A study on the radon concentration in water in Coonoor, India

The gas collection measurement method was employed to determine radon activity concentrations in the water of Coonoor. Open well water, dam water and stream water have been investigated for their radon concentrations. It is observed that the highest radon concentration is in the open well water and the lowest in stream water. From these measurements, the corresponding annual effective ingestion dose is determined.     

Distribution patterns of gamma radiation dose rate in the high background radiation area of Odisha,India

Journal of Radioanalytical and Nuclear Chemistry - Absorbed dose rates in air for 20 residential areas in Odisha were measured using a vehicle-mounted NaI(Tl) scintillation spectrometer. The...     

Study of radon,thoron and their progeny levels in indoor environment of Firozabad city in U.P., India

Twin cup pin-hole dosimeters having LR-115 as the detector were used to measure the concentration of radon and thoron in the dwellings of Firozabad city of Uttar Pradesh State in India. The mean values of radon, thoron, radon progeny and thoron progeny concentrations were found to be 37.4 Bqm^?3, 13.7 Bqm^?3, 4.0 and 1.5 mWL respectively. The average value of annual effective dose equivalent to the inhabitants of Firozabad city was found to be 1.1 mSv and is below the action level as recommended by the ICRP.     

Environmental gamma background measurements in China Jinping Underground Laboratory

To determine the environmental gamma background levels which affects rare events experiments, we measured in situ gamma spectrum at four locations in the China Jinping Underground Laboratory. The integral background count rates (40–2,700 keV) varied from 3.76 to 74.1 cps. The average count rate of the measurements inside the CJPL was 73.4 cps. The spectrometer was calibrated with a ¹⁵²Eu point source and Monte Carlo simulation to obtain the activity conversion factors for the rock and the air, respectively. The rocks that surrounded the CJPL was characterized by very low activity concentrations of ²³⁸U (3.69–4.21 Bq kg^?1), ²³²Th (0.52–0.64 Bq kg^?1) and ⁴⁰K (4.28 Bq kg^?1).     

Bismuth radionuclides in the natural background gamma radiation spectrum

The natural background gamma (NBG) spectrum was accumulated inside the laboratory, with 102.88 cm³ Ge(Li) detector, to investigate bismuth natural radionuclides in the energy range of 500–1700 keV. The relative intensities of identified²¹⁴Bi gamma lines were obtained from the spectrum. The results were in good agreement with that obtained from a source of a precise strength. Out of the 25 gamma lines of²¹⁴Bi, 19 lines were established including 6 lines observed for the first time in the NBG spectrum. Most of the gamma lines of²¹¹Bi and²¹²Bi were observed. Some of these lines are new.     

Comparison of thoron (220Rn) content and gamma radiation level in high background radiation area of Kollam district in Kerala,India

In order to map the thoron prone areas of the coastal region of Kollam district, a well known HBRA of south India, comparative study of radon and thoron exhalation rate was conducted. The in situ measurement of radon and thoron exhalation has been taken. These studies were correlated with the gamma radiation level. The average value of thoron exhalation is found to 5.55 ± 1.35 Bq m⁻² s⁻¹ along the coastal areas and the radon exhalation rate is found to 107.6 ± 32 Bq m⁻² h⁻¹. The value of thoron exhalation was found 12 times greater than the global values in Neendakara and Chavara region and about 6 times greater in the Alappad region.

     

Natural radioactivity in surface marine sediments near the shore of Vizag, South East India and associated radiological risk

Naturally occurring radioactive materials were determined in surface sediments from the marine environment near the shore of Vizag in the South eastern part of India using gamma spectrometry technique. The mean activity concentration was found to be 36 ± 11, 34 ± 15, 75 ± 38 and 782 ± 223 Bq/kg and ranged from 19 to 48 Bq/kg, 11 to 57 Bq/kg, 31 to 145 Bq/kg and 363 to 1,024 Bq/kg for ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K, respectively. The mean radium equivalent activity, external hazard index, air absorbed gamma dose rate and annual effective dose equivalent are 203 ± 62 Bq/kg, 0.6 ± 0.2, 94 ± 27 nGy/h and 0.12 ± 0.03 mSv/year respectively. This data will serve as the baseline level for naturally occurring radionuclides in the study area and will be useful for tracking and assessing any pollution inventory in the environment of this region.     

