It is estimated that approximately 4.2 million in the United Kingdom wear contact lenses and one in five persons throws them away down the sink or toilet.
After being flushed, the lenses float through the wastewater system to sewage treatment plants.
Wastewater treatment facilities in the US simply don't do a good enough job of filtering out the tons of contact lenses that are disposed of through the sewer system, according to new research presented Sunday at the American Chemical Society's meeting in Boston.More news: Virgil van Dijk issues trophy challenge after Crystal Palace win
The researchers exposed five polymers found in many manufacturers' contact lenses to anaerobic and aerobic microorganisms present at wastewater treatment plants for varying times and performed Raman spectroscopy to analyze them. These microplastics can not be filtered out of the waste water unlike larger plastic particles. Currently, researchers are stating that disposing of these lenses down the drain could be adding to microplastic pollution in waterways. "We'd love to have a dialogue [with manufacturers] and establish a solid protocol for consumers to dispose of or even recycle their contact lenses", Rolsky says.
Direct observation of what happens to these lenses in a wastewater treatment plant was a challenge for several reasons.
Rolf's team - which was already involved in plastic pollution research - couldn't find a single study detailing what happens to these lenses after use. This is a pretty substantial number given that it is estimated around 45m people in the country use contact lenses, many of which are disposed of daily.
'With the toilet, although it might be tempting you shouldn't flush wet wipes, kitchen roll or anything other than toilet roll down the loo, ' Michelle Ringland, head of marketing at Lanes Group tells Metro.co.uk.More news: UCF ranked No. 21 in preseason AP top 25 poll
Many people rely on contact lenses to improve their vision.
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.
Halden said people don't think of the lenses as plastic waste because they feel like fluid, nearly like water. "Once these lenses dry, they become incredibly brittle and will very likely shatter into very small particles". They can take their used packaging and lenses to any of more than 2,000 participating doctors' offices. These animals belong to a long food chain.
Contact lenses are a godsend to those with ocular difficulties. "We found that there were noticeable changes in the bonds of the contact lenses after long-term treatment with the plant's microbes", says Kelkar. Halden remarks, "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". By tallying this detritus and studying how it persists in this environment, the study provides the first estimate of the potential burden of these tiny plastics, or microplastics.More news: South Koreans meet relatives in North after decades apart