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No Clear and Plastic Danger
By Todd Seavey
An article on the website of the Sierra Club has given new life to the Internet rumor that plastic water bottles are a health hazard, possibly the cause of birth defects such as Down Syndrome. Years of studies on the purported culprit chemical, bisphenol-A (BPA), have not shown any health effects on humans, but one study showing minor effects on mouse egg cells, led by Dr. Patricia Hunt at Case Western Reserve University, has provided the grain of truth leading to the latest excessive fear.
In this experiment conducted by Hunt and co-workers, BPA was fed to female mice and the oocytes that they produced were examined. The results suggested BPA caused an increase in chromosomal abnormalities in these oocytes. However:
- The study has not been replicated by other scientists.
- Comprehensive, large-scale studies (while they may in theory have failed to detect increased oocyte chromosomal abnormalities) have not shown any increase in actual birth defects.
- Previous studies appearing to show BPA effects have not been reproducible.
- The single study by Hunt is unlikely to change the prevailing weight of scientific evidence, which the FDA and other scientific bodies say show no risk from "environmental endocrine disruptors."
- Health effects in humans are probably even less likely than health effects in mice, since a recent study (by Volkel et al) suggests that BPA is far more rapidly and completely metabolized in humans than in rodents, decreasing the odds of it doing damage by lingering in the body.
- Humans are not routinely exposed to the large amounts of the chemical that the mice were.
Still, the single mouse oocyte study has rapidly grown legs, mutating into an increasingly scary tale as it was retold by first the Sierra Club and then multiple college newspapers, which picked up on the story. Dr. Hunt's tendency to hyperbole has made things easy for the activists: the Sierra Club quotes her saying "we have been stunned by what we have seen" and "If we wait for really hard evidence in humans, it will be too late."
The Sierra Club article quickly segues from Hunt's limited study to discussion of the more radical claims of Theo Colborn, author of Our Stolen Future, who calls widespread endocrine disrupters in the environment a "very, very sticky problem...that's everywhere, and in everything." Colborn warns of risks to pregnant women, newborns, young children, and women who might get pregnant, advising people to switch to other types of containers.
Subsequent newspaper articles have tended to gloss over the multiple steps of supposition and speculation that led to plastiphobia: if the single oocyte study is replicated, if the oocyte effects are real, if the oocyte effects translate into developmental abnormalities, if BPA has the same effect on humans, if the minuscule amounts of BPA available in plastic water bottles were leaching out in amounts large enough to effect humans — none of which has yet been shown — and if the resultant hypothetical risk to humans were large enough to warrant changing our behavior (not every risk is or we'd avoid everything), there might be reason to worry. In the meantime, there is, in all likelihood, just one more in the endless series of unnecessary chemical scares and, inevitably, a few newspaper articles that skip over all the maybes and logical leaps and simply say: a chemical may be leaking out of your water bottle and causing Down Syndrome!
People's default reaction to any manmade chemical these days is fear — though manmade chemicals have not been shown to be any more likely than naturally-occurring ones to have health effects on humans, despite the widespread public assumption to the contrary. We've been using plastic water bottles — and studying chemicals of the sort used in them — for decades without any sign of ill effects on humans. The FDA says that Hunt's lone study is insufficient to reverse the conclusion that such plastics are safe. Don't let the Sierra Club frighten you into going thirsty.
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| Responses:
March 17, 2004
Perhaps the folks who are so concerned about plastic bottles should just go back to drinking tap water out of glasses (or drinking fountains) instead of paying manufacturer for a totally unnecessary product. Then, at least, their irrational assessment of risks will help them avoid a very real risk to their pocketbook. Last time I looked, 12 oz. of perfectly healthy tap water was less than 1/8 of a penny and a bottle of water from the Coke folks was $1.25.
And thanks again to ACSH for trying to direct people's fears away from the microscopic and toward the more important such as smoking and overeating.
