DNA DAMAGE BY POLYSTYRENE MICROPLASTICS IN ZEBRAFISH

In recent years, plastic pollution has become global environmental concern affecting both terrestrial and aquatic environments.1,2 Microplastics (MPs) derived from the degradation of plastic through physical-chemical processes, can be ingested by organ-isms and reach humans through the food chain. Although the mechanism of action and the health impact on the of exposed organisms are not yet fully understood, the literature data confirm deleterious health consequences following exposure to different types of microplastics.3,4 The aim of this research was to evaluate the in vitro genotoxic effects of polystyrene MPs on Danio rerio cells using RAPD-PCR, to quantify the genomic template stability (GTS), TUNEL reaction to evaluate MP-induced DNA fragmenta- tion (DFI) and DCF assay to highlight a possible ROS-dependent mechanism of damage. Zebrafish blood cells were exposed to MPs (105 μg/mL) for 30, 60 and 90 min. The RAPD- PCR results showed a 20% reduction in GTS after 30 and 60 min of MP expo- sure reaching up to 40% after 90 min. Similarly, a time-dependent increase in MP- induced DFI was observed, with DFI reaching values up to 37% for the maximum exposure time. Furthermore, the presence of intracellular ROS was highlighted for the longer exposure times. These results confirm the harmfulness of MPs, in particular their ability to interfere with genetic material causing apoptosis via oxidative imbalances. Further in vitro and in vivo studies evaluating tbe bioaccumulation processes will be needed to establish the mechanisms underlying the MPs damage.