Vermouth, mussels and plastics

Microplastics are fragments of artificial polymeric material ranging in size from less than 5 mm down to 1 micrometre, the millionth part of a millimetre. These particles are sometimes manufactured specifically at this size, as in the case of pellets or abrasive materials used in cosmetic products, or they are formed by the fragmentation of larger plastic pieces, for example through the abrasion of tyres or the shedding of fibres from synthetic textiles such as polyester and polyamide.

Microplastics are found everywhere: in the air we breathe, in farmland, on mountain peaks, and many end up in seas and oceans, where they can be ingested by fish and other animals, in particular bivalves (mussels, scallops, oysters, clams, cockles, etc.), a class of molluscs that feed by filtering water or collecting particles from sediment. Thus, these organisms capture microplastics and in many cases cannot expel them; in fact, the plastics can remain in the animals even after the purification processes they undergo before reaching the market.

The Centre for Environmental, Food and Toxicological Technology (TecnATox) at the Universitat Rovira i Virgili has analysed the presence of these substances in more than 2,300 molluscs (mussels, oysters, tellins, razor clams, whelks and cockles) produced off the Catalan coast. In all the organisms they analysed, they found microplastics, mostly in the form of polyester fibres less than one millimetre in size.

It is estimated that the average adult consumer of shellfish ingests around 8,000 microplastics a year, a figure that can reach 20,000 a year in the case of heavy consumers. Unfortunately, molluscs and other aquatic organisms are not the only source of exposure to microplastics. They have been found in drinking water, both bottled and tap water, in table salt, in honey, in beer, and they can even be inhaled from face masks and indoor air.

Much research still needs to be done into the toxicity of microplastics, but there is growing evidence that these particles, and the substances they carry, affect our health. So, if we want to look after our health, the best thing we can do is look after the environment.