Long-term exposure to nanoplastics reduces life-time in Daphnia magna

• Published in: Scientific reports 2020-04, Vol.10 (1), p.5979-7, Article 5979
• Main Authors: Kelpsiene, Egle, Torstensson, Oscar, Ekvall, Mikael T., Hansson, Lars-Anders, Cedervall, Tommy
• Format: Article
• Language: English
• Subjects: 704/158; 704/172; Acute toxicity; Animals; Aquatic ecosystems; Aquatic environment; Aquatic organisms; Biologi; Biological Sciences; Biota; Daphnia - drug effects; Daphnia magna; Ecology; Ecosystems; Ekologi; Environmental Exposure; Freshwater invertebrates; Humanities and Social Sciences; Invertebrates; Microplastics - toxicity; multidisciplinary; Nanoparticles; Natural environment; Natural Sciences; Naturvetenskap; Offspring; Plastic debris; Polystyrene; Science; Science (multidisciplinary); Water Pollutants, Chemical - toxicity
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-63028-1

Plastics are widely used in todays society leading to an accelerating amount of plastic waste entering natural ecosystems. Over time these waste products degrade to micro- and, eventually, nanoplastic particles. Therefore, the break-down of plastics may become a critical threat to aquatic ecosystems and several short term studies have demonstrated acute toxicity of nanoplastics on aquatic organisms. However, our knowledge about effects of chronic or life-time exposure on freshwater invertebrates remains elusive. Here, we demonstrate results from life-time exposure (103 days) of a common freshwater invertebrate, Daphnia magna , exposed to sub-lethal concentrations of polystyrene nanoparticles. 53 nm positively charged aminated polystyrene particles were lethal at concentration of 0.32 mg/L which is two magnitudes lower than previously used concentrations in short-term (24 h) tests. At this concentration the life-time of individuals was shortened almost three times. Negatively charged carboxylated 26 and 62 nm polystyrene particles, previously demonstrated to be non-toxic at 25 and 50 mg/L concentrations in short-term tests, were toxic to D. magna at all concentrations used in our long-term study. Although total reproductive output was not significantly affected at increasing concentrations of polystyrene nanoparticles, there was a decreasing trend in the number of offspring over their life-time. Hence, in order to understand how the potential future environmental problem of nanoplastic particles may affect biota, long-term or life-time studies resembling environmental concentrations should be performed in order to provide information for predictions of future scenarios in natural aquatic environments.