But Hunt counters that there is plenty of corroboration to consider BPA a problem. In response to the Harvard study, she helped to produce a “state of the evidence” paper for Reproductive Toxicology in 2007. Along with 36 other researchers, led by vom Saal, the group analyzed hundreds of government-funded studies and found that 90 percent had concluded BPA was a health risk. It was the dozen or so industry-funded studies, vom Saal says, that failed to replicate other BPA research.
More important than these conspiratorial undertones, Hunt says, is one of communication between toxicology (the way skeptics look at BPA) and endocrinology (the way she looks at it). For instance, according to a statement on www.bisphenol-a.org, a Web site created by the American Chemistry Council (which represents dozens of companies engaged in plastics manufacturing), the toxicology of BPA is “well understood,” and “BPA exhibits toxic effects only at very high levels of exposure.” Current U.S. Food and Drug Administration guidelines, based partly on these findings, set a safe daily exposure to BPA at 50 micrograms per kilogram of body weight.
But according to Hunt, treating BPA like a traditional toxin is dangerous because it “doesn’t play by the rules.” Standard toxicology states that if a chemical is bad, “then higher doses are worse and an even higher dose is even worse,” Hunt explains. But with hormones (and estrogen mimics like BPA), she says, high doses can sometimes “shut down” the body’s response, and low doses are enough to exert effects.
Indeed, her lab rodents show BPA effects at just 20 micrograms per kilogram; other labs have found similar thresholds, making them one-half to one-third the FDA levels. These experiments yield bodily concentrations of BPA in ranges of parts per million, but some recent studies have even found that when BPA interacts with hormone receptors on cell membranes, concentrations of one part per trillion can stimulate physiological responses.
That means basically any exposure to BPA could have consequences, an alarming conclusion, considering that in 2004 the Centers for Disease Control and Prevention found unmetabolized BPA in the urine of 93 percent of more than 2,500 human subjects. According to the National Toxicology Program of the U.S. Department of Health and Human Services, BPA has also been detected in human blood and breast milk.
With such ubiquitous exposure, one might expect to see numerous problems already afflicting humans. And perhaps this lack of any definitive effects most bothers skeptics. “Why do we have to work so hard to try to replicate and show these low doses really have an effect?” Sipes asks. “Why don’t [reactions to BPA] stand out in black and white?”
Hunt is asking the same question. She is now working on a paper about how diet can alter responses to the chemical. It is one of many unstudied facets of the issue that, she says, may be making it difficult for scientists to reproduce their research: “There’s a lot of complexity and a lot of things we just don’t understand.”
While scientists grapple to get a better handle on BPA, the public domain has made up its mind. On April 17 the National Institutes of Health raised concerns about BPA’s established “safe” levels. Four days later Health Canada, the Canadian version of the FDA, announced a ban on polycarbonate baby bottles, citing concerns over BPA. The moves rattled the industry, as consumer outcry led stores such as Wal-Mart and CVS to announce they would phase out some polycarbonate products. And Nalgene, a company synonymous with its popular shatter-resistant bottles, decided to pull them from shelves.
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8 Comments
Add CommentSo, what would be the impact of the removal of BPA from plastics intended for food/beverage containers or, obviously, bio-research?
Reply | Report Abuse | Link to thisBesides millions of dollars in cost we would be replacing it with something possibly more harmful and less understood.
Reply | Report Abuse | Link to thisI'd read a report from the EU stating that BPA had no effect on primates as it wasn't absorbed into our bodies. I'd be curious to know more about that. I don't see how this could be hazardous and yet not have caused any harm in humans, this product has been widely available for decades.
Legislators, consumers, and regulatory agencies should have well-justified concerns about the estrogenic activity (EA) exhibited by BPA and phthalates in water bottles and other plastics like baby bottles. While estrogens occur naturally in the body, many scientific studies have shown that significant health problems can occur when chemicals are ingested that mimic or block the actions of these female sex hormones; the fetus, newborn, or young child is especially vulnerable.
Reply | Report Abuse | Link to thisHowever, BPA and phthalates are just two of several hundred chemicals that exhibit EA in plastics. These chemicals having EA leach from almost all plastics sold today, including polyethylene, polypropylene, PET, etc. That is, plastics advertised as BPA-free or phthalate-free are not EA-free; almost all these plastics still leach chemicals having EA and often have more total EA than plastics that release BPA or phthalates.
Current legislation is attempting to solve this problem by removing chemicals having EA (BPA, phthalates) one at a time. This approach, for legislators or the FDA, is not an appropriate solution for consumers because thousands of chemicals used in plastics exhibit EA, not just BPA and phthalates. This approach is a marketing-driven solution, not a health-driven solution. The appropriate health-driven solution is to manufacture safer plastics that are EA-free. This is not a pie-in-the-sky solution, as the technology already exists to produce EA-free plastics that also have the same advantageous physical properties, as do almost all existing EA-releasing plastics on the market today. In fact, some of these advanced-technology EA-free plastics are already in the marketplace. The cost of these safer EA-free plastics are just pennies more than EA-releasing plastics, when both are used to manufacture the same product in similar quantities.
The real solution is to use glass.
Reply | Report Abuse | Link to thisI have been stuggling with a horrible mystery rash for over a year. 2 rounds of very strong steroids, creams, lotions, biopsies, blood tests, etc... can not determine what it is. It is not from something I am touching. It is on the upper inside of my arms & thighs. It flares up twice a month, during ovulation & menstration. When I saw that BPA chemicals found in plastics are linked to horomones, it started making sense. I used to use plastic for everything -packing, heating, freezing lunches & dinners, drink containers, everthing. I couldn't remember the last time I had used a ceramic or glass dish due to always being on the run.
Reply | Report Abuse | Link to thisSince I have eliminated as much plastic as possible from my food and drink sources, my rash has diminished significantly & has continued to a little more each month. This did what all the steroids, creams & lotions could not. It finally provided a clue & some relief.
The rash flared up a little more this month because I have been eating out more recently & not watching / knowing what my food / drink has been stored in.
I want more information about BPA testing. What should I be asking for?
One place to check for bisphenol-a leaching is in plastic bottles of alcoholic drinks; the leaching may be associated with hightened depression as per personal anecdotal observation.
Reply | Report Abuse | Link to thisGlass, glass and glass; oh, and no cooking with utensils that are coated with crap.
Reply | Report Abuse | Link to thisBPA is also in most canned food liners. One of the worst foods are acidic like tomatoes since they leach much more BPA from the liners.
Reply | Report Abuse | Link to thisIf you do a web search on BPA cancer research, you can find articles like this:
http://cancerres.aacrjournals.org/content/68/7/2076.short
http://cancerres.aacrjournals.org/content/66/11/5624.short
http://www.breastcancerfund.org/assets/pdfs/bpaandbc_factsheet_120808.pdf
http://mct.aacrjournals.org/content/1/7/515.short
along with many others.
We have gotten rid of all canned food and use GlassLock containers instead of plastic. You can find some manufacturers that are using non-BPA lined cans and jars. For tomatoes we use Pomi Tetra paks and Eden tomato products in jars.