Hippie swag bottles pose significant health risk
Guest post by Jason Pollens
The Nalgene bottle is a ubiquitous accessory among members of the progressive Jewish community. Nalgene bottles branded with institutional logos are also commonly offered as promotional items by Jewish organizations. However, there is a dirty little secret about the safety of this bottle. It turns out that most Nalgenes (the ones which claim they are indestructible) can actually do a lot of harm to you. If you look on the bottom of your Nalgene and see it has a number 7 in the triangle that means that it is made with polycarbonate plastics which are suspected to leach endocrine disruptors. (For info on other types of plastics click here.) The most worrisome chemical is bisphenol-A, a known hormone disruptor.
As Sierra Club magazine reports:
For years, scientists have been finding that endocrine disrupters like BPA can impair the reproductive organs of rats and mice, reduce sperm counts in rats, and bring about changes in tissue that resemble early-stage breast cancer, among other effects. But Nunc International, maker of Nalgene bottles, maintains that its products are “safe for use with human consumables”; cites other research that found no dangerous leaching; and points to a 2002 study in which rats fed a diet containing BPA at levels higher than those in Hunt’s laboratory suffered no apparent reproductive or developmental effects. Hunt counters that the rat study did not look at eggs or embryos. “The [plastics] industry says this is just rodent studies,” she says, “but we know that the human egg is more fragile than the mouse egg. If we wait for really hard evidence in humans, it will be too late.”
If you are using a number 7 plastic you are more at risk of birth miscarriages and defects along with breast cancer. For men the plastic can affect levels of testosterone in a negative way. The danger is most apparent when the bottle is showing signs of wear or has been exposed to heat.
There is an alternative which isn’t expensive (in some cases cheaper) and much safer. Of course there is an option of buying a water bottle with a number 2, 4, or 5 on the bottom; however the safest way to go is with a light weight stainless steel bottle. An example is the Kleen Kanteen which has served me well. In a world where we often don’t know what is best for us there is at least an easy solution for what type of water bottle we should use.
The results of this research is still very unclear. Citing a couple of studies showing small effects of bisphenol-A does not mean these bottle are toxic. In addition, the key issue is chemicals leaching out of the plastic and into the liquid. This will happen minimally, if at all, without any heating. (i.e. nalgene bottles filled with water)
Even if these articles are true, what is the total volume of bisphenol-A in a nalgene bottle. If every drop ended up in your body, does it reach the levels that caused damage in the articles? I don’t know all this research in detail, but I suspect a couple of days sunbathing is more carcinogenous.
There is also currently a Nalgene boycott, due to particularly vile restraints they produce for the animal testing industry.
Isn’t this the same “other” material used for water cooler canisters?
Thank you for posting this. bsci, there are more than a couple of studies showing the risks of bisphenol-A from plastics. Nature, a top-tier scientific journal, published a study a couple of years back and since then there have been many studies backing up the case against using these type of plastics. The biggest problem is that endocrine disruptors can have unfortunate effects, even at low doses. See here: http://www.yale.edu/opa/v35.n19/story1.html
The plastics industry has been very successful at keeping this issue under the radar. Could you imagine the class-action lawsuits? Baby bottles are made of this type of plastic! And it has been shown that leaching increases with harsh washing (dishwashers) and microwaving.
We need to take our happy blinders off and recognize that there’s something we can do about this. At the very least, toss your Nalgene bottles when they show wear (scratching or clouding).
baby bottles? Ugh. Thanks for posting this. I just put all my shwag Jewish philanthropy bottles in the garbage.
Judi, This issue hasn’t been under the radar. There was a series of front page articles in the San Francisco Chronicle several months ago. If the plastics industry cares about a class action lawsuit, suppression of known facts has proven to be the main way to lose a lawsuit. They are probably concerned about losing some business (whether or not the the facts end up supporting the dangers), but not lawsuits.
There are some situations where this may have a small increase in dangers, but I still haven’t seen anything about about leaching from using cold water in a bottle.
