Radon Content In Water Research Articles

CONCENTRATION OF RADON AND OTHER ELEMENTS IN GROUNDWATERS OF THE JOS AND BUKURU YOUNGER GRANITE AQUIFERS

The Jos – Bukuru crystalline rocks have high radioactivity, but not much is known about the concentration of radon in waters of its aquifers. In this work, the activity concentrations of Radon-222 (222 Rn) were investigated from twenty (20) water samples collected at different locations within the Jos – Bukuru area. The analysis of radon was done using Liquid Scintillation counter. A total of fifteen (15) out of the twenty water samples were analysed for anions and cations. The anions (SO4-2 and Cl-) were analysed using a multiparameter and HCO3- by titration. The cations (major ions, trace elements and rare earth elements were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Radon concentration in groundwater of the study area ranges from 1.62Bq/L to 24.55Bq/L with a mean value of 15.62Bq/L. only twenty five percent (25%) of the water sources had radon above the 10 Bq/L recommended by the WHO. These values were obtained within the Jos and Bukuru Boitite Younger Granite Aquifers. The variation in radon content in water are the results of: (1) the actual use of the wells in the area such as extraction of groundwater which increases the groundwater circulation thereby decreasing the radon content and (2) Bad well constructions with inflow of surface water and (3) bedrock geology. Radon behaved independently with regards to the major ions and some of the trace elements, but showed positive but not significant relationship with uranium and some of the rare earth elements indicating possible contribution of these elements to concentration of radon in the waters. The Annual Effective Doses due to ingestion of 222Rn in water for the three (3) categories of people varies from 0.038 mSv/y, 0.077 mSv/y and 0.271 mSv/y for adults, children and infants respectively. These are within the recommended limits of 0.1 mSv/y for adults and children but high for infants. The composition of the groundwaters in the area is dominated by natural water–rock interactions while other areas were highly impacted by anthropogenic sources. On the basis of TDS, all the samples are within the range of desirable to permissible for drinking.

Determination of Radon Content in Water Respecting to Directive of Council 2013/51/EURATOM

In accordance with the recommendations of the most recent Directive of Council EURATOM No. 2013/51, which concerns requirements for the protection of the health of the general public with regard to radioactive substances in water intended for human consumption, we are obligated to monitor the level of approximate dose of radioactive substances. The directive indicates two basic isotopes: tritium and radon, which ought to be monitored continuously. Essential are also para-metric values as well as frequency, methods of monitoring of radioactive substances and equipment requirements. Directive states that measurements of content of tritium and radon ought to be taken as well as calculations of approximate dose natural and artificial radionuclides content should be done, apart from tritium, potassium-40, radon and short-living products of radon disintegration. In case if one of radioactive concentrations is over 20% of computational value or concentration of tritium is over parametric value analysis of additional radionuclides is required. A detailed list of radionuclides is presented in appendix No. 3 in the Directive. Laboratory of Nuclear Control Systems and Methods in the Institute of Nuclear Chemistry and Technology (INCT) worked out a Miniature Liquid Scintillation Counter (LCS) [1] [2], within a project titled “New generation of intelligent radiometric devices with cordless transmission of information” (UDA-POIG.01.03.01-14-065/08) co-financed by European Union from the European Regional Development Fund (ERDF). This Miniature Liquid Scintillation Counter may be used as a basic equipment resulting in the above mentioned directive. This article presents results of conducted research based on LCS and comparison of this results with the measurements carried out by Accredited Laboratory for Cali-bration of Dosimetric and Radon Instruments in Central Laboratory for Radiological Protection in Warsaw (CLOR).

