Have you had your BPA today?

http://english.pravda.ru/news/science/15-05-2008/105230-bisphenol_A-0



FDA approves use of products made of bisphenol A



The U.S. Food and Drug Administration has recently approved the use of products made of organic compound bisphenol A (abbreviated BPA).Bisphenol A’s current uses are numerous. It is used in the synthesis of polyesters, polysulfones, and polyether ketones, as an antioxidant in some plasticizers, and as a polymerization inhibitor in PVC. It is a key monomer in production of polycarbonate plastic and epoxy resins. Polycarbonate plastic, which is clear and nearly shatter-proof, is used to make a variety of common products including baby and water bottles, sports equipment, medical devices, CDs, and household electronics.

The chemical is actually quite controversial because it mimics estrogen and thus could induce hormonal responses. In spite of this, the FDA and the chemical industry unanimously defend the safety of BPA.

The first evidence of the estrogenicity of BPA came from experiments in the 1930s in which it was fed to rats. Since then, its endocrine disrupting properties have been extensively investigated, and more than 100 studies have been published "raising health concerns" about the chemical. For example, studies have demonstrated developmental toxicity, carcinogenic effects, and possible neurotoxicity at low doses in animal models. Recent studies suggest it may also be linked to obesity by triggering fat-cell activity and have confirmed that bisphenol A exposure during development has carcinogenic effects and produce precursors of breast cancer. However, neither the U.S. Environmental Protection Agency nor the International Agency for Research on Cancer have evaluated Bisphenol A for possible carcinogenic activity.

In 2007, a consensus statement by 38 experts on bisphenol A concluded that average levels in people are above those that cause harm to animals in laboratory experiments, and a panel convened by the U.S. National Institutes of Health determined that there was "some concern" about BPA's effects on fetal and infant brain development and behavior.

A 2008 draft report by the U.S. National Toxicology Program (NTP) agreed with the panel, concluding that "there is some concern for neural and behavioral effects in fetuses, infants, and children at current human exposures," and that there is "some concern for bisphenol A exposure in these populations based on effects in the prostate gland, mammary gland, and an earlier age for puberty in females." The NPT also concluded that there is negligible concern that "exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects or reduced birth weight and growth in their offspring" or that it causes adverse effects in exposed adults.

In April 2008, the Canadian government released its Draft Screening Assessment for bisphenol A, which concluded that the chemical may pose some risk to infants and proposed classifying the chemical as "'toxic' to human health and the environment." This action follows Canadian regulators selection of bisphenol A in 2006 as one of 200 substances deserving of thorough safety assessments after preliminary studies had found it to be "inherently toxic"; the chemical had not previously been studied by them in depth, having been accepted under grandfather clauses when stricter regulations were passed in the 1980s.
In contrast to the recent actions in North America, in January 2006 the German Federal Institute for Risk Assessment announced that polycarbonate baby bottles are safe and stated that published research on the health effects of Bisphenol A is "difficult to interpret and is occasionally contradictory". An assessment released later that year by the European Union’s Food Safety Authority reached a similar conclusion, expressing "considerable reservations" about the biological significance and robustness of the low-dose exposure studies on rodents. In 2007 Japan also concluded that "the current exposure levels of BPA will not pose any unacceptable risk to human health that a ban is not needed."

Some toxicologists and regulatory agencies have criticized low-dose toxicity studies, especially those that involved injecting bisphenol A directly into animals, since human exposures typically involve ingestion and subsequent metabolization in the liver, and the experimental design of some of these studies has also been questioned. Studies have also appeared pointing out flaws in chemical industry funded studies that found no evidence of adverse effects from low dose exposure, and a study from 2008 concluded that blood levels of bisphenol A in neonatal mice are the same whether it is injected or ingested.


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This is why I don't like to heat anything in the microwave on a very high power that is in a plastic container. This causes the release of more of these estrogen type substances.

Norma

http://www.bloggingstocks.com/2008/06/12/wal-mart-removes-bpa-products-from-shelves-for-good/


Wal-Mart removes BPA products from shelves for good

Posted Jun 12th 2008 12:56PM by Brian White
Filed under: Products and services, Consumer experience, Wal-Mart (WMT)
Wal-Mart Stores, Inc. (NYSE: WMT) is taking steps to eliminate the chemical Bisphenol-A (BPQA) from plastic products on its shelves due to safety concerns. Products containing the chemical are no longer available on store shelves. Previously, they were marked as such to give consumers the choice to purchase BPA-free products. Now, BPA products are gone for good.

The chemical, which is used to make plastic products shatter-proof, is used in baby bottles and water bottles, among other products. Although the FDA has not officially banned BPA from consumer products, several powerful consumer groups have disagreed

While some retailers speak of removing products that contain controversial chemicals or ingredients, it's refreshing to see the world's largest retailer leading the charge on this one. Also joining Wal-Mart in banning BPA products from shelves will be children's toy retailer Toys R Us.

