NYC-WTC_000187708

NYC 9/11 Public Portal Document

i Liberty Mutual

Industrial Hygiene Air Sample Results Summary for Wedc of 11/25 to 12/1

Attached is a summary of the results of the samples collected by ATC associates at the World Trade Caito* site for the ^lecified week.

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

A lead cmcoitration of 23 times the PEL on a grappler operator on 10/17 A quartz concentration of 5 times the PEL on a laborer during concrete demolitian on 11/16 A quartz ooncentradon of 1,5 times die PEL on concrete mixer operator on 11/19

Some ofdie columns in die attached summary mxy require eqplanation:

Agent Clan - This column includes general calvary of die agents (substances) whidi 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, dien die number of analytes will equal the number of samples. However, most samples are analyzed for more than one agent as follows:

Bfatab: Aluminum, antimony, arsenic, barium, beiydlium, cadmium, calrium, chromium, cobalt, copper, iron, lead, magnesnim, manganese, nidcd, selenium, silver, thallium, tin, titanium, vanadium, and zinc. Metal sanqdes are sometimes also anafyzed for total partiodate.

PAHs: Acenaphthene, acenajhtiiyiene, antiiraoene, benz(a)Bndir8oene, benz(b)fluoranthene, benzo(a)pyrene, beazio^i)pei^ene, benzo(k)fluoranthene, dnysene, (fibenzo(a,h)andiraoene, fluoranthene, fluorene, indeno(l,23-cd)pyrene, naphthalene, phenanthrene and pyrene.

Armnatics; Baizene, ethyl benzene, toluene, and xyloie.

Silica: Respirable dust, quartz; and cristobalite.

Aldehydes: Acetalddiyde, acrolein, bsizaldehyde, formaldehyde, n-butyralddiyde, propionaldehyde, and Metaldehyde.

Acids: Hydratxurrfc add, hydroMoricac^ hydrofluoric ac^nMc acid ptiosphoric acid and

Highest Analyte - The analyte found in the highest concentration with respect to its occupational exposure limit

Highest Result - The concentratimi of die highest analyte.

CITY_21MC100_0 12250405

NYC-WTC_000187708