Thursday, October 17, 2013

Strongest Evidence Yet Between BPA and Thyroid Cancer

Hypomethylation Of Cdk5 Protein Offers Possible Causal Link Between BPA and Medullary Thyroid Cancer

SUMMARY: Over-expression of Cdk5 protein causes medullary thyroid carcinoma in rats. BPA causes hypomethylation (over-expression) of Cdk5-related genes. Could BPA exposure cause epigenetic changes that promote medullary thyroid carcinoma?

By Lewis Perdue
Copyright 2013, All rights reserved

Bisphenol A (BPA) has been suspected in many studies(1-5) of disrupting thyroid hormones.

In addition, BPA exposure in pregnant mice has been shown to induce epigenetic changes in offspring(6).

Various mechanisms have been proposed including hypomethlyation in early development, specifically, "CpG methylation also was decreased at another metastable locus, the CDK5 activator-binding protein (Cabp IAP)(7) .

This previous work with BPA as a thyroid endocrine distruptor may offer significant insight into the origins of medullary thyroid carcinoma (MTC) when viewed in light of a recent accidental discovery in Texas..


According to a study published Oct 14 in Cancer Cell(8) research at The University of Texas Southwestern's Department of Psychiatry were investigating the origins of dementia and created a transgenic mouse that over-expressed the Cdk5 protein they felt could be connected with myloid plaques.

The study, run by Dr. James Bibb, Associate Professor of Psychiatry and Neurology and Neurotherapeutics, quickly found that the mice had all developed medullary thyroid carcinoma.

Monday, October 14, 2013

Does Fungicide Treatment on Grape Vines Lead to Thyroid Cancer in Humans?

One major concern regarding the use of fungicides in grape growing and other agricultural areas is the environmental and human health impacts of the use of synthetic fungicides.  Studies have found significant health impacts related to the use of conazole fungicides, including thyroid tumors and other cancers.  It is thought that these fungicides are related to higher incidences of cancerous tumors as a result of their endocrine disruption properties.  In fact, endocrine disrupting compounds have been demonstrated in many studies to cause significant health problems in both wildlife and humans, including but not limited to reproductive health issues, neurological problems, and cancer.

Are synthetic fungicides harmful for wildlife or human health based on their endocrine-disrupting properties?

If these fungicides are harmful, who is at risk?  The workers in the vineyard?  Or perhaps the people drinking the wine made from fungicide-treated grapes?

The Academic Wino highlights a recent study on this topic, and answers some of these questions and more.  Please follow this link to read more on this fascinating study.

Wednesday, October 9, 2013

Eastman Ekes Out Equivocal Lawsuit Win, Judge Says Verdict Not Necessarily Based On Trial Evidence

Eastman Chemical company has been denied all damage claims against two small start-up companies it accused of a laundry list of violations including deceptive advertising. Eastman did win a symbolic victory from a Texas jury, but the presiding judge expressed his views that the jury verdict was not necessarily based on the evidence presented and that he could easily have returned a different verdict.

When George Bittner (University of Texas neurobiology professor) decided to go into the business of testing and marketing "safe" plastics there was no indication that he'd wind up dodging a million-dollar, howitzer-sized bullet lobbed at him by a $9 billion chemical company who didn't like being his target.

And Eastman Chemicals, who sued Bittner's companies -- CertiChem and PlastiPure -- probably didn't think it would have to eat almost $4 million in legal fees to gain a mostly phyrric victory for what they claimed was Bittner's bad science and over-the-top marketing.

But life's full of surprises and that's what they both got at the hands of a Texas jury of average citizens who were asked to try and make sense out of rules, lab tests and science that even the best of scientists cannot agree upon.

Indeed, while Eastman Chemical touts its court victory as proof that its star plastic -- Tritan -- is safe, the verdict was so equivocal that the federal trial judge stated on the record that given his choice, he might well have found against Eastman, and that the jury verdict was not necessarily supported by the evidence presented at the trial:

"The jury ultimately sided with Eastman, but was by no means required to do so based on the record at trial ...."

The battle shaped up as on between two market competitors: Eastman Chemical, New York Stock Exchange company with $9 billion in revenues, versus a couple of small-sister company start-ups.

When the battles heated up in 2008 over concerns and bans over BPA (Plastic-bottle scare is a boon for some) Eastman began promoting its Tritan product as the "safe" alternative. This, despite mounting evidence, that BPA is one of hundreds of endocrine disruptors -- most of which have not been tested.

