Assessment of Radiological Hazards of Sedimentary, Igneous and Sediments Natural Rocks

Gamma-ray spectroscopy based on a 100% efficiency hyper-pure germanium detector was used to evaluate the activity concentrations of 226Ra, 232Th, and 40K natural radionuclides in sedimentary, conglomerate, igneous and sedi-ments rock samples collected from four different locations in Eastern desert in Egypt. The obtained activity concentrations are used to evaluate the radi-ological hazards indices, absorbed dose rate, annual effective dose equivalent in air, radium equivalent, external and internal hazard index, radiation level index, annual gonadal dose equivalent, excess lifetime cancer risk and expo-sure rate. The results show that 1) the absorbed dose rate depends on the rock type, 2) the annual effective dose equivalent in air in 71% of sample below 20 mSvy-1 (permissible limit for workers), 3) the conglomerate rocks show low radioactivity level, 4) sedimentary rocks are rich in radium while igneous rocks are rich in thorium and the sediments rocks are rich in both radium and thorium.

Evaluation of natural radioactivity and radiological hazards in basement rocks from Gabel Abu El-Hassan in the North Eastern Desert of Egypt by multivariate statistical approach with remote sensing data

Purpose The present work deals with the natural radioactivity levels of basement rocks from Gabel Abu El-Hassan in the North Eastern Desert of Egypt.Methods The activity concentrations of 226Ra,232Th and 40K in rock samples were measured using a gamma-ray spectrometry with an HPGe detector.Landsat Enhanced Thematic Mapper Plus(ETM+)data were processed and interpreted to create rock forming radioactive map.Results and conclusion The activity concentrations of 226Ra,232Th and 40K varied from 28.2±9.4 to 259.6±38.6 Bq/kg,37.9±9.9 to 297.4±54.6 Bq/kg and 487.0±73.4 to 5514.6±786.0 Bq/kg,respectively.The radiological hazard indices(gamma index),the annual effective dose rate and excess life-time cancer risk were estimated to assess the radiological hazards due to the use of rock samples as building material.Remote sensing data were also used to integrate between radioactive analysis and Landsat-7(ETM+)data processing to detect radioactive anomalies and to identify the uraniferous alteration zones in Abu El-Hassan area.

Assessment of Natural Radioactivity in Rivers Sediment and Soil from the Copper Belt Artisanal Mining Region, Democratic Republic of the Congo

The concentrations and distribution of naturally occurring radionuclides (238U, 235U, 234U, 230Th, 226Ra, 210Pb, 232Th, 228Ra, and 40K) were determined by alpha and gamma spectrometry in soil and sediments collected from Luilu and Dilala rivers located in the mining district of Kolwezi (Lualaba Province) of the Democratic Republic of the Congo. The average concentrations of 238U and 226Ra in the analyzed samples were 5 - 10 times higher than the world average values for soil provided by the United Nations Scientific Committee on the Effects of Atomic Radiation. However, the average concentrations of 232Th were found similar to the world average. In both river basins, artisanal mining activities and mineral washing sites displayed the higher concentration values of radionuclides. The mean values of health risk indices calculated for those sites were found significantly higher compared to world average levels. Radiation protection measures seem needed to ensure the radiation safety of local populations. Graphical Abstract