| S/N | α-Activity Bq l−1 | β-Activity Bq l−1 | City/Country of the Study | References |
| 1 | 10.30 | 0.79 | Delta State, Nigeria | Avwiri and Agbalagba [6] |
| 2 | 0.782 | 0.816 | Bendimalu River, Turkey | Selçuk et al. [47] |
| 3 | 0.0118 | Not available | Owian-Aladja, Nigeria | Ogundare and Adekoye [1] |
| 4 | 0.0089 | 0.271 | Kastamonu, Turkey | Kam and Bozkurt [48] |
| 5 | 0.267 | 1.539 | Abia State, Nigeria | Enyinna and Avwiri [35] |
| 6 | 0.589 | 0.236 | Ado- Ekiti, Nigeria | Fasae [36] |
| 7 | 0.60 | Not available | Venezuela | Sojo-Bohus et al. [37] |
| 8 | 6.35 | Not available | Kaduna, Nigeria | Onoja et al. [25] |
| 9 | 0.35 | Not available | Sokoto, Nigeria | Sa’idu et al. [49] |
| 10 | 0.057 | 3.535 | Kebbi, Nigeria | Baba-Kutigi et al. [50] |
| 11 | 1.00 | 20.30 | Niger Delta, Nigeria | Present study |