Speaker
Description
Extreme weather events, such as the isolated high-level depressions (DANA) in Valencia in October 2024, may result in significant erosion and soil structural degradation. This study presents the results of the assessment of the impact of the DANA on the natural radiological levels of agricultural soils of citrus fields in the Valencia region. The natural radioactivity levels in these soils, both before and after the DANA, were analysed by gamma spectrometry. Thus, 214Pb and 228Ac concentrations were determined for 238U and 232Th chains, respectively. In addition, 40K and 137Cs were determined, the latter as an artificial isotope of interest. Furthermore, the geoaccumulation index (Igeo) was calculated to evaluate the ecological risk before and after the DANA.
When calculating the Igeo, three scenarios were considered: A) unaltered soils of citrus fields (SU) were compared with a background radionuclide level (B) obtained from historical data of the Environmental Radioactivity Laboratory (LRA) for uncontaminated soils in the province of Valencia between 2011 and 2025. The Igeo confirmed that there was no geoaccumulation in SU; B) the citrus soil before DANA (SB) was compared with the SU soil. The results indicated that the soil had a high concentration of 214Pb and 40K, and similar results for 228Ac and 137Cs, potentially related to fertilisation practices resulting in moderate alteration in the studied field; C) the radiological profile before and after the flooding (SB and SA) was compared, noting that the concentrations of Cs137 and K40 decreased, likely due to leaching effects, however the Igeo values confirmed there was no alteration of the soil after the DANA. In conclusion, the Igeo analysis findings do not suggest that flooding or sludge movement into agricultural fields has altered the soil's radiological risk.
Acknowledgements:
Thanks to Generalitat Valenciana (CIAICO/2024/254) and to Next Generation EU (AGROALNEXT/2022/043).