Organic Pollutants in Snow and Seasonal Melting Water from King George Island, Antarctica

Abstract

Despite its isolation and scarce occupation, Antarctica is not exempt from the input of contaminants related to present and past human activities. Several deleterious compounds, such as the persistent organic pollutants (POPs) may reach Antarctic ecosystems, mostly via atmospheric long-range transport and further deposition. In this context, snow and its seasonal melting water represent a sink to these pollutants and also the last compartment before they reach marine primary producers. In order to assess the concentration of a selection of organic contaminants, a PDMS headspace extraction method was chosen due to its improvement in fieldwork sampling. Samples were collected in King George Island, during the austral summers from 2007 to 2010. PBDEs and PAHs remained under the method detection limits in all of the cases, restricting data interpretation to organochlorine compounds: average Σ HCHs ranged from 1.46 to 4.17, HCBs from 1.36 to 3.77, Σ Drins from <0.35 to 4.29, Σ Chlordanes from 5.72 to 13.3, Σ DDTs from 4.32 to 24.4, and PCBs from 132 to 156 (always in pg kg−1). Results were, in general, in agreement with previous literature. Nevertheless, due to the fact that samples were collected progressively later into the austral summer, one trend can be noticed: the sum of the concentrations in both matrixes seems to decrease, with a proportional increase in snow. Some exceptions can be remarked, hypothetically linked to the passage of South American frontal systems. Finally, results for these two compartments are compatible with the exposure expected for lower trophic-level organisms from such ecosystem.