Now you can add your favorite chewing gum to the list, thanks to the alarming findings of a new study. Chewing gum, whether natural or synthetic, contains plant-based or synthetic plastic polymers to enhance texture and flavor retention,

“Our initial hypothesis was that the synthetic gums would have a lot more microplastics because the base is a type of plastic,” Lisa Lowe, the study’s co-collaborator and a graduate student in Mohanty’s lab, explained in a statement. (Yes, certain types of synthetic gum contain petroleum-based polymers.)

They found that a gram (0.04 ounces) of gum released an average of 100 microplastic fragments, though some shed more than 600. The average weight of a stick of gum is around 1.5 grams. People who chew around 180 pieces of gum a year could be ingesting roughly 30,000 microplastics, the researchers said.