Why are “endocrine disruptors” a concern?

6 03 2015

 

In 2012, Greenpeace analyzed a total of 141 items of clothing, and found high levels of phthalates in four of the garments and NPE’s in 89 garments – in quantities as high as 1,000 ppm – as well as a variety of other toxic chemicals. Phthalates and NPE’s are among the chemicals known as “endocrine disruptors” (EDCs) – chemicals which are used often and in vast quantities in textile processing.

The endocrine system is the exquisitely balanced system of glands and hormones that regulates such vital functions as body growth (including the development of the brain and nervous system), response to stress, sexual development and behavior, production and utilization of insulin, rate of metabolism, intelligence and behavior, and the ability to reproduce. Hormones are chemicals such as insulin, thyroxin, estrogen, and testosterone that interact with specific target cells.  The endocrine system uses these chemicals to send messages to the cells – similar to the nervous system sending electrical messages to control and coordinate the body.

Diabetes, a condition in which the body does not properly process glucose, is an endocrine disease, as is hypoglycemia and thyroid cancer. According to the Centers for Disease Control (CDC), 29.1 million people have diabetes.[1] The three types of diabetes are a good illustration of the two main ways that something can “go wrong” with hormonal control in our bodies. In type I diabetes, his/her pancreas is unable to make insulin. Without insulin, the liver never “gets the message” to take glucose out of the bloodstream, so blood glucose remains too high, while the stores of glucagon in the liver are too low. In type II diabetes, the person’s pancreas is making enough insulin, but the insulin receptor sites on the liver cells are “broken” (possibly due to genetic factors, possibly do to “overuse”) and cannot “get the message.” Because the liver is unable to receive the instructions (despite the presence of lots of insulin), it does not take glucose out of the bloodstream, so blood glucose remains too high, while the stores of glucagon in the liver are too low. In type III diabetes (AKA Alzheimer’s Disease)[2], it is the neurons in the brain, specifically, which “don’t get the message,” (though it sounds like researchers have yet to determine whether that’s due to lack of the brain-produced insulin upon which they depend, or whether that’s due to receptors on the neurons that either are or become “broken”) and thus, cannot take in the sugar that they need, with the result that, without an alternative fuel source such as medium-chain triglycerides, the neurons will starve.

endocrine disruptor

Over the past 60 years, a growing number of EDC chemicals have been used in the production of almost everything we purchase. They have become a part of our indoor environment, found in cosmetics, cleaning compounds, baby and children’s toys, food storage containers, furniture and carpets, computers, phones, and appliances. We encounter them as plastics and resins every day in our cars, trucks, planes, trains, sporting goods, outdoor equipment, medical equipment, dental sealants, and pharmaceuticals. Without fire retardants we would not be using our computers or lighting our homes. Instead of steel and wood, plastics and resins are now being used to build homes and offices, schools, etc. A large portion of pesticides are endocrine disruptors.

What this constant everyday low-dose exposure means in terms of public health is just beginning to be explored by the academic community. We have learned over time that many chemical substances can cause a range of adverse health problems, including death, cancer, birth defects, and delays in development of cognitive functions. For instance, it is well established that asbestos can cause a fatal form of lung cancer, thalidomide can cause limb deformities, and breathing high concentrations of some industrial solvents can cause irreversible brain damage and death. Only relatively recently have we learned that a large number of chemicals can penetrate the womb and alter the construction and programming of a child before it is born. Through trans-generational exposure, endocrine disruptors cause adverse developmental and reproductive disorders at extremely low amounts in the womb, and often within the range of human exposure.

Recent research is giving us a new understanding of EDCs since Dr. Theo Coburn wrote Our Stolen Future.  Thanks to a computer-assisted technique called microarray profiling, scientists can examine the effects of toxins on thousands of genes at once (before they could study 100 at a time at most). They can also search for signs of chemical subversion at the molecular level, in genes and proteins. This capability means that we are beginning to understand how even small doses of certain chemicals may switch genes on and off in harmful ways during the most sensitive period of development. In a recent talk at the National Academy of Sciences, Linda Birnbaum, the head of the National Institute of Environmental Health Sciences (NIEHS) and the National Toxicology Program, called toxicogenomics—the study of how genes respond to toxins—the “breakthrough” that pushed the study of poisons beyond the “obvious things,” that is, the huge doses that led to “death or low birth weight.”

