Soil radon in winter months under snowpack in Hokkaido, Japan

Soil radon (²²²Rn) has been monitored during winter months under cool-temperate deciduous stands of different surface geology in Tomakomai and in Sapporo, Hokkaido, Japan. Radon level was lower in Tomakomai of immature soil of porous volcanic ash emitted from an active volcano (Mt. Tarumae), compared with those in Sapporo of alluvial sediments. In Tomakomai, mean value of the ²²²Rn activity concentration was higher in winter (570 Bq m^?3) than in summer (350 Bq m^?3) at a depth of 1 m, which is consistent with the results in cold and dry winter reported in the literature. In contrast, soil radon decreasing with decreasing soil temperature from mid-September (5.0 kBq m^?3) remained low (2.6 kBq m^?3) under persistent snow in Sapporo, which had already been observed in the same location. Measurements of the activity concentrations of ²²²Rn in snow and in snow air as well as in soil air indicate that the small amount of ²²²Rn is released from the ground surface to the overlying snowpack with a ²²²Rn flux density of 0.4 mBq m^?2 s^?1 under thick snow cover in Sapporo.     

Short- and long-term gas hazard: the release of toxic gases in the Alban Hills volcanic area (central Italy)

In the Alban Hills area, strong areally diffuse and localised spot degassing processes occur (Tivoli, Cava dei Selci, Solforata, Tor Caldara). The gas comprises a large proportion of CO₂, with minor CH₄, H₂S and Rn. These advective features are generated by fluid leakage from buried reservoirs hosted in the structural highs of the Mesozoic carbonate basement. Gas migration towards the surface is controlled by fault and fracture systems bordering the structural highs of the carbonate formations (e.g. Ciampino high). His release is triggered when the total pressure of the fluid phase exceeds the hydrostatic pressure, thus forming a free gas phase. Furthermore, both the sudden and catastrophic, and slow and continuous gas release at surface, of naturally occurring toxic species (CO₂, H₂S and Rn) poses a serious health risk to people living in this geologically active area.This paper presents data obtained from soil gas and gas flux surveys, as well as gas isotopes analyses, which suggest the presence of a deep origin gas flux enriched in carbon dioxide and minor species (CH₄ and H₂S), as well as a channelled migration of geogas mixtures having a Rn component which is not produced in situ.In regards to the health risk to local inhabitants, it was found that some anomalous areas had been zoned as parkland while others had been heavily developed for residential purposes. For example, many new houses were found to have been built on ground which has soil gas CO₂ concentrations of over 70% and a CO₂ flux of about 0.7 kg m⁻² day⁻¹, as well as radon values of more than 250 kBq/m³. In addition, an indoor radon survey has been conducted in selected houses in the town of Cava dei Selci to search for a possible correlation between the local geology and the radon concentration in indoor air. Preliminary results indicate high indoor values at ground floor levels (up to 1000 Bq/m³) and very high values in the cellars (up to 250.000 Bq/m³). It is recommended that land-use planners incorporate soil gas and/or gas flux measurements in the environmental assessment of areas of possible risk (i.e. volcanic or structurally active areas).     

汶川M_s 8.0地震破裂带CO_2、CH_4、Rn和Hg脱气强度

地震活动断裂带能够向大气释放大量的温室气体、放射性气体和有毒气体(CO_2、CH_4、Rn和Hg),并对大气环境的影响产生复杂的影响。利用静态暗箱法,对汶川M_s8.0地震破裂带CO_2、Rn和Hg脱气强度进行实地测量,并计算了CO_2和Hg脱气对大气的年贡献量。结果表明:(1)破裂带土壤气中CO_2、CH_4、Rn和Hg异常浓度最大值分别可以达到7.98%、2.38%、524.30k Bq/m~3和161.00ng/m~3;破裂带CO_2、Rn和Hg脱气平均通量是34.95g·m~(-2)d~(-1)、36.11m Bq·m~(-2)s~(-1)和26.56ng·m~(-2)h~(-1),最大值分别达到259.23g·m~(-2)d~(-1)、580.35m Bq·m~(-2)s~(-1)和387.67ng·m~(-2)h~(-1);(2)汶川Ms8.0地震破裂带向大气脱气的CO_2年贡献量是0.95Mt,Hg的年贡献量是15.94kg。汶川Ms8.0地震破裂带破裂CO_2、CH_4、Rn和Hg等的脱气强度,不仅与破裂带渗透率有关,还与断裂带浅部存在的气藏、煤层以及磷矿层等气体源有重要的联系。     

