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Gentamicin-induced nephrotoxicity limits its therapeutic use as an effective aminoglycoside. Herbal drugs have a distinct place in the world of pharmaceuticals since they are safe, effective, and cost-efficient. Acacia nilotica (L.) has long been recognized for its antihypertensive, antioxidant, anti-inflammatory, and antiplatelet aggregatory benefits in traditional medicine. Still, the protective effect of Acacia nilotica on gentamicin-induced nephrotoxicity is still unknown. Thus, the goal of this research was to examine the protection of ethanolic extract of Acacia nilotica (ANE) against nephrotoxicity triggered by Gentamicin.Thirty-six rats were randomly divided into six groups containing six rats in each group. The distilled water were given in control group. The rats in groups two and three were administered metformin and gentamicin respectively. In groups five and six, rats were administered ANE at doses of 100 and 200 mg/kg. Ten days of daily treatments were given. The urea, creatinine, uric acid, and LDH levels were analyzed on serum, whereas histological evaluation, MDA, GSH, SOD, CAT, TNF-α, IL-6, and caspase-3, were performed on kidney tissue on day 11. The gentamicin-treated group exhibited a significantly elevated MDA, and lower levels of antioxidant enzymes. Kidney function markers, inflammatory markers and caspase-3 expression were significantly elevated in the gentamicin-treated group. ANE significantly restored kidney function biomarkers, upregulated biochemical levels, inhibited TNF-α, caspase-3, cytokine expression, and reduced histological lesions.In conclusion, ANE has the ability to prevent gentamicin-induced nephrotoxicity and reduce nephrotoxic damage. As such, it may represent an effective therapy for patients receiving gentamicin treatment.
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To assess public exposure to radon, thoron, and their progeny, measurements were conducted in 50 dwellings within the bauxite-rich area of Fongo-Tongo in western Cameroon. Passive integrating radon-thoron discriminative detectors (specifically RADUET) were employed for radon and thoron measurements. Additionally, concentrations of short-lived radon and thoron progeny were estimated using Direct Radon Progeny Sensors (DRPSs) and Direct Thoron Progeny Sensors (DTPSs) based on LR-115 detectors. The findings revealed indoor radon concentrations ranging from 31 to 123 Bq m-3 with a geometric mean (GM) of 62 Bq m-3, and indoor thoron concentrations ranging from 36 to 688 Bq m-3 with a GM of 242 Bq m-3. The Equilibrium Equivalent Radon Concentration (EERC) ranged from 3 to 86 Bq m-3 with a GM of 25 Bq m-3, while the Equilibrium Equivalent Thoron Concentration (EETC) ranged from 1.2 to 12.5 Bq m-3 with a GM of 7.6 Bq m-3. Notably, all dwellings recorded radon concentrations below 100 Bq m-3. Arithmetic means of radon and thoron equilibrium factors were calculated as 0.47 and 0.04, respectively. To assess annual effective doses from radon and thoron inhalation, equilibrium factors were used along with direct measurements of EERC and EETC. The differences observed in annual effective doses were 4.5% for radon and 42.5% for thoron. Furthermore, the contribution of thoron and its decay products to the annual effective dose from radon, thoron, and their progeny ranged from 12 to 94%, with an average contribution of 58%. Thus, this study found that the effective dose due to thoron inhalation in the study area exceeded that due to radon inhalation. It is concluded that, when evaluating radiation doses and health risks, it is crucial to consider both thoron and its progeny alongside radon and its progeny. This underscores the importance of considering direct measurements for accurately estimating radiation doses.
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Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Doses de Radiação , Monitoramento de Radiação , Produtos de Decaimento de Radônio , Radônio , Radônio/análise , Camarões , Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Produtos de Decaimento de Radônio/análise , Monitoramento de Radiação/métodos , Humanos , HabitaçãoRESUMO
Attachment of 222Rn progenies, upon their formation, to the atmospheric aerosols and inhalation of these radioactive aerosols causes inhalation dose to the human being. Aerosols have the characteristics of small particle size, long-time suspension and long-distance transmission and easy access to the deep respiratory tract. Aerosols are responsible for viral infection risk such as the recent worldwide pandemic caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2, or COVID-19). Understanding the formation and behaviour of aerosols in a confined environment in various human habitations is essential to combat such detrimental exposures. Experiments have been performed to study the distribution of aerosol size fractions in the walk-in type 222Rn calibration chamber. The real-time applied particle technology monitors (APT-Maxima stationary monitors) were used for the simultaneous measurements of PM1, PM2.5, and PM10 size fractions. The variation of the mass densities (µg m-3) of different size fractions at different positions inside the chamber was monitored by placing APTs. The PM1, PM2.5, and PM10 sizes fractions were distributed homogeneously within the chamber volume and the concentration ratios of these fractions were 1:1.5:1.6 for concentration values of < 1500 µg m-3, and 1:7:9 for the concentration values of > 1500 µg m-3.
