Some tea producers are moving in the direction of replacing traditional paper bags with plastic bags.
From a study published in the scientific journal Environmental Science and Technology, researchers at Canadian McGill University in Montreal took four different types of tea bags, all made of nylon.
The researchers found that these sachets, in contact with heat, release an incredible amount of microplastics into the tea.
To conduct their analysis, the researchers used four different teabags packed in plastic bags.
- They cut the tea bags, removed the tea leaves and washed the empty tea bags.
- They then heated the tea bags in water containers to simulate the infusion conditions.
- Using electron microscopy, the team found that a single plastic tea bag at infusion temperature released about 11.6 billion microplastic particles and 3.1 billion nanoplastic particles into the water, the latter less than 100 nanometres in size (a human hair, for example, measures 75 thousand nanometres).
These levels were thousands of times higher than those previously reported in other foods.
What are the health risks of microplastics?
According to a recent study presented at the Plastic Health Summit in Amsterdam, microplastics kill cells in the human immune system.
Although the risks to humans from microplastics have not yet been established, it is known that every day we ingest a large amount of plastic, hidden in the drinks and food we eat.
Scientists have also tested the effects of these particles on some specimens of daphnia magna, a small marine crustacean often used in laboratories, recording that, although they survived, the organisms showed anatomical and behavioural abnormalities.
The advice is to orient your choice towards alternative materials or loose tea, as this has nothing to do with the quality of the leaves used for the decoction, but depends on the box in which they are contained.