Researchers found that chewing gum releases thousands of microplastics into our saliva.
Over the past few years, scientists have discovered microplastics in disturbing places, from Arctic ice to human blood, testicles, and even the brain. In fact, plastic is so widespread that it triggered a new era of geology. Now, researchers have added chewing gum to their growing list of products that expose humans to microplastics.
A team of researchers revealed that chewing a piece of gum can release hundreds to thousands of microplastics into our saliva, which is likely to be ingested. The researchers presented a pilot study at the American Chemical Society (ACS) spring meeting on Tuesday.
“Our goal is not to be alert to anyone,” Sanjay Mohanty, an engineer at UCLA, said in an ACS statement. “Scientists don't know if microplastics are not safe for us. There is no human trial. But we know we have been exposed to plastic in our daily lives, and that's what we want to check here.” Although more research is needed, it's worth noting that previous studies have linked microplastics to health complications.
Scientists previously estimated that people consume at least 50,000 microplastics per year. In view of this assessment, Mohanty and his colleagues decided to study the amount of microplastics that chewing gum is being released. They tested 10 commercially available brands: 5 synthetic glues and five natural glues. To avoid considering different saliva and chewing methods, the team had only one participant chewing seven of each brand.
“Our initial assumption was that the synthetic gums would have more microplastics because alkali is a type of plastic,” explained Lisa Lowe, a graduate student at Mohanty's Lab.
When participants chewed each piece of gum, the researchers took saliva samples at different time intervals. They then measure the amount of microplastic in the sample by staining red and staining them with a microscope or by a technique called Fourier conversion infrared spectroscopy, which can identify components in the mixture.
Ultimately, the team found that chewing gum released an average of 100 microplastics per gram of chewing gum, while 94% of the total microplastics recorded in the study were released within the first eight minutes of chewing. The release of microplastics is the result of the mechanics of chewing abrasives, which separates particles from the gum rather than from saliva.
“It's surprising that both synthetic and natural gums release similar amounts of microplastics when we chew,” Lowe said.
Some gum sticks released up to 600 microplastics per gram. According to estimates of 160 to 180 per year, although some sources approach the number 300, a person may swallow only about 30,000 microplastics from chewing gum each year. As the researchers' instruments limit them to detect microplastics 20 microns or larger, smaller particles may make that number higher.
Additionally, “the plastic released into the saliva is a small part of the gums,” Mohanty notes, meaning that once it is done, it still causes environmental plastic pollution. “So be careful about the environment and don’t just throw it outside or stick it to the gum wall.”
