VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

rather than more physiologically relevant inhalation techniques employed in this report are not absolute, and exposure methodology. We believe that utilizing significant quantities of PM > 2.5 pm are present in the oropharyngeal aspiration, as described in the Experimental samples. Furthermore, analysis of the WTC PM2.5 and Design section, had many advantages and was necessary PM53 samples showed that they were similar in in these circiunstances. However, this report indicates that composition (Tables 3 and 5), suggesting that only future studies may be needed to more closely examine differences in respiratory tract deposition patterns of fine bronchoconstriction and sensory irritation during and coarse WTC PM would affect biological responses. inhalation exposure to WTC PM in mice and in guinea Coarse mode PM may be more relevant for upper airways pigs, a species known to be especially sensitive to sensory sensory irritation because larger particles will mainly irritants (Costa and Schelegle, 1999). Secondly, these deposit in the upper airways where sensory innervations studies only evaluated short-term toxicological effects are predominant (Costa and Schelegle, 1999). However, (endpoints were examined 1,3, or 6 days after exposure) chronic effects of fine PM may be greater than coarse PM after acute exposure and no direct information is provided since it can be inhaled more deeply and deposit in on the long term effects of acute or chronic exposures to peripheral regions of the lungs, and is more slowly WTC PM2.5. Thirdly, gaseous and vapor-phase toxicants cleared. Coarse PM is much less inhalable in small (e.g. dioxin and volatile organic compounds such as rodents than in humans, and less is deposited in the benzene) were certainly released, especially during the respiratory tract (Menache et al., 1995). Consequently, fires which continued for months after September 11 interpretation of results derived from exposure of mice to (EPA, 2002c). The collection and processing techniques coarse PM is problematic, and small rodents are probably described in this report do not allow investigation of these not the ideal species to study effects of course PM. important toxic species, nor are the interactions of Nevertheless, because upper airways irritant responses particles with gases or organic vapors considered (Mautz seem to be so important in people exposed to WTC- et al., 2001). Finally, these studies only examined fine derived dust, future studies should examine the specific PM2.5, while the toxicity of coarse mode and larger size toxicity of coarse WTC PM on respiratory responses in PM fractions were not investigated. However, it is appropriate animal models. important to remember that the size-fractionation

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NYC-WTC_000149190