Abstract:
Cements contain traces of natural radionuclides because the raw materials originate from the earth’s
crust. Elevated levels of natural radioactivity can have harmful health effects on living tissues. This study aimed
at establishing the radiological safety of cements used in Kenya by quantifying gamma ray-emitting natural
radionuclides present in the cements. A Sodium Iodide Thallium-doped gamma ray spectrometer was used in
counting gamma rays emitted by 40K and progenies of 238U and 232Th in the selected cement brands. The average
activity concentrations and radiation safety indicators of selected cement brands were determined and compared with
global averages. The activity concentrations of 238U, 232Th, and 40K were estimated using gamma-ray photopeak
energies of 214Pb at 352 KeV, 212Pb at 239KeV and 1460 KeV respectively. The average activity concentrations 232Th, 238U, and 40K were found to be 52.70±3.3, 35.88±4.3, and 432.31±50.7 BqKg-1
. The absorbed dose rate of
most cement samples was higher than the world average of 59nGhy-1
. Cement class and clinker content determined
the amounts of primordial radionuclides. Values of indoor and outdoor hazard indices, annual effective dose rates
and radium equivalent activity were within stipulated safety limits. These metrics of radiation hazard indicators were
within safety limits, and therefore, there is no significant radiation risk linked to the use and handling of the cements
used in Kenya.