Eastman did not like having the tables turned on it by Bittner and his upstart companies who conducted a National Institutes of Health-funded study indicating that Eastman's Tritan plastic was one of several in a study done by Bittner and coauthors they said leached a class of endocrine disruptors (EDCs) that -- like BPA -- exhibit estrogenic activity (Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved).

Thus began a legal battle -- not over the paper itself -- but over what Eastman termed "false advertising" claims made in CertiChem and PlastiPure promotional material.

After a long, bitter, tangled trial filled with secret testimony and sealed documents, a federal jury in Texas District Court held the opinion that CertiChem and PlastiPure went over the promotional line when -- according to Eastman's court filings -- Bittner's companies used their study data in an attempt to sell their plastics and testing services.

Sam Sparks, the gruff, no-nonsense District Court trial judge on the other hand, seemed skeptical of the jury's decision and denied Eastman's request for $3,458,859.40  million in lawyer's billings and $318,745.73 in expenses.

Monday, October 7, 2013

Could Resveratrol in Red Wine Give Us a Clue Into the Mechanism of Action Behind Endocrine Disruptors?

The compound most commonly studied in terms of examining the health benefits of red wine is resveratrol.  Structurally, resveratrol is very similar to estrogen diethylstilbestrol (DES), a synthetic estrogen that is notorious for being given to pregnant women from the 1940s to the 1970s resulting in significant birth defects, with many of the children continuing to have significant health problems throughout the remainder of their lives.  Like DES, resveratrol has been shown to interact with estrogen receptors (ER), though more so with ERα than ERβ.  Unlike DES, resveratrol and its derivatives seem to have a positive effect on health, whereas DES has quite the opposite effect.

Studies have shown that the health benefits of resveratrol and its derivative may be a result of their interactions with estrogen receptors, however, what is unclear is exactly which form or forms of the metabolized compound is most important, or even the relative importance of all of the metabolites together.  A recent study by a group of collaborating scientists from the University of Parma, the University of Glasgow, and the University of Milan examined the interactions of resveratrol and its derivatives in the presence of human estrogen receptors; in hopes to gain further understanding of how exactly resveratrol in its various forms interacts on a chemical level in humans.

"If resveratrol is so structurally similar to DES, a harmful synthetic endocrine disruptor that is linked to a plethora of birth defects and health problems, how could it have such an opposite effect?”

"Could learning about the estrogenic activity of resveratrol help us understand the mechanisms of these more harmful synthetic endocrine disruptors?  Additionally, could understanding the estrogen activity and mechanisms of resveratrol help us develop a sort of “antidote” to harmful endocrine disruptors?" 

Read more on The Academic Wino here....

Saturday, October 5, 2013

Are Your Receipts Trying to Kill You?

We’ve mentioned several times already on this blog about bisphenol A (BPA) and how this endocrine disrupting chemical is present in all sorts of plastics from water bottles, baby bottles, and dental sealants.  What may not be inherently obvious is where else BPA can be found in everyday products.  One example is with thermal printing paper:  were you aware that thermal printing paper contains BPA and once touched could possibly transfer onto your fingers?

Who Uses Thermal Paper?

Thermal paper is found in many places, though most commonly it is found in the receipt paper at a store, or the paper used in certain recorders in various laboratories.  Could employees working the cash register or even the customer handling the receipt to file away in their records be exposed to BPA through the thermal paper?  Could researchers working with recorders be exposed to BPA when handling the paper to analyze their results?

What exactly IS thermal paper?

I already mentioned that thermal paper is the paper that’s used often in cash registers as well as recorders in the laboratory.  Breaking it down even further, imagine a piece of thermal cash register paper.  On the side to be printed, there is a layer of printing ink covering the entire surface.  The color used to print contains a leuco dye, which is a chemical that can exist in two forms: a colored form and a colorless form.  When it comes time to print, the thermal head of the printer causes the leuco dye and other chemicals on the surface to melt and react with one another, which results in the dye taking on its dark colored form.  These chemicals, in combination with the heating and melting process, result in chemical products including the endocrine disruptor, BPA.

Could the BPA on the thermal paper transfer to our skin?

This is certainly an interesting question, and one that has not been studied too often.  Those few studies in animals examining absorption of BPA by the skin found that BPA can be absorbed by the udders of cows, as well as through pig skin.  What about humans?  Is handling this thermal paper on our receipts a cause for concern?  Can the BPA on this paper be absorbed through our skin as it has been shown to occur in cows and pigs?