Spatial distribution mapping and radiological hazard assessment of groundwater and soil gas radon in Ekiti State,Southwest Nigeria

Groundwater constitutes the major source of utility water in Ekiti State with the majority of the population depending on groundwater for drinking and other household uses. Soil in the area is commonly used as a component of building materials, which may produce radon in the indoor environment. Excessive concentrations of radon in water and soil can cause radiological health risks to human as witnessed by the increased cases of lung cancer among non-smokers in Nigeria, which may be traceable to the ingestion and inhalation ²²²Rn in drinking water and indoor air. In the present study, comparative in situ measurements of radon in groundwater and soil gas were carried out at one hundred selected locations across the Ekiti State in southwest Nigeria, using a RAD7 radon detector to generate a radon distribution map and to estimate radiation hazards due to radon. The concentrations of radon in groundwater ranged from 0.9 to 472 Bq L^?1 with a mean of 34.7?±?4.4 Bq L^?1, while those of soil gas ranged from 0.1 to 315 kBq L^?1 with a mean of 38.9?±?1.4 kBq L^?1. The total annual effective dose due to inhalation and ingestion of radon in groundwater amounted to 94.7 µSv year^?1, which is lower than the reference dose of 100 µSv year^?1 recommended by the World Health Organization (WHO). The radon map generated for groundwater and soil gas identified three distinct areas with radon levels ranging from low to high. The results of this study show that some locations (Emure, Gbonyin, Ijero and Ikole) show mean total annual effective doses which are higher than the recommended limit. It can then be inferred that the groundwater samples pose significant radiological hazards to the population and that the noticed increase in lung cancer cases may be attributed to the consumption of groundwater in the area.     

Using field analogue soil column experiments to quantify radon-222 gas migration and transport through soils and bedrock of Halifax,Nova Scotia,Canada

Radon gas is a human health hazard; long-term exposure to high radon concentrations through inhalation is the second leading cause of lung cancer. Nova Scotia has been previously identified as a potential high risk region because of the geology. As such, the gas transport through Halifax’s fine grained leucomonzogranite (FGL) unit of the South Mountain Batholith needed to be quantified to further remediation efforts. Using controlled laboratory experiments, four different soil columns were created using the Halifax Regional Municipality’s (HRM) highest producing field tills and bedrock. Permeability, diffusivity, radon-222 gas concentrations, and gas transit time/speed were measured in both dry tills (field moisture) and wet tills (simulated rain event moisture). Columns with HRM till displayed the highest radon concentrations, and were less permeable with additional moisture. Radon diffusivity calculated from CO₂ was 7.52 × 10^?8 m² (dry), and 3.37 × 10^?8 m² (wet); diffusivity calculated from ²²²Rn was 7.30 × 10^?7 m² (dry), and 6.47 × 10^?7 m² (wet). The average FGL transit time in a 60 cm column was 3.57 days (dry), and 3.82 days (wet). Locally this study presents two different methods for diffusivity calculations, for a unit lacking previous diffusivity information. The radon gas concentrations and transport speeds quantified the transport mechanisms within the till. Globally, the correlation between soil moisture, and radon/permeability values was established using these results. The link between diffusivity and permeability was also confirmed using field tills. Implications were made for building foundations, as well as the depth and type of material necessary to reduce radon gas from reaching the surface.     

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.     

