SUMMARY Squirrel monkeys were exposed to nominal concentrations of 2.5 mg/m3 of the following generated aerosols: zinc ammonium sulfate at both low (40%) and high (85%) nominal relative humidities@ histamine diphosphate at low relative humidity@ and ammonium bisulfate at low relative humidity. There were few statistically significant changes in oscillatory resistance; however@ several trends towards increased resistance were present. Statistically significant changes in monkeys' resistance were considered significant health effects only when accompanied by statistically significant changes in group resistance values@ increased clinical signs@ or other corroborating evidence (such as N2 washout). Differences between high and low humidity exposures to the same aerosols did not appear statistically significant; possible interpretations of the observed data are discussed. Data previously reported by Amdur et al (19)@ on the comparative ranking of irritant potency of sulfate salts in guinea pigs@ has been corroborated in our laboratory using squirrel monkeys. Additional studies were performed using two different aerosol nebulizers to produce histamine diphosphate particles in two distinct size distributions@ an order of magnitude different in size. Marked increases in oscillatory resistance@ present when an aerosol diameter of four microns was used@ were absent in exposures employing a particle MMAD of .52 microns. These results@ supported by data collected during sulfur dioxide exposures of squirrel monkeys@ are used to discuss the suitability of S sciureus as a sensitive indicator species and oscillatory resistance as valuable measurement of proximal airway changes. Finally@ work is reported on the development of the esophageal balloon technique as a means of measuring compliance and resistance in the unanesthetized squirrel monkey.
API PUBL 26-60029-1977 history
1977API PUBL 26-60029-1977 EFFECTS OF SULFATE AEROSOLS UPON CARDIOPULMONARY FUNCTION IN SQUIRREL MONKEYS