ASU researcher asks: What happens to contacts after their lifespan is over? 
 
 ASU researcher asks: What happens to contacts after their lifespan is over? 
 
 ASU scientists report 1st nationwide study showing environmental costs of lenses 
 
 Every year, about 45 million Americans rely on contact lenses to see the world more clearly. This $2.7 billion U.S. market has made contact lenses more comfortable and disposable. Every day, these plastic lenses are tossed away by consumers in various ways, perhaps without much thought to their ultimate environmental fate. 
 
 Now, Arizona State University scientists are reporting the first nationwide study that shows consumers, by discarding used lenses down the drain, may be unknowingly contributing to plastic pollution. 
 
 The ASU research team is presenting their results today at the 256th National Meeting and Exposition of the American Chemical Society (ACS), held in Boston from August 19–23. 
 
 The inspiration for this work first began from personal experience. 
 
 “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?” 
 
 Halden, Charles Rolsky and a third member of the team, Varun Kelkar, began to investigate. 
 
 His team had already been working on plastic pollution research, and it was a startling wake-up call when they couldn’t find studies on what happens to contact lenses after use. 
 
 “Then we began looking into the U.S. market and conducted a survey of contact-lens wearers,” said Rolsky, a PhD student who is presenting the work. 
 
 “We found that 15 to 20 percent of contact-lens wearers are flushing the lenses down the sink or toilet," he said. “This is a pretty large number, considering roughly 45 million people in the U.S. alone wear contact lenses, amounting to 1.8–3.36 billion lenses flushed per year, or about 20–23 metric tons of wastewater-borne plastics annually." 
 
 They examined the fate of 13 different contact-lens brands made from nine different types of plastic polymers. 
 
 Lenses that are washed down the drain typically are conveyed to wastewater-treatment plants. The study showed that wastewater plants fragment them into microplastics, which accumulate in sewage sludge. For about every two pounds of wastewater sludge, a pair of contact lenses typically can be found. 
 
 Sewage sludge is an abundant material routinely applied on land for sludge disposal and soil conditioning, thereby creating a pathway of macro- and microplastics from lenses to enter terrestrial ecosystems where potential adverse impacts are poorly understood, Halden said. 
 
 Entry of wastewater-borne contact lenses into aquatic environments also is a potential concern, although it was not directly observed in the study. However, it is known that run-off from sludge-amended soils can pollute surface waters. Fragmented contact lenses also may pass through the wastewater-treatment plant to enter surface waters as microplastics contained in reclaimed water. 
 
 Aquatic organisms are known to mistake microplastics for food, introducing the indigestible plastics into long food chains. 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 that tend to stick to the surface of plastics. 
 
 Analyzing what happens to contact lenses and lens fragments once emitted by wastewater-treatment plants has been a challenge for researchers. First, contact lenses are transparent, which makes them difficult to observe in the complicated milieu of a wastewater-treatment plant. Second, the unusual plastics used in contact lenses — a combination of poly(methylmethacrylate), silicones and fluoropolymers to create a soft material that allows oxygen to pass through the lens to the eye — are not routinely screened for environmental monitoring studies. Thus, pollution from contact lenses has avoided detection until now. 

 Rebecca Rosenberg typically throws away her contacts in the trash, but occasionally disposes of them in the toilet “either because my trash was empty and I didn’t want them to stick to the bottom, or when I’m really mad at them for hurting my eye, I angrily flush to say goodbye,” she says. “Sometimes the toilet is also just closer.” 
 
 And Celia Eckert doesn’t dispose of them in the toilet, but does flush them down the sink, “usually because they accidentally get in there,” she says. She rinses them down the drain because “they’re natural-ish … They’re in your body.” 
 
 Approximately 14 billion contact lenses get discarded every year in the United States, 3 billion of which are flushed down the toilet or sink, says Rolf Halden, the director of the Biodesign Center for Environmental Health Engineering at Arizona State University and one of the authors of the new study. The issue with flushing them, he says, is that the contacts don’t decompose, and as a result, nearly 50 tons of contacts could end up in American water supplies each year. 
 
 His study, one of the first of its kind, surveyed 409 contacts wearers on their disposal habits and found each year that approximately 28,000 pounds of lenses end up being turned into treated sewage sludge that’s used as crop fertilizer. That means that tiny pieces of transparent plastic, known as microplastic, are sinking into the soil, which could then impact small animals, insects, and even end up in groundwater sources that eventually flow into the ocean. 
 
 So far, studies on the effects of microplastics have primarily focused on oceans, but researchers are beginning to study the impacts on land as well, and it’s not pretty. The environmental and health effects of microplastics are “a big topic that’s being focused on, and is kind of the hot question right now: How bad is the problem actually?” says Lisa Watkins, a graduate student and the lead of Cornell University’s Soil and Water Lab microplastics-research team. The answer is unclear. “We find that earthworms carry that plastic [from the sewage sludge] into their burrows,” Watkins says. “But there haven’t been that many studies on what happens to plastics on land.” 
 
 Halden acknowledges that there’s a lack of concrete evidence for the lasting effects. “If [microplastics] get out in sewage sludge and end up in the environment, they might pose a risk to aquatic organisms—think mussels and fish,” he says. “We don’t know if these plastics go up the food chain. Earthworms take them up, birds could eat them, and what happens when a bird ingests the contact lens? Does it disrupt the G.I. tract? These are all unanswered questions.” 
 