  1. Age at time of exposure is critical. There is even a new terminology to explain the consequences of exposure to EDCs: “the fetal basis of adult disease”, which means that the maternal and external environment, coupled with an individual’s genes, determine the propensity of that individual to develop disease or dysfunction later in life.  This theory, known as the “developmental origins of health and disease,” or DOHad, has blossomed into an emerging new field. DOHad paints a picture of almost unimaginably impressionable bodies, responsive to biologically active chemicals until the third generation.
  2. The developmental basis of adult disease also has implicit in its name the concept that there is a lag between the time of exposure and the manifestation of a disorder. In other words, the consequences of exposure may not be apparent early in life.
  3. Exposures don’t happen alone – other pollutants are often involved, which may have additive or synergistic effects.[3]
  4. Even infinitesimally low levels of exposure – or any level of exposure at all – may cause endocrine or reproductive abnormalities, particularly if exposure occurs during a critical developmental window[4]. Surprisingly, low doses may even exert more potent effects than higher doses.

    Carol Kwiatkowski, director of TEDX

    Carol Kwiatkowski, director of TEDX

  5. EDCs may affect not only the exposed individual but also the children and subsequent generations.[5]

TEDX (The Endocrine Disruption Exchange, Inc.) is the only organization that focuses primarily on the human health and environmental problems caused by low-dose and/or ambient exposure to endocrine disrupting chemicals.

TEDX’s work is prevention driven, and it is the only environmental organization that focuses on the problems associated with endocrine disruption attributable to synthetic chemicals found in the general environment. While there are other national, international, and local organizations that address the public health and environmental consequences of toxic chemicals in the environment, none of them expressly emphasize endocrine disruption. By mainly focusing on substances in the environment that interfere with development and function throughout all life stages, TEDX has one of the most complete databases in the world on this topic, available for those concerned about public health and environmental quality. This database was developed because traditional toxicological protocols have used high doses on fully developed tissues and individuals that heretofore missed the consequences of chemical substances on developing tissues.

TEDX is unique because it focuses on the damaging activity of chemicals on biological systems from an entirely new approach. This new approach focuses on the effects of very low and ambient levels of exposure on developing tissue and resulting function before an individual is born, which can lead to irreversible, chronic disorders expressed at any time throughout the individual’s life.

Endocrine disruption takes into consideration the vulnerability of every individual in the population during their most vulnerable life stages. By providing this unique perspective on the actions of endocrine disruptors, TEDX fills in the very large gap in public health protection that traditional toxicology and government regulatory agencies do not fill. Drawing upon its computerized databases on endocrine disruption and coordination with researchers in the field of endocrine disruption, TEDX provides the very latest summaries of the state of knowledge and its meaning for human health and the environment.

 As the TEDX website states:   “The human health consequences of endocrine disruption are dire. Yet, no chemical has been regulated in the U.S. to date because of its endocrine disrupting effects – and no chemical in use has been thoroughly tested for its endocrine disrupting effects.. The U.S. government has failed to respond to the evolving science of endocrine disruption. While much remains to be learned in regard to the nature and extent of the impact of endocrine disruptors on human health, enough is known now to assume a precautionary approach should be taken. TEDX provides concerned persons and organizations with a science-based foundation for individuals to act and promote responsive public policy-making. Moreover, as federal government resources devoted to research on endocrine disruption have diminished due to budget cuts, TEDX must assume an even more prominent role in developing and disseminating information on the human and environmental impacts of endocrine disruption.”

To date, no chemical in use has been thoroughly tested for its endocrine disrupting effects. Traditional toxicological testing protocols were not designed to test for endocrine disruption and to test at ambient or low exposure levels.

 

 

[1] http://www.cdc.gov/diabetes/pubs/statsreport14/national-diabetes-report-web.pdf

[2] De la Monte, Suzanne, and Wands, Jack R., “Alzheimer’s Disease is Tyupe 3 Diabetes – Evidence Reviewed”, J. Diabetes Sci Technol 2008 Nov; 2(6): 1101-1113

[3] Crews D, Putz O, Thomas P, Hayes T, Howdeshell K 2003 Animal models for the study of the effects of mixtures, low doses, and the embryonic environment on the action of endocrine disrupting chemicals. Pure and Applied Chem- istry, SCOPE/IUPAC Project Implications of Endocrine Ac- tive Substances for Humans and Wildlife 75:2305–2320

[4] Sheehan DM, Willingham EJ, Bergeron JM, Osborn CT, Crews D 1999 No threshold dose for estradiol-induced sex reversal of turtle embryos: how little is too much? Environ Health Perspect 107:155–159

[5] Anway MD, Skinner MK 2006 Epigenetic transgenera- tional actions of endocrine disruptors. Endocrinology 147: S43–S49

 

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Phthalate concerns for pregnant women

29 01 2015

Three pregnant women

As if we needed something else to worry about, a peer-reviewed study from the Mailman School of Public Health at Columbia University, published in December 2014, found evidence that chemicals called phthalates can impact the children of pregnant women who were exposed to those chemicals. Children of moms who had the highest levels of phthalates during pregnancy had markedly lower IQs at age 7. [1] Phthalates had previously been linked to effects ranging from behavioral disorders and cancers to deformations of the sex organs.