Here’s a baby bottle press release and some responses from 2002:
http://www.mindfully.org/Plastic/Plasticizers/BPA-Baby-Bottle2apr02.htm
My opinion about this is that, like the company says, the bottles have been used for 30+ years with virtually very person in this country (and others) using these bottles. If there is a negative effect in humans, it is small. Whether is is larger or smaller than the many other risks we take from what we eat or do is still unknown.
Out of curiousity, have you tested all your vinyl lunchbags and soft sided coolers for lead? That’s a clear and well documented danger:
http://www.cfsan.fda.gov/~dms/pbltr2.html
I suspect swag soft sided coolers, which are most likely to be outsourced to cheap manufacturers most likely to contain lead.
Thanks everyone for your comments thus far.
bsci- Leaching can also happen from regular wear and tear, and I suspect could also come from putting it in a dishwasher or cleaning it with hot water. It may not happen the first time you use it but really, why take a chance.
As for the amount of time it has been used; 30 years is a relatively short time. The only reason why there aren’t studies on people is because they would never get approval to carry them out (this is why the baby bottle manafacturer can claim they have never been “proven” to harm humans in a study.)
As Judi points out there have been plenty of studies done by reputable and independent sources to raise concerns about the safety of number 7 bottles. Furthermore, I don’t particularly trust anything companies making these bottles have to say. They are only interested in selling as many bottles as they can. Who should we trust, scientists conducting these tests or the companies selling the bottles?
To mention your last point I’m in complete agreement that there are many products out there which are also harmful to us. Our government should be doing more to protect us and ban products which are harmful to our health. Unfortunately, most of the time industries are influencing government agencies which are supposed to be regulating them.
In the meantime, not only should we avoid buying number 7 plastics but we should also make sure institutions we’re affiliated with don’t give them out.
30 years is an entire generation. Epidemiological studies can and probably have been done on people. The wikipedia page has some good links:
http://en.wikipedia.org/wiki/Bisphenol_A
Multiple countries have done serious studies and found no reason to ban bisphenol A.
There’s a good German government site at:
http://www.bfr.bund.de/cd/7294
To answer the question about alternative baby bottles:
The BfR considers that, given the scientific status of current findings, it is not necessary to stop using baby bottles made of polycarbonate. However, parents who are still uncertain have the option of changing to glass bottles. Bottles made of polyethersulfone can also be purchased and these are advertised as “B-free”. However, to date, this substance has been subjected to far fewer scientific tests than bisphenol A.
I remember reading somewhere that broken glass bottles were a much greater risk, which is why people changed in the first place. So you can use bisphenol A bottels or bottles of an unknown risk. (and don’t say breast feed because unless a women plans to never leave a baby’s side for 1+ years some breast milk will be given with bottles).
Another article evaluating the EU policy (with links is at):
http://www.stats.org/stories/2007/euro_safety_bpa_feb01_07.htm
“The Panel considered that low-dose effects of BPA in rodents have not been demonstrated in a robust and reproducible way, such that they could be used as pivotal studies for risk assessment. Moreover, the species differences in toxicokinetics, whereby BPA as parent compound is less bioavailable in humans than in rodents, raise considerable doubts about the relevance of any low-dose observations in rodents for humans. The likely high sensitivity of the mouse to oestrogens raises further doubts about the value of that particular species as a model for risk assessment of BPA in humans.
At this point the EU and US governments say no harm is enough to create a ban and even the San Francisco ban was rescinded before it even went into effect.
The problem with knee-jerk reactions on unclear science is that they dilute the responses to quality scienctific warnings. If you want to discourage nalgene bottle swag because it’s stupid to waste resources filling people’s shelves with unused water bottles that’s fine, but please don’t try to support your opinion by citing questionable science.
