Assessment of naturally occurring radioactive materials in the surface soil of uranium mining area of Jharkhand, India

• Activity concentration of 238U, 226Ra, 230Th and 210Po was measured in soil.
• Assessed radiological hazard and compared with similar studies.
• The external and internal hazard indices were estimated.
• Radium equivalent activity and effective dose to the population were evaluated.
• Excess nominal life time cancer risk was comparable to world average 0.29 × 10− 3.

Activity concentration of naturally occurring radioactive materials in surface soil was measured in 30 different locations in the uranium mineralized area of Jaduguda, India. The mean activity concentration of 238U, 226Ra, 232 + 234Th and 210Po in soil was found to be 35 ± 34, 47 ± 24, 106 ± 56, and 49 ± 35 Bq.kg− 1 respectively. Gamma dose rate, external and internal hazard indices and radium equivalent activity in surface soil were estimated and the obtained result suggests that the mean external and internal hazard indices were 0.47 and 0.57 respectively. The average radium equivalent activity was found to be 187 Bq.kg− 1. The annual effective dose to population was in the range of 31–170 μSv y− 1 with a mean value of 98. The excess life time cancer risk was found to be in the range of 0.12 × 10− 3–0.65 × 10− 3 with an average value of 0.39 × 10− 3. The risk is comparable to global value of 0.29 × 10− 3.