Determination of radon activity concentration in drinking water and evaluation of the annual effective dose in Hassan district, Karnataka state, India

Assessment of contamination level of radon (222Rn) in drinking water around Tulsishyam geothermal area and Savarkundla fault in Saurashtra, India

This study aimed to estimate radon concentrations in groundwater and surface water to evaluate radon (222Rn) contamination in drinking water within the Amreli region of Saurashtra, Gujarat, India. Water samples from 84 sites, covering about 3000 km2, were analyzed using the RAD7 device from Durridge Instruments. Samples were collected in 250 ml radon-tight bottles. Radon concentrations ranged from 0.1 to 13.6 Bq/L, averaging 4.52 Bq/L. At three sites (P9, P29, P35), radon levels exceeded the USEPA limit of 11.1 Bq/L. P9 and P29 are near the Tulsishyam geothermal area, while P35 is close to the Savarkundla fault. Geothermal fluids in Tulsishyam may facilitate radon migration, and swarm-type earthquakes near Savarkundla could also contribute to radon migration. Concurrently, physicochemical parameters like Potential of Hydrogen (pH) and Total Dissolved Solid (TDS) were measured, with no significant correlation found between radon levels and these parameters. Samples were taken from tube wells with depths ranging from 105 to 750 feet, averaging 359 feet. A strong and significant correlation (0.83) was observed between radon concentration and water depth. Health risks from radon exposure were assessed by estimating annual effective dose rates for different age groups through ingestion and inhalation. In some instances, the annual effective dose rate surpassed the WHO-recommended value of 100 µSv/year. However, in most instances, the presence of radon in the water does not indicate a significant radiological risk.

Study on seasonal variation of radon, thoron, and their progeny levels in indoor environments and their radiological effects on human health

Indoor radon (222Rn), thoron (220Rn) and their progeny concentrations have been measured in different types of buildings at different locations in different dwellings in different seasons in Hassan city, Karnataka, using time-integrated passive radon dosemeters containing LR-115 Type II solid-state nuclear track detectors. The annual effective dose due to radon and thoron has been estimated. The activity concentrations were observed to be highest in winter and lowest in summer, and the data also shows that bathrooms and kitchens have significantly higher radon-thoron concentrations and annual effective doses.

Analysis of radon concentrations in drinking water in coastal regions of Karnataka, South India

The measurements of radon activity in water samples from several parts of Karnataka were studied. Drinking water quality is a routine tool in health and environmental research. Radon exposure puts the entire public at risk for radiological damage through inhalation and ingestion. Radon concentrations were measured using the emanometry technique. Estimated 222Rn activity concentration in water has been found to vary from 2.05 to 28.02 Bq l-1 with an average value of 7.38 Bq l-1. For all samples under study, the total average annual effective doses are much less than the safe limit of 100 μSv y-1.

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.

Measurement of Radon Concentration in Water within Ojo Axis of Lagos State, Nigeria

Background: The problem of radon (Radon-222) in water is one of the daily health hazards faced by those in Ojo Axis, Nigeria. Therefore, continuous monitoring of radon contamination in different types of water is essential. In the present work, sixteen groundwater and surface-water samples (wells, boreholes, and sachets) were collected from six different locations within the Ojo Local Government area in Nigeria. The water samples collected were stored in 75 cl bottles that were already sterilized with distilled water to avoid contamination. Water samples were then taken to the laboratory for the analysis of radon levels using a RAD7, an active electronic device produced by the Durridge Company in the USA. The radon level in the water is higher than the safe limits of 11.1 Bq/L, as per EPA regulations, except for two sample points from the studied areas. The total annual effective doses from ingestion and inhalation for drinking and groundwater were higher than the safe limit of 0.1 mSv y−1 that is recommended by the World Health Organization and the European Union Commission. Conclusions: The obtained results underline the importance of the development and/or updating of databases regarding radon levels in drinking and groundwater in the Ojo Local Government area in Nigeria.

Radon concentration measurement and effective dose assessment in drinking groundwater for the adult population in the surrounding area of a thermal power plant

Radon in the household water collected from hand pumps is measured using a continuous radon monitor. Water samples are collected from 25 villages from the surrounding regions of the National Capital Power Cooperation (NTPC), Dadri. The radon concentration ranges from 17±1 to 68±3 Bql^-1 with a mean value of 33±13 Bql^-1. The measured radon concentration in all collected samples lies well within the limit of 100 Bql^-1as set by the World Health Organization (WHO). The mean values of the annual effective dose due to ingestion of radon and due to the inhalation of radon released from water are 84±33 and 167±65 μSvy^-1, respectively. In addition, the mean values of estimated total annual effective doses are found to be 167±65 μSvy^-1. The mean value of total annual effective doses is found to be higher than the reference dose level of 100 μSvy^-1 recommended by the WHO and the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The mean values of effective doses per annum to the lungs and stomach are 9.9±3.9 and 10.1±3.9 μSv, respectively.

