RP6 Chiral Chemistry: Toxicology of Environmental Contaminants and Phase Transfer
Thursday, 17 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(OVE-1117-805571) Acute Toxicity of Fipronil Enantiomers to Marine and Freshwater Non-Targets.

Overmyer, J¹, Garrison, A², Avants, J², DeLorenzo, M³, Key, P³, Chung, K³, Konwick, B¹, Wilson, W¹, Black, M¹, ¹ University of Georgia, Athens, GA, USA² US Environmental Protection Agency, Athens, GA, USA³ NOAA/National Ocean Service, Charleston, SC, USA

ABSTRACT- Fipronil is a phenylpyrazole insecticide used in agriculture and domestic settings for controlling various insect pests in crops, lawns and residential structures. Fipronil is chiral; however, it is released into the environment as a racemic mixture of the two enantiomers. A recent study has shown that aquatic non-target organisms can be more susceptible to one enantiomer than the other. However, current work has demonstrated that susceptibility to the separate enantiomers might be organism specific. In this study, the acute toxicity of the (+) and (-) enantiomers and the racemic mixture of fipronil will be assessed using Ceriodaphnia dubia (water flea), Simulium vittatum IS-7 (black fly), Xenopus laevis (African clawed frog), Palaemonetes pugio (grass shrimp), Mercenaria mercenaria (hardshell clam), and Dunaliella tertiolecta (phytoplankton). Results will provide a better understanding of the toxicity of the individual enantiomers in diverse organisms and might aid in identifying a form of fipronil with reduced environmental impacts.

Key words: Fipronil, Enantiomers, Chiral, Non-targets