Dynamics of plastic debris and its density change between river compartments in the Tuul River system, Mongolia

Munkhbat, D.*; Battulga, B. ; Oyuntsetseg, B.*; Kawahigashi, Masayuki*

Plastic pollution in river environments has become an emerging concern in recent decades, and river plastic studies have received worldwide attention. However, most plastics research has focused on the dynamics of microsized plastics in surface water and sediments, whereas less research has been conducted on the gradual degradation and size reduction of plastics in the environment. Additionally, the migration of plastic debris between river compartments and changes in its properties are less understood despite their impact on its fate. In this study, we investigated changes in plastic debris distribution in terms of abundance, size, shape, polymer types, and photodegradation stages in the floodplain, surface water, and sediment compartments of the Tuul River system in Mongolia. The plastic abundance was 5.463.53 items/m in the floodplain, 155100.7 items/m in the surface water, and 128.476.3 items/kg in the sediment.