[Radiation effects of the Chernobyl accident on the Hungarian population]

Due to the nuclear accident at Chernobyl in April 1986, the atmospheric transport spread the released radioactivity throughout the whole Europe. The initial plume moved into the north-western direction and a portion of this plum turned to west and later on to south-west. The central European countries including Hungary became affected in 29-30 April. The release during the last period (5-7 May) was directed to Romania, Bulgaria and Greece. In addition to the main trajectories of the atmospheric transport, the local meteorological conditions with winds of different directions at various altitudes, rainfalls etc. produced a very complex deposition pattern in Central Europe. The contamination of the soil surface and vegetation were strongly influenced by the wash-out of the radioactive materials from the local air. Due to the high geographical variation of the rains the surface contamination provided a similar heterogeneity among the territories of the country. The northern-west part and the region of the capital Budapest became nearly 5 times higher contaminated than the middle part of the country. Radiation doses of the population have been provided by activity concentrations in air, soil, vegetation, foods etc. and the external dose rates, mainly due to the surface contamination by the isotopes of 131I, 134Cs and 137Cs. The average effective dose contribution received by the individuals (adults) in Hungary during the 15 years following the accident has been assessed to be 0.30 mSv while the annual dose from the natural background is 2.5-3 mSv. Contribution to total dose from the internal pathway (committed effective dose) resulted about 0.10 mSv and the external radiation provided 0.19 mSv. The contributions of the external exposure from the contaminated air and inhalation are less than 5% of the total one.