Spatial distribution of 222Rn concentrations and dose estimations in various waters

In this article, the levels of ²²²Rn concentrations, annual effective doses, and excess lifetime cancer risk estimations were investigated for water samples in the city of Osmaniye, located in the southern part of Turkey. The measurements were conducted using a radon gas analyzer (AlphaGUARD PQ 2000 PRO). The arithmetic average of ²²²Rn concentrations was 0.44 Bq.L^?1 with a geometric standard deviation of 0.19 and geometric average 0.41 Bq.L^?1. The results obtained were compared with the findings of other studies. All measured radon concentrations were below the values recommended by the World Health Organization and the U.S. Environmental Protection Agency. The associated radiological parameters such as annual effective doses (AED) and excess lifetime cancer risk (ELCR) from consumption of these waters were calculated. The computed average annual effective doses for ingestion and inhalation as well as excess lifetime cancer risk were estimated to be 1.13 μSv.y^?1, 1.10 μSv.y^?1, and 3.95 × 10^?6, respectively. ²²²Rn concentration, AED, and ELCR interpolated values of the region were determined and mapped using the Kriging method. The results of radon concentrations in this study provide a data baseline for future studies on subsequent evaluations of possible future environmental contamination of Osmaniye Province.     

Distribution of 222Rn in groundwater and estimation of resulting radiation dose to different age groups: A case study from Bangalore City

Ingesting waters holding high levels of natural occurring radioactive element like Radon would contribute to increase in the effective dose received by people followed by an increased prevalence of cancer. The current study is an attempt to describe the extent of contribution of ²²²Rn to natural background radiation and the resultant effective dose to public of different age groups. In order to do so, 65 groundwater samples from selected parts of Bangalore city were collected and analyzed for radon activity using RAD7 radon monitor coupled with RAD H₂O accessories. The radon activity was in the range of 3.05–696 Bq/L (mean: 91.39 Bq/L) and 92.31% of the groundwater samples recorded elevated radon concentration above the United States environmental protection agency (USEPA's) Maximum Contaminant Level (MCL) value of 300 pCi/L, corresponding to 11.1 Bq/L. The mean annual effective dose contribution of people falling under different age groups (viz., infants, children, teens: males and females, adults: males and females, pregnant and lactating women) due to ingestion of water-borne ²²²Rn ranged from 0.082 to 0.444 mSv/y and was found to be higher in all the age groups of males compared to respective female age groups, but well within the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and World Health Organization (WHO) proposed limit of 1 mSv/y.     

Study of radon/thoron exhalation rate,soil-gas radon concentration,and assessment of indoor radon/thoron concentration in Siwalik Himalayas of Jammu & Kashmir

In the present study, the soil-gas radon concentration was assessed at different depth intervals, i.e., 15 cm, 30 cm, 60 cm, and 100 cm from the 30 villages of Jammu &; Kashmir, India using RAD7, an electrostatic solid state alpha detector. The radon mass exhalation and thoron surface exhalation rate has also been measured in the selected 18 soil samples out of 30 of different grain sizes (i.e., 1 mm, 300 µm, 150 µm). The active radon and thoron concentrations were also assessed in the 20 villages. Both the exhalation rates and active radon/thoron concentration were measured using SMART Rn Duo, a portable radon monitor. The average values of soil-gas radon concentration were 210 ± 84 Bq m^?3, 1261 ± 963 Bq m^?3, 4210 ± 1994 Bq m^?3, and 671 ± 305 Bq m^?3 at the depth intervals of 15 cm, 30 cm, 60 cm, and 100 cm, respectively. The exhalation rate of radon and thoron from soil was found to decrease with the increase of grain size, as smaller soil particles make relatively more contribution to radon and thoron exhalations from the ground surface than larger soil particles. The measured Pearson's correlation coefficient was obtained as statistically significant between different quantities under two-tailed test.     