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Radônio , Humanos , Calibragem , SARS-CoV-2 , Aerossóis , Material ParticuladoRESUMO
BACKGROUND: Diabetic neuropathy is a debilitating manifestation of long-term diabetes mellitus. The present study explored the effects of the roots of Rubia cordifolia L. (R. cordifolia L.) in the Wistar rat model for diabetic neuropathy and possible neuroprotective, antidiabetic, and analgesic mechanisms underlying this effect. MATERIALS AND METHODS: Rats were divided into five experimental groups. An amount of 0.25% carboxy methyl cellulose (CMC) in saline and streptozotocin (STZ) (60 mg/kg) was given to group 1 and group 2, respectively. Group 3 was treated with STZ and glibenclamide simultaneously while groups 4 and 5 were simultaneously treated with STZ and hydroalcoholic extract of the root of R. cordifolia, respectively. Hot plate and cold allodynias were used to evaluate the pain threshold. The antioxidant effects of R. cordifolia were assessed by measuring Thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). At the end of the study, sciatic nerve and brain tissues were collected for histopathological study. Bcl-2 proteins, cleaved caspase-3, and Bax were assessed through the Western blot method. RESULTS: R. cordifolia significantly attenuated paw withdrawal and tail flick latency in diabetic neuropathic rats. R. cordifolia significantly (p < 0.01) improved the levels of oxidative stress. It was found to decrease blood glucose levels and to increase animal weight in R. cordifolia-treated groups. Treatment with R. cordifolia suppressed the cleaved caspase-3 and reduced the Bax:Bcl2 ratio in sciatic nerve and brain tissue compared to the diabetic group. Histopathological analysis also revealed a marked improvement in architecture and loss of axons in brain and sciatic nerve tissues at a higher dose of R. cordifolia (400 mg/kg). CONCLUSION: R. cordifolia attenuated diabetic neuropathy through its antidiabetic and analgesic properties by ameliorating apoptosis and oxidative stress.
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AIM: This work aimed to encapsulate Hypericum perforatum extract (HPE) into nanophytosomes (NPs) and assess the therapeutic efficacy of this nanocarrier in neuropathic pain induced by partial sciatic nerve ligation (PSNL). METHODS: Hydroalcoholic extract of Hypericum perforatum was prepared and encapsulated into NPs by thin layer hydration method. Particle size, zeta potential, TEM, differential scanning calorimetry (DSC), entrapment efficiency (%EE), and loading capacity (LC) of NPs were reported. The biochemical and histopathological examinations were measured in the sciatic nerve. RESULTS: Particle size, zeta potential, %EE, and LC were 104.7 ± 1.529 nm, -8.93 ± 1.71 mV, 87.23 ± 1.3%, and 53.12 ± 1.7%, respectively. TEM revealed well-formed and distinct vesicles. NPHPE (NPs of HPE) was significantly more effective than HPE in reducing PSNL-inducing pain. Antioxidant levels and sciatic nerve histology were reversed to normal with NPHPE. CONCLUSIONS: This study demonstrates that encapsulating HPE with phytosomes is an effective therapeutic approach for neuropathic pain.
