Cadmium was continuously input to aquatic microcosm channels resulting in concentrations of 5 and 10 micrograms Cd/l. Cadmium accumulation into both biotic and abiotic components was determined. Biological effects of cadmium were determined by monitoring structural and functional properties of the entire system as well as structural changes in populations and compared to control systems, which received no cadmium. Cadmium inputs and outputs equilibrated within approximately 20 days of initial cadmium inputs. However, approximately 20% of the cadmium leaving the channels was associated with particulates. Community components accumulated cadmium proportional to cadmium exposure levels. Cadmium was rapidly eliminated from all biotic components, with concentrations returning to levels similar to those in control channels within a few weeks in the aufwuchs community to a few months in macrophytes. Organic headpool sediments showed no significant decrease in cadmium content six months after cessation of cadmium inputs, indicating that the abiotic half time for contaminated environments is very long. Half times for elimination from channel sediments were 72 and 38 days for 5 and 10 micrograms/l inputs, respectively, after Cd inputs were terminated.

Savannah River Ecology Laboratory, Institute of Ecology, University of Georgia. "EPA 600-3-79-039." "April 1979." Cover title. Includes bibliographical references (pages 128-144). Interagency agreement IAG-D6-0369-1 between U.S. Environmental Protection Agency and U.S. Department of Energy.