The Study of Natural Radiation Distribution inSoil of Sao Bernardo do Campo

摘要

We have studied the distribution of natural radioactivity in the soil of five sites of thecity Sao Bernardo do Campo, Sao Paulo, Brazil. The main contribution of the radiation dose isdue to the isotope ~(40)K,with smaller contributions from the elements of the series of ~(238)Uand~(232)Th.The results indicate the dose in all of the studied areas is around the average internationaldose due to external exposure to gamma rays (0.48 mSv/yr) proceeding from natural terrestrialelements.