13 search results for "bisphenol"

Bye Bye, Bisphenol A

Canada is expected to formally declare on Saturday that the controversial chemical bisphenol A (BPA) is a hazardous substance.

The move will make Canada the first country in the world to put the chemical on a list of toxic substances that will ban the material from being used in such products as baby bottles.

via CTV.ca | Canada to put BPA on toxic substances list

Good for Canada. Timing of when cans (the biggest potential source of adult exposure) will be BPA free is up in the air.

Feds punt on Bisphenol A

By studiously ignoring all the subtle hormone disruption effects of bisphenol A and concentrating on easily observable neurological effects, the CERHR essentially does the industry’s bidding.

Some risk linked to plastic chemical – Los Angeles Times

A federal panel of scientists concluded Wednesday that an estrogen-like compound in plastic could be posing some risk to the brain development of babies and children.

Bisphenol A, or BPA, is found in low levels in virtually every human body. A component of polycarbonate plastic, it can leach from baby bottles and other hard plastic beverage containers, food can linings and other consumer products.

Culminating months of scientific debate, the decision by the 12 advisors of the Center for the Evaluation of Risks to Human Reproduction — part of the National Institutes of Health — is the first official, government action related to the chemical. Their recommendation will be reviewed for a federal report that could lead to regulations restricting one of the most used chemicals.

The scientists ranked their concerns about BPA, concluding they had “some concern” about neurological and behavioral effects in fetuses, infants and children, but “minimal” or “negligible” concern about reproductive effects. The findings put the panel roughly in the middle — between the chemical industry, which has long said there is no evidence of danger to humans, and the environmental activists and scientists who say it is probably harming people.

For a detailed look at how bisphenol research has been corrupted by industry sponsored “focused counter research” – where the goal is to show no effects and the experiment is tiled to ensure this goal, read this excellent article in the The Public Library of Science Biology Open Source Journal. Note, because it is Open Access, you can actually read it without selling a kidney! Some highlights…

The moment we published something on bisphenol A, the chemical industry went out and hired a number of corporate laboratories to replicate our research. What was stunning about what they did,” vom Saal says with a mix of outrage and bemused disbelief, “was they hired people who had no idea how to do the work. Each of the members of these groups came to me and said, ‘We don’t know how to do this, will you teach us?’”


The HCRA report, commissioned before Schwartz’s tenure, concluded that “the weight of the evidence for low-dose effects is very weak” [15]. Industry groups hailed the report as a comprehensive review by independent experts and quickly disseminated its findings. Yet the “comprehensive” report reviewed just 19 of 47 studies available in April 2002, and when it was published more than two years later, three panelists asked not to be listed as authors.

What the hell, just read the whole article, especially the bit about the Harvard Center for Risk Analysis and its well documented industry shillness.

The key to understanding bisphenol research is to realize that it is a hormone disruptor that works at low doses. At high doses, normal toxicological testing doses that is, it floods the hormone receptors and slows down the receptor pathways. So, the usual technique of testing in rats and mice at high doses and extrapolating will not work.

Bisphenol A – Getting More Powerful Everyday

So is it Mondays with Bisphenol?? You know what, the scary thing about this chemical is that its acute (short term, immediate) toxicity at high doses, which is the only safety testing that is ever done, does not correlate with all the subtle effects that are seen at low doses (chronic). Here’s another study where ambient level exposure to bisphenol A interferes with prostate cancer treatment by making the tumor cells androgen independent, so the standard testosterone deprivation therapy will not work any more.

Environmental Health News: New Science

A common plastic molecule to which virtually all Americans are exposed may interfere with the standard medical treatment for prostate cancer, according to new experiments with human prostate tumors implanted into mice. The doses of the plastic molecule, bisphenol A, were chosen specifically to be within the range of common human exposures. Tumor size and PSA levels were significantly greater in exposed animals just one month after treatment.

One of the principal known sources of exposure to bisphenol A in the U.S. is through its use to make a resin that lines the majority of food cans sold in markets. These new results by Wetherill et al. suggest men concerned about prostate cancer may want to reduce their consumption of canned goods and their use of polycarbonate water bottles, another common source of exposure

This is one powerful (if not actually more dangerous) chemical. it is so ubiquitous that finding a substitute is not going to be easy.

