Evaluation of the Equivalent Radium Activity of Clay Brickworks in Backlands of Paraiba, Brazil

The natural radioactivity can reach high levels, depending on the geological formation of each area of the planet. Construction materials contain amounts of natural radioactive elements that may have concentrations upper of established limits, varying according to the composition of rock and soil from which they originated, causing greater exposure to human beings through the use of clay as raw material for ceramics used in construction. The radioecology dosimetry of these materials is defined in terms of the Equivalent Radium activity (Ra_Eq). In this context, this study aimed to establish the calculation of RaEq in the raw material of potteries in the badlands of Paraiba, area adjacent to the uranium deposits of Espinharas, to estimate the risks associated with primordial radionuclides attributed to TENORM activities from the extraction and use of clay in manufacture of bricks and tiles. Analysis were performed by high resolution gamma spectrometry with HPGe detector-Be, assuming the state of secular radioactive equilibrium. The results ranged from 84.49 to 747.78 Nq.kg^-1, with a mean 333.97 Bq.kg^-1. Some samples had values that exceeded the limit of 370 Bq.kg^-1 established by UNSCEAR for construction materials, surpassing until on doubled, suggesting greater monitoring and control of these mining areas. (Author)