The second part is concerned with the determination of radon gas concentration in samples of tap water obtained from networks in dwellings in Al-Najaf governorate, the results indicate that the highest average radon concentration in water samples was found in (Meassan) region which was (0.59±0.08 Bq/L), while the lowest average radon concentration was found in (Al-Jamhorah) region which was (0.16±0.04 Bq/L), with an average value of (0.36±0.1 Bq/L), the present results show that the radon gas concentrations in tap water is below the allowed limit from (ICRP) agency which is (0.5994 Bq/L), while the radon exhalation rate (RER) ranged from (2.15-0.58 μSv/y), and average value which was (1.28±0.31 μSv/y).
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.
The concentration of Radon in mines varies tremendously according to the country rock, type of mineralization and area. Ventilation is also an impor- tant factor. The absence of ventilation in mines tends to allow a higher con- centration of Radon to build up. This is very dangerous for the miners work inside. In this present work, the radon gas concentration is practically meas- ured in closed uranium prospect mine located at Gabal (G.) Gattar. CR-39 solid state nuclear track detector technique is used. It is found that the radon concentration is around 80 kBq m −3 and an effective ventilation rates should
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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.
In this work measurement the radon gas concentrations in different dwellings in 50 locations for Baghdad go- vernorate. Table 1 presents the radon gas concentrations in indoor dwellings in 50 locations for Baghdad go- vernorate. From Table 1 it can be noticed that, the highest average radon gas concentration in air in dwellings was found in Shaab city which was (190.00 ± 2.7 Bq/m 3 ), while the lowest average radon gas concentration was found in AL-Karada city which was (40.67 ± 3.1 Bq/m 3 ), see Figure 3, with an average value of (113.66 ± 30.2 Bq/m 3 ) and see Figure 4 shows that the in the first one the map radiations for indoor radon gas concentrations by using the RAD-7 detector in Baghdad governorate, all radon gas concentrations in Baghdad governorate was less than the lower limit of the recommended ranged (200 - 300 Bq/m 3 ) (International Committee on Radiation Protection ICRP, 2009) . Finally, we would like to mention that the present study is considered to be very important and vital because it is concerned with people health and safety in the first place, and to the best of our knowledge.
Now to Build a Radon Daughter Collection Device: The ionization chamber is the simplest of all gas- filled radiation detectors, and is widely used for the detection and measurement of certain types of ionizing radiation. Using the can opener, remove both ends of an ordinary soup can, affix the can to the intake of a squirrel cage fan using epoxy. Apply a bead of epoxy to the lip of the can, making sure to leave no gaps, and place the can on the fan's intake. After the epoxy has had plenty of time to cure, cut the connector off the end of the fan's cable with heavy-duty scissors and remove some insulation from the red and black wire with the wire strippers. Cut off the end of the 12-V power supply cable and strip off some of the outer insulation. For the supply positive wire from the supply is connected to the red wire of the fan. The negative wire from the supply goes to the black wire of the fan. The other wires may be cut short. Connect the wires by twisting them together and then soldering. Cover the bare wire with electrical tape or heat-shrink tubing. Add some feet to the bottom of the fan, so that it can stand vertically. Secure a piece of the dusting cloth to the open end of the can with a heavy rubber band. Plug in the fan and verify that it pulls air through the filter. Now the testing of the instrumentation can be done by the following steps: Set up the fan in an area that is likely to have elevated radon, such as a basement. Turn on the fan with the filter facing up and let it run for 2 to 3 hours. Connect the ionization chamber to a digital multimeter and turn on the DC voltage meter. Make an initial meter reading and record it in a lab notebook. Unplug the fan and tip the collector over to the horizontal position. Move the end with the collection cloth as close to the end of the ionization chamber as possible without pressing on the foil with significant force. We find the meter reading increases for several seconds and settle out at a significantly higher reading, indicating that radioactive material has been collected on the collection material. Run the fan in a different room or in other locations for a specific time, perhaps for more hours, and measure the resulting radiation. Different locations are likely to exhibit different levels of radiation due to different levels of radon gas.
