Mean Values Of Radon Concentrations Research Articles

A Review of Radon Concentration in Water Sources in Nigeria and its Impact

Given the characteristics of radon, people may unwittingly be exposed to radon through water ingestion. Research on radon concentration has increased over the years due to its negative impact on the body being the major causes of lung cancer. This study reviewed twenty (20) journal publications on radon concentration in water sources (such as well, boreholes, stream and taps) in Nigeria from year the 2016 to 2023. The type of sample, sample location, devices used, the range and mean values of radon concentration (RnC) and annual effective dose (AED) were considered. From the reviewed journals, the average values of RnC ranged from 1.9 Bq/L to 88.0 Bq L-1. When compared with WHO and US EPA recommended limits of 100 Bq L-1 and 11.1 Bq L-1 respectively, all reviewed journals recorded average values of RnC below 100 Bq L-1 and 75 % of the reviewed journals recorded average values of RnC above US EPA recommended limit of 11.1 Bq L-1. The mean AED reported is within the range of 0.02 mSv yr-1 and 92 mSv yr-1 with 30 % above the recommended limit of 0.1mSv yr-1. This result shows that the majority of the radon concentration in water sources in Nigeria reported may not pose any immediate health risk. However, there is a need for continuous monitoring and protective measures to be taken.

Assessment of Radon Concentration in Blood Samples of Different Kinds of Cancer by Using CR-39 Nuclear Track Detectors

The goal of this work to measure the radon concentrations in twenty blood samples taken from a cancer patient and a healthy group of Erbil governorates, by using CR-39 NTD. The results obtained the average concentrations of radon in blood samples for cancer patients and the healthy group were 19.318 ±3.86 Bq/m3 and 8.5077 ±1.84 Bq/m3 respectively. The mean value of radon concentration of the cancer group is higher than the healthy group. The variation in concentrations of radon in different locations may be caused due to the variation in the nature of blood samples and nuclei content in these samples. also depending on the allergic reaction of the body to radiation. This increase could be caused by pollution of environment with radioactive materials including uranium since cancer can be caused by ionization radiation results showed that the all of concentration of radon in blood samples for cancer and healthy group were less than the global permissibility limiting of exhibition to radon 200 Bq.m−3 (IAEA, 2010.)This work owes its importance to the fact that it aims at knowing and measuring the radon concentrations in the blood samples and impact it on the cancer in particular.

RADON SURVEY IN THE BUILDINGS OF PRE-UNIVERSITY EDUCATION IN MONTENEGRO

During the academic year 2016/17 (September − June), radon was surveyed in all 519 buildings of the pre-university education in Montenegro – primary, high and vocational schools, kindergartens, institutes for children with special needs and student dormitories. Radon detectors (Radosys,RSFV type) were placed in all classrooms, rooms occupied by children and offices on ground floor, and in some rooms on the upper floors. The total number of detectors was 4078, of which 285 were duplicate (control) detectors. During the radon survey, 11.4% of the detectors were lost or damaged. Average 9-month radon activity concentrations were obtained for 3345 rooms in 507 buildings. Mean values of radon concentrations in the rooms were AM = 243 Bq/m3 and GM = 142 Bq/m3, while the corresponding values for Montenegrin dwellings, found in the national radon survey, were more than twice lower. Radon concentrations above 300 Bq/m3 were found in 23.3% of all surveyed rooms and in 3.4% of the rooms they were above 1000 Bq/m3. Radon activity concentrations above 300 Bq/m3 were measured in some rooms in 44% of the buildings, and those above 1000 Bq/m3 in 9.5% of the buildings. Radon levels in educational buildings are significantly higher than in Montenegrin homes, which means that children and educators are more exposed to the harmful effects of radon in schools and kindergartens than at homes (for equal durations of stay in them). This could be resulting from the type of construction of educational buildings, which are usually large low-rise structures, and from a relatively high average age of these buildings.

