In the present study, samples were taken from two beaches of the Salamina Island. The results of microplastics characterization agree well with the predicted results based on the land uses both locally and from across the mainland. The first beach, Psili Ammos, is affected by increased anthropogenic and industrial activity. Based on the Attenuated Total Reflectance (ATR) - Fourier Transform Infra-Red spectroscopy (FTIR) analysis mainly polyethylene (PE) fragments are observed than in the second beach, Kanakia. A high percentage of plastic pellets from industrial activity among fragments are found as well as the most fresh and the most degraded particles (based on the ester, keto, and vinyl indices). The second beach, Kanakia, has a high percentage of expanded polystyrene (EPS) particles suggesting an impact from fishing activities rather than industrial ones and all PE samples are found to be degraded suggesting that sources of non-fishing microplastic pollution are further away.