As plastic waste has reached endemic proportions around the world, tiny plastic particles have been entering our food. Even table salt and bottled water have been found to be contaminated with microplastics.
Unknowingly, each of us consumes about 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 each week, along with all the microplastics in our diet.
It gets worse
New research indicates that nanoplastics can accumulate in plant tissues, "which may have direct ecological effects and implications for agricultural sustainability and food security," explain the experts behind it.
Nanoplastic particles can be the result of the degradation of plastic waste over time due to the weather and other environmental factors until the particles are often no larger than a protein or virus, that is, invisible to the naked eye. But what impact these tiny particles have on living organisms is still largely unknown.
Scientists set out to discover some of that by experimenting withArabidopsis thaliana, popularly known as watercress thale, which is a type of grass commonly found on the roadsides. The researchers grew the plants in soil mixed with nanoplastics so they could assess how this affected the plants' weight and height, as well as their chlorophyll content and root growth.
After seven weeks, plants that were exposed to nanoplastics in the soil had lower biomass and plant height than plants that weren't, the scientists found.
"The nanoplastics reduced the total biomass of the 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 is not good for the plant, the yield is low and the nutritional value of the crops can be compromised ”.
The researchers also examined the seedlings to see how sensitive plant roots were to nanoplastics in the soil. After exposure to nanoplastics for 10 days, the seedlings grew less robustly than plants without such exposure.
How nanoplastic contamination in the environment affects various crop plants that we consume will need to be further explored. "Until then, we don't know how it can affect crop yields and food crop safety," Xing says.