222Rn Concentration Measurements Research Articles

Study of variation of indoor radon levels in houses and prediction of indoor concentrations using house characteristics and outdoor radon levels.

The measurement of 222Rn concentrations in indoor and outdoor air was carried out in certain locations of Mandya city, Karnataka, using the Solid State Nuclear Track Detectors (SSNTD) technique. The annual mean values of 222Rn in indoor and outdoor are found to be 20.5±1.4 and 9.0±0.5Bqm-3, respectively. The observed mean value of indoor radon concentration is found to be well within the world and the Indian average of 40 and 42Bqm-3, respectively. Outdoor radon concentrations have been measured in the vicinity of houses where yearlong radon measurements carried out using the SSNTD technique. The seasonal variation in the outdoor radon was studied and the average concentrations during summer, rainy and winter are 9.1, 6.9 and 12.9Bqm-3 respectively. Considering the possible factors such as house characteristics (Volume, Surface area of building material, Leakage area, etc.), indoor-outdoor temperature difference and outdoor radon concentration into account, the indoor radon levels were predicted using the existing model which is based on the mass balance equation. The results are systematically analysed and discussed. The predicted values are compared with the measured values.

Spatial distribution of radon contamination in hot springs water and its cancer and non-cancer risks in the Hunza-Nagar valley, Pakistan.

Radon (222Rn) is a ubiquitous radioactive gas and could threaten human life due to its potential for cancer and non-cancer risks. This study examined the measurement of 222Rn concentration and associated health risks in the hot springs of Hunza-Nagar valley. For this purpose, the hot springs water of Hunza and Nagar districts and the background sites were analyzed for 222Rn concentration using the RAD7 detector (Durridge Company, USA). The average concentrations of 222Rn were 46.1 ± 0.94, 65.3 ± 0.45, and 5.47 ± 0.25Bq/L in the Hunza district, Nagar district, and background sites, respectively. Results showed that 222Rn concentrations of hot springs water were multifold higher than the background sites. 222Rn concentrations for hot springs water in Hunza-Nagar valley had surpassed the maximum contamination level set by the US environmental protection agency (USEPA). Humans' annual mean exposure dose rates of various age groups were calculated for the estimated lifetime cancer risk (ELCR) and non-cancer risks. The total annual mean exposure doses from 222Rn in water (EwTotal) values were (187 ± 3.80, 265 ± 1.84, and 22.2 ± 1.02μSv/a) for infants (143 ± 2.92, 203 ± 1.40, and 17.0 ± 0.78μSv/a) children, and (138 ± 2.80, 196 ± 1.35, and 16.4 ± 0.76μSv/a) adults in the Hunza district, Nagar district, and background, respectively. Among the age groups of humans, infants showed a higher risk than others. Results showed that hot springs water consumption surpassed the world health organization threshold of 100μSv/y for chronic or non-cancer and USEPA 0.1 × 10-3 for ELCR risks.The concentration of 222Rn showed a positive correlation (> 0.68) with hot springs' water temperature and pH suggesting a common origin.

Characteristic of Pollutant Element and the Side Effect with People Living Environments

Radon could be a natural hot gas while not odor, color or style. It found rocks, soil, concrete and bricks. The measurements of 222Rn concentration in a total of twelve completely different soil samples in kombolcha city were investigated. The concentrations were measured by alpha qualitative analysis detection technique with Corentium digital element detector. Within the general population, element exposure could be an explanation for carcinoma. The aim of a system was to assess the danger of hot element exposure to human health. Knowledge regarding health risks is vital, and efforts may be created to guard against associated health issues. Underneath the surface, there is a much better chance of reducing the impact of element exposure on public health and resulting in more practical interference with a variety of respiratory organ diseases. Many scientific and health organizations, including the World Health Organization, consider element gas to be hepatotoxic to humans. The elements that have the greatest impact on the human environment, with a focus on metastasis diseases. The hot gassy part is found in most building materials, and thus the land on which the buildings are built is created. One of the most important challenges that we have a tendency to face nowadays in the field of pollution is element pollution's thought-about as a hot part emitting continuous radiation throughout its short era. Several researchers have recently expressed an interest in studying the effects of element on human health, as it is regarded as one of the most common indoor air contaminants due to its malignant neoplastic disease properties.

