| Countries | HR (mSv∙an−1) | References |
| Turkey | 0.5*; 0.3** | Turhan S et al. (2008) [12] |
| Ghana | (0.21)* | Kpeglo et al., (2011) [7] |
| Tunisia | (0.27)*; 0.16** | FatenTurqui (2010) [10] |
| Egypt | 0.09 | El Alfifi M.E. et al. [13] |
| Cote d’Ivoire | 0.358* - 0.513* (0.427)* 0.252** | This work |