Assessment of radiometric standard and potential health risks from building materials used in Bangladeshi dwellings

Accurate knowledge of the terrestrial radionuclides concentrations in building components is crucial for radiation exposure assessment to the dwellers. The present investigation determines the natural radioactivity levels in common building materials (the structural and decorative) used in Bangladeshi dwellings via HPGe gamma-ray spectrometry. The measured activity levels of ²²⁶Ra, ²³²Th and ⁴⁰K in the studied materials ranged between 7.33 ± 3.49 and 157.13 ± 13.03 Bq kg⁻¹, 4.08 ± 1.84 and 131.65 ± 6.87 Bq kg⁻¹ and 128.38 ± 10.27 and 1234.5 ± 39.77 Bq kg⁻¹, respectively. Majority of the studied materials, especially the cement and paint, show the elevated concentrations of terrestrial radionuclides. However, for most of the samples, the total activity in terms of hazardous radium, show lower values compared to the OECD reported limiting index of 370 Bq kg⁻¹, except in paint samples. The potential radiological hazards owing to the investigated samples were assessed by calculating a number established screening parameters, and compared with the agreed limits set by international regulatory bodies. The calculated indoor and outdoor absorbed dose rates for most of the materials (apart from sand) overdo the agreeing limiting standards of 84 and 59 nGy h⁻¹, as suggested by UNSCEAR (2000). Therefore, continuous radiation level monitoring, especially for paint and cement samples, need to be continued to avoid undesirable exposure from radiation to occupants. Overall, the calculated data may help to set up recommendations for using building materials for dwelling resolutions.