Thanks, Jason- well said. Yaaziel, I hear you. My kids recently brought home ncsy swag bottles made of this type of plastic. Seeing as how several researchers have been trying to evaluate a link between BPA and ADHD… David Kelsey, are you reading this? (btw, those bottles make cute flower vases)
bsci, as a scientist associated with a prestigious research facility, I cannot help but see evil in the plastic industry’s vehement denial of the preponderance of data that shows (not infers, shows) real effects of BPA on developing organ systems. Here’s another link that tells a compelling story:
http://www.ehponline.org/members/2005/7713/7713.html.
As bsci (and Avent, a leading manufacturer of plastic baby bottles- surprise, surprise! http://www.mindfully.org/Plastic/Plasticizers/BPA-Baby-Bottle2apr02.htm) points out, plastic baby bottles have been used for 30+ years. Gee, good thing there haven’t been any currently unexplainable increases in cancers (especially breast and prostate) and conditions such as ADHD! Um, wait a minute… bsci, the content on the site you saw is frequently referred to as “propaganda”. I prefer to get my scientific info from scientists without financial links to the plastics industry (a problem which has dogged several panels evaluating the risks of BPA. For example, the HCRA- the H stands for Harvard- issued a study in 2002 that discounted any research that didn’t support the safety of BPA. Who sponsored it? The plastics industry!!!).
Big point here: 95% of us have detectable levels of BPA in our urine. Are y’all okay with that?
judi,
As a full time scientific researcher directly employed by a prestigious university (and receiving no direct or indirect corporate money), I decided it wasn’t appropriate to use a vague reference to academic credentials to state my views are superior to others.
I know how finanical incentives affect research, but I also know how to critically read data and press releases. This is not my scientific area of expertise and, unless this is within your area of expertise, trying to put down other people’s opinions based on where you are associated is not proper.
Some of the links I presented were biased in each direction and some were from European governmental organizations. From what I’ve read, I’d say that the concensus is BPA is not extremely harmful and the alternatives are either untested or have other problems. If BPA was as harmful has some of these groups are saying it is, the effects would be huge over 30+ years. The rise in ADHD (compared to the rise in diagnosis) is probably real, but not large. (this is closer to my area of expertise)
As for urine. Do you have references to all the modern, synthetic chemicals in our urine? How do those compare to BPA and why is BPA the one that’s causing the problems? Not to mention, being in urine usually means the body is filtering and getting rid of it. I didn’t pull up the related articles, but the German Federation study linked to above says that humans metabolize and break down BPA at a much higher rate than the mice used in the scariest studies so it’s unclear how the dose charts should be altered.
I have no problem stating “a vague reference to academic credentials” because I have no need to publicize who I am and besides, the info I’m presenting stands on its own merit. I make no claim that my views are superior to others. I simply demand complete disclosure when presenting data to argue the case for the safety of a problematic compound.
As for the urine question- anyone can easily look up the multitude of synthetic compounds we excrete. And I am in no way trying to present BPA as the nastiest. But it may be possible to lower the potential risk by making simple lifestyle changes. By mentioning the presence of BPA in urine, I was trying to make the point that yes, we do absorb some amount of BPA in our daily lives. Maybe blood levels- or how about placental levels- would be a more satisfying indicator? Okay. http://www.ehponline.org/members/2002/110pA703-A707schonfelder/schonfelder-full.html
But enough of the pissing contest, please (sorry- couldn’t resist the pun). We can agree it’s a controversial compound- perhaps requiring further study. Until then, I’ll send you my bottles, if you want.
Reference, people, reference. Whether or not you are a real live scientist, you too can cite something better than the Sierra Club. If it’s in the peer reviewed literature, give a citation. If it isn’t, go back to worrying about trans fats or something.
Judi,
What got me bothered about the original post was “significant” health risk. There may be a risk, but this post and many of the publications are trying to hype it up way beyond any existing amount of evidence.
