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Gamma-ray spectrometry was employed to assess the activity concentrations of primordial radionuclides ( 238 U, 232 Th, and 40 K) in various construction materials, including those used for building, roofing, furnishing, flooring, and plastering. The measured activity concentrations of the radionuclides ranged as follows: 238 U (25 to 477 Bq kg -1 ), 232 Th (below detection limit to 239 Bq kg -1 ), and 40 K (285 to 1915 Bq kg -1 ). Based on these values, the materials were categorized in descending order of radioactivity threat as: Furnishing > Roofing > Building > Flooring > Plastering. The potential radiation dose and radiological hazards to occupants from continuous exposure were estimated using risk parameters. The absorbed dose rates for flooring (217.7 nGy h -1 ), building (286.9 nGy h -1 ), furnishing (353.1 nGy h -1 ), roofing (322.5 nGy h -1 ), and plastering ( 1 76.8 nGy h -1 ) were all found to exceed both the world average value and the typical indoor gamma dose rate of 84 nGy h -1 . This study highlights significant radiological risks to inhabitants associated with the use of certain materials in building construction. These include clay tiles for roofing, wood, specific granite varieties (reddish/brown granite), and certain types of bricks (fly ash, burnt, and AAS)., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The present investigation is the first of its kind which aims to study the characteristics of microbial consortium inhabiting one of the natural high background radiation areas of the world, Chavara Coast in Kerala, India. The composition of the microbial community and their structural changes were evaluated under the natural circumstances with exorbitant presence of radionuclides in the sediments and after the radionuclide's recession due to mining effects. For this purpose, the concentration of radionuclides, heavy metals, net radioactivity estimation via gross alpha and beta emitters and other physiochemical characteristics were assessed in the sediments throughout the estuarine stretch. According to the results, the radionuclides had a significant effect in shaping the community structure and composition, as confirmed by the bacterial heterogeneity achieved between the samples. The results indicate that high radioactivity in the background environment reduced the abundance and growth of normal microbial fauna and favoured only the growth of certain extremophiles belonging to families of Piscirickettsiacea, Rhodobacteriacea and Thermodesulfovibrionaceae, which were able to tolerate and adapt towards the ionizing radiation present in the environment. In contrast, communities from Comamondacea, Sphingomonadacea, Moraxellacea and Erythrobacteracea were present in the sediments collected from industrial outlet, reinforcing the potent role of radionuclides in governing the community pattern of microbes present in the natural environment. The study confirms the presence of these novel and unidentified bacterial communities and further opens the possibility of utilizing their usefulness in future prospects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)