WorldWideScience

Sample records for alpha-emitters radon lung

  1. High-LET alpha-emitters: Radon, lung cancer and smoking

    International Nuclear Information System (INIS)

    The National Academy of Sciences BEIR IV Report deals with the health effects in human populations exposed to internally-deposited alpha-emitting radionuclides and their decay products. Quantitative risk estimates for cancer induction are derived, mainly from analyses of epidemiological data. The Report addresses the health outcomes of exposure to radon and its daughters, primarily lung cancer risks of worker exposure to radon progeny in underground mines and in the general public in indoor domestic environments. An excess relative risk model of lung cancer mortality and exposure to radon progeny is developed; this models the excess risk per Working Level Month in terms of time intervals prior to an attained age, and is dependent on time-since-exposure and age at risk. Risk projections are presented and cover exposure situations of current public health concern. For example, lifetime exposure to 1 WLM y/sup /minus/1/ is estimated to increase the number of deaths due to lung cancer by a factor of about 1.5 over the current rate for both males and females in a population having the current prevalence of cigarette-smoking. Occupational exposure to 4 WLM y/sup /minus/1/ from ages 20 y to 40 y is projected to increase lung cancer deaths by a factor of 1.6 over the current rate of this age cohort in the general population. In all of these cases, most of the increased risk occurs to smokers for whom the risk is up to ten times greater than for non-smokers. 8 refs., 1 tab

  2. Microscopic dose to lung from inhaled alpha emitters in humans

    International Nuclear Information System (INIS)

    Because of the short range of alpha particles in tissue, the degree of uniformity of irradiation of the lung varies greatly depending on the form of the inhaled material. Animal studies have shown that the degree of dose uniformity influences the risk of lung cancer. This study investigates the radiation dose distribution of plutonium in human lung. Numerical maps of tissue configuration and target cell locations are obtained from histological sections of human lung tissue stained to enhance the identification of putative cell types for parenchymal lung cancers, i.e. alveolar type II cells and Clara cells. Monte Carlo simulations are used to obtain dose distribution around individual particles, and these distributions are used to compute dose distribution in volumes of lung tissue. Lung dose is characterised both by the degree of non-uniformity of irradiation and the relative degree of irradiation of all tissue versus the special cells of interest. (authors)

  3. Alpha-emitters in the workplace

    International Nuclear Information System (INIS)

    A number of groups of workers have been exposed to α;-particle-emitting radionuclides, of particular importance being the radium dial painters, underground hard rock miners exposed to radon and its decay products, and, more recently, plutonium workers. These occupationally exposed groups are of interest because they allow the direct study of the health effects of exposure to alpha-emitters and the comparison with the level of such effects present among groups exposed predominantly to external sources of low-LET radiation. Hence, these worker groups are important in testing the assumptions that underlie radiological protection. The radium dial painters experienced a pronounced excess of bone cancers and cancers of the paranasal sinuses and mastoid air cells, while a clear radon-related excess of lung cancer is present among the underground hard rock miners. There is little evidence for a radiation-related excess risk of other cancers being present in these groups. A number of groups of workers have been exposed to plutonium in the weapons and civil nuclear industries. The group of plutonium workers at the Mayak nuclear facility in Russia is especially important because of the large numbers exposed to high levels. The Mayak workers have pronounced plutonium-related excess risks of lung, liver and bone cancers, and possibly of other solid tumours, but not leukaemia. Where organ-specific internal doses have been derived, which is presently confined to the lung, risk coefficients are compatible with predictions based on standard models. However, further investigations of the Mayak workforce are required before reliable risk estimates for plutonium exposure may be derived, but this group of workers has the potential of generating definitive risk coefficients for health effects arising from exposure to plutonium. (orig.)

  4. Lung cancer risk of low-level exposures to alpha emitters: critical reappraisal and experiments based on a new cytodynamic model

    Energy Technology Data Exchange (ETDEWEB)

    Bogen, Kenneth T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-02-20

    Ecologic U.S. county data suggest negative associations between residential radon exposure and lung cancer mortality (LCM)-inconsistent with clearly positive associations revealed by occupational data on individual miners, but perhaps explained by competing effects of cell killing vs. mutations in alpha-exposed bronchial epithelium. To assess the latter possibility, a biologically based "cytodynamic 2-stage" (CD2) cancer-risk model was fit to combined 1950-54 age- specific person-year data on lung cancer mortality (LCM) in white females of age 40+ y in 2,821 U.S. counties (-90% never-smokers), and in 5 cohorts of underground miners who never smoked. New estimates of household annual average radon exposure in U.S. counties were used, which were found to have a significant negative ecologic association with 1950-54 LCM in U.S. white females, adjusted for age and all subsets of two among 21 socioeconomic, climatic and other factors considered. A good CD2 fit was obtained to the combined residential/miner data, using biologically plausible parameter values. Without further optimization, the fit also predicted independent inverse dose-rate effects shown (for the first time) to occur in nonsmoking miners. Using the same U.S. county-level LCM data, a separate study revealed a positive ecologic association between LCM and bituminous coal use in the U.S., in agreement with epidemiological data on LCM in women in China. The modeling results obtained are consistent with the CD2-based hypothesis that residential radon exposure has a nonlinear U-shaped relation to LCM risk, and that current linear no-threshold extrapolation models substantially overestimate such risk. A U-shaped dose-response corresponds to a CD2-model prediction that alpha radiation kills more premalignant cells than it generates at low exposure levels, but not at higher levels. To test this hypothesis, groups of Japanese medaka (ricefish minnows) were exposed for 10 to 14 weeks to different concentrations of

  5. Radon and radiation biology of the lung

    International Nuclear Information System (INIS)

    The main papers presented at the meeting dealt with the behaviour of radon and the indoor environment, radiation biology of the lung, lung dosis and the possible cancer risk caused by radon in homes, contamination of the room air. A series of special papers treated the radon problem in detail: sources and transport mechanisms of radon, geological aspects of the radon radiation burden in Switzerland, radon in homes, search for radon sources, and the Swiss radon-programme RAPROS. 67 figs., 13 tabs., 75 refs

  6. Instrument for measuring total alpha particle energies of alpha emitters in ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberg, S.; Brucker, G.J.; Cummings, B.; Bechtel, E.; Gentner, F.; Horne, S

    2000-11-11

    This paper describes the design, fabrication, testing and evaluation of a self-reading, carbon fiber, electrometer-type instrument. It is used for measuring the total energy of alpha particles emitted in air by progenies of {sup 222}Rn ({sup 218}Po, {sup 214}Pb, and {sup 214}Bi), and sometimes by other types of alpha emitters (e.g. {sup 212}Pb, {sup 238}U, and {sup 239}Pu). The purpose of these measurements is to assess the energy delivered by alpha emission from these sources to the lung tissue. A sample (charged progenies attached to aerosols) is collected on filter paper from a known volume of air and placed on the instrument. The discharge rate indicates the alpha energy in MeV l{sup -1} of air per min that is produced by the alpha emitters. The calibration procedure shows that the instrument has an energy sensitivity for alpha particles of 800.5 MeV/scale unit. The range of the readout scale is 30 units. Measurements of alpha contamination in air were made using this instrument in buildings, private homes and in a standard chamber. The value of the radon concentration in this chamber is traceable back to the US Environmental Protection Agency (EPA) and to the National Institute of Standards and Technology (NIST)

  7. Indoor radon and lung cancer in China

    International Nuclear Information System (INIS)

    Radon has long been known to contribute to risk of lung cancer, especially in undergound miners who are exposed to large amounts of the carcinogen. Recently, however, lower amounts of radon present in living areas have been suggested as an important cause of lung cancer. In an effort to clarify the relationship of low amounts of radon with lung cancer risk, we placed alpha-track radon detectors in the homes of 308 women with newly diagnosed lung cancer and 356 randomly selected female control subjects of similar age. Measurements were taken after 1 year. All study participants were part of the general population of Shenyang, People's Republic of China, an industrial city in the northeast part of the country that has one of the world's highest rates of lung cancer in women. The median time of residence in the homes was 24 years. The median household radon level was 2.3 pCi/L of air; 20% of the levels were greater than 4 pCi/L. Radon levels tended to be higher in single-story houses or on the first floor of multiple-story dwellings, and they were also higher in houses with increased levels of indoor air pollution from coal-burning stoves. However, the levels were not higher in homes of women who developed lung cancer than in homes of controls, nor did lung cancer risk increase with increasing radon level. No association between radon and lung cancer was observed regardless of cigarette-smoking status, except for a nonsignificant trend among heavy smokers. No positive associations of lung cancer cell type with radon were observed, except for a nonsignificant excess risk of small cell cancers among the more heavily exposed residents. Our data suggest that projections from surveys of miners exposed to high radon levels may have overestimated the overall risks of lung cancer associated with levels typically seen in homes in this Chinese city

  8. Risk estimates for exposure to alpha emitters

    International Nuclear Information System (INIS)

    The primary scope of this report is to evaluate the risk of lung cancer from occupational exposure to short-lived daughters of radon and thoron. The Subcommittee on Risk Estimates considers that inhalation of radon and thoron daughters is the major radiation hazard from alpha radiation in uranium mining. The secondary scope of this report is the consideration of the applicability of the risk estimates derived from miners to the general public. The risk to members of the public from radium-226 in drinking water is also considered. Some research requirments are suggested

  9. Models for comparing lung-cancer risks in radon- and plutonium-exposed experimental animals

    International Nuclear Information System (INIS)

    Epidemiologic studies of radon-exposed underground miners have provided the primary basis for estimating human lung-cancer risks resulting from radon exposure. These studies are sometimes used to estimate lung-cancer risks resulting from exposure to other alpha- emitters as well. The latter use, often referred to as the dosimetric approach, is based on the assumption that a specified dose to the lung produces the same lung-tumor risk regardless of the substance producing the dose. At Pacific Northwest Laboratory, experiments have been conducted in which laboratory rodents have been given inhalation exposures to radon and to plutonium (239PuO2). These experiments offer a unique opportunity to compare risks, and thus to investigate the validity of the dosimetric approach. This comparison is made most effectively by modeling the age-specific risk as a function of dose in a way that is comparable to analyses of human data. Such modeling requires assumptions about whether tumors are the cause of death or whether they are found incidental to death from other causes. Results based on the assumption that tumors are fatal indicate that the radon and plutonium dose-response curves differ, with a linear function providing a good description of the radon data, and a pure quadratic function providing a good description of the plutonium data. However, results based on the assumption that tumors are incidental to death indicate that the dose-response curves for the two exposures are very similar, and thus support the dosimetric approach. 14 refs., 2 figs., 6 tabs

  10. Measurement of alpha emitters in radioactive waste

    International Nuclear Information System (INIS)

    The alpha emitters measurement in radioactive waste (10-2Ci/T) is essential for a good fissil materials management. This paper describes 3 classes of devices: device using a neutronic passive counting, device using a neutronic activation and detection of fission gamma, device using a neutronic activation and detection of prompt neutrons fission

  11. Radon and lung cancer in Spain

    International Nuclear Information System (INIS)

    It is known that the incidence of lung cancer is related to inhalation of radon and radon daughters. However, the magnitude of the risk and its dependence upon physiological and environmental factors are still not well defined either experimentally or epidemiologically. Occupational studies of underground miners are the only available human epidemiological information to estimate the risk of exposure to radon daughters in the indoor environment. The results are shown of a study carried out to determine whether lung cancer mortality rates in Spain are significantly correlated with the average indoor radon levels. For this purpose, we have used indoor radon data generated from the national survey carried out in 1989. Lung cancer distribution by cities and deaths, by year of death and sex, were retrieved for each of the different provinces of Spain for the period 1960-1985, showing the evolution and changes in the incidence of lung cancer in the population. Data referring to the evolution of lung cancer for males and females from 1940 until 1985 are also shown. Since cigarette smoking has been linked to lung cancer the effect of smoking habits in the Spanish population was also considered in this analysis. The first results of this study establish no clear evidence of any substantial association between lung cancer mortality rates and indoor radon for males. However, a relationship was evident for females. (author)

  12. American Lung Association's radon public information program

    International Nuclear Information System (INIS)

    The American Lung Association (ALA), the nation's oldest voluntary health organization, is dedicated to the conquest of lung disease and the promotion of lung health. The objective of the ALA Radon Public Information Program is to reduce public exposure to elevated indoor radon levels through implementing grassroots-based radon public awareness campaigns by 22 local ALA groups. The program, which is funded by a grant from the US Environmental Protection Agency (EPA), was initiated in December 1989; the first phase will continue until May, 1991. Activities of local Lung Associations include distribution of free or reduced-cost radon kits; presenting programs in elementary and secondary schools; presenting information on TV news series and talk shows, and on radio Public Service Announcements and talk shows; presenting articles and feature stories in the print media; holding conferences, workshops, and displays at fairs and other exhibitions; distributing radon fact sheets through libraries and utility company mailings; and distributing videos through video chains and libraries. The local Lung Associations also serve as promoters for the EPA/Advertising Council Radon Public Service Announcement Campaign. We will highlight the activities of the groups in communicating radon health risks to the public; we will describe the results obtained and will attempt to evaluate the merits of the various approaches on the basis of the initial results

  13. Czech studies of lung cancer and radon

    International Nuclear Information System (INIS)

    According to the International Agency for Research on Cancer, there is a significant evidence to classify radon as a carcinogen. Using extrapolations from occupational studies, it can be shown that for some countries environmental exposure to radon is the second most important cause of lung cancer in the general population after cigarette smoking. Czech studies among uranium miners, established in 1970 by Josef Sevc, and in the general population aim to contribute to knowledge on the risk from radon, particularly by evaluating temporal factors and interaction of radon exposure and smoking

  14. Lung cancer and radon in dwellings

    International Nuclear Information System (INIS)

    Positive correlations between radon and lung cancer have been found only for mine workers but not for the general population in dwellings. In this study we are looking for a connection between the mean radon values in 41 different regions of Switzerland and the corresponding lung cancer mortalities. For yound woman in general and young men and young women from rural areas a correlation was found. Such calculations, however, do not prove a causal connection, since they use only present day radon levels and can account neither for their temporal variations nor for the mobility and life habits of the population or for the real amount of time spent inside the dwellings. (orig.)

  15. Relation between indoor radon and lung cancer

    International Nuclear Information System (INIS)

    Objective: Low level of exposures to residential radon and dosimetric uncertainties due to mobility have hampered the evaluation of lung cancer risk and the comparison to radon-exposed miners. To address these limitations, the authors conducted a case-control study in a predominantly rural area of China with low mobility and high radon levels. Methods: Cases studied including all lung cancer patients diagnosed between January 1994 and April 1998, aged 30-75 years, and resided in two prefectures of Gansu Province. Controls were randomly selected from census lists and matched on age sex and prefecture. Radon detectors were placed in all houses having been occupied two or more years in the past 5-30 years prior to enrollment. Measurements covered 77% of the possible exposure time. Results: Mean radon concentration were 230.4 Bq/m3 for the cases (n = 768) and 222.2 Bq/m3 for the controls (n = 1659). Lung cancer risk increased along with increasing of the radon level (P 3 was 0.19 (95% CI:0.05, 0.47) for all subjects, and 0.31(95% CI:0.10, 0.81) for subjects with 100% coverage of the exposure interval. Adjusting for exposure uncertainties increased estimates about 70%. Conclusion: The results support increased lung cancer risks with indoor radon exposures, which may equal to or exceed extrapolation-based risks from miner data

  16. Alpha-emitters for medical therapy workshop

    Energy Technology Data Exchange (ETDEWEB)

    Feinendegen, L.E.; McClure, J.J.

    1996-12-31

    A workshop on ``Alpha-Emitters for Medical Therapy`` was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference.

  17. Alpha-emitters for medical therapy workshop

    International Nuclear Information System (INIS)

    A workshop on ''Alpha-Emitters for Medical Therapy'' was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference

  18. Chronic smoker lung dosimetry of radon progeny

    International Nuclear Information System (INIS)

    The purpose of this study is to determine how cigarette smoking affects the dose of radon progeny in the lungs. An extensive survey of the medical literature suggests that about six physiological parameters may influence deposition as well as clearance of radon progeny and thus, affecting the resulting doses received by sensitive bronchial target cells. The calculations reflect a difference between the dose of a nonsmoker lung and the lung of the heavy long-term smoker, of a multiplicative factor 1,8. (authors)

  19. Lung pathology and exposure to radon daughters

    International Nuclear Information System (INIS)

    The data presented suggest that the primary carcinogen of lung cancer in uranium miners is cigarette smoking because the incidence of lung cancer in noncigarette smokers is insignificant. In cigarette-smoking uranium miners, however, the incidence of cancer in those exposed to significant amounts of radon daughters is higher than in the smoking, nonmining population. This suggests that radon is an additive carcinogen if the lung has been injured by the cigarette-smoking carcinogen. Preliminary studies measuring DNA, T cells, and rosette inhibition immunological studies indicate closer monitoring of uranium miners' health during this occupation may be justified

  20. Radon potential, geologic formations, and lung cancer risk

    OpenAIRE

    Hahn, Ellen J.; Yevgeniya Gokun; William M. Andrews Jr.; Bethany L. Overfield; Heather Robertson; Amanda Wiggins; Mary Kay Rayens

    2015-01-01

    Objective: Exposure to radon is associated with approximately 10% of U.S. lung cancer cases. Geologic rock units have varying concentrations of uranium, producing fluctuating amounts of radon. This exploratory study examined the spatial and statistical associations between radon values and geological formations to illustrate potential population-level lung cancer risk from radon exposure. Method: This was a secondary data analysis of observed radon values collected in 1987 from homes (N = ...

  1. Environmental radon and lung cancer risk

    International Nuclear Information System (INIS)

    Data on lung cancer (LC) deaths have been collected from OPCS statistics for England and Wales over the period 1950-1987. The male deaths after an initial increase levelled off in the seventies; the female deaths remained fairly constant during the fifties and mid-sixties, followed by a sharp rise which is continuing. Employing ICRP 50 analysis of U-miners, a small positive correlation has been found between the female LC-deaths in the fifties and the radon concentrations as obtained by the NPRB national survey. The male and female LC-deaths in five countries with the highest radon concentrations as calculated by the BEIR IV procedure, do not correlate well with the OPCS values. It is concluded that the use of US statistics in the calculation, the inaccuracy of radon concentration values and the basis of the BEIR IV report itself possibly contributed to the disagreement. (author)

  2. Calculated lung cancer mortality due to radon

    International Nuclear Information System (INIS)

    From studies of miners, it is clear that an exposure to high concentrations of radon daughters leads to an increased incidence of lung cancer. In this Chapter the authors discuss how the experience for miners is used to estimate the incidence of radon-induced lung cancer among the general population. Such estimates cannot be very precise, in part because the miners studies do not lead to a well-determined relationship between the rate of cancer induction and the exposure levels. In particular, there are disparities in the results of studies for different groups of miners. These disparities may arise from the difficulties in obtaining accurate crucial data, such as the year-by-year exposure history over the working lifetime of the individual miners. Other differences may arise from differences in the smoking patterns in different groups and in details of the handling of the data. In any event, there remain substantial uncertainties in the conclusions for the miners themselves, both as to the ''average'' rate of cancer induction per WLM and as to the variation of this rate with the magnitude of the total exposure. Further, there are problems in using results obtained for miners at relatively high radon exposure levels for the prediction of the effects of radon at the much lower levels encountered in the normal indoor environment. Here one faces the problem of extrapolating from large dose levels to small dose levels. The generally adopted solution is to assume linearity

  3. Lung cancer and radon daughter exposure in mines and dwellings

    International Nuclear Information System (INIS)

    Four case-referent studies have been undertaken, two regarding miners with occupational exposure to radon and radon daughters and two regarding rural populations with indoor radon daughter exposure. Furthermore, a correlation study was perfomed with regard to background gamma radiation, assumed to correlate with radon emanation, and the countyspecific, directly age-standardized lung cancer mortality. The results as well as other facts indicate that radiation might be important for the initiation of lung cancer, and that smoking is likely to mainly act as a promoter. In mines, exposure to radon and its daughters is associated with a substantial risk for lung cancer, but there seems to be a complex relationship between radon and radon daughter exposure and smoking since smoking also causes bronchitis, hindering the exposure of the epithelium to the very short ranging alpha radiation, resulting in a more or less additive relation between radon daughter exposure and smoking. In dwellings a multiplicative interaction between the two factors is rather clearly pronounced, however. The studies in the rural polulations as well as the correlation study strengthen the hypothesis that exposure to radon and radon daughters in dwellings is pertinent to the question of the etiology of lung cancer. Calculations of etiological fractions suggest that about 30% of the lung cancer mortality in the population might be due to avoidable indoor exposure to radon and radon daughters

  4. Modelling high redshift Lyman-alpha Emitters

    CERN Document Server

    Garel, Thibault; Guiderdoni, Bruno; Schaerer, Daniel; Verhamme, Anne; Hayes, Matthew

    2012-01-01

    We present a new model for high redshift Lyman-Alpha Emitters (LAEs) in the cosmological context which takes into account the resonant scattering of Ly-a photons through expanding gas. The GALICS semi-analytic model provides us with the physical properties of a large sample of high redshift galaxies. We implement a gas outflow model for each galaxy based on simple scaling arguments. The coupling with a library of numerical experiments of Ly-a transfer through expanding or static dusty shells of gas allows us to derive the Ly-a escape fractions and profiles. The predicted distribution of Ly-a photons escape fraction shows that galaxies with a low star formation rate have a f_esc of the order of unity, suggesting that, for those objects, Ly-a may be used to trace the star formation rate assuming a given conversion law. In galaxies forming stars intensely, the escape fraction spans the whole range from 0 to 1. The model is able to get a good match to the UV and Ly-a luminosity function (LF) data at 3 < z <...

  5. Age dependence and latency periods for lung cancer from radon

    International Nuclear Information System (INIS)

    Children are exposed as much, or even more, than adults to domestic radon. As children are supposed to be more sensitive to radiation, childhood exposure should cause more lung cancer than exposure at elderly ages. Assuming a latency period of 20 years, as found for lung cancer for miners, the lung cancer cases from radon should be expected to start in the age groups between 20-35 years. Even in high radon countries, as for example Sweden and the other Nordic countries, lung cancer is very rare in the age group of less than 35 years. Thus, either children do not seem to be very sensitive to radon or the latency period is longer. Assuming a latency period of 35 years, instead, the expected lung cancer cases from domestic radon to children should be expected in the age group 35-50 years. Although the lung cancer cases start rising in that age period, most of the lung cancer cases are at much higher ages. Most of the lung cancer cases occur among heavy smokers and smoking is considered the by far highest risk factor for lung cancer. Children are generally not smokers. Thus it should be of great value to study the relationship between lung cancer and domestic radon for this age group. The lack of lung cancer cases at younger ages makes such a study difficult. At elderly ages, the smoking habits make a study of the relationship between domestic radon and lung cancer difficult and inexact. It could be suggested that lung cancer starts about 20 years after smoking debut, both what concerns radon related and smoking related lung cancer

  6. Sex and smoking sensitive model of radon induced lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhukovsky, M.; Yarmoshenko, I. [Institute of Industrial Ecology of Ural Branch of Russian Academy of Sciences, Yekaterinburg (Russian Federation)

    2006-07-01

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  7. Sex and smoking sensitive model of radon induced lung cancer

    International Nuclear Information System (INIS)

    Radon and radon progeny inhalation exposure are recognized to cause lung cancer. Only strong evidence of radon exposure health effects was results of epidemiological studies among underground miners. Any single epidemiological study among population failed to find reliable lung cancer risk due to indoor radon exposure. Indoor radon induced lung cancer risk models were developed exclusively basing on extrapolation of miners data. Meta analyses of indoor radon and lung cancer case control studies allowed only little improvements in approaches to radon induced lung cancer risk projections. Valuable data on characteristics of indoor radon health effects could be obtained after systematic analysis of pooled data from single residential radon studies. Two such analyses are recently published. Available new and previous data of epidemiological studies of workers and general population exposed to radon and other sources of ionizing radiation allow filling gaps in knowledge of lung cancer association with indoor radon exposure. The model of lung cancer induced by indoor radon exposure is suggested. The key point of this model is the assumption that excess relative risk depends on both sex and smoking habits of individual. This assumption based on data on occupational exposure by radon and plutonium and also on the data on external radiation exposure in Hiroshima and Nagasaki and the data on external exposure in Mayak nuclear facility. For non-corrected data of pooled European and North American studies the increased sensitivity of females to radon exposure is observed. The mean value of ks for non-corrected data obtained from independent source is in very good agreement with the L.S.S. study and Mayak plutonium workers data. Analysis of corrected data of pooled studies showed little influence of sex on E.R.R. value. The most probable cause of such effect is the change of men/women and smokers/nonsmokers ratios in corrected data sets in North American study. More correct

  8. Residential radon and lung cancer incidence in a Danish cohort

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Andersen, Claus Erik; Sørensen, Mette;

    2012-01-01

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993–1997. We followed each cohort member for cancer...... occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used...... to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and...

  9. Residential Radon Exposure and Risk of Lung Cancer in Missouri

    Science.gov (United States)

    A case-control study of lung cancer and residential radon exposure in which investigators carried out both standard year-long air measurements and CR-39 alpha detector measurements (call surface monitors)

  10. Residential radon and lung cancer incidence in a Danish cohort

    International Nuclear Information System (INIS)

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993–1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m3. The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69–1.56) in association with a 100 Bq/m3 higher radon concentration and 1.67 (95% CI: 0.69–4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

  11. Residential radon exposure and lung cancer in Sweden

    International Nuclear Information System (INIS)

    BACKGROUND. Residential radon is the principal source of exposure to ionizing radiation in most countries. To determine the implications for the risk of lung cancer, we performed a nationwide case-control study in Sweden. METHODS. The study included 586 women and 774 men 35 to 74 years of age with lung cancer that was diagnosed between 1980 and 1984. For comparison, 1380 female and 1467 male controls were studied. Radon was measured in 8992 dwellings occupied by the study subjects at some time since 1947. Information on smoking habits and other risk factors for lung cancer was obtained from questionnaires. RESULTS. Radon levels followed a log-normal distribution, with geometric and arithmetic means of 1.6 and 2.9 pCi per liter (60.5 and 106.5 Bq per cubic meter), respectively. The risk of lung cancer increased in relation to both estimated cumulative and time-weighted exposure to radon. In comparison with time-weighted average radon concentrations up to 1.4 pCi per liter (50 Bq per cubic meter), the relative risk was 1.3 (95 percent confidence interval, 1.1 to 1.6) for average radon concentrations of 3.8 to 10.8 pCi per liter (140 to 400 Bq per cubic meter), and it was 1.8 (95 percent confidence interval, 1.1 to 2.9) at concentrations exceeding 10.8 pCi per liter. The estimates of risk were in the same range as those projected from data in miners. The interaction between radon exposure and smoking with regard to lung cancer exceeded additivity and was closer to a multiplicative effect. CONCLUSIONS. Residential exposure to radon is an important cause of lung cancer in the general population. The risks appear consistent with earlier estimates based on data in miners

  12. Residential radon and lung cancer incidence in a Danish cohort

    Energy Technology Data Exchange (ETDEWEB)

    Braeuner, Elvira V., E-mail: ole@cancer.dk [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Danish Building Research Institute, Aalborg University (Denmark); Andersen, Claus E. [Center for Nuclear Technologies, Radiation Research Division, Riso National Laboratory for Sustainable Energy, Technical University of Denmark, Roskilde (Denmark); Sorensen, Mette [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Jovanovic Andersen, Zorana [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Center for Epidemiology Screening, Department of Public Health, University of Copenhagen (Denmark); Gravesen, Peter [Geological Survey of Denmark and Greenland, Copenhagen (Denmark); Ulbak, Kaare [National Institute of Radiation Protection, Herlev (Denmark); Hertel, Ole [Department of Environmental Science, Aarhus University, Aarhus (Denmark); Pedersen, Camilla [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark); Overvad, Kim [Department of Epidemiology, School of Public Health, Aarhus University, Aarhus (Denmark); Tjonneland, Anne; Raaschou-Nielsen, Ole [Diet, Genes and Environment, Danish Cancer Society Research Centre, Copenhagen (Denmark)

    2012-10-15

    High-level occupational radon exposure is an established risk factor for lung cancer. We assessed the long-term association between residential radon and lung cancer risk using a prospective Danish cohort using 57,053 persons recruited during 1993-1997. We followed each cohort member for cancer occurrence until 27 June 2006, identifying 589 lung cancer cases. We traced residential addresses from 1 January 1971 until 27 June 2006 and calculated radon at each of these addresses using information from central databases regarding geology and house construction. Cox proportional hazards models were used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for lung cancer risk associated with residential radon exposure with and without adjustment for sex, smoking variables, education, socio-economic status, occupation, body mass index, air pollution and consumption of fruit and alcohol. Potential effect modification by sex, traffic-related air pollution and environmental tobacco smoke was assessed. Median estimated radon was 35.8 Bq/m{sup 3}. The adjusted IRR for lung cancer was 1.04 (95% CI: 0.69-1.56) in association with a 100 Bq/m{sup 3} higher radon concentration and 1.67 (95% CI: 0.69-4.04) among non-smokers. We found no evidence of effect modification. We find a positive association between radon and lung cancer risk consistent with previous studies but the role of chance cannot be excluded as these associations were not statistically significant. Our results provide valuable information at the low-level radon dose range.

  13. Are radon gas measurements adequate for epidemiological studies and case control studies of radon-induced lung cancer?

    International Nuclear Information System (INIS)

    The lung dose derived from radon is not attributed to the radon gas itself, but instead to its short-lived progeny. However, in many epidemiological studies as well as in case control studies of the radon risk, the excess number of cancers are related to the radon gas exposure, and not to the radon progeny exposure. A justification for such an approach has resorted to the assumption that there is self-compensation between the radiation doses from the unattached and attached fractions. In the present study, we used the Jacobi model to calculate the radon progeny concentrations in a room by varying the attachment rate and then calculated the resulting lung dose. It was found that self-compensation was not fully realised, and the effective dose can vary by a factor up to ∼2 for the same radon gas concentration. In conclusion, the radon gas concentration alone does not provide adequate information on the effective dose. (authors)

  14. Imaging of alpha emitters in a field environment

    International Nuclear Information System (INIS)

    Cameras sensitive to ultraviolet light can be applied to detection of surface contamination induced by alpha particle emitters. When absorbed in air, alpha particles excite nitrogen molecules and the radiative relaxation creates a faint light emission. This radioluminescence can be used for detection purposes, provided that background lighting levels are low. In this work, three low-light sensitive camera technologies (CCD, EMCCD and ICCD) were utilized in a nuclear facility, and their performance in detecting alpha emitters was investigated. The results show that low readout noise is essential for the detection of radioluminescence, as it allows short exposure times to be used. The ICCD camera was found to perform slightly better than the EMCCD camera in the field, while both enable the detection of MBq level alpha activities in 100 s in the test configuration (camera-target distance 0.5 m). Overall, the cameras and techniques used in this study are shown to be effective in detecting alpha emitters in a standard glovebox. This technology can be applied to nuclear security, safety and safeguards, when stand-off detection of alpha emitters is required

  15. Canadian population risk of radon induced lung cancer: a re-assessment based on the recent cross-Canada radon survey

    OpenAIRE

    J. Chen; Moir, D.; Whyte, J.

    2012-01-01

    Exposure to indoor radon has been determined to be the second leading cause of lung cancer after tobacco smoking. Canadian population risk of radon induced lung cancer was assessed in 2005 with the radon distribution characteristics determined from a radon survey carried out in the late 1970s in 19 cities. In that survey, a grab sampling method was used to measure radon levels. The observed radon concentration in 14 000 Canadian homes surveyed followed a log–normal distribution with a geometr...

  16. Non-linearity between dose and cancer risk for internally deposited alpha emitters in animals

    International Nuclear Information System (INIS)

    The risk of cancer in experimental animals exposed to low doses and dose rates of internally deposited alpha emitting radionuclides was analyzed in 27 animal experiments comprising 78 groups exposed to specific dose levels (dose groups). In these experiments, 3041 animals were exposed to eight different alpha emitters, by injection or by inhalation. Radiation doses ranged from about 60 mGy to more than 7 Gy. There were 1655 control animals. The target organs were the lung and the skeleton. The cancer incidence in exposed groups was compared to that predicted by the Linear No-Threshold Hypothesis (LNTH). In the 3041 exposed animals, 49 cancers were observed, against 83 predicted by the LNTHT. The LNTH appears to be a reliable risk predictor in 11 of the 78 dose groups, but it overestimates the risk in the 67 other dose groups (71 predicted cases, 8 cases observed). No cancer was observed in 53 dose groups, when 23 were predicted by the LNTH. In these 53 dose groups, the probability of not observing a single case of cancer was extremely small. These observations led to the conclusion that, at least in the case of alpha emitters with long physical and biological half-lives, the LNTH is not a good predictor of the risk of cancer. (author)

  17. Radon and lung cancer - history and current issues

    International Nuclear Information System (INIS)

    Its historical roots date back to the late middle ages when silver mining was started in the Schneeberg region. Today the problem of mining-associated exposure to radon persists in uranium mining. In addition there is the problem of radon exposure in building which has been detected some 20 years ago. The author briefly surveys the history and causes of radon exposure and resulting issues of modern radiation protection. Inhalation of indoor-air-borne radon decay products in buildings consitutes the greatest shave of the population's exposure to natural and artificial radiation sources. Next to tobacco smoking, these natural radionuclides have to be rated as the most important environmental noxions agent for lung cancer induction. (Uhe)

  18. The use of track registration detectors to reconstruct contemporary and historical airborne radon (222Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

    International Nuclear Information System (INIS)

    Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted 210Po activity density. The implanted activity is used to reconstruct the cumulative radon and radon progeny exposure from the age of the glass and the ratios of the contemporary deposited activities to airborne radon gas activity. We placed over 2500 of these detectors in more than 1000 homes and retrieved 97% of them after a one-year exposure period. A preliminary analysis of the 1280 detectors that have undergone quality assurance review shows that the modules are meeting their accuracy and precision goals (10%). There is good correlation (r2∼0.5) between the total radon exposure estimated from contemporary radon gas measurements and historical average reconstructed from the implanted 210Po surface activity. The linear regression slope of the airborne radon exposure to implanted activity is the same as the room model slope based on typical room parameters. This correlation improves (r2∼0.7) when the deposited surface activity measurements are added to the linear regression. Thus, track-registration detectors can contribute to accurate radon

  19. Lung doses from radon in dwellings and influencing factors

    International Nuclear Information System (INIS)

    The radon concentration in Norwegian dwellings and the lung doses received by the Norwegian population are reported. The biological effects of these doses are discussed. The mean value of radon-daughters in Norwegian dwellings was found to be about 7x10-3 WL (working levels). This corresponds to an annual exposure of about 0.3 WLM (working level months). From studies of the lung cancer statistics of Norway, this exposure may account for about 10% of the annual lung cancer cases in Norway. The variations in the radon concentration inside dwellings are discussed, and the influence of exhalation, ventilation and meteorological parameters upon the respiratory dosage is studied. From the risk estimates performed, the consequences of an increased indoor radon concentration due to reduced ventilation or introduction of building materials with high radium concentrations are discussed. From comparison of the population doses from different sources of radiation, it is evident that a possible future increase in the radon concentration in dwellings is one of the most serious radiation protection problems of our time. (author)

  20. Lung cancer risk by indoor exposure to radon

    International Nuclear Information System (INIS)

    The National Institute of Radiation Hygiene has performed radon measurements in about 1500 homes (blocks of flats excluded). In each dwelling measurements were made for equal time periods in the living room and in one of the bedrooms. All measurements were made during the heating season. The mean concentration of radon during the summer was about 50% of the mean concentration in the winter. This implies that the average annual level is about 75% of the level in the heating season. Based on these measurements it was calculated that the average level of radon decay products is 55 Bq/m3 EER (Equlibrium Equivalent Radon) in dwellings located on the ground floor and/or ground floor and first floor; and 18 Bq/m3 EER in appartments on the first floor. It was estimated that in dwellings on the ground floor and/or ground floor and first floor, about 10% of the dwellings have levels of radon decay products above 100 Bq/m3 EER, 3% levels above 200 Bq/m3 EER and 1% levels above 400 Bq/m3 EER. Approximately 3 million Norwegians are living in dwellings located on the ground floor and/or ground floor and first floor (estimaed dose due to radon: 2.8 mSv/year), while about 400.000 are living in appartments on the first floor (estimated dose due to radon: 1.0 mSv/year). Based on the WHO risk factors it was calculated that in Norway approximately 120 - 360 cases of lung cancer deaths per year are due primarily to indoor exposure to radon and its decay products. This corresponds to about 10 - 30% of all lung cancer deaths in Norway

  1. Modeling Lung Carcinogenesis in Radon-Exposed Miner

    NARCIS (Netherlands)

    Dillen, Teun van; Dekkers, Fieke; Bijwaard, Harmen; Brüske, Irene

    2015-01-01

    Epidemiological miner cohort data used to estimate lung cancer risks related to occupational radon exposure often lack cohort-wide information on exposure to tobacco smoke, a potential confounder and important effect modifier. We have developed a method to project data on smoking habits from a case-

  2. Measurement of Alpha Emitters Concentration in Imported Cigarettes

    International Nuclear Information System (INIS)

    The aime of this study was to measured the alpha emitters concentration of (15) different kinds of imported cigarettes. the nuclear reaction used U-235(n, f) obtained by the bombardment of U-235 with thermal neutrons from (AmBe)neutron source with thermal flux of(5*103 n.cm-2.s-1). The Results obtained showed the values of the Uranium concentration, and varies from (0.041 ppm) in five stares kind to (2.374ppm) in Machbeth (chocolate) 100's kind. All the result obtained are within the limit levels as given by UNSCAR data

  3. Incineration of technological waste contaminated with alpha emitters

    International Nuclear Information System (INIS)

    The French Atomic Energy Commission (CEA), has for several years been engaged in a major program of research and development concerned with the incineration of technological waste contaminated with alpha-emitters. The technical objectives set for this program were: a sizeable reduction in the volume of the waste, ash of a quality suitable for plutonium recovery, built-in flexibility in the operation of the facility, minimum output of secondary waste, nuclear and chemical emissions conforming to accepted standards, and a process entirely consistent with safe practice (with special reference to containment and criticality). This paper discusses how the program was conducted and developed in the laboratory and on a pilot plant

  4. Radon and lung cancer: an epidemiological study in Norway

    International Nuclear Information System (INIS)

    The objectives and strategy of an epidemiological study on the effects of exposure to radon in Norwegian dwellings is presented. The study is a cooperation between the National Institute of Radiation Hygiene and the Norwegian Cancer Registry in Norway and the National Radiological Protection Board of the United Kingdom, with funding by the Norwegian Cancer Society. Measurements of radon are being made in 10,000 dwellings representing all Norwegian municipalities. The potential for detecting an effect of radon exposure by such a study in Norway is unique because: (1) Radon concentrations are high and there are large regional variations. (2) Data from the Norwegian Cancer Registry is of high quality: all cancers have been subject to compulsory reporting since 1955. These data can be broken down according to municipality, sex and age. (3) In 1964/1965 a large scale survey of smoking habits was carried out in Norway. These data can also be broken down according to municipality, sex and age, and by types of smoking and smoking rate. It is intended to examine the correlation between lung cancer incidence and geographical variation in radon levels after making allowance for smoking habits. Radon measurements were started in early 1987 and the results of the study are expected to be published in 1989. (author)

  5. Predicted reduction in lung cancer risk following cessation of smoking and radon exposure

    International Nuclear Information System (INIS)

    Recently there has been considerable public and regulatory concern that radon, produced by the decay of naturally occurring uranium, can accumulate in homes, offices, and schools at levels that may substantially increase the risk of lung cancer. The major cause of lung cancer is smoking, and radon appears to interact multiplicatively with smoking in causing lung cancer. Thus, the most effective way to reduce the increased risk of lung cancer resulting from radon exposure is to cease smoking. In this paper, a model for the risks associated with radon exposure that was developed by a committee of the National Academy of Sciences is used to calculate the benefits, in terms of reduction in lifetime risk of lung cancer, of ceasing to smoke, ceasing radon exposure, or ceasing both. Ceasing to smoke is considerably more beneficial than ceasing radon exposure, and thus policymakers addressing the health effects of radon should place priority on encouraging individuals to stop smoking

  6. Risk of lung cancer by radon, disagreement in international regulation

    International Nuclear Information System (INIS)

    Diverse international organizations have evaluated the risk of lung cancer starting from epidemic studies in miners of uranium mines, where the corresponding effective dose was determined relating with the dose received by the population during Hiroshima and Nagasaki events. Alternately, the equivalent dose has been calculated by means of based models on the energy deposited by the breathable radon fractions and its decay products in the breathing ducts. A unique factor agreed by the diverse organizations that allows converting radon concentration to effective dose does not exist. Neither an agreement exists among the different countries on which duty to be the value of the maximum concentration of radon, in interiors starting from which an intervention is required and if this intervention is standardized, recommended or nonexistent. In this work study cases in Mexico are presented and their interpretation alternative based on the international agreements absence. (Author)

  7. Radon level mapping of indoor air with respect to lung cancer

    International Nuclear Information System (INIS)

    Lung cancer is a stubborn illness to the health of human being. The pathogenicity and the prevention of lung cancer remain to be solved as a world puzzle. However, radon level mapping being an extension of uranium deposit exploration approach, may give help in understanding and investigating the relationship of radon level in living environments to pathological changes of human lung

  8. Conception and optimisation of a new apparatus for the radioactive aerosols alpha emitters measurement in real time

    International Nuclear Information System (INIS)

    The measurement of the atmospheric contaminations due to artificial radioelements alpha emitters (239 Pu, 241 Am, 244 Cm,...) is a very difficult problem to resolve because of the three following reasons: the nature of the radiation to detect; very small activities, which correspond to LDCA; existence in the atmosphere of descendants radon and thoron, which are alpha emitters too. To avoid the drawbacks that the present apparatus present, we have conceived, realised and focused a new apparatus based on the following principals: aerosols collection by gas jet technic on solid state support and measurement in real time under a few millibar pression using a solid detector. First of all, we have tried to make the aerosol collection rate better studying the collector nature and dimension influence, the distance between the collector and the gas jet exit and the air flow. Using different supports, we have shown that the energy resolution is not depending on the support nature, but it depends very much on atmospheric conditions. Direct measurements of the radioactive samples are made by the annular detector insered between the nozzle and the collector. The good resolution, the efficacity and the discrimination of natural and artificial contaminations show off the feasibility of this apparatus

  9. Air pollution, environmental tobacco smoke, radon, and lung cancer

    International Nuclear Information System (INIS)

    The health of populations in industrialized societies has been affected for many years by ambient air pollutants presenting a threat of chronic bronchitis and lung cancer. In the 1980s indoor pollutants received much needed investigation to assess their hazards to health. Exposure to environmental tobacco smoke and radon is now the subject of much research and concern. This review attempts to put some perspective on lung cancer that is attributable to lifetime exposure to airborne pollutants. The view is expressed that air pollution control authorities have played and are playing a major role in health improvement

  10. Molecular characterization of radon-induced rat lung tumors

    International Nuclear Information System (INIS)

    The radon gas is a well known lung carcinogenic factor in human at high doses but the cancer risk at low doses is not established. Indeed, epidemiological studies at low doses are difficult to conduct because of the human exposure to other lung carcinogenic factors. These data underlined the necessity to conduct experiments on lung tumors developed on animal model. The aim of this work was to characterize rat lung tumors by working on a series of radon-induced tumors that included adenocarcinomas (A.C.), squamous cell carcinomas (S.C.C.) and adeno-squamous carcinomas (A.S.C.), that are mixed tumors with both A.C. and S.C.C. cellular components. A C.G.H. analysis of the three types of tumors allowed us to define chromosomal recurrent unbalances and to target candidate genes potentially implicated in lung carcinogenesis, as p16Ink4a, p19Arf, Rb1, K-Ras or c-Myc. A more precise analysis of the p16Ink4a/Cdk4/Rb1 and p19Arf/Mdm2/Tp53 pathways was performed and indicated that the Rb1 pathway was frequently inactivated through an absence of p16Ink4a protein expression, indicating that it has a major role in rat lung carcinogenesis. Finally, a comparative transcriptomic analysis of the three types of tumors allowed us to show for the first time that the complex tumors A.S.C. have a transcriptomic profile in accordance with their mixed nature but that they also display their own expression profiles specificities. This work allowed us to find molecular characteristics common to murine and human lung tumors, indicating that the model of lung tumors in rat is pertinent to search for radiation-induced lung tumors specificities and to help for a better molecular identification of this type of tumors in human. (author)

  11. Calculation of lung cancer incidence in the Netherlands by smoking and radon exposure. Implications for the effect of radon

    International Nuclear Information System (INIS)

    Although the main cause of lung cancer is smoking cigarettes, part of the cases are subscribed to radon exposure, in particular α-radiation from daughter products. However, the relation between lung cancer and radon exposure is rather insecure. Based on international reports (e.g. BEIR VI) and extrapolation of lung cancer incidence in uranium mine workers to the population of the USA and subsequently to the Netherlands, the number of lung cancer cases in the Netherlands is estimated to be circa 800 per year, varying between 200-2000. Results of the analysis are summarized in this article. 10 refs

  12. Smoking cessation programmes in radon affected areas: can they make a significant contribution to reducing radon-induced lung cancers?

    International Nuclear Information System (INIS)

    Domestic radon levels in parts of the UK are sufficiently high to increase the risk of lung cancer in the occupants. Public health campaigns in Northamptonshire, a designated radon affected area with 6.3% of homes having average radon levels over the UK action level of 200 Bq m-3, have encouraged householders to test for radon and then to carry out remediation in their homes, but have been only partially successful. Only 40% of Northamptonshire houses have been tested, and only 15% of householders finding raised levels proceed to remediate. Of those who did remediate, only 9% smoked, compared to a countywide average of 28.8%. This is unfortunate, since radon and smoking combine to place the individual at higher risk by a factor of around 4, and suggests that current strategies to reduce domestic radon exposure are not reaching those most at risk. During 2004-5, the NHS Stop Smoking Services in Northamptonshire assisted 2,808 smokers to quit to the 4-week stage, with some 30% of 4-week quitters remaining quitters at 1 year. We consider whether smoking cessation campaigns make significant contributions to radon risk reduction on their own, by assessing individual occupants' risk of developing lung cancer from knowledge of their age, gender, and smoking habits, together with he radon level in their house. The results demonstrate that smoking cessation programmes have significant added value in radon affected areas, and contribute a greater health benefit than reducing radon levels in the smokers' homes, whilst they remain smokers. Additionally, results are presented from a questionnaire-based survey of quitters, addressing their reasons for seeking help in quitting smoking, and whether knowledge of radon risks influenced this decision. The impact of these findings on future public health campaigns to reduce the impact of radon and smoking are discussed. (author)

  13. Indoor radon exposure and lung cancer: a review of ecological studies.

    Science.gov (United States)

    Yoon, Ji Young; Lee, Jung-Dong; Joo, So Won; Kang, Dae Ryong

    2016-01-01

    Lung cancer has high mortality and incidence rates. The leading causes of lung cancer are smoking and radon exposure. Indeed, the World Health Organization (WHO) has categorized radon as a carcinogenic substance causing lung cancer. Radon is a natural, radioactive substance; it is an inert gas that mainly exists in soil or rock. The gas decays into radioactive particles called radon progeny that can enter the human body through breathing. Upon entering the body, these radioactive elements release α-rays that affect lung tissue, causing lung cancer upon long-term exposure thereto. Epidemiological studies first outlined a high correlation between the incidence rate of lung cancer and exposure to radon progeny among miners in Europe. Thereafter, data and research on radon exposure and lung cancer incidence in homes have continued to accumulate. Many international studies have reported increases in the risk ratio of lung cancer when indoor radon concentrations inside the home are high. Although research into indoor radon concentrations and lung cancer incidence is actively conducted throughout North America and Europe, similar research is lacking in Korea. Recently, however, studies have begun to accumulate and report important data on indoor radon concentrations across the nation. In this study, we aimed to review domestic and foreign research into indoor radon concentrations and to outline correlations between indoor radon concentrations in homes and lung cancer incidence, as reported in ecological studies thereof. Herein, we noted large differences in radon concentrations between and within individual countries. For Korea, we observed tremendous differences in indoor radon concentrations according to region and year of study, even within the same region. In correlation analysis, lung cancer incidence was not found to be higher in areas with high indoor radon concentrations in Korea. Through our review, we identified a need to implement a greater variety of

  14. The use of track registration detectors to reconstruct contemporary and historical airborne radon ( sup 2 sup 2 sup 2 Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

    CERN Document Server

    Steck, D J

    1999-01-01

    Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted sup 2 sup 1 sup 0 Po activity density. The implanted activity is used to reconstruct the cum...

  15. Studies on the biological effects of internal exposure of alpha emitters. Carcinogenicity test of plutonium

    International Nuclear Information System (INIS)

    Outlines of carcinogenicity tests in animals given with injected or inhaled plutonium (Pu) were described. Insoluble 239PuO2 particles were nasally inhaled in rats maintained for life. The dose response relationship between incidence of their lung tumor and absorbed radiation dose in the lung revealed that>1 Gy dose increased the incidence of malignant lung tumors, which differed from findings in the U.S. probably due to the difference between particle sizes. Further, a carcinogenic mechanism specific for alpha-ray was suggested based on tumor-related gene analysis. After soluble 239Pu (citrate salt) was injected in mice, significant reduction of lifetime and early tumor- or non-tumor-death were observed when the bone dose exceeded 3 Gy. Tumors were mostly osteosarcoma, lymphoma and other soft tissue solid cancers and were different from those induced by gamma-ray, X-ray and neutron irradiation. Studies on the strain difference, on the carcinogenic mechanism and alpha-ray induced mutation and transformation are in progress, which may lead to elucidation of the biological effects of internal exposure of alpha-emitters. (K.H.)

  16. Japanese individual risks of radon induced lung cancer for different exposure profiles

    International Nuclear Information System (INIS)

    Indoor radon has been determined to be the second leading cause of lung cancer after tobacco smoking. There is an increasing need among radiation practitioners to have numerical values of lung cancer risks for men and women, smokers and nonsmokers exposed to radon in homes. This study evaluates individual risks for the Japanese population exposed to indoor radon at different radon concentrations and for different periods of their lives. Based on the risk model recently developed by U.S. Environmental Protection Agency (EPA), individual risks of radon induced lung cancers are calculated with Japanese age-specific rates for overall and lung cancer mortalities (1996-2000) as well as the Japanese smoking prevalence data in 2002. Convenient tables of lifetime relative risks are constructed for lifetime exposures and short exposures between any two age intervals from 0 to 110, and for various radon concentrations found in homes from 25 to 600 Bq/m3. The risk of developing lung cancer from residential radon exposure increases with radon concentration and exposure duration. For short exposure periods, such as 10 or 20 years, risks are higher in middle age groups (30-50) compared especially to the later years. Individuals could lower their risks significantly by reducing their radon exposure levels earlier in life. The tables can help radiation protection practitioners to better communicate indoor radon risks to members of the public. (author)

  17. Shelter and indoor air in the twenty-first century: Radon, smoking and lung cancer risks

    International Nuclear Information System (INIS)

    This document describes the relationship between indoor radon exposure, cigarette smoking, and lung cancer. The author explains the sources of radon, the tissues at risk, the human populations most likely to be affected, and the estimates of lung cancer in the population. 6 refs., 2 tabs

  18. Determination of substraces of alpha emitter elements in water

    International Nuclear Information System (INIS)

    To determine alpha emitter elements in water by alpha spectrometry, it is necessary to use large volumes of samples, concentration techniq-ues and to separate the elements of interest. In this report a study is presented about two concentration techniques and the process of analysis. Firstly, the stages of concentration method by iron hydroxide coprecipitation were studied in order to improve the results. The combination of liquid-liquid extraction and ion exchange techniques was the best way. Secondly, the technique by adsorption on manganese dioxide was studied. To apply this technique it was necessary to develop analysis methods to separate uranium, thorium, plutonium, americium and radium. These methods were designed combining several techniques of separation: liquid-liquid extraction, liquid-solid extraction, ionic exchange and coprecipitation. After the analysis methods were developped the adsorption on manganese dioxide with artificial samples was studied in the laboratory. Finally, the method of adsorption on manganese dioxide was studied to determine uranium, thorium and radium in the drinking water of Madrid. (Author)

  19. Canadian population risk of radon induced lung cancer: A re-assessment based on the recent cross-Canada radon survey

    International Nuclear Information System (INIS)

    Exposure to indoor radon has been determined to be the second leading cause of lung cancer after tobacco smoking. Canadian population risk of radon induced lung cancer was assessed in 2005 with the radon distribution characteristics determined from a radon survey carried out in the late 1970's in 19 cities. In that survey, a grab sampling method was used to measure radon levels. The observed radon concentration in 14 000 Canadian homes surveyed followed a log-normal distribution with a geometric mean (GM) of 11.2 Bq m-3 and a geometric standard deviation (GSD) of 3.9. Based on the information from that survey, it was estimated that ∼10 % of lung cancers in Canada resulted from indoor radon exposure. To gain a better understanding of radon concentrations in homes across the country, a national residential radon survey was launched in April 2009. In the recent survey, long-term (3 month or longer) indoor radon measurements were made in roughly 14 000 homes in 121 health regions across Canada. The observed radon concentrations follow, as expected, a log-normal distribution with a GM of 41.9 Bq m-3 and a GSD of 2.8. Based on the more accurate radon distribution characteristics obtained from the recent cross-Canada radon survey, a re-assessment of Canadian population risk for radon induced lung cancer was undertaken. The theoretical estimates show that 16 % of lung cancer deaths among Canadians are attributable to indoor radon exposure. These results strongly suggest the ongoing need for the Canadian National Radon Program. In particular, there is a need for a focus on education and awareness by all levels of government, and in partnership with key stakeholders, to encourage Canadians to take action to reduce the risk from indoor radon exposure. (authors)

  20. Lung Cancer Attributable to Indoor Radon Exposures in Two Radon--Prone Areas, Stei (Romania) and Torrelodones (Spain)

    International Nuclear Information System (INIS)

    Radon and radon progeny are present indoors, in houses and others dwellings, representing the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for both smokers and nonsmokers. For medium and low concentrations which are the typical residential radon levels, recent researches have also demonstrated increased risks of lung cancer for people exposed. The work presents a comparative analysis of the radon exposure data in the two radon--prone areas, Stei, Transylvania, (Romania), in the near of old Romanian uranium mines and in the granitic area of Torrelodones town, Sierra de Guadarrama (Spain). One important difference between the two studied areas is related to the houses built using uranium waste as construction material in Stei area. Measurements of indoor radon were performed in 280 dwellings (Romania) and 91 dwellings (Spain) by using nuclear track detectors, CR 39. The highest value measured in Stei area was 2650 Bq·m-3. and 366 Bq·m-3 in the Spanish region. The results are compute with the BEIR VI report estimates using the age-duration model at an exposure rate below 2650 Bq·m-3. A total of 233 lung cancer deaths were calculated in the Stei area for a period of 13 years (1994-2006), which is 116.82% higher than observed from the national statistics. In comparison, in Torrelodones area, a number of 276 deaths caused by lung cancer were estimated along a period of 13 years, which is 2.09 times higher than the number observed by authorities. This represents a significantly evidence that elevated risk can strongly be associated with cumulated radon exposure.

  1. Lung cancer mortality and indoor radon concentrations in 18 Canadian cities

    International Nuclear Information System (INIS)

    Indoor radon and radon daughter concentrations were measured in a survey of 14,000 homes in 18 Canadian cities conducted in the summers of 1978 through 1980. Mortality and population data for the period 1966 through 1979 were retrieved for the geographic areas surveyed in each city. The results of analysis of the relation between lung cancer and radon daughter concentration, smoking habits and socioeconomic indicators for each city showed no detectable association between radon daughter concentrations and lung cancer mortality rates with or without adjustment for differences in smoking habits between cities

  2. Age dependent hit probabilities for lung cancer induction following exhalation of ingested radon

    International Nuclear Information System (INIS)

    Previous calculations of the risk following ingestion of 222Rn (radon) in drinking water have been concerned primarily with the solubilization of the radon in body tissues, followed by in situ decay. Much less attention has been directed towards the escape of radon from lung tissue and blood into the alveolar air, which should lead to doses to lung tissue as the newly formed progeny deposit in lung passages prior to exhalation. The present report details the calculation of hit probabilities to the basal cells of the bronchial epithelium and alveolar cells in various age groups following ingestion of radon in drinking water. Results are compared with those obtained for the in situ decay of radon within the lung mass. (author)

  3. Radon

    Science.gov (United States)

    ... with elevated radon underwent changes to reduce radon pollution. 1 How Can Radon Be Detected? The only ... of Americans Live with Unhealthful Levels of Air Pollution News: 'State of the Air 2016' – Health of ...

  4. Lung cancer and environmental radon exposure: a case-control study

    International Nuclear Information System (INIS)

    Lung cancer accounts for approximately 100,000 deaths annually and nearly 30% of these are due to factors other than smoking. The prognosis for lung cancer is very poor and control of this disease depends on the identification and manipulation of etiologic agents. Radon is a demonstrated pulmonary carcinogen among uranium miners and is a ubiquitous environmental agent. This study addresses two principal issues: (a) the assessment of the potential health effects due to radon exposure from radioactive waste disposal in Canonsburg, Pennsylvania, and (b) the broader scientific question of the existence of an association between lung cancer and environmental radon exposure. Indoor radon concentrations were taken in the homes of 50 lung cancer cases and 48 ASHD controls as an index of cumulative exposure. The distribution of concentrations was similar among case and control homes. The range of exposures was within background expectations as were lung cancer rates in the area. There was, furthermore, no geographic clustering of cases near the tailings site. Although an association between lung cancer and environmental radon exposure cannot be ruled out, the evidence suggests that radon exposure due to the disposal of tailings did not have a significant impact on the health of the residents living in the area and that indoor radon is not an important lung cancer risk factor at concentrations less than about 4pCi/I

  5. A novel technique for the rapid identification of alpha emitters released during a radiological incident.

    Science.gov (United States)

    Dilbeck, George A; Taylor, Bud; Leitch, Jerrold; Silverstone, Marina; Moore, Brian; Honsa, Patricia

    2006-10-01

    Before the May 2003 TOPOFF II exercise in Seattle, the U.S. EPA's Laboratory in Las Vegas prepared five spiked samples to be analyzed by the Washington State Department of Health's (WSDOH) Radiation Laboratory. Two of these were simulated deposition samples prepared on packaging tape. Laboratories throughout the world are investigating rapid methods for analyzing plume-borne radioactive materials. While measuring gamma emitters in environmental samples is fairly straightforward, the potential presence of alpha emitters adds complexity. The short range of alpha particles and the high degree of energy interference between nuclides usually require chemical separations and very thin mounts for alpha spectrometry. Work published on Frisch-Grid alpha counting of transuranics in soil and the commercial development of radon-rejection for air filters indicate that alpha spectrometry can be used directly on some media with success. This suggests that plume-borne material sampled from air or freshly deposited surface layers may be counted directly by alpha spectrometry, making it possible to identify both alpha and gamma emitters and determine their relative concentrations. The long-range objective is to propose a sampling method that can be used for rapid qualitative and semi-quantitative analyses using conventional radioanalytical instruments, with minimal preparation. This paper describes experimentation with this approach during a real-time exercise. All samples were prepared by spiking with (137)Cs, (241)Am, (238)Pu, and (239)Pu and presented to the WSDOH's Radiation Laboratory for analysis during TOPOFF II. The laboratory quickly identified and determined the ratios of all four contaminants on the tape samples using sequential alpha spectrometry and gamma-ray spectroscopy without chemical separations. PMID:16966874

  6. Risk of lung cancer and residential radon: pooled results of two studies in China

    International Nuclear Information System (INIS)

    Objective: To verify the prognosis that miners' exposure to radon is the second leading cause of lung cancer. Methods: The authors collected data from two case-control studies of residential radon representing two large radon studies conducted in China. The studies included 1050 lung cancer cases and 1996 controls. Results: Based on a linear model, the excess odds ratio (EOR) with 95% confidence intervals (CI) at 100 Bq/m3 was 0.133 (0.01, 0.36). For subjects living in the current home for 30 years or more, the EOR was 0.315 (0.07, 0.91). EOR estimates were similar to those in the extrapolations from miner data and consistent with residential radon studies in North American and Europe. Conclusion: Long-term radon exposure at concentrations found in many houses increases lung cancer risk

  7. Risk of lung cancer and residental radon in China: pooled results of two studies

    International Nuclear Information System (INIS)

    Studies of radon-exposed underground miners predict that residential radon is the second leading cause of lung cancer mortality; however, case-control studies of residential radon have not provided unambiguous evidence of an association. Owing to small expected risks from residential radon and uncertainties in dosimetry, large studies or pooling of multiple studies are needed to fully evaluate effects. We pooled data from 2 case-control studies of residential radon representing 2 large radon studies conducted in China. The studies included 1,050 lung cancer cases and 1,996 controls. In the pooled data, odds ratios (OR) increased significantly with greater radon concentration. Based on a linear model, the OR with 95% confidence intervals (CI) at 100 Becquerel/cubic-meter (Bq/m3) was 1.13 (1.01, 1.36). For subjects resident in the current home for 30 years or more, the OR at 100 Bq/m3 was 1.32 (1.07, 1.91). Results across studies were consistent with homogeneity. Estimates of ORs were similar to extrapolations from miner data and consistent with published residential radon studies in North American and Europe, suggesting long-term radon exposure at concentrations found in many homes increases lung cancer risk. (orig.)

