Pulmonary host defense responses to inhalation of sulfuric acid and ozone.
The effects of simultaneous exposure to ozone (O3) and sulfuric acid [H2SO4, 0.23 microns volume median diameter (VMD)] and a single exposure to ultrafine (less than 0.1 micron VMD) H2SO4 under various conditions were studied using the infectivity/mortality and the ciliary beating frequency model systems. A 3-h exposure to a combined aerosol of 196 micrograms O3/m3 and 483 or 241 micrograms H2SO4/m3 significantly increased the susceptibility of mice to a laboratory-induced respiratory infection. However, exposure to 543 micrograms ultrafine H2SO4/m3 for 2 h or 365 micrograms/m3 2 h/d for 5 d did not significantly affect this parameter. Upper airway response, as measured by changes in hamster tracheal ciliary beating frequency, was not affected by either a 3-h combined exposure to 196 micrograms O3/m3 and 847 micrograms H2SO4/m3 or a 2-h exposure to 458 micrograms ultrafine H2SO4/m3.
D000336:Aerosols; D000818:Animals; D002923:Cilia / Q000187:drug effects; D006224:Cricetinae; D005260:Female; D006813:Humidity; D008168:Lung / Q000276:immunology*; D008297:Male; D008647:Mesocricetus; D051379:Mice; D010126:Ozone / Q000633:toxicity*; D013290:Streptococcal Infections / Q000276:immunology; D013297:Streptococcus pyogenes; D013464:Sulfuric Acids / Q000633:toxicity*; D013696:Temperature
D000336:Aerosols; D013464:Sulfuric Acids; D010126:Ozone