Variability of Pb, Mn, Al and Na Concentrations in Snow Deposited from Winter to Early Summer 1998 in Livingston Island, Antarctic Peninsula

Abstract

The concentrations of Pb, Mn, Al and Na were measured from a total of 26 snow samples collected from a 1.5m deep snow pit in Livingston Island, South Shetland Islands, at the northern tip of the Antarctic Peninsula. Our sampling location is of great concern,because of its proximity to the southern extremity of South America, a candidate for the source regions of pollutant aerosols entering Antarctica. The mean concentrations of Pb and Mn were found to be 4.97 p gg -1 and 20.6pgg"1, respectively. These concentrations levels are similar to those reported for recent snow at other Antarctic sites,with pronounced spring maxima for both metals. Contributions from natural sources are estimated to be minor (— 16%) for Pb, For Mn, on the other hand, contribution from rock and soil dusts is found to be very important. Excess Pb over Pb from natural sources is likely to be anthropogenic, especially from South America. Our results show that yearly Pb fallout flux is much greater in Antarctic coastal areas than at other Antarctic locations far from the coast, indicating that the transport and deposition patterns of pollutant aerosols are not simple in Antarctica. It is also suggested that the recycling of anthropogenic Pb in seawater to the atmosphere could significantly contribute to the Pb fallout flux in the Antarctic coastal regions.