  8. Lung Deposition And Biological Effects Of Inhaled Radon Progenies

    International Nuclear Information System (INIS)

    Inhaled radon progenies provide more than the half of natural radiation exposure. There is increasing evidence that the cellular distribution of radiation burden is an important factor regarding the biological response to ionisation radiation, thus, one of our tasks was the characterisation of the distribution of cellular exposure. Histological studies of former uranium miners presented strong correlation between primer deposition hot spots and neoplastic lesions. Most of these lesions were located along the carinal regions of the large bronchial airways. In the present work, computational fluid dynamics (CFD) approaches have been applied to simulate the deposition distribution of inhaled radon progenies along central human airways. The geometry and the cellular structure of epithelial lung tissue were numerically reconstructed based on anatomical and histological data. Single and multiple ha-hit and cellular dose distributions have been computed applying Monte Carlo modelling techniques at different breathing conditions. Figure 1. Deposition enhancement factor (EF) of inhaled radon progenies on a central airway bifurcation in airway generations 4-5 during light physical activity breathing condition. Size of scanning surface element is a 45μm side triangle. Left panel: EF max=1400,Dp=200 nm (attached). Right panel: EF max1290, Dp= 1 nm (unattached). Values of local per average deposition densities, that is, enhancement factors (Figure 1), hit probabilities and doses may be up to two-three orders of magnitude higher in the deposition hot spots than the average values. Dose calculations revealed that some cell clusters may receive high doses even at low exposure conditions. Applying the model to different radiation exposure conditions useful relations can be received regarding the linear-non threshold hypothesis

  9. Bio-mathematical models for radon daughters inhalation. The ModeLung software

    International Nuclear Information System (INIS)

    Radon and its decay daughters are the most important sources for natural irradiation of population. ModeLung software is based on the human respiratory tract compartment model and is computing radiation doses on several internal organs and tissues for subjects inhaling radon daughters attached to aerosols. Radiation doses are presented for several subjects performing different types of activity under specific environmental conditions. (authors)

  10. Design issues in studies of radon and lung cancer: Implications of the joint effect of smoking and radon

    International Nuclear Information System (INIS)

    Many case-control studies have been undertaken to assess whether and to what extent residential radon exposure is a risk factor for lung cancer. Nearly all these studies have been conducted in populations including smokers and nonsmokers. In this paper, we show that, depending on the nature of the joint effect of radon and tobacco on lung cancer risk, it may be very difficult to detect a main effect due to radon in mixed smoking and nonsmoking populations. If the joint effect is closer to additive than multiplicative, the most cost-effective way to achieve adequate statistical power may be to conduct a study among never-smokers. Because the underlying joint effect is unknown, and because many studies have been carried out among mixed smoker and nonsmoker populations, it would be desirable to conduct some studies with adequate power among never-smokers only. 30 refs., 4 figs., 2 tabs

  11. Radon,Lung Cancer Risk and Environmental Geology in Gejiu Area

    Institute of Scientific and Technical Information of China (English)

    卢伟; 王任重; 等

    1997-01-01

    The incidence of lung cancer in the Gejiu area of Yunnan Province ranks the first in the world.The radon level(indoor,soil) was measured in the Gejiu area by the SSNTD method from 1990 to 1996,The result indicates an extensive high-level of indoor radon in that area though U and Th are lower in local limestones,The indoor radon level of houses located in the geologic fault zone is 6 times high that 2km far from the fault zone.The reason probably is that the radon level of soil in the fault is 6-8 times high that 1 km far from the faults.our data indicate that a lower range of radon levels,0-100Bq.m-3,exists in healthy families.However,a higher radon level,over 800 Bq.m-3,is often found corresponding to that of cancer patients' homes(the house-owners are suffering from either lung cancer or leukaemia or liver cancer),Obviously,an increase in lung cancer incidence follows an increase in indoor radon level,The risk of cancer induced by indoor radon is no longer an inference,but a fact.

  12. Lung cancer incidence after smoking and exposure to radon using a two-mutation model

    International Nuclear Information System (INIS)

    A study to analyze lung cancer in humans as a function of exposure to radon and smoking, used three types of data: population statistics in non-smokers habits of British radiologists and radon exposure of the Colorado uranium miners. Using a simplified two-mutation carcinogenesis model and only six unknown variables yielded a coherent description of lung cancer dependence on exposure to radon and smoking. For risk estimates the radiation effect of radon can be concluded to be highly dependent on smoking habits, e.g. the radiation effect differs (in absolute terms) by a factor of about 7 between non-smokers, but the relative risk is much higher in non-smokers than in smokers. The results to data justify a thorough investigation of the analysis method to realize improved radon risk estimates. (author)

  13. Combined effect of radon exposure and smoking and their interaction in Czech studies of lung cancer

    International Nuclear Information System (INIS)

    The aim is to compare lung cancer risks from radon in smoking categories in Czech residential radon and uranium miners studies and to evaluate interactions between smoking and radon exposure. The residential and occupational studies are based on one hospital based case-control study and three case-control studies nested within cohort studies, two among uranium miners and one in the general population in a radon prone area. Controls in the nested studies are individually matched by sex, age and year of birth. Smoking data were collected in person or from relatives of deceased subjects. In the occupational studies, some smoking data were obtained from medical files. Radon exposures were based on measurements of radon in houses by open track detectors LR115 in the radon prone area and by closed detectors and electrets in the hospital based study. Exposures in uranium mines were based on extensive measurements and personal dosimetry. The analyses are based on conditional logistic regression with linear dependence of the risk on radon exposure adjusted for smoking. The study resulted in 300 cases and 1035 controls in the residential study and 672 cases and 1491 controls in the study of uranium miners. The dependence of lung cancer risk on radon exposure adjusted for smoking was not substantially different from analyses when smoking was ignored and reflected mainly the risk among smokers. However, the excess relative risk per unit exposure among non-smokers was 3-10 fold higher in comparison to that in smokers. The relative risk from radon among non-smokers was consistently higher in the occupational and residential studies, reflecting probably differences in lung morphometry, clearence and unattached fraction of radon progeny in houses of non-smokers. Risks from combined effects are substantially lower than the risk derived from the multiplicative model, but consistent with the additive model. (author)

  14. Residential radon and lung cancer in a high exposure area in Gansu province, China

    International Nuclear Information System (INIS)

    Low exposures to residential radon and dosimetric uncertainties due to mobility have hampered the evaluation of lung cancer risk and comparison to radon-exposed miners. To address these limitations, the authors conducted a case-control study in a predominantly rural area of China with low mobility and high radon levels. Cases included all lung cancers diagnosed between January 1994 and April 1998, aged 30 to 75 years, and resident in two prefectures. Controls were randomly selected from census lists and matched on age, sex and prefecture. Radon detectors were placed in all houses occupied two or more years in the 5-30 years prior to enrollment. Measurements covered 77% of the possible exposure time. Mean radon concentrations were 230.4 Bq/m 3 for cases (n=768) and 222.2 Bq/m 3 for controls (n=1,659). Lung cancer risk increased with radon level (p<0.001). Based on a linear model, the excess odds ratio (EOR) at 100 Bq/m 3 was 0.19 (95% CI: 0.05, 0.47) for all subjects, and 0.31 (95% CI: 0.10,0.81) for subjects with 100% coverage of the exposure interval. Adjusting for exposure uncertainties increased estimates about 70 percent. Results support increased lung cancer risks with indoor radon exposures which may equal or exceed extrapolations based on miner data

  15. Molecular and cytogenetic characterization of radon-induced lung tumors in the rat

    International Nuclear Information System (INIS)

    Radon is a natural radioactive gas. This radioelement, which is an α-particle emitter, is omnipresent in the environment. Inhalation of atmospheric radon is the major exposure route in man of natural radioactivity which results in respiratory tract contamination. An increased lung cancer risk associated with radon inhalation has been shown both in humans and animals by epidemiological and experimental studies, respectively. In rats, characterization of dose-effect relationships has led to the construction of statistical models that may help theoretically in the prediction of human health involvements of both occupational and domestic chronic exposure to radon. However, little is known about the cellular and molecular mechanisms of radon-induced lung carcinogenesis. In the laboratory, a model of lung cancers induced in rats after radon inhalation is available. This model represents a good tool to identify and characterize the genetic events contributing to the development of radon-induced lung tumors. Carrying out a global approach based on the combined use of classical and molecular cytogenetic methods, the analysis of 17 neoplasms allowed the identification of chromosomal regions frequently altered in these tumors. Numerous similarities have been found between our results and the cytogenetic data for human lung cancers, suggesting common underlying genetic molecular mechanisms for lung cancer development in both species. Moreover, our study has allowed to point to tumor suppressor genes and proto-oncogenes potentially involved in radon-induced lung carcinogenesis. Thus, our results may aid further molecular studies aimed either at confirming the role of these candidate genes or at demonstrating the involvement of yet to be identified genes. (author)

  16. Case-control study of radon and lung cancer in New Jersey

    International Nuclear Information System (INIS)

    Radon is known to cause lung cancer in humans; however, there remain uncertainties about the effects associated with residential exposures. This case-control study of residential radon and lung cancer was conducted in five counties in New Jersey and involved 561 cases and 740 controls. A yearlong α-track detector measurement of radon was completed for ∼93% of all residences lived in at the time of interview (a total of 2063). While the odds ratios (ORs) for whole data were suggestive of an increased risk for exposures >75 Bq m-3, these associations were not statistically significant. The adjusted excess OR (EOR) per 100 Bq m-3 was -0.13 (95% CI: -0.30 to 0.44) for males, 0.29 (95% CI: -0.12 to 1.70) for females and 0.05 (95% CI: -0.14 to 0.56) for all subjects combined. An analysis of radon effects by histological type of lung cancer showed that the OR was strongest for small/oat cell carcinomas in both males and females. There was no statistical heterogeneity of radon effects by demographic factors (age at disease occurrence, education level and type of respondent). Analysis by categories of smoking status, frequency or duration did not modify the risk estimates of radon on lung cancer. The findings of this study are consistent with an earlier population-based study of radon and lung cancer among New Jersey women, and with the North American pooling of case control radon seven studies, including the previous New Jersey study. Several uncertainties regarding radon measurements and assumptions of exposure history may have resulted in underestimation of a true exposure-response relationship. (authors)

  17. Lung cancer mortality among nonsmoking uranium miners exposed to radon daughters

    International Nuclear Information System (INIS)

    Radon daughters, both in the workplace and in the household, are a continuing cause for concern because of the well-documented association between exposure to radon daughters and lung cancer. To estimate the risk of lung cancer mortality among nonsmokers exposed to varying levels of radon daughters, 516 white men who never smoked cigarettes, pipes, or cigars were selected from the US Public Health Service cohort of Colorado Plateau uranium miners and followed up from 1950 through 1984. Age-specific mortality rates for nonsmokers from a study of US veterans were used for comparison. Fourteen deaths from lung cancer were observed among the nonsmoking miners, while 1.1 deaths were expected, yielding a standardized mortality ratio of 12.7 with 95% confidence limits of 8.0 and 20.1. These results confirm that exposure to radon daughters in the absence of cigarette smoking is a potent carcinogen that should be strictly controlled

  18. Indoor radon and risk of lung cancer: an epidemiological study in Finland

    International Nuclear Information System (INIS)

    The main aim of the present study was to establish whether high radon concentrations in dwellings in Finland had increased the risk of lung cancer. Previous studies had shown an association between the α-active radon daughters and elevated lung cancer risk among miners. Convincing evidence of the risk among the general population exposed to radon indoors was, however, lacking. A descriptive analysis was first conducted in an area in southern Finland with high indoor radon exposure. In 18 rural municipalities this analysis yielded no significant correlation between the average radon exposure and incidence of male lung cancer. A case-control study within a cohort of the same rural population was then designed. The data included 238 male cases of lung cancer diagnosed in 1980-85 and 434 controls (390 smokers and 44 nonsmokers) from the male population. Radon exposure was measured, when possible, in all the dwellings occupied by a case or control in 1950-1975. Measurements were available for the total 25-year period, or for a proportion of it, for 164 cases and 334 controls; for the rest only estimates were available. In spite of the fact that the controls were mainly selected among smokers, the amount smoked still appeared to be the most important lung cancer risk factor in the data, the risk increasing linearly with the quantity of cigarettes smoked in a lifetime. The risk of lung cancer was not associated with the radon exposure level when the whole data were studied. In heavy smokers, however, a positive though not significant, effect on the risk from radon exposure was found. In the range of uncertainty the findings do not conflict with most of those observed among miners or the general population so far. (orig.)

  19. Risk of lung cancer by radon, disagreement in international regulation; Riesgo de cancer pulmonar por radon, discordancia en reglamentacion internacional

    Energy Technology Data Exchange (ETDEWEB)

    Balcazar, M.; Pena, P.; Villamares, A.; Avelar, J. R., E-mail: miguel.balcazar@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    Diverse international organizations have evaluated the risk of lung cancer starting from epidemic studies in miners of uranium mines, where the corresponding effective dose was determined relating with the dose received by the population during Hiroshima and Nagasaki events. Alternately, the equivalent dose has been calculated by means of based models on the energy deposited by the breathable radon fractions and its decay products in the breathing ducts. A unique factor agreed by the diverse organizations that allows converting radon concentration to effective dose does not exist. Neither an agreement exists among the different countries on which duty to be the value of the maximum concentration of radon, in interiors starting from which an intervention is required and if this intervention is standardized, recommended or nonexistent. In this work study cases in Mexico are presented and their interpretation alternative based on the international agreements absence. (Author)

  20. Cigarette use and the estimation of lung cancer attributable to radon in the United States

    International Nuclear Information System (INIS)

    Residential exposure to radioactive radon and its decay products has been estimated to account for 10-12% of all lung cancer deaths in the US. It has been difficult to evaluate fully the impact of cigarette smoking, the most important cause of lung cancer, on this estimate, because factors for patterns of tobacco use have not been included in the risk models, since risk models are derived from studies of underground miners exposed to radon and detailed data on smoking are limited. Lung cancer risk estimates for exposure to radon progeny in smoker and non-smoker populations are obtained by applying the same risk model to each population group, thereby assuming the joint effects of smoking and exposure to radon progeny are multiplicative. However, in miners, joint relative risks (RR) for the two exposures are most consistent with an intermediate relationship between multiplicative and additive, so that the present approach likely results in an overestimate of risk in smokers and an underestimate of risk in nonsmokers. One approach for adjusting risk models to incorporate smoking status is based on the relative magnitude of the effects of radon progeny in smokers and nonsmokers and therefore may not be applicable to non-miner populations if the proportion of smokers and the RR for smoking differ. We show that the modification can be derived explicitly by assuming an arithmetic mixture model for the joint RR for smoking and exposure to radon progeny. In this way, smoking parameters in the population of interest (the proportion of smokers and the RR of smoking) can be used directly to adjust radon progeny risk models and obtain risk estimates that are specific for smokers and nonsmokers. With an intermediate RR relationship for smoking and radon progeny, the attributable percentage of lung cancer deaths from residential radon may be twofold greater in nonsmokers than in smokers. 20 refs., 1 fig., 3 tabs

  1. Lung cancer in women and type of dwelling in relation to radon exposure

    International Nuclear Information System (INIS)

    A case-control study based on interviews with 210 incident female lung cancer patients, 209 age-matched population controls, and 191 hospital controls was carried out in Stockholm County, Sweden. Radon measurements made in a sample of 303 dwellings in which the study subjects had lived showed that dwellings with ground contact had an average concentration of approximately 160 Bqm-3, twice the average concentration of other dwellings. A cumulated radon exposure index was calculated for each subject based on data from the interviews and the measurements. For the total group of lung cancer patients there was a relative risk (RR), adjusted for smoking, age, and degree of urbanization, of 1.8 (95% confidence interval: 1.2-2.9) and 1.7 (0.9-3.3) associated with intermediate and high exposure to radon. The trend was statistically significant (p = .03). For small cell cancer, which showed the strongest association with estimated radon exposure, the corresponding RRs were 1.9 (0.6-4.5) and 4.7 (1.5-14.2), respectively (ptrend = .01). There seemed to be some positive interaction between radon exposure and smoking in relation to lung cancer. Our findings show that domestic radon may be important for inducing lung cancer, particularly for some histological types

  2. RELATED GENES IN LUNG CANCER TISSUES ASSOCIATED WITH RESIDENTIAL HIGH RADON EXPOSURE

    Institute of Scientific and Technical Information of China (English)

    夏英; 杨梅英; 张守志; 叶常青

    2002-01-01

    Objective: To investigate the related genes in lung cancer tissues associated with residential high radon exposure. Methods: Differentially expressed gene fragments in lung cancer and normal lung tissues were discovered by differential display and reverse Northern blot hybridization method. The fragments positive in lung cancer and negative in normal lung tissue were determined. Results: Seven differential displayed fragments were sequenced. One of them named NA7 is 95% homologous with AI208667 in EAT of Genbank. Another fragment named NG2 is up to 98% homologous with five fragments. The remained one CA1 may be a new gene fragment. Conclusion: 3 gene fragments were discovered from lung cancer and normal lung tissues of high radon exposure resident.

  3. A device for the remote detection of alpha emitters under field conditions

    NARCIS (Netherlands)

    Simakov, AB

    2005-01-01

    The portable DOP device was designed for the ecological monitoring of the radiation of alpha radioactive nuclides, such as plutonium, uranium, radium, etc. Under field conditions, it can detect alpha emitters at distances of up to 0.5 m. The device's performance data are as follows: the lower thresh

  4. Radon Control Activities for Lung Cancer Prevention in National Comprehensive Cancer Control Program Plans, 2005–2011

    OpenAIRE

    Antonio Neri, MD, MPH; Sherri L. Stewart, PhD; William Angell, MS

    2013-01-01

    Introduction Radon is the second leading cause of lung cancer among smokers and the leading cause among nonsmokers. The US Environmental Protection Agency recommends that every home be tested for radon. Comprehensive Cancer Control (CCC) programs develop cancer coalitions that coordinate funding and resources to focus on cancer activities that are recorded in cancer plans. Radon tests, remediation, and radon mitigation techniques are relatively inexpensive, but it is unclear whether coalition...

  5. Temporal Patterns of Lung Cancer Risk from Radon, Smoking and their Interaction

    International Nuclear Information System (INIS)

    Studies of uranium miners conducted since the late 1960s demonstrated that the risk depends on cumulated exposure in terms of working level months (WLM) integrating both duration of exposure and concentration of radon. It has been also demonstrated that the risk from radon decreases with time since exposure. The objective of the work is to study temporal patterns of lung cancer risk from occupational and residential radon and from smoking. The present analysis of temporal changes of relative risk is based on a model, where the total individual exposure is partitioned into components in dependence on time. Exposure to radon is studied in a cohort of 9411 Czech uranium miners with 766 cases of lung cancer and in a residential study of 1 803 inhabitants exposed to radon in houses with 218 cases. Temporal patterns of smoking are analyzed in a case-control study of patients from a major Prague hospital including 566 cases. for both carcinogens, the relative risk decreases with time since exposure. In comparison to period with exposure before 5-19 years, the risk from exposures before 20-34 years is 36% and 34% for smoking and randon, respectively. The effect of exposures from more distant periods 35-49 is only 5% for smoking and 14% for radon in comparison to 5-19 years. Combined effect of smoking and radon is studied by a nested case-control approach including 434 cases and 962 controls. Analyses of the joint effects of smoking and radon, conducted in the occupational and the residential studies, suggest a sub-multiplicative interaction. The relative risk from radon among non-smokers is higher by a factor of 2-3 in comparison to smokers, suggesting different patterns of lung deposition and clearance among smokers and non-smokers. (Author) 13 refs

  6. Determination of alpha-emitters in Brazilian tobacco

    International Nuclear Information System (INIS)

    The decay products of uranium and thorium natural series are widely distributed in all the terrestrial crust. Their concentrations are considerable in the phosphates utilized as fertilizer in the Brazilian agriculture. In this work analysis was performed on 238U, 234U, 232Th, 226Ra and 210Po in 22 Brazilian tobacco samples. The results showed 238U and 234U are in isotopic activity equilibrium (0.5±0.2 mBq/g). The equilibrium was not reached in the case of thorium isotopes: the 228/232Th ratio was about 6.4. The average values obtained were 34.3 mBq/g for 228Th and 5.4 mBq/g for 232Th. The 226Ra values were higher than its radioactive precursor, 238U. This can be explained by the high affinity of radium to tobacco plant and the uranium removal during physical and chemical processes. The high concentration of 210 Po(20 mBq/g) in tobacco samples may be due to radon daughter products being electrically charged and then attaching themselves to inert dusts, which then become attached to tiny hairs on tobacco leaves. The results of this work are consistent with values presented in specialized literature. (author) 15 refs.; 4 tabs

  7. Dosimetric and Microdosimetric approach for the estimation of radon - induced damages in human lungs

    International Nuclear Information System (INIS)

    In this paper the estimation of radiation risk of radon and radon progen on induced damages in human lungs is presented. For estimation of radiation risk dosimetric and microdosimetric approach was used. The quality factor in the bronchial an and bronchial region were calculated, they are for homogeneous and heterogeneous distribution, respectively: 16.02 for all cells; 16.72 for secretory cells (BB) and 19.02 for secretory cells (bb); and 12.70 for basal cells

  8. Studies on the mechanism of apoptasis by radon in lung tissue of mice

    International Nuclear Information System (INIS)

    Objective: To study the mechanism of apoptasis by radon in lung tissue of mice. Methods: Male BALB/c mice were exposed to radon with the cumulative dose of 0.02, 30 or 60 working level month (WLM) respectively, and then were raised for different time (24 h, 30 d or 90 d). Apoptosis was detected by terminal deoxynucleotidy transferase-mediated dUTP-biotin nick end labeling (TUNEL). The expression of p 53 and Bcl-2/Bax protein was observed by immunohistochemistry. Results: As compared with the control group, the apoptotic index in lung tissue increased along with the increasing of expose dose and the raise time. The protein expression of p 53 increased significantlyin the 30 d and 90 d groups. But Bcl-2/Bax expression decreased. Conclusions: The apoptosis by radon in lung tissue of mice had close relationship with p 53 and.Bcl-2/Bax pathway. (authors)

  9. Lower radiation weighting factor for radon indicated in mechanistic modelling of human lung cancer

    International Nuclear Information System (INIS)

    A two-mutation carcinogenesis (TMC) model was fitted to the age-dependent lung cancer incidence in a cohort of Dutch Hodgkin patients treated with radiotherapy. Employing the results of previous TMC analyses of lung cancer due to smoking (by British doctors) and due to exposure to radon (for Colorado miners) a model fit was obtained with an estimate for the low LET radiation effect at the cellular level. This allows risk calculations for lung cancer from low LET radiation. The excess absolute risks are in tune with the values reported in the literature, the excess relative risks differ among the exposed groups. Comparing the cellular radiation coefficients for radon and for low LET radiation leads to an estimated radiation weighting factor for radon of 3 (0.1-6). (author)

  10. Residential radon exposure and lung cancer: an overview of published studies

    International Nuclear Information System (INIS)

    A possible link between presumed or measured household radon exposure and lung cancer is reviewed on the basis of published epidemiologic studies. Evidence of a link is reported as a result of studies in Sweden; findings are inconsistent elsewhere. A number of methodological problems were found. Many of the studies are ecological in design and are, therefore, primarily hypothesis generating. A number of studies lack any data on the number of lung cancers and are, therefore, difficult to evaluate. Some other studies provide results that are internally inconsistent. Of the case/control studies, there are many with minimal or no information on active and passive smoking, occupation, family history of cancer, and diet. The case/control studies are generally small in size and of low statistical power. Exposure classifications are nonstandardized, inconsistent in their findings, and often gross in their characterization of radon concentrations. Relatively few of the studies actually measured radon exposure. Some of the studies showed significant positive associations either with geological characteristics, water supply contamination, or house type. No significant associations were found with residence near uranium or radium processing waste. Where radon levels were measured, a relatively small percentage of studies found a statistically significant positive association with lung cancer. Overall, the evidence for an association between residential radon exposure and lung cancer is weak. There is a need for a more decisive case/control epidemiologic study of this problem.55 references

  11. Residential radon exposure and lung cancer risk in Misasa, Japan. A case-control study

    International Nuclear Information System (INIS)

    In order to investigate an association between residential radon exposure and risk of lung cancer, a case-control study was conducted in Misasa Town, Tottori Prefecture, Japan. The case series consisted of 28 people who had died of lung cancer in the years 1976-96 and 36 controls chosen randomly from the residents in 1976, matched by sex and year of birth. Individual residential radon concentrations were measured for 1 year with alpha track detectors. The average radon concentration was 46 Bq/m3 for cases and 51 Bq/m3 for controls. Compared to the level of 24 or less Bq/m3, the adjusted odds ratios of lung cancer associated with radon levels of 25-49, 50-99 and 100 or more Bq/m3, were 1.13 (95% confidence interval; 0.29-4.40), 1.23 (0.16-9.39) and 0.25 (0.03-2.33), respectively. None of the estimates showed statistical significance, due to small sample size. When the subjects were limited to only include residents of more than 30 years, the estimates did not change substantially. This study did not find that the risk pattern of lung cancer, possibly associated with residential radon exposure, in Misasa Town differed from patterns observed in other countries. (author)

  12. Lung cancer in women and type of dwelling in relation to radon exposure

    International Nuclear Information System (INIS)

    A case-control study based on interviews with 210 incident female lung cancer patients, 209 age-matched population controls, and 191 hospital controls was carried out in Stockholm county, Sweden. Radon measurements made in a sample of 303 dwellings, in which the study subjects had lived, showed that dwellings with ground contact had an average concentration of approximately 160 Bqm-3, twice the average concentration of other dwellings. A cumulated radon exposure index was calculated for each subject based on data from the interviews and the measurements. For the total group of lung cancer a relative risk (RR), adjusted for smoking, age, and degree of urbanization, of 1.8 (95% confidence interval: 1.2-2.9) and 1.7 (0.9-3.3) associated with ''intermediate'' and ''high'' exposure to radon was found. There was also a significant trend to a positive dose-response relationship (Ptrend = 0.03). For small cell cancer the corresponding figures for RRs were 1.9 (0.6-4.5) and 4.7 (1.5-14.2), respectively (Ptrend = 0.01). There seemed to be a positive interaction between radon exposure and smoking in relation to lung cancer. The findings indicate that domestic radon may be of importance for the induction of lung cancer, particularly for some histological types

  13. Risk of lung cancer in animals following low exposures to Radon-222 progeny

    International Nuclear Information System (INIS)

    Owing to the facts that a) large uncertainties affect the epidemiology of radon progeny-induced lung cancer in humans (especially at low exposures), and b) the rat is a good model for studying the carcinogenicity of radon progeny in humans, the risk of lung cancer following low exposures to low concentrations of radon progeny can be estimated from data obtained in the laboratory on rats exposed under controlled conditions. From the limited set of laboratory data on the induction of lung cancer in laboratory rats it appears that, at low exposures, the risk of lung cancer decreases with decreasing concentration, and that exposures of the order of 25 WLM, at an exposure rate of 2 WL do not produce any excess lung cancers. Since 20 WLM is a lifetime exposure comparable to those expected in occupational or indoors conditions and 2 WL is an exposure rate about 20 times higher dm current occupational exposures rates and 100 times higher than indoor ones, these observations may be indicative of threshold conditions for the induction of lung cancer by radon progeny. (author)

  14. Temporal patterns of lung cancer risk from radon and smoking - consequences to remediation measures

    International Nuclear Information System (INIS)

    Studies of uranium miners conducted since the late 1960s demonstrated that the risk depends on cumulated exposure in terms of working level months (WLM) integrating both duration of exposure and concentration of radon. It has been also demonstrated that the risk from radon decreases with time since exposure. The present analysis of temporal changes of relative risk is based on a model where the total individual exposure is partitioned into components in dependence on time. Exposure to radon is studied in a cohort of 9411 Czech uranium miners with 766 cases of lung cancer and in a residential study of 11 803 inhabitants exposed to radon in houses with 218 cases. In addition, temporal patterns of the risk from smoking are analyzed in a case-control study of patients from a major Prague hospital including 566 cases. For both carcinogens, the relative risk decreases with time since exposure. The risk from exposures before 20-34 years is 36% and 34% in comparison to period 5-19 for smoking and radon, respectively. The effect of exposures from more distant periods 35-49 is only 5% for smoking and 14% for radon in comparison to 5-19 years. This substantial decrease of relative risk with time may contribute to a better evaluation of remediation measures taken in houses and in the cost effectiveness of remediation. Combined effect of smoking and radon is studied by a nested case-control approach including 434 cases and 962 controls. Analyses of the joint effects of smoking and radon, conducted in the occupational and the residential studies, suggest a sub-multiplicative interaction. The relative risk from radon among non-smokers is higher by a factor of 2-3 in comparison to smokers, suggesting different patterns of lung deposition and clearance among smokers and non-smokers. (author)

  15. Lifetime loss through lung cancer in Denmark and Sweden in relation to radon levels

    International Nuclear Information System (INIS)

    Radon levels in Swedish houses are 2.1 times higher than in Danish. Results show no positive correlation with cumulative lifetime loss due to lung cancer for the period 1972-1978, which in Denmark was 2.0 times that in Sweden. Neither do they show any positive correlation with lifetime loss due to leukemia, which was the same in Sweden and Denmark, or with lifetime loss due to total neoplasms. Lung cancer mortality figures resemble those for bronchitis, asthma and emphysema. The authors thus see no special radiogenic effect of the high Swedish radon levels. (author)

  16. Remote system for measurement of radon alpha emitter for population safety guards

    International Nuclear Information System (INIS)

    The objective of this research project is to study the OSL properties for high doses of dosemeters traditionally applied in thermoluminescent dosimetry (TL), as CaF2: Dy (TLD 200) and CaF2: Mn (TLD 400), and thus verify the applicability of OSL technique in high-dose dosimetry

  17. Preliminary studies for the determination of alpha emitters using the gross alpha coprecipitation methods

    International Nuclear Information System (INIS)

    The radiological quality of drinking water in Spain is regulated by Nuclear Security Guideline No, 7.7 (Rev.1) of the Nuclear Security Council (NSC). this guideline establishes the protocol to follow when the radiological level exceeds 0,1 Bq.l''1. When this level is passed, the responsible alpha emitter must be identified; ''210 Po, ''226Ra, ''230Th, ''239Pu, ''224Ra, ''234 U and ''138 U. Activity due to these isotopes is usually determined using alpha spectrometry with semiconductor detectors. This method allows the activity of the alpha emitters to be determined with a good sensitivity. however, it requires long radiochemical isolations and long counting times, so the method is not suitable for rough estimate radiological analysis. In this preliminary work, we present the conditioning of the sample-precipitate that is essential for further radiochemical isolations. (Author) 9 refs

  18. Alpha spectrometry of thick sources. I. Application to alpha emitters determination

    International Nuclear Information System (INIS)

    A method for determining alpha emitters by silicon surface barrier detector spectroscopy using thick sources is studied. Two types of spectra have been obtained. They have different shapes of line according to the procedure used for preparing the sources. For both spectra a computing least square programme has been developed. In this way it is possible to calculate line intensities with accuracy better than 20 percent. (author)

  19. Epidemiology of Czech and French Uranium Miners; Lung Cancer Risk Linked to low Radon Exposure

    International Nuclear Information System (INIS)

    Full text: Comprehensive results from miners cohorts have demonstrated a clear association between lung cancer risk and radon exposure cumulated during occupational life. However a large proportion of these miners had cumulated high radon exposure during a short period. The French and Czech cohorts of uranium miners allow to analyse the potential risk linked to low radon exposures protracted over long duration. Furthermore, the study will allow to consider the modifying effects of other factors present in the mining atmosphere. The present analysis is based on 5098 miners employed in French uranium mines for at least one year since 1945, and followed up to 1994. A total of 5002 Czech miners employed since 1952 have been followed up to 1995. Mean cumulative exposures are 36 and 57 WLM among French and Czech miners, respectively, protracted in average over 11 and 10 years. A significant excess of lung cancer deaths is observed in both cohorts. A linear association of this risk with cumulative exposure to radon was confirmed. he purpose of the joint analysis is to study the influence of low annual exposures (exposure rate effect). According to these analyses, the occupational exposure gives the opportunity to evaluate lung cancer risk for annual exposures to radon in the range of 2 WLM or less, the levels that are comparable to exposures of about 400-500Bq/m3 in dwellings. (author)

  20. Factors modifying the risk of lung cancer associated to radon in the french cohort of uranium miners

    International Nuclear Information System (INIS)

    The radon is classified lung carcinogen for man, but questions stay about the effects for low doses irradiation.The results of the analysis radon-lung cancer and the factors modifying on this relationship in the French cohort of miners followed until to 1999 is reported. This analysis confirms that the risk lung cancer is different according the period of exposure. A best precision in the measurement of exposure after 1956 could explain this difference. (N.C.)

  1. Contribution of Radon Exposure to the Risk of Lung Cancer Assessed by Applying a Multifactor Analysis

    International Nuclear Information System (INIS)

    Full text: It is well known that many different carcinogenic risk factors contribute to the development of lung cancer. Smoking, occupational exposure to carcinogens, chronic lung diseases and industrial air pollution are the most significant of them. Indoor radon exposure is considered a weak carcinogenic risk factor in the Urals, Russia. A drawback of traditionally applied monofactor methods of epidemiologic analysis is that different carcinogenic risk factors are analysed separately and their complex effect on public health is not taken into account. With such an approach it is impossible to adequately assess each factor's contribution in the total carcinogenic risk. For this reason it is expedient to apply methods of multifactor analysis in epidemiologic studies. We applied mathematical methods of pattern recognition when analysing the effect of indoor radon exposure on the development of lung cancer in the population of two Ural cities. We assessed the association between radon/thoron exposures and lung cancer using both BEIR VI model and the above-mentioned methods. The results were significantly different. According to BEIR VI model the contribution of radon/thoron in the risk of lung cancer varied from 7.2% to 33%, whereas this contribution assessed in the multifactor analysis was only 0.5%. We think that the contribution assessed in BEIR VI model is overestimated. Our considerable experience in conducting epidemiologic studies using mathematical methods of pattern recognition, gives us grounds to state that the assessment of radon/thoron exposure on lung cancer risk obtained in the multifactor analysis is more adequate and precise. (author)

  2. Measurement of radon concentration in dwellings in the region of highest lung cancer incidence in India

    International Nuclear Information System (INIS)

    Monitoring of radon exhalation from soil and its concentration in indoor is found to be helpful in many investigations such as health risk assessment and others as radiation damage to bronchial cells which eventually can be the second leading cause of lung cancer next to smoking. The fact that Aizawl District, Mizoram, India has the highest lung cancer incidence rates among males and females in Age Adjusted Rate (AAR) in India as declared by Population Based Cancer Registry Report 2008 indicates the need for quantification of radon and its anomalies attached to it. Measurement of radon concentration had been carried out inside the dwellings in Aizawl district, Mizoram. A time integrated method of measurement was employed by using a solid state nuclear track detector (SSNTD) type (LR-115 films) kept in a twin cup dosimeter for measurement of concentration of radon and thoron. The dosimeters were suspended over bed rooms or living rooms in selected dwellings. They were deployed for a period of about 120 days at a time in 63 houses which were selected according to their place of location viz. fault region, places where fossil remains were found and geologically unidentified region. After the desired period of exposure, the detectors were retrieved and chemically etched which were then counted by using a spark counter. The recorded nuclear tract densities are then converted into air concentrations of Radon and Thoron

  3. Radon

    International Nuclear Information System (INIS)

    Three slide sets which can be used in lectures about radiation protection have been published by NRPB. The slide sets are based on publications in the NRPB's ''At-a-Glance'' series of broadsheets, which use illustrations as the main source of information, supported by captions; the series generally avoids the jargon of radiation protection, although each leaflet is based on scientific studies. Slide Set Number 2, ''Radon'', describes the characteristics of the gas, the means by which it builds up in homes, the nature and level of the risks and the remedies and preventative measures. It also summarises the problems posed by, and solutions to, radon in the workplace. (Author)

  4. Lung cancer mortality among nonsmoking uranium miners exposed to radon daughters

    International Nuclear Information System (INIS)

    This paper reports on radon daughters, both in the workplace and in the household, that are a continuing cause of concern because of the well-documented association between exposure to radon daughters and lung cancer. To estimate the risk of lung cancer mortality among nonsmokers exposed to varying levels of radon daughters, 516 white men who never smoked cigarettes, pipes, or cigars were selected from the U.S. Public Health Service cohort of Colorado Plateau uranium miners and followed up from 1950 through 1984. Age-specific mortality rates for nonsmokers from a study of U.S. veterans were used for comparison. Fourteen deaths from lung cancer were observed among the nonsmoking miners, while 1.1 deaths were expected, yielding a standardized mortality radio of 12.7 with 95% confidence limits of 8.0 and 20.1. These results confirm that exposure to radon daughters in the absence of cigarette smoking is a potent carcinogen that should be strictly controlled

  5. Lung cancer risk due to exposure to indoor radon in Western Germany

    International Nuclear Information System (INIS)

    In a case-control study in West-Germany the lung cancer risk due to exposure to indoor radon was investigated. From 1990 to 1996 incident lung cancer patients as well as a random sample recruited from the population were interviewed according to their residential history, smoking, occupational exposure and other risk factors. 2 charcoal canisters and 2 alpha track detectors were placed for 1 year in the present and former dwellings of participants. The evaluation included 1449 cases and 2297 controls recruited from the entire study area, and 365 cases and 595 controls recruited from radon-prone matching areas within the entire study area. Odds ratios were estimated according to a logistic regression model simultaneously adjusted to smoking and to exposure to asbestos. Furthermore the linear trend was calculated. In the entire study area no elevated odds ratio is seen. However, in the radon-prone matching areas a clear influence of exposure to radon on the lung cancer risk is observed. The adjusted odds ratio [95% CI] is 1.59 [1.08, 2.27], 1.93 [1.19, 3.13] and 1.93 [0.99, 3.77] for 50-80, 80-140 and over 140 Bq/m3 compared to 0-50 Bq/m3. The odds ratio for the linear trends is 1.13 [0.88, 1.46] for an increase in exposure of 100 Bq/m3. (orig./MG)

  6. The damage effect of radon and its progeny on lung and blood of rats

    International Nuclear Information System (INIS)

    To investigate the pathological damage of lung and peripheral blood damage in rats exposed to radon and its progeny, Sprague-Dawley rats were exposed to radon in multifunction ecological radon chamber with the cumulative dose up to 60, 90 and 120 WLM, respectively. The numbers and proportions of white cells in peripheral blood were measured meanwhile the degree of lung and its bronchus injury was observed. It was found that proportions of white blood cells increased in the proportion of granulocytes and decreased in the proportion of lymphocytes (p<0.05). A series of pathological alterations were observed including hyperaemia and edema in the alveolus, emphysema, infiltration of inflammatory cells. The occurrence of different pathology, its scope and the serious degree, alveolar capillaries and incidence of thrombosis increased with the accumulation exposure dosage. As a result, radon and its progeny can increase the proportion of granulocytes and decrease the proportion of lymphocytes in peripheral blood cells. At the same time the serious degree of lung and its bronchus injury will increase with the increment of the accumulation exposure dosage. (authors)

  7. Lung cancer incidence after exposure of rats to low doses of radon: influence of dose rate

    International Nuclear Information System (INIS)

    To study the effect on lung cancer incidence of a long exposure to low levels of radon, 500 male 3-months-old Sprague-Dawley rats, were exposed to a cumulative dose of 25 WLM of radon and its daughters, 6 hours a day, 5 days a week, during 18 months. Exposure conditions were controlled in order to maintain a defined PAEC: 42 x 106 J.m-3 (2 WL), in the range of domestic and environmental exposures. Animals were kept until they died or given euthanasia when moribund. Mean survival times were similar in both irradiated and control groups: 828 days (SD = 169) and 830 days (SD = 137), as well as lung cancer incidence, 0.60% at 25 WLM and 0.63% for controls. The incidence of lung lesions was compared statistically with controls and those previously obtained at cumulative exposures of 25 and 50 WLM delivered over a 4-6 month period, inducing a significant increase of lung cancer, 2.2% and 3.8% respectively. Such a comparison showed a decreased lung cancer incidence related to a decrease in the dose rate for low levels of radon exposure. (author)

  8. Interactive session: alpha emitters, fashion or reality? radionuclides and molecules availability

    International Nuclear Information System (INIS)

    Full text of publication follows. This introduction to the interactive session will simply be based on statements related to the future of therapy in nuclear medicine with some emphasis on the use of alpha-emitters. Some hypotheses will be developed on topics such as 'How will look nuclear medicine in 2025?', 'Do we have enough information to support the use of alpha in therapy?' 'Does it make sense to develop alpha-labelled molecules without long term financial commitment?', 'Will sufficient amounts of radionuclides available when the drugs will be ready for marketing?', 'Do we know enough about alpha emitters toxicity?', 'Is personalized medicine really the solution of the future of health care?', 'How can we convince authorities about the advantages of alpha labelled molecules?', 'Is the development of alpha RIT more expensive or more difficult than beta RIT?', 'Where are all the beta-emitter under development gone?', 'With alpha-emitters, are we speaking about 2025 or 2050?', 'Will Xofigo be a success?', 'What will be the real role of pharmaceutical companies in radiotherapy?', 'Who are the most afraid about radioactivity, the patients or the authorities?'. The speaker will provide his own opinion about each topic. Will you agree or not with him? What is your opinion? (author)

  9. Radiative Transfer Modeling of Lyman Alpha Emitters. I. Statistics of Spectra and Luminosity

    OpenAIRE

    Zheng, Zheng; Cen, Renyue; Trac, Hy; Miralda-Escude, Jordi

    2009-01-01

    We combine a cosmological reionization simulation with box size of 100Mpc/h on a side and a Monte Carlo Lyman-alpha (Lya) radiative transfer code to model Lyman Alpha Emitters (LAEs) at z~5.7. The model introduces Lya radiative transfer as the single factor for transforming the intrinsic Lya emission properties into the observed ones. Spatial diffusion of Lya photons from radiative transfer results in extended Lya emission and only the central part with high surface brightness can be observed...

  10. Optical imaging of alpha emitters: simulations, phantom, and in vivo results

    Science.gov (United States)

    Boschi, Federico; Meo, Sergio Lo; Rossi, Pier Luca; Calandrino, Riccardo; Sbarbati, Andrea; Spinelli, Antonello E.

    2011-12-01

    There has been growing interest in investigating both the in vitro and in vivo detection of optical photons from a plethora of beta emitters using optical techniques. In this paper we have investigated an alpha particle induced fluorescence signal by using a commercial CCD-based small animal optical imaging system. The light emission of a 241Am source was simulated using GEANT4 and tested in different experimental conditions including the imaging of in vivo tissue. We believe that the results presented in this work can be useful to describe a possible mechanism for the in vivo detection of alpha emitters used for therapeutic purposes.

  11. Indoor radon levels and lung cancer risk estimates in seven cities of the Bahawalpur Division, Pakistan

    International Nuclear Information System (INIS)

    Indoor radon concentration levels were measured in seven major cities of the Bahawalpur Division, Pakistan. These included Fort Abbas, Minchin Abad, Hasilpur, Bahawalpur, Liaqatpur, Rahimyar Khan and Sadiq Abad. In order to select houses for this survey, the inhabitants were approached through their school-registered children. Due to several constraints, only those 100 houses were chosen in each city that were relatively the best representatives of the built-up area. The selected houses were then divided into five categories according to the house locations and building characteristics. CR-39 detectors, placed in polyethylene bags, were installed at head height in bedrooms and sitting rooms of all the selected houses and were exposed to radon and its daughter products for 90 days. Four such measurements were performed over a year in order to average out the seasonal variation in radon levels. After exposure, all the detectors were etched and counted under an optical microscope. The track densities of four measurements were averaged out and related to radon concentration levels. The radon levels were found to be 20, 20, 26, 28, 34, 42, 47 Bq m-3 in the bedrooms and 24, 26, 27, 26, 37, 40, 43 Bq m-3 in sitting rooms of Hasilpur, Rahimyar, Khan, Minchin Abad, Fort Abbas, Sadiq Abad, Bahawalpur and Liaqatpur respectively. The observed variation in the radon level may be attributed to the geological variation in the area. Based on the observed data, excess lung cancer risk was assessed using the risk factors recommended by the USEPA, UNSCEAR and the ICRP. According to the EPA model, the lifetime excess lung cancer risk due to the lifetime exposure is found to vary from 12-102 per million per year in the houses surveyed. This variation is from 16-114 and 26-62 per million per year if UNSCEAR and ICRP limits are applied respectively. (author)

  12. Radon and Lung Cancer Case-Control Study in Middle Ural

    International Nuclear Information System (INIS)

    Full text: The pilot phase of radon and lung cancer case-control study has been performed in Karpinsk and Pervouralsk towns of Middle Ural region of Russia. The case group consists of 341 persons with lung cancer and living in that towns at least five previous years. The lung cancer diagnoses were carefully verified by instrumental techniques and 70% of its were morphologically validated. The persons for the control group (448) were chosen from the population living in that towns at least five years taking into account the age and sex. The special epidemiological questionnaire was developed which includes the items by the groups of factors as follow: clinical data, social factors, chronic lung diseases, life habit, tobacco smoking, alcohol drinking, diet preference etc. The epidemiological questionnaires were fulfilled for each member of case and control groups. Radon gas concentration and thoron equilibrium equivalent concentration measurements had been performed using nuclear track detectors and grab sampling accordingly in the dwellings of case and control groups members. By preliminary estimation the odds ratios are 1, 0.91, 1.2, 1.1 in the ranges of radon and thoron equilibrium equivalent concentration 0-6, 3-13, 13-36 and 36-370 Bq/m3 respectively. The deeper and more rigorous analysis as well as different independent approaches will be discussed in the paper.(author)

  13. Estimation and management of risk for lung cancer induced by radon progeny

    International Nuclear Information System (INIS)

    Estimation and management of risk for lung cancer induced by radon progeny. Radon is a radioactive gas released form soils and materials containing radium. Once inhaled in the respiratory tract, its decay products irradiate the tissues and provoke a risk of cancer. The estimation of this risk is carried out through an epidemiologic or a dosimetric approach. The former uses data on the mortality of miners who were exposed to radon. Then the results are extrapolated to the general population. More recently, some studies tried to estimate the risk directly on the general population. The latter approach tries to compute the rate of conversion between the radon concentration in the indoor environment and the dose absorbed by the respiratory tract. The risk of cancer is estimated through a coefficient which has been inferred from studies on the Hiroshima and Nagasaki survivors. The risk management requires the definition of general principles and of a set of recommendations. In the past, the ICRP stated that risks provoked by natural sources of irradiation should not be taken into consideration. Since 1984, it has changed its mind and limits of acceptability concerning radon concentration in dwellings have been defined. We should stress that the cancer risk estimations are tainted by uncertainties. 'Experts judgements' play an important part. On the other hand, 'value judgements' are essential in the field of risk management. Obviously, it is a problem which has a trans-disciplinary character and which rises the question of the relationship between science and society. (authors)

  14. Radon and Cancer

    Science.gov (United States)

    ... low levels outdoors. However, in areas without adequate ventilation, such as underground mines, radon can accumulate to ... radon levels. What have scientists learned about the relationship between radon and lung cancer? Scientists agree that ...

  15. Studying reionization with the next generation of Ly-alpha emitter surveys

    CERN Document Server

    Jensen, Hannes; Iliev, Ilian; Laursen, Peter; Mellema, Garrelt; Zackrisson, Erik

    2014-01-01

    We study the prospects for constraining the ionized fraction of the intergalactic medium (IGM) at $z>6$ with the next generation of large Ly$\\alpha$ emitter surveys. We make predictions for the upcoming Subaru Hyper Suprime-Cam (HSC) Ly$\\alpha$ survey and a hypothetical spectroscopic survey performed with the James Webb Space Telescope (JWST). Considering various scenarios where the observed evolution of the Ly$\\alpha$ luminosity function of Ly$\\alpha$ emitters at $z>6$ is explained partly by an increasingly neutral IGM and partly by intrinsic galaxy evolution, we show how clustering measurements will be able to distinguish between these scenarios. We find that the HSC survey should be able to detect the additional clustering induced by a neutral IGM if the global IGM neutral fraction is greater than $\\sim$20 per cent at $z=6.5$. If measurements of the Ly$\\alpha$ equivalent widths (EWs) are also available, neutral fractions as small as 10 per cent may be detectable by looking for correlation between the EW an...

  16. Alpha emitters in nuclear waste. Extension of the procedure for low and medium level activity waste

    International Nuclear Information System (INIS)

    The present paper describes a separative method for the determination of U, Pu, Am, Np, Th and Cm as alpha emitters and 3H, Sr, and Ni as beta emitters, when present in aqueous samples of nuclear waste, by using chromatographic separations, liquid scintillation counting and alpha spectrometry. The main separation is performed in one step by coprecipitation of the alpha emitters with yttrium hydroxide at pH = 9-10 after distillation of tritium until dryness and dissolution of the residue in 2M HCI. Actinides are precipitated while strontium and nickel remain in supernatant. Nickel is separated by precipitation with dimetyglioxime in the supernatant and measured by LSC. Strontium is separated by chromatography after conditioning the supernatant (which also contained nickel) and measured by LSC. The actinides fraction is re dissolved in nitric acid and percolated through three chromatographic columns (TEVA, U-TEVA and TRU-SPEC) conditioning the different fractions for measuring by alpha spectrometry. The spectra of the different fractions are presented together with the detection limits and the recoveries obtained on spiked samples. (author)

  17. An Atlas of z=5.7 and z=6.5 Ly alpha Emitters

    CERN Document Server

    Hu, E M; Barger, A J; Capak, P; Kakazu, Y; Trouille, L

    2010-01-01

    We present an atlas of 88 z~5.7 and 30 z~6.5 Ly alpha emitters obtained from a wide-field narrowband survey. We combined deep narrowband imaging in 120A bandpass filters centered at 8150A and 9140A with deep BVRIz broadband imaging to select high-redshift galaxy candidates over an area of 4180 square arcmin. The goal was to obtain a uniform selection of comparable depth over the 7 targeted fields in the two filters. For the GOODS-N region of the HDF-N field, we also selected candidates using a 120A filter centered at 9210A. We made spectroscopic observations with Keck DEIMOS of nearly all the candidates to obtain the final sample of Ly alpha emitters. At the 3.3A resolution of the DEIMOS observations the asymmetric profile for Ly alpha emission with its steep blue fall-off can be clearly seen in the spectra of nearly all the galaxies. We show that the spectral profiles are surprisingly similar for many of the galaxies and that the composite spectral profiles are nearly identical at z=5.7 and z=6.5. We analyze...

  18. Can galactic outflows explain the properties of Ly-alpha emitters?

    CERN Document Server

    Orsi, Alvaro; Baugh, Carlton M

    2011-01-01

    We study the properties of Ly-alpha emitters in a cosmological framework by computing the escape of Ly-alpha photons through galactic outflows. We combine the GALFORM semi-analytical model of galaxy formation with a Monte Carlo Ly-alpha radiative transfer code. The properties of Ly-alpha emitters at 0

  19. DNA damage in lung cells after radon exposure detected by comet assay

    International Nuclear Information System (INIS)

    The comet assay was applied to measure DNA breaks and oxidised bases in isolated alveolar macrophages and epithelial type II cells from the rat lung. The cells were exposed to radon for 60 min. Radon exposure was estimated at (1.25 - 2.45) MBq.h.m-3. Strand breaks were significantly elevated above the background level after irradiation of epithelial type II cells. In contrast, no strand breaks were induced in alveolar macrophages, but a high level of oxidised bases, mostly purines, was found. Alveolar macrophages and epithelial type II cells isolated from the rat lung provide and exceptionally suitable cell model for investigation of potential hazards of air-born environmental contaminants. (authors)

  20. Lung cancer risk among Czech miners exposed to radon

    International Nuclear Information System (INIS)

    Studies of underground miners of uranium and other substances are at present the principal source of information on the effects of exposure to radon and its progeny. One of the largest such studies is that of uranium miners in West Bohemia (Jachymov). This study, sometimes referred to as the S cohort, was set up in 1970 by the late Josef Sevc. About ten years later, two further cohorts were delineated by him. One of uranium miners (N) who worked under improved conditions mostly in the Pribram mines, and the second one of burnt clay miners (L) located in the Rakovnik district. Brief characteristics of the cohorts are shown

  1. Synergy of radon inhalation and tobacco smoking in the induction of lung cancer

    International Nuclear Information System (INIS)

    The problem of contribution of tobacco smoking to the induction of lung cancer in persons living in environments with the enhanced radon concentrations is treated. An attempt is made to interpret the sub-multiplicative mechanism of the synergy of the two factors, i.e. a situation where the contribution of the two factors acting jointly is larger than their simple addition but lower than their multiplication, as currently assumed to hold. (P.A.)

  2. New aspects of the etiology of lung carcinomas in respect to radon 222

    International Nuclear Information System (INIS)

    Radon is the reason for the high cancer risk of uran miners. It also is present in building materials and therefore in the air inside houses. In the last year the radium content in houses increased because of the use of other row materials for building materials and because of a better isolation of the houses. This may increase the risc of lung cancer. (P.W.)

  3. Localization of alpha emitters by damage production in a thin film. Application to the study of alpha emitter diffusion in irradiated samples

    International Nuclear Information System (INIS)

    The process of recording α particles on cellulose nitrate films, called alpha-graphy, is applied to the study of the diffusion of α-emitting elements in irradiated alloys. The existence of diffusion is shown by attacking the film with concentrated caustic soda after exposition. The insensitivity of the recorder to β γ radiation emitted by the sample after passing in the reactor makes it possible to operate with long exposure times and to detect small diffusions. The concentration-penetration curves are drawn up after carrying out a densitometric analysis of the alpha-graphies. - As the cellulose nitrate is affected only by α particles of energies of between 0.5 and 4 MeV, it was first necessary to determine the yield of the recorder for α particles emitted by a thick source, i.e. whose energy varies between 0 and E0, E0 being the energy of the alpha emitter. - The concentration C of the α-emitter, as a function of the optical density D of the alpha-graphy, and of the exposure time t is given by a simple relationship: C = D/at where a is an experimental constant determined by calibration. It depends on the nature of the cellulose nitrate, of the α-emitting element and of the alloy studied. (authors)

  4. Reply to 'Explaining the lung cancer versus radon exposure data for USA counties'

    International Nuclear Information System (INIS)

    Full text: Professor Cohen states in his letter that his analysis 'encompasses all of the Doll suggestions'. It is, however, logically impossible for it to have done so using data at the level of counties. This is because the effect of cigarette smoking on the relationship between residential radon and individual lung cancer risk will be determined by the relationship between smoking status and lung cancer among the individuals within each county. Unless smoking is irrelevant to lung cancer risk (which we know to be untrue) or smoking status and residential radon are uncorrelated within each county (which seems unlikely), the relationship between residential radon and lung cancer at the county level will differ from that at the level of the individual in a way that cannot be overcome by including corrections for smoking habits at the county level, even if these corrections correctly represent the smoking habits of the individuals within each county. The difference in the relationship between a risk factor and a disease rate at the level of the individual and at an area level is the ecologic fallacy and is described in detail by Greenland and Robins (1994) and Morgenstern (1998). Lubin (1998) has also demonstrated that biases caused by the ecologic fallacy can be of any magnitude from minus infinity to plus infinity. In two recent studies (Lagarde and Pershagen 1999, Darby et al 2000), parallel individual and ecological analyses have been carried out of identical data from case-control studies of residential radon (Peshagen et al 1994, Darby et al 1998). These analyses have shown that, in addition to any bias caused by the ecological fallacy, ecological studies of residential radon and lung cancer are also prone to biases caused by determinants of lung cancer risk that vary at the level of the ecological unit concerned. In these two examples, the additional variables were latitude and urban/rural status respectively. The explanation of these variables is not yet

  5. Lung cancer from radon and smoking: a multistage model for the WISMUT uranium miners

    International Nuclear Information System (INIS)

    Full text: In the world's third-largest uranium-mining province located in areas of Saxony and Thuringia in the former German Democratic Republic, the WISMUT Company conducted extensive uranium mining starting in 1946. Up to 1990, when mining activities were discontinued, most of the 400,000 employees had been exposed to uranium ore dust and radon and its progeny. It is well established that, besides smoking, such exposures are associated with an increased risk of lung cancer. From about 130,000 known miners a huge cohort of 59,000 miners has been formed and in an epidemiological analysis lung cancer risks have been evaluated (Grosche et al., 2006). We will present an alternative approach using a biologically-based multistage carcinogenesis model quantifying the lung-cancer risk related to both the exposure to radon and smoking habits. This mechanistic technique allows for extrapolation to the low exposures that are important for present-day radiation protection purposes and the transfer of risk across populations. The model is applied to a sub-cohort of about 35,000 persons who were employed at WISMUT after 1955, with known annual exposures estimated from the job-exposure matrix (Lehmann et al., 2004). Unfortunately, detailed information on smoking is missing for most miners. However, this information has been retrieved in two case-control studies, one of which was nested in the cohort while the other was not (Brueske-Hohlfeld et al., 2006). For these studies, the relevant smoking parameters are assembled in so-called smoking spectra that are next projected onto the entire cohort using a Monte-Carlo sampling method. Individual smoking habits that are randomly assigned to the cohort members, together with the information on annual exposure to radon, is used as an input for the multistage model. Model parameters related to radon and tobacco exposure are fitted with a maximum-likelihood technique. We will show results of the observed and expected lung

  6. Effect of the number of cigarettes smoked and of radon exposure on the lung cancer risk

    International Nuclear Information System (INIS)

    The relation between the extent of cigarette smoking and the lung cancer risk in people exposed to radon was examined. The changes in the airway geometry due to an increased production of mucus caused by smoking were taken into account. The mucous layer protects the target cells from the effects of ionizing radiation. The radiation risk per unit exposure decreases with the number of cigarettes smoked, in contrast to the total risk, which increases to stagnate in the range of extensive daily cigarette smoking. Lung damage in chronic smokers should be taken into account, though. (orig.)

