Chewing gum releases hundreds of tiny plastic pieces straight into people's mouths, researchers said on Tuesday, also warning of the pollution created by the rubber-based sweet.
"I don't want to alarm people," Sanjay Mohanty, the lead researcher behind the new study which has not yet been peer-reviewed, told AFP.
There is no evidence directly showing that microplastics are harmful to human health, said Mohanty of the University of California, Los Angeles (UCLA).