Measurement of gamma natural background radiation at Chamaraja Nagar, Karnataka state, India

International Nuclear Information System (INIS)

Nagaraju, K.M.; Chandrashekara, M.S.; Paramesh, L.

2012-01-01

The radioactive elements and their radiation are ubiquitous in the environment. The Influence of radiation on living organisms is imminent and very important to study. The ocean, the mountains, the air, and our food all expose us to small amounts of natural background radiation. Cosmic rays from outer space are another large contributor of natural background radiation. Much of the earth's natural background radiation is in the form of gamma radiation, a part of which comes from outer space. Some part of cosmic ray is filtered out by the presence of earth's atmosphere, so there are natural controls for the amount of radiation that people receive. The amount of radiation received by an individual depends on altitude, latitude type of building and the building construction materials. In the present study, measurements of natural background radiation were made in the temples, schools, dwellings, and hill stations in Chamaraja Nagar area, Karnataka state, India by using environmental dosimeter technique. The results show that, absorbed dose rate of background radiations at inside schools varies from 93.96 to 120.93 nGyh -1 with a standard deviation of 10.62 nGyh -1 and outside schools it varies from 60.9 to 113.1 nGyh -1 with a standard deviation of 15.1 nGyh -1 . In temples, the absorbed dose rate varies from 104.4 to 244.91 nGyh - 1 with a standard deviation of 48.34 nGyh -1 and outside the temples it varies from 87.9 to 176.61 nGyh -1 with a standard deviation of 30.896 nGyh -1 . The absorbed dose rate of background radiations at dwellings in indoor varies from 94.0 to 139.2 nGyh -1 with a standard deviation of 16.6 nGyh -1 and in outdoor it varies from 60.9 to 118.32 nGyh -1 with a standard deviation of 19.41 nGyh -1 . The measurements were also carried out in dwellings on hill stations in Chamaraja Nagar district. Indoor gamma dose rate varies from 103.53 to 236.64 nGyh -1 with a standard deviation of 59.8 nGyh -1 and outdoor gamma dose rate varies from 78.3 to 119

Policy implications with regard to controllable forms of natural background radiation

International Nuclear Information System (INIS)

Heijningen, R.J.J. van; Bartels, J.H.M.; Ackers, J.G.; Hogeweg, B.; Rijn, H.T.U. de; Walle, F.B. de

1988-04-01

The RENA (Regulable forms of Natural Background radiation) has started in order to broaden the technical-scientific insights in the domain of the natural background radiation and to continue the SAWORA-study. With regard to the policy implications it has appeared to be desirable to define more detailed the environment-protectional economical and governmental aspects and to consider their mutual relationships in order to prepare a coherent programme which is directed at policy actions to be undertaken as well as at the supporting study needed. (author). 34 refs.; 3 figs.; 11 tabs

Natural background radiation induces cytogenetic radioadaptive response more effectively than occupational exposure in human peripheral blood lymphocytes

International Nuclear Information System (INIS)

Monfared, A.S.; Mozdarani, H.; Amiri, M.

2003-01-01

Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area were evaluated. Peripheral blood samples were prepared and exposed to challenge dose of 0 and 2 Gy. Lymphocytes were scored using analysis of metaphase, for the presence of chromosomal aberrations. An adaptive response was observed in HNBR and radiation workers groups in comparison with sham controls. A significant increase in adaptive response was observed in the HNBR group if compared with the occupationally exposed group. These findings indicate that both natural background radiation and occupational exposure could induce cytogenetic radioadaptive response and it is more significant regarding to natural background ionising radiation. (author)

Background radiation

International Nuclear Information System (INIS)

Arnott, D.

1985-01-01

The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

Geographically determined dependencies in the value of the constant natural radiation gamma-background

International Nuclear Information System (INIS)

Miloslavov, V.

2001-01-01

The problem of the assessment of the influence of natural gamma background changes on the population is discussed. It is considered that the populations in different geographic regions have adapted by evolution mechanisms to the respective unchanged (without human activities) radiation background. The background limits for each area form the 'radiation comfortable zone' which varies very much for the different geographic areas. Leaving the 'comfortable zone' leads to a triggering of adaptive mechanisms in the population including the natural selection in order to reach an equilibrium. Thus, the radiation impact exceeding the 'comfortable zone' is expected to cause harm for a part of the population which is preliminarily burden or uncapable to adapt. From this point of view the increased morbidity due to radiation factor in those cases remains hidden. As a conclusion it is pointed out that the proposed increase of the annual dose for the population might result with harmful consequences for the whole human population

Level of natural background radiation and dose to population in Zhejiang Province

International Nuclear Information System (INIS)

Zhao Yifang; Chen Guopei; Wang Zanxin; Ma Mingqiang

1994-01-01

The natural background radiation in Zhejiang Province was measured and the dose to population was estimated. The results showed that the population-weighted average values of the absorbed dose rate in air from cosmic ray ionization were 3.0 x 10 -8 Gy·h -1 outdoors and 2.7 x 10 -8 Gy·h -1 indoors. The average absorbed dose rates in air from terrestrial γ-radiation were 9.1 x 10 -8 Gy·h -1 outdoors and 14.9 x 10 -8 Gy·h -1 indoors. The average values of radon in air were 17.2 Bq· -3 indoors and 12.7 Bq·m -8 outdoors. The contents of natural radionuclides in food and water were measured. The total annual individual average effective dose from natural background radiation was about 2.0 mSv. The contributions of cosmic rays, terrestrial radiation radon and thoron daughters exposure in air and internal exposure within the body were about 0.24, 0.77, 0.67 and 0.35 mSv, respectively. The annual collective effective dose to population in the province was estimated to be 8.5 x 10 4 man Sv·a -1

Epidemiological studies on disturbances of human fetal development in areas with various doses of natural background radiation. I. Relationship between incidences of Down's syndrome or visible malformation and gonad dose equivalent rate of natural background radiation

International Nuclear Information System (INIS)

Ujeno, Y.

1985-01-01

The relationship between environmental radiation to the gonads and incidences of Down's syndrome and visible malformation was analyzed using Kendall's rank correlation method. The subjects, studied during a 3-yr period (1979-1981), were inhabitants of 46 prefectures in Japan that had various dose rates of natural background ionizing radiation. Results showed that the natural background very low-dose radiation rate was not a predominant factor responsible for inducing Down's syndrome or other visible malformations

Level of natural background radiation and dose to population in Jilin Province

International Nuclear Information System (INIS)

Li Wanxi; Chen Huiying; Ju Cuixiang; Li Fulin; Li Xianggao

1994-01-01

The natural background radiation in Jilin Province was measured and the population dose was estimated. The results showed that the population-weighted average value of the absorbed dose rate in air from cosmic ray ionization was 3.2 x 10 -8 Gy·h -1 . The average absorbed dose rates in air from terrestrial γ radiation were 7.7 x 10 -8 Gy·h -1 outdoors and 9.8 x 10 -8 Gy·h -1 indoors. The average values of radon in air were 8.7 Bq·m -3 outdoors and 5.8 Bq·m -3 indoors. The average concentration of natural radionuclides U, Th, 226 Ra, and 40 K were 3.7 x 10 -2 , 2.4 x 10 -2 , 14.7 x 10 -2 and 81.5 Bq·kg -1 in food, and 2.3, 0.1, 1.1 and 0.3 Bq·L -1 in drinking water, respectively. The total annual individual average effective dose equivalent from natural background radiation was about 1.5 mSv

A new possibility of separate the natural and industrial components of the ambient radiation background

International Nuclear Information System (INIS)

Purghel, L.; Valcov, N.; Celarel, A.

1997-01-01

The ambient radiation background, sometimes considered as a gamma-ray background, is actually composed by a natural radiation field and an industrial radiation field, produced by nuclear facilities. This work presents a possibility to separate and to measure simultaneously both components by using the statistical discrimination method. As the statistical discrimination method is able to measure mixed radiation fields, characterized by essentially different statistical factors k = σ 2 / I (I - the mean value and σ 2 - the variance of the ionization current), this basic assumption of the method is checked, for the natural background and the gamma-ray checked, for natural background and the gamma-ray fields. The obtained value of the ratio k B / k γ = 9 has confirmed the validity of the statistical discrimination method as well as the assumption of a small contribution of the gamma-ray field to the ambient radiation background. Some estimations of the statistical uncertainties, associated with the measurement of two components of the ambient background field have been made. For a 10 liters, atmospheric pressure air - filled ionization chamber (or its equivalent, i.e. 2 liters, 5 atmospheres air -filled chamber) and a 30 s integration time constant, the minimum detectable absorbed dose rate of gamma-rays, for a 0.1 μ Gy / h natural background absorbed dose rate, is equal to 0.02 μ Gy / h. The statistical relative uncertainty of measurement for a 0.5 μ Gy / h absorbed dose rate gamma-ray field, corresponding to the admissible value of the equivalent dose rate of 0.6 μ Sv / h, for non-professional population is about 4 %. (authors)

Level of natural background radiation and dose to population in Heilongjiang province

International Nuclear Information System (INIS)

Liang Yicheng; Wang Lu; He Yongjiang

1992-01-01

The natural background radiation in Heilongjiang Province was measured and the population dose was estimated. The results showed that the population-weighted average values of the absorbed dose rate in air from cosmic ray ionization were 3.3 ± 10 -8 Gy·h -1 outdoors and 3.0 x 10 -8 Gy·h -1 indoors. The average values of radon in air were 11.3 Bq·m -3 outdoors and 20.8 Bq·m -3 indoors. The average concentrations of natural radionuclides U, Th, 226 Ra, and 40 K were 6.1 x 10 -2 , 1.1 x 10 -2 , 8.4 x 10 -2 , and 68.9 Bq·kg -1 respectively in food, and 4.8 x 10 -2 , 2.0 x 10 -4 , 1.2 x 10 -2 and 4.6 x 10 -2 Bq·L -1 respectively in drinking water. The total annual individual average effective dose equivalents from natural background radiation were about 2200 μSv. Among them the contributions of cosmic rays, terrestrial radiation, radon and thoron daughters exposure in air, internal exposure within the body were about 320, 630, 860, and 390 μSv, respectively

Cancer occurrence in the high natural background radiation area of Kerala coast

International Nuclear Information System (INIS)

Krishnan Nair, M.; Sreedevi Amma, N.; Ramachandran, T.P.; Varghese Cherian; Jayalakshmy, P.; Mani, K.S.; Boban, T.G.; Jayadevan, S.; Gangadharan, P.

1994-01-01

In order to assess the health effects if any, in populations living in high background radiation areas, the Department of Atomic Energy has sanctioned a 5-year project to establish a Registry covering Karunagappally taluk. The study proposes to cover a population of about 1,00,000 persons living in high background radiation areas where the radiation levels range anywhere between 10 and 825 μR/h inside the houses; for comparison the study proposes to cover another 3,00,000 persons living in nearby normal areas where the natural radiation levels range between 6 and 200 μ R/h. The data collected so far in the first 2.5 years are presented in this paper which covers a population of about 1,10,000 persons living in three villages. No attempt is made to interpret the data at this preliminary stage. (author). 7 tabs

Effect of background radiation shielding on natural radioactivity distribution measurement with imaging plate

International Nuclear Information System (INIS)

Mori, C.; Suzuki, T.; Koido, S.; Uritani, A.; Miyahara, H.; Yanagida, K.; Miyahara, J.; Takahashi, K.

