POLYSTYRENE TRIGGERS CELL STRESS IN MUSSELS: ANALYSIS OF MORPHOFUNCTIONAL AND PHYSIO- LOGICAL EFFECTS

Plastic materials were designed to improve human living condi-tions but have now become a risk to the environment and the safe- ty of the planet1. Plastic is present in all matrices (water, air and soil) representing a threatening pollution problem due to the generation of micro and nano fragments. In this work, we determined the effects of polystyrene micro (MPs, 5 μm) and nanoparticles (NPs, 0.1 μm) on Mytilus galloprovincialis. Exposition times (1, 3, or 11 days) and concentrations were environmentally realistic4. Histological and immunohistochemical analyses were conducted to detect interferences with different organs, namely gills, responsible for feeding and breeding, digestive glands, and gonads, all considered biological indicators of environmental pol- lution. Results demonstrated that both MPs and NPs trigger marked cytotoxic effects, in particular on gills. The lamellar struc- ture is altered, and the stress condition is evidenced by the increase in the number of goblet cells and by the alterations of parameters linked to oxidative stress condition, such as reactive oxygen species levels, oxidative damage to lipids, in vitro susceptibility to oxidants, and total antioxidant capacity. Together, this evidence indicates a severe impairment of gill function. In conclusion, plastic reduction in the oceans is an issue that can no longer be postponed; the first step seems to be a more conscious use of this material.