The activity concentrations of uranium and thorium have been determined in soils and mineral sands
from the Nigerian tin mining area of Bisichi, located in the Jos Plateau, and from two control areas in
Nigeria (Jos City and Akure) using high-purity germanium detectors (HPGe). High resolution sector field
inductively coupled plasma mass spectroscopy (HR-SF-ICP-MS) was used to determine uranium and
thorium in liquids and foodstuffs consumed locally in the mining area. The activities of uranium and
thorium measured in the soils and mineral sands from Bisichi ranged from 8.7 kBq kg1 to 51 kBq kg1
for 238U and from 16.8 kBq kg1 to 98 kBq kg1 for 232Th, respectively. These values were significantly
higher than those in the control areas of Jos City and Akure and than the reference values reported in the
literature. They even exceeded the concentrations reported for areas of high natural radioactive background.
Radionuclide concentrations in samples of the local foodstuffs and in water samples collected in
Bisichi were found to be higher than UNSCEAR reference values. The results reveal the pollution potential
of the mining activities on the surrounding areas.