## 3 Results and Discussion
### Major and Trace Element Assessment in Soil
#### 3.2.2 Other Major and Trace Elements in Soil  
In conducting soil analysis within the Lower Danube Basin, PIGE nuclear method proved particularly useful in identifying and quantifying LEs, including Al, Mg, Na, Cl, Si, and F. Some of these elements, such as fluorine, can be hazardous even in low amounts. Figure 6 illustrates the distribution of light elements in the upper layer of the agricultural soil in the Lower Danube Basin. \begin{table}
\begin{tabular}{l c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Reference**} & **Cd** & **Co** & **Cr** & **Co** & **Mn** & **Ni** & **Pb** & **Zn** & **F** & **Cl** & **Ti** & **Si** & **Na** & **Mg** & **Fe** \\ \cline{2-13} \multicolumn{1}{c}{**(mg kg\({}^{-1}\))**} & & & & & & & & & & & & & & & \\ \hline \multicolumn{13}{c}{**(m)**} \\ \hline \multicolumn{13}{c}{**Continued crust [62]**} & 0.08 \(\sim\)0.10 & 10 & 100 & 55 & 900 & 20 & 15 & 70 & 452 & 640 & 4400 & - & - & - & 5 \\ \hline \multicolumn{13}{c}{**World soils [62]**} & 0.08 \(\sim\)0.41 & 11.3 & 59.5 & 36.9 & 488 & 29 & 27 & 70 & 321 & 300 & 7028 & - & - & - & 3.5 \\ \multicolumn{13}{c}{**European soils [63]**} & 0.284 & 8.91 & 32.6 & 16.4 & 541 & 367.7 & 25.9 & 64.9 & - & - & - & 600 & 6.4 & 1.35 & 1.18 & 2.17 \\ \multicolumn{13}{c}{**Enumstein soils [64]**} & 0.43 & 13.0 & - & 3.27 & 175.820 & 35.6 & 21.3 & 87 & - & - & - & - & - & - & - \\ \multicolumn{13}{c}{**Enumstein [64]**} & 0.25 & 11.1 & 23 & 20 & 594 & 22 & 57 & 78 & - & - & - & - & - & - & - \\ \multicolumn{13}{c}{**Enumstein [64]**} & 0.25 & 13.1 & 84 & - & 538 & 67 & - & 108 & - & - & 2000 & - & 0.03 & 0.76 & 3.15 \\ \hline \multicolumn{13}{c}{**Bottomary volume (fund with uncertainty one)**} \\ \multicolumn{13}{c}{**NV [62]**} & 1 & 15 & 30 & 20 & 900 & 20 & 20 & 100 & - & - & - & - & - & - & - \\ \multicolumn{13}{c}{**AT**} \\ \multicolumn{13}{c}{**IT**} & 3 & 50 & 300 & 200 & 100 & 1500 & 75 & 50 & 300 & 150 & & & & & \\ \hline \multicolumn{13}{c}{\({}^{1}\) Average values in upper layer (aqua regia digestion); \({}^{*}\)[68]; NV = normal value, AT = alert threshold, and IT = intervention threshold.} \\ \end{tabular}
\end{table} 
Table 4: Average concentration values of trace (mg kg\({}^{-1}\) d.w.) and major (in% d.w.) elements in the upper layer of continental crust, world, European, and Romanian soils synthesized after various authors and the Ministry of Water, Forests, and Environmental Protection of Romania [62; 63; 64; 65; 66; 67; 68]. In the TUL region, sodium levels in the 0-5 cm layer range from 5.8 to 6.7 g kg\({}^{-1}\), while in the 5-30 cm layer, they vary from 5.6 to 6.7 g kg\({}^{-1}\). Aluminum content ranges between 39.7 and 47.8 g kg\({}^{-1}\) (0-5 cm) and 32.8 and 46.3 g kg\({}^{-1}\) (5-30 cm). Silicon concentration in the first soil section is between 278.5 and 363.8 g kg\({}^{-1}\), while in the second soil section, it ranges from 279.1 to 341.3 g kg\({}^{-1}\). Chlorine shows the lowest content values compared to other elements. In the first 5 cm layer, it falls within the range of <2.4-<3.7 g kg\({}^{-1}\), while in the second layer, it varies between <0.2 and <6.7 g kg\({}^{-1}\). In the SEN area, the uppermost soil layer (0-5 cm) has a sodium content ranging from 6.4 to 7.3 g kg\({}^{-1}\). In the second soil section, sodium values range between 6.4 and 6.6 g kg\({}^{-1}\). The aluminum level ranges from 43.0 to 46.6 g kg\({}^{-1}\) (0-5 cm) and from 41.9 to 43.9 g kg\({}^{-1}\) (5-30 cm). Silicon content follows a similar trend, with concentrations ranging from 234.8 to 288.5 g kg\({}^{-1}\) in the first 5 cm of soil and from 300.4 to 302.2 g kg\({}^{-1}\) in the next 25 cm. Chlorine, on the other hand, has low concentrations that fall below <3.8-<4.0 g kg\({}^{-1}\) at 0-5 cm and <4.0 <4.1 g kg\({}^{-1}\) at 5-30 cm. In the VAD land, the sodium content ranges from 6.3 to 8.3 g kg\({}^{-1}\) in the top 5 cm of soil, while in the next 25 cm layer, it is between 6.0 and 7.7 g kg\({}^{-1}\).