NYC-WTC_000232933

NYC 9/11 Public Portal Document

and burning structural steel at the rubble pile have resulted in instances of overexposures as follows: copper (15); iron oxide (26); lead (18); antimony (1); and cadmium (2). 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 224 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.

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. Results show no elevated levels of concern from either known building latent radiation sources or any terrorist origin source materials.

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NYC-WTC_000232936