Nanoplastics in food: this is why it is (still) important to talk about it

Of Daniela Maurizi

Despite the awareness of the need to limit the use of single-use plastics, and the certainty that microplastics come from the most unexpected sources (remember fleece clothing and contact lenses), there still remain fundamental gaps in the knowledge of nanoplastics due to the lack of techniques effective analytics. Let’s see together what the most recent studies have discovered on the subject and understand, as consumers, what we can do to protect our health and that of the Planet.

What is plastic doing in our food?

To open this discussion, it will be important to clarify a fundamental aspect: when we talk about microplastics we are referring to residues ranging from 1 µm to 5 mm in length; nanoplastics, on the other hand, have decidedly smaller dimensions, even below 1 μm. It is the latter in particular that have raised the most concerns, since they are believed to be more toxic: their smaller size makes them, in fact, much more suitable for entering the human body than microplastics.

But how does plastic get into our food? Unfortunately, no part of the food supply chain is free from the risk of contamination. This depends on the level of environmental pollution to which ecosystems, in their integrity, are now exposed. Think for example of our seas: it is no secret that there is an enormous concentration of plastic in the oceans due to pollution coming mainly from population centers which, by discharging into rivers or directly into the sea, devastate the marine ecosystem. This means that many aquatic animal species, starting with fish and molluscs – which are real sponges for polluting agents – ingest many of these micro and nano particles of plastic, which naturally end up on our tables together with them.

Not only that: contamination can occur at multiple levels, not just due to environmental pollution. In fact, nano and microplastics can enter food even during storage, since light and temperature favor the migration of contaminants from packaging to food. It is no coincidence that MOCA, materials and objects in contact with food, are subject to strict European regulations, specifically:

• The general requirements that all materials in contact with food must meet are governed by the EC framework regulation 1935/2004;
• Good manufacturing practices for materials and articles intended to come into contact with food are described in EC regulation 2023/2006;
• Regulation (EU) No. 10/2011 specifies the rules for verifying the composition of plastic materials of objects intended to come into contact with food.

The actual risks to our health

Given their danger, nanoparticles have been the subject of many studies to assess the real extent of the risk of food contamination. A recent study, promoted by Columbia University and published in the scientific journal Proceedings of the National Academy of Sciences (PNAS), has developed a powerful optical imaging technique for the rapid analysis of nanoplastics with unprecedented sensitivity and specificity. Until now, in fact, the great limitation has always been the impossibility of observing the detection of nanoplastics with analytical precision, managing to precisely identify only microplastic residues, therefore of larger dimensions. Thanks to this study, which focused mainly on the presence of nanoplastics inside one-litre water bottles, it was possible to quantify the presence of over 105 particles in each liter of water in each bottle, a value two or three orders higher than magnitude compared to results reported by previous studies, which focused only on large microplastics.

Within the European Union, EFSA, the European Food Safety Authority, supervises the health of citizens. In fact, this body regularly monitors the food market and submits its scientific opinions to the European Commission, which is responsible for formulating and updating the regulations in force accordingly. An example is given by the new evaluation of the health risks caused by bisphenol (BPA), a chemical substance generally used in combination with other substances to produce plastics and resins. It is used for example to produce reusable containers for water dispensers, drinks and food storage, but also for epoxy resins used in films and internal coatings for cans and containers for food and drink.

According to what emerged from EFSA’s analysis, BPA-based products can transmigrate in small quantities into the foods and drinks they contain: this is why EFSA scientists periodically review their safety in light of new data available. I don’t want to generate alarm, but it is right to specify that the conclusion of the scientific committee was to declare BPA dangerous for health, since it can affect the organism, genetics and nutrition.

Becoming aware consumers: how to protect our tables

I often hear people who try to shop healthily and safely ask me how to behave when faced with these risks. The first thought that we must always keep in mind is that, fortunately for us, by the time the food products arrive on the supermarket shelves, they have already gone through a long process of safety and quality controls, with the constant supervision of the national authorities. and Europeans ready to avoid the danger of fraudulent activities.

This obviously does not exempt us from paying a little more attention, not only for our health, but also for respect for the environment: trying to reduce to a minimum, if not eliminate, the consumption of disposable plastics inside the home is an excellent way to avoid putting them back into the large disposal cycle which could, unfortunately, lead to them polluting ecosystems. For example, where possible, we always prefer to consume tap water, at most by applying purifiers in our sinks, rather than purchasing cases of bottled water.

For all those materials intended for contact with food (MOCA), if we want to be sure that they are suitable, we can identify symbols on the packaging that certify the origin of the packaging materials. For example, the FSC brand (whose logo depicts a sapling) indicates that the paper used to produce that packaging comes from raw materials deriving from forests correctly managed with respect for the environment.

Finally, my advice is always to read the labels and prefer organic foods: it will be easy to identify them since it will not be enough for it to say “bio” or “organic” on the package, but the organic symbol must be present, i.e. a leaf white on a green background made up of stars.