Bisphenol-A is much harder to avoid than one would think. It’s getting easier, and in a few years hopefully it will be mostly history, but for now you’ve got to stay on your toes to avoid it.
First, what’s wrong with it. Before BPA was used in plastic, it was synthesized as a man-made estrogen substitute. A drug. You’ll see people reporting that it “mimics estrogen”, but the fact is that it mimics it so well that your body can’t tell that it isn’t estrogen. The amount of estrogen in a fetus determines the sex of the child. In young children, where things are still in flux, it is especially bad — and yet it lines cans of baby formula!
Rodent offspring exposed to supposedly safe levels of BPA in the uterus exhibited things like abnormal weight gain, insulin resistance, prostate cancer, and excessive mammary gland development.
BPA has the ability to bind to not one, but three hormone receptors — the estrogen, the male hormone and the thyroid hormone receptors. In other words, it screws up all kinds of things.
It increases the risk factors for breast and prostate cancer. It screws with the whole dopamine system (which, among other things, can make people more prone to drug and alcohol addiction). It messes with the endocrine system, and going down that road shows links to BPA with diabetes, heart disease, obesity, etc.
A 2009 study on Chinese workers in BPA factories found that workers were four times more likely to report erectile dysfunction, reduced sexual desire, and overall dissatisfaction with their sex life than workers with no heightened BPA exposure. BPA workers were also seven times more likely to have ejaculation difficulties. They were also more likely to report reduced sexual function within one year of beginning employment at the factory, and the higher the exposure, the more likely they were to have sexual difficulties.
EWG has an excellent timeline, if you are interested in seeing the political ping pong game that has gone back and forth with this chemical. I believe this is a case of the chemical companies paying the right politicians, and moving the correct chess pieces around the board, to keep this toxin in the marketplace. Here is a Wired.com report, where they point out that the Federal Center for the Evaluation of Risks to Human Reproduction contracted with Sciences International, a private consulting firm, for them to prepare a report on BPA and select a panel to make decisions based on the report. However, Sciences International is funded by the companies that make Bisphenol A. I know I’ve said a few times during this series that the results of a study depend on who is funding the study – and this is the kind of thing I’m talking about. If you want to know the rest of the story, the NIH did eventually fire Sciences International. It’s been five years, if I were a betting person I’d be willing to bet the bigwigs at SI turned around and started a new company and got a new contract, though.
Two years ago, Consumer Reports tested BPA in canned goods. The tests included items like soups, juice, tuna, and green beans, and found that almost all of the 19 name-brand foods in the test contained some BPA. The canned organic foods did not always have lower BPA levels than non-organic brands of similar foods. They even found the chemical in some products in cans that were labeled “BPA-free.” EWG did a similar test a few years before, you can read their complete report without a subscription. Basically, chicken soup, baby formula, and ravioli had some of the highest levels of BPA. For 1 in 10 cans of all food tested, and 1 in 3 cans of infant formula, a single serving contained enough BPA to expose a woman or infant to BPA levels more than 200 times the government’s traditional safe level of exposure for industrial chemicals. These servings contained levels of BPA less than 5 times lower than doses that harmed lab animals. In other words, four servings and an adult is close to the levels (per kilogram of body weight) where lab animals exhibited symptoms. The worst culprits were baby formula, pastas like ravioli, vegetables, and soup. Beans, tuna, fruits, and sodas apparently do not leech as much out, and the levels were low.
The chemical manufacturers are quick to point out that the estimated dietary intake of BPA from can coatings is less than 0.00011 milligrams per kilogram of body weight per day — more than 450 times lower than the maximum acceptable dose (per the EPA) of 0.05 milligrams per kilogram body weight per day. According to them, an average adult would have to eat about 500 pounds of canned food and beverages in a day to exceed the EPA acceptable levels.
Of course, there are also studies that suggest we are exposed to at least eight times the “accepted dose” level every day.
But then we see information like: Children who are of an age to eat out of cans metabolize BPA exactly the same way as adults do. When BPA is ingested, it is rapidly detoxified, first in the gastrointestinal tract (GI) and then in the liver by enzymes, which add a sugar molecule to BPA, transforming it into a water soluble BPA-glucuronide. The sugar conjugate is easily and quickly excreted in urine. The half life of BPA-glucuronide is six hours. There is a minor metabolic pathway in which some BPA is converted to a sulfate, but this is also water soluble and quickly excreted from the body.
