Radon levels assessment in some Northern Romanian salt mines

Due to their low radioactivity background, underground salt mines spaces offer a unique possibility for speleotherapy use. The knowledge of radon concentration levels in such underground environments is essential for therapeutic purposes of different respiratory and rheumatic diseases. In order to develop speleotherapy in Romania, this paper presents the results of an indoor radon concentration levels survey in some salt mines in Romania. The survey was carried out using radon monitor Pylon AB-5 system methodology validated by a CIS-P5M system. In order to investigate whether differences in depth and microclimate parameters translate into significant differences in salt mine indoor radon concentrations, have been chosen three salts mine test sites placed in the Northern part of Romania (Turda, Cacica and Ocna Dej) in stable areas of the mining field at 32?C120?m depth. Environmental microclimate conditions (mean values of air temperature 10?C14.5?°C, air humidity 65?C80%, air velocity 0.2?m/s saline aerosols and low microbial factors) have anti-bacterial, anti-microbial, and anti-inflammatory properties and recognized therapeutically effects on human body??s health. Air temperature is one of the most important factors which need to be considered when carrying out a survey of indoor radon concentrations in salt mines because temperature largely determines close spaces ventilation rates, and ventilation habits are known to have significant effects on indoor radon concentrations. The analyzed environmental conditions and recorded low levels of indoor mean radon concentration (6.9?±?0.39 and 96.5?±?4.76?Bq/m³) demonstrated the best suitability of the investigated three salt mines in Romania for speleotherapeutic applications.     

Investigations on the presence and distribution of radon in the Cacica salt mine,Romania

An important parameter for evaluating the possibilities of use of enclosed spaces (mines, caves, spas, etc.) for therapeutic purposes is the concentration of radon in different conditions of ventilation. The aim of this paper is to present the results of continuous radon gas measurement that were performed for ten days, at 20 min time intervals in different locations from Cacica salt mine (Romania) using a portable radon monitor. The average radon concentration was found to be between 96.5 ± 4.76 Bq/m³ and 20.5 ± 1.30 Bq/m³. These values are suitable for therapeutic applications and are useful for future experiments regarding the development of the radon therapy and speleotherapy in this salt mine.     

Evaluation of the radon concentration in Ocna Dej salt mine,Romania

Measurement of radon is of interest both for the health risk assessment and development of radon therapy in enclosed spaces like as caves, mines and spas. In Romania, radon therapy is not in use, yet. The development of this treatment method in mines from our country involves primarily, the evaluation of radon levels in the salt mines. In this paper, the results of radon gas measurement that were performed at Ocna Dej salt mine (Romania) are presented. The radon measurements were performed using two systems: radon monitor Pylon AB-5 system and CIS-P5M system. The average radon concentration was found to be between 9.14 ± 5.10 Bq/m³ and 31.70 ± 2.76 Bq/m³. These radon levels are lower in comparison to those reported for mines, caves or spas in other countries where radon therapy and speleotherapy is frequently in use. Radon concentration and environmental conditions from Ocna Dej salt mine are suitable for therapeutic applications.     

Partitioning of natural radionuclides in sediments around a former uranium mine and mill

Partitioning of natural radionuclides in sediments from streams affected by the waste piles of the former uranium mine and mill located at ?irovski vrh, Slovenia, was performed by applying a sequential extraction procedure. The sediments were collected at three sites located upstream and three sites located downstream of the waste piles. Then the four-step Community Bureau of Reference (BCR) sequential extraction protocol was applied to the samples and the natural radionuclides ²³⁸U, ²³⁰Th, ²²⁶Ra, ²¹⁰Pb and ²¹⁰Po were analysed in each extraction fraction. It was expected that the fractionation of natural radionuclides originating from the waste piles would differ from that upstream of the influence of waste piles because their chemical environment had been altered during the processes of uranium extraction. This difference could allow tracing of the radionuclides coming from the waste piles downstream of the affected watercourses. The results definitely showed that the total activity concentrations at sites downstream of the influence of the waste piles were higher than at sites upstream of the piles. However, this difference was geographically very limited and could no longer be detected already at a distance of about 5 km downstream. Unexpectedly, the fractionation of radionuclides upstream and downstream of the area of influence of the waste piles did not appear to be significantly altered. The sole differences found were for ²³⁸U and ²²⁶Ra in the second fraction (the “Fe/Mn oxides” fraction) and for ²¹⁰Po in the fourth fraction (the “residue” fraction) of the BCR sequential extraction protocol.     

