Bioaccumulation potential of chlorpyrifos in resistant Hyalella azteca: Implications for evolutionary toxicology

Given extensive use of pesticides in agriculture, there is concern for unintended consequences to non-target species. The freshwater amphipod, Hyalella azteca has been found show resistance the organophosphate (OP) pesticide, chlorpyrifos, resulting from an amino acid substitution acetylcholinesterase (AChE), suggesting a selective pressure pesticide exposure. Since resistant organisms can survive contaminated habitats, potential them accumulate higher concentrations insecticides, increasing risk trophic transfer. In present study, we estimated uptake and elimination chlorpyrifos non-resistant US Lab, Ulatis Creek (ULC Resistant), H. populations by conducting 24-h 48-h toxicokinetic experiments with 14C-chlorpyrifos. Our results indicated that had larger clearance coefficient (1467 mL g−1 h−1) than animals (557 h−1). half-life derived models also steady state conditions were reached at 13.5 32.5 h Lab ULC, respectively. Bioaccumulation was compared between exposing six different environmentally relevant 28 h. Detection animal tissues exposed high capable accumulating insecticide up 10-fold animals. Metabolite analysis 28-h concentration showed 20 50 % parent compound detected azteca. These imply bioaccumulation be more significant may essential factor assessing full impacts toxicants on critical food webs, especially face chemical runoff.