Potential Alpha Energy Research Articles

Determination of radon concentrations near mobile towers in selected cities of Babylon governorate, Iraq

Determination of radon concentration in a dwelling is preferred method for monitoring the internal exposure of radiological contaminants. Measurement the concentration of radon and their daughter products in indoor and outdoor of dwelling for Al-Medhatyah and Al-Hashimiyah cities, Babylon governorate near mobile stations were carried out by nuclear track detectors (CR-39) in a bare mode. The results show that the concentrations of indoor radon were found to vary from 85.51 Bq/m3 to 157.48 Bq/m3 with an average value of 131.43 ± 20.71 Bq/m3.This values was lower than the ICRP reco mmended values of (200 – 300 Bq/m3) and thus is within safe limits. The outdoor radon concentrations was vary fro m 100.75 Bq/m3 to 110.06 Bq/m3 with average 105.26 ± 3.8 Bq/m3, the outdoor radon concentration is usually low and less than average indoor levels. The equilibriu m-equivalent radon concentration (EECRN), potential alpha energy concentration (PAEC), annual exposure to potential alpha energy (EP), annual effective dose (AED) and the lung cancer cases per year per million people (CPPP) were calculated.

Spatial and Temporal Variations of Indoor Airborne Radon Decay Product Dose Rate and Surface-Deposited Radon Decay Products in Homes.

The temporal variations of the airborne radon decay product dose rate and deposited radon decay product activities, as well as the within-house and house-to-house variations of radon concentrations, were evaluated through repeated field measurements. Long-term average radon and surface-deposited radon decay product concentrations were measured in 76 rooms of 38 houses. Temporal variation of radon, as well as airborne and surface-deposited radon decay products, were measured in 11 of the 38 houses during two different seasons. Environmental factors that have the potential to influence airborne dose rate and deposited radon decay products were also studied. Airborne dose rates were calculated from the unattached and attached potential alpha energy concentrations using two dosimetric models. For one model, the observed dose variations were 103%, 74%, 58%, and 60% for the total, house-to-house, within-house, and within-room temporal variations, respectively. For the other model, the dose variations were 100%, 66%, 61%, and 46%, respectively. Surface-deposited Po showed variations of 79%, 57%, 42%, and 48%, respectively. These substantial radon decay product concentration variations suggest that multiple locations and time-integrated measurements are needed to make an accurate assessment of the chronic radon-related doses in homes. Smoking was the environmental factor that had the largest temporal and spatial effect on airborne radon decay product dose rates.

MEASUREMENT OF THE POTENTIAL ALPHA ENERGY CONCENTRATION OF RADON PROGENY BY USING LIQUID SCINTILLATION COUNTING METHOD.

For more accurate measurement of the potential alpha energy concentration (PAEC) of radon progeny by the liquid scintillation counting (LSC) method, its counting efficiency was studied in this work. A radon progeny standard source was used to provide different concentrations of radon progeny, and the progeny collected on the sampling filters were measured with a low background liquid scintillation counter. The result showed that the quenching effect could not be ignored, and the counting efficiency was estimated to be 86.12%. The co-comparison experiments showed that the PAECs of radon progeny measured by the LSC methods were in generally consistent with those of other three methods. It indicates that for more accurate measurements of PAEC of radon progeny by using the LSC method, the counting efficiency should be well determined.

Radon concentration measurements in sludge of oil fields in North Oil Company (N.O.C.) of Iraq

In this study the assessment radon concentration in sludge of OilFields in North Oil Company (N.O.C.) of Iraq have been studiedusing CR-39 solid–state nuclear track detector technique. A total of34 samples selected from 12 oil stations in the company have beenplaced in the dosimeters. The average radon concentration was foundto be 162.29 Bq/m3 which is fortunately lower than the standardinternational limit. The potential alpha energy concentration andannual effective dose have been calculated. A proportionalrelationship between the annual effective dose and radonconcentration within the studied region has been certified.

