Plastic pollution represents a global environmental challenge, and once in the environment plastic can fragment into smaller and smaller pieces.
A new study shows for the first time that some of the tiniest particles found in the environment can be absorbed into the edible sections of crops during the growing process.
The research used radishes to demonstrate, for the first time, that nanoplastics – some measuring as little as one millionth of a centimetre in diameter – can enter the roots, before spreading and accumulating into the edible parts of the plant.
The researchers say the findings reveal another potential pathway for humans and animals to unintentionally consume nanoplastics and other particles and fibres that are increasingly present in the environment.
It also underscores the need for further research to investigate what is an emerging food safety issue, and the precise impacts it could have on environmental and human health.
The study – published in the journal Environmental Research – involved experts in plant science, environmental chemistry and plastic pollution from the University of Plymouth.
It applied similar techniques to those previously used by the team to demonstrate the rapid uptake of plastic nanoparticles by commercially important species of molluscs and fish, adding evidence that these particles can move and build up throughout the food chain.
For the new research, scientists placed radishes in a hydroponic growing system, with the plant’s non-fleshy roots in contact with a solution of polystyrene nanoparticles that contained radiolabeled carbon.
After five days, they examined how far into the plant the particles had penetrated, finding that nearly 5% of those originally in the solution had been retained by the root system – amounting to millions of nanoplastics entering the crop.
Of those particles, around a quarter had made their way into the edible fleshy roots, while 10% had accumulated in the leaves.
Dr Nathaniel Clark
Professor Richard Thompson OBE FRS
