Polyester and our health

13 10 2011

Polyester is a very popular fabric choice – it is, in fact, the most popular of all the synthetics.  Because it can often have a synthetic feel, it is often blended with natural fibers, to get the benefit of natural fibers which breathe and feel good next to the skin, coupled with polyester’s durability, water repellence and wrinkle resistance.  Most sheets sold in the United States, for instance, are cotton/poly blends.

It is also used in the manufacture of all kinds of clothing and sportswear – not to mention diapers, sanitary pads, mattresses, upholstery, curtains  and carpet. If you look at labels, you might be surprised just how many products in your life are made from polyester fibers.

So what is this polyester that we live intimately with each day?

At this point, I think it would be good to have a basic primer on polyester production, and I’ve unabashedly lifted a great discussion from Marc Pehkonen and Lori Taylor, writing in their website diaperpin.com:

Basic polymer chemistry isn’t too complicated, but for most people the manufacture of the plastics that surround us is a mystery, which no doubt suits the chemical producers very well. A working knowledge of the principles involved here will
make us more informed users.

Polyester is only one compound in a class of petroleum-derived substances known as polymers. Thus, polyester (in common with most polymers) begins its life in our time as crude oil. Crude oil is a cocktail of components that can be separated by industrial distillation. Gasoline is one of these components, and the precursors of polymers such as polyethylene are also present.

Polymers are made by chemically reacting a lot of little molecules together to make one long molecule, like a string of beads. The little molecules are called monomers and the long molecules are called polymers.

Like this:

O + O + O + . . . makes OOOOOOOOOOOOOOOO

Depending on which polymer is required, different monomers are chosen. Ethylene, the monomer for polyethylene, is obtained directly from the distillation of crude oil; other monomers have to be synthesized from more complex petroleum derivatives, and the path to these monomers can be several steps long. The path for polyester, which is made by reacting ethylene glycol and terephthalic acid, is shown below. Key properties of the intermediate materials are also shown.

The polymers themselves are theoretically quite unreactive and therefore not particularly harmful, but this is most certainly not true of the monomers. Chemical companies usually make a big deal of how stable and unreactive the polymers are, but that’s not what we should be interested in. We need to ask, what about the monomers? How unreactive are they?

We need to ask these questions because a small proportion of the monomer will never be converted into polymer. It just gets trapped in between the polymer chains, like peas in spaghetti. Over time this unreacted monomer can escape, either by off-gassing into the atmosphere if the initial monomers were volatile, or by dissolving into water if the monomers were soluble. Because these monomers are so toxic, it takes very small quantities to be harmful to humans, so it is important to know about the monomers before you put the polymers next to your skin or in your home. Since your skin is usually moist,
any water-borne monomers will find an easy route into your body.

Polyester is the terminal product in a chain of very reactive and toxic precursors. Most are carcinogens; all are poisonous. And even if none of these chemicals remain entrapped in the final polyester structure (which they most likely do), the manufacturing process requires workers and our environment to be exposed to some or all of the chemicals shown in the flowchart above. There is no doubt that the manufacture of polyester is an environmental and public health burden
that we would be better off without.

What does all of that mean in terms of our health?  Just by looking at one type of cancer, we can see how our lives are being changed by plastic use:

  • The connection between plastic and breast cancer was first discovered in 1987 at Tufts Medical School in Boston by
    research scientists Dr. Ana Soto and Dr. Carlos Sonnenschein. In the midst of their experiments on cancer cell growth, endocrine-disrupting chemicals leached from plastic test tubes into the researcher’s laboratory experiment, causing a rampant proliferation of breast cancer cells. Their findings were published in Environmental Health Perspectives (1991)[1].
  • Spanish researchers, Fatima and Nicolas Olea, tested metal food cans that were lined with plastic. The cans were also found to be leaching hormone disrupting chemicals in 50% of the cans tested. The levels of contamination were twenty-seven times more than the amount a Stanford team reported was enough to make breast cancer cells proliferate. Reportedly, 85% of the food cans in the United States are lined with plastic. The Oleas reported their findings in Environmental Health Perspectives (1995).[2]
  • Commentary published in Environmental Health Perspectives in April 2010 suggested that PET might yield endocrine disruptors under conditions of common use and recommended research on this topic. [3]

These studies support claims that plastics are simply not good for us – prior to 1940, breast cancer was relatively rare; today it affects 1 in 11 women.  We’re not saying that plastics alone are responsible for this increase, but to think that they don’t contribute to it is, we think, willful denial.  After all, gravity existed before Newton’s father planted the apple tree and the world was just as round before Columbus was born.

Polyester fabric is soft, smooth, supple – yet still a plastic.  It contributes to our body burden in ways that we are just beginning to understand.  And because polyester is highly flammable, it is often treated with a flame retardant, increasing the toxic load.  So if you think that you’ve lived this long being exposed to these chemicals and haven’t had a problem, remember that the human body can only withstand so much toxic load – and that the endocrine disrupting chemicals which don’t seem to bother you may be affecting generations to come.

