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.     

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.     

Measurement of activity concentration of primordial radionuclides in soil samples from Thirthahalli taluk and the assessment of resulting radiation dose

The activity concentration of primordial radionuclides ²²⁶Ra, ²³²Th, and ⁴⁰K in soil samples of Thirthahalli taluk were measured systematically by using a low background HPGe detector coupled to 16 K MCA. The measured activity concentration of ²²⁶Ra lies between 5.1?±?0.2 and 79.5?±?1.7 Bq kg^?1with an average activity of 25.99 Bq kg^?1, ²³²Th ranges from 5.1?±?0.3 to 95.3?±?2.2 Bq kg^?1with an average activity of 33.60 Bq kg^?1and that of ⁴⁰K varies from 18.3?±?1.5 to 833.4?±?17.5 Bq kg^?1with an average activity of 175.52 Bq kg^?1. Higher concentration of these radionuclides were found in the soil samples where the regional geology is granites. The consequential gamma dose and the corresponding radiation hazard was also estimated and is found to be within the permissible limits. The possible radiological impact on the public was also determined and these results are presented in this paper.     

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.     

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).     

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.     

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.     

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.     

Radiometric analysis of rock and soil samples of Leepa Valley; Azad Kashmir, Pakistan

In this article, we present results obtained from a radiometric survey that was conducted in the Leepa Valley of Azad Jammu & Kashmir, Pakistan. The purpose of current study is to appraise the radioactivity levels and the associated health hazards due to the terrestrial radionuclide in soil and rock samples. In this regard, 16 soil and 17 rock samples were collected from different locations of the Leepa Valley. After processing the samples, activity concentrations of primordial (²³²Th, ²²⁶Ra and ⁴⁰K) and anthropogenic (¹³⁷Cs) radionuclides were determined using a P-type coaxial high purity germanium detector. From the results obtained the mean activity concentrations of radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the soil samples were found to be 31.25 ± 0.46, 44.1 ± 1.07 and 575 ± 8.89 Bq kg^?1 respectively. Whilst, in rock samples ²²⁶Ra, ²³²Th and ⁴⁰K mean activities were found as 28.46 ± 0.45, 48.63 ± 1.12 and 666.7 ± 9.39 Bq kg^?1, respectively. The ¹³⁷Cs concentration level in soil and rock samples is found to be 15.04 ± 0.29 and 5.7 ± 0.16 Bq kg^?1, respectively. The average radium equivalent activity (R _aeq) was found as 143.16 and 142.93 Bq kg^?1 in soil and rock samples, respectively. These findings are less than the recommended safe value of 370 Bq kg^?1 as given in OECD report (1979). The values of external (H _ex) and internal hazard index (H _in) are also less than unity. Mean value of absorbed dose rate was found as 69.78 nGy h^?1 for the soil samples, which is in good agreement with the world wide average value (70 nGy h^?1). Mean value of absorbed dose rate from rock samples was found as 70.01 nGy h^?1. Mean values of the annual effective dose is also lower than the values reported for different other countries of the world.     

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.     

Measurement of 137Cs in the soil in Korea by low-level background gamma-ray spectrometer

¹³⁷Cs was measured in soil samples collected in Korea from 2006 to 2008 using a low-level background gamma-ray spectrometer that was designed and developed by KRISS (Korea Research Institute of Standards and Science). The objectives of this study are to evaluate the newly developed low-level background gamma-ray spectrometer and, consequently, to provide information on the horizontal and vertical distribution of ¹³⁷Cs in Korean soil. ¹³⁷Cs concentrations in surface soil varied from 12.8 ± 0.9 to 108 ± 4 Bq kg^?1, and the vertical profiles of ¹³⁷Cs from the Nari basin in Ulleung Island in the East Sea/Sea of Japan and Seongsan Ilchulbong Peak, Jeju Island, showed a higher concentration in the surface layer that gradually decreased with depth. On the other hand, the ¹³⁷Cs concentration in soil samples collected from Bukhan Mountain National Park in Seoul showed a subsurface maximum and decreased with depth. The ¹³⁷Cs inventories in the soil column were calculated to be 1,830–4,360 Bq m^?2 with a mean of 2,770 Bq m^?2, which was the same order of magnitude as the global fallout inventories in the mid-latitude region of the Northern Hemisphere.     

