Tests have found that a single plastic tea bag sheds billions of microplastic particles into each cup.
These tests, carried out by a Canadian Team, found that steeping a plastic tea bag releases around 11.6 billion microplastics - microscopic pieces of plastic measuring between 100 nanometers - 5 millimetres. All of this plastic in just one cup of tea.
These findings are some of the highest for microplastic consumption in food and drink.
“That it is a lot when compared to other foods that contain microplastics” says Nathalie Tufenkji from McGill University.
“Table salt, which has a relatively high microplastic content, has been reported to contain approximately 0.005 micrograms of plastic per gram salt. A cup of tea contains thousands of times greater mass of plastic, at 16 micrograms per cup”
Tufenkji’s team tested four different teas bags from cafes and shops in Montreal, cutting them open and washing them, steeping them in 95°C Water, and analysing the water through electron microscopes and spectroscopy.
The team also used a control factor of uncut tea bags; which were used to check that cutting the bags was not the cause of the microplastics being leached out.
There are great concerns as to the toxicity of these plastic tea bags.
Despite microplastics increasingly being found in drinking water, the World Health Organisation says there is no evidence of health risks for humans.
Unconvinced by this statement, Tufenkji and her colleagues exposed water fleas to the contaminated water.
“The particles did not kill the water fleas, but did cause significant behavioural effects and developmental malformations” she says, but highlighted that more research would need to be done to understand the health impacts on humans consuming these large quantities of microplastics, especially on a regular basis.
Meanwhile, Tufenkji advises that people avoid plastic tea bags.
“Tea can be purchased in paper tea bags, or as loose-leaf tea, which eliminates the need for this single-use plastic packaging”