Authors :
John A. Ocheje; Franca Oyiwoja Oko
Volume/Issue :
Volume 8 - 2023, Issue 6 - June
Google Scholar :
https://bit.ly/3TmGbDi
Scribd :
https://tinyurl.com/yte7fhed
DOI :
https://doi.org/10.5281/zenodo.8171251
Abstract :
Nigeria as one of the developing countries, has
most of its farmlands contaminated by human activities
like; mining, waste disposal, industrial waste,
agricultural practices, use of inorganic fertilizers,
sewage, sludge, and other anthropogenic activities. This
research work evaluated the activity concentrations of
natural radionuclides, and excess lifetime cancer risk
(ELTCR) in soil and crop samples from twenty locations
of farmlands in Nasarawa state, Nigeria. High purity
Germanium (HpGe) detector was used to determine the
activity concentration of radionuclides. The absorbed
dose rate and ELTCR for 60 years were forecasted and
evaluated using the ResRad off-site computer model.
The mean activity concentrations of 40K, 232Th, and 238U
in the soil samples were 408.69, 24.08, and 30.71 Bq kg−1
,
respectively, while the average activity concentration of
40K, 232Th, and 238U in crop samples were 142.63, 46.06,
and 17.45 Bqkg−1, respectively. The Raeq concentration,
the external, and internal hazard indices were evaluated
and ranged from 81.77 to 159.09 Bqkg−1, 0.22 to 0.43,
and 0.28 to 0.53, with average values of 115.50, 0.31, and
0.40Bqkg−1, respectively. The ELTCR ranged from 0.17
×10−3 to 1.16 ×10−3, with a mean of 0.46 ×10−3. This value
is above the average value approved by UNSCEAR
2000.Correlation analysis showed a strong positive
correlation between activity concentration of
radionuclides in soil and crop for 40K and 232Th and a
weak correlation for 238U due to soil type and microbial
activities in most of the study area, the total cancer risks
in the zone, particularly in Akwanga and Doma, were
higher than the safety limits. Excessive use of organic
fertilizer on farmland should be checked from time to
time.
Keywords :
Radionuclide, Res Rad Off-Site Model, Excess Lifetime Cancer Risk, Activity Concentration.
Nigeria as one of the developing countries, has
most of its farmlands contaminated by human activities
like; mining, waste disposal, industrial waste,
agricultural practices, use of inorganic fertilizers,
sewage, sludge, and other anthropogenic activities. This
research work evaluated the activity concentrations of
natural radionuclides, and excess lifetime cancer risk
(ELTCR) in soil and crop samples from twenty locations
of farmlands in Nasarawa state, Nigeria. High purity
Germanium (HpGe) detector was used to determine the
activity concentration of radionuclides. The absorbed
dose rate and ELTCR for 60 years were forecasted and
evaluated using the ResRad off-site computer model.
The mean activity concentrations of 40K, 232Th, and 238U
in the soil samples were 408.69, 24.08, and 30.71 Bq kg−1
,
respectively, while the average activity concentration of
40K, 232Th, and 238U in crop samples were 142.63, 46.06,
and 17.45 Bqkg−1, respectively. The Raeq concentration,
the external, and internal hazard indices were evaluated
and ranged from 81.77 to 159.09 Bqkg−1, 0.22 to 0.43,
and 0.28 to 0.53, with average values of 115.50, 0.31, and
0.40Bqkg−1, respectively. The ELTCR ranged from 0.17
×10−3 to 1.16 ×10−3, with a mean of 0.46 ×10−3. This value
is above the average value approved by UNSCEAR
2000.Correlation analysis showed a strong positive
correlation between activity concentration of
radionuclides in soil and crop for 40K and 232Th and a
weak correlation for 238U due to soil type and microbial
activities in most of the study area, the total cancer risks
in the zone, particularly in Akwanga and Doma, were
higher than the safety limits. Excessive use of organic
fertilizer on farmland should be checked from time to
time.
Keywords :
Radionuclide, Res Rad Off-Site Model, Excess Lifetime Cancer Risk, Activity Concentration.
