This proposed investigation is concerned with the accurate determination and environmental assessment of contemporary and prehistoric fluxes of mercury from the atmosphere. The geographic focus of the research is Antarctica, and the program is a collaborative effort between Professor William F. Fitzgerald, The University of Connecticut, and Dr. Claude F. Boutron, Laboratoire de Glaciologie et Geophysique de l'Environnement, Saint-Martin-D'Heres, France. An excellent suite of Antarctic snow and ice collections have been obtained by Boutron and colleagues. Using sample from these collections, which have been carefully processed and stored, this research program is designed to achieve the following objectives: 1. to accurately quantify Mercury concentrations in recent snows and prehistoric ice and to determine the temporal variation of Mercury in the Antarctic icesheet; 2. to evaluate the importance of atmospheric Mercury deposition to these polar latitudes and to integrate the results within a general framework for the cycling of Mercury at the earth's surface; 3. to identify and quantify the influence of anthropogenic contributions on eolian Mercury fluxes to the Antarctic continent.