Contact Lenses Not Biodegradable, Fragments Found in Water

Marco Green
Августа 20, 2018

A new study done by researchers out of Arizona State University released this weekend says many users dispose of their old contact lenses by flushing them, instead of placing them in trash cans.

"These are medical devices - you would not expect them to be super-biodegradable", the Director of the Center for Environmental Health Engineering at Arizona State University, Rolf Halden, told the Times.

"We found that there were noticeable changes in the bonds of the contact lenses after long-term treatment with the plant's microbes", Kelkar said in a statement.

Some 4.2million people in the United Kingdom wear contact lenses, and one in five wearers dispose of them through the drainage system instead of with other solid waste - sometimes after just a single day's use.

Even if the whole contact lens does not escape through waste water filters, the fragments of them can be risky, too, contaminating the environment.

The researchers say the plastics used for contact lenses can likely soak up contaminants from the sludge at wastewater treatment plants.

Many people rely on contact lenses to improve their vision.

"They are a real improvement in quality of life and are a justified use of plastic, so if we decide as a society that we want to use plastic for these purposes, we should also present the consumer with the chance to get rid of these materials in a responsible fashion". When they lose their firmness, they break down into smaller chunks, causing them to eventually turn into microplastics that can't be filtered out by conventional water filtration methods.

That's because a new study finds that discarding contacts lenses in these ways may ultimately end up contributing to microplastic pollution in waterways.

Analyzing what happens to contact lenses and lens fragments once emitted by wastewater-treatment plants has been a challenge for researchers.

He added: 'This is a pretty large number, considering roughly 45 million people in the U.S. alone wear contact lenses'.

They found 15-20% of US users simply flick these fiddly lenses down the drain via the bathroom sink or toilet. These animals are part of a long food chain. Further, the plastics used in contact lenses are different from other plastic waste, such as polypropylene, which can be found in everything from auto batteries to textiles. They found that 19 percent of contact lens wearers flushed them down the drain when they didn't need them anymore.

"This began as an exploratory venture but we have information to support the fragmentation of contact lenses into microplastics within a wastewater treatment plant", said Charles Rolsky, one of the study's authors and a graduate student at ASU.

Contact lenses are often made from a mixture of acrylic glass, silicones and fluoropolymers that allows manufacturers to create a softer plastic material which permits oxygen to pass through to the eye. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies.

"Ultimately, we hope that manufacturers will conduct more research on how the lenses impact aquatic life and how fast the lenses degrade in a marine environment".

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