Study of radon in soil gas,trace elements and climatic parameters around South Kordofan state,Sudan

This study was conducted primarily to measure and map radon activity concentration in soil gas and to understand the effect of geology and lithology and meteorology on radon concentration. Portable radon meter has been used for the measurement of soil gas radon at 30 different locations around Uro and Korn area in eastern Nuba Mountain South Kordofan State. The results indicate that the activity concentrations of ²²²Rn in soil gas fall within the range of 20–1,359 Bq/m³ with geometric mean of 102.80 Bq/cm³. The obtained data show that samples around Uro have anomaly of ²²²Rn concentrations than the sample around Korn. The reason could be attributed to differences in the geological structure, lithology and climate parameters. GIS predicative map has shown that the elevated levels of radon concentration were measured in North study area. Upon comparing the results with global data, it was found that the obtained values are far below the reported range of India, Slovenia, Portugal and Syria. However, the range of ²²²Rn concentrations in the soil observed in this study is significantly high relative to similar data reported from Libya. The regression analysis has shown that no correlation was noted between radon concentrations, climatic parameters and trace element.     

Study of soil gas radon variations in the tectonically active Dharamshala and Chamba regions,Himachal Pradesh,India

Soil gas radon measurements were made in Chamba and Dharamshala regions of Himachal Pradesh, India, to study the correlation, if any, between the soil gas radon, radium activity concentration of soil, and the geology/active tectonics of the study region. Soil gas radon surveys were conducted around the local fault zones to check their tectonic activities using the soil gas technique. Soil gas radon activity concentration at thirty-five different locations in Dharamshala region has been found to be varying from 13.2 ± 1.5 to 110.8 ± 5.0 kBq m^?3 with a geometrical mean of 35.9 kBq m^?3 and geometrical standard deviation of 1.8. Radon activity concentration observed in the thirty-seven soil gas samples collected from the Chamba region of Himachal Pradesh varies from 5.2 ± 1.0 to 35.6 ± 2.5 kBq m^?3, with geometrical mean of 15.8 kBq m^?3 and geometrical standard deviation of 1.6. Average radium activity concentrations in thirty-four soil samples collected from different geological formations of Dharamshala region and Chamba region are found to be 40.4 ± 17 and 38.6 ± 1.7 Bq kg^?1, respectively. It has been observed that soil gas radon activity concentration has a wide range of variation in both Dharamshala and Chamba regions, while radium activity concentrations in soil samples are more or less same in both the regions. Moreover, soil gas radon activity concentration has a better positive correlation with the radium activity concentration in soil samples collected from Chamba region as compared to Dharamshala region.     

Statistical approach for the geochemical signature of two active normal faults in the western Corinth Gulf Rift (Greece)

Soil–gas measurements of different gas species were performed in two distinct areas of the Corinth Gulf Rift (Greece): the Aigion-Neos Erineos-Lambiri (ANEL) fault zone and the Rion-Patras fault zone. Both zones lie in one of the most seismically active areas of the Euro-Mediterranean region, where a fast-opening continental rift is located. In particular, the geochemical investigations were focused on fault segments and fracture systems previously inferred by geomorphological, lithological and structural studies.In this work the applicability of soil–gas geochemistry surveys for the exploration of buried/hidden faults was tested by using various statistical methods. Moreover, a comprehensive geostatistical treatment of the collected data provided new insights into the control exerted by active structures on deep-seated gas migration towards the surface. In both investigated areas, the highest ²²²Rn and CO₂ concentration peaks correspond with zones where the interaction among fracture and fault segments was inferred by structural and morphological methods. This indicates a clear correlation between the shape and orientation of the anomalies and the different attitude and kinematic behavior of the faults recognized in the two areas. Furthermore, obtained results show that gases migrate preferentially through zones of brittle deformation by advective processes, as suggested by the relatively high rate of migration needed to obtain anomalies of short-lived ²²²Rn in the soil pores.     