INFLUENCE OF BUILDING FEATURES ON RADON ACCUMULATION IN KINDERGARTENS OF THE SVERDLOVSK REGION

Objective: To study the levels of radon accumulation in kindergartens in Sverdlovsk Region and to deter­mine the relationship between radon concentration, and building characteristics. To perform a detailed anal­ysis of radon entry and accumulation in the kindergarten, in which radon concentration exceeds the safety standards. Materials and methods : Track detectors REI-4 on the base of LR-115 film were used. Detectors were installed in playrooms and bedrooms for day nap. In each kindergarten, at least 3 rooms were examined. The measurements were carried out twice a year, during the warm and cold seasons. The duration of exposure of the detectors was 2–3 months in each season. The AlphaGUARD radon monitor was installed in the kinder­garten with a high level of radon concentration. Results: It is shown that the distribution of radon concentration in the kindergartens of the Sverdlovsk region can be described by a lognormal distribution with an average value of 60 Bq/m 3 , a geometric mean of 44 Bq/m 3 and a standard geometric deviation of 2.23. A statistically significant differ­ence was found between the mean values of radon concentration in subgroups of buildings constructed at different periods. For the kindergartens constructed in 1950–1969, the average radon concentration was 85 Bq/m 3 , for buildings built in 1970–1989 – 54 Bq/m 3 . When comparing subgroups of rooms with different types of windows (all buildings, ground floors) it was found that in rooms with PVC windows, radon concentration is almost twice as high then in rooms with wooden windows. For the kindergarten, in which the annual radon concentration in the playroom was 620 Bq/m 3 , it was shown, that if the proper ventilation regime of this room is observed, the average radon concentration during the presence of children does not exceed 120 Bq/m 3 . Conclusions . Factors affecting the indoor radon accumulation in the kindergartens are the type of building materials associated with different periods of building construction and the type of windows. When radon concentration measured in kindergartens reach sanitary standards, it is advisable to conduct an additional study of the daily radon variations, since during the active operation of the premises (working hours) radon levels may be significantly lower

Seasonal variation of radon concentration in water and assessment of whole-body dose to the public along South-west coast of Kerala, India

The South-west coast of Kerala is a well-reported high background radiation area. Hence, the radiological protection of the population in this region has great concern. In view of this, the study has been undertaken to understand the distribution of radon ( 222 Rn) concentration in drinking water collected from the region. The seasonal variation of radon concentration in drinking water also forms part of the study. Emanometry method is used for the quantification of dissolved radon concentration in water collected from various open wells. The mean values of radon concentration obtained for pre- and post-monsoon were 0.95 Bq/l and 0.58 Bq/l, respectively. The whole-body dose ranges from 0.39 to 29.34 μSv/y for premonsoon and 1.33–18.76 μSv/y for postmonsoon. The average value of effective dose was below the recommended limit of 0.1 mSv/y suggested by WHO and EU council, and the water from the region can be safely consumed from the radiological protection point. All the results are presented and discussed in the manuscript.

Estimation of radon concentrations and associated radon doses by using active technique in drinking water sources of Abbottabad, KPK, Pakistan

In-situ measurement of radon concentration was carried out in three types of drinking water sources (spring, surface and bore/well). Water samples from all three sources were collected from the city of Abbottabad and its surroundings. Radon concentrations were measured through active technique, using the AB-5 series of portable radiation monitor (Pylon). The mean concentrations (ranges) of radon in the phosphate region were 13.4 ± 2.0 (9.1–23.6), 11.2 ± 1.5 (6.2–20.1) and 7.1 ± 0.9 (4.3–14) kBq m−3 in well, spring and surface waters, respectively. Similarly, the mean concentrations (ranges) of radon outside the phosphate region were 7.2 ± 1.0 (3.4–11.5), 5.4 ± 0.7 (2.5–8.9) and 3.1 ± 0.4 (1.7–5.8) kBq m−3 in well, spring and surface waters, respectively. The arithmetic mean values of radon concentration in drinking waters in the phosphate and non-phosphate parts or rocks were 10.76 ± 1.5 and 5.10 ± 0.70 kBq m−3, respectively. Respective doses of radon taken in by the people via water ingestion and inhalation were calculated as 0.029 ± 0.004 and 0.014 ± 0.002 mSv. The mean values of radon concentrations in drinking water samples collected from Abbottabad phosphate and non-phosphate rocks were below the US EPA Maximum Contamination Level (MCL) of 11.1 kBq m−3. The annual mean effective doses of all samples are lower than the reference level of 0.1 mSv a−1 for drinking water as recommended by WHO. Thus, the drinking water of Abbottabad and its surroundings is generally below the recommended levels as regards to radon-related health hazards.