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Antineoplásicos , Hypericum , Neuralgia , Neuralgia/tratamento farmacológico , Antioxidantes , Óleos de Plantas , Extratos Vegetais/uso terapêuticoRESUMO
Among the several aspects of decay products behavior, deposition is of special significance because of its prominent role in the activity removal from the environment, which eventually results in the occurrence of decay product disequilibrium with the parent gas. This point is particularly important in case of thoron dosimetry where thoron progeny 212Pb accounts for the most of the radiological dose. The deposition depends on the size distribution of decay products and the structure of air turbulence at the air-surface interface. In the present work, the effect of varying air-flow (fan speed) and aerosol count median diameter (CMD) was studied on the deposition and distribution profile of 212Pb using computational fluid dynamics (CFD). The simulations have been carried out in a cubical calibration chamber of volume 8 m3, facilitated at RP&AD, BARC. Simulated results showed that the increase of total depositional loss rate of attached fraction of 212Pb due to increase of the fan speed was significant for CMD up to 400 nm, beyond which this effect started becoming less prominent with increasing diameter. Besides, a minimum of the total depositional loss rate curve was seen to be shifted to the higher CMD with increase of the fan speed. CFD results were found to be in good agreement with experimental observations obtained in the controlled conditions with thoron source.
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Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Poluentes Radioativos do Ar/análise , Chumbo , Poluição do Ar em Ambientes Fechados/análise , Calibragem , Hidrodinâmica , Monitoramento de Radiação/métodos , Radônio/análise , Produtos de Decaimento de Radônio/análise , AerossóisRESUMO
The present work determines the contents of active and passive indoor 222Rn, 220Rn, and their daughter in the 32 houses of the Reasi district of J&K, India. The passive 222Rn and 220Rn concentration was measured by dosimeters, whereas the active content was measured by active radon monitor. Progeny sensors and integrated samplers were operated for the evaluation of passive and active daughter contents of 222Rn and 220Rn. The measured averaged values of indoor 220Rn and 222Rn were 73 ± 40 and 22 ± 8 Bqm-3, respectively. The radon and thoron equilibrium factor has varied from 0.3 to 1.7 and from 0.006 to 0.6. The fine fraction of the above-mentioned gases was also calculated. The results of Mann-Whitney test statistically demonstrated significant differences between the content of indoor 222Rn, 220Rn, and their daughter for different seasons. The values of 222Rn, 220Rn, and their daughter content were appeared to be elevated in set of mud houses among all sets of houses. The values of all daughter concentration and indoor 222Rn were appeared to lie within the limit proposed by various agencies. The total doses were detected less than range commended by ICRP that suggested the district is safe as a health hazard point of view.
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Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Radônio/análise , Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento de Radiação/métodos , Habitação , ÍndiaRESUMO
Indoor radon and thoron survey has been carried out in 50 dwellings under Kohima district, Nagaland, India, using the latest measurement technology. The survey has been carried out for a one-year period in 3 different seasons, and the dwellings were selected according to the building materials used for construction. Indoor radon and thoron concentrations, as well as their progeny, followed a predictable pattern with greater levels in the winter and lower levels in the summer. Concrete housing had greater radon and thoron concentrations than bamboo and semi-wood/bamboo homes. The equilibrium factor (E.F.) and inhalation dose due to radon, thoron, and their corresponding progeny were also studied in the present study.
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Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Radônio/análise , Estações do Ano , Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Índia , HabitaçãoRESUMO
Indoor radon (222Rn), thoron (220Rn) and their progeny concentrations were detected in several homes in Dimapur district, Nagaland, utilizing Direct Radon and Thoron progeny sensors based on solid-state Nuclear Track Detectors (Type-2 film) and pinhole type radon-thoron discriminating dosemeters. For three separate seasons, the annual inhalation dose has been determined in 80 residences in the research regions. The residences were chosen to have various types of housing, such as concrete, semi-wood/bamboo and bamboo, with varying levels of ventilation that contribute to indoor 222Rn, 220Rn and their progeny. The inhalation dose in the survey area lies between 0.33 and 3.04 mSvy-1 and is within the reference value as suggested by ICRP, 2018.
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Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Habitação , Índia , Radônio/análise , Produtos de Decaimento de Radônio/análiseRESUMO
Inhalation doses due to radon and thoron are predominantly due to the inhalation of progeny of Radon and Thoron. The progeny/decay-products of radon and thoron are particulates unlike their parent gas and exhibit different physical properties like attachment to the aerosols and deposition on different surfaces. All these properties in turn depend on the environmental conditions such as air velocity, aerosol concentration, attachment rate, etc. The role of air velocity on deposition on surfaces decides the progeny particles left in the air for inhalation. Therefore, in the present work, we have studied the effect of air velocity on the inhalation dose due to radon and thoron progeny at the centre of a 0.5-m3 calibration chamber as well as on all surfaces. Hence, the studies were carried out at different air velocities, and inhalation doses were measured using deposition-based direct radon and thoron progeny sensors.
