THE ACCIDENTAL TOXICOLOGIST: A geneticist by training, she discovered that bisphenol A (BPA), an estrogen mimic, was leaching from polycarbonate plastics, which harmed her lab mice and ruined her experiments. BIG ISSUE: In 2004 6.4 billion pounds of bisphenol A were created for compact discs, eyeglasses, baby bottles and other consumer products. Production grows 10 percent every year. CAUSE FOR ALARM?: When Hunt's first report came out, other scientists took note. Says colleague Frederick vom Saal: "In the field one thing people say is, 'Pat does not get it wrong.'"
" data-pin-do="buttonBookmark">, an estrogen mimic, was leaching from polycarbonate plastics, which harmed her lab mice and ruined her experiments.</p>
<p>BIG ISSUE: In 2004 6.4 billion pounds of bisphenol A were created for compact discs, eyeglasses, baby bottles and other consumer products. Production grows 10 percent every year.</p>
<p>CAUSE FOR ALARM?: When Hunt's first report came out, other scientists took note. Says colleague Frederick vom Saal: )
PATRICIA HUNT:
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On the day Patricia Hunt’s career veered into an entirely different field, her graduate students at Case Western Reserve University were grumbling, itching to use some exciting new data in their own experiments, but were told to wait while Hunt (just one last time) checked on her subjects.
Hunt, a geneticist, was exploring why human reproduction is so rife with complications. She had a hunch the chromosomally abnormal eggs that plague human pregnancies were tied to our hormones. A paper outlining the results of Hunt’s experiments on the hormone levels of female mice was ready for publication. All she needed was to ensure that her control population, the mice left alone in the study, was normal. Instead Hunt stumbled on a disturbing result—40 percent had egg defects.
Hunt shelved hopes of publication and scrutinized every method and piece of lab equipment used in her experiment. Four months later she finally fingered a suspect.
It was the janitor. In the laboratory. With the floor cleaner.
A single breach in protocol had turned the rodents’ safe environs into acutely toxic habitats. A maintenance worker had used an abrasive floor cleaner, instead of the usual mild detergent, to wash out cages and water bottles. The acidic solution scarred the hard, polycarbonate surface of the plastic and enabled a single chemical culprit to leach out—bisphenol A (BPA).
Hunt’s unnerving discovery, in 1998, led her to speak out on the possible human health threats of BPA; she and Frederick vom Saal, a biologist at the University of Missouri–Columbia, have become prominent scientists sounding the alarm. To critics, however, Hunt and vom Saal have been alarmists; they argue that there have been no documented cases of BPA-based plastic harming humans and that fears of the chemical are overblown.
First synthesized in 1891, bisphenol A came into use as a synthetic estrogen in the 1930s. Later, chemists discovered that, combined with phosgene (used during World War I as a toxic gas) and other compounds, BPA yielded the clear, polycarbonate plastic of shatter-resistant headlights, eyeglass lenses, DVDs and baby bottles.
But during the manufacturing process, not all BPA gets locked into chemical bonds, explains Tim A. Osswald, an expert in polymer engineering at the University of Wisconsin–Madison. That residual BPA can work itself free, especially when the plastic is heated, whether it’s a Nalgene bottle in the dishwasher, a food container in the microwave, or a test tube being sterilized in an autoclave.
In recent years dozens of scientists around the globe have linked BPA to myriad health effects in rodents: mammary and prostate cancer, genital defects in males, early onset of puberty in females, obesity and even behavior problems such as attention-deficit hyperactivity disorder.
For her part, the 54-year-old Hunt, now at Washington State University, focuses on aneuploidy, or an abnormal number of chromosomes in eggs that causes birth defects and miscarriages. Last year she co-authored a paper in PLoS Genetics that, she says, makes her original discovery look like “child’s play.” Hunt exposed pregnant mice to BPA just as the ovaries in their developing female fetuses were producing a lifetime supply of eggs. When the exposed fetuses became adults, 40 percent of their eggs were corrupted, which spelled trouble for their offspring. BPA’s effects, it seemed, were not confined to the mouse receiving the dose. “With that one exposure,” Hunt says, “we’re actually affecting three generations simultaneously.”
Although experts debate whether mice make good models for human effects, the crux of the argument over BPA is that experimental results have not been reproduced. A 2004 report from the Harvard Center for Risk Analysis found “no consistent affirmative evidence for low-dose BPA effects.” According to I. Glenn Sipes of the University of Arizona, a co-author of that paper, it is this inconsistency that bothers skeptics. “I’ve never had a problem saying that we can see biological effects in these low-dose studies,” he says. “But why are we seeing these studies that can’t be repeated?” A onetime result in a rodent model, Sipes argues, cannot be extrapolated to mean negative impacts for human health.
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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.