Contact lens can make your eyes look big and bright, and it is a must-have item for many women. However, a new study recently released at the annual meeting and exhibition of the American Chemical Society reminds people that contact lenses such as “cosmetic eye contacts” should not be thrown away, so as not to cause pollution of plastic particles in rivers.
Researchers at Arizona State University found that in the United States, about 45 million people wear contact lenses, and 15% to 20% of them will throw used contact lenses into the toilet or sink. It is estimated that they will enter the US sewers every year. The total weight of the glasses is 6 to 10 tons.
Contact lenses are usually made of materials such as silicone hydrogels and are plastics. The researchers selected five commercially available contact lens materials and exposed them to anaerobic and aerobic microbial environments used in wastewater treatment plants, and then detected by Raman spectroscopy. They found that after long-term treatment with the microorganisms used in the sewage treatment plant, the contact lenses physically degraded and eventually formed plastic particles.
These plastic particles are discharged into the natural environment with the treated sewage, posing a threat to aquatic organisms.
Because glasses usually break down into smaller pieces, they make them easy to eat by aquatic wildlife. In the past, studies have shown that plastics can easily return to the human table by eating plastic fish. In other words, if you throw the contact lens into the toilet, you will eat it again soon.
Researchers have called for contact lens manufacturers to include hints on packaging to remind people not to throw discarded contact lenses into the sewer, but rather to treat them with other solid waste.