Agin, this is a blog which is supposed to cover topics in textiles:   polyester is by far the most popular fabric in the United States.  Even if made of recycled yarns, the toxic monomers are still the building blocks of the fibers.  And no mention is ever made of the processing chemicals used to dye and finish the polyester fabrics, which as we know contain some of the chemicals which are most damaging to human health.

Why does a specifier make the decision to use polyester – or another synthetic –  when all the data points to this fiber as being detrimental to the health and well being of the occupants?  Why is there not a concerted cry for safe processing chemicals at the very least?


[2] http://www.prnewswire.com/news-releases/zwa-reports-are-plastic-products-causing-breast-cancer-epidemic-76957597.html

[3]  Sax, Leonard, “Polyethylene Terephthalate may Yield Endocrine Disruptors”,
Environmental Health Perspectives, April 2010, 118 (4): 445-448





How to buy a sofa: part 4: so which fabric will it be?

16 09 2011

So for the past two weeks we’ve discussed the differences between synthetic and natural fibers.  But there’s more to consider than just the fiber content of the fabric you buy.  There is the question of whether a natural fiber is organically grown, and what kind of processing is used to create the fabric.

First, by substituting organic fibers for conventionally grown fibers you are supporting organic agriculture, which has myriad environmental, social and health benefits.  Not only does organic farming take far less energy than conventional farming (largely because it does not use oil based fertilizers) [1] , which helps to mitigate climate change, but it also:

  • eliminates the use of synthetic fertilizers, pesticides and genetically modified organisms (GMOs) which is  an improvement in human health  and agrobiodiversity;
  • conserves water (making the soil more friable so rainwater is absorbed better – lessening irrigation requirements and erosion);
  • ensures sustained biodiversity;
  • and compared to forests, agricultural soils may be a more secure sink for atmospheric carbon, since they are not  vulnerable to logging and wildfire.

Organic production has a strong social element and includes many Fair Trade and ethical production principles.  As such it can be seen as more than a set of agricultural practices, but also as a tool for social change.[2]  For example, one of the original goals of the organic movement was to create specialty products for small farmers who could receive a premium for their products and thus be able to compete with large commercial farms.

Organic agriculture is an undervalued and underestimated climate change tool that could be one of the most powerful strategies in the fight against global warming, according to Paul Hepperly, Rodale Institute Research Manager. The Rodale Institute Farming Systems Trial (FST) soil carbon data (which covers 30 years)  shows conclusively that improved global terrestrial stewardship–specifically including regenerative organic agricultural practices–can be the most effective currently available strategy for mitigating CO2 emissions. [3]

But if you start with organic natural fibers (a great choice!)  but process those fibers conventionally, then you end up with a fabric that is far from safe.  Think about making applesauce:  if you start with organic apples, then add Red Dye #2, preservatives, emulsifiers, stablizers and who knows what else – do you end up with organic applesauce?  The US Department of Agriculture would not let you sell that mixture as organic applesauce, but there is no protection for consumers when buying fabric.  And the same issues apply, because over 2000 chemicals are used routinely in textile processing.(4)  Many of the chemicals used in textile processing have unknown toxicity, and many others are known to be harmful to humans (such as formaldehyde, lead, mercury, bisphenol A and other phthalates,  benzenes and others).   In fact, one yard of fabric made with organic cotton fiber  is about 25% by weight synthetic chemicals – many of which are proven toxic to humans. (5)

I know you’re saying that you don’t eat those fabrics, so what’s the danger?  Actually, your body is busy ingesting the chemicals, which are evaporating (so we breathe them in), or through skin absorption (after all, the skin is the largest organ of the body).  Add to that the fact that each time you brush against the fabric, microscopic pieces of the fabric abrade and fly into the air – so we can breathe them in.  Or they fall into the dust in our homes, where pets and crawling babies breathe them in.

Should that be a concern?  Well, there is hardly any evidence of the effects of textiles themselves on individuals, but in the US, OSHA does care about workers, so most of the studies have been done on workers in the textile industry.  Greenpeace also did a study on specific items manufactured by Disney, but I would guess the results pertain all across the spectrum:

  • Autoimmune diseases (such as IBD, diabetes, rheumatoid arthritis,  for example, and linked to many of the chemicals used in textile processing) are reaching epidemic rates,  and a 14 year study published by the University of Washington and the National Institutes of Health found that people who work with textiles (among other industries) are more likely to die of an autoimmune disease than people who don’t (6);
  • We know formaldehyde is bad for us, but in fabric?  A study by The National Institute for Occupational Safety and Health found a link in textile workers between length of exposure to formaldehyde and leukemia deaths.[7]  Note: most cotton/poly sheet sets in the U.S. are treated with a formaldehyde resin.
  • Women who work in textile factories with acrylic fibers have seven times the risk of developing breast cancer than does the normal population.[8]
  • A study in France revealed a correlation between the presence of cancer of the pharynx and occupation in the textile industry.(9)
  • A high degree of colorectal cancer, thyroid cancer, testicular cancer and nasal cancer has been found among textile workers, and a relationship between non-Hodgkin’s lymphoma and working in the textile industry was observed.(10)

And consider this:

  • The Mt. Sinai Children’s Environmental Health Center published a list of the top 10 chemicals they believe are linked to autism – and of the 10, 6 are used in textile processing and 2 are pesticides. (11)
  • Phthalates are so toxic that they have been banned in the European Union since 2005. They have recently been banned in the State of California in children’s toys.   They are ubiquitous –  and are also found  in most  textile inks.[12]  So parents careful not to bring toxic toys into their homes for  can be  nevertheless  unknowingly putting their kids to sleep on cute printed sheets full of phthalates.

