Algalita Marine Research Blog

Greening Laundry Day: Avoid Polyester Fabrics

Posted by: Sarah Mosko

By Sarah (Steve Mosko

A single polyester garment can shed >1900 microplastic fibers per wash

If you have already switched to an eco-friendly laundry detergent, as many people do to contribute less to water pollution, you might be surprised to learn that the pollution you generate on wash day has as much to do with the kind of fabrics your clothes, bedding and towels are made of as the detergent you wash them in.

Recent studies have revealed that a single garment made of polyester can shed innumerable tiny fibers into the wash water, and those fibers are finding their way to the ocean. The pollution they cause is worsened by the fact that, like plastic materials in general, polyester attracts oily pollutants in seawater so is a vehicle for the transfer of potentially dangerous chemicals into the food web when the fibers are ingested by sea creatures.

Although we don’t usually think of polyester fabrics as plastic per se, polyester is nonetheless a plastic material synthesized from crude oil and natural gas. And, like other plastics, polyester is a long polymer chain, making it non-biodegradable in any practical human scale of time, especially in the ocean because of the cooler temperatures.

Particular attention to ocean pollution from plastics has intensified ever since the late ‘90s when Captain Charles Moore of the Algalita Marine Research Foundation based in California first trawled a now infamous area of the Pacific Ocean dubbed the “Great Pacific Garbage Patch” to quantify the extent of plastic pollution. The startling discovery at that time was that plastic debris already outweighed zooplankton (organisms at the base of the ocean food web) by a factor of six to one. Moore just revisited the same area last year and reports that the ratio of plastic debris to zooplankton has increased six-fold in under a decade.

When we reflect on ocean pollution from plastics, we tend to think of larger eyesores of plastic debris, like plastic bags, foam cups, abandoned fishing nets and drink bottles & caps. It’s already well-documented that many fish, seabirds, turtles and marine mammals die each year because of ingestion or entanglement in such obvious plastic refuse. But when exposed to sunlight and other environmental stresses, plastics break apart into smaller scraps which, nevertheless, remain as a plastic polymer and non-biodegradable. Once fragmented into bits less than one millimeter (the size of a pin head), they are called “microplastics.”

The breakdown of larger plastics is not the only known source of microplastics pollution. Two others have been identified in the sewage stream: tiny plastic granules, used in beauty products and cleaning agents as scrubbers, and spillage of plastic powders and pellets which are the industrial raw materials for fabricating consumer plastics. Microplastic fibers of an unknown source are also showing up in the sewage stream.  Because waste treatment plants are not designed to filter out microplastics, any that enter the sewage stream end up in the ocean and anywhere else the outflow from waste treatment plants is dumped.

Though invisible to the casual observer, microplastics are accumulating throughout marine habitats, and research is showing that they already outnumber larger plastic fragments. For example, one study sampling a British estuary – where the ocean tide meets a river’s end – found that microplastics accounted for 65 percent of all plastic debris.

Although it might seem counterintuitive, the tiny dimension of microplastics actually adds to the dangers they represent as ocean pollutants. Since a pioneering study published in 2001, we’ve known that, because plastics are lipophylic (oil-loving), oily contaminants in seawater are drawn to them. Japanese researchers found that plastic pellets no more than a half millimeter in diameter could adsorb hazardous chemicals (like polychlorinated biphenyls, nonylphenols and derivatives of DDT) onto their surfaces at up to one million times the concentrations in the surrounding water. The kicker about microplastics is that, because of their smallness, the surface area is large relative to the overall size, providing more surface area to which chemicals can adhere: Think of a bottle filled with marbles – the total surface area of all the marbles is greater than the surface area of the bottle.

And, the miniscule size of microplastics means that even minute creatures could ingest them, either by accident or by mistaking them for food, thereby introducing any chemicals on board into the very bottom of the food chain. Adding to this worry, plastics themselves are generally complex substances with several chemical additives, some with known negative health effects in lab animals and humans. Scientists have already documented ingestion of microplastics by little ocean critters like sandworms, barnacles and small crustaceans called amphipods. Research has also shown that, once ingested by animals, microplastics are stored in tissues and cells with unknown health consequences for both the animals and us eating up at the top of the food chain.

Another obvious downside to microplastics is that their size makes them utterly impossible to clean up once they get into the ocean, or any other environment for that matter.

What all this has to do with polyester fabrics on wash day is pretty straightforward. Polyester cloths are used in innumerable items routinely laundered at home, such as blankets, towels and every sort of garment. They are by design composed of tiny plastic fibers, so on a hunch that polyester fibers from laundering are a major source of the microplastic fibers polluting ocean habitats, a team of researchers from the British Isles, Canada and Australia measured the quantity of microplastic fibers from polyester blankets, shirts and fleeces that are discharged into the wastewater from domestic washing machines. As reported in a November 2011 issue of the journal Environmental Science & Technology, a single polyester item can produce more than 1900 fibers in one washing. Every article tested produced more than 100 microfibers per liter of wastewater, and the worst offenders were the fleeces.

The researchers also provided strong evidence linking polyester from laundering to ocean pollution. They found that every one of 18 shorelines sampled across the globe was fouled with microplastic fibers, predominantly of polyester. The shorelines of more densely populated areas or where sewage is discharged were the most contaminated. Furthermore, by characterizing the microplastics in the outflow of sewage treatment plants, they were able to show that polyester fibers from laundering were the prime source of microplastic pollution in general, more than from fragmentation of larger plastics or from cleaning products.

Polyester fleece has been touted as a good environmental choice because it can be manufactured out of recycled plastic bottles, but these new findings on microplastics put a whole new slant on the sustainability of any polyester fabrics. Even when manufactured from recycled plastic, the persistent ocean pollution polyester inevitably creates downstream should outweigh any arguments in favor. The fact that polyester is ultimately derived from petroleum oil and natural gas, both non-renewable resources, adds further weight to such misgivings.

