Marine Pollution Bulletin 143 (2019) 140–143

Authors: Chiara Gambardella, Veronica Piazza, Marina Albentosa, Maria João Bebianno,Cátia Cardoso, Marco Faimali, Francesca Garaventa, Soledad Garrido, Sergio González,Sara Pérez, Marta Sendra, Ricardo Beiras

Products Used:  Clear Polyethylene Microspheres - CPMS-0.96 1-4um

Abstract:

In this study, the acute toxicity of microplastics (MPs) on unicellular organisms as marine decomposers and
microalgae was assessed, by evaluating standards endpoints included in International Standard Organization (ISO) protocols. The bacteria Vibrio fischeri and the diatom Phaeodactylum tricornutum were exposed to different sizes (1–500 µm) of polyethylene MPs in order to evaluate bioluminescence inhibition and microalgal growth. No acute toxicity was found on bacteria or microalgae in an order of magnitude above environmentally relevant concentrations, suggesting that tested MPs did not affect the investigated biological processes. In conclusion, standard ecotoxicological endpoints are not sufficiently sensitive to assess the potential effects of MPs on decomposers and primary producers, conversely to nanoplastics. These findings highlight that the current approachfor MP risk assessment in unicellular species should be revised, by providing alternative endpoints to be  included in standardized protocols, able to monitor the fate and biological effects of MPs.