Assessment of uranium concentration in the drinking water and associated health risks in Eastern Haryana,India

Quantification of uranium in drinking water has great significance considering its effects on human health. Drinking water samples collected from different sources, viz., hand pumps, tube-wells, and public water supply from Sonipat and Panipat districts of Haryana, India have been analyzed for uranium and other physico-chemical parameters. Uranium concentration in water samples was measured using Pulsed LED Fluorimeter. Uranium concentration in collected water samples ranges from 9.1 to 155.1 µg/L in Sonipat district and 14.9 to 123.3 µg/L in Panipat district. It was inferred from the data that uranium concentration in some water samples was higher than WHO &; USEPA recommended limit of 30 µg/L. The mean cancer risk due to uranium in drinking water in Sonipat and Panipat districts was found to be 1.40 × 10^?4 and 1.63 × 10^?4, respectively, which is lower than the maximum permissible limit (<10^?3). Total Dissolve Salts (TDS) in water samples of some villages in Sonipat district was higher than permissible limits for drinking prescribed by WHO &; BIS.     

Comparison of antioxidative effects between radon and thoron inhalation in mouse organs

Radon therapy has been traditionally performed globally for oxidative stress-related diseases. Many researchers have studied the beneficial effects of radon exposure in living organisms. However, the effects of thoron, a radioisotope of radon, have not been fully examined. In this study, we aimed to compare the biological effects of radon and thoron inhalation on mouse organs with a focus on oxidative stress. Male BALB/c mice were randomly divided into 15 groups: sham inhalation, radon inhalation at a dose of 500 Bq/m³ or 2000 Bq/m³, and thoron inhalation at a dose of 500 Bq/m³ or 2000 Bq/m³ were carried out. Immediately after inhalation, mouse tissues were excised for biochemical assays. The results showed a significant increase in superoxide dismutase and total glutathione, and a significant decrease in lipid peroxide following thoron inhalation under several conditions. Additionally, similar effects were observed for different doses and inhalation times between radon and thoron. Our results suggest that thoron inhalation also exerts antioxidative effects against oxidative stress in organs. However, the inhalation conditions should be carefully analyzed because of the differences in physical characteristics between radon and thoron.

     

Health Risk Assessment of Fluoride Exposure in Soil,Plants, and Water at Isfahan,Iran

Fluoride is a potentially toxic element, with a narrow range of tolerable amounts taken up via food or drinking water. To evaluate F content in surface soils, 255 topsoil samples (0–20 cm) in an area of 6800 km² in Isfahan province of central Iran were collected. Crop plants and randomly sampled water samples from wells were evaluated during the spring and summer seasons. Total F concentration in 96% of soil samples was lower than the global suggested average of 200 mg kg^?1. The mean F concentration of water samples in the study area was 0.05 and 0.3 mg L^?1 in summer and spring, respectively. Fluoride concentrations in different plant species were in the range of normal values. The total hazard quotient (HQ) for both population groups via consumption of cereals, vegetables, and water; incidental ingestion of soil; inhalation of soil particulates; and dermal contact with water and soil was less than 1.0, resembling no obvious risk. It is suggested that neither age group in Isfahan province will experience a significant potential health risk through their dietary intake of cereals, vegetables, and water; ingestion of soil; inhalation of particulates; and dermal contact.     

Alkaline single cell gel electrophoresis and human biomonitoring for genotoxicity: a study on subjects with residential exposure to radon.

Based on theoretical estimates and various correlation studies, it has been suggested that ingestion of radon in drinking water represents an increased risk for cancer. Such a risk has never been conclusively shown in epidemiological or experimental animal studies, however, and it has been questioned whether the radon level in the drinking water is of any significance in terms of overall radon exposure. Using primary DNA damage as a biological marker for an ongoing exposure to ionising radiation, the present study was undertaken to investigate whether people with different types of residential radon exposures differed with regard to their levels of DNA damage in circulating lymphocytes. DNA damage was measured in coded blood samples from 125 residents living in 45 households with different levels of radon-222 in the drinking water (10-2410 Bq/l) and indoor air (35-1025 Bq/m3) using alkaline single cell gel electrophoresis (the 'Comet' assay). Increased levels of radon in indoor air (>200 Bq/m3) were found to be associated with an increased level of DNA damage in peripheral lymphocytes (P相似文献   

Measurements of radon activity concentration in mouse tissues and organs

The purpose of this study is to investigate the biokinetics of inhaled radon, radon activity concentrations in mouse tissues and organs were determined after mice had been exposed to about 1 MBq/m³ of radon in air. Radon activity concentrations in mouse blood and in other tissues and organs were measured with a liquid scintillation counter and with a well-type HP Ge detector, respectively. Radon activity concentration in mouse blood was 0.410?±?0.016 Bq/g when saturated with 1 MBq/m³ of radon activity concentration in air. In addition, average partition coefficients obtained were 0.74?±?0.19 for liver, 0.46?±?0.13 for muscle, 9.09?±?0.49 for adipose tissue, and 0.22?±?0.04 for other organs. With these results, a value of 0.414 for the blood-to-air partition coefficient was calculated by means of our physiologically based pharmacokinetic model. The time variation of radon activity concentration in mouse blood during exposure to radon was also calculated. All results are compared in detail with those found in the literature.     

