A comparative study of the elevated radioactivity in beach placer deposits of Bangladesh.

This article examines the natural radioactivity levels in beach sand deposits at Kolatoli and Kuakata, two major heavy mineral-rich beaches and tourist sites in Bangladesh. It identifies that the elevated radioactivity in Kolatoli beach sand primarily arises from thorium series radionuclides (Th-232 and Ra-228) associated with higher concentrations of heavy minerals, especially monazite and zircon, whereas Kuakata beach sand shows significantly lower radioactivity dominated by uranium series radionuclides (U-238 series) and potassium-40 (K-40), linked to its lower heavy mineral content. The study utilized gamma and alpha spectrometry to measure radionuclide activity in bulk sand and separated mineral fractions, revealing that monazite fractions exhibit the highest radioactivity levels. The findings highlight the need for further geochemical and provenance studies to understand sediment evolution and support environmental and radiological monitoring in these coastal areas.