Microplastic Characteristics in Equus kiang (Tibetan Wild Ass) Feces and Soil on the Southern Tibetan Plateau, China

Abstract

Microplastics (MPs) are emerging pollutants, and limited research has focused on their exposure to terrestrial wildlife and transport mode on the remote Tibetan Plateau (TP). Therefore, we investigated MPs in the southern soil and feces of Equus kiang (Tibetan wild ass), a species peculiar to the TP, which is known as the "third pole." We found that MP median abundances were 102 and 4.01 particles/g of dry feces and soil, respectively. In both media, the MP morphology mainly comprised ∼50 μm slender fibrous particles. In total, 29 MP types were identified in the feces, compared to 26 types in the soil. Among them, the acrylate copolymer (35.9%) and polyurethane (24.9%) were predominant in the feces, while polyurethane (22.5%) and silicone (20.4%) were predominant in the soil. After ingesting MPs at one location, E. kiang may become a source of MP pollution when moving to other meadows on the TP. The potential MP transport flux of a herd of 20 kiangs has been estimated at 1736 particles m −2 a −1 . A unique "source−sink−source" MP transport model comprising an "atmospheric deposition−vegetation−feces−atmosphere" cycle on the TP was observed based on atmospheric transport simulations and terrestrial food chain transfer processes. Owing to human settlements in south and East Asia adjacent to the TP, atmospheric long-distance transmission is an essential route for MPs to enter the TP.

Multifaceted Aquatic Environmental Differences between Nanoplastics and Microplastics: Behavior and Fate

“…As a new type of pollutant, MNPs have been spread globally due to their characteristics such as small size and high mobility, causing major environmental impacts . For example, 26 types of MPs have been detected in the soil of the southern Tibetan Plateau in China with an abundance of 4.01 pcs/g . MPs abundances of 200–2200 pcs/L have been detected in sediments from the deepest part of the Earth, the Mariana Trench .…”

Effects of Microplastics on the Transport of Soil Dissolved Organic Matter in the Loess Plateau of China

“…Elucidating nutrient cycling is important to ensuring the stability of the local ecosystem . Plastic pollution usually occurs in areas with high urbanization and intensive agricultural practices, but a large portion, mainly via MPs, may still be transported to remote areas, such as the plateau, through the atmosphere and precipitation. , However, there is limited knowledge of the linkage between soil nutrient turnover and MPs in the Loess Plateau and the role of DOM.…”