Monday, September 12, 2005

Fire last time

Now that we know that WTC workers and community residents were sickened by their exposures, it’s worth looking back at what those exposures were. This NIOSH paper recounting 1200 bulk and air samples, confirms again that exposures were less than [actually much less than] OSHA limits.

BrooklynDodger is willing to be convinced that the combination of exposures – smoke and dust together – is more toxic than either alone, or that some not usually measured contaminant – particles larger than PM 10 – caused the observed effects. It’s more radical to say that the PM 2.5 [or respirable fraction] PEL should be lowered to less than 100 micrograms/M3

Toxicol Ind Health. 2001 Jun;17(5-10):247-53.
Occupational exposures during the World Trade Center disaster response.Wallingford KM, Snyder EM.National Institute for Occupational Safety and Health 4676 Columbia Parkway (R-11), Cincinnati, Ohio 45226, USA. kwallingford@cdc.govUpon the request of the New York City Department of Health, the Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health (NIOSH) monitored occupational exposures among emergency response workers during the rescue and recovery activities at the World Trade Center disaster site from September 18 through 4 October 2001. During this period, over 1,200 bulk and air samples were collected to estimate or characterize workers' occupational exposures. Samples were collected and analyzed for asbestos, carbon monoxide (CO), chlorodifluoromethane (Freon 22), diesel exhaust, hydrogen sulfide, inorganic acids, mercury and other metals, polynuclear aromatic hydrocarbons, respirable particulate not otherwise regulated (PNOR), respirable crystalline silica, total PNOR, and volatile organic compounds. Exposures to most of these potential hazards did not exceed NIOSH Recommended Exposure Limits or Occupational Safety and Health Administration Permissible Exposure Limits. However, one torch cutter was overexposed to cadmium and another worker (and possibly three others) was overexposed to CO. The elevated cadmium and CO levels were the result of workers using oxy-acetylene cutting torches and gasoline-powered cutting saws. Recommendations were made to ensure adequate ventilation and worker understanding when using these tools and, where possible, to substitute rechargeable, battery-powered cutting saws for gasoline-powered ones.

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