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New Study Reveals Exactly Why Flushing Your Contact Lenses Down The Toilet Is A Bad Idea

By Alex Maxx

Our oceans are filled with plastic, and as it continue to worsen and impact the environment and animals in it, people are learning ways to be more sustainable. One of the most recent warnings? Contact lenses being flushed down the toilet.

Scientists are giving a warning to the 45 million people who wear contact lenses in the United States: don't flush them! 

Recent research was presented by authors from Arizona State University, at the meeting for the American Chemical Society in Boston. Said research shows that the current wastewater treatment facilities cannot filter out the 1.8 to 3.3 billion contact lenses that are flushed down the toilet every year.

Charles Rolsky, lead author of the study, said this translates to "about 20 to 23 metric tons of wastewater-borne plastics annually."

Researchers interviewed waste treatment employees, who confirmed that they can see lenses in the wastewater. Director of ASU's Center for Environmental Health Engineering Rolf Haden explained that although the plastic particles might be small, microplastics are anything but a small issue:

"It sounds like a very small problem, because the lenses themselves are tiny, but they come by the billions." 

Flushing contact lenses is contributing to polluting oceans with even more plastic, and in turn, harming animals. But, it affects a lot more than animals and our waterways: these lenses can end up on our dinner plates.

Up to 51 trillion microplastics, weighing a whopping 236,000 tons, are floating in the ocean, making them a massive source of pollution. Microplastics end up being ingested by organisms that live in the ocean, including fish, and studies have shown that this sometimes means the fish we eat are filled with plastic.

Varun Kelkar, co-author of this study, explained how microplastics form:

"We found that there were noticeable changes in the bonds of the contact lenses after long-term treatment with the plant’s microbes. When the plastic loses some of its structural strength, it will break down physically. This leads to smaller plastic particles which would ultimately lead to the formation of microplastics."

How many people are tossing their used lenses in the toilet? About one in five.