August 24, 2018
New York: If you are flushing your contact lenses, then you are contributing to the growing problem of microplastic pollution. According to a study presented at the American Chemical Society’s meeting, when you flush contacts down the toilet or wash them down the sink, lenses make their way to a wastewater treatment facility.
The lenses do not biodegrade easily, and they may fragment and make it into surface water, causing environmental damage, reported New York Times. A 2015 study found that there were 93,000 to 236,000 metric tons of microplastic swirling in the ocean.
Rolf Halden, the director of the Center for Environmental Health Engineering at Arizona State University, and Charles Rolsky, a graduate student and the study’s lead author, said filters keep some nonbiological waste out of wastewater treatment plants.
But lenses are flexible, so they squeeze through. Contact lenses also didn’t degrade when exposed to bacteria used to break down biological waste in treatment plants, as the study found. They were intact even after seven days.
“These are medical devices — you would not expect them to be super-biodegradable,” Dr. Halden said. “Good for the contact lens wearer during use, not so good when the things get out into the environment.”
The team also found a few fragments of contacts in treated waste, a sign that processing might break them into pieces, which could be ingested by marine animals later when they make it to water bodies.