Concentrations of iodine isotopes (I-129 and I-127) and their isotopic ratios in aerosol samples from Northern Germany

摘要

New data about I-129, I-127 concentrations and their isotopic ratios in aerosol samples from the trace survey station of the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Northern Germany, are presented and discussed in this paper. The investigated samples were collected on a weekly basis during the years 2011 to 2013. Iodine was extracted from aerosol filters using a strong basic solution and was separated from the matrix elements with chloroform and was analysed by accelerator mass spectrometry (AMS) for I-129 and by inductively coupled plasma mass spectrometry (ICP-MS) for I-127. The concentrations of I-127 and I-129 in aerosol filters ranged from 0.31 to 3.71 ng m(-3) and from 0.06 to 0.75 fg m(-3), respectively. The results of I-129/I-127 isotopic ratios were in the order 10(-8) to 10(-7). The I-129 originated directly from gaseous emissions and indirectly from liquid emissions (via sea spray) from the reprocessing plants in Sellafield and La Hague. In comparison with the results of I-131 after the Fukushima accident, no contribution of I-129 from this accident was detectable in Central Europe due to the high background originating from the I-129 releases of the European reprocessing plants. I-129 atmospheric activity concentrations were compared with those of an anthropogenic radionuclide (Kr-85). We did not find any correlation between I-129 and Kr-85, both having nuclear reprocessing plant as the main source. (C) 2016 Elsevier Ltd. All rights reserved.