Adsorption of polyethylene microbeads and physiological effects on hydroponic maize

• Published in: The Science of the total environment Vol. 741; p. 140216
• Main Authors: Urbina, Mauricio A., Correa, Francisco, Aburto, Felipe, Ferrio, Juan Pedro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2020
• Subjects: Bioaccumulation; Green fodder; Hydroponics; Microplastic uptake; Microplastics; Stable isotopes; Microplastic uptake; Microplastics; Green fodder; Bioaccumulation; Hydroponics; Stable isotopes
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2020.140216

About 90% of the plastic garbage remains in terrestrial ecosystems, and increasing evidence highlights the exposure of crops to plastic particles. However, the potential bioaccumulation of microplastics by plants and their effects on plants' physiology remains unexplored. Here, we evaluated the adsorption, potential uptake, and physiological effects of polyethylene (PE) microbeads in an experimental hydroponic culture of maize. Using isotope analysis, taking advantage of the different carbon isotope composition (δ13C) of fossil-derived PE and C4 plants (e.g., maize), we estimated that about 30% of the carbon in the rhizosphere of microplastic-exposed plants was derived from PE. Still, we did not find evidence of PE translocation to the shoots. Plastic bioaccumulation in the rhizosphere caused a significant decline in transpiration, nitrogen content, and growth. Our results indicate that plastic particles may accumulate in the rhizosphere, impairing water and nutrient uptake, and eventually reaching root eaters. Due to the implications for food production and livestock feeding, our findings encourage further research on the mechanism leading to the bioaccumulation of microplastics on the surface of belowground tissues. [Display omitted] •Different carbon isotope composition (δ13C) of fossil-derived PE and C4 plants allows accurate estimations of polymers uptake.•Microplastics (3 μm) accumulate on the roots of plants, but do not translocate to aboveground tissues.•Microplastics on the rhizosphere can impair water and nutrient uptake, and eventually reach root eaters.•Isotope labelling is a promising tool for the assessment of organic polymer uptake/adsorption into living organisms.