This paper investigates the natural and anthropogenic processes controlling sediment
chemistry in Admiralty Bay, King George Island, Antarctica, emphasizing the area affected
by the Brazilian Antarctic Station Comandante Ferraz (Ferraz). Total and bioavailable
concentrations of sixteen elements were determined in 32 sediment and 14 soils samples.
Factor analysis allowed us to distinguish three groups of samples: (1) Ferraz sediments,
with higher content of total trace metals and organic matter; (2) control sediments,
with intermediate characteristics; (3) Ferraz soils, with higher bioavailability of
most metals due to its oxidizing condition and low organic matter content. Major elements
such as Fe, Al, Ca and Ti presented similar levels in all three groups. Enrichment
factor calculations showed that paints, sewage and petroleum contamination enhanced
metal concentrations in Ferraz surface sediments as follows: B, Mo, and Pb (>90%);
V and Zn (70-80%); Ni, Cu, Mg, and Mn (30-40%). Despite evidence of contamination
in these sediments, the low bioavailability, probably caused by iron-sulfide, indicates
small environmental risks.