Effects on humans and animals are still being studied
A striking recent study found microscopic plastic fibers in 94% of tap water samples from sites in the United States, including the Capitol building, the Environmental Protection Agency headquarters, and Trump Tower in Manhattan. In all, the study looked at tap water from 14 countries around the world and found the fibers in more than 80 percent of the samples.
Plastic fibers are microscopic strands about 10 microns or smaller in diameter (one-tenth the diameter of a human hair) and ranging from around 1 to 8 mm long.
Sherri Mahon, a researcher at the State University of New York, Fredonia, helped design the study for Orb Media in conjunction Elizabeth Wattenberg of the University of Minnesota School Of Public Health. Mahon is known for her work on round plastic beads a millimeter or smaller in size, which she and her students found in fish caught throughout the waters of Lake Erie.
Mahon’s research inspired Congress in 2015 to prohibit use of microbeads in personal care products, where they were used as an abrasive. But her research found that the vast majority of microplastics particles in the fish were fibers, such as those used in acrylic, nylon, and polyester clothing — which were not outlawed.
According to U.S. Geological Survey hydrologist Austin Baldwin, who led a study of microplastics in Great Lakes tributaries, microfibers:
[…] represent up to 85% of the plastic pollution found on shorelines around the world. You only have to look in your closet to get a sense of the extent of the problem.
How Did They Get There?
Municipal drinking water generally comes from large bodies of fresh water, such as lakes, rivers, and reservoirs, where plastic fibers given off by vehicle tires, washing machine vents, or industrial processes may be washed down from the atmosphere with the rain.
According to a recent study by Ireland’s Environmental Protection Agency, water also can be contaminated with microplastics through other avenues, including runoff from agricultural land fertilized with biosolids (sewage sludge) or percolation through the soil from activated sludge ponds or landfills.
Filtering out Microfibers
According to Orb Media, one microfiber fleece jacket can shed 1,900 fibers in a single wash, which drains directly into the municipal wastewater treatment system.
The Irish EPA study found that sand filtration systems in treatment plants can capture particles as small as 10 microns, but many plastic fibers are even smaller. Though the researchers discovered less than one piece of plastic per gallon escaped the filters at these plants, after testing effluent from 17 plants, they found that “on average, each of these facilities is releasing four million pieces of plastic per day,” nearly 60 percent of which are microfibers.
Unknown Effects of Fiber Pollution
Scientists don’t yet understand all the dangers of microplastic fibers to living organisms. In addition to fish, they have been found in species throughout the aquatic food chain, from plankton to shellfish to seabirds. When enmeshed in the walls of the animals’ digestive tracts, the fibers can interfere with feeding, digestion, and reproduction.
There is concern that chemicals in the plastics, such as flame retardants, could further harm wildlife. These materials also could attract and hold toxins in the water, including pesticides and PCBs, then release them into organisms that ingest them.
Microfibers and Human Health
At this time, scientists have not determined the full effects of plastic fibers in drinking water. The Irish study so far has found reports of only mild-to-moderate risk to human health from plastic fibers, including irritation of the gut wall and uptake into the lymphatic system.
However, plastics are a new material, only introduced into the general environment beginning in the 1950s. As more and more types are developed and used, the extent of their presence and effects on humans — and ecosystems — remains to be discovered.
According to Molly Bingham, Orb Media founder and CEO:
I am concerned by the implications of our research. At the very least, I hope that our work triggers large scale, global research on plastic contamination and the ramifications for human health particularly that of children.