Nanoplastics can accumulate even in the tissues of plants

As plastic waste has reached endemic proportions worldwide, minute plastic particles have been getting into our food. Even table salt and bottled water have been found to be contaminated with microplastics.

Unknowingly, every one of us consumes an estimated 52,000 tiny plastic particles a year, according to Canadian researchers. Meanwhile, according to research by the World Wide Fund for Nature, we each consume the equivalent of a plastic credit card every week what with all the microplastics in our diet.

It gets worse.

New research indicates that nanoplastics can accumulate in the tissues of plants, “which can have both direct ecological effects and implications for agricultural sustainability and food safety,” explain the experts behind it.

Nanoplastic particles can result from plastic waste degrading over time from weathering and other environmental factors until particles are often no larger than a protein or a virus, which is to say invisible to the naked eye. But it remains largely unknown what impacts these tiny particles have on living organisms.

The scientists have set out to find some of that out by experimenting with Arabidopsis thaliana plants, popularly known as thale cress, which is a type of weed commonly found by roadsides. The researchers grew the plants in soil mixed with nanoplastics so they could assess how this affected the weight and height of plants as well as their chlorophyll content and root growth.

After seven weeks, plants that were exposed to nanoplastics in the soil had lower plant biomass and height than plants that weren’t, the scientists found.

“Nanoplastics reduced the total biomass of model plants,” explains Xian-Zheng Yuan, a scientist at Shandong University in China, who helped lead the project. “They were smaller and the roots were much shorter. If you reduce the biomass, it’s not good for the plant, yield is down and the nutritional value of crops may be compromised.”

The researchers also examined seedlings to see how sensitive the roots of plants were to nanoplastics in the soil. After being exposed to nanoplastics for 10 days, seedlings grew less robustly than plants without such exposure.

How nanoplastic pollution in the environment impact various crop plants that we consume will need to be explored further. “Until then, we don’t know how it may affect crop yield and food crop safety,” Xing says.