Abstract: In this study Soil gas radon 222 Rn activity was measured in different locations at Al-Tuwaitha Nuclear Site and the surrounding areas using RAD7 (radon detector). Radon activity in the soil gas varied from (866±150 to 16004±521 ) Bq/m 3 near Alaibtihal School and Ishtar \ Al-Ttakhi School respectively. These concentrations values are well below the allowed levels that range from (0.4 to 40) KBq/m 3 . The annual effective doses related to the inhalation of radon gas and its progeny which were calculated from the Concentration of emanation in air near ground ranged from (0.0082305 to 0.152102) mSv/y. these results are less than the recommended global average dose from the inhalation of radon from all sources, which is 1 mSv/y. The Health risks originating from indoor radon concentration can be attributed to natural factors and is characterized by geogenic radonpotential (GRP), The highest values were found in Ishtar \ Al-Ttakhi school which is (16.004) and The lowest values were found Near Alaibtihal school which is (0.288666667), the lowest value according to Neznal was classified as low (GRP < 10) and the highest value was classified as medium (10 < GRP < 35), according to Barnet and Pacherová low GRP causes <230 Bq m -3 while medium GRP causes 230-460 Bq m -3 indoor radon concentration. From these different values of GRP a geogenic radon risk map was created, which assists human health risk assessment and risk reduction since it indicates the potential of the source of indoor radon. The results from this study shows that the region has background radioactivity levels within the natural limits.
Early radon studies in Piemonte, an administrative district in North-West Italy (25200 km − 2 , around 4300000 inhabitants) have been done since 1990- 1991, when a general radon survey of the dwellings of Piemonte was per- formed in order to assess the average radon exposure of the whole popula- tion. The survey, executed in the framework of the National Radon Survey by the National Environmental Protection Agency (former ANPA, now IS- PRA) and ISS (National Health Institute), involved about 430 dwellings, chosen randomly with a stratiﬁed sampling technique.
The method to measure the radonpotential and the emanation factors is described by López-Coto et al. . From growth curves of radon inside a closed chamber it is possible to calculate the exhalation rate of the block and, under specific experimental conditions, the radon po- tential of the tested material. In addition, once crushed a portion of the specimen (about one third), from a sec- ond measurement in the chamber for obtaining radonpotential and the real emanation factor of the material.
In each of the local authority regions, all the domestic dwellings in areas of at least 5% radonpotential were identified using the Royal Mail Post Office Address Files. The resultant data-set of addresses was compared with the UK National Radon Database and addresses with an existing valid radon measurement were removed since these would not need to be re-measured. This procedure identified a total of 539 individual dwellings. Information for individual areas is shown in Table 2. Tables 2 and 3 include the administrative area code used by the Office for National Statistics.
Step 4: image retrieval is the main aim of this step. Suppose a test query is selected. This query goes through the proposed chain of processing. Figure 6 depicts, 90 equidistant Radon projections of the computed samples. Then the converted datum is fed to the CNN to obtain the most relevant category. Each IRMA code of the selected category can be chosen as the retrieved code of the original test query. Therefore, the Python code, provided by ImageCLIFmed09 is used to calculate the error between the original and the retrieved image. We achieved an IRMA error of 248.7 by utilizing the same scenario to all test queries. This outcome significantly surpasses that of the methods that use Radon projections on IRMA dataset.
Background: One of the most important natural sources of human exposure is inhalation of radon radioactive gas and its decay products in homes and at workplaces. According to the World Health Organization, radon is the second leading cause of lung cancer. This study is the first survey of indoor radon concentration in dwellings of the Aleshtar city (west of Iran). Materials and methods: In this work, radon concentrations were measured in 24 dwellings by using a passive method known as Alpha Track Detectors (ATDs) with CR-39 polycarbonate film for three months during the year 2016. In addition, the annual effective dose due to radon exposure was estimated for residents. Results: The indoor radon concentration ranged from 1.01 to 206.53 Bq/m 3 with an average value of 55.19 Bq/m 3 (CI (Confidence Interval) 95%: 31.46 - 78.92), and the average annual effective dose to the population in Aleshtar was estimated to be 1.39 mSv/y. According to the result of this study, there was a significant difference between apartment buildings and villas as well as between different floors in terms of the average radon concentration. Conclusion: It was found that radon concentration in 20.8% of dwellings was higher than the reference levels recommended by the World Health Organization (100 Bq/m 3 ).
