NYC-WTC_000226957

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan January 15, 2002 Air Sampling for Mercury Page 2 Stuyvesant High School ATC ProiectNo. 15-19125-0246

TABLE 2 Airborne Mercury (Hg) Concentrations , January 9,2002 SarnpleNo?and.;/j, WB 96 0.000417 1 Floor Main Lobby 0.0350 96 0.000365 2“‘‘ floor bridge lobby 11^3 0.0360 96 0.000375 Roof Hg-4 0.0390 Blank * milligrams per cubic meter of air / Not blank corrected

After the Hg levels in the blanks are subtracted, the maximum concentrations in the indoor samples drop to 0.000010 mg/m^ on both days. The outdoor levels drop to 0.000010 mg/m’ on January 3"“ and below the limit of detection on January 9*

There are currently no federal ambient air standards for mercury. The Occupational Safety and Health Administration’s (OSHA) Permissible Exposure Limit (PEL) for mercury is l.Omg/lOm^ (O.lmg/m^). This is considerably above the levels that were detected or that would otherwise be expected in a school or office and it is not an applicable standard.

ATC appreciates the opportunity to provide this indoor air quality service to the BOE. Please call me at (212) 353-8280 extension 212 if you have any questions.

Sincerely, ATC Associates, Inc.

James R. Cohn, CIH, CSP Regional Manager Industrial Hygiene Division

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CITY_2IMCl00_000490961 NYC-WTC_000226958