Diurnal Dynamics of Atmospheric Microplastic Content in the Central Regions of Uzbekistan

¹ Navoi state university, Navoi, Uzbekistan
² Tomsk state university, Tomsk, Russia
³ International Centre of Molecular Allergology, Tashkent, Uzbekistan

Abstract

Data on atmospheric microplastics (AMPs) in Central Asia remain scarce despite increasing documentation of aquatic contamination. This study assesses AMP dynamics in two distinct regions of Uzbekistan: Navoi (industrial) and Bukhara (residential). Sampling was conducted at a height of 15 m using a Lanzoni VPPS 2010 volumetric trap, with samples analyzed in two-hour intervals to evaluate diurnal variability. Identification followed standardized visual criteria and the “hot needle test.” Microplastics (fibers and fragments) were ubiquitous at both sites. Mean concentrations in Bukhara (0.83 ± 0.42 items/L) and Navoi (0.69 ± 0.35 items/L) showed no statistically significant difference (p = 0.5639). Morphological analysis revealed a prevalence of fibers (1000 – 4000 µm). Diurnal peaks during morning and early afternoon correlated with anthropogenic activity and arid-zone thermal convection. The results suggest an “urban carpet” effect in Bukhara equivalent to the industrial load in Navoi. This study establishes a vital baseline for the Kyzylkum region’s atmospheric MP cycles.