NYC 9/11 Public Portal Document
OSHA SAMPLING RESULTS SUMMARY AS OF 2/13/02
Asbestos: A total of 1027 samples (excluding bulk and blank sampiesi for las u been
From 9/13 -9/21, 177 samples were taken in the financial district. They were taken on
OSHA personnel as they walked within certain predetermined zones. Results rex’ealcd
asbestos concentrations ranging from ND (none detected) to .037 fee., well below
OSHA’s permissible exposure limit (PEL) of 0,1 f/cc. After 9/21, sampling focused on
the rubble pile and those workers working on or immediately next to it. 139 of the
samples analyzed exceeded OSHA’s limit via PCM analysis. However, upon further
analysis using discriminating counting methods and/or TEM analysis, the number of
asbestos fibers found dropped dramatically to below detectable levels or well below ,1
f/cc.
Carbon Monoxide; A total of 109 personal samples of workers on the rubble pile showed results ranging
from 1 ppm to 34 ppm which are well below the OSHA permissible exposure limit of 50
PPM.
Noise: OSHA is monitoring the noise exposures of employees who perform (or work near) noisy
operations such as jack hammering and dulling. To date the 95 samples collected
indicate that employee noise exposures range from 73.7 dBA to 94.5 dB.A. One personal
sample and one area sample taken dunng core drilling operations have e.xcceded the
applicable permissible exposure limit of 90 dBA. Accordingly, OSHA continues to
recommend the use of appropriate hearing protection in noisy operations.
Total Dust (PNOR) A total of 141 samples (excluding bulk and blank samples) for total dust in and around
the rubble pile were taken. 5 samples were found to be in excess of the PEL for Total
dust (15mg/m3). The highest exposure was found on one operator who was exposed at
approximately 4X PEL.
Respirable
Silica; The overwhelming majority' of 674 silica samples (excluding bulk and blank samples)
show no detectable levels of airborne silica. Howexer, 41 exposures exceeded the PEL.
The highest sample result was approximately twenty-one times the OSHA limit (jack
hammering concrete 16 feet below grade). The other elevated exposures were
approximately one to fourteen times the OSHA limit. These exposures occurred during;
1) pre-drilhng /slurry' wall 2) jack hammering, 3) rubble removal and loading operations
near the Winter Garden; 4) during the breaking up of concrete in the pit; 5) ts hile
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