Radium and Radon in Earth Sciences

Các hoạt động khai thác quặng, dầu và khí tự nhiên, các mạch nước ngầm gây ra
phơi nhiễm phóng xạ tự nhiên trong môi trường. Điều này dẫn đến hàm lượng phóng xạ
tại các địa điểm diễn ra các hoạt động trên có khả năng vượt ngưỡng an toàn phóng xạ
cho phép. Trong số các đô ng vị phóng xạ, 226Ra được xem là một đô ng vị quan trọng do
có chu kỳ bán rã dài, khả năng ion hóa cao và có tính chất hóa học tương đô ng với nhiều
kim loại kiềm thổ khác trong đất. Các đô ng vị con cháu của 226Ra cũng có có khả năng
ion hóa cao, đặc biệt 226Ra còn sinh ra 222Rn, một đô ng vị phóng xạ dạng khí có khả năng
phân tán vào môi trường rất cao

Due to a recent upward trend in the price of uranium and subsequent increased interest in uranium mining, accurate modeling of baseline dose from environmental sources of radioactivity is of increasing interest. Residual radioactivity model and code (RESRAD) is a program used to model environmental movement and calculate the dose due to the inhalation, ingestion, and exposure to radioactive materials following a placement. This paper presents a novel use of RESRAD for the calculation of dose from non-enhanced, or ancient, naturally occurring radioactive material (NORM). In order to use RESRAD to calculate the total effective dose (TED) due to ancient NORM, a procedural adaptation was developed to negate the effects of time progressive distribution of radioactive materials. A dose due to United States' average concentrations of uranium, actinium, and thorium series radionuclides was then calculated. For adults exposed in a residential setting and assumed to eat significant amounts of food grown in NORM concentrated areas, the annual dose due to national average NORM concentrations was 0.935 mSv y ؊1 . A set of environmental dose factors were calculated for simple estimation of dose from uranium, thorium, and actinium series radionuclides for various age groups and exposure scenarios as a function of elemental uranium and thorium activity concentrations in groundwater and soil. The values of these factors for uranium were lowest for an adult exposed in an industrial setting: 0.00476 Sv kg Bq ؊1 y ؊1 for soil and 0.00596 Sv m 3 Bq ؊1 y ؊1 for water (assuming a 1:1 234 U: 238 U activity ratio in water). The uranium factors were highest for infants exposed in a residential setting and assumed to ingest food grown onsite: 34.8 Sv kg Bq ؊1 y ؊1 in soil and 13.0 Sv m 3 Bq ؊1 y ؊1 in water. Health Phys. 97(1):50 -67; 2009

In the present study, the roles of atmospheric wind profiles in the neutral atmosphere and surface roughness parameters in a complex terrain were examined to determine their impacts on radon (222Rn) dispersion from an actual uranium mine ventilation shaft. Simulations were completed on 222Rn dispersion extending from the shaft to a vulnerable distance, near the location of an occupied farmhouse. The eight dispersion scenarios for the ventilation shaft source included four downwind velocities (0.5, 1.0, 2.0 and 4.0 m s−1) and two underlying surface roughness characteristics (0.1 m and 1.0 m). 222Rn distributions and elevated pollution regions were identified. Effective dose estimation methods involving a historical weighting of wind speeds in the direction of interest coupled to the complex dispersion model were proposed. Using this approach, the radiation effects on the residents assumed to be outside at the location of the farm house 250 m downwind from the ventilation shaft outlet were computed. The maximum effective dose rate calculated for the residents at the outside of the farm house was 2.2 mSv y−1, which is less than the low limit action level of 3–10 mSv y−1 recommended by the International Commission on Radiological Protection (ICRP) occupational exposure action level for radon.

Abstract
In 1999, urged by a resident of Cisterna, we began a speleological investigation in the area between Cisterna di Latina and Cori. First, we explored the natutal Cave of San Biagio. Near the cave entrance, two old lime kilns, likely related to the exploitation of the nearby travertine    quarries, convinced us to undertake detailed researches of possible artificial underground structures. Our interest was excited by the almost total absence of findings in the area, in contrast with the many historical and literary references. The investigations allowed the identification of a good number of hypogea of anthropic origin.
Since April 2011, thanks to the agreement between the municipality of Cisterna and the Italian Commission for Artificial Cavities SSI, our Association, also for geographical proximity, has been studying the Grotte Caetani. The renewal of the investigations in the area was the starting point for other explorations, still in progress. Here we publish the results of the studies already completed, divided into: natural caves,large and small artificial caves.

