Dados do Trabalho

Título

IMPACTS OF MICROPLASTIC CONTAMINATION ON PHYSICAL PROPERTIES OF AN ANTARCTIC MARINE TERRACE SOIL

Resumo

Microplastics (MPs) are emerging contaminants ubiquitous in most environmental matrices around the planet, and terrestrial environments of Antarctica are no exception. This study investigated impacts of MP contamination on physical attributes of a marine terrace soil from the Fildes Peninsula (King George Island, Antarctica). The effects of two types of MPs were tested at three different levels: polypropylene fragments (0.01, 0.1, 1.0% w w-1) and polyacrylic fibers (0.001, 0.01 0.1% w w-1). The treated soils, in addition to a control treatment (C), were placed in plastic pots (Ø = 10 cm; h ≈ 10 cm) and experienced natural field conditions for 22 days at the sample site. After this period, undisturbed samples (volumetric rings) were obtained from each pot and submitted to analyzes of hydraulic conductivity (k0), macro and microporosity (-60 kPa), total porosity and soil bulk density (D). All parameters were affected by treatments (ANOVA; p‑value < 0.05). Fibers show a concentration-dependent behavior in all evaluated parameters, but fragments only for k0. Low doses of fibers promote greater microporosity but lower macroporosity, suggesting an increase in soil aggregation and consolidation. Conversely, the higher concentration promotes the opposite effect and the increase of macropores – probably by a greater interaction between MPs particles. Impacts on total porosity were mostly influenced by macroporosity. On the other hand, fragments seem to interact with the soil matrix more harmoniously and differences in porosity are not significant. The lower D of soils treated with fragments is therefore due to the lower density of polypropylene (0.9 g cm-3) compared to polyacrylic (1.2 g cm-3). MP contamination can potentially affect physical properties of Antarctic soils and, consequently, the biotic and abiotic processes that use it as a substrate in ice-free areas of the continent.

Palavras-chave

bulk density; porosity; Fildes Peninsula; polypropylene; polyacrylic.

Instituição financiadora

CNPq

Agradecimentos

Projetos Terrantar/Permaclima; PROANTAR; Marinha do Brasil; UFV