Microplastics in the Soils of the Thala Hills, East Antarctica

Abstract

For the first time, on an example of the Vecherny Oasis, Thala Hills, Enderby Land, data on the content of microplastic particles (less than 5 mm) in the soils of East Antarctica were obtained. Seven samples taken from a depth of 0–15 cm were analyzed. Two soil fractions (less than 1 mm and 1–5 mm) were studied in 3 replicates (42 individual samples). The technique for isolating microplastic particles included soil sieving, density separation in zinc chloride solution, centrifugation, vacuum filtration, and microscopic analysis. For filtration, glass fiber filters with a pore diameter of 1.6 μm were used. Quantification of microplastic particles was carried out using a microscope, digital camera and advisory software. It was found that microplastic particles present in all analyzed samples. Their number varies from 66 to 1933 units/kg of dry soil. In most cases, particles less than 1 mm predominate, accounting from 70 to 100%. In 70% of cases, fibers dominate, in 30% – fragments of irregularly shaped plastics; films occur singly. There is no clearly defined confinement of increased amount of microplastic particles to infrastructure facilities; this may be a consequence of the influence of other factors, including local and long-range transport.