NYC-WTC_000205510

NYC 9/11 Public Portal Document

iw Mutual. Liberty

Industrial Hygiene Measurements Summary for Week of 03/15/02 to 03/22/02

Attached is a summary of the laboratory results completed during the week of March 15, 2002 to March 22, 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 the following:

Elevated Quartz concentrations were as follows: • 617% of the shift adjusted OEL on a laborer working neat boring machine in WTC 6- • 504% of the shift adjusted OEL while operating Brokk in WTC 6, Level B5. • 408% of the shift adjusted OEL while Core Drilling N. slurry wall in WTC 6, Level B4. • 342% and 54% of the shift adjusted OEL on a drill operator in WTC 6, B5 level. • 163% of the shift adjusted OEL while Core Drilling @ Path in WTC 6. • 142% of the shift adjusted OEL on a flagger in WTC 6. • 50% and 75% of the shift adjusted OEL on jack hammer operators. • 67% of the shift adjusted OEL on a carpenter in WTC 6.

Elevated Diesel Exhaust Particulate concentrations were as follows: • 581% of the shift adjusted OEL on a Laborer by boring machine in WTC6. • 287% of the shift adjusted OEL while Cote Drilling N. slurry wall in WTC 6, Level B5. • 169% of the shift adjusted OEL while drilling in WTC 6. • 127% of the shift adjusted OEL on a spotter in the PATH tunnel. • 112% of the shift adjusted OEL while torch cutting at WTC 6. • 110% of the shift adjusted OEL while torch cutting in depression @ WTC 2. • 103% of the shift adjusted OEL while torch cutting in depression @ WTC 2. • 98% of the shift adjusted OEL on an equipment (unspecified) operator at the WTC 4 site.

Elevated asbestos concentrations as follows: • 120% of the shift adjusted OEL while on an equipment (unspecified) operator at the WTC 4 site. This sample has been sent for transmission electron microscope (TEM) analysis to determine the actual identification of the fibers counted. • 64% of the shift adjusted OEL on a water truck operator in the pit. • 62% of the shift adjusted OEL on an equipment (unspecified) operator in the pit.

• Elevated respirable dust concentrations as follows: • 68% of the shift adjusted OEL on a laborer working near boring machine in WTC 6.

CITY_21MC100_002989017

NYC-WTC_000205510