Although this ban was officially announced by Wal-Mart in April, it's great to see the world's largest retailer act on it so quickly. If this is the kind of response to "consumer demand" that makes changes happen, it's impressive to see a compressed timeframe on a consumer safety issue like this one.

http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2007/2007-0803newboldetal.html

Context: Bisphenol A was first synthesized in 1891 and subsequently, in the 1930s, found to be estrogenic. Assays of the day indicated it was much weaker than another synthetic estrogen, diethylstilbestrol (DES), so it was not deemed useful for medical purposes. More than a decade later, polymer chemists discovered BPA molecules could be put together in molecular chains to form polycarbonate plastic. It has since become ubiquitous, used in a wide array of consumer products such as in the clear rigid plastic above.
Additionally, BPA is used to form epoxy resins that line the majority of food cans sold in American supermarkets. It also lines soda cans, for example, holding products like Coca-Cola. BPA-based resins are also used to coat teeth to prevent cavities.
This widespread use has led to the reality that almost all people in developed countries, including the US, have measureable levels of biologically-active BPA in their tissues. Median levels in a series of studies are typically 1 - 2 nanograms per milliliter (ppb). In classic toxicology, these levels would not have stimulated concern, but the last ten years of research on endocrine disruption, especially BPA, have demonstrated numerous adverse effects of BPA at those levels in animal experiments.
Before this study by Newbold et al., none of the research has examined impacts of developmental exposure to BPA on reproductive tract effects in middle age, despite numerous studies in people and animals demonstrating strong effects of DES on reproductive tracts in adult women. This gap is especially troubling because of the unexplained commonness in women of uterine abnormalities like fibroids. Up to 20% of white women in the US and 50% of black women suffer from fibroids. They are an important contributor to infertility and the most common medical diagnosis leading to hysterectomy.

http://www.ourstolenfuture.org/NewScience/oncompounds/bisphenola/2007/2007-0803newboldetal.html


Newbold, RR, WR Jefferson, and EP Banks. 2007.


Long-term Adverse Effects of Neonatal Exposure to Bisphenol A on the Murine Female Reproductive Tract.


Reproductive Toxicology 24:253-258.
A new study with mice is the first to link low level neonatal exposure to bisphenol A to uterine diseases the women develop as they age, including fibroids, adenomysois and cystic ovaries. Some of the adverse conditions induced by BPA in mice have been previously described in daughters of mothers who took the drug diethylstilbestrol (DES), a synthetic estrogen which is structurally and functionally similar to bisphenol A. Extensive research on DES has shown that animal studies can be useful in predicting effects in people.
These new results add to a growing body of research showing that exposure to environmentally-relevant levels of BPA cause long-term adverse effects if exposure occurs during critical periods of development.


What did they do? Newbold et al. exposed neonatal mice to bisphenol A via subcutaneous injection, one per day, from days 1 through 5. They used three doses, 10, 100 or 1000 µg/kg/day (parts per billion), dissolving the BPA in corn oil. Control animals received corn oil alone. At the age of 18 months, they dissected the animals to examine their ovaries and reproductive tract. What did they find? Ovarian and reproductive tract abnormalities were more common in treated animals than controls.
While low and high dose treatments did not differ from controls in the number of cystic ovaries, animals receiving 100 µg/kg/day had almost twice as many (39% in controls vs 70% in treated; p < 0.05).
Para-ovarian cysts were not observed in any controls but were seen in all groups of the treated animals (4% , 10% and 6% in animals in the 10, 100 and 1000 treatment groups, respectively).
Progressive proliferative lesion did not occur in controls but was seen in all groups exposed to BPA (13%, 15% and 6% in BPA-10, BPA-100 and BPA-1000, respectively).
Cystic endometrial hyperplasia was more frequent in all treatment groups compared to controls, but only statistically significantly more frequent in the BPA-100 group (6% in controls vs. 45% in BPA-100; p < 0.01). This is a typical response to excessive estrogen stimulation. People with this condition are at increased risk to cancer.
Uterine leiomyomas (fibroids) were also more common in BPA treated animals. None were found in controls (18) whereas 1 out of 20 animals in the BPA-10 group developed them, 2 out of 20 in the BPA-100 and 1 out of 16 in the BPA-1000 group. One of the animals in the BPA-100 group with fibroids had multiple lesions.
Stromyl polyps were seen in all groups, with the highest number (5 out of 20) in the BPA-100 group.
Another defect seen in BPA-treated animals but not in controls were enlarged mesonephric duct remains.
What does it mean? This is the first study of BPA to report abnormalities in the reproductive tract of middle-aged mice following neonatal exposure. The two lower doses used are low enough to be environmentally-relevant. The results are not surprising, given that similar effects have been in DES-exposed mice and that DES is structually and functionally similar to BPA. They are important because decades of research with DES has shown that effects found in mice are highly predictive of effects found in people. They are also important because similar abnormalities are common in middle-aged women and little is known about the causes of most cases. They are important contributors to human infertility and disease.
One recurrent pattern in the results presented by Newbold et al. was that in several cases, the intermediate dose of 100 ppb produced larger effects than either the lower or the higher dose. The sample sizes in the experiment were small, limiting the strength of that observation, but it resembles non-monotonic dose-response patterns seen in other experiments with endocrine disrupting compounds like BPA.




Up to 20% of US white women and 50% of US black women experience fibroids. Hysterectomy is a common medical treatment.

Bought my DIL

glass baby bottles for new (8/1/08) grandson. A week ago she tells me she discovered something wonderful about them; they wash up beautifully and are therefore totally re-usable, saving them money. I smiled nicely and said, "That's true."