Radiation hazard in soil from Ajaokuta North-central Nigeria

Abstract

Background: Measurement of the radia on dose distribu on is important in assessing the health risk a popula on and serve as reference in documen ng changes to environmental radioac vity in soil due to man-made ac vi es. Materials and Methods: The ac vity concentra on of 238 U, 232 Th and 40 K in soil samples obtained from different loca ons in Ajaokuta Local Government area was measured using Hyper Pure germanium Detec on System (HPGe). Results: The calculated average concentra on of the radionuclides ranged from 12 ± 1 Bqkg-1 to 59 ± 2 Bqkg-1 for 238 U, 14 ± 1 Bqkg-1 to 78 ± 5 Bqkg-1 for 232 Th and 49 ± 2 Bqkg-1 to 1272 ± 23 Bqkg-1 for 40 K. In order to evaluate the radiological hazards due to natural radionuclides within Ajaokuta, the absorbed dose rate, gamma index, radium equivalent and excess life me cancer risk were es mated. According to measured data from the top soil (0-10 cm), the es mated radium equivalent (Ra eq) ranges from 55.7 Bqkg-1 at Steel Complex to 253.3 Bqkg-1 obtained from Forest samples. Conclusion: The mean absorbed dose rate, annual effec ve dose and gamma radia on index evaluated were 66.2 nGyh-1 , 81.2 µSvy-1 and 1.05 respec vely which are higher than the recommended limit for normal background radia on. Thus, we conclude that people living in these loca ons may be exposed to higher radia on.

Measurement of exposure to radionuclides (40-K, 226-Ra, and 232-Th) in the oil and gas drilling industry

“…The external hazard index (Hex) is defined to limit the external γ -radiation dose and calculated by equation (5) (13) .…”

“…Hex=CRa/370+CTh/259+CK/4810≤1 (5) The internal hazard index (Hin) which is obtained from the equation ( 6), measures the internal exposure to radon and its daughter products (13) .…”

Gamma Background Radiations and Measurements with Applications

“…The mean assimilated portion rate, yearly successful portion, and gamma radiation record assessed were 66.2 nGyh −1 , 81.2 μSvy −1 , and 1.05 individually which are higher than as far as possible for ordinary foundation radiation. In this manner, it is argued that individuals living in these areas might be presented to higher radiation [47].…”

Monitoring of radon concentration for different building types in Covenant University, Nigeria

“…Indoor radon is known to vary from buildings to buildings and it can be elevated in house of all types (Agency for Toxic Substances and Disease Registry (2012,2018,2017,2018)) especially, in the environment that has been previously noted to be rich in primordial radionuclide content Oyeyemi et al, 2017;Usikalu, Oderinde et al, 2018) which can influence radon concentration level in buildings. The impact of radiation, radon gas and possible health burden of other radiological parameters assessment (Olise et al, 2013;Usikalu, Fuwape et al, 2017;Usikalu, Rabiu et al, 2017) reveals the need for monitoring of radon gas level of inhabited structures. The convenience and safety of dwellers are primarily influenced by structural and non-structural elements.…”