Spatial patterns of total petroleum hydrocarbons in the terrestrial environment at McMurdo Station, Antarctica

Fossil fuels are used throughout the United States Antarctic Program. Accidental releases of petroleum hydrocarbons are the leading source of environmental contamination. Since 1999 McMurdo Station has been the site of the most extensive environmental monitoring programme in Antarctica. Nearly 2500 surface soil samples were collected from 1999-2007 to determine the spatial "footprint" of petroleum hydrocarbons. Total petroleum hydrocarbons (TPH) concentrations were measured using a high-resolution capillary gas chromatographic method with flame ionization detection. Three distinct TPH patterns were detected: low molecular weight gasoline/JP5/AN8, residual weathered petroleum and an unresolved complex mixture of high molecular weight material. Overall TPH concentrations were low with 38% of the samples having TPH concentrations below 30 ppm and 58% below 100 ppm. Total petroleum hydrocarbon concentrations above 30 ppm are largely confined to the central portions of the station, along roads and in other areas where elevated TPH would be expected. Peripheral areas typically have TPH concentrations below 15 ppm. Areas of elevated TPH concentrations are patchy and of limited spatial extent, seldom extending over distances of 100 m. This environmental monitoring programme is ongoing and can serve as an example to other Antarctic programmes concerned with monitoring environmental impacts.