Heavy metal pollution in Antarctic soils.

Abstract

Soil samples from 8 sites (7 contaminated and 1 reference) at Marble Point and Scott Base were assessed for heavy metal pollution. Samples were acid leached and analysed by differential pulse anodic stripping voltammetry and electrothermal atomic absorption spectrometry for lead, zinc, cadmium and copper. Weathering of these metals from point source contaminants was established. Sequential leaching was then performed to evaluate the potential fate ofthe contaminants using the same techniques. Studies were limited to exchangeable fraction and metal fractions bound to carbonates, oxides and organic matter. In the majority of the samples, the oxide fraction formed the largest sink for extractable lead and zinc. In addition, increase in organic matter was observed for some soils. Low levels of extractable aluminium were found, confirming the limited extent of weathering possible in the cold, arid Antarctic climate. Two modes of origin of soluble salts were inferred from levels of sodium, potassium, calcium and magnesium detected in the soils.