Indoor risk assessment of radon gas in the science college buildings-University of Mustansiriyah using RAD-7 detector

In the present work, a set of indoor Radon concentration measurements was carried out in a number of rooms and buildings of Science College in the University of Mustansiriyah for the first time in Iraq using RAD-7 detector which is an active method for short time measuring compared with the passive method in solid state nuclear track detectors (SSNTD's). The results show that, the Radon concentrations values vary from 9.85±1.7 Bq.m-3 to 94.21±34.7 Bq.m-3 with an average value 53.64±26 Bq.m-3 which is lower than the recommended action level 200-300 Bq/m3 [ICRP, 2009].The values of the annual effective dose (A.E.D) vary from 0.25 mSv/y to 2.38 mSv/y, with an average value 1.46±0.67 mSv/y which is lower than the recommended the range 3-10 mSv/y [ICRP, 1993]. While the values of lung cancer cases per year per million person vary from 4.50 per million person to 42.84 per million person with an average value 24.35±12 per million person which is lower than the recommended range 170-230 per million person [ICRP, 1993].The values of the potential alpha energy concentration were found to vary from 10.18 mWL to 1.06 mWL, with an average value 5.79±2.8 mWL which is lower than the recommended value of 53.33 mWL given by [UNSCEAR, 1993].

RaDoM: a lung dosimeter for radon progeny

This paper discusses a novel Timepix-based on-line radon dose monitor called RaDoM. The detector provides a direct estimate of the effective dose to the lung via a system of filters having the same absorption characteristics as this organ and a measurement of the PAEC (the potential alpha energy concentration). Measurements performed in a reference radon chamber and in normal environmental conditions showed that RaDoM well follows changes in the radon concentration and is accurate in both long- and short-term measurements. The paper describes the detector and associated software for data acquisition and analysis, and compares the measurement of the lung dose with the value derived from a measurement of the radon concentration.

Radon Concentration Measurement in Ainkawa Region Using Solid State Nuclear Track Detector

Radon is the air contaminant radioactive gas which people exposed to, is a reason for lung damages and lung cancer. The areas that are subject to high radon levels are found by radon concentration measurement. The radon activity concentration, annual effective dose, and potential alpha energy concentration (PAEC), were measured in houses of Ainkawa region using CR-39 solid state nuclear track detectors SSNTDs with the sealed-can technique. In the present paper the estimated values for radon activity concentration are in the range 55.99-112.8 Bq/m 3 with 84.30 Bq/m 3 as a mean value, the range of annual effective dose are 1.411-2.872 mSv/y , with mean value 2.124 mSv/y , and the potential alpha energy concentration range are 6.0533-12.323 mWL with mean of 9.1133 mWL . The mean value of the radon concentration is below of 100 Bq/m 3 the reference level of (WHO) World Health Organization, and well below of UK National Radiation Protection Board (NRPB) and European Commission Recommendation Level of 200 Bq/m 3 .

Estimate Level of Radon Concentration for Drinking Water in Some Regions of Baghdad City

In this study, the assessment of radon concentration in drinking water in some regions of Baghdad city in Iraq has been studied using CR-39 solid-state nuclear track detector technique. A total of 18 samples selected from 6 region (5 samples from each region) in Baghdad city have been placed in the dosimeters for 50 day. The average radon concentration was found to be 516.1 hbox { Bq/m}^{3} which is greater than the standard international limit (300 hbox { Bq/m}^{3}). The potential alpha energy concentration and annual effective dose have been calculated. A proportional relationship between the annual effective dose and radon concentration within the studied region has been certified.

Determination of Radon Concentration and Annual Effective Dose Inside Houses in Left Side of Mosul City During Winter

In this study, radon concentration, annual effective dose, potential alpha energy concentration (PAEC), and average of lung cancer per million persons from radon were measured using (closed can technique) containing CR-39 nuclear track detector. Measurements were carried during winter season inside twenty four hoses in eight locations in the left side of Mosul City. The average radon concentration ranged between (52.97±5.315 to 74.98±5.433) Bq.m-3 with an average value (62.36±7.518) Bq.m-3 which is much lower than the recommended by ICRP action level (200-600) Bq.m-3. The results showed that the potential alpha energy concentration ranged between (5.71×10-3±0.566 ×10-3 to 8.11×10-3 ±0.586 ×10-3) WLM with an average value (6.7×10-3±0.820×10-3) WLM, while the annual effective dose ranged between (1.34±0.134 to 1.89±0.137) mSvy-1 with an average value (1.57±0.189) mSvy-1. It is observed that this value less than the recommended levels (3-10) mSvy-1 reported by ICRP. The average lung cancer cases per year per million persons were found to be 28.3±3.404, there were no induction of existence of radon problems in this survey

Particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist Route “Liczyrzepa” Mine in Kowary Adit

Central Laboratory for Radiological Protection, in cooperation with Central Mining Institute performed measurements of radon concentration in air, potential alpha energy concentration (PAEC), particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist-Educational Route “Liczyrzepa” Mine in Kowary Adit. A research study was developed to investigate the appropriate dose conversion factors for short-lived radon progeny. The particle size distribution of radon progeny was determined using Radon Progeny Particle Size Spectrometer (RPPSS). The device allows to receive the distribution of PAEC in the particle size range from 0.6 nm to 2494 nm, based on their activity measured on 8 stages composed of impaction plates or diffusion screens. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometres to about 20 micrometres using Aerodynamic Particle Sizer (APS) spectrometer and the Scanning Mobility Particle Sizer Spectrometer (SMPS).