The effect of a high level of ambient 222 Rn gas on thermoluminescence dosemeters (TLDs) is examined. Groups of LiF:Mg,Ti and CaF 2 :Dy TLDs were exposed to 222 Rn under controlled environmental conditions over ∼7 d using a luminous 226 Ra aircraft dial. LiF:Mg,Ti TLDs were tested bare, and both types were tested mounted in cards used for environmental dosimetry and mounted in cards enclosed in plastic badges. A passive continuous radon monitor was used to measure the 222 Rn level in the small chamber during the experiments. The data were analysed to determine the relationship between the integrated 222 Rn level and the TLD response. Although both LiF:Mg,Ti and CaF 2 :Dy TLDs showed a strong response to 222 Rn, the badges prevented measurable radon detection by the TLDs within. The TLDs were not used to directly measure the radon concentration; rather, a correction for its influence was desired.

Indoor radon-in-air (IR) concentrations in dwellings situated on a fault line passing underneath Muzaffarabad City were measured with a continuous radon monitor. Measurements were taken at half an hour intervals at 11 sites for 48 h. The values ranged from 14 ± 1 to 155 ± 4 Bq.m− 3 with an average value of 42 ± 2 Bq.m−3. The geometric mean (GM), standard deviation (STD) and geometric standard deviation (GSD) were 32 ± 2, 40.2 ± 0.8 and 1.5 Bq.m−3, respectively. Annual mean effective doses ranged between 0.35 ± 0.03 and 3.9 ± 0.1 mSv.y−1 with an overall mean value 1.05 ± 0.05 mSv.y−1. The experimental data were analysed by comparing algorithms to extract phase space dynamical information in the radon time series. Such approaches are potentially useful for deriving methods of extrapolation of short-term measurements to annualized average predictions and for earthquake detection. The computed values for Hurst exponent (H) from the rescaled range analysis and the Lyapunov exponent (L) provided estimates of the degree of chaotic regime. The Hurst exponent (0.877) for the radon time series indicates that the radon time series is a persistent time series. The value of Lyapunov exponent (0.0021) shows deterministic chaos in the data. The permutation entropy value was 0.6894 reflecting the irregularity in IR time series. The value of entropy obtained confirmed that the predictability of the IR time series is restricted to approximately one time step into the future. The mean value of IR concentrations corresponds to excess relative risks (ERR) of radon-induced lung cancer for 35- and 55-year-olds at all sites of 0.25 ± 0.01 and 0.205 ± 0.01, respectively. The observed 48-h average level (42 ± 2 Bq.m−3) was less than those recommended by the World Health Organization (WHO) (100 Bq.m−3), US Environmental Protection Agency (148 Bq.m−3) and Health Protection Agency, UK (200 Bq.m−3).

Cet article analyse quelques plis et faux plis radioactifs à travers des œuvres artistiques phares de l’ère atomique. On comprendra les applications positives et les accidents et agressions de l’ère atomique comme des « plis » et « faux plis ». L’article se concentre en particulier sur le nucléaire militaire et sur les œuvres d’art des victimes de « la » bombe et des centaines de bombes testées dans le Pacifique pendant la guerre froide. Cette analyse mènera, entre autres, en France et aux États‑Unis, du temps de la recherche des Curie, jusqu’au Japon, en Océanie et même en Afrique, de l’après‑guerre à nos jours. Mais à travers cette étude, c’est surtout l’entremêlement ontologique des arts et de la science qui sera mis en évidence, l’impossibilité de les démêler ou déplier entièrement.

