Ask most people about the problem of waste plastics in the environment and they will talk about plastic bags caught in trees and the vast slicks of plastic trash found in remote areas of the Atlantic and Pacific. But the most menacing plastic waste problem is less visible and not so well publicized.
It’s the tiny fibers, less than one millimeter wide, that come from our clothes when we launder them. These fibers make their way into the world’s rivers and seas through the sewage and drainage systems of our cities. The pollution is worst near urban areas, but it is global and has increased by more than 450 per cent since the 1960s.
These minute strands of plastic — virtually invisible to the human eye — are made from a variety of natural (animal and plant) and artificial polymers. You can’t see them when you walk along the seashore at low tide, but they’re there, by the ton.
In the samples my team and I recovered on shorelines from the poles to the Equator between 2004 and 2007, they were often over six times more abundant by number than larger plastic debris like bottles, bags and wrappers.
The presence of such fibers in the environment is particularly problematic not only because they sneak their way into the food chain, but also because they can damage the lungs of humans and animals. It’s not just plastics; natural fibers, including those from cotton and flax, can also harm lung function and cause scarring.
Tiny fiber-size synthetic polymers migrate from the lungs and guts into the bloodstream, potentially circulating for months. In extreme cases in the past, research established a link between textiles containing fibers of chrysotile (a type of asbestos) and cancer and death in humans.
At the National Center for Ecological Analysis and Synthesis in California, my colleagues and I reviewed numerous medical, toxicological and ecological studies about the links between micro- and nano-size debris and disease and mortality in humans and wildlife. Medical studies showed, for example, that injecting hamsters with plastic particles caused blood cells to form clots. Other research found that plastics can cause damage by increasing concentrations of metal and protein in cells. This damages DNA, and kills cells and causes tissue inflammation.
It’s not just ingestion of microscopic synthetic polymers that’s a problem for humans and wildlife. These microplastic fibers (including natural fibers) are often infused with harmful chemicals, including dyes that can cause skin rashes in humans, surfactants often used in detergents that are known to compromise the immune system, and antimicrobials like triclosan, which can kill wildlife.
There are large concentrations of such chemicals in clothing and in areas that receive discharges from textile factories, storm-water drains and sewage-treatment plants. These areas also contain significant levels of textile fibers.
The garment industry largely works within rules made by governments. Every year, apparel companies turn 70 million metric tons of fibers into400 billion square meters of fabric, to make around 150 billion items of clothing. These companies aren’t funding scientific work to determine whether these fibers are safe for the environment or for our health.
This is an example where government-mandated proof-of-harm policies encourage companies to manufacture products without testing their impacts on ecology and health. Manufacturers have no incentive to innovate and so reduce fiber pollution. Instead, governments must lead by creating proof-of-safety policies that require the industry to reduce emissions of toxic fibers from products.
A new policy regime could also encourage ecologists, designers and engineers to work together to identify features of clothing that cause the shedding of fibers, developing safer alternatives. With some plastics found as debris, governments and businesses are altering how products are made, used and disposed of.
Deposit schemes for bottles and cans, for example, discourage littering and can ease the financial burden of recycling on the taxpayer. Many state governments, including California, Illinois, New Jersey, Maine, Colorado, Maryland, Indiana, Connecticut and Wisconsin, are banning “microbeads”— plastic exfoliants used in cosmetics.
The problem with such initiatives is that they often bypass research into their impacts. And without proper scientific measurement, we can’t be sure of the consequences of actions intended as meliorative.
We need to apply similar measures to our most abundant form of plastic debris: clothing fibers. Even where regulations apply, government and industry have not invested in the scientific research needed to determine whether they’re effective.
The Benign by Design program, a partnership between the University of New South Wales in Australia, the University of California, Northwestern University and the clothing designer Eileen Fisher, aims to change this. We’re pioneering tests to investigate whether washing apparel with filters can control emissions of toxic fibers. We also hope to resolve the longstanding debate over whether natural fibers are more damaging than plastic ones — an issue of obvious concern to consumers.
Industry-led changes by market leaders can mitigate ecological harm, though it is less clear how useful their existing measures are. There is a tool used by the apparel and footwear industries to try to reduce the environmental impacts of their products: the Higg Index. It is designed to monitor and reduce the quantity of water, energy, chemicals and labor manufacturers use, as well as how much waste they produce.
Like many “green chemistry” programs, it uses laboratory data about chemicals that, at sufficient concentrations, can damage organisms to modify products. The result is supposed to be cleaner processing and fewer hazardous chemicals.
To date, though, no one has done the scientific work to show whether this approach reduces the emissions and impacts of fibers. Without more research, green chemistry programs may encourage companies to abandon older chemicals that are more likely to be regarded as hazardous simply because they’ve been tested more, and to replace them with newer chemicals that may be mistakenly believed safer.
Laboratory tests are insufficient because they can’t reproduce the complex mixture of chemicals found on fibers in nature. Polymers at large often accumulate additional chemicals and biological material, including pathogens, which affects their potential to harm humans and wildlife.
A new partnership between government and industry to reduce clothing fiber pollution would fund more research and set precautionary standards. One important task would be to establish whether there is a safe “load” of fibers by using field experiments to determine how many fibers can be added to the ecosystem before there is an impact, with similar studies needed to examine effects on human health.
We also need garment makers and the manufacturers of washing machines to work together in a coordinated way to make ecologically sound decisions about materials and technologies. Right now, we can only hypothesize about what might reduce the shedding of fibers during laundering — perhaps altering their strength and type, or the ways they’re woven or filtered by washing machines — so we need to run tests to find this out. This knowledge could help the industry achieve its wish to reduce impacts on ecology and health.
Public awareness about the need for safer fabrics and cleaning methods is vital: The gold standard would be a labeling program for companies to signal their ecological compliance with trust and transparency. Something as small as the label on your winter fleece could make a world of difference.
Dr Mark Browne is a senior research associate at UNSW.
This article first appeared in The New York Times.