Soil Contamination by Toxic Metals Near an Antarctic Refuge in Robert Island, Maritime Antarctica: A Monitoring Strategy

Abstract

The anthropogenic effects of Antarctic refuge buildings and research stations on the surrounding soils are scarcely investigated, especially when the structures are small-sized, and sporadically used or visited. The Coppermine Peninsula (Robert Island, South Shetland Islands archipelago) possesses one of the richest flora in Antarctica, being classified as an Antarctic Specially Protected Area (ASPA). There, a small refuge (Luis Risopatron) has been seasonally occupied for scientific purposes since 1957, although no studies on the anthropic disturbances in the surroundings soils are reported. The aim of this study was the determination of the potentially toxic metals (Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn) mass fractions in surface soils (n = 40) collected at the surroundings of the Luis Risopatron refuge. Enrichment factors (EF) and geoaccumulation index (I geo) were also calculated, using Zr as the reference element, in order to evaluate the anthropogenic impacts of these small buildings in the studied area. The main contaminants were Pb and Zn, which presented EF and I geo values ranging from 1.0 to 18.3 and from −1.8 to 3.5. The mass fractions of these elements determined after an aqua regia extraction varied from 5.4 to 102 mg kg−1 Pb and from 43 to 210 mg kg−1 Zn. These results highlight that a small refuge can show environmental disturbance from low to moderate, with few hotspots with heavily contaminated soils. Environmental monitoring strategy for similar refuges anywhere in Antarctica is recommended.