Assessment of radiation dose and biological effects on inhabitants of an area with rare earth element ore deposits in Lai Chau province, Vietnam

Rare earth element (REE) surface deposits containing primordial radionuclides such as uranium (²³⁸U), thorium (²³²Th), and potassium (⁴⁰K) were identified in the Dong Pao region, northern Vietnam. As the area is inhabited, an in-depth investigation assessed environmental radioactivity, radiation doses, radiobiological parameters, and DNA alterations to evaluate health risks. Investigations were conducted in the REE deposit area and a control area 20 km away. Soil, water, and locally produced foods were analysed by gamma spectrometry to determine concentrations of ²³²Th, ²²⁶Ra, and ⁴⁰K, allowing estimation of annual effective doses from external gamma radiation. Ambient dose equivalent was measured with a survey meter and compared with dose estimates based on soil activity concentrations. Effective doses from ingestion were calculated from radionuclide concentrations in food and water. Inhalation doses were estimated from indoor ²²²Rn and ²²⁰Rn concentrations measured by solid-state nuclear track detectors in dwellings of both areas. Hematological parameters were analysed in blood samples using ADVIA2120 equipment. Peripheral blood counts of both groups were within normal ranges. <i>t</i>-tests revealed significant differences in neutrophil and lymphocyte counts in white blood cells of females from the REE area compared to controls. Neutrophil-to-platelet and platelet-to-lymphocyte ratios in adult females from the ore deposits area were significantly higher, indicating possible inflammation, an early sign of cancer. <i>TP53</i> gene sequencing showed significantly higher genotype frequencies of rs137852793 and c.701 + 25 variants in individuals from the REE area. Results clearly indicate that ionising radiation from REE ore deposits poses a health hazard to the local population, particularly females. Polymorphism of the <i>TP53</i> gene may serve as a biomarker for radiation exposure.