Chewing gum, a daily habit for millions of people maybe a significant source of microplastic contamination in the human body, according to a recent study by researchers at Queen’s University Belfast.
Plastics comprise part of the “gum base” in many chewing gum brands, but the average consumer would not know this from reading the label. The ingredients listed on many chewing gum brands will simply list “gum base” without further explanation.
The International Chewing Gum Association is equally vague about the composition of gum base. Its website describes gum base as “a combination of food-grade polymers, waxes, and softeners that give gum the texture desired by consumers.” It goes on to explain that polymers are a string of molecules that can either be found in the natural environment or may be manmade, and the manmade polymers “provide guaranteed consistency, quality, and purity that are not always found in some natural materials.”
The website also stresses that all polymers used in gum are “food-grade and legally permitted for use by international/national regulatory agencies.”
However, in an article in The Conversation, David Jones, a teaching fellow at the University of Portsmouth, gave more details on the ingredients found in most chewing gum.
“Chemical analysis shows that gum contains styrene-butadiene (the durable synthetic chemical used to make car tyres), polyethylene (the plastic used to make carrier bags and bottles) and polyvinyl acetate (woodglue) as well as some sweetener and flavouring,” Jones wrote.
He noted that the 730,000 metric tons of synthetic gum base produced each year does not biodegrade and can remain in the environment for decades. Over the years, it will harden, crack, and break down into microplastics.
While Jones’ article focused on the environmental impact of gum base, researchers at Queens University Belfast wanted to understand how microplastics might transfer to the human body through chewing gum.
To find out, they asked a middle-aged volunteer to chew gum for an hour while the team measured his saliva samples at two-minute intervals using automated Raman spectroscopy. They discovered that in one hour of gum chewing, an astonishing 251,244 microplastics were released, most of which occurred in the first twenty minutes of chewing.
The Queen’s University study indicated that a markedly higher number of microplastic particles were released during chewing compared to a similar study by researchers at UCLA, who found that an average of 100 microplastics were released per gram of gum over a 20-minute chewing period, although some types released as much as 600 microplastics per gram of gum. Depending on the size of the piece of gum, as much as 3,000 particles could be released.
However, the UCLA study noted that it could only identify microplastics that were 20 micrometers wide or larger due to the limitations of the instruments and techniques used, which may account for the discrepancy between the two studies.
While the exact effects of microplastics and nanoplastics on the human body are unclear, mounting evidence links these particles to a wide range of maladies, including strokes, heart attacks, dementia, hormone imbalances, and cancer.
Rachel Adams, a senior lecturer at Biomedical Science at Cardiff Metropolitan University, has suggested that ingesting microplastics could cause other potentially harmful effects, such as tissue-damaging inflammation and auto-immune responses, while serving as a carrier of for other toxins, the Daily Mail reported.