Patricia Corcoran has joined a global fight to curb plastic pollution.

A geologist and Western University Earth sciences professor, Patricia became interested in plastic pollution when she made a shocking discovery in 2012.

She and visual artist Kelly Jazvac were on Kamilo Beach on the island of Hawaii and discovered a bizarre phenomenon: stone formed through the intermingling of melted plastic, beach sediment, lava rock and coral fragments, and organic debris. With oceanographer Charles Moore, they coined the term “plastiglomerate,” capturing the world’s attention in a landmark 2014 study.  

That work led Patricia to focus on microplastics – pellets less than five millimetres in size – and how they are showing up in natural environments. Using sedimentary geology techniques, Patricia's pioneering research traced when microplastics initially appeared in the Great Lakes, and she was the first to publish on their plastic pollution levels. She later mapped the rise and fall of microplastic pollution compared to major economic downturns.

“Microplastics are bad because unlike larger discarded plastic items, they’re affecting thousands of organisms on the food chain, from plankton to animals as large as whales.”

Not only can they become lodged in the gastrointestinal tracts of animals, studies show if a very small animal ingests microplastic and is then eaten by a larger animal, that plastic can move up the food chain.

“If those plastics carry toxic chemical substances, the chemicals can become more concentrated and dangerous to species throughout the food chain – including humans.”

There is evidence the toxic pollutants in the microplastics are impacting the reproductive rates of some species and could result in other long-term health effects.

In 2018, Patricia and her team studied 66 beaches along the Great Lakes. In the sand, they discovered a shocking abundance of two to five millimetre pellets, which are the building blocks of everyday plastic products. Their research shows these pellets were particularly prevalent on Baxter Beach (near Sarnia, Ont.), Rossport Beach, (on the north shore of Lake Superior) and Bronte Beach (on the western shore of Lake Ontario near Oakville, Ont.).  

When they returned six years later, nothing had changed.  

“We found two of the three beaches that were the most contaminated with pellets in 2018, were still the most contaminated in 2024.”

Patricia’s research has also helped identify major but lesser-known sources of microplastics, including tire wear, industrial plastic pellets and particles from paints and coatings. Understanding where the pollution originates, she says, is essential for developing effective solutions.

“If you want to make policy, then you need to have the facts to back it up. And you can't make up facts. You actually have to do the scientific research to find those facts.”

Patricia and her team took their evidence to academic conferences, government workshops, advocacy groups and the public, and partnered with an environmental group to drive change. Patricia helped develop the Canada-wide Strategy on Zero Plastic Waste, an action plan to mitigate plastic pollution.

“Plastic pellet manufacturers can put screens in their drains to easily capture pellets. That was one of the things we proposed. It’s that simple.”

Today, Patricia also collaborates with Chippewas of the Thames First Nation and communities in the Northwest Territories to study how microplastics and associated chemicals move through local environments and food systems.

Patricia is quick to point out that collaboration is essential in making a positive impact.  

“None of this is done alone. Our work involves chemists, biologists, artists, humanities scholars, social scientists and local communities.”

And in the larger effort to stop plastic pollution, citizens have a huge role to play.  

“It's everyone’s responsibility. Don't buy certain products if you don't want them to keep being produced. If you buy single-use plastics and then just toss them, you're contributing to the waste problem. If you're selling plastic straws, you're contributing to the problem. Every day, we have the ability to choose a replacement to make a positive impact.”