Acute pulmonary effects of ultrafine particles in rats and mice.

摘要: Ambient fine particles consist of ultrafine (< 100 nm) and accumulation-mode (approximately to 1,000 nm). Our hypothesis that can have adverse effects in humans is based on results our earlier studies with both sizes the finding urban reach mass concentrations 40 50 micrograms/m3, equivalent number 3 4 x 10(5) particles/cm3. The objectives exploratory reported here were (1) evaluate pulmonary induced rats mice by known high toxicity (although not occurring ambient atmosphere) order obtain information principles particle toxicology; (2) characterize generation coagulation behavior are relevant for air; (3) study influence animals' age disease status; (4) copollutants as modifying factors. We used Teflon (polytetrafluoroethylene [PTFE]*) fumes (count median diameter [CMD] approximately 18 generated heating a tube furnace 486 degrees C might be helpful understanding potential particles. at micrograms/m3 extremely toxic when inhaled only 15 minutes. found neither alone argon nor fume gas-phase constituents air after 25 minutes exposure. Only combination phases caused toxicity, suggesting existence either radicals surface or carrier mechanism adsorbed compounds. also rapid translocation across epithelium their deposition, which appears an important difference from larger Furthermore, could prevented adapting animals short 5-minute exposures days prior 15-minute This shows importance preexposure history susceptibility acute Aging fresh 3.5 led predicted resulting greater than nm no longer exposed animals. result consistent compared When establishing dose-response relationships intratracheally instilled titanium dioxide (TiO2) size (20 (250 nm), we observed significantly inflammatory response TiO2 mice. correlated well area per mass. Ultrafine carbon, platinum, iron, iron oxide, vanadium, vanadium oxide electric spark discharge characterized environmental relevance study. CMD carbon was 26 nm, metal 20 geometric standard deviations (GSDs) 1.4 1.7. For particles, 12 10(6) Homogeneous these animal exposure chamber occurred rapidly 1 10(7) particles/cm3, so quickly grew nm. Thus, controlled aging allowed (due growth) use comparative studies. developed technique generate consisting stable isotope 13C using 13C-graphite electrodes made laboratory amorphous powder. These particularly useful tools determining deposition efficiencies respiratory tracts extrapulmonary sites. compromised animals, chronic emphysema; low-dose endotoxin inhalation aimed priming target cells lung developed. Other factors copollutant (ozone) Exposure rodent selected basis doses occur people inhaling Concentrations achieved same burden unit alveolar rodents. (ABSTRACT TRUNCATED)