Microplastics represent a growing environmental concern for the oceans due to their potential of
adsorbing chemical pollutants, thus representing a still unexplored source of exposure for aquatic organisms.
In this study polyethylene (PE) and polystyrene (PS) microplastics were shown to adsorb pyrene
with a time and dose-dependent relationship. Results also indicated a marked capability of contaminated
microplastics to transfer this model PAH to exposed mussels Mytilus galloprovincialis; tissue localization
of microplastics occurred in haemolymph, gills and especially digestive tissues where a marked accumulation
of pyrene was also observed. Cellular effects included alterations of immunological responses,
lysosomal compartment, peroxisomal proliferation, antioxidant system, neurotoxic effects, onset of
genotoxicity; changes in gene expression profile was also demonstrated through a new DNA microarray
platform. The study provided the evidence that microplastics adsorb PAHs, emphasizing an elevated
bioavailability of these chemicals after the ingestion, and the toxicological implications due to responsiveness
of several molecular and cellular pathways to microplastics