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).     

Capillary chromatographic analysis of volatile organic compounds in the indoor environment

The wide variety of volatile organic compounds found in the indoor environment can present a difficult chromatographic problem for the analyst. Capillary-column gas chromatography is required to achieve adequate separation. Thermal desorption/capillary gas chromatography/mass spectrometry is usually the preferred method for broad spectrum analysis of the volatile organics detected indoors. Cryogenic trapping is required for capillary gas chromatographic analysis of the more volatile components.     

Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district,Tamil Nadu,India

Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv.     

被动采样法测定室内空气环境中的二氧化氮

用基于气体分子扩散理论研制的被动采样器 (Passivesampler) ,结合Saltzman法 ,离子色谱法 (IC)分析、测定室内空气环境中的NO2 ,利用风洞实验装置进行模拟曝露实验 ,着重研究捕集液的种类、浓度和风洞内NO2 初始浓度、湿度对捕集NO2 能力的影响以及采样器的材料、结构与采样性能的关系。结果表明 ,本文研制的采样器在空气中曝露数个小时后 ,测定空气中NO2 浓度可达n×1 0 μg/L ,与用NOx 分析仪直接测定结果比较误差在 2 0 %以内。本采样器体积小、质量小、结构简单 ,不仅适用于生活环境中NO2 的测定 ,也适用于NO2 个人曝露量的测定     

Seasonal effects on the intensity of natural background gamma radiation spectrum

The natural background gamma (NBG) radiation spectra were accumulated indoors, using a 7.6 cm×7.6 cm NaI(Tl) detector, for a period of 18 months. Six prime peaks of different origins were chosen to study the seasonal effects on the intensity of NBG radiation spectrum in Baghdad. The energy range covered by this work stretched from 0.2 to 7.0 MeV. The standard deviation (due to seasonal effects) of the corrected net area of prime peaks varied from 1.7% to 12.1%. This confirms the seasonal effects on some peaks. A quantitative measurement of the peaks is given in terms of relative intensity.     

Effect of seasonal variation on dust samples of a winter fog affected urban environment of India,South East Asia

Physical and chemical characteristics of leaf dust (LD) samples, collected between 2011 and 2013, of a severely winter fog affected and polluted urban environment (Allahabad, India) of Indo-Gangetic plain are presented in this study. The weather changes in the study area are grouped into three effective annual seasonal periods – winter fog, pre-monsoon and post-monsoon. The pronounced impact of seasonal variations is observed in LD characteristics, as ~46% of the winter fog period samples ranges in size between 2.5 and 20 µm with high magnetic susceptibility (up to 938.22 × 10^?8 m³ kg^?1). In comparison, 35% of the LD from pre-monsoon period occurs in the size range of 100–300 µm with low magnetic susceptibility (up to 43.29 × 10^?8 m³ kg^?1). The fractal analysis involving submicroscopic clast dimension of LD also reveals a seasonal influence. The toxic metals (Pb, Zn, Cd, Cr and Ni) in LD belonging to winter fog and post-monsoon periods increase in comparison to samples from pre-monsoon time. Multivariate statistical analysis of trace element data suggests that the LD collected from winter fog and post-monsoon periods originate predominantly from anthropogenic source, whereas those collected during pre-monsoon owe their origin to crustal and anthropogenic sources, mainly. The present study has demonstrated the role of seasonal variation in controlling the physical and chemical properties of particulate matter based on multiple parameter analyses, and the derivation of the dust load from a mixed source (upper continental crust, anthropogenic and vehicular) for the study area for the first time.     

