• Assess activity of radionuclide (238U, 226Ra, 232Th, 40K) in beach sediments in northern of Vietnam;
• Assess the risks and impacts of radioactive radiation on humans and organisms, and find ways to minimise the harm.

Theoretical results:
Beach sediments in northern Vietnam were analysed for grain size distribution, mineral composition, and natural radioactivity, alongside the calculation of radiological risk indices including Raeq, ADR, AEDE, Iγr, AUI, Hex, AGDE and ELCR. The sediments were classified into four types: very fine sand, fine sand, medium sand, and coarse sand. Mineralogical analysis showed that quartz dominated (80.6%), followed by illite (5.4%), feldspar (3.3%), kaolinite (2.4%), chlorite (2.0%), goethite (2.0%), gibbsite (0.2%), and amphibole (0.8%). The mean activities of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K were 23.3, 23.1, 27.1 and 214.9 Bq/kg, respectively. The radiological indices were calculated as: Raeq = 78.38 Bq/kg, ADR = 38.8 nGy/h, AEDE = 0.04 mSv/y, Iγr = 0.57, AUI = 0.56, Hex = 0.21, AGDE = 256.1 µSv/yr and ELCR = 0.16×10⁻³.
The radionuclides predominantly originate from terrestrial sediments, with additional contributions from marine and atmospheric sources. Overall, the average radioactivity levels and associated radiological risk indices are lower than global averages and UNSCEAR recommendations, indicating that the sediments in this region pose no significant radiological risk to humans or biota. Nevertheless, higher values observed at certain sites in Thanh Hoa, Nam Dinh (now is Ninh Binh), Nghe An, and Ha Tinh provinces areas that require further investigation and monitoring for early warning and risk mitigation.

Applied results:
The project’s results can serve as a valuable resource for units and organisations under the Departments of Agriculture and Environment, tourism management authorities, as well as local communities. These findings help enhance understanding of the beach environment and provide a scientific basis for developing appropriate and sustainable economic activities in the region.