The Black Sea suffers from pollution originating mainly from land-based sources. The sea receives plastic waste from three major transboundary rivers – the Danube, Don, and Dnieper. Additionally, plastic debris of all sizes (macro, meso, micro, and nanoplastics) can carry various anthropogenic toxicants, such as heavy metals and persistent organic pollutants, over long distances, and they can also leach hazardous substances like bisphenol A and phthalates. The negative effects of MPs on aquatic organisms, resulting from plastic ingestion or entanglement, are already well documented globally. However, comprehensive studies on the ecological status of the Black Sea in Bulgaria are extremely scarce, especially those that include analysis of MP content in commercially important mussel species, surface waters, and sediments. The scientific hypothesis we have formulated is that the Black Sea and mussels are contaminated with MPs. Therefore, the main goal of this project is, for the first time in Bulgaria, to investigate and assess the quantity and composition of MPs in commercially important mussels, waters, and sediments from the Black Sea area, and their negative impact. Emerging contaminants such as MPs require innovative analysis techniques. The environmental samples will be sent to an accredited laboratory , and quantum cascade laser spectroscopy will be used (the Agilent 8700 Laser Direct Infrared Chemical Imaging System). The mussels will also be studied for a set of biomarkers. Last but not least, an assessment will also be conducted on the potential risk to human health associated with the consumption of Black Sea mussels contaminated with MPs.

Acknowledgements: This study is financed by the Department of Scientific Research of University of Plovdiv, project MUPD25BF001 - “Research and assessment of the quantity, composition, and size of microplastic particles in commercially important mussels from the Black Sea area, their negative impact on specific biomarkers, and the risk to human health”.