Modeling of the two assumption related to the behavior of radon gas on the soil matrix was carried out where there is a homogeneous distribution of the radon decay products on the soil matrix based on the emanation process of radon from radium atoms (referred as volume source), and the other is a non-uniform distribution of radon’s progeny on the soil matrix based on the exhalation of radon gas from the soil matrix to the sample volume’s atmosphere and re-deposition of the radon progeny on the surface of the soil (refereed as surface source). The results of the two assumptions showed that there are big differences in the absolute efficiency of the detector. The study highlighted that during the determination of 226 Ra through the short lived daughters of 222 Rn gas by gamma spectrometry; it is
The half-life of 222 Rn 3.8 days is long enough for part of it to diffuse from the indoor radon sources to the in- side of the room. Therefore 222 Rn is the most dominant hazardous radionuclide among the radon isotopes. Both radon and its progeny attached to aerosols are present in the ambient air. 222 Rn gas can enter the house from the soil. When it penetrates into closed rooms and become concentrated, it sometimes reaches harmful levels for public health .
environment . Plastic track detectors were used to measure the radon concentration and exhalation rate from soil samples . In the present paper radon exhalation rate from soil samples collected from nearby Panki Thermal Power Plant have been carried out “Sealed Can Technique” using LR-115 type II solid state nuclear track detector.
planning aids for administration purposes to estimate the necessary further efforts and preventive measures. The exposure of man to this alpha-particle-emitting gas is mainly to lung by inhalation. The indoor radon, thoron and their decay products from geogenic and/or anthropogenic origin are the main contributors of the total inhalation dose which has long been recognized as a potential radiological health hazard ,. The potential effects of radon on human health lie in its decay products rather than the gas itself. The risk of radon exposure is associated with high levels of radon concentration in confined environments and the subsequent inhalation, increasing the risk of damaging the organ cells where radon short-life products are deposited. In houses, building characteristics and lifestyle, i.e. often or forced ventilation, have a significant impact on radon entry and dilution by fresh atmospheric air. Generally, health effects of exposure to radon in indoor environments (indoor air) depend mainly on the concentration of inhaled radon, the ventilation rate of the place, frequency and duration of the exposure.
Radon je radioaktiven plin brez okusa in vonja. Nastane, ko se radij topi v nekaterih prsteh in kameninah, posebej v granitu, radioaktivno razpada. Izpostavljanje kombinaciji tobaènega dima in visoki stopnji radona pomeni resno ogroanje zdravja. Kadilec cigaret ima trikrat veèjo monost obolenja za pljuènim rakom od nekadilca, ki je izpostavljen visoki stopnji radona. Glede na izraèune je bilo v Hong Kongu leta 1986 od vseh smrti za pljuènim rakom 13% tistih, ki jih je povzroèil radon.
Considering the portability, of the actual device and fast and accurate measurement of radon exhalation rate, the radon collector needs to be as small as possible and the radon concentration equilibrium time should be as short as possible without affecting the accuracy of measurement. However, in practice, the DURRIDGE RAD7 Radon Delecter (Abbreviated as RAD7) radon detector will extract the gas (0.7L) from the radon collector in the measurement, which means that the volume of the radon collector must be larger than that of the gas pumped by the radon detector. In practice, over-high radon collector will lead to uneven gas in the radon collector, so the height should be less than the diameter of the bottom. The final parameters range can be obtained by optimization calculation:
exposure measurements, however, the results from such studies may be uncertain. Many additional assumptions are needed when risks estimated in miner studies are extrapolated to residential exposure conditions (3,10).Taking these circumstances into account, there has been great interest in developing direct estimates of residential risk for the general population using case–control studies. The environmental conditions in mines and homes are quite different. For a precise evaluation of radon exposures, the contribution of Thoron should be considered if the radon level is low in homes. Its presence often results in misleading estimation of radon concentrations. Before conducting a case–control study on residential radon exposures, it is important to understand those characteristics in the study area (10).
