Flushing with contact lenses in the sink or toilet contributes to the plastic pollution in oceans and rivers – and could even lead to them being served in our food, new research has warned.
Approximately 4.2 million people in the United Kingdom wear contact lenses, and one in five carriers carries them through the drainage system instead of with other solid waste – sometimes after just one day of use.
Now a US-based research team has shown for the first time how they can be eaten by fish and other marine life and is returned to us on our plates.
The study, presented at a meeting of the American Chemical Society in Boston, was inspired by personal experience.
Dr. Rolf Halden, environmental engineer at Arizona State University, said: "I had worn glasses and contact lenses for most of my adult life.
Flushing contact lenses in the sink or toilet contributes to plastic pollution in oceans and rivers, a new study has warned (file photo)
& # 39; But I started to wonder if someone has done research on what happens to these plastic lenses? & # 39;
His team had already done research on plastic pollution and it was a surprising wake-up call when they could not find relevant studies.
Lab member Charlie Rolsky, a PhD student, told the conference: "We started looking at the American market and conducted a survey of 139 people.
& # 39; We found 19 percent of contact carriers flushing the lenses through the sink or toilet. & # 39;
He added: & # 39; This is a fairly large number, as approximately 45 million people in the US only wear contact lenses. & # 39;
The team estimates that up to 10 tons of plastic lenses end up in wastewater every year in the US.
Because they are denser than water, they sink and endanger the aquatic life, especially soil feeds that they can swallow, explained Dr. Halden.
But transparent material is difficult to observe in wastewater. Moreover, contact lenses of plastics used in other products, such as polypropylene, are found to be found in everything from automotive batteries to textiles.
They are often made with a combination of poly (methyl methacrylate), silicone and fluoropolymers to create a softer material that allows oxygen to pass through the lens. It is therefore unclear how wastewater treatment affects them.
In the first study of its kind, five polymers found in many contact lenses were scanned after being exposed to microorganisms in wastewater treatment plants for various periods of time.
A research team estimated that up to 10 tons of plastic lenses end up in wastewater every year in the US (file photo)
Research assistant Varun Kelkar said: & # 39; We discovered that there were noticeable changes in the sutures of the contact lenses after long-term treatment with the microbes of the plant. "
The microbes actually changed the surface of the lenses, causing the plastic polymers to become weaker.
Mr. Kelkar said:" When the plastic loses some of its structural strength, it will physically break down. to smaller plastic particles that would ultimately lead to the formation of microplastics. "
Aquatic organisms can confuse microplastics for food and since plastics are indigestible, this has a dramatic effect on the digestive system of marine animals. These animals are part of a long food chain.
Some eventually find their way to the food supply, which can cause people to be exposed to plastic contaminants and contaminants that stick to the surfaces.
By paying attention to the problem, the team hopes that the lens manufacturers will take it into account and at least give a label on the packaging that describes how they can be properly disposed of with other solid waste.
Dr Halden added: "Ultimately, we hope that manufacturers will do more research on how the lenses affect life in the water and how quickly the lenses degrade in a marine environment. & # 39;
Microplastics are particles that measure less than five millimeters (0.2 inches). Improper disposal has meant that tons of waste have found its way to the ocean. They have been found in three of the four deep-sea fish.
The amount of plastic waste in the world's oceans will outweigh the fish by 2050 unless the world takes drastic measures to further recycle. More than 80 percent of the tap water in the world is contaminated with plastic.
Scientists warn that microplastics are so small that they can penetrate organs. We have found that creatures of all shapes and sizes have consumed the plastics, directly or indirectly.
Previous research has also shown that microplastics absorb toxic chemicals, which are then released into the intestines of animals.