BUFFALO, N.Y. -- The first region-wide study to look at how much plastic is in the rivers and streams that feed the Great Lakes has concerning numbers for the some 40 million people who rely on the lakes for drinking water.

Sherri Mason is a professor at SUNY Fredonia. About four years ago, she and a few other researchers embarked on the first large-scale plastics pollution study of the Great Lakes. Her latest research surveyed 29 water sources, making up 20 percent of the water that feeds into the Great Lakes. Every one of them had plastic pollution.

"For every large piece of plastic you see, there are literally millions of microplastics that you can't see," Mason said.

Mason worked with the U.S. Geological Survey on the study, the findings of which show the concentrations of plastic are highest in lakes Erie and Ontario.

"Lake Ontario the counts increased to on average, 230,000 plastic parts per square kilometer, a quarter of a million plastic particles per square kilometer," Mason said. "Outside of Toronto, we had our highest sample to date. It was 1.3 million plastic particles per square kilometer, and the counts that we're finding in the rivers are higher."

"Unfortunately, the Great Lakes have been sort of a dumping ground for various chemicals of concern really since the dawn of the industrial age," Mason added.

"We've done a lot of work in dredging out the contaminated sediments, restoring some of the habitats that continues to provide filtration and ecosystem services," Kerrie Gallo, Buffalo Niagara Riverkeepers Deputy executive director.

The worry is that plastic pollution compounds chemicals already in the waterways.

"Because of the nature of plastics, they tend to absorb these toxins onto their surface, so they basically become little poison pills in the water," Mason said. "They can actually accumulate toxins up to a million times greater than what's in the water."

Experts say the larger pieces of plastic are almost easier to deal with because they're easier to get out of the system, but those microplastics are a major concern. They say the best thing to do now is to stop those from getting into the system at the source, which starts with you the consumer.

"Every one of us has the ability to decide not to buy facial cleaners with microbeads in them," Gallo said.

Experts say plastic in the water is a health concern not just for people who eat fish from our waterways, but also for the millions of people who rely on the Great Lakes for drinking water because most treatment plants are not equipped to filter the millions of chemicals in the water.