Assessment of occupational exposure in a granite quarry and processing factory

Workers in the granite industry face an occupational hazard: silicosis due to the crystalline silica present in inhalable dust. As granite can also present a variable, and occasionally significant, content of naturally occurring radionuclides, they may also face a radiological hazard. In order to assess the risk, a granite industry with a quarry and processing factory was selected to assess the occupational exposure. Three main potential pathways were observed: external irradiation, inhalation of granite dust, and radon exposure. The external dose rate was similar to that in a nearby farming area. A slight increment (0.016–0.076 mSv yr−1) was observed in the quarry and stockpile, due to quarry faces and granite blocks. The effective dose due to granite dust inhalation was 0.182 ± 0.009 mSv yr−1 in the worst case scenario (3 mg m−3 dust load in air and no use of filter masks). Thus, the mean value of the effective dose from these two pathways was 0.26 mSv yr−1, lower than the reference level of 1 mSv yr−1 for the general population. The annual mean value of radon concentration in the indoor air was 33 Bq m−3. However, during granite processing works the radon concentration can increase up to 216 Bq m−3, due to mechanical operations (sawing, polishing, sanding, etc). This radon concentration was below the 600 Bq m−3 reference level for action in working places. Therefore, workers in this granite factory face no significant additional radiological exposure, and no-one needs to be designated as occupationally exposed and subject to individual dosimetry.

Radon Concentration in Al-Gazalia City, Baghdad, Iraq

Inhalation of indoor radon has been recognized as one of the health hazards. In the present work a set of indoor radon measurements was carried out, in different Iraqi houses in Al-Gazalia city/ Baghdad, built of the same type of building materials. Radon concentration determined by using time–integrated passive radon dosimeters containing CR-39 solid state nuclear track detector. Measurements were carried out from September to November 2011. The results show that, the radon concentrations varied from (38.7 to 200) Bq m -3 . The mean values of radon concentrations in second floor hall and first floor of living rooms, kitchens and bathrooms, were: (46.56±9.13), (68.32±8.55), (128.03±21.65) and (168.92±33.52) Bq.m -3 respectively. This data shows that, bathrooms and kitchens have significantly higher radon concentrations and the second floor is lower radon concentration in all dwellings.

Residential radon exposure in some areas of Bangalore city, India

Background: Two isotopes, 222 Rn and 220 Rn of the natural radioactive gas radon are generally of radiological importance. About half of the total radiation effective dose to the general public is due to the irradiation of the lungs by alpha particles following the inhalation of radon decay products. In view of this, 222 Rn and 220 Rn measurements were carried out for a period of 1 year in about 50 dwellings belonging to different residential areas of Bangalore city. The results obtained were systematically analysed and discussed. Materials and Methods: 222 Rn and 220 Rn measurements were carried using Solid State Nuclear Track Detectors. The gamma exposure rate measurements were also carried out in all the dwellings using a G M tube based Environmental Radiation Dosimeter. Results: The concentration of 222 Rn and 220 Rn was found to be highest in the dwellings having mud flooring (Bare) and lowest in the dwellings having mosaic flooring. The geometric mean values of the concentrations of 222 Rn and 220 Rn were found to be 24.1 ± 8.3 and 24.5 ± 10.8 Bq m -3 respectively. The annual mean value of the gamma absorbed dose rate is found to be 175.8 nGy y -1 . Conclusion: The mean value of radon concentration is well within the indian average (42 Bq m -3 ) and world average (40 Bq m -3 ) values. The mean effective dose was found to be 1.19 mSv y -1 and is well within the action level as prescribed by ICRP-65.

