Measurements of atmospheric concentrations of CS 2 in the eastern United States

Measurements of atmospheric concentrations of CS 2 were made at Philadelphia, PA and Wallops Island, VA. In relatively unpolluted air the mean CS 2 level was approximately 38 pptv. At the Wallops Island site a CS 2 level of 30 pptv was found in air that had spent an extended period of time over the Atlantic Ocean. Thus we estimated that the background CS 2 level in the northern hemisphere is less than 30 pptv. In air which has been obviously influenced by anthropogenic sources, CS 2 concentrations of 65 to 339 pptv were observed, the average being 150 pptv. This estimate of the CS 2 background level and the published rate data for reactions of OH with CS 2 , OCS and SO 2 revealed that CS 2 can account for a maximum of 20 percent of the atmospheric OCS concentration and an upper limit of 33 percent of the background SO 2 level.