Coimbra, Portugal, May 18, 2026 (Lusa) - An international team from the University of Coimbra (UC) has found widespread microplastics in the rivers Mondego and Vouga, two of the main rivers in central Portugal.
The University of Coimbra's Faculty of Sciences and Technology (FCTUC) said on Monday in a statement to Lusa that the Marine and Environmental Sciences Centre (MARE-UCoimbra, a specialised research unit) led the team.
The researchers analysed suspended microplastics in the water of these two rivers and detected them at all sampling sites.
The research results "confirm that plastic pollution has spread widely, even in inland freshwater ecosystems."
The study, which resulted from a collaboration between the University of Coimbra and the Indian Institute of Science Education and Research Kolkata, "identified variations in contamination levels stemming from different anthropogenic pressures (environmental stress derived from human activities), including urban activities, tourism, agriculture, and infrastructure."
FCTUC said most of the detected particles measured less than one millimetre, with fibres being the most common type.
"The most frequent polymers include polyethylene and polypropylene, which feature widely in packaging and single-use plastics," the statement noted.
The investigation used international pollution and hazard indices to assess ecological risk alongside quantifying the contamination.
"Despite moderate overall concentrations, several areas of the rivers Mondego and Vouga showed risk levels between low and potentially high, mainly due to the presence of small particles, which aquatic organisms more easily transport and ingest," it added.
The study leader and researcher at MARE and the University of Coimbra's Department of Life Sciences, Seena Sahadevan, said in the statement that "this work provides important baseline information on microplastic contamination in freshwater systems in Portugal and shows the need for continuous monitoring and mitigation strategies."
FCTUC pointed out that the investigation constitutes one of the first integrated ecological risk assessments concerning suspended microplastics in the rivers Mondego and Vouga, contributing relevant data for aquatic ecosystem conservation and environmental management in Portugal.
Sarra Ben Tanfous participated as the first author, alongside researchers Abhishek Mandal, Juliana Barros, and Gopala Krishna Darbha.
FBP/LYT // AYLS
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