Study of uranium level in groundwater of Balod district of Chhattisgarh state,India and assessment of health risk

Uranium contamination in groundwater at Balod district of Chhattisgarh state was measured by laser fluorimetric technique. Most of the samples were found under safe limit for uranium contamination as recommended by WHO and USEPA (<30 µg l^?1) except Deur Tarai village (78.93 µg l^?1).The excess lifetime carcinogenic risk and chemical risk due to ingestion of groundwater were calculated using USEPA recommendations.     

Preliminary dose estimation from indoor radon for the medical staff of Radiation Oncology and Nuclear Medicine

The aim of this preliminary study was to measure the indoor radon activity concentration in the houses and offices of Radiation Oncology and Nuclear Medicine staff at Dokuz Eylül University and to assess the results from a radiological perspective. LR-115 type II solid-state nuclear track detectors were installed in the homes and hospital and were exposed for 2 months. LR-115 type II detectors were etched for 90 min in 10% (2.5 M) NaOH solution at 60°C and radon activity concentration was determined from observed microscopic track densities. It was observed that measured indoor radon concentration ranged between 18 and 624 Bq/m³ with a geometric mean of 95 Bq/m³ in hospital, and between 22 and 560 Bq/m³ with a geometric mean of 129 Bq/m³ in homes. Estimates of the annual effective dose received by medical staff who participated in the study ranged between 0.76 and 8.79 mSv. On average, the hospital building contributed 41% to the annual effective dose. The reported values for radon concentrations and the corresponding estimated annual effective equivalent doses were within the limits recommended by the International Commission on Radiological Protection as well as the Turkish Atomic Energy Commission recommended limits for workplaces and houses.     

Assessments of 226Ra and 222Rn concentration in well and tap water from Sik,Malaysia, and consequent dose estimates

Abstract

The ingestion of ²²⁶Ra, inhalation, and ingestion of ²²²Rn in water is considered the primary health risk for lungs and stomach. This study presents the concentrations of ²²⁶Ra and ²²²Rn in well and tap water collected from Sik, Malaysia, using HPGe and RAD7 detectors. Maximum average concentrations of ²²⁶Ra and ²²²Rn were found 47.6?±?3.6 mBq/l and 9.3?±?1.4?Bq/l in well water, respectively, and minimum were found 17.1?±?3.6 mBq/l and 1.6?±?1.0?Bq/l in tap water, respectively. A positive correlation (R=.88) was found between ²²⁶Ra and ²²²Rn determined by HPGe and RAD7 detectors, respectively. Infants in the age group of 0–1 y appeared to be at risk with respect to the annual effective doses from ²²⁶Ra and ²²²Rn as compared to the other age groups. However, annual effective doses for all three age groups from intake of ²²⁶Ra and ²²²Rn in well and tap drinking water were found below the World Health Organization (WHO) recommended level of .1 mSv/y_.     

Does balneotherapy with low radon concentration in water influence the endocrine system? A controlled non-randomized pilot study

Radon bath is a well-established modality of balneotherapy for the management of degenerative musculoskeletal disorders. The present study was conducted to ascertain whether baths of relatively low (80 Bq/l) radon concentration have any influence on the functioning of the endocrine system. In the study, a non-randomized pilot study, 27 patients with degenerative musculoskeletal disorders received 30-min radon baths (of 31–32°C temperature and 80 Bq/l average radon concentration) daily, for 15 days. Twenty-five patients with matching pathologies were subjected to balneotherapy according to the same protocol, using thermal water with negligible radon content (6 Bq/l). Serum thyroid stimulating hormone, prolactin, cortisol, adrenocorticotropic hormone, and dehydroepiandrosterone levels were measured before and after a balneotherapy course of 15 sessions. Comparison of the accumulated data using the Wilcoxon test did not reveal any significant difference between pre- and post-treatment values or between the two patient groups. It is noted that while the beneficial effects of balneotherapy with radon-containing water on degenerative disorders is widely known, only few data have been published in the literature on its effect on endocrine functions. The present study failed to demonstrate any substantial effect of thermal water with relatively low radon content on the functioning of the endocrine system.     

