Research

Sounding the alarm on microplastic pollution

Environmental chemist Sherri Mason’s work has influenced federal legislation and changed public perception.

Credit: Sherri Mason. All Rights Reserved.

By Robb Frederick

Microplastic pollution has existed since plastics came into widespread use in the 1950s. Our awareness of its pervasiveness has expanded over the past 10 years, thanks to the work of Penn State Behrend's Sherri Mason and others.


There are four basic ingredients in beer: grain, hops, yeast and water. The water often introduces a fifth, which passes unfiltered into a typical pilsner.

In 2017, working with two colleagues, Sherri “Sam” Mason, then a faculty member at the State University of New York at Fredonia, analyzed 12 brands of beer brewed using water drawn from the Great Lakes. Every sample she tested contained small particles of plastic — tiny pieces of synthetic debris. We ingest that plastic when we drink the beer.

Cheers!

It is not clear what effect, if any, that plastic has in our bodies. Some of it passes through undigested: In 2018, researchers in Austria found microplastics — polymer particles smaller than 5mm — in the stool samples of people in eight countries.

New research at the University of California, Irvine, and in the Netherlands found microplastics in volunteers’ lungs and blood. Other studies have found plastic particles in hair samples and fingernail clippings.

“There is absolutely no doubt this material is getting into our bodies,” says Mason, who is now the director of sustainability at Penn State Behrend, in Erie, Pennsylvania. “What we don’t yet fully understand is what it’s doing to us.”

Microplastic fibers, which are believed to be associated with polymers in clothing, including fleece, are more likely to attach to or entangle in the body, due to their elongated shape, Mason says. She has found plastic fibers attached to the digestive systems of fish.

“They weave themselves into the intestinal tract,” she says.

Plastic particles enter our bodies when we drink, when we eat, and even when we breathe, Mason says. Most are too small to see.

Much of that plastic begins as packaging: grocery bags, water bottles, and take-out containers. Since the 1950s, when the material was introduced, approximately 10 billion metric tons of plastic waste has been generated, according to the United Nations Environment Programme. Less than 10% of that has been recycled.

As plastic enters the environment, including water systems, it often drifts, moved by currents, runoff, and prevailing winds, degrading into ever-smaller pieces.

“The size of the particles surprised me,” says Mason, who netted plastic debris from the surfaces of lakes Superior, Huron, and Erie in 2012. She found additional plastic material in all five of the Great Lakes in 2013 and 2014.

“I thought we would be capturing bags and bottles, identifiable items,” Mason says. “What we saw was much smaller.”

The largest known accumulation of aquatic plastic pollution is the “Great Pacific Garbage Patch,” which was discovered by oceanographer Charles Moore in 1997. The patch, located in the waters off California, is, in fact, two distinct debris fields, which together cover an estimated 1.6 million kilometers — an area roughly three times the size of France. The debris constantly churns, as if in a washing machine, held in place by the currents of the North Pacific Subtropical Gyre.

The debris is buoyant. Some of it is still identifiable — fishing nets, for example, and rubber from vehicle tires — but the majority is microplastics. Those smaller particles are suspended in the water column, “like flecks of pepper floating throughout a bowl of soup,” according to the National Oceanic and Atmospheric Administration.

Similar materials litter the Great Lakes. You’ll need to give up more than beer to keep them out of your body: Mason’s 2018 study, published in the journal PLOS ONE, also found microplastics, or “anthropogenic contamination,” in sea salt and tap water.

Previous research had found polymer fragments in German beers. No one had looked for those contaminants in tap water, however. Mason and her colleagues analyzed 159 water samples, collected from 14 countries. They found plastic in 81% of the samples. The water sourced from developed nations, including those in the European Union, contained more plastic — 6.85 particles per liter, on average, compared to 4.26 particles per liter in lesser-developed nations. The water from U.S. taps was the most contaminated: 9.24 particles per liter.

Mason’s team determined that the typical American, consuming an average amount of water, beer and sea salt, ingests more than 5,800 particles of plastic every year from those sources alone.

In a follow-up study, also published in 2018, Mason analyzed 11 brands of bottled water. She found plastic in 93% of the samples.