Why are we talking about this in a blog about fabrics?

Because phthalates are in the fabrics we use.  Generally, phthalates are used to make plastic soft: they are the most commonly used plasticizers in the world and are pretty much ubiquitous. They’re found in perfume, hair spray, deodorant, almost anything fragranced (from shampoo to air fresheners to laundry detergent), nail polish, insect repellent, carpeting, vinyl flooring, the coating on wires and cables, shower curtains, raincoats, plastic toys, and your car’s steering wheel, dashboard, and gearshift. (When you smell “new car,” you’re smelling phthalates.) Medical devices are full of phthalates — they make IV drip bags and tubes soft, but unfortunately, DEHP is being pumped directly into the bloodstream of ailing patients. Most plastic sex toys are softened with phthalates.

Phthalates are found in our food and water, too. They are in dairy products, possibly from the plastic tubing used to milk cows. They are in meats (some phthalates are attracted to fat, so meats and cheeses have high levels, although it’s not entirely clear how they are getting in to begin with). You’ll find phthalates in tap water that’s been tainted by industrial waste, and in the pesticides sprayed on conventional fruits and vegetables.

And fabrics. People just don’t think to even mention fabrics, which we continue to identify as the elephant in the room. Greenpeace did a study of fabrics produced by the Walt Disney Company in 2004 and found phthalates in all samples tested, at up to 20% by weight of the fabric.[2] Phthalates are one of the main components of plastisol screen printing inks used on fabrics. These plasticizers are not chemically bound to the PVC, so they can leach out. They’re also used in the production of synthetic fibers, as a finish for synthetic fibers to prevent static cling and as an intermediary in the production of dyes.

Phthalates are what is termed an “endocrine disruptor” – which means they interfere with the action of hormones. Hormones do a lot more than just make the sexual organs develop. During the development of a fetus, they fire on and off at certain times to affect the brain and other organs.

“The developing brain relies on hormones,” Dr. Factor-Litvak, the lead scientist of the study, said. Thyroid hormones affect the development of neurons, for example. There might be a window of vulnerability during pregnancy when certain key portions of the brain are forming, she said, and kids whose moms take in a lot of the chemicals during those times might be at risk of having the process disrupted somehow.

“These findings further suggest a potential role for phthalates on neurodevelopment,” said Dr. Maida P. Galvez, who did not work on the study but has a specialty in environmental pediatrics. The associate professor is in the Department of Preventive Medicine and Pediatrics at the Icahn School of Medicine at Mount Sinai. “While this requires replication in other study populations for confirmation, it underscores the fact that chemicals used in everyday products need to be rigorously evaluated for their full potential of human health impacts before they are made widely available in the marketplace.”[3]

In the United States, the new Consumer Product Safety Improvement Act of 2008 (CPSIA) banned certain phthalates from use in toys or certain products marketed to children. In order to comply with this law, a product must not contain more than 0.1% of any of six banned phthalates. But just these six – the class of phthalates includes more than 25 different chemicals.

Gwynne Lyons, policy director of the campaign group, CHEM Trust, said: “The number of studies showing that these substances can cause harm is growing, but efforts by Denmark to try and get EU action on some phthalates had run into difficulties, largely because of concerns about the costs to industry.” [4] (our highlight!)

[1] Factor-Litvak, Pam, et al., “Persistent Associations Between Maternal Prenatal Exposure to Phthalates on Child IQ at Age 7 Years”, PLOS One, December 10, 2014; DOI: 10.1371/journal.pone.0114003

[2] Pedersen, H and Hartmann, J; “Toxic Textiles by Disney”, Greenpeace, Brussels, April 2004

[3] Christensen, “Exposure to common household chemicals may cause IQ drop”, CNN, December 11, 2014 http://www.cnn.com/2014/12/11/health/chemical-link-to-lower-iq/

[4] Sample, Ian, “Phthalates risk damaging children’s IQs in the womb, US researchers suggest”, The Guardian, December 10, 2014





TED Talks and endocrine disruptors

18 04 2013

Last week we talked about endocrine disruptors in fabric, and how they might affect us, a reposting from a few years back. This post is also a bit aged, but startling and topical nonetheless.

Today’s post features a video clip from TEDWomen, featuring filmmaker Penelope Jagessar Chaffer and Dr. Tyrone Hayes, an endocrinologist at the University of California, Berkeley, and an expert in how genes and hormones direct the developmental stages of amphibians. Dr. Hayes believes if the health of frogs is effected, then so too is the health of humans. In 2002, Nature published research by Hayes and colleagues showing that “developing male frogs exhibited female characteristics after exposure to atrazine … at exposure levels deemed safe by the US Environmental Protection Agency (EPA)”.(1)

Filmmaker Penelope Jagessar Chaffer – who has won several British Academy Award nominations for her films – was curious about the chemicals she was exposed to while pregnant: Could they affect her unborn child?.

