NYC-WTC_000234895

NYC 9/11 Public Portal Document

Industrial Hygiene Air Sample Results Summary for Weeks of 12/21/01 to 01/04/02

Attached is a summary of the results of the samples collected by ATC associates at the World Trade Center site for the specified week.

The vast majority of the samples collected by ATC are “personal samples’’, meaning that the worker wore the sampling device. The vast majority of results have shown exposure levels to be below occupational exposure limits. The exceptions were:

An ozone concentration of 81 % of the TLV on a drill operator in the depression

A Diesel exhaust fume concentration of 86% of the TIW on torch cutter in the WTC 1 depression A Diesel exhaust fume concentration of 91% of the TLV on torch cutter in the WTC 1 depression A Diesel exhaust fume concentration of 102% of the TLV on torch cutter in the WTC 1 depression A Diesel exhaust fume concentration of 56% of the TLV on torch cutter in the WTC 1 depression A Diesel exhaust fume concentration of 98% of the TLV on truck operator moving material to surface

A quartz concentration of 62 % of the TLV on a slurry wall drill operator A quartz concentration of 72 % of the TLV on a jackhammer operator in the cable pit A quartz concentration of 466 % of the TLV on a jackhammer operator west of wash station A quartz concentration of 96 % of the TLV on a drill operator

An asbestos concentration of 56 % of the TLV on a grappler operator

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

Analyte Class - This column includes general category of the agents (substances) which were sampled.

# of Samples - This indicates how many individual samples were collected for the agent class listed.

# of Analytes - This is the number of individual analysis performed. If only one analyze is determined on each sample, then the number of analytes will equal the number of samples. However, most samples are analyzed for more than one agent as follows:

Metals: Aluminum, antimony, arsenic, barium, beryllium, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, nickel, selenium, silver, thallium, tin, titanium, vanadium, and zinc. Metal samples are sometimes also analyzed for total particulate.

PAHs: Acenaphthene, acenaphthylene, anthracene, benz(a)anthracene, benz(b)fluoranthene, benzo(a)pyrene, benzo(ghi)perylene, benzo(k)fluoranthene, chrysene, dibenzo(a,h)anthracene, fluoranthene, fluorene, indeno(l,2,3-cd)pyrene, naphthalene, phenanthrene and pyrene.

Aromatics: Benzene, ethyl benzene, toluene, and xylene.

CITY_21MC100_006311529

NYC-WTC_000234895