A new study shows that hundreds of tons of plastic are building at the bottom of the Great Lakes and Lake Erie alone has about 380 tons of plastic. A similar scenario is possible for Lake Ontario. Plastic is no stranger to the Great Lakes and studies have shown and mapped how certain plastics move at the surface. This is the first we have a look at how the plastic moves in 3D.
“There’s been plastic found in tap water that’s sourced from the lakes,” said Juliette Daily, third year PhD student at RIT, “there’s been plastic found in beer that used water sourced from the lakes.”
Several different types of plastics were analyzed as some have different buoyancies. “We estimate that about 60 percent are negatively buoyant, so it will start to sink after entering the lake”, said Daily.
Population was used to estimate how much pollution was entering the system. Lake Erie has about double the population as Lake Ontario, but pollution may mirror each other. “We can look at surface samples and kind of make an estimate on how much plastic is at the surface, but these numbers are usually off by orders of magnitude, so there’s a lot of missing plastic.”
Matthew Hoffman is an associate professor at the school of mathematical sciences and says the plastic underneath the surface is something like 50 times as much as what sits at the surface. “Plastic is definitely changing the bottom of our lakes,” said Hoffman. “When you look at the 3D pathways, a lot of it is going to end up sitting at the bottom, so people have already found in the sediment that there’s a lot more plastic in there than there is in the water.”
Certain plastics do evolve as they enter into water as some fall apart and sinks while others may turn into microbeads. The scientists plan on modeling Lake Ontario over the next few years. That may give a clue into how some plastic could travel over Niagara Falls from Lake Erie to Lake Ontario.
At this time, there have been no significant studies that how how plastic impacts human health. Plastic has been found in every aspect of our lives, but it still has not shown to alter health. It has shown to impact animals and the environment.