Uranium and its decay products in radioactive anomalies of oxidized brown coals (western part of Kansko-Achinsk brown coal basin)

Vertical distribution of uranium and its decay products (226Ra and 210Pb) in the uppermost layers of the oxidised brown coals was studied for some deposits and natural outcrops of the Western part of the Kansko-Achinsk brown-coal basin. Abnormal accumulation of the mentioned radioactive elements is observed in all studied sites. Several types of radioactive anomalies are differed by the ratio of activities of 238U and 226Ra: 1) Equilibrium; 2) Radium; 3) Uranium. The depletion of 210Pb in the radioactive horizons of some sites indicates an active emanation of 222Rn in the underlying coal layers. Uranium besides the form sorbed on coal is presented in poral solutions. It says about its potential mobility and is confirmed experimentally. Radium is actively absorbed by the plants growing on radioactive coals