The radioactive isotope Sulfur-35 is an ideal tracer of sulfur emissions from anthropogenic sources because it would undergo the same chemical transformations in the atmosphere as the more common isotopes of sulfur, and further it has a very low natural background concentration. A conceptual experiment using a simple transport model shows that for continual releases over a year and requiring detection at 1000 km, a source strength of about 180 curies per week is necessary. Calculations using a wind rose Gaussian plume model indicated that the air concentrations near the release point would be below Federal minimum values set for protection of the public safety. Production of the isotope is within existing technology although material costs could run as high as one million dollars for a full years release. Sampling and detection methods would require state-of-the-art technology with an investment of about one half the material costs. The general conclusion is that such a tracer experiment is technically feasible. Public perception was not considered in the study and a major effort of public education would be necessary before such an experiment could be carried out. An analysis of the possibility of using the stable isotopes Sulfur-34 and Sulfur-36 would require the development of new very expensive and specialized technology. Thus the use of stable isotopes was not considered to be feasible at the present time.

Caption title. "January 1986." "EPA/600/3-86/010." Microfiche.