Seasonal input of heavy metals to Antarctic snow

Cadmium, copper, lead and zinc concentrations have been measured on a sequence of snow blocks covering 2 years’ accumulation at a site on the east coast of the Antarctic Peninsula. Careful collection and analysis techniques have ensured good data quality despite the very low concentrations, which averaged Cd 0.08 ng kg-1, Cu 4 ng kg-1, Pb 4 ng kg-1, Zn 0.4 ng kg-1. The elements show significant variations through the year. Pb has peaks in the autumn/winter period when both the crustal and marine aerosol are also at their maxima; despite a probable pollutant origin, Pb appears to be associated with natural aerosol in long range transport. No clear seasonal signal is observed for the other metals. At this site, the marine contribution to the concentrations of some metals may be significant.