Already toxic for fauna and flora, pollution with plastic microparticles could eventually have serious consequences on human health, according to various studies.
- Since 1950, 8.3 billion tons of plastics have been produced, half of them in the last fifteen years. And plastic production should double again by 2040, according to Inserm.
- The size of microplastics is between 5 millimeters and a few hundred nanometers, or 70 times smaller than the thickness of a hair.
Microplastics, these plastic particles less than 5 millimeters in diameter, are a scourge for the environment, but also for human beings who, every week, would ingest about 5 grams, the equivalent of a credit, according to the WWF association. Disseminated throughout the air, nature and the food chain, we find them nestled in the body: in our stools, in the placenta, in breast milk, in our lungs, and even in our blood. What are the effects of this microplastic contamination on our health?
An “influence on the risk of developing diseases”
At present, according to ANSES, the most common microplastics are polyethylene, polypropylene and polystyrene. All these plastics contain various additives (to give flexibility or solidity for example) which “are potential chemical contaminants”but also “bacteria that can be biological contaminants”. However, although there is currently no real scientific consensus on the subject, “many elements suggest that these microparticles could influence the risk of certain cancerous, inflammatory or immune diseases”, says Mathilde Body-Malapelresearcher at the National Institute of Health and Medical Research (Inserm), who evokes the harmful “cocktail effect” of these microparticles.
Brain, intestines: microplastics attack our organs
First observation, microplastics attack the brain, according to South Korean researchers. Upon entering the body, they accumulate in microglial cells, small immune cells of the central nervous system, and disrupt their functioning. These cells eventually die and the brain is no longer protected by an effective immune response. Other studies revealed that microplastics could even, in time, participate in the proliferation of “superbugs” that are particularly resistant to antibiotics.
In view of experiences carried out on mice, food contamination with microplastics could also harm the proper functioning of our intestine, by altering the structure and immune function of the intestinal wall, and therefore the composition of the microbiota. The smallest plastic particles can even enter the bloodstream, the lymphatic system and even reach the liver. This is one of the main dangers of microplastics: that they end up reaching the organs.
The cells themselves are disrupted by microplastics
Other works have shown that microplastics act as endocrine disruptors, which have the unfortunate reputation of disrupting hormonal functioning and being the cause of many ailments, according to the authorities : decrease in the quality of sperm, alteration of the reproductive organs, lowering of the age of puberty…
Broadly speaking, microplastics can affect the very cells of the body, reveals a recent study. On the bleak agenda: cell death, allergic reactions, tissue damage, oxidative stress, damage to the genetic information of cells… So many cell disturbances that “can be the triggering event for many health problems”believe the researchers, who plead for more research to be carried out on the long-term health consequences of these microplastics.