Concentration of natural radionuclides in various types of building materials in Slovakia

The building materials and products whose content of natural radionuclides are contributors to the radiation exposure of the population. In this study several types of building materials used for construction of living buildings in Slovakia were examined. The concentrations of natural radionuclides (²²⁶Ra,²³²Th and⁴⁰K) were determined by -ray spectrometry with an HPGe detector. In the second part of the work, sixty samples of building products (panel), used for dwelling construction in several towns in Slovakia, were analysed. The concentration of natural radionuclides and the radium equivalent activity content in the inner-and outerside of the wall were estimated. The results were used for the calculation of the annual mean effective photon dose rates, by the model and calculation procedure of KRISIUK and KARPOV.     

Natural and artificial radioactivity in volcanic ash soils of Jeju Island,Republic of Korea,and assessment of the radiation hazards: importance of soil properties

Journal of Radioanalytical and Nuclear Chemistry - In this study, we investigated the activity concentrations of natural (226Ra, 232Th, 40K) and artificial (137Cs) radionuclides of soils in Jeju...     

Lognormal distribution of natural radionuclides in freshwater sediments and coal-ash repositories

The distribution of natural radionuclides,⁴⁰K,²²⁶Ra, and²³²Th, in freshwater sediments and in coal-fired power-plant ash repositories has been tested for lognormality. Thereafter, lognormality for natural radionuclide concentration frequency distribution was accepted with a high probability. The lognormal natural radionuclide distribution in sediments and coal-ash indicated single population groups. The anthropogenic modifications of the natural radionuclide concentrations in the environment are indicated. The adsorbed dose rates, in mGy y^–1, in air from gamma field of the natural radionuclides were calculated.     

Interaction of radionuclides with natural and manmade materials using XAFS technique

The X-ray absorption fine structure (XAFS) technology has exhibited a very unique application in the study of sorption mechanism, chemical species and microstructures of radionuclides at the natural solid-water interfaces. In this review, the interaction mechanism of radionuclides with clay minerals and nanomaterials under different environmental conditions are summarized from the XAFS spectroscopy analysis. The coordination number and the bond distances of radionuclides, the oxidation-reduction reactions, the influence of humic substances and microorganisms on the species and structures of radionuclides at molecule level are reviewed and compared. This review is helpful to understand the interactions of radionuclides with oxides, natural clay minerals and nanomaterials, which is also crucial to evaluate the physicochemical behaviors of radionuclides in the natural environment.     

Radiological assessment of natural radionuclides in soil from playgrounds in Southwestern Nigeria and evaluation of radiation dose

Journal of Radioanalytical and Nuclear Chemistry - The activity concentrations of natural radionuclides in soil from playground were determined by gamma spectrometry using NaI(Tl) detector. Annual...     

Assessment of natural radionuclide enrichment and radiation hazard from building materials in Kannur District,Kerala

Journal of Radioanalytical and Nuclear Chemistry - The activity concentrations of natural radionuclides from the 238U and 232Th series and singly occurring radionuclide 40K have been assessed in...     

Natural radioactivity in springs of Sverdlovsk region,Middle Urals,Russia

Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural radionuclides were determined in water from 31 springs of Sverdlovsk region, Middle Urals, Russia. Activity...     

Sedimentation process in Ariake Bay using NAA and gamma-spectrometry

In order to assess the effect of marine and terrestrial environmental change in the last decades on the sedimentation environment in Ariake Bay, we collected three sediment cores. The concentrations of natural and anthropogenic radionuclides, major elements, and rare-earth elements were measured using gamma-spectrometry and neutron activation analysis. Vertical distributions of both radionuclides and sedimentation rates, determined using Cs-137 and Pb-210_ex dating methods, varied significantly among the sites.     

Activation analysis and radiochemistry,comments to their interrelations

It is the aim of this paper, to demonstrate the manyfold interrelation between radiochemistry and activation analysis. One of the main problems of both fields is the behaviour of submicro concentrations of elements and of their compounds in solids, in solution and in the gas phase. The radiochemists were the first, who have accumulated much experience, investigating the properties of the natural radionuclides. HEVESY has, somewhat later, by his proposal of activation analysis, pointed out a special and powerful way for the determination of submicro amouts of substances. In the further development till to the present day, both fields have stimulated each other. Their exponents are specialists in understanding and handling submicro concentrations, i.e. in a section of science and technology, growing up to an outstanding importance.     

