Chewing gum was found to release hundreds of tiny microplastic particles directly into people's mouths, researchers announced on Tuesday.
This revelation comes amid growing concerns about the presence of microplastics in various environments, from mountaintops to the deepest parts of the ocean, and even in the air we breathe.
The research, conducted by scientists from the University of California, Los Angeles (UCLA), highlights yet another unexamined route through which these minute plastic fragments enter the human body. The pilot study explored how chewing gum, often perceived as an innocent treat, could be contributing to the widespread problem of plastic pollution.
"I don't want to alarm people," Sanjay Mohanty, the lead researcher and professor at UCLA, stated during an interview with the foreign news agency.
"However, our findings shed light on a previously overlooked source of microplastics." While Mohanty clarified that there is no direct evidence linking microplastics to harmful health effects, the study's results are concerning.
Lisa Lowe, a PhD student at UCLA, chewed seven pieces of gum from ten different brands for the study. Following this, the researchers conducted a chemical analysis of her saliva. The results revealed that a gram of gum (approximately 0.04 ounces) released an average of 100 microplastic fragments, with some brands shedding more than 600 pieces. As the average weight of a stick of gum is around 1.5 grams, it means that individuals chewing approximately 180 pieces of gum a year could be ingesting up to 30,000 microplastic particles.
Although this number pales in comparison to other common sources of microplastics, Mohanty emphasized that the study draws attention to another little-explored method of microplastic ingestion. For instance, other research has estimated that a litre of water from a plastic bottle may contain as many as 240,000 microplastic pieces.
The majority of gum sold in supermarkets is synthetic, made with petroleum-based polymers, researchers explained. Despite this, the packaging typically lists only the vague term "gum-based" and does not mention plastics specifically. "Nobody will tell you the ingredients," Mohanty remarked.
The researchers tested both synthetic and natural gums, which use plant-based polymers such as tree sap, and were surprised to find that microplastics were present in both types. Lowe added that the majority of microplastics were released within the first eight minutes of chewing.
David Jones, a researcher at the University of Portsmouth in the UK, expressed his surprise at the findings. While he was not involved in the study, Jones suggested that the plastics discovered might have come from sources other than the gum itself. Despite this, he stated that the overall findings were "not at all surprising."
He explained that people often react with shock when they learn that chewing gum shares similar building blocks with materials found in car tyres, plastic bags, and bottles.
Lowe also highlighted the environmental implications of chewing gum, particularly when discarded improperly. "The plastic pollution from gum becomes a significant issue, especially when people spit it out onto the sidewalk," she noted.
The study has been submitted for publication in a peer-reviewed journal and was presented at a meeting of the American Chemical Society in San Diego. A request for comment from Wrigley, the world's largest chewing gum manufacturer, went unanswered.