1996-01-01

Distribution images of natural radioactivity contained in various natural materials such as vegetable, animal meat and pottery work can be obtained with an imaging plate which has high sensitivity for nuclear radiations. For such very low levels of radioactivity, natural background radiations must be reduced using a shielding box. The lining, on the inside of the box, with low atomic number material such as acrylic resin is very effective in reducing electrons, β-rays and low energy X- and γ-rays emitted from the inner surface of the shielding material. Some images of natural radioactivity distribution were obtained and the radioactivity, mainly 40 K, contained in natural materials was measured by using an HPGe detector and also the imaging plate itself. (orig.)

Estimation of effective dose to public from external exposure to natural background radiation in saudi arabia

International Nuclear Information System (INIS)

Khalid, A. A.

2003-01-01

The effective dose values in sixteen cities in Saudi Arabia due to external exposure to natural radiation were evaluated. These doses are based on natural background components including external exposure to terrestrial radiation and cosmic rays. The importance of evaluating the effective dose to the public due to external exposure to natural background radiation lies in its epidemiological and dosimetric importance and in forming a basis for the assessment of the level of radioactive contamination or pollution in the environment in the future. The exposure to terrestrial radiation was measured using thermoluminescent dosimeters (TLD). The exposure from cosmic radiation was determined using empirical correlation. The values evaluated for the total annual effective dose in all cities were within the world average values. The highest total annual effective dose measured in Al-Khamis city was 802 μSv/y, as compared to 305 μSv/y in Dammam city, which was considered the lowest value

Natural background radiation in Canada

International Nuclear Information System (INIS)

Grasty, R.L.; Carson, J.M.; Charbonneau, B.W.; Holman, P.B.

1984-01-01

Published airborne gamma ray survey data from 33 areas of Canada were used to compile information on the average ground level exposure from natural radiation. The exposures at ground level were calculated from the surface concentrations of potassium, uranium and thorium. The highest levels of radioactivity were found in northern Canada and were generally related to granitic rocks; the lowest levels with the Athabasca sandstone. Summer outdoor exposure rates have a population-weighted average of 3.7 +- 2.3 μR.h -1 , of which 48 percent orginated from potassium, 43 percent from the thorium series and 9 percent from the uranium series. This low level of radioactivity, compared to worldwide data, has resulted from erosion of a geologically old continental crust in which radioactivity decreases with depth. When seasonal variations of soil moisture and snow cover are considered, the annual population-weighted average outdoor exposure rate decreases to 2.8 +- 1.7 μR.h -1 corresponding to an annual outdoor dose-equivalent of 150 +- 90 μSV. Factors increasing the annual outdoor dose-equivalent are cosmic radiation (320 +- 30 μSV) and the internal radioactivity of the body (190 μSV). Using the ratio between indoor and outdoor values for worldwide published data, the average annual Canadian whole-body dose-equivalent from all sources of natural radiation is estimated to be 690 +-130 μSV

Background radiation levels and standards for protection from ionizing radiations

International Nuclear Information System (INIS)

Farai, I.

1999-01-01

Apart from the amount of radiation which a worker may receive while he performs his work, he is also exposed to radiation because of the nature of his environment. In other words, all individuals are subject to some irradiation even though they may not work with radioactive substances. This source of radiation exposure is often referred to as background radiation. In most environments, it is low-level and can be grouped into two natural and man-made. Background radiation provides the basis on which allowable exposure limits for workers are drawn

Low energy background radiation in India

International Nuclear Information System (INIS)

Gopinath, D.V.

1980-01-01

Spectral distribution of background radiation at 9 locations spread all over India has been measured. Specifications of the counting set-up standardised for measurement are given. At one of the places, the background spectrum was measured with four different types of detectors. A broad peak in 60-100 keV with differing intensity and standard deviation is observed in all the spectra. In the Kalpakkam area, the peak near the seashore is observed to be more intense than away from the shore. This could be due to the presence of monazite sands on the seashore. The natural background radiation is observed to have a steep rise below 20 keV. Peak intensity is found to be independent of both the location (i.e. the source of energy) and the type of detector used for measurement. The calculated spectra due to multiple scattered radiation (with a nominal source energy of 1 MeV) through paraffin wax and the measured background spectrum with the detector shielded with 20 cm wax show good agreement above 40 keV. This shows that 80 keV hump in the natural background radiation is a property of air. The peak, therefore, in the spectra of natural background radiation is essentially a property of medium and it is independent of location or detector. (M.G.B.)

Characteristics of natural background external radiation and effective dose equivalent

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1989-01-01

The two sources of natural radiation - cosmic rays and primordial radionuclides - are described. The factors affecting radiation doses received from natural radiation and the calculation of effective dose equivalent due to natural radiation are discussed. 10 figs., 3 tabs

Background radiation map of Thailand

International Nuclear Information System (INIS)

Angsuwathana, P.; Chotikanatis, P.

1997-01-01

The radioelement concentration in the natural environment as well as the radiation exposure to man in day-to-day life is now the most interesting topic. The natural radiation is frequently referred as a standard for comparing additional sources of man-made radiation such as atomic weapon fallout, nuclear power generation, radioactive waste disposal, etc. The Department of Mineral Resources commenced a five-year project of nationwide airborne geophysical survey by awarding to Kenting Earth Sciences International Limited in 1984. The original purpose of survey was to support mineral exploration and geological mapping. Subsequently, the data quantity has been proved to be suitable for natural radiation information. In 1993 the Department of Mineral Resources, with the assistance of IAEA, published a Background Radiation Map of Thailand at the scale of 1:1,000,000 from the existing airborne radiometric digital data. The production of Background Radiation Map of Thailand is the result of data compilation and correction procedure developed over the Canadian Shield. This end product will be used as a base map in environmental application not only for Thailand but also Southeast Asia region. (author)

World high background natural radiation areas: Need to protect public from radiation exposure

International Nuclear Information System (INIS)

Sohrabi, Mehdi

2013-01-01

Highlights of findings on radiological measurements, radiobiological and epidemiological studies in some main world high background natural radiation (HBNR) areas such as in Brazil, China, India and Iran are presented and discussed with special regard to remediation of radiation exposure of inhabitants in such areas. The current radiation protection philosophy and recommendations applied to workers and public from operation of radiation and nuclear applications are based on the linear non-threshold (LNT) model. The inhabitants of HBNR and radon prone areas receive relatively high radiation doses. Therefore, according to the LNT concept, the inhabitants in HBNR areas and in particular those in Ramsar are considered at risk and their exposure should be regulated. The HBNR areas in the world have different conditions in terms of dose and population. In particular, the inhabitants in HBNR areas of Ramsar receive very high internal and external exposures. This author believes that the public in such areas should be protected and proposes a plan to remedy high exposure of the inhabitants of the HBNR areas of Ramsar, while maintaining these areas as they stand to establish a national environmental radioactivity park which can be provisionally called “Ramsar Research Natural Radioactivity Park” (RRNRP). The major HBNR areas, the public exposure and the need to remedy exposures of inhabitants are reviewed and discussed. - Highlights: ► Highlights of findings on studies in HBNR areas are reviewed and discussed. ► The need to protect HBNR area inhabitants and remedy public exposure is emphasized. ► A collective approach is proposed to remedy exposure of Ramsar HBNR area inhabitants. ► Relocation of HBNR area inhabitants and establishing a park at the location is proposed. ► The advantages and disadvantages of the methods are discussed and recommendations are made

Human exposure to high natural background radiation: what can it teach us about radiation risks?

International Nuclear Information System (INIS)

Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner; Simon, Steven L; Wojcik, Andrzej; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

2009-01-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222 Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

Human exposure to high natural background radiation: what can it teach us about radiation risks?

Science.gov (United States)

Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

2014-01-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case–control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case–control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors. PMID:19454802

Human exposure to high natural background radiation: what can it teach us about radiation risks?

Energy Technology Data Exchange (ETDEWEB)

Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna (Austria); Simon, Steven L [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Wojcik, Andrzej [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Cardis, Elisabeth [Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar) and CIBER Epidemiologia y Salud Publica - CIBERESP, Barcelona (Spain); Laurier, Dominique; Tirmarche, Margot [Radiobiology and Epidemiology Department, Radiological and Human Health Division, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses (France); Hayata, Isamu [National Institute of Radiological Sciences, Chiba (Japan)], E-mail: jhendry2002uk@yahoo.com

2009-06-01

Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of {sup 222}Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

Exposure to background radiation in Australia

International Nuclear Information System (INIS)

Solomon, S.B.

1997-01-01

The average effective dose received by the Australian population is estimated to be ∼1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m -3 in Queensland to 16 Bq m -3 in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year

Optimal Background Attenuation for Fielded Radiation Detection Systems

International Nuclear Information System (INIS)

Robinson, Sean M.; Kaye, William R.; Schweppe, John E.; Siciliano, Edward R.

2006-01-01

Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to terrestrial background from the surrounding area. A low background is desired in most cases, especially when the background noise is of comparable strength to the signal of interest. The problem of shielding a generalized RPM from terrestrial background is considered. Various detector and shielding scenarios are modeled with the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to attenuate the terrestrial background to varying degrees are given, along with optimal shielding geometry to be used in areas where natural shielding is limited, and where radiation detection must occur in the presence of natural background. Common shielding solutions such as steel plating are evaluated based on the signal to noise ratio and the benefits are weighed against the incremental cost.

Exposure to background radiation in Australia

Energy Technology Data Exchange (ETDEWEB)

Solomon, S.B. [Australian Radiation Lab., Melbourne, VIC (Australia)

1997-12-31

The average effective dose received by the Australian population is estimated to be {approx}1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m{sup -3} in Queensland to 16 Bq m{sup -3} in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year. 9 refs., 2 tabs., 4 figs.

Natural radiation environment

International Nuclear Information System (INIS)

Vohra, K.G.; Mishra, U.C.; Pillai, K.C.; Sadasivan, S.

1982-01-01

The volume presented contains papers presented at the Second Special Symposium on Natural Radiation Environment held at Bombay, India, during January 1981. The papers deal with such topics as : 1)high natural radiation background areas; 2)environmental natural radioactivity; 3)measurement techniques; 4)technologically enhanced radioactivity; 5)indoor radiation environment; 6)radon and daughters in ambient air, and 7)applications in Geosciences. Each of the 87 papers presented has been abstracted and indexed for the U.S. Department of Energy Technical Information Center's Energy Data Base

Social economical and psychological considerations in conveying potential radiation risks from high level natural background radiation to the residents of Ramsar, Iran

International Nuclear Information System (INIS)

Mortazavi, S. M. J.; Ghiassi-nejad, M.

2003-01-01

X-rays and radioactivity were discovered more than 100 years ago but the need for protection against very low doses of ionizing radiation and especially different levels of natural radiation is still among the most controversial matters in radiobiology and radiation protection. According to formal reports, some areas in Ramsar, a city in northern Iran, are the inhabited areas with the highest levels of natural radiation studied so far. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy y''-1 and the highest recorded external gamma dose rates are about 130 mGy y''-1. We have previously shown that in high background radiation areas (HBRAs), cultured human lymphocytes of the inhabitants whose cumulative radiation doses were as much as 170 times more than those of a control area when subjected to 1.5 Gy challenge dose,were significantly more radioresistant compared to the residents of the control area (Mortazavi et al. 2002a,b, Mortazavi and Karam 2002, Ghiassi-Najed et al. 2002). The people who live in these areas are usually unaware of the high levels of natural radiation in their environment. Studies performed on the residents of these areas have indicated that the effective dose of the inhabitants, in some cases, is much higher than the dose limits for occupational irradiation. Considering recent policies of ICRP regarding suggesting dose limits for exposure to natural sources of ionizing including radon, it seems that the inhabitants should become familiar with the possible risks of the exposure to high levels of ionizing radiation. They should also realize that studies performed over the past years have indicated no detrimental effect. On the other hand, according to ICRP suggestions and considering the experiences in other countries, especially evacuation of the residents of contaminated areas after Chernobyl accident, setting any radiation protection regulation for the inhabitants without considering social, economic and

Nature of the Background Ultraviolet Radiation Field at High Redshifts

Indian Academy of Sciences (India)

tribpo

J. Astrophys. Astr. (2000) 21, 19-27 .... to know the shape of the ionizing radiation to determine the ionization parameter from the C II to C IV ratio. ... different shapes of the background radiation spectrum as explained in the text. The solid lines.