Three statistical methods: Bayesian, randomized data binning and Maximum Entropy Method (MEM) are described and applied in the analysis of US radon data taken from the US registry. Two confounding factors—elevation of inhabited dwellings, and UVB (ultra-violet B) radiation exposure—were considered to be most correlated with the frequency of lung cancer occurrence. MEM was found to be particularly useful in extracting meaningful results from epidemiology data containing such confounding factors. In model testing, MEM proved to be more effective than the least-squares method (even via Bayesian analysis) or multi-parameter analysis, routinely applied in epidemiology. Our analysis of the available residential radon epidemiology data consistently demonstrates that the relative number of lung cancers decreases with increasing radon concentrations up to about 200 Bq/m ³ , also decreasing with increasing altitude at which inhabitants live. Correlation between UVB intensity and lung cancer has also been demonstrated.

This paper deals with a particular kind of radon-in-air Springs: the degassing from spring and related
channels in a rural and urban landscape. The two study areas are located, the first, at the Cilento Geopark
Geosite of Capodifiume spring group and, the second, in the Montoro alluvial plain (southern Italy). Based on
previous hydro-geological studies, field measurements campaigns have been carried out during the 2013
spring-autumn time on monitoring stations located along springs and downstream irrigation channels.
Laboratory analysis and environmental calculations have yet provided insight on space-time radon distribution
in spring and stream flow, confirming radon as effective tracer in hydro-geomorphological analysis. Beside
this, field experiments on radon-in-air concentration and diffusion by radon degassing from the surface flowing
water have been performed in order to define influenced areas by radon diffusion. Results give effective
insights in radon risk assessment for urban planning and radon mitigation actions.

) were made for a number of 168 measurements of soil samples in some towns of the Gezira State in the central part of the Sudan. In this survey, we used the can technique, containing CR-39, to estimate the radium concentration and radon on exhalation rates from the soils of: El-Hosh, El-Managil and Medani towns in the Gezira State-Central Sudan. The results of radium concentrations and mass and surface exhalation rates from soil samples were found to be 91 ± 7 Bq.kg -1 , 0.10 ±0.01 Bq.kg -2 .h -1 and 4.86 ± 0.66 Bq.m -2 .h -1 for El-Hosh soils, 182 ± 48 Bq.kg -1 , 0.20 ±0.09 Bq.kg -2 .h -1 and 9.77 ± 4.38 Bq.m -2 .h -1 for El-Managil soils and 249 ± 14 Bq.kg -1 , 0.27 ±0.03 Bq.kg -2 .h -1 and 13.35 ±1.30 Bq.m -2 .h -1 for Medani soils. All the values of radium content in soil samples of study towns were found to be quite lower than the permissible value of 370 Bq.kg -1 recommended by Organization for Economic Cooperation and Development and larger than the average global value of 30 Bq.kg -1 , the surface and mass exhalation rates were compared with other values in another countries.

Peatlands can play an important role in the hydrological dynamics of a watershed. However, interactions between groundwater and peat water remain poorly understood. Here, we present results of an exploratory study destined to test radon (222 Rn) as a potential tracer of groundwater inflows from flu-vioglacial landform aquifers to slope peatlands in the Amos region of Quebec, Canada. 222 Rn occurs in groundwater but is expected to be absent from peat water because of its rapid degassing to the atmosphere. Any 222 Rn activity detected in peat water should therefore derive from groundwater inflow. 222 Rn activity was measured in groundwater from municipal, domestic wells and newly drilled and instru-mented piezometers from the Saint-Mathieu-Berry and Barraute eskers (n ¼ 9), from the Harricana Moraine (n ¼ 4), and from the fractured bedrock (n ¼ 3). Forty measurements of 222 Rn activity were made from piezometers installed in five slope peatlands, along six transects oriented perpendicular to the fluvioglacial deposits. The relationship between 222 Rn and total dissolved solids (TDS) measured in water from the mineral deposits underlying the peat layer suggests that 222 Rn is introduced by lateral inflow from eskers and moraine together with salinity. This input is then diluted by peat water, depleted in both TDS and 222 Rn. The fact that a relationship between TDS and 222 Rn is visible calls for a continuous inflow of groundwater from lateral eskers/moraines, being 222 Rn rapidly removed from the system by radioactive decay. Although more research is required to improve the sampling and tracing techniques, this work shows the potential of 222 Rn tracer to identify groundwater inflow areas from granular aquifers found in eskers and moraines to slope peatlands.