Experimental tests on the reduction of radon decay products’ unattached fraction in indoor environment and its influence on effective dose

The work studies the influence of how the unattached fraction of radon daughters can influence effective dose. An experimental work was carried out for measuring the unattached fraction in presence of different size aerosols, and for each test an estimate of the effective dose was given. Tests were carried out at fixed radon concentrations and with different size aerosols. Potential alpha energy concentrations of both total and free fractions were measured, together with radon and aerosols air concentrations. Results showed increments of the equilibrium factor, reduction of the unattached fraction, and decrease of the effective dose.

MEASUREMENTS OF AIRBORNE CONCENTRATIONS OF RADON AND THORON DECAY PRODUCTS.

Liquid scintillation counting (LSC) is a measuring technique, broadly applied in environmental monitoring of radionuclides. One of the possible applications of LSC is the measurement of radon and thoron decay products. But this method is suitable only for grab sampling. For long-term measurements a different technique can be applied-monitors of potential alpha energy concentration (PAEC) with thermoluminescent detectors (TLD). In these devices, called Alfa-2000 sampling probe, TL detectors (CaSO4:Dy) are applied for alpha particles counting. Three independent heads are placed over the membrane filter in a dust sampler's microcyclone. Such solution enables simultaneous measurements of PAEC and dust content. Moreover, the information which is stored in TLD chips is the energy of alpha particles, not the number of counted particles. Therefore, the readout of TL detector shows directly potential alpha energy, with no dependence on equilibrium factor, etc. This technique, which had been used only for radon decay products measurements, was modified by author to allow simultaneous measurements of radon and thoron PAEC. The LSC method can be used for calibration of portable radon decay products monitors. The LSC method has the advantage to be an absolute one, the TLD method to measure directly the (dose relevant) deposited energy.

Radiological characterization of the ancient Roman tuff-pozzolana underground quarry in Orvieto (Italy): A natural laboratory to revisit the interactions between radionuclides and aerosols

Orvieto (Italy) has a large network of underground tunnels quarried to extract tuff and pozzolana by Etruscans and Romans. One of these tunnels was chosen as natural laboratory to compare different radiation measurement and dose assessment methods. Indeed, tuff and pozzolana are very rich in natural radioactivity and are interesting from the radiation protection point of view since they are still used as building materials. In order to characterize this site an in situ experimental procedure was followed. It consisted in measurements carried out with different instruments: two portable gamma ray spectrometers, two gamma dose rate meters, two radon monitors and one two channel working level monitor. Samples of tuff and pozzolana stones were also collected to be measured with gamma spectrometry in laboratory. Due to the high content of 238U, 232Th (more than 200 Bq kg−1 for both radionuclides) and 40K (more than 2000 Bq kg−1) of tuff and pozzolana, elevated levels of exposure to natural radioactivity were found: indeed, with different instruments and approach, a gamma dose rate of about 1 μGy h−1 and an average radon concentration of about 10,000 Bq m−3, with a Potential Alpha Energy Concentration (PAEC) of 288 MeV cm−3, were measured. The radiological characteristics of Orvieto underground quarry make it a perfect site for “in field” intercomparisons of different measurement and dose assessment methods.

The influence of particle size distribution on dose conversion factors for radon progeny in the underground excavations of hard coal mine

In Polish underground mines, hazards caused by enhanced natural radioactivity occur. The sources of radiation exposure are short-lived radon decay products, mine waters containing radium 226Ra and 228Ra and the radioactive sediments that can precipitate out of these waters. For miners, the greatest exposure is usually due to short-lived radon decay products. The risk assessment is based on the measurement of the total potential alpha energy concentration (PAEC) and the evaluation of the related dose by using the dose conversion factor as recommended by relevant legal requirements. This paper presents the results of measurements of particle size distributions of ambient aerosols in an underground hard coal mine, the assessment of the radioactive particle size distribution of the short-lived radon decay products and the corresponding values of dose conversion factors. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometers to about 20 μm. The study therefore included practically the whole class of respirable particles. The results showed that the high concentration of ultrafine and fine aerosols measured can significantly affect the value of the dose conversion factors, and consequently the corresponding committed effective dose, to which the miners can be exposed.

