Atmospheric microplastic dispersion in diverse land-use context: insight from the black sea coastal region in Türkiye

The atmospheric deposition of microplastic particles is a critical pathway for their input into the environment; however, available information remains limited. This study investigates atmospheric microplastics across urban, suburban, and rural areas in the humid/subtropical climate region of Black Sea coastline, specifically Düzce, Türkiye. The highest mean total microplastic deposition fluxes were recorded during the winter season, highlighting the influence of seasonal factors, such as meteorological conditions, on microplastic deposition. Fibers were the dominant type of microplastics (84%), with the primary colors being black, red, blue, and white/transparent with predominantly 0.5–1 mm in size range. During the winter period, characterized by heavy precipitation and peak microplastic depositions rates, dominant air mass trajectories pointed towards Eastern Europe and the Black Sea regions. In contrast, during the summer season, with lower deposition rates and minimal precipitation, the prevailing air trajectories predominantly originated from Northern Europe, Scandinavia, and Russia, moving in northwestern and northeastern directions. While this study provides evidence of microplastic deposition and transport, it is crucial to address significant uncertainties arising from variations in sampling methodologies. Factors such as sampling height, sampler size, sampling duration, and seasonal differences can impact results and complicate comparisons across studies. Therefore, further investigations are necessary to resolve these methodological discrepancies and to gain a more comprehensive understanding of the implications of atmospheric microplastics on human and ecosystem health, particularly from a One Health perspective.