Natural background levels of heavy metals in Texas estuarine sediments.

The purpose of this report was to develop and compile data on the natural background levels of selected heavy metals in sediments located in Texas estuarine waters. The heavy metals selected for this study were the three specifically listed in the EPA criteria, namely zinc, lead, and mercury, as well as those strongly suggested by the EPA including iron, cadmium, copper, chromium, arsenic and nickel. Manganese was also included since analysis for it could be carried out with minimal additional effort. Available data for heavy metals in sediments of these areas was very limited. Davis (1968) reported values for five metals at five stations in Galveston Bay and at two Gulf of Mexico stations near Galveston while Hann and Slowey (1972 a,b) have presented data on eleven metals at twenty-two Galveston Bay stations and six metals at twelve stations located in the lower Neches and Sabine Rivers. Although additional and more comprehensive heavy metal studies are presently being carried out by other investigators in this area, their results were not readily available or were scheduled to be published too late to be incorporated in this study.