Mapping the exposure of the Brazilian population to natural background radiation - cosmic radiation

Energy Technology Data Exchange (ETDEWEB)

Rochedo, Elaine R.R., E-mail: elaine@ird.gov.br [Instituto de Radioprotecao e Dosimetria (lRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Salles, Krause C.S.; Prado, Nadya M.C., E-mail: krausesalles@yahoo.com.br, E-mail: nadya@ime.ib.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

2013-07-01

The main objective of this work is to statically and graphically describe the exposure of the Brazilian population to natural background radiation. in this stage, doses due to cosmic rays is being assessed based on sea level dose rates, corrected by latitude and altitude, according to the model recommended by UNSCEAR. In this work, the doses were estimated for ali Brazilian municipalities with more than 100.000 inhabitants. The 253 municipalities selected for this study include about 52% of the Brazilian population. Average dose rate was estimated to be about 50 n Sv/h with a variation coefficient of 31%. The estimated doses have shown a strong influence of altitude on dose rates, with a correlation coefficient of 0,998 for ao exponential fit. This result confirms previous studies that show a large effect of the altitude 00 exposure from cosmic radiation. Considering the same occupation and shielding conditions used by UNSCEAR as global averages, average annual dose was estimated to be 0,37 (0,24 - 0,76) mSv/y, very close to UNSCEAR worldwide average of 0,38 (0,3 - 1,0) mSv/y. (author)

Mapping the exposure of the Brazilian population to natural background radiation - cosmic radiation

International Nuclear Information System (INIS)

Rochedo, Elaine R.R.; Salles, Krause C.S.; Prado, Nadya M.C.

2013-01-01

The main objective of this work is to statically and graphically describe the exposure of the Brazilian population to natural background radiation. in this stage, doses due to cosmic rays is being assessed based on sea level dose rates, corrected by latitude and altitude, according to the model recommended by UNSCEAR. In this work, the doses were estimated for ali Brazilian municipalities with more than 100.000 inhabitants. The 253 municipalities selected for this study include about 52% of the Brazilian population. Average dose rate was estimated to be about 50 n Sv/h with a variation coefficient of 31%. The estimated doses have shown a strong influence of altitude on dose rates, with a correlation coefficient of 0,998 for ao exponential fit. This result confirms previous studies that show a large effect of the altitude 00 exposure from cosmic radiation. Considering the same occupation and shielding conditions used by UNSCEAR as global averages, average annual dose was estimated to be 0,37 (0,24 - 0,76) mSv/y, very close to UNSCEAR worldwide average of 0,38 (0,3 - 1,0) mSv/y. (author)

Measurement of the natural radiation background level of Riyadh City

International Nuclear Information System (INIS)

Al-Kusayer, T.A.; Al-Haj, A.N.

1987-01-01

A gamma spectroscopy system was used to analyze the radionuclides in soil samples and to determine the cumulative radioactivity of terrestrial origin in the Riyadh City area. Minimal work has been done in the 1980s to measure the natural background radiation level in Saudi Arabia by using thermoluminescent dosimeters. The measurement of the natural radioactivity in the Riyadh area for the radionuclide concentration in becquerels per kilogram, the exposure rate arising from radionuclides in grays per hour, and the equivalent dose rate in sieverts per hour are the goals of this work. Soil samples were collected from 21 places in Riyadh City. Each site was sampled for two depth profiles, 0 to 5 cm and 5 to 15 cm. These measurements were taken before the Chernobyl accident, and in the absence of any measurements for that area in the past, this work can be considered in future work for a reference 137 Cs concentration in Riyadh soil to determine the 137 Cs increase in the soil after the Chernobyl accident

A geophysical tour of high background radiation areas of the world

International Nuclear Information System (INIS)

Krishnan, D.; Kher, R.K.; Nambi, K.S.V.

1995-01-01

A comparison of the findings including health effects in four major high natural background areas of the world are given. Such high background areas could prove to be a radiation ecology laboratory gifted by nature and provide further insight in the relation of radiation, natural or otherwise and human health. 3 refs., 2 tabs

Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

International Nuclear Information System (INIS)

Little, Mark P; Wakeford, Richard; Kendall, Gerald M

2009-01-01

The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.

Measurement of high natural background radiation levels by TLD at Cox's Bazar coastal areas in Bangladesh

International Nuclear Information System (INIS)

Mollah, A.S.; Rahman, M.M.; Koddus, M.A.; Husain, S.R.; Malek, M.A.

1987-01-01

High natural background radiation levels at the Cox's Bazar coastal areas in Bangladesh were measured by LiF (TLD-100) dosemeters. The dose rates varied from 2621 to 35391 μGy.y -1 with a mean of 11968 μGy.y -1 . The average dose rate is found to significantly higher than the world average value. In order to formulate appropriate guidelines for radiation protection of the population in this area, the necessary recommendations are described. (author)

Correlation between natural radiation exposure and cancer mortality, (4)

International Nuclear Information System (INIS)

Noguchi, Kunikazu; Shimizu, Masami; Sairenji, Eiko; Anzai, Ikuro.

1987-01-01

In the previous studies, using Pearson's product moment correlation coefficient, we found that in most cases of cancers, statistically significant positive correlations were observed between natural background radiation exposure rate and crude cancer mortality rate over the period 1950 - 1978. Furthermore, we found that the statistical significance of correlation between natural background radiation exposure rate and the age-adjusted cancer mortality rate in the same period mostly disappeared. We studied the cause of this apparent correlation and found that the prefecture with a higher natural background radiation exposure rate had a greater component ratio of older people. In Japan, a number of prefectures with a higher natural background exposure rate are located in relatively thinly populated districts which have been experiencing an outflow of the younger generation to more highly industrialized and urbanized areas. Therefore, statistically significant positive correlations were observed for almost all cancers between natural background radiation exposure rate and crude cancer mortality rate. In the present investigation, we statistically tested the frequency distributions of natural background radiation exposure rate and age-adjusted cancer mortality rate, and calculated Spearman's rank correlation coefficient between natural background radiation exposure rate and the age-adjusted cancer mortality rate. The frequency distribution of the natural background radiation exposure rate and that of the age-adjusted mortality rate appeared normal in most cases of cancer, and the statistical significance of correlation between natural background exposure rate and the age-adjusted cancer mortality rate did not differ much on the whole, even though we used Spearman's rank correlation coefficient between them. (author)

Correlation between natural radiation exposure and cancer mortality, (4)

Energy Technology Data Exchange (ETDEWEB)

Noguchi, Kunikazu; Shimizu, Masami; Sairenji, Eiko; Anzai, Ikuro

1987-03-01

In the previous studies, using Pearson's product moment correlation coefficient, we found that in most cases of cancers, statistically significant positive correlations were observed between natural background radiation exposure rate and crude cancer mortality rate over the period 1950 - 1978. Furthermore, we found that the statistical significance of correlation between natural background radiation exposure rate and the age-adjusted cancer mortality rate in the same period mostly disappeared. We studied the cause of this apparent correlation and found that the prefecture with a higher natural background radiation exposure rate had a greater component ratio of older people. In Japan, a number of prefectures with a higher natural background exposure rate are located in relatively thinly populated districts which have been experiencing an outflow of the younger generation to more highly industrialized and urbanized areas. Therefore, statistically significant positive correlations were observed for almost all cancers between natural background radiation exposure rate and crude cancer mortality rate. In the present investigation, we statistically tested the frequency distributions of natural background radiation exposure rate and age-adjusted cancer mortality rate, and calculated Spearman's rank correlation coefficient between natural background radiation exposure rate and the age-adjusted cancer mortality rate. The frequency distribution of the natural background radiation exposure rate and that of the age-adjusted mortality rate appeared normal in most cases of cancer, and the statistical significance of correlation between natural background exposure rate and the age-adjusted cancer mortality rate did not differ much on the whole, even though we used Spearman's rank correlation coefficient between them.

Variation of Natural Gamma Radiation in Isparta

International Nuclear Information System (INIS)

Akkurt, I.

2004-01-01

There is always a radiation in the earth, and its level is generated primarily by galactic cosmic rays (GCR), consisting of energetic nuclei of all naturally occurring elements, interacting with atmospheric constituents, through atomic and nuclear collisions. The other sources of natural radiations are global average background radiation from terrestrial sources such as soils, rocks ete. Background radiation levels in the atmosphere vary in intensity with latitude, altitude and phase of the solar cycle. Variation of natural radiation as a function of altitude, geological structure etc has been investigated. The measurements were performed using portable radiation counter which connected to NaI(Tl) probe

Is natural background or radiation from nuclear power plants leukemogenic?

International Nuclear Information System (INIS)

Cronkite, E.P.

1989-01-01

The objective in this review is to provide some facts about normal hemopoietic cell proliferation relevant to leukemogenesis, physical, chemical, and biological facts about radiation effects with the hope that each person will be able to decide for themselves whether background radiation or emissions from nuclear power plants and facilities significantly add to the spontaneous leukemia incidence. 23 refs., 1 tab

Influence of NORMs on the natural background radiation level in petroleum-producing countries

International Nuclear Information System (INIS)

Ali, F.M.

2002-01-01

Naturally occurring radioactive materials (NORMs) which are found in the Earth's crust, in the form of 226 Ra and 228 Ra and their associated radionuclides, are brought to the surface of the ground as a result of oil production processes, and are known under the name of technologically enhanced natural radioactivity (TENR). These represent a potential hazard of significant scale. 226 Ra, an α emitter, represents a potential internal radiation exposure hazard to both workers and members of the public, arising from the inhalation and ingestion of the dust produced during cleaning operations for the descaling of pipes and separator tanks. In addition to this, a higher than normal background γ exposure rate is to be observed both around and directly at the areas where the mud from the separator tanks and pipe cleaning operations was routinely dumped. Therefore, the aim of this work was to present the data on radiation levels measured in contaminated areas located near to a number of oilfields in Egypt and in Syria. The decontamination processes undertaken and the precautions necessary to ensure elimination of the possible transport mechanisms for contaminated dust into public areas by wind are presented. (orig.)

Quantification of DNA repair capacity (DRC) in peripheral blood lymphocytes of individuals from natural high background radiation areas of Kerala, India

International Nuclear Information System (INIS)

Vivek Kumar, P.R.; Seshadri, M.

