South Middlesex Times

Micro- and nanoscale plastic particles present in soil and water have been found to significantly increase the absorption of toxic chemicals by plants and human intestinal cells, according to two studies from Rutgers Health. These findings raise new concerns about food safety related to plastic pollution.

The first study, published in NanoImpact, discovered that lettuce exposed to both nanoscale plastic particles and common pollutants like arsenic absorbed more toxins than those exposed only to pollutants. A related study in the Microplastics journal demonstrated similar effects on human intestinal tissue.

The research suggests a potentially hazardous cycle of contamination. Micro and nano plastics could cause plants to absorb more toxic chemicals, which may then be consumed by humans. This increases the likelihood of our bodies absorbing both these toxins and the plastics themselves, posing heightened disease risks for vulnerable populations.

"We’ve already put about 7 billion metric tons of plastics into the environment that keep breaking apart," stated Philip Demokritou, director at the Nanoscience and Advanced Materials Center at Rutgers University and senior author of both studies. "They pollute everything around us – the water we drink, the food we eat, the air we breathe."

Using a model of the human small intestine along with a lab-based gastrointestinal apparatus simulating digestion, researchers found that nano-size plastic particles increased arsenic absorption nearly six-fold compared to arsenic exposure alone. The same effect was observed with boscalid, a pesticide.

Moreover, environmental pollutants also increased plastic absorption by intestinal tissue; plastic uptake doubled when toxins were present.

"We know nanoscale materials can bypass biological barriers," noted Demokritou. "The smaller the particles, the more they can bypass biological barriers in our bodies that protect us."

In another paper, researchers exposed lettuce plants to polystyrene particles sized 20 nanometers and 1,000 nanometers along with arsenic and boscalid. Smaller particles had a greater impact on arsenic uptake into edible plant tissues compared to exposure without plastics.

These effects were seen in hydroponic systems as well as realistic soil conditions. Advanced imaging showed that plastic particles accumulated in plant tissues with smaller ones moving from roots into shoots.

Micro- and nanoplastics originate from larger pieces breaking down over time. "Even if we stop today producing plastics or using plastics," said Demokritou, "we have plenty of plastic waste unfortunately out there."

This research is part of a USDA-funded project examining food safety issues related to micro- and nanoplastics. More research is needed for long-term implications understanding and solution development.

"We need to stick with ‘three-R’ waste hierarchy – reduce use of plastics, reuse recycle," advised Demokritou. In agriculture where much plastic is used for weed control among other things he suggested biodegradable alternatives.

Researchers are working on developing new biodegradable materials replacing conventional plastics while improving detection methods for measuring particle presence in food/water yet preventing further contamination remains key priority.

"It's not that technically we cannot address some issues," added Demokritou but highlighted challenges retaining benefits from useful material while reducing harm due social/economic obstacles linked production/use needing overcoming.”