NYC-WTC_000205208

NYC 9/11 Public Portal Document

Latest WTC Air Monitoring Summaries Page 2 of 3 J

s! perchloroethylene, phosgene, styrene, toluene, 1-3 butadiene, trichloroethylene, vinyl chloride, and xylene. Screening samples initially showed elevated levels of some organic chemicals, resulting from the fires burning in the rubble pile. Subsequent personal and area samples show worker exposure levels to be below OSHA limits. However, one personal sample result for benzene was found to be at the 8-hr. OSHA Allowable Limit concentration of 1 ppm. This was found on a backhoe operator moving debris. See information Is below for polynucleated aromatics. Freon R-22, phosgene and dioxin.

Oxides of Nitrogen/Sulfur Sampling on grappler operators on the rubble pile, and on employees manning truck wash stations revealed trace levels of nitric oxide and nitrogen dioxide. SO2 personal and area results were found to be below OSHA limits.

Metals As of 11/3/01, OSHA has taken 368 air samples to monitor worker exposures to dusts, fumes, oxides, and other compounds of metals, such as antimony, beryllium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, vanadium, zinc, cadmium, magnesium, arsenic, and mercury. Results I from these samples are generally well below the applicable OSHA limits. However, torch cutting and burning structural steel at the rubble pile have resulted in instances of overexposures as follows: copper (6); iron oxide (8); lead (5); and cadmium (2). Accordingly, OSHA is recommending that workers engaged in these operations wear appropriate respiratory protection.

Ionizing Radiation A survey of the rubble pile was conducted on 10/22 - 10/23 to check for latent radiation with particular attention to alpha radiation. Preliminary results show no elevated levels.

Dioxins The single sample taken by OSHA and analyzed by the EPA, representing 1 exposure on the pile, showed elevated levels of dioxins. These levels were substantially higher than background levels, but comparable to levels found by the EPA on the rubble pile. The dioxins found here are emitted from the on­ going rubble fire. OSHA does not have a worker standard for dioxins. Dioxins are considered collectively as suspect human carcinogens. Some of the individual compounds are considered to be known human carcinogens. OSHA has taken additional samples, which have all been forwarded for analysis. OSHA is coordinating with EPA and OSHA's Salt Lake Technical Center to more fully characterize exposure and risk around the rubble pile.

Polynucleated Aromatic Hydrocarbons OSHA identified several elevated samples, three of which reached or exceeded OSHA's coal tar pitch volatile PEL of 0.2 mg/M3. These personal samples were <i http://www.osha.gov/nyc-disaster/summary.html 11/10/2001

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