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RESPIRATORY TOXICOLOGCAL EFFECTS OF WORLD TRADE CENTER FINE PARTICULATE MATTER IN MICE
Citation:
Gavett, S H., N. H. HaykalCoates, Chen, Lung Chi, Cohen, Mitchell D, AND D L. Costa. RESPIRATORY TOXICOLOGCAL EFFECTS OF WORLD TRADE CENTER FINE PARTICULATE MATTER IN MICE. Presented at Society of Toxicology 42nd Annual Meeting, Salt Lake City, Utah, March 9-13,2003.
Description:
ABSTRACT BODY:
The destruction of the World Trade Center (WTC) caused the release of high levels of airborne pollutants which were reported to cause adverse respiratory responses in rescue workers and nearby residents. We examined whether WTC-derived fine particulate matter (PM2.5) has detrimental respiratory effects in mice. Samples of WTC PM2.5 were derived from settled dust collected at several locations around Ground Zero on September 12 and 13. Chemical analysis showed high levels of calcium sulfate and calcium carbonate. Aspirated samples of WTC PM2.5 induced mild to moderate degrees of pulmonary inflammation one day after exposure, but only at a relatively high dose (100 micrograms). This response was not as great as that caused by 100 mg PM2.5 derived from residual oil fly ash (ROFA) or Washington DC ambient air PM (NIST 1649a). However, this same dose of WTC PM2.5 caused airway hyperresponsiveness to methacholine aerosol comparable to NIST 1649a and to a greater degree than ROFA. Mice exposed to lower doses by aspiration or inhalation exposure did not develop significant inflammation or hyperresponsiveness. These results show that a high dose of WTC PM2.5 can promote mechanisms of airflow obstruction in mice. Airborne concentrations of WTC PM2.5 which would cause comparable doses in people are high but conceivable in the immediate aftermath of the collapse of the towers. We conclude that a high-level exposure to WTC PM2.5 could cause pulmonary inflammation and airway hyperresponsiveness in people. The effects of chronic exposures to lower levels of WTC PM2.5, the persistence of any respiratory effects, and the effects of coarser WTC PM are unknown and were not components of these studies. Degree of exposure and respiratory protection, individual differences in sensitivity to WTC PM2.5, and species differences in responses are important elements in the health risk assessment of WTC PM2.5. This abstract does not necessarily reflect U.S. EPA policy.