2011-01-01

Human populations residing in the coastal areas of Kerala from Neendakara in south to Purakkad in north receive high level natural background radiation primarily due to the presence of thorium ( 232 Th) in the monazite containing beach sand. This provides a unique opportunity to investigate the health effects of natural high level radiation on humans. Earlier studies from our laboratory in newborns for incidence of congenital malformations, structural and numerical chromosome aberrations failed to show any significant health or biological effects due to high level natural radiation exposure. The current study used alkaline single cell gel electrophoresis (comet) assay due to its sensitivity, speed, flexibility and low cost. Biological effects of low level natural radiation was studied by assessing individual's DNA Repair Capacity (DRC), which is essential for maintaining the genome integrity. DNA damage was estimated in terms of DNA strand breaks per million base pairs (SB/106 bp). In our earlier study using comet assay, DNA SBs increased with age in subjects from normal background radiation area (NBRA). However, significant inverse correlation was observed in subjects from high background radiation area (HBRA). Further, spontaneous DNA SBs in elderly subjects (? 41 years) from HBRA was significantly lower compared to the subjects from NBRA. The present study was carried out in 90 healthy adult male subjects of which, 63 subjects belonged to HBRA and 27 subjects from NBRA. The annual effective dose in HBRA subjects was 5.87 ± 4.17 mSv year-1 (Mean ± S.D., range 1.07-17.41) and in NBRA subjects was ? 1mSv year-1. Peripheral blood lymphocytes from these individuals were irradiated with 4Gy of 60 Co gamma rays (1.4Gy/minute, Low dose irradiator 2000, BRIT, India) and DNA repair was assessed at 30 minutes. As the results were not normally distributed, the data were log transformed to normalize variance. Regression analysis was carried out to determine the relative

Study of the natural radiation background affected on the human body in some areas of Viet Nam

International Nuclear Information System (INIS)

Ngo Van Thanh

2008-01-01

The author had studied the natural radiation background in 68 districts belong 40 provinces and cities of Vietnam from 2002 to 2005. The estimated results clearly show that the average external irradiation dose levels and the average annual external radiation equivalent dose affected on the human body are 0.181± 0.0189 μSv/h and 1599 ± 171.8 μSv/year respectively, both are in normal limit; the highest levels are in Lai Chau district (Lai Chau province); the lowest levels are in Buon Ma Thuot city (DakLak province), Phuoc Son district (Quang Nam province), Tan An district (Long An province). The radon concentration in the human being and the average annual internal inhalation irradiation equivalent dose affected on the human beings are 26.9 ± 15.89 Bq/m 3 and 392.88 ± 231.99 μSv/year respectively; the maximums are in Nha Trang city (Khanh Hoa province), Bac Binh district (Binh Phuoc province); the minimums are in Vung Tau city (Ba Ria- Vung Tau province), Tan An district (Long An province), Rach Gia district (Kien Giang province). The terrestrial radionuclide concentrations in the cereals, foodstuffs (rice, meat, vegetables), water, earth and the average annual internal irradiation equivalent dose are 829.2 ± 38.06 Bq/kg and 229.3 ± 67.70 μSv/year respectively; the highest levels are in Phong Tho district (Lai Chau province), Dien Bien city; the lowest levels are in Dong Xoai district (Binh Phuoc province), Tan An district (Long An province). The average total annual natural radiation background effective equivalent dose level affected on the human body is 2206.9 ± 529.30 μSv/year; the highest levels are in Lai Chau district (Lai Chau province); the lowest levels are in Tan An district (Long An province). The 14 maps of Natural Radiation Background in several localized regions belong 40 provinces and cities of Viet Nam had been set up. These results can reserve for serviceman and public health in the both wartime and peacetime. (author)

Spectrum and isotropy of the submillimeter background radiation

International Nuclear Information System (INIS)

Muehlner, D.

1977-01-01

Two great astronomical discoveries have most shaped our present concept of the Big Bang universe. Like the Hubble recession of the galaxies, the discovery of the 3 0 K background radiation by Penzias and Wilson in 1965 has given rise to a line of research which is still very active today. Penzias and Wilson's universal microwave background at 7 cm was immediately interpreted by R.H. Dicke's group at Princeton as coming from the primordial fireball of incandescent plasma which filled the universe for the million years or so after its explosive birth. This interpretation gives rise to two crucial predictions as to the nature of the background radiation. Its spectrum should be thermal even after having been red shifted by a factor of approximately 1000 by the expansion of the universe, and the radiation should be isotropic - assuming that the universe itself is isotropic. If the background radiation is indeed from the primordial fireball it affords us the only direct view at the very young universe. This paper deals with the spectrum and then the isotropy of the background radiation, with emphasis on high frequency or submillimeter measurements. Prospects for the future are discussed briefly. (Auth.)

Effects of reduced natural background radiation on Drosophila melanogaster growth and development as revealed by the FLYINGLOW program.

Science.gov (United States)

Morciano, Patrizia; Iorio, Roberto; Iovino, Daniela; Cipressa, Francesca; Esposito, Giuseppe; Porrazzo, Antonella; Satta, Luigi; Alesse, Edoardo; Tabocchini, Maria Antonella; Cenci, Giovanni

2018-01-01

Natural background radiation of Earth and cosmic rays played a relevant role during the evolution of living organisms. However, how chronic low doses of radiation can affect biological processes is still unclear. Previous data have indicated that cells grown at the Gran Sasso Underground Laboratory (LNGS, L'Aquila) of National Institute of Nuclear Physics (INFN) of Italy, where the dose rate of cosmic rays and neutrons is significantly reduced with respect to the external environment, elicited an impaired response against endogenous damage as compared to cells grown outside LNGS. This suggests that environmental radiation contributes to the development of defense mechanisms at cellular level. To further understand how environmental radiation affects metabolism of living organisms, we have recently launched the FLYINGLOW program that aims at exploiting Drosophila melanogaster as a model for evaluating the effects of low doses/dose rates of radiation at the organismal level. Here, we will present a comparative data set on lifespan, motility and fertility from different Drosophila strains grown in parallel at LNGS and in a reference laboratory at the University of L'Aquila. Our data suggest the reduced radiation environment can influence Drosophila development and, depending on the genetic background, may affect viability for several generations even when flies are moved back to normal background radiation. As flies are considered a valuable model for human biology, our results might shed some light on understanding the effect of low dose radiation also in humans. © 2017 Wiley Periodicals, Inc.

Background radiation levels and medical exposure levels in Australia

International Nuclear Information System (INIS)

Webb, D.V.; Solomon, S.B.; Thomson, J.E.M.

1999-01-01

The average effective background dose received by the Australian population has been reassessed to be ∼1.5 millisievert (mSv) per year. Over half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This background is to be compared with medical radiation, primarily diagnostic, which could add half as much again to the population exposure. This paper reviews research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background and from medical use. While the latter exposure is accepted to have a social benefit, there is a need to ensure that doses are no more than necessary to provide effective diagnosis and optimal treatment. Copyright (1999) Australasian Radiation Protection Society Inc

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

International Nuclear Information System (INIS)

Deva Jayanthi, D.; Maniyan, C.G.; Perumal, S.

2011-01-01

Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: → The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. → The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. → As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. → Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. → These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

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

Energy Technology Data Exchange (ETDEWEB)

Deva Jayanthi, D., E-mail: d.devajayanthi@gmail.co [Department of Physics, Women' s Christian College, Nagercoil 629001 (India); Maniyan, C.G. [Environmental Assessment Division, BARC, Mumbai 400085 (India); Perumal, S. [Department of Physics and Research Centre, S.T.Hindu College, Nagercoil 629002 (India)

2011-07-15

Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv. -- Highlights: {yields} The effective dose received by the villages of Natural High Background Area (NHBRA) such as Enayam, Midalam and Mel Midalam is high when compared with other study areas. {yields} The high dose indicates higher concentration of radioactive nuclides like Thorium and Uranium in the soil. {yields} As radiation is harmful to human life, the external and internal doses can be reduced by removing the monazite content present in the soil by mineral separation. {yields} Contribution from vegetables, fruits, fish and other non vegetarian items are also being examined. {yields} These results along with other socio-economic factors can throw considerable light on the epidemiological impacts due to low levels of chronic exposure.

Properties of Natural Radiation and Radioactivity

International Nuclear Information System (INIS)

Strom, Daniel J.

2009-01-01

Ubiquitous natural sources of radiation and radioactive material (naturally occurring radioactive material, NORM) have exposed humans throughout history. To these natural sources have been added technologically-enhanced naturally occurring radioactive material (TENORM) sources and human-made (anthropogenic) sources. This chapter describes the ubiquitous radiation sources that we call background, including primordial radionuclides such as 40K, 87Rb, the 232Th series, the 238U series, and the 235U series; cosmogenic radionuclides such as 3H and 14C; anthropogenic radionuclides such as 3H, 14C, 137Cs, 90Sr, and 129I; radiation from space; and radiation from technologically-enhanced concentrations of natural radionuclides, particularly the short-lived decay products of 222Rn ('radon') and 220Rn ('thoron') in indoor air. These sources produce radiation doses to people principally via external irradiation or internal irradiation following intakes by inhalation or ingestion. The effective doses from each are given, with a total of 3.11 mSv y-1 (311 mrem y-1) to the average US resident. Over 2.5 million US residents receive over 20 mSv y-1 (2 rem y-1), primarily due to indoor radon. Exposure to radiation from NORM and TENORM produces the largest fraction of ubiquitous background exposure to US residents, on the order of 2.78 mSv (278 mrem) or about 89%. This is roughly 45% of the average annual effective dose to a US resident of 6.2 mSv y-1 (620 mrem y-1) that includes medical (48%), consumer products and air travel (2%), and occupational and industrial (0.1%). Much of this chapter is based on National Council on Radiation Protection and Measurements (NCRP) Report No. 160, 'Ionizing Radiation Exposure of the Population of the United States,' for which the author chaired the subcommittee that wrote Chapter 3 on 'Ubiquitous Background Radiation.'

Radiation dose in the high background radiation area in Kerala, India.

Science.gov (United States)

Christa, E P; Jojo, P J; Vaidyan, V K; Anilkumar, S; Eappen, K P

2012-03-01

A systematic radiological survey has been carried out in the region of high-background radiation area in Kollam district of Kerala to define the natural gamma-radiation levels. One hundred and forty seven soil samples from high-background radiation areas and five samples from normal background region were collected as per standard sampling procedures and were analysed for (238)U, (232)Th and (40)K by gamma-ray spectroscopy. External gamma dose rates at all sampling locations were also measured using a survey meter. The activities of (238)U, (232)Th and (40)K was found to vary from 17 to 3081 Bq kg(-1), 54 to 11976 Bq kg(-1) and BDL (67.4 Bq kg(-1)) to 216 Bq kg(-1), respectively, in the study area. Such heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of beach sand soil in the region. Radium equivalent activities were found high in several locations. External gamma dose rates estimated from the levels of radionuclides in soil had a range from 49 to 9244 nGy h(-1). The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples.

Study of natural background radiation levels with special reference to the granite industries and quarries in some places of Karnataka State

International Nuclear Information System (INIS)

Sannappa, J.; Srilatha; Ningappa, C.