Preliminary Findings

Friday, October 4, 2013

Endocrine Disruptors and Behavior: BPA Exposure in utero Disrupts Sexual Differentiation and Associated Behaviors in Rats

You all have the image of someone you know or you’ve seen on TV in the past when you hear the term “a man’s man”.  Big, tough, pillars of masculinity wound tightly around a body of bulging muscles and brawn.  How, or better yet, when does this masculinization actually occur?  Is it something that is learned?  Or is there a chemical game of football that goes on in the body that seals the deal?  It’s probably a little of both, but without certain chemical processes happening at particular stages of development, the line in the sand between male and female behavior gets a little blurred.

In rats, testicular androgen is believed to be in charge of masculinization and feminization, which occurs sometime between days 18 and 27 after conception and involves the conversion of androgen to estrogen by the enzyme brain aromatase.  Timing of this conversion process, as well as other chemical dances involved, is critical to establish sexual differentiated behavior.  In other words, the timing of certain sex-related hormone conversion is very important in establishing “typical male behaviors” and “typical female behaviors”, respectively.

Blurred Lines

As you can imagine, something that needs to occur in such a specific time frame can be very sensitive to bumps in the road.  What happens if this process of androgen-estrogen conversion does not occur at the proper time or does not occur in the proper amounts?  When this happens, you get a sort of fuzzy distinction between male and female behaviors, with the de-masculinization of males or de-feminization of females.  Since this process is completed by hormonal balances, anything that can disrupt this balance can potentially interfere with the distinction in behaviors between the male and females sexes.

Endocrine disruptors, for example Bisphenol A (BPA), a commonly used chemical in plastic coating of food cans, baby bottles, lining of trash cans, and dental sealants, act in similar manners and interact with the same receptors of which androgens, estrogens, and other hormones also interact and function.  That being said, could these endocrine disrupting chemicals cause problems with sexual differentiation and sex-related behaviors in those living things that are exposed to them?

Endocrine Disruptors and Behavior

Nearly all studies to date related to endocrine disruptors effects on sexual behavior has been done in rodents, or at least species other than humans.  However, since studies in rodents can often be comparable to those in humans, it is certainly a good starting point for asking more specific questions humans.  In rats, BPA exposure has been linked to increased anxiety levels, changes in “typical” behaviors for the individual sexes, as well as changes in spatial learning.  In a few studies, when pregnant rats were given BPA during their pregnancy and also during the lactation period after pregnancy, changes in some sex-specific behaviors were observed at doses as low as 1ppm.

One of the few studies with humans focused on diethylstilbestrol (DES), a synthetic estrogen-like compound that at one time (between the 1940s and 1970s) had been given to women with the thought that it would protect them against problems in pregnancy.  In fact, DES had quite the opposite effect, causing major complications and birth defects in those children born from women who were given the drug.  In regards to behavior, one study found that children of those women given DES during pregnancy had increased rates of various psychiatric complications or diseases, including depression and anxiety.

Thursday, October 3, 2013

BPA and In Vitro Fertilization: Making Things Hard For People Already Struggling to Conceive

There is a whole host of research out there examining the effects of Bisphenol A (BPA) on reproduction both in vitro (a.k.a. in the lab) and in vivo in various species of animal.  Though one can often translates the effects of in vitro studies and in vivo studies on animals to how things might happen in humans, however, this is not always the case.  Therefore, there is a need to provide evidence in the human body prior to making sweeping judgments on the results based on effects seen in other animals or in the test tube.

In the mouse model, studies have shown that exposure to BPA at doses known to be present in the environment increases oocyte aneuploidy, which may result in miscarriage or severe birth defects.  Further studies elaborate on the mechanism behind this error in chromosome distribution in egg cells showing that BPA contributes to increased aneuploidy by disrupting meiotic spindle formation, as well as centrosome behavior and chromosome alignment and subsequent division.  Adding to the list of negative reproductive effects in animal models, BPA has been shown to inhibit the production of the natural hormone, estradiol, as well as negatively impacting fertility in general.

What about human studies?

Preliminary studies looking at the effects of BPA in humans, specifically in the area of in vitro fertilization (IVF), have shown that there may be significant negative relationships between BPA levels in urine and decreases estradiol and numbers of eggs retrieved at the finale of the IVF retrieval process.  There have been very few studies directly examining the effects of BPA on women undergoing the IVF process, in particular the associations between BPA and early reproductive outcomes, oocyte quality, and early embryonic growth (i.e. cleavage) rates.

