Current status of gross alpha/beta activity analysis in water samples: a short overview of methods

Detection and measurement of radioactive substances in water and food: a narrative review

Contamination of food and water with radioactive substances is a serious health problem. There are several methods to detect and measure radioactive materials, some of which have been developed in recent years. This paper aims to discuss the methods of detecting and measuring radioactive substances in food and water. The principles and the advantages and disadvantages of each method have been discussed. The results showed that some of these methods, such as spectrometry γ-ray high-purity germanium, portable radon gas surveyor SILENA, RAD7, and inductively coupled plasma mass spectrometry, have a higher sensitivity for detection and measurement. The spectrometry γ-ray high-purity germanium method has attracted more attention than other methods because it can measure a wide range of radionuclides with high resolution.

Estimation of gross α-β and tritium activities in groundwater samples using LSC-TDCR technique in and around the geothermal region of Eastern India

The present study is an attempt to assess the radiogenic quality of groundwater on the basis of gross α, gross β and tritium (3H or H-3) activities in the Bakreswar-Tantloi geothermal region of Chotanagpur Plateau, West Bengal and Jharkhand, India. The aforesaid parameters in groundwater samples were measured using liquid scintillation counting triple to double coincidence ratio (LSC-TDCR) technique. Groundwater samples collected from Bakreswar-Tantloi geothermal region show gross α activities from below the minimum detectable activity (BMDA) to 0.5 ± 0.05 Bq/L, gross β activities from BMDA to 0.2 ± 0.01 Bq/L and H-3 activities from BMDA to 63.42 Bq/L. The average gross α, gross β and H-3 activities are also within the permissible limits prescribed by the World Health Organization (WHO). Though the annual effective doses in some samples were higher than the reference dose level of 0.1 mSv, the overall result suggests that the groundwater in the Bakreswar-Tantloi geothermal region is radiologically safe considering the radionuclides covered in this study.

Fast analysis of gross alpha with a new plastic scintillation resin

Radionuclides analysis is a complex task, with high time and economic costs. In decommissioning activities and environmental monitoring, it is very evident, in which, to obtain an appropriate information, it is necessary to perform as many analyses as possible. The number of these analyses can be reduced using screening gross alpha or gross beta parameters. However, the currently used methods cannot give an answer as fast as it would be desired and, moreover, more than 50% of the results reported in the interlaboratory exercises fall outside the acceptance range. This work presents the development of a new material and method to gross alpha activity determination using a plastic scintillation resin (PSresin) in drinking and river water samples. A specific procedure was developed involving a new PSresin (using bis-(3-trimethylsilyl-1-propyl)-methanediphosphonic acid as an extractant) that is selective for all actinides, radium and polonium. Quantitative retention and 100% detection efficiencies were obtained at pH 2 with nitric acid. PSA value of 135 was used for α/β discrimination. Eu was used to determine or estimate retention in sample analyses. The method developed can measure, in less than 5 h from the reception of the sample, the gross alpha parameter with quantification errors comparable or even lower to those obtained with conventional methods.

Rapid radionuclide specific screening procedures in drinking water: alternative options to replace inaccurate gross activity measurements

It was concluded from two European wide proficiency tests that the gross alpha/beta methods used for drinking water analysis have fundamental pitfalls regardless of the specific gross-counting methods. The majority of gross-counting methods suffer from serious trueness and repeatability issues. To replace inaccurate gross activity measurements an alternative rapid radionuclide specific screening procedure for water analysis is proposed. This procedure considers liquid scintillation counting, alpha-particle- and gamma-ray spectrometry. The proposed procedure is more robust and can achieve lower uncertainties than gross-counting methods. Furthermore, qualitative and quantitative analytical data can be obtained with turnaround times comparable to the gross-counting methods.

Application of grading evaluation method of water radioactivity level in Chongqing section of Yangtze River

The major rivers in a region are usually vital sources of drinking water for local populations, and the concentration of radionuclides in the water is intimately tied to people's health. The varying concentration limits set by the World Health Organization are appropriate as screening values for determining the pollution of water sources, but their capacities as regulatory or early warning limits are restricted. In daily management, the regulatory authority needs to manage water bodies by level based on the concentration of radionuclide to indicate the potential pollution risks. From 2017 to 2019, a statistical analysis and dosage evaluation were conducted on the water radioactivity level in the Chongqing section of the Yangtze River in this study. The Modified Nemerow Index method based on the dose conversion coefficients was applied for the grading evaluation of the water radioactivity level, allowing the grading effect discussed. The results showed that the concentration of radionuclides in the Chongqing section of the Yangtze River and its contribution to the annual effective dose of the human body were lower than the limits stated in the Guidelines for Drinking Water Quality (Fourth Edition). And the samples in the section were 52.94% in Grade Ⅰand 47.06% in Grade Ⅱ, meaning few potential radioactive pollution risks exist there. Compared with other methods. The Modified Nemerow Index method combines the Traditional Nemerow Index method with the dose conversion coefficient of nuclides making it more realistic for the early warning and control of radioactive pollution in water bodies, which is worth popularizing and implementing.