Measurement of 222Rn concentration in drinking water in the environs of Thirthahalli taluk, Karnataka, India

The dissolved radon concentration in water samples collected from various aquifers in and around Thirthahalli taluk was measured by employing active technique through Scintillation Radon Monitoring system. The measured radon concentration lies in the range of 0.37 ± 0.05 Bq/l to 87.02 ± 2.11 Bq/l. The resulting annual effective radiation dose to the public, who consume this water, lies in the range of 1.01μSvy−1 to 237.56 μSvy−1. However, no significant change in the radon concentration with respect to seasonal variation was observed in majority of the sample. Few samples show higher radon concentration during summer season and lower concentration in rainy season. All these results are presented in this paper.

High-resolution mapping and time-series measurements of 222Rn concentrations and biogeochemical properties related to submarine groundwater discharge along the coast of Obama Bay, a semi-enclosed sea in Japan

High-resolution mapping along the coast and time-series measurements of the radon-222 (222Rn) concentrations in the shallow zone in a semi-enclosed sea, Obama Bay, Japan, were undertaken in 2013. The temporal and spatial variations in the 222Rn concentrations were analyzed in parallel with meteorological conditions, physical–biogeochemical characteristics, and the submarine groundwater discharge (SGD) flux measured with a seepage meter. These data indicate that the groundwater influences the water properties of the bay and that the groundwater supply pathways are not limited to the local SGD. The concentrations of 222Rn flowing into the bay from rivers was known to be relatively high because groundwater seeps from the river bed. High-222Rn water was almost always present around the river mouth, and northward advection of the water affected the distribution of 222Rn concentrations in the bay. The southward wind suppressed the advection of the high-222Rn water and largely controlled the temporal variations in 222Rn concentrations at a station located on the north side of the river mouth, whereas the local SGD affected the short-term changes in the 222Rn concentrations. The concentrations of 222Rn and chlorophyll-a, an indicator of phytoplankton biomass, show a significant positive correlation in the surface layer along the coastline in seasons when the nutrient supply was the main factor limiting primary productivity.

Measurement of soil-gas radon in some areas of northern Rajasthan, India

The health hazards of the radioactive gas radon on general public are well known. In order to understand the level and distribution of 222Rn concentrations in soil-gas in Sri Ganganagar district of Rajasthan, a 222Rn survey was carried out for the first time using RAD7, an electronic radon detector manufactured by Durridge Company (USA), at different locations covering a total area of 10,978 km 2, having a population of approximately 20 lakh. The measurement of 222Rn concentration in soil-gas was carried out at four different depths (10, 40, 70, and 100 cm). The radon concentration in soil-gas for 10, 40, 70, and 100 cm depths ranged from 0.09–4.25, 0.15–6.30, 0.50–9.18, and 0.72–10.40 kBq m −3, respectively. The minimum value of radon concentration is observed in 33 GB village at 10 cm depth and maximum for Mohanpura village at 100 cm depth. As expected, our data show an increase of soil-gas radon concentration levels with depth. The present results are compared with the available radon data from other studies.

Measurement of 222Rn Concentration and Exhalation Rate from Phosphate Rocks Using SSBD Detector in Saudi Arabia

The radon concentrations and exhalation rates of phosphate rocks samples were measured using a silicon surface barrier detector. In this study, samples were collected from different locations of phosphate mine in Northern Saudi Arabia. The radon concentrations varied from 17 ± 0.5 to 77 ± 1.3 Bq m−3, and the radon exhalation rates from these samples ranged from 0.1255 (0.024) to 0.5791 Bq m−2 h−1 (0.111 Bq kg−1 h−1. The annual effective doses varied from 0.429 to 1.943 mSv y−1. The data were compared with the global values of radon concentration.

Measurement of 222RN concentration in drinking water in Sakarya, Turkey

In this paper, the first measurement of (222)Rn concentrations in drinking water from wells, springs and bottled waters in the city of Sakarya, Turkey was presented. The measurements were performed using RAD 7, a solid-state alpha detector, with RAD H2O (radon in water) accessory manufactured by Durridge Company, Inc. The measured activity concentrations ranged from 1.98 to 20.80 Bq l(-1) with an average value of 9.05 Bq l(-1) for well water, from 0.75 to 59.65 Bq l(-1) with an average value of 13.78 Bq l(-1) for spring water and from 0.75 to 22.8 Bq l(-1) with an average value of 5.41 Bq l(-1) for bottled water. Although these results indicated relatively high (222)Rn concentrations compared with that from other parts of the Turkey, they are still below the World Health Organization recommended level of 100 Bq l(-1) for radon. Using the measured activities of (222)Rn, the age-dependent associated committed effective doses due to the ingestion of (222)Rn as a consequence of direct consumption of drinking water were calculated. The committed effective doses from (222)Rn were estimated to range from 2.59 to 205.97 µSv y(-1), from 1.55 to 123.28 µSv y(-1) and from 1.31 to 104.48 µSv y(-1) for age groups 1-2, 8-12 and >17 y, respectively.