During the 12 years of functioning of the Integrated system for the control of and accounting for the exposure doses as well as the formation in 2001 of "The Federal data bank on doses to the population of the Russian Federation at the expense of natural and technological changes in the radiation background", a unique array of information was collected on the levels of radon and its DPR in the air of residential buildings. The geography of these data is very wide and covers almost all regions of the Russian Federation. According to the 2001-2012 data , in Russia there are 5 regions in which average annual individual effective doses of public exposure to the natural sources of ionizing radiation are higher (in the range of 5 to 10 mSv / year): the Republic of Altai, the Tyva Republic, Stavropol, Transbaikalia territory, and Jewish AO. At the same time, more than 60% of the dose is inhaled radon isotopes and DPR. Despite the fact that the average doses in other regions are not elevated, there are population groups for which the radon dose can greatly exceed the average for the region, as well as the geographic areas and neighborhoods characterized by elevated radon. These regions include, among others, St. Petersburg with an average value of radon EEVA in the air of residential buildings in the entire city of about 21 Bq / m3 , in some areas the value of this index reaches several hundreds or even thousands of Bq / m3 that exceeds the norm tenfold. These areas include, for example, Krasnoselsk and Pushkin where the main source of radon in buildings is the underlying rocks with a high content of uranium and radium - Dictyonema shales, with uranium content above background 10-100 times that come to the surface, or located in close proximity to the earth surface .
(UNSCEAR, 2000). The indoor radon concentrations in the studied hospitals are categorized according to the floor number versus hospitals as shown in Table 2. According to this, the obtained mean values are vary from 92 to 202 Bqm -3 with overall mean of 158 Bqm -3 in underground floor (F-1), from 33 to 187 Bqm -3 with overall mean of 146.4 Bqm -3 in ground floor (GF), from 84 to 277 Bqm -3 with overall mean of 143 Bqm -3 in first floor (F1), from 120 to 192 Bqm -3 with overall mean of 154.8 Bqm -3 in second floor (F2), from 151 to 163 Bqm -3 with overall mean of 157 Bqm -3 in third floor (F3), and from 116 to 164 Bqm -3 with overall mean of 140 Bqm -3 in fourth floor (F4). The GF and F1 are generally characterized by a high mean radon concentration level compared with the other floors; this can be interpreted due several reasons, such as: Firstly, the upper floors have better ventilation than the lower ones. Secondly, the chance for radon to reach upper floors is very small as compared to that in lower ones. Thirdly, the radon exhalations rates from the ground are decreasing fast as going to higher floors. However, there is a large variation in the radon concentrations within the same floor, especially in underground, ground and the first floor.
The authors are grateful to the Institute for Environmental Research (IER) of Tehran University of Medical Sciences (grant number: 92- 01-46-20840) and Research Center for Environmental Pollutants, Qom University of Medical Sciences (grant number ( 91335 : for -inancially and technically supporting this research. Moreover they wish to express their appreciation to the Reference Radon lab, Central Research Laboratory, Vice Chancellor of Research and Technology, (Mazandaran University of Medical Sciences) for the technical and laboratory support.
Experimental method for radium and radon detection is based on alpha particle counting of radon. Alpha spectroscopy detection method with the help of Corentium digital radon detector was used for the measurements of radon in the construction materials of Wolaita Sodo, Ethiopia (Nigus M. et al 2017). Sixteen building material samples were collected from wolaita Sodo town construction sites. The samples are grouped in to six types; those are cement, metal, sand, rock, clay brisk and gypsum. These samples were dried in oven, milled, crushed, sieved by 2.5 mm mesh in order to get fine quality of the samples, 50 gm of each sample was placed inside a plastic cylindrical container a period of four weeks in order to get equilibrium between radium and radon, placed Corentium digital radon detector in to sample for a period of one day. The detector can count all the tracks of alpha particles in the volume of the cane. The radiological effects of radon from construction materials were calculated according to the following equations.
