Gourmet tea that comes in “silken” bags instead of paper has been found to shed billions of particles of microplastics when brewed. A new study from McGill University in Montreal, led by Nathalie Tufenkji, a professor of chemical engineering, investigated several different plastic tea bags to see if they broke down when steeped. What they discovered was alarming.
Brewing the bags at a temperature of 95°C releases around 11.6 billion microplastics—tiny pieces of plastic between 100 nanometers and 5 millimeters in size—into a single cup! “We were shocked when we saw billions of particles in a single cup of tea,” Tufenkji told CBC News. One cup from a single tea bag could contain 11.6 billion microplastic and 3.1 billion nanoplastic particles, the researchers estimated from their results.
That amount far exceeds all quantities found in food and drinks to date—including tap and bottled water, beer, honey, fish and shellfish, chicken, and salt. Tufenkji said, “We think that it is a lot when compared to other foods that contain microplastics. Table salt, which has a relatively high microplastic content, has been reported to contain approximately 0.005 micrograms plastic per gram salt. A cup of tea contains thousands of times greater mass of plastic, at 16 micrograms per cup.”
Tufenkji said this is because for most foods and beverages, the plastic is an accidental contaminant. With this tea, “you’re literally adding plastic into the beverage.”
Whether or not this is a health hazard remains unclear. The World Health Organization has stated that plastic particles in drinking water are a “low” risk to humans at their current levels. The Tea and Herbal Association of Canada also said that “the materials used in the tea bags in the study, PET (polyethylene terephthalate, found in plastic drink bottles) and nylon (used in many food bags and pouches), have been deemed safe for use in contact with hot food and beverages.”
Overall, there is no evidence yet that microparticles pose a risk to human health—although that may just be because there isn’t much data on the impact of microplastics on human health. “There’s really no research. But this really points to the need to do those studies,” Tufenkji said. “Think of people who drink one or two or three cups of tea a day, every day.”
To see what sort of impact the potentially toxic particles had on a living thing, Tufenkji and her team conducted a test on water fleas. “The particles did not kill the water fleas but did cause significant behavioral effects and developmental malformations,” Tufenkji told New Scientist. She said the results point to the need for more studies on the particles’ effects and also to see if other plastic packaging might be releasing particles into food and beverages.
Tufenkji said, “Personally, I would say avoid the plastic tea bags because it’s just another single-use plastic. Tea can be purchased in paper tea bags or as loose-leaf tea, which eliminates the need for this single-use plastic packaging.”
In the end, even if it is not bad for your health, it certainly is bad for the environment. There’s no need to use it when there are sustainable non-plastic options available!
