Normalization of metal concentrations in estuarine sediments from the Gulf of Mexico

Estuaries
By: , and 

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Abstract

Metal concentrations were examined in sediments from 497 sites within the estuaries of the Gulf of Mexico by the United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP). Data were normalized for extant concentrations of aluminum to isolate natural factors from anthropogenic ones. The normalization was based on the hypothesis that metal concentrations vary consistently with the concentration of aluminum, unless metals are of anthropogenic origin. Strong linear correlations (>75% variation explained) were observed between Al and Cr, Cu, Pb, Ni, and Zn. Moderate correlations (50–75% variation explained) were observed between Al and As or Ag. Weak but significant correlations (30–40% variation explained) were observed between Al and Hg or Cd. Based on these results, the spatial extent of contamination was examined. About 39% of sites with contamination by at least one metal occurred near population centers, industrial discharge sites, or military bases. The remainder of the observed contamination represented a dispersed pattern, including the lower Mississippi River (7%) and numerous agricultural watersheds (54%), suggesting that the contamination might be from nonpoint sources.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Normalization of metal concentrations in estuarine sediments from the Gulf of Mexico
Series title Estuaries
DOI 10.2307/1352519
Volume 19
Issue 3
Year Published 1996
Language English
Publisher Springer
Contributing office(s) Wetland and Aquatic Research Center, National Wetlands Research Center
Description 14 p.
First page 581
Last page 594
Country United States
State Alabama, Florida, Louisiana, Mississippi, Texas
Other Geospatial Gulf of Mexico