Radiation hazard assessment in Egyptian painting oxides. A comparative study

Building materials are potential sources of radiation, which represents a risk factor for human disease including cancer. In this work, the natural radioactivity due to the presence of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K in different painting oxides has been measured using gamma spectrometry with a Hyper Pure germanium detector. The concentrations of the heavy metals (Cd, Co, Mn, Pb, Ni, Sr, Rb, Cr, Cu and Zn) were determined by atomic absorption spectrometry in order to investigate their possible correlation with radioactive elements. The activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K ranged from 15 ± 0.75 to 126 ± 14, 2.35 ± 0.09 to 72.96 ± 1.96, 1.76 ± 0.31 to 12.88 ± 0.7 and 2.26 ± 0.09 to 200 ± 3.34 Bq kg⁻¹, respectively. The calculated radium-equivalents were lower than values recommended for construction materials (370 Bq kg⁻¹). The absorbed dose rates due to the natural radioactivity of the investigated samples ranged from 8.11 ± 0.24 to 68.46 ± 4.20 nGy/h. Also, the results revealed that some heavy metals (Cd, Co, Mn and Rb) were correlated with ²³⁸U, ²²⁶Ra, ²³²Th or ⁴⁰K.