Quantitative health impact of indoor radon in France

Radon is the second leading cause of lung cancer after smoking. Since the previous quantitative risk assessment of indoor radon conducted in France, input data have changed such as, estimates of indoor radon concentrations, lung cancer rates and the prevalence of tobacco consumption. The aim of this work was to update the risk assessment of lung cancer mortality attributable to indoor radon in France using recent risk models and data, improving the consideration of smoking, and providing results at a fine geographical scale. The data used were population data (2012), vital statistics on death from lung cancer (2008–2012), domestic radon exposure from a recent database that combines measurement results of indoor radon concentration and the geogenic radon potential map for France (2015), and smoking prevalence (2010). The risk model used was derived from a European epidemiological study, considering that lung cancer risk increased by 16% per 100 becquerels per cubic meter (Bq/m³) indoor radon concentration. The estimated number of lung cancer deaths attributable to indoor radon exposure is about 3000 (1000; 5000), which corresponds to about 10% of all lung cancer deaths each year in France. About 33% of lung cancer deaths attributable to radon are due to exposure levels above 100 Bq/m³. Considering the combined effect of tobacco and radon, the study shows that 75% of estimated radon-attributable lung cancer deaths occur among current smokers, 20% among ex-smokers and 5% among never-smokers. It is concluded that the results of this study, which are based on precise estimates of indoor radon concentrations at finest geographical scale, can serve as a basis for defining French policy against radon risk.     

Occurrence of radon in some schools of Parma and Reggio Emilia (Northern Italy)

Summary Forty-seven measurement of radon concentration were made in some schools of Parma, Reggio Emilia, Albinea and Borzano. The method used was that of activated carbon canisters, which were placed in classrooms, laboratories, libraries and headmaster's offices for at least 48 hours in the period November '90–March '91. It was possible to determine the amount of radon in each canister counting the Pb-214 and Bi-214 gamma emitters by means of NaI (Tl) and Ge (I) detectors. The mean radon concentrations were: 20 Bq/m³ in Parma; 24 Bq/m³ in Reggio Emilia; 46 Bq/m³ in Borzano and 52 Bq/m³ in Albinea. The values recorded in schools are similar to the values previously recorded in dwellings of Parma and Reggio Emilia.     

Risk assessment of natural radioactivity in surface water and sediments from a waterfall site in Osun State,Nigeria

Activity concentration of natural radionuclides in surface water and sediment from a waterfall site, Erin-Oke, Osun, Nigeria, has been determined by gamma spectrometry. The mean activity concentration of ⁴⁰K, ²²⁶Ra, and ²³²Th were estimated to be 61.015 ± 15.50, 8.165 ± 2.05 and 5.24 ± 1.57 Bq/l, respectively in water samples and 172.023 ± 35.433, 19.282 ± 4.95, and 17.089 ± 4.37 Bq/kg respectively in sediment samples. Total annual effective dose ingested by an individual ranges from 10.73 ± 3.36 to 15.18 ± 4.44 mSv/y, 2.50 ± 0.80 to 3.58 ± 0.96 mSv/y, and 2.30 ± 0.72 to 3.23 ± 0.93 mSv/y, with mean values of 13.25 ± 3.89, 3.10 ± 0.90, and 2.83 ± 0.83 mSv/y for infants, children, and adults, respectively. These values are greater than International Commission on Radiological Protection (ICRP) and the World Health Organization's recommended limit of 1.0 and 0.1 msv/y, respectively. Mean activity concentrations in sediment are 172.023 ± 35.433, 19.823 ± 4.95, and 17.089 ± 4.37 Bq/kg for ⁴⁰K, ²²⁶Ra, and ²³²Th, respectively, with mean absorbed dose of 26.91 nGyh^?1. This value is lesser than UNSCEAR world average value of 55 nGyh^?1. Health hazard index and radium equivalent for sediments showed lower values than absorbable limits.     

