title: Sulfuric acid effect on the deposition of radioactive aerosol in the respiratory tract of guinea pigs.
abstract: The effect of inhalation of sulfuric acid (H2SO4) aerosol on respiratory deposition of radiolabeled streptococcus aerosol was investigated in guinea pigs. A 60 minute exposure to 3020 mugm/m3 H2SO4 (1.8 mum CMD) resulted in a 60% greater total respiratory deposition rate than control animals and a proximal shift in the regional pattern of deposition to the nasopharynx. Dose-response experiments revelaed that a concentration of 30 mugm/m3 H2SO4 (0.25 mum CMD) also induced a proximal shift in the regional pattern of particle deposition but in this instance the shift was to the trachea. The interrelationship between mass concentration of H2SO4 and its particle size to the interpretation of these results is discussed. A hypothesis concerning the relationship of these data to previously reported respiratory physiologic effects of H2SO4 inhalation and to a pathophysiologic mechanism which may underlie effects attributed to sulfur oxides by epidemiologic studies is described.
mesh_terms: D000336:Aerosols; D000393:Air Pollutants; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D009305:Nasopharynx / Q000382:microbiology / Q000502:physiology; D010316:Particle Size; D010761:Phosphorus Radioisotopes; D012119:Respiration; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000382:microbiology; D013291:Streptococcus; D013464:Sulfuric Acids / Q000494:pharmacology*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D010761:Phosphorus Radioisotopes; D013464:Sulfuric Acids