First study on 236U in environmental samples from Bangladesh by ICP-MS/MS prior to the operation of its first nuclear power plant

For the first time, using ICP-MS/MS, the 234 U, 235 U, 236 U, and 238 U in the sediment samples from coastal region, Bangladesh, were measured as 5.13–5.48, 0.234–0.252, (2.70–4.59) × 10 –5 , and 4.92–5.31 Bq kg −1 , and the 236 U/ 238 U atom ratios were (2.87–4.57) × 10 –8 , indicating the predominate influence of global fallout on 236 U. For the rock samples from hilly area, the corresponding concentrations were much higher as 18.7–4023, 0.902–173, 9.58 × 10 –5 –1.29 × 10 –2 , and 18.8–2279 Bq kg −1 , but the 236 U/ 238 U atom ratios were in the same range of (1.52–3.04) × 10 –8 , indicating the 236 U was primarily due to the natural nuclear reactions.