Use of geochemical tracers for estimating groundwater influxes to the Big Sioux River,eastern South Dakota,USA

Understanding the spatial distribution and variability of geochemical tracers is crucial for estimating groundwater influxes into a river and can contribute to better future water management strategies. Because of the much higher radon (²²²Rn) activities in groundwater compared to river water, ²²²Rn was used as the main tracer to estimate groundwater influxes to river discharge over a 323-km distance of the Big Sioux River, eastern South Dakota, USA; these influx estimates were compared to the estimates using Cl^? concentrations. In the reaches overall, groundwater influxes using the ²²²Rn activity approach ranged between 0.3 and 6.4 m³/m/day (mean 1.8 m³/m/day) and the cumulative groundwater influx estimated during the study period was 3,982–146,594 m³/day (mean 40,568 m³/day), accounting for 0.2–41.9% (mean 12.5%) of the total river flow rate. The mean groundwater influx derived using the ²²²Rn activity approach was lower than that calculated based on Cl^? concentration (35.6 m³/m/day) for most of the reaches. Based on the Cl^? approach, groundwater accounted for 37.3% of the total river flow rate. The difference between the method estimates may be associated with minimal differences between groundwater and river Cl^? concentrations. These assessments will provide a better understanding of estimates used for the allocation of water resources to sustain agricultural productivity in the basin. However, a more detailed sampling program is necessary for accurate influx estimation, and also to understand the influence of seasonal variation on groundwater influxes into the basin.     

Geological and tectonic influence on water–soil–radon relationship in Mandi–Manali area,Himachal Himalaya

Radon measurements in soil and groundwater (springs, thermal springs and handpumps) were made in a variety of lithological units including major thrusts between Mandi and Manali in Himachal Himalaya. Analysis of radon data in light of lithological controls and influence of deep-seated thrusts has been made to elucidate the causative factors for anomalous emanation of radon. The lithological types include banded gneisses, schists, quartzite, granite, phyllites, volcanics and mylonites. The low-grade metasedimentries of Shali and Dharamsala generally show low and narrow range of radon concentration in water (5.6–13.4 Bq/l) as well as in soil (1.8–3.2 kBq/m³) except for the samples related to thrusts. On the other hand, sheared and deformed rocks of Chail and Jutogh show moderate radon content (average 5.03 kBq/m³, range 2.9–11.1 kBq/m³) in soil. However, the groundwater radon concentration shows wide variation in different types of sources (2.1–80.8 Bq/l). The quartzite and volcanic rocks of Rampur formation in this area present as a window separated by Chail thrust. Radon emanations on these rock types are relatively high (6.3–68.1 Bq/l in water and 5.5–15.9 kBq/m³ in soil) and are exceptionally high in samples that are related to uranium mineralization, deep-seated thrusts and hot springs (13.5–653.5 Bq/l). It is generally observed that anomalous high radon content is associated with mineralization, deeper source and tectonic discontinuities. Whereas it is obvious that subsurface radioactive mineralization would facilitate enhanced radon production, however, thrust plains provide easy pathways for escape of gases from the deeper sources. Shallow and deep sources of the groundwater have contrasting radon content particularly in the deformed and metamorphosed rocks of Jutogh and Chail. Shallow groundwater sources, mainly handpumps, have lower radon concentration due to limited superficial water circulation, whereas deeper sources, mainly perennial springs, show higher radon content because of larger opportunity for water–rock interaction.     

Radon variations in an active landslide zone along the Pindar River, in Chamoli District, Garhwal Lesser Himalaya, India

