# An Assessment of the Impact of Gypsum Deposit Development on Changes in the Radiation Environment
## 3 Results and Discussions
### Bottom Sediments  
#### 3.2.1 Activity Concentrations of Radionuclides in River Sediments  
Table 2 shows the results of determining the activities of radionuclides in bottom sediments. The results of the study of the physical and chemical parameters of the bottom sediments are given in Table 3. Table S1 contains descriptive statistics of the considered parameters of bottom sediments. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**ID** & **\({}^{137}\)Cs** & **\({}^{228}\)Ra** & **\({}^{232}\)Th** & **\({}^{40}\)K** & **\({}^{238}\)U** & **\({}^{234}\)U** & **\({}^{234}\)U** \\  & & & **(Bq kg\({}^{-1}\))** & & & **(Bq Bq\({}^{-1}\))** \\ \hline BS-1 & 4.50 \(\pm\) 0.88 & 20.9 \(\pm\) 2.7 & 13.2 \(\pm\) 2.3 & 373 \(\pm\) 43 & 9.93 \(\pm\) 1.49 & 11.1 \(\pm\) 1.6 & 1.11 \(\pm\) 0.7 \\ BS-2 & 3.52 \(\pm\) 0.62 & 16.6 \(\pm\) 2.2 & 11.3 \(\pm\) 1.9 & 350 \(\pm\) 38 & 7.52 \(\pm\) 1.13 & 6.51 \(\pm\) 0.97 & 0.87 \(\pm\) 0.13 \\ BS-3 & 6.24 \(\pm\) 1.25 & 11.2 \(\pm\) 2.1 & 3.33 \(\pm\) 0.51 & 338 \(\pm\) 39 & 3.13 \(\pm\) 0.47 & 2.97 \(\pm\) 0.44 & 0.95 \(\pm\) 0.14 \\ BS-4 & 1.61 \(\pm\) 0.57 & 10.8 \(\pm\) 1.4 & 4.67 \(\pm\) 1.15 & 251 \(\pm\) 26 & 3.87 \(\pm\) 0.58 & 4.28 \(\pm\) 0.64 & 1.11 \(\pm\) 0.17 \\ BS-5 & 6.12 \(\pm\) 1.12 & 17.5 \(\pm\) 2.2 & 19.9 \(\pm\) 2.3 & 407 \(\pm\) 42 & 17.6 \(\pm\) 2.64 & 17.5 \(\pm\) 12.6 & 0.99 \(\pm\) 0.15 \\ BS-6 & 20.8 \(\pm\) 3.0 & 23.5 \(\pm\) 3.6 & 11.9 \(\pm\) 2.0 & 302 \(\pm\) 41 & 7.3 \(\pm\) 11 & 89.5 \(\pm\) 13.4 & 1.22 \(\pm\) 0.18 \\ BS-7 & 10.2 \(\pm\) 2.1 & 13.3 \(\pm\) 2.5 & 8.67 \(\pm\) 1.71 & 208 \(\pm\) 31 & 62.6 \(\pm\) 9.4 & 54.8 \(\pm\) 8.2 & 0.87 \(\pm\) 0.13 \\ BS-8 & 1.33 \(\pm\) 0.30 & 20.6 \(\pm\) 2.8 & 12.1 \(\pm\) 2.2 & 380 \(\pm\) 38 & 4.38 \(\pm\) 0.66 & 3.63 \(\pm\) 0.54 & 0.83 \(\pm\) 0.12 \\ BS-10 & 10.3 \(\pm\) 2.5 & 27.0 \(\pm\) 4.1 & 5.12 \(\pm\) 0.92 & 199 \(\pm\) 28 & 12.5 \(\pm\) 1.9 & 9.24 \(\pm\) 1.38 & 0.74 \(\pm\) 0.11 \\ BS-13 & 1.52 \(\pm\) 0.51 & 18.1 \(\pm\) 2.5 & 5.93 \(\pm\) 1.74 & 396 \(\pm\) 46 & 5.68 \(\pm\) 0.85 & 5.07 \(\pm\) 0.76 & 0.89 \(\pm\) 0.13 \\ Mean & 6.61 \(\pm\) 1.29 & 18.0 \(\pm\) 2.6 & 9.61 \(\pm\) 1.68 & 320 \(\pm\) 37 & 20.0 \(\pm\) 3.0 & 20.5 \(\pm\) 3.1 & 0.96 \(\pm\) 0.14 \\ \hline \end{tabular}
\end{table} 
Table 2: Specific activity of radionuclides in bottom sediments (BS). The maximum activity concentrations of \({}^{238}\)U (62.6 \(\pm\) 9.4 and 73 \(\pm\) 11 Bq kg\({}^{-1}\)), which correspond to uranium contents of 4.3-6.8 mg kg\({}^{-1}\), were found in two of these lakes (BS-6 and BS-7) (Figure 5e). Also, in two lakes (BS-6 and BS-10), the maximum activities of \({}^{226}\)Ra (23.5 \(\pm\) 3.6 and 27.0 \(\pm\) 4.1 Bq kg\({}^{-1}\)) were recorded. In the BS-6 sample, the maximum uranium isotope ratio of 1.22 \(\pm\) 0.18 was established (Figure 5f). The maximum activities of \({}^{232}\)Th (19.9 \(\pm\) 2.3 Bq kg\({}^{-1}\)) and \({}^{40}\)K (407 \(\pm\) 42 Bq kg\({}^{-1}\)) were determined in the BS-5 sample (Figure 5c,d), for the composition of which no features were found in the distribution of physical and chemical parameters (Table 3). Overall, the average values of \({}^{226}\)Ra, \({}^{232}\)Th and \({}^{40}\)K activities were 18.0, 9.6 and 320 Bq kg\({}^{-1}\), respectively, which are lower than the world average values (33.0, 45.0 and 420 Bq kg\({}^{-1}\), respectively) [53; 54; 55]. 2.2 The Ratio of Radionuclide Activity, the Concentrations of Chemical Elements and the Main Parameters Characterizing Bottom Sediments  
Table 4 shows the correlation matrix of radionuclide activities, the concentrations of chemical elements and the main parameters characterizing the bottom sediments. A more complete correlation matrix is provided in the Supplementary Materials (Table S4). The distribution of chemical elements in the bottom sediments of rivers and lakes in the area of the Glubokoye gypsum deposit is presented in Table S3.