Trace Elements and Their Associations in Sediments Over the Hampton Roads Harbor and Lower Chesapeake Bay Area

摘要

Acid extractable Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were determined on sediments from the Inner Virginia Shelf, and from shipping channels in the lower Chesapeake Bay and Hampton Roads Harbor system. Levels of Cd, Cu, Pb, and Zn exceeded average crustal abundances for most of the study sites. Cumulative frequency curves suggested that there were two major populations for all metals and perhaps a third and smaller one for Cd, Cr, and Mn. Plots of metal vs Fe indicated no anthropogenic inputs of metals for shelf and Chesapeake Bay channel sites, but suggested anthropogenic influences for all metals in several of the inshore sites. Enrichment factor calculations showed enrichment of Cd, Cu, Pb, and Zn with respect to average crustal abundances. A recommendation of this study for evaluation of environmental geochemical metals data is to utilize mean concentrations, cumulative frequency plots, and metal vs Fe and/or enrichment factor calculations when evaluating the pollution status of sediments. (Author)