A sampling program was initiated by the Swedish Polar Research Secreta
riat with the purpose of exploring the possibility of using trace anal
yses of snow samples to identify anthropogenic influences in the envir
onments of two small research stations in Antarctica. During the field
season 1991/92, surface snow samples and a short firn core were colle
cted in the vicinity of the Swedish station Wasa and the Finnish stati
on Aboa. Surface snow was sampled again in 1993/94. Major ions (Na+, M
g2+, Ca2+, Cl-, NO3- and SO42-) were analyzed and the total amount of
light-absorbing material was determined. Increased concentrations of b
oth light-absorbing material and of all the ions were observed in the
area near the stations after the two periods of occupation. There are
several possible explanations for the increase. One source for the lig
ht-absorbing material is the burning of fossil fuels and waste. The in
crease of ion concentrations is also consistent with the breakdown and
dispersion of salt encrustations formed during the weathering of loca
l rocks. During storms and helicopter activities, salt and mineral fra
gments might be transported from snowfree areas to the sampling site c
losest downwind from the stations. Thus, the increased concentrations
of trace substances could be due to a combination of anthropogenic and
natural input. No significant increase in concentrations of trace sub
stances could be observed 1.5 km upwind or 3 km downwind of the statio
ns. This study clearly shows that the influence from activities at the
research stations was very local.