This study investigated the impact of polyethylene microplastics on the growth, root length, and chlorophyll-a content of Lemna minor (duckweed) while evaluating its potential as a phytoremediation tool to address microplastic pollution in aquatic ecosystems. Microplastics, prevalent in the environment, cause physiological stress in plants, and polyethylene is the most abundant type. Duckweed samples (1g per container in 500 mL freshwater) were cultivated for 7 days, then exposed to microplastic concentrations of 0 mg/L (control), 25 mg/L, 50 mg/L, and 100 mg/L for another 7 days. A One-Way ANOVA revealed no significant difference in the specific growth rate between the test groups. However, the highest mean frond count occurred at 50 mg/L (M = 768.875), and the lowest was observed in the control (M = 654.875). Root length decreased as microplastic concentration increased, plateauing after four days; the control group had the highest average root length (M = 0.631), while the lowest was seen at 50 mg/L (M = 0.485). Chlorophyll-a content declined significantly during the first four days (p < 0.05) but stabilized afterward, indicating potential plant adaptation. These results suggest that microplastics impair root development and chlorophyll-a content, likely by obstructing roots and reducing light for photosynthesis. Although growth rate remained unaffected, the findings highlight duckweed's potential to mitigate microplastic pollution, supporting its role in promoting cleaner and safer aquatic environments.

References

• N. Ajith, S. Arumugam, S. Parthasarathy, S. Manupoori, and S. Janakiraman, "Global distribution of microplastics and its impact on marine environment—a review," Environmental Science and Pollution Research, vol. 27, no. –, pp. 25970 25986, 2020. Retrieved from https://link.springer.com/article/10.1007/S11356-020-09015-5
• A.G. Basu, R.S. Paul, F. Wang, and S. Roy, "Impact of microplastics on aquatic flora: Recent status, mechanisms of their toxicity and bioremediation strategies," Chemosphere, vol. 370, no. –, pp. 143983, 2025. Retrieved from https://www.sciencedirect.com/science/article/pii/S0045653524028911
• X. Cui, T. Yang, Z. Li, and B. Nowack, "Meta-analysis of the hazards of microplastics in freshwaters using species sensitivity distributions," Journal of Hazardous Materials, vol. 463, no. –, pp. 132919, 2024. Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S0304389423022033
• S. Ceschin, M. Crescenzi, and M.A. Iannelli, "Phytoremediation potential of the duckweeds Lemna minuta and Lemna minor to remove nutrients from treated waters," Environmental Science and Pollution Research, vol. 27, no. 13, pp. 15806–15814, 2020. Retrieved from https://link.springer.com/article/10.1007/s11356-020-08045-3
• S. Ceschin, F. Mariani, D. Di Lernia, I. Venditti, E. Pelella, and M.A. Iannelli, "Effects of microplastic contamination on the aquatic plant Lemna minuta (least duckweed)," Plants, vol. 12, no. 1, pp. 207, 2023. Retrieved from https://www.mdpi.com/2223 7747/12/1/207
• L. Jia, L. Liu, Y. Zhang, W. Fu, X. Liu, Q. Wang, M. Tanveer, and L. Huang, "Microplastic stress in plants: effects on plant growth and their remediations," Frontiers in Plant Science, vol. 14, no. –, pp. 1226484, 2023. Retrieved from https://doi.org/10.3389/fpls.2023.1226484
• G. Kalčíková, A. Ž. Gotvajn, A. Kladnik, and A. Jemec, "Impact of polyethylene microbeads on the floating freshwater plant duckweed Lemna minor," Environmental Pollution, vol. 230, no. –, pp. 1108–1115, 2017. Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S0269749117311247
• P. Kumari and D. Raj, "Microplastics in Indian aquatic systems and its effects on plants, aquatic organisms and humans, and its methods of remediation," Chemistry and Ecology, vol. 40, no. 2, pp. 136–165, 2024. Retrieved from https://www.tandfonline.com/doi/full/10.1080/02757540.2023.2297714
• J. Li, S. Yu, Y. Yu, and M. Xu, "Effects of microplastics on higher plants: a review," Bulletin of Environmental Contamination and Toxicology, vol. 109, no. 2, pp. 241–265, 2022. Retrieved from https://link.springer.com/article/10.1007/s00128-022 03566-8
• U. Rozman and G. Kalčíková, "The response of duckweed Lemna minor to microplastics and its potential use as a bioindicator of microplastic pollution," Plants, vol. 11, no. 21, pp. 2953, 2022. Retrieved from https://www.mdpi.com/22237747/11/21/2953
• U. Rozman, A.J. Kokalj, A. Dolar, D. Drobne, and G. Kalčíková, "Long-term interactions between microplastics and floating macrophyte: The potential for phytoremediation of microplastics in the aquatic environment," Science of the Total Environment, vol. 831, no. –, pp. 154866, 2022. Retrieved from https://www.sciencedirect.com/science/article/pii/S0048969722019593
• Y. Yu, L. Miao, T.M. Adyel, K. Waldschläger, J. Wu, and J. Hou, "Aquatic plastisphere: interactions between plastics and biofilms," Environmental Pollution, vol. 322, no. –, pp. 121196, 2023. Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S0269749123001987
• H. Yu, W. Qi, X. Cao, Y. Wang, Y. Li, Y. Xu, et al., "Impact of microplastics on the foraging, photosynthesis and digestive systems of submerged carnivorous macrophytes under low and high nutrient concentrations," Environmental Pollution, vol. 292, no. –, pp. 118220, 2022. Retrieved from https://www.sciencedirect.com/science/article/abs/pii/S0269749121018029