Gamma spectroscopic assays of radionuclide contents and heavy metal in soil samples from waste dump sites in
selected cities in southwestern Nigeria were carried out. The activity concentration level due to 40K, 226Ra, 228Th, 137Cs, 109Cd, 210Pb, 214Bi, and 208Tl in the samples were determined using coaxial-type Ge detector. The maximum
concentrations of 40K, 226Ra, 228Th, and 137Cs are 357±12, 68±7, 132±10, and 0.96 Bqkg-1 at Ado, Abeokuta, Lagos,
and Ibadan; while the minimum concentrations are 180±6, 40±5, 22±2, and 0.19 Bqkg-1 at Akure, Ado, Osogbo, and
Abeokuta, respectively. The maximum concentrations of heavy metals 208Ti, 210Pb, 214Bi, and 109Cd are 35±1, 46±5,
104±7, and 49±1 Bqkg-1 at Lagos, Ibadan, and Ado, while the minimum concentrations are 5±0.24, 20±3, 17±2 and
40±1 Bqkg-1 at Ado and Ibadan, respectively. The highest and the lowest average outdoor effective dose rates were
recorded at Lagos and Ibadan.