NYC-WTC_000208358

NYC 9/11 Public Portal Document

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Chromium Air Monitoring Data Summary for Lower Manhattan WTC Sampling

Totals (for sampling through 01/15/02, in ug/m3) Total Samples 8 Samples Above Screening Level 0 % Above 0.00% Samples Below 8 Maximum Value (10/15/01): 0.51 Minumum Value: Not Detected Screening Level*: 0.6 Average 0.08

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■M is Chromium is a naturally occurring element commonly used in metal alloys and plumbing coatings in high rise I I ■ Samples Abase Screening Level □ Samples Below buildings such as the World Trade Center (WTC). Hexavalent chromium, the most hazardous form, can cause cancer and other health problems at high levels. People can be exposed to chromium by eating food, drinking water, 100% or breathing air that is contaminated. In air, chromium compounds are present mostly as fine dust particles that eventually settle over land and water.

Levels of chromium measured at sites surrounding the WTC work zone have been below the screening level, which was set to protect against significantly increased risks of cancer and other health problems. The screening level is based on continuous exposure for a year to an average concentration of 0.6 micrograms of hexavalent chromium per cubic meter. **

EPA anticipates that the average chromium concentration will remain below the screening level and will continue to monitor levels of chromium in the air.

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NYC-WTC_000208358