Distribution of selected metals in bottom sediments, water, clams, tubificid mnnelids, and fishes of the Middle Illinois River

This study was designed to assess the potential application for further research of metal contamination in a large mid-western river that is utilized by industries and certain cities as a source of potable water as well as for sewage disposal. Analyses were made for thirteen metals in bottom sediments, twelve in water, and ten in tubificid worms, clams, and fishes. The study revealed that the ten metals, for which analyses were made in biota, do not concentrate along successive tropic levels as is the case with pesticides. Organisms such as clams and worms that inhabit the mud or mud-water interface where metal concentrations were observed to be the highest, exhibited the highest metal concentrations. At higher trophic levels, however, concentrations were lower, with fishes that are primarily carnivorous in nature exhibiting the lowest concentrations. The problem of metal contamination in aquatic systems is just now being recognized as a potential hazard to human health while the degree to which aquatic biota are affected remains speculative. This study, basically a pilot study, outlines procedures by which similar studies can be made and provides data that others may use in assessing the degree of metal contamination in multiple use rivers.U.S. Department of the InteriorU.S. Geological SurveyOpe