Studies on radon concentration in drinking water around Hemavathi river basin,Karnataka State,India

Concentrations of radon in drinking water collected from 32 locations of Hemavathi river basin, Karnataka, India have been measured by emanometry method. The radon concentration in water ranged from 2.7 ± 0.1 to 138.5 ± 1.5 Bq l⁻¹ with a geometrical mean of 25.3 ± 1.1 Bq l⁻¹. The study revealed that about 82.35% of drinking water samples contained radon concentration more than 11.1 Bq l⁻¹, the limit is fixed by Environmental Protection Agency. Among the different parameters measured, concentration of radon showed weak correlation with chloride and no correlation with alkalinity, pH, nitrate, sulphate, fluoride and total dissolved substance.

     

Radon isotope assessment of submarine groundwater discharge (SGD) in Coleroon River Estuary,Tamil Nadu,India

Submarine groundwater discharge is the fresh groundwater discharge to sea that impacts the coastal regions. Radon (²²²Rn) isotope has been used to quantify SGD in coleroon river estuary, India. Continuous ²²²Rn analyses were attempted for 10 days in groundwater and pore water samples at three different locations. ²²²Rn in groundwater ranges between 35.0 and 222.0 Bq m^?3 and in pore water between 14.0 and 150.0 Bq m^?3 irrespective of locations. The radon mass balance estimated total SGD rate ranges between 2.37 and 7.47 m days^?1. The SGD increases with distance from coast, influenced by tides and hydrological features.     

Radon measurements in water samples from the thermal springs of Yalova basin, Turkey

The radon concentration has been measured in thermal waters used for medical therapy and drinking purposes in Yalova basin, Turkey. Radon activity measurements in water samples were performed using RAD 7 radon detector equipped with RAD H₂O (radon in water) accessory and following a protocol proposed by the manufacturer. The results show that the concentration of ²²²Rn in thermal waters ranges from 0.21 to 5.82 Bql^?1 with an average value of 2.4 Bql^?1. In addition to radon concentration, physicochemical parameters of water such as temperature (T), electrical conductivity, pH and redox potential (E_h) were also measured. The annual effective doses from radon in water due to its ingestion and inhalation were also estimated. The annual effective doses range from 0.2 to 0.75 μSvy^?1 for ingestion of radon in water and from 2.44 to 9 μSvy^?1 for inhalation of radon released from the water.     

Studies on radionuclides around Hemavathi river basin of Karnataka,India

The activity concentration and total annual effective dose of the terrestrial naturally occurring radionuclides (²³²Th, ²²⁶Ra and ⁴⁰K) were measured in soil and rock samples collected from various locations of Hemavathi river basin in Karnataka, using HPGe detector. The results revealed that activity concentration of radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K in the soil had geometrical mean values of 16.7 ± 0.6, 33.9 ± 1.2 and 359.9 ± 9.2 Bq kg^?1, respectively. In rock samples activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K had geometrical mean values of 20.2 ± 0.7, 18.0 ± 0.9 and 276 ± 9.6 Bq kg^?1, respectively. The external Hazard index and indoor hazard index were found to be within safety limits prescribed by European commission 1999 report.     

Fast concentration of dissolved forms of cesium radioisotopes from large seawater samples

The method developed for cesium concentration from large freshwater samples was tested and adapted for analysis of cesium radionuclides in seawater. Concentration of dissolved forms of cesium in large seawater samples (about 100 L) was performed using composite absorbers AMP-PAN and KNiFC-PAN with ammonium molybdophosphate and potassium–nickel hexacyanoferrate(II) as active components, respectively, and polyacrylonitrile as a binding polymer. A specially designed chromatography column with bed volume (BV) 25 mL allowed fast flow rates of seawater (up to 1,200 BV h^?1). The recovery yields were determined by ICP-MS analysis of stable cesium added to seawater sample. Both absorbers proved usability for cesium concentration from large seawater samples. KNiFC-PAN material was slightly more effective in cesium concentration from acidified seawater (recovery yield around 93 % for 700 BV h^?1). This material showed similar efficiency in cesium concentration also from natural seawater. The activity concentrations of ¹³⁷Cs determined in seawater from the central Pacific Ocean were 1.5 ± 0.1 and 1.4 ± 0.1 Bq m^?3 for an offshore (January 2012) and a coastal (February 2012) locality, respectively, ¹³⁴Cs activities were below detection limit (<0.2 Bq m^?3).     

