The radioactive contamination study in south-western Greenland tundra in 2012-2013

The paper presents results of the radioecological investigation carried out in south-western Greenland shoreline. There were examined over 50 samples of lichens and mosses collected from 7 locations during two scientific expeditions conducted in the summer of 2012-2013. The levels, trends and the most likely origin were determined for following natural and artificial radionuclides: ⁹⁰Sr, ¹³⁷Cs, ^{230, 232}Th, ^{234, 238}U, ^{238, 239+240}Pu and ²⁴¹Am. The radioactive pollution was found as relatively low, reaching the maximum values at: 25.3 ± 2.04 Bq/kg for ⁹⁰Sr, 293 ± 27 Bq/kg for ¹³⁷Cs, 4.01 ± 0.13 Bq/kg for ^239+240Pu, 0.1381 ± 0.0070 Bq/kg for ²³⁸Pu and 1.90 ± 0.21 Bq/kg of ²⁴¹Am, 9.15 ± 0.48 Bq/kg for ²³⁰Th, 25.1 ± 1.2 Bq/kg for ²³²Th, 7.5 ± 1.5 Bq/kg for ²³⁴U and 7.26 ± 0.80 Bq/kg for ²³⁸U. Both activity and mass isotopic ratio assays revealed dominant contribution of the global fallout + SNAP 9A on the presence of plutonium isotopes and ²⁴¹Am in Greenland tundra. However, noticeable deviations of ²⁴¹Am/^239+240Pu and to a lesser extend of ²⁴⁰Pu/²³⁹Pu ratios from the GF level have been observed. The origin of ¹³⁷Cs was evidently connected with the coexistence of global and Chernobyl fallout, while the presence of ⁹⁰Sr was caused by nuclear weapon tests and affected by leaching process. The seaborne signature of uranium isotopes was manifested in research material as well.