scholarly journals A Preliminary Study of Radon Equilibrium Factor at a Tourist Cave in Okinawa, Japan

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1648
Author(s):  
Ryohei Yamada ◽  
Yuki Tamakuma ◽  
Takahito Suzuki ◽  
Shunya Nakasone ◽  
Yoshitaka Shiroma ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Radon Concentration ◽  
Meteorological Data ◽  
Radiological Protection ◽  
Large Fluctuation ◽  
Okinawa Island ◽  
Equilibrium Factor ◽  
Different Seasons ◽  
Preliminary Study ◽  
Radon Concentrations

The International Commission on Radiological Protection (ICRP) issued its Publication 137, Occupational Intakes of Radionuclides: Part 3 in which the radon equilibrium factor is fixed as 0.4 for tourist caves; however, several studies have reported a different value for the factor and its seasonal variation has also been observed. In this study, the radon concentration, equilibrium equivalent radon concentration and meteorological data were measured, and the equilibrium factor was evaluated in a tourist cave, Gyokusen-do Cave located in the southern part of Okinawa Island in southwestern Japan. Radon concentrations were measured with an AlphaGUARD and their corresponding meteorological data were measured with integrated sensors. Equilibrium equivalent radon concentration was measured with a continuous air monitor. The measured radon concentrations tended to be low in winter and high in summer, which is similar to previously obtained results. By contrast, the equilibrium factor tended to be high in winter (0.55 ± 0.09) and low in summer (0.24 ± 0.15), with a particularly large fluctuation in summer. It was concluded that measurements in different seasons are necessary for proper evaluation of radon equilibrium factor.

scholarly journals A reconnaissance study of radon concentrations in Hamadan city, Iran

2010 ◽  
Vol 10 (4) ◽  
pp. 857-863 ◽  
Author(s):  
G. K. Gillmore ◽  
N. Jabarivasal
Keyword(s):  
Radon Concentration ◽  
Limit Of Detection ◽  
Indoor Radon ◽  
Alluvial Fan ◽  
Winter Period ◽  
Radiological Protection ◽  
Indoor Radon Concentration ◽  
Western Iran ◽  
Surficial Deposits ◽  
Radon Concentrations

Abstract. This paper presents results of a reconnaissance study that used CR-39 alpha track-etch detectors to measure radon concentrations in dwellings in Hamadan, western Iran, significantly, built on permeable alluvial fan deposits. The indoor radon levels recorded varied from 4 (i.e. below the lower limit of detection for the method) to 364 Bq/m3 with a mean value of 108 Bq/m3 which is 2.5 times the average global population-weighted indoor radon concentration – these data augment the very few published studies on indoor radon levels in Iran. The maximum radon concentration in Hamadan occurs during the winter period (January to March) with lower concentrations during the autumn. The effective dose equivalent to the population in Hamadan is estimated from this study to be in the region of 2.7 mSv/y, which is above the guidelines for dose to a member of the public of 1 mSv/y suggested by the International Commission on Radiological Protection (ICRP) in 1993. This study supports other work in a number of countries that indicates such permeable "surficial" deposits as being of intermediate to high radon potential. In western Iran, the presence of hammered clay floors, the widespread presence of excavated qanats, the textural properties of surficial deposits and human behaviour intended to cope with winds are likely to be important factors influencing radon concentrations in older buildings.

scholarly journals Seasonal Variation of Kaurenoic Acid, a Hypoglycemic Diterpene Present in Wedelia paludosa (Acmela brasiliensis) (Asteraceae)

2004 ◽  
Vol 59 (3-4) ◽  
pp. 229-232 ◽  
Author(s):  
Louisiane Faccio V. Bresciania ◽  
Rosendo Augusto Yunes ◽  
Cristiani Bürger ◽  
Luis Eduardo De Oliveira ◽  
Kauê Leal Bóf ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Kaurenoic Acid ◽  
Different Seasons ◽  
Hypoglycemic Diterpene

We evaluated the variation of the concentration of kaurenoic acid (1), which is a bioactive diterpene, in leaves, flowers, stems and roots from Wedelia paludosa (Acmela brasiliensis) for different seasons using the HRGC/FID method. The results indicated that the concentration of 1 is higher in the roots and stems during the autumn. The pharmacological results suggested that kaurenoic acid is responsible, at least in part, for the hypoglycemic potential detected in this plant.