Human population went from 2.5 billion in 1950 to seven billion today and is expected to reach nine billion by 2050. We probably can’t do anything about the microplastics that are already contaminating our oceans and other environments, but we can stem the flow of further microplastics by making smarter, more responsible choices of what we purchase and throw into the washing machine on laundry day.

Natural fiber cloths of cotton, silk, wool, bamboo, hemp and even soy are available. All derive from renewable sources, are intrinsically biodegradable, and their fibers would not attract oily chemicals out of seawater.

Date Posted: August 20, 2012 @ 5:51 pm Comments (0) | Comment Shortcut

Are Plastics Making America Fatter?

Posted by: Sarah Mosko

By Sarah (Steve) Mosko

Still disappointingly chubby after cutting back on junk foods and exercising regularly?

Two-thirds of U.S. adults are now either overweight or down right obese. And while an unhealthy diet and sedentary lifestyle can contribute to an expanding waistline, evidence is accumulating that exposure to substances in everyday plastics and other industrial chemicals can fatten us up too.

Doctors gauge fatness by the Body Mass Index (BMI), based on a person’s height and weight. For adults, the cutoffs are 25 for overweight and 30 for obesity.

The average U.S. man or woman now has a BMI of 28.7, according to the Centers for Disease Control. One-third of adults are overweight, and another third are obese. Even those at the lower end of normal are showing an upward trend.

And not just adults are tipping the scales. A national survey of children and teens found that 32 percent are overweight or obese. Even animals living among humans seem to be gaining weight, including pet dogs and cats, lab animals and feral rodents. The ubiquity of the problem has led scientists to suspect environmental influences.

Environmental Obesogens
The term “obesogen” was coined in 2006 to denote environmental chemicals that promote fat. Bruce Blumberg, a biology professor at the University of California, Irvine, discovered that the hormone-disruptor tributyltin (TBT), known to cause sex reversal in fishes, makes mice grow up fatter even though they were only exposed in utero and ate a normal diet.  TBT activates receptors within a cell’s nucleus called PPAR-gamma which regulate the number and size of fat cells by instructing stem cells that give rise to fat cells.

Among its uses, TBT prevents yellowing of clear plastics and catalyses the synthesis of polyvinyl chloride plastics, though a related compound, dibutyltin, is more commonly used nowadays. Research ethics prevent intentional human exposure to toxic chemicals, but Blumberg says there is no doubt these tin compounds would promote obesity in humans because we already have medications for diabetes which activate the very same receptors and cause weight gain – Actos and Avandia.

In a July 13 interview, Blumberg stated that there is already good evidence for about 20 obesogens. Given the tens of thousands of industrial chemicals in use today, many more could be lurking about. Although research on obesogens is still in its infancy, among the known obesogens are two more associated with common plastics: phthalates and BPA (bisphenol-A).

Phthalates are a family of plasticizers (softeners) used in polyvinyl chloride plastics. Human studies have documented bigger waistlines and higher BMIs in adults whose urine shows higher levels of the breakdown products of phthalates. Though how phthalates (or their metabolites) promote fatness is not well understood, there is evidence from animal studies that PPAR-gamma receptors are sometimes involved.

While TBT is thought to have greater potency as an obesogen, human exposure to phthalates is conceivably greater because phthalates are used in a myriad of personal care products and consumer plastics – everything from shower curtains and medical IV bags to children’s toys. Phthalates can migrate out of plastics, explaining in part why over 90 percent of Americans test positive for phthalates.

BPA is a building block of polycarbonate plastics and also found in the epoxy lining of canned foods and beverages and on cash register receipts. It too leaches out of products, and ingestion contributes to its widespread presence in human tissues, including breast milk.

Most of the obesogen research on BPA has been done in cell cultures or lab rodents exposed early in development, though higher BPA exposure has been documented in obese women. BPA actually reduces the number of fat cells, but instead makes them grow much larger, according to Frederick vom Saal of the University of Missouri. How BPA does this is unclear, but Blumberg has shown that the PPAR-gamma receptor is not involved. He speculates that BPA’s ability to mimic the hormone estrogen might be.

Blumberg’s latest research reveals that a chemical cousin of BPA (called BADGE for short), used in the epoxy lining of milk and other cardboard beverage cartons, pushes human stem cells to morph into fat cells by an unknown mechanism. Like BPA, BADGE also leaches into a container’s contents.

A 2011 National Toxicology Program workshop on obesogens also identified several pesticide obesogens, and prenatal nicotine exposure through maternal smoking during pregnancy is the obesogen with the strongest support from human studies. The hypothesis driving current research is that early developmental exposure to obesogens programs fat cells and the neural circuits controlling feeding behaviors which, combined with a less healthy lifestyle, set the stage for obesity.

Though adult exposure to some obesogens might also add to weight struggles, scientists are most interested in the prenatal period through puberty when a person’s fat cell makeup and metabolic set point for weight gain are established. Blumberg says to expect investigations in the near future revealing transgenerational effects where prenatal exposure affects subsequent generations too.

Blumberg does not, however, think that early obesogen exposure necessarily destines a person to becoming fat, but it could make weight control tougher.

It will be a while before scientists sort out how environmental obesogens figure into America’s obesity epidemic. However, given that obesity increases risk for serious medical conditions, including diabetes, cardiovascular disease and cancer, minimizing unnecessary exposures seems wise.

Blumberg recommends avoiding plastics and tobacco smoke, filtering water, and eating fresh organic foods in lieu of canned/prepackaged items.

Date Posted: August 1, 2012 @ 1:19 am Comments (0) | Comment Shortcut