Radiological measurement of hazardous levels in construction tiles in Bungoma county, Kenya

Abstract

Twenty (20) different local and imported tiles were sampled from major hardware’s in Bungoma. The samples collected were separately ground, sieved, through a 0.5mm mesh, dried at 110° C, weight and packed in a 200ml stoppered plastic bottles. The samples were stamped with identification numbers and kept for 30 days for secular equilibrium to be reached between the activity of 238U,232Th ,40K radium and their progeny. The average activity concentration of 238U, 232Th and 40K was found to be 109±5.48Bqkg-1, 11±0.55 Bqkg-1 and 1574±78.7 Bqkg-1 respectively. The average absorbed dose rate was found to be 140±7.03 nGyh-1 which is higher than the worlds average value of 60 nGyh-1. The average radium equivalent was found to be 288±14.44 Bqkg-1 which is lower than the world limit value of 370Bqkg-1. External and internal hazard indices were found to be 0.70±0.03 msvy-1 and 0.80±0.04 msvy-1respectively. Therefore, the sampled tiles used in Bungoma county for construction has minimal radiological threat to population.