Soil-to-maize Transfer Factor of Natural Radionuclides in a Tropical Ecosystem of Nigeria

Abstract

Soil-to-plant transfer factor (TF) is a parameter utilized in predicting the accumulation of radionuclides in the plant system. Virgin soil from an uncultivated area and tailings from an abandoned tin mining site were used to formulate three soil groups. Group A (virgin soil only), group B (tailings only) and group C (equal mixture by mass of the virgin soil and tailings). Pot experiments were performed using the soil groups to determine the transfer factors of 40K, 238U and 232Th in maize (Zea mays L.) plants for the tropical ecosystem of Nigeria. The activity concentrations of 40K, 238U and 232Th in the soil groups and the maize plant compartments (seed, stem, leaf and root) were determined using NaI(Tl) gamma-detector. The geometric mean (GM) of the TF values for 40K, 238U and 232Th respectively ranged from 0.02 to 0.27, below detectable limit (BDL) to 0.008 and 0.01 to 0.09 in the in the seeds; 0.04 to 1.74, BDL to BDL and 0.01 to 0.29 in the stems; 0.03 to 0.93, BDL to 0.33 and 0.02 to 0.08 in the leaves and 0.03 to 1.29, 0.05 to 0.38 and 0.08 to 0.41 in the roots.. Potassium-40 had the highest TF values and exhibited the plant accumulation strategy for all the plant compartments. The stem samples had the highest TF for 40K and BDL values for 238U for all the soil groups. Significance differences were observed only in the accumulation of 40K and 232Th across the soil group.
 Keywords: Radioactivity, potassium, mining, Gamma-ray detectors, calibration

Soil to Cassava Transfer Factors of Natural Radionuclides in Farms in Ini Local Government Area, Akwa Ibom State, Nigeria

“…The mean value of the AC of potassium obtained for this study is higher than that obtained in Oyo state, Nigeria [20], Delta State, Nigeria [21,22,23]. However, the mean value in Uta farm is higher than world mean of 400 Bq/Kg for 40 K. This high value of potassium could be as a result of the fact that potassium is an essential element required for proper plant growth [24,25]. Furthermore, it was reported that the presence of potassium and calcium in the soil affect the transfer of other radionuclides into the plants which could also be responsible for the lower value of activity concentration of uranium and thorium presented [26].…”

Determination of Activity Concentrations and Soil to Cassava Transfer Factors of Natural Radionuclides in Ikot Ekpene Local Government Area, Akwa Ibom State, Nigeria

“…The specific activity of radionuclides in Cassava in Ufam farm is presented in Table 3 Results presented show a high deposition of potassium in the cassava tubers while absorption of other radionuclides is low. The mean values of the specific activity of potassium obtained for this study are slightly below the world mean of 400 Bq/Kg for 40 K. This high value of potassium could be as a result of the fact that potassium is an essential element required for proper plant growth [14,9]. Furthermore [15] reported that the presence of potassium and calcium in the soil affect the transfer of other radionuclides into the…”

“…This work is necessary because the information obtained will address the concern of the dearth of data from tropical and sub-tropical ecosystem on the effect of radionuclide in edible plant. However, there is information from some parts of Nigeria on TF for different plants including maize [8,9]. Cassava [7], palm oil and other crops [10].…”

Radıometrıc Measurements in of Ladybird (Berberis Thunbergii), Bowood (Buxus Sempervirens Rotundifolia) and Gold Tassel (Euonymus Japonica Var. Aurea) Under Cadmıum and Zınc Stress

“…Using the equation given below, TF values were calculated with the mean radionuclide activity concentrations found in the leaves of Red barberry, Boxwood, and Gold tassel plants and the soil samples used in growing the plants [11,25].…”

“…and 32.52±2.65, between 236.83±7.53 and 889.65±17.63, and between 7.63±1.26 and 39.44±8.57. In another study, Adesiji & Ademola[25] found the 238U, 232Th, and 40K activity concentrations of soil samples they used in growing corn plant to be in the range of 242 13. ± 429.10-2763.90 ± 2345.77, 15294.77 ± 6924.46-26211.90 ± 7178.22, and 374.01 ± 590.51-5008.18 ± 2427.165 Bqkg-1, respectively, and those values are much higher than the results achieved in the present study.…”