Investigating Contaminant Inputs via Submarine Groundwater Discharge to Coastal Waters Using Radium Isotopes.

摘要

Our long-term goal is to determine if submarine groundwater discharge (SGWD) is an important mechanism for delivering contaminants (i.e. heavy metals, organics) to harbors. We plan to accomplish this goal using a suite of naturally-occurring radium isotopes as tracers of SGWD and the dispersion of contaminants from the embayment (Buesseler/WHOI). In addition, we plan to develop a comprehensive hydrological model (Harvey/MIT) to determine the importance of SGWD in the transport of pollutants to coastal harbors. We will apply recently developed analytical techniques for measuring radium (223Ra, 224Ra delayed coincidence counting; 226Ra, 228Ra low-background gamma counting) in the study of contaminant fluxes via SGWD. Recent studies suggest that groundwater may be important in the mass balance of many elements in nearshore environments and cannot be ignored in the accurate prediction of the fate of contaminants originating in marine sediments and pore waters. Even if SGWD flows are modest, pollutant concentrations in groundwater may be sufficiently high for SGWD to have an important impact on the source and fate of pollutants in coastal harbors and estuaries.