Thermophysical properties of neat and radiolytically degraded acidic extractants present in room temperature ionic liquid

In the present work, radon concentrations were measured in surface and underground water samples in Faridabad District of Southern Haryana, India using an active radon monitor based on alpha scintillation technique and results have been inter-compared. The average radon concentration in the underground water samples was observed to be 4 times higher than in the surface water samples. The estimated annual effective dose varied from 5.7 to 58.5 μSvy^?1 with an average of 24.2 μSvy^?1 for underground water samples and 1.1 to 12.5 μSvy^?1 with an average of 6.7 μSvy^?1 for surface water samples. The estimated annual effective dose for both type of samples was found to be less than 0.1 mSvy^?1, which is the safe limit as suggested by World Health Organisation and EU Council.

     

Measurement of 222Rn and 226Ra in municipal supply tap water to evaluate their radiological impacts

ABSTRACT

Radon (²²²Rn) and its parent radionuclide Radium (²²⁶Ra) are classified as carcinogen. Human exposes to radon in water via inhalation and ingestion, although ingestion is the only way for radium to enter the human body. In this research, tap water collected from Bornova distinct was studied to determine the concentration of radon (²²²Rn) and radium (²²⁶Ra) for evaluating their radiological impact. For this reason, the annual effective doses for ingestion and inhalation were estimated. The measurements were performed using a collector chamber method. The mean concentrations of ²²²Rn and ²²⁶Ra were determined as 0.85 and 0.76 Bq/L, respectively. It can be stated that the ²²²Rn and ²²⁶Ra concentrations of tap waters here are lower than the international reference levels. Obtained concentration levels were applied to estimate annual effective dose due to the inhalation and ingestion. The dose values are also found to be lower than the recommended maximum values. On the other hand, it should be considered that consumption of these waters (2 L) and average radon and radium concentrations of water are the significant factors for estimating doses.     

Radon (222Rn) in underground drinking water supplies of the Southern Greater Poland Region

Activity concentration of the ²²²Rn radionuclide was determined in drinking water samples from the Sothern Greater Poland region by liquid scintillation technique. The measured values ranged from 0.42 to 10.52 Bq/dm³ with the geometric mean value of 1.92 Bq/dm³. The calculated average annual effective doses from ingestion with water and inhalation of this radionuclide escaping from water were 1.15 and 11.8 μSv, respectively. Therefore, it should be underlined that, generally, it’s not the ingestion of natural radionuclides with water but inhalation of the radon escaping from water which is a substantial part of the radiological hazard due to the presence of the natural radionuclides from the uranium and thorium series in the drinking water.     

Evaluation of radon concentration and heavy metals in drinking water and their health implications to the population of Quetta,Balochistan, Pakistan

ABSTRACT

The purpose of this study is to estimate the concentrations of radon and heavy metals in drinking water and assess their health implications to the population of Quetta, Pakistan. The concentration of radon and heavy metals was measured in drinking water collected from tube wells of different depths of the Quetta, Balochistan, Pakistan, using RAD7 detector and Atomic Absorption Spectrometer, respectively. The results show that the concentration of radon ranged from 3.56 ± 0.98 to 8.56 ± 1.32Bq/L with an average of 5.67 ± 1.34Bq/L. The average value of contribution of radon in water to indoor air was found 2.02 ± 0.47mBq/L. In addition to concentration of radon in drinking water, physiochemical parameters like pH and electrical conductivity (EC), and annual effective doses for different age groups were also estimated. Positive correlation of (R² = 0.8471) was observed between depth of well and concentration of radon, however no such relations were found among pH and EC with concentration of radon. Average values of annual effective doses due to intake of radon for age groups 0–1 years (infants), 2–16 years (Children) and ≥17 years (adults) were found (3.00 ± 0.71)×10^?2, (1.1 ± 0.26)×10^?2 and (1.45 ± 0.34)×10^?2 mSv/y, respectively. Average values of heavy metals concentrations were found 1.85 ± 0.64, 3.21 ± 0.75, 5.06 ± 1.19, and 2.47 ± 0.77 and 5.58 ± 1.23 µg/L for As, Cr, Ni, Cd and Pb, respectively. The values of radon concentration and heavy metals in drinking water were found below the USEPA permissible limits, Thus we conclude that, the investigated waters are safe.     

