METAL TO ALUMINUM CORRELATION IN LOUISIANA COASTAL WETLANDS - IDENTIFICATION OF ELEVATED METAL CONCENTRATIONS

Elevated toxic metal concentrations in Louisiana coastal wetlands are obscured by natural heterogeneity in baseline levels. Normalization of heavy metal concentrations to Al is a promising method for intersite comparison and for the identification of metal-contaminated sites. We determined that Al significantly correlates with Pb (r2 = 0.88), Cd (r2 = 0.81), Cr (r2 = 0.45) in sediment samples from coastal Louisiana. These relationships were used to evaluate sites for metal contamination. Data from two potentially contaminated sites, Capitol Lake (Baton Rouge) and Bayou Trepagnier, fell well outside the prediction limits of the Al metal regression line for several of the metals. Samples from additional sites with no known metal contamination fell within the predictive limits of the regression equations. Metal: Aluminum regression relationships provide another tool for identifying areas of potential metal contamination in coastal wetlands but must be regionally correlated.