Controlled exposures of human volunteers to sulfate aerosols. Health effects and aerosol characterization.
Our laboratory has undertaken the study of possible acute adverse health effects of sulfate aerosols through controlled exposures of volunteer human subjects. Both healthy and asthmatic adult men were exposed for 2-hour periods (with intermittent exercise) to ammonium sulfate, ammonium bisulfate, and sulfuric acid of particle size distributions and concentrations intended to simulate "worst case" exposures during Los Angeles smog episodes. Lung function tests were performed by the subjects on entering and before exiting from a carefully controlled environmental chamber. Subject symptoms were evluated in a standardized manner. Aerosol concentrations and size distributions were determined by an on-line computer/aerometric monitoring  system; gravimetric and chemical analyses were performed on impactor and total filter samples after test exposures. We found little or no evidence of adverse health effects from 2-hour multiple-day exposures to any of the compounds at "worst case" ambient concentrations.
D000336:Aerosols; D000645:Ammonium Sulfate / Q000008:administration & dosage / Q000009:adverse effects; D001249:Asthma / Q000503:physiopathology; D001273:Atmosphere Exposure Chambers; D006801:Humans; D005082:Physical Exertion; D012129:Respiratory Function Tests; D012905:Smog; D013431:Sulfates / Q000008:administration & dosage / Q000009:adverse effects*; D013464:Sulfuric Acids / Q000008:administration & dosage / Q000009:adverse effects
D000336:Aerosols; D012905:Smog; D013431:Sulfates; D013464:Sulfuric Acids; D000645:Ammonium Sulfate