Plastics undergo uncontrolled deterioration and fragmentation into microplastics (<5 mm) and nanoplastics (<1 μm) by physicochemical processes in the natural environment. Given their troubles in the food chain, small plastics have been cited as an emerging issue of environmental concern. However, there still remains significant knowledge gaps in understanding the uptake and ecological effects of micro- and nanoplastics in aquatic plants.

Prof. YANG Yuyi's team from Wuhan Botanical Garden of the Chinese Academy of Sciences and collaborators from the University of Southern Denmark, Qingdao University, Leiden University, and Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), recently traced and quantified the uptake and transport of micro-and nanoplastics in various aquatic plants using europium-doped polystyrene particles.

Research shows that micro-and nanoplastics mainly accumulate in the intercellular space of aquatic plants and are transported from roots to leaves via the apoplastic path and vascular bundle. Floating plant Eichhornia crassipes has a higher absorption capacity of plastic particles than those of submerged plant Vallisneria denseserrulata, and emergent plant Iris tectorum. A large amount of submicrometre plastic particles accumulate in the roots of aquatic plants, which has a far higher enrichment performance than known information in terrestrial plants.

Prolonged exposure to relatively high concentrations of plastic particles has no significant adverse impact on the growth of aquatic plants, suggesting a low health risk of plastic particles at currently predicted environmental concentrations.

The unique advantages of aquatic plants in absorbing nanoplastics and high tolerance to nanoplastic exposure show their great potential for the phytoremediation of fine plastics in freshwater environments.

The research was published in Water Research entitled “Tracing and trapping micro- and nanoplastics: Untapped mitigation potential of aquatic plants”. This work was supported by the National Natural Science Foundation of China and the Special Research Assistant Program, Chinese Academy of Sciences.