Implications of damming and morphological diversity of microplastics in the sediment from a tropical freshwater reservoir

• Published in: Journal of environmental chemical engineering Vol. 12; no. 2; p. 112234
• Main Authors: Queiroz, Lucas Gonçalves, Pompêo, Marcelo, de Moraes, Beatriz Rocha, Ando, Rômulo Augusto, Rani-Borges, Bárbara
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-04-2024
• Subjects: Billings Reservoir; Dam; Plastic pollution; South America; Surface waters; South America; Dam; Surface waters; Billings Reservoir; Plastic pollution
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2024.112234

Microplastic pollution is ubiquitous in freshwater environments, including rivers, lakes, and reservoirs. Plastic particles can accumulate in the sediment mainly in lentic environments offering several risks to the benthic community. While there are records on the distribution of microplastics in freshwater systems worldwide, limited research has been conducted on their distribution in reservoirs in the Southern Hemisphere. We investigated the levels of microplastic pollution in the sediments from the Billings Reservoir, Brazil, located in an area with high anthropogenic activities. Microplastics were recovered from all sediment samples, indicating their extensive distribution in the reservoir. Microplastic abundance in the sediment ranged from 11,800 to 31,900 particles.kg−1 dry weight. We observed different abundances between the shapes of microplastics: fiber > fragment > film > foam. Colorless fibers were the most abundant particles and small-sized (100 – 300 µm) microplastics were predominant. Of all the microplastics identified by FTIR, polyethylene was the most common type (25.0%), followed by polycarbonate, polypropylene, and nitrocellulose, each polymer representing 15.0% of the analyzed particles. The entry and the damming area of the reservoir seem to be more susceptible to the accumulation of microplastics in the sediment. This study was the first to report microplastic pollution in a Brazilian reservoir, which elucidates the incipience of the studies investigating microplastic pollution in Brazil.
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•Tropical reservoirs are potential accumulation zones for microplastics.•High amounts of microplastics (20070 ± 6671.8 particles.kg−1) were found in Billings Reservoir.•Fibers were the most predominant shape in the sediment, followed by fragments.•PE, PC, PP, and nitrocellulose are the most frequent microplastic types found.•Microplastic pollution seems to be related to the critical state of conservation of the reservoir.