Just last year, a group at Massachusetts General Hospital in Boston, MA,  a teaching hospital affiliated with Harvard University, set out to determine how BPA influenced the IVF process, in particular effects on the quality of the egg and developing embryo, as well as fertilization rates and cleavage rate of the developing blastocyst. 

Battle of the Sexes: Men Found to Have Higher Levels of BPA in Their Blood Than Women

There are many studies examining the levels of Bisphenol A (BPA) and other endocrine disruptors present in the environment, and a large number of studies investigating the mechanisms or pathways these chemicals may take to wreak havoc on living things. 

BPA and several other endocrine disruptors have been linked to a whole host of health problems, including but not limited to cancer, low testosterone and low sperm motility, miscarriages, and birth defects.

How much do I really have in my body?

Sure, that’s all fine and dandy if you can tell me just how a certain amount of BPA can affect my health, but really, is BPA even present in these amounts in my body?  Or are the amounts required to elicit these hazardous consequences much too large to have any meaning biologically?

In 2002, a team of researchers in Japan set out to answer a few simple, yet highly important questions: 1) How much BPA is present in human blood; 2) Are there any differences in BPA levels between men and women?; and 3) What are the relationships between BPA and sex hormones present in our bodies?

Guinea Pigs

Well, not ACTUAL guinea pigs, but real human beings…a group of 14 healthy women, a group of 16 women with diagnosed polycystic ovary syndrome (PCOS), and a group of 11 healthy men were recruited to give blood serum samples for this study. 

What they found…

What this team of researchers found was that serum BPA levels were significantly higher in healthy men than in healthy women.  Serum BPA levels in these healthy men were 1.49 +/- 0.11 ng/mL, while serum BPA levels in healthy women were 0.64 +/- 0.10 ng/mL (CONVERT TO PPM…..).  Also, they found that serum BPA levels significantly correlated with both free testosterone levels and total testosterone levels.  Interestingly, serum BPA levels were not significantly correlated with any other sex-related hormone, including luteinizing hormone, follicle stimulating hormone, prolactin, and estradiol.  Finally, these levels found in both men and women were HIGHER than the levels reported to cause problems

Why do the men have it all?

Why did the men in this study have a significantly higher level of the chemical in their blood than women?  Well, this study didn’t explicitly study the “why” side of things; however, a few possibilities come to mind.

Wednesday, October 2, 2013

Does BPA Exposure Cause Miscarriages?

BPA, along with many other man-made chemicals, has become quite prevalent in our environment, and have been shown to possess estrogen-like characteristics which have led to significant health problems for humans and wildlife alike.  BPA, along with other similar endocrine disruptors, can be found in many different products, including the plastic in your water bottle, to the thermal paper for your printer, and even in your dental sealants.  As you can imagine, something so potentially damaging and yet so prevalent in our environment is great cause for concern.

BPA can interrupt or otherwise harm many different hormone-dependent systems in the human body, one of which is the reproductive system.  Other endocrine disruptors, such as dioxin and DDT, have been implicated as linked to some cancers, endometriosis, small birth weights, and pre-term births.  Since these are endocrine disruptors that are known to cause problems in the reproductive system, the next question becomes whether or not these man-made chemicals are somehow associated with miscarriage early on in pregnancy. 

How common are miscarriages?

Somewhere between 10 and 25% of all pregnancies will likely result in spontaneous abortions, i.e. miscarriages.  Between 40 and 70% of these miscarriages are associated with chromosome abnormalities, in particular aneuploidy (having too few or too many chromosomes).
Previous studies have shown that BPA exposure during oogenesis or spermatogenesis results in increased incidences of aneuploidy, so naturally, the most obvious question would be: is BPA associated with miscarriages? 

BPA à Aneuploidy; Aneuploidy à Miscarriage; BPA --?--> Miscarriage?

BPA has been found to be present in the urine of at least 90% of Americans.  In Japan, about 350,000 tons of BPA per year is produced for various plastic-based products.  Thus, as in the US, BPA is very common in Japan as well as other parts of the world, and where a group of researchers set out to determine if BPA is at any way associated with miscarriages in the population.

45 women with a history of 3 to 11 miscarriages were examined during this study, with 32 healthy non-pregnant and no history of infertility or miscarriage used as controls.  Serum BPA levels were measured for all women in the study, in addition to several antibodies, immune response cells, progesterone, and prolactin.