Radon measurements were made in the soil and spring/seepage water in and around an active landslide located along the Pindar river in the Chamoli District of Uttaranchal in Garhwal Lesser Himalaya, to understand the application of radon in geological disasters. The landslide is a compound slide i.e. a slump in the crown portion, and debris slide and fall in the lower part. The bedrock consists of gneisses and schists of the Saryu Formation of the Almora Group of Precambrian age. The presence of several small slump scars and debris slide/fall scars along the length of the slide indicates continuous downward movement. The radon concentrations in the present study are much lower in comparison to values reported from other regions. However, the present radon data show relative variation in the slide zone. The concentration of radon measured in landslide zones varies from 3.1 Bq/l to 18.4 Bq/l in spring water and from 2.3 kBq/m³ to 12.2 kBq/m³ in the soil gas of the debris. Along the section of the slide, the radon values in water and soil are slightly higher in the upper slopes i.e. toward the crown portion of the landslide as compared to the distal portion. The relatively low concentration of radon both in soil gas and water in the toe portion of the landslide may be due to the high porosity of the debris, which does not allow radon to accumulate in the soil and water, whereas, towards the crown portion, the high frequency of fractures increases the surface area due to particle size reduction, and the near absence of debris enhances the radon emanation in soil.     

Soil temperature and moisture controls on surface fluxes and profile concentrations of greenhouse gases in karst area in central part of Guizhou Province, southwest China

In order to better understand the spatiotemporal variations and interrelationships of greenhouse gases (GHG), monthly surface fluxes and profile concentrations of GHG (CO₂, N₂O and CH₄) in karst areas in the Guizhou Province, southwest China, were measured from June 2006 to May 2007. GHG fluxes showed high variability, with a range of 460.9?C1,281.2?mg?m^?2?h^?1 for CO₂, ?25.4 to 81.5???g?m^?2?h^?1 for N₂O and ?28.7 to ?274.9???g?m^?2?h^?1 for CH₄, but no obvious seasonal change trends of the fluxes existed. Profile concentrations of CO₂, N₂O and CH₄ varied between 0.5 and 31.5?mL?L^?1, 0.273 and 0.734, and 0.1 and 3.5???L?L^?1, respectively. In general, concentrations of CO₂ and N₂O increased with depth, while CH₄ had an inverse trend. However, in October, November and January, the reversal of depth patterns of GHG concentrations took place below 15?cm, close to the soil?Crock interface. The spatiotemporal distribution of CO₂ in soil profile was significantly positively correlated with that of N₂O (p?<?0.05?C0.01) and negatively correlated with that of CH₄ (p?<?0.01). The correlation analysis showed that soil temperature and moisture may be responsible for GHG dynamics in the soils, rather than the exchange of GHG between land and atmosphere.     

Soil-gas radon anomalies in three study areas of Central-Northern Calabria (Southern Italy)

Soil-gas radon concentrations and exhalation rates have generally been observed to be anomalously high along active faults in many parts of the world. The soil-gas method is based on the principle that faults and fractures in rocks are highly permeable pathways along which gases can migrate upward from deep crust and mantle to soil cover, retaining their source signatures. The present study summarizes the influence of fault zones on anomalous radon concentrations in soil by integrated geophysical and geo-structural analyses in three study areas of Central-Northern Calabria (Southern Italy). Soil-gas radon surveys have been carried out by means of an alpha scintillation counting system, at 12,509 locations between 2002 and 2004. A geostatistical approach has been used to estimate the spatial distribution of soil radon concentrations. Relations among soil-gas distribution and geo-structural features have been evaluated by ordinary multi-Gaussian kriging. Highest soil radon concentrations (ca. 90 kBq m^?3) have been measured in the Rossanese sector. In the three study areas, no appreciable differences can be noticed among lithotypes, with the highest concentration values (ca. 89 kBq m^?3) measured in alluvial deposit and in clay. Measurements of soil-gas radon reveal anomalies clearly connected to the tectonic structures. Increased signals are linearly distributed along regional WNW–ESE trending shear zones, with main pathways of concentration also recognizable along the E–W fault system in the Rossanese sector, the N–S fault system in the Crati Graben and the Catanzaro Trough, and the NE–SW fault system in the Catanzaro Trough. The distribution of epicentres of historical earthquakes occurred between 1184 and 2001 confirms the recent activity of the same fault systems. Soil-gas radon concentrations generally increase, as expected, with decreasing distance to the faults.     

