NYC-WTC_000187513

NYC 9/11 Public Portal Document

Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Interim Air Sampling Report Friday, September 21, 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 potential exposures. Below are the interim sampling results for Friday, September 21,2001.

Air Samples

Asbestos • 4 personal air samples and 9 area air samples were collected by NIOSH investigators o Personal sample 8-hour time-weighted average concentrations were below 0.017 fibers/cc as determined by PCM o Area sample results were below 0.010 fibers/cc as determined by PCM o All 13 samples were analyzed by TEM; 10 were below the limit of detection, 3 were <0.004 fibers/cc) • 97 personal and 16 area air samples were collected by NYDOH contractors o Personal sample 8-hour time-weighted average concentrations were below 0.05 fibers/cc as determined by PCM o All short-term exposure limit samples were below 0.10 fibers/cc as determined by PCM o All area sample results were below 0.01 fibers/cc as determined by PCM o 19 personal and 3 area samples were analyzed by TEM; most were non-detectable (two were below 0.016 fibers/cc) Carbon Monoxide • 5 real-time personal breathing zone samples were collected for carbon monoxide o Most 8-hour time-weighted average concentrations were below 2 ppm (one was 32 ppm) o A single peak of 823 ppm was observed on a torch cutter Crystalline silica • 2 personal and 2 area air samples were collected for crystalline silica o No crystalline silica was detected on any of the air samples Mercury • 2 personal and 10 area air samples were collected for mercury o No mercury was detected on any of the air samples Metals • 7 personal and 7 area air samples were collected for metals o Nothing of concern was found regarding metal analysis Total Dust • 15 personal air samples were collected for total dust o Personal sample 8-hour time-weighted average concentrations were below 1.0 mg/m’ Volatile Organic Compounds (VOCs) • 7 personal and 7 area air samples were collected with charcoal adsorbent tubes o Concentrations of VOCs on all samples were below detectable limits K-M-Wallingfoid 10/15/01

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NYC-WTC_000187513