Effect of the Chernobyl accident on the gamma radiation level in the Belgrade region

After Chernobyl accident a monitoring programme was initiated in VINCA, Beograd, ( Institute in Belgrade. The main part of the programme was continual measurement of the gamma radiation level. It has been possible to detect the radioactive cloud coming across from the Chernobyl over Belgrade region, due to this measurements. The first maximal gamma radiation level, because of presence of the radioactive cloud, was registered at 10.30 a.m. on the May 1 st, 1986. The second maximal radiation level then was registered in the morning of May 2 nd, due to heavy rain and intensive thunders. After that, the gamma radiation level has started to decrease, following approximately, effective radioactive decay of gamma emitting mixture and influence of many environmental factors. Measurements have been done by high pressure argon ionization chamber, model RSS-111. Complete set of measured data, from the April 30, 1986 up to now, are given and discussed in this paper. These data, according to authors opinion, could be used for testing of the atmospheric dispersion models and for many other purposes