the dynamics governing the movement of the radon are complex and dependent on many factors. In the present study, we characterise the nature of temporal variations of 2-hourly and daily radon measurements in several monitoring sites of the Italian Radon monitoring Network (IRoN) in Italy. By means of continuous wavelet transformation, a spectral analysis in time-frequency domain is performed. The results reveal that there are sub-daily, daily and yearly persistent periodicities that are common for all the stations. We observe structural seasonal breaks, that occur at the same frequency but at distinct time. Variations in radon concentration and local temperature are studied in terms of frequency contents and synchronicity. When analysing several long time series together, it is evident that the phase difference at low frequency movements (365-day period) between the radon and local temperature time series is depending on the sites' location and therefore strongly controlled by local factors. this could at least partially explain the apparently contrasting results available in the literature obtained investigating smaller dataset about the relationships between temperature and radon variations. on the other hand, results show that all radon time series are characterised by marked cycles at 1 and 365-days and less evident cycles at 0.5-day and 180-days. They would be all ascribable to environmental-climatic factors: the short-period cycles to temperature and pressure variations, the long-period cycles also to seasonal rainfall variations. Radon (222 Rn) is a radioactive gas with a half-life of 3.8 days. Radon originates in the natural decay of other radioactive elements in the Earth's crust; it is a noble gas and extremely stable, without relevant interaction with other elements. The transport of radon in soil or water is mainly performed by other gases or fluids (e.g. CO 2) acting as carriers. The monitoring of soil radon emission is today a topic of interest because of the risk that this element poses to human health but also for its relationship with several geological-environmental processes. The World Health Organization (WHO, http://www.who.int/en/) and the International Agency for Research on Cancer (IARC, http://www.iarc.fr/) have classified radon as a class 1 carcinogenic factor and it is considered by the scientific community the second cause of lung cancer after cigarette smoke. The relatioships between radon and the environmental processes concern the volcanic activity, tracing in atmospheric, marine and hydro-geological issues, it is studied as a tracer of tectonic activity and earthquake precursor 1-3. Indeed, the latter topic encounters a great interest worldwide since clues of tectonic-induced anomalies in radon signals have been suggested in several cases 2,4-8. Such anomalies likely arise from the preparatory crust fracturing processes leading to an earthquake: the release of stress within the crust eases the migration of radon from deeper sources. Earthquake-related anomalies cannot be easily and univocally discriminated from other anomalies of different origin, and therefore the use of radon as a precursor of seismic activity is debated and should be taken with great caution. The signals from radon sources are directly and indirectly influenced by several factors. Besides the transient geological-tectonic processes above mentioned, they are: flux of carrier gases, environmental and climatic variables, characteristics of the ground soil, tide, solar effect, etc 9-16. Therefore, radon time series, either in the short-and in the long-term, present a complex dynamic structure and the study of the occurrence of long-range correlations and of fractal scaling properties are of great interest 17. Some controlling factors, such as climate or tidal forces, reflect in a multiple-seasonality of the radon time series: hourly, diurnal, multi-day, and annual cycles have been detected in different worldwide studies and put in relationship with the above mentioned controlling factors 18-23. In all the papers dealing with radon time series the behaviours of the controlling factors is not univo-cal and therefore their influence has been suggested to be site-specific 24. Moreover, the effect of controlling factors acting at larger scale can be subordinated in term of amplitude and masked by primary factors (e.g. climate and

h i g h l i g h t s < Computational fluid dynamics can account for complex meteorology and geography. < Modeling of radon dispersion from uranium mine shafts. < Increasing surface roughness causes Rn accumulation for small wind speeds. < Increasing wind speeds increases radon dispersion. < Field measurements agree closely with the numerical investigations. a b s t r a c t Radon ( 222 Rn) found in uranium mine shaft ventilation exhaust gases could pose hazards to the surrounding environment and the public by virtue of its progeny. Radon migration under complex terrain is complicated by pollution source characteristics, geographical features of the dispersion region, meteorological conditions and precipitation. Fluid dynamics computations of 222 Rn dispersion are performed for uranium mine shaft exhausts for complex models of the actual physical terrain corresponding to a mine in the Jiangxi Province of China. The eight cases studied included a ventilation shaft source, four downwind velocities (0.5, 1.0, 2.0, 4.0 m s À1 ) and two underlying surface roughness characteristics (0.1 m, 1.0 m). 222 Rn distributions in the vicinity of uranium mine ventilation shaft are computed and compared with field measurements.