Intercomparison measurements of 222Rn concentration in water samples in Poland

The paper presents the results of intercalibration measurements of 222Rn concentration in water samples. The aim of the experiments was to evaluate the different measurement methods of radon determination in water samples performed by eleven laboratories in Poland and to test these methods in field work. In the years 2001–2003 three national intercomparison experiments were organized. The results allowed the participating laboratories to improve their measurement methodologies and to achieve better, i.e. more convergent results of determining radon concentration in water samples. The results show that the use of liquid-scintillation technique seems to be the best measurement method. It should be emphasized that comparative experiments are essential for all laboratories and they should be carried out as often as possible, based both on prepared samples with known concentration values of 222Rn and natural water samples, the most commonly used in laboratory practice.

Indoor radon survey in a university campus of Nigeria.

CR-39 tracketch detectors were used for the measurement of 222Rn concentration in 24 offices in Nigeria’s oldest university campus in order to estimate the effective dose to the occupants from 222Rn and its progeny. The dosimetric measurements were made over a period of 3 months. Questionnaires were distributed and analyzed. The radon concentration ranged from 157 to 495 Bq/m3, with an arithmetic mean and standard deviation of 293.3 and 79.6 Bq/ m3, respectively. The effective dose to the workers was estimated and this varied from 0.99 to 3.12 mSv/ y, with a mean of 1.85 mSv/y. The radon concentrations were found to be within the reference levels of ICRP.

222Rn concentrations in greenhouses in Aomori Prefecture, Japan

Greenhouses are possible places with high 222Rn concentrations, since soil, the source of 222Rn, is directly exposed inside them. To examine this point, 222Rn concentrations in 28 greenhouses at five locations in Aomori Prefecture were measured for approximately 1 year with passive Rn detectors. For 1 week, measurements of 222Rn concentration and working level were also carried out with active detectors to get equilibrium factors and the ratio of 222Rn concentration in working time to non-working time in selected greenhouses. The geometric mean of annual 222Rn concentrations in greenhouses was 13 Bq m −3, and the same as that in dwellings and lower than that in indoor workplaces in the prefecture. However, variation of the 222Rn concentrations was far larger than in other environments, and ranged from the lowest level in outdoor workplaces to the highest level in indoor workplaces. Significant seasonal variation was also observed in 222Rn concentrations. The mean effective dose from 222Rn and its progenies was estimated to be 0.047 mSv year −1 for a farmer working in a greenhouse.

Measurement of 222Rn Concentrations in Surface Water in Northeast Thailand

In northeast Thailand, salinization caused by the discharge of salty groundwater is a serious problem. Locations where groundwater flows into surface water must be identified before measures against salinization can be taken. Radon-222 (222Rn) is a useful indicator for determining areas of groundwater discharge. We measured 222Rn concentrations in surface waters in the region and found that groundwater flows into streams and lakes in low-elevation areas (below 180 m) . Our results agree with the results of published simulations of groundwater flow.

Radon concentration in indoor occupational environments in Aomori Prefecture, Japan

The 222Rn concentrations in indoor workplaces were measured in Aomori Prefecture, Japan, and the results are reported here. This survey was part of a program to measure background natural radiation dose rate in the prefecture where the first Japanese nuclear fuel cycling facilities are now under construction. The survey of the 222Rn concentrations in indoor workplaces was carried out at 107 locations from 1996 to 1998. The 222Rn concentrations were measured for approximately one year at each site with passive Rn detectors, which used a polycarbonate film for counting α-rays and could separate concentrations of 222Rn from 220Rn. Weeklong measurements of 222Rn concentration and working level were carried out with active detectors to get the ratio of 222Rn concentration during working hours to non-working hours as well as equilibrium factors in selected locations. Diurnal variation of 222Rn concentration depended on building structure, air-conditioning, time of day and day of the week (week days or weekend). The 222Rn concentration during working hours was generally lower than that in non-working hours. Although the annual average 222Rn concentration in indoor occupational environments was higher than that in dwellings, radiation dose for Aomori Prefecture residents from Rn in the former was 14% of the total indoor dose by Rn because of the lower concentration in working hours and lower occupancy factor.