MEASUREMENT OF RADON CONCENTRATION IN SOIL SAMPLES OF MAZAT AND KAFI-HABU MINING SITES, PLATEAU, NIGERIA

2021 ◽  
Vol 4 (4) ◽  
pp. 295-301
Author(s):  
Abubakar Sadiq Aliyu ◽  
Aminu Ismaila ◽  
A. M. Na'Inna ◽  
Ahmed Mohammed
Keyword(s):  
Dose Rate ◽  
Radon Concentration ◽  
Background Radiation ◽  
Average Concentration ◽  
Soil Samples ◽  
Radiological Protection ◽  
Sampling Point ◽  
Monitoring And Control ◽  
Tailing Dump ◽  
Mining Sites

Radon and its short-lived progenies contributed significantly to natural background radiation. Long-term exposure to such radiation increases the probability of lung cancer to persons. To assess the radiological hazards associated with the inhalation of radon gas from ore dust in Mazat and Kafi-Habu mining sites of Plateau, Nigeria, 12 soil samples from an abandoned tailing dump ground were collected and analysed for radon using RAD-7 electronic detector. The dose rate of each sampling point was directly measured using RADOS RDS -120 portable survey meter. The results gave a mean radon concentration ranging from 771.51 ± 21.9 Bq/m3 to 5666.13 ± 28.8 Bq/m3 with 3451.13 ± 42.9 Bq/m3as the average value for all measurements. The average concentration of measurements from Mazat and Kafi-Habu is 3671.6 ± 41.2 Bq/m3 and 3010.16 ± 46.5 Bq/m3 respectively. The average values obtained from the analysis are significantly higher than the upper limit of 300 Bq/m3 set by the International Commission on Radiological Protection (ICRP) suggesting quick remediation on the host communities. The geometrical mean value of Dose Rate (DR) and Annual Effective Dose Equivalent (AEDE) were 870 nGy/hr and 1.04 mSv/yr respectively. Again, these values are above the global average limits of 59 nGy/hr and 1 mSv/yr. The result indicates that miners working in those sites and dwellers of the study areas are at higher risk of getting exposed to radon and need to employ protective measures. This work is useful in monitoring and control of radon level for the on-site workers and the 

scholarly journals Radon measurements with CR-39 track detectors at specific locations in Turkey

2004 ◽  
Vol 19 (1) ◽  
pp. 46-49 ◽  
Author(s):  
Asiye Ulug ◽  
Melek Karabulut ◽  
Nilgün Celebi
Keyword(s):  
Radon Concentration ◽  
Indoor Radon ◽  
Active Faults ◽  
Indoor Radon Concentration ◽  
Arithmetic Means ◽  
Radon Measurements ◽  
New Buildings ◽  
Main Factor ◽  
Ventilation Conditions ◽  
Radon Concentrations

Indoor radon concentration levels at three sites in Turkey were measured using CR-39 solid state nuclear track detectors. The annual mean of radon concentration was estimated on the basis of four quarter measurements at specific locations in Turkey. The measuring sites are on the active faults. The results of radon measurements are based on 280 measurements in doors. The annual arithmetic means of radon concentrations at three sites (Isparta Egirdir, and Yalvac) were found to be 164 Bqm?3, 124 Bqm?3, and 112 Bqm?3 respectively, ranging from 78 Bqm?3 to 279 Bqm?3. The in door radon concentrations were investigated with respect to the ventilation conditions and the age of buildings. The ventilation conditions were determined to be the main factor affecting the in door radon concentrations. The in door radon concentrations in the new buildings were higher than ones found in the old buildings.

scholarly journals Measurements of Radon-222 and its Daughters Concentrations in Buildings of Department Physics in College of Sciences of Baghdad University

2008 ◽  
Vol 5 (4) ◽  
pp. 605-611
Author(s):  
Baghdad Science Journal
Keyword(s):  
Solid State ◽  
Radon Concentration ◽  
Indoor Radon ◽  
Radon Level ◽  
Nuclear Track Detectors ◽  
Radioactive Sources ◽  
Radon Concentrations

The present work aims to investigate approaches, measures and detection of indoor radon level in buildings of the department of physics in college of science of Baghdad University. CR-39 solid state nuclear track detectors were used to measure the radon concentrations inside the rooms, including five laboratories and five workplace rooms in ground and first storey of the department. The average radon concentration at first storey was found to be 43.1±13.2 Bq/m3 and 40.1±13.4 Bq/m3 at the ground storey. The highest level of radon concentration at the first storey in the radioactive sources store was 87.5±29 Bq/m3 while at the ground storey in room(2) was 70.2±24 Bq/m3 which is due to the existence radioactive sources in some selected places at the buildings.