Gross alpha/beta activity concentrations in spa and mineral waters in North Vietnam

There is little available information on the radioactivity concentrations in the thermal and drinking water sources in North Vietnam. In the current study, the gross alpha and gross beta activity concentrations were determined in 8 water sources in the area. The average activities of gross alpha and beta in the 8 sources are 38.7 mBq L− 1 and 88.0 mBq L− 1. These activity concentrations are lower than WHO recommendations for drinking water. In this study, the gross alpha and gross beta show a weak correlation.

Radiogenic quality assessment of ground and riverine water samples collected from Indian Sundarbans

The present study attempts to generate the first baseline data on gross α and β activities in groundwater and riverine water samples collected from different regions of Indian Sundarbans, a part of the world's largest mangrove ecosystem. Until the present, no information is available related to radioactivity measurement in water samples from this vast area. Gross alpha-beta activities were measured by liquid scintillation counting-triple to double coincidence ratio (LSC-TDCR) technique. The minimum detectable activities in present experimental condition were found to be 21 mBq L^-1 and 55 mBq L^-1 for gross α and β respectively. Gross alpha activities in all groundwater and riverine samples were found to be below the detection limit (BDL), whereas gross beta activities in groundwater and riverine samples varied from BDL to 0.46 ± 0.24 Bq L^-1 and BDL to 0.90 ± 0.26 Bq L^-1 respectively, which are below WHO recommended value 1 Bq L^-1. Annual effective doses were below 0.1 mSv. U and Th concentrations in the water samples were determined by ultrasonic-nebulizer assisted Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) and found to be BDL. For assessing ³H activity, double-distilled water samples were measured by LSC-TDCR technique, which provided BDL result.

Screening Level of Gross Alpha and Beta Activities in Building Materials

The objective of the present study is the screening of the gross alpha and gross beta activity of some building materials commercialized in Saudi Arabia. The measurements were carried out using a gas flow proportional counter. The study has shown that the gross alpha activity ranged between 0.21 and 8.27 Bq/kg with an average activity of about 1.96 Bq/kg, whereas the gross beta activity ranged between 6.47 and 276.47 Bq/kg with an average activity of about 65.27 Bq/kg. The obtained values of gross alpha and beta activities are in the worldwide range and no significant activity was observed that accentuate the attention, which show that no radiation risks come from these building materials and, therefore, from their origin areas.

Rapid separation of Po-210 from Pb-210 based on the usage of a commercial Sr-Specific chromatographic resin

The efficient extraction of small quantities of ²¹⁰Po is necessary for preparing ²¹⁰Po standard reference materials. Herein, a commercially available strontrium-specific chromatographic resin (Sr spec resin) was used to rapidly and selectively extract ²¹⁰Po from a ²¹⁰Pb-²¹⁰Bi-²¹⁰Po mixture, and the distribution ratios of Pb, Bi, and ²¹⁰Po on Sr spec resin were probed using batch experiments. In contrast to ²¹⁰Pb and ²¹⁰Bi, ²¹⁰Po was retained on the Sr spec cartridge in 8 M HCl and was then effectively eluted by 0.1 M HNO₃. The contents of ²¹⁰Pb and ²¹⁰Bi in the thus obtained ²¹⁰Po solution were checked using a high purity germanium gamma-ray detector and the corresponding decay curve, respectively, and were found not to exceed 2%. Moreover, the ²¹⁰Pb and ²¹⁰Bi eluates could be used to regenerate ²¹⁰Po by the same method after a certain time period. Therefore, the extracted ²¹⁰Po solution was suitable for the preparation of the ²¹⁰Po standard area source and ²¹⁰Po standard reference materials.

Blending as the best compliance option for the management of radioactivity in drinking water supplied from the deep sandstone aquifer in Southern Jordan

This paper describes management options and interventions taken by the Government of Jordan to ensure that the quality of drinking water supplied to consumers via the Disi Water Conveyance Project (DWCP) meets Jordanian drinking water standards and WHO guidelines for drinking water quality in respect of their radiological composition. Results from an initial survey of radioactivity present in water abstracted from each of the 55 wells (which comprise the operational well field) indicated an average radiological dose of 0.8 milliSieverts per year (mSv/y) would be accrued by members of the population if consuming water directly from the well head. During full scale operation, the estimated accrued dose from the well field as a whole decreased to an average of 0.7 mSv/y which was still approximately 1.4 times the Jordanian reference radiological limit for drinking water (0.5 mSv/y). Following assessment of treatment options by relevant health and water authorities, blending prior to distribution into the consumer network was identified as the most practicable remedial option. Results from monthly sampling undertaken after inline blending support the adoption of this approach, and indicate a reduction in the committed effective dose to 0.4 mSv/y, which is compliant with Jordanian standards.

