Some studies were carried out next to McMurdo Station (the largest scientific base in Antarctica). The more interesting area is Winter Quarters Bay, in consideration of its contamination problems. The concentration and the stable carbon isotopic composition of PAHs at McMurdo Station were determined in samples collected from land and from the subtidal Area; PAHs in the study areas were ... characterized by high amounts of naphthalene and alkylated naphthalenes from petroleum products, the total concentration of PAHs ranged from 61 to 5024 ng g-1. Compositional assignments of origins were confirmed using compound specific stable carbon isotopic analysis. In the same area, was determined the sediment concentrations of PCBs, metals, and hydrocarbonfuels. The main aim was to map the distribution of organic contaminants in WQB and assess the toxicity of sediments using a simple microbial test.