A Risk Assessment for Dimilin Use in the Northern Chesapeake Bay: A Model Study for Non point Source Runoff
Chemicals have played a major role in the development of modern agriculture and in protecting crops and trees against pest infestation. The downside of their use, however, has been the runoff into natural waters of compounds that are potential toxicants. While several chemicals have been banned from use because of their impact on non-target species (for example, DDT on birds), what has been lacking is a realistic assessment of the fate and effects of many others, particularly in how they affect aquatic organisms.
In this project, David Wright and Rodger Dawson will characterize the role of one such pesticide, Dimilin, which has been used widely in the Chesapeake basin for gypsy moth control. While Dimilin has no demonstrable effect on birds and mammals, low concentrations can affect crustaceans, particularly zooplankton which are key prey species for fish. Using two test species of zooplankton, the researchers will assess the toxic effects on mortality, reproduction and other abnormalities in conducting a hazard assessment for this compound's mode of action. They will combine chemical application information, run-off data and toxicity data to generate a model risk assessment for non point source pesticide run-off that will be important for understanding Dimilin and that can also serve as a model for other pesticides.
|
David A. Wright
Rodger Dawson
Chesapeake Biological Laboratory
University of Maryland Center for Environmental Science
|
|
|