Though some argue that we’re less prepared because we’re confronting fewer natural pathogens, it’s also true that we’re  encountering an endless barrage of artificial pathogens that are taxing our systems to the maximum.  And our children are the pawns in this great experiment.

Are these rates of disease and the corresponding rise in the use of industrial chemicals a coincidence? Are our increased rates of disease due to better diagnosis?   Some argue that we’re less prepared because we’re confronting fewer natural pathogens.  All plausible.   But if you think they are the main culprits, your opinion is not shared by a goodly number of scientists, who believe that this endless barrage of artificial pathogens that is taxing our systems to the maximum  has replaced bacteria and viruses as the major cause of human illness.  We don’t have to debate which source is primary; especially because, with the rise of super bugs, it’s a silly debate. The point remains that industrial pollution is a cause of human illness – and it is a cause we can take concrete actions to stem.

Textiles are the elephant in the room – the industry is global, relatively low tech, and decentralized –  certainly not the darling of venture capatalists who look for the next big thing.  So not many research dollars are going into new ways of producing fabrics.    Most of the time people are looking for the lowest price fabric for their projects or products – so the industry is on a race to cut costs in any way possible:   in 2007, the Wall Street Journal’s Jane Spencer detailed the pollution caused by Chinese textile industries who were being pushing by their multinational clients to cut costs, resulting in untreated effluent discharge (13).

 


[1] Aubert, C. et al.,  (2009) Organic farming and climate change: major conclusions of the Clermont-Ferrand seminar (2008) [Agriculture biologique et changement climatique : principales conclusions du colloque de Clermont-Ferrand (2008)]. Carrefours de l’Innovation Agronomique 4. Online at <http://www.inra.fr/ciag/revue_innovations_agronomiques/volume_4_janvier_2009>

A study done by Dr. David Pimentel of Cornell University found that organic farming systems used just 63% of the energy required by conventional farming systems, largely because of the massive amounts of energy requirements needed to synthesize nitrogen fertilizers.

[2]  Fletcher, Kate, Sustainable Fashion and Textiles, p. 19

[3] http://www.rodaleinstitute.org/files/Rodale_Research_Paper-07_30_08.pdf  Also see:  Muller, Adrian, “Benefits of Organic Agriculture as a Climate change Adaptation and Mitigation Strategy for Developing Countries’, Environement for Development, April 2009

(4)  See the American Association of Textile Chemists and Colorists’ (AATCC) Buyers Guide, http://www.aatcc.org/

(5) Lacasse and Baumann, Textile Chemicals:  Environmental Data and Facts, Springer, New York, 2004, page 609

(6) Nakazawa, Donna Jackson, “Diseases Like Mine are a Growing Hazard”, Washington Post, March 16, 2008

(7) Pinkerton, LE, Hein, MJ and Stayner, LT, “Mortality among a cohort of garment workers exposed to formaldehyde: an update”, Occupational Environmental Medicine, 2004 March, 61(3): 193-200.

(8) Occupational and Environmental Medicine 2010, 67:263-269 doi:
10.1136/oem.2009.049817  SEE ALSO:  http://www.breastcancer.org/risk/new_research/20100401b.jsp  AND http://www.medpagetoday.com/Oncology/BreastCancer/19321

(9) Haguenour, J.M., “Occupational risk factors for upper respiratory tract and upper digestive tract cancers” , Occupational and Environmental Medicine, Vol 47, issue 6 (Br J Ind Med1990;47:380-383 doi:10.1136/oem.47.6.380).

(10)  http://www.fibre2fashion.com/industry-article/3/297/safety-and-health-issues-in-the-textile-industry2.asp

(11) http://www.mountsinai.org/patient-care/service-areas/children/areas-of-care/childrens-environmental-health-center/cehc-in-the-news/news/mount-sinai-childrens-environmental-health-center-publishes-a-list-of-the-top-ten-toxic-chemicals-suspected-to-cause-autism-and-learning-disabilities

(12)  “Textile Inkmaker Tackles Phthalates Ban”, Esther D’Amico, Chemical Week,  September 22, 2008  SEE ALSO:  Toxic Textiles by Disney, http://archive.greenpeace.org/docs/disney.pdf

(13) Spencer, Jane, “China Pays Steep Price as Textile Exports Boom”, Wall Street Journal, August 22, 2007.