2012-01-01

Radiation is present all around us which may be also called natural background radiation. It is divided into natural and anthropogenic. The sources of natural radiation are extra terrestrial (cosmic ray) radiation and terrestrial radiation; it arises due to naturally occurring radionuclides present in soil, rocks and building materials. Whereas anthropogenic radiation sources includes X rays used for medical diagnosis nuclear weapon testing nuclear power plants radioisotopes used in varies fields, other industry applications and scientific research. Out of the total radiation exposure nearly 97.7% is from natural sources and remaining 2.3% is due to artificial sources. Nature has gifted several geological material to mankind for building purposes. The granite rocks are used as building material, these rocks are quite rich in radioactive nuclides. The radiation from these nuclides are exposed to mankind and the rocks are exploited and extracted by miners to construct the buildings. Natural radiation is of importance because it accounts for the largest contributor of radiation exposure to the world population from all natural sources (UNSCEAR 2008). Understanding the magnitude of natural sources of radiation and their distribution in the living environment may help any one to develop a pragmatic approach towards radiation and its effects. This article provides a radiation levels measured in granite quarries and industries and assessment of health effects to the workers and publics of the study area. The total occupational dose to the workers is lower than ICRP recommended value and the total dose for the public is slightly higher than the global average value. There is no regulation control for the granite mining. As per the IAEA report regulatory control is needed for mining and processing of granite rocks The study area is granite region of Bangaluru rural district, Tumkur and Mysore. (author)

Health effects in residents of regions with high background radiation

International Nuclear Information System (INIS)

Hanson, G.P.

1984-01-01

Possible health problems created by high natural levels of background radiation are hard to detect, partly because the health problems involved would exist to some degree irrespective of radiation exposure, partly because other factors affect the incidence of such problems, and partly because the differences between normal background radiation levels and radiation levels found in most high-radiation areas are not extreme. Nevertheless, the need to know about such health effects is evident, and so various studies conducted over the past 30 years have sought to determine whether those effects exist and what they are. Overall, however, the fragmentary and uncertain nature of many of these findings makes it hard to draw firm conclusions about the health risks involved or the desirability of countermeasures. So despite considerable efforts and some progress over the past three decades, the need for a clear quantitative assessment of the consequences is as great as ever

Cytogenetic studies on newborns from high level natural background radiation areas of Kerala coast, South India

International Nuclear Information System (INIS)

Cherian, V.D.; Kurien, C.J.; Das, Birajalaxmi

1997-01-01

The human population residing in the monazite bearing high level natural background radiation (HLNBR) areas of Kerala, along the South-West coast of India provides unique opportunities of assessing directly in man, the health effects of chronic low-level radiation exposure. The per capita dose received by this population is nearly four times the normal background radiation level. While this is the average dose, the radiation levels prevailing in these HLNBR areas are in the range of 1 to over 35 mGy per year. Chromosomal aberration studies in the lymphocytes of newborns and adults from these areas have been in progress for two decades. So far, 4156 newborn babies from HLNBR and 7321 from normal background radiation (NBR) areas have been screened for the incidence of chromosomal aberrations (dicentrics and rings). The mean frequency of dicentrics and rings did not show any significant difference between the newborns in the control and the HLNBRA population. Assessment of the frequency of micronuclei in cytochalasin-B blocked binucleated lymphocytes of 49 newborns from control areas and 131 newborns from radioactive areas also showed similar values. While an age-dependent increase in chromosome aberration frequency was observed in the adult samples from control and the study areas, the regression analysis of the data indicated a marginally higher slope for the samples from HLNBRA. Karyotype anomalies recorded so far among the newborns have not revealed any significant difference in the incidence of numerical (including Down syndrome) and structural alterations between the control and the exposed populations. A noteworthy observation, herein reported for the first time from any HLNBR area is that there is no discernible increase in the incidence of micronuclei and chromosomal aberrations in the peripheral lymphocytes of newborn babies hailing from HLNBR areas, where their ancestral generations have lived for several hundreds of years. (author)

Criteria for radiological protection against exposure to natural radiation

International Nuclear Information System (INIS)

Cardenas Herrera, Juan

2012-01-01

Exposure of humans to natural sources of radiation has been a continuous and inevitable feature of life on earth. This exposure exceeds all due to artificial sources combined for most people. Many exposures to natural radiation sources are modified by human action. In particular, natural radionuclides are released into the environment in mineral processing and in activities such as the production of phosphate fertilizers and the use of fossil fuels. An increase of exposures to this natural radiation is caused. The relevance of exposure to natural radiation is confirmed by the fact that, for most people, the exposures to natural background radiation have been much more significant than exposures to artificial sources, with exceptions. Among these exceptions have been noted: medical exposures, accidents with release of radionuclides and some specific workplaces. In all cases, however, the natural background radiation has formed the basis on which all the others exposures are added and is a common level serving as compared to other exposures. Regulations and instructions have begun to establish in some countries to regulate natural radiation, countries like Spain, have already incorporated into its regulations on health protection against ionizing radiation the subject of natural radiation. (author) [es

Background radiation dose and leukemia mortality in north Japan

International Nuclear Information System (INIS)

Sakka, Masatoshi

1978-01-01

In 7 prefectures in north Japan where natural environment as well as socioeconomic status are similar, the relation of natural background dose rate and death rate caused by leukemia was examined. More than 2500 deaths were recorded in the last 10 years which distributed normally throughout the entire area with a mean of 3.68 and a SD of 1.14 per 10 5 per year. There are no significant, differences in the observed values of each prefecture in spite of having different population. Natural background radiation dose rate has also a normal distribution with a mean of 8.98 μR/h and a SD of 2.12. The highest dose rate in Niigata (10.44) was significantly higher than the lowest value in Aomori (6.48) whereas the death rates caused by leukemia were not different between the both prefectures. The null hypothesis that a positive regression exists between dose rate and death rate even in the smallest dose range was not supported in north Japan. Leukemogenic effect of background radiation, if any, seems to be within a practical threshold. (auth.)

Measurements of Background Gamma Radiation on Some Localities of North-East Kosovo

OpenAIRE

, G. Hodolli; , Y. Halimi; , R. Gashi; , Se. Kadiri; , B. Xhafa; , A. Jonuzaj

2016-01-01

The measurement of natural environmental radiations is one of the most important subjects in health physics. The main sources of background radiation are cosmic, terrestrial and cosmogenic radiation produced by reactions with cosmic rays and atmospheric nuclei. Terrestrial radiation varies in different regions in the world. Generally the background dose rate from cosmic rays depends on the latitude and altitude. The dose rate range obtained in some northeast Kosovo, the dose rate varies from ...

Investigation of natural radiation background and assessment of its population dose in China

International Nuclear Information System (INIS)

1989-01-01

This paper presents the nationwide survey in 1984-1988 of environmental external radiation by integrating measurements, and the assessment of population doses from obtained data. Thermoluminescent dosimeters (TLD) model ETLD-80 with CaSO 4 : Dy were used. The survey was conducted in two different scales. In general survey, TLDs were distributed in whole area of every investigated provinces; and in local survey, one city and one village within each province were selected and investigated for the purpose of comparison of the natural radiation levels between the rural and urban areas. A marked characteristics was noted that the level of natural environmental radiation in south China seems to be higher than that in north China. It may be attributed to the geological difference in both parts. The annual individual average and collective effective dose equivalents to population of China from natural environmental radiation were estimated to be 780 μSv and 8.1 x 10 5 man. Sv, based on the model recommended by UNSCEAR 1988 Report

The estimation of doses to the inhabitants arising from natural radiation source in the high background radiation area of Yangjiang, China

International Nuclear Information System (INIS)

Yuan Yongling; Shen Hong; Morishima, H.; Wei Lvxin; Jian Yuannu

2004-01-01

Objective: The purposes is to estimate the average annual effective dose of the inhabitants and absorbed dose in some human tissues and organs arising from natural radiation sources in the High Background Radiation Area (HBRA) of Yangjiang and in the neighboring Control Area (CA). In order to provide more effective evidence for analyzing the dose-effect relationships among the cohort members in the investigated areas, authors divided the local inhabitant into different dose-groups. Methods: The authors measured the environmental gamma external radiation levels and individual accumulated doses of 5293 people in the investigated areas. The concentrations for 222 Rn, 220 Rn and their decay products in air were also surveyed. The authors estimated the internal doses of natural radionuclides based on the results obtained from measurements in food, in drinking water, in human teeth, in several human tissues, in human placenta, and in activity concentration of exhaled 222 Rn and 220 Rn of the residents living in the investigated areas. Results: The estimation of average annual effective doses in HBRA and CA based on the data of environmental measurements of radiation level respectively are 2.12 ± 0.29 mSv a -1 and 0.69 ± 0.09 mSv a -1 . The sources of higher background radiation in HBRA are mainly contributed from terrestrial gamma radiation. The estimation of average annual effective doses to the residents arising from inhalation of 222 Rn, 220 Rn and their decay products was 3.28 mSv a -1 in HBRA, while that in CA was 1.03 mSv a -1 . The values of the absorbed dose of the residents in their trachea-bronchial tree and lung in HBRA arising from inhalation of 222 Rn, 220 Rn and their decay products are 5.40 mGy a -1 and 1.08 mGy a -1 respectively, which are about four times of the values of the absorbed dose in CA. The estimation of average annual effective doses to the inhabitants caused by 226 Ra and 228 Ra in HBRA and CA were 281.88 μSv a -1 and 84.54 μSv a -1

Epidemiological and radio-biological studies in high background radiation areas of Kerala coast: implications in radiation protection science and human health

International Nuclear Information System (INIS)

Das, Birajalaxmi

2018-01-01

Till date, Linear No Threshold hypothesis (LNT) is well accepted in radiation protection science in spite of its limitations. However, dose response studies using multiple biological end points from high-background radiation areas have challenged the linearity. Radio-biological and epidemiological studies from high level natural radiation areas of Kerala coast showed non-linearity as well as efficient repair of DNA damage in HLNRA indicating that dose limits for public exposure needs to be revisited which may have implications in radiation protection science, human health and low dose radiation biology. However, further studies using high throughput approach is required to identify chronic radiation signatures in human population exposed to elevated level of natural background radiation

Health effects in residents of high background radiation regions

International Nuclear Information System (INIS)

Hanson, G.P.; Komarov, E.

1983-01-01

Studies carried out in various countries and by the World Health Organization on health effects of exposure of populations to high levels of natural background radiation result in observations of different significance. There are indications of changes in chromosome aberration rate; Down's syndrome has been observed to be possibly related to radiation exposure; malignant neoplasms in bone apparently correspond to high concentrations of 226 Ra in drinking water. Although various researchers have looked for them, effects have not been demonstrated regarding cancer mortality (other than malignant neoplasms involving bone), gross congenital abnormalities, fertility index, growth and development, hereditary disease (other than the possibility of Down's syndrome), infant mortality, longevity, multiple births, sex ratio, or spontaneous abortion rate. On the basis of reported data clear quantitative conception of the risk of low-level radiation from natural sources could not be developed and feasibility studies of further epidemiological programmes should be organized. The possibility of reducing the collective population dose from natural sources could be further explored and a basis for necessary legal action on establishment of standards for possible sources of natural radiation, such as building materials, fertilizers, natural gas and water, might be developed. (author)

Role of natural radiations in human leukemogenesis

International Nuclear Information System (INIS)

Jacobson, A.P.; Plato, P.A.; Frigerio, N.A.

1976-01-01

Some 3 billion years ago, life arose from a warm pool of primordial ooze amid a constant drizzle of radiation. Steadily, man evolved from the lesser forms of life because of or in spite of his natural background-radiation environment. This study is an attempt to determine to what extent these background radiations are responsible for human disease, namely leukemia. Dose rate data were compared with data on all forms of leukemia in the 50 United States for four population subgroups. For the total U. S., no relation between background radiation and leukemia is apparent. A positive correlation appears, however, if various states are deleted from the analysis. It appears that conditions relative to populations and their environment could mask a radiation effect if in fact one is present

Natural radioactivity and associated radiation characteristic of the new high background radiation area of lambwe east southern Kenya

International Nuclear Information System (INIS)

Achola, S.O.; Patel, J.P.; Angeyo, H.K.; Mustapha, A.O.

