Effects of ultraviolet-B radiation and larval growth on toxicokinetics of waterborne bisphenol A in common frog (Rana temporaria) larvae.

In 1989, researchers discovered that amphibians, particularly frogs and toads from many parts of the world, appeared to be declining. In many ecosystems amphibians play a central role in ecosystem energy flow and nutrient cycling, and they act as keystone species. The recent increase in solar ultraviolet-B radiation (UVB, 280-320nm) has been thought to be one stressor responsible for the decline in amphibian populations. Along with other stressors, such as habitat destruction, anthropogenic influences and natural causes, UVB radiation could contribute to adverse effects among amphibians. Amphibians provide a good model for examining the effects of environmental stressors, because both lethal and sub-lethal responses are well documented in a range of studied xenobiotics in many species. In this experiment, the effects of UVB radiation on the accumulation and depuration kinetics of bisphenol A (BPA) were studied. Additionally, the accumulation was further modeled with correction for growth dilution. The results indicate that UVB radiation did not affect the toxicokinetics of BPA, and that the applied growth correction had only a negligible influence on the toxicokinetic estimations in this experiment. However, BCFs values calculated as k(u)/k(e) where closer to C(a)/C(w) calculated values when growth dilution was incorporated in the model. This method can be used in other experiments, where the growth dilution can affect toxicokinetic estimations.