Evidence that microplastics at environmentally relevant concentration and size interfere with energy metabolism of microalgal community.

To address two current issues in evaluating the toxicity of microplastics (MPs) namely, conflicting results due to species specificity and the ecological irrelevance of laboratory data, this study conducted a 10-day exposure experiment using a microalgal community comprising three symbiotic species. The experiment involved virgin and Benzo[a]pyrene-spiked micron-scale fibers and fragments made of polyethylene terephthalate (PET) and polypropylene (PP). The results showed that, from a physiological perspective, environmentally relevant concentrations of micron-scale MPs decreased saccharide accumulation in microalgal cells, as confirmed by ultrastructural observations.