A Comparative Study of the Radiological Hazard in Sediments Samples from Drinking Water Purification Plants Supplied From Different Sources

The natural radiation level has been determined for 135 sediment samples from forty-six drinking water purification plants supplied from different sources (Nile River, Ibrahimia Canal and Bahr Yousif Canal) with an aim of evaluating the radiation hazard. The concentration of natural radionuclides (226Ra, 232Th and 40K) has been investigated by using gamma spectrometry (NaI (Tl) 3″x 3″) detector. The results showed that the concentrations of average activity in the sediment samples collected from drinking water purification plants supplied from Nile River, Ibrahimia Canal and Bahr Yousif Canal are (29±2, 30±2 and 240±8 Bq kg-1), (47±3, 46±8 and 258±12 Bq kg-1) and (28±2, 27±3 and 219±18 Bq kg-1) for 226Ra, 232Th and 40K, respectively. In general, the distributions of average activity concentrations of samples under investigation are within the world values although some extreme values have been determined. Radiological hazard effects such as: absorbed dose rate (D), outdoor and indoor annual effective dose equivalent (AEDE), radium equivalent activities (Raeq), hazard indices (Hex and Hin), gamma index (Iγ), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) for the corresponding samples were also estimated

A Comparative Study of the Radiological Hazard in Sediments Samples from Drinking Water Purification Plants Supplied From Different Sources

The natural radiation level has been determined for 135 sediment samples from forty-six drinking water purification plants supplied from different sources (Nile River, Ibrahimia Canal and Bahr Yousif Canal) with an aim of evaluating the radiation hazard. The concentration of natural radionuclides (226Ra, 232Th and 40K) has been investigated byusing gamma spectrometry (NaI (Tl) 3″x 3″) detector. The results showed that the concentrations of average activity in the sediment samples collected from drinking water purification plants supplied from Nile River, Ibrahimia Canal and Bahr Yousif Canal are (29±2, 30±2 and 240±8 Bq kg-1), (47±3, 46±8 and 258±12 Bq kg-1) and (28±2, 27±3 and 219±18 Bq kg-1) for 226Ra, 232Th and 40K, respectively. In general, the distributions of average activity concentrations of samples underinvestigation are within the world values although some extreme values have been determined. Radiological hazard effects such as: absorbed dose rate (D), outdoor and indoor annual effective dose equivalent (AEDE), radium equivalent activities (Raeq), hazard indices (Hex and Hin), gamma index (Iγ), excess lifetime cancer risk (ELCR) and annual gonadal doseequivalent (AGDE) for the corresponding samples were also estimated.Key words: Drinking water purification plants, Sediment, Radiological hazard indice

Seasonal behavior of radon decay products in indoor air and resulting radiation dose to human respiratory tract

Most of radiation hazard of indoor radon is largely due to the radon progenies, which are inhaled and deposited in the human respiratory tract. It is essential to evaluate aerodynamic characteristics of the radon progenies, which are either attached or unattached to aerosol particles, because the dose is strongly dependent on the location of deposition in respiratory tract and hence on the aerodynamic characteristics of the aerosol particles. This paper presents the seasonal behavior of radon decay products in indoor air under domestic conditions at Nagoya University, Japan. A low pressure cascade impactor as an instrument for classifying aerosol sizes and imaging plate as a radiation detector have been employed to characterize the activity size distribution of short-lived radon decay products. In parallel, radon and its progenies concentrations were measured. Taking into account the progeny characteristics, the inhalation dose in the different seasons was also estimated based on a lung dose model with the structure that is related to the ICRP66 respiratory tract model. The result evident that, the highest dose 0.22 mSvy−1 was observed during the winter where the highest value of equilibrium equivalent concentration of radon (EEC) and lowest value of the activity median aerodynamic diameter (AMAD) were found in this season; whereas, the dose in spring appeared to be lowest 0.02 mSvy−1

Natural radioactivity levels and radiological hazards indices of chemical fertilizers commonly used in Upper Egypt

In order to determine the radiological hazards indices of chemical fertilizers commonly used in Upper Egypt, The concentrations of natural radionuclides 226Ra, 232Th and 40K in seven types of chemical fertilizers used in Upper Egypt have been measured by gamma spectrometry using NaI (Tl) 3″ × 3″ detector. The ranges of concentration levels of 226Ra, 232Th and 40K were 12 ± 0.6–244 ± 12.6, 3 ± 0.2–99 ± 4.9, and 109 ± 5.5–670 ± 34 Bq kg−1, respectively. In the other side, the range values obtained from fertilizer samples under investigation were (33.1–392.3 Bq kg−1), (0.6–2.7), (15.6–177.8 nGy h−1) and (20.1–229.1 μSv y−1) for radium equivalent activity, γ-radiation hazard index Iγr, Dose rate (nGy h−1) and annual effective dose equivalent (AED) in the air to the occupational workers, respectively. The obtained values were compared with available reported data from other countries in literature. Keywords: Radioactivity, Chemical fertilizers, Radiological hazard

Measurement of natural radioactivity in granites and its quartz-bearing gold at El-Fawakhir area (Central Eastern Desert), Egypt

The distribution of natural radionuclides (226Ra, 232Th and 40K) in Granites and its quartz-bearing gold at El-Fawakhir area (Central Eastern Desert, Egypt) were measured by using γ-ray spectroscopy [NaI (Tl) 3″ × 3″]. X-Ray Fluorescence technique was used for chemical analyses of the studied samples. The specific activity of 226Ra, 232Th and 40K values are in range (3 ± 0.5 to 43 ± 2 Bqkg−1), (5 ± 0.7 to 41 ± 2 Bqkg−1) and (128 ± 6 to 682 ± 35 Bqkg−1) respectively. The absorbed dose rates ranged from 13.8 to 58.4 nGy h−1, where the total effective dose rates were determined to be between 16.7 and 70.9 μSvy−1. The maximum external hazard index (Hex) is 0.3 nGyh−1. The calculated values of the excess lifetime cancer risks (ELCR) and annual effective dose rate values are in between (8.48 × 10−5 and 2.63 × 10−4) and (24.2 and 72.9 μSvy−1) respectively. Geochemically, the studied granites consist of major oxides, they are characterized by SiO2, K2O, Na2O, Al2O3, and depleted in CaO, MgO, TiO2, and P2O5. The average absorbed dose rate (Do) in air is 37.8 nGyh−1 for the whole studied samples, this value is about 3.78% of the 1.0 mSvy−1 recommended by (ICRP-60,1991) to the public, so there is no radiological risk for the workers in that area