It was her question about the effects of chemicals on her unborn child which led to her production of the documentary/surrealist film Toxic Baby. Today she works to bring to light the issue of environmental chemical pollution and its effect on babies and children.

Here Hayes and Chaffer tell their story. It’s stunningly disturbing.

(1) Tyrone Hayes, Kelly Haston, Mable Tsui, Anhthu Hoang, Cathryn Haeffele & Aaron Vonk, “Herbicides: Feminization of male frogs in the wild”, Nature 419, 895-896 (31 October 2002) | doi:10.1038/419895a





Endocrine disruptors – in fabric?

11 04 2013

jeansThis post was published about two years ago, but it’s time to re-run it, because Greenpeace has published its expose of the endocrine disruptors (APEOs and NPEOs) they found in garments produced by major fashion brands (like Levis, Zara, Calvin Klein and others). Click here to read their report.
Many chemicals used in textile processing – and elsewhere in consumer products – have been identified as “endocrine disruptors”. I never paid too much attention to “endocrine disruptors” because it didn’t sound too dire to me – I preferred to worry about something like “carcinogens” because I knew those caused cancer. I knew that endocrine disruptors had something to do with hormones, but I didn’t think that interfering with acne or my teenager’s surliness was much of a concern. Boy was I wrong.
What is an “endocrine disruptor”?
The Environmental Protection Agency defines an endocrine disruptor as an external agent that interferes in some way with the role of natural hormones in the body. (Hmm. Still doesn’t sound too bad.)
The endocrine system includes the glands (e.g., thyroid, pituitary gland, pancreas, ovaries, or testes) and their secretions (i.e., hormones), that are released directly into the body’s circulatory system. The endocrine system controls blood sugar levels, blood pressure, metabolic rates, growth, development, aging, and reproduction. “Endocrine disruptor” is a much broader concept than the terms reproductive toxin, carcinogen, neurotoxin, or teratogen. Scientists use one or more of these terms to describe the types of effects these chemicals have on us.
How do they work? This is from The Society of Environmental Toxicology and Chemistry (SETAC):

Humans and wildlife must regulate how their bodies function to remain healthy in an ever-changing environment. They do this through a complicated exchange between their nervous and endocrine systems. The endocrine systems in humans and wildlife are similar in that they are made up of internal glands that manufacture and secrete hormones. Hormones are chemical messengers that move internally, start or stop various functions, and are important in determining sleep/wake cycles, stimulating or stopping growth, or regulating blood pressure. Some of the most familiar hormones in humans or wildlife are those that help determine male and female gender, as well as control the onset of puberty, maturation, and reproduction. An endocrine disruptor interferes with, or has adverse effects on, the production, distribution, or function of these same hormones. Clearly, interference with or damage of hormones could have major impacts on the health and reproductive system of humans and wildlife, although not all of the changes would necessarily be detrimental.

But why the fuss over endocrine disruptors — and why now? After all, scientists had known for over fifty years that DDT can affect the testes and secondary sex characteristics of young roosters[1]. And for almost as long, it has been well known that daughters born to women who took the drug diethylstilbestrol (DES), a synthetic estrogen, early in their pregnancies had a greatly increased risk of vaginal cancer. [2]
And it has been known for over 25 years that occupational exposures to pesticides could “diminish or destroy the fertility of workers.”[3]

It wasn’t until Theo Colborn, a rancher and mother of four who went back to school at age 51 to get her PhD in zoology, got a job at the Conservation Foundation and began to put the pieces together that the big picture emerged. Theo’s job was to review other scientists’ data, and she noticed that biologists investigating the effects of presumably carcinogenic chemicals on predators in and around the Great Lakes were reporting odd phenomena:

  • Whole communities of minks were failing to reproduce;
  • startling numbers of herring gulls were being born dead, their eyes missing, their bills misshapen;
  •  and the testicles of young male gulls were exhibiting female characteristics.