Indoor radon concentration: impact of geology in the 2005 Kashmir earthquake-affected Bagh area, Azad Jammu and Kashmir, Pakistan

The early Miocene Murree Formation, late Miocene Nagri Formation and recent alluvium rock units are exposed in the sub-Himalayas of the Bagh area, State of Azad Jammu and Kashmir, Pakistan. The Bagh area was badly affected by the Kashmir earthquake of October 8th 2005 which, along the Muzaffarabad Fault, deformed both the hanging and footwall blocks. The cracks, joints, fissures and fractures in houses and bedrocks might have affected the emission of radon to the surface. Indoor radon concentration measurements were carried out in some dwellings of the Bagh area, Azad Kashmir, Pakistan. The measurements were based on passive integrative detection of radon using CN-85 plastic track detectors in box-type dosimeters. The radon concentration in dwellings was between 50 ± 11.6 Bq·m-3 and 167.1 ± 21.4 Bq·m-3 with an overall average of 95.1 ± 15.8 Bq·m-3 (geometric mean = 93.4 Bq·m-3 ). The average radon concentrations in pucka, semi-pucka and kucha houses were 97.6 ± 15.4 Bq·m-3 , 89.7 ± 15.2 Bq·m-3 and 101.9 ± 15.9 Bq·m-3 , respectively. The mean values of radon concentrations in the Nagri Formation, Murree Formation and recent alluvium lithology were 99.3 ± 15.8, 90.1 and 96.2 ± 15.5 Bq·m-3 , respectively. The annual effective dose to the Bagh population was calculated as 2.38 ± 0.77 (1.33 ± 0.2 to 4.7 ± 0.5) mSv. The average radon (95.1 ± 15.8 Bq·m-3 ) concentration in dwellings for the inhabitants of the Bagh area was safe from radon-related health hazards and was within the recommended action level (ICRP publication 65 (1993) Protection against radon at home and at work, International Commission on Radiological Protection, Ann. ICRP 23(2)).The indoor radon values obtained in the present study are more than the world average of 40 Bq·m-3 (UNSCEAR (2000) United Nations Scientific Committee on the Effects of Atomic radiation, Report to the General Assembly, United Nations, New York).

Indoor exposure of population to radon in the FYR of Macedonia

The authors present the results of a year-long survey of the indoor radon concentration levels in the FYR of Macedonia. A total number of 437 dwellings in eight statistical regions were subject to radon concentration measurements by using CR-39 track detectors. The annual mean indoor radon concentration in each measuring site was estimated from the four individual measurements with 3 months duration. The measuring period was from December 2008 to December 2009. The distribution of the results was nearly log-normal. The arithmetic and geometric mean values of the annual mean value of radon concentration were estimated to be 105 ± 84 and 84*/1.9 Bq m(-3), respectively. The annual effective dose due to indoor exposure to radon in the dwellings was estimated to be 2.1*/1.9 mSv y(-1).

Variability of Radon Levels in Different Rooms of Egyptian Dwellings

Inhalation of indoor radon has long been recognised as a risk to health. The major sources of the indoor radon and also its daughters are building materials, natural gas and an underground-derived water supply. In this work a set of radon measurements was carried out, using the CR-39 solid state nuclear track detector, in different rooms of dwellings in Cairo. These compartments were located in apartment complexes built of the same building materials. The results showed that the radon concentration and exhalation rate in these houses varied from 47.94 to 84.32Bq·m-3 and 2.59 to 4.04mBq·m-2·h-1, respectively. The mean values of radon concentration in living rooms, bedrooms, bathrooms and kitchens were 50.98 ± 1.94, 53.18 ± 3.69, 79.36 ± 2.96 and 81.29 ± 1.93Bq·m-3, respectively. The mean values of exhalation rate were 2.68 ± 0.11, 2.79 ± 0.19, 4.01 ± 0.18 and 4.22 ± 0.12mBq·m-2·h-1, respectively. This data showed that bathrooms and kitchens had a significantly higher radon concentration and exhalation rate compared with both other rooms and the outdoor levels.

