NYC-WTC_000205510

NYC 9/11 Public Portal Document

r Liberty Mutual, Industrial Hygiene Measurements Summary for Week of 03/15/02 to 03/22/02

• 8 Hour equivalent time weighted average noise levels above 90 dBA were as follows: • 95 dBA on a Bobcat Operator, WTC 6 Path tunnel. • 93 dBA on a Boring Machine Operator, WTC 6, B5, V9. • 93 dBA on a Spotter, WTC 6 B3, cleaning debris. • 93 dBA on a Laborer by Borakk 150 Machine, WTC 6, B3. • 92 dBA on an Asbestos Handler, WTC 6 B5, breaking concrete wall. • 92 dBA on a Borakk 150 Machine Operator • 92 dBA on a Core Driller, WTC 6 B5. • 95 dBA on a Laborer @ WTC 6 Path tunnel. • Elevated Carbon Monoxide concentrations as follows: • 200% of the Peak Max exposure limit on a Laborer operating a Bobcat, cleaning debris @WTC6, B4 • 146% and 110% of the Peak Max exposure limit on a Torch Cutter, cutting rebar from broken up concrete@ WTC 6 • 100% of the Peak Max exposure limit on a Spotter, cutting conduit, cleaning debris • 60% of the shift adjusted OEL on a Spotter for boring machine preparation, WTC 6, B5

Elevated exposures to asbestos are based on the results of analysis by phase contrast microscopy (PCN^. This method counts all fibers detected that meet the criteria of “fiber”. Materials that are not asbestos may be included in the reported analysis. These samples have been submitted for further analysis by transmission electron microscopy (TEM) to make a definitive determination of the fibers detected by PCM analysis.

Contractors: Please note that OSHA regulations require that results of IH measurements be communicated to exposed workers. This is covered by the Hazard Communication Standard as well as other standards for specific substances such as lead, cadmium, asbestos, and others. It has come to our attention that some contractors do not feel that they have an obligation to do this. Not only is it required, but it is the right thing to do.

We are continuing to follow up on measuring the siUca and diesel exposure in WTC 6. We have not seen the extremely high silica results previously reported, but sihca, diesel and noise exposures remain consistendy high. Everyone is reminded that work in WTC basement levels requires the use of ’/a face respirators unless you are associated with operations that may generate “significant dust levels”. Such tasks require the wearing of a full face respirator.

If you have any questions concerning this information or would like further details about these results, feel free to contact the Liberty Mutual Industrial Hygienist on duty @ 917-566-2576.

Victor Hillman, CIH, CSP Liberty Mutual Group

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