The purpose of this research was to examine the effects of photodegraded Bisphenol A (BPA) and Bisphenol S (BPS) on Dugesia dorotocephala.

Bisphenol A, an industrial chemical, is used most commonly in the production of epoxy resins and polycarbonate plastics. While awareness has been raised about the harmful health effects of Bisphenol A, little research has been done on its surrogate, Bisphenol S. With increasing plastic pollution and chemical disposure, BPA, as well as other substitutes, have contaminated streams, lakes, and rivers. BPS, however, is not amenable to biodegradation, and therefore is more likely to accumulate in the aquatic environment, posing a greater threat to the environment.

The chemicals were tested on Dugesia dorotocephala flatworms as they are commonly found in freshwater environments and have a sensitive neurological system. The chemicals at concentrations found currently in the environment were tested on the worms to examine the current effects of BPA and BPS on organisms living in the ecosystem. Higher concentrations were used to determine lethal amounts of BPA on the flatworms.

It was hypothesized that BPS and BPA would kill the planarians at concentrations of 4.44*10-4 mg/mL BPS and 4.52*10-4 mg/mL BPA and after photodegradation under UV light, the chemicals would no longer harm the model organism. In this study, planarians were exposed to varying concentrations of BPA and BPS for 96 hours and mortality rate was recorded. At concentrations found in the environment (4.52*10-5 mg/mL BPA), the worms began to reproduce more rapidly than the control group with spring water. The highest concentration, about 1000 times more concentrated than environmental levels was proven to be lethal to the worms. The effects of Bisphenol S were observed as well; however, the results showed that planarians reproduce at an even higher rate than when exposed to Bisphenol A at these same levels.

BPA photodegradation was attempted using three methods: UV light, sunlight, and UV light with hydrogen peroxide as a catalyst. The initial absorbance of the BPA concentrations at a wavelength of 265 nm was measured using a UV-VIS spectrophotometer. The absorbance levels were measured once again after photodegradation. The results showed that hydrogen peroxide and UV light were the most effective at photodegrading Bisphenol A. Using BPA as a precursor, BPS was also exposed to UV light and hydrogen peroxide; however, no apparent photodegradation was observed. The photodegraded BPA was introduced to the flatworms, but was still found toxic to the worms. The results showed that BPA is amenable to photodegradation, but its apparent slow rate of photodegrading without a catalyst (hydrogen peroxide) is problematic and proposes a greater threat to the environment as it breaks down.