Geochemical aspects of atmospherically transported trace metals over the Georgia Bight

Abstract

There has been considerable evidence in recent years that a significant portion of the trace metals reaching coastal waters are transported by the atmosphere. The present study had the following three purposes: to assess trace metal concentrations and enrichment factors in the nearshore atmosphere over the Georgia Bight between Charleston, South Carolina and Jacksonville, Florida; to determine the sources of the metals; and to evaluate the solubilities of some of the metals in seawater. Atmospheric trace metal concentrations and enrichment factors generally decrease from Charleston to Jacksonville. Five metals (Cd, Zn, Cu, Ni, and Pb), were found to be anomalously enriched over the Georgia Bight. Observations from this study suggest that seawater may influence Cu and Zn concentrations in Georgia Bight air. Solubilities of Zn and Cu in seawater are source dependent, as seen by correlation with EF/sub crust/. No significant solubility of Ni in seawater was observed. Yearly fluxes of eight trace metals from atmosphere to seawater in the Georgia Bight were estimated. These trace metal fluxes are comparable to fluxes in other areas along the east coast. The fluxes of Cu, Cd, and Zn make considerable contributions to dissolved metal levels in Georgia Bight water. An attempt tomore » use trace metal concentrations in Spanish mosses as a means of tracing sources of trace metals over the Georgia bight was inconclusive.« less