Did you know that according to a study carried out in 2019 we can find around 11.6 billion microplastics in a cup of tea?
Before explaining how we find these particles in our tea, it is important to understand how they form in the environment.
What are microplastics and how are they formed?
According to the Portuguese Environment Agency, microplastics are plastic particles less than 5 mm in size. To understand how they are formed, it is important to know better the material that gives them origin: plastic.
Plastics comprise more than 20 families of polymers, including polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PUR), polystyrene (PS) and polyamide (PA), which represent around 90% of total world production. In addition to the main polymer, plastics contain a series of additives to improve certain properties such as: ductility, hardness, durability or climate resistance. In relation to some of these additives, especially certain plasticizers, there is a strong suspicion that they are endocrine disruptors for animals and humans.
Once in the environment, these plastics undergo mechanical (erosion, abrasion), chemical (photo-oxidation, temperature, corrosion) and biological (degradation by microorganisms) degradation. The fragmentation of plastic is considered an infinite process that can continue down to the molecular level and can lead to the continuous formation of microplastics and even nano plastic particles (particles smaller than 1 µm) in the environment.
Microplastics in tea
So where do these microparticles that we can find in our cup of tea come from?
Although many of us are unaware, most of the tea bags we find on sale are made from materials such as nylon, polypropylene and other polymers or paper coated with epichlorohydrin (a potentially carcinogenic substance), so as not to dissolve in water and subsequently sealed with plastic derivatives
Why do we continue to use these materials?
If it is scientifically documented that plastic easily releases small particles that pass from packaging (water bottles, tea bags) into the environment, why do we continue to use it? Plastic is a very versatile, cheap and easy-to-produce material and we still have a long way to go before it is replaced by other more ecological materials with less environmental impact.
It is estimated that each year we ingest between 39 and 52,000 microplastic particles
Regarding the impact that microplastics could have on our body, no study has yet been carried out that could objectively assess the long-term impact that a material with such a variable composition could have on a system as complex as the human body, which is already exposed to so many stimuli on a daily basis. .
The negative points of tea bags don't stop there.
Tea bags cannot be recycled or placed in the composter and can take hundreds of years to decompose.
Agência Portuguesa do Ambiente, “Microplásticos”, disponível em https://apambiente.pt/residuos/microplasticos, consultado a 14/01/2024
Ali, T., Habib, A., et al., "Health risks posed by microplastics in tea bags: microplastic pollution – a truly global problem"
Hernandez, L. xu, Elvis, Larson, H. et al. , "Plastic Teabags Release Billions of Microparticles and Nanoparticles into Tea", Environmental Science & Technology 2019 53 (21), 12300-12310
Parker, Laura, “Microplastics are in our bodies. How much do they harm us?, National Geographic, published May 8, 2023, disponivel em https://www.nationalgeographic.com/environment/article/microplastics-are-in-our-bodies-how-much-do-they-harm-us