2010-01-01

Rocks and soils from a number of areas underlined by carbonatite rocks in Kenya have been associated with high levels of natural background radioactivity. People in such high background radiation areas (HBRA), are exposed to abnormally high annual absorbed dose (that have health implications) than the global normal 1 mSvyr-1. In this paper, results of field background radiation measurements, activity concentrations of primordial radionuclides in (mainly carbonatite rock and soil) matrices, and estimated annual external effective dose rates are presented for South and North Ruri hills in Lambwe East location of Suba District, which lies roughly between latitudes 0°30'S and 1°00'S, bounded on the east by longitude 34°30'E and on the west by the shores of Lake Victoria 16 and Winnam Gulf. Altitudes in the region range from about 1000 m on the shores of Lake Victoria to above 1800 m on top of the Ruri hills. The main geological features are carbonatite formations. Twenty one samples were analyzed using high-purity germanium (HPGe) gamma-ray spectrometer. The activity concentrations ranged 14.18 - 6559.99 Bqkg-1 (average: 1396.85 Bqkg-1) for Th-232; 2.73 - 499.24 Bqkg-1 (average: 178.69 Bqkg-1) for U-238; and 56.67 - 1454.73 Bqkg-1 (average: 508.67 Bqkg-1) for K-40. The variability in Th distribution could be due to another contributing factor apart from carbonatite: Homa hills geothermal field fluids might be responsible for delivery of Th to surface rocks; some hot spots have travertine deposits. Measured absorbed dose rates in air outdoors range 700 - 6000.00 nGyh-1 (mean: 2325.84 nGy h-1); assuming 0.4 occupancy factor, these values correspond to individual annual effective dose rates of 1.717 - 14.717 mSvyr-1 (mean: 5.705 mSv yr-1). Measured absorbed dose rates are higher than calculated values since they include the contribution of cosmic rays. The natural radioactivity is fractionated with higher levels in the soils than carbonatite rocks

Relation between cancer incidence or mortality and external natural background radiation in Japan

International Nuclear Information System (INIS)

Ujeno, Y.

1983-01-01

Analysis was performed on the relationships between the organ dose-equivalent rate due to natural background radiation (mSv/a) and three parameters of cancer risk: the age-adjusted cancer incidence (patients x 10 5 persons x a -1 ) in 13 large areas, the standardized mortality ratio of cancers in 46 large areas, and the cancer mortality in the population aged more than 40 years old (cancer deaths x 10 5 persons x a -1 ) in 649 small areas. The age-adjusted liver cancer incidence in males fitted the exponential model significantly (p<0.01) and the relationship of stomach cancer mortality of aged males in small areas fitted the linear model significantly (p<0.05). No relationship was observed with regard to female cancer in either case. The relationships between the three parameters and various other cancers of both sexes were not statistically significant. (author)

Research on cloud background infrared radiation simulation based on fractal and statistical data

Science.gov (United States)

Liu, Xingrun; Xu, Qingshan; Li, Xia; Wu, Kaifeng; Dong, Yanbing

2018-02-01

Cloud is an important natural phenomenon, and its radiation causes serious interference to infrared detector. Based on fractal and statistical data, a method is proposed to realize cloud background simulation, and cloud infrared radiation data field is assigned using satellite radiation data of cloud. A cloud infrared radiation simulation model is established using matlab, and it can generate cloud background infrared images for different cloud types (low cloud, middle cloud, and high cloud) in different months, bands and sensor zenith angles.

Microbiology of the surface water samples in the high background radiation areas of Ramsar, Iran

International Nuclear Information System (INIS)

Motamedifar, Mohammad; Zamani, Khosrow; Sedigh, Hadi; Mortazavi, Seyed Mohammad Javad; Taeb, Shahram; Haghani, M.; Mortazavi, Seyed Ali Reza; Soofi, Amir

2014-01-01

Residents of high background radiation areas of Ramsar have lived in these areas for many generations and received radiation doses much higher than the dose limit recommended by ICRP for radiation workers. The radioactivity of the high background radiation areas of Ramsar is reported to be due to 226 Ra and its decay products, which have been brought to the surface by the waters of hot springs. Over the past years the department has focused on different aspects of the health effects of the elevated levels of natural radiation in Ramsar. This study was aimed to perform a preliminary investigation on the bioeffects of exposure to elevated levels of natural radiation on the microbiology of surface water samples. Water samples were collected from surface water streams in Talesh Mahalleh district, Ramsar as well as a nearby area with normal levels of background radiation. Only two strains of bacteria, that is, Providencia stuartii and Shimwellia blattae, could be isolated from the water samples collected from high background radiation areas, while seven strains (Escherichia coli, Enterobacter asburiae, Klebsiella pneumoniae, Shigella dysenteriae, Buttiauxella agerstis, Tatumella punctuata and Raoultella ornithinolytica) were isolated from the water samples collected from normal background radiation areas. All the bacteria isolated from water samples of high and normal background radiation areas were sensitive to ultraviolet radiation, heat, betadine, alcohol, and deconex. Although other investigators have reported that bacteria isolated from hot springs show radioresistance, the results reported here do not reveal any adaptive response. (author)

Biological effects of high level natural background radiation on human population residing in Kerala coast, South West India

International Nuclear Information System (INIS)

Seshadri, M.

2010-01-01

The populations residing in Kerala coast are exposed to elevated natural background radiation since many generations. Extensive studies conducted by Bio-Medical group, Bhabha Atomic Research Center have generated wealth of data from this area dealing with epidemiology, monitoring the newborns for malformations, Health Audit Survey, Dosimetry and biological studies using cytogenetic and molecular biology techniques. Our studies on congenital malformations and chromosomal anomalies in children born to parents residing in High Level Natural Radiation Areas in Kerala have not shown any significant difference from normal radiation areas. Screening of over 1,25,000 consecutively born children showed an incidence rate which is comparable in both areas. Other factors such as consanguinity, maternal age and gravida status are more significant contributors than radiation dose to the risk for having malformation in child. Radiation prevalent in the HLNRA is in the dose range of above 1.5 to about 50 mGy per year which translates to doses in the range of nGy per hour. This clearly indicate the number of cells exposed to radiations will be one in few thousand or ten thousands. This throws up challenges in our capability to investigate the effects of radiation on cells. It has become imperative to develop and exploit techniques which will detect responses in single cells and would be able screen large number of cells at a time. Developments in cell biology and molecular biology are now giving us these capabilities. Use of flowcytometer and next generation sequencing would enable us to address many of these questions and provide meaningful approaches to understand the effects of such low dose radiation

Estimation and comparison of baseline frequencies of micronuclei among the new-borns from natural high background radiation and control areas of Kerala coast in south India

International Nuclear Information System (INIS)

Das, Birajalaxmi; Karuppasamy, C.V.; Thampi, M.V.

1994-01-01

Based on the studies it is concluded that the elevated level of natural radiation has no significant effect of micronucleus formation in high background radiation area (HBRA) new-borns as compared to control area. It is also in agreement with the results of cytogenetic investigations on new-borns from HBRA and control area using chromosome aberration analysis method. The significance, if any, of the slightly lower micronuclei (MN) frequency observed in HBRA, is not clear at this stage. Further investigations on a larger number of new-borns from both the areas are necessary in order to draw firm conclusions. It appears that, this is the first attempt to estimate the baseline frequency of MN among the new-borns from a natural high background radiation area. (author). 9 refs

Long-range correlation in cosmic microwave background radiation.

Science.gov (United States)

Movahed, M Sadegh; Ghasemi, F; Rahvar, Sohrab; Tabar, M Reza Rahimi

2011-08-01

We investigate the statistical anisotropy and gaussianity of temperature fluctuations of Cosmic Microwave Background (CMB) radiation data from the Wilkinson Microwave Anisotropy Probe survey, using the Multifractal Detrended Fluctuation Analysis, Rescaled Range, and Scaled Windowed Variance methods. Multifractal Detrended Fluctuation Analysis shows that CMB fluctuations has a long-range correlation function with a multifractal behavior. By comparing the shuffled and surrogate series of CMB data, we conclude that the multifractality nature of the temperature fluctuation of CMB radiation is mainly due to the long-range correlations, and the map is consistent with a gaussian distribution.

Rain-Induced Increase in Background Radiation Detected by Radiation Portal Monitors

Energy Technology Data Exchange (ETDEWEB)

Hausladen, Paul [ORNL; Blessinger, Christopher S [ORNL; Guzzardo, Tyler [ORNL; Livesay, Jake [ORNL

2012-07-01

A complete understanding of both the steady state and transient background measured by Radiation Portal Monitors (RPMs) is essential to predictable system performance, as well as maximization of detection sensitivity. To facilitate this understanding, a test bed for the study of natural background in RPMs has been established at the Oak Ridge National Laboratory. This work was performed in support of the Second Line of Defense Program's mission to detect the illicit movement of nuclear material. In the present work, transient increases in gamma ray counting rates in RPMs due to rain are investigated. The increase in background activity associated with rain, which has been well documented in the field of environmental radioactivity, originates from the atmospheric deposition of two radioactive daughters of radon-222, namely lead-214 and bismuth-214 (henceforth {sup 222}Rn, {sup 214}Pb and {sup 214}Bi). In this study, rainfall rates recorded by a co-located weather station are compared with RPM count rates and High Purity Germanium spectra. The data verifies these radionuclides are responsible for the dominant transient natural background fluctuations in RPMs. Effects on system performance and potential mitigation strategies are discussed.

Doses arising from natural radiation sources in Hong Kong

International Nuclear Information System (INIS)

Tso Man-yin, W.

1993-01-01

The first reactor of the Daya Bay Nuclear Power Plant, located 30 km from Hong Kong, should become operational at the end of 1993. People in Hong Kong are more concerned with their exposures to radiation, both man-made and natural. The local environmental background radiation baseline values should be established well before 1993 so that the radiological impact of the power plant on the environment can be assessed. However, there has not been much information on these aspects. In view of the situation, the Radioisotope Unit of the University of Hong Kong has launched a series of studies with the general goal of gaining a better understanding of Hong Kong's natural background radiation and a more accurate estimate of the natural radiation exposure of the local people. The scope of the measurement programmes is described and the doses from the various sources are derived. (1 tab.)

Radiation levels at the boundaries of the Frascati center and natural background

International Nuclear Information System (INIS)

Lucci, F.; Pelliccioni, M.

1975-01-01

The results of dosimetric controls carried out with thermoluminescent dosimeters along the boundaries of the Frascati Center since 1969 are presented. The average yearly exposure observed during the period 1969-1974 is 206mR/y, while no significant tendency is evident. In particular neither effects of accelerator shutdowns nor seasonal ones are noticed. The measurements at the boundary are also compared with measurements of natural background carried out near Frascati and in Rome, Thus we can estimate that the machine contribution to the total dose along the boundaries is equal to a small fraction of either the natural background or the general population dose limit [fr

Cellular and molecular effects of natural background radiation on human population in Kerala coast, India: from chromosome ends to transcriptome

Energy Technology Data Exchange (ETDEWEB)

Das, Birajalaxmi; Jain, Vinay; Saini, Divyalakshmi; Ghosh, Anu; Seshadri, M. [Radiation Biology and Health Sciences Division, Bio-Medical Group, Bhabha Atomic Research Centre, Mumbai (India); Sandhya Kiran, P. [Ocimum Biosolutions India Limited, Hyderabad (India)

2010-07-01

Venous blood samples of 32 male volunteers (age group 35-45 years) from different background dose groups. Factors like life style, smoking, drinking alcohol, chewing, previous exposure to radiation and medical history etc. were properly recorded. Microarray analysis was performed using Affymetrix FlGU133 plus 2.0 chip and the expression level of 54,675 genes were obtained for each sample. In order to assess the effect of chronic natural background radiation we have categorized our samples into four groups. To derive genes that are differentially regulated between these four groups, 'Exposed group versus Control' was set up and the linear model was fitted to each gene using the expression data on samples. A fold change threshold of 1.3, 1.5 and 2.0 and an adjusted p-value threshold of 0.05 was set in the study. Analysis was done using 'limma' library of R and Genowiz.