Radon concentration in drinking water sources of the Main Campus of the University of Peshawar and surrounding areas, Khyber Pakhtunkhwa, Pakistan

Radon and its progenies in indoor environment have been identified as the main sources of radiation dose to the people from natural radioactive sources. Presence of radon in drinking water causes radiation related health hazards both through inhalation and ingestion. In this study 36 drinking water samples from taps, boreholes and deep tube wells within the Main Campus of the University of Peshawar and adjoining area were analyzed with RAD7 electronic device for radon content determination. These water samples have a mean, maximum and minimum radon value of 8.8 ± 0.8, 18.2 ± 1.0, and 1.6 ± 0.3 Bq L⁻¹, respectively. Eleven drinking water samples analyzed have radon levels in excess of the EPA recommended maximum contaminant level (MCL) of 11.1 Bq L⁻¹. These include 89% from tube wells, 8% from tap water, and 50% from shallow boreholes. Radon levels of about 31% of the total samples used by the inhabitants of the study area are higher than the EPA advised level of 11.1 Bq L⁻¹. The annual effective dose from radon in water due to its ingestion and inhalation per individual has also been estimated. The mean radon concentration and mean annual effective dose due to radon in water of this study have been compared with the mean radon concentration and mean annual effective dose of earlier investigators due to radon in water from different localities of India and Pakistan. The mean annual effective doses of all the samples are lower than the reference level of 0.1 mSv a⁻¹ for drinking water of WHO and EU Council. It has been concluded that drinking water of the study area is generally safe as far as radon related health hazards are concerned with the exception of a few isolated cases. It has been found that radon levels within the region have a positive correlation with depth of the water sources.     

Radon concentration in well water from Namom district (Southern Thailand): a factor influencing cancer risk

The radon concentrations were determined in well water samples from Namom district, Southern Thailand, by using a RAD7 radon monitoring system. The measured values ranged from 0.1 to 483.0 Bq l^?1, while the average ±1σ across all measured samples was 32.0 ± 9.2 Bq l^?1. Regarding the health risks from radon in household drinking water, some settlements had radon concentration exceeding 100 Bq l^?1, an upper limit set by the European Union Directive EC2013/51/EURATOM. It is of concern that the results indicate health risks, especially to those consumers who directly use well water with high radon concentration.     

Radon concentration in drinking water in villages nearby Rafsanjan fault and evaluation the annual effective dose

Abnormal amount of radon in water results in increasing health risks. Concentrations of ²²²Rn in 56 samples of drinking water resources, in villages surrounding “Rafsanjan fault” were measured in the fall of 2013. Range radon concentration is 0 and 18.480 BqL^?1, respectively. The maximum annual effective dose for adults and children were 181.5 and 248.95 μSvY^?1, respectively, and the lowest was zero for both groups. Radon concentration is higher on the right side of the fault than the left side. In order to reduce the radon concentration, water ventilation is recommended before use.     

Calibration technique for a CR-39 detector for soil and water radon exhalation rate measurements

The calibration factor of 0.029 ± 0.0002 track cm^?2 per Bq d m^?3 for radon concentration measurements was determined using CR-39 and RAD7 detectors. The ²²²Rn concentration varied from 2,225 to 9,950 and 12 to 1,002 Bq m^?3 in soil and water, respectively. The highest radon exhalation and gamma dose rates were found in Acid and undifferentiated granitic rocks and Miscellaneous soils.     

Assessment of natural uranium and 226Ra concentration in ground water around the uranium mine at Narwapahar, Jharkhand, India and its radiological significance

A brief study on dissolved radionuclides in aquatic environment, especially in ground water, constitutes the key aspect for assessment and control of natural exposure. In the present study the distribution of natural uranium and ²²⁶Ra concentration were measured in ground water samples collected within a 10 km radius around the Narwapahar uranium mine in the Singhbhum thrust belt of Jharkhand, India in 2007–2008. The natural uranium content in the ground water samples in this region was found to vary from 0.1 to 3.75 μg L^?1 with an average of 0.87 ± 0.73 μg L^?1 and ²²⁶Ra concentration was found to vary from 5.2 to 38.1 mBq L^?1 with an average of 13.73 ± 7.34 mBq L^?1. The mean annual ingestion dose due to intake of natural uranium and ²²⁶Ra through drinking water pathway to male and female adults population was estimated to be 6.55 and 4.78 μSv y^?1, respectively, which constitutes merely a small fraction of the reference dose level of 100 μSv y^?1 as recommended by WHO.     

Investigation of radon and thoron concentrations in a landmark skyscraper in Tokyo

The temporal variation of the radon concentration, and the radon and thoron concentrations every 3 months for a year were measured using two types of devices in a landmark skyscraper, the Tokyo Metropolitan Government Daiichi Building. In the measurement of temporal variation of the radon concentration using a pulse type ionization chamber, the average radon concentration was 21 ± 13 Bq m^?3 (2–68 Bq m^?3). The measured indoor radon concentration had a strong relationship with the operation of the mechanical ventilation system and the activities of the office workers. The radon concentration also increased together with temperature. Other environmental parameters, such as air pressure and relative humidity, were not related to the radon concentration. In the long-term measurements using a passive radon and thoron discriminative monitor, no seasonal variation was observed. The annual average concentrations of radon and thoron were 16 ± 8 and 16 ± 7 Bq m^?3, respectively. There was also no relationship between the two concentrations. The annual average effective dose for office workers in this skyscraper was estimated to be 0.08 mSv y^?1 for 2000 working hours per year. When considering the indoor radon exposure received from their residential dwellings using the annual mean radon concentration indoors in Japan (15.5 Bq m^?3), the annual average effective dose was estimated to be 0.37 mSv y^?1. This value was 31 % of the worldwide average annual effective dose.     

