Distribution characteristics of radionuclides (²²⁶Ra, ²³⁴U, and ²³⁸U) and ratios (²²⁶Ra/²³⁴U, ²²⁶Ra/²³⁸U, and ²³⁴U/²³⁸U) in quarry lake environment: experimental and model assessment

The abandonment of stone quarries establishes a quarry lake ecosystem that includes soil, water, fish, and vegetarian cover. The activity concentrations (ACs) of natural radionuclides in the waters of several quarry lakes worldwide have not been investigated. In addition, the features of radionuclides, such as distribution, seasonal variability, and health risks, have not been studied. In this study, the ACs of ²²⁶Ra, ²³⁴U, and ²³⁸U were measured in a typical quarry lake in Vietnam with an area of approximately 4000 m². The average ACs of ²²⁶Ra, ²³⁴U, and ²³⁸U were 8.3, 13.8, and 17.7 mBq L⁻¹, respectively. The ratios of ²²⁶Ra/²³⁴U, ²²⁶Ra/²³⁸U, and ²³⁴U/²³⁸U were 0.47, 0.6, and 0.79, respectively. A linear correlation was found between ACs and water depth. The ACs predicted by the QWASI (Quantitative Water, Air, Sediment Interaction) model agree with the measured values.