Often, the offspring of creatures exposed to chemicals were worse off than the animals themselves. Colborn concluded that nearly all the symptoms could be traced to things going wrong in the endocrine system.
In 1991, Colborn called together a conference, whose participants included biologists, endocrinologists and toxicologists as well as psychiatrists and lawyers, at the Wingspread Conference Center in Racine, Wisconsin. They produced what become known as the “Wingspread Statement,” the core document of the endocrine-disruption hypothesis, in which these researchers concluded that observed increases in deformities, evidence of declining human fertility and alleged increases in rates of breast, testicular and prostate cancers, as well as endometriosis are the result of “a large number of man-made chemicals that have been released into the environment”.[4]
Endocrine disruption—the mimicking or blocking or suppression of hormones by industrial or natural chemicals— appeared to be affecting adult reproductive systems and child development in ways that far surpassed cancer, the outcome most commonly looked for by researchers at the time. Potential problems included infertility, genital abnormalities, asthma, autoimmune dysfunction, even neurological disorders involving attention or cognition. In one early study that Colborn reviewed, for instance, the Environmental Protection Agency (EPA) commissioned psychologists to study children whose mothers ate fish out of the Great Lakes. The researchers found that the children “were born sooner, weighed less, and had smaller heads” than those whose mothers hadn’t eaten the fish. Moreover, the more endocrine-disrupting chemicals that were found in the mother’s cord blood, the worse the child did on tests for things such as short-term memory. By age eleven, the most highly exposed kids had an average IQ deficit of 6.2.[5]
The endocrine disruptor hypothesis first came to widespread congressional attention in 1996, with the publication of the book Our Stolen Future – by Theo Colborn, Dianne Dumanoski and John Peterson Myers.[6]
In the years since the Wingspread conference, many of its fears and predictions have been fleshed out by new technologies that give a far more precise picture of the damage that these chemicals can wreak on the human body – and especially on developing fetuses, which are exquisitely sensitive to both the natural hormone signals used to guide its development, and the unexpected chemical signals that reach it from the environment.[7]
Thanks to a computer-assisted technique called microarray profiling, scientists can examine the effects of toxins on thousands of genes at once (before they could study 100 at a time at most). They can also search for signs of chemical subversion at the molecular level, in genes and proteins. This capability means that we are beginning to understand how even tiny doses of certain chemicals may switch genes on and off in harmful ways during the most sensitive period of development.
The endocrine disruption hypothesis has also unleashed a revolution in toxicity theory. The traditional belief that “the dose makes the poison” (the belief that as the dose increases, so does the effect; as the dose decreases, so does its impact) has proven inadequate in explaining the complex workings of the endocrine system, which involves a myriad of chemical messengers and feedback loops.
Experimental data now shows conclusively that some endocrine-disrupting contaminants can cause adverse effects at low levels that are different from those caused by high level exposures. For example, when rats are exposed in the womb to 100 parts per billion of DES, they become scrawny as adults. Yet exposure of just 1 part per billion causes grotesque obesity.[8] Old school toxicology has always assumed that high dose experiments can be used to predict low-dose results. With ‘dose makes the poison’ thinking, traditional toxicologists didn’t pursue the possibility that there might be effects at levels far beneath those used in standard experiments. No health standards incorporated the possibility.
Jerry Heindel, who heads a branch of the National Institute of Environmental Health Science (NIEHS) that funds studies of endocrine disruptors, said that a fetus might respond to a chemical at “one hundred-fold less concentration or more, yet when you take that chemical away, the body is nonetheless altered for life”. Infants may seem fine at birth, but might carry within them a trigger only revealed later in life, often in puberty, when endocrine systems go into hyperdrive. This increases the adolescent’s or adult’s chances of falling ill, getting fat, or becoming infertile – as is the case with DES, where exposure during fetal development doesn’t show up until maturity.
And not just the child’s life, but her children’s lives too. “Inside the fetus are germ cells that are developing that are going to be the sperm and oocytes for the next generation, so you’re actually exposing the mother, the baby, and the baby’s kids, possibly,” says Heindel.[9]
So it’s also the timing that contributes to the poison.
According to Our Stolen Future, “the weight of the evidence says we have a problem. Human impacts beyond isolated cases are already demonstrable. They involve impairments to reproduction, alterations in behavior, diminishment of intellectual capacity, and erosion in the ability to resist disease. The simple truth is that the way we allow chemicals to be used in society today means we are performing a vast experiment, not in the lab, but in the real world, not just on wildlife but on people.”
Now that I know what “endocrine disruptor” means, I’m not dismissing them any more as mere irritants.
________________________________________
[1] Burlington, F. & V.F. Lindeman, 1950. “Effect of DDT on testes and secondary sex
characteristics of white leghorn cockerels”. Proc. Society for Experimental Biology
and Medicine 74: 48–51.
[2] Herbst, A., H. Ulfelder, and D. Poskanzer. “Adenocarcinoma of the vagina: Association of maternal stilbestrol therapy with tumor appearance in young women,” New England Journal of Medicine, v. 284, (1971) p. 878-881.
[3] Moline, J.M., A.L. Golden, N. Bar-Chama, et al. 2000. “Exposure to hazardous substances
and male reproductive health: a research framework”. Environ. Health Perspect.
108: 1–20.
[4] Shulevitz,Judith, “The Toxicity Panic”, The New Republic, April 7, 2011.
[5] Ibid.
[6] Colborn, Theo, Dianne Dumanoski, and John Peterson Myers. Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival? A Scientific Detective Story. New York: Penguin. (1996) 316 p.
[7] http://www.ourstolenfuture.org/Basics/keypoints.htm
[8] http://www.ourstolenfuture.org/NewScience/lowdose/2007/2007-0525nmdrc.html#lightbulb
[9] Shulevitz,Judith, op. cit.