What did they find?

Results of the study found that BPA is highly associated with the history of miscarriage in Japanese women, particularly with those women that were ANA-positive (a.k.a. they have antinuclear antibodies present in their blood, which may or may not be a red flag for an immune response and has also been linked to recurrent miscarriages). 

While this was not a study to get at the question of HOW BPA can cause miscarriage, however it does provide evidence that BPA exposure is associated with recurrent miscarriage and deserves further research.

Why are these pregnancies aborted?  Does BPA increase aneuploidy in eggs or sperm?  Does BPA interfere with early embryonic development in another manner?  More research will certainly give us the answer, and as luck would have it, that research has been done!  Stay tuned….

Source: Sugiura-Ogasawara, M., Ozaki, Y., Sonta, S., Makino, T., and Suzumori, K. 2005. Exposure to bisphenol A is associated with recurrentmiscarriageHuman Reproduction 20(8):2325-2329.

Tuesday, August 27, 2013

Evaluating Nanoparticle Breakthrough during Drinking Water Treatment

Use of engineered nanoparticles (NPs) in consumer products is resulting in NPs entering drinking water sources. Subsequent NP breakthrough into treated drinking water is a potential exposure route and human health threat.


This study investigated the breakthrough of common NPs, silver, titanium dioxide (TiO2), and zinc oxide (ZnO), into finished drinking water following conventional and advanced treatment.


NPs were spiked into five experimental waters: groundwater, surface water, synthetic freshwater, synthetic freshwater with natural organic matter, and tertiary wastewater effluent. Bench scale coagulation/flocculation/sedimentation simulated conventional treatment, and microfiltration (MF) and ultrafiltration (UF) simulated advanced treatment.

Breakthrough of NPs into treated water was monitored by turbidity removal and inductively coupled plasma – mass spectrometry (ICP-MS).


Conventional treatment resulted in 2-20%, 3-8%, and 48-99% of silver, TiO2, and ZnO NPs or their dissolved ions remaining in finished water, respectively. Breakthrough following MF was 1-45% for silver, 0-44% for TiO2, and 36-83% for ZnO. With UF, NP breakthrough was 0-2%, 0-4%, and 2-96% for silver, TiO2, and ZnO, respectively. Variability was dependent on NP stability with less breakthrough of aggregated NPs compared to stable NPs and dissolved NP ions.


Although a majority of aggregated or stable NPs were removed by simulated conventional and advanced treatment, NP metals were detectable in finished water. As environmental NP concentrations increase, we need to consider NPs as emerging drinking water contaminants, and determine appropriate drinking water treatment processes to fully remove NPs in an effort to reduce their potential harmful health outcomes.


Monday, August 19, 2013

New study: Many flame retardants in house dust -- unsafe levels | Science Codex

From Science Codex, Nov. 28, 2012

"A peer-reviewed study of the largest number of flame retardants ever tested in homes found that most houses had levels of at least one flame retardant that exceeded a federal health guideline. The journal Environmental Science & Technology will publish the study online on November 28, 12:01am Eastern. 

"The study led by scientists at Silent Spring Institute tested for 49 flame retardant chemicals in household dust, the main route of exposure for people and especially for children. Forty-four flame retardant chemicals were detected and 36 were found in at least 50% of the samples, sometimes at levels of health concern. The flame retardants found in house dust are in furniture, textiles, electronics, and other products and include hormone disruptors, carcinogens, and chemicals with unknown safety profiles. 

"The highest concentrations were found for chlorinated organophosphate flame retardants. This chemical group includes TCEP and TDCIPP (or chlorinated "Tris"), which are listed as carcinogens under California's Proposition 65. 

"TDBPP (or brominated "Tris") was banned from children's pajamas in 1977 due to health concerns but is still allowed in other products, and was present in 75% of homes tested in 2011.
There are no federal rules requiring that flame retardants be safety tested. Among the limited number of flame retardants with EPA health risk guidelines, the study found five at levels higher than those guidelines -- BDE 47, BDE 99, TCEP, TDCIPP and BB 153

Read the rest in Science Codex

Office workers carry biomarker of potentially harmful flame retardant, study finds | Science Codex

From Science Codex, March 25, 2013

"A flame retardant removed from children's pajamas 30 years ago but now used in polyurethane foam is prevalent in office environments, especially in older buildings, where urine testing of workers turned up widespread evidence of its biomarker, a new study led by Boston University School of Public Health researchers has found.
"The study, published in the journal Environment International, found that the chemical known as TDCPP -- chlorinated tris(1,3-dichloro-2-propyl) phosphate, or 'chlorinated tris' -- was present in 99 percent of dust samples taken from participants' homes, vehicles and offices, "demonstrating the widespread presence of this flame retardant in the indoor environment." The research team recruited 31 adults who worked and lived in the Boston area for the testing.