Now that you’ve given away your bottles, what is the appropriate way to feed babies (assuming a mother can’t be personally present for every feeding)? Do you prefer the significatly less tested polyethersulfone bottles or breakable glass bottles? Frankly I’m more afraid of a child cutting herself on glass shards than injesting BPA. (yes I have a child and she uses bottles with BPA)
As far mitigating risk, what is your opinion about the millions of perfectly healthy women who injest measurable levels of progestin and sometimes estrogen in their bodies, which have been proven without-a-doubt to radically affect their fertility sometimes for even months after the intake of these substances drop? In addition there is a small chance of stroke, migraines, mood changes and other problems. Of course, birth control has benefits too, but I have trouble believing the long term effects of microgram doses of BPA are worse than milligram does of estrogen and progestin. Especially with other good birth control options, why are progestin based methods an acceptible risk and BPA a lifethreatening danger?
All I know is that I tossed my bottles in the recycling bin yesterday night and when I went out an hour later to put more stuff in the bin, they were gone.
Homeless people LOVE Camp Tawonga, Schusterman Foundation and NutsOnline.com water bottles!
bsci,
You ask, “Especially with other good birth control options, why are progestin based methods an acceptible risk and BPA a lifethreatening danger?”
The big difference is that BPA may be present throughout critical stages of organ development in the fetus (see my citation above). One might consider this analogous to gestational alcohol or drug use- although people have the right to mess themselves up any way they want, the presence of high and/or sustained levels of alcohol or other drugs have been proven to have profound and lasting effects on a developing fetus and should be avoided.
As for the examples you mentioned, women should be made aware at the time the prescription is written of the risks (and they’re clearly stated and freely discussed) of any synthetic hormones they allow into their bodies for whatever therapeutic or preventative reasons. Likewise, we should know the risks of similarly-acting compounds we might ingest unknowingly.
is there any data on the effects on normal people… not babies? Hikers for example drink from Nalgenes almost exclusively. Are the levels of this chemical high enough to be relevant? I don’t know. Plus with any studies conducted with mice they usually have to give these poor animals close to the LD50 in order to get any kind of response, and as the usual battle cry goes about everything from sun to alcohol…a little is harmless, but too much of anything is bad for you.
just a thought, anyone have any solid data on the effects on adults?
BSCI,
I think that we can all acknowledge that there are plenty of questions about the safety of these bottles, there have been many peer reviewed articles as well as stories in major media outlets. According to the wikipedia article Canadian scientists will be studying this more in depth b/c there are so many concerns. This article from the San Francisco Chronicle lists out some of the peer reviewed articles on the issue of biophenal a: http://sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/03/31/BAGIOC13FM1.DTL.
In terms of the general arguments that there are many harmful things out there; well yeah there are. Unfortunately our government isn’t protecting us so there are many products out there which are harmful to us. When we have all this evidence which is pointing to it’s harmful effects but continue to use the products we are putting ourselves in needless danger. These arguments feel very similar to the ones on global warming which say that we don’t know for sure that humans are causing global warming so we’re not going to do anything about it. This is the same with abestos, smoking etc… This seems to me like the only reason someone would argue for its continual usage is because we’re living comfortably and don’t want to change our habits.
In the meantime, the fact is that there are easy replacements for number 7 water bottles and baby bottles. The green guide lists a number of baby bottles which are made of plastics not known to leach (number 5, http://www.thegreenguide.com/doc/ask/saferbabybottles) So yes there is another option besides glass and number 7 baby bottles and you even have 6 different ones to choose from.
Yirmiyahu, If you only use the Nalgene bottles to drink cold water and replaced the bottle approximately every year, I think you’d have trouble finding a respected expert in the field saying that you are endangering yourself.
Jason,
Here’s a more accurate link to what’s happening in Canada:
http://www.chemicalsubstanceschimiques.gc.ca/interest-interet/bisphenol_e.html
You’ll note that they are continuing studies, but saw no reason to change the current safe exposure levels. Interestingly they reference the EU conclusions, and as noted in the stats.com link above, the EU also saw no reason to change safe levels based on their research.
