Pfas in plastics and packaging: they are chemical compounds not present in nature, not biodegradable and harmful to health

Like all the medals that are respected, also the Pfas, an acronym of the perfluoroalkyl and polifluoroalkyl substances, have their shiny side and their dark side.

The chemical compounds of these families, which number about 4700, were created in the laboratory and widely used since the 1950s in the food packaging industry, in pesticides, in non-stick pans, in cardboard containers, in fire foams, in shampoos , in paints, in stain-resistant products and in many other applications.

In plastics we find them in the form of elastomers (Vinylidene fluoride, Fluorurates in general, Tetrafluoroethylene) or in polymeric materials (Magnesium salt-sodium-fluoride of silicic acid).

The advantages of these substances, applied to finished products, lies in their water repellency, oil-repellency and thermo-resistance , which allow us to make, for example, a waterproof jacket , not to stick an egg to the pan , not to get dirty mayonnaise or oily substances when we eat a sandwich filled with paper and not let our hands get dirty in the cinema when we eat popcorn.

Their chemical bond composed of fluorine and carbon makes the resulting molecule an element irreplaceable today in industrial applications, but also makes it non-biodegradable and extremely dangerous, as it is odorless, tasteless and colorless.

These characteristics allow it to be easily dispersed in water, soil and air, remaining to damage the environment and human health for a long time.

The plants absorb the Pfas through the irrigation water, they give it to the fruits and the animals , of which they feed and thus, magically end up on our tables and in our body.

From the health point of view, many studies have shown that the accumulation of these substances in the human body can favor spontaneous abortions, alter fertility, cause testicular, thyroid and kidney cancer.

What are the means available today to defend ourselves from the sneaky pollution of the Pfas?

At present there are not many: we can count on active carbon filters in which the porosity of the filtering carbon has shown a certain effectiveness in intercepting the Pfas, but it is not an effective system on all molecules.

But once again, biochemistry could give us an answer to the problem as a team of American researchers has discovered a bacterium, called Acidimicrobium A6 , which would have the characteristic of breaking the bond between fluorine and carbon in Pfas.

The bacterium was discovered in an American swamp and studied for a long time as a result of its ability to split ammonium, exploiting the iron present in the soil, without using oxygen.

This named reaction, Feammox , was reproduced in the laboratory, after cultivating new strains of bacteria and subjecting the new families to other tests relating to the substances present in the waste water.

After 100 days of cultivation in waters containing, among others, also the Pfas, it was noticed that the bacterium had the ability to break down the two main binders, fluorine and carbon, reducing them by 60%.

The discovery could be interesting, not only in the liquid contaminated by Pfas, but also in the soils because the bacterium acts in hypoxic conditions, that is of poor oxygen.