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Poluentes Radioativos do Ar , Poluição do Ar em Ambientes Fechados , Monitoramento de Radiação , Radônio , Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Habitação , Radônio/análise , Produtos de Decaimento de Radônio/análiseRESUMO
The main contribution to population exposure is due to radon and thoron progenies and not radon itself. The aim of this study was therefore to estimate annual effective dose using the results of Direct Radon and Thoron Progeny Sensors were exposed in 69 selected schools and 319 dwellings in several regions of Balkans: in Serbia: regions of Sokobanja and Kosovo and Metohija, Republic of Macedonia, Republic of Srpska and Slovenia. Obtained average total effective doses are in the range from 0.22 mSv a-1 (schools in Republic of Srpska) to 2.5 mSv a-1 (dwellings in Kosovo) and are below the reference level of 10 mSv a-1 recommended by International Commission on Radiological Protection.
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Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento de Radiação/métodos , Produtos de Decaimento de Radônio/análise , Radônio/análise , Península Balcânica , Habitação , HumanosRESUMO
The research work involved the ingestion and inhalation doses due to the intake of radon and uranium through water samples used by the inhabitants, measured in the villages of the Shiwalik Himalayas of Jammu and Kashmir, India. The uranium concentration in collected water samples was assessed by LED fluorimetric technique. All values of doses were found to be below the proposed limit of 100 µSv year-1 for all age categories except for infants due to the high-dose conversion factor. The annual effective doses for the various body organs due to the intake of radon was also calculated and found the maximum dose for lungs than other organs. The concentration of radon in water samples was assessed by Smart Rn Duo portable monitor and compared with RAD7. Statistical analysis was carried out and the Shapiro and Wilk (Biometrika, 52(3/4), 591-611, 1965) test has been also used for the distribution of the data. The physicochemical parameters were also measured in the collected water samples.
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Água Potável/química , Exposição Ambiental/análise , Exposição por Inalação/análise , Radônio/toxicidade , Urânio/toxicidade , Poluentes Radioativos da Água/toxicidade , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Humanos , Índia , Lactente , Recém-Nascido , Doses de Radiação , Monitoramento de Radiação , Radônio/análise , Urânio/análise , Poluentes Radioativos da Água/análiseRESUMO
Indoor radon and thoron concentrations in the domestic environment result in natural radiation exposure to the public due to the inhalation of their short-lived decay products. Keeping this in view, the annual effective dose and other radiation risks due to radon/thoron progenies have been calculated. In this study, newly developed time deposition-based progeny sensors (DTPS/DRPS) were used for long-term passive determination of progeny concentrations in the environment of Jammu and Kashmir, Himalayas, India. The total equilibrium equivalent radon (EECRA + U) and thoron (EECTA + U) concentrations ("A" and "U" referring to attached and unattached fractions) were found to vary from 5 to 38 Bq m-3 with an average value of 18 Bq m-3 and from 0.48 to 5.49 Bq m-3 with an average value of 1.69 Bq m-3, respectively. The aerosol concentration, equilibrium factors, and unattached fractions for radon and thoron progeny have been estimated in normal living conditions and their dependence on each others have also been studied. The annual equilibrium factor for radon and thoron progeny has been determined from the calculated data. The estimated annual effective dose due to radon progeny (0.34 to 2.42 mSv y-1) and thoron progeny (0.13 to 1.54 mSv y-1) is found to be below the world's recommended level. Based on measurements of mean values of the unattached fraction, dose conversion factors (DCFs) in units of mSv per working level month (WLM) has been calculated and the average calculated values of DCFs are 24, 10, and 13 mSv WLM-1. The variability of equilibrium factor and radon/thoron progeny with different seasons, ventilation conditions, and types of houses were also analyzed.