Conflicts of Interest in Bisphenol A Decision Making

I have written about bisphenol A recently. It’s a chemical found in polycarbonate plastics that has been linked with some crazy effects in mice at ambient levels including disruption of oogenesis (egg production) and effects two generations removed (grandmother effects).

Public health agency linked to chemical industry – Los Angeles Times

For nearly a decade, a federal agency has been responsible for assessing the dangers that chemicals pose to reproductive health. But much of the agency’s work has been conducted by a private consulting company that has close ties to the chemical industry, including manufacturers of a compound in plastics that has been linked to reproductive damage.

In 1998, the Center for the Evaluation of Risks to Human Reproduction was established within the National Institutes of Health to assess the dangers of chemicals and help determine which ones should be regulated. Sciences International, an Alexandria, Va., consulting firm that has been funded by more than 50 industrial companies, has played a key role in the center’s activities, reviewing the risks of chemicals, preparing reports, and helping select members of its scientific review panel and setting their agendas, according to government and company documents.

This kind of work is too important to be left to contractors like Sciences International (however good they may be), which also has contracts with companies that manufacture and market products containing Bisphenol A. It’s very simple, most companies, for profit entities and even non-profits dependent on funding sources tend to maximize short term gain over long term good. While the political arm of the government does that as well, the institutions stable enough to do reliable work on policy issues that affect our long term well being are few in number. Government run research with stable funding, good employees and good management will do this work well, it’s a good match between the nature of the work and the nature of the organizations.

The ever excellent Pump Handle has more, I read their post as I was writing this one and so, nothing more to say, really, except, remember Children of Men! Fertility is not to be toyed with, any chemical that has the ability to affect egg production two generations down needs to be handled with care. 

Bisphenol A Linked to Breast Cancer

Chemical & Engineering News: Latest News – Bisphenol A May Trigger Human Breast Cancer

Soto and her colleagues exposed pregnant rats to bisphenol A at doses ranging from 2.5 to 1,000 µg per kg of body weight per day. By the time the pups exposed at the lowest dose reached the equivalent of puberty (50 days old), about 25% of their mammary ducts had precancerous lesions, a proportion three to four times higher than among the nonexposed controls. Mammary ducts from all other exposure groups showed elevated levels of lesions. Cancerous lesions were found in the mammary glands of one-third of the rats exposed to 250 µg/kg/day.

Bisphenol A is used in the manufacture of polycarbonate plastics and epoxy resins. It is found in many food and beverage containers, including baby bottles. It is also found in canned food linings and dental composites, and it leaches from all of these products. In one study, Soto notes, urine samples from 95% of the human subjects contained the chemical.

The Environmental Protection Agency has set a safe human intake dose of 50 µg/kg/day for bisphenol A. “On the basis of the effects observed in recent studies, this seems to be an unsafe level,” Soto says.

Bisphenol A is old news, BTW, people have known for a while about this chemical’s propensity to carcinogenicity. Of course, there’s that whole argument about pregnant mice being more susceptible to chemicals than humans, etc. So, the jury is still out. but Soto is right, 50 µg/kg/day seems to not provide enough of a safety factor. The EU uses 10 µg/kg/day, though they do say that

realistic worst-case estimates of consumer exposure via foodstuffs, range from 0.00048 mg/kg bw/day for adults to 0.0016 mg/kg bw/day for infants, which is well below the maximum exposure level

Of course, who knows what additive effects this chemical may have with the multitude of other chemicals floating around. Doing tests of single chemicals and trying to link that to epidemiological data is a perilous undertaking, the connections are tenuous most of the time and the plastics companies routinely fund studies that prove otherwise, because as you know, if you know what you’re going to find before you study it, you will find it!

Read the wikipedia stub on polycarbonates. Us yuppies who drink religiously from Nalgene bottles to avoid phthalates and nasty tastes would do good to take note! I guess glass is the best, though it does have that annoying tendency to shatter when dropped… Water from glass bottles do have the best taste, though.

