DIAGNOSIS OF HEAVY METAL POLLUTION IN SURFACE SEDIMENT OF TERMINOS LAGOON, CAMPECHE: A STATISTICAL APPROACH

Abstract

The levels of heavy metals in sediments of Terminos Lagoon, one of the largest coastal lagoons and of great ecological importance of Mexico, were evaluated; the analysis of heavy metals included geochemical approaches (normalization) and multivariate statistics. Sediment samples were collected at 45 sites in October 2010; digestion was accomplished according to the 3050B method of the Environmental Protection Agency of the United States and quantification was performed by inductively coupled plasma mass spectrometry. Additionally, organic matter content and particle size distribution were determined. The heavy metal concentrations found in this study are relatively low and similar to those reported previously. The spatial distribution of several of the metals analyzed here is probably influenced by the rivers discharge, especially for B, Ba, Co, Mn, Ni and Zn. Significant positive correlations between elements used as normalizers (organic matter content, silt and Fe) indicated that concentrations of most metals analyzed here can be explained by natural biogeochemical processes, except As and Mg. Principal Component Analysis indicated that some of the stations near of the Atasta lagoon mouth, Chumpán River and Palizada River, have higher concentrations ranges in comparison to the local background and therefore are considered vulnerable sites to heavy metal  pollution.