238U, 234U and 226Ra concentrations in mineral waters and their contribution to the annual committed effective dose in Turkey

Activity concentrations of ²³⁴U, ²³⁸U and ²²⁶Ra in mineral waters were determined on the basis of nine water bottling facilities using alpha particle spectrometry. The mineral water samples were collected from three geographic regions of Turkey. The radiochemical separation used in the uranium analysis is based on the isolation of uranium radioisotopes from other radionuclides such as Th, Am, Pu and Np using UTEVA resin. Alpha sources were prepared using electrodeposition method. The activity concentration of ²²⁶Ra was determined after deposition on a membrane using BaSO₄ co-precipitation method. The activity concentrations (mBq L^?1) of ²²⁶Ra, ²³⁸U and ²³⁴U ranged from <0.56 to 165, from <0.42 to 439 and from <0.42 to 464, respectively. The measured activity concentrations were used for the calculation of the average total annual effective ingestion doses for children and adults. The committed effective doses were calculated for three different scenarios according to mineral water consumption rate. In the most extreme scenario (for age group 12–17), all water samples except MW1 and MW2 cause annual committed effective doses below the reference level (0.1 mSv year^?1) recommended by World Health Organization (WHO).     

Radon concentration in drinking water sources of the region adjacent to a tectonically active Karak Thrust,southern Kohat Plateau,Khyber Pakhtunkhwa,Pakistan

A total of 84 drinking water samples from tube wells, natural springs, hand pumps and open wells in the region adjacent to a tectonically active Karak Thrust, Pakistan, were analyzed for radon content determination. These samples have a mean, maximum and minimum radon values of 9.4 ± 0.4, 25.1 ± 0.9, and 1.1 ± 0.2 Bq l^?1, respectively. This study indicates that 24 % of samples from tube wells, 44 % from springs, and 50 % from hand pumps have radon levels in excess of the EPA recommended maximum contaminant level of 11.1 Bq l^?1. The mean annual effective doses of all the samples are lower than the reference level of 0.1 mSv a^?1. Drinking water from majority of the sources within the region is generally safe as far as radon related health hazards are concerned with exception of few isolated cases.     

Measurement of radon concentration in groundwater in the Ashanti region of Ghana

Radon in groundwater and their annual effective dose in the Ashanti region of Ghana have been determined using the continuous grab sampling technique and an AB-5 detector. Mean levels of radon were in the range of 0.51–46.16 Bq L^?1. Effective annual doses ranged from 0.18–16.16, 0.13–12.08 and 0.09–8.31 μSv y^?1 for infants, children and adults, respectively. These values are significantly lower than the reference level of 0.1 mSv y^?1 recommended by the WHO and United Nations Scientific Committee on the Effects of Atomic Radiation for members of the public.     

238U and 222Rn activity concentrations and total radioactivity levels in lake waters

The concentrations and distributions of natural radioactivity, uranium and radon in lake waters from around Van, Turkey were investigated with an aim of evaluating the environmental radioactivity. Fourteen lake waters were collected from different six lakes around Van (Turkey) to determine ²³⁸U, ²²²Rn and total alpha and total beta distributions in 2009. The total α and total β activities were counted by using α/β counter of the multi-detector low background system (PIC-MPC-9604) and the ²³⁸U concentrations were determined by inductively coupled plasma-mass spectrometry (Thermo Scientific Element 2) and radon concentrations were measured with the solid state nuclear track detector technique. The activity concentrations ranging from ND to 0.039 Bq L^?1 and from 0.026 to 3.728 Bq L^?1 for total alpha and beta, respectively, and uranium concentrations ranging from 0.083 to 3.078 μg L^?1, and radon concentrations varying between 47.80 and 354.86 Bq m^?3 were observed in the lake waters.     

