British scientists from the University of Plymouth have shown for the first time that nanoplastics can penetrate the edible parts of vegetables, bypassing the natural barriers of the root. An experiment with radishes in hydroponics confirmed this: in five days, almost 5% of polystyrene nanoparticles introduced into the solution ended up in the root system, with about a quarter of this volume in the fleshy (edible) part of the root crop; some of the particles also reached the above-ground shoots. The results are published in the journal Environmental Research.
The authors emphasize that the particles are able to cross the Casparian strip, a hydrophobic barrier in the root that normally prevents harmful substances from entering the plant's vascular system. This indicates the potential translocation of nanoplastics throughout the plant during vegetation.
The experiment was laboratory and did not fully replicate agricultural conditions (hydroponics and ^14C-labeled polystyrene nanoparticles were used), however, according to the team, the established mechanism is likely relevant to other crops. Head of the microplastics department, Professor Richard Thompson, emphasizes: the problem of plastic pollution concerns not only the sea and seafood - now the path of nanoplastics entering plant products has been demonstrated.
The university reported the work as "the first evidence" of plastic nanoparticles accumulating in edible vegetable tissue, noting the need for further research into field scenarios, soil concentrations, and actual risks to human health.
Context: Nanoplastics are particles smaller than 1 micron in size that are formed when larger plastics break down. Previously, the focus has been on their presence in aquatic ecosystems and seafood; the current work expands the understanding of their entry into the food chain through plant products.