 Despite the need for more evidence, Nick Mallos, the director of the Trash Free Seas program at the Ocean Conservancy, remains concerned about how these improperly disposed-of contact lenses could be affecting waterways. “Any amount of plastic that is getting into the environment has a potential impact,” he says. “It’s really important that we not get fixated on the magnitude of inputs. Certainly, when we think of solutions and how we prioritize interventions, it’s important to think about those trade-offs. But for something like this, we know the source, and it really is a simple fix.” 

 CLOSE This odd vessel looks like a cross between an oil rig and a floating swimming pool and may help clean up the Great Pacific Garbage Patch. USA TODAY 
 
 Researcher Charles Rolsky of Arizona State University, who was part of the team that looked into issues surrounding recycling of contact lenses, at work in the laboratory. Photo by Todd MacMillan (Photo: @gotoddrun, ) 
 
 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. 
 
 How a disposable contact lense appears after going through a sewage treatment center (Photo: Arizona State University) 
 
 The ASU study, being 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. 
 
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 Image copyright Getty Images 
 
 Researchers in the US have been investigating the final journeys taken by disposable contact lenses. 
 
 They found 15-20% of US users simply flick these fiddly lenses down the drain via the bathroom sink or toilet. 
 
 The Arizona State University study suggests that much of the plastic material then ends up in waste water treatment plants. 
 
 The lenses are consequently spread on farmland as sewage sludge, increasing plastic pollution in the environment. 
 
 Around 45m people wear contacts in the US, while rates in other countries vary, with between 5 and 15% of the population in Europe using them. 
 
 Over the last decade, the use of softer plastic contact lenses has grown rapidly with people using daily, weekly or monthly disposables in greater numbers than ever before. 
 
 This new study suggests that in the US at least, around 14 billion lenses are thrown away, amounting to around 200,000kg (441,000lb) of plastic waste every year. 
 
 Image copyright Charles Rolsky Image caption A contact lens recovered from sewage sludge 
 
 The authors of the study surveyed wearers in the US and found that 15-20% of them flick their lenses down sinks and toilets, meaning they will most likely end up in waste water treatment plants. 
 
 Much of the waste water material ends up as a digested sludge which is then often spread on farmland. The authors estimate that around 13,000kg of contact lens plastic ends up deposited in this way. 
 
 "They persist during water treatment, they become part of sewage sludge," Prof Rolf Halden, from the Centre for Environmental Health Engineering at Arizona State told BBC News. 
 
 "We know that whatever's in sludge can make its way into runoff from heavy rains, back into surface water and that is a conduit to the oceans; there is the potential of these lenses being taken on quite a journey." 
 
 Image copyright AFP Image caption Contact lenses can accumulate in sewage sludge before it is spread on farm land 
 
 The researchers are concerned that this poses an ecological risk and may allow the accumulation of persistent toxic pollutants in vulnerable organisms such as worms and birds. 
 
 "If earthworms consume the soil and birds feed on it, then you could see that plastic make the same journey as is done by plastics debris in oceans, they are incorporated by biota that are also part of the human food chain," said Prof Halden. 
 
 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. 
 
 To work out the impact of waste water plants on these materials, the researchers exposed five polymers in contact lenses to anaerobic and aerobic micro-organisms commonly found in these treatment facilities. 
 
 Image copyright Getty Images Image caption Lenses will dry out quickly and shatter forming smaller pieces of plastic 
 
 "We found that there were noticeable changes in the bonds of the contact lenses after long-term treatment with the plant's microbes," said Varun Kelkar, one of the authors from Arizona State University. 
 
 "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." 
 
 The researchers want manufacturers to provide information on the label, informing people how to properly dispose of their contacts. 
 
 Lenses are not generally recycled, although one of the largest manufacturers Bausch + Lomb introduced a programme last year. 
 
 The authors of the study say that lenses should be recycled where this is possible, but if not they should be disposed of by putting them in with other solid, non-recyclable waste. 
 
 "The simple fix to this is for people not to put the lenses down the sink or shower or toilet!" said Prof Halden. 
 
 "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." 
 
 The research has been presented at the national meeting of the American Chemical Society in Boston.
– If you're one of the approximately 45 million Americans who wear contact lenses, researchers at Arizona State University have a request based on their new study: Stop flushing them down the sink or toilet. The researchers concluded that disposing of lenses this way—and they estimate that up to 20% of wearers do so—takes a surprisingly large environmental toll. The study, presented at the National Meeting and Exposition of the American Chemical Society, estimates that up to 3.36 billion lenses get flushed per year, and that amounts to about 50,000 pounds of plastic, reports USA Today. The problem is that the lenses don't just dissolve when they reach wastewater treatment plants—they break down into potentially dangerous microplastics that wind up in sewage sludge, and that sludge is routinely applied on land for soil conditioning. "We know that whatever's in sludge can make its way into runoff from heavy rains, back into surface water and that is a conduit to the oceans," researcher Rolf Halden tells the BBC. "There is the potential of these lenses being taken on quite a journey." One remedy is obvious, notes the Atlantic. The researchers looked at 11 brands and did not find any directions for proper disposal. Users should skip the sink or toilet and instead put their contacts with their solid trash, though one hope for the future is that manufacturers will get better about recycling old lenses. As of now, the researchers say that only one major manufacturer, Bausch + Lomb, is seriously pursuing such an initiative. (This contact lens wearer recently got a bizarre, 28-year-old surprise.)