  7. An assessment of ecological and case-control methods for estimating lung cancer risk due to indoor radon

    International Nuclear Information System (INIS)

    Studies of underground miners indicate that indoor radon is an important cause of lung cancer. This finding has raised concern that exposure to radon also causes lung cancer in the general population. Epidemiological studies, including both case-control and ecological approaches, have directly addressed the risks of indoor residential radon; many more case-control studies are in progress. Ecological studies that associate lung-cancer rates with typical indoor radon levels in various geographic areas have not consistently shown positive associations. The results of purportedly negative ecological studies have been used as a basis for questioning the hazards of indoor radon exposure. Because of potentially serious methodologic flaws for testing hypotheses, we examined the ecological method as a tool for assessing lung-cancer risk from indoor radon exposure. We developed a simulation approach that utilizes the Environmental Protection Agency (EPA) radon survey data to assign exposures to individuals within counties. Using the computer-generated data, we compared risk estimates obtained by ecological regression methods with those obtained from other regression methods and with the open-quotes trueclose quotes risks used to generate the data. For many of these simulations, the ecological models, while fitting the summary data well, gave risk estimates that differed considerably from the true risks. For some models, the risk estimates were negatively correlated with exposure, although the assumed relationship was positive. Attempts to improve the ecological models by adding smoking variables, including interaction terms, did not always improve the estimates of risk, which are easily affected by model misspecification. Because exposure situations used in the simulations are realistic, our results show that ecological methods may not accurately estimate the lung-cancer risk associated with indoor radon exposure

  8. Radon measurement and its risk in the development of lung cancer in indoor spaces at the historical center of Quito, Ecuador

    International Nuclear Information System (INIS)

    In Ecuador, as in other countries around the world, the presence of radon is eminent. This study compiles some information about the effects that radon has over human beings, its incidence in lung cancer and the methodologies used to determine radon. High concentrations of radon, superior to international limits have been found in indoor sites in the center of Quito and Cuenca Ecuador. (The author)

  9. Lung cancer mortality and radon concentration in a chronically exposed neighborhood in Chihuahua, Mexico: a geospatial analysis.

    Science.gov (United States)

    Hinojosa de la Garza, Octavio R; Sanín, Luz H; Montero Cabrera, María Elena; Serrano Ramirez, Korina Ivette; Martínez Meyer, Enrique; Reyes Cortés, Manuel

    2014-01-01

    This study correlated lung cancer (LC) mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K) and Inverse-Distance Weighting (IDW) spatial interpolations were carried out. Deaths were georeferenced and Moran's I correlation coefficients were calculated. The mean values (over n = 171) of the interpolation of radon concentrations of deceased's dwellings were 247.8 and 217.1 Bq/m(3), for K and IDW, respectively. Through the Moran's I values obtained, correspondingly equal to 0.56 and 0.61, it was evident that LC mortality was directly associated with locations with high levels of radon, considering a stable population for more than 25 years, suggesting spatial clustering of LC deaths due to indoor radon concentrations. PMID:25165752

  10. Lung Cancer Mortality and Radon Concentration in a Chronically Exposed Neighborhood in Chihuahua, Mexico: A Geospatial Analysis

    Directory of Open Access Journals (Sweden)

    Octavio R. Hinojosa de la Garza

    2014-01-01

    Full Text Available This study correlated lung cancer (LC mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K and Inverse-Distance Weighting (IDW spatial interpolations were carried out. Deaths were georeferenced and Moran’s I correlation coefficients were calculated. The mean values (over n=171 of the interpolation of radon concentrations of deceased’s dwellings were 247.8 and 217.1 Bq/m3, for K and IDW, respectively. Through the Moran’s I values obtained, correspondingly equal to 0.56 and 0.61, it was evident that LC mortality was directly associated with locations with high levels of radon, considering a stable population for more than 25 years, suggesting spatial clustering of LC deaths due to indoor radon concentrations.

  11. Quantitative evaluation of the lung cancer deaths attributable to residential radon: A simple method and results for all the 21 Italian Regions

    International Nuclear Information System (INIS)

    Pooled analyses of epidemiological case-control studies on lung cancer and residential radon have shown that radon exposure in dwellings increases lung cancer risk, and that the increase is statistically significant also for prolonged exposures to low-medium level of radon concentration, i.e. levels commonly found in many dwellings. In this paper, a simple method to evaluate the health burden due to the presence of radon in homes (i.e. the number of lung cancer deaths attributable to radon exposure in dwellings) was presented. This method is based on the following parameters: i) the excess relative risk per unit of exposure evaluated in case-control studies; ii) the average radon concentration that can be considered representative of population exposure in dwellings; iii) the total number of lung cancer deaths occurring each year. Moreover, the interaction between radon and cigarette smoking is needed to be taken into account: in fact, although most of the persons are non-smokers, most of the lung cancer deaths attributed to radon are actually due to the multiplicative effect of radon and cigarette smoking. To show this effect, the number of radon related lung cancer deaths estimated to occur among current, former and never smokers was calculated separately for males and females, taking into account the relative risk of lung cancer for the different smoking categories and the prevalence of smoking habits. The methodology described in this work was applied to all the 21 Italian Regions in order to illustrate it. The overall fraction of lung cancer deaths attributable to radon in Italy is about 10%, with values in individual Regions ranging from 4% to 16%. The greater part of the lung cancers attributable to radon is estimated to occur among current smokers for both males and females (72% and 60%, respectively, at national level). This is due to the synergistic effects of radon and cigarette smoking, which should therefore be taken into account in policies aimed to

  12. Expected lung cancer risk from radon daughter exposure in dwelllings

    International Nuclear Information System (INIS)

    Different concepts and approaches for the assessment of the lung cancer risk of populations from indoor exposure and its decay products are outlined. They proceed from the epidemiological data on the excess lung cancer frequency observed among Rn-exposed uranium miners and γ-exposed atomic bomb survivors, taking into account appropriate correction factors for indoor conditions. Inparticular a proportional hazard model is presented which enables an individual - and population - related risk assessment. The results lead to the conclusion that at the present time probably about 10-20% of the total observed lung cancer frequency in the Swedish population might be associated with the indoor inhalation of 222-Rn daughters. For most other countries these values are about a factor 0.5 lower. The absolute radiation risk for males is probably about a factor 2-3 higher than that for females. (Author)

  13. Early bone changes after incorporation of low quantities of alpha emitters in male rats

    International Nuclear Information System (INIS)

    This work shows the early effects of cancergenic doses of alpha emitters in long bones of rats. The investigations were based on radiographic, morphologic, angiographic, histologic and electronmicroscopic methods. A special method for bone angiography in the rat was elaborated and a new method was developed for measurement of the femur neck-head angle. Numerous disturbances in bone growth and bone structure, in the blood supply of bone and also of the bone building cells were observed. There was a correlation between the severity of the damage and the radiation dose, the spacial distribution of the nuclide and partially the age of the rats. The bone injury due to plutonium was markedly reduced by administration of the chelating agent Zn-DTPA. (orig.)

  14. Radon and lung cancer: The BEIR IV Report

    International Nuclear Information System (INIS)

    The National Academy of Sciences' BEIR IV Report (1988) deals primarily with lung cancer risks in human populations exposed to internally deposited alpha-emitting Rn and its decay products. Quantitative risk estimates for lung cancer are derived from analyses of epidemiologic data. A modified excess relative risk model of lung cancer mortality of worker exposure to Rn progeny in underground miners is developed. This models the excess risk per WLM (working level month) in terms of time intervals prior to an attained age, and is dependent on time since exposure and age at risk. Risk projections for the general public in indoor domestic environments are presented and cover exposure situations of current public health concern. For example, lifetime exposure to 1 WLM y-1 is estimated to increase the number of deaths due to lung cancer by a factor of about 1.5 over the current rate for both males and females in a population having the current prevalence of cigarette smoking. Occupational exposure to 4 WLM y-1 from ages 20 to 40 y is projected to increase lung cancer deaths in the general population by a factor of 1.6 over the current rate of this age cohort. In all of these cases, most of the increased risk occurs to smokers for whom the risk is up to 10 times greater than for nonsmokers. Discussion includes the extrapolation of estimates of lung cancer mortality risks from the underground miner data to the general population exposed to Rn and its decay products in the indoor domestic environment

  15. Lung Cancer Mortality and Radon Concentration in a Chronically Exposed Neighborhood in Chihuahua, Mexico: A Geospatial Analysis

    OpenAIRE

    Hinojosa de la Garza, Octavio R.; Sanín, Luz H.; María Elena Montero Cabrera; Korina Ivette Serrano Ramirez; Enrique Martínez Meyer; Manuel Reyes Cortés

    2014-01-01

    This study correlated lung cancer (LC) mortality with statistical data obtained from government public databases. In order to asses a relationship between LC deaths and radon accumulation in dwellings, indoor radon concentrations were measured with passive detectors randomly distributed in Chihuahua City. Kriging (K) and Inverse-Distance Weighting (IDW) spatial interpolations were carried out. Deaths were georeferenced and Moran's I correlation coefficients were calculated. The mean values (o...

  16. Use of various microdosimetric models for the prediction of radon induced damage in human lungs.

    Science.gov (United States)

    Böhm, R; Nikodémová, D; Holý, K

    2003-01-01

    Exposure to radon and radon decay products in some residential areas and at workplaces constitutes one of the greatest risks from natural sources of ionising radiation. Recently, increasing attention has been paid to the precise estimations of this health risk by numerous models. The compartmental model published in ICRP Publication 66 (HRTM) has been used for calculating alpha activity concentration in human lung. Energy deposition in the tissue was calculated by the Bethe-Bloch equation. The aim of this study was to check the performance and to compare the reliability of the microdosimetric models. In this work different thicknesses of mucus in the cases of non-smokers and smokers has been considered. Transformed cells were considered as the radiation risk parameters. The radiation risk evaluation for different exposure levels was based on homogeneous and heterogeneous distributions of target cells. The results of application of these procedures were compared with the epidemiological study of Czechoslovakian uranium miners. PMID:12918790

  17. Factors modifying the risk of lung cancer associated to radon in the french cohort of uranium miners; Facteurs modifiants du risque de cancer du poumon associe au radon au sein de la cohorte francaise des mineurs d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Vacquier, B.; Rogel, A.; Laurier, D. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay aux Roses (France); Caer, S.; Acker, A. [Areva NC, 75 - Paris (France)

    2008-09-15

    The radon is classified lung carcinogen for man, but questions stay about the effects for low doses irradiation.The results of the analysis radon-lung cancer and the factors modifying on this relationship in the French cohort of miners followed until to 1999 is reported. This analysis confirms that the risk lung cancer is different according the period of exposure. A best precision in the measurement of exposure after 1956 could explain this difference. (N.C.)

  18. Epidemiologic studies of lung disease among miners exposed to increased levels of radon daughters

    International Nuclear Information System (INIS)

    The mortality of uranium miners from both lung cancer and other respiratory diseases is strongly dependent on exposure to radon daughters, cigarette smoking, and height. Lung cancer among 15 different mining groups was analyzed to determine what factors influence incidence and the induction-latent period. At low exposures or at low exposure rates, alpha radiation is more efficient in inducing lung cancer, producing an upward convex exposure-response curve. The induction-latent period is shortened by an increased age at the start of mining, by cigarette smoking, and by high exposure rates. For follow-up periods of 20 to 25 years, the incidence increases with age at the start of mining, with the magnitude of exposure, and with the amount of cigarette smoking. Instead of extrapolating downward from high exposures to estimate risk at low levels, it might be more appropriate to use cancer rates associated with background radiation as the lowest point on the exposure-response curve

  19. An experimental two-stage rat model of lung carcinoma initiated by radon exposure

    International Nuclear Information System (INIS)

    We present the results of a two-stage biological model of lung carcinogenesis in rats. The histogenesis of these tumors was examined, and DNA content of lung cells was measured by flow cytometry during the evolving neoplastic stage. Tumors were induced in rat lungs after radon inhalation (1600 WLM) followed by a promoter treatment; six intramuscular injections of 5,6-benzoflavone (25 mg/kg of body weight/injection) every 2 wk. Less than 3 mo after the first injection of benzoflavone, squamous cell carcinoma was observed in the lungs of all rats exposed to radon. The preneoplastic lesions gradually developed as follows: hyperplastic bronchiolar-type cells migrated to the alveoli from cells that proliferated in bronchioles and alveolar ducts; initial lesions were observed in almost all respiratory bronchioles. From some hyperplasias, epidermoid metaplasias arose distally, forming nodular epidermoid lesions in alveoli, which progressed to form squamous papilloma and, finally, epidermoid carcinomas. The histogenesis of these experimentally induced epidermoid carcinomas showed the bronchioloalveolar origin of the tumor. This factor must be considered when comparing these with human lesions; in humans, lung epidermoid carcinomas are thought to arise mainly in the first bronchial generations. The labeling index of pulmonary tissue after incorporation of 3H-thymidine by the cells was 0.2% in control rats. This index reached a value of 1 to 2% in the hyperplastic area of the bronchioles and 10 to 15% in epidermoid nodules and epidermoid tumors, respectively. DNA cytometric analysis was performed on cell suspensions obtained after enzymatic treatment of paraffin sections of lungs from rats sacrificed during different stags of neoplastic transformations. Data showed the early appearance of a triploid cell population that grew during the evolution of nodular epidermoid lesions to epidermoid carcinomas

  20. Increased risk for small cell lung cancer following residential exposure to low-dose radon: A pilot study

    International Nuclear Information System (INIS)

    Alpha track radon detectors were placed in the homes of 35 lung cancer patients and 35 matched controls for a period of 8 to 10 mo. Twenty lung cancer patients had small cell lung carcinoma; 11 had adenocarcinoma, 2 had squamous cell carcinoma, and 2 had unclassified carcinoma among 15 nonsmokers. Mean overall living on ground level was significantly higher in the group with small cell lung carcinoma (50 y ± 15) than among controls (33 y ± 19); the adjusted odds ratio for lung cancer was 5.2 (90% confidence interval [90% CI] = 1.1--24.9) per decade of living on the ground floor for the group with small cell lung carcinoma. Radon exposure of more than 1.0 pci/l in the group with small cell lung carcinoma was associated with increased risk of lung cancer, although it did not reach statistical significance [odds ratio = 1.5 (90% CI = 0.4--5.4)], adjusting for differences in smoking habits. The study supports the presence of a differentially increased risk for small cell lung carcinoma following long-term radon exposure. 12 refs., 2 tabs

  1. Measurements of size distributions of radon progeny for improved quantification of the lung cancer risk emanating from exposure to radon decay products

    International Nuclear Information System (INIS)

    A major issue in radiation protection is to protect the population from the harmful effects of exposure to radon and radon progeny. Quantification of the lung cancer risk emanating from exposure to radon decay products in residential and working environments poses problems, as epidemiologic studies yield information deviating from the results obtained by the indirect method of assessment based on dosimetric respiratory tract models. One important task of the publication here was to characterize the various exposure conditions and to quantify uncertainties that may result from application of the ''dose conversion convention''. A special aerosol spectrometer was therefore designed and built in order to measure the size distributions of the short-lived radon decay products in the range between 0.5 nm and 10 000 nm. The aerosol spectrometer consists of a three-step diffusion battery with wire nets, an 11-step BERNER impactor, and a detector system with twelve large-surface proportional detectors. From the measured size distributions, dose conversion coefficients, E/Peq, were calculated using the PC software RADEP; the RADEP program was developed by BIRCHALL and JAMES and is based on the respiratory tract model of the ICRP. The E/Peq coefficients indicate the effective dose E per unit exposure Peq to radon decay products. (orig./CB)

  2. The bystander effect in experimental systems and compatibility with radon-induced lung cancer in humans

    International Nuclear Information System (INIS)

    Bystander effects following exposure to α-particles have been observed in C3H 10T 1/2 cells and in other experimental systems, and imply that linearly extrapolating low-dose risks from high-dose data might materially underestimate risk. The ratio of lung cancer risk among persons exposed to low and high doses of radon daughters is 2.4-4.0, with an upper 95% confidence limit (CL) of about 14. Assuming that the bystander effect observed in the C3H 10T 1/2 data applies to human lung cells in vivo, the epidemiological data imply that the number of neighbouring cells that can contribute to the bystander effect is between 0 and 1, with an upper 95% CL of about 7. As a consequence, the bystander effect observed in the C3H 10T 1/2 system probably does not play a large part in the process of radon-induced lung carcinogenesis in humans. Other experimental data relating to the bystander effect after α-particle exposure are surveyed; some of these data are more compatible with the epidemiological data. (author)

  3. Radon progeny exposure and lung cancer risk: Analyses of a cohort of Newfoundland fluorspar miners

    International Nuclear Information System (INIS)

    A cohort study of the mortality experience (1950-1990) of 1744 underground miners and 321 millers or surface workers has been conducted. Excess mortality among underground miners was noted for cancers of the lung, buccal cavity, pharynx and mouth, urinary tract and for silicosis and pneumoconioses. A highly statistically significant relationship was noted between radon daughter exposure and risk of dying of lung cancer; the small numbers of buccal cavity/pharynx cancers (n = 6) precluded meaningful analysis of exposure-response. No statistically significant excess was found for any cause of death among surface workers. The exposure-response data for lung cancer were fitted to various mathematical models. The model selected included terms for attained age, cumulative dose, dose rate and time since last exposure. Because risk varies according to each of these factors, a single summary risk estimate was felt to be misleading. The joint effects of radon and smoking could not be adequately assessed using this cohort. (author). 46 refs., 16 tabs., 1 fig

  4. Modeling Lung Carcinogenesis in Radon-Exposed Miner Cohorts: Accounting for Missing Information on Smoking.

    Science.gov (United States)

    van Dillen, Teun; Dekkers, Fieke; Bijwaard, Harmen; Brüske, Irene; Wichmann, H-Erich; Kreuzer, Michaela; Grosche, Bernd

    2016-05-01

    Epidemiological miner cohort data used to estimate lung cancer risks related to occupational radon exposure often lack cohort-wide information on exposure to tobacco smoke, a potential confounder and important effect modifier. We have developed a method to project data on smoking habits from a case-control study onto an entire cohort by means of a Monte Carlo resampling technique. As a proof of principle, this method is tested on a subcohort of 35,084 former uranium miners employed at the WISMUT company (Germany), with 461 lung cancer deaths in the follow-up period 1955-1998. After applying the proposed imputation technique, a biologically-based carcinogenesis model is employed to analyze the cohort's lung cancer mortality data. A sensitivity analysis based on a set of 200 independent projections with subsequent model analyses yields narrow distributions of the free model parameters, indicating that parameter values are relatively stable and independent of individual projections. This technique thus offers a possibility to account for unknown smoking habits, enabling us to unravel risks related to radon, to smoking, and to the combination of both. PMID:27198876

  5. Lung cancer risk among Czech miners exposed to radon related to histological types

    International Nuclear Information System (INIS)

    Long term exposure to radon and its progeny is one of the most important health problems. Epidemiological studies have demonstrated that exposure of miners to radon in a mine atmosphere can cause lung cancer. It has been recognized that lung cancer risk in uranium miners is associated with increased incidence of certain histological types, especially epidermoid and small cell. Recent results showed that the basic dependence of the relative risk for the two main histological types is linear with cumulative exposure. However, there is a suggestion that time and age modifiers of the dependence may be different for the two types. The aim of the study was firstly to verify the assumed differences in incidence of histological types of lung cancer for the studied cohort and general population and secondly to characterize the relation of histological types specific incidence to different exposure patterns. The study is based on data of the oldest Czechoslovak cohort, which belongs among the largest ones with the longest follow-up. The cohort includes 4320 former uranium miners who started their work in uranium mines in West Bohemia in the period 1948-59, and were working at least for 4 years and their complete personal and anamnestic data were available

  6. Risk of lung cancer from radon exposure: contribution of recently published studies of uranium miners

    International Nuclear Information System (INIS)

    The International Commission on Radiological Protection (ICRP) recently estimated the risk of lung cancer associated with radon exposure, and a statement was issued in ICRP Publication 115. This was based on recent epidemiological studies and the results from a joint analysis of cohorts of Czech, French, and German uranium miners, and indicated that the excess relative risk of lung cancer per unit of exposure should be expressed with consideration of chronic exposure over more than 10 years, by modelling time since median exposure, age attained or age at exposure, and taking in account, if possible, interaction between radon and tobacco. The lifetime excess absolute risk (LEAR) calculated from occupational exposure studies is close to 5 × 10−4 per working level month (WLM) (14 × 10−5 per hm J/m3). LEAR values estimated using risk models derived from both miners and domestic exposure studies are in good agreement after accounting for factors such as sex, attained age, and exposure scenario. A sensitivity analysis highlighted the high dependence of background mortality rates on LEAR estimates. Using lung cancer rates among Euro-American males instead of the ICRP reference rates (males and females, and Euro-American and Asian populations), the estimated LEAR is close to 7 × 10−4 per WLM (20 × 10−5 per hm J/m3).

  7. The unattached fraction of radon decay products: Potential effects of in-home air cleaners on lung cancer risk

    International Nuclear Information System (INIS)

    Radon decay products are a factor in the development of lung cancer. Because of their efficient deposition within the lung, the fraction of decay products not attached to particulate (i.e., the unattached fraction) is very important in lung dosimetry. This study simulated the use of two in-home air cleaning devices to reduce airborne particulate concentrations, measure the effect on the unattached fraction, and estimate the radon lung cancer risk. Radon was released into a chamber having a volume-to-surface-area ratio similar to a small home. At radon-decay product equilibrium, radon and airborne particle concentrations were measured, and the concentration of the unattached fraction was estimated. The effect of particle concentration on the unattached fraction was then determined. The average unattached fractions corresponding to the particle concentration ranges expected for the air cleaning devices were used to calculate the annual alpha radiation dose and annual radon lung cancer for men, women and children at rest and under light activity. The annual doses and related risks were compared to those used in the models published by the Environmental Protection Agency. For particulate concentrations of a home with no particulate generating activities (e.g., smoking, cooking), the electronic air cleaner is predicted to reduce the unattached fraction from seven percent (the value used by the NCRP and confirmed in this study) to four percent. These conditions represent the maximum reduction in the unattached fraction. The decrease in the unattached fraction is tentatively attributed to an increase in plateout. Based on these results, a reduction of less than ten percent in the calculated annual lung cancer risk is found in all cases

  8. Study of epidemiological risk of lung cancer in Mexico due indoor radon exposure

    Science.gov (United States)

    Ángeles, A.; Espinosa, G.

    2014-07-01

    In this work the lifetime relative risks (LRR) of lung cancer due to exposure to indoor 222Rn on the Mexican population is calculated. Cigarette smoking is the number one risk factor for lung cancer (LC), because that, to calculate the number of cases of LC due to exposure to 222Rn is necessary considers the number of cases of LC for smoking cigarette. The lung cancer mortality rates published by the "Secretaría de Salud" (SSA), the mexican population data published by the "Consejo Nacional de Población" (CONAPO), smoking data in the mexican population, published by the "Comisión Nacional Contra las Adicciones" (CONADIC), the "Organización Panamericana de la Salud" (OPS) and indoor 222Rn concentrations in Mexico published in several recent studies are used. To calculate the lifetime relative risks (LRR) for different segments of the Mexican population, firstly the Excess Relative Risk (ERR) is calculated using the method developed by the BEIR VI committee and subsequently modified by the USEPA and published in the report "EPA Assessment of Risks from Radon in Homes". The excess relative risks were then used to calculate the corresponding lifetime relative risks, again using the method developed by the BEIR VI committee. The lifetime relative risks for Mexican male and female eversmokers and Mexican male and female never-smokers were calculated for radon concentrations spanning the range found in recent studies of indoor radon concentrations in Mexico. The lifetime relative risks of lung cancer induced by lifetime exposure to the mexican average indoor radon concentration were estimated to be 1.44 and 1.40 for never-smokers mexican females and males respectively, and 1.19 and 1.17 for ever-smokers Mexican females and males respectively. The Mexican population LRR values obtained in relation to the USA and Canada LRR published values in ever-smokers for both gender are similar with differences less than 4%, in case of never-smokers in relation with Canada

  9. Exposure to radon progeny, tobacco use and lung cancer in a case-control study in Southern China

    International Nuclear Information System (INIS)

    A case-control study of lung cancer in underground tin miners in southern China was conducted to examine the interplay between exposure to radon progeny and tobacco use. A total of 460 incident cases and 1,043 controls were evaluated. Among the exposed, mean radon progeny exposures were 600 and 427 working level months (WLM) for cases and controls, respectively. The excess relative risk per WLM (ERR/WLM) was 0.28% overall, with a 95% confidence interval of 0.1-0.6%, similar to the estimate from a cohort study in a related population of underground miners. The established patterns of lung cancer associated with radon were seen; the ERR/WLM decreased with attained age and time since last exposure. Conditional on total exposure, risk was highest for exposures delivered at a low rate. The ERR/WLM did not differ significantly among current and former smokers or within categories of time since last exposure. The relative risk relationship between exposure to radon progeny and tobacco use was consistent with a multiplicative model, but the best-fitting model was intermediate between additive and multiplicative; an additive association was rejected. Adjustment for exposure to inorganic arsenic, a known lung carcinogen, reduced the estimate of the ERR/WLM from 0.86% to 0.28%. The ERR/WLM estimate was homogeneous across subgroups defined by workers not exposed to arsenic and quartiles of cumulative arsenic exposure. Although squamous cell carcinoma was the predominant cell type, small cell and adenocarcinoma histologies appeared more strongly associated with exposure to radon progeny. The finding of a stronger trend with exposure with small cell carcinomas and adenocarcinomas, compared to squamous cell carcinomas, occurred primarily at younger ages at diagnosis. Finally, the risk of lung cancer was higher if exposure to radon progeny and tobacco use occurred together than if the exposure to radon progeny entirely preceded tobacco use. 24 refs., 3 figs., 8 tabs

  10. Radon-induced lung cancer in smokers and non-smokers: risk implications using a two-mutation carcinogenesis model

    International Nuclear Information System (INIS)

    Three sets of data (population statistics in non-smokers, data from an investigation of the smoking habits of British doctors and a study of Colorado uranium miners) were used to analyse lung cancer in humans as a function of exposure to radon and smoking. One of the aims was to derive implications for radon risk estimates. The data were analysed using a two-mutation radiation carcinogenesis model and a stepwise determination of the model parameters. The basic model parameters for lung cancer were derived from the age dependence fit of the spontaneous lung cancer incidence in non-smokers. The effect of smoking was described by two additional parameters and, subsequently, the effect of radon by three other parameters; these five parameters define the dependence of the two mutation steps on smoking and exposure to radon. Using this approach, a consistent fit and comprehensive description of the three sets of data have been achieved, and the parameters could, at least partly, be related to cellular radiobiological data. The model results explain the different effect of radon on non-smokers and smokers as seen in epidemiological data. Although the analysis was only applied to a limited number of populations, lung cancer incidence as a result of radon exposure is estimated to be about ten times higher for people exposed at the age of about 15 than at about 50, although this effect is masked (especially for smokers) by the high lung cancer incidence from smoking. Using the model to calculate the lung cancer risks from lifetime exposure to radon, as is the case for indoor radon, higher risks were estimated than previously derived from epidemiological studies of the miners' data. The excess absolute risk per unit exposure of radon is about 1.7 times higher for smokers of 30 cigarettes per day than for non-smokers, even though, as a result of the low spontaneous tumour incidence in the non-smokers, the excess relative risk per unit exposure for the smokers is about 20 times

  11. Optimization of operating parameters for low level measurements of alpha emitters by alpha spectrometry

    International Nuclear Information System (INIS)

    The members of public are exposed to both natural and anthropogenic sources of radiation. Naturally occurring radioactive materials comprises of uranium, thorium and their decay products with other radionuclides such as 40K, 3H, 22Na, 7Be, etc. Anthropogenic radionuclides comprises of 137Cs, 90Sr, 239Pu, 241Am, etc. They emit alpha, beta and gamma radiations. Measurement at low level radioactivity is challenging due to interference and other inherent uncertainties. Alpha emitters comprises of 238U and 232Th with their daughters along with those of anthropogenic origin like 239Pu, 241Am, etc. Measurement of alpha emitters is essential by considering the adverse effects of alpha radiation while inside the body. Alpha spectrometry is a sensitive and direct technique to identify and quantify the alpha emitters having detection limit, two to three order of magnitude lower than gamma spectrometry. Standardization of operating parameters is imperative prior to analysis. An attempt has been made to optimize the parameters for an Eight Chamber Alpha Spectrometer (ORTEC) with 450 mm2PIPS detector surface area, with an operating voltage of 50 volt and current of 20-30 nano amperes. Energy calibration of each chamber was done with Pu-Am mixed source and natural uranium standard source. Efficiency of each detector measured with various sources to detector distance for the standard sources was nearly same at equivalent distances, e.g. it is coming around 16% at 8 mm source to detector distance (Rack 2) of each chamber. At 4 mm source to detector distance (Rack-1) it is 25% and gradually it decreases upto 2% at 40 mm source to detector distance (Rack-10). Resolution of 241Am peak was found to 20-25 keV at 8 mm source to detector distance and varies with distance from the detector. It was found that 50% decrease in resolution i.e. FWHM value with the increase in source to detector distance. In the energy range of 4-10 MeV, 8 counts is obtained as background count per 86,000 secs

  12. Lowering the UK domestic radon Action Level to prevent more lung cancers-is it cost-effective?

    International Nuclear Information System (INIS)

    Case studies have shown that radon gas can accumulate within domestic properties at sufficiently high levels that it can cause lung cancer, and recent studies have suggested that this risk remains significant below the UK domestic Action Level of 200 Bq m-3. Raised radon levels can be reduced by engineering measures, and it has been shown that domestic radon remediation programmes in UK Affected Areas can result in reduced risks to the population and can be cost-effective. We consider here the benefits and costs of the domestic radon remediation programme in Northamptonshire, UK, and consider the implications for that programme of reducing the UK Action Level below its present value. A radon remediation programme based on an Action Level above 200 Bq m-3 will cost less and will target those most at risk, but will be less cost-effective and will lead to higher residual dose and greater risk of cancer in the remaining population. Reducing the Action Level below 200 Bq m-3 will prevent more cancers, but at significantly higher cost. It will also be less cost-effective, because remediation of a significant number of houses with moderate radon levels will provide only a modest health benefit to occupants. Overall, a completed radon remediation programme of the type implemented in Northamptonshire is most cost-effective for an Action Level between 200 and 300 Bq m-3. The implications for future health policy are discussed

  13. Effect of radon and its progeny on the expression and mutation of p53 in lung tissues of mice

    International Nuclear Information System (INIS)

    Objective: To explore the effect of radon and its progeny on the expression and mutations of p53 in lung tissue of mouse model. Methods: Apoptosis was detected by terminal deoxynucleotidy transferase-mediated dUTP-biotin nick end labeling. The expression of p53 gene was analyzed by immunohistochemistry, Western blot and realtime-PCR. PCR-SSCP was used to detect the mutation of p53 in lung tissues. Results: Compared with those in the control group, the apoptotic index were increased significantly in 30 WLM and 60 WLM groups (t=18.11, -10.30, P<0.05). The p53 protein was increased significantly (t=-11.08, P<0.05; t=-7.00, P<0.05) in 30 WLM and 60 WLM groups. The mutation of p53 gene was not detected in lungs of radon-exposure mice. Conclusions: Lung and bronchus might be the targets of radon and its progeny, and p53 gene plays an important role in the progression of radon-induced lung injury. (authors)

  14. Age-dependent lung dosimetry of radon progeny

    International Nuclear Information System (INIS)

    Two morphometric models differing in the tracheobronchial region, were compared in the present paper: Model 1 is based on the adult morphology of Weibel, assuming that all bronchial airways grow in equal proportion; while Model 2 adopts the adult structure proposed by Yeh and Schum, using measured airway dimensions in the right upper lobe as a function of age. Tidal volume and respiratory frequency also vary with age: while the breathing frequency decreases with rising age, tidal volume increases. Radiation doses in each bronchial airway generation were computed for the deep lying basal cells as well as for the more uniformly distributed serous (SMGS) cells, which are currently assumed to be the progenitor cells for bronchial carcinomas. Radiation doses to both target cells were significantly higher in the newborn than in the adult, for all simulated breathing patterns, showing the highest relative increase in upper bronchial airways. Comparing both tracheobronchial growth models, Model 1 predicts higher doses at early ages, but produced lower doses in the adult lung

  15. Personal characteristics and environmental factors influencing lung dosimetry of inhaled radon decay products

    International Nuclear Information System (INIS)

    The attempt to interpret lung cancer incidence caused by inhaled radon decay products in items of radiation dose raises the question of the relevant dose. The various dosimetric approaches published by now are characterized by an increasing complexity in the structure of the models used. Due to uncertainties of physical and biological parameters involved and the application of different anatomical and physiological models the calculated doses are varying up to one order of magnitude. Independent of the choice of these dosimetric models applied to the calculation of lung doses, deposition, clearance and resulting dose are affected essentially by the properties of the inhaled aerosol as well as by personal characteristics. Both the properties of the exposed individual as well as of the inhaled environmental atmosphere have to be considered in radiation protection. It is the main objective of this paper to illustrate the influence of both parameter sets on basal cell doses by varying the above parameters

  16. Dosimetric concepts for inhaled radon decay products in the human lung

    International Nuclear Information System (INIS)

    The primary objective of lung dosimetry is to provide a physical basis in terms of radiation doses for establishing the relationship between airborne radon decay products and lung cancer induction as the most important biological endpoint. In order to accomplish this goal, several dosimetric approaches have been developed which are based on reasonable approximations of the anatomical structure of the respiratory tract, of clearance mechanisms for particles deposited, and of energy deposition at the cellular level. Usually lung cancer risk is correlated with the mean radiation dose to the stem cells in the bronchial epithelium. A different approach is presented here through the application of stochastic models which allow for the biological variability inherent in all anatomical and physiological parameters. Thus, the specific energy distribution in cells or cell nuclei and the number of sensitive targets hit are more appropriate quantities for the interpretation of lung cancer incidence. The relevance of dosimetric approaches at the cellular level is, however, intimately connected with models describing the transformation towards malignancy, and further improvements of lung dosimetry can only be achieved by a more profound insight into the basic biological mechanisms involved in radiation-induced carcinogenesis

  17. On the Use of Ly-alpha Emitters as Probes of Reionization

    CERN Document Server

    Jensen, Hannes; Mellema, Garrelt; Iliev, Ilian T; Sommer-Larsen, Jesper; Shapiro, Paul R

    2012-01-01

    We use numerical simulations to study the effects of the patchiness of a partly reionized intergalactic medium (IGM) on the observability of Ly-alpha emitters (LAEs) at high redshifts (z ~ 6). We present a new model that divides the Ly-alpha radiative transfer into a (circum-)galactic and an extragalactic (IGM) part, and investigate how the choice of intrinsic line model affects the IGM transmission results. We use our model to study the impact of neutral hydrogen on statistical observables such as the Ly-alpha restframe equivalent width (REW) distribution, the LAE luminosity function and the two-point correlation function. We find that if the observed changes in LAE luminosity functions and equivalent width distributions between z ~ 6 and z ~ 7 are to be explained by an increased IGM neutral fraction alone, we require an extremely late and rapid reionization scenario, where the Universe was ~ 40 % ionized at z = 7, ~ 50 % ionized at z = 6.5 and ~ 100 % ionized at z = 6. This is in conflict with other observa...

  18. Narrow-band surveys for very high redshift Lyman-alpha emitters

    CERN Document Server

    Nilsson, Kim K; Lacey, Cedric G; Baugh, Carlton M; Thommes, Eduard

    2007-01-01

    Context: Many current and future surveys aim to detect the highest redshift (z >~ 7) sources through their Lyman-alpha (Ly-alpha) emission, using the narrow-band imaging method. However, to date the surveys have only yielded non-detections and upper limits as no survey has reached the necessary combination of depth and area to detect these very young star forming galaxies. Aims: We aim to calculate model luminosity functions and mock surveys of Ly-alpha emitters at z >~ 7 based on a variety of approaches. Methods: We calculate model luminosity functions at different redshifts based on three different approaches: a semi-analytical model based on CDM, a simple phenomenological model, and an extrapolation of observed Schechter functions at lower redshifts. The results of the first two models are compared with observations made at redshifts z ~ 5.7 and z ~ 6.5, and they are then extrapolated to higher redshift. Results: We present model luminosity functions for redshifts between z = 7 - 12.5 and give specific num...

  19. Radiative Transfer Modeling of Lyman Alpha Emitters: I. Statistics of Spectra and Luminosity

    CERN Document Server

    Zheng, Zheng; Trac, Hy; Miralda-Escude, Jordi

    2009-01-01

    We combine a cosmological reionization simulation with box size of 100Mpc/h on a side and a Monte Carlo Lyman-alpha (Lya) radiative transfer code to model Lyman Alpha Emitters (LAEs) at z~5.7. The model introduces Lya radiative transfer as the single factor for transforming the intrinsic Lya emission properties into the observed ones. Spatial diffusion of Lya photons from radiative transfer results in extended Lya emission and only the central part with high surface brightness can be observed. Because of radiative transfer, the appearance of LAEs depends on density and velocity structures in circumgalactic and intergalactic media as well as the viewing angle, which leads to a broad distribution of apparent (observed) Lya luminosity for a given intrinsic Lya luminosity. Radiative transfer also causes frequency diffusion of Lya photons. The resultant Lya line is asymmetric with a red tail. The peak of the Lya line shifts towards longer wavelength and the shift is anti-correlated with the apparent to intrinsic L...

  20. Exploiting 21cm - Ly$\\alpha$ emitter synergies: constraints on reionization

    CERN Document Server

    Hutter, Anne; Müller, Volker; Trott, Cathryn

    2016-01-01

    We couple a $z \\simeq 6.6$ hydrodynamical simulation (GADGET-2) with a radiative transfer code (pCRASH) and a dust model to simultaneously obtain the 21cm emission from the spin-flip transition of neutral hydrogen (HI) as well as the sub-population of galaxies visible as Lyman Alpha Emitters (LAEs). Cross-correlating 21cm data with the underlying galaxy population, and especially the subset visible as LAEs, our aim is to constrain both the average intergalactic medium (IGM) ionization state ($\\langle \\chi_{HI} \\rangle$) and the reionization topology (outside-in versus inside-out). We find that LAEs occupy the densest and most-ionized regions resulting in a very strong anti-correlation between the LAEs and the 21cm emission. Within errors, a 1000h SKA-LOW1 - Subaru Hyper Suprime Cam experiment can provide exquisite constraints on $\\langle \\chi_{HI} \\rangle$, allowing us to distinguish between IGM ionization levels of 50%, 25%, 10% and fully ionized at scales $\\leq 10$ comoving Mpc. Our results support the insi...

  1. A Search for z=7.3 Ly{\\alpha} Emitters behind Gravitationally Lensing Clusters

    CERN Document Server

    Ota, Kazuaki; Iye, Masanori; Shibuya, Takatoshi; Egami, Eiichi; Kashikawa, Nobunari

    2012-01-01

    We searched for z=7.3 Ly{\\alpha} emitters (LAEs) behind two lensing clusters, Abell 2390 and CL 0024, using the Subaru Telescope Suprime-Cam and a narrowband NB1006 ({\\lambda}c ~ 1005 nm, FWHM ~ 21 nm). Combination of the fully depleted CCDs of the Suprime-Cam, sensitive to z ~ 7 Ly{\\alpha} at ~ 1 {\\mu}m, and magnification by the lensing clusters can be potentially a powerful tool to detect faint distant LAEs. Using NB1006 and deep optical-infrared images taken with the Hubble and Spitzer Space Telescopes, we investigated if there exist objects consistent with the color of z=7.3 LAEs behind the clusters. We could not detect any LAEs to the unlensed Ly{\\alpha} flux limit F(Ly{\\alpha}) ~ 6.9 x 10^{-18} erg s^{-1} cm^{-2}. Comparison with z ~ 7 LAE field searches suggests that a blank field survey covering an area sufficiently larger than lensing clusters is more efficient in finding a large number of z ~ 7 LAEs than both a lensing survey observing many clusters with shallow imaging and a lensing survey imaging ...

  2. The VLT LBG Redshift Survey - V. Characterising the z = 3.1 Lyman Alpha Emitter Population

    CERN Document Server

    Bielby, R M; Shanks, T; Francke, H; Crighton, N H M; Bañados, E; González-López, Jorge; Infante, L; Orsi, A

    2016-01-01

    We present a survey of Ly$\\alpha$ emitting galaxies in the fields of the VLT LBG Redshift Survey, incorporating the analysis of narrow band number counts, the rest frame UV luminosity function and the two-point correlation function of Ly$\\alpha$ emitters at $z\\approx3.1$. Our photometric sample consists of 750 LAE candidates, over an area of 1.07 deg$^2$, with estimated equivalent widths of $\\gtrsim65$ \\AA, from 5 fields based on deep Subaru Suprime-Cam imaging data. Added to this we have obtained spectroscopic follow-up observations, which successfully detected Ly$\\alpha$ emission in 35 galaxies. Based on the spectroscopic results, we refined our photometric selection constraints, with the resulting sample having a success rate of $78\\pm18\\%$. We calculate the narrow band number counts for our photometric sample and find these to be consistent with previous studies of LAEs at this redshift. We find the $R$-band continuum luminosity function to be $\\sim10\\times$ lower than the equivalent luminosity function o...

  3. Clustering and lifetime of Lyman Alpha Emitters in the Epoch of Reionization

    CERN Document Server

    Hutter, Anne; Müller, Volker

    2015-01-01

    We calculate Lyman Alpha Emitter (LAE) angular correlation functions (ACFs) at $z\\simeq6.6$ and the fraction of lifetime (for the 100 Myrs preceding $z\\simeq6.6$) galaxies spend as Lyman Break Galaxies (LBGs) with/without Lyman Alpha (Ly\\alpha) emission using a model that combines SPH cosmological simulations (GADGET-2), dust attenuation and a radiative transfer code (pCRASH). The ACFs are a powerful tool that significantly narrows the 3D parameter space allowed by LAE Ly$\\alpha$ and UV luminosity functions (LFs) alone. With this work, we simultaneously constrain the escape fraction of ionizing photons $f_{esc}=0.05-0.5$, the mean fraction of neutral hydrogen in the intergalactic medium (IGM) $\\leq 0.01$ and the dust-dependent ratio of the escape fractions of Ly$\\alpha$ and UV continuum photons $f_\\alpha/f_c=0.6-1.2$. Our results show that reionization has the largest impact on the amplitude of the ACFs, and its imprints are clearly distinguishable from those of $f_{esc}$ and $f_\\alpha/f_c$. We also show that...

  4. The Discovery of Two Lyman$\\alpha$ Emitters Beyond Redshift 6 in the Subaru Deep Field

    CERN Document Server

    Kodaira, K; Kashikawa, N; Kaifu, N; Ando, H; Karoji, H

    2003-01-01

    We have performed a deep optical imaging survey using a narrowband filter ($NB921$) centered at $\\lambda =$ 9196 \\AA ~ together with $i^\\prime$ and $z^\\prime$ broadband filters covering an 814 arcmin$^2$ area of the Subaru Deep Field. We obtained a sample of 73 strong $NB921$-excess objects based on the following two color criteria; $z^\\prime - NB921 > 1$ and $i^\\prime - z^\\prime > 1.3$. We then obtained optical spectroscopy of nine objects in our $NB921$-excess sample, and identified at least two Ly$\\alpha$ emitters at $z \\sim$ 6.5 -- 6.6, each of which shows the characteristic sharp cutoff together with the continuum depression at wavelengths shortward of the line peak. These new data allow us to estimate the first meaningful lower limit of the star formation rate density beyond redshift 6; $\\rho_{\\rm SFR} \\sim 5.2 \\times 10^{-4} M_\\odot$ yr$^{-1}$ Mpc$^{-3}$. Since it is expected that the actual density is higher by a factor of several than this value, our new observation reveals that a moderately high lev...

  5. Exploring the nature of the Lyman-$\\alpha$ emitter CR7

    CERN Document Server

    Hartwig, Tilman; Magg, Mattis; Bromm, Volker; Klessen, Ralf S; Glover, Simon C O; Whalen, Daniel J; Pellegrini, Eric W; Volonteri, Marta

    2015-01-01

    CR7 is the brightest Lyman-$\\alpha$ emitter observed at $z>6$, which shows very strong Lyman-$\\alpha$ and HeII 1640 \\AA\\ line luminosities, but no metal line emission. Previous studies suggest that CR7 hosts either young primordial stars with a total stellar mass of $\\sim 10^7\\,\\mathrm{M}_\\odot$ or a black hole of $\\sim 10^6\\,\\mathrm{M}_\\odot$. Here, we explore different formation scenarios for CR7 with a semianalytical model, based on the random sampling of dark matter merger trees. We find that primordial stars cannot account for the observed line luminosities because of their short lifetimes and because of early metal enrichment. Black holes that are the remnants of the first stars are either not massive enough, or reside in metal-polluted haloes, ruling out this possible explanation of CR7. Our models instead suggest that direct collapse black holes, which form in metal-free haloes exposed to large Lyman-Werner fluxes, are more likely the origin of CR7. However, this result is derived under optimistic ass...

  6. Carcinogenic risk of non-uniform alpha particle irradiation in the lungs: radon progeny effects at bronchial bifurcations

    International Nuclear Information System (INIS)

    The combined effect of enhanced deposition and reduced clearance at bronchial bifurcations leads to increased radon progeny doses within branching sites compared with uniformly distributed activity within a given airway generation. A multi-stage carcinogenesis model was used to predict the probability of lung cancer induction at different sites of the bronchial region. For relatively low radon progeny exposures, lung cancer risk is significantly higher in bifurcation zones, particularly at carinal ridges, than along tubular segments. At sufficiently high exposures, however, lung cancer risk is highest in the tubular portions of a generation. This suggests that the common assumption of a uniform dose distribution provides realistic risk estimates for high uranium miner exposures, but may underestimate lung cancer risk at low, environmental exposures. If concomitant exposure to cigarette smoke is factored into our risk analysis in a multiplicative fashion, then the effect related to risk inhomogeneity becomes even more pronounced. (author)

  7. Quality assurance exercise for estimating low-levels of alpha emitters in urine samples: performance of Trombay's bioassay laboratory

    International Nuclear Information System (INIS)

    As a part of quality assurance, Trombay's bioassay laboratory took part in the international intercomparison exercise organized by International Atomic Energy Agency (IAEA) for estimating low-levels of alpha emitters (234U, 238U, 239+240Pu and 241Am) in urine samples. In this paper, performance of the Trombay's bioassay laboratory in the intercomparison exercise is presented. The results submitted by the laboratory were found to be in good agreement with the organizers (spiked) values. (author)

  8. Studies on the atomic and molecular processes produced by alpha emitters in gaseous media using track detection

    International Nuclear Information System (INIS)

    The main purpose of the studies consists in obtaining new and reliable experimental data on certain atomic and molecular physical processes which take place at low speed or/and very low amounts, such as: diffusion, adherence, fallout, etc. of the alpha emitters in gaseous media. By using the track analysis method, most experimental data can be visualized by optical microscopy, so that reliable qualitative and quantitative investigations can be performed. In the first stage, the alpha track method was used. Two plastic detectors were used: CR - 39 (Page, England) and RL - 115 types 1 and 2 (Kodak, France). For these detectors new etching conditions were developed. In the present stage, a calibration of CR - 39 and RL - 115 track detectors for the alpha particles emitted from gaseous radionuclides, particularly for 222 Rn and its alpha descendants, is performed. For this purpose the track detectors were suspended in tight vessels and the following alpha emitter sources were used: - a diuranate source calibrated in uranium prepared in our laboratory; - a calibrated 226 Ra solution; - sources calibrated in 222 Rn and 226 Ra. The amounts and activities of each alpha decay product of these sources are calculated using a radioactive accumulation computation programme UURASE based on the Bateman general equation. The alpha particle ranges were calculated using the TRIM computation programme. In the future stages of this investigation the following studies will be performed: - the diffusion of gaseous alpha emitters; - the sorption of alpha emitter gases and aerosols on different materials; - 222 Rn monitoring in dwelling houses and working places and the implementation of the alpha track method in the National Networks for surveillance of the environmental alpha radioactivity. (authors)

  9. Critical review for the determination of the minimum detectable activity (MDA) of alpha-emitter radionuclides in environmental samples

    International Nuclear Information System (INIS)

    Different criteria for the calculation of the Minimum Detectable Activity (MDA) of an alpha emitter in environmental levels are reviewed in this report. Practical examples of its application to previously analyzed samples are shown. The authors propose a criteria based on prior calculations that applies to the radiochemical activities performed in the laboratory. The calculation procedure has been discussed with scientist from other laboratories in order to establish a general criteria to calculate the MDA

  10. Reply to Cohen's letter on 'The potential for bias in Cohen's ecological analysis of lung cancer and residential radon'

    International Nuclear Information System (INIS)

    Dear Sir, In the above letter, Cohen repeats arguments that he as made in the past; however, the thrust of those comments indicates a fundamental misunderstanding of the point of my article and indeed of my prior articles on this topic. It was not and has never been my goal to identify a specific factor (or several factors) that induced the negative correlation between the estimates of county-level mean radon concentration and county lung cancer mortality rates. Other investigators have offered powerful examples, both theoretical and practical, that Cohen's results are indeed an artifact of ecological regression. The primary purpose of my contributions to this topic has been to demonstrate the fundamental deficiencies of the methodology itself, in particular the unboundedness of the bias. The current article demonstrates that the ecological fallacy always applies, that the addition of county-level adjustment variables does not reduce bias and increase validity, and that an observed ecological risk pattern can differ markedly from the true risk pattern. Because of these deficiencies, epidemiologists have never used ecological regression as a tool for confirmatory analysis. For radon and lung cancer, results of 25-30 analytic studies of individuals clearly prove the deficiency of the method. There are numerous risks factors for lung cancer, including smoking, age, various occupational exposures, air pollution, previous lung diseases, and so on. I take an extremely simplified model for lung cancer in radon and smoking status, and demonstrate that the induced county-level model is non-linear. A more realistic, and complex, model for lung cancer would include all principal risk factors, and would also generate a non-linear model at the county level. Cohen's claims, which are based on his linear (or linear-quadratic) model for county lung cancer rates, are therefore built on a false premise, and his continual reference to the 'scientific method' is fatuous. One could

  11. Dose-rate effects on lung cancers induced by exposure to radon progeny in rats

    International Nuclear Information System (INIS)

    Epidemiological studies in uranium miners and other underground miners showed an association between an excess risk of lung cancer and exposure to radon and its progeny, but the evidence of an excess risk of lung cancer from residential radon indoor exposure is less certain. Animal studies were used in addition to epidemiological studies to investigate the effects of exposure, exposure rate and other factors in predicting risks resulting from human exposures both in the home and in the workplace. The advantage of animal data is that animal experiments are generally conducted under well controlled conditions and that exposure and exposure rate can be estimated more accurately. Radon animal data, obtained primarily in adult rats, were provided mainly by the Pacific Northwest Laboratory (PNL) in USA and our group in France. Despite the fact that significant cumulative exposures at typical residential exposure rates of about 1.810-5 Jhm-3 per week, approximately 0.005 WLM per week, cannot be tested in a short-lived species like the rat, the rat model is valuable for reducing the uncertainties that exist in human data, particularly in regard to the exposure-rate effect. In PNL lifespan animal experiments, a trend towards increasing tumour risk with decreased exposure rate has been reported in Wistar rats exposed at 2.1 mJm-3 (100 WL) and 21 mJm-3 (1,000 WL) and cumulative exposures varying from 2.3 Jhm-3 (640 WLM) up to 18.4 Jhm-3 (5,120 WLM). A trend towards increasing tumour risk with decreased exposure rate was observed in our Sprague-Dawley rats exposed at cumulative exposure varying from about 0.72 Jhm-3 (200 WLM) up to 10.8 Jhm-3 (3,000 WLM) and high exposure rates varying from 0.09 Jhm-3 (25 WLM per week) to 1.8 Jm-3 (500 WLM per week). In contrast, the results obtained at low cumulative exposure, comparable to domestic indoor exposures showed no evidence of an inverse exposure-rate effect. Chronic radon exposure at 0.09 Jhm-3 (25 WLM), protracted over a 18

  12. Case-control study on radon exposure and lung cancer in an Italian region. Preliminary results

    International Nuclear Information System (INIS)

    The present estimates of the lung cancer risk for the general population due to radon exposure in dwellings are generally obtained by extrapolating the risk estimates derived from epidemiologic studies on miner cohorts. However, due to uncertainties related to this extrapolation, numerous case-control studies in Europe and North America were planned to estimate directly the risk in dwellings. Most of these studies are still underway and, thanks to their similar design and compatible protocols, it will be possible to perform a pooled analysis in order to improve statistical power. One of these projects is being conducted in the Lazio region of Italy, which is one of the Italian regions with the highest levels of radon indoors. A total of 408 cases and 424 controls older than 34 years, who lived for 25 years or longer in the Lazio Region, were recruited in a hospital of Rome. Detailed information regarding smoking, and occupational exposure of the subjects were collected by interviews in hospital. Residential histories (periods and addresses) during the 35 years preceding the enrolment were ascertained for all study members from the local Register and from a short questionnaire to the subjects or to the next-of-kin, resulting in 2068 dwellings to be monitored within the Lazio region. The distribution of the number of dwellings among cases and controls was the following: 25.7% of the cases and 27.3% of the controls had lived all the preceding 35 years in a single dwelling, whereas only a minority (7.9%) changed five addresses or more. The mean number of dwellings was very similar among cases (2.47) and controls (2.50). In each dwelling, radon dosemeters were placed in both the main bedroom and living room for two consecutive six-month periods. In the second six-month period, two thermoluminescent dosemeters were also collocated in each monitored room to measure gamma radiation emitted by the building materials, in order to evaluate more comprehensively the exposure of

  13. Epidemiologic approach to determining the REM dose to bronchial epithelium from radon daughter exposures in man

    International Nuclear Information System (INIS)

    Dosimetric evaluation of exposures to the bronchial epithelial stem cells from inhalation of alpha emitters is complex and the number of assumptions required leads to substantial uncertainty. Moreover, it is evident that many factors such as variable breathing patterns will modify the results. An empirical approach to determining the rem dose biologically effective in producing bronchial cancer by inhalation of radon daughters is possible by comparison of cumulative exposure in terms of Working Level Months with the dose of penetrating low-LET radiation to produce the same bronchial cancer risk in other groups investigated. This method is possible when the dosimetry of the comparison groups is well known and lung cancer risks are reasonably well-defined. A number of epidemiologic considerations must be taken into account in such comparisons, however. These include age at exposure, length of following, age at expression of or death from cancer, and for underground miners exposed to radon daughters the lung cancer-latent period model applied to long-term exposures. Use of these methods gives results consistent with dosimetry derived from models of bronchial deposition and clearance, as well as reasonable values for the quality factor for alpha radiation. This comparison gives an average equivalent dose for a working population exposed to short-lived isotopes

  14. Present state and future perspective of radionuclide therapy with alpha emitters

    International Nuclear Information System (INIS)

    Described are the advantage of alpha emitters in cancer treatment, developmental process of therapeutics of bone metastasis with 223Ra and future perspective of radiotherapy with the emitters. Alpha-ray has characteristics of high linear energy transfer (LET) and short range. The average energy of emitted alpha-rays from 223Ra and its daughter nuclides is 27.4 MeV and the range in the tissue, 89Sr are 0.58 MeV and 2.4 mm, respectively. Alpha's LET 80 keV/mc-m is 400 times as high as that of 89Sr beta-ray (0.2 keV/mc-m), indicating the much higher relative biological effectiveness (RBE) of the former. Phase I-III trials concerning the efficacy and safety of 223Ra (chloride) conducted in Western countries have led to the approval of the agent by FDA in 2013 for the therapy of patients with castration-resistant bone metastases of prostate cancer. In Japan, the medical 223Ra is readily usable and investigations for its application to the therapy of the hormone-resistant prostate cancer have been under completion by Japan Society of Nuclear Medicine. The exact mechanism of the 223Ra efficacy on the metastasis is rather obscure but is conceivably related with various interactions between alpha-ray and biological substrates. Future problems of the emitters for internal medical use such as their radiation management, micro-dosimetry and delivery system are now eagerly discussed in the world. (T.T)

  15. Risk coefficient of radon-induced lung cancer and combined effect of arsenic in miners of Yunnan tin mine of China

    International Nuclear Information System (INIS)

    Objective: To identify the suitability of excess relative risk (ERR) coefficient of radon-induced miner lung cancer proposed by NIH Publication (1994) which was based on the data of Yunnan tin miners. Methods: Using the collected materials of epidemiology, underground ventilation, radon progeny monitoring and environmental arsenic pollution, the problems in the process of estimation of cumulative exposure of radon progeny and adjustment of combined effect of arsenic exposure for Yunan tin miners by NIH Publication were analyzed. Results: Because of overestimation of the time of underground d working and actual exposure to radon progeny for previous Yunnan tin miners by NIH, the resultant ERR coefficient of radon induced lung cancer was underestimated. The relative risks of different radon-arsenic exposure groups were used by NIH to adjust the combined effect of arsenic without considering the difference of environmental pollution in miner and control groups; that was the another reason for the decrease of ERR coefficient. Conclusion: The ERR coefficient of radon-induced lung cancer was probably underestimated for Chinese miners by NIH Publication; therefore it is unsuitable to be used in the risk projection and risk management for radon-induced lung cancer in China. It may be premature to use the Yunnan tin miner data as the value for Chinese miners in the combined analysis of world miner studies

  16. Indoor radon levels in some regions of Jordan and assessment of the associated excess lung cancer risk

    International Nuclear Information System (INIS)

    CR-39 based cup type dosimeters were used for indoor radon level measurements in randomly selected dwellings in the cities of Jerash, Irbid and Ajloun in Jordan. The average values of radon concentration levels in the above mentioned cities were found to be 53-2 +-7.3 Bq m /sup -3/ and 55.2+- 9.2 Bq m/sup -3/, respectively. The indoor radon level in Irbid was found to be normal but was double of the global average in Jerash and Ajloun. The excess lung cancer risk was assessed using the above measured values of indoor radon concentration levels for the general population. For this assessment, UNSCEAR and EPA models were used. The life time lung cancer risk due to the life time exposure was found to vary from 17 to 34 per MPY at the age of 70 when value of the risk factors of EPA model was used. In the case, when higher value of risk factors proposed by UNSCEAR was used, then the estimated excess lung cancer risk at the age of 70 varied from 66 to 135 per MPY. (author)

  17. Assessment of indoor radon exposure and risk of lung cancer in the population of the Sverdlovsk region, Russia

    International Nuclear Information System (INIS)

    Adverse radioecological situation in the Sverdlovsk Region of Russia forms elevated radiation load on the population. To adequately assess the influence of exposure to radon on the development of lung cancer, a cohort study employing a multivariate analysis was conducted in the city of Pervouralsk, Russia. According to the chosen method, 200 lung cancer cases were randomly matched with 237 controls. Each of the 437 cohort members was characterized by a complex of 26 parameters reflecting known risk factors of lung cancer. Analytical tasks were solved based on methods of discriminant analysis. None of the three parameters directly characterizing the indoor level of radiation pollution by radon and thoron was found to be one of the most informative cancer risk factors. Thus, as compared to other analyzed risk factors of lung cancer, the contribution of radon and thoron exposure of population inhabiting multi story residential buildings in the city of Pervouralsk could not be considered as the most important cause of lung cancer. (authors)

  18. A study of indoor radon levels in Indian dwellings, influencing factors and lung cancer risks

    International Nuclear Information System (INIS)

    Passive integrating solid state nuclear track detectors (SSNTDs) were used to study the Radon-222 (Rn) concentrations in Indian dwellings. The study was made in 300 dwellings in the cities of Lucknow and Kanpur in northern India. The influence of some factors e.g. age of the house, number of floors and ventilation conditions, etc. on indoor Rn concentrations were studied. The equilibrium factor in 65 dwellings were also investigated. Average Rn concentrations in living rooms were found to be 34±8 Bq.m-3 and 40±10 Bq.m-3 respectively, with equilibrium factors of 0.35 and 0.38. Assuming an occupancy factor of 0.8, the annual average effective dose equivalents in living rooms of the two places are estimated as 0.8 and 1.0 mSv respectively. The average life-time risks of lung cancer for radon exposure of the Lucknow and Kanpur populations at home would be about 0.26% and 0.34% respectively and the mean relative loss of life expectancies were 0.06% and 0.074% respectively

  19. Mechanisms of radon injury

    International Nuclear Information System (INIS)

    In this new project, they conduct molecular, cellular and whole-animal research relevant to understanding the inhalation toxicology of radon and radon-daughter exposures. The work specifically addresses the exposure-rate effect in radon-daughter carcinogenesis; the induction-promotion relationships associated with exposure to radon and cigarette-smoke mixtures; the role of oncogenes in radon-induced cancers; the effects of radon on DNA as well as on DNA repair processes; and the involvement of growth factors and their receptors in radon-induced carcinogenesis. Preliminary experiments showed that oncogenes are activated in radon-induced lung tumors. They have therefore begun further exposures pertinent to the oncogene and growth-factor studies. An in vitro radon cellular-exposure system was designed, and cell exposures were initiated. Initiation-promotion-initiation studies with radon and cigarette-smoke mixtures have also begun; and they are compiling a radon health-effects bibliography

  20. Explaining the lung cancer versus radon exposure data for USA counties

    International Nuclear Information System (INIS)

    Our study of lung cancer mortality rates, m, versus average radon levels in homes, r, for 1601 USA counties (Cohen 1995) found a very strong negative correlation. In a recent exchange (Cohen 1999), Sir Richard Doll suggested that these discrepancies may be due to lack of consideration of details on smoking habits, specifically 'the amount smoked, the proportion of ex-smokers who have stopped for different periods, the proportion of smokers who smoked cigarettes, cigars or pipes, and the age at which those smoking in different ways began'. The purpose of this letter is to explore these Doll suggestions. Our analysis is performed for males because the data are of better quality, but the results would be quite similar for females. Letter-to-the-editor

  1. The validity of risk assessments for lung cancer induced by radon daughters

    International Nuclear Information System (INIS)

    Available input data for the risk assessment from low level radon daughter (Rn-d) exposure are mostly either of low quality, partially contradicting or simply ''guesstimates''. Therefore at present only the upper limit of this risk can be estimated. Results of epidemiological studies amongst miners are associated with large uncertainties with regard to the assessment of past radiation exposure, lung cancer diagnostic and/or classification and synergistic effects due to smoking and dust exposure. An alternative approach uses dosimetric modelling for Rn-d inhalation to obtain Rn-d exposure-dose conversion factors. Large uncertainty is caused by individual variability due the influence of life style, physical and biological parameters. It is concluded that for ''normal'' indoor Rn-d exposure the resulting risk is neglegible compared to other risks ''accepted'' by society

  2. Radon and its daughters in ore mine air in North Bohemian Region and incidence of occupational lung cancer in exposed miners

    International Nuclear Information System (INIS)

    Hygienic conditions are described in nonuranium ore mines in the North Bohemian region with respect to expo-sure of miners to radon and its short-lived daughter products. The concentrations of radon before the introduction of forced ventilation were considerably high. Before 1980, altogether 45 cases of occupational lung cancer were reported associated with exposure to radon and its daughter products. In spite of the fact that forced ventilation of mines resulted in reduced exposure of miners, new cases of tumours are reported in miners exposed to radon and its daughters in the previous period. (author)

  3. Reliable method to count tracks from solid state nuclear track detectors in the measurement of radon concentration

    International Nuclear Information System (INIS)

    Radon is an alpha emitter that accounts for about 50% of internal dose for man and is an important cause of death by lung cancer. For this reason, reliable methods to measure the radon concentration in the air are of great concern to the area of radiological protection. From the radiological point of view, the 222Rn is more relevant than the 220Rn because the latter has a shorter half-life and thus is less likely to reach the human body. This paper describes the method used at the Instituto de Engenharia Nuclear (IEN) to measure the 222Rn concentration (Bq.m-3) in occupational and domestic environments. This method is based on the well-known track etch technique and the detector employed is the LEXAN plastic. It is described the electrochemical process used to reveal the tracks generated at the detector surface by the incidence of the alpha particles from radon and its progeny decay. In order to count the tracks, a program based on image processing techniques was developed at the IEN. This program processes the grey-scale images that are obtained by scanning the revealed detectors. The counting uncertainty of this program was estimated by comparing its results with those found by manual counting. As will be seen, this program gives reliable results even if the tracks overlap and the electrochemical revelation process provides tracks with high shape distortion. Other issues relating to the performance of this program are also discussed. (author)

  4. Indoor radon

    International Nuclear Information System (INIS)

    The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies

  5. Measurements of size distributions of radon progeny for improved quantification of the lung cancer risk emanating from exposure to radon decay products; Messungen der Groessenverteilungen von Radon-Folgeprodukten zur Verbesserung der Quantifizierung des durch Radonexposition verursachten Lungenkrebsrisikos

    Energy Technology Data Exchange (ETDEWEB)

    Haninger, T.

