More than 45 million Americans wear contact lenses — and many of them are unknowingly contributing to micro-plastic pollution in water.
Three researchers from Arizona State University presented their studies on the chemical and physical changes of contact lenses through water treatment processes on Sunday during the American Chemical Society’s National Meeting & Exposition.
The researchers anonymously surveyed and evaluated the disposal method of contact wearers and non-wearers and observed degradative effects on lenses.
Varyb Kelkar, Rolf Ulrich Halden, and Charles Rolsky hope more research can be done to properly rid the world of contact lens waste.
“We found that 15 to 20% of contact wearers are flushing the lenses down the sink or toilet,” Rolsky said.
Contact lenses are usually made with silicones, fluoropolymers, and poly(methylmethacrylate) to obtain the soft texture lenses need to appeal to the human eye.
“Once these lenses dry, they become incredibly brittle and will very likely shatter into very small particles,” ASU researcher Halden said, of the estimated “six to 10 metric tons of plastic” that end up in wastewater each year.
Kelkar explained, “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 micro-plastics.”
The NOAA’s National Ocean Service describes micro-plastics as plastic debris less than five millimeters in length, which is dangerous to fish who misidentify the particles as food.
Since Braush + Lomb is the only contact manufacturer that has a recycling program, the ASU research trio suggests throwing contact lenses “in the solid waste compartment of the house—the garbage can is preferable to the sink or the toilet.”