Bisphenol A (BPA) Contamination in Yellow-Bellied Sliders (Trachemys scripta scripta)

Abstract

Bisphenol A, also known as BPA, is a chemical that is recognized for being in a variety of consumer products, particularly to make plastic food containers and drink bottles (Makinwa, 2015). It was estimated in 2011 that about 5.5 million metric tons of BPA have been consumed globally (Flint, 2011). This is cause for alarm because it is classified as moderately toxic to aquatic life by the Environmental Protection Agency (EPA) (Flint, 2011). BPA can negatively affect gene expression and hormone pathways. It is also known for triggering sex changes during embryonic stages in turtles and caiman (Flint, 2011). A major source of BPA is littering of plastics, which enter ponds and wetlands and may become incorporated into the food web of aquatic species (Campani, 2013). When plastic products degrade, BPA is leached into the soil and can potentially flow into neighboring waterways (Makinwa, 2015). Animals acquire BPA through direct ingestion of plastic particles or through consuming plants or animals that have accumulated BPA. Previous research has shown that Bisphenol A acts as an endocrine disruptor on painted turtles, caiman, fish, and amphibians (Jandegian, 2015). It mimics the hormone estrogen, which at sufficient concentrations, may cause developing male embryos to produce female reproductive tissue. Snails have been observed to undergo “superfeminization” when exposed to about 1 μg/L (Flint, 2011). This superfeminization caused “additional female organs, enlarged sex organs, and oviduct deformities” (Flint, 2011). There is evidence that Bisphenol A causes feminization in most animals that have been studied, although the mechanism has yet to be found (Krüger, 2005). Turtles are often used as environmental indicators because they are omnivorous and tend to be long-lived. Their longevity makes them more likely than short-lived species to bioaccumulate toxins.If BPA concentrations are high in turtles, then it is likely that humans have absorbed a certain amount that may contribute to unknown biological consequences. Research has shown that there are links between this contaminant and the rates of cancer development, obesity, and the probability of a child developing neurological problem when exposed. According to the analysis of 315 urine samples “93% of people had detectable levels of BPA” (Kinch, 2015). The objective of my research was to quantify BPA concentrations in Yellow-bellied sliders (Trachemys scripta scripta) and their habitat. Blood samples were collected from the subcarapacial or dorsal coccygeal vein of each turtle captured. Additionally, soil samples were taken at the edge of the water. Study Areas Blood samples were collected from 9 turtles trapped at Reed Creek Park. Additional samples were collected from 22 turtles from Brick Pond Park. Reed Creek Park is in Martinez, Georgia (33.53375598, -82.08555523) (Google maps, 2016). Brick Pond Park is in North Augusta, South Carolina (33.4874273, -81.9786814) (Google maps, 2016). Ten soil samples were collected at each location. The soil samples were analyzed for BPA quantities and compared with the amounts of BPA that were recorded from the blood samples taken from the captured turtles. [Introduction]