## 3 Results and Discussion
The lowest values, 25.05 Bq\(\cdot\)kg\({}^{-1}\), were recorded in the Artuklu, Dargecit, Derik, Nusaybin, Savur, and Yesilli districts. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Districts** & **Coordinates** & \begin{tabular}{c} **Ra-226** \\ **(Bq\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} & \begin{tabular}{c} **Th-232** \\ **(Bq\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} & \begin{tabular}{c} **K-40** \\ **(Bq\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} & \begin{tabular}{c} **Cs-137** \\ **(Bq\(\cdot\)kg\({}^{-1}\))** \\ \end{tabular} \\ \hline \begin{tabular}{c} Mardin \\ (Artuklu) \\ \end{tabular} & \begin{tabular}{c} 37.31290\({}^{\circ}\) N, \\ 40.73411\({}^{\circ}\) E \\ 37.54618\({}^{\circ}\) N, \\ 41.72038\({}^{\circ}\) E \\ 37.36466\({}^{\circ}\) N, \\ 40.26794\({}^{\circ}\) E \\ 37.19138\({}^{\circ}\) N, \\ 40.58595\({}^{\circ}\) E \\ 37.47737\({}^{\circ}\) N, \\ 40.48674\({}^{\circ}\) E \\ 37.41515\({}^{\circ}\) N, \\ 41.37343\({}^{\circ}\) E \\ 37.06964\({}^{\circ}\) N, \\ 41.21400\({}^{\circ}\) E \\ 37.40311\({}^{\circ}\) N, \\ 40.95482\({}^{\circ}\) E \\ 37.53393\({}^{\circ}\) N, \\ 40.88709\({}^{\circ}\) E \\ 37.33961\({}^{\circ}\) N, \\ 40.82302\({}^{\circ}\) E \\ \hline \begin{tabular}{c} Max \\ \end{tabular} & \begin{tabular}{c} 37.31290\({}^{\circ}\) N, \\ 40.73411\({}^{\circ}\) E \\ 37.54618\({}^{\circ}\) N, \\ 41.72038\({}^{\circ}\) E \\ 37.36466\({}^{\circ}\) N, \\ 41.21400\({}^{\circ}\) E \\ 37.40311\({}^{\circ}\) N, \\ 40.95482\({}^{\circ}\) E \\ 37.53393\({}^{\circ}\) N, \\ 40.88709\({}^{\circ}\) E \\ 37.33961\({}^{\circ}\) N, \\ 40.82302\({}^{\circ}\) E \\ \hline \begin{tabular}{c} Max \\ \end{tabular} & - & 62.55 & 45.05 & 450.05 & 75.05 \\ \hline \begin{tabular}{c} Min \\ \end{tabular} & - & 15.05 & 25.05 & 250.05 & 5.00 \\ \hline \begin{tabular}{c} Mean \\ \end{tabular} & - & 33.66 & 29.37 & 385.63 & 20.52 \\ \hline \
\begin{tabular}{c} Turkiye \\ (mean) \({}^{\star}\) \\ \end{tabular} & - & 27.56 & 32.65 & 439.93 & 12.03 \\ \hline
\begin{tabular}{c} UNSCEAR ** \\ \end{tabular} & - & 35.00 & 30.00 & 400.00 & N/A \\ \hline \hline \end{tabular}  
* TAEK, [24]. ** UNSCEAR, 2000 [1]—World (median). N/A: Not available.  
\end{table} 
Table 4: Activity concentrations of districts of Mardin province (taken from TAEK [24]). The spatial distribution of the K-40 activity concentrations is shown in Figure 6a, with district-wise comparisons illustrated in Figure 6b. The K-40 activity concentrations range from 250.05 Bq\(\cdot\)kg\({}^{-1}\) to 450.05 Bq\(\cdot\)kg\({}^{-1}\), with an average of 385.63 Bq\(\cdot\)kg\({}^{-1}\), which is lower than the Turkish average of 439.93 Bq\(\cdot\)kg\({}^{-1}\). The highest K-40 activity concentration was observed in the Artuklu, Kiziltepe, Mazidag, Midyat, and Omerli districts, with a value of 450.05 Bq\(\cdot\)kg\({}^{-1}\), and five out of ten districts exceeded the UNSCEAR world median of 400.00 Bq\(\cdot\)kg\({}^{-1}\). The lowest concentration, 250.05 Bq\(\cdot\)kg\({}^{-1}\), was measured in the Nusaybin district. The spatial distribution of the Cs-137 activity concentrations is illustrated in Figure 7a, while comparisons among the districts are presented in Figure 7b. Cs-137 activity concentrations range from 5.00 Bq\(\cdot\)kg\({}^{-1}\) to 75.05 Bq\(\cdot\)kg\({}^{-1}\), with an average of 20.52 Bq\(\cdot\)kg\({}^{-1}\), which is higher than the Turkish average of 12.03 Bq\(\cdot\)kg\({}^{-1}\). The highest Cs-137 activity concentration was found in the Yesilli district, with a value of 75.05 Bq\(\cdot\)kg\({}^{-1}\), and seven out of ten districts exceeded the Turkish average. The lowest values, 5.00 Bq\(\cdot\)kg\({}^{-1}\), were recorded in the Derik, Kiziltepe, and Nusaybin districts. Figure 4: (**a**) Spatial distribution of Ra-226 activity concentrations (taken from [24]). (**b**) Comparison of Ra-226 activity concentrations (taken from [24]). The color range used in the (**a**) represents varying levels of radioactivity.