Metals in sediments of Texas estuaries, USA

Concentrations of metals (Cu, Cd, Zn, Pb, Ni, Cr, V, Fe, and Al) were deter mined in sediments from 34 sites within the estuaries of Texas, USA. Anomal ies in metal concentrations were found at some sites and were related to pr obable sources such as military facilities, landfill leaching, and municipa l and industrial discharges. The metal concentrations were normalized to Fe and Al for distinguishing natural and anthropogenic sources. Most metals s howed positive correlations with Fe and Al which suggests the natural varia bility of metals in sediments. The concentrations of metals, except Cd, at most of the sites were found to be below threshold concentrations thought t o produce toxic effects in marine and estuarine organisms.