Can your fabric choices make you fat?

31 01 2013

We have all heard the stories of our “growing obesity epidemic” – especially in western nations. It’s an important national problem, and is partly responsible for our soaring health care costs. We often point to obesity as being caused by overeating, fast food, and/or sedentary lifestyles for those having a genetic predisposition to the disease. But the rates of obesity have escalated in such an exponential manner that the commonly held causes of obesity – overeating and inactivity – cannot explain the current obesity epidemic. A growing number of studies have suggested a new culprit: environmental rather than genetic causes.

Our world is different than it was 100 years ago. We have developed many synthetic organic and inorganic chemicals to make our lives easier – and used them in a fabulously wide range of products. In fact, you could say, as some do, that we’re living in a toxic soup of these chemicals. And those chemicals are changing us. Some of the chemicals changing us are called “endocrine disruptors” (which we discussed in last week’s post) since they interfere with the body’s hormone balance, which confuses the body. Initially, they caused concern because of their links to cancers and the malformation of sex organs. Those concerns continue, but the newest area of research is the impact that they have on fat storage.

It has been found that the developing organism (us!) is extremely sensitive to chemicals with estrogenic or endocrine disrupting activity and that exposure to these chemicals during critical stages of development may have permanent long-lasting consequences, some of which may not be expressed or detected until later in life.(1)

But back to obesity, which is what we’re concentrating on this week. (I know it’s difficult to stay on task, because these chemicals are synergistic, have multi-dimensional effects and often degrade into different substances altogether).

Nicholas Kristof, writing in the New York Times last weekend, talked about the results of a study which I found disturbing. Look at these two mice:

The only difference between these mice: The one at the top was exposed at birth to a tiny amount of an endocrine-disrupting chemical.  New York Times

The only difference between these mice: The one at the top was exposed at birth to a tiny amount of an endocrine-disrupting chemical. New York Times

According to Kristof, “they’re genetically the same, raised in the same lab and given the same food and chance to exercise. Yet the bottom one is svelte, while the other looks like, well, an American. The only difference is that the top one was exposed at birth to just one part per billion of an endocrine-disrupting chemical (2) . The brief exposure programmed the mouse to put on fat, and although there were no significant differences in caloric intake or expenditure, it continued to put on flab long after the chemical was gone.”

Bruce Blumberg, a developmental biologist at the University of California, Irvine, coined the term “obesogen” in a 2006 journal article to refer to chemicals that cause animals to store fat. Initially, this concept was highly controversial among obesity experts, but a growing number of peer-reviewed studies have confirmed his finding and identified some 20 substances as obesogens.

Manufacturers have already exploited obesogens by using them to fatten livestock, and by formulating pharmaceuticals to induce weight gain in grossly underweight patients. A study by Dr. Baillie-Hamilton presents the hypothesis that the current level of human exposure to these chemicals may have damaged many of the body’s natural weight-control mechanisms and that these effects, together with a wide range of additional, possibly synergistic, factors may play a significant role in the worldwide obesity epidemic.(3) And these changes continue generation after generation. It’s clear that the most important time for exposure is in utero and during childhood.(4)

The magazine Scientific American recently asked whether doctors should do more to warn pregnant women about certain chemicals.(5)  It cited a survey indicating that only 19% of doctors cautioned pregnant women about pesticides, only 8% about BPA (an endocrine disruptor in some plastics and receipts), and only 5% about phthalates (endocrine disruptors found in cosmetics and shampoos). Dr. Blumberg, the pioneer of the field, says he strongly recommends that people — especially children and women who are pregnant or may become pregnant — try to eat organic foods to reduce exposure to endocrine disruptors, and try to avoid using plastics to store food or water. “My daughter uses a stainless steel water bottle, and so do I,” he said.

Endocrine disruptors are found in fabrics – Greenpeace did a study of 141 clothing items purchased in 29 different countries from authorized retailers. Endocrine disruptors were found in 89 of the 141 articles tested. According to the report: “Overall, a variety of hazardous chemicals were detected within the broad range of high street fashion textile products analysed. These covered a diverse range of brands and countries of manufacture. These results indicate the ongoing – and in some cases widespread – use of hazardous chemicals in the manufacture of textile products openly marketed to consumers.”

