Synergistic Effects of Air Pollutants: Ozone Plus a Respirable Aerosol

This report describes a study by Dr. Last to investigate possible synergistic effects of multiple air pollutants on pulmonary measures in rats. Rats were exposed for 1-9 days to mixtures of O₃ or NO₂ and aerosols of sulfuric acid, ammonium sulfate, or sodium chloride, and to each pollutant individually. Responses were evaluated by various biochemical and morphometric analyses of lung tissue and lavage fluid. An additional preliminary experiment treated exposed rats in vivo with various free-radical scavengers to elucidate possible protective properties.