Assessment of natural radioactivity and associated radiological risks from tiles used in Kajang, Malaysia.

The activity concentration and radiological risk of commonly used flooring materials (tiles) in Malaysia were studied. The natural radionuclide concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were measured using high-purity germanium detector. The average concentration of ²²⁶Ra, ²³²Th and ⁴⁰K in the samples were 65.75±1.1 Bq kg⁻¹, 61.92±1.43 Bq kg⁻¹ and 617.77±6.72 Bq kg⁻¹ respectively. The mean concentration of radium equivalent activity, absorbed dose rate, external and internal hazard indices and annual effective dose equivalent were 195.21±2.88 Bq kg⁻¹, 92.75±1.27 nGy h⁻¹, 0.53±0.01, 0.7±0.01 and 0.44±0.0 mSv y⁻¹ respectively. The aim was to assess the possible radiological risks attributed from the tile materials. Even though, the activity concentrations were higher than worldwide average values, but none of the radiological impact parameters exceeded the maximum recommended values. Hence, it was concluded that, contribution of tiles to radiation exposure is negligible and therefore, radiologically safe to use as building materials. [ABSTRACT FROM AUTHOR]