Nanoplastics reach edible parts of radishes in Plymouth study

Researchers from the University of Plymouth have warned that nanoplastic particles can accumulate in vegetables, potentially entering edible tissues during the growing process. In a hydroponic study using radishes, researchers demonstrated that nanoplastics — some as small as one millionth of a centimeter — can penetrate root tissue and migrate into the parts of the plant that are eaten.

Over five days, the team exposed radish roots to a solution containing microplastic particles and then analyzed how far the particles spread. They found that about 25 percent of the accumulated plastics reached the edible fleshy root, while roughly 10 percent extended into the shoots. The researchers note that the radish was the model, but they believe the same dynamics would apply to other vegetables grown in similar conditions.

Dr. Nathaniel Clark, the study's lead author, cautioned that there is no reason to believe this is unique to radishes and warned of the possibility that nanoplastics could be absorbed by various types of produce grown around the world.

Using the same techniques, the team also found evidence of plastic particles in several mollusk and fish species, reinforcing the idea that microplastics can accumulate across different food chains. Professor Richard Thompson, a senior author on the study, said the findings align with prior work showing microplastic pollution is widespread and added that this study provides clear evidence that particles in the environment can accumulate not only in seafood but also in vegetables, contributing to understanding of potential health effects.

Health implications remain under study. Scientists say microplastics can carry toxic or carcinogenic chemicals, and some rodent studies have shown organ damage after high levels of exposure, including effects on the intestines, lungs, liver, and reproductive system. Human studies are early, but some research has suggested links between microplastic exposure and cardiovascular disease and bowel cancer. Experts caution that more research is needed to establish cause and effect in humans.

Microplastics are defined as plastic particles smaller than five millimeters. They originate from wear and tear of clothing and carpets, degraded products, or waste that enters waterways. The global picture is stark: analyses have warned that plastic waste dumped into oceans could outstrip fish by 2050 if trends continue; and numerous studies have shown microplastics in tap water around the world, with reported contamination in many nations. In this context, the Plymouth study adds to a growing body of evidence that microplastics can permeate food sources, including vegetables, not just seafood.

Researchers say the findings justify continued investigation into how nanoplastics move through soil or hydroponic systems and how processing might alter exposure. The team emphasizes that their work is an early step in understanding the exposure pathway and notes that reducing microplastic pollution remains urgent.