## 4 Conclusions  
This study examines the levels of natural and artificial radiation in the soil near the Maanshan NPP. The results show that manmade radionuclides have not contaminated the soil. The average activity concentrations of natural nuclides \({}^{40}\)K, \({}^{226}\)Ra, and \({}^{232}\)Th were below the global average activity concentrations in the soil. The activity ratios of \({}^{40}\)K/\({}^{226}\)Ra and \({}^{40}\)K/\({}^{232}\)Th were higher than global activity ratios, suggesting that the soil primarily comprises light minerals. The activity concentrations varied considerably, indicating that the soil composition is complex. However, the activity concentrations of natural nuclides were positively correlated with each other and clay content while they were negatively correlated with sand content. The difference in activity concentrations can be attributed to particle size and soil mineral composition. Some soil samples comprised light minerals, while a few contained shells and coral reef debris. The radiological hazard indices Ra\({}_{\text{eq}}\) and H\({}_{\text{ex}}\) were lower than the safe recommended limits of 370 Bq/kg and 1.0, respectively. Additionally, all samples' D\({}_{\text{Rex}}\) and AED\({}_{\text{ex}}\) values were lower than the global average values. These findings suggest that the soil surrounding the Maanshan NPP does not pose a significant radiological risk to residents and tourists. These results provide a foundation for the future monitoring of soil activity concentrations around the NPP, particularly during its decommissioning in 2025.  
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Location** & **Ra\({}_{\text{eq}}\)** & **H\({}_{\text{ex}}\)** & **D\({}_{\text{Rex}}\)** & **AED\({}_{\text{ex}}\)** & **Reference** \\ \hline NPP/Taiwan & 98.2 a  & 0.27 (0.15–0.39) & 46.6 (22.7–66.2) & 57.2 (27.9–81.7) & [11] \\ NPP IV/Taiwan & 106.6 (14.92–171.1) & 0.27 (0.04–0.46) & 49.3 (7.33–82.8) & 60.5 (9.0–101.5) & [16] \\ NPP/Thailand & 126 (14–446) & 0.34 (0.04–1.20) & 58 (6–203) & 71 (8–249) & [17] \\ DIRAMS */Korea & 88.8 (71.5–94.7) & 0.24 (0.19–0.26) & — (37.6–45.3) & 50 (50–60) & [13] \\ MAPS **/India & 189 (96.3–331.4) & 0.51 (0.26–0.89) & 74.6 (41.2–131.9) & 91.5 (50.5–161.7) & [18] \\ NPP III/Taiwan & 83.0 (17.5–116.3) & 0.22 (0.05–0.31) & 39.0 (8.3–54.4) & 47.8 (10.1–66.7) & Present Study \\ \hline \end{tabular}
\end{table}
Table 7: Radiological hazard indices in the soil from the present study and from soils around NPPs in other countries.  
**Author Contributions:** Conceptualization, T.-C.C., F.-C.Z., and W.-H.H.; methodology, C.-C.L. and Y.-L.Y.; formal analysis, W.-H.H. and F.-C.Z.; investigation, W.-H.H. and F.-C.Z.; resources, C.-C.L. and Y.-L.Y.; writing--original draft preparation, W.-H.H., F.-C.Z., and T.-C.C.; writing--review and editing, W.-H.H. and T.-C.C. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was partially funded by the nuclear safety commission, Taiwan, grant number 111-2001-02-28-05.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The raw data supporting the conclusions of this article will be made available by the authors on request.  
**Acknowledgments:** The authors appreciate the technical assistance from the Radiation Monitoring Center, Nuclear Safety Commission.  
**Conflicts of Interest:** The authors declare no conflicts of interest.