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Bisphenol-A

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Bisphenol-A (or BPA) is an organic compound used in the industrial production of plastics. It was first synthesised around 100 years ago, and has been used to produce polycarbonate plastics and epoxy resins since the 1960s (US-FDA, 2012). Polycarbonate plastics are lightweight and rigid, therefore used in products such as CDs, DVDs, sports and medical equipment, food and drink containers and some water supply pipes. Epoxy resins are used as protective coatings in food cans, paints and adhesives (Aschberger, 2010). According to the US Environmental Protection Agency, there are over three million tonnes of BPA produced worldwide each year. Humans are exposed to BPA as it has the ability to hydrolyse (react with water) when catalysed by hydroxide, …show more content…

When digested, BPA is absorbed into the bloodstream through the intestinal wall. The blood is then transported directly to the liver by the hepatic portal vein. During this time it reacts with glucoronic acid or sulfuric acid in the bloodstream to form BPA-glucoronide or BPA-sulfate respectively (Aschberger, 2010). These reactants are water soluble and therefore can be rapidly eliminated through the urine. It is for this reason that the US Environmental Protection Agency states that BPA has a low bioaccumulation potential. Furthermore, when in the form of BPA-glucoronide or BPA-sulfate, the shape of the molecule has changed and cannot bind to any hormone receptors. Each hormone receptor has a specific shape, by which only hormones complementary in shape will bind. However, in tissue sites containing the enzymes -glucoronidase and arylsulfatase-C, BPA-glucoronide and BPA-sulfate react to produce the free form of BPA (Aschberger, 2010). These enzymes are present in higher concentrations within the placenta, leading the US Food and Drug Administration to suggest that foetuses have a higher exposure level to BPA than …show more content…

For example, Lang et al (2008) claims that higher levels of BPA in the urine were associated with cardiovascular disease and type-2 diabetes. However, higher levels of BPA in the urine could also suggest a high consumption of packaged food. The packaged food is higher in sugar, salt and fat content, therefore would lead to a higher risk of type-2 diabetes. The US Environmental Protection Agency concludes that these studies “are insufficient for use in risk assessment because of a variety of flaws in some of the study designs”. They further question the findings stating that there is an “inability of other researchers to reproduce the effects in standardised

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