have been carried out to determine the radium equivalent activity of soil samples in many countries (Singh et al., 2003; Al-Jundi et al., 2003; Mireles et al., 2003; Ibrahim et al., 1999; Sroor et al., 2001 and Ibrahiem et al., 1993). Radioactivity is a part of the natural environment (Malik, et al., 2011). Environment contains some naturally occurring radioactive materials (NORM) which are found in soils, rocks, vegetation, air, water and also in building materials (Mehra et al., 2009). Naturally occurring radioactive materials (NORM) generally contains radionuclides found in nature i.e. thorium, uranium, and their progeny. Existences of three primordial radio nuclides ( 40 K, 238 U and 232 Th) in building materials cause internal and external exposures to residents. External exposure is caused by gamma radiation emitted from 40 K and daughter products of 238 U and 232 Th (Nassiri et al., 2011). Gamma radiation has always been existed in environment since the big- bang occurred due to the long half-lives of the radionuclides from the 238 U and 232 Th series, and their decay products (Kumar et al., 2000). Historical antecedents of studies conducted on natural radioactivity have established that the presence of the uranium-thorium series and potassium-40 in various materials constitute potential exposure to the global population (Forlkerts, 1984). In the present paper radon exhalation rates have been measured in soil samples, collected about 50 m away from Kasimpur Thermal Power Plant to investigate the effect of fly ash spread out from the plant on the nearby soil. The analysis of radioactivity in soil samples has been measured by low level gamma ray spectrometer. In addition, absorbed radiation doses and radiation risk have also been estimated.
While of monitoring parametric wells a connection between changes of radon concentration, conductivity and water level has been found out (Figure 3). Temperature of water within the aquifer was stable during the moni- toring period. However, sometimes abnormal concentration is not connected with any parameters (Figure 3(b)). One of the reasons could be unstable volume of spontaneously bubbling gases. At the moment this important parameter cannot be controlled.
The investigated area is located on Mt. Etna, a complex volcano (more than 3300 m high and 40 km in diameter) with four summit craters (SC), more than 300 lateral vents and cones on its ﬂanks, and with several fault systems. Since the actual volcanic activity prevalently concerns the eastern ﬂank and since our previous data [9, 17–21], continuously collected from 2001 to 2004 in the Etnean area, showed for the NE ﬂank a possible correlation between the radon trend and eruptive events, we carried out an investigation of in- soil radon levels in the eastern region (see ﬁg. 1), in particular near the villages of Vena (V) [NE, 825 m a.s.l.], Cugno di Mezzo (CM) [E, 1400 m a.s.l.], Santa Venerina (SV) [SE, 400 m a.s.l.].
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The above calculations rely on several assumptions. An essential requirement is a complete horizontal mixing of the lake on a time scale smaller than the half-life of 222 Rn, ad- mitting the assumption of horizontal homogeneity so that the central profile can be taken as representative for the entire lake. Peeters et al. (1996) reported horizontal eddy diffu- sivities in lakes in the range of 0.02 to 0.3 m 2 s −1 . Using these values and a typical horizontal dimension of 100 m (half width) for Lake Willersinnweiher, the mixing timescale lies between 5 and 70 h. This is comparable to the radon half- life of 92 h, hence the requirement of horizontal homogene- ity is at best approximately fulfilled. In fact, the horizontal sections revealed inhomogeneity especially in the epilimnion (see Fig. 5 and Table 3). The activity is decreasing from the suspected groundwater entry zone (south-west) to the north- eastern end of the main basin of the lake.
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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.
After performing the radon measurement in water or air measurement, the RAD7's internal sample cell will continue to contain the radon that was measured. If this radon is still present when a new measurement started, it will erroneously influence the next measurement. A common cause of error is incomplete purging of the system before a measurement. If residual radon exists in the RAD7 and tubing when the RAD H 2 Ovial is hooked up to it, that residual radon will be added to
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The SSNTD type of CR-39 made by Landauer Nordic, Sweden was used for the determination of radon concentrations indoors. The detector configuration is shown in Figure 2. A piece of detector (1.4 cm 2 ) is mounted into a cup (diffusion chamber) made of anti-static plastic. Each cup has a unique serial number. The cup containing detector is then closed but leaving a small hole/slit (to allow radon gas entering the cup). The detector set (cup + SSNTD) were installed by hanging from ceiling or wall inside houses where radon concentration is to be measured (e.g. living room, bedroom etc.) for a period of minimum 3 months. Most detectors were installed at ground floor level.