NYC-WTC_000187710

NYC 9/11 Public Portal Document

Liberty Mutual-

Industrial Hygiene Air Sample Results Summary for Week of 2/15/02 to 2/22/02

Attached is a summary of the laboratory results and direct reading measurements completed during the week of February 15,2002 to February 22, 2002. The air samples were collected and the measurements made by ATC associates at the World Trade Center site.

The majority of the samples collected by ATC are “personal samples”, meaning that the worker wore the sampling device. Most of results have shown exposure levels to be below shift adjusted occupational exposure limits. The exceptions were;

• Quartz concentration of 733%, 237%, and 179%of the shift adjusted OEL on three tie-back hole drillers in WTC 6. • Quartz concentration of 625% of die shift adjusted OEL on a laborer at SW section of slurry wait • Quartz concentration of 114 % of the shift adjusted OEL on Core driller at WTC 6 Level B2. • Quartz concentration of 110 % of the shift adjusted OEL on spotter in Depression between N Tower & S Tower. • Lead concentration over 1500 % and Arsenic concentration of 278% of the shift adjusted OEL on a Torch Cutter in Depression North from Tower 2.

In addition, the following results ate at or above 50% of the shift adjusted OEL (but below 100% of dieshiftadjustedOEL).The operations associated with these results should receive attention to ensure that these results are an accurate reflection of actual exposures and that feasible steps are taken in an attempt to ensure that exposures do not elevate over time;

• Asbestos concentration of 76 % of the shift adjusted OEL on IH tech Walking all Ground Zero Work Areas. • Asbestos concentration of 66 % and 54 % of the shift adjusted OEL on grappler operator in depression at 5 WTC. • Asbestos concentcatioo of 64 % of the shift adjusted OEL on Torch cutter in depression south of tower #1. • Asbestos concentration of 60 % of the shift adjusted OEL on operator in depression EoflWTC. • Asbestos concentration of 58 % of the shift adjusted OEL on spotter in depression Tower #1 & 2. • Quartz concentration of 83 % of the shift adjusted OEL on Driller at 6 WTC Level B2. • Iron concentration of 82 % of the shift adjusted OEL on Torch Cutter in Depression North from Tower 2.

Some of the columns in the attached summary may require explanation:

CITY_21MC100_0 12250410

NYC-WTC_000187710