Cellular and molecular effects of natural background radiation on human population in Kerala coast, India: from chromosome ends to transcriptome

International Nuclear Information System (INIS)

Das, Birajalaxmi; Jain, Vinay; Saini, Divyalakshmi; Ghosh, Anu; Seshadri, M.; Sandhya Kiran, P.

2010-01-01

Venous blood samples of 32 male volunteers (age group 35-45 years) from different background dose groups. Factors like life style, smoking, drinking alcohol, chewing, previous exposure to radiation and medical history etc. were properly recorded. Microarray analysis was performed using Affymetrix FlGU133 plus 2.0 chip and the expression level of 54,675 genes were obtained for each sample. In order to assess the effect of chronic natural background radiation we have categorized our samples into four groups. To derive genes that are differentially regulated between these four groups, 'Exposed group versus Control' was set up and the linear model was fitted to each gene using the expression data on samples. A fold change threshold of 1.3, 1.5 and 2.0 and an adjusted p-value threshold of 0.05 was set in the study. Analysis was done using 'limma' library of R and Genowiz

Natural radiation

International Nuclear Information System (INIS)

Feliciano, Vanusa Maria Delage

2016-01-01

Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included

Genetic damage from low-level and natural background radiation

International Nuclear Information System (INIS)

Oftedal, P.

1988-01-01

Relevant predictions that have been made of possible low level biological effects on man are reviewed, and the estimate of genetic damage is discussed. It is concluded that in spite of a number of attempts, no clear-cut case of effects in human populations of radiation at natural levels has been demonstrated. The stability of genetic material is dynamic, with damage, repair and selection running as continuous processes. Genetic materials are well protected and are conservative in the extreme, not least because evolution by genetic adaptation is an expensive process: Substitution of one allele A 1 by another A 2 means the death of the whole A 1 population

Measurement of background gamma radiation in the northern Marshall Islands

OpenAIRE

Bordner, Autumn S.; Crosswell, Danielle A.; Katz, Ainsley O.; Shah, Jill T.; Zhang, Catherine R.; Nikolic-Hughes, Ivana; Hughes, Emlyn W.; Ruderman, Malvin A.

2016-01-01

Sixty-seven nuclear tests were conducted on two atolls in the northern Marshall Islands between 1946 and 1958. These tests produced radioactive fallout, which even today gives rise to radiation measurable above naturally occurring background levels. Rather than obtain new data, recent estimates of contamination levels in the northern Marshall Islands use measurements made decades ago to calculate present radiation levels. In contrast, we report on timely measurements on three different atolls...

Biological effects of low-dose radiation on human population living in high-background radiation areas of Kerala coast

International Nuclear Information System (INIS)

Das, Birajalaxmi

2016-01-01

High-level natural radiation areas (HLNRA) of Kerala coast is densely populated and known for its wide variation in background radiation dose levels due to uneven distribution of monazite in the beach sand. The background radiation dose varies from 1 to 45 mGv/y. The areas with >1.5mGy/y is considered as HLNRA. Human population inhabiting in this area are exposed to low-dose chronic radiation since generations. Hence, this population provides an ideal situation to study dose response and adaptive response, if any, due to natural chronic low-dose exposure. It has been investigated extensively to study the biological and health effects of long-term low-dose/low-dose radiation exposure. So far over 150, 000 newborns monitored from hospital-based study did not reveal any significant difference in the incidence of any of the malformations and stillbirth between HLNRA and adjacent control areas. A case-control study on cleft lip/palate and mental retardation did not show any association with background radiation dose. Cytogenetic investigation of over 27,000 newborns did not show any significant increase in the frequency of chromosome aberrations and karyotype anomalies. DNA damage endpoints, such as micronuclei, telomere length and DNA strand breaks, did not reveal any significant difference between control and exposed population. Studies on DNA damage and repair revealed efficient repair of DNA strand breaks in HLNRA individuals. Molecular studies using high throughput microarray analysis indicated a large number of genes involved in various molecular and cellular pathways. Indications of in vivo radioadaptive response due to natural chronic low-dose exposure in this population have important implications to human health. (author)

EPR dosimetry of radiation background in the Urals region

Energy Technology Data Exchange (ETDEWEB)

Shishkina, E.A.; Degteva, M.O.; Shved, V.A. [Urals Research Center for Radiation Medicine, 48-A Vorovsky, Chelyabinsk 454076 (Russian Federation); Fattibene, P.; Onori, S. [Istituto Superiore di Sanita and Istituto Nazionale di Fisica Nucleare (Italy); Wieser, A. [GSF, Forschungszentrum fuer Umwelt und Gesundheit, Ingolstaedter Landstr (Germany); Ivanov, D.V.; Bayankin, S.N. [Institute of Metal Physics, Russian Academy of Sciences (Russian Federation); Knyazev, V.A.; Vasilenko, E.I.; Gorelov, M. [ZAO, Closed Corporation ' Company GEOSPETSECOLOGIA' (Russian Federation)

2006-07-01

Method of Electron Paramagnetic Resonance is extensively applied to individual retrospective dosimetry. The background dose is unavoidable component of cumulative absorbed dose in the tooth enamel accumulated during the lifetime of donor. Estimation of incidental radiation dose using tooth enamel needs in extraction of background dose. Moreover, the variation of background doses in the population is a limited factor for reliable detection of additional irradiation especially for low dose level. Therefore the accurate knowledge of the natural background radiation dose is a critical element of EPR studies of exposed populations. In the Urals region the method applies for such two large cohorts as the workers of Mayak (Ozersk citizens) and Techa River riverside inhabitants (rural population). Current study aimed to investigate the Urals radiation background detected by EPR spectrometry. For this aim two group of unexposed Urals residents were separated, viz: citizens of Ozersk and rural inhabitants of Chelyabinsk region. Comparison of two investigated territories has demonstrated that from the point of view of radiation background it is impossible to assume the Urals population as uniform. The reliable difference between the urban and rural residents has been found. The average background doses of Ozersk donors is in average 50 mGy higher than those detected for rural residents. The individual variability of background doses for Osersk has been higher than in the rural results. The difference in background dose levels between two population results in different limits of accidental dose detection and individualization. The doses for 'Mayak' workers (Ozyorsk citizens) can be classed as anthropogenic if the EPR measurements exceed 120 mGy for teeth younger than 40 years, and 240 mGy for teeth older than 70 years. The anthropogenic doses for Techa River residents (rural population) would be higher than 95 mGy for teeth younger than 50 years and 270 mGy for

EPR dosimetry of radiation background in the Urals region

International Nuclear Information System (INIS)

Shishkina, E.A.; Degteva, M.O.; Shved, V.A.; Fattibene, P.; Onori, S.; Wieser, A.; Ivanov, D.V.; Bayankin, S.N.; Knyazev, V.A.; Vasilenko, E.I.; Gorelov, M.

2006-01-01

Method of Electron Paramagnetic Resonance is extensively applied to individual retrospective dosimetry. The background dose is unavoidable component of cumulative absorbed dose in the tooth enamel accumulated during the lifetime of donor. Estimation of incidental radiation dose using tooth enamel needs in extraction of background dose. Moreover, the variation of background doses in the population is a limited factor for reliable detection of additional irradiation especially for low dose level. Therefore the accurate knowledge of the natural background radiation dose is a critical element of EPR studies of exposed populations. In the Urals region the method applies for such two large cohorts as the workers of Mayak (Ozersk citizens) and Techa River riverside inhabitants (rural population). Current study aimed to investigate the Urals radiation background detected by EPR spectrometry. For this aim two group of unexposed Urals residents were separated, viz: citizens of Ozersk and rural inhabitants of Chelyabinsk region. Comparison of two investigated territories has demonstrated that from the point of view of radiation background it is impossible to assume the Urals population as uniform. The reliable difference between the urban and rural residents has been found. The average background doses of Ozersk donors is in average 50 mGy higher than those detected for rural residents. The individual variability of background doses for Osersk has been higher than in the rural results. The difference in background dose levels between two population results in different limits of accidental dose detection and individualization. The doses for 'Mayak' workers (Ozyorsk citizens) can be classed as anthropogenic if the EPR measurements exceed 120 mGy for teeth younger than 40 years, and 240 mGy for teeth older than 70 years. The anthropogenic doses for Techa River residents (rural population) would be higher than 95 mGy for teeth younger than 50 years and 270 mGy for teeth older

Natural radiation; A radiacao natural

Energy Technology Data Exchange (ETDEWEB)

Feliciano, Vanusa Maria Delage

2016-07-01

Cosmic radiation, as well as cosmogenic radiation, terrestrial radiation, radon and thorium are introduced in this chapter 3. The distribution of natural radiation sources is treated, where the percentage distribution of the contribution relative to exposure to radiation from natural and artificial sources is also included.

Natural background radiation at flight altitudes; Natuerliche Strahlenexposition in Flughoehen durch kosmische Strahlung

Energy Technology Data Exchange (ETDEWEB)

Wissmann, F. [Physikalisch-Technische Bundesanstalt, Berlin (Germany). FB Ionenbeschleuniger und Referenzstrahlungsfelder

2006-12-15

At sea level, the background radiation of about 40 nSv/h consists of about 80 percent of muons and electrons and about 0 percent of neutrons. The picture is different at an altitude of 10 km. Here, the background dose equivalent of about 5000 nSv/h (= 5 {mu}Sv/h) consists of about 60 percent of neutrons and about 25 percent of muons and electrons. Protons account for about 15 percent. This particle composition makes dosimetric measurements difficult. In addition, the energy emitted by the particles is far beyond the the measuring range of conventional radiation protection dosemeters. For these reasons, conventional dosemeters are not suited for applications in aeroplanes and such. The PTB method for measuring local dose rates uses a proportional counter whose wall consists of a tissue equivalent material and which is operated with tissue equivalent counting gas at very low pressure (about 40 hPa). (orig.)

Evaluation of detector responses to natural environmental and fall-out gamma radiation

International Nuclear Information System (INIS)

Arvela, H.

1988-01-01

Instrument responses to the thorium, uranium and potassium components of the natural environmental as well as the fall-out radiation field were evaluated. The responses to the 137 Cs fall-out radiation field differ by less than 6% from the response at 0.662 MeV, except for that of the NaI scintillator. Differences of more than 30% were found in the responses of two energy compensated instruments to normal natural background radiation and to radiation from fresh fall-out. The best estimate of the terrestrial component of the dose rate measured was obtained by carrying out the following corrections of the measured readings: cosmic ray contribution and internal background subtraction with response correction, including 137 Cs calibration correction. After the Chernobyl accident the dose rate levels due to 137 Cs and 134 Cs fall-out were comparable to the natural background gamma radiation. The responses calculated as well as the results from measurements of the low level environmental exposure levels caused by the Chernobyl fall-out, confirmed the need to take into account the instrument response to natural as well as fall-out radiation fields. (author)

Past and present views in the approach to the problem of high natural background areas

International Nuclear Information System (INIS)

Mastino, G.G.

