Microplastic Abundance In Volga River: Results Of A Pilot Study In Summer 2020

Abstract

In order to analyze the problem of microplastics pollution a comprehensive environmental survey was conducted along the entire Volga river in summer of 2020. The analysis of 34 water samples allowed us to determine the average concentration of microplastic (MP) in the surface water layer of the Volga river which accounted for 0.90 items/m3 (0.21 mg/m 3 ). MP particles were found in all samples taken. The concentrations ranged from 0.16 to 4.10 items/m 3 (from 0.04 mg/m3 to 1.29 mg/m 3 ). The maximum MP concentrations were recorded in large cities downstream of the sewage treatment plants. For Tver, Nizhny Novgorod, Kazan and Volgograd they reached 3.77, 1.91,4.10 and 1.34 items/m 3 respectively. The key role of large settlements as sources of MP in the Volga water was revealed. The minimum MP concentrations were recorded upstream of the large cities showing relatively stable levels of 0.25 items/m 3 (0.05 mg/m 3 ). The lowest MP content (0.16 items/m3) was revealed in the downstream area of the Cheboksary reservoir near Cheboksary. The results of weighing MP particles showed that their average concentration in the Volga water is 0.21 mg/m 3 . In each of the investigated samples particles of three determined fractions - fragments, fibers and films - were found, however, their ratio was not constant. On average, the proportion of fragments and films in the Volga water was 41% and 37% respectively and share of fibers accounted for 22%.