NYC-WTC_000203043

NYC 9/11 Public Portal Document

Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Interim Air Sampling Report Thursday, September 27, 2001

Investigators from the National Institute for Occupational Safety and Health (NIOSH) collected air samples in areas immediately adjacent to the debris pile and on personnel actively involved in rescue efforts on or in the vicinity of the debris pile to characterize occupational exposures. Below are the interim sampling results for Thursday, September 27, 2001.

Air Samples

Acid Gases • 6 area air samples were collected for acid gases o Trace amounts of acid gases were detected on most area air samples (1 had 0.8 mg m ' of sulfuric acid)

Asbestos • 114 personal air samples were collected by NYDOH contractors o Most personal sample 8-hour time-weighted average concentrations were below 0.024 fibers/cc as determined by PCM (12 were <0.042 fibers/cc and 1 was 0.28 fibers/cc) o Most short-term exposure limit samples were below 0.17 fibers/cc as determined by PCM (1 was 1.8 fibers/cc)

Carbon Monoxide • 25 real-time personal breathing zone samples were collected for carbon monoxide o Most 8-hour time-weighted average concentrations were below 25 ppm (two were an 8-hour time-weighted average concentration of 40 ppm) o A single peak of 1368 ppm was observed on a saw operator

Diesel Exhaust (Elemental Carbon) • 1 personal and 3 area air samples were collected for diesel exhaust (elemental carbon) o Personal air sample concentrations were below 0.019 m^m^ o Area air sample concentrations were below 0.015 mg/m^

Polynuclear Aromatic Hydrocarbons (PAHs) • 3 personal and 1 area air samples were collected for PAHs o Trace amounts of 8 different PAHs were identified

K.M. Wallingfoid 10/15/01

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NYC-WTC_000203043