Ingestion of microplastics during chewing gum consumption

Chewing gums typically contain plant-based or synthetic plastic polymers to improve their texture and flavor retention. These polymer fragments or microplastics can be released into the environment when disposed of improperly or ingested while chewing gums. Yet, how many microplastics a person may ingest while chewing gums is unknown. Analyzing microplastics released into saliva from 5 natural and 5 synthetic chewing gums, we found that each gram of chewing gum could release up to 637 microplastics, and 94 % of microplastics were released within the first 8 min of chewing. Surprisingly, synthetic chewing gum released a similar (p > 0.8) number of microplastics as natural or plant-based chewing gums. Microplastics released from the chewing gums were predominantly small, with a median size of 45.4 µm. Both of the chewing gum types released four types of plastic polymers—polyolefins, polyterephthalates (PET), polyacrylamides, and polystyrenes,— among which polyolefins were the most abundant. The result reveals that chewing gum consumption, irrespective of the type of chewing gums, could result in direct ingestion of microplastics. • Chewing gums released 4–636 microplastics g −1 to saliva. • Synthetic and natural chewing gums released similar numbers of microplastics. • 94 % of microplastics are released within the first 8 min of chewing. • Most microplastics released are smaller than 50 µm.