April 19, 2025 – A significant research achievement on microplastic pollution has recently captured the industry’s attention. A study conducted by research teams led by Professor Wang Lei and Professor Sun Hongwen from the College of Environmental Science and Engineering at Nankai University, in collaboration with Professor Baoshan Xing’s team from the University of Massachusetts Amherst in the United States, as well as multiple institutions including the Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, has been published online in Nature, one of the world’s top academic journals.
Titled “Leaf absorption contributes to accumulation of microplastics in plants,” the research focuses on the crucial issue of the potential absorption of atmospheric microplastics by plant leaves. Leveraging advanced detection techniques such as mass spectrometry and hyperspectral imaging, the research team overcame the challenge of quantitatively characterizing the particle size and bioaccumulation levels of microplastics in environmental samples. They not only managed to observe microplastic particles absorbed within plant leaves in real-world environments but also uncovered the internal relationship between the microplastics accumulated in leaves and those in the atmosphere. Through simulated exposure experiments, the team elucidated the absorption and accumulation mechanism of microplastics, which enter through leaf stomata, travel along the apoplast pathway into the vascular bundles, and accumulate in trichomes.
According to AsiaMB, this study holds great significance. It is the first to clearly demonstrate that the absorption of atmospheric microplastics by leaves is a significant pathway for microplastics to enter the food chain and human bodies. This breakthrough greatly advances the understanding in the field of microplastic pollution research and stands as another landmark achievement in China’s research on emerging pollutants, providing a solid scientific basis for the formulation of subsequent pollutant management policies.
Plant uptake has long been recognized as an important route for pollutants to enter the food chain. Previous research indicated that although plants can absorb microplastics from the soil through their roots, the upward transport efficiency is relatively low, resulting in minimal impact on the edible parts above ground. However, if the widely present microplastic pollution in the atmosphere can be directly absorbed by plant leaves, it will pose a more immediate ecological pollution risk. The emerging pollutants research team at Nankai University integrated multidisciplinary methods and cutting-edge technologies from geology, ecology, and analytical chemistry to conduct in-depth field investigations and laboratory simulations.
During the research process, the team selected typical areas such as polyester production enterprises and landfills. By using the original “chemical depolymerization – monomer compound mass spectrometry detection” technique, they accurately measured the pollution levels of polyethylene terephthalate (PET) and polystyrene (PS) microplastics and plastic oligomers in tree leaves. They found that the concentrations of PET and PS polymers in some plant leaves could reach up to 10^4 ng/g at the highest, and were closely related to leaf growth time, gas exchange capacity, and atmospheric pollution levels. With the help of hyperspectral imaging (HSI) and atomic force microscopy – infrared spectroscopy (AFM-IR) techniques, the team successfully observed absorbed PET, PS, PA (nylon), and PVC (polyvinyl chloride) microplastic particles in the leaves of field plants.
In addition, through various exposure experiments and by using HSI, laser confocal microscopy, and other means, the research team revealed the behavioral patterns of absorption, transportation, and accumulation of microplastics in the stomata of corn leaves. The study also disclosed the concentration of microplastics in vegetables, highlighting the significant impact of open-field leafy vegetables on human exposure to microplastics, and further clarifying the crucial role of plants in the potential risks to ecosystems and human health during the process of microplastics entering the food chain.
Notably, Nankai University led this research as the first corresponding institution. Professors Wang Lei, Baoshan Xing, and Sun Hongwen served as the corresponding authors of the paper, and Li Ye, a 2021 doctoral student majoring in environmental science at the College of Environmental Science and Engineering, was the first author. This research was strongly supported by the National Key Research and Development Program of China, General Program of the National Natural Science Foundation of China, and the international cooperation project of the Asia-Pacific Network for Sustainable Development of the Bio-sphere (APN).