In my house, we only permit BPA-free toys, sippy cups, and other plastics while trying to minimize our use of plastic altogether. Doing so is supposed to spare us from hormone-disrupting chemicals found in bisphenol-A. But these plastic items still aren’t safe (if by safe we mean products that don’t leach other hormone-disrupting chemicals). Research now indicates that nearly every plastic product (including BPA-free) is made up of chemicals that stimulate estrogenic activity (EA) in human cells.
Estrogen made by our bodies in the right quantities at the right time is a good thing. But chemicals with EA have been linked to a whole slew of frightening problems like increased rates of asthma, obesity, premature puberty in girls, infertility, reproductive cancers, and a number of neurodevelopmental disorders.
To perform the study, University of Texas researchers purchased 455 widely available plastic products. Although most were labeled “BPA-free” it wasn’t possible to determine exactly what chemicals they contained. Apparently this is proprietary information closely guarded by industry. To determine if the products had estrogenic effects, researchers exposed extracted versions to solvents meant to mimic food and beverage items these plastics were likely to contain. Then, they exposed these extracts to a type of human breast cancer cell that’s highly receptive to estrogen. Cells that multiplied in the presence of plastic extracts indicated that those particular chemicals were estrogenic.
The results? Nearly every plastic product they tested leached EA chemicals. Some BPA-free products actually released more EA than other plastics. That included eco-friendly plastics made from plant products, which apparently released EA due to the additives used.
A more recent study by University of Calgary scientists indicates that bisphenol-S, found in many products with the “BPA-free” label, might actually be more harmful than BPA itself. Researchers exposed zebra fish, a good model to study human brain development, to bisphenol-S (an ingredient found in many products deemed “BPA-free”). The results showed abnormally timed growth of neurons in the embryos, the same growth surges found when embryos are exposed to BPA. The disruption of prenatal cellular activity appeared to result in hyperactive behavior. In fact, early abnormal growth of brain cells was specific to male hormones, perhaps indicating why more boys than girls are diagnosed with certain neurodevelopmental disorders.
Researcher Deborah Kurrasch was surprised by the results, especially since the dose used was “a very, very, very low dose, so I didn’t think using a dose this low could have any effect.” Another researcher in the study, Hamid Habibi, said “Finding the mechanism linking low doses of BPA to adverse brain development and hyperactivity is almost like finding a smoking gun.” They recommend pregnant women limit their exposure to products containing bisphenols and say this and other studies support removing bisphenols and structurally similar chemicals from consumer products.
Ninety percent of Americans show trace amounts of BPA in urine, breast milk, and umbilical cord blood. Why are potentially dangerous plastics used in toys, food packaging, and beverage cups (as well as in healthcare)? The Food and Drug Administration considers compounds safe until proven otherwise.
Resources & Further Reading on This Topic
- Eliminating Plastic From Our Lives
- Nine Ways To Reduce Plastic Use
- Leaning Disabilities Linked to Environmental Toxins—Take Action
- Unacceptable Levels
- Plastic-Free: How I Kicked the Plastic Habit and How You Can Too by Beth Terry
image CC by 2.0 from hottholler’s flickr photostream