In the present work, we have measured the radon gas concentrations in tap water samples are taken directly from drinking tap water in sites houses being carried in Thi-Qar governorate by using nuclear track detector (CR-39). The results of measurements have shown that the highest average radon concentration in water samples is found in AL-Refai region which is equal to (0.223 ± 0.03 Bq/L), while the lowest average radon gas concentration is found in AL-Fajr region which is equal to (0.108 ± 0.01 Bq/L), with an average value of (0.175 ± 0.03 Bq/L). The highest value of annual effective dose (AED) in tap water samples is found in AL-Refai region, which is equal to (0.814 μSv/y), while the lowest value of (AED) is found in AL-Fajr region which is equal to (0.394 μSv/y), with an average value of (0.640 ± 0.1 μSv/y). The present results have shown that radon gas concentrations in tap water samples are less than the recommended international value (11.1 Bq/L). There for tap water in all the studied sites in Thi-Qar governorate is safe as for as radon concentration being concerned.
Electret ion chambers (EIC) is a passive devices that function as integrating detectors for measuring the average radon gas concentration during the measurement period. The electret serves both as the source of an electric field and as a sensor in the ion chamber. Radon gas enters the chamber by passive diffusion through a filtered inlet. Radiation emitted by radon and its decay products formed inside the chamber ionizes the air within the chamber volume. The negative ions are collected by the positive electret located at the bottom of the chamber. The discharge of the electret over a known time interval is a measure of time-integrated ionization during the interval. This in turn is related to the radon concentration. The electret discharge in volts is measured using a noncontact battery-operated volt reader. This value, in conjunction with a duration and calibration factor, yields the radon concentration in desired units.
The report measured radon levels in summer and winter respectively 25.1 Bq/L and 152 Bq / L and the dose for residents of Hamadan stay indoors in winter to a maximum of 10 hours 1.44mSv and for the summer season with 0.2mSv was calculated(14, 15). Radon measurement results show that the average concentration of radon gas in the city of Sari in the winter than the other seasons (Table 2 and 3 and 4). Accordingly, the dose is higher in winter than other seasons (Table 5 and 6 and 7). This difference could be due to lack of airflow and radon indoors in winter is stillness (16, 17). In Figure 3 and the effects of radon gas cycle is shown. due to the lack of natural ventilation or mechanical man-made and well above the doors and windows are closed. Resulting in high levels of radon can cause lung cancer. Sari province of radon concentration measurements in comparison to the state average radon concentration in the houses of the US and China and Mashhad city and city of Hamadan in Iran and the international standard (average radon concentration in air of approximately 0.4PCi is lower (18). In cold climates to keep warm, open houses are closed; radon can penetrate the cracks in the floor. In these areas, buildings with basements, open floors are recommended. This risk is lower in environments that have proper ventilation (19, 20). Table 1 about exposure to radon gas in the U.S., Europe and China are listed (21, 22).The standard reference values specified in the table (23). Figure 4 Map of Radon measure absorbed dose to the northern city of Sari in Iran is shown. Figure 5 Sources of radon gas and its distribution is shown in the homes of residents (24, 25).
We briefly introduce an observation and analysis of atmo- spheric radon concentration preceding the 1995 Kobe earth- quake based on Yasuoka and Shinogi (1997) and Yasuoka et al. (2006). The atmospheric radon concentration was moni- tored continuously using a flow-type ionization chamber (18 litre volume) from January 1984 to February 1996 (except during January 1989 to December 1989 when the cham- ber was out of order). The monitoring station is located at the Kobe Pharmaceutical University and directly above the Rokko fault zone (Fig. 1) in which the aftershocks of the Kobe earthquake happen. The air 5 m above the surface was filtered into the chamber, and the atmospheric radon concen- tration was measured. The radon decay products are assumed to be trapped by the high-efficiency particulate air filter be- fore measuring the concentration of radon in the ionization chamber.