Environmental radioactivity measurements in north–western Greece following the Fukushima nuclear accident

The impact of the Fukushima nuclear accident in north–western Greece was assessed through an environmental monitoring programme activated by the Nuclear Physics Laboratory of the University of Ioannina. Measurements of ¹³¹I were carried out in atmospheric particulate, ovine milk and grass samples. In daily aerosol samplings, radioiodine was first detected on March 25–26, 2011 and reached maximum levels, up to 294 μBq m^?3, between April 2 and April 4, 2011. In ovine milk samples, ¹³¹I concentrations ranged from 2.0 to 2.7 Bq L^?1 between April 2 and April 6, 2011, while an average activity of 2.7 Bq kg^?1 was measured in grass samples on April 4, 2011. The ^134,137Cs isotopes were below detection limits in all samples and could only be determined in the air, by analysis of multiple daily filters. A maximum average activity concentration of ¹³⁷Cs amounting to 24 μBq m^?3 was measured during the period from April 5 to April 9, 2011, with the ¹³⁴Cs/¹³⁷Cs activity ratio being close to unity. Activity concentrations were consistent with measurements conducted in other parts of the country and were well below those reported in May 1986 after the Chernobyl accident. The committed effective dose to the whole body and to the thyroid gland from inhalation of ¹³¹I was estimated for the adult and infant population and was found to be of no concern for the public health.     

137Cs, 40K, alkali–alkaline earth element and heavy metal concentrations in wild mushrooms from Turkey

In 2002, an extensive study was performed in forest sites of Izmir. This first study results led on the one hand, to quantify of ¹³⁷Cs and ⁴⁰K concentration in mushrooms collected in the Izmir region and to a first evaluation of dose in people due to the ingestion of radionuclide-contaminated mushrooms. The mushroom concentration values varied over a wide range from below detection limit to 401 ± 4 Bq kg^?1 (dry wt) for ¹³⁷Cs. The ⁴⁰K concentration values obtained for different species of mushrooms ranged from 588 ± 26 Bq kg^?1 to 2024 ± 63 Bq kg^?1 (dry wt). The annual effective dose values due to mushroom ingestion for ¹³⁷Cs are lower than the ICRP-2007’s reference level value of 1 mSv for “existing” exposure situation. Inductively coupled plasma-mass spectrometry was used to measure many alkali–alkaline earth elements and heavy metals in mushroom samples. The relationships among the concentrations of ¹³⁷Cs and the stable elements were presented and the occurrence of metals in mushrooms was evaluated.     

Emanation studies of radium containing materials by a simple radon monitoring system

The applicability of a radon emanation system to radium determination in fine-grained solid samples has been investigated by means of a closed radon emanation system consisting of a radon monitor and an aluminium vessel. The system has been calibrated with radium-containing fine-grained samples (e.g. phosphogypsum, granite and pitchblende) and the evaluation of the calibration data included linearity, detection limits and analytical resolution of the method. The studied radon emanation system presents very good linear response (R ² = 0.99) to the radium content of the samples, the detection limit for radon is 25 Bq m^?3 and the analytical resolution 15 Bq m^?3. In addition, the relation between particle size of the materials and radon emanation has indicated that the applicability of the radon emanation system to radium determination is strongly depended not only on the mineral type but also on the particle size of the grained material.     

Radioactivity in coffee

This research was dedicated to the study of the background levels of ²¹⁰Po and natural gamma emitters as ⁴⁰K, ²¹⁴Pb, ²¹⁴Bi, ²²⁸Ac, ²¹²Pb and ²¹²Bi in coffee powder and in coffee beverage; also the artificial ¹³⁷Cs was determined. In the coffee powder the mean ²¹⁰Po activity resulted 7.25 ± 2.25 × 10^?2 Bq kg^?1. ⁴⁰K showed a mean activity of 907.4 ± 115.6 Bq kg^?1. The mean activity concentration of ²¹⁴Pb and ²¹⁴Bi, indicators of ²²⁶Ra, given as mean value of the two radionuclides, resulted 10.61 ± 4.02 Bq kg^?1. ²²⁸Ac, ²²⁸Ra indicator, showed a mean activity concentration of 13.73 ± 3.20 Bq kg^?1. The mean activity concentration of ²¹²Pb, ²²⁴Ra indicator, was 8.28 ± 2.88 Bq kg^?1. ²⁰⁸Tl, ²²⁴Ra indicator, presented a mean activity concentration of 11.03 ± 4.34 Bq kg^?1. In all samples, the artifical ¹³⁷Cs resulted below the detection limit (2.0 Bq kg^?1). The arithmetical mean value of percentage of ²¹⁰Po extraction in coffee beverage resulted 20.5 ± 6.9. The percentage of transfer of gamma emitters,⁴⁰K, ²¹⁴Pb, ²¹⁴Bi, ²²⁸Ac, ²¹²Pb, ²⁰⁸Tl resulted of 80.0, 33.5, 24.7, 30.0, 35.1 and 53.5 % for ⁴⁰K, ²¹⁴Pb, ²¹⁴Bi, ²²⁸Ac, ²¹²Pb and ²⁰⁸Tl respectively.