The radiological environment of Svalbard

This paper presents a detailed survey of the radiological environment of the Svalbard area carried out from 2000 to 2002, in both the marine and terrestrial environment. In the marine environment in 2001, Tc-99 activity concentrations in seawater were 0.13 to 0.36 Bq/m(3), 5 fold higher than those in 1994, reflecting the increase in Tc-99 discharges from Sellafield in the mid 1990s. Cs-137 activity concentrations in seawater were 2.23 to 2.43 Bq/m(3), ca. 10 fold lower than those in the 1980s, reflecting the reduction in discharge of this radionuclide. Pu-238, Pu239+240 and Am-241 activity concentrations in seawater were <0.3 to 0.7 mBq/m(3), 5.6 to 8.9 mBq/m(3) and 0.6 to 2.4 mBq/m(3) respectively, with activity ratios suggesting global fallout to be the dominant source. Tc-99 activity concentrations in brown algae were up to 18 fold higher than those in the 1980s with highest concentrations in Fucus distichus (25.7 to 58.7 Bq/kg d.w.). In the terrestrial environment, typical Cs-137 activity concentrations in soil were between <0.5 and 63 Bq/kg d.w. whilst activity concentrations of the natural radionuclides U-238 (17 to 72 Bq/kg d.w.), Ra-226 (21 to 70 Bq/kg d.w.), Th-232 (10 to 57 Bq/kg d.w.) and K-40 (115 to 818 Bq/kg d.w.) were similar to global averages. In terrestrial vegetation, 137Cs activity concentrations varied from 29 to 292 Bq/kg d.w. in mosses, 30 to 140 Bq/kg d.w. in lichen and 19 to 109 Bq/kg d.w. in flowering plants. Elevated activity concentrations of Cs-137, U-238, Ra-226, Pu isotopes and Am-241 were found in some matrices associated with seabird colonies.