Concentrations of 222Rn, 220Rn and their progeny in residences in Hong Kong

The standardized charcoal canisters of diameter 4″ recommended by USEPA for passive measurements of 222Rn concentrations were modified for active air sampling. Through calibrations, the concentrations of 222Rn and 220Rn in air can be simultaneously obtained by counting the areas under the γ-ray peaks for 222Rn and 220Rn progenies using an HPGe γ-spectrometer. 222Rn and 220Rn concentrations in 62 residences in Hong Kong were surveyed. In addition, the potential α-energy concentrations (PAEC) of 222Rn and 220Rn progeny were simultaneously recorded at the same sites. The mean values of gas concentration, PAEC and equilibrium factor for 222Rn are 27±9 Bq m -3, 1.8±1.4 mWL and 0.24±0.13, respectively, and the corresponding values for 220Rn are 11±4 Bq m -3, 1.2±0.9 mWL and 0.029±0.015, respectively. Factors affecting the concentrations of 222Rn and 220Rn and progeny were also studied, including the air-cooling method, building characteristics, site location and meteorological parameters.

Measurement of 222Rn concentration in Kenyan groundwater.

Groundwater samples from different parts of Kenya have been analyzed for their 222Rn concentrations. Samples were drawn from municipal supplies, springs, wells and bore holes in different geological terrains. In the analysis, conventional liquid scintillation counting, using the Packard protocol for measuring radon in water, was employed. This is the first time these water sources are being tested for radioactivity. The preliminary results are presented, and they showed that 222Rn is the main contributor to the radioactivity in most portable waters in Kenya. 222Rn activity concentrations range from 0.8 +/- 0.5 to 371.7 +/- 33.5 Bq L(-1).

Some Problems on the Measurement of 222Rn Concentrations by Passive Cup Method

A passive cup monitor has been constructed by using a 50 mm radius stainless steel hemisphere. The conductive housing has reduced the scatter in track densities. In dwellings with high 220Rn concentrations, it is particularly necessary to measure 222Rn concentration with a monitor having a radon exchange rate less than 0.1 h-1.

Distribution of indoor 222RN concentrations in Tennessee, Kentucky, Georgia, and Florida

Short-term measurements of 222Rn concentrations using diffusion barrier charcoal canisters were made in living areas at the request of volunteer households in Tennessee, Kentucky, Georgia, and Florida from 1986 through 1989. We analyzed the observed radon concentrations in regional sub-areas within these states. After adjusting for oversampling that had occurred in some areas, we estimated state-wide geometric means of radon concentrations in living rooms as 59.7 Bq m −3 in Kentucky, 51.9 Bq m −3 in Tennessee, and 60.0 Bq m −3 in Georgia. Measurements in Florida were scattered over the state and the coverage was inadequate to allow a state-wide estimate. Estimates of the percentage of homes having indoor radon levels equal to or above the action level of 148 Bq m −3 are 21.6% in Kentucky, 17.0% in Tennessee, and 6.8% in Georgia, respectively.

Location of groundwater seepage points into a river by measurement of 222Rn concentration in water using activated charcoal passive collectors

A new method to measure 222Rn concentration in water is described. This method is an application of the activated charcoal passive collector method, which is sometimes used for measurement of 222Rn concentration in air. The model and the equation which express the quantity of 222Rn adsorbed in activated charcoal in the collector were constructed, inspected experimentally, and proved to work well enough for the measurement of relative concentration of 222Rn in water. We used this method to measure the 222Rn concentration in water at ∼ 20 points in an actual river. Based on the fact that the concentration of 222Rn in ground water is generally much higher than that of surface water, we found several possible groundwater seepage points along the river. For the absolute measurement of 222Rn concentration in water by this method, it would also be necessary to investigate the effect of temperature on the quantity of 222Rn collected in a collector.

Influence of tuff on the radon concentration in dwellings

Measurements of 222Rn concentrations were made under closed conditions in 40 dwellings in Orvieto, a medieval Italian town on a tuff plateau, tuff also being the main building material. The method used was that involving activated carbon canisters, which were placed in basements and in upper floors for at least 48 h during the period November 1989–May 1990. The amount of 222Rn in each canister could be determined by counting the 214Pb and 214Bi gamma-emitters using NaI(Tl) and Ge(I) detectors. The mean concentration of radon was 362 Bq/m 3 in the living areas and 5821 Bq/m 3 in the cellars.

On the application of a proportional counter to continuous monitoring of 222Rn concentration in the study of thermal diffusion in RnCO 2 mixture

A proportional counter has been used as a small thermodiffusional chamber for continuous measurements of 222Rn concentration in the study of the thermal diffusion process in the RnCO 2 mixture by means of the two-bulb method. The design of the proportional counter has been described and the methods used for adjusting and continuous monitoring of its working point have been discussed.