Radiological assesment of natural radioactivity levels in selected ceramic tile brands used in Kenya

Abstract

The assessment of the radiation levels of the natural radionuclides 232Th, 238U and 40K in ceramic tiles used in Kenya has been studied. The radiometric analysis was done using a high-efficiency gamma-ray spectrometer. A total of thirty-seven (37) samples of ceramic tiles were pulverized, weighed accurately, and packaged in 250ml standard plastic containers, well labelled and stored for 28 days to attain secular equilibrium. Analysis of specific gamma energies from activities of 232Th, 238U and 40K reported activity of 53.73±2.34 Bqkg-1, 43.17±3.40 Bqkg-1, and 525.99±36.10 Bqkg-1 respectively. The variatiations in the radiation activity concetration is attributed to the composition of geological raw material used for tiles manufacturing. The average radium equivalent, absorbed dose, indoor and outdoor annual effective dose, and hazard indices (internal and external) obtained were 159.59 BqKg-1, 75.55nGyh-1, 0.28, 0.19, 0.54 and 0.43 respectively. The results obtained from the study showed that the use of ceramic tiles in Kenya does not pose any significant harmful radiation effects to users.