Historical Fluxes of Pollutants from Deconvolution of Sedi- mentary Records

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This project is a renewal of one initiated under NSF Grant No. 87-01184 to develop methods for recovery of the historical input record of pollutants from analysis of sedimentary deposits obtained by coring lake sediments. In this prior work, a frequency domain deconvolution method was developed to extract past input fluxes of these types of pollutants from their sedimentary record. Pollutants of interest include lead, zinc, cadmium, polychlorinated biphenyls and polycyclic aromatic hydrocarbons. This renewal will permit enhancement of the experimental methods developed previously for analysis of polycyclic aromatic hydrocarbons and for the gamma-emitting radioactive tracer Cesium-137. Sedimentary deposits of particle-associated pollutants can provide valuable information for use in devising environmental models and in their validation. However, these records are often distorted reflections of past fluxes because of the variety of physical, chemical and biological environmental processes to which the particles are subjected during and following their deposition. These processes include mixing, biodegradation, radioactive decay and compaction. This project has the potential for obtaining more information than is now possible from an analysis of sedimentary deposits. This in turn may prove useful in validating models of climate and hydrological processes as they relate to pollutant deposition in coast regions of the United States.