"The study found that the office environment was the strongest predictor of metabolized TDCPP in urine, with significantly lower concentrations of the chemical among workers in a new office building than in older buildings. Similarly, the average concentration of TDCPP in dust was significantly lower in the new office building than in the older office buildings."

Read the rest in Science Codex

Study finds increasing atmospheric concentrations of new flame retardants | Science Codex

From Science Codex:

"Compounds used in new flame-retardant products are showing up in the environment at increasing concentrations, according to a recent study by researchers at Indiana University Bloomington.

"The study, published in the journal Environmental Science & Technology, reports on concentrations of two compounds measured in atmospheric samples collected in the Great Lakes region between 2008 and 2010. Authors are doctoral student Yuning Ma, Assistant Research Scientist Marta Venier and Distinguished Professor Ronald A. Hites, all of the IU School of Public and Environmental Affairs.

"The chemicals -- 2-ethylhexyl tetrabromobenzoate, also known as TBB; and bis(2-ethylhexyl) tetrabromophthalate, or TBPH -- are used to reduce flammability in such products as electronic devices, textiles, plastics, coatings and polyurethane foams.

"They are included in commercial mixtures that were introduced in recent years to replace polybrominated diphenylethers (PBDEs), widely used flame retardants that have been or are being removed from the market because of their tendency to leak from products into the environment."

Read the rest in Science Codex.

Study finds flame retardants at high levels in pet dogs

From Science Codex

"Indiana University scientists have found chemical flame retardants in the blood of pet dogs at concentrations five to 10 times higher than in humans, but lower than levels found in a previous study of cats.

"Their study, "Flame Retardants in the Serum of Pet Dogs and in their Food," appeared in April 2011 in the journal Environmental Science & Technology. Authors are Marta Venier, an assistant research scientist in the School of Public and Environmental Affairs, and Ronald Hites, a Distinguished Professor in SPEA.

"Venier and Hites explore whether pets could serve as "biosentinels" for monitoring human exposure to compounds present in the households that they share. Dogs may be better proxies than cats, they say, because a dog's metabolism is better equipped to break down the chemicals. 

"The study focuses on the presence of polybrominated diphenyl ethers (PBDEs) in the blood of dogs and in commercial dog food. PBDEs have been widely used as flame retardants in household furniture and electronics equipment. The compounds can migrate out of the products and enter the environment."

 Read the rest in Science Codex.

Tuesday, August 13, 2013

Common Household Chemical Is Powerful Endocrine Disruptor

A common chemical compound found in a wide range of household products is the prime suspect for widespread liver tumors found in California's marine estuaries by researchers from California Polytechnical State University, San Luis Obispo.

According to a journal paper article published in Chemosphere [87 (2012) 490-97)] the compound is nonylphenol ethoxylate which is banned in Europe, but widely used in the United States as a stabilizer in plastics, a spermicide in contraceptives, a softening agent in toilet paper and a surfactant (wetting agent) in detergents, agricultural sprays and personal care products.

What's more, the wastewater treatment process creates an endocrine disrupting compound (EDC) -- 4-nonynlphenol (4-NP) -- that builds up in the environment and accumulates in the food chain.

4-NP acts as a "xenoestrogen" (xeno- meaning, foreign, not native to an organism) and has been shown to disrupt reproduction and cause liver damage in fish and other marine organisms.

The CalPoly researchers looked at four California estuaries -- Morro Bay, San Francisco Bay, Drake's Bay and Tomales Bay.

They found that  4-NP accumulated in the food chain at every step, from ghost shrimp, mussels and oysters up through fish, seabirds and mammals.

While the NP-4 concentrations were some times as low as 1 nanogram/liter, the bioaccumulation factors at the top of the food chain (mammals) were 1,793 to 8,762 times higher for Sea Lions and Otters.

No inference was drawn for human consumption.

