Biodegradable Nanoplastics: An Overlooked Polluting Terra Incognita Towards Global Plastic Risk Assessment?

To mitigate environmental plastic accumulation and close the loop on plastic, the development of biodegradable plastics has presented a promising prospect for overcoming the global plastic pollution issue. However, it is critical to examine not only their benefits but also their unintended ecological consequences, especially for smaller-sized biodegradable nanoplastics. Our work highlights the often-overlooked risks associated with biodegradable nanoplastics. Due to the lack of environmental in situ monitoring data, the global occurrence, fate, and ecological risk of biodegradable nanoplastics remain poorly understood. Likewise, it remains unclear and questionable whether nanoplastics are eco-friendly as a promising alternative to the circular and sustainable plastic economy. We, therefore, call for a coordinated global effort to proactively mitigate the potential risks of biodegradable nanoplastics, including establishing a full-chain risk assessment system, developing key detection and simulation technologies, designing and optimizing bioplastic structures, and improving the legal supervision mechanism. These holistic efforts will facilitate the development of a sustainable practice for the closed-loop recycling of biodegradable plastics, which simultaneously helps establish a sustainable biodegradable plastic circular economy.