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Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monitoramento de Radiação/métodos , Produtos de Decaimento de Radônio/análise , Radônio/análise , Poluição do Ar em Ambientes Fechados/prevenção & controle , Radiação de Fundo , Habitação/normas , Humanos , Índia , Exposição à Radiação , Estações do Ano , VentilaçãoRESUMO
Radon concentration was measured in water samples of 41 different locations from Udhampur district of Jammu & Kashmir, India, by using RAD7 and Smart RnDuo monitor. The variation of radon concentration in water ranged from 1.44 ± 0.31 to 63.64 ± 2.88 Bq L-1, with a mean value of 28.73 Bq L-1 using RAD7 and 0.64 ± 0.28 to 52.65 ± 2.50 Bq L-1, with a mean value of 20.30 Bq L-1 using Smart RnDuo monitor, respectively. About 17.07% of the studied water samples recorded to display elevated radon concentration above the reference range suggested by United Nation Scientific Committee on the Effects of Atomic Radiations (UNSCEAR). The mean annual effective dose of these samples was determined, and 78.95% samples were found to be within the safe limits set by World Health Organisation (WHO) and European Council (EU). The study revealed good agreement between the values obtained with two methods. Heavy metals (Zn, Cd, Fe, Cu, Ni, As, Hg, Co, Pb and Cr) were determined in water samples by microwave plasma atomic emission spectrometer, and their correlation with radon content was also analysed.
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Água Subterrânea/química , Metais Pesados/análise , Radônio/análise , Poluentes Químicos da Água/análise , Poluentes Radioativos da Água/análise , Bases de Dados Factuais , Monitoramento Ambiental/métodos , Índia , Doses de Radiação , Espectrofotometria Atômica , Qualidade da ÁguaRESUMO
The level of radon concentration has been assessed using the Advanced SMART RnDuo technique in 30 drinking water samples from Jammu district, Jammu and Kashmir, India. The water samples were collected from wells, hand pumps, submersible pumps, and stored waters. The randomly obtained 14 values of radon concentration in water sources using the SMART RnDuo technique have been compared and cross checked by a RAD7 device. A good positive correlation (R = 0.88) has been observed between the two techniques. The overall value of radon concentration in various water sources has ranged from 2.45 to 18.43 Bq L, with a mean value of 8.24 ± 4.04 Bq L, and it agreed well with the recommended limit suggested by the European Commission and UNSCEAR. However, the higher activity of mean radon concentration was found in groundwater drawn from well, hand and submersible pumps as compared to stored water. The total annual effective dose due to radon inhalation and ingestion ranged from 6.69 to 50.31 µSv y with a mean value of 22.48 ± 11.03 µSv y. The total annual effective dose was found to lie within the safe limit (100 µSv y) suggested by WHO. Heavy metal analysis was also carried out in various water sources by using an atomic absorption spectrophotometer (AAS), and the highest value of heavy metals was found mostly in groundwater samples. The obtained results were compared with Indian and International organizations like WHO and the EU Council. Among all the samples, the elemental analysis is not on the exceeding side of the permissible limit.
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Água Potável/química , Radônio/análise , Geologia , Água Subterrânea/química , Humanos , Índia , Metais Pesados/análise , Controle de Qualidade , Doses de Radiação , Monitoramento de Radiação/métodos , Poluentes Radioativos da Água/análiseRESUMO
Among radiation exposure pathways to human beings, inhalation dose is the most prominent one. Radon, thoron, and their progeny contribute more than 50 per cent to the annual effective dose due to natural radioactivity. South west coast of India is classified as a High Natural Background Radioactivity Area and large scale data on natural radioactivity and dosimetry are available from these coastal regions including the Neendakara-Chavara belt in the south of Kerala. However, similar studies and reports from the northern part of Kerala are scarce. The present study involves the data collection and analysis of radon, thoron, and progeny concentration in the Wayanad district of Kerala. The radon concentration was found to be within a range of 12-378 Bq/m3. The thoron concentration varied from 15 to 621 Bq/m3. Progeny concentration of radon and thoron and the diurnal variation of radon were also studied. In order to assess source term, wall and floor exhalation studies have been done for the houses showing elevated concentration of radon and thoron. The average values of radon, thoron, and their progeny are found to be above the Indian average as well as the average values reported from the High Natural Background Radioactivity Areas of Kerala. Exhalation studies of the soil samples collected from the vicinity of the houses show that radon mass exhalation rate varied from below detectable limit (BDL) to a maximum of 80 mBq/kg/h. The thoron surface exhalation rate ranged from BDL to 17470 Bq/m2/h.