The importance in the measurements of radon isotopes lies in their detrimental effect on human. Since they occur in nature, man has always been exposed, mainly through inhalation of their decay products. Radon is released to the atmosphere through three modes namely; i) emanation: as its atom emanated from radium decay is escaping by recoil energy into the pores of the grains; ii) transport or diffusion: which is the diffusion flow that causes the movement of radon atoms to ground surface and iii) exhalation: where the transported atoms are exhaled to the atmosphere . The most important factor relating to radon concentration is the emanation coefficient which is the fraction of radon that reaches the pore space. It depends on different factors such as crystalline structure, grain size and moisture contents [3 7 4]. The values of emanation coefficient vary from 1% to 50% over a wide range of materials, conditions, definitions and measurement methods [5 & 6]. The radon exhalation from soil surface is affected by the soil’s characteristics like radium contents, the internal structure, grain size, porosity, permeability and the emanation coefficient, etc. For the determination of emanation coefficient of 222 Rn using gamma spectrometry, the sample is sealed in a container and the
The advantage of either QALYs or DALYs as outcome measures when allocating resources is that they capture the two main dimensions on which an intervention for the prevention or treatment of any disease can be assessed – mortality and morbidity – and therefore allow comparisons to be made across many alternative uses of resources intended to improve health. By comparing cost-effectiveness ratios and systematically selecting those with more favourable ratios, the total health gained from a specified budget can be maximized. The approach is similar whether QALYs or DALYs are used; the main difference being that within the QALY framework, the cost-effectiveness ratio would be the cost per quality-adjusted life-year gained, whereas in the DALY framework the ratio would be the cost per disability adjusted life year averted. In the example below, the QALY is used but the overall approach is not dependent on this choice. Cost-effectiveness analysis can therefore help promote efficiency when allocating health resources, and provides a useful framework within which to evaluate the likely costs and benefits of new interventions or policies. The following simplified example demonstrates how the cost-effectiveness approach could be used in radon prevention and mitigation to obtain a maximum health benefit within a given budget. Suppose that a new radon prevention measure has been shown to be effective in a pilot study, and that the radiation protection agency is instructed to introduce this measure into all previously unprotected school buildings. However, it is given no additional budget to implement this policy. It begins by evaluating the total costs and effects for all existing programmes. In total, ten separate and independent programmes are identified, each with different costs and effects, and from these it is possible to calculate the cost-effectiveness ratio for each programme, by dividing the programme cost by its effectiveness (in each case, the added or incremental cost compared to the next best alternative and the added or incremental effectiveness). Table 11 presents the results of ten hypothetical interventions in different types of houses, workplaces, and schools. In such an example, it is evident that cost- effectiveness varies widely, from around À 6 700 (programme 3) to À 62 500 per QALY gained (programme 7).
C( 222 Rn) = C( 218 Po)·(C( 218 Po)/C( 214 Bi))·k with k = 0.3. Cycle time is 1 h, and the filter is changed every 24 h. The manufacturer describes the detection limit of this in- strument as 0.2 Bq m −3 , the uncertainty of measured activity with ± 5 %, and the uncertainty of estimated 222 Rn assuming equilibrium with ± 25 %. (Method description from the op- erating manual of “Tracerlab WLM ASF 200” by TRACER- LAB GmbH, Aachener Str. 1354, 50859 Cologne, Germany.) 2.3 Method of comparison between radon monitors As an example of the comparison method used throughout this study, here we compare observations between an origi- nal HRM (i.e. our reference monitor, called HD-R (Heidel- berg reference), that is used as reference throughout the com- parison project to calibrate all other monitors that were sent to the various stations) and a modernized HRM in Heidel- berg. A typical comparison period is displayed in Fig. 1. The upper panel of Fig. 1 shows the atmospheric 214 Po activity concentrations measured over 6 weeks in spring 2012 with two Heidelberg monitors (HD-R and the first prototype of the modernized version called “1_HD”). For a quantitative evaluation of the compatibility of measurements between the two monitors we first calculate the half-hourly activity ra- tios. The mean of these ratios (Fig. 1b) was 1.012 ± 0.127 in the concentration range 1 to 15 Bq m −3 , which is typi- cal for the Heidelberg measurement site, sampling air from about 30 m a.g.l. The half-hourly activity ratios show increas- ing scatter when ambient concentrations decrease. Linear re- gression of the half-hourly activity concentration data is dis- played in Fig. 1c. The slope of the York fit (York et al., 2004), taking into account errors in both the x and y components, is 1.021 ± 0.016, i.e. not significantly different from unity