In general, what is clear is that there are a nontrivial number of peer reviewed articles saying there are dangers and a nontrivial number that say there is no/minimal danger and current human dose thresholds. This is the main difference between this topic and global warming. With global warming, there was strong, respected evidence 2-3 decades ago and there has been a clear scientific consensus on global warming for over a decade. There is no scientific concensus on this topic. If there was, wouldn’t there be at least one country what would ban #7 plastics in some form?
And there’s still the issue of alternatives. For baby bottles, the green guide link says #5 plastics don’t leach potential hormone disruptors, but it doesn’t say what they do leach and whether there have been any studies on danger. The simple test (not 100% accurate) with plastic is to fill a container with tomato sauce. If the container gets stained red, then there were probably chemical interactions with the plastic. Regardless of baby bottles, should you stop eating canned food which have BPA in the plastic lining to help prevent botulism? Do you think the dangers of BPA are greater than botulism?
If you want to compare to global warming probably the best comparison is to say that there is global warming and the solution to get our energy from burning coal instead of oil.
If you’re original post stated there might be problems with hippie swag bottles and you should use alternatives when possible that would be a reasonable statement, but to say they pose a significant health risk has minimal if any scientific backing. I suspect even the researchers studing this would say exposure from drinking cold water is extraordinatly small. Can you find a single source documenting a nontrivial amount of BPA in cold water from a nalgene bottle?
BSCI,
I have to disagree and say there is overwhelming evidence that bisphenol A has had harmful effects on animals who have been tested. Here is a listing of many of the peer reviewed articles on this subject: http://www.ourstolenfuture.org/Policy/2006/2006-0107ab319.html. It seems to me that the ones saying there are no issues are funded by the plastic industry and therefore untrustworthy. I find the evidence from independent scientists to overwhelmingly find significant issues with biophenal a. An article in the SF Gate has a consensus statement by several dozen scientists saying that biopenal a is probably causing reproductive issues in people and that was after looking through 700 studies. And there have been 150 studies where animals have had health effects from low doses of biophenal a. http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/08/03/MNG7RC98J1.DTL&hw=baby+bottles+banned&sn=002&sc=987. Again I see eerie similarities between this debate and the one on global warming. The plastics/chemical industry is acting the same way oil companies have.
As for the Nalgene bottle they are made with biophenal a, there is nothing I can find about how much is in each but biophenal a is in the plastic and as sited earlier even low doses have had adverse effects on animals.
Saying that there could be trouble with number 5 plastic is really muddying the water and moving away from anything concrete. There is nothing to suggest that number 2, 4, or 5 plastics are dangerous or leach anything, no peer reviewed articles, and they are recommended by the green guide who have surveyed what plastics are safe to use.(I reference from the original post). This shouldn’t be so confusing, it’s pretty straight forward about which plastics are and aren’t okay for human use. And there is more than enough evidence out there to thoroughly convince me to avoid using number 7 plastics.
sarah, most cities only recycle plastics with “1” or “2” on the bottom. Very few places recycle bottles with a “7.”
Jason, after reading your cited source (the first link didn’t work) from San Francisco, it seems to me that the effects on humans are completely unknown. Scientists are guessing, and it says so in the article, that BPA may have an effect on humans (they even say without certainty that it may affect babies). Sure most of our science today is done through guesswork by looking at evidence and hypothesizing that said chemical is the cause because everything seems to point to it. But to cause any reasonable alarm this requires more than the few studies cited here.
In the SF article they state that there is reason to believe that Humans have received higher doses of BPA than doses which caused problems in mice. In almost all studies that I know of involving mice, the dose needed to have an effect on humans is MUCH higher… which would seem logical. And, in some cases, the same chemical that can have devastating effects on mice, has absolutely no (at least no detrimental) effect on humans at any dosage. The fact that there have been no studies on humans with BPA is strong evidence that enough solid data on mice still hasn’t been collected. Usually any kind of epidemiological study won’t move up to humans unless it is convincing with mice… and causality can be a hard thing to show.
