Chewing gum releases hundreds of small plastic particles directly into people's mouths, say researchers, while warning of the environmental pollution caused by the gum-based candy. The study comes as researchers around the world are increasingly finding small plastic particles, known as microplastics, from mountain peaks to the ocean floor and even in the air we breathe. They have also found that the entire human body is contaminated with microplastics, including in the lungs, blood, and brain. This raises concerns about the potential impact on the Health .
"I don't want to alarm people," Sanjay Mohanty, lead researcher of the new study, which has not yet been peer-reviewed, told AFP. There is no direct evidence that microplastics are harmful to human health, said Mohanty of the University of California, Los Angeles (UCLA). Rather, the aim of the pilot study was to highlight another, still little-researched route through which these largely invisible pieces of plastic enter our bodies: chewing gum.
Lisa Lowe, a doctoral student at UCLA, chewed seven sticks of gum each from ten brands before researchers conducted a chemical analysis of her saliva. They found that one gram (0,04 ounces) of gum releases an average of 100 microplastic fragments, but some release more than 600. The average weight of a stick of gum is about 1,5 grams. A person who chews about 180 sticks of gum annually may ingest around 30 microplastic particles, the researchers say. This is negligible compared to the many other ways people ingest microplastics, Mohanty emphasized. Other researchers estimated last year, for example, that one liter (000 fluid ounces) of water in a plastic bottle contains an average of 34 microplastic particles.
The researchers said the most commonly sold chewing gum in supermarkets is so-called synthetic gum, which contains petroleum-based polymers to create the chewy effect. However, the packaging does not list the presence of plastics in the ingredients, simply stating "gum-based." "No one will reveal the ingredients," Mohanty said. The researchers tested five brands of synthetic gum and five brands of natural gum that use plant-based polymers such as tree resin. "It was surprising that we found abundant microplastics in both," Lowe told AFP.
David Jones, a researcher at Britain's University of Portsmouth who was not involved in the study, said he was surprised that the researchers found certain plastics not known to be present in chewing gum, suggesting they could have come from another source in the lab. But the overall results were "not surprising at all," he told AFP. People tend to panic when told that the building blocks of chewing gum are similar to those found in car tires, plastic bags, and bottles, Jones said. Oliver Jones, a chemistry professor at Australia's RMIT University, said that the relatively small amount of microplastics, if swallowed, "would probably pass right through the human body without any effect." "I don't think you need to stop chewing gum just yet." But Lowe warned about plastic pollution from chewing gum—especially when people "spit it out on the pavement."
The National Confectioners Association, which represents chewing gum manufacturers in the United States, said in a statement that the study authors acknowledged there was "no cause for concern." "The gum can be enjoyed safely, as it has been for over 100 years," it added. The ingredients are approved by the U.S. Food and Drug Administration. The study, submitted to a peer-reviewed journal, was presented at a meeting of the American Chemical Society in San Diego.