Trace detection of I-131 in aerosols and atmospheric deposition in Romania from the NPP accident at NEC Fukushima - Japan

The presence of artificial radionuclide I-131 in the atmosphere was continuously monitored throughout Romania in the period 23.03.2011 - 30.04.2011 by the National of Environmental Radioactivity Surveillance Network (NERSN). The I-131 radionuclide activity levels in samples were determined using gamma spectrometry method with germanium detectors (HPGe) of high purity and resolution of the NERSN. Gamma spectrometric analysis performed on samples of atmospheric deposition and atmospheric aerosols revealed the presence of artificial radionuclide concentrations comparable to those reported by other countries in Europe. Maximum concentration of atmospheric aerosols I-131 was recorded in samples taken from the Toaca Peak from Ceahlau Mountain and was 3.49 mBq/m3. In atmospheric deposition samples, the maximum concentration of I-131 was 1.34 Bq/m2 per day and has been measured in Constanta. Estimated dose calculated for population revealed an insignificant contribution, the exposure due to inhalation of iodine-131 in the sampling points appeared to be over 1000 times lower than natural radiation background. (authors)