Comparative role of biofilm-covered microplastic and sand particles as vectors of ¹⁴C-PCB-153 to Paracentrotus lividus

Microplastics (MPs) are contaminants of concern per se, but also based on their ability to concentrate and disseminate environmental contaminants (such as polychlorinated biphenyls; PCBs), acting as vectors for the transfer of toxic chemicals into marine organisms. However, the relevance of the role of MPs as vectors of contaminants adsorbed onto their surfaces (i.e., co-contaminant) is currently a matter of debate highlighting the hypothesis that MPs would play a minor role as vectors compared to naturally occurring particles (e.g. sediments) because of their relative abundance in the environment. The present study compares the role of biofilm-covered microplastics (500-600 µm; negatively buoyant polyethylene beads) and sand particles as vectors of ¹⁴C-PCB-153 into adult specimens of the sea urchin Paracentrotus lividus. Results showed that after 14 days of exposure, the transfer of ¹⁴C-PCB-153 from biofilm-covered particles to sea urchin tissues occurred to a similar extent for both types of particles, suggesting that MPs located on the seafloor may act as vectors of PCB-153 in a similar way than other natural particles such as sand. Also see: https://micro2024.sciencesconf.org/558786/document