| dc.description |
Purpose. To establish pre-mining indicators to assess radiological impact as a result of release of radionuclides to
environment during uranium mining at Mkuju River Project radioactivity of 226Ra, 232Th and 40K in soil, plants,
fruits and cereals.
Methods. The High Purity Germanium detector was used to determine the radioactivity and the data were subsequently
used to establish soil to plant transfer factors and annual effective dose.
Findings. The results revealed a strong positive correlation (r) of 0.947 and 0.950 for 226Ra and 232Th, respectively,
between values determined in soils and plants. Implicit in these finding is that the distribution of radionuclides in
soils is directly proportional to the corresponding radionuclides in plants.
Originality. The roots of wild grass had the highest specific radioactivity (Bqkg-1) for 226Ra (2.15 ± 0.02), 232Th
(1.43 ± 0.02) and 40K (198.16 ± 1.72) and the roots of cabbage had the highest values for 226Ra (1.38 ± 0.04), 232Th
(1.34 ± 0.03) and 40K (146.12 ± 1.02) among the food crops, an indication of a higher ability to uptake radionuclides
from soil. Similarly, since the TFs were found higher in wild grass for 226Ra (0.0533 ± 0.04), 232Th (0.0374 ± 0.002)
and 40K (0.5297 ± 0.05) and cabbage for 226Ra (0.0362 ± 0.03), 232Th (0.0360 ± 0.001) and 40K (0.4173 ± 0.05).
Practical implications. It is an evident that these plants can serve as good bio indicators to assess release of radionuclides
from inside the mining site to the public domain. Moreover, the annual effective dose (mSvy-1) for 40K
(0.23 ± 0.02), 226Ra (0.046±0.004) and 232Th (0.073 ± 0.006) in edible crops when consumed in the vicinity of the
MRP before the mining operations were, as expected, insignificant. |
|