NYC-WTC_000199923

NYC 9/11 Public Portal Document

QSHA WTC Sampling Results Page 3 of 4 Inorganic Acids

OSHA has taken approximately 255 samples for inorganic acids such as hydrochloric, phosphoric, and sulfuric acids. Four samples for sulfuric acid were found to exceed OSHA's permissible exposure limit (PEL) of 1 mg/m^. Workers were sorting debris.

Oxides of Nitrogen/Sulfur

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

Metals

OSHA has taken a total of 1331 samples (excluding bulk and blank samples) to monitor worker exposures to dusts, fumes, oxides, and other compounds of metals such as antimony, beryllium, chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel, vanadium, zinc, cadmium, magnesium, and arsenic. To minimize the length of the "WTC OSHA Heavy Metal Monitoring Data tables" only the samples that showed detected results for these metals are listed. Results 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 (17); iron oxide (28); lead (19); zinc oxide (1), antimony (1); and cadmium (3). Accordingly, OSHA is recommending that workers engaged in these operations wear appropriate respiratory protection. See information below for the specific counts in regards to mercury.

Mercury

OSHA has taken 242 air samples for inorganic mercury. No mercury was detected. Also, 36 bulk samples previously collected from rubble were re-analyzed for mercury and none was detected. Additionally, 10 bulks were taken on 1/3, with one sample detecting mercury at 0.9ppm and nine samples did not contain mercury. 38 bulk samples were taken between 1/8 and 1/11/02; results Indicate 0.1 to 0.2 ppm mostly in around the footprint of Bldg.-6, and in the pit between WTC tower 1&2. 10 bulks taken on 6/5, inside 130 Cedar, detected mercury from 0.3 to 0.5 ppm. One bulk taken in 130 Cedar on the Sth floor in the lab area (off floor below lab table) detected 10.0 ppm mercury.

Ionizing Radiation

o A survey of the rubble pile was conducted on 10/22-10/23 to check for latent radiation with particular attention to H alpha radiation. Results show no elevated levels of concern from either known building latent radiation sources or any K I terrorist origin source materials. I—i s o I—i o Back to Top www.osha.qov www.dol.qov o I o o o Contact Us | Freedom pt Information Act) Information Quality | Customer Survey (_71 NO

O http://www.osha.gov/nyc-disaster/summary.html 10/20/2003

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