I know the polyester fabric costs less, but what else comes with it?

19 06 2013

When plastic was introduced in 1869, it was advertised as being able to replace natural products like ivory and tortoiseshell in items such as jewelry, combs and buttons – so it would “no longer be necessary to ransack the earth in pursuit of substances which are constantly growing scarcer.”(1)

What a success: Plastics are versatile – they can be hard or soft, flexible or brittle, and are durable, lightweight, formable – in fact, they’re so versatile that they’ve become a vital manufacturing ingredient for nearly every existing industry. They are practically ubiquitous. And now we’re beginning to find that our relationship with plastic is not healthy. Using dwindling fossil fuels to manufacture the stuff, plastic leaches toxic chemicals into our groundwater, litters landscapes and destroys marine life. As Susan Freinkel points out in her book, Plastic: A Toxic Love Story, it’s worth noting that discoveries of plastic’s toxic effects are being made in a world that is at least ten times more plastic than it was half a century ago. In the ’60s, an American might have used about 30 pounds of plastic a year – in 2011, 300 pounds. And we’re producing 300 million tons more every year.(2)

Plastics were marketed as “the material of the future”. And how true that is, because large polymers take practically forever to break down, so much of the plastic that has ever been manufactured is still with us, in landfills, in the plastic filled gyres found in our oceans (where the mass of plastic exceeds that of plankton sixfold) (3), and the stomachs of northern seabirds. And it will stay there for hundreds if not thousands of years.

Just as some chemicals can impact children’s bodies much more than adult bodies, Judith Shulevitz, writing in the New Republic, reminds us: “plastic totally dominates the world of the child. Children drink formula in baby bottles and water in sippy cups, eat food with plastic spoons on bright melamine trays, chew on bath books and rubber ducks, and, if they don’t do these things at your house, they’ll do them at someone else’s or at school, no matter how many notes you write or mad-housewife-ish you’re willing to appear.” (4)

There are many studies to support the belief that these plastics are changing us – but what has really changed is that the scientific understanding of how these chemicals are poisoning us has undergone a conceptual revolution – our grandchildren may see our current attitudes about living with these chemicals as being analogous to doctors in the 1950s who appeared in ads for cigarettes.

Old toxicological notions are being stood on their heads. Certainly, the old “dose makes the poison” notion, which was first expressed by Paracelsus in the 16th century and which means that a substance can only be toxic if it is present in a high enough concentration in the body – because all things are poisonous in the right amounts. He wrote: “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy”. But today scientists are finding that timing of exposure might be the critical factor – a fetus might respond to a chemical at one-hundredfold less concentration or more than in an adult, and when the chemical is taken away the body is altered for life. Another theory is known as the “developmental origins of health and disease,” or DOHaD (for more about DOHaD, click here), and it paints a picture of almost unimaginably impressionable bodies, responsive to biologically active chemicals until the third generation.(5)

New methods have been developed which have taken the guesswork out of what were once theories: for example, biomonitoring now means that scientists can actually discover the degree to which people have been exposed to poisonous stuff when in the past their conclusions were largely guesswork; and microarray profiling, which means we’re beginning to understand how tiny doses of certain chemicals switch genes on or off in harmful ways during exquisitely sensitive periods of development.

Exposure to all that plastic has a cumulative effect. Now toxicologists can see that lots of tiny doses from many different estrogen-mimicking chemicals entering the body by multiple pathways can have a big impact. “If you’re being exposed to two-hundred fifty chemicals and only thirty of them have estrogenic activity, but they’re each very low, still, thirty of them might add up to be significant,” says Jerrold Heindel, of the National Institute of Environmental Health Sciences (NIEHS).

Judith Shulavith asks– if we live in this plastic environment – why we’re not sicker than we are? And sicker than we used to be? “The answer is, we’re healthier in some ways and sicker in others. Medical advances mean we’re likelier than ever to survive our illnesses, but all kinds of diseases are on the rise. Childhood cancers are up 20 percent since 1975. Rates of kidney, thyroid, liver, and testicular cancers in adults have been steadily increasing. A woman’s risk of getting breast cancer has gone from one in ten in 1973 to one in eight today. Asthma rates doubled between 1980 and 1995, and have stayed level since. Autism-spectrum disorders have arguably increased tenfold over the past 15 years. According to one large study of men in Boston, testosterone levels are down to a degree that can’t be accounted for by factors such as age, smoking, and obesity. Obesity, of course, has been elevated to the status of an epidemic.”(6)

There are many ways to explain upticks in rates of any particular ailment; for starters, a better-informed populace and better tools for detecting disease mean more diagnoses. Other environmental stressors include Americans’ weirdly terrible eating habits, our sedentary lifestyle, and stress itself. But why can’t we just figure this out and come to some conclusions about certain chemicals as the cause of certain diseases? John Vandenberg, a biologist, explains the difficulty : “Well, one of the problems is that we would have to take half of the kids in the kindergarten and give them BPA and the other half not. Or expose half of the pregnant women to BPA in the doctor’s office and the other half not. And then we have to wait thirty to fifty years to see what effects this has on their development, and whether they get more prostate cancer or breast cancer. You have to wait at least until puberty to see if there is an effect on sexual maturation. Ethically, you are not going to go and feed people something if you think it harmful, and, second, you have this incredible time span to deal with.”(7)

Which diseases, exactly, have fetal origins and which chemicals have the power to sidetrack development, and how, is the goal of a giant, 21-year study of 100,000 children called the National Children’s Study (NCS), under the auspices of the National Institutes of Health. However, in 2013, it was announced that the decade-old effort would undergo radical restructuring to cut costs.(8)

Meanwhile, what can you do to protect yourself and your family, since the government isn’t doing that job?  I’ll have some ideas next week.

(1) Freinkel, Susan, “Plastic: Too Good to Throw Away”, The New York Times, March 17, 2011
(2) Ibid.
(3) Moore, C.J., et al, “Density of Plastic Particles found in zooplankton trawls from coastal waters of Northern California to the North Pacific Central Gyre”, Algalita Marine Research Foundation
(4) Shulevitz, Judith, “The Toxicity Panic”, The New Republic, April 7, 2011
(5) Ibid.
(6) Ibid.
(7) Groopman, Jerome, “The Plastic Panic”, The New Yorker, May 31, 2010.
(8) Belli, Brita, “Changes to Children’s Study Threaten its value, experts say”, Simons Foundation Autism Research Initiative; 7 March 2013

Advertisements




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.