Your daily cup of tea may come with billions of microplastics, according to a new Canadian study.
Plastic teabags — the ones that commonly come in a pyramid shape and are made of “silken” material — release approximately 11.6 billion microplastics and 3.1 billion nanoplastics when steeped into a single cup of hot water, researchers out of Montreal’s McGill University found.
“We were very, very surprised,” Dr. Nathalie Tufenkji, a professor of chemical engineering at McGill University and co-author of the study, told Global News.
“We thought [plastic teabags] maybe release a couple of hundred [plastic] particles, maybe a few thousand. So we were really shocked when we saw they’re releasing billions of particles into a cup of tea.”
Microplastics, which are tiny particles or fibres of plastic 5 mm or less in diameter, down to the microscopic level, have been detected in bottled water, drinking water, fish and sea salt in various studies.
Tufenkji said she decided to test silken tea bags after drinking a cup of tea one day and realized that boiling water may be breaking down the material in her cup.
She asked one of her PhD students if they would run some tests, and they agreed. The team then analyzed different brands of plastic teabags that they steeped in hot water for five minutes.
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“We used a very powerful microscope to look at what could be in the water,” Tufenkji explained, “and we did this by taking a small sample of the water and drying it on a flat surface and looking at what was left after the water had dried.
“That’s where we could see all these particles that are left behind.”
Tufenkji said they discovered two different types of plastic from teabags: polyethylene terephthalate (PET) and nylon.
The health effects of ingesting microplastics from teabags are not fully known, Tufenkji said, and more research is needed.
The World Health Organization recently released its first-ever report on microplastics in drinking water and concluded there’s not much evidence that ingesting these particles is harmful to human health.
But from an environmental perspective, single-use teabags are not great.
“In Canada, we’re trying to phase out the use of single use plastics,” she said.
“So just in that respect, my personal recommendation is to avoid using plastic teabags.”
— With a file from Leslie Young