Groundwater,Acid and Carbon Dioxide Dynamics Along a Coastal Wetland,Lake and Estuary Continuum

Coastal wetlands are hotspots for biodiversity and biological productivity, yet the hydrology and carbon cycling within these systems remains poorly understood due to their complex nature. By using a novel spatiotemporal approach, this study quantified groundwater discharge and the related inputs of acidity and CO₂ along a continuum of a modified coastal acid sulphate soil (CASS) wetland, a coastal lake and an estuary under highly contrasting hydrological conditions. To increase the resolution of spatiotemporal data and advance upon previous methodologies, we relied on automated observations from four simultaneous time-series stations to develop multiple radon mass balance models to estimate groundwater discharge and related groundwater inputs of acidity and dissolved inorganic carbon (DIC), along with surface water to atmosphere CO₂ fluxes. Spatial surveys indicated distinct acid hotspots with minimum surface water pH of 2.91 (dry conditions) and 2.67 (flood conditions) near a non-remediated (drained) CASS area. Under flood conditions, groundwater discharge accounted for ～14.5 % of surface water entering the lake. During the same period, acid discharge from the acid sulphate soil section of the continuum produced ～4.8 kg H₂SO₄?ha^?1 day^?1, a rate much higher than previous studies in similar systems. During baseflow conditions, the low pH water was rapidly buffered within the estuarine lake, with the pH increasing from 4.22 to 6.07 over a distance of ～250 m. The CO₂ evasion rates within the CASS were extremely high, averaging 2163?±?125 mmol m^?2 day^?1 in the dry period and 4061?±?259 mmol m^?2 day^?1 under flood conditions. Groundwater input of DIC could only account for 0.4 % of this evasion in the dry conditions and ～5 % during the flood conditions. We demonstrated that by utilising a spatiotemporal (multiple time-series stations) approach, the study was able to isolate distinct zones of differing hydrology and biogeochemistry, whilst providing more reasonable groundwater acid input estimates and air–water CO₂ flux estimates than some traditional sampling designs. This study highlights the notion that modified CASS wetlands can release large amounts of CO₂ to the atmosphere because of high groundwater acid inputs and extremely low surface water pH.     

Natural Gas Hazard (CO2, 222 Rn) within a Quiescent Volcanic Region and Its Relations with Tectonics: The Case of the Ciampino-Marino Area, Alban Hills Volcano, Italy

Groundwater surveys were performed by detailed(around 300 sites) grid-analysis of water temperature, pH, redox potential, electrical conductivity, ²²²Rn, alkalinity and by calculating the pCO₂, throughout the Ciampino and Marino towns in the Alban Hills quiescent volcano (Central Italy). Following several episodes of dangerous CO₂ exhalation from soils during the last 20 years and earlier ashistorically recorded, the work aimed at assessing the Natural Gas Hazard (NGH) including the indoor-Rn hazard. The NGH was defined as the probability of an area to become a site of poisonous peri-volcanic gas exhalations from soils to the lower atmosphere (comprising buildings). CO₂ was found to be a ``carrier' for the other poisonous minor and in trace components (H<sub>s</sub>S, CH<sub>4</sub>, <sup>222</sup>Rn, etc.). This assessment was performed by extrapolating in the aquifer CO<sub>2</sub> and <sup>222</sup>Rn conditions, and discriminating sectors where future CO<sub>2</sub> flux in soils as well as indoor-Rn measurements have to be noted. A preliminary indoor-Rn survey was performed at about 200 sites. The highest values were found in the highest pCO<sub>2</sub> and high <sup>222</sup>Rn values in groundwater. This indicates convection and enhanced permeability in certain sectors of the main aquifer, i.e., along the bordering faults and inside the gas-trap of the Ciampino Horst., where ``continuous gas-phase micro-macro seepage mechanism' is invoked to explain the high peri-volcanic gases flux.     

