SHEDDING LIGHT ON INDIRECT PHOTODEGRADATION OF BPA IN VERMONT SURFACE WATER

The Food and Drug administration now believes that Bisphenol A (4,4’-(propane-2,2-diyl) diphenol) is responsible for toxic effects on the brain and is extended to behavioral problems in small children. Small doses have been found to produce a wide variety of hormonal effects in test animals. BPA has been detected in numerous aquatic environments and in 90% of humans around the world showing that BPA is of widespread concern throughout the globe. Sources of BPA include polycarbonate plastics from food packaging and epoxy resins, which are concentrated in landfills that can then leach this contaminant into nearby water bodies. Both the health of aquatic ecosystems and humans using these water resources can be impacted. Potential environmental sinks of BPA include microbial degradation and indirect photochemical decay. Slow BPA degradation from direct photochemical processes (due to BPA’s lack of absorption of light in the solar spectrum reaching the earth’s surface) has put an emphasis on microbial decomposition, but secondary photochemical pathways could also be significant. Recent studies have only monitored BPA photodegradation in model systems, not natural water systems. This study observed indirect photochemical degradation of BPA in the lab under a solar simulator using surface water runoff collected from four regionally dominant landscape sources (agricultural, urban, wetland, and forested). Preliminary results show a 20% decrease in BPA concentration over 24 hours in water from the wetland, which had higher dissolved organic matter (DOM). We will also be evaluating the role of nitrate. Further results will shed light on our understanding of the major BPA degradation pathways in sunlit surface waters and help determine the longevity of this contaminant in our aquatic ecosystem.