Estimation of Excess Lifetime Cancer Risk and Radiation Hazard Indices in Yunusari, Yobe State, Nigeria

Abstract

Although mining is crucial, unregulated quarry mining operations may expose people to radiation and
pollute the environment, mutually of which could have a negative effect on the host communities. This
study used a sodium iodide (NaI) detector to amount the activity concentrations of 226Ra, 232Th, and
40K in soil samples from five mining sites in Yunusari Yobe State. Thirty soil samples were taken using
systematic sampling techniques from the five mining areas at a depth of 15 cm and 50 meters apart. These
samples were then investigated for activity concentration at Ahmadu Bello University Zaria's Centre for
Energy Research and Training (CERT). Calculations were made for the External Hazard Index, Annual
Effective Dose Rate, Radium Equivalent Activity, Gamma Absorbed Dose Rate, and Excess Life Cancer
Risk. Findings indicate that the average activity concentrations of 226Ra, 232Th, and 40K in soil samples
were found to be 108.27 Bq/Kg, 58.99 Bq/Kg, and 287.95 Bq/Kg, respectively, according to the results.
With the exception of 40K, which had a value of 287.95Bq/Kg, which is less than the UNSCEAR world
standard of 400Bq/Kg, the values of 226Ra and 232Th were all greater than the UNSCEAR world
standard of 35Bq/Kg and 30Bq/Kg, respectively. The average Radium Equivalent Activity was
214.090Bq/Kg, which is lower than the world standard of 370Bq/Kg, but the Gamma Absorbed Dose
Rate (D) was 97.612nGh-1, which is greater than the 84nGh-1 standard. 0.3200mSv/y, 0.120mSv/y, and
0.300mSv/y were the mean values of the External Hazard Index, Annual Effective Dose Rate, and Excess
Life Cancer Risk, respectively, and were below the International System of Radiological Protection's
(ICRP) suggested public exposure limit of 1 mSv/y. To sum up dissemination of naturally occurring
radionuclides in the soil samples surrounding the research area is displayed in the results. With the
exception of 40K, which is lower than the global average, the average activity concentrations of 226Ra,
232Th, and 40K from this investigation are greater than the global average values. As a result, mining
operations may present radioactive risks to the host populations.