The presumptions of impacts of plastic pollution on human, animal and even plant health were very heavy, but this is the first time that a pathology formally related to its ingestion is described scientifically. And all indications are that this new kind of disease is just the beginning of a very long list of harms from the plastic that saturates the entire planet.
By Antoine Palangié
Young and adults, they struggle to feed, have growth problems, are less resistant to diseases, die prematurely. They are the pale-footed puffins of Lord Howe Island, small seabirds that nest on a rock lost in the Pacific 600 km away from Australia. The problem could therefore seem anecdotal, but precisely: if a population so far away from human activities is so severely affected, it is a very, very bad omen for the health of the oceans and the planet as a whole.
And since puffins are not particularly sensitive birds and the pollution of their habitat is not particularly acute, there is no reason to think that other vertebrate species, including mammals and ultimately humans, are not affected, conclude the researchers behind the publication. (www.sciencedirect.com/Plasticosis)
Permanent injury
Plastic has the very big defect of its very great qualities: as it repels water, is non-putrescible, it is not biodegradable and therefore particularly indigestible. When birds swallow pieces, they injure the inner walls of their digestive tract. These repeated aggressions, coupled with the inflammatory reaction of rejection of these foreign bodies, cause thickening and stiffening of scar tissue which gradually replace the superficial functional tissues in charge, for example, of nutrient uptake.
Worse, non-biodegradable means bio-accumulative, and plastic waste piles up in birds, making up to 10% of chicks’ weight. More plastic, so more wounds and more inflammation, so less functional tissue: this is the vicious mechanism of plasticosis.
Small is NOT beautiful
What about humans? Of course, unlike many animals, we know how to detect a bottle cap or a styrofoam bead in our food and do not consciously swallow particles large enough to be visible. But microplastics – the mostly invisible particles that result from the erosion and fragmentation of macroscopic plastic – are ubiquitous in our packaging, the food we eat, the water we drink, the clothes we wear, the air we breathe… to the point that studies show that we ingest an average of 5 grams per week, as much as in a credit card! (PDF: Assessing plastic ingestion from nature to people)
Research on the health impact of plastic pollution is only beginning, but the first findings are worrying: the fineness of certain synthetic fibres, such as those used in disposable masks, and the extreme division of plastics in the environment allows its particles to penetrate so deeply into the body that they are found in the lung tissue, in the blood, in the placenta.
These tiny fragments cannot open wounds as larger pieces do and have no intrinsic acute toxicity. Yet it is these finer particles that worry researchers the most: because they behave like mini-magnets for other real poisons like heavy metals and VOCs, nanoplastics are potentially the Trojan horse of the worst pollutants up to the brain or even DNA if it turns out that they actually cross cell walls and blood-brain barrier.
Additional source on Microglial phagocytosis of polystyrene microplastics results in immune alteration and apoptosis in vitro and in vivo
https://pubmed.ncbi.nlm.nih.gov/34627918/