Results of a European interlaboratory comparison on gross alpha/beta activity determination in drinking water

An interlaboratory comparison was organised by JRC-IRMM among environmental radioactivity monitoring laboratories for the determination of gross alpha/beta activity concentration in drinking water. Independent standard methods were used for the reference value determination. The performance of participating laboratories was evaluated with respect to the reference values using relative deviations. Sample preparation and measurement methods used by the participating laboratories are detailed, in particular in the view of method-dependency of the results. Many of the participants’ results deviate by more than two orders of magnitude from the reference values regardless of the techniques used. This suggests that gross methods need revision.

Critical remarks on gross alpha/beta activity analysis in drinking waters: conclusions from a European interlaboratory comparison

The most common gross alpha/beta standard methods used for drinking water analysis are discussed, and sources of interferences are reviewed from a metrological point of view. Our study reveals serious drawbacks of gross methods on the basis of an interlaboratory comparison analyzing commercial mineral water samples with the participation of 71 laboratories. A proposal is made to obtain comparable measurement results using true standardized methods.

A comparative experimental study of gross alpha methods in natural waters

The aim of the present work was to compare the results obtained with gross alpha methods such as evaporation, co-precipitation and total evaporation by liquid scintillation counting and to check whether these results are representative of the real total alpha activity concentration on the sample. The study was carried out on eight natural waters with very different radioactive characteristics. For all the samples uranium ((238)U, (235)U, and (234)U), radium ((226)Ra and (224)Ra), (210)Po, and (232)Th isotopes were also assayed by using radiochemical separation and alpha spectrometry in order to determine the sum of the activities of these alpha emitters. Precision (expressed as relative standard deviation) was below 28% for evaporation and below 18% for co-precipitation. In the case of total by liquid scintillation counting it was below 10% for samples with Total Alpha activity above 0.1 Bq/L (this value is about three times the MDA). Furthermore, for most of the studied waters, the Total Alpha activity and the gross alpha activity determined by the three methods were comparable. The obtained bias by the evaporation, co-precipitation, and total evaporation by liquid scintillation counting methods was lower than 40%, 25% and 20%, respectively. The ANOVA test was applied to find out if there was significant variability among the methods. For the samples with the most common radiochemical characteristics there were no significant differences among the three studied methods. However differences were detected for samples with a high saline content or with a very low activity level.

Experimental analysis of the mass efficiency curve for gross alpha activity and morphological study of the residue obtained by the co-precipitation method

Gross alpha activity determination in drinking water is one of the radiological parameters that must be determined in order to decide whether further specific analyses of radionuclides in samples is required. This parameter can be determined by the co-precipitation method using a ZnS(Ag) scintillation detector or a proportional counter. The method consists of collecting all alpha emitters of interest using barium and iron as carriers as they provide more uniform and homogeneous residues than the evaporation method, especially for highly saline waters. In the course of our work, the efficiencies of the gas proportional and ZnS(Ag) detectors for alpha particle detection in water residues were studied in function of sample mass (precipitate) with residues ranging between 16.0 and 35.0mg. In addition, the structure and morphological composition of a residue collected by the co-precipitation method was studied with the aim of verifying whether the residue is a homogeneous mixture. The effect of alpha energy on the efficiency and stability of the calibration samples (mass and efficiency) was studied using (230)Th, natural uranium ((nat)U) and (241)Am radionuclides.

Natural radionuclides in major aquifer systems of the Paraná sedimentary basin, Brazil

This paper describes the natural radioactivity of groundwater occurring in sedimentary (Bauru and Guarani) and fractured rock (Serra Geral) aquifer systems in the Paraná sedimentary basin, South America that is extensively used for drinking purposes, among others. The measurements of gross alpha and gross beta radioactivity as well the activity concentration of the natural dissolved radionuclides ⁴⁰K, ²³⁸U, ²³⁴U, ²²⁶Ra, ²²²Rn, ²¹⁰Po and ²¹⁰Pb were held in 80 tubular wells drilled in 21 municipalities located at São Paulo State and its border with Mato Grosso do Sul State in Brazil. Most of the gross alpha radioactivity data were below 1 mBq/L, whereas values exceeding the gross beta radioactivity detection limit of 30 mBq/L were found. The radioelement solubility in the studied systems varied according to the sequence radon>radium>other radionuclides and the higher porosity of sandstones relatively to basalts and diabases could justify the enhanced presence of dissolved radon in the porous aquifer. The implications of the data obtained in terms of standards established for defining the drinking water quality have also been discussed. The population-weighted average activity concentration for these radionuclides was compared to the guideline value of 0.1 mSv/yr for the total effective dose and discussed in terms of the choice of the dose conversion factors.