October 11, 2018
By Judith S. Weis
Plastic pollution is a clear and severe problem in our world’s oceans, as well as freshwaters and land. Most of the studies to date have focused on the marine environment. The billions of pieces of plastic floating around and accumulating on beaches and in “great garbage patches” have been documented by scientists, videographers and photographers around the world. Their effects on marine life are generally well-known: entanglement and ingestion leading to an untimely death.
Photos of marine wildlife tangled in plastic bags, 6-pack rings or fishing gear are common, as are pictures of autopsied dead whales or birds, their stomachs full of plastics. Some sea birds that fly far out to sea eat plastic and come back to land and poop it out. In the summer issue of the Sierra Atlantic, Lisa DiCaprio wrote about the problems of plastic in general in “Initiatives to Reduce Plastic Pollution.”
But what about the plastics that don’t appear in the pictures because they’re too small? I’m talking about microplastics.
Microplastics range in size from a few millimeters down to microscopic and come from a variety of sources. Some are produced when larger plastic pieces break up into progressively smaller pieces. Some are from personal-care products. A few years ago, the US banned the use of plastic “microbeads” in personal-care products, such as tooth paste and facial scrubs. Many non-plastic abrasive substitutes are available.
Microplastics are mostly invisible — and they’re everywhere. Initially, scientists believed they were solely a marine problem, since microplastics were first discovered floating in the oceans, so sampling was done near the water surface. They soon discovered that this notion was very wrong. Microplastics are dispersed throughout the water column, even on the bottom of the seven-mile deep Marianas Trench. They’re also found trapped in Arctic sea ice. Numbers in rivers, lakes and oceans reach the trillions and quadrillions — and they don’t break down. Worse, these tiny bits of plastic act as magnets for chemical contaminants in the water.
These microscopic and sometimes contaminated pieces of plastic are eaten by small planktonic animals as well as larger animals, such as clams and oysters, that eat by filtering the water. In some small species, microplastics can block the digestive system and limit the amount of real food these animals consume. Some marine organisms even seem to prefer microplastics over real food. Microplastics consumed by small marine animals are then passed up the food web. Research in this relatively new field suggests that microplastics are harmful to the health and physiology of many marine species.
Since microplastics attract chemicals in the water, they provide a route for toxic chemicals to move into marine organisms. Furthermore, chemicals in the plastic itself may be available to the animals that consume it, going up the food web. And who sits on top of the food web?
We do. Undoubtedly, we all have microplastics in our tissues. Even if you don’t eat sea food, the sea salt that you might buy in a health food store contains microplastics since it is produced by evaporating sea water. Microplastics are also in the air we breathe and the water we drink. (Incidentally, there are more in bottled water than in tap water, another reason to avoid those drinks in plastic.)
By far the most abundant (approximately 85%) type of microplastic in our oceans tends to be long thin pieces, called microfibers. Where do they come from? Look no further than your laundry basket. Synthetic clothing sheds thousands of microfibers in washing machines. These fibers are too small to be trapped in washing-machine filters. Many are captured at wastewater facilities after going down the drain, but billions still escape into water bodies, including rivers, and drift down to the ocean.
They come from fleece jackets, nylon, polyester, rayon, acrylic and spandex. While some people are aware that there are environmental problems associated with growing cotton (e.g., water and pesticide use), few consumers know of the environmental problems associated with synthetics.
Why should we care? How do these little fibers affect us? They’re being found as “fallout” in our air and our drinking water. They’ve even been found in human lung biopsies. They’ve become ubiquitous. The potential for humans to ingest microplastics (and their adhering pollutants) in the seafood we eat is certain, but we don’t yet understand how much this may affect our health.
The outdoor clothing company Patagonia, which sells synthetic clothing, is very concerned and has been working on the issue of microplastics. It funded a study showing that top-loading washing machines release many times more microfibers than front loaders, that washing in hot water releases far more than washing in cold water and that old clothes release more than new clothes.
One proposed solution for reducing microfibers is a device that can be put into washing machines to catch the microfibers at their source. But this would require individuals to buy the devices and clean them off periodically. What fraction of the population is realistically likely to do this? In any case, these devices catch only about one-third of the microfibers. People are also talking about re-engineering washing machines, so the filters would catch them. I’m not an engineer but have difficulty imagining how pores of a filter could be small enough to trap microfibers and not clog up very quickly.
Marine and environmental scientists are continually exploring this problem, from how microplastics enter our natural world to how they move about and how they affect different species in the environment. But we cannot solve the problem on our own. A large part of the solution should ultimately lie at the source — the manufacture of synthetic fabrics (from petroleum, in case you didn’t know). We need to re-engineer synthetic fabrics, not washing machines.
Fiber and textile scientists have the knowledge and ability to help find ways to at least limit the shedding properties of synthetic fabrics. Environmental scientists and textile scientists are beginning to join forces and put their heads together in workshops, conferences and research. A workshop being planned, that I am part of, will include not only textile scientists, but major clothing makers and retailers. A session I am co-organizing for the American Association for the Advancement of Science, in February 2019, will bring together environmental and textile scientists, and policy specialists to better understand how we can solve this global problem. It is at once both tiny and enormous.
Judith S. Weis is a marine biologist, Professor Emerita at Rutgers University. She is a member of the New York City Group and part of the core group of the Sierra Club National Marine Team.