The distribution of 4-nonylphenol in marine organisms of North American Pacific Coast estuaries

  • Jennifer Diehl, Sarah E. Johnson, Kang Xia, Amy West  Lars Tomanek

Monday, August 12, 2013

Non-Monotonic Chemicals: Why They Matter


The lack of predictability is a serious flaw in the current government method which  assumes that the chemical being tested always expresses itself the same way at every concentration. It assumes a greater effect at high concentration, a lesser effect at lower doses. In scientific terms, this predictability is called a monotonic dose response.

But EDCs and many other compounds are not so predictable because they affect different biological structures when present in varying concentrations. This is especially true for natural hormones, endocrine disrupters, many pharmaceuticals and even the ethanol in wine, beer and spirits.

The Vandenberg/Myers study explained that, “For all monotonic responses, the observed effects may be linear or nonlinear, but the slope [of the plotted line or curve] does not change sign. This assumption justifies using high-dose testing as the standard for assessing chemical safety. When it is violated, high-dose testing regimes cannot be used to assess the safety of low doses.”

The study then pointed out that EDCs as a group violate the rule by being non-monotonic.


Many chemical compounds are simply toxic: they damage and kill cells. The higher the concentration, the more toxic and the more cells die – the dose makes the poison.
Regardless of the concentration, these chemicals kill cells the same way. And, at the level of no observed adverse effects, they stop killing, or are tolerated by cells. This is a monotonic dose response.

But non-monotonic chemicals can affect different mechanisms in the body depending on the concentration.

One well-known non-monotonic response is the “U” shaped curve of the “French Paradox” or the activity of pharmaceuticals including aspirin and many hormones.

With these compounds, there is no effect at low concentrations. As concentration levels increase, scientific studies show an increasing beneficial effect. Then, beyond that level, the beneficial effect diminishes and later, high levels can be toxic and damaging.

This odd behavior is non-monotonic because the substances act on different parts of the body at different concentrations. At high levels they are toxic. At lower levels, they act on a variety of microscopic cell receptors and structures that allow them to have a different and beneficial effect.
Indeed, research has shown that at very low levels, EDCs can magnify or suppress the effects of natural hormones in the body or cause their own unique syndromes.

But nothing in nature says non-monotonic behavior always goes from damaging to beneficial as the concentrations go from high to low. Significantly, the effects of EDCs and other low-concentration chemicals are generally unstudied and unknown. However, in those few cases where they are better understood, EDCs have been found to have damaging effects.

Clearly, EDCs are an example of non-monotonic behavior that can go from deadly toxic (poisoning cells) to invisibly deadly (tumors, genetic effects, metabolic disorders and other diseases).

Indeed, as a future article in this series will explore, an increasing number of studies indicate that EDCs may be responsible for part of the current obesity and diabetes epidemics. They may also contribute to the decline of endangered species including salmon, frogs and other “cold-blooded” animals which seem to be more susceptible than mammals to chemical compounds.

Toxic Irrigation: Hazardous Chemicals Found in Recycled Wastewater Used For Vineyards And Other Crops

Recycled wastewater may more hazardous to use for crop and landscape irrigation than previously thought due to flaws in the way danger thresholds are currently determined.

NOTE: This article originally appeared in the June 14, 2010 issue of Wine Industry Insight. 

By Lewis Perdue

According to a major study published in June 2012 in the peer-reviewed scientific journal Endocrine Reviews, the current risk assessment methods to assess the dangers of endocrine disrupting compounds (EDCs) found in treated wastewater are severely flawed.

EDCs – including estrogens from birth control pills, powerful antibiotics, plasticizers like BPA and many other chemicals -- can disrupt or mimic human hormones in unpredictable ways even in the extremely small concentrations that are currently disregarded as inconsequential by government regulators. Many of the EDCs and chemicals find their way into wastewater by being flushed down a toilet or sink.

"Whether low doses of EDCs influence certain human disorders is no longer conjecture, because epidemiological studies show that environmental exposures to EDCs are associated with human diseases and disabilities," concluded the study.


The massive scientific paper cited 845 other studies and was created by a team of twelve scientists led by Laura N. Vandenberg of the Tufts University Center for Regenerative and Developmental Biology, Medford, MA and by J. P. Myers of Environmental Health Sciences, Charlottesville, VA.
Other institutions represented by investigators of the study included:
  • The University of California,
  • Massachusetts General Hospital,
  • National Institutes of Environmental Health Sciences,
  • National Institutes of Health,
  •  Department of Health and Human Services,
  • University of Minnesota School of Public Health
Their work was supported by the National Institutes of Health and also by grants from a number of foundations including the Susan G. Komen Foundation, the Mitchell Kapor Foundation, Cornell-Douglas Foundation, the Wallace Global Fund and the Kendeda Foundation.
More information about the investigators and their connections can be found at the end of this article.