Endocrine Disrupting Chemicals – A new Resource

Critical Windows of Development is a timeline of how the human body develops in the womb, with animal research showing when low-dose exposure to endocrine disrupting chemicals during development results in altered health outcomes.

Critical Windows of Development

This promises to be an easy to use database showing development timelines of infants, and the documented effects of endocrine disrupting chemicals at these timelines. The prime focus is bisphenol A and phthalates at this point in time. The Environmental Health News has more about the program here. It is not out for public consumption yet, so stay tuned…

How NAFTA infringes on local environmental regulations

Dow AgroSciences is considering using the controversial investor-protection provisions of the North American free-trade agreement to seek compensation from the federal government over Quebec's ban on the cosmetic use of pesticides.

The company, a maker of the weed-killer 2,4-D, filed a notice of intent to submit a claim to arbitration under NAFTA in late August. The 27-page legal action was posted yesterday on the Foreign Affairs website, where it is listed as a dispute to which Canada is a party.

via globeandmail.com: Ban on pesticides may face NAFTA test

Here is Sierra Club’s assessment of 2,4-D. It is not as bad as, say, DDT, but not something an average householder would ever need to use. Limiting use and exposure is in everyone’s best interest except Dow’s, which is why they have filed this lawsuit.

I would say it infringes on a province’s right to set strict health and safety standards for its people, but if we accept that corporations have more rights than people, we would expect this kind of lawsuit to happen with more frequency.

Note that a much more egregious actor, lindane, which was deregistered by even the Bush EPA is subject of a similar challenge in Canada, and Bisphenol A is probably next.

Can’t blame the companies for exploiting loopholes (that they no doubt inserted, of course), but it seems that countries should always have the right to enforce stricter standards if they so desire.

Flame Retardants and Hyperthyroidism in Cats

Caveat Emptor: They found a correlation, not a causative mechanism. But Polybrominated Diphenyl Ethers (PBDEs, yum!) have structures that can mimic endocrine hormones. Because hormones signal at very low doses and continuously, our whole toxicological risk testing structure of looking for acute effects at high doses and trying to extrapolate those effects to low doses is flawed for endocrine disrupting compounds. We are finally beginning to see some new research, especially with other toxics such as Bisphenol A, which test for chronic conditions and subtle gene and hormonal signalling effects at low doses. After all, small changes in hormone regulation especially at childbirth and a young age can have very serious effects later on in life.

Inside Bay Area – NEW: Flame retardants linked to thyroid disease in cats

A mysterious epidemic of thyroid disease in cats may be linked to flame retardants common in carpets, foam furniture and mattresses, according to U.S. Environmental Protection Agency researchers, who suggest that scientists have underestimated the damaging health risk the chemicals pose to humans.

The research, published Wednesday in the journal Environmental Science and Technology, does not prove these compounds, known as PBDEs, caused the rash of hyperthyroidism in the nation’s household cats over the past 30 years.

Rather, it lays out a hypothesis, showing that cats are heavily contaminated by these compounds, which leach from household products and are found everywhere, particularly household dust. Cats, meticulous cleaners, ingest PBDE-contaminated dust daily.

The case of fire retardants is especially difficult because they save many lives, so manufacturers can always point to that fact and resist change. The logical fallacy, however is as follows:

  1. Fire retardants save lives (therefore good)
  2. PBDEs are fire retardants
  3. Therefore, PBDEs are good!!

The search for a safer fire retardant needs to continue, and will not happen unless the old ones are under pressure of being phased out.

Common chemicals are linked to breast cancer

The LA Times features a study arising from the Silent Spring institute.

Common chemicals are linked to breast cancer – Los Angeles Times

More than 200 chemicals — many found in urban air and everyday consumer products — cause breast cancer in animal tests, according to a compilation of scientific reports published today.

Writing in a publication of the American Cancer Society, researchers concluded that reducing exposure to the compounds could prevent many women from developing the disease.

The research team from five institutions analyzed a growing body of evidence linking environmental contaminants to breast cancer, the leading killer of U.S. women in their late 30s to early 50s.

