Dose estimation of radioactivity in groundwater of Srinagar City, Northwest Himalaya, employing fluorimetric and scintillation techniques

Assessment of Threshold Dose of Thoron Inhalation and Its Biological Effects by Mimicking the Radiation Doses in Monazite Placer Deposits Corresponding to the Normal, Medium and Very High Natural Background Radiation Areas

The dose contributed from thoron (²²⁰Rn) and its progeny has been neglected in the dose assessment because of its short half-life (t_1/2 = 55.6 s) and generally low concentrations. Recently, concentrations of ²²⁰Rn gas and its progeny were found to be pronounced in the traditional residential dwellings in China, on beaches of India and in other countries. Accordingly, we investigated the biological effects of thoron (²²⁰Rn) decay products in various mouse organs, succeeding inhalation of thoron gas in BALB/c mouse. We investigated the biological effects upon thoron inhalation on mouse organs with a focus on oxidative stress. These mice were divided into (4 random groups): sham inhalation, thoron inhalation for 1, 4 and 10 days. Various tissues (lung, liver and kidney) were then collected after the time points and subjected to various biochemical analyses. Immediately after inhalation, mouse tissues were excised for gamma spectrometry and 72 h post inhalation for biochemical assays. The gamma spectrometry counts and its subsequent calculation of the equivalent dose showed varied distribution in the lung, liver and kidney. Our results suggest that acute thoron inhalation showed a differential effect on the antioxidant function and exerted pathophysiological alterations via oxidative stress in organs at a higher dose. These findings suggested that thoron inhalation could alter the redox state in organs; however, its characteristics were dependent on the total redox system of the organs as well as the thoron concentration and inhalation time.

A comprehensive study of radon in drinking waters of Hanumangarh district and the assessment of resulting dose to local population

Study of radon concentration in drinking water from different sources (groundwater and surface water) used across the Hanumangarh district of Rajasthan, India, was done using scintillation-based detector. The concentration of radon in surface water varied from 0.12 to 2.07 Bq/l with an average value of 0.62 Bq/l and a standard deviation of 0.55 Bq/l and in groundwater samples varied from 1.61 to 8.73 Bq/l with an average value of 4.8 Bq/l and a standard deviation of 2.24 Bq/l. The ingestion and inhalation dose were calculated to assess the health risk for infants, children and adults. The resulting average annual effective dose has been found to be considerably lower than the recommended safe limit of 0.1 msv/y (WHO, In: Incorporating first and second addenda, third ed. WHO Press, Geneva. 3rd ed. World Health Organisation, Geneva, Switzerland, 2008). It can be concluded that radon in water does not pose a significant radiological health risk to the population of the studied area.

Radiological risk assessment to the public due to the presence of radon in water of Barnala district, Punjab, India

Various research studies have shown that exposure to radon gas is a cause of concern for health effects to the public. The present work has been carried out for the radiological risk assessment to the public due to the presence of radon isotopes in drinking water of Barnala district of Punjab, India, for the first time using scintillation-based radiation detector. A total of 100 samples were collected from different sources of water (canal and underground water) from 25 villages on grid pattern of 6 × 6 km² in the study area for uniform mapping. In situ measurements were carried out to find out Rn-222 concentration in water samples. The measured values have been found to vary from 0.17 ± 0.01 to 9.84 ± 0.59 BqL^-1 with an average value of 3.37 ± 0.29 BqL^-1, which is well below the recommended limit of 100 BqL^-1(WHO 2004). The annual effective dose due to ingestion and inhalation of radon has also been calculated for various age groups like infants, children and adults to understand the age-wise dose distribution. The calculated values suggest that there is no significant health risk to the general public from radon in water.

Occurrence of 222Rn and 226,228Ra in underground water and 222Rn in soil and their mutual correlations for underground water supplies in southern Greater Poland

European Union Council Directive 2013/51/EURATOM recently sets out so-called indicator parameters for: radon, tritium and indicative dose of water intended for human consumption. The aim of this research was to elaborate an effective procedure for determination of radon and radium ^226,228Ra isotopes (which are potentially the main contributors to the internal dose from drinking and cooking water) and to find the possible relationships between these radionuclides in underground water reservoirs and ²²²Rn concentration in the soil gas in their vicinity. The research was performed by applying a non-volatile and water-immiscible scintillation cocktail based on a pure diisopropylnaphthalene (Ultima Gold F: UGF), which allow for efficient radon extraction from 0.5 dm³ of water samples to 20 cm³ of scintillation phase and its direct determination with a detection limit of 5 × 10^-3 Bq dm^-3. The further preliminary concentration of 3 dm³ of crude water samples by evaporation to 0.5 dm³ samples led to the removal of all unsupported ²²²Rn activity and allowed the ²²⁶Ra determination via equivalent ²²²Rn detection after one-month samples storage using a low-background Triathler liquid scintillation counter in the α/β separation counting mode. Together with determination of ²²⁶Ra isotope in water samples, the simultaneous measurements of ²²⁸Ra and ²²²Rn radionuclides concentrations in water as well as ²²²Rn activity in the soil gas around the water supply sites were performed. The achieved limit of ²²⁶Ra detection was at a very low level of 10^-3 Bq dm^-3. The measured values of ²²⁶Ra concentration in 50 public underground water supply units for the Kalisz district of Poland were relatively low and ranged from below detection limit to 28.5 × 10^-3 Bq dm^-3 with arithmetic mean and median values of 12.9 and 12.2 × 10^-3 Bq dm^-3, respectively. Weak correlations were observed between activity concentrations of ²²⁶Ra and ²²²Rn in the crude water samples (R² = 0.31) and ²²²Rn in water and its concentration in the nearby soil gas (R² = 0.48).