While the Vandenberg/Myers study did not deal specifically with irrigation, it focused on many of the same chemical compounds found in the same concentrations as in treated wastewater used for irrigation.

For that reason, the study’s conclusions hold serious consequences for industrial and recreational landscape irrigation as well as the thousands of acres of premium California vineyards currently irrigated with highly treated wastewater.

Significantly for winegrape growers and ordinary citizens, every recent Environmental Impact Report (EIR) on treated wastewater irrigation conducted in Napa and Sonoma Counties acknowledges the presence of EDCs.

Those EIRs conclude, as did the North Sonoma County Agricultural Reuse Project EIR:  “it is not currently possible, using existing standards and/or regulatory agency risk assessment methodology, to evaluate the endocrine effects of these chemicals, if any, at the low concentrations reported.”

Carnegie Mellon chemicals may break down water contaminants safely

From Science Codex

"PITTSBURGH—A family of molecules developed at Carnegie Mellon University to break down pollutants in water is one step closer to commercial use. Study results published online in the journal Green Chemistry show that the molecules, which are aimed at removing hazardous endocrine disruptors from water sources, aren't endocrine disruptors themselves as they proved to be non-toxic to developing zebrafish embryos.

 "Created by Carnegie Mellon green chemist Terry Collins, the molecules, called TAML activators, provide an environmentally friendly method for breaking down toxic compounds that contaminate water, including endocrine disruptors. Endocrine disrupters, which are found in almost 25 percent of our streams, rivers and lakes, can disrupt the normal functions of the endocrine system by mimicking or blocking the activities of hormones in wildlife leading to impaired development.

"While the connections between the adverse effects of endocrine disrupting water contaminants on aquatic organisms and human health have yet to be established, animal studies suggest that endocrine disruptors may be involved in a host of modern-day health epidemics including cancers, learning disabilities, obesity, and immune and reproductive system disorders."

Read the rest of the article in Science Codex

BPA In Your Body

BPA has been a frequent topic in the news in recent years, because it’s an endocrine-disrupting chemical -- a compound that can imitate or disrupt the natural chemical regulators in your body such as those that control insulin and sex hormones. Disrupting hormones will affect your health.

By Becca Yeamans

Bisphenol A (BPA) is a chemical used in the production process of many plastic water bottles,  food containers, as well as liners of food cans and the coating on thermal paper cash register tape. 

BPA has been a frequent topic in the news in recent years, as it was discovered not too long ago that it’s an endocrine-disrupting chemical, which can wreak havoc on the environment and cause many public health problems.


It was originally thought that BPA was a relatively weak estrogenic compound, though studies have recently suggested that BPA is just as strong an estrogenic compound than natural hormones like estradiol. 

 In other words, what was thought of as being relatively benign, BPA can actually cause significant problems at the levels currently present in the environment.


 Often times, humans are exposed to BPA by consuming food or beverages out of plastic containers that have been treated with the compound.   The levels of BPA ingested are particularly high when the plastic container has been heated in one way or another (i.e. by a microwave). 


A significant number of people can be exposed to BPA through the water supply.  At some point during the water treatment process, the water travels through PVC piping, the plastic of which is treated with BPA.   In fact, many homes have water pipes plumbed with PVC -- identifiable by its white plastic nature.

As water travels through these pipes laden with BPA, it picks up the chemical and carries it to homes and businesses.  In human, ingesting BPA has been associated with the development of diabetes, asthma, ovarian dysfunction, and obesity, and only in July of 2012 was this substance banned from baby bottles and drinking containers.


While research indicates that BPA can have serious effects once it's inside the human body, it actually doesn’t live for long in the environment. 

Once it hits the environment, it’s quickly broken down by microorganisms, resulting in a half-life of only 2.5 to 4 days.


If BPA has such a short half-life, then how can it still exist in the environment and cause problems?

 In essence, while a single molecule of BPA is broken down relatively quickly, the fact remains that since BPA is present in so many man-made products and in the pipes carrying our drinking water, new molecules of BPA are continually added to the system. 

While BPA is present in the environment, it’s not known whether derivatives of this chemical have the same negative consequences as the original chemical, or if reactions with other chemicals in the environment somehow either inactivate or further worsen these effects.