Quantifying the radiological hazards due to the naturally occurring radionuclides in specific agricultural land in the Tangail district of Bangladesh

The rapid development of industries near forest and river has led to concerns about the toxic metal contamination of agricultural land following the release of radiotoxic elements. The study area, characterized by agricultural land influenced by the Jamuna River, Madhupur forest and numerous industries, has been assessed for concentrations of natural radionuclides and associated radiological hazards. A total of 48 agricultural soil samples were collected from twelve upazilas of the Tangail district. The measurement was performed using gamma-ray spectrometry, employing a high-purity germanium (HPGe) detector. The measured mean activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in soil samples were found to be 25.63 ± 5.00, 43.63 ± 2.00, and 451 ± 15 Bq kg^-¹, respectively. The mean radium equivalent activity, absorbed dose rate for indoor and outdoor environments, and indoor and outdoor annual effective doses were lower than the world average value. Hazard indices such as external hazard index (H_ex), and internal hazard index (H_in) were found to be less than unity. However, the gamma index (I_γ) was found higher than unity for some locations. The annual gonadal dose equivalent (AGDE) and excess lifetime cancer risk (ELCR) exceeded the global average. These findings are likely attributed to the natural environmental features of Tangail, including the geological characteristics of the Jamuna River, Madhupur forest, and industrial regions. The presented data may serve as the baseline radioactivity data for this area and may be useful for assessing any future radiological risk of this region.