TITLE:
Natural Radionuclides Content in Granites from Operational Quarry Sites
AUTHORS:
Jamiu Idowu Lawal
KEYWORDS:
Activity Concentration, Radionuclides, Granite, Quarries, Radiological Parameters
JOURNAL NAME:
Detection,
Vol.7 No.1,
January
25,
2019
ABSTRACT: Natural radionuclides content in
granite from eight functional quarries in Osun State, Southwestern Nigeria was assessed. Eighty
granite samples comprise¾inches.½inch and stone-dust
were collected from Wolid, Slava, Ayofe, Espro, Ife/Modakeke, Krystal Vountein,
Clario and Omidiran quarries in the State. Measurement was done using a high
purity germanium (HPGe) detector. The statistical analysis was carried out
using Statistical Package for Social Sciences (SPSS) software to determine if
granite size has an impact on the activity concentrations. The results revealed
that the mean activity concentrations of 238U (12.64 ± 1.89 Bq·kg -1) and 232Th (16.93 ± 2.46 Bq·kg -1) were highest in¾inch granite
and lowest in stone-dust (5.01 ± 0.77 and 8.97 ± 1.37 Bq·kg -1 respectively), whereas 40K is highest in the ¾inches (266.19 ± 35.53
Bq·kg -1) and lowest in½inches
(151.85 ± 25.09 Bq·kg -1) granite. Espro has the highest (23.75 ± 3.74 Bq·kg -1) while Wolid has the lowest (4.11 ± 0.73 Bq·kg -1) 238U activity concentration and Slava has
lowest for 232Th (8.21 ± 1.12 Bq·kg -1) and 40K
(109.54 ± 11.06 Bq·kg -1). The radiological hazard parameters such as absorbed
dose, annual effective dose radium equivalent, gamma index, external index, and internal index, were calculated to assess the radiation hazards
associated with granite samples. The results obtained are lower than the
recommended limits. The results were compared with the published data of other
countries. Although, all the
calculated radiation hazard indices were lower than the permissible limits.
Therefore, people working in the quarries, granite end-users and the
general public are safe from radiological health risks from the quarries, since
there is no significant health hazard. The research will give reliable
information on activity concentrations of natural radionuclides in granite
rocks, contribute to a better understanding of radioactivity distribution in
granite, and develop standards.