Radish study finds nanoplastics can reach edible parts of vegetables

Scientists warn that vegetables may harbor thousands of dangerous microplastics in their edible parts after a radish-based experiment by researchers at the University of Plymouth. The study sought to understand how plastic particles are absorbed during plant growth and found that nanoplastics — some as small as one millionth of a centimeter — can enter plant roots and spread to the edible tissue.

In a hydroponic setup, radishes were placed with their roots in a solution containing microplastic particles. After five days, analyses showed about 25 percent of the plastics accumulated in the edible root flesh, while roughly 10 percent reached the above-ground shoots. 'There is no reason to believe this is unique to this vegetable,' said Dr Nathaniel Clark, the study's lead author, 'there is the clear possibility that nanoplastics are being absorbed into various types of produce being grown all over the world.'

Clark stressed that the same methods suggested the phenomenon could apply to other crops, not just radishes. 'There is no reason to believe this is unique to radishes, and nanoplastics could accumulate in other crops grown worldwide,' he added. The researchers also used similar techniques to look at mollusks and fish, finding plastic particles in several species, indicating that accumulation in the environment crosses multiple food chains. 'To some extent, these findings shouldn't be a surprise—after all, in all our previous work we have found microplastic pollution everywhere we have looked for it,' said Professor Richard Thompson, a senior author on the study. 'However, this study provides clear evidence that particles in the environment can accumulate not only in seafood but also in vegetables. This work forms part of our growing understanding on accumulation, and the potentially harmful effects of micro- and nanoparticles on human health.'

Currently, research investigating how microplastics affect human health is still in its infancy, but a growing body of evidence suggests they could be harmful. Some rodent studies have linked exposure to high levels of microplastics to damage in organs such as the intestines, lungs, liver, and reproductive system. In humans, early studies have suggested possible associations with cardiovascular disease and bowel cancer.

Microplastics are defined as plastic particles smaller than five millimetres. They have entered oceans and waterways through weathering and improper disposal, and they can be transported by wind and water. The spread of microplastics into food and water supplies remains a growing concern for researchers and policymakers as they work to assess potential health risks and mitigation strategies.