Radon and radium concentration in water from North-West of Romania and the estimated doses

Radiological investigation of natural carbonated spring waters from Eastern Carpathians, Romania

The current study presents a radiological water-quality assessment on 64 spring water samples from four Romanian counties. The study area is abundant in CO2-rich spring waters consumed by locals and tourists. Gross alpha activities ranged between 21 ± 2 and 7530 ± 658 mBq L−1, with 27% of the samples exceeding the WHO threshold. Gross beta values ranged from 40 ± 2 to 5520 ± 430 mBq L−1, with 29% exceeding the recommended values. Radionuclide activities fluctuated between 0.6 ± 0.08 and 81 ± 6 Bq L−1 for 222Rn, 15 ± 2 to 1154 ± 112 mBq L−1 for 226Ra, and from 18 ± 2 to 64 ± 5 mBq L−1 for 210Po. The annual effective doses attributed to radium varied between 0.002 and 0.23 mSv yr−1.

ASSESSMENT OF ANNUAL EFFECTIVE DOSE FROM EXPOSURE TO NATURAL RADIOACTIVITY SOURCES IN A CASE-CONTROL STUDY IN BIHOR COUNTY, ROMANIA

The purpose of the article is to evaluate the annual effective dose for 80 women divided into two samples; one sample located in the former uranium Băiţa-Ştei area, hereinafter referred to as case sample, respectively for a control sample, located in the same county, but exposed in most cases to indoor radon activity concentrations <300 Bq m-3. In this regard, the homemade 'RaThoGamma' kit was used, which contained two thermoluminescent dosimeters, a CR-39 track detector (RSKS) for indoor radon activity concentration, two CR-39 track detectors (Radtrak2®/ Radtrak2T®) for radon and thoron activity concentrations as well as Direct Radon Progeny Sensors/Direct Thoron Progeny Sensors for measuring time-averaged radon and thoron progenies concentrations. In addition, a total of 80 water samples were collected in order to evaluate the ingestion dose due to radon and radium activity concentrations in drinking water. The maximum total annual effective dose in the control sample was 14.1 mSv, while in the case sample the maximum annual effective dose was 60.5 mSv. This difference is mainly due to radon progenies inhalation. Other pathways did not show a statistically significant difference between the two samples, showing a minor contribution to the annual effective dose.

Radon concentration in self-bottled mineral spring waters as a possible public health issue

Since 2013, the Council Directive 2013/51/Euratom has been regulating the content of radioactive substances in water intended for human consumption. However, mineral waters are exempted from this regulation, including self-bottled springs waters, where higher radon concentration are expected. Therefore, a systematic survey has been conducted on all the 33 mineral spring waters of Lazio (a region of Central Italy) in order to assess if such waters, when self-bottled, may be of concern for public health. Waters have been sampled in two different ways to evaluate the impact of bottling on radon concentration. Water sampling was possible for 20 different spring waters, with 6 samples for each one. The results show that 2 (10%) of measured mineral spring waters returned radon concentrations higher than 100 Bq L^-1, i.e., the parametric value established by the Council Directive. These results, if confirmed by other surveys involving a higher number of mineral spring waters, would suggest regulating also these waters, especially in countries like Italy for which: (i) mineral water consumption is significant; (ii) mineral concession owners generally allow the consumers to fill bottles and containers, intended for transport and subsequent consumption, directly from public fountains or from fountains within the plant; (iii) the consumers' habit of drinking self-bottled mineral water is widespread.

A COMPREHENSIVE STUDY OF RESIDENTIAL, GEOGENIC AND WATER RADON IN THE NORTH AREA OF MUREŞ COUNTY, ROMANIA

This study presents results of a complex survey about residential, soil and water radon in the North of Mureş county (Romania). Indoor radon measurements were performed by using CR-39 track detectors, while radon concentrations in soil and in water were measured by using the LUK3C device and accessories. The indoor radon concentrations of 157 houses ranged from 9 to 414 Bq m-3, with an arithmetic mean of 131 Bq m-3 and a geometric mean of 105 Bq m-3. In ~3.2% of the investigated houses exceed the recommended reference level of 300 Bq m-3. The soil gas radon concentrations in 137 sampling points varied from 5.0 to 88.0 kBq m-3, with a geometric mean of 14.6 kBq m-3. Results of 190 water samples shows radon concentrations from 0.2 to 28.0 Bq L-1, with a geometric mean of 5.0 Bq L-1. Beside these results, indoor, soil and water radon maps were performed, divided into cells of 5 km × 5 km.

Residential, soil and water radon surveys in north-western part of Romania

The exposure to radon and radon decay products in homes and at workplaces represents the greatest risk from natural ionizing radiation. The present study brings forward the residential, soil and water radon surveys in 5 counties of Romania. Indoor radon measurements were performed by using CR-39 track detectors exposed for 3 months on ground-floor level of dwellings, according to the NRPB Measurements Protocol. Radon concentrations in soil and water were measured using the LUK3C device. The indoor radon concentrations ranged from 5 to 2592 Bq⋅m^-3 with an updated preliminary arithmetic mean of 133 Bq⋅m^-3, and a geometric mean of 90 Bq⋅m^-3. In about 6% of the investigated grid cells the indoor radon concentrations exceed the threshold of 300 Bq⋅m^-3. The soil gas radon concentration varies from 0.8 to 169 kBq⋅m^-3, with a geometric mean of 28.4 kBq⋅m^-3. For water samples, the results show radon concentrations within the range of 0.3-352 kBq⋅m^-3 with a geometric mean of 7.7 Bq⋅L^-1. The indoor radon map was plotted on a reference grid developed by JRC with the resolution 10 × 10 km².

Radon-222 and radium-226 occurrence in water: a review

A total of 2143 dissolved radon-222 and radium-226 activity concentrations measured together in water samples was compiled from the literature. To date, the use of such a large database is the first attempt to establish a relationship for the 226Ra–222Rn couple. Over the whole dataset, radon and radium concentrations range over more than nine and six orders of magnitude, respectively. Geometric means yield 9.82±0.73 Bq l−1 for radon and 54.6±2.7 mBq l−1 for radium. Only a few waters are in 226Ra–222Rn radioactive equilibrium, with most of them being far from equilibrium; the geometric mean of the radium concentration in water/radon concentration in water (CRa/CRn) ratio is estimated to be 0.0056±0.0004. Significant differences in radon and radium concentrations are observed between groundwaters and surface waters, on the one hand, and between hot springs and cold springs, on the other. Within water types, typical ranges of radon and radium concentrations can be associated with subgroups of waters. While the radium concentration characterizes the geochemistry of the groundwater–rock interaction, the radon concentration, in most cases, is a signal of non-mobile radium embedded in the encasing rocks. Thus, the 226Ra–222Rn couple can be a useful tool for the characterization of water and for the identification of water source rocks, shedding light on the various water–rock interaction processes taking place in the environment.