Constrains in gamma spectrometry analysis of fallout <Superscript>137</Superscript>Cs in coastal marine environment of Arabian sea in India

In this study, an accurate faster gamma spectrometry method for measuring the low level activity concentrations of ¹³⁷Cs using in situ pre-concentration technique on copper ferrocyanide cartridge was standardized. Due to unavailability of reference standard in the copper ferrocyanide matrix, efficiency calibration curves were plotted using RGU and RGTh reference standards. To harmonize the difference in density of standard and sample the required density correction factors for photo peak efficiency were generated. The in situ pre-concentration technique followed by gamma-ray spectrometry was applied for activity determination in surface seawater from eight locations in the coastal marine environment of Arabian Sea. The mean activity concentration of ¹³⁷Cs ranged between 0.71 and 0.91 Bq/m³. Higher activity concentrations were observed at location with latitude, longitude of 21.6°N, 69.57°E as compared to concentration observed at location with latitude, longitude 16.98°N, 73.25°E. The observed concentrations were found to be in range of data reported in Asia–Pacific Marine radioactive database (ASPARMARD). The results will fill up the gaps in the existing database. The generated data will be useful for monitoring fresh input of anthropogenic radionuclide into coastal marine environment for post Fukushima environmental assessment.     

Natural and artificial radionuclides in tea samples determined with gamma spectrometry

Journal of Radioanalytical and Nuclear Chemistry - The aim of the present work is to determine natural and artificial radioactivities in the twenty tea samples available at the local Vietnamese...     

Natural radioactivity studies of Bidar soil samples using gamma spectrometry

The activity of the terrestrial primordial radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K are measured for Bidar soil samples. The collected soil samples are analyzed using HPGe detector based on high resolution gamma spectrometric system. The activity of the three radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K were found to be in the range of BDL–47.68, 7.65–59.08 and BDL–260.65 Bq kg^?1 respectively. The mean gamma absorbed dose rate in air above 1 m from ground is estimated to be 34.47 nGy h^?1. Annual effective dose equivalent and the radium equivalent activity were within the limits in the present study and it is found that the activity of the radionuclides are comparable with the worldwide literature values. Also the external hazard indices for the soil samples of Bidar district were within the limit of unity.     

Risk assessment from gamma dose rate in Balod District of Chhattisgarh,India

Journal of Radioanalytical and Nuclear Chemistry - People are generally exposed to the natural radiation that presents inside and outside the houses. This investigation has been carried out gamma...     

Natural radioactivity and indoor radiation measurements in buildings and building materials in Gobichettipalayam town

Samples of natural and manufactured building materials used by the people of Gobichettipalayam town have been analyzed for ²²⁶Ra, ²³²Th and ⁴⁰K using gamma-ray spectrometry. Radium equivalent activity of the materials has been measured using the formula given by OECD and the geometric mean value of sand, clay and cements are found to be 53.53 Bq·kg⁻¹, 89.09 Bq·kg⁻¹ and 72.25 Bq·kg⁻¹, respectively. The radium equivalent activities obtained in the building materials are all well below the acceptable limit. The indoor gamma-dose has been measured using thermoluminescence dosimeters and it was found in the range of 1051.2–3946.0 μGy/year. The annual effective indoor gamma radiation dose to the people of Gobichettipalayam town has been found to be 0.8 mSv/y.     

Natural radioactivity distribution in geological matrices around Kaiga environment

Summary The activity and absorbed dose rate of the naturally occurring radionuclides, viz. ²³⁸U, ²³² Th and ⁴⁰K were determined in soil and rock samples collected around Kaiga site. The mean activity levels (Kaiga soil) of naturally occurring ²³² Th are comparable with that in worldwide soil, while concentrations of ²³⁸U and ⁴⁰K are lower than those in worldwide soil. The absorbed dose rate in outdoor air ranged 20-58 nGy ^. h^-1 with a mean of 33.3 nGy ^. h^-1, which is below the world average of 60 nGy ^. h^-1. The total effective dose rate in outdoor air for soils ranged 25.6-74.4 mSv ^. y^-1 with a mean of 43.0 mSv ^. y^-1. The estimated dose rate at Kaiga is comparable with that estimated at Kakrapar and Rawatbhata and much less than that estimated at coastal sites of India.