NYC-WTC_000234706

NYC 9/11 Public Portal Document

Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Interim Air Sampling Report Sunday, September 30, 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 Sunday, September 30, 2001.

Air Samples

Acid Gases • 2 personal and 5 area air samples were collected for acid gases o Trace amounts of acid gases were detected on most area air samples (1 had 0.26 mg/m’ of sulfuric acid)

Carbon Monoxide • 10 real-time personal breathing zone samples were collected for carbon monoxide o Most 8-hour time-weighted average concentrations were below 4 ppm (a fireman had an 8-hour time-weighted average concentration of 11 ppm) o A single peak of 286 ppm was observed on a fireman on the debris pile

Crystalline silica • 3 personal and 2 area air samples were collected for crystalline silica o No crystalline silica was detected on any of the air samples

Metals • 6 area air samples were collected for metals o Nothing of concern was found regarding metal analysis

Respirable Dust • 3 personal and 7 area air samples were collected for respirable dust o Personal sample 8-hour time-weighted average concentrations were below 0.13 mg/nV o Area air sample 8-hour time-weighted average concentrations were below 0.10 mg/m’

Total Dust • 6 area air samples were collected for total dust o Most personal sample 8-hour time-weighted average concentrations were below 1.0 mg/m^ (one was 1.9 mg/m^)

K.M. Wallingford 10/15/01

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NYC-WTC_000234706