Effective gamma-ray doses due to natural radiation from soils of southeastern Brazil.

We have used gamma-ray spectrometry to study the distribution of natural radiation from soils of southeastern Brazil: Billings reservoir, São Bernardo do Campo Parks, Diadema Parks, Interlagos region, São Paulo, and soil from São Paulo and Rio de Janeiro beaches. In most of the regions studied we have found that the dose due the external exposure to gamma-rays, proceeding from natural terrestrial elements, are between the values 0.3 and 0.6 mSv/year, established by the United Nations Scientific Committee on the Effects of Atomic Radiation. [ABSTRACT FROM AUTHOR]