Assessment of radioactivity associated with a low ore grade open cast mine at Banduhurang, Jharkhand, India and estimation of occupational exposure to the miners

The study summarizes radiological characteristics of Banduhurang open cast mine which includes qualitative and quantitative behavior of ²²²Rn concentration, external gamma radiation level over the mine pit as well as in its adjoining environment, long-lived alpha (LLα) activity concentration associated with the respirable size of ore dust and assessment of dose to the mine workers in 2006–2008. The investigations reveal that geometric means (χ_g) of measured radon concentration were 36.39, 38.69, 26.64 and 24 Bq m^?3 with respective geometric standard deviations (σ_g) were 1.52, 1.55, 1.36 and 1.68 Bq m^?3 and χ_g of gamma absorbed dose rates were 0.54, 0.64, 0. 45 and 0.15 μGy h^?1 with respective σ_g were 1.63, 1.53, 1.52 and 1.72 μGy h^?1 over the mine pit, ore yard, waste yard and in the surrounding environment within a 10 km radius to the mine, respectively. The χ_g of LLα activity was observed to be 16 mBq m^?3 with σ_g of 1.9 mBq m^?3. The annual mean effective dose equivalent received by the member radiation workers of Banduhurang mine was estimated to 1.41 mSv y^?1, which is about 7% of the prescribed dose limits of 20 mSv y^?1.     

Ultralight sulfonated graphene aerogel for efficient adsorption of uranium from aqueous solutions

The radon activity concentration was measured in 67 rooms in kindergartens in Visegrad countries over a period of 1 year using the SSNTD method within the framework of the standard V4 project. In 7.5% of rooms radon activity concentration exceeded 300 Bq m^?3, the reference value recommended by the Council Directive 2013/59/EURATOM. The annual effective doses due to radon inhalation ranged from 0.5 to 13.3 mSv for children and from 0.3 to 8.3 mSv for staff.

     

Tritium in water bodies around the Kaiga generating station

Tritium concentration was monitored in different water sources collected around Kaiga Nuclear Power plant, India. The concentration was in the ranges?<?1.9–27.4 Bq L^?1 (GM?=?4.0 Bq L^?1) for groundwater,?<?1.9–42.1 Bq L^?1 (GM?=?3.5 Bq L^?1) for surface water and in 12.4–42.0 Bq L^?1 (GM?=?24.07 Bq L^?1) for reservoir water. The concentration values observed in this study are similar to those reported for other PHWR stations of the world. The radiation dose to the public due to ingestion of Tritium through groundwater was computed to be 0.08 μSvy^?1.

     

Radiation dose due to radon,thoron and their decay products in indoor environment of Khurja City,U.P., India

Inhalation of radon, thoron and their decay products can cause a significant health hazard when present in enhanced levels in the indoor environment like a human dwelling. In the present work a set of indoor radon and thoron measurements was carried out using time-integrated passive twin cup dosimeters containing LR-115 Type II solid state nuclear track detectors in different houses of Khurja City in Bulandshahar district of U.P. in India, built of the same type of building materials. The radon gas concentration was found to vary from 9.18 to 23.19 Bq m^?3 with an average value of 16.02 Bq m^?3 (SD = 3.68) and the thoron gas concentration varied from 2.78 to 9.03 Bq m^?3 with an average value of 5.36 Bq m^?3 (SD = 1.58). The radon progeny concentration ranged from 0.99 to 2.51 mWL with an average value of 1.77 mWL (SD = 0.40) and the concentration of thoron progeny was found to vary from 0.30 to 0.98 mWL with an average value of 0.58 mWL (SD = 0.17). The annual effective dose varied from 0.27 to 0.67 mSv year^?1 with an average value of 0.47 mSv year^?1(SD = 0.10).     

Evaluation of radon induced lung cancer risk in occupants of the old and new dwellings of the Dera Ismail Khan City,Pakistan

In order to carry out indoor radon measurement in new and old buildings of the Dera Ismail Khan city, CR-39 based radon detectors were installed in bed rooms and sitting rooms/TV lounges in 25 (each) old and new houses and were exposed to indoor radon for 90 days. After processing, mean weighted average indoor radon concentrations in old and new houses were found to be 275 ± 33 and 86 ± 18 Bq m^?3 whereas mean annual effective doses expected to be received by the occupants were 6.86 ± 0.79 and 2.1 ± 0.43 mSv year^?1, respectively. From the measured weighted average indoor radon concentration, excess relative risk factor was calculated using the risk model of BEIR VI for the age group of 35 and 55 years. Average excess lung cancer risk was found to be 1.63 ± 0.19 and 1.35 ± 0.16 and 0.5 ± 0.10 and 0.4 ± 0.08 for old and new houses, respectively.     

Estimation of indoor radon and the annual effective dose from building materials by ionization chamber measurement

Indoor radon and its annual effective dose from the building materials commonly used in Thailand were reported. Radon emission from samples collected in the closed chamber was measured by an ionization chamber. Indoor radon and the annual effective dose were calculated from radon concentration in the closed chamber. Granite yields the highest annual effective dose. Three samples of granite shown the annual effective dose higher than the annual exposure limit for the general public of 1 mSv year^?1 recommended by the International Commission on Radiological Protection. Applying appropriate surface coating, the radon emission from some building materials has decreased substantially.