Deposition of radon progeny on skin surfaces and resulting radiation doses in radon therapy

In the Gastein valley, Austria, radon-rich thermal water and air have been used for decades for the treatment of various diseases. To explore the exposure pathway of radon progeny adsorbed to the skin, progeny activities on the skin of patients exposed to thermal water (in a bathtub) and hot vapour (in a vapour chamber) were measured by alpha spectrometry. Average total alpha activities on the patients’ skin varied from 1.2 to 4.1 Bq/cm² in the bathtub, and from 1.1 to 2.6 Bq/cm² in the vapour bath. Water pH-value and ion concentration did affect radon progeny adsorption on the skin, whereas skin greasiness and blood circulation did not. Measurements of the penetration of deposited radon progeny into the skin revealed a roughly exponential activity distribution in the upper layers of the skin. Based on the radon progeny surface activity concentrations and their depth distributions, equivalent doses to different layers of the skin, in particular to the Langerhans cells located in the epidermis, ranged from 0.12 mSv in the thermal bath to 0.33 mSv in the vapour bath, exceeding equivalent doses to the inner organs (kidneys) by inhaled radon and progeny by about a factor 3, except for the lung, which receives the highest doses via inhalation. These results suggest that radon progeny attachment on skin surfaces may play a major role in the dosimetry for both thermal water and hot vapour treatment schemes.     

Radon in Norwegian dwellings and the feasibility of epidemiological studies

Summary The results of a pilot study on radon in Norwegian dwellings are presented together with a discussion on the feasibility of an epidemiological study on the correlation between lung cancer and radon progeny exposure in dwellings. There are large variations in the mean radon concentration in Norwegian municipalities, and the population average indoor radon concentration is high (80–100 Bq m^–3). The large variations and high absolute values, together with excellent lung cancer and smoking habit data, make it feasible to conduct epidemiological studies based on representative exposure data in the Norwegian population.     

Absorbed doses of lungs from radon retained in airway lumens of mice and rats

This paper provides absorbed doses arising from radon gas in air retained in lung airway lumens. Because radon gas exposure experiments often use small animals, the calculation was performed for mice and rats. For reference, the corresponding computations were also done for humans. Assuming that radon concentration in airway lumens is the same as that in the environment, its progeny’s production in and clearance from airways were simulated. Absorbed dose rates were obtained for three lung regions and the whole lung, considering that secretory and basal cells are sensitive to radiation. The results showed that absorbed dose rates for all lung regions and whole lung generally increase from mice to rats to humans. For example, the dose rates for the whole lung were 25.4 in mice, 41.7 in rats, and 59.9 pGy (Bq m^?3)^?1 h^?1 in humans. Furthermore, these values were also compared with lung dose rates from two other types of exposures, that is, due to inhalation of radon or its progeny, which were already reported. It was confirmed that the direct inhalation of radon progeny in the natural environment, which is known as a cause of lung cancer, results in the highest dose rates for all species. Based on the present calculations, absorbed dose rates of the whole lung from radon gas were lower by a factor of about 550 (mice), 200 (rats), or 70 (humans) than those from radon progeny inhalation. The calculated dose rate values are comparatively small. Nevertheless, the present study is considered to contribute to our understanding of doses from inhalation of radon and its progeny.     

Human health risk assessment of trace elements in shallow groundwater of the Linhuan coal-mining district,Northern Anhui Province,China

Enrichment of trace elements in groundwater poses considerable risks to human health. The concentrations of seven trace elements (Cr, Mn, Ni, Cu, Zn, Cd, and Pb) in 34 samples of shallow groundwater from the study area were estimated. We assessed the concentrations of the trace elements and health risks with statistical analysis and the US Environment Protection Agency (USEPA) model. The results showed that the mean concentrations of trace elements decreased as follows: Mn > Zn > Ni > Cr > Cu > Cd > Pb. Apart from Mn at one sampling point, the concentrations of all trace elements were below the guideline values of the World Health Organization for drinking water. Correlation and cluster analysis indicated that the trace elements fell into groups, with Ni and Cu in one group, and Mn, Zn, and Cd in another, which suggested that the trace elements grouped together had similar sources. The total non-carcinogenic risk values ranged from 8.52 × 10^?4 to 1.27 × 10^?1. The total carcinogenic risk caused by Cr and Cd averaged 1.62 × 10^?6, which exceeded the acceptable level of 1 × 10^?6 recommended by the USEPA. The carcinogenic risk of Cr accounted for 75.93% of R_total.