It’s not clear whether most obesogens will do much to make an ordinary adult, even a pregnant woman, fatter (although one has been shown to do so). But what about our children, and their children? How does fabric processing impact my weight, or my child’s weight? Should I avoid certain processing chemicals in my own home?

The government made a tremendous impact on public health when it outlawed lead in gasoline. Now we need to make those same hard choices about doing without some of the things we’ve learned to like but which we know to be impacting our health. Support the Safe Chemicals Act and spread the word. This is too important to ignore.

[1] Newbold, R. R., Padilla-Banks, E., Snyder, R. J. and Jefferson, W. N. (2005), Developmental exposure to estrogenic compounds and obesity. Birth Defects Research Part A: Clinical and Molecular Teratology, 73: 478–480. doi: 10.1002/bdra.20147

[2] Newbold, R. R., Padilla-Banks, E., Snyder, R. J. and Jefferson, W. N. (2005), Developmental exposure to estrogenic compounds and obesity. Birth Defects Research Part A: Clinical and Molecular Teratology, 73: 478–480. doi: 10.1002/bdra.20147

[3] Baillie-Hamilton, PF, “Chemical toxins: a hypothesis to explain the global obesity epidemic”, Journal of Alternative and Complementary Medicine, April 2002,

[4] Blumberg, Bruce et al, “Transgenerational Inheritance of Increased Fat Depot Size, Stem Cell Reprogramming, and Hepatic Steatosis Elicited by Prenatal Obesogen Tributyltin in Mice”, Environmental Health Perspectives, January 15, 2013.

[5] Kay, Jane, “Should Doctors Warn Pregnant Women about Environmental Risks?”, Scientific American, December 10, 2012.





Toxic Baby

13 06 2012

Since I’ve managed to figure out how to embed videos in the blog, I can’t seem to help showing you some of the most electrifying clips I’ve seen.  This is one of them – please watch it!

Filmmaker Penelope Jagessar Chaffer was curious about the chemicals she was exposed to while pregnant: Could they affect her unborn child?

Ms.  Chaffer won her first British Academy Award Nomination for her BBC4 debut, Me and My Dad, followed by Shakespeare’s Stories for the BBC, for which she received a BAFTA nomination.

It was her question about the effects of chemicals on her unborn child which led to her production of the  documentary/surrealist film Toxic Baby.   Today she works to bring to light the issue of  environmental chemical pollution and its effect on babies and children.

In working on the film, she worked with scientist Tyrone Hayes, an expert on amphibians at the University of California, Berkeley.  He is a critic of atrazine (a herbicide used on corn), which he has found to interfere with the development of frog endocrine systems.

Onstage together at TEDWomen, Hayes and Chaffer tell their story.  It’s stunningly disturbing.





What are PBDE’s and why should I be concerned?

21 07 2010

PBDE’s are chemical compounds that are used as flame retardants.  They can be found in almost anything that carries an electrical current or is highly flammable.  They’re in, for example, your TV, your computer, your cellphone,  your car, your toaster and your sofa. 

PBDE stands for polybrominated diphenyl ether – a compound which contains bromine atoms.  PBDE’s come in different forms, depending on the number and location of the bromine atoms.   There are 209 possible variations.  Often in the U.S. PBDE’s are marketed with trade names such as DE-60F or Saytex 102E (among others).  Variations of the polybrominated diphenyl ethers (PBDE’s)  include pentabrominated diphenyl ethers (pentaBDE’s); octabrominated diphenyl (octaBDE) and decabrominated diphenyl ethers (decaBDE’s).   Penta and Octa BDE’s are on the way out worldwide (are actually no longer produced in the US), but the chemical industry is waging a fierce fight to retain the use of the third major PBDE compound, Deca, which is the most widely used of the PBDE’s – about 50 million pounds a year in the U.S. alone.

PBDEs are released into the environment during manufacturing operations, as products containing these chemicals degrade, or when the products containing the PBDE’s  are disposed.

WHY SHOULD I BE CONCERNED?

SHORT ANSWER:   PBDE’s are everywhere, they accumulate and they spread.  And they’re really not good for us.

LONGER ANSWER:

Demand for flame retardants is up:  The average “escape time” that a person has to get out of a burning home has dropped from 17 minutes in 1975 to only 3 minutes today, according to a study by Underwriters Laboratories released in October 2007.  The reason for this is that plastics, from which so much of our consumer products are made, are made from oil, which is actually considered an accelerant in fires.  And synthetic fabrics (according to the UL study) produce hotter fires and more toxic smoke than natural fiber furnishings. The higher fire load of consumer products and home decorations has effectively made home fires so dangerous that fire alarms sounding will often not provide adequate time for occupants to escape. The flame retardants for plastics therefore have become more critical than ever before. Increasingly stringent fire codes and flammability requirements, especially in building materials and consumer products, are driving demand for flame retardants steadily higher.

