PHAs in Soil at McMurdo Station, Antarctica

Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds that have attracted much attention over the past several years. The United States Environmental Protection Agency (USEPA) has identified numerous PAHs as known or probable human carcinogens. The quantity of PAHs in the environment has dramatically increased, with the majority emitted from fossil fuel combustion sources. Surface soil samples were collected at McMurdo Station, Antarctica (77 degrees 51' S, 166 degrees 41' E), during peak summer activity and analyzed for PAHs. PAHs were detected at several locations, with maximum concentrations for naphthalene, acenaphthene, acenaphthylene, and fluoranthene at 27 000, 17 800, 15 700, and 13 300 mg/kg, respectively. Results suggest anthropogenic activities may be contributing to increased levels of PAHs present in McMurdo soils.
However, available data on Antarctic soils show that PAH pollution is highly localised, and concentration in samples from control areas is usually below detection limits. In the environment around Davis Station, in 1995 was found very low concentration, and the content of individual PAHs around a fuel deposit only exceeded 1 ng g-1 dry wt. When deposited on soils, PAHs may have a number of possible fates such as volatilisation, photo-oxidation, leaching or microbial degradation; it therefore seems likely that the risk of possible adverse effects on functional properties of Antarctic soils are negligible, except at sites directly affected by spillage of fuels.