The specific activity of U-238 and Th-232, as well as K-40 radionuclides, in twenty-nine investigated medicinal herbs used in Egypt has been measured using a high-purity germanium (HP Ge) detector. The measured values ranged from the BDL to 20.71 ± 1.52 with a mean of 7.25 ± 0.54 (Bq kg−1) for uranium-238, from the BDL to 29.35 ± 1.33 with a mean of 7.78 ± 0.633 (Bq kg−1) for thorium-232, and from 172 ± 5.85 to 1181.2 ± 25.5 with a mean of 471.4 ± 11.33 (Bq kg−1) for potassium-40. Individual herbs with the highest activity levels were found to be 20.71 ± 1.52 (Bq kg−1) for uranium-238 (H4, Thyme herb), 29.35 ± 1.33 (Bq kg−1) for thorium-232 (H20, Cinnamon), and 1181.2 ± 25.5 (Bq kg−1) for potassium-40 (H24, Worm-wood). (AACED) Ingestion-related effective doses over the course of a year of uranium-238 and thorium-232, as well as potassium-40 estimated from measured activity concentrations, are 0.002304 ± 0.00009 (minimum), 0.50869 ± 0.0002 (maximum), and 0.0373 ± 0.0004 (average)(mSv/yr). Radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), absorbed gamma dose rate (Doutdoor, Dindoor), gamma representative level index (I), annual effective dose (AEDtotal), external and internal hazard index (Hex, Hin), and excess lifetime cancer risk were determined in medicinal plants (ELCR). The radiological hazards assessment revealed that the investigated plant species have natural radioactivity levels that are well within the internationally recommended limit. This is the first time that the natural radioactivity of therapeutic plants has been measured in Egypt. In addition, no artificial radionuclide (for example, 137Cs) was discovered in any of the samples. Therefore, the current findings are intended to serve as the foundation for establishing a standard safety and guideline for using these therapeutic plants in Egypt.

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The optimum conditions for the removal of uranium-238, thorium-232, and potassium-40 from wastewater and the discharge of nuclear facilities using multiwalled carbon nanotubes (CNTs) are described. The adsorption mechanism is mainly attributed to chemical interactions between the metal ions and surface functional groups of the CNTs. Batch adsorption experiments are carried out in order to study the effect of different parameters such as pH, contact time, initial metal ion concentration, adsorbent dose, and temperatures. Maximum metal removal (>98%) from solutions containing 20–120 Bq/L metal ions is achieved using a contact time of 15 min, a pH of 6.0, and 10 mg/L CNTs. The effect of temperature on the kinetics and equilibrium of adsorption on CNT particles is examined. Consistent with an exothermic reaction, an increase in the temperature resulted in an increase in the adsorption rate. Langmuir, Freundlich, and Dubinin–Radushkevich isotherms are applied to the data obtained at various temperatures. The Langmuir adsorption model is the best for data interpretations. The kinetics of adsorption reveals a pseudo-second-order mechanism. Thermodynamic parameters at 293 K (Δ G °, Δ H °, and Δ S °) for U-238, Th-232, and K-40 are −14590.7 kJ/mol, −6.66 kJ/mol, and 26.47 J/(mol K), −96,96.5 kJ/mol, −2.48 kJ/mol, and 14.17 J/(mol K), and −3922.09 kJ/mol, −1.32 kJ/mol, and 6.12 J/(mol K), respectively.

Twenty soil and 25 sediment samples were collected from the banks and bottom of the River Nile in the surroundings of biggest cities located close to it. Natural radioactivity concentrations of Ra,Th and K have been evaluated for all samples by means of γ spectrometric analysis. The radioactivity levels of soil and sediment samples fall within the internationally recommended values. Nevertheless, high natural background radiation zones are detected in the Kafr El-Zayat region due to the presence of a fertilizer factory, and in the Rosetta region due to the presence of black sand deposits. The absorbed dose rate, the γ index and excess life time cancer risk are calculated. High values for some of the radiation health parameters are detected in the Kafr El-Zayat and Rosetta regions representing a serious problem to public health because the soil and sediment are used as constructing material for buildings. Furthermore, the isotope analysis of uranium for representative collected sediment samples via α spectrometry showed average specific activities of 18.7 ± 3.6, 0.087 ± 0.0038 and 18.6 ± 3.8 Bq kg for U,U and U, respectively. In general, these values confirm the balance in the isotopic abundance of U isotopes.

Nuclear facilities / Radioactivity measurement / γ -spectrometry / α-spectrometry / Laser fluorimetry Summary. The monitoring and evaluation of the radioactivity levels around the Egyptian nuclear facilities located at Inshas, near Cairo, namely, two research reactors, an R & D fuel fabrication laboratory and a fuel fabrication pilot plant, were carried out. Soil, water and plant samples were collected from locations near and around the facilities and analyzed by using gamma, laser and alpha spectrometry. A preoperational radiological map for the new reactor site was established. The results of the postoperational monitoring around the first reactor show that the 38year operation of this reactor did not increase the radioactivity level around the facility. The observed man-made 137 Cs was found to be (0.3-9.2 Bq/kg) and 239+240 Pu 0.096-0.158 Bq/kg. The observed tritium was found to be in the range 0.6-1.48 Bq/L. The absorbed dose rate and radium equivalent are calculated and presented.

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Radium isotopes can be analyzed by different analytical methods based on gamma spectrometric measurements or alpha spectrometry. An improved method was developed to determine radium isotopes from water using gamma spectrometry after radiochemical separation. The Radium was selectively extracted from acidified samples using co-precipitation procedure with iron hydroxide and followed by precipitation of radium as radium sulphate Ba(Ra)SO 4 . The precipitate Ba(Ra)SO 4 was filtered through the Millipore filter paper, dried and weighed to calculate chemical yield. 226 Ra and 228 Ra activities were measured using low-background gamma spectrometry in water samples. Radium was pre-concentrated from environmental samples by co-precipitation with BaSO 4 . The amounts of 226 Ra and228 Ra on the sample were obtained by gamma-ray spectrometry for the 351 keVγ-ray from 214 Pb and for the 911 keV γ-ray from 228 Ac, both in radioactive equilibrium with precursors, respectively. The accuracy, selectivity, traceability, applicability and Minimum Detectable Activity (MDA) of the technique were discussed. Also, the effect of physical and chemical characteristics of the water samples such as TDS, pH, soluble species, sulphate and bicarbonate that effect on the radium determination were taking into consideration. The method has been validated with a certified reference material supplied by the International Atomic Energy Agency and reliable results were obtained. The radiochemical yields for radium were 70% -90% and recovery was 97% and 80% for 226 Ra and 228 Ra, respectively.

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