Samples of particles collected by impaction in the antarctic atmosphere near the earth's surface during November and December 1966 contained much higher concentrations of sulfur than similar samples collected in most parts of the world. The sulfur was largely in the form of , but some may also have been present. The cations mere largely and H+. Most samples contained little sodium chloride. The concentrations in the air of collected particles varied from 0.1 to 1 cm−3. Possible explanations for the high sulfur to chlorine ratio are suggested.