NYC-WTC_000196481

NYC 9/11 Public Portal Document

Mr. Bernard P. Orlan January 7, 2002 Air Sampling for Mercury Page 2 Stuyvesant High School ATC Project No, 15-19125-0246

TABLE 2 Airborne Mercury (Hg) Concentrations* December 26, 2001

■I Hg-1 0.028 96 0.000292 1® Floor Main Lobby H?2 0.03 96 0.000312 2”*^ floor bridge lobby hF3 0.029 96 0.000302 Roof Hp 0.025 Blank * milligrams per cubic meter of air / Not blank corrected

After the Hg level in the blank is subtracted, the maximum concentrations in the indoor samples drop to below the detection limit on December 20* and 0.000052 mg/m^ on December 26*. The outdoor levels drop to below the limit of detection on December 20* and 0.000042 mg/m^ on December 26*.

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.

Mercury was detected in the samples at levels just above the detection limit.

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_21MC100_003056459

NYC-WTC_000196482