    1997-12-31

    A major issue in radiation protection is to protect the population from the harmful effects of exposure to radon and radon progeny. Quantification of the lung cancer risk emanating from exposure to radon decay products in residential and working environments poses problems, as epidemiologic studies yield information deviating from the results obtained by the indirect method of assessment based on dosimetric respiratory tract models. One important task of the publication here was to characterize the various exposure conditions and to quantify uncertainties that may result from application of the ``dose conversion convention``. A special aerosol spectrometer was therefore designed and built in order to measure the size distributions of the short-lived radon decay products in the range between 0.5 nm and 10 000 nm. The aerosol spectrometer consists of a three-step diffusion battery with wire nets, an 11-step BERNER impactor, and a detector system with twelve large-surface proportional detectors. From the measured size distributions, dose conversion coefficients, E/P{sup eq}, were calculated using the PC software RADEP; the RADEP program was developed by BIRCHALL and JAMES and is based on the respiratory tract model of the ICRP. The E/P{sup eq} coefficients indicate the effective dose E per unit exposure P{sup eq} to radon decay products. (orig./CB) [Deutsch] Eines der groessten Probleme des Strahlenschutzes ist der Schutz der Bevoelkerung vor einer Strahlenexposition durch Radon und seine Folgeprodukte. Die Quantifizierung des Lungenkrebsrisikos, das durch Radonexpositionen in Wohnungen und an Arbeitsplaetzen verursacht wird, ist ein grosses Problem, weil epidemiologische Studien ein anderes Ergebnis liefern, als die indirekte Methode der Abschaetzung mit dosimetrischen Atemtrakt-Modellen. Eine wichtige Aufgabe der vorliegenden Arbeit war es, unterschiedliche Expositionsbedingungen zu charakterisieren und die Unsicherheiten zu quantifizieren, die sich aus der

  6. Lung Cancer Risk from Occupational and Environmental Radon and Role of Smoking in Two Czech Nested Case-Control Studies

    Directory of Open Access Journals (Sweden)

    Ladislav Tomasek

    2013-03-01

    Full Text Available The aim of the present study was to evaluate the risk of lung cancer from combined exposure to radon and smoking. Methodologically, it is based on case-control studies nested within two Czech cohort studies of nearly 11,000 miners followed-up for mortality in 1952–2010 and nearly 12,000 inhabitants exposed to high levels of radon in homes, with mortality follow-up in 1960–2010. In addition to recorded radon exposure, these studies use information on smoking collected from the subjects or their relatives. A total of 1,029 and 370 cases with smoking information have been observed in the occupational and environmental (residential studies, respectively. Three or four control subjects have been individually matched to cases according to sex, year of birth, and age. The combined effect from radon and smoking is analyzed in terms of geometric mixture models of which the additive and multiplicative models are special cases. The resulting models are relatively close to the additive interaction (mixing parameter 0.2 and 0.3 in the occupational and residential studies, respectively. The impact of the resulting model in the residential radon study is illustrated by estimates of lifetime risk in hypothetical populations of smokers and non-smokers. In comparison to the multiplicative risk model, the lifetime risk from the best geometric mixture model is considerably higher, particularly in the non-smoking population.

  7. Purification of scintillation cocktails containing the alpha emitters americium and plutonium

    International Nuclear Information System (INIS)

    One efficient way of measuring alpha emitters is by the usage of liquid scintillation counting (LSC). A liquid sample is placed in a vial containing a scintillation cocktail. The alpha particles excite electrons in the surrounding liquid, and when they are de-excited photons are emitted. The photons are detected and the activity can be quantified. LSC has a high efficiency for alpha radiation and is therefore a fast and easy way for measuring alpha emitting samples. One drawback is that it does not differentiate very well between alpha energies; measurements of for example curium and plutonium simultaneously are impossible and demand other techniques. Another drawback is the production of a liquid alpha active waste. In Sweden alpha radioactive waste liquids with an activity over some kBq per waste container cannot be sent for final storage. If, however, the activity of the liquids could be reduced by precipitation of the actinides, it would be possible to send away the liquid samples to municipal incineration. In this work a method for a purification of alpha active scintillation cocktails was developed. The method was first tried on a lab scale, and then scaled up. Until today (March, 2013) more than 20 liters of scintillation liquids have successfully been purified from americium and plutonium at Chalmers University of Technology in Sweden. The four scintillation cocktails used were Emulsifier Safe®, Hionic-Fluor®, Ultima Gold AB® and Ultima Gold XR®. The scintillation cocktails could all be purified from americium with higher yield than 95%. The yield was kept when the liquids were mixed. Also plutonium could be precipitated with a yield over 95% in all cocktails except in Hionic-Fluor® (>55%). However, that liquid in particular could be purified (>95%) by mixing it with the three other cocktails. Up-scaling was performed to a batch size of 6-8 L of scintillation cocktail. In neither the americium nor the plutonium system, adverse effects of increasing the

  8. Mechanistic study on lung cancer mortality after radon exposure in the Wismut cohort supports important role of clonal expansion in lung carcinogenesis.

    Science.gov (United States)

    Zaballa, I; Eidemüller, M

    2016-08-01

    Lung cancer mortality after radon exposure in the Wismut cohort was analyzed using the two-stage clonal expansion (TSCE) model. A total of 2996 lung cancer deaths among the 58,695 male workers were observed during the follow-up period between 1946 and 2003. Adjustment to silica exposure was performed to find a more accurate estimation of the risk of radon exposure. An additional analysis with the descriptive excess relative risk (ERR) model was carried out for comparison. The TSCE model that best describes the data is nonlinear in the clonal expansion with radon exposure and has a saturation level at an exposure rate of [Formula: see text]. The excess relative risk decreases with age and shows an inverse exposure rate effect. In comparison with the ERR model, the TSCE model predicts a considerably larger risk for low exposures rates below [Formula: see text]. Comparison to other mechanistic studies of lung cancer after exposure to alpha particles using the TSCE model reveals an extraordinary consistency in the main features of the exposure response, given the diversity in the characteristics of the cohorts and the exposure across different studies. This suggests that a nonlinear response mechanism in the clonal expansion, with some level of saturation at large exposure rates, may be playing a crucial role in the development of lung cancer after alpha particle irradiation. PMID:27334643

  9. Genetic and molecular analysis of radon-induced rat lung tumours

    International Nuclear Information System (INIS)

    We have a model of radon-induced rat lung tumours, which allow us to analyse the cytogenetic and molecular alterations of the tumours. The aim is to better understand the mechanisms of radio-induced carcinogenesis and to define if it exists a specificity of radio-induced genetic alterations as compared to the genetic alterations found in the sporadic tumours. We have started our analysis by developing global cytogenetic and molecular approaches. We have shown that some alterations are recurrent. The genes that are potentially involved are the oncogene MET and the tumour suppressor Bene p16, which are also frequently altered in human lung tumours. Simultaneously, we have focussed our analysis by targeting the search of mutation in the tumour suppressor gene TP3. We have found that 8 of 39 tumours were mutated by deletion in the coding sequence of TP53. This high frequency of deletion, which is not observed in the human p53 mutation database could constitute a signature of radio-induced alterations. On this assumption, this type of alteration should not be only found on TP53 Bene but also in other suppressor genes which are inactivated by a mutation such as p16 for example. The work we are carrying out on radio-induced tumours among humans and animals is directed to this end. (author)

  10. Estimate of lifetime excess lung cancer risk due to indoor exposure to natural radon-222 daughters in Korea

    International Nuclear Information System (INIS)

    Lifetime excess lung cancer risk due to indoor 222Rn daughters exposure in Korea was quantitatively estimated by a modified relative risk projection model proposed by the U.S. National Academy of Science and the recent Korean life table data. The lifetime excess risk of lung cancer death attributable to annual constant exposure to Korean indoor radon daughters was estimated to be about 230/106 per WLM, which seemed to be nearly in the median of the range of 150-450/106 per WLM reported by the UNSCEAR in 1988. (1 fig., 2 tabs.)

  11. Similarities and uniqueness of Ly$\\alpha$ emitters among star-forming galaxies at z=2.5

    CERN Document Server

    Shimakawa, Rhythm; Shibuya, Takatoshi; Kashikawa, Nobunari; Tanaka, Ichi; Matsuda, Yuichi; Tadaki, Ken-ichi; Koyama, Yusei; Hayashi, Masao; Suzuki, Tomoko L; Yamamoto, Moegi

    2016-01-01

    We conducted a deep narrow-band imaging survey with the Subaru Prime Focus Camera on the Subaru Telescope and constructed a sample of Ly$\\alpha$ emitters (LAEs) at z=2.53 in the UDS-CANDELS field where a sample of H$\\alpha$ emitters (HAEs) at the same redshift is already obtained from our previous narrow-band observation at NIR. The deep narrow-band and multi broadband data allow us to find LAEs of stellar masses and star-formation rates (SFRs) down to $\\gtrsim$$10^8$ M$_\\odot$ and $\\gtrsim$0.2 M$_\\odot$/yr, respectively. We show that the LAEs are located along the same mass-SFR sequence traced by normal star-forming galaxies such as HAEs, but towards a significantly lower mass regime. Likewise, LAEs seem to share the same mass--size relation with typical star-forming galaxies, except for the massive LAEs, which tend to show significantly compact sizes. We identify a vigorous mass growth in the central part of LAEs: the stellar mass density in the central region of LAEs increases as their total galaxy mass gr...

  12. Analysis of alpha emitters in the coral, Favites virens, from Bikini lagoon by solid-state track detection

    International Nuclear Information System (INIS)

    A quantitative method for the non-destructive analysis of alpha emitters in CaCO3 matrices by solid-state track detection in cellulose nitrate was developed. 0.4pCi/g in an area of 4 mm2 can be measured routinely; smaller concentrations can be determined but with a lower resolution. Calibration methods used were a Pu source of 0.15 μCi in conjunction with polycarbonate and CaCO3 absorbers of different thickness, 2-30 μm, and a powdered coral sample from Enewetak Atoll which had been radiochemically analyzed for plutonium radionuclides, 241Am and other long-lived fission and activation products. Slabs of a coral, Favites virens, from Bikini lagoon were analyzed. A quantity of the alpha emitters detected in regions of the coral identified with growth during the years of nuclear testing, 1954, 1956 and 1959, are found in small discrete spots. Thin sections cut parallel to the direction of coral growth give different patterns of distribution. No such hot spots are evident in any post-test year growth sections although plutonium and other long lived fission and activation products were measured in these sections by radiochemical techniques. (author)

  13. The BOSS Emission-Line Lens Survey. III. : Strong Lensing of Ly$\\alpha$ Emitters by Individual Galaxies

    CERN Document Server

    Shu, Yiping; Kochanek, Christopher S; Oguri, Masamune; Perez-Fournon, Ismael; Zheng, Zheng; Mao, Shude; Montero-Dorta, Antonio D; Brownstein, Joel R; Marques-Chaves, Rui; Menard, Brice

    2016-01-01

    We introduce the BOSS Emission-Line Lens Survey (BELLS) GALaxy-Ly$\\alpha$ EmitteR sYstems (BELLS GALLERY) Survey, which is a Hubble Space Telescope program to image a sample of galaxy-scale strong gravitational lens candidate systems with high-redshift Ly$\\alpha$ emitters (LAEs) as the background sources. The goal of the BELLS GALLERY Survey is to illuminate dark substructures in galaxy-scale halos by exploiting the small-scale clumpiness of rest-frame far-UV emission in lensed LAEs, and to thereby constrain the slope and normalization of the substructure mass function. In this paper, we describe in detail the spectroscopic strong-lens selection technique, which is based on methods adopted in the previous Sloan Lens ACS (SLACS) Survey, BOSS Emission-Line Lens Survey, and SLACS for the Masses Survey. We present the BELLS GALLERY sample of the 21 highest-quality galaxy-LAE candidates selected from $\\approx 1.4 \\times 10^6$ galaxy spectra in the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital...

  14. Radon in workplaces

    International Nuclear Information System (INIS)

    The naturally occurring radioactive gas radon has been found at excessive levels in many workplaces other than mines throughout the country. Prolonged exposure to radon and its decay products increases the risk of developing lung cancer, and controls to protect employees from excessive exposure are included in the Ionising Radiations Regulations 1985. The control of occupational exposure to radon is discussed here. (author)

  15. Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiological and experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Timarche, M

    2004-03-15

    Radon is a radioactive gas produced during the decay of uranium 238 that is present in soil. It was classified as a human lung carcinogen in 1988, based on evidence both from animal studies and from human studies of miners with high levels of radon exposure. Radon is present everywhere; therefore the quantification of the risk associated with exposure to it is a key public health issue. The project aimed to analyse the risk associated with radon inhalation at low doses and at low rates of exposure. It involved researchers from three different fields: epidemiology, animal experiments and mechanistic modelling and provided a unique opportunity to study the influence of dose rate, mainly in the range of low daily exposures over long periods, by analysing in parallel results from both animal and epidemiological studies. The project comprised 6 work packages (W.P.). Firstly, the partners involved in epidemiology and animal experiments worked on the validation and the analysis of the data. Secondly, the data from W.P.1 and W.P.4 were transferred to the partners involved in W.P.5 for the application of mechanistic models. In the final step a synthesis of the results was prepared. (N.C)

  16. Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiological and experimental data

    International Nuclear Information System (INIS)

    Radon is a radioactive gas produced during the decay of uranium 238 that is present in soil. It was classified as a human lung carcinogen in 1988, based on evidence both from animal studies and from human studies of miners with high levels of radon exposure. Radon is present everywhere; therefore the quantification of the risk associated with exposure to it is a key public health issue. The project aimed to analyse the risk associated with radon inhalation at low doses and at low rates of exposure. It involved researchers from three different fields: epidemiology, animal experiments and mechanistic modelling and provided a unique opportunity to study the influence of dose rate, mainly in the range of low daily exposures over long periods, by analysing in parallel results from both animal and epidemiological studies. The project comprised 6 work packages (W.P.). Firstly, the partners involved in epidemiology and animal experiments worked on the validation and the analysis of the data. Secondly, the data from W.P.1 and W.P.4 were transferred to the partners involved in W.P.5 for the application of mechanistic models. In the final step a synthesis of the results was prepared. (N.C)

  17. Radon in caves: clinical aspects

    OpenAIRE

    Craven Stephen A.; Smit Berend J.

    2006-01-01

    Historical, experimental and clinical evidence is presented to suggest that radon constitutes a relatively small carcinogenic risk for casual visitors to caves. The risk is dependent on radon levels and the smoking of tobacco. Show cave guides, chronically exposed to radon, may be at increased risk for lung cancer due to the effects of radon, especially if they are smokers of tobacco.

  18. Shelter and indoor air in the twenty-first century--radon, smoking, and lung cancer risks

    International Nuclear Information System (INIS)

    Recognition that radon and its daughter products may accumulate to high levels in homes and in the workplace has led to concern about the potential lung cancer risk resulting from indoor domestic exposure. While such risks can be estimated with current dosimetric and epidemiological models for excess relative risks, it must be recognized that these models are based on data from occupational exposure and from underground miners' mortality experience. Several assumptions are required to apply risk estimates from an occupational setting to the indoor domestic environment. Analyses of the relevant data do not lead to a conclusive description of the interaction between radon daughters and cigarette smoking for the induction of lung cancer. The evidence compels the conclusion that indoor radon daughter exposure in homes represents a potential life-threatening public health hazard, particularly in males, and in cigarette smokers. Resolution of complex societal interactions will require public policy decisions involving the governmental, scientific, financial, and industrial sectors. These decisions impact the home, the workplace, and the marketplace, and they extend beyond the constraints of science. Risk identification, assessment, and management require scientific and engineering approaches to guide policy decisions to protect the public health. Mitigation and control procedures are only beginning to receive attention. Full acceptance for protection against what could prove to be a significant public health hazard in the twenty-first century will certainly involve policy decisions, not by scientists, but rather by men and women of government and law

  19. Combined effect of radon exposure and smoking on lung cancer risk - result of a case-control study among Czech miners

    International Nuclear Information System (INIS)

    Because of the predominant role of cigarette smoking as a cause of lung cancer, an understanding of the joint effect of smoking and radon exposure is needed for the assessment of the risk from radon. The aim of the present work is to verify differences in smoking specific risk coefficients observed earlier (BEIR VI). The present study includes two cohorts of uranium miners in west and central Bohemia and one cohort of burnt clay miners exposed to radon. In the nested study, for each case of lung cancer (observed in 1954-2007) with smoking data up to three controls were selected from all cohort members matched by year of birth, age, and the cohort. Data on smoking in the study were collected from subjects in person, from medical records, and from relatives. The statistical assessment of the study was based on conditional logistic regression with linear dependence of estimated relative risk on radon exposure

  20. Lung cancer risk, exposure to radon and tobacco consumption in a nested case-control study of French uranium miners

    International Nuclear Information System (INIS)

    Introduction: A nested case-control study was conducted among the French uranium miners cohort in order to assess the effect of protract ed radon exposure on lung cancer risk taking into account tobacco consumption. Material and methods: One hundred uranium miners employed by the French company CEA-COGEMA and who died of a lung cancer between 1980 and 1994 were identified as cases among the cohort. For each case, five controls were randomly matched on birth period and attained age at the time of death of the corresponding case. Cumulated radon exposure during employment was reconstructed for each of these 100 cases and 500 controls. Smoking habits were retrospectively determined from three complementary sources: 1) medical files, 2) forms filled in by occupational physicians and 3) questionnaires applied in face-to-face interviews, phone calls or mailings. Analysis was performed by conditional logistic regression using a linear excess relative risk (ERR) model. A multiplicative model was fitted to assess the joint effect of radon exposure and smoking on lung cancer risk. Results: Smoking status was established for 62 cases and 320 controls and two categories ('ever smokers' vs. 'never smokers') were defined. Ninety percent of the cases and 73% of the controls were classified as 'ever smokers'. Mean five-year lagged cumulated radon exposures were 82.0 and 47.6 working level months (WLM) for the cases and the controls, respectively. The excess relative risk per WLM (ERR/WLM) was 1.1% with a 95%-confidence interval (CI) of 0.2-2.0%. When adjusting for smoking, radon exposure effect was little modified (ERR/WLM = 0.8%, 95% -CI = 0.1- 2.8%). The effect of smoking on lung cancer risk was comparable to results reported in previous miners cohorts (OR = 3.04, 95% -CI = 1.20-7.70). Discussion: A consequent effort was carried out to collect smoking status from three sources for the miners included in this nested case-control study. This analysis shows that, when adjusting on

  1. Multi-stratified multiple regression tests of the linear/no-threshold theory of radon-induced lung cancer

    International Nuclear Information System (INIS)

    A plot of lung-cancer rates versus radon exposures in 965 US counties, or in all US states, has a strong negative slope, b, in sharp contrast to the strong positive slope predicted by linear/no-threshold theory. The discrepancy between these slopes exceeds 20 standard deviations (SD). Including smoking frequency in the analysis substantially improves fits to a linear relationship but has little effect on the discrepancy in b, because correlations between smoking frequency and radon levels are quite weak. Including 17 socioeconomic variables (SEV) in multiple regression analysis reduces the discrepancy to 15 SD. Data were divided into segments by stratifying on each SEV in turn, and on geography, and on both simultaneously, giving over 300 data sets to be analyzed individually, but negative slopes predominated. The slope is negative whether one considers only the most urban counties or only the most rural; only the richest or only the poorest; only the richest in the South Atlantic region or only the poorest in that region, etc., etc.,; and for all the strata in between. Since this is an ecological study, the well-known problems with ecological studies were investigated and found not to be applicable here. The open-quotes ecological fallacyclose quotes was shown not to apply in testing a linear/no-threshold theory, and the vulnerability to confounding is greatly reduced when confounding factors are only weakly correlated with radon levels, as is generally the case here. All confounding factors known to correlate with radon and with lung cancer were investigated quantitatively and found to have little effect on the discrepancy

  2. Assessment of excess lung cancer risk due to the indoor radon exposure in some cities of Jordan

    International Nuclear Information System (INIS)

    Indoor radon concentration levels were measured in the cities of Amman, Zarka, and Sault using Cr-39 etch track detectors. The average values of indoor concentration levels in these cities were found to be 41.3 Bq m/sup -3/, 30.7 Bq m/sup -3/ and 51.2 Bq m/sup -3/ respectively. Based on these data, excess lung cancer risk was assessed using the risk factors recommended by UNSCEAR. The life time excess lung cancer risk due to the life time exposure has been determined and is found to vary from 33 per MPY to 55 MPY at the age of 70 when lower value of the risk factors is used. On the other hand, if upper value of the risk factors is used then the estimated excess lung cancer risk at the age of 70 varies from 74 per MPY to 125 per MPY. (author)

  3. Theory of the induction of bone sarcoma by bone-seeking alpha emitters and its application to risk assessment

    International Nuclear Information System (INIS)

    This work discusses the theory of bone sarcoma induction by bone seeking alpha emitters, which is based strictly on biological considerations relative to the mechanism of radiation-induced carcinogenesis, identification of cells at risk and their location in bone, bone tissue renewal processes and bone cell kinetics with or without radiation exposure. The model is consistent with the data on bone sarcoma incidence human with incorporated long-lived isotopes Ra-226 + Ra-228. Extrapolation of these data to a low intake region of the basis of the developed theoretical approach suggests that the linear ICRP-UNSCEAR model overestimates carciogenic risk at low doses, possibly by a factor of 2-4. The model suggests a linear response of target cells to the initiation effects of alpha irradiation. The non-linear (linear-quadratic) initial part of dose-response curve for osteosarcoma induction is explained quantitatively by a model based on a promoter effect of regenerative hyperplasia resulting from invitation effects of alpha radiation. The maximum overestimation inherent to the model of the low-level risk due to the the dose-dependent promotion factor is estimated using bo+1/bo, where bo is a model parameter which is proportional to the normal division rate of osteogenic cells in vivo and which can be estimated within the framework of the model. The model provides confirming evidence that, for radiation protection purposes, endosteal cells may be considered the only group of cells at risk of sarcoma induction by low doses of bone-seeking alpha emitters, whereas the role of marrow stromal (osteogenic) cells as target cells is much more significant with increasing intakes, and can become dominating if intake is high enough

  4. Theory of the induction of bone sarcoma by bone-seeking alpha emitters and its application to risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Petojan, I.M.

    1992-06-01

    This work discusses the theory of bone sarcoma induction by bone seeking alpha emitters, which is based strictly on biological considerations relative to the mechanism of radiation-induced carcinogenesis, identification of cells at risk and their location in bone, bone tissue renewal processes and bone cell kinetics with or without radiation exposure. The model is consistent with the data on bone sarcoma incidence human with incorporated long-lived isotopes Ra-226 + Ra-228. Extrapolation of these data to a low intake region of the basis of the developed theoretical approach suggests that the linear ICRP-UNSCEAR model overestimates carciogenic risk at low doses, possibly by a factor of 2-4. The model suggests a linear response of target cells to the initiation effects of alpha irradiation. The non-linear (linear-quadratic) initial part of dose-response curve for osteosarcoma induction is explained quantitatively by a model based on a promoter effect of regenerative hyperplasia resulting from invitation effects of alpha radiation. The maximum overestimation inherent to the model of the low-level risk due to the the dose-dependent promotion factor is estimated using bo{sup +1}/bo, where bo is a model parameter which is proportional to the normal division rate of osteogenic cells in vivo and which can be estimated within the framework of the model. The model provides confirming evidence that, for radiation protection purposes, endosteal cells may be considered the only group of cells at risk of sarcoma induction by low doses of bone-seeking alpha emitters, whereas the role of marrow stromal (osteogenic) cells as target cells is much more significant with increasing intakes, and can become dominating if intake is high enough.

  5. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-06-01

    The quantitative estimation of the carcinogenic risk of low-dose, high-LET radiation in the case of exposure to radon daughters and lung-cancer is subject to numerous uncertainties. The greatest of these concerns the parametric values of the dose-response curve. We lack knowledge and an understanding of the dosimetry and the distribution of aggregates of radioactivity that remain localized as hot spots in specific regions of the lungs and the influence on greater or lesser risk of lung cancer per average lung dose than uniformly deposited radiation (NRC76). We have only a limited understanding of the response to exposure to high-LET radiations, such as alpha particles, for which linear risk estimates for low doses are less likely to overestimate the risk, and may, in fact, underestimate the risk (BEIR80). Other uncertainties include the length of the latency period, the RBE for alpha radiation relative to gamma radiation, the period during which the radiation risk is expressed, the risk projection model used - whether absolute or relative - for projecting risk beyond the period of observation, the effect of dose rate and protraction of dose, and the influence of differences in the natural incidence of lung cancer in different populations. In addition, uncertainties are introduced by the biological and life-style risk characteristics of humans, for example, the effect of sex, the effect of age at the time of irradiation and at the time of appearance of the cancer, the influence of length of observation or follow-up of the study populations, and the influence of perhaps the most important confounding bias, cigarette-smoking. The collective influence of these uncertainties is such as to deny great credibility to any estimate of human lung cancer risk and other cancer risk that can be made for low-dose, high-LET radon daughter radiation exposure.

  6. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    International Nuclear Information System (INIS)

    The quantitative estimation of the carcinogenic risk of low-dose, high-LET radiation in the case of exposure to radon daughters and lung-cancer is subject to numerous uncertainties. The greatest of these concerns the parametric values of the dose-response curve. We lack knowledge and an understanding of the dosimetry and the distribution of aggregates of radioactivity that remain localized as hot spots in specific regions of the lungs and the influence on greater or lesser risk of lung cancer per average lung dose than uniformly deposited radiation (NRC76). We have only a limited understanding of the response to exposure to high-LET radiations, such as alpha particles, for which linear risk estimates for low doses are less likely to overestimate the risk, and may, in fact, underestimate the risk (BEIR80). Other uncertainties include the length of the latency period, the RBE for alpha radiation relative to gamma radiation, the period during which the radiation risk is expressed, the risk projection model used - whether absolute or relative - for projecting risk beyond the period of observation, the effect of dose rate and protraction of dose, and the influence of differences in the natural incidence of lung cancer in different populations. In addition, uncertainties are introduced by the biological and life-style risk characteristics of humans, for example, the effect of sex, the effect of age at the time of irradiation and at the time of appearance of the cancer, the influence of length of observation or follow-up of the study populations, and the influence of perhaps the most important confounding bias, cigarette-smoking. The collective influence of these uncertainties is such as to deny great credibility to any estimate of human lung cancer risk and other cancer risk that can be made for low-dose, high-LET radon daughter radiation exposure

  7. Mechanistic model of radon-induced lung cancer risk at low exposure levels based on cellular alpha particle hits

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Hofmann; Hatim, Fakir [Salzburg Univ., Div. of Physics and Biophysics, Dept. of Material Science (Austria); Lucia-Adina, Truta-Popa [Babes-Bolyai Univ., Faculty of Physics (Romania)

    2006-07-01

    To explore the role of the multiplicity of cellular hits by radon progeny alpha particles for lung cancer incidence, the number of single and multiple alpha particle hits were computed for basal and secretory cells in the bronchial epithelium of human airway bifurcations employing Monte Carlo methods. Hot spots of alpha particle hits were observed at the branching points of bronchial airway bifurcations, suggesting that multiple alpha particle hits may occur primarily at carinal ridges. Random alpha particle intersections of bronchial cells during a given exposure period, selected from a Poisson distribution, were simulated by an initiation-promotion model, based on experimentally observed cellular transformation and survival functions. To consider potential bystander effects, which have been observed in cellular in vitro studies, alpha particle interactions were also simulated for larger sensitive target volumes in bronchial epithelium, consisting of a collection of cells. Lung cancer risk simulations indicated that cancer induction for continuous exposures is related to the cycle time of an irradiated cell, thus exhibiting a distinct dose-rate effect. While the dominant role of single hits leads to a linear dose-response relationship at low radon exposure levels, predicted lung cancer risk for a collection of interacting cells exhibits a linear-quadratic response, suggesting that bystander effects, if operating at all under in vivo irradiations, may be restricted to a small number of adjacent cells. (author)

  8. Mechanistic model of radon-induced lung cancer risk at low exposure levels based on cellular alpha particle hits

    International Nuclear Information System (INIS)

    To explore the role of the multiplicity of cellular hits by radon progeny alpha particles for lung cancer incidence, the number of single and multiple alpha particle hits were computed for basal and secretory cells in the bronchial epithelium of human airway bifurcations employing Monte Carlo methods. Hot spots of alpha particle hits were observed at the branching points of bronchial airway bifurcations, suggesting that multiple alpha particle hits may occur primarily at carinal ridges. Random alpha particle intersections of bronchial cells during a given exposure period, selected from a Poisson distribution, were simulated by an initiation-promotion model, based on experimentally observed cellular transformation and survival functions. To consider potential bystander effects, which have been observed in cellular in vitro studies, alpha particle interactions were also simulated for larger sensitive target volumes in bronchial epithelium, consisting of a collection of cells. Lung cancer risk simulations indicated that cancer induction for continuous exposures is related to the cycle time of an irradiated cell, thus exhibiting a distinct dose-rate effect. While the dominant role of single hits leads to a linear dose-response relationship at low radon exposure levels, predicted lung cancer risk for a collection of interacting cells exhibits a linear-quadratic response, suggesting that bystander effects, if operating at all under in vivo irradiations, may be restricted to a small number of adjacent cells. (author)

  9. The significance of radon in radioactive pollution of environment. Pt. 2. Radon effect on living organism

    International Nuclear Information System (INIS)

    Authors review the history of radon monitoring. Epidemiological studies of lung cancer and its correlation to radon concentration in mines and buildings are described. The influence of radon on animals living in the buildings built from waste materials is described. Authors review plans concerning creation of radon monitoring system in Poland. The necessity of monitoring influence of radon on animals is described

  10. Remote system for measurement of radon alpha emitter for population safety guards; Sistema remoto de medicion de radon alfa emisor para la salvaguarda poblacional-3599

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Vasquez, E-mail: jesus.vasguez@lnl.infn.it [Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Laboratorio Nazionale di Legnaro; Sajo-Bohus, Laszlo; Palacios, Daniel; Barros, Haydn, E-mail: sajobohus@gmail.com, E-mail: sanjuro.perdomo@gmail.com, E-mail: lab.nuclear@gmail.com [Universidad Simon Bolivar (USB), Caracas (Venezuela, Bolivarian Republic of). Laboratorio de Fisica Nuclear

    2013-07-01

    The objective of this research project is to study the OSL properties for high doses of dosemeters traditionally applied in thermoluminescent dosimetry (TL), as CaF2: Dy (TLD 200) and CaF2: Mn (TLD 400), and thus verify the applicability of OSL technique in high-dose dosimetry.

  11. The role of the implementation of policies for the prevention of exposure to Radon in Brazil—a strategy for controlling the risk of developing lung cancer

    OpenAIRE

    Lino, Aline da Rocha; Abrahão, Carina Meira; Amarante, Marcus Paulo Fernandes; de Sousa Cruz, Marcelo Rocha

    2015-01-01

    Lung cancer is the leading cause of cancer death in the United States and other industrialised countries. The most important risk factor is active smoking. However, given the increased incidence of lung cancer in non-smokers, it is necessary to improve knowledge regarding other risk factors. Radon (Rn) is a noble gas and is the most important natural source of human exposure to ionizing radiation. Exposure to high levels of this radioactive gas is related to an increased risk of developing lu...

  12. Radon Progeny In Underground Phosphate Mines and Their Activity Distributions In Human Lung

    International Nuclear Information System (INIS)

    In addition to workers in uranium mines, the staff of other underground mines, such as worker in underground phosphate mines, Can be exposed to 222Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure to the workers in those sites. Active techniques are employed to fulfill the objective of measuring individual radon progeny concentrations (CRaA, CRaB and CRaC). The mean reported values of radon progeny concentrations exceed the action levels recommended by ICRP 65 (1993). Based on the physical properties of attached radon progeny aerosol and physiological parameters for heavy work activity which recommended by ICRP 66 (1994). the deposition fraction for each airway generation was calculated. From the measured individual radon progeny concentrations in these mines and the calculated values of deposition fractions, the surface activity distribution per generation were calculated in human respiratory system (BB and regions). The maximum values of these activities were found in the upper bronchial airway generations. According to the obtained results, some of the corrective actions were recommended in this study

  13. Radon dosimetry and radon risks in perspective

    International Nuclear Information System (INIS)

    Some recollections are given regarding the introduction of alpha track etching detectors for integrating radon individual and environmental monitoring 25 years ago. The current status, and efforts to standardise these methods, are briefly described. However, more important than improving measurement techniques appears to be a balanced judgment of the potential health risks associated with radon, in particular in dwellings. New radio-epidemiological studies in former East Germany confirm earlier observations that there is little or no evidence of increased lung cancer risk for populations living in high-radon areas. Only among early uranium miners is there an increase in lung cancer, to be explained by synergistic effects of heavy smoking, ore dust, toxic fumes, etc., and extremely high radon exposures. The large scale and obviously effective worldwide application of radon for therapeutic reasons also indicates that lung cancer from early mining should not be used as a basis for risk estimates in buildings, and intervention levels (if required at all) should become substantially increased. Also, detectable differences in the genotoxic effects of radon and smoking in lung cancers deserve special attention in the discussion about potential radon health hazards. (author)

  14. Estimated risk of lung cancer from exposure to radon decay products in U.S. homes: a brief review

    International Nuclear Information System (INIS)

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in U.S. homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average 222Rn concentrations with an arithmetic mean of 55 Bq m-3 and approximately 2% of homes having 300 Bq m-3 or more. Application of the results of occupational epidemiological studies to indoor exposures, either directly or using recent advances in lung dosimetry, suggests that the average indoor concentration entails a lifetime risk of lung cancer of about 0.4%, contributing about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m-3 or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m-3 correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. Such average and high-level risks greatly exceed ordinarily-considered environmental risks, forcing development of a new perspective on environmental exposures. (author)

  15. Lyman Alpha Emitters at z=7 in the Subaru/XMM-Newton Deep Survey Field: Photometric Candidates and Luminosity Function

    CERN Document Server

    Ota, Kazuaki; Kashikawa, Nobunari; Shimasaku, Kazuhiro; Ouchi, Masami; Totani, Tomonori; Kobayashi, Masakazu A R; Nagashima, Masahiro; Harayama, Atsushi; Kodaka, Natsuki; Morokuma, Tomoki; Furusawa, Hisanori; Tajitsu, Akito; Hattori, Takashi

    2010-01-01

    We conducted a deep narrowband NB973 (FWHM = 200 A centered at 9755 A) survey of z=7 Lyman alpha emitters (LAEs) in the Subaru/XMM-Newton Deep Survey Field, using the fully depleted CCDs newly installed on the Subaru Telescope Suprime-Cam, which is twice more sensitive to z=7 Lyman alpha at ~ 1 micron than the previous CCDs. Reaching the depth 0.5 magnitude deeper than our previous survey in the Subaru Deep Field that led to the discovery of a z=6.96 LAE, we detected three probable z=7 LAE candidates. Even if all the candidates are real, the Lyman alpha luminosity function (LF) at z=7 shows a significant deficit from the LF at z=5.7 determined by previous surveys. The LAE number and Lyman alpha luminosity densities at z=7 is ~ 7.7-54% and ~5.5-39% of those at z=5.7 to the Lyman alpha line luminosity limit of L(Ly-alpha) >~ 9.2 x 10^{42} erg s^{-1}. This could be due to evolution of the LAE population at these epochs as a recent galaxy evolution model predicts that the LAE modestly evolves from z=5.7 to 7. How...

  16. Morphological Properties of Lyman Alpha Emitters at Redshift 4.86 in the COSMOS Field: Clumpy Star Formation or Merger?

    CERN Document Server

    Kobayashi, Masakazu A R; Koekemoer, Anton M; Murayama, Takashi; Taniguchi, Yoshiaki; Kajisawa, Masaru; Shioya, Yasuhiro; Scoville, Nick Z; Nagao, Tohru; Capak, Peter L

    2016-01-01

    We investigate morphological properties of 61 Lyman-alpha emitters (LAEs) at z = 4.86 identified in the COSMOS field, based on Hubble Space Telescope Advanced Camera for Surveys (ACS) imaging data in the F814W-band. Out of the 61 LAEs, we find the ACS counterparts for the 54 LAEs. Eight LAEs show double-component structures with a mean projected separation of 0."63 (~ 4.0 kpc at z = 4.86). Considering the faintness of these ACS sources, we carefully evaluate their morphological properties, that is, size and ellipticity. While some of them are compact and indistinguishable from the PSF half-light radius of 0."07 (~ 0.45 kpc), the others are clearly larger than the PSF size and spatially extended up to 0."3 (~ 1.9 kpc). We find that the ACS sources show a positive correlation between ellipticity and size and that the ACS sources with large size and round shape are absent. Our Monte Carlo simulation suggests that the correlation can be explained by (1) the deformation effects via PSF broadening and shot noise or...

  17. Lyman-\\alpha{} Emitters in the context of hierarchical galaxy formation: predictions for VLT/MUSE surveys

    CERN Document Server

    Garel, Thibault; Blaizot, Jérémy

    2015-01-01

    The VLT Multi Unit Spectroscopic Explorer (MUSE) integral-field spectrograph can detect Ly\\alpha{} emitters (LAE) in the redshift range $2.8 \\lesssim z \\lesssim 6.7$ in a homogeneous way. Ongoing MUSE surveys will notably probe faint Ly\\alpha{} sources that are usually missed by current narrow-band surveys. We provide quantitative predictions for a typical wedding-cake observing strategy with MUSE based on mock catalogs generated with a semi-analytic model of galaxy formation coupled to numerical Ly\\alpha{} radiation transfer models in gas outflows. We expect $\\approx$ 1500 bright LAEs ($F_{Ly\\alpha}$ $\\gtrsim$ $10^{-17}$ erg s$^{-1}$ cm$^{-2}$) in a typical Shallow Field (SF) survey carried over $\\approx$ 100 arcmin$^2$, and $\\approx$ 2,000 sources as faint as $10^{-18}$ erg s$^{-1}$ cm$^{-2}$ in a Medium-Deep Field (MDF) survey over 10 arcmin$^2$. In a typical Deep Field (DF) survey of 1 arcmin$^2$, we predict that $\\approx$ 500 extremely faint LAEs ($F_{Ly\\alpha}$ $\\gtrsim$ $4 \\times 10^{-19}$ erg s$^{-1}$...

  18. The HETDEX Pilot Survey V: The Physical Origin of Lyman-alpha Emitters Probed by Near-infrared Spectroscopy

    CERN Document Server

    Song, Mimi; Gebhardt, Karl; Hill, Gary J; Drory, Niv; Ashby, Matthew L N; Blanc, Guillermo A; Bridge, Joanna; Chonis, Taylor; Ciardullo, Robin; Fabricius, Maximilian; Fazio, Giovanni G; Gawiser, Eric; Gronwall, Caryl; Hagen, Alex; Huang, Jia-Sheng; Jogee, Shardha; Livermore, Rachael; Salmon, Brett; Schneider, Donald P; Willner, S P; Zeimann, Gregory R

    2014-01-01

    We present the results from a VLT/SINFONI and Keck/NIRSPEC near-infrared spectroscopic survey of 16 Lyman-alpha emitters (LAEs) at $z$ = 2.1 - 2.5 in the COSMOS and GOODS-N fields discovered from the HETDEX Pilot Survey. We detect rest-frame optical nebular lines (H$\\alpha$ and/or [OIII]$\\lambda$5007) for 10 of the LAEs and measure physical properties, including the star formation rate (SFR), gas-phase metallicity, gas-mass fraction, and Ly$\\alpha$ velocity offset. We find that LAEs may lie below the mass-metallicity relation for continuum-selected star-forming galaxies at the same redshift. The LAEs all show velocity shifts of Ly$\\alpha$ relative to the systemic redshift ranging between +85 and +296 km s$^{-1}$ with a mean of +180 km s$^{-1}$. This value is smaller than measured for continuum-selected star-forming galaxies at similar redshifts. The Ly$\\alpha$ velocity offsets show a moderate correlation with the measured star formation rate (2.5$\\sigma$), but no significant correlations are seen with the SFR...

  19. Indoor radon: deadliest pollutant

    International Nuclear Information System (INIS)

    Radon in individual homes may be the greatest source of radiation that people are exposed to during a lifetime. In areas where radon concentrations in homes are high, people may be exposed to more radiation than were the Russian people living in the vicinity of Chernobyl Nuclear Power Plant. Studies indicate that the radon exposure contributes to 5000 to 20,000 deaths per year from lung cancer and that smoking may have a lethal interaction with the radon exposure. One study found an average annual concentration of radon in living spaces of 1.5 picocuries per liter. 7% of U.S. homes were found to have a radon concentration above the 4 picocuries per liter level set by the Environmental Protection Agency, and 1 - 3% of the homes have levels above 8 picocuries. Some ways are described for changing the air pressure in a house so that air is not constantly drawn from the permeable soil where the radon originates

  20. Lowering the UK domestic radon action level to reduce radiation-induced lung cancer in general population: when and where is it cost effective?

    International Nuclear Information System (INIS)

    Case studies have shown that radon gas can be present within domestic properties at sufficiently high levels that it can significantly increase the risk of lung cancer in occupants. Recently, Darby et al. (2006) have shown that this risk exists at radon concentrations as low as 100 Bq·m-3, which is below the UK domestic Action Level of 200 Bq·m-3. As a result, there have been suggestions that national domestic Action Levels should be reduced. This paper considers the benefits and costs of the domestic radon remediation programmes in the UK, when a range of Action Levels from 125 Bq·m-3 to 600 Bq·m-3 are applied. The variations of total cost, cost-effectiveness, dose reduction and lung cancers saved for each proposed action level, and the proportion of houses over the proposed action level, were estimated. The study shows that, for an Action Level above 200 Bq·m-3, a completed domestic radon remediation programme in Northamptonshire, where 6.3% of existing houses have initial radon levels over 200 Bq·m-3, will cost less and will target those most at risk, but will be less cost effective. In addition, a higher Action Level leaves a higher residual dose and greater risk of cancer in the population living in unremediated homes. Reducing the Action Level below 200 Bq·m-3 will prevent more cancers, but at significantly higher cost. It will be less cost-effective, because a significant number of houses with moderate radon levels will be remediated with modest health benefit to occupants. The study suggests that a completed radon remediation programme is most cost-effective with an action level of around 250 to 300 Bq·m-3. The finding appears to be independent of the percentage of houses over the Action Level. This has clear implications for future health policy. (author)

  1. Radon in the indoor environment

    International Nuclear Information System (INIS)

    A precise retrospective assessment of long-term radon exposures in dwellings is essential for estimating lung-cancer risks. The objectives of this research are (1) to investigate the deposition of radon progeny in the human respiratory tract by means of direct measurements as a function of aerosol conditions, (2) to assess the radon concentrations in buildings retrospectively with volume traps

  2. Influence of radon-daughter exposure rate and uranium ore dust concentration on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Groups of male SPF Wistar rats were exposed concurrently to several levels of radon daughters and uranium ore dust to study the effect of these variables on pulmonary disease states. Clinical pathology data at 1 yr postexposure indicate no significant differences among exposed animals when compared with controls. Preliminary histopathologic data suggest a trend toward increasing lung tumor risk as the exposure rate is decreased (constant total dose), but the differences are not statistically significant at the 0.05 level. A similar trend occurs with decrease in ore dust concentration (except for the 2560-WLM exposure group), but these differences are also not significant at the 0.05 level. The tumor risk is significantly (0.05 level) increased as the exposure level increases from approximately 320 and 640 WLM to 2560 WLM at the high ore dust concentration

  3. What Is Radon?

    Science.gov (United States)

    ... Learn About Cancer » What Causes Cancer? » Other Carcinogens » Pollution » Radon Share this Page Close Push escape to ... Cancer Colon/Rectum Cancer Lung Cancer Prostate Cancer Skin Cancer Show All Cancer Types News and Features ...

  4. Simulation of radon short lived decay daughters' inhalation using the lung compartmental model

    International Nuclear Information System (INIS)

    Radon and its short-lived decay daughters are the main source of radiation on natural ways for population. The radon gas, released from soil, water or construction materials is producing by radioactive decay the following solid daughters: Po-218, Bi-214, Pb-214, and Po-214, which can attach to aerosols, and consequently penetrate the organism by inhalation. The human respiratory tract can be approximated by aid of a compartment model that takes into account the different anatomical structures exposed to contamination and irradiation, as well as the respective physiological processes. This model is associated to a mathematical equation system that describes the behavior of the radioactive material inside the body. The results represent the dose equivalent on different organs and tissues, as a function of subject and the activity performed in contaminating environment. (author)

  5. Measurement of radon gas concentration in fertilizer samples by using nuclear track detector (CR-39)

    International Nuclear Information System (INIS)

    In the present work, we have measured the radon gas concentration in ten fertilizers samples for three kinds { mixed fertilizer (M.F), triple super phosphate (T.S.P), single super phosphate (S.S.P) } by using alpha-emitters registrations which are emitted form radon gas in (CR-39) nuclear track detector.The results obtained have shown that the highest average radon gas concentration in fertilizer samples was found in triple super phosphate sample(T.S.P.), which was (177.5Bq/m3) (Iran origin), while the lowest average radon gas concentration was found in single super phosphate (S.S.P.) sample, which was (72.2Bq/m3) (Iraq origin).The present results show that the radon gas concentration in all fertilizers samples is below the allowed limit from (International Commission of Radiation Protection) (ICRP) agency

  6. STUDY ON LUNG DOSE FOR DIFFERENT ANIMALS BY INHALATION OF SHORT—LIVED RADON DAUGHTERS

    Institute of Scientific and Technical Information of China (English)

    李素云; 张升慧; 等

    1994-01-01

    The dose distribution in the lung is inhomogeneous.The dose to the basal cell layer of trachea and main bronchi is much higher than the dose to total lung both for rabbits at different ages and for different animals.A maximum value of the dose to lung tissue for rabbits at ages of 20-40d is observed.The dose decreases with increasing body weight.The relationship between the dose and body weight can be descreibed by a power function.The dose to total lung increases exponentially with the minute breathing volume per unit of lung weight.

  7. Managing the radon risk

    International Nuclear Information System (INIS)

    Preliminary studies have shown a linear relationship between radon dose and lung cancer, first for miners and later for inhabitants. Lethal risk exists even at very low dose rates (nearing 200 Bq/m3) if the person has stayed in the building for a very long period (20 to 30 years). Studies on cohorts of uranium miners suggest a link between radon dose and leukemia. Other studies have shown the multiplier effect of smoking on the radon effect. The World Health Organisation proposes a maximal concentration of 100 Bq/m3 to minimize the radon risk in the habitat. In France and every year, between 1200 and 2900 deaths from lung cancer can be attributed to the exposure to radon. A new National Action Plan has been launched by French authorities, it concerns buildings that are open to the public in 31 departments where terrestrial radon concentration is important. Radon monitoring and ventilation measures will have to be implemented. The radon risk due to the presence of nearby tailings is considered through the 'Bessine case' in which a family has lived in a house that had been built on waste rocks and tailings from uranium mining activities. 20 European countries represented by people in charge of radioprotection, have taken part in a workshop to share their experience of the radon risk. (A.C.)

  8. Contribution of radon and radon daughters to respiratory cancer

    International Nuclear Information System (INIS)

    This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime

  9. Radon and cancer

    International Nuclear Information System (INIS)

    This publication proposes an overview on what is known about the carcinogenic effect of radon. It recalls the origin of radon, its presence in the environment, and its radioactivity. It comments data on the relationship between exposure to radon and lung cancer, and with other forms of cancer. It discusses the role of the exposure level, and the cases of professional and domestic exposure with respect to these risks. It indicates the hazardous areas in France which are well identified, outlines that smokers are more likely victims of risks related to radon, that this risk is still underrated and underestimated (notably by the public). It gives an overview of existing regulations regarding exposure to radon, of public health policies and national plans concerning radon, and recalls some WHO recommendations

  10. Expressions of lung cancer related genes and miRNA in peripheral blood of the residents surrounding hot springs with extremely high radon

    International Nuclear Information System (INIS)

    Objective: To investigate the expressions of lung cancer related genes and miRNA in peripheral blood of the residents surrounding the extremely high radon hot springs in Ruoergai County, Sichuan Province. Methods: Peripheral blood samples were collected from the local residents. Expressions of lung cancer related genes (p53, k-ras) and miRNA (let-7a, miR-34a/b) were detected by real-time PCR and the protein expressions of p53 and k-ras were detected by Western blot. Results: The expressions of p53 and k-ras mRNA of the residents in high radon area were 0.97 and 1.33 times of the control respectively (t=0.13, -1.12, P>0.05), and the p53 and k-ras protein levels were 0.70 and 1.23 times of the control respectively (t=0.72, 0.46, P>0.05). The let-7a of the residents in high radon area was lower (t=1.63, P>0.05) while the miR-34a and miR-34b were significantly higher than those of the controls (t=-3.20, -3.32, P<0.05). Conclusions: Based on the expressions of p53 and k-ras gene and miRNA, it can be concluded that the residents surrounding the high radon hot springs received radiation damage. (authors)

  11. Scopingreport radon

    International Nuclear Information System (INIS)

    This report contains general information on radon concerning the existing standards, sources and emissions, the exposure levels and effect levels. lt serves as a basis for the discussion during the exploratory melting to be held in November/December 1989, aimed at determining the contents of the Integrated Criteria Document Radon. Attention is focussd on Rn-222 (radon) and Rn-220 (thoron), presently of public interest because of radon gas pollution in private homes. In the Netherlands air quality standards nor product standards for the exhalation rate of building materials have been recommended. The major source of radon in the Netherlands is the soil gas (> 97%), minor sources are phosphate residues and building materials (> 2% in total). Hence, the major concern is the transfer through the inhalation of air, the lung being the most critical organ at risk to develop cancer. Compared to risks for humans, the risks of radon and its daughters for aquatic and terrestric organisms, as well as for agricultural crops and livestock, are assumed to be limited. In the Netherlands the average dose for man due to radon and thoron progeny is appr. 1.2 mSv per year, the estimated dose range being 0.1-3.5 mSv per year. This dose contributes for about 50% to rhe total exposure due to all sources of ionizing radiation. Of this dose respectively 80% is caused by radon and about 90% is received indoor. The estimated dose for the general population corresponds to a risk for inducing fatal cancers of about 15 x 10-6 per year, ranging from 1.2 x 10-6 to 44 x 10-6 which exceeds the risk limit of 1 x 10-6 per year -as defined in the standardization policy in the Netherlands for a single source of ionizing radiation-with a factor 15 (1- 44). Reduction of exposure is only possible in the indoor environment. Several techniques have been described to reduce the indoor dose, resulting from exhalation of the soil and building materials. )aut- hor). 37 refs.; 3 figs.; 8 tabs

  12. “Deposition-flux to lung dose” – a new approach in radon inhalation dosimetry using wire-mesh capped direct radon progeny sensor

    International Nuclear Information System (INIS)

    Assigning indoor radon doses to populations based on the widely used, cumulative radon concentration monitoring techniques is beset with errors arising due to uncertain equilibrium factors and unattached fractions. Moreover, the dose conversion factor (DCF) of radon decay products may vary by a factor of ∼40 within the particle size range from ∼0.5 nm to tens of micrometers. An ideal detector should have a response, which closely mimics the strong dependence of the DCF on the particle size. In this context, we propose a new approach in which the doses are computed directly from the time integrated progeny deposition fluxes on a suitably tailored surrogate surface. The deposition on this wire-mesh capped detector system closely mimics the deposition rate in human respiratory tract. The detection unit consists of an optimally designed wire-mesh capped Direct Radon Progeny Sensor (DRPS) system. Of the different wire-mesh types, 100 mesh types were found to be suitable considering the fine and coarse fraction penetration efficiencies. The calibration factor was theoretically derived as 0.0077 {mSv (Tracks cm−2)−1}, for converting the measured atom flux in the 100-mesh capped DRPS system to inhalation dose attributed to radon progeny. - Highlights: • A new approach to compute the doses directly from the progeny deposition fluxes. • The detection unit consists of wire-mesh capped Direct Radon Progeny Sensor (DRPS). • Calibration Factor derived as 0.0077 {mSv (Tracks cm−2)−1}

  13. Gene mutation discovery research of non-smoking lung cancer patients due to indoor radon exposure

    OpenAIRE

    Choi, Jung Ran; Park, Seong Yong; Noh, O Kyu; Koh, Young Wha; Kang, Dae Ryong

    2016-01-01

    Although the incidence and mortality for most cancers such as lung and colon are decreasing in several countries, they are increasing in several developed countries because of an unhealthy western lifestyles including smoking, physical inactivity and consumption of calorie-dense food. The incidences for lung and colon cancers in a few of these countries have already exceeded those in the United States and other western countries. Among them, lung cancer is the main cause of cancer death in wo...