Determination of radioactivity level of water supply network in Trabzon province, Turkey

In the present study, the radioactivity levels of water samples collected from the main water supply network in Trabzon province and districts and soil samples taken from the vicinity of the water network were measured. An Alphaguard-PQ2000 radon gas detector was used to determine the seasonal radon gas level in the water samples. An HPGe detector was used to determine the level of radioactivity in soil and water samples. The average concentration of ²²²Rn in drinking water ranges from 0.56 ± 0.51 to 13.3 ± 5 Bq L^-1. In water samples, average gross alpha and gross beta values were measured as 8 ± 1 and 43 ± 1 mBq L^-1, respectively. The average concentrations of ²³⁸U, ²³²Th, ¹³⁷Cs, ⁴⁰K radionuclides in soil were measured as 51 ± 2, 21 ± 2, 16 ± 1, 28 ± 7 Bq m^-3, respectively. The average concentrations of ²³⁸U, ²³²Th, ¹³⁷Cs, ⁴⁰K radionuclides in drinking water were measured as 147 ± 5, 25 ± 2, 77 ± 2, 12 ± 2 mBq L^-1, respectively. When the radon concentrations for drinking water were examined, it was found that the radon concentration of the three samples was above the limit value (11 Bq L^-1) allowed by the US-EPA for drinking water. All other results are below the limit values.

GROUNDWATER AND DRINKING WATER RADON CONCENTRATIONS IN THE COASTAL AND INTERIOR AREAS OF CHENNAI METRO CITY AND ITS IMPACT ON PUBLIC HEALTH

One hundred forty-eight water samples were collected from in and around Chennai and 222Rn concentrations were measured using radon emanometry method. The average 222Rn concentration was estimated to be 6.88, 2.01, 1.17, 0.19 and 0.10 Bq L-1 for borewell water, openwell water, tank water, metro water and lake water, respectively, which were within the U.S. Environmental Protection Agency's (USEPA) Standard limit of 11.1 Bq L-1 and World Health Organization (WHO) global average 10 Bq L-1. The total effective dose obtained has varied from 0 to 157.57 μSv y-1 with ±10% standard deviation. The mean values were 19.608, 8.092, 4.692, 0.761 and 0.423 μSv y-1 for closed borewell, open well water, tank water, metro water and for lake water, respectively. All these values were below the reference point 0.1 mSv y-1 (100 μSv y-1) set by WHO.

The assessment of the annual effective dose due to ingestion of radionuclides from drinking water consumption: calculation methods

In the present paper the different ways of assessing the annual effective dose due to ingestion of radionuclides by drinking water consumption were examined and exemplified. On a set of 10 samples the gross alpha activity, the gross beta activity, the concentration of 210Po, 210Pb, 238U, 232Th and, 226Ra were measured. The highest annual effective dose values assessed by relying on the investigated sample set were found by using the rationale according to which all the gross alpha and beta activity is due to the alpha and beta radionuclide, with the highest effective dose coefficient, namely 210Po and 210Pb/228Ra, respectively.

RADON IN GROUNDWATER OF MAGADI TALUK, RAMANAGARA DISTRICT IN KARNATAKA

Radon is a water-soluble radioactive noble gas produced from the alpha decay of 226Ra in uranium series. Its presence in drinking water and open air increases the risk of lung and intestinal cancers in human beings. In view of this, radon concentration in groundwater and its dose due to inhalation and ingestion to the population of Magadi taluk of Ramanagara district in Karnataka state, India was studied. The groundwater samples were analyzed for radon concentration using emanometry technique. The study showed that the radon concentration in this area varied from 27.4 ± 1.0 to 167.5 ± 3.9 Bq/L and the effective dose ranged from 104.2 ± 2.7 to 636.2 ± 11.0 μSv/a. The study also revealed that 95% of the 37 samples studied showed higher radon concentration compared to the UNSCEAR recommendation (40 Bq/L) and all the samples showed higher than the USEPA recommendation (11.1 Bq/L). Ten samples have concentration above the maximum permissible level prescribed by WHO (100 Bq/L). The groundwater samples are found to be slightly alkaline within the permissible limit of Indian Standards.

Effect of grain size on radon emanation coefficient, surface and mass exhalation rates and the correlation coefficient between them in different masses of soil and phosphate fertilizer

It is important to study the behavior of recoiling radon atoms 222Rn after decay of parent 226Ra and the effect of parameters on their access to the surrounding medium. The present study was carried out using CR-39 detector to study the effect of grain size on the correlation between surface and mass exhalation rates and the correlation between emanation coefficient and exhalation rate at different masses of soil and phosphate fertilizer. In addition, the relationship between emanation coefficient and the sample mass was studied for different grain sizes (0.1, 0.3, 0.5 and 1 mm). The results showed that there is no effect of grain sizes on the correlation coefficient between surface and mass exhalation rates in soil and fertilizer. The correlation coefficient between emanation coefficient and exhalation rate in different masses of soil was slightly influenced by the grain sizes. While the correlation coefficient between emanation coefficient and exhalation rate in different masses of phosphate fertilizer samples was not affected by the grain sizes (0.1, 0.3 and 0.5 mm). However, it was found that the emanation coefficient decreases exponentially with the mass for soil and phosphate fertilizer. This relationship was not significantly affected by grain size in soil except grain size 1 mm. While this relationship was affected by grain size >0.3 mm in phosphate fertilizer.