Natural and anthropogenic radionuclides in urban soil around non-nuclear industries (Northern Al Jubail), Saudi Arabia: assessment of health risk

Determination of natural radioactivity levels in soil samples from irrigated vegetable farming land in and around Addis Ababa, Ethiopia

Soil samples were collected from vegetable agricultural areas in and around Addis Ababa, and their levels of radioactivity were measured. Gamma spectrometry with high-purity germanium detector was used to quantify radioactivity level. The average concentration of 226Ra, 232Th, and 40K were 32.8 ± 2.1, 62.4 ± 4.4, and 544.3 ± 23.3 Bq kg-1 respectively. The mean values of 232Th and 40K are higher, whereas the value of 226Ra is comparable with world average values. Radiological hazard indices, including radium equivalent activity (Raeq), absorbed dose rate (Dr), outdoor annual effective dose equivalent (Deff), external hazard index (Hex), internal hazard index (Hin), and gamma radiation representative level index (Iγ), were calculated based on the activity concentration of 226Ra, 232Th and 40K. The mean values were 163.9 Bq kg-1, 78.7 nGy h-1, 0.10 mSv y-1, 0.44, 0.53, and 0.60 respectively. All indices are lower than global recommended limit values. These results revealed that radiation hazard due to radionuclides in the soil of the study area is insignificant.

Radiological hazard assessments of radionuclides in building materials, soils and sands from the Gaza Strip and the north of Sinai Peninsula

Radiological hazards to the residents of the Gaza Strip, Palestine and the north of the Sinai Peninsula, Egypt, were determined using the naturally occurring radionuclides (²²⁶Ra, ²³²Th and ⁴⁰K) in 69 samples of building materials (demolition debris, plasters, concretes, from recycling plants and raw cements from suppliers), soils and sands collected in the field. The radiological hazard indices and dose rates calculated with the activity concentrations of radionuclides in those materials determined by gamma-ray spectrometry indicate that the values are all within the global limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation 2000 and European Commission 1999. The results of Spearman's correlation and hierarchical cluster analysis for ²¹⁰Pb in the building materials, soils and sands suggest that the samples include ²¹⁰Pb from the atmospheric fallout. The medium correlation between ²³²Th and ⁴⁰K in demolition debris implies that their activity concentrations are characteristic of the building materials and constituents of the demolition debris. Non-natural ratio of ²³⁸U/²³⁵U was found in the soil and sand samples collected in the Gaza Strip. Furthermore, ¹³⁷Cs and ²⁴¹Am were detected in some soil, sand and demolition debris samples analyzed in this study. The origins of those anthropogenic radionuclides were considered.