The U.S. Environmental Protection Agency (EPA) develops testing methods to support assessments of the environmental risks associated with the release of microorganisms and microbial pest control agents. Microcosms may be used as one step in the progression of product development from laboratory to field experimentation. The utility of microcosms in this process is, in some measure, dependent on the capacity of the test system to simulate environmental complexity, and consequently, to provide relevant answers to questions of environmental concern that may be raised by the regulatory community. The usefulness of current microcosm systems to evaluate and provide relevant information on a variety of regulatory endpoints pertinent to environmental risk assessment of microbial products was examined by workshop participants who met at Hunt Valley, MD, on January 23-27, 1989. A total of 14 generic and site-specific microcosms, portraying terrestrial and aquatic habitats with varying degrees of ecosystem complexity, was examined. The endpoints of ecological effects and other performance characteristics were compared for each microcosm system. Finally, future directions of microcosm research that appear to be required to fill gaps in the state-of-the-science were recommended.

"Office of Research and Development." "Office of Toxic Substances." "EPA/600/R-92/066." "May 1992." "May 19, 1992, Hunt Valley, Maryland."