While doing my homework on polycarbonate plastic and plastic recycling, I came across several online discussions about Bisphenol A or BPA. There has been a lot of concern about this chemical in recent years due to the adverse findings of scientists about it and the “controversy” raging on in the scientific community about Bisphenol A’s harmful effects on humans.
Bisphenol A, what is it?
Bisphenol A is the synthetic chemical used in the manufacture of polycarbonate plastic and epoxy resin. As polycarbonate plastic or epoxy resin compound, bisphenol A is used in a wide array of applications such as plastic water bottles (Nalgene), food can linings, infant feeding bottles, food and beverage containers, cell phone casing, compact disks, bottle tops, and dental sealants. It’s everywhere!
Polycarbonate plastic is labelled with plastic recycle symbol number 7. It must be noted, however, that not all plastic products labelled number 7 are polycarbonate plastic. Please see Recycling Symbol for more information.
Leaching Bisphenol A
People are constantly exposed to or ingest varying levels of bisphenol a from soup cans, infant formula cans, baby feeding bottles, canned food, bottled beverages, etc. Bisphenol A is found to migrate from the polycarbonate plastic container or from the can lining to food, soup, powdered milk, etc. The most rapid leaching of bisphenol A to food has been observed to occur at higher temperatures, like a hot baby milk preparation or heated soup and canned food.
According to the Environmental Working Group, a Washington DC-based independent research organization who spearheaded the study of bisphenol A exposure in the US:
Of all foods tested, chicken soup, infant formula, and ravioli had BPA levels of highest concern. Just one to three servings of foods with these concentrations could expose a woman or child to BPA at levels that caused serious adverse effects in animal tests.
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.
Bisphenol A, what’s the danger?
Mounting evidence from peer-reviewed scientific experiments conducted on laboratory animals suggest that Bisphenol A in low doses, can act as a hormone disruptor. According to Dr.Frederick Vom Saal, a developmental biologist at the University of Missouri:
These hormones control the development of the brain, the reproductive system and many other systems in the developing fetus…The most harm is to the unborn or newborn child.
According to the Environmental Working Group’s report on Bisphenol A:
As of December 2004, 94 of 115 peer-reviewed studies had confirmed BPA’s toxicity at low levels of exposure. At some of the very lowest doses the chemical causes permanent alterations of breast and prostate cells that precede cancer, insulin resistance (a hallmark trait of Type II diabetes), and chromosomal damage linked to recurrent miscarriage and a wide range of birth defects including Down’s syndrome (vom Saal and Hughes 2005). Few chemicals have been found to consistently display such a diverse range of harm at such low doses.
Bisphenol A, what’s the controversy?
Controversy comes into the picture when valid and credible objections coming from independent sectors, are raised. Dr. Steven G. Hentges, executive director of the Polycarbonate Business Unit at the American Plastics Council contests the scientific findings that tagged bisphenol A as a hormonal disruptor:
If you look at all the data together, you don’t find a consistent pattern of effects that are characteristic of an estrogenic chemical.
A study funded by the Society of the Plastics Industry (July 2002) Toxicological Sciences that explored the effects of low doses on three generations of rats found no effect on reproduction or development.
Is there controversy, really?
Clearly, “independent” is not an adjective you can use on people like Hentges. These studies sponsored by the plastics industry are “profoundly flawed and in some cases exhibit outright fraud,” says Dr. Vom Saal. In a paper published in 2005, Dr. Vom Saal exposed this pattern of fraudulent results by comparing 11 plastic industry-sponsored studies (all of which found no ill-effects from bisphenol A ingestion) to government-funded low-dose bisphenol A studies, 104 of which or 90% of the total number found harmful effects of bispenol A on humans. Asserts Dr. Vom Saal:
Among people who have actually read this literature there is no debate, just an illusion of controversy.
In the meantime, evidence continues to mount proving that Bisphenol A is bad news for us and our children. Perhaps the most potent blow on the plastics industry’s position is the National Toxicology Program’s “Draft Brief on Bisphenol A (BPA)” released last April 14, 2008 which found that the “possibility that Bisphenol A may alter human development can not be dismissed.” This is a strong statement and a reversal to its 2001 position on the subject.
Scientists involved in the various researches on Bisphenol A have urged for action to be taken now. Dr. Ana Soto, a professor and researcher at Tufts University School of Medicine in Boston, who has found that BPA alters mammary-gland development in mice, in an interview with The Green Guide, said:
Science is not in the business of demonstrating anything beyond a shadow of a doubt…We cannot wait that long to discover whether this chemical is harming human reproduction and development.
Apparently, the plastics industry has found a way to game the system. By providing “evidence” from their own paid hacks, they’ve effectively tied up the system into countless hours of debate on the issue in an “illusion of controversy.” For us ordinary consumers and parents, its a deadly illusion. As regulatory agencies like the FDA pussyfoots on the issue, plastic manufacturers who continue to use Bisphenol A are laughing all the way to the bank. In the meantime, the chemical continues to wreak untold havoc on our health and the health and future of our children.
Next topic: Alternatives to Bisphenol A-polycarbonate plastic
Update: Added CDC fact sheet (pdf) to references.
Sources and References:
- Environmental Working Group. “Bisphenol A: Toxic Plastics Chemical in Canned Food“
- National Toxicology Program (NTP) Department of Health and Human Resources
Draft Brief on Bisphenol A (BPA)
- National Geographic’s Green Guide. “The Bisphenol-A Debate: A Suspect Chemical in Plastic Bottles and Cans” by Catherine Zandonella, M.P.H
- Environmental Defense, Canada: Bisphenol A Fact Sheet
- Centers for Diseases Control (CDC) – “Spotlight on Bisphenol A” (bisphenol A fact sheet – pdf)