Two recently published studies have made the elephant in the room even harder to ignore: the extremely serious problem that plastic represents for the environment and, consequently, for our health. An Austrian study has demonstrated, for the first time, that plastic is now also inside us. Not that it was difficult to predict — microplastics, those plastic fragments with a diameter ranging from 330 micrometres to 5 millimetres, have long since entered the food chain, and it was only a matter of time before they ended up in the stomach of an apex predator such as Homo sapiens.

Microplastics in faeces

The study conducted by researchers at the Medical University of Vienna and the Austrian Environment Agency showed for the first time the presence of microplastics in human faeces. The researchers analysed a small group of volunteers, consisting of just eight people from eight different countries: Austria, Italy, Finland, Japan, the Netherlands, Poland, Russia and the United Kingdom. Plastic particles were found in all of their stool samples; specifically, nine different types of plastic were identified, the most common being polypropylene and polyethylene terephthalate.

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Oceans of plastic

This news, as mentioned, is anything but surprising given that every year eight million tonnes of plastic pour into the oceans and that plastic is ingested by the majority of marine animals. A study published in 2015, for example, found that up to 90 per cent of seabirds around the world have plastic residues in their gut. And yet, perhaps, we had not yet fully grasped the scale of the problem — after all, this is an emerging field of study and not much is yet known about microplastics and their impact. The Austrian researchers estimated that more than 50 per cent of the world's population could have microplastics in their faeces.

The implications for our health

"This study, the first of its kind, confirms what we have long suspected — said Philipp Schwabl, a researcher at the Medical University of Vienna who led the study — namely that plastic ultimately reaches the human gut." This discovery could be important, according to Schwabl, for the study of gastrointestinal diseases that might be directly linked to the presence of microplastics in the intestine. Plastic particles could in fact weaken the gut's immune defences or poison the body with the pathogens and toxic chemicals they contain. "The smallest microplastics are capable of entering the bloodstream, the lymphatic system, and can even reach the liver," Schwabl explained. "Now that we have the first evidence of microplastics in humans, we need further research to understand what this means for our health."

Microplastics in table salt too

A study published in the journal Environmental Science & Technology on 4 October last year twisted the knife further, revealing that microplastics are present in 90 per cent of table salt samples analysed. The authors of the study, conducted by researchers at South Korea's Incheon University in collaboration with Greenpeace East Asia, analysed salt samples from 39 brands sourced from 21 countries across Europe, North and South America, Africa and Asia, finding plastic fragments in 36 of them (including three salt samples from Italy). "The results suggest that human ingestion of microplastics via seafood products is strongly correlated with plastic emissions or releases in a given area," explained one of the study's authors, Seung-Kyu Kim, professor of Marine Sciences at Incheon University. To prevent microplastics from posing an ever greater risk to our health and to the environment, there is only one solution: stop the introduction of plastic into the sea and drastically reduce its production.