9/11 Public Portal Document

104 East 25th St New York, New York 10010 WWW ate- enviro.corn 212.353.8280 Fax 212.353.8306 ASSOCIATES INC.

February 19, 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. ISOM 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 performed on January 29 and February 4, 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.

ATC collected three (3) samples for metals at specified locations on both dates. Samples were collected for a minimum, of ten (10) hours using 37 mm mixed cellulose ester filter connected to battery-powered sampling pumps at a flow rate of 2 liters per minute. Pumps were calibrated before and after each sampling period. One (1) sample was collected inside the building and two (2) were collected from the outside. One blank sample per day was also submitted for analysis. 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), cliromium (Cr), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni) and zinc (Zn). The January 29* samples were also analyzed for lead (Pb). Copies of the analytical reports are attached.

The sampling locations were as follows:

Outdoor - Plaza, roof (South) and T' floor lobby.

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 established an ambient air standard for Pb of 1.5 ug/m’ based on a three month exposure. The 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. The samples here were analyzed for total chromium (trivalent and hexavalent).

CITY_21MC100_0 02954360

NYC-WTC_000187693