Activity concentration and radon exhalation rate in Nile River sediments: evaluation of radiological hazard using gamma spectrometry and CR-39 detectors.
This study assessed the radiological hazard associated with sediment and silt samples collected from the Nile River. The results consistently demonstrated low levels of natural radioactivity. Calculated dose parameters were found to be well within international safety limits. The average outdoor annual effective dose equivalent (AEDEout) was 50 µSv/y for sediments and 60 µSv/y for silt. Similarly, the average indoor AEDE (AEDEin) values were 280 and 350 µSv/y, respectively, remaining significantly below the worldwide limit of 450 µSv/y. Long-term risk assessment further supported these findings, with the annual gonadal dose equivalent (AGDE) averaging 0.28 mSv/y for sediments and 0.36 mSv/y for silt. Finally, the calculated excess lifetime cancer risk (ELCR) remained low, at 1.15 × 10-3 for sediments and 1.44 × 10-3 for silt. The average radon concentrations in soil were 7.17 Bq/m3 for sediment and 5.65 Bq/m3 for silt. In conclusion, all measured activity concentrations and derived radiological risk factors confirm that the Nile River sediment and silt samples pose no significant radiological hazard to the public.