Synthetic organic toxicants in Lake Superior

Abstract

Numerous synthetic organic toxicants have been reported in Lake Superior in the past quarter century although relatively few industrial centers are located on its shores. The chemicals enter the lake primarily through atmospheric deposition via transport from regional and distant sources. This contribution discusses research issues regarding the processes by which the chemicals enter and exit the lake, their in-lake cycling and bioaccumulation, and recently reported potential toxicological effects. Research issues that remain for historically important synthetic organic toxicants are discussed as well as those of emerging chemicals of concern. Although concentrations of some historically important toxicants are decreasing in Lake Superior's waters through volatilization and sedimentation and burial, abiotic and biotic in-lake cycling opens routes of entry into the lake's lower food web, contributing to concentrations in fish that warrant consumption advisories in certain cases. Concentrations of some non-...