After my questions before, I read a little more than just the posts here and decided that more research needs to be done before i toss my nalgenes… although with babies I suppose you may want to use even irrational amounts of caution… but then again, consider that mankind (rather, womankind) had babies long before the development of modern medicine, and we all turned out ok.
Yirmiyahu, Here is the correct link for the first article, sorry about that: http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/bpauses.htm.
I admit that scientists don’t know the effects on humans directly because no studies have been done on this. And I do believe we need to study this more and that it seems like this could be happening in the near future. However the 38 scientists from the SF gate article do think harm to humans from BPA is likely and this includes 4 scientists from federal health agencies. And what you categorize as a few studies is more around 150 showing harm to animals. That seems like more than enough to warrant concern.
Furthermore, I just found this study from the link above: “Elsby show that rat experiments may underestimate the effects of bisphenol A on humans because of differences in the way that these two species metabolize the contaminant. Rats more efficiently convert BPA into a non-estrogenic metabolite than do humans. The human fetus shows even less ability to make this conversion, as the metabolic pathway responsible for conversion does not appear to develop until after birth.”
This seems to suggest that atleast with biophenal A the health concerns for humans could be greater than with rats. Between this study, the 150 others that show harm to rats and mice, and the respected opinions of those 38 scientists who study this for a living I stand by the danger I see in number 7 plastics and that we should avoid using them.
Fair enough, I was unaware that there have been 150 studies (if this is true I guess the effects on mice are obvious), and thanks for the new link…
one more question though: How is it possible for this quote below to be true if no studies have been done on humans? Barring the scenario described below, where the fetus has not yet developed this pathway (obviously making metabolysis (sp?) an impossibility, and thus the argument valid), how is it possible to hypothesize the differences metabolizing BPA with any validity?
“Elsby show that rat experiments may underestimate the effects of bisphenol A on humans because of [[[[differences in the way that these two species metabolize the contaminant.]]]] Rats more efficiently convert BPA into a non-estrogenic metabolite than do humans. The human fetus shows even less ability to make this conversion, as the metabolic pathway responsible for conversion does not appear to develop until after birth.â€
sorry for the poorly worded response, but I think you can understand what I’m saying.
First, I want to re-note that BPA is also in the lining of most canned food where there is a much longer period of interaction with what you will eventually eat. Are you planning to throw out all cans with your nalgene bottles?
Also, this may be like global warming, but it might also be like mercury in vaccines. At one point there was some good evidence hinting at the mercury in vaccines and autism link. The evidence was so good that alternative non-mercury vaccines replaced the entire stock in the US and other countries. This had no effect on autism rates, but the cranks supporting this theory have only grown louder. I suspect BPA will end up being somewhere between global warming and vaccination. Enough problems will be found to support decreasing, but not ending, the usage of BPA, especially around food. Frankly, the exposure rates in people make it seem like the intake is more from general environmental exposure and not hippies who drink from nalgene bottles.
The consensus statement seems like a good source so I quickly read it. Not sure if it’s directly available if you don’t have academic journal access so I’ll paste some sections here. It’s currently in the in-press section of Reproductive Toxicology (put online 7/27/07) The Chronicle article poorly represents that document.
First, the scientists cite the biggest concerns are in utero exposure so the bottle issue is less significant.
They divide their consensus into two categories:
“We are confident of the followingâ€: This category applied when there were findings reported in multiple papers from multiple labs that were in agreement. There should have been no papers reporting conflicting findings, unless there were flaws in those papers, in which case
the flaw(s) should have been identified.
“We believe the following to be likely but requiring confirmationâ€: This category applied
when there were multiple consistent findings from one lab, or there may have been some
conflicting reports along with reports of significant findings.
On the section on health effects, here are their consensus points where they were confident:
1. Sensitivity to endocrine disruptors, including BPA, varies extensively with life stage, indicating that there are specific windows of increased sensitivity at multiple life stages. Therefore, it is essential to assess the impact of life stage on the response to BPA in studies involving wildlife, laboratory animals, and humans.
