Natural radioactive materials present in rocks, soil, water, and air contribute to daily radiation exposure, particularly in indoor environment where people spend approximately 80% of their time. This exposure is further influenced by building materials such as granite, which is commonly used in construction. This study investigated 21 varieties of granite tiles commercially available and commonly used as decorative finishing materials in residential building in Erbil City - Kurdistan region of Iraq. Gamma-ray spectrometry employing a "3 × 3" NaI(Tl) scintillation detector was used to determine the activity concentrations of 226Ra, 232Th, and 40K. The activity of 226Ra was arranged from 12 ± 05 to 163 ± 09 Bq.kg-1 with an average value of 81 ± 16 Bq.kg-1. In contrast, the activity concentration of 232Th varied from 0.7 ± 0.40 Bq.kg-1 to 153 ± 12 Bq.kg-1, with an average of 59 ± 07 Bq.kg-1. For 40K, the average activity concentration ranged from 220 ± 15 Bq.kg-1 to 2177 ± 46 Bq.kg-1 with an average of 1548 ± 39 Bq kg-1. When compared with established global average values, the majority of the analyzed granite tiles exhibited elevated levels of natural radioactivity. To assess the potential radiation hazard effects associated with 226Ra, 232Th, and 40K in granite samples, several radiological hazard indices were calculated.
Habeeb Hanna Mansour (Fri,) studied this question.