As the climate crisis worsens, we have heard a lot about the rising number of microplastics in the ocean, drinking water, and, increasingly, the food chain. But have you heard about the microplastics in your tea? Well, gird yourself. A new study from McGill University published in Environmental Science & Technology suggests that those pyramid-shaped "silken" teabags are leaching billions (yes, with a "b") of microplastic particles into your afternoon tea. Yum.
Nathalie Tufenkji, a chemical engineering professor at the Montreal-based school, purchased a tea bag like tat her local coffee shop, per the CBC. When she saw the bag looked like plastic, she asked a graduate student in her lab, Laura Hernandez, to buy similar bags from four different brands.
They conducted tests and discovered that there weren't just hundreds of thousands of parts micro- and nano-sized plastic particles, but billions. "We were shocked," she told the CBC. The study found that a cup using a single tea bag could contain as many as 11.6 billion microplastic particles and 3.1 billion nano-sized particles. This is an above-average number compared to other foods and beverages that have been found to have traces of microplastics. This is in part because micro- and nanoplastic materials are generally accidental contamination, Tufenkji notes, but in this instance "you're literally adding plastic into the beverage."
The study did not, however, look at whether this is an actual danger to humans. "Possible health effects of ingesting these particles are currently unknown," the report states. In a statement to the CBC, the Tea and Herbal Association of Canada said that the materials in these bags -- PET (polyethylene terephthalate) and nylon -- are safe for use in contact with hot consumables. The World Health Organization (WHO) previously stated that the risk of microplastics in drinking water is low.
Nonetheless, the long-term impact of microplastics on human health is unknown. "There's really no research. But this really points to the need to do those studies," Tufenkji told the CBC. "Think of people who drink one or two or three cups of tea a day, every day." She also notes that the microplastics themselves might keep some tea-drinkers away, but it should also be noted that these tea bags are yet another single-use plastic, which may provide more incentive to stick to loose-leaf and paper tea bags.