  14. Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

    International Nuclear Information System (INIS)

    The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

  15. Radon progeny distributions inside a diffusion chamber and their contributions to track density in SSNT detectors

    International Nuclear Information System (INIS)

    Diffusion of alpha emitter radon progeny inside a cylindrical diffusion chamber was simulated. In the simulation of atomic movements, we took into account the random nature of the diffusion direction and the decay process. The alpha emitter distributions in volume, lateral wall and top cover of a 6.0cm height diffusion chamber for different diameters were determined. Results show non-uniform distribution of radon progeny. As chamber diameter increases, the tendency of radon progeny is to accumulate in central regions of the chamber volume (218Po) and inner wall (218Po and 214Po). Depending on chamber diameter and detector size, non-uniform distribution of radon progeny deposited on SSNTs surface can be achieved if the detector is horizontally located at the bottom. The fraction of surface where 222Rn progeny are deposited diminishes as chamber diameter increases. Due to the relatively short 218Po half-life, for diameters larger than the assumed height its subsequent atoms decay in air before their deposition on chamber wall. The form in which radon progeny is distributed in volume and walls of chamber can affect the quantity and distribution of tracks in detector

  16. The lung cancer risk from inhalation of radon-222 decay products

    International Nuclear Information System (INIS)

    The results of surveys in the USA and the CSSR on the lung cancer mortality among uranium miners are compared. The relation between the observed excess lung cancer mortality and the cumulative exposure of these miners by inhaled Rn-daughters is discussed and the risk coefficients for radiation-induced lung cancer are estimated. The relative risk coefficients of both study groups of U-miners agree within the confidence limits and are in the range of 0.001 to 0.005 WLM-1. The derived absolute risk coefficients of 20 +- 10 (USA group) and 150 +- 50 (CSSR group) additional lung cancer deaths per WLM and 106 miners are, however, significantly different. The influence of synergistic or cocancerogenic actions is discussed. The increase of lung cancer mortality with Rn-exposure is significantly correlated with an increase of the small-cell, undifferentiated type of carcinoma. (author)

  17. Analysis of the joint effects of radon exposure and smoking on lung cancer risk in three nested case-control studies in Europe

    International Nuclear Information System (INIS)

    Full text: Objectives: Three case-control studies nested in the French (Fr), German (Ge) and Czech (Cz) cohorts of uranium miners were conducted in the frame of a European research Project, named Alpha-Risk, on the quantification of risks associated with multiple radiation exposures. These case-control studies aimed at assessing the effect of protracted radon exposure on lung cancer risk taking into account individual tobacco consumption. Material and methods: In the three case-control studies, cases were miners of the corresponding cohort who died of lung cancer (100, 704, 672 cases for the Fr, Ge and Cz study, respectively). For each case, controls were randomly matched on birth period and attained age at the time of death of the corresponding case (500, 1398 and 1491 controls for the Fr, Ge and Cz study, respectively). Cumulated radon exposure during employment was obtained from ambient and individual measurements for the Fr and Cz studies, and from a job exposure matrix for the Ge study. Smoking habits were retrospectively determined from medical archives and questionnaires applied in face-to-face interviews, phone calls or mailings. Analysis was performed by conditional logistic regression using a linear excess relative risk (ERR) model. A multiplicative model was fitted to assess the joint effect of radon exposure and smoking on lung cancer risk. Results: Smoking status was established for 62, 421, and 672 cases and 320, 620, and 1491 controls for the Fr, Ge, and Cz study, respectively. Two categories ('ever smokers' vs. 'never smokers') were defined. The percentages of 'ever-smokers' were 90%, 95%, and 92% for the cases and 73%, 75%, and 73% for the controls, for the Fr, Ge and Cz study, respectively. Mean five-year lagged cumulated radon exposures were 115, 717 and 174 working level months (WLM) for the cases, and 71, 505 and 118 WLM for the controls, for the Fr, Ge and Cz study, respectively. The excess relative risk per WLM (ERR/WLM) was 0.98% with a 95

  18. Survey of indoor radon concentrations in Fukuoka and Kagoshima prefectures

    International Nuclear Information System (INIS)

    It is now well established that radon and its daughter products account for nearly half of the average population exposure to ionizing radiations and that radon is the greatest single source of natural radiation to the population. Radon and its daughters are alpha-emitters, which are more biologically damaging than beta- and gamma-radiations. A nationwide survey of radon concentration was conducted by the National Institute of Radiological Sciences in order to estimate the contribution of radon and its daughters to the population dose in Japan. Authors surveyed indoor radon concentrations in Fukuoka and Kagoshima prefectures as part of this project. A passive type radon dosimeter, in which a sheet of polycarbonate film as the alpha-ray detector was mounted, was used to measure indoor radon concentrations. The resulting distribution of the average annual indoor radon concentrations in both prefectures can be characterized by an arithmetic mean of 24.4 Bq/m3 and a standard deviation of 13.1 Bq/m3, by a geometric mean of 22.2 Bq/m3, and by a median of 20.7 Bq/m3. The geometric means of the distributions for Fukuoka and Kagoshima were 25.4, and 18.4 Bq/m3, respectively. Radon concentrations were also generally high in winter and low in summer. Regarding the analysis of correlations between the concentrations and construction materials, radon concentrations were generally high in Japanese houses with earthen walls and in concrete structures. These results showed that seasons, the type of building materials, and regional differences were significant factors in the variation of indoor radon concentration. (author)

  19. The influence of biological and aerosol parameters of inhaled short-lived radon decay products on human lung dose

    International Nuclear Information System (INIS)

    The purpose of this article is to assess the influence of biological and aerosol parameters on human lung dose with regard to a comparison with the corresponding recommended dose values of the International Commission on Radiological Protection (ICRP). The dose conversion factor which gives the relationship between effective dose and potential alpha energy concentration of inhaled short-lived radon decay products (218Po, 214Pb, 214Bi/214Po) is calculated with a dosimetric approach. The calculations are based on a lung dose model with a structure that is related to the recently recommended ICRP respiratory tract model. Because of the short half-lives of the investigated nuclides, simplifying modification of the model were possible. Firstly, the underlying assumptions of the model are described. Secondly, important input parameters of the model are varied to assess the uncertainty of the dose conversion factor due to uncertainty of these parameters. The main emphasis is focused on biological and aerosol parameter variability like variation of breathing rate and breathing mode, clearance rates, critical cells for the induction of lung cancer, particle size and dispersion of the activity size distributions. The possible range of dose conversion factors is discussed both for indoor and mine aerosol conditions in the framework of the presented dose model. The investigation shows that the dosimetric approach leads to a dose conversion convention which is a factor of more than two times higher than the recommended epidemiological values of the ICRP of 3.9 mSv.WLM-1 for the public and 5.1 mSv.WLM-1 at working places. The dosimetric results yield both for indoor and mine aerosol conditions dose conversion factors in the range of 10 mSv.WLM-1 to 15 mSv.WLM-1 depending on breathing mode. (author)

  20. The radon; Le radon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    This booklet is intended to answer briefly the most important questions about the nature and sources of radon, its pathways from environment to organism, as well as the ways to minimize its concentration in the habitat's atmosphere. The radon is a naturally appearing radioactive gas, produced through the decay of uranium and radium present in the terrestrial crust. It can be found everywhere on the planet's surface and it is emitted particularly from the granite and volcanic underground rocks as well as from certain construction materials. It is one of the agents producing pulmonary cancer, although not so dangerous as the tobacco is. The following items are elaborated in this booklet: - the place of radon in the average exposure to ionizing radiations of the French population; - the risk; - the radon in the environment (the meteorological conditions, the nature of the rocks); - radon in dwellings (radon measurements in the French dwellings, the entrance pathways of radon, the dependence of radon concentration on the profession and way of life of the inhabitants); - radon measurements; - how to reduce the radon concentration in dwellings.

  1. Use of threshold-specific energy model for the prediction of effects of smoking and radon exposure on the risk of lung cancer

    International Nuclear Information System (INIS)

    Lung cancer is the leading cause of cancer death in both men and women. Smoking causes 80-90 % of cases of lung cancer. In this study, an attempt was made to assess the impact of cigarette smoking on the risk of lung cancer by the so-called threshold-specific energy model. This model allows to analyse the biological effects of radon daughter products on the lung tissue, and is based on the assumption that the biological effect (i.e. cell inactivation) will manifest itself after the threshold-specific energy z0 deposited in the sensitive volume of the cell is exceeded. Cigarette smoking causes, among others, an increase in the synthesis of the surviving protein that protects cells from apoptosis and thereby reduces their radiosensitivity. Based on these facts, an attempt was made to estimate the shape of the curves describing the increase in the oncological effect of radiation as a function of daily cigarette consumption. (authors)

  2. Study of radon exhalation rate from different types of building construction materials using SSNTDds and estimation of lung cancer risk

    International Nuclear Information System (INIS)

    Uranium is a radiotoxic element found in trace quantities in almost all naturally occurring materials like soil, rock and sand etc. Building materials are derived from these materials. Radon, an inert radioactive gas whose predecessor is uranium is emitted from soil beneath the house and from building materials. Building materials are the main source of radon inside the dwellings. Because of low level of radon emanation from these materials, long term measurements are needed. Can technique using LR-115 type II solid state nuclear track detector has been employed for the measurement of radon activity and radon exhalation rate from a number of building materials commonly used for construction in Kerala. Radon activity is found to vary from 75.0 to 2212.7 Bqm-3 with an average value of 477.7 Bqm-3, radon exhalation rate from 44.0 to 1337.7 mBqm-2h-1 with an average value of 286.3 mBqm-2h-1 and effective dose equivalent from 5.2 to 157.7 μSv y-1 with an average value 33.7 μSv y-1 for different building construction materials. Radon emanation from granite is found to be maximum while cement brick (hollow) and Kadappa stone give minimum radon emanation. In the case of plastered bricks covered with sealants, radon exhalation is found to increase slightly with acrylic exterior and acrylic emulsion while it decreases with others. (author)

  3. Comparison of urinary excretion of radon from the human body before and after radon bath therapy

    International Nuclear Information System (INIS)

    Theoretically, the human body absorbs radon through the lungs and the skin and excretes it through the lungs and the excretory organs during radon bath therapy. To check this theory, the radon concentrations in urine samples were compared before and after radon bath therapy. During the therapy, the geometric mean (GM) and the geometric standard deviation of the radon concentration in air and in the bath water were 979 Bq m-3, 1.58 and 73.6 Bq dm-3, 1.1, respectively. Since radon was detected in each urine sample (GM around 3.0 Bq dm-3), urinary excretion of radon was confirmed. The results of this study can neither reject nor confirm the hypothesis of radon absorption through the skin. A 15 times higher increment of inhaled radon level did not cause significant changes in radon of urine samples. (authors)

  4. A creeping suspicion about radon

    International Nuclear Information System (INIS)

    Who would expect an odorless, invisible gas that occurs nearly everywhere on earth to cause such trouble? Yet radon, the gas emitted by decay of uranium in the earth's crust, is one of America's most significant environmental risks, according to the EPA, which estimates that residential radon levels lead to approximately 13,600 lung cancer deaths each year. A new National Cancer Institute analysis of multiple studies of miners confirms early estimates, putting the number at 15,000. No other risk comes close, not even environmental tobacco smoke, which is estimates to cause some 3,000 deaths each year. Hot debate surrounds the assessment of risk from radon exposure to Americans via indoor air and water supplies. The primary culprit is not radon gas itself, but its decay products, including polonium-214 and polonium-218, which have long half-lives and emit alpha particles - positively charged particles - and lung cancer when inhaled. Radon seeps into homes from the ground or is present in water supplies. Waterborne radon may be inhaled as radon or its progeny during household use - cooking or showering - or it may be ingested. But the EPA estimates that water sources contribute only about 5% of total airborne radon exposure, leaving indoor air as the worst offender. While the EPA estimates that approximately 200 cancer cases per year result from exposure to radon from public groundwater systems, estimates of annual lung cancer deaths from indoor air radon range from 7,000 to 30,000

  5. Sequence analysis of laci mutations obtained from lung cells of radon-exposed big blue{trademark} transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Layton, A.D.; Cross, F.T.; Steigler, G.L.; Stillwell, L.S.; Jostes, R.F. [Pacific Northwest Laboratory, Richland, WA (United States); Lutze, L.H. [Univ. of California, San Francisco, CA (United States)

    1994-12-31

    We have exposed Big Blue{trademark} transgenic mice by inhalation to 320, 640 and 960 Working Level Months (WLM) of radon progeny. Mice were sacrificed after 3, 6 and 9 days; the time periods required to obtain the exposures. Control mice were also sacrificed at each time interval. In each case all tissues were excised, flash frozen in liquid nitrogen, and stored at -80{degrees}C for further analysis. Twelve lacI mutations have been isolated from the lung tissue of a mouse from the 960-WLM exposure group; the lacI genes from these mutants have been sequenced. Sequence data indicate that three of the mutants have a C;G deletion at BP 978 and are possibly clonal in origin. Two mutants have multiple events within the gene: one has a an A:T to C:G transversion and a C:G insertion separated by 291 BPs; the second has a G:C to A:T transition as well as an A:T deletion followed by 6 base pairs downstream by a T:A insertion. Other mutations include a single G:C to A:T transition, a two base pair deletion, and a C:G to T:A transition. Mutant plaques are being evaluated from individual mice at other dose levels. Time course experiments are also planned. These studies will help define the molecular fine structure of mutations induced by high-LET radiation exposure.

  6. Sequence analysis of laci mutations obtained from lung cells of radon-exposed big blue trademark transgenic mice

    International Nuclear Information System (INIS)

    We have exposed Big Blue trademark transgenic mice by inhalation to 320, 640 and 960 Working Level Months (WLM) of radon progeny. Mice were sacrificed after 3, 6 and 9 days; the time periods required to obtain the exposures. Control mice were also sacrificed at each time interval. In each case all tissues were excised, flash frozen in liquid nitrogen, and stored at -80 degrees C for further analysis. Twelve lacI mutations have been isolated from the lung tissue of a mouse from the 960-WLM exposure group; the lacI genes from these mutants have been sequenced. Sequence data indicate that three of the mutants have a C;G deletion at BP 978 and are possibly clonal in origin. Two mutants have multiple events within the gene: one has a an A:T to C:G transversion and a C:G insertion separated by 291 BPs; the second has a G:C to A:T transition as well as an A:T deletion followed by 6 base pairs downstream by a T:A insertion. Other mutations include a single G:C to A:T transition, a two base pair deletion, and a C:G to T:A transition. Mutant plaques are being evaluated from individual mice at other dose levels. Time course experiments are also planned. These studies will help define the molecular fine structure of mutations induced by high-LET radiation exposure

  7. Effect of chronic smoking and radon exposure on the risk of lung cancer

    International Nuclear Information System (INIS)

    Smoking may change the morphological and physiological parameters of lungs. The mucus layer can be up to five times thicker in smokers than in non-smokers and thus protect the target cells from ionizing radiation. On the other hand, mucociliary clearance is impaired in heavy long-term smokers, due to which the radiation doses are up to twice as high in such smokers than in non-smokers. The primary objective of the present study was to quantify the impacts of the above factors on the risk of lung cancer development. (orig.)

  8. A preliminary radon map for Canada according to health region

    International Nuclear Information System (INIS)

    The recent publications of the combined analyses of residential radon studies in Europe and North America have shown that there is a significant risk of lung cancer at residential radon levels. In order to assess the population risk due to radon, the knowledge of the spatial distribution of indoor radon levels is essential. Here a preliminary radon map for Canada is presented, based on historical radon measurements collected in 6016 locations across Canada with the health region as the basic geographic units. (authors)

  9. Molecular analysis of the Ink4a/Rb1-Arf/Tp53 pathways in radon-induced rat lung tumors

    International Nuclear Information System (INIS)

    Inhalation of radon is closely associated with an increased risk of lung cancers. While the involvement of Ink4a in lung tumor development has been widely described, the tumor suppressor gene has not been studied in radon-induced lung tumors. In this study, loss of heterozygosity (LOH) analysis of the Cdkn2a locus, common to the Ink4a and Arf genes, was performed on 33 radon-induced rat lung tumors and showed a DNA loss in 50% of cases. The analysis of p16Ink4a protein expression by immunohistochemistry revealed that 50% of the tumors were negative for this protein. Looking for the origin of this lack of expression, we observed a low frequency of homozygous deletion (6%), a lack of mutation, an absence of correlation between promoter methylation and Ink4a mRNA expression and no correlation between LOH and protein expression. However, a tendency for an inverse correlation between p16Ink4a and pRb protein expression was observed. The expressions of p19Arf, Mmd2 and Mdm4 were not deregulated and only 14% of the tumors were mutated for Tp53. These results indicated that Ink4a/Cdk4/Rb1 pathway deregulation, more than Arf/Mdm2/Tp53 pathway, has a major role in the development of these tumors through p16Ink4a deregulation. However, all known mechanisms of inactivation of the pathway do not play a recurrent role in these tumors and the actual origin of the lack of p16Ink4a protein expression remains to be established. (author)

  10. The French cohort of uranium miners: Analysis of lung cancer risk linked to radon exposure in a population exposed to relatively low concentration over a long duration

    International Nuclear Information System (INIS)

    In France, about 5,000 miners have been employed in uranium mining industry since 1946. Most of these miners have experienced relatively low annual exposures in comparison to other cohorts of miners. Consequently, the hypothesis to be tested in our study was the potential risk of cancer in a relatively low exposed population, characterised by a long period of underground work. A first analysis of the ''oldest'' cohort (1,785 miners having worked underground before 1972) has been published in 1993, based on a follow-up to December 1985. Recently, this follow-up has been extended up to 1994. Compared to the first analysis, the size of the cohort has increased by 24 %, and the number of lung cancer deaths has increased by about 90 % (from 45 to 85 deaths). Mean cumulated exposure to radon is of 71.5 WML, protracted over more than 15 years. After 1956, radon exposure is lower than 2 WLM/year for 50 % of the miners. The Standardised Mortality Ratio for lung cancer is 1.65, with confidence interval CI95% = [1.3-2.0]. The Excess Relative Risk coefficient for lung cancer with cumulated exposure to radon is ERR/WLM 0.40 % (p = 0.05). This estimate is very similar to the one obtained in the first analysis. The contribution of this population to the estimation of the risk coefficient of lung cancer, in relation to low dose-rates and low cumulative exposure is far from negligible. Enlargement of the French cohort exposed after 1956 is ongoing. Moreover a European joint analysis of cohorts with low levels of exposure rates (French, Czech and German cohorts) will be performed in a near future. (author)

  11. Measuring your radon risk

    International Nuclear Information System (INIS)

    In its annual report for 1992/93, the NRPB has warned that tens of thousands of UK employees may be exposed to high levels of radon at work. In addition to those who work underground, employees at risk of radon-induced lung cancer are typically those who spend long periods indoors. This article reviews the implications for all employers especially those in low or unknown levels of radon who resist taking measurements in the belief that by not measuring, they are not liable. (UK)

  12. Indoor radon; Le radon dans les batiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies.

  13. Modelling lung cancer due to radon and smoking in WISMUT miners: Preliminary results

    International Nuclear Information System (INIS)

    A mechanistic two-stage carcinogenesis model has been applied to model lung-cancer mortality in the largest uranium-miner cohort available. Models with and without smoking action both fit the data well. As smoking information is largely missing from the cohort data, a method has been devised to project this information from a case-control study onto the cohort. Model calculations using 256 projections show that the method works well. Preliminary results show that if an explicit smoking action is absent in the model, this is compensated by the values of the baseline parameters. This indicates that in earlier studies performed without smoking information, the results obtained for the radiation parameters are still valid. More importantly, the inclusion of smoking-related parameters shows that these mainly influence the later stages of lung-cancer development. (authors)

  14. Radon - The management of the risk related to radon

    International Nuclear Information System (INIS)

    This leaflet briefly explains what radon is, where it comes from, and what it becomes. It indicates and briefly comments its concentrations in French departments, describes how radon can affect our health (lung cancer), describes how the risk can be reduced in buildings, and indicates the existing regulatory provisions

  15. Radon Research Program, FY 1992

    International Nuclear Information System (INIS)

    The United States Department of Energy, Office of Health and Environmental Research (DOE/OHER) is the principal federal agency conducting basic research related to indoor radon. The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. There still remains a significant number of uncertainties in the currently available knowledge that is used to estimate lung cancer risk from exposure to environmental levels of radon and its progeny. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny and to identify and understand biological mechanisms of lung cancer development and required copollutants at low levels of exposure. Information useful in radon control strategies is also provided by the basic science undertaken in this program

  16. The health risk of radon

    International Nuclear Information System (INIS)

    Although radon is the second leading cause of lung cancer in the United States, second only to cigarette smoking, many members of the public are not aware that radon is one of the most serious environmental cancer risks in the US. Based on extensive data from epidemiological studies of underground miners, radon has been classified as a known human carcinogen. In contrast to most pollutants, the assessment of human risk from radon is based on human occupational exposure data rather than animal data. That radon causes lung cancer has been well established by the scientific community. More is known about radon than most other cancer causing environmental carcinogens. While there are some uncertainties involved when estimating radon risk to the public, it is important to recognize that the risk information is based on human data and that the uncertainties have been addressed in the risk assessment. The US Environmental Protection Agency (EPA) estimates that the number of annual US lung cancer deaths due to residential radon exposures is approximately 14,000 with an uncertainty range of 7,000 to 30,000. The abundant information on radon health risks that supports EPA's risk assessment indicates that recommendations for public action by the federal government and other public health organizations constitute prudent public policy

  17. Radon dosimetry based on the depth distribution of nuclei in human and rat lungs

    International Nuclear Information System (INIS)

    Calculation of the absorbed dose by different lung cells is necessary for predicting the critical cells that are subject to injury from inhaled Rn and other alpha-particle sources. The absorbed dose was determined for cells in the airways of human and rat lungs, based on airway epithelial thickness and on cell cytoplasm and nuclear volume density as a function of depth from the luminal surface of the airway epithelium. The thickness of the stratified columnar epithelium of human airways varied from 57.8 micron in bronchi to 9.8 microns in bronchioles. The cell populations of all bronchi in human lungs were comparable. The cell populations of trachea and intrapulmonary airways in rats, however, were significantly different. Basal cell populations in rat trachea and human bronchi were similar and formed a nearly continuous layer. In rat bronchi, basal cells were not present in significant numbers. Measurements of epithelial thickness and volume density were used to estimate the absorbed dose for an alpha-particle source (214Po or 218Po) distributed uniformly in the mucus with an equivalent activity of 1 dpm per cm2 of epithelial surface. The following model predictions of dose to human bronchial epithelial cell nuclei for a 218Po alpha-particle source are provided in units of nanogray (nGy) for specific cell types: secretory 158, preciliated 114, ciliated 44, goblet 86, basal 78, and indeterminate cell nuclei 73. The absorbed dose to specific types of rat bronchial epithelial cell nuclei was also predicted: secretory 237, precillated 216, ciliated 203, goblet 204, basal 200, and indeterminate cell nuclei 166 nGy. These and other results indicate that human and rat airway dosimetry have significant differences that may contribute to the differences in cancer cell induction between the two species

  18. Radon - The management of the risk related to radon; Le radon la gestion du risque lie au radon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This leaflet briefly explains what radon is, where it comes from, and what it becomes. It indicates and briefly comments its concentrations in French departments, describes how radon can affect our health (lung cancer), describes how the risk can be reduced in buildings, and indicates the existing regulatory provisions

  19. Radon Research Program, FY 1991

    International Nuclear Information System (INIS)

    The scientific information being sought in this program encompasses research designed to determine radon availability and transport outdoors, modeling transport into and within buildings, physics and chemistry of radon and radon progeny, dose response relationships, lung cancer risk, and mechanisms of radon carcinogenesis. The main goal of the DOE/OHER Radon Research Program is to develop information to reduce these uncertainties and thereby provide an improved health risk estimate of exposure to radon and its progeny as well as to provide information useful in radon control strategies. Results generated under the Program were highlighted in a National Research Council report on radon dosimetry. The study concluded that the risk of radon exposure is 30% less in homes than in mines. This program summary of book describes the OHER FY-1991 Radon Research Program. It is the fifth in an annual series of program books designed to provide scientific and research information to the public and to other government agencies on the DOE Radon Research Program

  20. Radon and energy efficient homes

    International Nuclear Information System (INIS)

    Radon and its daughters in indoor air are presently responsible for dose equivalents of about 31 mSv/year (3 rem/year) to parts of the respiratory tract. Linear extrapolation from the dose response values of uranium miners heavily exposed to radon and its decay products would suggest that almost all lung cancers in the non-smoking population are caused by environmental 222Rn. Using epidemiological data on the types of lung cancer found in non-smokers of the general public as compared to the miners, a smaller effect of low level radon exposure is assumed, which would result in a lung cancer mortality rate due to radon of about 10 deaths per year and million or 25% of the non-smoker rate. Higher indoor radon concentrations in energy efficient homes mostly caused by reduced air exchange rates will lead to a several fold increase of the lung cancer incidence from radon. Based on the above assumption, about 100 additional lung cancer deaths/year-million will result both from an increase in radionuclide concentrations in indoor air and a concomitant rise in effectiveness of radiation to cause cancer with higher exposure levels. Possibilities to reduce indoor radon levels in existing buildings and costs involved are discussed. (Auth.)

  1. Alpha-risk or quantification of risks associated with chronic exposure to Alpha emitters; Alpha-risk ou la quantification du risque associe a une exposition chronique aux emeteurs ALPHA

    Energy Technology Data Exchange (ETDEWEB)

    Timarche, M. [Institut de Radioprotection et de Surete Nucleaire, DS, 92 - Fontenay-aux-Roses (France)

    2010-07-15

    This article discusses the results obtained by a European research program on long term health risks associated with a chronic internal contamination by alpha radiation emitters. The researchers outlined that, in the case of an exposure to radon, the lung cancer risk, with respect to the cumulative dose, progressively reduces once the exposure has stopped. They also notice that this risk is present for smokers as well as for not smokers

  2. [Initiation, promotion, initiation experiments with radon and cigarette smoke: Lung tumors in rats]. Progress report

    International Nuclear Information System (INIS)

    During the past several years, the authors have made considerable progress in modeling carcinogenesis in general, and in modeling radiation carcinogenesis, in particular. They present an overview of their progress in developing stochastic carcinogenesis models and applying them to experimental and epidemiologic data sets. Traditionally, cancer models have been used for the analysis of incidence (or prevalence) data in epidemiology and time to tumor data in experimental studies. The relevant quantities for the analysis of these data are the hazard function and the probability of tumor. The derivation of these quantities is briefly described here. More recently, the authors began to use these models for the analysis of data on intermediate lesions on the pathway to cancer. Such data are available in experimental carcinogenesis studies, in particular in initiation and promotion studies on the mouse skin and the rat liver. If however, quantitative information on intermediate lesions on the pathway to lung cancer were to be come available at some future date, the methods that they have developed for the analysis of initiation-promotion experiments could easily be applied to the analysis of these lesions. The mathematical derivations here are couched in terms of a particular two-mutation model of carcinogenesis. Extension to models postulating more than two mutations is not always straightforward

  3. Study of radon, thoron and toxic elements in some textile dyes

    International Nuclear Information System (INIS)

    Elemental analysis of textile dyes may provide valuable information concerning the content and concentrations of element, especially the toxic ones. Such information monitors the safety of handling and using these dyes in textile industry. In addition to the safety of wearing of clothes stained with these dyes. In the present work, the specific activity of both radon and thoron were measured in nine textile dyes by using alpha emitters registration which are emitted from radon and thoron gases in CR-39 nuclear track detectors. Unexpectedly, the results obtained reports a high concentration of both radon and thoron gases in some samples (samples D5 and D9). Also the concentration of toxic elements (Cu, Pb, Zn, Mn, Cd and Cr) in textile dyes were determined by flame and graphite furnace atomic absorption spectrometry. (author)

  4. Constitution of a group of Czech and French uranium miners in order to estimate lung cancer risk linked to low chronic exposure to radon decay products

    International Nuclear Information System (INIS)

    West Bohemian and French uranium miners are characterized by a long duration of exposure to radon and its decay products, in comparison to most of the other groups of miners, studied in the recent international joint analysis by the National Cancer Institute (NCI) in USA. This analysis has confirmed the linearly increasing risk of lung cancer by cumulative radon exposure, describing the different factors that may influence this dose-response relationship. One of the main factors presently discussed is the influence of the exposure-rate effect: in other words, has the same cumulated exposure spread over 10 years the same risk of lung cancer as if it is cumulated in 2 years? The implication of an inverse exposure-rate effect for low chronic exposures as well as some methodological approaches will be discussed and tested by using the data of the Czech and French cohorts. These two cohorts present annual exposures varying by a factor of 5 to 10, French exposure rates being close or even less than 0.1 Working Level during the last 20 years. The project is integrated in a larger European project on uranium miners, co-ordinated by IPSN. (author)

  5. An overview of Ireland's National Radon Policy

    International Nuclear Information System (INIS)

    In Ireland radon is a significant public health issue and is linked to 150-200 lung cancer deaths each year. Irish National Radon Policy aims to reduce individual risk by identifying and remediating buildings with high radon concentrations and also to reduce collective dose through radon prevention as required by revised building regulations. Achievements to date are significant and include the completion of the National Radon Survey, the testing of every school in Ireland, the on-going testing of social housing, collaboration between the public health and radiation protection authorities and the inclusion of radon in inspections of workplaces. However, this work now needs to be drawn together centrally to comprehensively address the radon problem. The RPII and the relevant central governing department, the Dept. of Environment, Heritage and Local Government are currently working to constitute a group of key experts from relevant public authorities to drive the development of a National Radon Control Strategy. (authors)

  6. Radon in homes

    International Nuclear Information System (INIS)

    Radon 222 and its radioactive decay products can enter buildings and, through inhalation, expose the inhabitants' pulmonary tissues to ionizing radiation. Studies of radon levels in the US indicate that variations of 100-fold or greater exist among private dwellings. In one region, 55% of homes had levels exceeding 4 pCi/L (0.15 Bq/L), which is the guidance level recommended by the US Environmental Protection Agency. Ventilation and tightness of construction are important determinants of radon levels. In some instances, fans or heat exchangers can reduce excessive concentrations, but in others more elaborate remedial measures may be required. Physicians may obtain information about radon through Environmental Protection Agency regional offices and state radiation control programs. The risk of radiogenic cancer is believed to increase with exposure to ionizing radiation. According to some estimates, concentrations of radon decay products in US homes could be responsible for several thousand cases of lung cancer per year. Studies of radon levels in representative buildings and guidelines are needed to ensure safe, effective, and cost-effective counter-measures. Architects, contractors, designers, building code administrators, health physicists, and biomedical investigators can help with solutions

  7. Radon: radiation aspects of residential hygiene

    International Nuclear Information System (INIS)

    The article attempts to outline the role that radon plays in the radiation hygiene of the living environment. The natural occurrence of 222Rn and the internal irradiation doses caused by the daughter products are discussed. The induction of lung cancer in various groups of mine workers exposed to radon and radon daughter products is considered and the factors affecting the concentration of radon in buildings, particularly houses, are presented. A number of case studies concerning the occurrence of radon in dwellings in different countries, are outlined. (C.F.)

  8. Radon overview

    International Nuclear Information System (INIS)

    This tutorial presents the history of the radon industry, currently-used testing and mitigation techniques and future private industry and governmental plans. The significance of radon for homeowners, realtors and the construction industry is discussed. As a result of this tutorial, participants will: (1) Know how we became aware of the radon problem; (2) Learn what private industry and government officials are doing about it; (3) Understand the implications of radon for homeowners, realtors, builders and weatherization professionals

  9. Radon campaigns. Status report 2008

    International Nuclear Information System (INIS)

    Radon campaigns aim at activating citizens to make indoor radon measurements and remediation as well as increasing the common awareness of indoor radon questions. Indoor radon increases the risk of lung cancer. Through radon campaigns Radiation and Nuclear Safety Authority (STUK) also promotes the attainment of those goals that the Ministry of Social Affairs and Health has set for municipal authorities in Finland for prevention of the harmful effects of radon. The Ministry of Social Affairs and Health supports this campaign. Radon campaigns were started in autumn 2003. By autumn 2008 the campaigns have been organised already in 64 regions altogether in 160 municipalities. In some municipalities they have already arranged two campaigns. Altogether 14 100 houses have been measured and in 2 100 of these the action limit of radon remediation 400 Bq / m3 has been exceeded. When participating in radon campaigns the house owners receive a special offer on radon detectors with a reduced price. In 2008 a new practice was introduced where the campaign advertisements were distributed by mail to low-rise residential houses in a certain region. The advertisement includes an order / deposit slip with postage paid that the house owner can send directly to STUK to easily make an order for radon measurement. In the previous radon campaigns in 2003 - 2007 the municipal authorities collected the orders from house owners and distributed later the radon detectors. The radon concentrations measured in the campaign regions have exceeded the action limit of 400 Bq / m3 in 0 - 39% of houses, depending on the region. The total of 15% of all measurements made exceeded this limit. The remediation activities have been followed by sending a special questionnaire on remedies performed to the house owners. In 2006 - 2007 a questionnaire was sent to those households where the radon concentration of 400 Bq / m3 was exceeded during the two first campaign seasons. Among the households that replied

  10. No evidence for Population III stars or a Direct Collapse Black Hole in the z = 6.6 Lyman-$\\alpha$ emitter 'CR7'

    CERN Document Server

    Bowler, R A A; Dunlop, J S; McLeod, D J; Stanway, E R; Eldridge, J J; Jarvis, M J

    2016-01-01

    The z = 6.6 Lyman-$\\alpha$ emitter 'CR7' has been claimed to have a Population III-like stellar population, or alternatively, be a candidate Direct Collapse Black Hole (DCBH). In this paper we investigate the evidence for these exotic scenarios using recently available, deeper, optical, near-infrared and mid-infrared imaging. We find strong Spitzer/IRAC detections for the main component of CR7 at 3.6 and 4.5 microns, and show that it has a blue colour ([3.6] - [4.5] $= -1.2\\pm 0.3$). This colour cannot be reproduced by current Pop. III or pristine DCBH models. Instead, the results suggest that the [3.6] band is contaminated by the [OIII]4959,5007 emission line with an implied rest-frame equivalent width of EW_0 (H$\\beta$ + [OIII]) $\\gtrsim 2000$\\AA. Furthermore, we find that new near-infrared data from the UltraVISTA survey supports a weaker He II 1640 emission line than previously measured, with EW_0 $= 40 \\pm 30$\\AA. For the fainter components of CR7 visible in Hubble Space Telescope imaging, we find no evi...

  11. A Dual Narrowband Survey for H\\alpha\\ Emitters at z=2.2: Demonstration of the Technique and Constraints on the H\\alpha\\ Luminosity Function

    CERN Document Server

    Lee, Janice C; Spitler, L; Labbe, I; Salim, S; Persson, S E; Ouchi, M; Dale, D; Monson, A; Murphy, D

    2012-01-01

    We present first results from a narrowband imaging program for intermediate redshift emission-line galaxies using the newly commissioned FourStar infrared camera at the 6.5m Magellan telescope. To enable prompt identification of H\\alpha\\ emitters, a pair of custom 1% filters, which sample low-airglow atmospheric windows at 1.19 \\mu m and 2.10 \\mu m, is used to detect both H\\alpha\\ and [OII]\\lambda 3727 emission from the same redshift volume at z=2.2. Initial observations are taken over a 130 arcmin^2 area in the CANDELS-COSMOS field. The exquisite image quality resulting from the combination of the instrument, telescope, and standard site conditions (~0.55" FWHM) allows the 1.19 \\mu m and 2.10 \\mu m data to probe 3\\sigma\\ emission-line depths down to 1.0e-17 erg/s/cm^2 and 1.2e-17 erg/s/cm^2 respectively, in less than 10 hours of integration time in each narrowband. For H\\alpha\\ at z=0.8 and z=2.2, these fluxes correspond to observed star formation rates of ~0.3 and ~4 Msun/yr respectively. We find 122 source...

  12. The Subaru FMOS Galaxy Redshift Survey (FastSound). I. Overview of the Survey Targeting on H$\\alpha$ Emitters at $z \\sim 1.4$

    CERN Document Server

    Tonegawa, Motonari; Okada, Hiroyuki; Akiyama, Masayuki; Dalton, Gavin; Glazebrook, Karl; Iwamuro, Fumihide; Maihara, Toshinori; Ohta, Kouji; Shimizu, Ikkoh; Takato, Naruhisa; Tamura, Naoyuki; Yabe, Kiyoto; Bunker, Andrew J; Coupon, Jean; Ferreira, Pedro G; Frenk, Carlos S; Goto, Tomotsugu; Hikage, Chiaki; Ishikawa, Takashi; Matsubara, Takahiko; More, Surhud; Okumura, Teppei; Percival, Will J; Spitler, Lee R; Szapudi, Istvan

    2015-01-01

    FastSound is a galaxy redshift survey using the near-infrared Fiber Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope, targeting H$\\alpha$ emitters at $z \\sim 1.18$--$1.54$ down to the sensitivity limit of H$\\alpha$ flux $\\sim 2 \\times 10^{-16} \\ \\rm erg \\ cm^{-2} s^{-1}$. The primary goal of the survey is to detect redshift space distortions (RSD), to test General Relativity by measuring the growth rate of large scale structure and to constrain modified gravity models for the origin of the accelerated expansion of the universe. The target galaxies were selected based on photometric redshifts and H$\\alpha$ flux estimates calculated by fitting spectral energy distribution (SED) models to the five optical magnitudes of the Canada France Hawaii Telescope Legacy Survey (CFHTLS) Wide catalog. The survey started in March 2012, and all the observations were completed in July 2014. In total, we achieved $121$ pointings of FMOS (each pointing has a $30$ arcmin diameter circular footprint) covering $20.6...

  13. The First Systematic Survey for Lyman Alpha Emitters at z=7.3 with Red-sensitive Subaru/Suprime-Cam

    CERN Document Server

    Shibuya, Takatoshi; Ota, Kazuaki; Iye, Masanori; Ouchi, Masami; Furusawa, Hisanori; Shimasaku, Kazuhiro; Hattori, Takashi

    2011-01-01

    We have performed deep imaging surveys for Lyman Alpha emitters (LAEs) at redshift ~ 7.3 in two blank fields, the Subaru Deep Field (SDF) and the Subaru/XMM-Newton Deep Field (SXDF), using the Subaru/Suprime-Cam equipped with new red-sensitive CCDs and a new narrow-band filter, NB1006 (lambda_c=10,052A, FWHM=214A). By comparing the NB1006 magnitudes of detected objects with those at other shorter wavelength bands, we identified four objects as LAE candidates that exhibit luminosity excess in NB1006. By carrying out deep follow-up spectroscopy for three of them using Subaru/FOCAS and Keck/DEIMOS, a definitively asymmetric emission line is detected for one of them, SXDF-NB1006-2. Assuming this line is LyA, this object is a LAE at z=7.215 which has luminosity of 1.2^{+1.5}_{-0.6} x 10^{43} erg s-1, star formation rate (SFR) of 11 Mo yr-1 estimated from the LyA emission line, and a weighted skewness S_w = 4.90+-0.86. Another object, SDF-NB1006-2, shows variable photometry and is thus probably a quasar (QSO) or an...

  14. Kiloparsec Mass/Light Offsets in the Galaxy Pair-Lyman-alpha Emitter Lens System SDSS\\,J1011$+$0143

    CERN Document Server

    Shu, Yiping; Moustakas, Leonidas A; Stern, Daniel; Dey, Arjun; Brownstein, Joel R; Burles, Scott; Spinrad, Hyron

    2016-01-01

    We report the discovery of significant mass/light offsets in the strong gravitational lensing system SDSS\\,J1011$+$0143. We use the high-resolution \\textsl{Hubble Space Telescope} (\\textsl{HST}) F555W- and F814W-band imaging and SDSS spectroscopy of this system, which consists of a close galaxy pair with a projected separation of $\\approx 4.2$ kpc at $z_{\\rm lens} \\sim 0.331$ lensing a Lyman-alpha emitter (LAE) at $z_{\\rm source} = 2.701$. Comparisons between the mass peaks inferred from lens models and light peaks from \\textsl{HST} imaging data reveal significant spatial mass/light offsets as large as $(1.72 \\pm 0.24 \\pm 0.34)$ kpc in both filter bands. Such large mass/light offsets, not seen in isolated field lens galaxies and relaxed galaxy groups, may be related to the interactions between the two lens galaxies. The detected mass/light offsets can potentially serve as an important test for the self-interacting dark matter model. However, other mechanisms such as dynamical friction on spatially differently...

  15. A hard ionizing spectrum in z=3-4 Ly-alpha emitters with intense [OIII] emission: Analogs of galaxies in the reionization era?

    CERN Document Server

    Nakajima, Kimihiko; Iwata, Ikuru; Inoue, Akio; Kusakabe, Haruka; Ouchi, Masami; Robertson, Brant

    2016-01-01

    We present Keck/MOSFIRE spectra of the diagnostic nebular emission lines [OIII]5007,4959, [OII]3727, and H-beta for a sample of 15 redshift z=3.1-3.7 Ly-alpha emitters (LAEs) and Lyman break galaxies (LBGs). In conjunction with spectra from other surveys, we confirm earlier indications that LAEs have a much higher [OIII]/[OII] line ratio than is seen in similar redshift LBGs. By comparing their distributions on a [OIII]/[OII] versus R23 diagram, we demonstrate that this difference cannot arise solely because of their lower metallicities but most likely is due to a harder ionizing spectrum. Using measures of H-beta and recombination theory, we demonstrate, for a subset of our LAEs, that xi_ion - the number of Lyman continuum photons per UV luminosity - is indeed 0.2-0.5 dex larger than for typical LBGs at similar redshifts. Using photoionization models we estimate the effect this would have on both [OIII]/[OII] and R23 and conclude such a hard spectrum can only partially explain such intense line emission. The...

  16. Quality assurance exercise for estimating radiochemical recovery and low-levels of alpha emitters in urine samples: performance of Health Physics Laboratory, Tarapur

    International Nuclear Information System (INIS)

    As a part of quality assurance, Health Physics Laboratory took part in National inter-comparison exercise organized by Internal Dosimetry Section (IDS), BARC, Trombay for estimating radiochemical recovery of 232U, 242Pu and low-levels of alpha emitter such as 239Pu, 238U and 234U in five urine samples coded D1, D2, D3, D4 and D5. In this paper, performance of Health Physics Laboratory in the inter-comparison exercise is presented. The results submitted by Health Physics laboratory were found to be in good agreement with the organizer's (spiked) values. Nearly 6 laboratories from India participated in this inter-comparison exercise. The samples received, sample pre-concentration, radiochemical separation and alpha activity quantification procedure followed and the results obtained were reported to Head, IDS, BARC, Trombay within stipulated time. The radiochemical analysis of U-isotopes and Pu-isotopes in bioassay samples has been carried out by standardized analytical procedures

  17. Effects of radon in indoor air studied

    International Nuclear Information System (INIS)

    Radon is an odorless, tasteless and colourless radioactive noble gas that enters indoor air from the ground. Radon causes lung cancer. A committee set up to evaluate the health risks of chemical substances has been drafting a report on radon, which will compile the major research findings on the lung cancer risk posed by radon. Animal tests have shown that even small doses of radon can cause lung cancer. Smokers seem to contract radon-induced lung cancer more readily than non-smokers. Because research findings have been conflicting, however, it is not known exactly how high the risk of lung cancer caused by indoor radon exposure really is. Several major research projects are under way to obtain increasingly accurate risk assessments. An on-going European joint project brings together several studies - some already finished, some still being worked on. In this way it will be possible to get more accurate risk assessments than from individual studies. In order to prevent lung cancer, it is important to continue the work of determining and reducing radon connects and to combat smoking. (orig.)

  18. Radon and lung cancer: protocol and procedures of the multicentre studies in the Ardennes-Eifel region, Brittany and the Massif Central region

    International Nuclear Information System (INIS)

    As part of a European coordinated project, the Ardennes-Eifel study was set up. In this project the study area coincides more or less with a geological zone, situated partly in France, Belgium, Luxembourg and Germany. In a first phase, a common protocol was worked out, dealing with general items as the selection of cases and (hospital/community) controls, the residential criteria for inclusion in the study and the specifications of the radon measurements. Much attention was given to the disease for the hospital controls and a list of ineligible diseases, most strongly related to tobacco, was agreed upon. A common core questionnaire is used, including items such as residential history since birth, occupational history, exposure to passive smoke (for non-smokers and occasional smokers) and educational attainment of the partner. Each country is also free to include additional items of its own. In France, this case-control study is extended to the granitic region of Britanny and in a second period to the region of the Massif Central. In these studies as well as in the national German study on radon and lung cancer, a protocol in all points comparable to that of the Ardennes study is used. (author)

  19. Radon - To mobilise civil society

    International Nuclear Information System (INIS)

    As radon is one of the two main sources of exposure of population to ionizing radiations in France, is notably said to be responsible of 1.000 to 3.000 deaths for lung cancer per year, and could be at the origin of other cancers like child leukaemia, this set of articles evokes the different factors which promote radon transfer from soils to buildings, studies performed to better identify geological sources of radon, actions implemented to assess radon presence in dwellings (distribution of 'radon kits' in Brittany), the performance of radiological expertise by the IRSN on the request of public authorities, the project of dwelling inventory and population information. A second article reports examples of intervention by the IRSN to inform local authorities, inhabitants, academics, public utilities, building professions, and even children. Technical solutions adopted in the United Kingdom are briefly evoked

  20. A review of exposures to radon, long-lived radionuclides and external gamma at the Czech uranium mine

    International Nuclear Information System (INIS)

    This paper presents the results of the personal exposure monitoring conducted in the Ron uranium mine in the Czech Republic. In this mine, which has been operated since the late 1950's, personal ALGADE dosemeters have been used since 1998. A group of 600 miners employed during the period 2000-09 has been analysed. Annual exposures to radon decay products, long-lived alpha emitters and external gamma radiation are described. These components play an essential role in the estimation of the total effective dose. The dependence of the exposures on the type of mining job is also assessed. (authors)

  1. A review of exposures to radon, long-lived radionuclides and external gamma at the Czech uranium mine.

    Science.gov (United States)

    Marušiaková, M; Gregor, Z; Tomášek, L

    2011-05-01

    This paper presents the results of the personal exposure monitoring conducted in the RoŽná uranium mine in the Czech Republic. In this mine, which has been operated since the late 1950s, personal ALGADE dosemeters have been used since 1998. A group of 600 miners employed during the period 2000-09 has been analysed. Annual exposures to radon decay products, long-lived alpha emitters and external gamma radiation are described. These components play an essential role in the estimation of the total effective dose. The dependence of the exposures on the type of mining job is also assessed. PMID:21471123

  2. Results of simultaneous radon and thoron measurements in 33 metropolitan areas of Canada

    OpenAIRE

    Chen, Jing; Bergman, Lauren; Falcomer, Renato; Whyte, Jeff

    2014-01-01

    Radon has been identified as the second leading cause of lung cancer after tobacco smoking. 222Rn (radon gas) and 220Rn (thoron gas) are the most common isotopes of radon. In order to assess thoron contribution to indoor radon and thoron exposure, a survey of residential radon and thoron concentrations was initiated in 2012 with ∼4000 homes in the 33 census metropolitan areas of Canada. The survey confirmed that indoor radon and thoron concentrations are not correlated and that thoron concent...

  3. Cases study of lung cancer deaths and analysis of radon levels in house-room of Mexicali, B. C; Estudio de casos de muertes de cancer pulmonar y analisis de niveles de radon en casas-habitacion de Mexicali, B. C

    Energy Technology Data Exchange (ETDEWEB)

    Lopez B, G.; Reyna C, M. A. [Universidad Autonoma de Baja California, Facultad de Ingenieria, Blvd. Benito Juarez y Calle de la Normal s/n, Col. Insurgentes Este, 21280 Mexicali, Baja California (Mexico)], e-mail: glopezbadilla@yahoo.com

    2009-10-15

    The lung cancer is a case of health of more importance as much in women as in men, with more frequency that the cancer of mamma, colon and prostate on the whole. A factor that influences in the cancer generation originating serious complications it is the exposition to radioactive substances in closed places, as house-room. In the investigation study, levels of radon concentration were measured in interiors of Mexicali homes, to study the relationship that this gas could have with the death cases by lung cancer into population. The gas radon is radioactive and it adheres easily to particles that remain suspended in air; when inhaling them small explosions take place inside the alveoli, changing the DNA of cells and lung cancer is generated. The meteorological, geographical and urban characteristics of Mexicali, favor conditions so that certain areas of the city present high indexes of suspended particles in atmosphere. One sample of gas radon inside 100 house-rooms, the analysis was made by paved and not paved colonies and for sex, to establish if the death cases by lung cancer had relationship with the genus and/or with some of two groups of colonies. The study found that the major number of deaths it was presented in colonies in which lacked the paving service and always happened with more frequency in women; and that in homes of having died by lung cancer the radon concentrations were more high that the homes where there was not death cases, with significant differences that go from 9.2% to 70%. This investigation project is presented as a cases study in the Mexicali City. (Author)

  4. The radon

    International Nuclear Information System (INIS)

    This booklet is intended to answer briefly the most important questions about the nature and sources of radon, its pathways from environment to organism, as well as the ways to minimize its concentration in the habitat's atmosphere. The radon is a naturally appearing radioactive gas, produced through the decay of uranium and radium present in the terrestrial crust. It can be found everywhere on the planet's surface and it is emitted particularly from the granite and volcanic underground rocks as well as from certain construction materials. It is one of the agents producing pulmonary cancer, although not so dangerous as the tobacco is. The following items are elaborated in this booklet: - the place of radon in the average exposure to ionizing radiations of the French population; - the risk; - the radon in the environment (the meteorological conditions, the nature of the rocks); - radon in dwellings (radon measurements in the French dwellings, the entrance pathways of radon, the dependence of radon concentration on the profession and way of life of the inhabitants); - radon measurements; - how to reduce the radon concentration in dwellings

  5. Radon monitoring and hazard prediction in Ireland

    Science.gov (United States)

    Elio, Javier; Crowley, Quentin; Scanlon, Ray; Hodgson, Jim; Cooper, Mark; Long, Stephanie

    2016-04-01

    Radon is a naturally occurring radioactive gas which forms as a decay product from uranium. It is the largest source of natural ionizing radiation affecting the global population. When radon is inhaled, its short-lived decay products can interact with lung tissue leading to DNA damage and development of lung cancer. Ireland has among the highest levels of radon in Europe and eighth highest of an OECD survey of 29 countries. Every year some two hundred and fifty cases of lung cancer in Ireland are linked to radon exposure. This new research project will build upon previous efforts of radon monitoring in Ireland to construct a high-resolution radon hazard map. This will be achieved using recently available high-resolution airborne gamma-ray spectrometry (radiometric) and soil geochemistry data (http://www.tellus.ie/), indoor radon concentrations (http://www.epa.ie/radiation), and new direct measurement of soil radon. In this regard, legacy indoor radon concentrations will be correlated with soil U and Th concentrations and other geogenic data. This is a new approach since the vast majority of countries with a national radon monitoring programme rely on indoor radon measurements, or have a spatially limited dataset of soil radon measurements. Careful attention will be given to areas where an indicative high radon hazard based on geogenic factors does not match high indoor radon concentrations. Where such areas exist, it may imply that some parameter(s) in the predictive model does not match that of the environment. These areas will be subjected to measurement of radon soil gas using a combination of time averaged (passive) and time dependant (active) measurements in order to better understand factors affecting production, transport and accumulation of radon in the natural environment. Such mapping of radon-prone areas will ultimately help to inform when prevention and remediation measures are necessary, reducing the radon exposure of the population. Therefore, given

  6. Status of radon monitoring in Haryana

    International Nuclear Information System (INIS)

    Radon is present in trace amounts almost everywhere (indoor and outdoor) on the earth, being distributed in the soil, the ground water and in the lower atmosphere. Radon migrates and appears mainly by diffusion processes from the point of origin following α- decay of 226Ra in underground soil and building materials used in the construction of floors, walls, and ceilings. The influx of radon is a function of (1) Permeability of the underlying soil (2) Geological, meteorological and structural factor and (3) Permeability of the medium. The concentration of radon in the atmosphere varies depending on the place, time, and height above the ground and meteorological conditions. When radon decays it forms its progeny 218Po and 214Po, which are electrically charged and can attach themselves to tiny dust particles, water vapours, oxygen, trace gases in indoor air and other solid surfaces. These daughter products (aerosols) remain air-borne for a long time and can easily be inhaled into the lung and can adhere to the epithelial lining of the lung, thereby irradiating the tissue. Bronchial stem cells and secretion cells in airways are considered to be the main target cells for the induction of lung cancer resulting from radon exposure. The exposure of population to high concentrations of radon and its daughters for a long period may lead to pathological effects like the respiratory functional changes and the occurrence of lung cancer. Some studies have been carried out by different researchers for radon monitoring in Haryana state of India using alpha sensitive LR-115 type II plastic track detectors. The following studies have been carried out: 1. Indoor radon in different dwellings like cemented, soil bricks, mud and fly ash bricks. 2. Radon in industrial units like thermal power plants, gas power plants, LPG bottling plants and refineries 3. Radon exhalation rates measurements in building materials viz; soil, fly ash, cement, sand and stones. 4. Radon diffusion studies

  7. A GRAVITATIONAL LENS MODEL FOR THE Ly{alpha} EMITTER LAE 221724+001716 AT z = 3.1 IN THE SSA 22 FIELD {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Nakahiro, Y.; Kajisawa, M.; Tanaka, A. R.; Hamada, K. [Graduate School of Science and Engineering, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Taniguchi, Y.; Shioya, Y.; Kobayashi, M. A. R. [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama, Ehime 790-8577 (Japan); Inoue, A. K. [College of General Education, Osaka Sangyo University, 3-1-1 Nakagaito, Daito, Osaka 574-8530 (Japan); Iwata, I. [Subaru Telescope, National Astronomical Observatory of Japan, 650 North A' ohoku Place, Hilo, HI 96720 (United States); Matsuda, Y. [ALMA Office, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hayashino, T. [Research Center for Neutrino Science, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578 (Japan)

    2013-04-01

    During the course of our Lyman continuum imaging survey, we found that the spectroscopically confirmed Ly{alpha} emitter LAE 221724+001716 at z = 3.10 in the SSA 22 field shows strong Lyman continuum emission ({lambda}{sub rest} {approx} 900 A) that escapes from this galaxy. However, another recent spectroscopic survey revealed that the supposed Lyman continuum emission could arise from a foreground galaxy at z = 1.76 if the emission line newly detected from the galaxy at {lambda}{sub obs} Almost-Equal-To 3360 A is Ly{alpha}. If this is the case, as the angular separation between these two galaxies is very small ( Almost-Equal-To 0.''6), LAE 221724+001716 at z = 3.10 could be amplified by the gravitational lensing caused by this intervening galaxy. Here we present a possible gravitational lens model for the system of LAE 221724+001716. First, we estimate the stellar mass of the intervening galaxy as M{sub *} {approx} 3.5 Multiplication-Sign 10{sup 9} M{sub Sun} from its UV luminosity and {approx}3.0 Multiplication-Sign 10{sup 7}-2.4 Multiplication-Sign 10{sup 9} M{sub Sun} through the spectral energy distribution fitting. Then, we find that the gravitational magnification factor ranges from 1.01 to 1.16 using the so-called singular isothermal sphere model for strong lensing. While LAE 221724+001716 is the first system of an LAE-LAE lensing reported so far, the estimated magnification factor is not so significant because the stellar mass of the intervening galaxy is small.

  8. Determination of radon prone areas by optimized binary classification

    International Nuclear Information System (INIS)

    Geogenic radon prone areas are regions in which for natural reasons elevated indoor radon concentrations must be expected. Their identification is part of radon mitigation policies in many countries, as radon is acknowledged a major indoor air pollutant, being the second cause of lung cancer after smoking. Defining and estimating radon prone areas is therefore of high practical interest. In this paper a method is presented which uses the geogenic radon potential as predictor and thresholds of indoor radon concentration for defining radon prone areas, from which thresholds for the geogenic radon potential are deduced which decide whether a location is flagged radon prone or not, in the absence of actual indoor observations. The overall results are different maps of radon prone areas, derived from the geogenic radon map, and depending (1) on the criterion which defines what a radon prone area is; and (2) on the choice of score whose maximization defines the optimal classifier. Such map is not the result of a transfer model (geogenic to indoor radon), but of the optimization of a classification rule. The method is computationally simple but has its caveats and statistical traps, some of which are also addressed. - Highlights: • A classification-based method for estimating radon prone areas. • Geogenic radon potential as predictor. • Optimization of ROC graphs

  9. Radon Measurements in Schools: An Interim Report.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Radiation Programs.

    Radon-222 is a colorless, odorless, tasteless, radioactive gas that occurs naturally in soil, rocks, underground water, and air. The United States Environmental Protection Agency (EPA) and other scientific organizations have identified an increased risk of lung cancer associated with exposure to elevated levels of radon in homes. Schools in many…

  10. A review of radon pollution in buildings in Hong Kong

    International Nuclear Information System (INIS)

    Indoor radon concentrations, radon emanation rates from building surfaces, radioactivity contents of building materials and the indoor gamma dose rates for Hong Kong are all in general higher than values obtained elsewhere. An interesting phenomenon has been noted that the values of indoor radon concentrations and radon emanation rates from building surfaces in Hong Kong tend to decrease with the age of the buildings, while the absorbed gamma dose remains about the same. The total average annual effective dose equivalent, and contribution from radon, thoron and their daughters, and that related to building materials will be shown. The number of radon-induced lung cancer deaths will also be discussed. (Author)

  11. Results of a Test and Win Contest to Raise Radon Awareness in Urban and Rural Settings

    Science.gov (United States)

    Hahn, Ellen J.; Rayens, Mary Kay; Kercsmar, Sarah E.; Robertson, Heather; Adkins, Sarah M.

    2014-01-01

    Background: Radon is a leading cause of lung cancer, but few test their homes to determine radon levels. Purpose: The study assessed feasibility and success of a Test and Win Contest to promote radon testing in rural and urban communities. Methods: The prospective, quasi-experimental study tested a novel contest to raise radon awareness. Paid and…

  12. A study on the thoron sensitivity of radon detectors available to Canadians

    International Nuclear Information System (INIS)

    Radon and its decay products have been identified as the second leading cause of lung cancer after tobacco smoking. Thoron is an isotope of radon. With increased awareness of radon, questions related to thoron are arising from the public. Currently, only radon detectors are commonly available to Canadian homeowners. A study on the thoron sensitivities of those radon detectors was undertaken. The average thoron sensitivity relative to radon varied from a factor of 0.012 to 0.74 for the five commonly available types of alpha track radon detectors. The potential impact of thoron sensitivity on radon test results is discussed. (paper)

  13. A perspective on risks from radon

    International Nuclear Information System (INIS)

    In its Statement on Radon (November 2009), the International Commission on Radiological Protection (ICRP) has reduced the upper reference level for radon gas in dwellings to 300 Bq m-3. The recommended level for workplaces is 1000 Bq m-3. A risk coefficient of 8 x 10-10 per Bq h m-3 is recommended without reference to smoking habits. On the basis of these figures: 1) The estimated risk of fatal cancer from exposure to radon at home and at work could be greater than the observed risk of accidental death from travelling by car, which would be surprising if true. 2) The estimated risk of lung cancer from radon could be greater than the observed risk of lung cancer from all causes, which is actually known to be dominated by smoking. The author is not aware of any direct evidence of risks from inhaling radon in Australian dwellings, 99% of which have radon levels below 50 Bq m-3. Evidence available from other countries shows that: 1) The effects of radon in the incidences of lung cancer are uncertain at levels less then about 50-100 Bq m-3. 2) The estimation of risks at levels below 200 Bq m-3 depends on extrapolation from risks observed at higher levels. 3) Risks to non-smokers from radon are 25 times less than risks to smokers. Its concluded that the ICRP Statement on Radon and radon policies in the US and UK have the potential to cause unwarranted concern. Some people may be made to feel they need to spend money modifying their homes and workplaces to protect occupants from exposure to radon when there is no compelling reason to show that this is necessary. The vast majority of non-smokers do not need to be protected from radon. (Author)

  14. Contribution of waterborne radon to home air quality

    International Nuclear Information System (INIS)

    Radon-222 is a member of the uranium decay chain and is formed from the decay of radium-226. Radon and its decay products emit alpha particles during the decay process. If radon is inhaled, alpha particles emitted from inhaled radon and its daughters increase the risk of lung cancer. Radon is soluble in water; thus when radon comes in contact with groundwater it dissolves. The radon concentration in groundwater may range from 100 pCi/L to 1,000,000 pCi/L. When water with a high radon level is used in the home, radon is released from the water to the air and thus can increase indoor air radon concentration. Considering the estimated health risk from radon in public water supply systems, EPA has proposed a maximum contaminant level (MCL) of 300 pCi/L for radon in public drinking water supplies. To address the health risks of radon in water and the proposed regulations, the American Water Works Association Research Foundation (AWWARF) initiated a study to determine the contribution of waterborne radon to radon levels in indoor household air

  15. Scopingsreport Radon

    NARCIS (Netherlands)

    Blaauboer RO; Vaas LH; Hesse JM; Slooff W

    1989-01-01

    Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de inho

  16. Asbestos and radon

    International Nuclear Information System (INIS)

    To understand the effects of inhaled agents on the lung, a characterization of both the lung and the inhaled agent is essential. Since deposition of the agent is the result of a dynamic process involving the particles as they move through the tracheobronchial tree, the authors' goal is to understand this interaction. To lay the groundwork for this they present basic tracheobronchial anatomy and physiology. Then they examine information on deposition and clearance of asbestos and radon and discuss how this relates to the resultant pathology

  17. RADON AND CARCINOGENIC RISK IN MOSCOW

    OpenAIRE

    S. M. Golovanev

    2015-01-01

    Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published...

  18. Project Radon

    International Nuclear Information System (INIS)

    The project started in March 1987. The objective is to perform radon monitoring in 2000 dwellings occupied by people employed by State Power Board and to continue to contribute to the development of radon filters. The project participates in developing methods for radon measurement and decontamination and in adapting the methods to large scale application. About 400 so called radon trace measurements (coarse measurement) and about 10 action measurements (decontamination measurement) have been made so far. Experience shows that methods are fully applicable and that the decontamination measures recommended give perfectly satisfactory results. It is also established that most of the houses with high radon levels have poor ventilation Many of them suffer from moisture and mould problems. The work planned for 1988 and 1989 will in addition to measurements be directed towards improvement of the measuring methods. An activity catalogue will be prepared in cooperation with ventilation enterprises. (O.S.)

