Table 4: The average activity concentration of radionuclides in the collected water samples (Bq/L ± SEM).

Water samples Mean radioactivity concentration
238U 232Th 40K

Mkuju River (W1)2.5 ± 0.41.9 ± 0.211.0 ± 2.0
Kilowelo River (W2)2.2 ± 0.31.8 ± 0.19.2 ± 1.2
Control sample2.1 ± 0.31.7 ± 0.22.0 ± 0.8