TOTAL GASEOUS MERCURY IN THE AREA OF SOUTHERN BALTIC AND IN THE COASTAL ZONE OF THE GULF OF GDANSK DURING SPRING AND AUTUMN

Total gaseous mercury (TGM) concentration was measured over the offshore waters of the Gdansk Deep during spring and autumn in the years 1999-2006. The results obtained were compared with TGM concentrations recorded at the same time in the air of the coastal zone of Gdynia and Sopot. Both offshore and in coastal zone, higher Hg(g) concentrations were measured in autumn than in spring. When analyzing mean Hg(g) concentrations in subsequent hours of the day, solar radiation effect on mercury level in the air was evident. Mercury levels in the air seemed to be controlled also by the presence of dissolved organic matter in the seawater, which is responsible for mercury complexation and for algae detoxification processes.