Microplastic pollution has emerged as a critical global environmental issue due to its widespread distribution, persistence, and adverse effects on ecosystems and human health. However, literature summarizing the impacts of microplastic pollution on agricultural land and human health remains limited. Microplastic contamination in soil affects the development and diversity of soil microorganisms, which in turn harms plant health. In addition, microplastics obstruct microbial movement, limit nutrient access, and reduce interactions with plant roots. Nutrient uptake is further decreased because microplastics disrupt beneficial interactions between fungi and plants (1).

Humanity has long strived to increase primary productivity and food production to feed a growing population. Global initiatives aim to expand arable land and enhance crop yields, but these efforts are now jeopardized by plastic pollution due to its ubiquity and negative impact on food security, as recognized by the Food and Agriculture Organization (FAO) (2).

Published research indicates that the main polymer particles found in cultivated soils are polystyrene (PS), polyethylene (PE), high-density PE, polypropylene, polyvinyl chloride (PVC), and PE terephthalate. Microplastics significantly affect plant growth and often lead to reduced height, biomass, and photosynthesis, decreased chlorophyll content, and altered secondary metabolites. Major effects on legume crops include decreased yield parameters and growth traits such as shoot and root fresh and dry weights, carbohydrates, lipids, proteins, and reductions in chlorophyll a, chlorophyll b, and total chlorophyll. Increased carotenoids were observed in mung bean exposed to PS microplastics. In soybean, PE and PVC microplastics increased malondialdehyde content and decreased net photosynthetic rate (Pn) due to impaired photosystem II. PE microplastics also decreased peroxidase activity, increased catalase activity, showed no significant effect on superoxide dismutase, and altered leaf metabolites, mainly amino acids, sugars, and organic acids. Polystyrene nanoplastics decreased stem and root length and induced toxicity in soybean. Major effects on cereal crops include decreased height, number of tillers and nodes, net Pn, stomatal conductance, and reduced leaf-level photosynthetically active radiation (PAR) in wheat exposed to PE microplastics. In addition, LDPE microplastics (i.e., 1%) reduced wheat biomass after 2 and 4 months of exposure. Fourier transform infrared spectroscopy can identify polymer types and distinguish microplastics from other substances based on characteristic spectral peaks (3).

Overall, advancing our understanding of micro- and nanoplastic impacts on plant systems is crucial to address an emerging environmental challenge and to support sustainable agricultural practices within a One Health perspective.

References

(1) M. Tariq, B. Iqbal, I. Khan, A.R. Khan, E.H. Jho, A. Salam, H. Zhou, X. Zhao, G. Li, D. Du; Plant Cell Reports, 2024, 43, 65.

(2) R. Zhu et al.; Proceedings of the National Academy of Sciences of the United States of America, 2025, 122, e2423957122.

(3) V. Liava, E.E. Golia; Waste Management & Research, 2024, 42, 634–650.

Dr. Umberto Granata