2. Developmental windows of susceptibility are comparable in vertebrate wildlife species and
laboratory animals.
3. BPA alters “epigenetic programming†of genes in experimental animals and wildlife that results in persistent effects that are expressed later in life [25]. These organizational effects (functional and structural) in response to exposure to low doses of BPA during organogenesis persist into adulthood, long after the period of exposure has ended. Specifically, prenatal and/or neonatal exposure to low doses of BPA results in organizational changes in the prostate, breast, testis, mammary glands, body size, brain structure and chemistry, and behavior of laboratory animals.
4. There are effects due to exposure in adulthood that occur at low doses of BPA. Substantial neurobehavioral effects and reproductive effects in both males and females have been observed
during adult exposures in laboratory animals.
5. Adult exposure studies cannot be presumed to predict the results of exposure during development.
6. Life stage impacts the pharmacokinetics of BPA
For the same section, they believe the following are likely:
1. Clearance of BPA in the fetus is reduced compared to other life stages. Different effects and metabolic clearance mechanisms are also observed in neonatal and adult animals. Conjugation (glucuronidation) and other mechanisms of metabolic clearance of BPA thus vary throughout life.
2. Exposure to BPA during different life stages differentially influences reproductive cancer etiology and progression, and exposure during sensitive periods in organogenesis may increase susceptibility to development of cancers in some organs, such as the prostate and mammary glands.
4. Early life exposure to environmentally relevant BPA doses may result in persistent adverse effects in humans.
5. The function of the immune system can be altered following adult exposure to BPA.
6. Effects on insulin metabolism occur following adult exposure.
Their conclusions highlight their causes for concern and the specific areas that need more research, but they do not recommend any immediate action to change BPA usage. (i.e. there is no consensus on this topic). Thus, the respected opinions of those 38 scientists who study this for a living do not stand by the danger you see in number 7 plastics and have not issued a statement that we should immediately avoid using them.
Here is the direct link to the study by Elsby: http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2001-04elsbyetal.htm. I do understand what you’re saying and have enjoyed debating this with you.
Your question on how they know this about humans is good and this is what I found further down on that page: “BPA incubated with female rat livers yielded one major and two minor metabolites. Elsby et al. identified the major metabolite as the monoglucoronide of BPA, which is not estrogenic. One of the minor metabolites did demonstrate estrogenic activity, but at a lower level than BPA. The preparation using human liver microsomes converted BPA to the glucuronide metabolite at a significantly lower rate than did the rat microsomes. Examining the estrogenicity of the metabolized preparation using the yeast estrogenicity assay, they found that rat microsomes were more effective at reducing estrogenicity than human microsomes.”
Jason, Yes, there are specific animal studies that show very bad things. The current consensus of the experts in the field is that this studies do not warrent any radical change in our behavior. This either means they don’t trust the results or there’s not enough evidence linking these results to real-world dangers. The fact that a consensus statement (made by committee stacked against BPA according to the industry rep in the Chronicle article) does not have the same immediate worries as you about the resutls of these individual papers should make you think about their direct relevance.
Jason, I also enjoyed the debate. It’s nice to know that people can still argue on the internet without resorting to personal attacks, which happens all too often. At some point, not tonight, I’ll read more about the science, but unfortunately I left the science world for other destinations after high school, so it will take a little brushing up. 🙂
Anyway, I’m out, I’ll leave it to you and bsci to debate the biochem. (I always leaned more toward the straight up chemistry)
Just a pointer – Plastic type #7 just means “Other”. It includes plastics that do not readily fit into types 1-6. ALL polycarbonates (BPA) are type 7. Many are not marked at all because #7s are usually not recycled anyway. There are other materials that may be marked as #7 and are not polycarbonate. In particular, a new material “tritan copolymer” will replace BPA based polycarbonates in many product lines. It looks like PC, and is also type #7, but has no BPA. I expect that the makers will heavily advertise this fact.