ABSTRACT
Regulatory guidelines for long term testing to assess the toxicity of xenobiotic compounds such as bisphenol A (BPA) with fish have focused on survival, growth, and development in early life stages. Early life stages are critical windows of exposure, but do not address later phases in the life cycle, such as reproduction, that are equally important for the continued survival of the organisms. Residual amounts of BPA are released to surface water. BPA has, therefore, been the subject of considerable toxicity testing with fish and other aquatic organisms. A long term multigeneration test with fish has been conducted to better interpret the environmental relevance of detectable levels of BPA. Fathead minnow (Pimephales promelas) were exposed for 444 days over the course of three generations that included F0 reproducing adults, F1 eggs grown to be reproducing adults, and F2 eggs. Endpoints included survival, growth, reproduction, and vitellogenin concentrations. Concentrations tested ranged from 1 to 1,280 µg/L. No observed effect concentrations (NOEC) of 640 µg/L and higher for growth parameters show few differences between age or generation. Reproductive NOEC in F0 and F1 breeding pairs were 640 and 160 µg/L, respectively. The lowest NOEC related to survival, growth and development or reproduction was 16 µg/L for F2 hatching success. This long term study covered both early life and adult reproduction stages that allowed examination of all critical windows of exposure. Overall, NOEC ranging from 16 to 1,280 µg/L were found, which are well above median and upper 95th percentile concentrations of BPA in fresh waters in North America and Europe (0.081 and 0.47 µg/L and 0.01 and 0.035 µg/L, respectively). The likelihood is low that measured concentrations of BPA in surface water would affect fish, even if exposed over more than one generation.