Radon chambers are typically able to maintain a constant, known concentration of radon by pumping a constant activity concentration of radon gas into the chamber. A radon chamber has been designed by placing a radon source inside the chamber volume and allowing radon to build up inside the chamber. Because the radon concentration is not constant, calculations have been made to determine the integrated equivalent constant radon concentration in MBqh Ϫ1 m Ϫ3 for up to 4 d. The chamber, made by placing a radium dial inside an incubator, has interior dimensions of 87.6 cm ϫ 55.9 cm ϫ 51.4 cm for a total volume of 0.25 m 3 . The chamber can produce an integrated equivalent constant radon activity concentration level of 0.013 MBq h Ϫ1 m Ϫ3 over the initial 24 h, 0.043 MBq h Ϫ1 m Ϫ3 over the initial 48 h, 0.078 MBq h Ϫ1 m Ϫ3 over the initial 72 h, and 0.118 MBq h Ϫ1 m Ϫ3 over the initial 96 h. The chamber can also demonstrate, for educational purposes, the kinetics of the build-up of a radioactive gas in an enclosed environment as well as the kinetics of washout and leakage. Health Phys. 89(Supplement 5):S78 -S84; 2005

Short-term measurements using activated-charcoal based devices remain a popular screening method for radon in indoor air. For this study, two charcoal-based radon detectors were compared for simultaneous measurements in as-deployed conditions. One radon detector, obtained and analyzed by a commercial vendor, consisted of nominally 12.8 g of activated charcoal in a cardboard packet. The second measurement system used metal canisters containing 76 g of activated charcoal with counting performed in the investigators' laboratory. Three hundred pairs of tests were distributed in southeast Michigan during the winter. For the comparison of simultaneous radon measurements, participants were instructed to place pairs of tests within 20 cm of each other and open and close the devices at the same time, with suggested deployment time of 5-6 d. Results showed that the radon concentration distributions were lognormal for both sets of data and that there was good correlation between cardboard packet and metal canister results in as-deployed conditions. Health Phys. 100(Supplement 1):S13-S20; 2011

Karst aquifers provide 25% of the overall drinking water resources to the world‟s population and
sustain aquatic life in most fluvial systems, providing several ecological services to human beings, although,
because of their complex links between surface and groundwater, turn out to be very vulnerable to
contamination and pollution. This paper describes the preliminary findings from Radon-222 activity
concentration measurement data collected in streamflow and instream springs during monthly field campaigns
in a typical Mediterranean karst river: the Bussento river (Campania region, Southern Italy). The general aim is
to investigate the complex interactions and exchanges between streamflow and groundwater, at scales that are
imperceptible to standard hydrological and hydraulic analyses. Experimental data about 222Rn activity
concentrations in streamflow and inflow spring waters, from selected sampling stations, have been acquired and
managed by means of the Radon-in-Air analyzer, RAD7, together with the Radon-in-water accessories,
Radon Water Probe and RADH2O (DURRIDGE Co. Inc.), for continuous and batch sampling measurements,
respectively. In addition, data about physical-chemical and streamflow rate have been, also, collected in-situ.
During preliminary surveys, appropriate sampling procedures and measurement protocols have been tested,
taking into account the different local hydrogeological and hydrological situations occurring along the Bussento
river basin

This paper deals with a particular kind of radon-in-air Springs: the degassing from spring and related channels in a rural and urban landscape. The two study areas are located, the first, at the Cilento Geopark Geosite of Capodifiume spring group and, the second, in the Montoro alluvial plain (southern Italy). Based on previous hydro-geological studies, field measurements campaigns have been carried out during the 2013 spring-autumn time on monitoring stations located along springs and downstream irrigation channels. Laboratory analysis and environmental calculations have yet provided insight on space-time radon distribution in spring and stream flow, confirming radon as effective tracer in hydro-geomorphological analysis. Beside this, field experiments on radon-in-air concentration and diffusion by radon degassing from the surface flowing water have been performed in order to define influenced areas by radon diffusion. Results give effective insights in radon risk assessment for ur...

