Insights from terrain influence on gamma dose rate variability in lower Shivalik Himalayas

Abstract

Abstract This study focused on assessing how natural background radiation levels vary due to spontaneous gamma emissions from the terrain of the Haridwar district. Gamma radiation levels are influenced by a mix of environmental and structural factors. Outdoor radiation is closely connected to soil composition and geology, while indoor radiation is affected by both external conditions and the characteristics of building materials. The range of observed indoor dose rates has been found from 0.07 to 0.31 µSv/h with an average value of 0.15 µSv/h, and outdoor dose rates from 0.06 to 0.28 µSv/h with an average of 0.13 µSv/h. The terrain of the administrative map of Haridwar district has been classified into two categories based on altitude, viz., Highland and Lowland. The results show that unexpectedly high radiation in certain areas and subtle variations between highlands and lowlands suggest unmodeled factors may be contributing to radiation exposure patterns. Indoor spaces showed higher gamma radiation compared to outdoors. Radiation exposure changes depending on age, with infants receiving the most. The interplay of potential outliers has been discussed in detail.