Iodine (¹²⁹I and ¹²⁷I) in aerosols from northern Europe

Huge amount of ¹²⁹I has been emitted to the environment during the last decades from a variety of anthropogenic nuclear activities. Aerosols represent a carrier of iodine in the atmosphere in addition to gaseous forms for which data are lacking in Sweden. In this study the first time series of iodine isotopes (¹²⁹I and ¹²⁷I) in aerosols covering the period of 1983 to 2008 from two sites in Sweden are presented. The results show that both ¹²⁹I and ¹²⁷I concentrations are considerably higher in southern compared to northern Sweden. Furthermore there is a significant difference in the relative concentrations between the sites being ∼6 times higher for ¹²⁹I compared to ∼3 times for ¹²⁷I. The portion of the ¹²⁹I related to dry deposition, based on aerosol data, represents only a minor amount of the total fallout which is dominated by wet deposition.