Plastic pollution is not only a problem for oceans and wildlife. It may also be affecting the very food we eat. A new study highlights how nanoplastics can penetrate crops, raising questions about food safety and human health.

Researchers have now shown that some of the smallest plastic particles can move into edible vegetable tissues.

Using radishes as their model, the team demonstrated that nanoplastics can enter roots and travel into the fleshy edible parts. These plastic particles measure as little as one millionth of a centimetre, making them nearly invisible but not harmless.

This work reveals a potential pathway for humans and animals to consume nanoplastics, beyond seafood and water sources.

The findings also call attention to an emerging food safety concern that could impact agriculture worldwide. If nanoplastics can enter vegetables during growth, then the issue extends far beyond marine ecosystems.

How plastic enters vegetables

The team at the University of Plymouth designed an experiment using a hydroponic system. Radishes were exposed to a solution of polystyrene nanoparticles tagged with radiolabeled carbon. After five days, the researchers measured how many particles were absorbed.

The experts discovered that nearly 5% of the original particles entered the plant. Millions of nanoplastics accumulated in the roots, with about a quarter moving into the edible tissues.

Even the leaves showed traces, holding around 10% of the absorbed particles. This provides direct evidence that nanoplastics are not confined to root surfaces but move throughout plant systems.

Plastic crosses plant barriers

“Plants have a layer within their roots called the Casparian strip, which should act as a form of filter against particles, many of which can be harmful,” noted Dr. Nathaniel Clark, the study’s lead author.

“This is the first time a study has demonstrated nanoplastic particles could get beyond that barrier, with the potential for them to accumulate within plants and be passed on to anything that consumes them.”

According to Dr. Clark, there is no reason to believe this is unique to this vegetable, with the clear possibility that nanoplastics are being absorbed into various types of produce being grown all over the world.

Plastic pollution beyond vegetables

This experiment builds on earlier work by the same team. They previously found that plastic nanoparticles can rapidly accumulate in fish and shellfish, adding to evidence that such particles move through the food chain.

The new results show that vegetables may also be part of this cycle, meaning exposure could come from both seafood and plant-based diets.

The University of Plymouth has led research on microplastics for over two decades. Their studies have documented plastic particles in extreme environments, from ocean depths to mountain peaks.

The researchers have also traced major sources, such as tire wear, laundry fibers, paint, and degraded waste. Their findings have influenced international policies on plastic pollution and driven greater awareness of hidden plastic pathways.

What this means for health

Study senior author Professor Richard Thompson is head of the University of Plymouth International Marine Litter Research Unit.

“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 Thompson.

“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.”

The discovery matters because the food chain is interconnected. When crops absorb nanoplastics, these particles may pass on to livestock that consume them, eventually reaching humans through multiple dietary routes.

Unlike larger plastics, nanoplastics are difficult to detect and nearly impossible to remove once inside biological tissues. This means exposure could be occurring daily, in small but continuous amounts.

Saving vegetables from plastics

The study makes it clear that plastic pollution does not remain confined to oceans and rivers. It can infiltrate plants, move into our diets, and possibly affect human health in ways we do not yet fully understand.

With plastic production still rising, questions about its long-term effects on food safety are only becoming more urgent.

Future research will need to explore whether different crops absorb nanoplastics at varying levels, and what this means for nutrition and health risks. Understanding these pathways is essential if we are to limit exposure and protect both ecosystems and people.

The study is published in the journal Environmental Research.

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