The Black Sea is increasingly impacted by pollution originating predominantly from land-based sources, with transboundary rivers such as the Danube, Don, and Dnieper serving as major conduits for plastic waste. These rivers introduce a complex mixture of plastic particles—macro-, meso-, micro-, and nanoplastics—into the marine environment. These particles not only persist but also act as vectors for various hazardous substances, including heavy metals, persistent organic pollutants (POPs), bisphenol A, and phthalates, all of which pose ecological and human health risks. While the global impacts of microplastics (MPs) on marine organisms are well documented, studies evaluating MP contamination in the Bulgarian sector of the Black Sea remain extremely limited, particularly in commercially important mussel species. This study addresses a critical knowledge gap by assessing, for the first time in Bulgaria, the presence, quantity, composition, and size distribution of MPs in Mytilus galloprovincialis, surface waters, and sediments from the Black Sea. The project also examines the potential biological effects of MPs on mussels through the use of selected biochemical biomarkers indicative of physiological stress or toxicity. Furthermore, an evaluation of the potential risk to human health from the consumption of MP-contaminated mussels will be conducted. Environmental samples will be processed using advanced analytical techniques, including quantum cascade laser spectroscopy with the Agilent 8700 Laser Direct Infrared Chemical Imaging System, in collaboration with an accredited laboratory. The integrated approach of this project aims to contribute to a better understanding of the environmental and health implications of microplastic pollution in the Black Sea region.

Acknowledgement:
This study is funded by the Department of Scientific Research at the University of Plovdiv under 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.”