The Alpha Particle Doses Received by Students and Staff in Twenty Schools in the North of Hebron Region - Palestine

2021 ◽  
Vol 14 (4) ◽  
pp. 309-316
Keyword(s):  
Effective Dose ◽  
Radon Concentration ◽  
Annual Effective Dose ◽  
Indoor Radon ◽  
Alpha Particles ◽  
Indoor Radon Concentration ◽  
The North ◽  
Cr 39 Detectors ◽  
Average Effective Dose ◽  
Radon Concentrations

Abstract: The aim of the current study was to measure indoor radon concentration levels and its resulting doses received by the students and staff in schools of the directorate of education in the north of Hebron region- Palestine, during the summer months from June to September (2018), using CR-39 detectors. In this study, a total of 567 CR-39-based radon detectors were installed in the selected schools. The average radon concentrations were found to be 90.0, 66.5 and 58.0 Bqm-3 in Halhul, Beit Umar and Alarrub camp schools, respectively. Based on the measured indoor radon data, the overall average effective dose for the studied area was found to be 0.31 mSvy-1. Reported values for radon concentrations and corresponding doses are lower than ICRP recommended limits for workplaces. The results show no significant radiological risk for the pupils and staff in the schools under investigation. Consequently, the health hazards related to radiation are expected to be negligible. Keywords: Radon concentration, Alpha particles, Annual effective dose, Schools. PACs: 29.40.−n.

Radiological Parameters Due to Radon-222 in Soil Samples at Baghdad Governorate (Karakh), Iraq

2017 ◽  
Vol 60 (2) ◽  
pp. 72-78
Author(s):  
Ali Abid Abojassim ◽  
Ahmed Rahim Shltake ◽  
Laith Ahmed Najam
Keyword(s):  
Radon Concentration ◽  
Annual Effective Dose ◽  
Track Detector ◽  
Soil Samples ◽  
Reference Level ◽  
Nuclear Track Detector ◽  
Radium Content ◽  
Can Technique ◽  
Level 3 ◽  
Radon Concentrations

Measurements of radon concentration, effective radium content, potential alpha energyconcentration (PAEC) and annual effective dose (AED) were estimated for soil samples in fifteen locationsof the Baghdad governorate (Karakh) in the central part of Iraq. In this survey we used the can technique,containing nuclear track detector (CR-39). The obtained values of radon concentration measurements weregenerally low, ranging from 38.12±13.46 to 94.51±16.5 Bq/m3, with an average 66.07 Bq/m3, while theeffective radium content varied from 5.80±0.21 Bq/kg to 14.39±0.33 Bq/kg with an average 10.09 Bq/kg. The average of the PAEC and AED were assessed to be 7.14 mWL 1.66 mSv/y, respectively. The resultsof the present study shows that the radium content are lower than the allowed limit reported by Organizationfor Economic Cooperation and Development (OECD) that is equal to 370 Bq/kg. In general, it is seen thatthe AED limit was within the recommended reference level (3 mSv/y to 10 mSv/y) of the World HealthOrganization. Also, it is found that there is a strong correlation (R2= 1) between radon concentrations andeffective radium content. The results obtained from this study indicate that the locations of Karakh hasbackground radioactivity(radon concentrations) levels within the natural limits.

Vitamin D (25-OH) concentrations in hospitalized patients, outpatients and dialysis patients depending on seasonal variation

2015 ◽  
Vol 51 (3) ◽  
pp. 209-212
Author(s):  
Magdalena Maria Ostrowska ◽  
Ewa Szulc-Mysińska ◽  
Dagna Bobilewicz ◽  
Marta Faryna
Keyword(s):  
Vitamin D ◽  
Seasonal Variation ◽  
Seasonal Changes ◽  
Hospitalized Patients ◽  
Optimum Concentration ◽  
Dialysis Patients ◽  
Total Vitamin ◽  
Different Seasons ◽  
Mean Concentration ◽  
Global Health Problem

Vitamin D deficiency, which is a global health problem, may result in numerous diseases, such as rickets in children and osteoporosis and osteomalacia in adults. The occurrence of the above-mentioned disorders is promoted by the wintertime and higher latitudes. The aim of the study was to compare the concentrations of vitamin D (25-OH) in hospitalized patients and outpatients in different seasons of the year (summer and winter), as well as in dialysis patients in December and May. The Roche test for the quantitativedetermination of total vitamin D (25-OH) was used in the study. The range from 30 to 80 ng/ml was accepted as the optimum concentration. In hospitalized patients and outpatients, both in summer and winter mean concentration of vitamin D (25-OH) reached the values below 30 ng/ml in over 80% of the patients. Only in the hospitalized patient group mean concentration of vitamin D (25-OH) in the summer was significantly higher than in the winter (p=0.0016). In the dialysis patients mean concentration of vitamin (25-OH) in May was significantly higher than in December (p=0.0085) and the percent of the results below 30 ng/ml amounted to 96.39% in December and 77.27% in May. In conclusion, the 25(OH)D concentrations in the whole population under study are lower than those recommended and undergo periodical seasonal changes in hospitalized patients.

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