A method for determining ages of Mid Ocean Ridge Basalts (MORB) erupted within the last 8000-10,000 years is presented and assessed. This technique employs radioactive disequilibrium between the U-series parent/daughter isotopes 230Th and 226Ra. Ba is used as a surrogate stable Ra isotope in order to constrain the amount of Ra-Th fractionation during generation of the basalts. Ages are determined by comparing the present day (226Ra/230Th) activity ratio to an inferred initial value. Measurements on a number of MORB from the East Pacific Rise (EPR) show that there is a strong correlation between Ba/Th and (226Ra/230Th) for the youngest basalts, giving confidence in this approach. The ages derived for dredged and submersible-collected basalts from the axial zone span a range from 0 to about 8000 years, and provide direct information about the time scale and possible episodicity of eruptions in this environment.

Measurements of radium concentration and radon exhalation rates (surface and mass exhalation rates) were made for a number of 120 soil samples from Singa and Rabak towns in Sudan. In this study we used the can technique, containing CR-39, to estimate the radium concentration and radon exhalation rates from the soils of the studied areas. The average radium concentrations from soil samples were found to be(82  8) Bq.kg-1 to (34  3) Bq.kg-1 for Singa and Rabak towns respectively. The radon concentration, surface and mass exhalation rates were found to be (19.9  2.0) kBq.m-3 , (17.6  1.8) Bq.m-2 .h-1 , (354  36) mBq.kg-1 .h-1 for Singa town, and (8.2  0.8) kBq.m-3 , (7.2  0.7) mBq.m-2 .h-1 , (145  15) mBq.kg-1 .h-1 for Rabak town. From this study we found that, there was a linear relationship between the indoor radon concentration and the radium concentration in the soil. All the values of radium content in soil samples of study areas were found to be lower than the permissible value of 370 Bqkg-1 recommended by Organization for Economic Cooperation and Development.

Peatlands can play an important role in the hydrological dynamics of a watershed. However, interactions between groundwater and peat water remain poorly understood. Here, we present results of an exploratory study destined to test radon (222Rn) as a potential tracer of groundwater inflows from fluvioglacial landform aquifers to slope peatlands in the Amos region of Quebec, Canada. 222Rn occurs in groundwater but is expected to be absent from peat water because of its rapid degassing to the atmosphere. Any 222Rn activity detected in peat water should therefore derive from groundwater inflow. 222Rn activity was measured in groundwater from municipal, domestic wells and newly drilled and instrumented piezometers from the Saint-Mathieu-Berry and Barraute eskers (n=9), from the Harricana Moraine (n=4), and from the fractured bedrock (n=3). Forty measurements of 222Rn activity were made from piezometers installed in five slope peatlands, along six transects Highlights  Radon measured in eskers and connected peatlands in Quebec  Radon is tested as novel tracer of groundwater inflow in peatlands  Shallower peat water is depleted in radon by degassing to atmosphere  Radon and TDS relation suggests inflow from esker and short residence time *Highlights (for review)

Karst aquifers provide 25% of the overall drinking water resources to the world"s population and sustain aquatic life in most fluvial systems, providing several ecological services to human beings, although, because of their complex links between surface and groundwater, turn out to be very vulnerable to contamination and pollution. This paper describes the preliminary findings from Radon-222 activity concentration measurement data collected in streamflow and instream springs during monthly field campaigns in a typical Mediterranean karst river: the Bussento river (Campania region, Southern Italy). The general aim is to investigate the complex interactions and exchanges between streamflow and groundwater, at scales that are imperceptible to standard hydrological and hydraulic analyses. Experimental data about 222Rn activity concentrations in streamflow and inflow spring waters, from selected sampling stations, have been acquired and managed by means of the Radon-in-Air analyzer, RAD7, together with the Radon-in-water accessories, Radon Water Probe and RADH2O (DURRIDGE Co. Inc.), for continuous and batch sampling measurements, respectively. In addition, data about physical-chemical and streamflow rate have been, also, collected in-situ. During preliminary surveys, appropriate sampling procedures and measurement protocols have been tested, taking into account the different local hydrogeological and hydrological situations occurring along the Bussento river basin.