“That was part of a larger 'a-ha' moment, when we began to better understand how much of what we eat and drink contains microplastics,” says Mary Kosuth, a co-author of the study of tap water, beer and sea salt.

“Scientists had been finding plastic debris in wildlife since the 1960s, when it began to appear in seabirds,” says Kosuth, now a research assistant at the University of Minnesota. “Then it was in the Sargasso Sea. Then it was in freshwater. As we learned that plastic was also in the fish we were eating and the water we were drinking, more people started to pay attention. Even the titles of the academic papers changed. The sentiment went from ‘ho hum’ to ‘Oh, my goodness!’”

Trawling for plastic in the Great Lakes

Mason’s passion for science and the environment began with an episode of the TV show “Diff’rent Strokes.” In season four, Kimberly, the sister of Arnold and Willis, washes her hair with contaminated water. When she takes the towel off, she screams: Her hair is green.

“That was the first time I realized that humans could have an adverse effect on the environment, and that there can be consequences for us,” Mason says.

She was 10 years old. The next year, for a school presentation, she squirted motor oil into a beaker filled with water. She swirled it, showing that the liquids wouldn’t mix. The teacher told her that was chemistry. It was the first time she had heard the word.

“From that point on, I always knew that I was going to be an environmental chemist,” she says.

Years later, at the University of Montana, where she would earn a doctoral in physical chemistry, Mason studied the chemicals that are present in the smoke plumes from forest fires. Her work was funded in part by NASA’s Earth System Science Fellowship Program.

By 2012, she was teaching at the State University of New York at Fredonia, near the southern shore of Lake Erie. Her first impression of the Great Lakes wasn’t a good one: Algal blooms were fouling the water and killing fish.

“I didn’t yet have an appreciation for the lakes,” she says. “I was more like, ‘This is disgusting.’”

That changed when she was invited aboard the U.S. Brig Niagara, a replica of Oliver Hazard Perry’s 1812 flagship, for a three-week teaching trip. The ship’s home port is in Erie, but in the summers, the Niagara sails the Great Lakes, often with students and research teams aboard.

“When you look at Lake Erie on a map, you think, ‘Yeah, that’s a lake,’” Mason says. “But when you’re out there on the water and you can’t see land, you get a very different sense of the size and scope of it. These lakes are enormous, and they’re all connected, but each is unique in some way. It just overwhelmed me, how beautiful they are.”

Her research would shift public perception again, upending what boaters, swimmers, and anglers know about the Great Lakes. Using a manta trawl, a fine-mesh net towed from a spinnaker pole, beyond the ship’s wake, she collected debris from the surfaces of lakes Erie, Huron and Superior. All but one of the 21 samples contained plastic, which she sorted into categories: fragments, foamed polystyrene, line, pellets and films.

Pellets and fragments were the most common form of plastic in the water. They accounted for 81% of the debris. Most of the pellets were blue, green, or purple — colors that are common in “rinse-off” cosmetic products, such as face-scrubs. Through microscopy and chemical analysis, Mason’s team determined that the pellets were microbeads, polymer abrasives that were added to personal-care products, including soaps and toothpaste, beginning in the 1990s. The plastic was cheaper and less abrasive than previous exfoliants, which had included salt, sugar and ground-up walnut shells.

When consumers used those personal-care products, the microbeads were washed down the drain and into municipal wastewater systems, which do not screen for debris that small. The plastic became part of our environment.

A ban on microbeads in cosmetics

Before her study of plastic in the Great Lakes was published — before she even stepped onto the ship, actually — Mason was fielding calls from journalists who wanted to know what was in the water. A writer for the Associated Press had learned about the project and wrote a story that appeared in regional newspapers. That led to additional stories, including a feature in the New York Times.

“It made a pretty big splash, which surprised all of us,” she says. “We hadn’t even begun the work.”

When the sail ended, Mason shared her data with media outlets, including the Buffalo News. A scientist in the Environmental Protection Bureau, a unit in the New York Attorney General’s office, read one of those stories and asked Mason for a meeting.

The scientist wrote a white paper, which amplified Mason’s overarching concern: Many plastic products include chemical additives — UV stabilizers, colorants and flame retardants — that are mixed into the polymers. Those chemicals can leach out when exposed to weathering and heat.