PBDE use has increased 40% from 1992 to 2003, and is forecast to grow by at least 3% per year from 2011;   they are ubiquitous in consumer products.

Food is the major source of exposure for many contaminants, including DDT and PCBs.   But food doesn’t seem to be the culprit in this case: Since PBDEs are used as additive flame-retardantsand do not bind chemically to the polymers, they leach fromthe surface of the product and easily reach the environment.  In fact, The Environmental Working Group calculations show that dust is likely to be a more important PBDE exposure route for children than food, as PBDEs migrate from furniture and electronics into house dust.

And they don’t stay put:  Sit down on a foam cushion and you’re releasing countless, invisible PBDE particles. When the TV gets hot, still more escape and land in the dust in our homes. They rinse off our clothes in the laundry and run down the shower drain, winding up in sewage that’s applied to farm fields as fertilizer.

And what about all that plastic in the ocean gyres or in landfills?  It is slowly leaching PBDE’s.

These chemicals have characteristics that make them intrinsically hazardous to humans and other animals:  they are stable (persistent), they are fat seeking and they have the potential to act as endocrine disruptors.  What is meant by these sorta innocuous sounding terms is:

  1. persistent:  they bioaccumulate, or build up, in fish and cats and Orcas and foxes – and people.  Our bodies cannot get rid of these contaminates, so our levels just increase over time.  We eat PBDEs when they contaminate our food, particularly meat and dairy products. They latch on to dust and other particles, so we breathe them in, or ingest them when dust settles on food or when children stuff their fingers into their mouths. Scientists look for PBDEs in breast milk because the chemicals stick to fat. In 1999, Swedish researchers reported that PBDE levels in women’s breast milk had increased 60-fold between 1972 and 1997.  Similar dramatic increases were documented in California harbor seals, ringed seals from the Arctic, gull eggs from the Great Lakes and human blood from Norway.   PBDE pollution has been found essentially everywhere scientists have looked: in the tissues of whales, seals, birds and bird eggs, moose, reindeer, mussels, eels, and fish; in human breast milk, hair, fat and blood; in hot dogs and hamburgers and the cheese we put on them;  in twenty different countries and remote areas such as the North Sea, the Baltic Sea and the Arctic Ocean, on top of mountains and under the sea.
  2. fat seeking: this causes them to magnify up the food chain, increasing in concentration at each successively higher  level. Once PBDE’s are released into the environment, they invariably find their way into humans, including pregnant women, where they pass  to the developing fetus in utero or through the breast milk to the nursing infant.  As evidence of fetal exposure, the infant at birth has levels of PBDE’s that are up to 25% of maternal levels.  And researchers have found that children’s PBDE levels are about 2.8 times higher than their mothers. Research in animals shows that exposure to brominated fire retardants in-utero or during infancy leads to more significant harm than exposure during adulthood, and much lower levels of PBDEs are needed to cause harm to infants and children than to adults.
  3. endocrine disruptors: Many of the known health effects of PBDEs are thought to stem from their ability to disrupt the body’s thyroid hormone balance, which plays an essential role in brain development.  Laboratory animals showed deficits in learning and memory with exposure to PBDE’s.   Studies of mice showed that a single exposure to PBDEs caused permanent behavioral aberrations that worsened as the mice got older.  One study, for instance, found that women whose levels of T4 measured in the lowest 10 percent of the population during the first trimester of pregnancy were more than 2.5 times as likely to have a child with an IQ of less than 85 (in the lowest 20 percent of the range of IQs) and five times as likely to have a child with an IQ of less than 70, meeting the diagnosis of “mild retardation.”
    1. In addition to their effects on thyroid hormones and neurological development, PBDEs have been linked to a gamut of other health impacts in laboratory animals, from subtle to dramatic.  In-utero exposures have  been associated with serious harm to the fetus, including limb malformation, enlarged hearts, bent ribs,  delayed bone hardening, and lower weight gain. The malformations of the fetus were consistently seen at levels much lower than doses harmful to the mouse mothers.
    2. Only one commercial PBDE mixture has been tested for its ability to cause cancer, in a single study more than 15 years ago. High doses of Deca given to rats and mice caused liver, thyroid and pancreas tumors.

What does all of that mean, exactly?  

Personal choices can make a difference. Buying furniture, fabric, cell phones or computers made without PBDEs is definitely a vote for a non-toxic future. But personal choices can only go so far – and the crisis is great.   PBDEs, like other contaminant issues, are at least as much a social as a personal issue and challenge. You can help your kids not only with your buying habits, but also by modeling social action for environmental change, and by campaigning for a non-toxic future, the kind of future where mother’s milk will regain its purity.