MEASUREMENTS OF DECAY PRODUCTSFROM RN-222 AND RN-220 NEAR GROUND LEVEL AND LOW ATMOSPHERE IN SÃO

The spectrum of low energy gamma rays (0.2 to 3.0 MeV)was measured in four points on the region of São José dos Campos, SP, Brazil. The distance of the four points measured it was less than 2 km one from another and in one location point 2 and 3, localized inone tour, it was measured in ground level and at 25 meter high. The monitoring of spectrum flux shows the strong presence of decay products of Rn-222, Rn-220 and potassium (40K) on the four places. The integrated counts rates in the same interval of energy and each place shows influence of geological parameters and the removal of 210Pband 210Poby fallout were taken also into account.