Immersed plastics also attract “hydrophobic pollutants” — chemicals that are present in the water and will quickly bind to a new host. Those pollutants, which include polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphnenyls (PCBs), and pesticides, all of which are believed to be toxic, are attracted to plastic. They accumulate on microbeads and polymer fibers until the chemical presence on the plastic is as much as one million times higher than it is in the water in which that plastic floats.

“Those chemicals are exceedingly long-lived,” Mason says. “We know they stick to plastic, at concentrations much, much higher than we find in the water, so that elevates the risk. When we ingest plastic, some really nasty stuff is coming in with it.”

The New York white paper spurred a legislative effort to ban the manufacturing, packaging and distribution of cosmetic products that included plastic microbeads. Seven states, including California and New Jersey, enacted bans. Eight counties in New York followed suit.

“We were already close to a tipping point, in terms of public awareness of plastics pollution,” says Marcus Eriksen, director of research at the 5 Gyres Institute and a co-author of Mason’s 2012 study. He provided the manta trawl and other equipment for the three-week Great Lakes excursion.

“Finding all those microbeads in the water — that was sort of the smoking gun,” Eriksen says. “It drew a straight line from the products we were buying to the pollution in the water.”

U.S. Sen. Kirsten Gillibrand, a Democrat from New York, proposed federal legislation, the Microbead-Free Waters Act of 2015, to balance the patchwork state-by-state approach to regulation. It passed unanimously, and with the support of cosmetic companies, which by then were under pressure from consumers to use alternative materials. President Barack Obama signed it into law on Dec. 28, 2015.

For Mason, that moment brought an immense sense of achievement.

“I felt a huge surge of humility, and appreciation, and accomplishment, all combined at the same time,” she says. “That 10-year-old in the back of my mind, that little girl who wanted to lessen human impact on the environment, she was just beaming.”

Science in the public interest

When the Niagara returned to port, Mason took an unusual step, for an academic: She shared her findings in real time, before the peer-review process was complete. A few colleagues questioned that decision, but Mason pressed forward. To her, it didn’t make sense to wait.

“Scientists tend to be very guarded, in the way we present information,” she says. “My style is a little different, I guess. I’m going to sound the alarm.”

At Penn State Behrend, Mason has fully embraced the public-facing approach. She still teaches, and she continues her research — a current study is focused on the debris that accumulates in litter booms and municipal street-sweepers — but she also manages broader sustainability initiatives across the college.

She was drawn to Behrend in part because of Wintergreen Gorge, a Natural Heritage Area with more than 14 miles of hiking and biking trails. The college has preserved much of that land, which is used for public recreation and as an environmental teaching space.

She also saw an opportunity to more broadly engage with students, faculty, and staff on varied but environmentally connected projects: a composting program in two student dining facilities, a season-extending high-tunnel greenhouse, a recycling system for filament from the college’s 3D printers, and a new hub site for the annual Worldwide Teach-In on Climate and Justice.

For that work, and for her continued study of microplastics, Mason was awarded the 2021 Great Lakes Leadership Award, which recognizes science and outreach efforts that raise awareness of critical issues in the Great Lakes ecosystem.

“My approach now is more holistic,” she says. “Every day, I meet people who care about these issues, who see the impact we are having on the planet and want to do better but aren’t sure where to start. I give them options. I find projects that fit their interests. I connect them to this broader community, so they know they aren’t alone.”

Every project she selects aligns with the 2030 Agenda for Sustainable Development, an environmental call to action by the United Nations member states. The document’s 17 goals expand the traditional “green” messaging — clean water, climate action, and habitat preservation — and map the ways other societal challenges, such as poverty and gender inequality, can hinder sustainability efforts.

“For me,” Mason says, “it’s always about science in the public interest. It’s about doing things that help to push our society in a better direction. Plastic pollution is a huge issue, with very real and proven consequences, and we need to find a solution. But plastic isn’t the only issue. To solve that problem — to solve any environmental problem, really — you have to be thinking about and trying to solve all these other, bigger issues. My goal is to make those connections, to engage people who want to make a difference, and to look for and support opportunities that move us all forward.”

This story first appeared in the Fall 2022 issue of Research/Penn State magazine.

Last Updated February 6, 2023