Experts say that family history and genes are responsible for a small percentage of breast cancer cases but that environmental or lifestyle factors such as diet are probably involved in the vast majority.

“Overall, exposure to mammary gland carcinogens is widespread,” the researchers wrote in a special supplement to the journal Cancer. “These compounds are widely detected in human tissues and in environments, such as homes, where women spend time.”

The scientists said data were too incomplete to estimate how many breast cancer cases might be linked to chemical exposures.

The resources to come out of this study include two databases, one that summarizes animal mechanistic studies, and one that summarizes human epidemiological studies. It’s a good start and I hope these databases are continually expanded. The study was essentially a big lit review and data organization project.

There are two major issues with the way carcinogenicity is studied. Firstly, animals other than humans are dosed at high levels to test for possible cancer outcomes. This leaves most researchers vulnerable to the charge that these high dose studies do not translate well to humans because the dose-response relationship at ambient levels is not well studied. So, the obvious criticism is that just because cancer endpoints were seen at high levels does not mean that the same thing will happen at low levels. This cuts both ways, though. We’re seeing with bisphenol A that low doses can cause more harm than intermediate doses. Another issue is the additivity of the interactions. Does 1 “dose” of PAH + 1 “dose” of PCB = 2 “doses” of PAH? We’re exposed to a whole host of chemicals all our lives, who knows which ones add, which ones subtract, which ones multiply, etc.

Of course, as with most diseases, some macro variables dominate. For instance, the US has seen 8-9% decline in breast cancer incidence recently due to a decreased use of hormone replacement therapy. So, as with all diseases, taking care of some of these big ticket items is very important. One discouraging story I read today reported on a four percentage point decline in mammograms (70 to 66%) in women age 40 and older. Why? decreased access to health insurance and dropping the ball on promotion.

The depressing fact of the matter is that the boring basics of good preventative healthcare, screening, good lifestyle and diet are the most important factors, and if we take care of these factors, we will make most health issues easier to deal with.

Glass baby bottles making comeback

More Bisphenol A blowback, apparently, SF parents are switching to glass.

Glass baby bottles making comeback / Stores selling out after health alarms raised about plastics

Glass baby bottles, replaced decades ago by unbreakable plastic, are making such a comeback that parents can’t get their hands on them.

Online and brick-and-mortar retailers report a run on glass baby bottles in recent weeks that they say was spurred by reports that the most common type of plastic in baby bottles may leach a toxic chemical.

San Francisco resident Sean Mullins said he decided to switch his 6-month-old son, Mickey, from plastic to glass bottles last month despite manufacturers’ insistence that plastic bottles are safe.

Independent tests done for The Chronicle and reported in November found bisphenol A, a chemical that mimics estrogen, in a baby bottle and several toys. Bisphenol A is also found in the lining of food cans, some anti-cavity sealants for teeth, and electronics.

Watch for plastics manufacturers to fight back, this study ought to provide some ammo.

Comparison of six samples of each of three brands of water available in both glass and polyethyelene terephthalate (PET(E)) showed that the waters bottled in glass contained approximately 57, 30, and 26 times more Pb due to leaching from the containers. Our study includes 25 brands of bottled water from Canada, and the median Pb concentration in these samples was 15.9 ng/L (n = 25), with a range from 2.1 to 268 ng/L. For comparison with the bottled waters, pristine groundwater from six artesian flows in southern Ontario, Canada, where some of the bottled waters originate, yielded a median concentration of 5.1 ng/L Pb (n = 18). In fact, all of the waters tested were well below the maximum allowable concentration established by the EU, Health Canada, and the WHO for Pb in drinking water (10000 ng/L).

It all depends on which bolded sentence you chose to emphasize! So, glass bottles do leach some lead out, but nowhere near the amount needed to cause any effects whatsoever. I guess this is all the American Chemistry Council can come up with as a problem with glass.

It’s irrefutable that glass can shatter, Hentges said. But there is “no scientific basis to conclude that BPA is something to be concerned about … at the extremely low levels that people might be exposed to from use of consumer products.”

There is plenty of scientific basis to conclude that Bisphenol A has some very subtle effects at ambient doses. But science has never stopped the American Chemistry Council!