Assessment of naturally occurring radioactive materials in dust samples collected from Savar, Bangladesh: radiological risk evaluation and implications for environmental safety

Naturally occurring radioactive materials (NORMs) can accumulate in surface dust near industrial zones and, upon inhalation, may pose potential health hazards. This study reports the activity concentrations of NORMs in dust collected from Savar Upazila, one of the most industrialized areas in Bangladesh. A total of 20 dust samples were collected from the vicinity of different industries and analyzed using a high-purity germanium (HPGe) detector. The measured concentrations of 226 Ra, 232 Th, and 40 K ranged from 17 ± 1 to 32 ± 2, 22 ± 2 to 51 ± 5, and 350 ± 25 to 520 ± 42 Bq/kg, respectively, with mean values below or close to the corresponding world averages of 30, 35, and 400 Bq/kg, respectively. 226 Ra levels stayed below the global average, but a few samples showed higher 232 Th and 40 K, which is probably due to local geology and some industrial influence. All the radiological hazard parameters were found within the international safety limits. These findings indicate that street dust in Savar does not show significant enrichment of NORMs and poses negligible radiological health risks to pedestrians and nearby residents. Nevertheless, continuous monitoring is recommended to ensure environmental and occupational safety in this rapidly industrializing region.