David C. Griffith
Commercialization Manager
Technology Solutions
ConocoPhillips
Houston, TX |
Michael (July 7, 2004)
Michael (July 7, 2004)
I have not been convinced one way or another concerning this BPA debate but I would like to point out one problem with the above article. The first bullet states that this experiment has not been replicated but this is actually untrue. With a small amount of searching I located quite a few experiments on the environmental health perspectives website (http://ehp.niehs.nih.gov/). Below are the links for two of those articles:
http://ehp.niehs.nih.gov/docs/2002/suppl-3/415-422palanza/abstract.html
http://ehp.niehs.nih.gov/docs/2003/5993/abstract.html
Randy (August 18, 2004)
The studies that Michael cites don’t replicate Hunt et al in the least. Palonza et al are looking at maternal behavior, not oocyte disruption or development and Howdeshell et al are concerned with how much BPA is released into water from new and old cages. Neither of these studies begins to address whether there is any oocyte developmental effects of BPA or whether those effects effect embryonic or fetal development in mice or humans. While there are other studies that look at health effects of BPA exposure in one way or another, I haven’t found any yet that actually replicate the results using the protocols of Hunt et al.
Laura (September 12, 2004)
I've so far gathered that this controversy hasn't been completely resolved--it could go either way from here. But my view on the matter is this: why should we risk our health for a water bottle? Until it's been proven without a doubt that the plastics used in Nalgenes aren't harmful, I don't see why anyone should put his or her health and life on the line. There are plenty of other water bottles out there, SOME of them are bound to have "safe" plastics. Then, of course, there's always the drinking fountain.
john (November 18, 2004)
The question is, have the results of Hunt et al been replicated or not per their protocols? Maybe leaching into cold liquids is insignificant, but what about habitual microwaving in Nalgene/polycarbonate, especially for a pregnant mother. I would not agree at all that there is 'No Clear and Present Danger'.... the negative evidence is still not convincing.
Jeannine Robinson (December 19, 2004)
I've been following this "debate" for quite a while and there are some things that have always bothered me. If this type of plastic is a "clear and present danger", then why are people focusing on one company, Nalgene - and their water bottles? Does the general public realize that this plastic is used throughout the restaurant/food service industry? So if people are that concerned about being exposed to BPA, they will not only have to stop using their water bottles, dining out would also be a big NO-NO.
Information was published on www.Bisphenol-a.org that refutes Patricia Hunt et al study. http://www.bisphenol-a.org/whatsNew/20041003Kamrin.html
A research panel created by the Harvard Center for Risk Analysis that studied how humans handle chemical compounds in comparison to the laboratory rats that are used for scientific research....The panel found that humans metabolize the BPA more effectively than the rats that were used as test species. Humans also clear the chemical out of their bodies a few hours after ingestion.
The above is from an article from the University of Arizona. Glenn Sipes, UA professor and department head of pharmacology was a member of this research panel. This is a link to the UA article. http://wildcat.arizona.edu/papers/98/14/01_1.html
Personally, I am more comfortable with the risks that I am taking by drinking water out of my Nalgene bottle that I am by consuming artificial sweetners or preservative filled foods.
D (July 18, 2006)
A lot of people (including David Griffith, whose comment appears below this article) are confusing two different plastics.
The plastic that leaches BPA is polycarbonate resin (brand name Lexan). It's used to make those colorful or clear refillable sports bottles - like the kind that bike riders keep clamped to the frames of their bicycles. The main product is the bottle. They are sold empty, and you
can fill them with water or whatever you want. The most famous brand is probably Nalgene. If a Lexan bottle has a recycle symbol on the bottom, it has a number 7 on it. Not many recycling facilities will take #7 plastics.
The plastic that is used for individual servings of bottled water (like Poland Springs) is Polyethylene Terephthalate, abbreviated "PET" or "PETE." They are sold filled with water, juice or soda. The main product is the water (or soda, juice or other liquid), and the bottles are designed to be used only once. It has a recycle symbol with the number 1 on the bottom. Lots of recycling facilities take #1 plastics.
If you're trying to avoid Lexan bottles, you don't have to give up your Poland Springs bottled water. Just look at the recycle code on the bottom of the bottle and avoid #7.
D
Sarah (November 22, 2006)
Jeanine - you make a good point about the website http://www.bisphenol-a.org/ debunking most of the negative claims about bisphenol-A. However look who's responsible for that website: The American Plastics Council The Association of Plastics Manufactures in Europe The Japan Chemical Industry Association I smell a big conflict of interest.
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