Is your head spinning yet? Here’s what I think – current “safe” levels are based on tests done in the early 80′s. Guess who funded the tests? There have been lots of tests since then that show damage happens at much, much, much, lower levels. The EPA or the FDA or NIH or someone should have stood up by now and changed the safety levels, but they haven’t. Money talks.
Animal studies show adverse effects, such as abnormal reproductive development, at exposures of 2.4 micrograms of BPA per kilogram of body weight per day. Current legal “safe dose” is .05 milligrams, or 50 micrograms, per kilogram body weight per day. That means the legal limit would have to be lowered from 50 micrograms to 2.4 micrograms. Except that if the government accepts that 2.4 is where problems start, then current guidelines would have the government making the official acceptable dose at much lower than 2.4 micrograms, as there has to be some cushioning built in.
Why are the food manufacturers holding on so tightly to BPA in cans? They tell us the BPA is acting as a preservative – without it, you get nasties like botulism. And, according to the food manufacturers, they don’t have an economical substitute.
BPA is not just in canned goods, though. So far, eleven US states, along with China, Canada, and the European Union, have banned BPA from baby bottles and sippy cups. If you aren’t in one of those states, it’s a good bet manufacturers have flooded your stores with it, trying to sell off their stock while they still can. Although, in many of those states the new laws gave manufacturers a few years to comply, so you’ve still got to be careful even if you are in one of those states.
In September of 2010 the Canadian Government defined Bisphenol A as a toxic substance. To quote: “A scientific assessment of the impact of human and environmental exposure to bisphenol A has determined that this substance constitutes or may constitute a danger to human health and the environment as per the criteria set out under section 64…” Perhaps some of our Canadian readers can weigh in and tell us what impact (if any) this has had on your canned goods?
We may get relief in the US in six or seven weeks. The FDA has agreed to make a decision of whether or not to ban BPA in food packaging by March 31st. A watchdog group had to sue them to get them to agree to make a decision though, so I’m not sure we should get our hopes up that they are going to actually ban the stuff.
How do you know if plastic has BPA in it? You don’t. You can check the recycling number, and in most cases the plastics marked with recycle codes 1, 2, 4, 5, and 6 are unlikely to contain BPA. No guarantees, but the odds are they are BPA free. Plastics marked with recycle codes 3 or 7 are more likely to have BPA. You should also avoid anything with “PC” on the bottom, as well as any clear, hard, plastic containers with no labeling. Generally speaking, the cloudy stuff usually doesn’t have BPA.
We’ve also got to be careful of plastic wrapped food, like cheeses. Uggh, I just ran across that little tidbit. It makes sense, but it’s the first I’ve seen that particular piece of advice.
Besides being in food packaging, canned foods, some plastic bottles, and some plastic food containers, it is also in thermal paper (receipts, some airline tickets, etc.), and is also used to form epoxy resin coating of water pipes — in older buildings these resin coatings are used to avoid replacement of deteriorating hot and cold water pipes. (I don’t believe I’ve mentioned yet that heating the plastic causes more bpa to leach out.) It’s also a component of non-metal dental fillings, and it is used in medical devices and equipment – like IV bags and tubing, for instance. And lots of other household items like shower curtains.
I believe the cartons of soup (you know, like a juice box, but bigger, and it’s soup) are safe – (update, maybe not, see comments). You can also buy tomatoes in jars instead of cans. Green beans have to be bought fresh or frozen, though. SpagettiO’s are history.
And finally, I leave you with this: PET bottles, the kind bottled water is in, are generally considered to be safe. However, a German study found that even the PET bottles leak out “estrogenic compounds”. I’m thinking that eventually we are going to learn that plastics and food just shouldn’t touch each other, period.
Previous posts in this series:
- Pollution in China (prequel to the series, sort of)
- High Fructose Corn Syrup – why it is bad
- Avoiding Toxins – Non Stick Pans
- Avoiding Toxins – Petroleum Products in lotions and make-up
- Avoiding Toxins – Flame Resistant Pajamas
- Avoiding Toxins – Fingernail Polish
- Avoiding Toxins – Sunscreen
- Avoiding Toxins – Bisphenol-A (BPA) in canned goods and other products