NYC-WTC_000199954

NYC 9/11 Public Portal Document

Liberty Mutual.

Industrial Hygiene Air Sample Results Summary for Week of 02-08-02 through 02-15-02

Attached is a summary of the laboratory results completed during the week of February 8, 2002, through February 15, 2002. The air samples were collected 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. In addition, the majority of results have shown exposure levels to be below shift adjusted occupational exposure limits. The exceptions were;

• A Sulfur Dioxide concentration of 1026% of the shift adjusted OEL. This was found on an area sample collected next to the Verizon Building at West & Vesey. None of the personal samples approached the OEL. • Five quartz concentrations as follows; 458 % of the shift adjusted OEL. This was on a bobcat operator in the depression at level B2 at WTC 6. 371 % of the shift adjusted OEL. This was found on a laborer cleaning debris on level Bl at WTC 6. 150 % of the shift adjusted OEL. This was found on a jack hammer operator on level B2 at WTC 6. 129 % of the shift adjusted OEL. This was found on a drilling operation on level B2 at WTC 6. 125 % of the shift adjusted OEL. This was found on a spotter on level B3 at WTC 6. • Two diesel exhaust particulate concentrations as follows: 206 % of the shift adjusted OEL. This was found on a torch cutter in the depression southeast of Tower 1. 151 % of the shift adjusted OEL. Tliis was found on a torcli cutter working on the surface next to the Verizon Building.

In addition, the following results are at or above 50% of the shift adjusted OEL (but below 100% of the shift adjusted OEL). 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;

• Four Quartz concentrations as follows: 92 % of the shift adjusted OEL. This was found on a bobcat operator on Level Bl at WTC6. 63 % of the shift adjusted OEL. Tliis was found on a laborer at a core drilling operation on the north slurry wall on level B2 at WTC 6. 54% of the shift adjusted OEL. This was found on a bobcat operating in the depression at level B3 at WTC 6. 54% of the shift adjusted OEL. This was found on a spotter in the depression near Tower 1 where trucks were loading.

CITY_21MC100_006916426

NYC-WTC_000199954