NYC-WTC_000205218

NYC 9/11 Public Portal Document

■l I 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 potential exposures. Below are the interim sampling results for Thursday, September 27, 2001.

Air Samples

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 1 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 mg/m^ o Area air sample concentrations were below 0.015 mg/m'^

J s

K.M. Wallingford 10/4/01

CITY_21MC100_007222520

NYC-WTC_000205218