Add millions of used contact lenses to the plastic waste that’s finding its way into oceans and lakes.
A new study released Sunday estimates that these slippery transparent discs, vital to the vision of an estimated 45 million Americans, are often flushed into the sewer instead of placed in the trash or recycled.
Worn for as little as a day, their small size contributes to the danger they could eventually wind up polluting a lake, river or go out to sea, says the study being presented at a conference by Arizona State University researchers.
“I wondered what happened to these lenses,” said Rolf Halden, director of ASU’s Biodesign Institute Center for Environmental Health Engineering. “In the bathroom, they can get lost in the sink or go down the toilet. I am an engineer, so let’s see how big the problem is.”
The answer, as it turns out, is that the problem is substantial. Up to 20 percent of wearers aren’t tossing their old lenses into waste containers, opting instead for disposal in sinks and toilets. But because lenses are made of such tough plastics, they don’t break down fully when exposed to microbes. ASU’s study found that after going through a sewage treatment plant, they become even smaller pieces, which can find their way into fish, birds or other animals.
Of about 14 billion contact lenses used in the U.S. every year, the study estimated that up to 50,000 pounds get flushed or otherwise go down the drain, most destined for waste treatment plants. Just how many end up in the ocean or waterways couldn’t be determined.
It’s a similar problem to other flotsam of daily life, from straws and forks to plastic bags. Recognition of how many plastic straws end up in the trash, and eventually the ocean, prompted Starbucks to say it is going to phase them out globally by 2020. McDonald’s plans to test alternatives in the U.S. later this year.
Researchers could find only one maker, Bausch + Lomb, that is seriously pursuing a contact lens recycling program. Since the program began in November 2016, the company says its One by One program has collected packaging waste and 2.5 million used lenses amounting to about 7 tons of waste.
“We are continuing it every year and continuing to raise awareness about it,” said Bausch + Lomb spokeswoman Kristy Marks.
Johnson & Johnson, which makes about 5 billion contact lenses a year through its popular Acuvue brand, has attacked the problem by reducing the amount of paper in its packaging and increasing the amount that can be recycled. It hasn’t put an emphasis on the lens itself, which it says weighs only 30 micrograms.
The ASU study, that was formally presented Sunday at a meeting of the American Chemical Society in Boston, found that used contact lenses are prevalent in wastewater sludge after sewage treatment. A pair of leftover lenses can usually be found in every 2 pounds of sludge, according to Charles Rolsky, a doctoral student who also worked on the study.
The problem is that since sludge is often deposited on land, those lenses can eventually wash into lakes or rivers where fish can consume them.
The answer, Halden believes, isn’t to ban contact lenses. Too many people, including himself, depend on them. And daily disposables, rather than the ones that people wear for a week or more, are one of the fastest-growing parts of the contact-lens market and more convenient and safe.
Rather, he said, the better solution is to encourage proper disposal. For its program, Bausch + Lomb partners with a company called TerraCycle that specializes in recycling smaller items that wouldn’t normally get separated in the standard process.
The issue with lenses is to deal with not only them but their packaging made up of foil and plastic, which has to be separated in order to go to recycling plants, said Rick Zultner, director of process and product development for TerraCycle.
“Every waste stream has its unique quirks,” he said.
The best ways to dispose of your contact lenses:
Bausch + Lomb has a recycling program that allows contact lens wearers to participate in either of two ways. They can take their used packaging and lenses to any of more than 2,000 participating doctors’ offices. Or they can mail them in directly to the recycling center that works with the company. The user puts their waste in a cardboard box, downloads a preprinted label and ships it.