They found that exposure to Bisphenol A, if you take a little bit of Bisphenol A and put it in corn oil and feet it to a mouse while she’s pregnant, and the amount that is in the mouse, that’s fed to the mouse is equivalent to two parts per billion of her body weight, that a male mouse in her womb at the time will grow up with a prostate that’s much bigger than it should be.  And also it’s structure has been changed so that it’s hypersensitive to hormone stimulation.  So for the life of that animal, it’s got a different prostate.  It’s got one that’s predisposed to prostate problems.  This was happening at an unheard of level.  It was a very controversial result, it’s subsequently been confirmed.

There’s a plastic material called Bisphenol A.  Bisphenol A was invented in 1938, the end of the thirties, during a period of chemical creativity when people were synthesizing all sorts of new things.  In this case they were looking for synthetic materials that could substitute for estrogen and they found Bisphenol A was capable of provoking estrogenic responses in animals.  They discovered Bisphenol A at the same time, the same period in which people discovered first synthesized Diethylstilbestrol, which is an infamous medical drug used as an estrogen to manage difficult pregnancies that has a very, very sorted history.  The two of them were there, they were being experimented with Diethylstilbestrol or DES was so much more powerful at first glance then Bisphenol A.  They focused on DES and basically put Bisphenol A up on the shelf.  It stayed there for about ten years.  Until a Polymer Chemist discovered that you could take the individual monomers, the individual molecules of Bisphenol A and combine them in a chain.  That’s what plastics are, chains of molecules.  Combine them in a chain and make polycarbonate plastic.  Now polycarbonate is ubiquitous.  It’s used to make all sorts of bottles for holding water.  It’s used to make a risen that lines food cans.  It’s used for lots of different things.  The problem is that the chemical bond that combines the monomers of Bisphenol A in to that polycarbonate, they’re not non-stable.  They degrade with time.  So the compound leeches into the food or the water that it comes in contact with.  Well that might not be a problem. 

The leeching rate puts parts per billion of Bisphenol A into food or into water and 15 years ago people would have thought well so what.  That’s irrelevant to health.  We need big amounts to cause affects.  Little amounts aren’t a problem.  Scientists at EPA had done an assessment.  They’ve looked at studies of high levels of Bisphenol A and discovered that the lowest affect level they could find was on the order of fifty parts per million.  Much, much higher than what was leeching into the food and water as polycarbonate degrades.  Well so it looked fine. But then some scientists began to ask questions from a somewhat different perspective and they weren’t Toxicologists.  They were basic reproductive biologists who had realized that the amount of hormones in the blood stream that’s free was much lower than people had originally thought.  In fact most estrogen that’s in our blood is tied up with other molecules and it’s bound.  It’s not biologically available to send signals.  What these scientists realized was that the compounds, the proteins that are binding estrogen don’t bind Bisphenol A.  Which means that Bisphenol A may be relatively weak compared to estrogen, there’s functionally more of it because it’s not being bound. So they did some calculations and realized that based on these calculations, Bisphenol A should be active, should have affects in the part per billion range which was just a totally unexpected prediction.  They tested that and they confirmed our predictions.  They found that exposure to Bisphenol A, if you take a little bit of Bisphenol A and put it in corn oil and feed it to a mouse while she’s pregnant, and the amount that is in the mouse, that’s fed to the mouse is equivalent to two parts per billion of her body weight, that a male mouse in her womb at the time will grow up with a prostate that’s much bigger than it should be.  And also it’s structure has been changed so that it’s hypersensitive to hormone stimulation.  So for the life of that animal, it’s got a different prostate.  It’s got one that’s predisposed to prostate problems.  This was happening at an unheard of level.  It was a very controversial result, it’s subsequently been confirmed.