Analysis of aliphatic and aromatic hydrocarbons in Antarctic marine sediment layers
THE presence of both paraffinic and polycyclic aromatic hydrocarbons (PAH) in sediments and soils from the Northern Hemisphere has been well documented1–5. Paraffinic hydrocarbons are generally assumed to be derived predominantly from land plants6 but the sources of PAH are still uncertain7. However, the general consensus seems to be that they are from the fallout of airborne combustion products3. Industrialised areas have higher PAH loadings5 whilst dated cores from areas with a history of increasing industrialisation show a concomitant increase in total PAH loads but no great change in the relative proportions of individual components. Considerable interest is also vested in the fate of hydrocarbons once deposited in sediments6. With mineral resources being depleted in more accessible areas, those of remote regions (including polar ones) are being considered. But little is yet known of the effects that near-zero temperatures may have on the rate of biochemical or chemical alteration of hydrocarbons such as those found in petroleum. We report here our attempts to test the ‘combustion source hypothesis’ and to investigate the fate of hydrocarbons in sediments from a remote sub-Antarctic island with a well-documented history of localised industrial pollution8 spanning the period 1904–65. Only very minor local inputs of pollutant hydrocarbons are likely to have occurred on either side of these dates.