Pre-Chernobyl deposition dynamics of anthropogenic radionuclides at Cluj-Napoca, Romania

The 137Cs bulk deposition samples measured in samples collected at Cluj-Napoca in 1965–1985 are analysed and compared with published 137Cs deposition data from New-York, St. Petersburg, Helsinki and Bratislava covering partially/totally the period 1955–1985. A total 137Cs deposition of 4.2 ± 0.9 kBq/m2 at Cluj-Napoca is estimated for 1955–1985 based on the comparison of available data. The signature of the atmospheric nuclear tests performed in 1977–1980 is presented using the monthly measured bulk depositions of 106Ru, 125Sb, 137Cs and 144Ce (1978–1982) and 95Zr, 103Ru, 141Ce for the year 1981, following the last atmospheric nuclear test of October 16, 1980.