Role of sediment-trace element chemistry in water-quality monitoring and the need for standard analytical methods

Multiple linear regression models calculated from readily obtainable chemical and physical parameters can explain a high percentage (70% or greater) of observed sediment trace-element variance for Cu, Zn, Pb, Cr, Ni, Co, As, Sb, Se, and Hg. Almost all the factors used in the various models fall into the category of operational definitions (e.g., grain size, surface area, and geochemical substrates such as amorphous iron and manganese oxides). Thus, the concentrations and distributions used in the various models are operationally defined, and are subject to substantial change depending on the method used to determine them. Without standardized procedures, data from different sources are not comparable, and the utility and applicability of the various models would be questionable.