Fipronil effects on freshwater benthic algal communities

Society of Environmental Toxicology and Chemistry (SETAC Europe) 28th Annual Meeting, Responsible and Innovative Research for Environmental Quality, 13−17 May 2018, Rome, Italy.-- 1 pageFipronil is a widely used broad-spectrum phenylpyrazole insecticide, effective against insects resistant to other agents as pyrethroids, organophosphates or carbamates. Accordingly, it has gained popularity worldwide as a pesticide in both agricultural and urban environments. Its wide use, resulted in the presence of fipronil in soil, surface and ground waters involving a risk to the environment and humans. In addition, humans and animals are also exposed to fipronil, by ingestion of products containing residues. Previous studies showed the toxicity of fipronil to aquatic freshwaterorganisms using model species, but there is scarce information about its impact on wild organisms. This study assesses, for the first time, the impact of fipronil on the photosynthesis of natural freshwater algal benthic community. This community –periphyton-is a key element of aquatic trophic chains, and is routinely used as indicators of water quality. Results show LC50values of 0,74 mg/l (0,63-0,89) (p> 0,001), exposing periphyton to fipronil under standard medium. However, toxicity was almost inexistent when assays were done using natural river water. In this last case, the bioavailability of the fipronil was hypothetized to be reduced by natural substances present in the river water (solid suspended solids, organic matter, etc..). These results would contribute to a more realistic assessment of the environmental impacts of the use of this kind of pesticidesPeer Reviewe