Seasonal changes in radon concentrations in buildings in the region of northeastern Poland

In this study, seasonal observations of radon concentration changes inside buildings carried out in the northeastern region of Poland is presented. One-year measurements of radon concentrations were performed in chosen buildings. The integral method of Cr-39 trace detectors in diffusive chambers was used. Mean values of radon concentrations were determined in monthly, 2-, 3-, 6-month, and annual observations. The fraction of a mean annual concentration of the value obtained in a shorter observation was calculated. Monthly concentration values were from about 0.2 to 14.9 of the annual mean. All buildings revealed seasonal fluctuation of radon concentration. Negative correlation of indoor radon concentration in the buildings and the mean temperature outside was observed in most examined buildings. The lowest coefficient range, determining which part of the annual mean value would be obtained in the 6-month observation, was gained for exposure begun in April or October.

Experience from retrospective radon exposure estimations for individuals in a radon epidemiological study using solid-state nuclear track detectors

The relation between increased risk of lung cancer and exposure to indoor radon is assessed in epidemiological studies. Both the quality and reliability of smoking data and the radon exposure data are of primary importance. Contemporary measurement of radon concentration in the dwellings of individuals in a case-control study is traditionally used to assess past history of radon exposure. These assessments are somewhat unreliable since presently measured radon concentration might not be representative for a given location long ago. The measurement of long-lived decay products from 222Rn remaining indoors on hard surfaces, such as glass, makes it possible to assess the exposure to indoor radon. At the Swedish Radiation Protection Institute, a combination of two different solid-state nuclear track detectors has been developed to assess the 210Pb activity implanted in glass surfaces by measuring 210Po alpha activity. This detector (a RETRO detector) is used in the Swedish radon epidemiological case-control study of non-smokers with the aim to provide an alternative estimate of individual radon exposure and to evaluate the usefulness of RETRO measurements. A total of 576 different objects were found and 568 were measured. For 225 individuals, we measured two personal objects that had been in the same person's possession for more than 20 years. The standard deviation of the average radon concentration obtained from these two objects had a median value of 13 Bq/m 3 indicating a precision of exposure of approximately 20%. The correlation between 210Po surface activity measured earlier and the mean values of radon concentrations in a number of Swedish dwellings is used to estimate the historical, average radon concentration. This average correlation factor seems also to be valid for measurements in the non-smoker epidemiological study.

A PRELIMINARY STUDY ON SOIL-GAS RADON GEOCHEMISTRY ACCORDING TO DIFFERENT BEDROCK GEOLOGY IN KOREA

Three study areas of Kwanak campus (Seoul National University), Boeun (Choong‐buk) and Gapyung (Kyonggi) were selected and classified according to their bedrock types in order to investigate soil–gas radon concentrations. The mean values of radon concentrations decreased in the order of Gapyung (40 Bq L−1) > Kwanak campus (30 Bq L−1) > Boeun (22 Bq L−1), and decreased in the order of granite gneiss > banded gneiss > granite > black slate–shale > mica schist > shale–limestone > phyllite schist according to bed rock types. Variation in radon emanation with water content in soils and with soil grain size was assessed by the modified Morse (1976) 3 min method. Soil–gas radon concentrations increased with increasing water content in the range of less than about 6–16 wt. %, but decreased above 6–16 wt. %. Radon concentrations also increased with decreasing soil grain size. Radioactivity analysis of radionuclides of 238U series in some soil samples indicated their possible radioactive disequilibrium between 226Ra and 238U due to the differing geochemical behaviour of intermediate radionuclides. Thus, a radioactive isotope geochemical approach should be necessary for soil–gas radon study.