Radiological risk assessment of natural radioactivity of flooring materials in Iraqi dwellings: A comparative study as of NaI (Tl) spectrometry

The current study considers the natural radioactivity level and the radiological risks in flooring material commonly used in Iraqi dwellings. A sample of 31 of them, including granite (n=7), ceramic (n=9), porcelain (n=8), and mosaic tiles (n=7) was purchased in local markets in Baghdad and adjacent provinces. The concentrations of radioactive elements were measured utilizing a scintillation detector NaI(Tl) of the species of 238U, 232Th and 40K by using a sodium iodide. Calibration has been done against standard reference sources to obtain accuracy. The average specific activities of the radionuclides were 22.09 Bq/kg, 13.35 Bq/kg, and 301.91 Bq/kg with the cases of 238U, 232Th and 40K respectively. The sample of imported granites (G1 -India) had the highest activity levels, and local mosaic tiles (M7 -Iraq) were the least active. The indicators of radiological hazards, which are radium equivalent (Raeq), the annual effective dose equivlent (AEDE), and the absorbed dose rate (Dab), were computed to estimate the possible health hazards. The maximum Raeq measured was 116.75 Bq/kg and this is far below the international regulatory level of 370 Bq/kg. Besides, the average of excess lifetime cancer risk was averaged at 0.132 which is less than the global mean of 0.29. As a result, the analysis indicates that, as far as all materials researched meet the radiological safety standards to be used at home, conventional local mosaic tile poses the most favorable level of safety as it has a rather smaller rate of radionuclide burden.