Radon Monitoring in Soil Gas and Ground Water for Earthquake Prediction Studies in North West Himalayas, India

Continuous monitoring of soil gas radon at Sarol and the daily monitoring of radon concentration in water at Banikhet is carried out in Chamba valley of North West Himalayas, India “a well known seismic zone” to study the correlation of radon anomalies in relation to seismic activities of the region. Radon monitoring in soil gas was carried out by using Barasol probe manufactured by Algade France and the radon content in water was recorded using RAD7 radon monitoring system of Durridge Company, USA. The effect of meteorological parameters viz. temperature and pressure on soil gas radon emission has been studied. Correlation coefficient has been calculated between radon in soil gas, soil temperature and soil pressure. The radon anomalies observed in the region have been correlated with the seismic events in the magnitude range 2.2 to 5.0 recorded by Wadia Institute of Himalayan Geology Dehradun in NW Himalayan. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined.

Earthquake precursory studies in Kangra valley of North West Himalayas, India, with special emphasis on radon emission

The continuous soil gas radon monitoring is carried out at Palampur and the daily monitoring of radon concentration in water is carried out at Dharamshala region of Kangra valley of North West Himalayas, India, a seismic zone V, to study the correlation of radon anomalies in relation to seismic activities. In this study, radon monitoring in soil was carried out by using barasol probe manufactured by Algade France, whereas the radon content in water was recorded using RAD 7 radon monitoring system of Durridge Company USA. The effect of meteorological parameters viz. temperature, pressure, wind velocity, rainfall, and humidity on radon emission has been studied. The seasonal average value and standard deviation of radon in soil and water is calculated to find the radon anomaly to minimize the effect of meteorological parameters on radon emission. The radon anomalies observed in the region have been correlated with the seismic events of M≥2 reported by Wadia Institute of Himalayas Geology Dehradoon and Indian Meteorological Department, New Delhi in NW Himalayas within 250 km distance from the monitoring stations.

Radon in groundwater of eastern Doon valley, Outer Himalaya

The radon content in water may serve as a useful tracer for several geohydrological processes. The hydrodynamic factor, presence of radium in host rocks, as well as the soil porosity and permeability control its concentration in groundwater. In order to understand the factors that control the occurrence of radon in groundwater of Doon valley in Outer Himalaya, a total of 34 groundwater samples were collected from handpumps and tubewells covering three hydrogeological units/areas in the eastern part of Doon valley. Radon variation in tubewells and handpumps varies from 25.4±1.8 to 92.5±3.4 Bq/ l with an average of 53.5±2.6 Bq/ l . A significant positive correlation between radon concentration and depth of the wells was observed in the Doiwala–Dudhli and Jolleygrant areas suggesting that radon concentration increases with drilling depth in areas consisting of sediments of younger Doon gravels, whereas samples of the Ganga catchment show negative correlation. The high radon levels at shallower depths in the Ganga catchment (consisting of fluvial terraces of Ganga basin) indicate uranium-rich sediments at shallower depth.

Natural radiation environment in China

The Ministry of Health, China conducted national survey of natural radiation level in 1980s. The following items are included in the nationwide survey. Cosmic radiation—outdoor average absorbed dose rate from cosmic radiation is 37.4 nGy/h. The highest average absorbed dose rate from cosmic radiation—116.2 nGy/h is found in Tibet. Terrestrial gamma radiation—outdoor average absorbed dose rate from terrestrial gamma radiation is 81.5 nGy/h in China. The highest average absorbed dose rate—188.0 nGy/h is found in Xunwu County, Jiangxi Province. Radionuclide content in soil—average contents of 238U, 226Ra, 232Th and 40K in Chinese soil are 38.5, 37.6, 54.6 and 584 Bq/kg, respectively. Yangjiang County of Guangdong Province has the highest average radionuclide contents in soil for 238U, 226Ra and 232Th. Radon level in air—average indoor radon level in China is 26.2 Bq/m 3. Average outdoor radon level is 13.5 Bq/m 3. Radon content in water—drinking water in some cities—9.04 kBq/m 3; surface water—1.26 kBq/m 3; well water—16.7 kBq/m 3; deep well water—34.9 kBq/m 3; hot spring water—278.9 kBq/m 3. There are some special areas in China, in which natural background radiation is obviously higher than in neighboring regions. Some epidemiological studies are going on in those areas. We hope to have more cooperation with other scientists in these areas.