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Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Exposição por Inalação , Exposição à Radiação , Radônio/análise , Monitoramento Ambiental , Habitação , Humanos , Índia , Estações do AnoRESUMO
Background The inhalation doses resulting from the exposure to radon, thoron, and their progeny are important quantities in estimating the radiation risk for epidemiological studies as the average global annual effective dose due to radon and its progeny is 1.3 mSv as compared to that of 2.4 mSv due to all other natural sources of ionizing radiation. Objectives The annual inhalation dose has been assessed with an aim of investigating the health risk to the inhabitants of the studied region. Methods Time integrated deposition based 222Rn/220Rn sensors have been used to measure concentrations in 146 dwellings of Udhampur district, Jammu and Kashmir. An active smart RnDuo monitor has also been used for comparison purposes. Results The range of indoor radon/thoron concentrations is found to vary from 11 to 58 Bqm-3 with an average value of 29 ± 9 Bqm-3 and from 25 to 185 Bqm-3 with an average value of 83 ± 32 Bqm-3, respectively. About 10.7% dwellings have higher values than world average of 40 Bqm-3 prescribed by UNSCEAR. The relationship of indoor radon and thoron levels with different seasons, ventilation conditions, and different geological formations have been discussed. Conclusions The observed values of concentrations and average annual effective dose due to radon, thoron, and its progeny in the study area have been found to be below the recommended level of ICRP. The observed concentrations of 222Rn and 220Rn measured with active and passive techniques are found to be in good agreement.
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Poluição do Ar em Ambientes Fechados/análise , Materiais de Construção/análise , Exposição por Inalação/análise , Radônio/análise , Geologia , Humanos , Índia , Radônio/química , Medição de Risco , Estações do AnoRESUMO
The radioactive noble gas radon (222Rn) and its decay products have been considered a health risk in the indoor environment for many years because of their contribution to the radiation dose of the lungs. The radioisotope thoron (220Rn) and its decay products came into focus of being a health risk only recently. The reason for this is its short half-life, so only building material can become a significant source for indoor thoron. In this study, dwellings with earthen architecture were investigated with different independent measurement techniques in order to determine appropriate methods for reliable dose assessment of the dwellers. While for radon dose assessment, radon gas measurement and the assumption of a common indoor equilibrium factor often are sufficient, thoron gas has proven to be an unreliable surrogate for a direct measurement of thoron decay products. Active/time-resolved but also passive/integrating measurements of the total concentration of thoron decay products demonstrated being precise and efficient methods for determining the exposure and inhalation dose from thoron and its decay products. Exhalation rate measurements are a useful method for a rough dose estimate only if the exhalation rate is homogeneous throughout the house. Before the construction of a building in-vitro exhalation rate measurements on the building material can yield information about the exposure that is to be expected. Determining the unattached fraction of radon decay products and even more of thoron decay products leads to only a slightly better precision; this confirms the relative unimportance of the unattached thoron decay products due to their low concentration. The results of this study thereby give advice on the proper measurement method in similar exposure situations.
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Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Exposição por Inalação/estatística & dados numéricos , Monitoramento de Radiação/métodos , Radônio/análise , Poluição do Ar em Ambientes Fechados/estatística & dados numéricos , Arquitetura , Exposição Ambiental , Meia-Vida , Habitação , Produtos de Decaimento de RadônioRESUMO
The annual exposure to indoor radon, thoron and their progeny imparts a major contribution to inhalation doses received by the public. In this study, we report results of time integrated passive measurements of indoor radon, thoron and their progeny concentrations that were carried out in Garhwal Himalaya with the aim of investigating significant health risk to the dwellers in the region. The measurements were performed using recently developed LR-115 detector based techniques. The experimentally determined values of radon, thoron and their progeny concentrations were used to estimate total annual inhalation dose and annual effective doses. The equilibrium factors for radon and thoron were also determined from the observed data. The estimated value of total annual inhalation dose was found to be 1.8 ± 0.7 mSv/y. The estimated values of the annual effective dose were found to be 1.2 ± 0.5 mSv/y and 0.5 ± 0.3 mSv/y, respectively. The estimated values of radiation doses suggest no important health risk due to exposure of radon, thoron and progeny in the study area. The contribution of indoor thoron and its progeny to total inhalation dose ranges between 13-52% with mean value of 30%. Thus thoron cannot be neglected when assessing radiation doses.