Radon and thoron progeny integrated measurement based on high-voltage sampling

ABSTRACTFor the purpose of directly measuring radon and thoron progeny concentrations simultaneously, an unattended battery-operated progeny measurement (UBPM) device, which samples aerosol particles in an electric field, was improved by adopting two different thickness aluminum foils for alpha particles discriminating. The equations for the calculation of the results were derived, and a series of calibration experiments and comparison tests were carried out in the potential alpha energy concentration calibration chamber in BfS Berlin and the HMGU experimental thoron house, respectively. Results show that the calibration coefficients are stable in different levels of radon and thoron progeny. The lower level detection limits of the device for radon and thoron progeny concentration are 1.22 and 0.14 Bq m−3, respectively, for three months exposure. The instrument proved to be independent from environmental conditions in ordinary living room conditions (humidity <65% RH, aerosol particle concentration >1500 cm−1). Comparison results show that the measurement results of the UBPM device are comparable with the reference instrument and suitable for long-term radon and thoron survey in dwellings.

Effect of indoor-generated airborne particles on radon progeny dynamics

In order to investigate the interaction between radon progeny and particles, an experimental campaign was carried out in a radon chamber at the Italian National Institute of Ionizing Radiation Metrology, quantifying the amount of attached and unattached radon daughters present in air, as well as the equilibrium factor in the presence of particles generated through indoor sources. A fixed radon concentration was maintained, while particles were generated using incense sticks, mosquito coils and gas combustion. Aerosols were characterized in terms of particle concentrations and size distributions. Simultaneously, radon concentration and attached/unattached potential alpha energy concentration in the air were continuously monitored by two different devices, based on alpha spectroscopy techniques.The presence of particles was found to affect the attached fraction of radon decay products, in such a way that the particles acted as a sink for radionuclides. In terms of sources which emit large particles (e.g. incense, mosquito coils), which greatly increase particle surface area concentrations, the Equilibrium Factor was found to double with respect to the background level before particle generation sessions. On the contrary, the radon decay product dynamics were not influenced by gas combustion processes, mainly due to the small surface area of the particles emitted.

ASSESSMENT OF INHALATION DOSE FROM THE INDOOR 222Rn AND 220Rn USING RAD7 AND PINHOLE CUP DOSEMETERS.

Radon is the most important source of natural radiation and is responsible for approximately half of the received dose from all sources. Most of this dose is from inhalation of the radon progeny, especially in closed atmospheres. Concentration of radon (222Rn) and thoron (220Rn) in the different villages of Jalandhar and Kapurthala district of Punjab has been calculated by pinhole cup dosemeters and RAD7. On an average, it has been observed from the study that the values of all the parameters calculated are higher in case of active monitoring than the passive monitoring. The calculated equilibrium equivalent 222Rn concentration (EECRn) and equilibrium equivalent 220Rn concentration (EECTh) fluctuate in the range from 5.58 to 34.29 and from 0.35 to 2.7 Bq m-3 as estimated by active technique, respectively. Similarly, the observed mean value of the potential alpha energy concentration of 222Rn (PAECRn) and 220Rn (PAECTh) is 4.55 and 4.34 mWL, respectively. The dose rate to the soft tissues and lung from indoor 222Rn varies from 0.06 to 0.38 and from 0.50 to 3.05 nGy h-1, respectively. The total annual effective dose for the residents of the study area is less than 10 mSv.

Measurements of Radon Concentrations and Dose Assessments in Physics Department-Science College-Al-Mustansiriyah University, Baghdad, Iraq