  19. Radon in British mines: a review

    International Nuclear Information System (INIS)

    A review of the occupational hazards experienced by non-coal miners in British mines is presented, with emphasis on the radiation hazards of radon. Topics reviewed include legislation and radiation standards, radiation monitoring methods in Britain, the geology of the Pennine range wherein the tin and fluorspar mines are located, and survey and workplace monitoring results. Lung cancer risk coefficients are derived from radon decay product data and from British epidemiology on lung cancer

  20. Dosimetry of inhaled radon and thoron progeny

    International Nuclear Information System (INIS)

    This chapter reviews recent developments in modeling doses received by lung tissues, with particular emphasis on application of ICRP's new dosimetric model of the respiratory tract for extrapolating to other environments the established risks from exposure to radon progeny in underground mines. Factors discussed include: (1) the influence of physical characteristics of radon progeny aerosols on dose per unit exposure, e.g., the unattached fraction, and the activity-size distributions of clustered and attached progeny; (2) the dependence of dose on breathing rate, and on the exposed subject (man, woman or child); (3) the variability of dose per unit exposure in a home when exposure is expressed in terms of potential α energy or radon gas concentration; (4) the comparative dosimetry of thoron progeny; and (5) the effects of air-cleaning on lung dose. Also discussed is the apparent discrepancy between lung cancer risk estimates derived purely from dosimetry and the lung cancer incidence observed in the epidemiological studies of radon-exposed underground miners. Application of ICRP's recommended risk factors appears to overestimate radon lung-cancer risk for miners by a factor of three. ''Normalization'' of the calculated effective dose is therefore needed, at least for α dose from radon and thoron progeny, in order to obtain a realistic estimate of lung cancer risk

  1. EPA's approach to assessment of radon risk

    International Nuclear Information System (INIS)

    The Environmental Protection Agency has assessed the potential lung cancer risk to the general population due to radon based on the Agency's general principles of risk assessment. This is the same approach that has been used to assess the impact on public health of other carcinogenic environmental pollutants. This paper describes the application of this approach to radon. This paper includes a description of the method used by the Agency to estimate that 20,000 lung cancer deaths per year may be related to radon exposure. Also presented are the weight-of-evidence for classifying radon as a known human carcinogen and the uncertainties associated with estimating risks from radon exposure. These reflect the extent of the underlying support and context for these estimates

  2. Radon: implications for the health professional

    International Nuclear Information System (INIS)

    Radon is a colorless, odorless gas formed by radioactive decay of radium and uranium, which are naturally present in the earth's crust. When concentrated indoors, this invisible gas becomes a potential health hazard. The Environmental Protection Agency estimates that up to 20,000 lung cancer deaths annually can be attributed to prolonged radon exposure. Radon is an important health issue that should be understood by all health care professionals. This paper discusses some of the important issues regarding radon, such as the incidences of lung cancer believed to be attributable to radon, the high-risk areas in the United States, federal safety guidelines, and public apathy. These issues and their impact on the health care required by professionals, especially nurse practitioners, are discussed

  3. Indoor radon concentrations in Vushtrri, Kosovo

    International Nuclear Information System (INIS)

    Indoor air radon concentration was measured by exposing trac ketch detectors in the two elementary schools, one high school, a kindergarten and the hospital in the city of Vushtrri. Measurements were performed with the radon monitor PRM-145, which uses alpha scintillation cells and serves to determine the current concentration of radon. The results we obtained are in the range between the average values of radon for the interior spaces, and values that pose a potential risk for lung cancer. Measuring the concentration of radon was done in total of 34 rooms and came up with values which are between 28Bqm-3 and 398Bqm-3. In order to reduce the concentration of radon, we have built a ventilation pump, then we performed repeated measurements and finally came with results between 130-145Bqm-3.

  4. Problems in the radon versus lung cancer test of the linear no-threshold theory and a procedure for resolving them

    International Nuclear Information System (INIS)

    It has been shown that lung cancer rates in U.S. counties, with or without correction for smoking, decrease with increasing radon exposure, in sharp contrast to the increase predicted by the linear-no-threshold (LNT) theory. The discrepancy is by 20 standard deviations, and very extensive efforts to explain it were not successful. Unless a plausible explanation for this discrepancy (or conflicting evidence) can be found, continued use of the LNT theory is a violation of open-quotes the scientific method.close quotes Nevertheless, LNT continues to be accepted and used by all official and governmental organizations, such as the International Commission on Radiological Protection, the National Council on Radiation Protection and Measurements, the Council on Radiation Protection and Measurements, the National Academy of Sciences - U.S. Nuclear Regulatory Commission Board of Radiation Effects Research, Environmental Protection Agency etc., and there has been no move by any of these bodies to discontinue or limit its use. Assuming that they rely on the scientific method, this clearly implies that they have a plausible explanation for the discrepancy. The author has made great efforts to discover these 'plausible explanations' by inquiries through various channels, and the purpose of this paper is to describe and discuss them

  5. Health Effects of Exposure to Radon. BEIR VI

    International Nuclear Information System (INIS)

    This National Research Council's report of the sixth Committee on Biological effects of Ionizing Radiations (BEIR VI) addresses the risk of lung cancer associated with exposure to radon and its radioactive progeny. Radon, a naturally occurring gas formed from the decay of uranium in the earth, has been conclusively shown in epidemiologic studies of underground miners to cause lung cancer. There is supporting evidence from experimental studies of animals that confirm radon as a cause of lung cancer and from molecular and cellular studies that provide an understanding of the mechanisms by which radon causes lung cancer. In addition to being present at high concentrations in many types of underground mines, radon is found in homes and is also present outdoors, raising concerns that radon in homes increases lung-cancer risk for the general population. For the purpose of developing public policy to manage the risk associated with indoor radon, there is a need to characterize the possible across the range of exposures received by the population. The BEIR VI committee faced the task of estimating the risks associated with indoor radon across the full range of exposures and providing an indication of the uncertainty to be attached to risk estimates across this range. In preparing this report, the BEIR VI committee, in response to its charge, reviewed the entire body of data on radon and lung cancer, integrating findings from epidemiologic studies with evidence from animal experiments and other lines of laboratory investigation. The committee also considered the substantial evidence on smoking and cancer and the more limited evidence on the combined effect of smoking and radon. The report's elements include comprehensive reviews of the cellular and molecular basis of radon carcinogenesis and of the dosimetry of radon in the respiratory tract, of the epidemiologic studies of miners and the general population, and of the combined effects of radon and other occupational

  6. Carcinogenic and cocarcinogenic effects of radon and radon daughters in rats

    International Nuclear Information System (INIS)

    It has been previously established that lung cancer could be induced in rats by exposure to radon and radon daughters. Although the oat-cell carcinomas that are common in humans were not found in rats, other histological types of lung carcinomas, especially squamous cell carcinomas and primitive lung adenocarcinomas, were similar to those observed in humans. A dose-effect relationship was established for cumulative doses varying from 25 to 300 working-level-months (WLM), which was similar for medium and high cumulative doses to that observed in uranium miners. This experimental protocol was also used to study the potential cocarcinogenic effects of other environmental or industrial airborne pollutants such as tobacco smoke, mineral fibers, diesel exhausts, or minerals from metallic mine ores that may act synergistically with radon exposure. In rats exposed to radon and tobacco smoke combined, the incidence of malignant thoracic tumors was observed in rats exposed to radon and fibers combined, but synergistic effects resulted in additivity. With diesel exhausts or minerals from metallic ores, a slight, nonsignificant increase in the incidence of lung carcinomas was observed compared with rats exposed to radon alone. These results demonstrated that it is possible to establish the potential cocarcinogenic action, showing either multiplicative, additive, or no effect of various environmental or industrial airborne pollutants combined with radon exposure. This radon model is valid for investigating possible interactions between two occupational exposures. 62 refs., 6 figs., 9 tabs

  7. Use of track detectors in solid phase in solving of radon problems

    International Nuclear Information System (INIS)

    In this thesis track detectors in solid phase in solving of radon problems were used. Risk of lung carcinomas formation is estimated. Results of radon monitoring in houses and caves in the Slovak Republic are presented

  8. Radon reduction

    International Nuclear Information System (INIS)

    During a radon gas screening program, elevated levels of radon gas were detected in homes on Mackinac Island, Mich. Six homes on foundations with crawl spaces were selected for a research project aimed at reducing radon gas concentrations, which ranged from 12.9 to 82.3 pCi/l. Using isolation and ventilation techniques, and variations thereof, radon concentrations were reduced to less than 1 pCi/l. This paper reports that these reductions were achieved using 3.5 mil cross laminated or 10 mil high density polyethylene plastic as a barrier without sealing to the foundation or support piers, solid and/or perforated plastic pipe and mechanical fans. Wind turbines were found to be ineffective at reducing concentrations to acceptable levels. Homeowners themselves installed all materials

  9. Assessment of risks associated to ionizing radiations: lung cancers after domestic radon exposure and thyroid cancers after accidental exposure to radioactive iodines

    International Nuclear Information System (INIS)

    The aim of this work is to develop a critical analysis of quantitative risk assessment in the field of ionizing radiation and to provide new estimates of attributable risks for particular situations of environmental exposure to ionizing radiation. This work is based on knowledge about dose-response relationships and ionizing radiation exposure of the general population. The work focuses on two different situations that both present an important interest for public health: lung cancer associated with domestic radon exposures (natural situation) and thyroid cancer associated with the Chernobyl accident fallout (accidental situation). The assessment of lung cancer risk associated with domestic radon exposure considers 10 dose-response relationships resulting from miner cohorts and case-control studies in the general population. A critical review of available data on smoking habits has been performed and allowed to consider the interactions between radon and tobacco. The exposure data come from measurements campaigns carried out since the beginning of the 1980 by the Institute for Radiation protection and Nuclear Safety and the Health General Directory in France. The French lung cancer mortality data are provided by the I.N.S.E.R.M.. Estimates of the number of attributable cancers are carried out for the whole country, stratified by 8 large regions (Z.E.A.T.) and by 96 departments for the year 1999 allowing to perform a sensibility analysis according to the geographical level of calculation. Uncertainties associated to risk coefficients and exposures have been quantified and it's impact on risk estimates is calculated. The estimated number of deaths attributable to domestic radon exposure ranges from 543 (90% uncertainty interval (U.I.): 75-1,097) to 3,108 (90% U.I.: 2,996-3,221). The corresponding risk fractions range from 2.2% (90% U.I.: 0.3%-4.4%) to 12.4% (90% U.I.: 11.9%-12.8%). The assessment of thyroid cancer risk in the most exposed area of France due to the

  10. Assessment of radon levels in some water resources in Egypt

    International Nuclear Information System (INIS)

    Radon is a naturally occurring radioactive gas that is produced by the radioactive decay of radium. Breathing high concentrations of radon can cause lung cancer. When radon gas migrates through the atmosphere, the solid radon progeny are deposited on the soil and water below, entering into the food chain. Radon generated from rocks containing its parents may escape to the underground or surface running water, which ultimately used as drinking water or for irrigation. In this work radon level was determined in different water resources in Egypt. Water from spring, tap water Nile and some commercially available drinking water were subjected to radon measurements using CR-39 detectors. Radon concentration in different water resources was found the range from 8.94 to 10.00 Bq/m3 while in trapped air above water was 9.3 to 10.38 Bq/m3

  11. How to Ensure Low Radon Concentrations in Indoor Environments

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Wraber, Ida Kristina

    2011-01-01

    This paper focuses on methods for measuring radon levels in the indoor air in buildings as well as on concrete solutions that can be carried out in the building to prevent radon leakage and to lower the radon concentration in the indoor air of new buildings. The radon provision in the new Danish...... Building Regulations from 2010 has been tightened as a result of new recommendations from the World Health Organization. Radon can cause lung cancer and it is not known whether there is a lower limit for its harmfulness. It is therefore important to reduce the radon concentration as much as possible in new...... buildings. The airtightness is a major factor when dealing with radon in buildings. Above the ground it is important to build airtight in compliance with energy requirements and against the ground it is important to prevent radon from seeping into the building. There is a direct connection between a...

  12. Effects of Radon Inhalation on Some Biophysical Properties of Blood in Rats

    Science.gov (United States)

    Essa, M. F.; Shahin, Fayez M.; Ahmed, Ashour M.; Abdel-Salam, Omar

    2013-03-01

    The major source of human exposure to natural radiation arises from the inhalation of radon (222Rn) gas. Exposure to high concentrations of radon 222Rn and its daughters for long period leads to pathological effects like lung cancer, leukaemia, skin cancer and kidney diseases. The present study was performed on rats to investigate the effect of radon exposure on the absorption spectra of hemoglobin. Measurements have been performed in a radon chamber where rats were exposed to radon for 1, 5 or 7 weeks. The inhalation of radon resulted in decrease in intensity of the absorption bands characterizing the hemoglobin molecular structure with increased radon doses.

  13. Radon in the Environment: Friend or Foe?

    International Nuclear Information System (INIS)

    Radon222 is a naturally occurring radioactive gas that is part of the Uranium decay series. Its Presence in the environment is associated mainly with trace amounts of uranium and its immediate parent, radium226, in rocks, soil and groundwater. About one-half of the effective doses from natural sources is estimated to be delivered by inhalation of the short lived radon progeny. Owing to this fact, radon is the most popular subject of studies on environmental radioactivity. The presence of high level of radon in indoor environment constitutes a major health hazard for man. The radon progeny is well established as causative agents of lung cancer and other types of caners. Radon unique properties as a naturally radioactive gas have led to its use as a geophysical tracer for locating buried faults and geological structures, in exploring for uranium, and for predicting earthquakes. Radon has been used as a tracer in the study of atmospheric transport process. There have been several other applications of radon in meteorology, water research and medicine. This paper summarizes the health effects and the potential benefits of radon and its progeny.

  14. Radon as a risk factor in mines and dwellings

    International Nuclear Information System (INIS)

    In mines, exposure to radon and radon daughters is the most important factor for the initiation of lung cancer. Tobacco smoke probably acts as a lung cancer promotor, but the relationship between minework, smoking and lung cancer is complicated. It is suggested that smokers may have a relative protection from a mucous sheet covering their basal cells. There is a connection between radon exposure in dwellings and lung cancer. Radon in buildings comes from the building material or the ground. The risk for developing lung cancer seems to be enhanced considerably by smoking. Tobacco contains some radioactivity itself (Lead 210 and Polonium 210), but tobacco smoke also adsorb electrically charged radon daughters and keeps them floating in the breathing air. Measurements show a doubling of radon daughter concentration in a room of normal size if 3-4 cigaretts is burnt out in it. A raised risk for lung cancer has been observed in connection with passive smoking. The relative risk for lungcancer is 2-3 for passive smokers and 5-6 for active smoking women. Children to smoking mothers who starts smoking themselves develops lung cancer more easily than other groups. There seems to be a connection between early exposure to radon daughters, passive smoking and lung cancer. (BoK)

  15. Interaction between smoking and exposure to radon daughters

    International Nuclear Information System (INIS)

    In a nationwide study of lung cancer among Swedish miners, an exposure-effect relationship between the lung cancer mortality and radon daughter concentrations in the mines is present. In another study of mining, lung cancer, and smoking among the mining population, there was no clear age difference between the lung cancer cases among smokers and nonsmokers

  16. Airborne radon concentrations in different environments in Korea

    International Nuclear Information System (INIS)

    Little information has been presented average radon concentrations in the living spaces in Korea to date although radon has become a great concern in recent years to the Korean population due to association with the lung cancer risk. Since radon related health risks depends on long-term exposure, it is vital to know the relationship between these short-term measurements and long-term radon concentrations in the different living spaces. Previous studies have shown that many factors may contribute to the temporal and geographic variation in radon entry and retention in living spaces. These factors may differ from one region of the country to another and over time. Thus, it is important that comparisons of different measurement protocols include samples drawn from a broad range of radon sources, different types of environments, and lifestyles. The present work compares the results of short-term and long-term surveys of radon measurements conducted in various areas in Korea that contains average radon-strength sources, different types of living spaces, and different seasons. Most of average airborne radon concentrations using track etch radon detectors were measured in different environments such as houses, subway stations, underground stores, indoor and outdoor office buildings. In addition to these studies, a series of radon surveys using passive integrating radon cup monitors were undertaken in different types of dwellings in Seoul for one year since April 1996, while the same survey using radon discriminative dosimeters were conducted in major six cities in Korea. Radon concentrations in basements in the selected dwellings were higher than those levels measured in the first floor, while indoor radon concentrations were significantly higher than the corresponding outdoor levels at six survey sites. The results suggest the need to more definitely assess sources of radon concentrations as well as to provide more information about technical measurements of different

  17. Radon, radiation effects and radiation protection

    International Nuclear Information System (INIS)

    Epidemiological studies among Rn-exposed miners revealed a significant increase in lung tumour occurrence with increased exposure to radon daughters. Radiation exposure of the lungs also is given through inhalation of Rn-decay products released from the building material of residential houses. The resulting lung cancer risk is one of the major issues of radiation protection of the population. Extensive data collections are available on Rn-concentrations in room air. Building planning and design should make better use of these data, particularly for selection of materials and design of the basement and foundation of buildings, as radon daughters are the major source of radiation exposure of the population. (DG)

  18. Radon exposure and oropharyngeal cancer risk.

    Science.gov (United States)

    Salgado-Espinosa, Tania; Barros-Dios, Juan Miguel; Ruano-Ravina, Alberto

    2015-12-01

    Oropharyngeal cancer is a multifactorial disease. Alcohol and tobacco are the main risk factors. Radon is a human carcinogen linked to lung cancer risk, but its influence in other cancers is not well known. We aim to assess the effect of radon exposure on the risk of oral and pharyngeal cancer through a systematic review of the scientific literature. This review performs a qualitative analysis of the available studies. 13 cohort studies were included, most of them mortality studies, which analysed the relationship between occupational or residential radon exposure with oropharyngeal cancer mortality or incidence. Most of the included studies found no association between radon exposure and oral and pharyngeal cancer. This lack of effect was observed in miners studies and in general population studies. Further research is necessary to quantify if this association really exists and its magnitude, specially performing studies in general population, preferably living in areas with high radon levels. PMID:26335172

  19. Radon resistant new construction

    International Nuclear Information System (INIS)

    This paper consist of the awareness about the ill effects of radon gas and the methods adopted to detect the presence of radon gas and to remove the radon gas. It explains the installation of radon resistant structures during home construction. Radon is commonly found in the air and water, where it poses little risk. But radon that creeps into your home from the soil can be a much greater risk. Radon-resistant construction combines common building techniques and materials to seal entry points and route the gases outdoors, helping to prevent radon from entering the home. The benefits due to radon resistant construction is also explained in this paper. (author)

  20. Radon exhalation from sub-slab aggregate used in home construction in Canada

    International Nuclear Information System (INIS)

    Exposure to elevated levels of radon in homes has been shown to result in an increased risk of developing lung cancer. The two largest contributors to indoor radon are radon in soil gas, formed from the rocks and soil surrounding the home, and building materials such as aggregate. This study measured the surface radon exhalation rates for 35 aggregate samples collected from producers across Canada. The radon exhalation rates ranged from 2.3 to 479.9 Bq m-2 d-1, with a mean of 80.7±112 Bq m-2 d-1. Using a simple, conservative analysis, the aggregate contribution to radon concentrations in an unfinished basement was determined. The maximum estimated radon concentration was 32.5±2.7 Bq m-3, or ∼16 % of the Canadian Radon Guideline. It can be concluded that under normal conditions radon exhalation from aggregate contributes very little to the total radon concentration in indoor air. (authors)

  1. Factors Afrecting Passive Monitoring of Radon

    OpenAIRE

    浅野 智宏; Kahn, B.

    1989-01-01

    In recent years, increasing cancer has been expressed as a possible health hazards associated with long-term exposures to a large population at a low level of radon in the environment. Because radon is ubiquitous nuclide, nation-wide monitoring is necessary to determine lung cancer risk. For such purpose, passive sampling methods with track etch detector or charcoal adsorption collector may have the advantage in lower cost and convenience. The charcoal adsorption collector is considered in th...

  2. Radon in coal power plant areas

    International Nuclear Information System (INIS)

    Radon, the radioactive colourless and inodorous noble gas, represents more than 55% of the natural average radioactivity. It is permanently released from the soil and majority of building materials, it builds up in the mine galleries, in dwelling houses and in other closed rooms. Radon gained increasingly in importance, particularly after 1990 when was doubtless identified as the second cause of lung cancer if a given concentration threshold is surpassed. This threshold is established differentially by each country as a function of the particular site and generally ranges between 150 Bq.m-3 and 600 Bq.m-3. The telluric radon consists of two isotopes, 222Rn, a daughter of radium descending from uranium, which induces 90% of the effects, and 220Rn from thorium series which have too short a lifetime to count in the risk assessments of radon inhalation. The interest of the authorities and population for diminishing the radon effects was illustrated by specific studies which in USA were managed by the National Counsel of Research, the BEIR VI committee of which has issued a report concerning the lung cancer produced by radon and its descendants. Coal mining, the transport, processing, burning, slag and ash disposal are activities entailing radon release. The miners' dwellings are placed in areas with the high radon potential. The local building materials have a high content of radioactive elements from the uranium or thorium series so that radon can build up in the closed rooms of these buildings. Hence the social responsible authorities in the coal power industry zones should consider this aspect long time ignored in the Balkans macro zone so far. The radon issue must be differentially approached in different areas hence a zonal mapping of the radon emission should be first done. It is worth to underline that the gaseous radioactive emission from operational nuclear power plants amounts up to a few percents of the radon natural emissions what entails a corresponding

  3. There's something rotten in radon carcinogenesis epidemiology

    International Nuclear Information System (INIS)

    It is shown that the cancer risk from radon exposure as determined from miner data is completely inconsistent with the data on environmental radon, over predicting the risk by at least one or two orders of magnitude. This discrepancy is real, it is very large, and it cannot be ignored. It means either that most of the lung cancer among miners is due to causes other than radon, or that the linear-no threshold dose-response relationship for radiation carcinogensis seriously over-predicts risks at low doses even for alpha particles. For the Swedish miners, whose exposures were essentially in the environmental dose region, the former explanation is required

  4. Dealing with radon emissions in respect of new development : evaluation of mapping and site investigation methods for targeting areas where new development may require radon protective measures

    OpenAIRE

    Appleton, J. D.; Miles, J.C.H.; Talbot, D.K.

    2000-01-01

    Radon gas comes from uranium that occurs naturally in the ground. The variation in radon levels between different parts of the country is mainly controlled by the underlying geology. Radon decays to form radioactive particles that can enter the body by inhalation. Inhalation of the short-lived decay products of radon has been linked to an increase in the risk of developing cancers of the respiratory tract, especially of the lungs, and is considered to cause approximately 5% of dea...

  5. Radon concentrations in coal mines of Baluchistan, Pakistan

    International Nuclear Information System (INIS)

    Prolonged exposure to radon, the largest source (69%) of natural radioactivity, may cause lung cancer and bronchial tissue damage. So monitoring of radon at places of high radioactivity and in underground mines is important to assess the radiological hazards to occupational workers. For these reasons radon measurements were carried out in some coal mines of Baluchistan, Pakistan. The measurements were based upon passive detection of radon using CN-85 track detectors in Box Type Dosimeters. The radon concentration varied from 121 to 408 Bq m-3 in the mines under study. The computed radon dose varied from 1.38 to 4.67 mSv yr-1 with an average of 2.19±0.5 mSv yr-1. These coal mines have been found to be safe from radon-related health hazards

  6. Measurement of individual radon exposures

    International Nuclear Information System (INIS)

    Full text: At the Institute for Radiation Protection of the Helmholtz Center Munich, recently, a new electronic radon exposure meter has recently been developed. The device is small and light and can therefore easily be carried on person. The battery life-time is about half a year. The device is suitable for measurement of individual public, medical and occupational radon exposures. As an example for public exposure, measurements have been performed on twenty-three members of the institute who agreed to place one exposure meter in their office and two exposure meters at home (sleeping room and living room). In addition, a fourth exposure meter was carried on person all the time, for about one week. Mean indoor radon concentrations in the sleeping rooms were between about 25 and 150 Bq/m3, those in the living rooms between 7 and about 110 Bq/m3, and those in the offices between 25 and about 1,900 Bq/m3. Individual mean radon concentrations as measured by the fourth exposure meter were between 26 and 170 Bq/m3. Note that, if individual exposures were calculated based on the radon concentrations in sleeping and living rooms and on typical residence times in these rooms - as was also done in epidemiological studies on lung cancer risk from indoor radon - individual radon concentrations that are about a factor two lower were obtained. As an example for occupational exposure, safe guards working in tombs of the Valley of the Kings in Luxor, Egypt, were asked to carry an exposure meter on person all the time, for about three days. During the same period of time, additional exposure meters were placed inside those tombs, to measure radon concentrations in air. Altogether, during this measurement campaign, 12 tombs were investigated. Measured radon concentrations in the tombs ranged from about 50 to almost 12,000 Bq/m3 depending on the investigated tomb. As a result, individual doses from radon inhalation were also high for some of the safe guards, and may exceed a value of

  7. Mineral dusts and radon in uranium mines

    International Nuclear Information System (INIS)

    The Environmental Protection Agency (EPA) continues to assert that radon is a major cause of lung cancer in this country. EPA is fostering a radon program that could entail huge financial and emotional costs while yielding negligible benefits to public health. Justification for the program was the occurrence of lung cancer in men exposed to huge amounts of radon, mineral dusts, and other lung irritants in uranium mines on the Colorado Plateau. Lung cancer has been reported in about 356 cigarette smokers and in about 25 nonsmokers. During the era of high radon levels, monitoring was sporadic. Conditions in only a small fraction of the mines were measured, and that on a few separate occasions. Later, cumulative exposure to radon was calculated on the basis of measurements involving only a tiny fraction of the miners. Some were exposed to more than 15,000 pCi/liter of radon and its products. The level in the average home is about 1.5 pCi/liter. In making extrapolations from mine to home, the assumption is made that residents are in their dwellings most of the time and that miners spend only 170 hours a month in the mine. Two major questionable assumptions are involved in extrapolations from high doses of radon in the mines to low doses in homes. One is that no threshold is involved; that is, that humans have no remediation mechanism for α particle damages. There is evidence to the contrary. The most unrealistic assumption is that heavy exposure to silica has no effect on inducing lung cancer. Many studies have shown that silica dust causes lung cancer in animals. Exposure of human culture cells to silica has resulted in formation of neoplastic tissue. EPA has no solid evidence that exposures to 4 pCi/liter of radon causes lung cancer in either smokers or nonsmokers. Indeed, there is abundant evidence to the contrary in the fact that in states with high levels of radon, inhabitants have less lung cancer than those in states with low levels

  8. Quantitative framework for assessing indoor radon policy

    International Nuclear Information System (INIS)

    Radon gas in the indoor environment is recognized as a problem of considerable magnitude; likely responsible for 5,000 to 20,000 lung cancer deaths per year in the United States (Cohen, 1978; Nero, 1986). Radon is an inert, radioactive element in the decay chain or uranium-238 which occurs ubiquitously in soil and rock. Radon emanating from the ground enters houses through cracks and porous building materials in the substructure. Depending on characteristics of the housing design, construction and ventilation practices, dangerously high concentrations can result. The U.S. Environmental Protection Agency (EPA) has taken a lead role in addressing the indoor radon problem. Their strategy is to work with the States and the private sector to characterize the extent of exposure in problem areas and identify alternative actions to reduce health risks. Since radon poses a risk that occurs in private homes, the responsibility for testing and remediation lies largely with the homeowner. This paper presents a quantitative framework to analyze indoor radon policy on a regional scale. A model is developed which describes regional radon risk reduction in terms of the percentage of homeowners in the region who decide to monitor their homes, the likelihood of homeowners taking alternative remedial actions, and the effectiveness of remediation methods in lowering radon concentrations. Different government policies are analyzed in terms of their potential effect on model parameters and resulting risk reductions

  9. Characterization of radon levels in indoor air

    Energy Technology Data Exchange (ETDEWEB)

    George, A.C.

    1982-01-01

    The purpose is to describe the different types of monitoring and sampling techniques that can determine the radiation burden of the general public from radon and its decay products. This is accomplished by measuring the range and distribution of radon and radon decay products through broad surveys using simple and convenient integrating monitoring instruments. For in-depth studies of the behavior of radon decay products and calculation of the radiation dose to the lung, fewer and more intensive and complex measurements of the particle size distribution and respiratory deposition of the radon decay products are required. For diagnostic purposes, the paper describes measurement techniques of the sources and exhalation rate of radon and the air exchange inside buildings. Measurement results form several studies conducted in ordinary buildings in different geographical areas of the United States, using the described monitoring techniques, indicate that the occupants of these buildings are exposed to radon and radon decay product concentrations, varying by as much as a factor of 20.

  10. Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

    International Nuclear Information System (INIS)

    Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation

  11. Strategy for the reduction of radon exposure in Norway

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-05-15

    Elevated indoor radon concentrations are a more extensive problem in Norway than in many other countries. It has been estimated that indoor radon causes approximately 300 deaths from lung cancer each year in Norway. On average, avoiding lung cancer increases life expectancy by 14 to 18 years. Radon is a radioactive noble gas formed continually is a decay product from uranium. Uranium is a natural constituent existing in varying concentrations in bedrock, minerals and soils. For this reason, both the soil air and groundwater contain radon. Radon in buildings normally originates from the soil air in the underlying ground. Indoor air pressure is often low, so that radon-containing air from the surrounding ground gets sucked in through cracks in the building foundations. Elevated indoor radon concentrations can be due to household water drawn from groundwater wells, and radon gas can also be emitted from building materials such as certain types of stone or concrete containing high levels of natural radioactivity. Norway, Sweden and Finland are among the the countries in the world with the highest average indoor radon concentrations. Geological conditions and the cool climate pose a big challenge, but the radon problem can be solved in a cost-effective way. Radon is the most common cause of lung cancer after active smoking. At a radon concentration of 100 Bq/m3, which is not far from the estimated average for Norwegian housing, the risks of dying of radon-induced lung cancer before the age of 75 are 0.1 % for non-smokers and 2 % for smokers, respectively. Many buildings in Norway have radon levels that exceed this. The most important health impact of radon exposure is the increased risk of lung cancer. This increase in risk is assumed to be linear in relation to radon concentration (i.e., the risk is 10 times higher at 1000 Bq/m3 compared to 100 Bq/m3). The risk also increases linearly with exposure time, i.e. there is a tenfold greater risk of contracting lung cancer

  12. Radon gas, bronchogenic carcinoma - Ontario experience

    International Nuclear Information System (INIS)

    A review of the procedures followed by the Ontario Worker's Compensation Board in paying insurance benefits to injured workers is presented. Topics include initial methods of handling lung cancer claims, the first guidelines for adjudication of lung cancer, the present guidelines, and a perspective on occupational lung cancers. The Ontario Board has accepted the cause-effect relationship between radon gas decay products and the development of certain bronchogenic carcinomas in those persons so exposed

  13. Health Risks due to Exposure to Radon in Homes in Ireland

    International Nuclear Information System (INIS)

    This document summarises the evidence that links exposure to radon in homes with an increase in lung cancer. Using the most recent risk estimates derived from epidemiological studies carried out abroad, the risk associated with radon exposure in homes in Ireland is derived. The relationship between exposure to radon and cigarette smoking is also discussed

  14. Radon Prevention in the Design and Construction of Schools and Other Large Buildings.

    Science.gov (United States)

    Leovic, Kelly W.; Craig, A. B.

    Radon is a naturally occurring radioactive gas in ambient air that is estimated to cause thousands of deaths from lung cancer each year. This report outlines ways in which to ameliorate the presence of radon in schools buildings. The first section is a general introduction for those who need background information on the indoor radon problem and…

  15. Radon in Estonian dwellings - Results from a National Radon Survey

    International Nuclear Information System (INIS)

    factor given by ICRP, annually about 90 Estonians are expected to develop lung cancer due to exposure to radon in their homes. Most of them, about 75, are smokers, which are affected by the synergetic effect of the two carcinogens, smoking and radon. In Estonia the source of indoor radon is radon-containing soil air that is transported into the buildings from the ground. Building materials with enhanced radium concentrations are not known in Estonia. In this survey, the highest indoor radon concentrations have been found in the northern part of Estonia where uranium rich Dictyonema shale and uranium containing phosphorous Glauconite sandstone exist in the bedrock and as fragments in the soils. Radon concentrations higher than 400 Bq/m3 have also been measured in buildings situated in areas with karst formations. Areas with Dictyonema shale, Glauconite sandstone and karst are areas with a special risk for radon

  16. The radon in the environment of Romania

    International Nuclear Information System (INIS)

    The present paper presents the main aspects related to the problem of radon, a concern approached with great interest in the last 10-15 years by the scientific community. Though one of the first radioactive elements discovered and despite its implication in the irradiation of exposed population (especially the proof that most cases of lung cancer among workers in uranium mines are caused by radon), only lately have radon been studied intensively. As an element with great mobility, impossibly to be fixed through chemical reactions, and, on the other hand, being perpetually generated by radium sources in soil and building materials, radon is ubiquitous, therefore it is desirable to know more about one of the elements inextricably linked to our life. Radon in dwellings requires special attention because both individual and collective doses owing to radon and its descendants are higher than those deriving from any other sources. People spend more than eighty per cent of their time indoors, and more than fifty per cent of their irradiation from different sources is caused by radon. In many countries there are individual doses much higher than those accepted in professional exposure, as it is the case for certain regions in ex - Eastern Germany, where uranium mining led up to an extreme high level of radon in dwellings. Besides its major contribution to exposure to radiation, very important is the fact than its target is very precise - the lungs, especially the bronchial epithelium. There is therefore an increased risk of lung cancer occurrence, assumed to be proportional with the exposure to higher concentrations in dwellings. A number of on-going studies try to estimate the risk factors. It was shown that radon is the second risk factor after smoking. The exposure to radon in such cases should be amended through interventions and modifications of the dwellings and inhabitants' behavior. The International Commission for Radiological Protection (ICPR) recommended certain

  17. Radon daughter exposure to uranium miners

    International Nuclear Information System (INIS)

    Radon exposures to U.S. uranium miners average about 1.3 WLM per year approximately equal to 60 WLM per full working lifetime. This is intermediate between (a) the lowest exposures for which there have been excess lung cancers reported among U.S. miners (120-240 WLM) and (b) average environmental radon exposures (16 WLM), so models based on these two situations are used to estimate expected effects on present uranium miners. In Model A, the loss of life expectancy is 45 days, the SMR (standardized mortality ratio) for lung cancer is 1.10, and the SMR for all causes between ages 18 and 65 is 1.013. In Model B these are 10 days, 1.03 and 1.002 respectively. It is shown that the radon exposures to miners are similar to those to millions of Americans from environmental exposure, and that miner health risks are comparable to those of other radiation workers. Their lung cancer risk from radon is 7-50 times less than their job-related accident mortality risk, and represents 0.7-4% of their total risk in mining. Miners suffer from many diseases with SMR very much larger than that for radon-induced lung cancer. (author)

  18. Assessment of soil radon potential in Hong Kong, China, using a 10-point evaluation system

    OpenAIRE

    Tung, S.; Wiegand, J; Wartenberg, W; Leung, JKC; Jiao, JJ

    2012-01-01

    Radon and its progenies have been ranked second of being responsible for lung cancer in humans. Hong Kong has four major groups of uranium-rich plutonic and volcanic rocks and is suffering from radon emanated therefrom. However, there is a lack of radon potential maps in Hong Kong to resolve the spatial distribution of radon-prone areas. A ten-point radon potential system was developed in Germany (2005) to predict radon potential using both the in situ geogenic and geographic parameters under...

  19. RADON AND CARCINOGENIC RISK IN MOSCOW

    Directory of Open Access Journals (Sweden)

    S. M. Golovanev

    2015-01-01

    Full Text Available Objective: comparative evaluation of carcinogenic risk inMoscowfrom radon in indoor and atmospheric pollutants.Materials and methods: the lung cancer incidence in Moscow; radiation-hygienic passport of the territory; .U.S. EPA estimated average age at all and radon induced deaths, years of life lost; Report of UNSCEAR 2006 and WHO handbook on indoor radon, 2009. Trend analysis of incidence; evaluation of the excess relative risk; assessment of ratio radon-induced population risk and published values оf total population carcinogenic risk from chemical carcinogens.Results: it is shown that the 304 cases of lung cancer per year (1. 85 10-3 on average from 2006 to 2011 (21280diseases for 70 years in addition to background level induced by radon; the differences in average trends of all lungcancer incidence in the districts can exceed 25%.Conclusion. The potential of risk reduction by measures of mitigation radon concentration exceeds 5 times the cost efficiency to reduce emissions from vehicles and can reduce cancer incidence, on average 236 cases per year; population risk 16520 cases over 70 years or save not less than 2832 person-years of life per year. The annual effect of reducing losses from not-survival of 12 years as a result of radon-induced lung cancer deaths exceeds 14160000 dollars. The evaluating of the carcinogenic risk from radon in accordance with the definition of population risk increases the predictive evaluation of the effectiveness of preventive measures more than twice.

  20. Contamination of individuals by radon daughters: a preliminary study

    International Nuclear Information System (INIS)

    Body radon daughter contamination reflects relative individual respiratory exposures to radon daughters; counts can be related both to household radon levels and to lung cancer risk factors such as sex and tobacco smoking. Radon daughters were counted by gamma spectroscopy from 180 adult residents of eastern Pennsylvania. A seven-position, 35-min scan was conducted in a mobile body counter, generally during afternoon or evening hours. Track-etch detectors for household radon were distributed, and were recovered from 80% of the subjects. Over 75% of the population had environmentally enhanced radon daughter contamination. House radon levels were strongly related, as anticipated, to radon daughter contamination in the 112 subjects for whom both sets of measurements were available (p less than .001); basement measurements were as strongly related to personal contamination as were living area measurements; bedroom measurements were slightly more strongly correlated. Both sex (p less than .02) and cigarette smoking (p less than .01) significantly modified the relationships, after nonlinear adjustment for travel times. Using a logarithmic model, a given house living-area radon level was associated in females with body contamination by radon daughters 2-3 times that in males. Nonsmokers had 2-4 times higher levels of contamination than smokers. Results are for the total of internal and external contamination, these being highly correlated in preliminary experiments. Time usage and activity patterns of the subjects are believed to be important in explaining these findings, and may become important variables in radon risk assessment

  1. BGS Radon Protective Measures GIS

    International Nuclear Information System (INIS)

    The British Geological Survey Radon Protective Measures Geographical Information System is described. The following issues are highlighted: Identification of development sites where radon protection is required in new dwellings; Mapping radon potential on the basis of house radon and geology; Radon Protective Measures GIS; Radon site reports; and Follow-up radon protective measures sire reports

  2. Working towards residential radon survey in South America

    International Nuclear Information System (INIS)

    Information about residential radon levels in low and middle income countries is very sparse. In response to the World Health Organization initiative in the International Radon Project, we propose a research project that will address this knowledge gap in South America by conducting a residential radon survey. Following initial in vitro and in vivo studies of radon and studies of uranium miners exposed to radon, over twenty large case-control studies of lung cancer risk from exposure to residential radon have been completed worldwide by year 2004. Recently pooled data from these individual studies have been analyzed. These collaborative analyses of the indoor studies in Europe, North America, and China provide strong direct evidence that radon is causing a substantial number of lung cancers in the general population. To reduce radon lung cancer risk, national authorities must have methods and tools based on solid scientific evidence to develop sound public health policies. We propose to conduct a survey in ten South American countries using the distribution and analysis of passive alpha tracking detectors in houses selected at random in pre-selected cities in each participating country. We also present an approach to estimate the cost of carrying out such a survey and the radon laboratory infrastructure needed. The results of the proposed survey will allow to conduct assessment of the exposure to residential radon in the populations of South American countries and to assess the health impact of this exposure. The results of the project will also help national health authorities in developing national residential radon action levels and regulations, as well as provide public health guidance for radon awareness and mitigation. (author)

  3. Working towards residential Radon survey in South America

    International Nuclear Information System (INIS)

    Information about residential radon levels in low and middle income countries is very sparse. In response to the World Health Organization initiative in the International Radon Project, we propose a research project that will address this knowledge gap in South America by conducting a residential radon survey. Following initial in vitro and in vivo studies of radon and studies of uranium miners exposed to radon, over twenty large case-control studies of lung cancer risk from exposure to residential radon have been completed worldwide by year 2004. Recently pooled data from these individual studies have been analyzed. These collaborative analyses of the indoor studies in Europe, North America, and China provide strong direct evidence that radon is causing a substantial number of lung cancers in the general population. To reduce radon lung cancer risk, national authorities must have methods and tools based on solid scientific evidence to develop sound public health policies. We propose to conduct a survey in ten South American countries using the distribution and analysis of passive alpha tracking detectors in houses selected at random in pre-selected cities in each participating country. We also present an approach to estimate the cost of carrying out such a survey and the radon laboratory infrastructure needed. The results of the proposed survey will allow to conduct assessment of the exposure to residential radon in the populations of South American countries and to assess the health impact of this exposure. The results of the project will also help national health authorities in developing national residential radon action levels and regulations, as well as provide public health guidance for radon awareness and mitigation. (author)

  4. An historical overview of radon and its progeny: Applications and health effects

    International Nuclear Information System (INIS)

    Since its discovery by Dorn in 1900, studies of radon and its progeny have contributed to such diverse scientific fields as meteorology, geophysics, mineral exploration and radiation health effects. In addition to terrestrial scientific studies of radon, NASA missions in recent decades have yielded data on the behaviour of radon and its progeny on the Moon and on Mars. Radon has been used therapeutically for ∼100 y in the form of radon seeds for the irradiation of malignant tumours. It is, however, for its negative health effects that radon is better and more justifiably known. The causal role of radon and, in particular, its progeny in the elevated incidence of lung cancer in underground uranium miners was established in the 1950's. It is of historical interest to note that the fatal lung disease of silver miners in Saxony and Bohemia in the 16. century, was undoubtedly lung cancer caused by the high levels of radon in the mines. In recent decades there has been an ever-growing interest in the public health effects of exposure to radon in homes. Extensive radon epidemiological studies both of underground miners and of the general public in recent decades have quantified the lung cancer risks from radon exposure. Radon was classified in 1988 by International Agency for Research on Cancer as a human carcinogen and in 2009 the World Health Organization identified radon as the second cause of lung cancer globally after smoking. Radon control strategies are used by many governments to control and reduce the risk to public health from radon. (authors)

  5. Radon in Africa: South African Lessons Learnt

    International Nuclear Information System (INIS)

    Radon remained a chemical curiosity for decades, promoted at some stage as a health giving gas. Mining related history: (based on ICRP 65) dating back to 15 Century when high mortality from lung cancer was observed among miners in Schneeberg. After the Curies had extracted Radium from Jachymov ores (1898), radon was identified. When measurements were done in Schneeberger and Jachymov mines high concentrations of radon were found. Initially a link was assumed between lung cancer and high radon concentration based on the measurements. (The assumption was not generally accepted).In 1953 William F. Bale indicated that the causative agents of lung cancer was the radon progeny and not radon gas. A possible lung cancer risk to members of the public was discovered very recently (first published results were based on the indoor measurements done in Sweden in a study initiated by Rolf Sievert) Much attention has been given to radon as a radiological health hazard: Recently human exposure to radon progeny in buildings has emerged as an important issue. Lung cancer is the principal concern associated with Rn exposure. The principal concern is associated with radon progeny. These species are chemically reactive, and may be deposited on respiratory tract tissues when inhaled. Subsequent alpha particle decay may damage cells near the deposition site, contributing to increased risk of lung cancer Radon: In Occupational Exposure Protection against Rn Exposure is a Techno-Legal Legal Aspects: There has to be a national legislative framework for the protection of workers against radon The legal framework should entail, inter alia: - Set up of regulator, development of regulations and standards to enable compliance assurance and other protection issues, training of technical people. 10 Legislative Framework in South Africa National Nuclear Regulatory Act (1999) Enables the regulator (NNR) to exercise oversight for Rn protection Occupational Exposure is mainly in Mining and Mineral

  6. Estimation of radon concentration in dwellings in and around Guwahati

    Indian Academy of Sciences (India)

    Gautam Kumar Dey; Projit Kumar Das

    2012-02-01

    It has been established that radon and its airborne decay products can present serious radiation hazards. A long term exposure to high concentration of radon causes lung cancer. Besides, it is also known that out of the total radiation dose received from natural and man-made sources, 60% of the dose is due to radon and its progeny. Taking this into account, an attempt has been made to estimate radon concentration in dwellings in and around Guwahati using aluminium dosimeter cups with CR-39 plastic detectors. Results of preliminary investigation presented in this paper show that the mean concentration is 21.31 Bq m−3.

  7. Hazards of radon daughters to the general public

    International Nuclear Information System (INIS)

    The risk estimates of lung cancer resulting from the inhalation by the general public of radon daughters which accumulate inside buildings are discussed. The cost-benefit relationship for decreasing radon daughter exposures in Canadian homes by increasing ventilation rates is also quantified. The main components in this relationship are identified together with the uncertainties associated with some of these components. The uncertainties in the calculated values appeared to be related primarily to the most appropriate risk estimates for inhalation of radon daughters and to actual radon daughter concentrations inside buildings at various ventilation rates. (UK)

  8. Radon content in underground waters from Maramures county

    International Nuclear Information System (INIS)

    Radon problem is a very current problem in the scientific world. It is well known that 222 Rn and its short-life descendants contribute to the effective equivalent dose, mainly through inhalation, by 50% of the total dose from natural sources (UNSCEAR 1988). The radon gas dissolved in water is transferred into the indoor air by normal utilisation of water for domestic purposes. Therefore the daily consumption of water containing radon causes radioactive dose buildup in human tissues, the largest dose being received by the lung and stomach. This paper presents the results of some radon measurements carried out on the underground waters from different locations in Maramures county. (authors)

  9. Aerosol properties of indoor radon decay products

    International Nuclear Information System (INIS)

    Lung cancer risks attributable to indoor radon are highly dependent on the properties of radon progeny aerosols which, in turn, are dependent on the nature and concentration of small particles in indoor air. In clean filtered air, radon progeny are attached to small hygroscopic particles of high mobility which are rapidly deposited on surfaces. By contrast, radon progeny attached to cigarette smoke are on large particles of low mobility which persist in air. Radon progeny ingaled by smokers are largely associated with smoke particles from 0.5 to 4.0 μm diameter. Such particles are selectively deposited at bronchial bifurcations and are highly resistant to dissolution. The attached radon progeny undergo a substantial degree of radioactive decay at deposition sites before clearance which gives rise to large alpha radiation doses in small volumes of bronchial epithelium. These processes provide new insights on mechanisms of bronchial cancer induction and on relative risks of lung cancer in smokers, passive smokers, and other non-smokers. (Author)

  10. Lung tumors and radon inhalation in over 2000 rats: Approximate linearity across a wide range of doses and potentiation by tobacco smoke

    International Nuclear Information System (INIS)

    More than 2000 rats were exposed to cumulative doses of up to 28,000 WLMs of radon gas. More than 300 pulmonary tumors were induced by this exposure, most being nonfatal lesions detected only at autopsy of animals that had died of unrelated causes. Above 6000 WLMs rats suffered increasingly from life shortening due to radiation-induced nonneoplastic causes and so had less time in which to develop tumors. When adjusted for these competing causes of death, the hazard function for the excess risk of developing pulmonary tumors was approximately linearly related to dose throughout the range of doses studied. This suggests that some previously reported high-dose ''reductions'' in radiogenic tumor-induction rates may chiefly have involved the killing of rats rather than the killing of precursor cells. Rats exposed to radon and then to six months of inhalation of tobacco smoke had a four times greater age-specific prevalence of pulmonary tumors than rats exposed to an identical radon dose either alone or preceded by tobacco smoke inhalation. This suggests that tobacco smoke may accelerate the carcinogenic process by acting as a promoter of radiation-induced somatic damage. These data suggest that, for assessing human risk from exposure to radon, the linear model should be assumed, but that the WLM is not on its own an adequate index of carcinogenic insult. 7 refs., 2 figs., 4 tabs

  11. Estimated risks of radon-induced lung cancer by two-mutation model for different exposures in mines and in homes

    International Nuclear Information System (INIS)

    In this work, the two-mutation model has been applied and compared with BEIR VI models for a prediction of the radon risk in various environments. The obtained results can be summarised into several points. The values of risk from the radon exposure predicted by the two-mutation model are comparable with the results obtained by BEIR VI for the short-time as well as for the long-time exposures. In the range of low exposures is this agreement of the results closer to the risk values assessed by the exposure-age-concentration model. In the range of higher exposures the results are closer to the values based on the age- duration model. The two-mutation model predicts the increase of dRR/dC with the increase of the radon concentration in the range of low concentrations. According to our results the inverse effect occurs only when the radon concentrations reach the value of 1500 Bq/m3. The two-mutation model can be taken as an universal model for the risk calculation in different environments, and for various smoking status. This model makes possible to analyse the influence of the fractionalisation of the exposure on the resulting RR. (authors)

  12. Doses and affects of radon and its daughters

    International Nuclear Information System (INIS)

    Radon and its short-lived daughters are one of the main contributors to the natural exposures of ionizing radiation to man. Their sources, levels and characteristics are described. By inhalation of radon and its daughters tissues in the lung are irritated by α-particles leading to an increased risk of lung cancer. Methods of calculation of doses and risks using the dosimetric approach and the epidemiological approach are described and discussed. (Author)

  13. New reasons for concern about indoor radon exposure?

    International Nuclear Information System (INIS)

    The author gives critical comments on a publication by Steindorf et al. (Lung cancer deaths attributable to indoor radon exposure in West Germany, Intern. J. Epidemiol. 24 (1995)), and compares the results published there with other, primarily international publications. Other than Steindorf, the author's conclusion is that there are no signs of an indoor radon effect on lung cancer incidence in the residential population. The author raises doubts about the seriosity of the publication of Steindorf et al. (VHE)

  14. Radon dynamics in underwater thermal radon therapy

    International Nuclear Information System (INIS)

    At a facility for underwater thermal radon therapy in Bad Hofgastein, experiments were carried out with the aim of establishing radon in the air exhaled by the treated patients and of radon decay products on the skin of the patients. The time course of radon concentration in the exhaled air shows a maximum a few minutes after entering the bath, then the Rn concentration remains constant over the remaining time spent in the bath. Taking into account several simplifying assumptions, the average dose to the epidermis from radon daughters is about 50 μGy. (A.K.)

  15. Factors affecting passive monitoring of radon

    International Nuclear Information System (INIS)

    In recent years, increasing cancer has been expressed as a possible health hazards associated with long-term exposures to a large population at a low level of radon in the environment. Because radon is ubiquitous nuclide, nation-wide monitoring is necessary to determine lung cancer risk. For such purpose, passive sampling methods with track etch detector or charcoal adsorption collector may have the advantage in lower cost and convenience. The charcoal adsorption collector is considered in this study. Various factors may significantly affect the charcoal adsorption mechanism on its practical application. Moisture effects are discussed here as having major impact on radon collection by charcoal. Set of equations are presented in this report to describe adsorption of radon including moisture effects. (author) 61 refs

  16. Draft of „National Radon Programme” 2013-2017

    International Nuclear Information System (INIS)

    The World Health Organization defines radon as the second most important causal factor for lung cancer after smoking and the number one factor for people who have never smoked. The draft of the new European Directive takes accounts the latest ICRP Recommendations for reducing radon exposure in buildings. The Directive requires Member States to bring into force the laws, regulations and administrative provisions. The main goal of „National Radon Programme” is establishment and implementation of long-term policy to reduce and prevent risks of public health resulting from exposure to high concentrations of indoor radon in buildings. To achieve this are required: – to establish an appropriate system; – to carry out national survey and mapping of areas with radon background; – to establish radon prevention strategies in newly constructed buildings and radon mitigation strategies in existing buildings; – to improve public awareness; – to lay down a system for protection against radon in workplaces. The implementation of the program will contribute to reducing the public exposure due to indoors due to radon. Along with the reduction of smoking, it will directly and indirectly improve the prevention of lung cancer risks. (author)

  17. Radon gas: detection techniques, health impacts and reduction methods

    International Nuclear Information System (INIS)

    Radon-222, a decay product of Uranium, is found to be radioactively contaminating homes throughout the US and causing hazardous working conditions for uranium miners. Radon gas decays to various heavy metal isotopes of polonium, bismuth and lead which in turn emit alpha particles. Despite an alpha particle's shallow penetration distance of approximately 20 microns, biological damage can be extensive if ingested, possibly resulting in lung cancer. The toll of lung cancer fatalities due to Radon exposure is estimated at 20,000 per year in the US. Statistical surveys approximate that 7% of homes in the US, or roughly four million, exceed the 4 picocurie per liter limit set by the EPA at which remedial action is recommended. In the Uranium mining industry, the common unit of measurement for radon radiation, the working level (WL), is set at a maximum of 4 WL per month per year. The instruments presently available to measure and monitor radon levels are: Working Level Meters, Charcoal Filters, and Track Etch Detectors. Construction Technology to reduce radon levels can be as easy as installing ventilation system and sealing off entry routes of radon gas. The paper will provide an overview of radon sources, detection techniques, the health impact on the public and construction technology in the reduction of radon levels

  18. Design Criteria for Achieving Acceptable Indoor Radon Concentration

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2016-01-01

    from the ground, and the third criteria can dilute the indoor air. By combining these three criteria, the indoor radon concentration can be lowered achieving an acceptable level. In addition, a cheap and reliable method for measuring the radon concentration in the indoor air is described. The provision......Design criteria for achieving an acceptable indoor radon concentration are presented in this paper. The paper suggests three design criteria. These criteria have to be considered at the early stage of the building design phase to meet the latest recommendations from the World Health Organization...... on radon in the Danish Building Regulations complies with the latest recommendations from the World Health Organization. Radon can cause lung cancer and it is not known whether there is a lower limit for when it is not harmful to human beings. Therefore, it is important to reduce the radon concentration...

  19. AN OVERVIEW OF INDOOR RADON RISK REDUCTION IN THE UNITED STATES

    Science.gov (United States)

    The paper presents an overview of indoor radon risk reduction in the U.S. EPA currently estimates that 15,000-20,000 Americans die each year fromradon-induced lung cancer. his estimate is based on epidemiological data which establish the link between radon and lung cancer, and su...

  20. Indoor radon: Health effects and future research trends

    International Nuclear Information System (INIS)

    Radon delivers the highest dose to man from all radiation sources and therefore has an increasing impact on society. Health effects attributed to radon decay product (Rn-d) inhalation are lung cancer, skin cancer and kidney diseases. Quantification of these risks is based largely on epidemiological evidence and subject to significant uncertainties. Best estimates of risk for lung cancer indicate that in excess of 5% of all cases may be caused by Rn-d. Further radon-related research is required in the areas of source term characterization, aerosol sciences and radiobiology. (author). 42 refs, 3 figs, 3 tabs

  1. The history of radon from a Swedish perspective

    International Nuclear Information System (INIS)

    Beginning in the 16. century, what was later found to be radon was thought to be causing sickness among miners. During the first decades of the 20. century, exposure to radon was seen as being healthy. During the 1940's, 1950's and 1960's researchers thought that the gamma radiation in residences could produce genetic damage. It was not until approximately 1970 that a quantitative risk estimate for lung cancer could be calculated for miners, and not until the 1990's that a risk estimate could be established based on epidemiological studies on radon in dwellings and lung cancer. (authors)

  2. Measurements of radon in soil gas

    International Nuclear Information System (INIS)

    Full text: After the decades of systematic and numerous studies performed at different countries of the World, it has been concluded that radon as well as its progeny is the main cause of lung cancer. It is well known that more than 50% of the effective annual radiation dose received by a human being is related to the radon and its progenies. Among the principle mechanisms that bring the radon inside the dwelling is the soil exhalation as well as exhalation and release from the water. Radon concentration in the soil and its transport (emanation, diffusion, advection and adsorption) to the surface depends on different physical, geological and ambient parameters such as the geology of the area, geochemical composition of the soil, its porosity and permeability, grain size, soil humidity, bottom sediments and inputs from streams, temperature, atmospheric pressure, etc. Since the main part of indoor radon originates in the soil, the measurements of radon concentration in soil gas have to be considered as an important tool and indicator of probable high levels of radon inside the dwellings. Present work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. The equipment was adjusted with air flow of 0.03 L

  3. Modeling the potential impacts of different radon policies for the U.S. housing stock

    International Nuclear Information System (INIS)

    According to the Environmental Protection Agency (EPA) and other public health agencies in the United States, radon may be the leading cause (along with passive smoking) of lung cancer deaths among nonsmokers. Radon is estimated to be the second leading cause of lung cancer death in smokers behind smoking-related lung cancer. EPA estimates that 7,000 to 30,000 lung cancer deaths each year are due to radon exposure. (It is implied that radon-related lung cancer deaths can be prevented by reducing radon levels below EPA's guideline levels). Current EPA radon policy is based on a strategy of education, the transfer of testing and remediation technologies to the public and private sectors, and recently proposed radon-resistant construction standards for new homes. This paper models the effectiveness of current proposed, and alternative policies for reducing radon risks in U.S. residential construction. The results of our analysis suggest that EPS's projections of 2,200 'lives saved annually' as a result of its current action level of 4 pCi/l will not be achieved with its current policy in the near future. Overall, the response of radon-related mortality to most policy options is delayed and flat due in part to the large number of houses with low radon levels and the long latency period between radon exposure and the development of cancer. The modeling results suggest that more aggressive smoking reduction programs may yield greater benefits in overall lung cancer mortality (but not reduced radon exposure) than most radon-related policies. (au)

  4. Evaluation of indoor radon

    International Nuclear Information System (INIS)

    In the indoor radon environment, building ventilation and indoor air quality problems are discussed. They take their origin from the building materials, and the ventilation rate, plate-out and recoil rate of radon daughters are effective in evaluating the concentration of indoor radon. The deposition processes depend on the physical properties of the free atoms and activity size distributions of the aerosols. The equilibrium factor, the radon daughter concentrations relative to the radon concentration, are influenced by the room specific parameters. This paper summarizes available information on indoor radon concentrations and on the physical characteristics of radon daughters. For evaluation fo the risk of radon, the measuring results of the degree of radioactive equilibrium, and its time variations, mean size of individual radon daughters are reported. (author)

  5. Lyman-Alpha Emitter Galaxies at z ~ 2.8 in the Extended Chandra Deep Field-South: I. Tracing the Large-Scale Structure via Lyman-Alpha Imaging

    CERN Document Server

    Zheng, Zhen-Ya; Rhoads, James E; Finkelstein, Steven L; Wang, Jun-Xian; Jiang, Chun-Yan; Cai, Zheng

    2016-01-01

    We present a narrowband survey with three adjacent filters for z=2.8--2.9 Lyman Alpha Emitter (LAE) galaxies in the Extended Chandra Deep Field South (ECDFS), along with spectroscopic followup. With a complete sample of 96 LAEs in the narrowband NB466, we confirm a large-scale structure at z~ 2.8. Compared to the blank field in NB470 and NB475, the LAE density excess in the NB466 field is ~6.0+/-0.8 times the standard deviation expected at z~2.8, assuming a linear bias of 2. The overdense large scale structure in NB466 can be decomposed into 4 protoclusters, whose overdensities are 4.6 - 6.6. These 4 protoclusters are expected to evolve into a Coma-like cluster at z~ 0. In the meanwhile, we investigate the average star-formation rates derived from Ly{\\alpha}, rest-frame UV and X-ray, the Ly{\\alpha} luminosity functions, the Ly{\\alpha} photon densities and their dependence on the environment. We find that the Ly{\\alpha} photon density in the overdense field (NB466) is ~50\\% higher than that in the blank field ...

  6. A remarkably high fraction of strong Ly_alpha emitters amongst luminous redshift 6.0

    CERN Document Server

    Curtis-Lake, E; Pearce, H J; Dunlop, J S; Cirasuolo, M; Stark, D P; Almaini, O; Bradshaw, E J; Chuter, R; Foucaud, S; Hartley, W G

    2011-01-01

    We present spectroscopic confirmation of ten highly luminous (L >= 2L*) Lyman alpha emitters in the redshift range 6.01= 6 Lyman break galaxies (LBGs) selected from an area of 0.25 square degrees within the UKIDSS Ultra-deep Survey (UDS). Overall, our high rate of spectroscopic confirmation (>= 71%) and low rate of contamination provides a strong vindication of the photometric redshift analysis used to define the original sample. By considering star-formation rate estimates based on the Ly_alpha and UV continuum luminosity we conclude that our sample is consistent with a Ly_alpha escape fraction of ~25%. Moreover, after careful consideration of the potential uncertainties and biases, we find that 40%-50% of our sample of L >= 2L* galaxies at 6.0= 25 Angs), a fraction which is a factor of ~2 higher than previously reported for L =2 L*) LBGs shows a similarly sharp increase to that observed in their lower-luminosity (L <= L*) counterparts.

