NYC-WTC_000206884

NYC 9/11 Public Portal Document

liberty Mutual

Industrial Hygiene Air Sample Results Summary for Weeks of 11/25 and 12/2 3

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 ^g” odor. Out of the 8 samples collected in that area, one sample showed a concentration 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 does 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 V quantified.

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

A lead concentration of 23 times the PEL on a grapplcr 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 columns in the attached summary: i

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. I # 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 (me 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)anthractaie, fluoranthene, fluorene, indeno(I,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

CITY_21MC100_006712815

NYC-WTC_000206884