Measurements of radon gas concentrations with their progeny and the annual effective dose indoor the building of Al-Mustansiriyah University College of Science-Physics Department have been carried out by using time-integrated passive radon dosimeters solid state nuclear track detector CR-39 technique. The detectors with 1cm x1cm have been distributed over 70 places and suspended for sitting (1m) and standing (1.75m) positions in each location under study. The dosimetric measurements are made over a period of 90 days from 30 January 2014 to 30 April 2014. The calibration process has been done using radium-226 source with known activity radiation. It has found that the indoor radon gas concentrations varing from 37.488±6.123Bg/m3 to 58.670±7.660Bg/m3 with an average value 51.398±7.156Bg/m3 at 1m , and varing from 35.964±5.997Bg/m3 to 56.994±7.549Bg/m3 with an average value 47.057±6.847Bg/m3 at 1.75m which are within the worldwide limits 148Bg/m3 (EPA, 2003) and 200-300Bg/m3 (ICRP, 2009). The annual effective dose of the inhalation exposure to radon gas has been estimated and this vary from 0.394mSv/y to 0.617mSv/y with an average value 0.540mSv/y at 1m, and varing from 0.378mSv/y to 0.599mSv/y with an average value 0.495mSv/y at 1.75m which are within the worldwide permissible limist 3-10mSv/y (ICRP, 1993). The potential alpha energy concentration found to vary from 4.053mWL to 6.343mWL with an average value 5.557mWL at 1m and vary from 3.888mWL to 6.162mWL with an average value 5.087mWL at 1.75m which are less than the recommended value 53.33mWL (UNSCEAR, 1993). The lung cancer cases per million person per year vary from 7.093 to 11.101 per million person per year with an average value 9.725 per million person per year at 1m and vary from 6.805 to 10.784 per million person per year with an average value 8.904 per million person per year which are less than the recommended range 170-230 per million person per year (ICRP, 1993). The number of decays per-minute using swabs measurements technique have been used for selected units within two swabs from building materials walls for each unite, with area of 100cm2 using Ludlum 3030, the average of three swabs measurements have been calculated. Hence, the effectiveness of emitted alpha particles from the walls has been calculated to be varied from 0.00000 to 0.02222Bq/cm2 with an average value 0.01169Bq/cm2 at 1m and 0.01015Bq/cm2 at 1.75m respectevily which are within the permissible limit 0.04Bq/cm2 (Danial, 2010).

Radon concentration Measurements in Qaysare of Erbil City

In this study the assessment of indoor radon concentration in the air of Qaysare in Erbil city have been studied by using CR-39 Solid–State Nuclear Track Detector Technique. A total of 18 selected zones inside the suq have been selected to place the dosimeters. The average radon concentration was found to be 21.54 ± 8.017 Bq/m3 ,which is fortunately lower than the standard international limit from 200-600 Bq/m3 as recommended by ICRP, IAEA. The potential alpha energy concentration and annual effective dose have been calculated. A proportional relationship between the annual effective dose and radon concentration within the studied region has been certified.

Measurements of Radon Concentrations and Dose Assessments in Physics Department-Science College-Al-Mustansiriyah University, Baghdad, Iraq

Measurements of radon gas concentrations with their progeny and the annual effective dose indoor the building of Al-Mustansiriyah University College of Science-Physics Department have been carried out by using time-integrated passive radon dosimeters solid state nuclear track detector CR-39 technique. The detectors with 1cm x1cm have been distributed over 70 places and suspended for sitting (1m) and standing (1.75m) positions in each location under study. The dosimetric measurements are made over a period of 90 days from 30 January 2014 to 30 April 2014. The calibration process has been done using radium-226 source with known activity radiation. It has found that the indoor radon gas concentrations varing from 37.488±6.123Bg/m3 to 58.670±7.660Bg/m3 with an average value 51.398±7.156Bg/m3 at 1m , and varing from 35.964±5.997Bg/m3 to 56.994±7.549Bg/m3 with an average value 47.057±6.847Bg/m3 at 1.75m which are within the worldwide limits 148Bg/m3 (EPA, 2003) and 200-300Bg/m3 (ICRP, 2009). The annual effective dose of the inhalation exposure to radon gas has been estimated and this vary from 0.394mSv/y to 0.617mSv/y with an average value 0.540mSv/y at 1m, and varing from 0.378mSv/y to 0.599mSv/y with an average value 0.495mSv/y at 1.75m which are within the worldwide permissible limist 3-10mSv/y (ICRP, 1993). The potential alpha energy concentration found to vary from 4.053mWL to 6.343mWL with an average value 5.557mWL at 1m and vary from 3.888mWL to 6.162mWL with an average value 5.087mWL at 1.75m which are less than the recommended value 53.33mWL (UNSCEAR, 1993). The lung cancer cases per million person per year vary from 7.093 to 11.101 per million person per year with an average value 9.725 per million person per year at 1m and vary from 6.805 to 10.784 per million person per year with an average value 8.904 per million person per year which are less than the recommended range 170-230 per million person per year (ICRP, 1993). The number of decays per-minute using swabs measurements technique have been used for selected units within two swabs from building materials walls for each unite, with area of 100cm2 using Ludlum 3030, the average of three swabs measurements have been calculated. Hence, the effectiveness of emitted alpha particles from the walls has been calculated to be varied from 0.00000 to 0.02222Bq/cm2 with an average value 0.01169Bq/cm2 at 1m and 0.01015Bq/cm2 at 1.75m respectevily which are within the permissible limit 0.04Bq/cm2 (Danial, 2010).