Radioactive elements in natural gas: a case study on distribution of gaseous 222radon and its origin mechanism

As natural gas becomes increasingly important in our daily life, studies have been carried out on trace elements such as mercury and arsenic within it. Other than those, the existence of radioactive gaseous radon from the combustion of natural gas indoors can cause severe diseases and damages to body organs, putting a hazardous impact on human health. At the same time, the radon can also corrode gas production and transportation equipment. A review of the literature on radon concentrations in natural gas produced from gas reservoirs in China and other countries have been studied. Radon is a decay product from ²³⁸U, which is closely related to the accumulation and migration of organic matter during diagenesis. Gas recovered from reservoirs with higher than average natural ²³⁸U contains higher than average levels of ²²²Rn. Massive fault systems and fracture zones appear to play a significant role in radon concentrations in natural gas.     

The cost of meeting increased cooling-water demands for CO2 capture and storage utilizing non-traditional waters from geologic saline formations

Deep (> ～800 m) saline water-bearing formations in the United States have substantial pore volume that is targeted for storage of carbon dioxide (CO₂) and the associated saline water can be extracted to increase CO₂ storage efficiency, manage pressure build up, and create a new water source that, once treated, can be used for power-plant cooling or other purposes. Extraction, treatment and disposal costs of saline formation water to meet added water demands from CO₂ capture and storage (CCS) are discussed. This underutilized water source may be important in meeting new water demand associated with CCS. For a representative natural gas combined-cycle (NGCC) power plant, simultaneous extraction of brine from the storage formation could provide enough water to meet all CCS-related cooling demands for 177 out of the 185 (96 %) saline formations analyzed in this study. Calculated total cost of water extraction, treatment and disposal is less than 4.00 US Dollars (USD) m^?3 for 93 % of the 185 formations considered. In 90 % of 185 formations, treated water costs are less than 10.00 USD tonne^?1 of CO₂ injected. On average, this represents approximately 6 % of the total CO₂ capture and injection costs for the NGCC scenario.     

Study of radium content and radon exhalation rates in soil samples of northern India

Radon is a radioactive hazardous and ubiquitous gas. It has been recognized to be one of the major contributors to natural radiation even causing lung cancer if present at enhanced levels. There are large variations in data available in the literature for radium content and radon exhalation rates of various materials. It is a well-documented fact that radon exhalation from the ground surface depends upon a number of parameters such as soil grain size, soil porosity and radium content. For this purpose, in this study the so-called can technique has been used to measure radium content and exhalation rates of radon in soil samples collected from different places of Aligarh, Etah and Mathura districts of Uttar Pradesh??a province in northern India. These districts lie within the subtropical region of the Indo-Gangetic plains. The values of effective radium content are found to vary from 8.11 to 112.83?Bq?kg^?1 with a mean value of 33.21?Bq?kg^?1 and a standard deviation of 28.15. The values of mass exhalation rates of radon vary from 0.76?×?10^?6 to 15.80?×?10^?6?Bq?kg^?1?day^?1 with a mean value of 4.21?×?10^?6?Bq?kg^?1?day^?1, while the surface exhalation rates vary from 1.97?×?10^?5 to 41.03?×?10^?5?Bq?m^?2?day^?1 with a mean value of 10.93?×?10^?5?Bq?m^?2?day^?1.     

广东中山地区土壤氡浓度填图研究

为了研究区域土壤氡填图的方法,利用RAD7电子测氡仪和RADON-JOK土壤气体渗透率仪在广东省中山市进行了面积为1 800 km2的测量工作,有效测点数为67个。中山市的平均土壤氡浓度为(100.41±154.64)kBq/m3;最大值和最小值分别为0.74 kBq/m3和1 199.24 kBq/m3。土壤气体渗透率测量结果表明,在风化花岗岩地区,高渗透率和中渗透率占优势;而第四纪沉积物地区大部分土壤气体渗透率较低。基于此,结合研究区土壤氡浓度和土壤气体渗透率,对研究区土壤氡风险进行了分级评价。为土壤氡风险分级的方法研究提供了有参考价值的研究实例。