| Radioisotope  | 
        Dose conversion factors (mSv Bq-1)  | 
      
      
        |   | 
        <1 y | 
        2–7 y  | 
        ≥ 17 y | 
      
      
        | 214Bi  | 
        1.4 × 10-9  | 
        3.6 ×10-10  | 
        1.1 × 10-10 (Ajayi    and Owolabi 2007)  | 
      
      
        | 226Ra | 
        4.7× 10-6  | 
        6.2 ×10-7  | 
        2.8 × 10-7 (Ajayi    and Owolabi 2007)  | 
      
      
        | 228Ac  | 
        7.4 × 10-9  | 
        1.4 × 10-9  | 
        4.3 × 10-10 (Ajayi and Owolabi 2007)  | 
      
      
        | 212Pb  | 
        1.5 ×10-7  | 
        3.3 × 10-8  | 
        6.0 × 10-9 (Ajayi    and Owolabi 2007)  | 
      
      
        | 235U  | 
        3.5 × 10-7  | 
        8.5 ×10-8  | 
        4.7 ×10-8 (Ajayi and Owolabi 2007)  | 
      
      
        | 40K | 
        6.2 × 10-8  | 
        2.1 × 10-8  | 
        6.2 × 10-9 (Ajayi and Owolabi 2007)  | 
      
      
        | 238U  | 
        3.4× 10-7  | 
        8 ×10-8  | 
        4.5 ×10-8 IRPA    2010 |