Incorporation of natural radionuclides and rare earth elements into a salt tolerant plant

A highly salt tolerant shrub, samphire (Halosarcia halocnemoides), found growing in the soild alkaline residues in an evaporation pond at a former uranium and monoazite treatment plant, has been analysed for natural radionuclides and rate earths. The data obtained have been copared with that for plants from the local natural environment. Vegetation-to-soil concentration ratios have been determined. The radionuclide concentration ratios for samples from the contaminated site are similar to those from the natural environment. Significant differences have been noted in the case of the rare earth elements with an apparent preferential incorporation of the light rare earth elements into the plant growing in the chemical residues.     

Application of tracer technique in remediation of Sr(II) from simulated low level radioactive waste

Journal of Radioanalytical and Nuclear Chemistry - Activity concentrations of natural (40K, 226Ra, 228Ra, 232Th, 238U) and artificial (134Cs, 137Cs) radionuclides were measured in powdered milk...     

Anthropogenic emissions of210Po,210Pb and226Ra in an estuarine environment

An extensive study on the distribution of natural radionuclides in an estuarine ecosystem located in Southwestern Spain is presented. This environment is highly affected by the wastes released by a phosphoric acid industry which uses phosphate rocks as raw material for fertilizer production. This rock has generally high concentrations of U and its daughters. The estuary is formed by two rivers, Odiel and Tinto, which have a common mouth into the Atlanic Ocean and a salt marsh (Odiel marsh) affected by the income of Odiel riverwaters. This river receives directly the liquid and part of the solid (gypsum) wastes released from the industries. Besides that, most of the phosphogypsum wastes are stored in uncovered piles at the right margin of the Tinto river. The study has concluded that the wastes from such industries are the cause of the enhanced concentrations found at the bed of both river channels as well as the enhancement found in surface soils in certain zones of the Odiel wet marshland. Indeed, the Northern marsh and the Mojarrera channel at the Odiel marsh seem to be the main sinks of the contaminant released by the phosphoric acid industry.     

Natural radionuclides in tidal saltmarsh soils in South Australia—An unusual distribution?

Sediments collected from tidal saltmarsh areas in South Australia have been analysed for natural radionuclides from the uranium and thorium decay series. The concentrations observed indicate a significant enhancement of some nuclides in comparison to inland soils, consistent with the recent incorporation of uranium, thorium and actinium into the sediments. The probable source of the nuclides is sea-water. It has been experimentally established that the organic residues from the decay of vegetable matter play a major role in this process.     

Analysis of Naturally Occurring Radioisotopes in Peat moss Greenhouse Soils and Agriculture Mud in Egypt

In this work, the activity concentrations (radioactivity) and distributions of natural radionuclides in peat moss samples were investigated. The measurements were performed using HP-Ge detector and XRD technique. The samples represent six types of soils. The concentrations of radionuclides of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K are ranged from 17.14 to 130.83, 13.19 to 26.09, 5.33 to 25.2 and 143.26 to 600.31 Bq · kg^–1 (dry weight), respectively, for the different samples. This work also highlights that no correlation has been observed between radionuclides present in the samples, which in turn reflects the random method behind the preparation of the samples. The obtained results from the XRD analysis were in good agreement with radiometry measurements. The safety of peat moss uses was limited for certain agricultural crops due to the presence of high percent of sulphur in some types of soil. The radon concentration calculated using the empirical formula is more accurate than those obtained from the manual measurements and significant values were expected to emanate from the samples under investigation.     

Microstructures and speciation of radionuclides in natural environment studied by advanced spectroscopy and theoretical calculation

The environmental behavior of radionuclides is mainly dependent on their speciation and microstructures at solid particles.The speciation and microstructures of radionuclides at molecular level can be achieved from advanced spectroscopy techniques and theoretical calculations.In this perspective,we give a brief introduction of the advanced X-ray absorption fine structure(XAFS) technique and theoretical calculation in the analysis of the speciation and microstructures of radionuclides in the natural environment,which is crucial to evaluate the physicochemical behavior of radionuclides in the environment.     

Assessment of radioactivity contribution and transfer characteristics of natural radionuclides in agroecosystem

Taking into account the importance of distribution and transfer of radionuclides in the soil–plant system, especially in agricultural fields, the aim of this research was assessment of radioactivity contribution and transfer characteristics of natural radionuclides in agroecosystem. The measurement of the natural radioactivity distribution was conducted in organic and sustainable farming management systems. Statistical evaluation of the physical and chemical properties of soils subjected to different farming systems, revealed the existence of differences in some parameters. Balanced distribution of natural radionuclides in soil-crop system was observed. Radionuclide ⁴⁰K was the most accessible to the investigated crops via uptake from the soil, then ²³²Th and ²²⁶Ra. The obtained results are useful for understanding the behavior of the radionuclides and provide an insight into the cumulative deposition of radioactivity in the agroecosystem.