By Michael Virtanen
Microplastics are polluting Adirondack streams and lakes once thought unaffected by the emerging environmental threat, according to recent research.
Eroded bits of cast-off water bottles and plastic bags, tiny synthetic fibers shed in laundering, and other manmade refuse contribute to the problem. These pollutants are defined as smaller than 5 millimeters—less than a fifth of an inch in their widest dimension. Many are microscopic.
Other research shows zooplankton eat the tiny but indigestible detritus, harmfully coating their gastrointestinal tracts and putting them into the food chain when they are eaten by larger animals.
“Microplastics are an emerging contaminant in freshwater systems and we are becoming more aware of them daily as new research is published,” said ecologist Danielle Garneau, professor of environmental science at the State University of New York at Plattsburgh.
Many microplastics aren’t caught and filtered by standard washing machines or wastewater treatment plants. They can leach out their chemical components over time as they break down, according to scientists. They collect in storm-water drains, fragments from litter, from car and truck tires, from farm runoff where sewage sludge is used as fertilizer.
The tiny particles then discharge into waterways. Research shows many get eaten, harming both the tiny floating animals at the bottom of the food chain and their predators, both larger fish and waterfowl.
Garneau and her students have been studying Lake Champlain since 2012, examining zooplankton and fish samples taken by fishermen, as well as others archived by the university’s Lake Champlain Research Institute, and finding microplastics in almost all species. “The majority of the type of plastic in their digestive tracts were fibers being retained,” she said.
Other types were fragments, foams, beads and films, which are pieces of bags and other sheet plastic. They found nurdles, the industrial pellets used in manufacturing various products, in lake water samples but not in the animals or the wastewater plants.
In separate research, samples taken five years ago from 15 streams in the Saranac River and St. Regis watersheds in the Adirondacks all showed some microplastics, with the highest numbers near two campgrounds, according to the Adirondack Watershed Institute at Paul Smith’s College. The most common found there were tiny weathered fragments from larger plastic items like water bottles, institute Executive Director Dan Kelting said.
Two student researchers, doing their senior capstone project, sampled each stream once for 30 minutes in 2014, measuring the volume of water through a net and counting the plastic caught. Counts ranged up to 112 particles collected in a half-hour at the Lake Clear Outlet, where two storm-water drainage pipes emptied.
“Everybody just assumes that’s not an issue up here, but we clearly saw it in our smaller study,” Kelting said. “And their work on Lake Champlain just confirms it.”
The scientists acknowledged that the Adirondack data so far is limited and they couldn’t say how its microplastics pollution compares to other areas. More research is needed.
“As for raw numbers, without whole water sampling and tributary inputs, it is not estimated for our lake yet,” Garneau said. “No one besides myself has done microplastics work extensively in Lake Champlain that I am aware.”
Congress in 2015 voted to ban the manufacture of microbeads used in face and body scrubs, and that prohibition went into effect last year. The law will ban interstate commerce in those products starting in July. It applies to rinse-off cosmetics, nonprescription drugs and toothpaste. It doesn’t address fabrics or other microplastic sources.
The Champlain researchers also sampled outflows at wastewater treatment plants on the lake—three in Vermont and the two in New York, at Plattsburgh and Ticonderoga, farther south in the eastern Adirondacks. They identified all as pathways for the pollutants.
Their samples indicated the Ticonderoga plant, which empties into the LaChute River flowing toward Champlain, discharges 9,218 daily particles, based on its flow rate. Some 39 percent of those identified from the samples in lab processing were fibers; 21 percent were fragments; 21 percent film; 10 percent pellets or beads; and 9 percent foam.
Plattsburgh had a lower average per gallon, but an estimated 14,665 particles daily because of its higher population and flows.
“Rivers are major sources of plastics into our lakes, so it might be easier to tackle the problem upstream, as opposed to trying to remove larger amounts from the lake,” Garneau said. She noted that the particles are so tiny, it’s hard to imagine a wastewater plant that could capture all of them, though some have extra filtration that can capture more.
They hope to test again following wastewater plant upgrades, she said. The Ticonderoga facility is getting an overhaul with an estimated cost of nearly $13.5 million.
“We’re in between funds right now,” Garneau said. “We’d like to go back and see if improvements made a difference.”
It remains unclear where the pre-manufacturing pellets known as nurdles originated. There are also unanswered questions about the potential loading of microplastics in the sludge from wastewater plants that’s shared with farmers for fertilizer, Garneau said.
Most sewage sludge is not used as farm fertilizer in New York, though some farmers are paid a tipping fee to take it, according to Jean Bonhotal, director of soil and crop sciences at the Cornell Waste Management Institute.
Research on the Great Lakes, with large cities on their shorelines, was among the first to document the problem of microplastic pollution in freshwater systems of inland waterways. It has been widely documented in the world’s oceans. Other studies have found it in bottled and tap waters, sea salt and some foods consumed by people.
“I don’t think anybody was surprised about the Great Lakes. But I think we were pretty surprised to find the microplastics up here up at the headwaters of these major rivers draining into Lake Champlain,” Kelting said. “It’s really fascinating from a science perspective but certainly concerning from the health of the fishery and other organisms. What’s in the fish that we’re eating?”
Sampled waters included Hatchery Brook, the Upper Saranac-Middle Saranac inlet and Fish Creek, among others in the Saranac River watershed. In the St. Regis watershed, they included Smitty Creek and Easy Street Creek.
Kelting’s crew found 194 fragmented pieces of plastic—the most common type—and cited storm water and roadside drainage as the primary source. They noted storm water can carry roadside trash and litter—which they saw—into culverts. They collected 77 fibers, many of them intertwined.
“When you look at the food chain,” Garneau said, “what we’re finding is that largely the fibers are retained by these organisms that are ingesting them.”
The journal Environmental Toxicology and Pharmacology in April published an analysis of the effects of the smallest microplastics on sea life. It found that so-called nanoplastics may alter reproduction or even kill creatures. An article by the National Center for Biotechnology Information last year raised fears about human ingestion. Garneau said it will take lengthy human tests to demonstrate any health effects.
The sun’s ultraviolet light causes plastic to incorporate oxygen atoms and become brittle, breaking into smaller and smaller pieces until they are metabolized by microbes. The process can take decades.
New York has joined the fight against plastic pollution, this year approving a ban on many single-use plastic bags. Some residents are taking steps to limit pollution, starting with their laundry.
Carol Fox, a New Yorker and frequent Adirondack hiker and skier, began laundering her athletic wear and other synthetics a year ago inside a special “Guppie Friend” bag made by German environmentalists. It was a gift from a friend, who was aware of the microplastics issue.
“You won’t see a lot of stuff,” Fox said of the residue caught by the bag’s fine filtering mesh. “I’m sort of taking their word for it.”
The bags cost $30 or so. According to the manufacturers, they limit the mechanical impact of the washing machine on those garments and thereby reduce fabric shedding. The fibers collect in the seams and can be removed and put in ordinary trash.