  7. Strategy to reduce radon exposure in Norway; Strategi for aa redusere radoneksponeringen i Norge

    Energy Technology Data Exchange (ETDEWEB)

    2009-06-15

    Radon in indoor air is a more widespread problem in Norway than in many other countries. It can be estimated that radon in indoor air causes about. 300 lung cancer deaths annually in Norway. Norway, together with Sweden and Finland, are among the countries in the world with the highest average concentration of radon in indoor air. Geological conditions and the cool climate provides great challenges, but radon problem can be solved in a cost effective way. The risk increases with exposure and is proportional with radon concentrations in indoor air and exposure time. The risk from radon, however, no lower threshold value. Moreover, the risk is highest for those who smoke and those who have smoked previously, but non-smokers can also develop lung cancer as a result of radon exposure. In recent years it has been conducted three large, important international joint studies that confirm earlier estimates of the risk. (AG)

  8. Dosimetric challenges for residential radon epidemiology.

    OpenAIRE

    Steck, Daniel J.; Field, R. William

    2006-01-01

    KEYWORDS CLASSIFICATION: adverse effects;analysis;Air Pollutants;Air Pollutants,Radioactive;Air Pollution,Indoor;biomarkers of exposure & effect: validation;Biological Markers;cancer epidemiology;Carcinogens;Carcinogens,Environmental;Dose-Response Relationship,Radiation;epidemiology;etiology;Environmental Exposure;Housing;Humans;Lung Neoplasms;Minnesota;Neoplasms,Radiation-Induced;Radon;Research;Risk Assessment;

  9. Radon risks from uranium mining in Germany

    International Nuclear Information System (INIS)

    Soviet mining for uranium in Germany after World War II caused widespread environmental damage and also a considerable number of lung cancers and other diseases amongst the workforce. Epidemiological studies of workers and of the general population are being set up to try to obtain information about the risks of radon exposure. (UK)

  10. Determination of Radon Concentration in Some Types of the Smoking Staff

    International Nuclear Information System (INIS)

    Radon concentrations were measured with long- term alpha-track radon detectors along with radon scout. Radon gas emanates from the radium content of terrestrial products, like tobacco leaves. Smoking materials contain, beside tobacco, many other additives that may also contain radium traces. These additives aim at exciting smoker’s feeling via chemical reactions, which may be disrupted by alpha particle simultaneous ionizing effect leading to mutation. This study may provide evidence of intimate relation between smoke’s radon and risk of lung cancer. Radon was measured by tracking its emitted alpha particles in solid state CR - 39 plastic detector and also by counting ionization pulses in silicon surface barrier detector (radon-scout). The results indicate that some of the cigarette staffs raise radon concentration in air to 270 bq/m3, corresponding to an annual effective dose of about 5500 μ Sv

  11. Radon in geological medium

    International Nuclear Information System (INIS)

    The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The av has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km2. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (av > 50 kBq/m3). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

  12. BEIR VI report. Public summary: the health effects of exposure to indoor radon

    International Nuclear Information System (INIS)

    For centuries it has been known that some underground miners suffered from higher rates of lung cancer than the general population. In recent decades, a growing body of evidence has casually linked their lung cancers to exposure to high levels of radon and also to cigarette smoking. The connection between radon and lung cancer in miners has raised concern that radon in homes might be causing lung cancer in the general population, although the radon levels in most homes are much lower than in most mines. The National Research Council study, which has been carried out by the sixth Committee on Biological Effects of Ionizing Radiations (BEIR VI), has used the most recent information available to estimate the risks posed by exposure to radon in homes. The most direct way to assess the risks posed by radon in homes is to measure radon exposures among people who have lung cancer and compare them with exposures among people who have not developed lung cancer. Several such studies have been completed, and several are under way. The studies have not produced a definitive answer, primarily because the risk is likely to be very small at the low exposure encountered from most homes and because it is difficult to estimate radon exposures that people have received over their lifetimes. In addition, it is clear that far more lung cancers are caused by smoking that are caused by radon. The risk of lung cancer caused by smoking is much higher than the risk of lung cancer caused by indoor radon. Most of the radon-related deaths among smokers would not have occurred if the victims had not smoked. Furthermore, there is evidence for a synergistic interaction between smoking and radon. In other words, the number of cancers induced in ever-smokers by radon is greater than one would expect from the additive effects of smoking along and radon alone. Nevertheless, the estimated 15400 or 21800 deaths attributed to radon in combination with cigarette-smoking and radon alone in never

  13. Environmental Radon Gas and Degenerative Conditions An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom)]|[School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom); Denman, A.R. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom); Woolridge, A.C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)]|[School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, P.S. [School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)

    2006-07-01

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of {sup 222}Rn and its progeny {sup 218}Po and {sup 214}Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  14. Environmental Radon Gas and Degenerative Conditions An Overview

    International Nuclear Information System (INIS)

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of 222Rn and its progeny 218Po and 214Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  15. Radon in homes. Council on Scientific Affairs

    International Nuclear Information System (INIS)

    Radon 222 and its radioactive decay products can enter buildings and, through inhalation, expose the inhabitants' pulmonary tissues to ionizing radiation. Studies of radon levels in the United States indicate that variations of 100-fold or greater exist among private dwellings. In one region, 55% of homes had levels exceeding 4 pCi/L (0.15 Bq/L), which is the guidance level recommended by the US Environmental Protection Agency. Ventilation and tightness of construction are important determinants of radon levels. In some instances, fans or heat exchangers can reduce excessive concentrations, but in others more elaborate remedial measures may be required. Physicians may obtain information about radon through Environmental Protection Agency regional offices and state radiation control programs. The risk of radiogenic cancer is believed to increase with exposure to ionizing radiation. According to some estimates, concentrations of radon decay products in US homes could be responsible for several thousand cases of lung cancer per year. Studies of radon levels in representative buildings and guidelines are needed to ensure safe, effective, and cost-effective countermeasures. Architects, contractors, designers, building code administrators, health physicists, and biomedical investigators can help with solutions

  16. Radon in dwellings

    International Nuclear Information System (INIS)

    An evaluation of methods for the radiation monitoring of radon in indoor air is given, together with guidelines for the investigation of building sites taking in consideration the radiation hazards from radon. 2 figs., 4 tabs

  17. Radon in dwellings

    International Nuclear Information System (INIS)

    Radon, a radioactive gas emitted from soils and construction materials, penetrates dwellings and is the principal source of natural background radiation. If they are inhaled continuously, radon and its daughter products may constitute a hazard for man

  18. Radon in Austria

    International Nuclear Information System (INIS)

    Several projects in Austria deal with the problem of enhanced radon exposure to the public. The Austrian Radon Project is the largest project within this task, with the aim of investigating the radon concentrations in Austrian homes. Another project concerns mitigation methods. According to the EU directive EURATOM 96/29 it is also necessary to check working places for possibly enhanced radon concentrations. These projects are and will be funded by the government. The federal government of Upper Austria sponsored a project to test the indoor air quality in kindergartens including radon measurements. Within an EU research project, the radon concentrations in Austrian springs and groundwater were systematically listed and analyzed. Additional investigations will focus on methods to improve the radon potential maps from the Austrian Radon Project by including geological and other information. (author)

  19. Radon exposure of the skin: I. Biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Charles, M W [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2007-09-15

    Radon progeny can plate out on skin and give rise to exposure of the superficial epidermis from alpha emitters Po-218 (7.7 MeV, range {approx}66 {mu}m) and Po-214 (6 MeV, range {approx}44 {mu}m). Dose rates from beta/gamma emitters Pb-214 and Bi-214 are low and only predominate at depths in excess of the alpha range. This paper reviews the evidence for a causal link between exposure from radon and its progeny, and deterministic and stochastic biological effects in human skin. Radiation induced skin effects such as ulceration and dermal atrophy, which require irradiation of the dermis, are ruled out for alpha irradiation from radon progeny because the target cells are considerably deeper than the range of alpha particles. They have not been observed in man or animals. Effects such as erythema and acute epidermal necrosis have been observed in a few cases of very high dose alpha particle exposures in man and after acute high dose exposure in animals from low energy beta radiations with similar depth doses to radon progeny. The required skin surface absorbed doses are in excess of 100 Gy. Such effects would require extremely high levels of radon progeny. They would involve quite exceptional circumstances, way outside the normal range of radon exposures in man. There is no definitive identification of the target cells for skin cancer induction in animals or man. The stem cells in the basal layer which maintain the epidermis are the most plausible contenders for target cells. The majority of these cells are near the end of the range of radon progeny alpha particles, even on the thinnest body sites. The nominal depth of these cells, as recommended by the International Commission on Radiological Protection (ICRP), is 70 {mu}m. There is evidence however that some irradiation of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is also necessary for skin cancer induction. Alpha irradiation of rodent skin that is restricted to the

  20. Radon exposure of the skin: I. Biological effects

    International Nuclear Information System (INIS)

    Radon progeny can plate out on skin and give rise to exposure of the superficial epidermis from alpha emitters Po-218 (7.7 MeV, range ∼66 μm) and Po-214 (6 MeV, range ∼44 μm). Dose rates from beta/gamma emitters Pb-214 and Bi-214 are low and only predominate at depths in excess of the alpha range. This paper reviews the evidence for a causal link between exposure from radon and its progeny, and deterministic and stochastic biological effects in human skin. Radiation induced skin effects such as ulceration and dermal atrophy, which require irradiation of the dermis, are ruled out for alpha irradiation from radon progeny because the target cells are considerably deeper than the range of alpha particles. They have not been observed in man or animals. Effects such as erythema and acute epidermal necrosis have been observed in a few cases of very high dose alpha particle exposures in man and after acute high dose exposure in animals from low energy beta radiations with similar depth doses to radon progeny. The required skin surface absorbed doses are in excess of 100 Gy. Such effects would require extremely high levels of radon progeny. They would involve quite exceptional circumstances, way outside the normal range of radon exposures in man. There is no definitive identification of the target cells for skin cancer induction in animals or man. The stem cells in the basal layer which maintain the epidermis are the most plausible contenders for target cells. The majority of these cells are near the end of the range of radon progeny alpha particles, even on the thinnest body sites. The nominal depth of these cells, as recommended by the International Commission on Radiological Protection (ICRP), is 70 μm. There is evidence however that some irradiation of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is also necessary for skin cancer induction. Alpha irradiation of rodent skin that is restricted to the epidermis does not

  1. Estimation of the Indoor Radon and the Annual Effective Dose from Granite Samples

    International Nuclear Information System (INIS)

    Inhalation of radon and radon daughters increases the risk of lung cancer. The main sources of indoor radon are the building materials especially granite. The aim of this research is to estimate the indoor radon and the annual effective dose from the building materials. Eighteen granite samples bought from the market in Thailand were measured using an ionization chamber (ATMOS 12 DPX) for the radon concentration in air. Radon exhalation rates were calculated using the radon concentration in air. And then the indoor radon and the annual effective dose were estimated from the granite samples using radon exhalation rates. The radon exhalation rates ranged from 0.05-15.55 Bq m-2 h-1 with an average of 5.87 Bq m-2 h-1. The indoor radon concentration ranged from 10.00-59.33 Bq m-3 with an average of 28.53 Bq m-3. The annual effective dose ranged from 0.25-1.49 mSv y-1 with an average of 0.72 mSv y-1. A good correlation between the radon exhalation rate and the indoor radon concentration was observed. Six samples showed the annual effective dose higher than the annual exposure limit for the general public (1 mSv y-1) recommended by the International Commission on Radiological Protection (ICRP).

  2. Radon in buildings

    International Nuclear Information System (INIS)

    This guide is intended to inform designers, householders and other building owners about the radon problem and to help in deciding if there is need to take any action to reduce radon levels in their homes or other buildings.It explains what radon is, how it enters buildings and what effect it may have on health. Reference is made to some of the usual ways of reducing the level of radon and guidance is given on some sources of assistance

  3. Radon exhalation from building materials for decorative use.

    Science.gov (United States)

    Chen, Jing; Rahman, Naureen M; Abu Atiya, Ibrahim

    2010-04-01

    Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m(-2) d(-1). Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m(-2) d(-1) for slate tiles and 42 Bq m(-2) d(-1) for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m(-2) d(-1), it would contribute only 18 Bq m(-3) to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange. PMID:20167403

  4. Radon exhalation from building materials for decorative use

    International Nuclear Information System (INIS)

    Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m-2 d-1. Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m-2 d-1 for slate tiles and 42 Bq m-2 d-1 for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m-2 d-1, it would contribute only 18 Bq m-3 to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange.

  5. Factors underlying residential radon concentration: Results from Galicia, Spain

    International Nuclear Information System (INIS)

    Radon causes lung cancer when inhaled for prolonged periods of time. A range of factors influence residential radon concentration and this study therefore sought to ascertain which dwelling-related factors exert an influence on radon levels. A cross-sectional study was conducted from 2001 to 2003 which analyzed 983 homes of as many subjects randomly selected from the 1991 census. Sampling was carried out by district and stratified by population density to ensure that more detectors were placed in the most heavily populated areas. Radon concentration and different dwelling characteristics were measured in each of the homes selected. Bivariate and multivariate analyses were performed to ascertain which factors influenced radon concentration. The geometric mean of radon concentration was 69.5 Bq/m3, and 21.3% of homes had concentrations above 148 Bq/m3. Factors shown to influence radon concentration in the bivariate analysis were: age of dwelling; interior building material; exterior building material; and storey on which the detector was placed. Explanatory variables in the multivariate analysis were: age of dwelling; number of storeys; distance off floor; and interior building material. The model was significant, but the variability explained was around 10%. These results highlight the fact that the study area is an area of high radon emission and that factors other than those directly related with the characteristics of the dwelling also influence radon concentration

  6. Central radon data base and digitized bedrock map of US EPA (Environmental Protection Agency) Region 1. Technical report

    International Nuclear Information System (INIS)

    This research entails compilation, management, and evaluation of existing data on domestic radon levels. The work requires the cooperation of radon programs throughout Region 1 states. The updated data base has geographic capabilities and can be used to gain a clearer picture of areas with high radon levels. The research for the report includes updating the radon data base for EPA's Region 1 and digitizing the existing Bedrock Geologic Map. Lifetime exposure to high indoor radon gas levels contributes to an increased risk of lung cancer. Geologic parameters are thought to be predictive factors of both well water and indoor radon levels. Therefore, because radon is an important environmental risk and because risk communication is likely to play a central role in EPA's policies for radon related risk, the project attempts to develop appropriate radon risk communication strategies

  7. Comparative risk assessment of residential radon exposures in two radon-prone areas, Stei (Romania) and Torrelodones (Spain)

    International Nuclear Information System (INIS)

    Radon and radon progeny are present indoors, in houses and others dwellings, representing the most important contribution to dose from natural sources of radiation. Most studies have demonstrated an increased risk of lung cancer at high concentration of radon for both smokers and nonsmokers. The work presents a comparative analysis of the radon exposure data in the two radon-prone areas, Stei, Transylvania, (Romania), in the near of old Romanian uranium mines and in the granitic area of Torrelodones town, Sierra de Guadarrama (Spain). Measurements of indoor radon were performed in 280 dwellings (Romania) and 91 dwellings (Spain) by using nuclear track detectors, CR 39. The highest value measured in Stei area was 2650 Bq m-3 and 366 Bq m-3 in the Spanish region. The results are computed with the BEIR VI report estimates using the age-duration model at an exposure rate below 2650 Bq m-3. We used the EC Radon Software to calculate the lifetime lung cancer death risks for individuals groups in function of attained age, radon exposures and tobacco consumption. A total of 233 lung cancer deaths were observed in the Stei area for a period of 13 years (1994-2006), which is 116.82% higher than expected from the national statistics. In addition, the number of deaths estimated for the year 2005 is 28, which is worth more than 2.21 times the amount expected by authorities. In comparison, for Torrelodones was rated a number of 276 deaths caused by lung cancer for a period of 13 years, which is 2.09 times higher than the number expected by authorities. For the year 2005 in the Spanish region were reported 32 deaths caused by pulmonary cancer, the number of deaths exceeding seen again with a factor of 2.10 statistical expectations. This represents a significantly evidence that elevated risk can strongly be associated with cumulated radon exposure.

  8. Radiological risk assessment of environmental radon

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Norafatin; Majid, Amran Ab; Yahaya, Redzuwan; Yasir, Muhammad Samudi [Nuclear Science Programme, School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    Measurements of radon gas ({sup 222}Rn) in the environmental are important to assess indoor air quality and to study the potential risk to human health. Generally known that exposure to radon is considered the second leading cause of lung cancer after smoking. The environmental radon concentration depends on the {sup 226}Ra concentration, indoor atmosphere, cracking on rocks and building materials. This study was carried out to determine the indoor radon concentration from selected samples of tin tailings (amang) and building materials in an airtight sealed homemade radon chamber. The radiological risk assessment for radon gas was also calculated based on the annual exposure dose, effective dose equivalent, radon exhalation rates and fatal cancer risk. The continuous radon monitor Sun Nuclear model 1029 was used to measure the radon concentration emanates from selected samples for 96 hours. Five types of tin tailings collected from Kampar, Perak and four samples of building materials commonly used in Malaysia dwellings or building constructions were analysed for radon concentration. The indoor radon concentration determined in ilmenite, monazite, struverite, xenotime and zircon samples varies from 219.6 ± 76.8 Bq m{sup −3} to 571.1 ± 251.4 Bq m{sup −3}, 101.0 ± 41.0 Bq m{sup −3} to 245.3 ± 100.2 Bq m{sup −3}, 53.1 ± 7.5 Bq m{sup −3} to 181.8 ± 9.7 Bq m{sup −3}, 256.1 ± 59.3 Bq m{sup −3} to 652.2 ± 222.2 Bq m{sup −3} and 164.5 ± 75.9 Bq m{sup −3} to 653.3 ± 240.0 Bq m{sup −3}, respectively. Whereas, in the building materials, the radon concentration from cement brick, red-clay brick, gravel aggregate and cement showed 396.3 ± 194.3 Bq m{sup −3}, 192.1 ± 75.4 Bq m{sup −3}, 176.1 ± 85.9 Bq m{sup −3} and 28.4 ± 5.7 Bq m{sup −3}, respectively. The radon concentration in tin tailings and building materials were found to be much higher in xenotime and cement brick samples than others. All samples in tin tailings were exceeded the

  9. Radiological risk assessment of environmental radon

    International Nuclear Information System (INIS)

    Measurements of radon gas (222Rn) in the environmental are important to assess indoor air quality and to study the potential risk to human health. Generally known that exposure to radon is considered the second leading cause of lung cancer after smoking. The environmental radon concentration depends on the 226Ra concentration, indoor atmosphere, cracking on rocks and building materials. This study was carried out to determine the indoor radon concentration from selected samples of tin tailings (amang) and building materials in an airtight sealed homemade radon chamber. The radiological risk assessment for radon gas was also calculated based on the annual exposure dose, effective dose equivalent, radon exhalation rates and fatal cancer risk. The continuous radon monitor Sun Nuclear model 1029 was used to measure the radon concentration emanates from selected samples for 96 hours. Five types of tin tailings collected from Kampar, Perak and four samples of building materials commonly used in Malaysia dwellings or building constructions were analysed for radon concentration. The indoor radon concentration determined in ilmenite, monazite, struverite, xenotime and zircon samples varies from 219.6 ± 76.8 Bq m−3 to 571.1 ± 251.4 Bq m−3, 101.0 ± 41.0 Bq m−3 to 245.3 ± 100.2 Bq m−3, 53.1 ± 7.5 Bq m−3 to 181.8 ± 9.7 Bq m−3, 256.1 ± 59.3 Bq m−3 to 652.2 ± 222.2 Bq m−3 and 164.5 ± 75.9 Bq m−3 to 653.3 ± 240.0 Bq m−3, respectively. Whereas, in the building materials, the radon concentration from cement brick, red-clay brick, gravel aggregate and cement showed 396.3 ± 194.3 Bq m−3, 192.1 ± 75.4 Bq m−3, 176.1 ± 85.9 Bq m−3 and 28.4 ± 5.7 Bq m−3, respectively. The radon concentration in tin tailings and building materials were found to be much higher in xenotime and cement brick samples than others. All samples in tin tailings were exceeded the action level for radon gas of 148 Bq m−3 proposed by EPA except monazite 0.15 kg, struverite 0

  10. Dust and radon: the legal implications

    International Nuclear Information System (INIS)

    It is known that radon gas is not generally considered to be a major problem when encountered in the working environment. However, in its process of decay, a series of four short lived daughter products are formed. In a dust-laden atmosphere these daughter products, which are ionized readily, attach to the particulate material and when inhaled are deposited in the alveoli of the lungs. Therefore, if respirable dust is controlled, the effects of radon daughters will also be minimized. The legal requirements for dust control in South Africa and their implications are discussed. 1 ill

  11. Radon-hazard potential the Beaver basin, Utah

    International Nuclear Information System (INIS)

    Indoor-radon levels in the Beaver basin of southwestern Utah are the highest recorded to date in Utah, ranging from 17.5 to 495 picocuries per liter (pCi/L). Because the U.S. Environment Protection Agency considers indoor-radon levels above 4 pCi/L to represent a risk of lung cancer from long-term exposure, the Utah Geological Survey is preparing a radon-hazard-potential map for the area to help prioritize indoor testing and evaluate the need for radon-resistant construction. Radon is a chemically inert radioactive gas derived from the decay of uranium-238, which is commonly found in rocks and soils. Soil permeability, depth to ground water, and uranium/thorium content of source materials control the mobility and concentration of radon in the soil. Once formed, radon diffuses into the pore space of the soil and then to the atmosphere or into buildings by pressure-driven flow of air or additional diffusion. The Beaver basin has been a topographic and structural depression since late Miocene time. Paleocene to Miocene volcanic and igneous rocks border the basin. Uraniferous alluvial-fan, piedmont-slope, flood-plain, and lacustrine sediments derived from the surrounding volcanic rocks fill the basin. A soil-gas radon and ground radioactivity survey in the Beaver basin shows that soils have high levels of radon gas. In this survey, uranium concentrations range from 3 to 13 parts per million (ppm) and thorium concentrations range from 10 to 48 ppm. Radon concentrations in the soil gas ranged from 85 to 3,500 pCi/L. The highest concentrations of uranium, thorium, and radon gas and the highest radon-hazard-potential are in the well-drained permeable soils in the lower flood- plain deposits that underlie the city of Beaver

  12. Study on the risk of late damage in humans after incorporation of the short-lived alpha emitter Ra-224; Studie zum Risiko von Spaetschaeden beim Menschen nach Inkorporation des kurzlebigen {alpha}-Strahlers Radium-224

    Energy Technology Data Exchange (ETDEWEB)

    Wick, R.R.; Nekolla, E.A.; Kellerer, A.M. [Muenchen Univ. (Germany). Strahlenbiologisches Inst.; Goessner, W. [Gesellschaft fuer Strahlen- und Umweltforschung mbH Muenchen, Neuherberg (Germany). Inst. fuer Pathologie

    2003-07-01

    An epidemiological study has been carried out at the GSF - National Research Center for Environment and Health - between 1948 and 1975, on 1460 ankylosing spondylitis (AS) patients. The aim of the study was to ascertain the late health effects suffered by these patients who had received repeated intravenous injections of the short lived {alpha}-emitter {sup 224}Ra. These patients have been followed together with a control group of 1323 ankylosing spondylitis patients not treated with radioactive drugs and/or X-rays. Causes of death have been ascertained for 842 exposed patients and 861 controls by the end of 2002. In the exposed group there has been a total of 219 malignant diseases and 206 cases among the controls. In particular, we observed 15 cases of leukaemia in the exposure group and 8 cases of leukaemia in the control group. Further subclassification of the leukaemias demonstrated a high increase of myeloid leukaemia in the exposure group (9 cases obs. vs. 2.5 cases exp.), and out of these especially the acute myeloid leukaemias (6 cases observed vs. 1.6 expected), whereas in the control group the observed cases are within the expected range (3 myeloid leukaemias vs. 2.6 cases). Out of these 6 cases of myeloid leukaemia, 3 cases have been observed at doses comparable to those of the currently applied {sup 224}Ra treatment with the preparation SpondylAT {sup registered}, in one case the {sup 224}Ra-dose was the 0.6fold, in another case 1.6fold, whereas in one case the total dose could not be verified exactly. The enhanced leukaemia incidence in our exposed group is in line with results from animal experiments in mice having been injected with bone seeking {alpha}-emitters given at low dose rates. (orig.) [German] Im Rahmen einer epidemiologischen Studie werden im GSF-Forschungszentrum 1460 Bechterew-Patienten beobachtet, die in den Jahren 1948 bis 1975 zur Behandlung ihrer Krankheit wiederholte intravenoese Injektionen von {sup 224}Ra erhalten haben. Daneben

  13. Influence of aerosol upon radon concentration of radon chamber

    International Nuclear Information System (INIS)

    On the basis of theoretical analysis, the influence on the radon concentration of radon chamber by the experiment of filling the radon chamber with aerosol, and the absorption of radon daughter on aerosol under the condition of different radon concentration and aerosol concentration was described. The results of experiment showed that: Aerosol did not affect the stability of the radon concentration of the radon chamber, but different aerosol concentration will change the combination state of radon daughter, thus it will affect the diffusion coefficient of radon daughter, so it will affect the results of the measure of the gross measuring instrument. (authors)

  14. Indoor radon level and dispersion study due to different type of building materials using CFD model

    International Nuclear Information System (INIS)

    Indoor radon is known for the contributing factor to natural radiation exposure to mankind. Radon progeny gets deposited into the lungs and increase the probability of lung cancer. The underneath soil is the main source of indoor radon. There are several pathways by which radon can migrate from the soil to indoor environment which can accumulate into the less ventilated room or dwellings. The diffusing barriers for radon entry from soil and indoor environment interface depends upon the type of building martial used for the flooring purpose. For this purpose the radon exhalation rates from different type of flooring was taken from the literature. The floors made of soil, marble, concrete and granite are main types of floors which are studied during the present work. The values of radon exhalation rate corresponding to the different type building material used for the construction of floor are used as the input parameter in CFD based model to study out the radon levels and dispersion pattern in less ventilated room. It has been found that CFD modeling is a good method to estimate the radon behavior under different situations. The indoor radon levels are found to be high for the mud flooring compare to other type of flooring. The visualization of indoor radon gas is also different for the different types of building materials. (author)

  15. Radon concentrations in some Egyptian dwellings using LR 115 detectors

    International Nuclear Information System (INIS)

    Radon, a well-established risk factor for human lung cancer, is present at low concentrations in most homes. Consequently, many countries have established national guidelines for residential radon concentrations. This survey provides additional information about indoor radon concentrations in Egypt. Indoor radon survey of a total of 15 randomly selected houses in Qena city, Upper Egypt was carried out. LR 115 detectors were exposed for one year, covering all the seasons. The estimated indoor radon levels varied from 19 to 59 Bq m3 with an average of 40 Bq m3. Using the bare and filtered LR 115 detectors, the average equilibrium factor F was assessed as 0.30 indoors. An average annual effective dose of 0.40 mSv has been estimated and was found to be lower than the ICRP-65

  16. Radon mitigation in soils

    International Nuclear Information System (INIS)

    Radon is produced in soil by radium decay, Ra-226 for radon (Rn-222) and Ra-224 for thoron (Rn-220). The radium content is about 40 Bq.kg-1 in crustal rocks and soils, 70 Bq.kg-1 in granite and only about 8 Bq.kg-1 in limestone. Being the heaviest gas in atmosphere, radon presents high concentration at surface and it is accumulating in closed or poorly ventilated places, both in underground cavities (caves or mines) and in dwelling. In comparison with the average radon concentration in atmospheric air of 8 Bq.m-3, the average indoor radon concentration reaches 10-100 Bq.m-3. International statistics indicate that radon contribution on natural irradiation is about 60%. The main sources of indoor radon are: radium content of the soil and of the concretes, water supply and natural gases

  17. A review of experimental animal radon health effects data

    International Nuclear Information System (INIS)

    Abundant epidemiological data from underground miners confirm that radon decay products (progeny) are carcinogenic, although the evidence is less conclusive on the quantitative risks of these exposures, especially for indoor air. The imprecision results principally from differences between exposures in mining and domestic environments and from uncertainties about the interaction between smoking and exposure to radon progeny. Experimental animal studies of radon-induced lung cancer are particularly valuable for understanding the carcinogenicity of human radon exposures in the home and in the workplace. Animals can be exposed to a variety of agents under carefully controlled conditions and then sacrificed for the study of developing lesions or held for their life span for tumor development. The doses to critical cells in the respiratory tract can be determined, and these in turn can be related to doses to critical cells in the respiratory tract of humans exposed to similar aerosols. The study of radon-induced mutations and changes in expression of oncogenes and tumor-suppressor genes as well as growth factors and growth factor receptors during tumor progression in animals also provides valuable evidence on the underlying mechanisms of radon carcinogenesis. This evidence, particularly that of the efficiency for oncogenic transformation at low dose rates, is crucial to the determination of the risk of lung cancer from exposure to indoor levels of radon. This review of animal health effects data emphasizes the carcinogenicity of radon exposures in rats; mechanistic data on radon-induced lung tumors in rats are currently sparse and are not reviewed here. (author). 15 refs, 1 fig., 1 tab

  18. Rehabilitation Measures against radon gas entry

    International Nuclear Information System (INIS)

    Radon gas is a pathological agent for inhabitants of buildings where it is present. Due to its origin in uranium decay chain, it bears radioactive effects that inside human body lead to higher risks of developing lung cancer. It comes from soils containing granite masses or other substrates containing uranium. It enters through common material used in constructions, such as concrete ground slabs, basement walls, etc. In order to avoid such gas immission into inhabited rooms, several measurements cab be considered for existing buildings. This study intends to show the results obtained for radon reductions by means of different constructive solutions, already designed and executed so as to stop radon gas immission into a prototype building constructed for this specific purpose

  19. Radon risk in ore miners

    International Nuclear Information System (INIS)

    Underground workers are exposed to various clastogenic agents. One of these agents, radon, attracts attention of recent research as it causes lung cancer in the population occupationally exposed to its various concentrations especially in mine air of uranium mines or ore mines. This paper is a pilot study in which the numbers of chromosomal aberrations (CA) in lymphocytes of ore mines (Nizna Slana-iron ore, Hnusta-talc ore) located in east central Slovakia were followed and related to the lifetime underground radon exposure and to lifetime smoking. Seventy miners volunteering after an informed consent served as donors of venous blood. Twenty healthy pro-bands, age matched with the miners, which never worked underground (mostly clerks) served as donors of control blood samples. The exposure to radon and smoking has been estimated according to working-records and personal anamnesis. The findings unequivocally showed a small but statistically significant clastogenic effect of the exposure to underground environment of the mines concerned. This study has shown also a small but significant influence of smoking, which in the subgroup of miners working underground less than 1500 shifts may have acted synergically with the underground exposure. It was concluded tat: (1) Significantly higher counts of chromosomal aberrations in lymphocytes of 70 miners than in an age matched control group of 20 white-collar workers were found; (2) The higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; (3) The positive dependence of the number of chromosomal aberrations from the exposure to smoking was loose and it was expressed by significantly higher chromosomal aberrations counts in the group of miners working less than 1500 shifts underground; (4) A dependence of chromosomal aberrations counts from the exposure to radon could not be assessed. At relatively low numbers of pro-bands in subgroups it was not ruled out the confounding

  20. Relationship among cancer,indoor radon and geology from Gejiu area

    Institute of Scientific and Technical Information of China (English)

    卢伟; 王任重; 等

    1996-01-01

    The mortality of lung cancer in Gejiu has reached the peak in the world.The indoor radon levels in Gejiu are measured by SSNTD.The results indicate that a higher indoor radon level widely exists in Gejiu area;the radon level in houses situated in geologic fault zone is 6 times as high as 2km from fault zone;the radon level in soil in faults is 6-8 times as high as 1km from faults;the radon level of the cancer patients' houses is 1.45 times as high as healths'.The relationship between indoor radon level and incidence of lung cancer is given for the firest time.

  1. Environmental radon dosimetry in Indian dwellings and workplaces

    International Nuclear Information System (INIS)

    Measurements of radon and its progeny in the dwellings and environment of workplaces are important because the radiation dose to human population due to inhalation of radon and its progeny contribute more than 50% of the total dose from natural sources and is the second leading cause of lung cancer after smoking. Recent experimental and epidemiological studies suggest that inhalation of radon progeny, which are the most important source of irradiation of the human respiratory track in workplace and domestic environment could be a cause of lung cancer. The quantification of individual radon exposure over a long time period is one of the main issues. In the present study, we will report the results of radon monitoring carried out in the environment of workplaces of an oil refinery, LPG bottling plant, thermal power plant and gas power plant, besides the typical and modern Indian dwellings using alpha sensitive L.R.-115 type II solid-state nuclear track detectors in order to quantify the dose to the workers and the inhabitants. For comparison, the radon and its progeny levels were also measured in dwellings far away from the plants. Radon and its progeny levels were found higher in the environment of workplaces and dwellings in the vicinity of the plants. The details of the results obtained will be reported in the full paper. (authors)

  2. Atmosphere purification of radon and radon daughter elements

    Science.gov (United States)

    Stein, L.

    1974-01-01

    A method of removing radon and radon daughter elements from an atmosphere containing these elements by passing the atmosphere through a bed of fluorinating compound whereby the radon and radon daughters are oxidized to their respective fluorides is discussed. These fluorides adhere to the fluorinating compound and are thus removed from the atmosphere which may then be recirculated. A method for recovering radon and separating radon from its daughter elements is also described. (Official Gazette)

  3. Interim indoor radon and radon decay-product measurement protocols

    International Nuclear Information System (INIS)

    The report provides EPA's procedures for measuring radon concentrations in houses with continuous radon monitors, charcoal canisters, alpha-track detectors, and grab radon techniques. It also provides procedures for measuring radon decay-product concentrations with a continuous-working-level monitor, a radon-progeny integrating sampling unit (RPISU), and grab radon decay-product methods. Specifications for the location of the measurement, the house conditions during the measurement, and minimum requirements for quality control are included in each procedure

  4. Internal Exposure of a Seoul Subway Passenger due to Radon Inhalation: Before and After PSD Installation

    International Nuclear Information System (INIS)

    Radon is the major source of public exposure to natural radiation and is also known to cause lung cancer. Platform screen doors (PSD) were installed primarily for passenger's safety purposes. Radon concentration and aerosol distribution have been changed since PSD installation. In this study, we have assessed the annual effective dose of regular subway passengers, before and after PSD installation, by employing current available data on air concentration of radon in Seoul subways with aerosol size distributions taken into account. ICRP recommends that the reference value for internal dose from radon be between 1.0 and 20.0 mSv. Korean Ministry of Environment enacted the indoor radon regulation, which requires the indoor radon level should not exceed 148 Bq/m3. Radon concentrations in Seoul subways and annual dose estimates meet the requirements

  5. An overview of PNL radon experiments with reference to epidemiological data

    International Nuclear Information System (INIS)

    Biological effects observed in dogs and rodents after the inhalation of radon and radon daughters have included, primarily, respiratory carcinoma, pulmonary fibrosis, emphysema, and life-span shortening. Extrapulmonary lesions observed are not considered significant except for certain hematological effects. In this paper we present biological effects data resulting from chronic exposures of hamsters, rats, and beagle dogs. Emphasis is placed on the carcinogenic effects of radon and radon daughters, including the influences of radon-daughter exposure rate, unattachment fraction, and disequilibrium and of concomitant exposure to other pollutants. These data are correlated with results from human epidemiological studies. Plausible values for the radon (radon-daughter) lifetime lung-cancer risk coefficient are provided. 30 refs., 3 tabs

  6. Measurement of concentration and size distribution of radon decay products in homes using air cleaners

    International Nuclear Information System (INIS)

    By removing particles, air cleaners can also eliminate radon decay products. However, by removing the particles, the open-quotes unattachedclose quotes fraction of the radon progeny is increased leading to a higher dose per unit exposure. Thus, both the concentration and size distributions of the radon decay products are needed to evaluate air cleaners. Three types of room air cleaners, NO-RAD Radon Removal System, Electronic Air Cleaner and PUREFLOW Air Treatment System were tested in a single family home in Arnprior, Ontario (Canada). Semi-continuous measurements of radon gas concentration and radon decay product activity weighted size distribution were performed in the kitchen/dining room under real living conditions. The effects of air cleaners on both the concentration and size distribution of the radon decay products were measured, and their impact on the dose of radiation given to the lung tissue were examined

  7. Radon Measurements in Egypt using passive etched track detectors. A Review

    International Nuclear Information System (INIS)

    Radon and its progeny may cause serious radiation harm to human health such as lung cancer and other types. Radon measurements based on alpha particles etched track detectors (LR-115, CR-39) are very attractive for assessment of radon exposure. This is due to their high sensitivity, low cost, easy to handle and retain a permanent record of data. Also these detectors can incorporate the effects of seasonal and diurnal fluctuation of radon activity concentrations due to physical, geological and meteorological factors. The present review is based mainly on the topic of passive etched track detectors for the measurements of radon in Egypt in the recent years. Published papers includes the measurements of radon in dwellings, working places, Cairo Metro stations, ancient Pharaonic places and uranium exploration galleries as well as assessment of radon in drinking water

  8. Alpha emitters in Chernobyl hot particles

    International Nuclear Information System (INIS)

    The alpha radioactive component of hot particles from the Chernobyl fallout was analysed for cases studied previously by gamma spectroscopy. Correlations established from the absolute alpha activity determination and high resolution analysis provided information on actinides release during accident and on some aspects of the Chernobyl reactor fuel composition. Unexpected features revealed during the analysis of one specific particle are presented. 11 refs., 5 figs., 5 tabs. (author)

  9. Quantum Estimates of Alpha Emitter Life Time

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2006-01-01

    Full Text Available Quantum estimates of several alpha radioactive life time have been made using the probability of quantum tunneling through the nuclear potential barrier. It is assumed that for a given nucleus with mass number A and isotopic number Z, there exists an alpha particle moving freely back and forth in the nucleus with mass and isotopic numbers A -4 and Z-2. If the probability of penetrating the nuclear potential barrier is Τ, then after N times (N=1/Τ hitting the barrier an alpha particle is emitted. To obtain the elapsed time for emitting an alpha particle requires N times τ0, where τ0 is the time travel for alpha across the nuclear diameter, which is dependent on alpha energy. It is assumed here that this kinetic energy is the same as the emitted energy. The emitting alpha kinetic energies here are calculated by the difference of the masses of the parent and daughter nuclei and the alpha particles. They are in closed agreement with the experimental observations. While the alpha radioactive life time are not the same order of magnitudes but give the same linearity on the logarithmic scale as function of the inverse square root of energy.

  10. Effects of internally deposited alpha emitters

    International Nuclear Information System (INIS)

    This study seeks to identify and quantify the human health effects of occupational exposures to radium, use the health effects data from the radium study to predict responses to other alpha-emitting and/or bone-seeking radionuclides at occupational exposure levels and above, and predict the effects of these radionuclides, specifically environmental radium and its daughters, at nonoccupational exposure levels. 14 refs

  11. Alpha emitters in Chernobyl hot particles

    Energy Technology Data Exchange (ETDEWEB)

    Broda, R.; Kubica, B.; Szeglowski, Z.; Zuber, K. (Institute of Nuclear Physics, Krakow (Poland))

    1989-01-01

    The alpha radioactive component of hot particles from the Chernobyl fallout was analyzed for cases studied previously by gamma spectroscopy. Correlations established from the absolute alpha activity determination and high resolution analysis provided information on the release of actinides during the accident and on some aspects of the Chernobyl reactor fuel composition. Unexpected features revealed during the analysis of one specific particle are presented. (orig.).

  12. Consumer's Guide to Radon Reduction

    Science.gov (United States)

    ... to Radon Reduction: How to Fix Your Home Consumer's Guide to Radon Reduction: How to Fix Your ... EPA’s About PDF page to learn more. 2013 Consumers Guide to Radon Reduction (PDF) (20 pp, 424 ...

  13. A study of indoor radon levels and radon effective dose in dwellings of some cities of Gezira State in Sudan

    Directory of Open Access Journals (Sweden)

    Elzain Abd-Elmoniem Ahmed

    2014-01-01

    Full Text Available Exposure to natural sources of radiation, especially 222Rn and its short-lived daughter products has become an important issue throughout the world because sustained exposure of humans to indoor radon may cause lung cancer. The indoor radon concentration level and radon effective dose rate were carried out in the dwellings of Medani, El Hosh, Elmanagil, Haj Abd Allah, and Wad Almahi cities, Gezira State - Central Sudan, in 393 measurements, using passive integrated solid-state nuclear track devices containing allyl diglycol carbonate plastic detectors. The radon concentration in the corresponding dwellings was found to vary from (57 ± 8 Bq/m3 in Medani to 41 ± 9 Bq/m3 in Wad Almahi, with an average of 49 ± 10 Bq/m3. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the annual effective dose rate from 222Rn in the studied dwellings ranges from 1.05 to 1.43 mSv per year and the relative lung cancer risk for radon exposure was 1.044%. In this research, we also correlated the relationship of radon concentration and building age. From our study, it is clear that the annual effective dose rate is larger than the “normal” background level as quoted by UNSCEAR, lower than the recommended action level of ICRP, and less than the maximum permissible dose defined by the International Atomic Energy Agency.

  14. Radon in soil and homes of Osijek

    International Nuclear Information System (INIS)

    Radon, 222Rn, is an inert radioactive gas which arises from decay of 226Ra and ultimately from 238U. These parent elements are ubiquitous in the crust of the earth, although with very various concentrations. It has been recognized that Rn gas can accumulate in homes, sometimes to levels that can exceed occupational standards for mines. Enhanced concentrations of indoor radon and its also-emitting progeny 214Po and 218Po can increase the risk of pulmonary diseases, that was first observed still among underground miners (ICRP, 1987; Lubin et al., 1990; Gilliland et al., 2000). Because of the uncertainty inherent in extrapolating risks from studies of miners to the general population, epidemiological studies have been undertaken to confirm the presumed harm (carcinogenesis) of indoor radon ( Stidley and Samet, 1993; Cohen, 1995). We undertook so called ecologic and case-control studies for inhabitants of the Osijek town (East Croatia, a hundred thousand citizens) to investigate an association between indoor radon exposure and lung cancer rate; some results showed a positive linear regression for the mentioned variables, although the correlation coefficient was not statistically significant, or statistical samples were not large enough (Planinic et al., 2002; further investigation is going on). A particular problem was to determine indoor radon concentrations with a satisfied precision (that reduces sample size), as well as to find a cause of their variation

  15. Tritium and radon risks for humans

    International Nuclear Information System (INIS)

    Full text: The gaseous and liquid releases into environment from the two CANDU type units of Cernavoda NPP now in operation has more tritium contents than other kind of western power reactors. CANDU type reactor uses heavy water as moderator and primary circuit heat transfer agent. In normal operation deuterium go to tritium by neutron capture, the molecule of tritiated heavy water can escape from nuclear systems in very small amounts and so it is released into environment. After release the tritium follows the way of water into environment. One year ago the antinuclear NGO led a hard attack against Units 3 and 4 during the procedure of public acceptance request. This attack tried to demonstrate the great risk for humans of the tritium released by Cernavoda NPP. Obviously this risk is very low as demonstrated by many years reactor operation. SNN as owner of Cernavoda NPP ensures by all kind of information channels about the radioactive potential risk for humans. By the other hand, ironically, the antinuclear NGO makes nothing to inform the people about radon risk magnitude in some areas. This is a well-known fact but the radon concentration in dwellings can be decreased by some improved building procedures. The radon is the first natural cause of lung cancer. The environmental NGO and Romanian authorities do not have an information service about radon hazard data neither in dwellings or in uranium mining areas. The paper compares the properties and risks for tritium and radon. (authors)

  16. Environmental radon monitoring in Khartoum dwellings

    International Nuclear Information System (INIS)

    Radon is a naturally occurring radioactive gas that is released into the surrounding environment. Existence of this gas indoors ( house and dwelling ) mainly depends on its source in the building materials, the soil beneath the buildings and the ventilation of the rooms. In this study the technique of ground activated charcoal and gamma spectrometry system are used for Radon measurement. This technique has been calibrated and optimized. The main reason for radon determination in house comes from the fact that Radon and its daughters are directly responsible of lung cancer and some kidney diseases. The measurements, in this study, have been performed for Khartoum indoors. 644 rooms have been measured. These rooms were sorted out into groups according to their building material as well as the ventilation of each room. The measurements covered the whole year ( the three main seasons ) to see the variation of Radon level, since its emanation is affected by the temperature. Also monthly outdoor measurements have been performed in different locations in Khartoum. On the basis of the results obtained, the radiation dose received by the public due to the inhalation of this gas has been calculated. The average annual effective dose was found to be 1.2 m Sv. (author). 33 refs., 17 tabs., 24 figs

  17. Radon exhalation rates from some building construction materials using SSNTDs

    International Nuclear Information System (INIS)

    Radon appears mainly by diffusion processes from the point of origin following α- decay of 226Ra in underground soil and building materials used. in the construction of floors, walls, and ceilings. In dwellings main source of radon are soil or rock underneath, building materials and portable water supplies. The major release of radon indoors is from building construction materials used. The radon measurements on the ground can give a clue about the hidden uranium. The exposure of population to high concentrations of radon and its daughters for a long period leads to pathological effects like the respiratory functional changes and the occurrence of lung cancer. In the present investigations radon exhalation rates from some soil and other building materials like fly ash, cement and sand collected from Panchkula, Ambala, Yamunanagar, Kurukshetra, Karnal and Panipat districts of Haryana have been estimated. For the measurement of radon concentration in these samples we used α-sensitive LR-115 type II plastic track detectors. The mass and the surface exhalation rates of radon emanated from these samples have also been calculated. The aim of study is the possible health risk assessment due to emission of radiation from building construction materials. (author)

  18. Cornerstones of the Austrian radon risk communication strategy

    International Nuclear Information System (INIS)

    On behalf of the Federal Ministry of Agriculture, Forestry, Environment and Water Management (BMLFUW), the National Radon Centre of Austria developed the National Radon Risk Communication Strategy. The superior goal is the reduction of the radon exposure of Austrian citizens as well as the reduction of radon-related lung cancer deaths. Austria, like many other countries, follows the approach to raise awareness and to inform the public to achieve this goal. The presented strategy deals with the question of how radon protection issues can be communicated to the public, existing fears can be reduced and affected people can be motivated to take action (perform a radon test, if necessary, mitigate or install preventive measures in new buildings). The cornerstones of the National Radon Risk Communication Strategy can be summarized as follows: - Definition of communication goals - Identification and categorization of target groups - Development of specific key messages for each of the target groups - Determination of communication channels and assessment of their efficiency - Integration of the radon issue in education and training - Cooperation with relevant organizations and platforms. The communication objectives, target groups and communication paths (and their evaluation) will be discussed during the presentation in detail.

  19. Effective dose from outdoor radon in children in dependence on their age

    International Nuclear Information System (INIS)

    Since radon concentration in outdoor air tends to decrease with increasing distance from the ground, tall people will inhale less radon than small people. Conversely, this implies that the radon-related radiation burden will be higher in children than in adults. This effect is enhanced by the fact that children's lung tissue is more sensitive to radiation damage. The aim of this paper is to quantify the radiation burden in children in the outdoor environment. (orig.)

  20. Radon: risk to health? El radón: ¿riesgo para la salud?

    OpenAIRE

    Juan Miguel Barros Dios

    2011-01-01

    Radon (Rn222) is a radioactive noble gas whose origin is Radium (Ra226) when it emits an alpha particle (two protons and two neutrons) or a helium nucleus. Rn222 transforms in another radioactive element (Po218) when an alpha particle is emitted. Its carcinogenic effect on the lung was discovered various decades ago, first on uranium miners and later on general population exposed at home to residential radon. The main factor influencing radon concentration in dwellings is the uranium content ...

  1. Measurement and apportionment of radon source terms for modeling indoor environments

    Energy Technology Data Exchange (ETDEWEB)

    Harley, N.H.

    1992-01-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters. The dosimetry has been extended to include organs other than the lung.

  2. Measurement and apportionment of radon source terms for modeling indoor environments

    International Nuclear Information System (INIS)

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters. The dosimetry has been extended to include organs other than the lung

  3. Rating radon through the looking glass

    International Nuclear Information System (INIS)

    Radon emerged as a health threat in the last five years as studies showed that exposure to high levels in the home can cause lung cancer. But many families move so often that its difficult to determine their exposure over a lifetime. Now, Battelle Memorial Institute scientists at the Energy Dept.'s Pacific Northwest Lab in Richland, Wash., have devised a clever way to do so. They tape a 2-inch-square piece of clear plastic polymer to the glass on an old mirror or framed picture. Such items as wedding photos are easily datable and normally carried from home to home. As radon decays over the years, it emits alpha particles, which embed themselves in glass. The particles leave tracks in the polymer. By analyzing these tracks, scientists can estimate a person's average annual exposure to indoor radon over 20 years or more. Starting in May, the technique will be used in a three-year National Cancer Institute study that examines radon, smoking, and diet as co-factors in the risk of lung cancer

  4. National residential radon survey

    International Nuclear Information System (INIS)

    This paper reports on the Superfund Amendments and reauthorization Act (SARA) which requires the EPA Administrator to conduct a national assessment of radon levels where people normally live and work, including educational institutions. The National Residential Radon Survey (NRRS) is the first comprehensive effort to estimate the frequency distribution of average annual radon concentrations nationwide. Also, the survey will provide data to correlate radon concentrations with construction characteristics. A stratified three stage area probability sample was used to randomly select approximately 12,000 homes. A questionnaire will provide information on living patterns, house construction, and heating, ventilation, and air conditioning (HVAC) characteristics. Two to four alpha-track detectors were placed in each home. It is expected that approximately 5,000 residents will return detectors with readable radon concentrations. With this data, EPA will be able to accurately estimate the frequency distribution of annual average radon concentrations nationwide

  5. Conference on provisions against radon

    International Nuclear Information System (INIS)

    The Proceedings contain 20 contributions dealing with diverse aspects of the radon problem. Information is presented on the occurrence of radon on the territory of Czechoslovakia, and on natural radioactivity of rocks. The majority of contributions concentrate on ways of radon measurement, on determination of the radon content of building materials and on radon propagation through buildings. Various technologies for removing radon from homes and for preventing radon leaks are described and assessed. The effect of radon on human health is also dealt with. (M.D.). 16 tabs., 34 figs., 39 refs

  6. Radon in buildings

    International Nuclear Information System (INIS)

    This guide is intended to inform designers, contractors, householders and other building owners about radon in buildings and to provide guidance where it has been decided to take action to reduce radon levels. It gives some pointers to good practice insofar as it relates to non complex buildings of normal design and construction. Reference is made to the usual ways of reducing l;levels of radon and guidance is given on sources of further information. I

  7. Radon in Caves.

    OpenAIRE

    Cigna Arrigo A.

    2005-01-01

    The physical characteristics of radon are reported as well as its sources,the transport in rock and its behaviour in caves. Then,the instruments,both active and passive, used for the measurement of radon concentration are discussed by taking into accounttheir respective advantages and disadvantages for the use in the cave environment. Since in many countries radon is the objectof regulations that were adopted for radiation protection purposes, this aspect is examined and the recommendations i...

  8. Radon in dwellings

    International Nuclear Information System (INIS)

    The report presents the function of the ventilation by natural draught in three-storey houses. In some cases also the measurement of gamma radiation, radon and radon daughters was made. The investigation took place in Uppsala. The houses were built of light weight concrete made of alum-shale. The measurements showed that the contents of radon daughters were far below the provisional limits. (G.B.)

  9. Radon diffusion modelling.

    Science.gov (United States)

    Wilkinson, P; Dimbylow, P J

    1985-10-01

    A mathematical model has been developed that examines the ingress of radon into houses, through a vertical crack in an otherwise impervious concrete floor. Initially, the model considered the diffusive flow of radon from its soil source and this simulation has highlighted the dependency of the flux of radon into the house on the magnitude of various parameters, such as the diffusion coefficient of radon in soil. A preliminary investigation of the modelling of pressure-driven flow into a building is presented, and the potential of this type of analysis is discussed. PMID:4081719

  10. YAPILARDA RADON FENOMENY

    OpenAIRE

    OZAN, Sadik Sezgin; EKİNCİ, Cevdet Emin

    2011-01-01

    Bu çaly?mada, yapylarda Radon konusu irdelenmi?tir. Radon, günlük hayatta sürekli maruz kaldy?ymyz radyasyonun yakla?yk %50'sini olu?turan ve topraktaki Uranyum'un bozunma zincirinin bir halkasy olan renksiz, kokusuz ve duyu organlaryyla algylanamayan radyoaktif bir gazdyr. Kayaçlardaki Uranyumun bozunmasy sonucu ortaya çykan Radon gazy, difüzyon yoluyla topra?a, oradan da atmosfere veya ortama yayylmaktadyr. Gazyn birikmesiyle, Radon yo?unlu?u kapaly mekânlarda veya iyi havalandyrylmayan yer...

  11. Assessment of risks associated to ionizing radiations: lung cancers after domestic radon exposure and thyroid cancers after accidental exposure to radioactive iodines; Evaluation des risques associes aux rayonnements ionisants: cancers du poumon apres exposition domestique au radon et cancers de la thyroide apres exposition accidentelle aux iodes radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Catelinois, O

    2004-09-15

    The aim of this work is to develop a critical analysis of quantitative risk assessment in the field of ionizing radiation and to provide new estimates of attributable risks for particular situations of environmental exposure to ionizing radiation. This work is based on knowledge about dose-response relationships and ionizing radiation exposure of the general population. The work focuses on two different situations that both present an important interest for public health: lung cancer associated with domestic radon exposures (natural situation) and thyroid cancer associated with the Chernobyl accident fallout (accidental situation). The assessment of lung cancer risk associated with domestic radon exposure considers 10 dose-response relationships resulting from miner cohorts and case-control studies in the general population. A critical review of available data on smoking habits has been performed and allowed to consider the interactions between radon and tobacco. The exposure data come from measurements campaigns carried out since the beginning of the 1980 by the Institute for Radiation protection and Nuclear Safety and the Health General Directory in France. The French lung cancer mortality data are provided by the I.N.S.E.R.M.. Estimates of the number of attributable cancers are carried out for the whole country, stratified by 8 large regions (Z.E.A.T.) and by 96 departments for the year 1999 allowing to perform a sensibility analysis according to the geographical level of calculation. Uncertainties associated to risk coefficients and exposures have been quantified and it's impact on risk estimates is calculated. The estimated number of deaths attributable to domestic radon exposure ranges from 543 (90% uncertainty interval (U.I.): 75-1,097) to 3,108 (90% U.I.: 2,996-3,221). The corresponding risk fractions range from 2.2% (90% U.I.: 0.3%-4.4%) to 12.4% (90% U.I.: 11.9%-12.8%). The assessment of thyroid cancer risk in the most exposed area of France due to

  12. Radon doses in mines and homes

    International Nuclear Information System (INIS)

    The risks of exposure to radon and its decay products under modern mining conditions and also in the home are discussed. A brief review of the background epidemiology is given. The lung tissues most at risk are the bronchial epithelium and particularly the basal stem cells. Doses to bronchial basal cells and alveoli from exposure to 1 Working Level Month (WLM) radon-222 daughters in a uranium mine atmosphere are calculated. The risk of lung cancer in relation to dose is then discussed. An effective dose equivalent of 5-8 mSv/WLM exposure for domestic exposure relative to 10 mSv/WLM in uranium mines is indicated. (U.K.)

  13. A Citizen's Guide to Radon. What It Is and What To Do about It.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    The U.S. Environmental Protection Agency (EPA) and the U.S. Centers for Disease Control (CDC) are concerned about the increased risk of developing lung cancer faced by persons exposed to above-average levels of radon in their homes. The purpose of this pamphlet is to help readers to understand the radon problem and decide if they need to take…

  14. Public perceptions of radon risk

    International Nuclear Information System (INIS)

    Since 1984, a significant amount of media attention has focused on health threats from radon gas exposure. Using a probability telephone survey of adults (n = 685), we studied public perceptions of risk from radon exposure versus other environmental health risks. The results indicated that 92% of those individuals who had heard of radon believe radon to be a health risk, although only 4% believe they are currently exposed to high levels of radon gas. Perception of risk from radon was positively related to other perceptions of environmental risks. Younger and less educated individuals were more likely to perceive radon as a health risk. Women were three-and-one-half times as likely as men to perceive risk from radon. However, there was no significant relationship between perceived risk from radon and cigarette smoking. Media attention has apparently led to public awareness of radon hazards, but further attention is needed to improve smokers' awareness of their special risks from radon

  15. Radon in dwellings in Finland

    International Nuclear Information System (INIS)

    For over ten years STUK (The Radiation and Nuclear Safety Authority) has performed systematic indoor radon mapping in Finland with health authorities in municipalities. The most efficient means of reducing indoor radon exposure is to locate and mitigate dwellings with radon concentration exceeding the action level of 400 Bq/m3 and to build new houses so that radon concentrations do not exceed 200 Bq/m3. Therefore STUK has made radon measurement plans and radon risk maps to identify radon-prone areas. During 1986 - 1996 the municipalities have ordered 33 000 dosemeters for radon measurements. Private persons have ordered 24 000 dosemeters and STUK has used for its own investigations 34 000 dosemeters. Today the basic radon database of STUK consists information of about 52 000 Finnish dwellings. This report is a summary of the radon measurements made by STUK in low-rise dwellings. The radon situation by provinces is presented in tables

  16. Inhibitory Effects of Pre and Post Radon Inhalation on Carbon Tetrachloride-induced Oxidative Damage in Mouse Organs

    OpenAIRE

    Nishiyama, Yuichi; Kataoka, Takahiro; Teraoka, Junichi; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori

    2012-01-01

    Radon inhalation activates antioxidative functions in some organs of mice. We examined the prevention effects of pre radon inhalation and the alleviation effects of post radon inhalation on carbon tetrachloride (CCl4)-induced oxidative damage in the brain, heart, lung, liver, and kidney of mice. In addition, we compared the effect of pre and post radon inhalation on oxidative damage. Mice inhaled radon at a concentration of 18000Bq/m3 for 6hrs before or after CCl4 administration. As a result,...

