Potential estrogenic effects of bifenthrin, a synthetic pyrethroid, on Corbicula fluminea

Bifenthrin is a member of the synthetic pyrethroid family of insecticides. We monitored burrowing behavior and vitellogenin production to access the potential of bifenthrin to mimic estrogen in Corbicula fluminea, using bifenthrin-contaminated water at 0.1, 2, and 15 ug/L, and estradiol and solvent alone as positive and negative controls, respectively. Eight clams were placed on gravel surface in 20 L of aged aerated tap water, and classified every 4 hours as completely, partially, or not burrowed. After 24 hours, clams were sacrificed on ice, gonads were dissected and homogenized in extraction buffer, vitellogenin was assayed indirectly using the ALP method and presented in terms of mugALP/mgProtein. Burrowing behavior was 17 and 18% greater in low and high bifenthrin animals, respectively, than in control. Vitellogenin was significantly higher in high bifenthrin animals than control (p < 0.05) and 46% more. These results suggest that acute bifenthrin exposure results in disruption of estrogen sensitive systems.