ASU study: Flushing contact lenses can harm environment

PHOENIX — An ASU study found that billions of contact lenses are flushed down the drain in the United States each year, which could produce plastic pollution.

Charles Rolsky, a PhD student and member of the ASU study, told ASU Now that 45 million people in the U.S. wear contacts, 15 to 20 percent of whom flush them down the toilet or sink.

With the amount of contacts each person goes through, he estimated that 1.8 to 3.36 billion lenses — at least 20 metric tons worth — are flushed annually.

The study found that lenses are moved to wastewater-treatment plants and turned into microplastics as they break down.

As microplastics get caught in sewage sludge, they can enter the ecosystem.

Some animals think the microplastics are food and eat it, bringing it into the food chain.

“Some microplastics eventually can find their way into the human food supply, causing inadvertent uptake and unwanted human exposures to both the plastic polymer and a spectrum of environmental contaminants,” ASU Now wrote.

The group presented its findings at the National Meeting and Exposition of the American Chemical Society earlier this week.

According to ASU Now, this is the first nationwide study on how contact lens disposal can effect the environment.

“I had worn glasses and contact lenses for most of my adult life,” said Rolf Halden, director of the Biodesign Institute’s Center for Environmental Health Engineering at ASU. “But I started to wonder, has anyone done research on what happens to these plastic lenses after their useful lifespan is over?”

Based on the group’s findings, Halden gave recommendations to fix this issue.

He said the contact producers should provide disposal information on packaging and users should put contacts in the garbage, not down the drain.

Long-term, Halden advised, it would help if lenses could be created to be “inert” while consumers use them but “degradable” in the environment.

Follow @KTAR923