Determination of natural radioactivity and estimation of radiation hazard in cultivated soil samples in El-Minia governorate (Upper Egypt)

Abstract

Natural radioactivity is a source of continuous exposure to human beings. It originates from both extraterrestrial sources and radioactive elements in the earth crust. Assessment of radioactive elements in the study area is very important from different point of view especially for human health. The natural radioactivity of soil samples were measured by Gamma spectrometry using 3ʺ×3ʺ NaI (Tl) well detector. Cultivated soil samples were collected from eight regions in El-Minia governorate including; Maghagha, BaniMazar, Mattay, Samallot, El-Minya, Abo Qurqas, Mallawy, and Deir Mawas district. The activity concentration ranged from12.43±0.62 Bq.kg -1 to 30.15±1.51 Bq.kg -1 with average 20.58±1.04 Bq.kg -1 for 226 Ra, 7.27±0.35 Bq.kg -1 to 25.74±1.28 Bq.kg -1 with average14.37±0.75Bq.kg -1 for 232 Th and 149.24±7.45 Bq.kg -1 to 270.94±13.59 Bq.kg -1 with average 210.20±10.55 Bq.kg -1 for 40 K. The measured values are comparable with other worldwide radioactivity and are within the range specified by UNSCEAR 2000 .Also radiological hazard indices were evaluated. All hazard indices are below the permissible limit. Therefore, the radiation hazard and cancer risk are insignificant in the investigated area.