NYC-WTC_000229622

NYC 9/11 Public Portal Document

liberty Mutual.

Industrial Hygiene Air Sample Results Summary for Weeks of 11/25 and 12/2 ■]

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

Sampling for hydrogen sulfide around the area of the south bridge was begun during the week of 12/2. This area has been a source of frequent complaints about “rotten egg” odor. Out ofthe 8 samples collected in that area, one sample showed a conccntraticHi of 16 ppm, which is below the OSHA ceiling PEL of 20 ppm, but above the 8 hour TLV of 10 ppm. This was an area sample taken near a suspected odor source (a storm sewer opening) so it docs not represent worker exposure. However, in response to this elevated result, we have included both personal and area samples for hydrogen sulfide in our sampling plan. The results of the other samples collected in the area were either very low or too low to be quantified.

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

A lead concentration of 2.3 times the PEL on a grappler operator on 10/17 A quartz concentration of 5 times the PEL on a laborer during concrete demolition on 11/16 A quartz concentration of 1.5 times the PEL on concrete mixer operator on 11/19

Following is an explanation of the colunms in the attached sum mary;

Agent 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.

Silica: Respirable dust, quartz, and cristobalite.

Aldehydes: Acetaldehyde, acrolein, benzaldehyde, formaldehyde, n-butyraldehyde, propionaldehyde, and valeraldehyde.

Acids: Hydrobromic acid, hydrochloric acid, hydrofluoric acid, nitric acid, phosphoric acid and sulfuric acid

CONFIDENTIAL INSURANCE INFORMATION, CITY_21MC100_007971938 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000229622