Biodegradation of bisphenol a in aquatic environments: River die-away

The biodegradability of bisphenol A (BPA) was assessed in surface waters fr om seven different rivers across the United States and Europe. Rapid biodeg radation of BPA was observed in all rivers following lag phases ranging fro m 2 to 4 d. Biodegradation half-lives for BPA were typically less than 2 d following the lag phase. Mineralization of BPA was observed in all river wa ters, with average carbon dioxide yields of approximately 76% of the theore tical maximum (range 59-103%) at the end of the incubation period (less tha n or equal to 18 d). Short half-lives (0.5 to 3 d) were noted for BPA biode gradation in river waters regardless of geographic location, sampling site (i.e., upstream vs downstream of wastewater outfalls), sediment addition (l ess than or equal to 0.05%), and initial test chemical concentration (50-5, 500 mug/L). Subsequent studies conducted at environmentally relevant concen trations (0.05 and 0.5 mug/L) also indicated short half-lives (3-6 d) for B PA and support the extrapolation of the half-lives measured in this study o ver a wide range of environmental concentrations. The fact that BPA was deg raded rapidly in surface waters taken from diverse locations in the United States and Europe as well as in studies recently conducted in Japan suggest s that BPA degrading microorganisms are widely distributed in nature. These observations provide clear evidence that BPA is not persistent in the aqua tic environment.