  17. A simulation study of lognormal measurement error effect: Discrimination problem of radon and thoron

    International Nuclear Information System (INIS)

    Several case-control studies have indicated an increased risk of lung cancer linked to indoor radon exposure. For a precise evaluation of radon-related lung cancer risk, however, contribution of thoron should be considered. There are a lot of studies in which passive type radon detectors are used without thoron discrimination techniques. Therefore, these passive type radon detectors may be strongly affected to the presence of thoron in case they are installed near a wall or floor as potential thoron sources. The thoron effect we consider here is an increase of radon signal in the radon detectors without the discrimination technique. This problem is classified as a part of measurement error problem in statistical literatures and the thoron is considered as a possible source of measurement error. In general, concentrations of radon and thoron follow a lognormal distribution. The effects of measurement error following normal distribution have been studied well, but there are few studies on measurement error following non-normal distribution. In order to evaluate the effect of measurement error due to thoron, we conducted a simulation study. We assumed a case-control study of lung cancer and indoor radon with hypothetical data where radon concentrations were measured with and without discrimination of thoron concentrations. We also assumed that logistic regression was used, and that the concentrations of radon and thoron were correlated, following lognormal distribution. The thoron disturbance in radon measurement resulted in an approximately 90% downward bias in the effect of radon, and this bias was almost constant when the parameters were varied. The downward bias was consistent with results from previous studies taking measurement error following normal distribution into account. It was confirmed that the effect of lognormal measurement error is concordant with the normal measurement error in this case. (author)

  18. Indoor radon distribution in metropolitan region of Belo Horizonte, Brazil

    International Nuclear Information System (INIS)

    Human beings are exposed to ionizing radiation from many natural sources. Radon and its progeny have been recognized as the most important contributors to the natural radioactivity dose, accounting for about half of all human exposure to ionizing radiation. Radon (222Rn) is a α-radioactive noble gas derived from the natural series of uranium (238U), which occurs in a wide concentration range in all geological materials, especially, in rocks, soils and waters. By diffusion and convection, radon migrates from the rocks and soils to atmosphere and through fissures, pipes and holes it may enter the dwellings and other buildings. Another important radon source in dwellings is its emanation from the construction material. The radon progeny concentration in dwellings has been receiving considerable global attention due to its potential effect in causing lung cancer if it deposited in upper respiratory tract when inhaled. This paper presents radon concentration distribution in dwellings in Metropolitan Region of Belo Horizonte - RMBH. The effective dose estimate is also presented for the RMBH inhabitants. The geological settings of the area are Archean rocks of Granitic Gnaissic Complex and of metasediments sequences of the great Precambrian unit of the Iron Quadrangle of Minas Gerais, Brazil. Radon concentration measurements were carried out with continuous detector AlphaGUARD PQ200PRO (Genitron), in passive mode and with passive detectors E-PERMR Eletret Ion Chamber-EIC. The radon progeny concentration was carried out with a solid state alpha spectroscope, the DOSEman PRO (Sarad). It was found an indoor radon concentration varying in a large range from 18.5 to 2671.4 Bq/m-3, with an average value of 148.0 Bqm-3 and geometric mean equal to 128.2 Bqm-3. The variable results are due mainly to region geological factors and building material composition of dwellings. The equilibrium factor between radon and its progeny were determined in dwellings, as 0.3 in average. (author)

  19. Air radon concentrations in Tunisia - A preliminary study

    International Nuclear Information System (INIS)

    Full text: Radon, a radioactive gas, may be one of the causative factors for lung cancer. In Tunisia, air radon concentrations are still unknown. We determined outdoor and indoor radon concentrations for the first time in different regions of the country, using open alpha track dosimeters containing a LCR 115 film. The study of outdoor radon concentrations was limited to twenty different points, and lasted from February 1997 to April 1998. Each device has been exposed during three months. Indoor radon concentrations were measured in two campaigns. During the first period extending from November 1999 and November 2000, measurements were performed in the capital. They concerned 67 dwellings in which dosimeters have been changed every two months. In the second period, determinations were made in seven hundred houses scattered over the country. Each dosimeter was also exposed during two months, between January and March 2002. The alpha track method was used to count the alpha particle impacts and the radon concentrations are expressed in Bq/m3. Our results show that the concentrations differed with the season and the location. Medians for indoor and outdoor air radon concentrations have been calculated. Outdoor radon concentrations extended from 0 to 47 Bq/m3. Most of the indoor radon results were less than 100 Bq/m3 and in rare cases values were between 200 and 400 Bq/m3. In Tunisia area, the highest rates were found in winter. Considering all the results, the highest levels were detected in Jendouba, Gafsa and Tataouine 'gouvernorats'. Lead mines are exploited in the first one and phosphate in the second one. This preliminary work shows that air radon concentrations are low in Tunisia except in some localized points. Studies are going on in order to increase the number of measurements with a particular attention to the geology, the seasonal and atmospheric variations, the architectural type and the building materials. (author)

  20. Radon in Schools

    Science.gov (United States)

    ... Radon Measurement in Schools Radon Prevention in the Design and Construction of Schools and Other Large Buildings (EPA 625- ... quality control and assurance to address complicated building designs and specialized airflow. What happens if your school fails the test? Every home should also take this ...

  1. Radon and its measurement

    International Nuclear Information System (INIS)

    The work reviews the topics concerning the problem of the indoor radon and its measurement. The initial stage deals with the general features of radon, from the historical remarks about its discovery to the formation mechanisms in the soil, then passing to describe the transport processes that lead the radon to enter into the buildings. The mean radon concentration distribution among the Italian regions is reported and compared with the situation in the other countries of the world. A particular importance is given to present the national law concerning the radioprotection from the natural sources of ionizing radiations; a paragraph is completely devoted to this argument and to discuss the differences between the Italian approach and the regulations applied in the Test of Europe for both workplaces and dwellings. Chapter 3 describes the different detectors and methods to measure the radon and its short mean live decay products concentrations, together with the operative procedures and guides provided by the Italian law and by the international bodies. As an example of typical radon passive measurement device. the new ENEA detector developed at the Institute of Radioprotection is presented and discussed. Appendix 1 is entirely devoted to discuss the main remedial actions for decreasing the radon indoor concentration both for old and new buildings; appendix 2 reports the main quantities related to radon and radioprotection

  2. Radon surveys and uncertainties

    International Nuclear Information System (INIS)

    Radon surveys are made primarily for estimating the radon risk for the population of an area but also for predicting the risk for inhabitants of future buildings. Therefore it is of essential importance to know the uncertainties of such predictions. The outcome of radon surveys is strongly influenced b y many factors with partly large uncertainties. In most cases passive radon detectors are exposed for some weeks or months (up to one-year measurements). In these cases, the contribution of uncertainties in the calibration of the detectors to the total uncertainty is most often of less importance. The main contribution to the uncertainties comes from the unknown treatment of the detectors by the inhabitants during the exposure and by the natural fluctuation of the indoor radon concentration in time. The latter is also true for one-year-measurements. Additional uncertainties are introduced when the measured data are normalized to some time period (e. g. one-year mean) or to some standardized measurement situation. Generally, it is of crucial importance to know the probability for a possible underestimation of the radon risk for an area. The main contributions to the final uncertainties, their sizes and the mathematical procedures which were used during the Austrian Radon Project (ARP) to estimate the uncertainties in the final categorization of areas in radon potential classes will be discussed. In addition, procedures which can be used to reduce some uncertainties will be presented. (author)

  3. Radon in indoor environments - a cost-benefit analysis of adoption of the new recommendations of WHO for radon limits

    International Nuclear Information System (INIS)

    The report's goal is to investigate the consequences of the authorities to adopt the new WHO recommended limit and guideline for radon in homes of 100 Bq/m3. The report's purpose is to provide a basis for decision if the radon and radon guideline limit should be lowered. 400,000 houses and 230,000 apartments in Sweden have a radon concentration of 100-200 Bq/m3, and thus must be decontaminated of radon if the guideline value would be raised. This corresponds to about 1.3 million residents. The cost of such a radon mitigation is estimated at 14-19 billion SEK (2-3 billion USD). The increase in operating costs is estimated at 500 million SEK per year. Remediation measures are not economically reasonable. For the cost to be reasonable, 65-85 lung cancer cases should be prevented per year. Reduction in lung cancer cases, with a reduction in guideline value is estimated at 40 cases. Remediation costs for individual buildings with blue concrete can be very high. Close to 5000 people each year move into newly built homes with radon levels higher than 100 Bq/m3 under the 2010 construction forecast. The cost of mitigation measures necessary to bring down radon below 100 Bq/m3 for new constructions is estimated at 130 million SEK for 2010. These measures are not economically reasonable. For the cost to be reasonable 0.45 lung cancer cases should be prevented per year. The decrease in the number of lung cancers, with a reduction in the limit is estimated at 0.15 cases or new buildings. The Radon Coordinating Group recommends retaining the current target and limit for radon in dwellings of 200 Bq/m3. It is not economically reasonable to implement a tightening of the guide and limit values. The benchmark and the limit for radon should be remain unaltered. To have different guidelines and limits for old and new dwellings will create confusion in the industry and can lead to decreased respect for the limits. It is unclear whether there are ways to get down radon concentrations

  4. Some aspects of radon and its daughter-products in man and his environment

    International Nuclear Information System (INIS)

    A major but short-lived postprandial increase in the exhalation rate of radon by persons containing no radium was observed. The concentrations of radon and its short-lived daughter-products in houses was unusually high (> 5 to 10 pCi l-1, > 185 to 370 Bq m-3) in some houses with unpaved crawl spaces, and with concrete basements. External counting of radon daughter-products in the residents of one of the radon-contaminated houses indicated that there may be interference with the assay of plutonium in the lungs of persons who live in those houses

  5. Indoor radon mitigation

    International Nuclear Information System (INIS)

    The action limit for indoor radon concentration in Finnish dwellings is 400 Bq/m3 which is exceeded in 50.000 dwellings. In these dwellings indoor radon mitigation is needed. The most important reason for high concentration is the soil air with high radon concentrations that flows into living spaces through openings and gaps in the building foundation. Slab on ground is the most prevalent type of foundation in Finnish single family houses. Without preventive measures, this type of foundation promotes the flow of radon-bearing soil air into living spaces. In the second popular foundation type, semi-basement houses, the flow of soil air through the walls in contact with soil still increases radon leakages. The key aim of indoor radon mitigation is to prevent or decrease the harmful flows of radon-bearing soil air into dwellings. This guide gives the basic information on Finnish regulations on indoor radon, leakage routes, effect of air exchange and under-pressure as well as pre-mitigation studies of houses. The results on the efficiency of various mitigation methods are based on a questionnaire study in 400 Finnish dwellings and on-site studies in numerous houses. In the case of sub slab suction, the Finnish guide published by the Ministry of Environment has also been utilized. Best mitigation efficiency has been achieved using sub slab suction and radon well. Typical indoor radon reduction factors for both methods are 70 - 90%, and the best results are above 95%. Sub slab suction can be implemented through both floor slab and foundation wall. An exhaust fan coupled to suction pit and exhaust piping creates underpressure and ventilation beneath the slab. In case of a radon well an exhaust fan sucks air from the soil and ventilates the soil air volume through a well construction placed outside the house. The depth of a radon well is 4 - 5 metres. A single radon well can reduce radon concentration in many dwellings at the distance up to 20 - 30 metres. Mitigation work

  6. Indoor radon mitigation

    International Nuclear Information System (INIS)

    The action limit for indoor radon concentration in Finnish dwellings is 400 Bq/m3 which is exceeded in 50.000 dwellings. In these dwellings indoor radon mitigation is needed. The most important reason for high concentration is the soil air with high radon concentrations that flows into living spaces through openings and gaps in the building foundation. Slab on-ground is the most prevalent type of foundation in Finnish single family houses. Without preventive measures, this type of foundation promotes the flow of radon-bearing soil air into living spaces. In the second popular foundation type, hill-side houses, the flow of soil air through the walls backing soil still increases radon leakages. The key aim of indoor radon mitigation is to prevent or decrease the harmful flows of radon-bearing soil air into dwellings. This guide gives the basic information on Finnish regulations on indoor radon, leakage routes, effect of air exchange and underpressure as well as pre-mitigation studies of houses. The results on the efficiency of various mitigation methods are based on a questionnaire study in 400 Finnish dwellings and on-site studies in numerous houses. In the case of sub-slab-suction the Finnish guide published by the Ministry of Environment has also been utilized. Best mitigation efficiency has been achieved using sub-slab-suction and radon well. Typical reduction factors for both methods are 70-90%, and the best results are above 95%. Sub-slab-suction can be implemented through both floor slab and foundation wall. An exhaust fan coupled to suction pit and exhaust piping creates underpressure and ventilation beneath the slab. In case of a radon well an exhaust fan sucks air from the soil and ventilates the soil air volume through a well construction placed outside the house. The depth of a radon well is 3-5 metres. A single radon well can reduce radon concentration in many dwellings at the distance up to 20-30 metres. Mitigation work based on ventilation aims at

  7. Radon in workplaces

    International Nuclear Information System (INIS)

    The EU Member States have to implement the new Basic Safety Standards Directive (BSS) by May 2000. The Title VII of the Directive applies in particular to radon in workplaces. The Member States are required to identify workplaces which may be of concern, to set up appropriate means for monitoring radon exposures in the identified workplaces and, as necessary, to apply all or part of the system of radiological protection for practices or interventions. The BSS provisions on natural radiation are based on the ICRP 1990 recommendations. These recommendations were considered in the Finnish radiation legislation already in 1992, which resulted in establishing controls on radon in all types of workplaces. In this paper issues are discussed on the practical implementation of the BSS concerning occupational exposures to radon basing on the Finnish experiences in monitoring radon in workplaces during the past seven years. (orig.)

  8. Radon and the environment

    International Nuclear Information System (INIS)

    This volume provides an interdisciplinary overview and analysis of radon and the environment, geared to both professional and lay perspectives. The radon issue spans many disciplines and has far-reaching implications for society. There are also many uncertainties stemming from a variety of sources. These include the often misleading and inconsistent media coverage of the topic, the newness of the issue, the lack of detailed scientific information and the way people perceive and respond to risk. While the effects of radon are still not fully understood as a public policy and health issue, there have been important new developments on the subject and this book brings together many of the key contributors our current knowledge. It attempts to clarify the policy issues, in a manner that will be of equal use to a radon professional, a government official, or a concerned citizen. Seven aspects of the radon issue are presented in the various sections of the book

  9. Radon concentration values in the field: Correlation with underlying geology

    Energy Technology Data Exchange (ETDEWEB)

    Durrani, S.A

    1999-06-01

    In epidemiological and ecological studies of radon as a health hazard in a given area or region, it is becoming widely recognized that it is necessary to establish the significance of correlations, if any, between the incidence of diseases (e.g. lung cancer or leukaemias) and local radon concentration values. Measurements of soil-radon concentration levels in the field, especially under geostatistically controlled conditions, have underscored the highly erratic nature of radon emission on a scale often of only a few metres. It would appear that, while underlying geology does determine the longer scale of variation in soil-radon, many localized parameters, e.g. fissures, moisture content, thickness of overburden, etc., make it imperative that detailed in-situ measurements of radon emission are made before a reliable correlation can be established between, say, leukaemia clusters and radon concentration levels. A broad survey of measurement methods and reported results, examined in the above context, is presented and conclusions drawn in this paper.

  10. Solar radon reduction at six homes in northeast Iowa

    International Nuclear Information System (INIS)

    Growing concern about radon lung cancer risks, carbon monoxide poisoning, and the sick building syndrome have increased demand for improved indoor air quality. Through solar pre-heating of ventilation air, the Solar Radon Reduction System (SRRS) provides energy benefits with lower installation costs than conventional air-to-air heat exchangers and sub-slab suction approaches. Indoor air quality is improved through dilution, combustion appliance make-up air, pressurization, and reduced radon infiltration through induced-draft solar air collectors drawing supply air from outdoors. Installed at six homes in Waterloo and Cedar Falls, Iowa, the SRRS was found to significantly reduce radon concentrations in all houses with energy benefits and improved overall indoor comfort. Up to 73% reductions from closed house levels as high as 20.9 pCi/L were achieved

  11. Survey: Knowledge level of the population about radon in Switzerland

    International Nuclear Information System (INIS)

    In 1995, a survey was conducted in order to investigate levels of knowledge about radon among the Swiss population. In 2008, a second survey, using a similar methodology, was carried out by the F.O.P.H.. The new study showed that about 40% of the Swiss population has heard of radon, which represents an increase of 8% over the 1995 survey. Most of the respondents knew that radon causes lung cancer, but believed that the gas also produces other health effects (in particular, migraine and skin conditions). In addition, older people, those with a high level of education and property owners tended to be more familiar with the radon issue than the public at large. The inhabitants of high-risk regions achieved markedly better results, which demonstrate that information campaigns in these regions have been successful. At the same time, additional communication efforts are required in low- and medium-risk municipalities, where the majority of the population lives. (authors)

  12. National radon programmes and policies: the RADPAR recommendations

    International Nuclear Information System (INIS)

    Results from epidemiological studies on lung cancer and radon exposure in dwellings and mines led to a significant revision of recommendations and regulations of international organisations, such as WHO, IAEA, Nordic Countries, European Commission. Within the European project RADPAR, scientists from 18 institutions of 14 European countries worked together for 3 y (2009-12). Among other reports, a comprehensive booklet of recommendations was produced with the aim that they should be useful both for countries with a well-developed radon programme and for countries with little experience on radon issues. In this paper, the main RADPAR recommendations on radon programmes and policies are described and discussed. These recommendations should be very useful in preparing a national action plan, required by the recent Council Directive 2013/59/Euratom. (authors)

  13. Radon: Characteristics in air and dose conversion factors

    International Nuclear Information System (INIS)

    The dose conversion factor (DCF) which gives the relationship between effective dose and potential alpha energy concentration of inhales short-lived radon decay products is calculated with a dosimetric approach. The calculations are based on a lung dose model with a structure that is related to the new recommended ICRP respiratory tract model. The characteristics of the radon decay products concerning the unattached fraction and the activity size distribution of the radon decay products are important input quantities for the calculation of DCF. Experimental data about these parameters obtained from measurements in homes, at working places, and in the free atmosphere at ground level in the last past years are summarized. Taking into account the measured aerosol characteristics the DCF fractions of the unattached (DCFu) and aerosol-attached (DCFae) radon decay products for different places were calculated

  14. Radon risks in animals with reference to man

    International Nuclear Information System (INIS)

    Radon inhalation studies in animals provide important supplementary information to human data. Because the measurement of exposure characteristics in experimental studies is more accurate than in epidemiological studies, animal studies may provide a more reliable assessment of the dependence of risks on radon-daughter cumulative exposure. Experimental data have also provided information on the dependence of risks on radon-progeny exposure rate, unattached fraction, and disequilibrium, as well as on concomitant exposures to cigarette smoke. A summary of radon studies in animals has been published. Two examples of results from these studies are included; in both cases, results were based on the percent of animals with lung tumors. 8 refs., 4 figs., 3 tabs

  15. Where's the radon? The geographic information system in Washington State

    International Nuclear Information System (INIS)

    As Washington's lead agency for radon issues, the Department of Health (DOH) is developing the analytical basis for establishing a public health policy regarding radon. The Geographic Information System (GIS) is a fundamental step in this analytical process to develop a map of the potential for indoor radon occurrence. The GIS analysis will take into account geology, geography, topography, soil permeability, indoor test results, population density and distribution, and housing. In addition, DOH is working to aid policy makers and residents by comparing residential exposures to the lowest exposure range at which miners evidenced excess lung cancers. This approach is a departure from the commonly used risk assessments that extrapolate from high to low exposure, and will help determine how many Washington residents are at risk. In conclusion there is an examination of Washington's radon prescriptive construction standards for residences. (author)

  16. Air radon concentration decrease in a waste water treatment plant

    International Nuclear Information System (INIS)

    222Rn is a naturally occurring gas created from the decay of 226Ra. The long-term health risk of breathing radon is lung cancer. One particular place where indoor radon concentrations can exceed national guidelines is in wastewater treatment plants (WWTPs) where treatment processes may contribute to ambient airborne concentrations. The aim of this paper was to study the radon concentration decrease after the application of corrective measures in a Spanish WWTP. According to first measures, air radon concentration exceeded International Commission Radiological Protection (ICRP) normative (recommends intervention between 400 and 1000 Bq m-3). Therefore, the WWTP improved mechanical forced ventilation to lower occupational exposure. This measure allowed to increase the administrative controls, since the limitation of workers access to the plant changed from 2hd-1 (considering a maximum permissible dose of 20 mSv y-1 averaged over 5 y) to 7 h d-1 (authors)

  17. The radon manual. 2. ed.

    International Nuclear Information System (INIS)

    This second edition of the Radon Manual provides an overview of the problem of radon contamination of buildings and remedial measures which are recommended for overcoming this problem. The Council's Code of Practice for those engaged in the detection of radon or remedial work to reduce natural radon levels in industry and residential buildings is included as an Appendix. The Council aims to promote a self-regulatory role for the radon industry based on the recommendations produced here. (UK)

  18. Another bogus radiation scare - radon in homes. Letter to the editor

    International Nuclear Information System (INIS)

    This article discusses Health Canada's research that radon in homes is causing unnecessary lung cancer deaths. Health Canada has carried out a cross-Canada survey of radon-concentrations in homes (Health Canada 2012). The aims of their study were to obtain an estimate of the proportion of the Canadian population living in homes, with radon gas levels above the guideline of 200 Bq/m to identify new areas of this health risk. Their results indicate that 6.9% of Canadians are in 3 such homes (similar to their 1970 results). The authors state that their results can be used by governments and health professionals to help prioritize radon outreach and education efforts, and testing and remediation. Their next step is to correlate radon level and home characteristics, and also develop radon mapping methods. Several sentences in the introduction link radon with lung cancer, based on early studies of uranium miners and later studies in homes. It is estimated that about 10% of all lung cancers worldwide are related to radon exposure.

  19. Environmental assessment of indoor radon gas exposure health hazards and some of its public risks

    International Nuclear Information System (INIS)

    This study examine the relationship between indoor radon gas exposure and the cancer risk and housing characteristics in lung cancer risk houses (CRH) compared to non lung cancer risk houses (NCRH). Mean radon concentrations measured by active method were significantly higher among CRH compared to NCRH, 9:93 pCi/L versus 4.56 pCi/L, respectively. There was no statistically significant diurnal variation as regards radon levels in all examined houses. Indoor radon concentrations show statistically significance in houses with bad ventilation (low air change rate) compared to houses with good ventilation (high air change rate). Houses with floor material of tiles, had statistically significant higher radon concentrations. Neither finishing wall material nor indoor gas source shows statistically significance as regard radon levels. Radon levels > 4 pCi/L (US EPA action level) were statistically significance higher in bed rooms compared levels in living rooms. High radon concentrations were reported in lung cane risk houses and in houses with bad ventilation

  20. Cigarette smoking increases radon working level exposures to all occupants of the smoker's home

    International Nuclear Information System (INIS)

    This paper reports that the 1988 National Academy of Sciences report on radon health risks evaluated the combined effects of radon exposures and cigarettes on the lung cancer risk to smokers. This report showed that the risk of lung cancer is about 10 times greater for smokers than for nonsmokers at the same Working Level exposures. In 1986, the Surgeon General reported that 106,000 lung cancer deaths occurred among smokers. Therefore, the health risks of cigarettes alone or in combination with radon exposures are well recognized. What has not been studied is the effect of cigarette smoke on the Working Levels in homes that increases the exposure to radon decay products to all occupants, both smokers and nonsmokers. Preliminary studies in a radon chamber at Radon QC showed that the smoke from a single cigarette increased the Working Levels by a factor of five within four hours. Furthermore, the Working Levels remained at an elevated level for more than 24 hours. The equilibrium ratio of radon decay products to radon gas also went from about 14% up to 71%, with a slow decrease over 24 hours. Similar studies in the homes of a smoker and nonsmoker confirmed the laboratory observations. The studies in homes also showed the effects of thoron decay products

  1. Lung

    International Nuclear Information System (INIS)

    At present no simple statement can be made relative to the role of radionuclidic lung studies in the pediatric population. It is safe to assume that they will be used with increasing frequency for research and clinical applications because of their sensitivity and ready applicability to the pediatric patient. Methods comparable to those used in adults can be used in children older than 4 years. In younger children, however, a single injection of 133Xe in solution provides an index of both regional perfusion and ventilation which is easier to accomplish. This method is particularly valuable in infants and neonates because it is rapid, requires no patient cooperation, results in a very low radiation dose, and can be repeated in serial studies. Radionuclidic studies of ventilation and perfusion can be performed in almost all children if the pediatrician and the nuclear medicine specialist have motivation and ingenuity. S

  2. [sup 210] Po as a long-term integrating radon indicator in the indoor environment

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Exposure to radon (Rn-222) decay products in the indoor environment is suspected of being a significant lung cancer agent in many countries. But quantification of the contemporary lung cancer risk (i.e. probability) on an individual basis is not an easy task. Only past exposures are relevant and assessing individual exposures in retrospect is associated with large uncertainties, if possible at all. One way to extend the validity of contemporary measurements to past decades is to measure long-lived decay products of radon, the long-lived radon daughters. After our laboratory had exemplified the correlation between implanted Po-210 and the estimated radon exposures in six different dwellings, the US Department of Energy and the Swedish Radiation Protection Institute granted funds for a one-year study, [sup 210]Po as a Long-Term Integrating Radon Indicator in the Indoor Environment.'' In this report the work performed under these two contracts is reported.

  3. statistical evaluation and discussion of the significance of naturally-occurring radon exposures

    International Nuclear Information System (INIS)

    Ambient concentrations of radon and its daughter products have been measured and analyzed by a number of investigators for a variety of purposes. Principal among these purposes have been: (1) descriptive, to characterize the distribution and changes in concentrations under various conditions; (2) research in the use of radon as a tracer gas in the study of atmospheric characteristics and motions, such as eddy mass transfer, diffusivity profiles, large scale circulations, and the like; and (3) the use of radon as an atmospheric tracer in exploration for uranium deposits. This information forms the basic data for this paper and for its placing the ambient natural, or non-anthropogenic, radon characteristics into the perspective of ambient radon health standards and lung cancer risk calculations. In this paper special consideration is also given to observations of the variability in time and space of radon flux rates, and to the impact of these phenomena on the use of such data for a variety of purposes

  4. Efficiency of radon reduction techniques and strategies

    International Nuclear Information System (INIS)

    Radon is a lung carcinogen recognized by the World Health Organisation and it is present in dwellings. In France, the first actions to measure the exposition of the population were made in 1982, and the first national recommendation was published in 1999. In parallel, information booklets on radon and possible actions to lower its concentration in house were made available to the public. The aim of this study was to test the economic feasibility of different methods to reduce radon level in housing. The first step was to identify the cost and the radon reduction rate of different methods, all based on insulation or ventilation of the buildings. Using the data of the Environmental Protection Agency (EPA), we selected six measures and combined them to obtain a total of twenty potential solutions. We also used the 'duration' model of the Biological Effects of Ionising Radiation committee (BEIR VI) to determine the probability of dying from a cancer associated to a fixed exposure to radon. Knowing this information, it was possible to make cost-efficiency analysis on our data and thus keep six interesting methods. Combining these results with the value of human life of the human capital approach we could find what was the most interesting method to apply for a known level of radon and a specific duration of exposure in a house. In given house, for each level of initial exposure, a cost benefit approach allowed to determine if one, or several techniques, or none, is worthwhile to apply. In favorable cases (i.e : easily remediable houses), and with a figure for the price of human life of about 0,9 MEuro, actions should be undertaken at levels as low as 80 Bq.m-3. As we know the radon distribution in France, the second step was to see what would be the effects on this distribution if all inhabitants used the optimal approach against their radon exposure defined by our function. Thus, overall costs and overall risks could be computed. However, in public health issues, the

  5. Radon house doctor

    International Nuclear Information System (INIS)

    The term house doctor may be generalized to include persons skilled in the use of instruments and procedures necessary to identify, diagnose, and correct indoor air quality problems as well as energy, infiltration, and structural problems in houses. A radon house doctor would then be a specialist in radon house problems. Valuable experience in the skills necessary to be developed by radon house doctors has recently been gained in an extensive radon monitoring and mitigation program in upstate New York sponsored by Niagara Mohawk Power Corporation and the New York State Energy Research and Development Authority. These skills, to be described in detail in this paper, include: (i) the use of appropriate instruments, (ii) the evaluation of the symptoms of a radon-sick house, (iii) the diagnostic procedures required to characterize radon sources in houses, (iv) the prescription procedures needed to specify treatment of the problem, (v) the supervision of the implementation of the treatment program, (vi) the check-up procedures required to insure the house cured of radon problems. 31 references, 3 tables

  6. Radon in dwellings

    International Nuclear Information System (INIS)

    The investigations deals with practical problems of radon in dwelllings. It is found that the estimation of risks is not satisfactory. It is evident that the main source of radon is the ground. The mechanisms which influence the radon inflow have been studied. The permeability and water content of the soil has the same importance as the contents of uranium and radium. Measuring methods need to be developed. The number of houses with radon daughters exceeding 400 Bq/m3 is estimated to approximately 40 000. A number of practical methods to eliminate the risk are presented, and the cost for preventing it might amount to 50 000 SEK per house. Some 10 % of the ground is to be considered high risk ground requiring expensive constructions. Recommendations have been made in consideration of radon content when starting new buildings. Special loans are to be granted to reconstruct houses with radon daughters exceeding 400 Bq/m3. It is stated that the follow up of the radon problems should be made by the National Swedish Institute of Radiation Protection. (G.B.)

  7. Radon levels in Cyprus

    International Nuclear Information System (INIS)

    Radon levels in atmospheric and aquatic systems in Cyprus have recently been measured using the radon monitor Alpha Guard. Indoor and outdoor radon levels were obtained in situ, whereas analysis of radon concentrations in water was performed using tap and ground water samples collected from several areas of the island. The average value for outdoor and indoor radon concentration is 11±10 and 7±6 Bq m-3, respectively, and for tap and ground water 0.4 Bq l-1 and 1.4 Bq l-1, respectively. From these data the annual dose equivalent of airborne radon to the Cypriot population is about 0.19 mSv y-1, which is quite low compared to the total dose equivalent of natural and man-made ionising radiation in Cyprus. Radon levels in aquatic systems are relatively low due to an exhaustive utilisation of ground water resources and also to the increased input of desalinated sea water in the water distribution network and eventually into the ground water reservoirs

  8. A Cohort Study on Risk Factors of Lung Cancer in Yunnan Tin Miners

    Directory of Open Access Journals (Sweden)

    Yong JIANG

    2013-04-01

    Full Text Available Background and objective Smoking is a major cause of lung cancer. Studies of lung cancer among miners have shown that occupational exposure also played an important role. The aim of this study is to investigate radon, cigarette use and other risk factors of lung cancer in Yunnan tin miners and to provide a scientific basis for the prevention and control of occupational lung cancer. Methods A prospective cohort study was conducted among Yunnan tin miners, the associations between potential risk factors for lung cancer were analyzed by multivariate Cox regression model. Effects of age at first radon exposure and radon exposure rate on lung cancer risk were analyzed. The relationship between cumulative working level month and lung cancer was analyzed according to smoking status. The joint effect of tobacco use and cumulative radon exposure was analyzed based on additive and multiplicative models. Results Increased risk of lung cancer was associated with age at enrollment, tobacco use, prior bronchitis, and cumulative arsenic and radon exposure, while higher education level was associated with decreased lung cancer risk. An inverse effect of radon exposure rate was observed. There was no significant association between lung cancer risk and first radon exposure age. There was a significant additive interaction between tobacco use and radon exposure on lung cancer risk. Conclusion Several risk factors may contribute to the high incidence of lung cancer in Yunnan tin miners. Further studies are warranted to evaluate joint effect of different risk factors.

  9. The Austrian radon project

    International Nuclear Information System (INIS)

    With the completion of the Austrian Radon Project, the map of the annual mean radon concentrations in Austrian homes is available now. The extrapolation of the indoor data to a standard situation was used to create a 'radon potential' map, which should indicate the radon risk from the ground without the influence of house type, living situation and all other parameters, that could influence the indoor radon concentration. This map specifies areas where radon-safe building techniques should be applied. In the next future the main task for the Austrian radon program will be the transformation of recommendations into use, i. e. to inform the public as well as to teach the persons who are responsible for the construction of a house, how to make a house radon-safe. It seems essential that all people who are involved in the construction of a house, starting from the planning and ending with the people working at the building site, should be informed about the problems with radon because a lack of knowledge in one part of the chain could substantially reduce the effectiveness of any protective measure. The way we try to inform the public as well as several special target groups will be demonstrated. An important question is the effectiveness of such information campaigns. This means: does the information reach the target groups, are the people accepting this information and finally do they apply the recommendations? Therefore it seems necessary to test the methods of information distribution for their efficiency already during the information campaigns. (orig.)

  10. The importance of radon and its daughter products in environmental hygiene

    International Nuclear Information System (INIS)

    Radon and its daughter products have recently been paid great attention as components of natural ionizing radiation. Their presence in houses and flats are focus of interest. The radon isotopes and their short-lived daughter products are represented briefly, followed by a condensed survey of the historical development of this topic. There are various reasons why this became topical only 80 years after radon had been proved in the atmospheric air. After the listing of the different sources of radon, a rough risk estimation is given regarding the role of radon in lung cancer incidence in the GDR. For environmental hygiene the houses with particularly high radon content of the air, the causes of which are given, are of special importance. Among these causes the ventilation of rooms is the factor having the greatest influence on the radon concentration. From the evidence of occasional, extremely high radon values efforts are derived to elaborate limits of radon concentrations in flats. Finally, the priority of the radon problem for environmental hygiene is pointed out by indicating the current interest of this problem in literature and at congresses. (author)

  11. Intercomparison of passive radon dosimeters developed by NIRS (Japan) and SSI (Sweden)

    International Nuclear Information System (INIS)

    Solid state nuclear track detectors (SSNTD) are widely applied for the assessment of mean radon concentration over long periods in human environment, because of their simple, reliable specifications. In Japan, National Institute of Radiological Sciences (NIRS) developed the passive radon-thoron discriminative dosimeter for the nationwide indoor radon and thoron survey project since 1992. The dosimeter contains two polycarbonate disks as SSNTD, which is ready for the low level indoor radon concentration (-3). In Sweden, Swedish Radiation Protection Institute (Statens straalskyddsinstitut, SSI) developed the passive radon dosimeter for the nationwide survey, which showed the Swedish indoor radon level to be 100 Bq m-3 in 1982. As well, the SSI passive radon dosimeter is adopted for the Swedish epidemiological (case control) study on residential radon and lung cancer in 1993. To compare technical features of above two types of passive radon dosimeters, intercomparison was performed at 24 Swedish houses in Stockholm. Two types of dosimeters were placed side by side in both living room and bed room from March to May (about 90 days). Gradient of the linear regression may reflect systematic difference between radon standards in Japan and Sweden. Intercept might be caused by the background uncertainty in either or both dosimeters. This is a first trial for the future cooperative studies between NIRS and SSI. (J.P.N.)

  12. Indoor radon in Slovenia

    Directory of Open Access Journals (Sweden)

    Vaupotič Janja

    2003-01-01

    Full Text Available The Slovenian Radon Programme started in 1990. Since then, radon and radon short-lived decay products have been surveyed in 730 kindergartens, 890 schools, 1000 randomly selected homes, 5 major spas, 26 major hospitals, 10 major municipal water supply plants, and 8 major wineries. Alpha scintillation cells, etched track detectors, electret-based detectors and various continuously measuring devices have been used. On the basis of estimated effective doses, decisions were made on appropriate mitigation. In total, 35 buildings have been appropriately modified. The programme is displayed and results reviewed chronologically and discussed.

  13. Radon in Dwellings in the Republic of Kalmykia

    Energy Technology Data Exchange (ETDEWEB)

    Aakerblom, Gustav (Aakerblom och Aakerblom HP, Skaerholmen (Sweden)); German, Olga; Soederman, Ann-Louise (Swedish Radiation Safety Authority, Stockholm (Sweden)); Stamat, Ivan; Venkov, Vladimir (Research Inst. of Radiation Hygiene, St. Petersburg (Russian Federation))

    2009-02-15

    The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m3, with a mean value of 122 Bq/m3. In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

  14. Risks related to exposure to radon Riesgos vinculados a la exposición al radón

    OpenAIRE

    Juan Miguel Barros Dios

    2010-01-01

    They discuss the different scientific evidence that radon and its short half-life descendants are responsible for the appearance of a considerable number of lung cancers among the exposed population in homes and public buildings (occupational exposure). It also draws a small glimpse at the road traveled by this knowledge and acceptance difficult administrations in many countries and, in particular, of Spain, as well as the various investigations that the team do Galego Radon and Radon Laborat...

  15. Measurement and apportionment of radon source terms for modeling indoor environments. Annual progress report, March 1991--February 1992

    Energy Technology Data Exchange (ETDEWEB)

    Harley, N.H.

    1992-02-01

    This research has two main goals; (1) to quantify mechanisms for radon entry into homes of different types and to determine the fraction of indoor radon attributable to each source and (2) to model and calculate the dose (and therefore alpha particle fluence) to cells in the human and animal tracheobronchial tree that is pertinent to induction of bronchogenic carcinoma from inhaled radon daughters. The dosimetry has been extended to include organs other than the lung.

  16. Surveys of radon levels in homes in the United States: A test of the linear-no-threshold dose-response relationship for radiation carcinogenesis

    International Nuclear Information System (INIS)

    The University of Pittsburgh Radon Project for large scale measurements of radon concentrations in homes is described. Its principal research is to test the linear-no threshold dose-response relationship for radiation carcinogenesis by determining average radon levels in the 25 U.S. counties (within certain population ranges) with highest and lowest lung cancer rates. The theory predicts that the former should have about 3 times higher average radon levels than the latter, under the assumption that any correlation between exposure to radon and exposure to other causes of lung cancer is weak. The validity of this assumption is tested with data on average radon level vs replies to items on questionnaires; there is little correlation between radon levels in houses and smoking habits, educational attainment, or economic status of the occupants, or with urban vs rural environs which is an indicator of exposure to air pollution

  17. Radon in residences

    International Nuclear Information System (INIS)

    This paper addresses the geographic variation in the presence of radon at relatively high levels. Its focus is the Commonwealth of Pennsylvania but it considers the incidence of residential radon in adjoining counties in contiguous states, and by state throughout the nation. Cartographic analysis provides a robust assessment of the broad impact of physiography, the local effects of housing and lifestyle, and the quality of the best available spatial data. By promoting a fuller understanding of the pattern and magnitude of the risk, radon maps constitute a basis for a more effective and efficient prophylaxis. Further, county-unit maps of age-adjusted mortality rates for successive decades demonstrate inconsistent and puzzling linkages between the geographics of radon and cancer

  18. ROE Radon Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The polygon dataset represents predicted indoor radon screening levels in counties across the United States. These data were provided by EPA’s Office of Radiation...

  19. Radon i danske lejeboliger

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn; Skytte Clausen, Louise

    I denne undersøgelse kortlægges radonindholdet i indeluften og det undersøges, hvordan indholdet af radon i indeluften er fordelt og spredes i en ejendom, og om det er muligt at pege på en bygningsdel eller en bygningskomponent som en spredningsvej for radon i boliger. Boligerne er lejeboliger og...... ligger i etageejendomme, kæde- og rækkehuse tilhørende bygningstyper opført fra 1850 og frem. De udvalgte ejendomme ligger i områder af landet, hvor der ved tidligere undersøgelser har vist sig at være en stor andel af huse med et højt indhold af radon i indeluften. Koncentrationen af radon er målt over...

  20. Radon in workplaces

    International Nuclear Information System (INIS)

    The radiological assessment of the results of radon measurements in dwellings is not automatically applicable to workplaces due to different forms of utilization, constructional conditions, time of exposure, heating and ventilation conditions, additional aerosol sources, aerosol parameters, chemical substances, etc. In order to investigate the peculiarities of the radon situation in workplaces located inside buildings compared with that in dwellings, long-time recordings of radon, attached radon progeny and unattached radon progeny concentrations (218Po, 214Pb, 214Bi) are carried out at several categories of workplaces (e.g. offices, social establishments, schools, production rooms, workshops, kitchens, agricultural facilities). 36 workplaces have been investigated. There have been carried out at least 2-3 long-time recordings for each workplace during different seasons. At the same time the gamma dose rate, meteorological conditions, aerosol particle concentrations have been registered. Many special dates from the workplaces and the buildings have been recorded. Activity size distribution of the aerosol-attached and unattached fraction of short-lived radon decay products have been determinated in 20 workplaces. Mainly the following measurement systems were used: Radon- and Radon Progeny Monitor EQF 3020, SARAD GmbH, Germany. Alpha-Track Radon Detectors, BfS Berlin, Germany. Screen Diffusion Batteries with Different Screens, University of Goettingen, Germany. Low-Pressure Cascade Impactor, Type BERNER. Condensation Nuclei Counter, General Electric, USA. PAEC-fp-Rn-Monitor, University of Goettingen, Germany. Through the measurements, many peculiarities in the course of the radon-concentration, the equilibrium factor F, the unattached fraction fp and the activity size distribution have been determined. These amounts are influenced mainly by the working conditions and the working intervals. The influence of these peculiarities in workplaces on the dose have been

  1. Radon in Dwellings in the Republic of Kalmykia. Results from the National Radon Survey 2006-2007

    International Nuclear Information System (INIS)

    The National Radon Survey in the Republic of Kalmykia, Russian Federation during 2006-2007 was carried out in a cooperation project between the Swedish Radiation Protection Authority (SSI) and the Russian Institute of Radiation Hygiene (RIRH). In August 2006 SSI, RIRH, federal and local authorities carried out a field study in Kalmykia when radon daughter measurements (equilibrium equivalent radon concentrations in the air) and gamma radiation measurements were made in 103 buildings. Gamma spectrometry measurements were made at several sites. During the visit the cooperating parties devoted some time to the education of local authorities on radon related issues. During three months in the winter season 2006-2007, long term radon trace measurements were made in 525 randomly chosen dwellings in the Republic of Kalmykia. The radon gas activity varied between 3 and 973 Bq/m3, with a mean value of 122 Bq/m3. In 19 of a total of 835 measurement points, the radon activity exceeded the maximum permitted value in Russia of 200 Bq/m3 of EERC. The year-round radon trace measurement were made in 20 houses in Elista, the capital of the Republic of Kalmykia, for comparison with the three-month measurements. The year-round measurements showed some higher values for the radon activity, and a correction factor of 0.85 was applied. Using data on the number of people living in detached houses and apartments, and applying the radon activities measured, the number of new lung cancer cases caused by radon was calculated to be 20 to 40 of the 100 new cases reported annually. The methods of construction of the dwellings in Kalmykia is greatly influenced by the history and culture. Most of them were built after World War II and there are only a few that are newly built because of the poor economic situation and the low population growth rate in the Republic. Most people live in detached houses, one-storied with 3-5 rooms, built directly on the ground or on coquina blocks or on a cast

  2. Personal radon daughter dosimetry

    International Nuclear Information System (INIS)

    The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

  3. Radon-Instrumentation

    International Nuclear Information System (INIS)

    The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

  4. Radon concentration measurements in therapeutic spring water

    International Nuclear Information System (INIS)

    It is believed that people undergoing a curative cycle in a given spa, may receive a dose in the range of 400 mSv/year which is many times the average annual dose so that their risk of lung cancer may increase by 3% or more. To determine the risk due to the natural radioactivity, of the most frequented spas in Budapest (H), we selected four and some others located on the country side being of particular interest. Results of the radon concentration in spring water are presented, with the evidence that some spas have a high radon concentration. We conclude that patients receiving treatment may be exposed to an additional dose in the range of 29-76 mSv/year that at the bronchia could be between 445-1182 mSv/year. (authors). 6 refs., 2 figs., 2 tabs

  5. Radon og boligen

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    Radon er en radioaktiv og sundhedsskadelig luftart, som ved indånding øger risikoen for lungekræft. Der er ingen dokumenteret nedre grænse for, hvornår radon er ufarligt. Derfor anbefales det, at man tilstræber et så lavt radonindhold i indeluften som muligt. Man kan hverken lugte, se, høre eller...... smage radon, så vil du vide, om du har radon i din bolig, må du måle radonindholdet i indeluften. Radon forekommer naturligt i jorden og kan suges ind sammen med jordluft, hvis der inde er et undertryk, og hvis konstruktionerne mod jord er utætte. Jordluft trænger ind gennem revner og utætte samlinger......, fx omkring rør til kloak, vand og varmeforsyning. Koncentrationen af radon i jorden varierer meget fra sted til sted, også lokalt og gennem året. Tidligere undersøgelser har vist, at der kan forekomme høje koncentrationer i Sydgrønland, specielt i området syd for Narsalik ved Paamiut, 61°30’N....

  6. Radon in Croatian spas

    International Nuclear Information System (INIS)

    There are ten thermal spas in Croatia and all of them provide health services for patients and visitors. Radon measurements were performed since there is a lack of data concerning natural radioactivity originated from radon and its short-lived progenies in such environments. The thermal water at two different sites (the indoor swimming pool with geothermal water and the spring) in each spa was sampled and radon concentrations were measured by AlphaGUARD radon measuring system. The obtained values were in the range of 0.7 to 19 Bq.dm-3 and 2 to 94 Bq.dm-3 for indoor swimming pools and springs, respectively. Integrated measurements of radon concentration in air were performed by two solid state nuclear track detectors LR-115 II (open and diffusion one) thus enabling estimation of equilibrium factor between radon and its daughters. The annual effective doses received by spa workers were found to be about 1 mSv/y (below the lower limit value of 3 mSv/y recommended by ICRP 65). The doses of patients and visitors were one or two order of magnitude lower than that of the personnel. (author)

  7. Radon gas management policy in Quebec

    International Nuclear Information System (INIS)

    In the absence of a provincial policy on radon, the 'Direction generale de la sante publique du ministere de la Sante et des Services sociaux du Quebec' (M.S.S.S.) gave the mandate to the 'Institut national de sante publique du Quebec' (I.N.S.P.Q.) to carry out the evaluation of this issue on a provincial scale. The formed working group had the main task to assess health risks associated to residential radon through a risk analysis approach. This article presents the principal aspects treated in the scientific report published in 2004 by this working group. It starts with the description of radon concentrations measured in residences in Quebec. Then it carries out a risk analysis based on one of the models designed by the B.E.I.R. VI Committee. According to this analysis, radon would explain approximately 10% of the deaths by lung cancer, that is approximately 430 of the 4 101 deaths associated each year to this type of cancer in Quebec. Thereafter, it glances at the various intervention strategies implemented throughout the world. It follows the analysis of intervention strategies which are possible for Quebec and the recommendations that the working group drew from this analysis, in particular two of them which were considered to be most promising: the adoption of preventive measures in the Quebec Code of Construction and radon screening in public buildings (schools, day care centres, etc). Lastly, it presents the work carried out at the federal level on the revision of the Canadian guideline which was fixed at 800 Bq/m3 since 1988. The Federal Radioprotection Bureau made a proposal to the Canadian Minister of Health to set the guideline down to 200 Bq/m3. This modification should be announced in the spring 2007. (author)

  8. Radon measurements in underground and ground constructions in Tashkent city

    International Nuclear Information System (INIS)

    More than half of the dose of the natural radioactivity received by population is related to radon and its progeny. Investigations of scientists all over the world have shown that excessive radon and its progeny exposure dose is associated with a risk of lung cancer. Short-lived radon daughters (Po-218 and Po-214) are considered to be of the most dangers. At a relaxation process resulting from an earthquake, the radon gas can release from the accumulators and get indoors, that enhances greatly the radon level there. According to seismologists data, as a result of the strong Tashkent earthquake in 1966, extensive breaks and faults have been formed along the city and its neighborhoods. The aim of our work was evaluation of radon concentration level and its variation in Tashkent subway stations and related underground offices and also in apartments of multi story buildings and detached houses. The measurements were conducted by two different techniques-with ionization chamber radiometer 'Alpha GUARD' and with solid state nuclear track detectors. The Alpha GUARD radiometer operates either in the mode of passive sampling, or by pumping air through the ionization camera being of 0.6 l in volume. The radiometer is capable of measuring a volumetric activity of radon-222 in air (Bq/m3), and it is equipped with the devices that measure some environmental parameters such as temperature, relative humidity and air pressure. The range of V A of 222Rn in air the device is able to measure is 10 to 2x106 Bq/m3, sensitivity is 1 pulse/min for 20 Bq/m3, and its self-background is less than 1 Bq/m3. The radon measurements in Tashkent subway stations and underground offices have shown that daily mean radon values were in the range of 14-65 Bq/m3, except for the Pushkin Station, where the daily mean V A was 137 Bq/m3. Such a high radon level is connected with availability near the station of one of the numerous faults and fractures of the terrestrial crust responsible for the magnitude

  9. Radon and radon daughter monitoring (including thoron daughter monitoring)

    International Nuclear Information System (INIS)

    Radon/radon daughter and thoron daughter measurement techniques are outlined. The necessary precautions and critical assessments of each method are also presented with a view to providing a better understanding of the various measurement methods

  10. Study of the response of superoxide dismutase in mouse organs to radon using a new large-scale facility for exposing small animals to radon

    International Nuclear Information System (INIS)

    We examined dose-dependent or dose rate-dependent changes of superoxide dismutase (SOD) activity using a new large-scale facility for exposing small animals to radon. Mice were exposed to radon at a concentration of 250, 500, 1000, 2000, or 4000 Bq/m3 for 0.5, 1, 2, 4, or 8 days. When mice were exposed to radon at 2000 day·Bq/m3, activation of SOD activities in plasma, liver, pancreas, heart, thymus, and kidney showed dose-rate effects. Our results also suggested that continuous exposure to radon increased SOD activity, but SOD activity transiently returned to normal levels at around 2 days. Moreover, we classified the organs into four groups (plasma, brain, lung; heart, liver, pancreas, small intestine; kidney, thymus; stomach) based on changes in SOD activity. Thymus had the highest responsiveness and stomach had lowest. These data provide useful baseline measurements for future studies on radon effects. (author)

  11. Acute Exposure from RADON-222 and Aerosols in Drinking Water

    Science.gov (United States)

    Bernhardt, George Paul, IV

    Radon-222 in water is released when the water is aerated, such as during showering. As a result, a temporary burst of radon-222 can appear as a short term, or acute, exposure. This study looked at homes with radon-222 concentrations in water from 800 picocuries per liter (pCi/l) to 53,000 pCi/l to determine the buildup of radon gas in a bathroom during showering. Samples from the tap and drain, compared to determine the percentage of radon-222 released, showed that between 58% and 88% of radon-222 in the water was released. The resultant radon-222 increase in air, measured with a flow-through detector, ranged from 2 pCi/l to 114 pCi/l in bathrooms due to a 10 to 15 minute shower with water flow rates ranging from 3 l/min to 6 l/min. Significantly, these rates did not fall rapidly but stayed approximately the same for up to 15 minutes after the water flow ceased. In examining exposures, the true danger is in the radon-222 progeny rather than the radon itself. The progeny can be inhaled and deposited in the tracheobronchial passages in the lung. Filter samples of bathroom air measured in a portable alpha spectrometer showed an increase in radon-222 progeny, notably polonium-218 and -214, in the air after showering. These increases were gradual and were on the order of 0.5 pCi/l at the highest level. Tap samples measured in a portable liquid scintillator showed that the progeny are present in the water but are not in true secular equilibrium with the radon-222 in the water. Therefore, the radon-222 does not have to decay to produce progeny since the progeny are already present in the water. A two stage sampler was used to examine the percentage of radiation available in aerosols smaller than 7 microns. Repeated trials showed that up to 85% of the radiation available in the aerosols is contained in the smaller, more respirable particles.

  12. Is the Health of Irish Workers adequately protected from the effects Radon Gas?

    International Nuclear Information System (INIS)

    Since the introduction of the workplace ban on smoking in March, 2004 radon is the most significant factor for lung cancer in the workplace in Ireland. Radon is a natural radioactive invisible gas which accounts for over 60% of the total radiation dose received in Ireland. It has been classified as a Group One carcinogen by the World Health Organisation and is the second most important risk factor for lung cancer worldwide, after tobacco smoking. Lung cancer is the most common type of cancer causing death in Ireland. The Radiological Protection Institute of Ireland estimate that there are approximately 200 deaths per year in Ireland linked to radon. The aim of this study was to determine if the health of Irish workers was being protected from the effects of radon gas. Indoor workplaces in Sligo and Ballina, two towns in High Radon Areas were surveyed, to assess awareness of, and compliance with the legislation governing radon in the workplace. The results show that of employers surveyed: at least 50% did not know that their workplace was located in a High Radon Areas, 43% were not aware of the legislation governing radon in the workplace, 48% had not identified radon as a hazard to health and safety, 64% had not included radon in the workplace Safety Statement and 58% had not carried out a measurement for radon. The results also show that: awareness and compliance was higher in Public Sector workplaces than in Private Sector workplaces, it was higher among larger employers with an international profile than among smaller local employers, employers knew where to go to for advice and guidance on carrying out radon surveys in the workplace, advice on radon was not readily available from State bodies like the Health and Safety Authority, Local Authorities and the Health Service Executive. In conclusion, more than half of all employers surveyed were failing to comply with legislation governing radon in the workplace, yet no employer in either town had ever been

  13. Radon and tritium in human life. The real threat aspects and social responsibilities

    International Nuclear Information System (INIS)

    Full text: Radon is the heaviest radioactive colorless, odorless, undetectable by human feelings and noble atomic gas, contributing by around 54% to the world average total radiation exposure and by more than 58% of the average natural radioactivity. Radon is released from all kind of soils and from building materials and can built up within dwellings and other closed spaces. Established until 1990 as the second cause of lung cancer, the scientists paid more attention to the radon and his daughters effects. The radon maximum permissible level was accepted between 150 Bq/m3 and 600 Bq/m3, being different for different countries. The telluric radon is represented by three abundant isotopes: Rn-222 as successor of U-238 via Ra-226 from uranium chain having more than 90% of effects, Rn-220 from thorium chain and Rn-219 from U-235, both last isotopes having a too short half time to be important in radiological risk by inhalation. The risk by direct body irradiation or by radon ingestion is 104 less than by radon inhalation risk. The interest of different countries in order to reduce the radon effects was sustained by appropriate studies. In USA the radon studies were monitored by National Research Center and as a consequence its Committee for Biological Effects of Ionizing Radiation (BEIR) VI issued a special report regarding radon. The activities regarding the mining, transport and processing are accompanied by radon release. The miner dwellings are located generally into areas of high potential radon release from all kind of natural sources as mountains, faults line or cracks. The existing type of dwellings is very permissive for gaseous elements, especially for radon. The building can accumulate the radon into the airtight or unventilated rooms like gap, cellar, and basement and so on. By the other side many antinuclear NGOs are very active and belligerent against Nuclear Power Plants, especially regarding tritium from CANDU reactor. It must be maintained that all

  14. Implementation of radon remedial techniques in dwellings of Baita uranium mining area in order to improve indoor air quality

    International Nuclear Information System (INIS)

    Full text: The lung cancer continues to be the most common causes of cancer death. Global statistics estimate that between 10% and 25% of all lung cancer worldwide is not attributable to smoking. A pilot study about radon exposure in dwellings located nearby Avram Iancu uranium mine (classified as 'radon-prone area'), Transylvania, is presented in order to provide efficient mitigation strategies for public protection against indoor radon. Our preliminary studies shows that 25% of lung cancer deaths per year were estimated to be attributable to exposure to indoor radon. Health is significantly affected by environmental pollution, confirmed by measurable indicators, so that the mortality rate is higher than in other regions, lung cancer incidence rate is also higher, and life expectancy is reduced by a number of years. The critical situation requires remedial actions to be applied, in the context in which until now in Romania a regional programme or a national strategy regarding Radon mitigation was not implemented so far. The present study will not only help establish an optimal strategy for managing the major radon problems in high radon areas, but will also provide the necessary groundwork essential for the determination of the radon measurements techniques used for building materials. (authors)

  15. House in Bessine-sur-Gartempe (87) built on uranium ore waste rocks and residues. Assessment of radon contents of the indoor air and induced health risks for dwellers

    International Nuclear Information System (INIS)

    After having recalled the origin of radon and how characterization measurements of exposure pathways are performed, this document reports an expertise investigation of the exposure to radon of dwellers of a house. It presents the main results of environmental radiological measurements: exposure to beta/gamma radiation and to radon, assessment of average radon concentrations in the house (measurement strategy, interpretation of average values). It reports the assessment of annual exposures to radon. It discusses the assessment of risks: status of knowledge of impacts of radon on health (radon and risk of lung cancer, other potential health effects of radon), risk assessment based on the efficient dose, method and results of assessment of the risk of lung cancer, impact of tobacco on this assessment, assessment of the risk of leukaemia

  16. Assessment of indoor radon-thoron levels in dwellings of north Indian states

    International Nuclear Information System (INIS)

    According to ICRP publication radon is the second leading cause of lung cancer for individuals who have never smoked. Radon and its progeny are radioactive and is the major contributor to environmental radioactivity. Being a gas radon has the advantage to spread like gases and its progeny has the advantage to attach to aerosols or dust particles and can be inhaled by the human beings leading to the exposure of lung tissues to the radiation. The accumulation of radon indoor is a big source of exposure of human beings to natural radiation. Radon can enter the home through cracks in the foundation floor and walls and other openings. It is also liberated by the building materials. Thus there is need of continuous monitoring for the radon levels in dwellings. Keeping this in mind the environmental monitoring of radon, thoron and their progeny in some dwellings of northern Haryana and southern Himachal Pradesh has been carried out using twin cup dosimeters. Out of different types of dwellings under study the levels are found to be higher in some dwellings in Shivalik foot hills of India as compare to other dwellings. The annual dose received due to radon-thoron and their progeny by the inhabitants in the dwellings under study have also been calculated. (author)

  17. Assessment of the health impact related to indoor exposure to radon in France

    International Nuclear Information System (INIS)

    Radon is a naturally occurring radioactive gas which concentrates in deficiently ventilated habitations. Radon is a well-established human pulmonary carcinogen agent. The exposition of the overall French population to various radon concentrations led scientists to assess its public health impact. This study proposes a predictive assessment of health impact attributable to indoor radon exposure in metropolitan France. Using all available data on the exposure-response between radon exposure and lung cancer mortality risk and on the assessment of indoor radon exposure in France, this study is based on quantitative safety risk assessment method associated to an analysis of both variability and uncertainty, which allows to measure an uncertainty interval related to the prediction. The estimated annual number of lung cancer deaths attributable to indoor radon exposure ranges from 1 234 (90% uncertainty interval, 593-2 156) to 2 913 (90% UI, 2 763-3 221), depending on the model considered. This result shows that indoor radon exposure is a serious public health problem in France. (author)

  18. Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: The Case of Radon and Smoking

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2011-09-01

    Full Text Available Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case example, given its large attributable risk, effect modification due to smoking, and significant variability in radon concentrations and smoking patterns. In spite of this fact, no study to date has estimated geographic and sociodemographic patterns of both radon and smoking in a manner that would allow for inclusion of radon in community-based cumulative risk assessment. In this study, we apply multi-level regression models to explain variability in radon based on housing characteristics and geological variables, and construct a regression model predicting housing characteristics using U.S. Census data. Multi-level regression models of smoking based on predictors common to the housing model allow us to link the exposures. We estimate county-average lifetime lung cancer risks from radon ranging from 0.15 to 1.8 in 100, with high-risk clusters in areas and for subpopulations with high predicted radon and smoking rates. Our findings demonstrate the viability of screening-level assessment to characterize patterns of lung cancer risk from radon, with an approach that can be generalized to multiple chemical and non-chemical stressors.

  19. Study of indoor radon and thoron levels in granite regions of Tumkur and Bangaluru Rural District

    International Nuclear Information System (INIS)

    Radon is a radioactive noble gas produced by decay of 226Ra, which in-tern is the decay product of uranium series, and thoron is the immediate decay product 224Ra from the thorium series. Both these noble gases decay to produce short-lived and long-lived daughter products. These particulate daughter products are responsible for potential health hazards. Recent studies have revealed that there is a clear positive relationship between indoor radon concentration and lung cancer risks even at the low exposure levels below 200 Bq.m-3. Thus, WHO launched the International Radon Project (IRP) in 2005. In this project, radon is regarded as the global burden of disease and the second leading causer of lung cancer, followed by tobacco smoking. The international organizations (UNSCEAR), (ICRP), (IAEA) and (WHO) provide guidelines and recommendations to address the radon problem and to reduce the health hazard burden from radon exposure in dwellings. The area of the study is granite region of Tumkur, and Bangaluru rural District. The rocks belong to the igneous and these are composed of granites, genesis, schists and harmlended. The work presented here describes the measurements of indoor radon and thoron levels by SSNTD in different dwellings and also discuss the variation of radon and thoron gases in different types of flooring and ventilation conditions of dwellings. The results obtained are analysed and presented. (author)

  20. Indoor air quality: radon - report on a WHO working group

    International Nuclear Information System (INIS)

    The WHO Regional Office for Europe organized a working group in Dubrovnik, Yugoslavia, on 26-30 August 1985, which discussed radon as a pollutant affecting indoor air quality. Much of the natural background radiation to which the general public is exposed comes from the decay of 226Ra which produces radon gas and other products. Because radium is a trace element in most rock and soil, indoor concentrations of radon can come from a wide variety of substances, such as building materials and the soil under building foundations. Tap water taken from wells or underground springs may be an additional source. Radon daughter concentrations are considerably higher indoors than outdoors and are of the order of 2-5 Bq m-3 equilibrium equivalent radon (EER) concentration. It has been estimated that current exposure to radon gas could account for as much as 5-15% of all lung cancer deaths. It was recommended that, in general, buildings with concentrations of more than 100 Bq m-3 EER, as an annual average, should be considered for remedial action to lower such concentrations if simple measures are possible. (author)