1982-01-01

High natural background areas are of great interest because they present anomalous conditions in their geological and geochemical features and consequently in the background radiation levels. High natural background areas have been recognised as representing a valid field of investigation for assessing the effects induced by low-level exposures. Such an approach represents the first attempt to draw an environmental impact evaluation, even if focussed on a single potentially harmful parameter only. Past and current studies on High Background Radiation Areas are reviewed with special emphasis on the ongoing programs and prospectives; their significance is discussed on the basis of the sectorial approach mostly used in the environmental studies. A more complete approach is suggested based on the impact evaluation and extention to all the potentially harmful environmental factors

Pre operational background radiation monitoring around Kudankulam Nuclear Power Project site - a decade long experience

International Nuclear Information System (INIS)

Vijayakumar, B.; George, Thomas; Sundara Rajan, P.; Selvi, B.S.; Balamurugan, M.; Pandit, G.G.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

Pre-operational environmental background radiation monitoring around nuclear power plants is very important to understand baseline values existing in the site and also to identify any hot spots of naturally occurring high background radiation areas and their sources. These baseline measurements will act as a benchmark for future comparison after the reactors go into operation. The radiation measurements are continued during the operational phase of the plant and the results are compared to see whether there is any impact of the operation of the plant on the environment. A comprehensive background radiation monitoring plan has been in vogue at site from 2004 to meet this objective. This paper describes the different monitoring strategies adopted around Kudankulam Nuclear Power Project site and throws light on the pre operational background radiation levels in the environment

Down syndrome and the high background radiation areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Ramachandran, E.N.; Karuppasamy, C.V.; Sudheer, K.R.; Andrews, V.J.; Soren, D.C.; Anil Kumar, V.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

Down syndrome (DS) or trisomy-21 is a complex human clinical entity compromising several functional, structural and developmental features with wide variation in expression levels. The diagnosis is confirmed in majority of the cases by an extra dose of chromosome 21 by cytogenetics and occasionally it may be due to either chromosomal translocation or mosaicism (different cell lines in the same individual). The extra chromosome 21 is usually formed by non-disjunction during meiosis and is the most common numerical chromosomal anomaly compatible with life, as chromosome 21 is one of the smallest with relatively fewer genes most of which are reckoned to be non lethal. Though exact causative factors and pathogenesis is not fully understood, a rise in maternal age at conception coupled with deleterious environmental influence on an ageing ovum is a recognized risk factor. The de novo nature of trisomy-21 and its relatively higher frequency makes it a reliable indicator to assess the role of chronic high background radiation in inducing germ line mutation and congenital malformation. Many other relatively common congenital malformations with multifactorial origin may not have this de novo property and associating its incidence with the prevailing natural background radiation become more complex. In vitro studies have shown association between high intensity radiation and genetics effects but such a relationship so far was not established between DS and radiation

Exposures to natural radiation in Switzerland

International Nuclear Information System (INIS)

Murith, Ch.; Gurtner, A.

1999-01-01

The exposure of human beings to ionising radiation from natural sources is a continuing and inescapable feature of life on earth. There are two main sources that contribute to this exposure: high-energy cosmic-ray particles incident to the earth's atmosphere and radioactive nuclides that originated in the earth's crust and are present everywhere in the environment, including human body itself. Both external and internal exposures to humans arise from these sources. Exposures to natural radiation sources in Switzerland and some of their variations are here summarised and the resulting effective doses are compared to those from man-made sources exposures. It results that the natural background exposures are more significant for the population than most exposures to man-made sources. (authors)

Remedial action in areas of enhanced natural background radiation levels (with particular emphasis in areas with mineral sand mining residues)

International Nuclear Information System (INIS)

Swindon, T.N.

1985-01-01

In areas where individuals may receive doses from natural background sources which are higher than those received in areas of normal background radiation, it may be considered desirable that some remedial action be taken to reduce those doses. Contributions to these higher doses may be through high gamma ray fields from the ground or from the use of local building materials, the intake of food or water derived from the areas or of food covered with dust from the areas, the ingestion of dirt and the inhalation of dust, and radon or thoron. Guidelines for remedial action in areas where residues from mineral sand mining and processing have been deposited are given

Natural background gamma-ray spectrum. List of gamma-rays ordered in energy from natural radionuclides

International Nuclear Information System (INIS)

Ichimiya, Tsutomu; Narita, Tsutomu; Kitao, Kensuke.

1998-03-01

A quick index to γ-rays and X-rays from natural radionuclides is presented. In the list, γ-rays are arranged in order of increasing energy. The list also contains γ-rays from radioactive nuclides produced in a germanium detector and its surrounding materials by interaction with cosmic neutrons, as well as direct γ-rays from interaction with the neutrons. Artificial radioactive nuclides emitting γ-rays with same or near energy value as that of the natural γ-rays and X-rays are also listed. In appendix, γ-ray spectra from a rock, uranium ore, thorium, monazite and uraninite and also background spectra obtained with germanium detectors placed in iron or lead shield have been given. The list is designed for use in γ-ray spectroscopy under the conditions of highly natural background, such as in-situ environmental radiation monitoring or low-level activity measurements, with a germanium detector. (author)

Natural background gamma-ray spectrum. List of gamma-rays ordered in energy from natural radionuclides

Energy Technology Data Exchange (ETDEWEB)

Ichimiya, Tsutomu [Japan Radioisotope Association, Tokyo (Japan); Narita, Tsutomu; Kitao, Kensuke

1998-03-01

A quick index to {gamma}-rays and X-rays from natural radionuclides is presented. In the list, {gamma}-rays are arranged in order of increasing energy. The list also contains {gamma}-rays from radioactive nuclides produced in a germanium detector and its surrounding materials by interaction with cosmic neutrons, as well as direct {gamma}-rays from interaction with the neutrons. Artificial radioactive nuclides emitting {gamma}-rays with same or near energy value as that of the natural {gamma}-rays and X-rays are also listed. In appendix, {gamma}-ray spectra from a rock, uranium ore, thorium, monazite and uraninite and also background spectra obtained with germanium detectors placed in iron or lead shield have been given. The list is designed for use in {gamma}-ray spectroscopy under the conditions of highly natural background, such as in-situ environmental radiation monitoring or low-level activity measurements, with a germanium detector. (author)

Unique signatures of natural background radiation on human Y chromosomes from Kerala, India.

Directory of Open Access Journals (Sweden)

Sanjay Premi

Full Text Available The most frequently observed major consequences of ionizing radiation are chromosomal lesions and cancers, although the entire genome may be affected. Owing to its haploid status and absence of recombination, the human Y chromosome is an ideal candidate to be assessed for possible genetic alterations induced by ionizing radiation. We studied the human Y chromosome in 390 males from the South Indian state of Kerala, where the level of natural background radiation (NBR is ten-fold higher than the worldwide average, and that from 790 unexposed males as control.We observed random microdeletions in the Azoospermia factor (AZF a, b and c regions in >90%, and tandem duplication and copy number polymorphism (CNP of 11 different Y-linked genes in about 80% of males exposed to NBR. The autosomal homologues of Y-linked CDY genes largely remained unaffected. Multiple polymorphic copies of the Y-linked genes showing single Y-specific signals suggested their tandem duplication. Some exposed males showed unilocus duplication of DAZ genes resulting in six copies. Notably, in the AZFa region, approximately 25% of exposed males showed deletion of the DBY gene, whereas flanking genes USP9Y and UTY remained unaffected. All these alterations were detected in blood samples but not in the germline (sperm samples.Exposure to high levels of NBR correlated with several interstitial polymorphisms of the human Y chromosome. CNPs and enhanced transcription of the SRY gene after duplication are envisaged to compensate for the loss of Y chromosome in some cells. The aforesaid changes, confined to peripheral blood lymphocytes, suggest a possible innate mechanism protecting the germline DNA from the NBR. Genome analysis of a larger population focusing on greater numbers of genes may provide new insights into the mechanisms and risks of the resultant genetic damages. The present work demonstrates unique signatures of NBR on human Y chromosomes from Kerala, India.

Survey of Gamma Dose and Radon Exhalation Rate from Soil Surface of High Background Natural Radiation Areas in Ramsar, Iran

Directory of Open Access Journals (Sweden)

Rouhollah Dehghani

2013-09-01

Full Text Available Background: Radon is a radioactive gas and the second leading cause of death due to lung cancer after smoking. Ramsar is known for having the highest levels of natural background radiation on earth. Materials and Methods: In this research study, 50 stations of high radioactivity areas of Ramsar were selected in warm season of the year. Then gamma dose and radon exhalation rate were measured.Results: Results showed that gamma dose and radon exhalation rate were in the range of 51-7100 nSv/hr and 9-15370 mBq/m2s, respectively.Conclusion: Compare to the worldwide average 16 mBq/m2s, estimated average annual effective of Radon exhalation rate in the study area is too high.

Radiation monitoring of soil cover of natural uranium in the Issyk-Kul province

International Nuclear Information System (INIS)

Djenbaev, B.M.; Toktoeva, T.E.; Kaldibaev, B.K.; Zholbolduev, B.T.

2015-01-01

This article presents the current state in the radioecological soil Issyk-Kul province of natural uranium. Found that the background radiation - exposure dose and artificial radionuclides in the soil of the coastal zone of the lake as a whole at the level of the background and the acceptance of lower standards except for natural technogenic and some natural areas. Radioecological this province is mild natural and industrial uranium province.We have previously established 10 experimental plots around Issyk-Kul and the measurement showed that the power of natural background radiation in the gamma radiation of the coastal lake zone is an average of 17 to 25 mR/h in some areas up to 40 mR/h. As the distance from the lake to the side slopes of its level in some places rises to 40 mR/h, especially in some mountainous areas, canyons, which are based on the rocks, granites and their fragments are small, red sand, with a slightly increased radioactivity. For small areas with high natural background radiation can be attributed to the beaches of the coastal zone v. Jenish, v. Ak-Terek, located on the southern shore of Issyk-Kul Lake. The radioactivity of 30 - 60 mR/h, and in areas with a high content of iron in the sand inclusions level exposure dose increases up to 400 mR/h. Small areas of the coastal zone of Issyk-Kul Lake, mostly mud deposits with characteristic brilliance giving high radiation background. These areas include: the beach v.Tosor - 40-50 mR/h, 10 km west of the coast v.Kaji-Sai - 32-40 mR/h, the shore around with. Toru-Aigyr - 30 mR/h, the coast around v.Tamchi - 40-50 mR/h. In general, cities in the Issyk-Kul basin Kara-Kol, Cholpon-Ata and Balykchy radiation situation quite well, the average exposure dose of gamma radiation does not exceed 20 - 22 mR/h, but in some places the use of crushed granite, as filler and construction material, the level of background radiation increases to 40-50 mR/h This indicates that these natural resources, without first

Detection of a stochastic background of gravitational radiation by the Doppler tracking of spacecraft

International Nuclear Information System (INIS)

Mashhoon, B.; Grishchuk, L.P.

1980-01-01

The possibility of detection of an isotropic background gravitational radiation of a stochastic nature by the method of Doppler tracking of spacecraft is considered. In the geometrical optics limit, the general formula for the frequency shift of an electromagnetic signal in the gravitational radiation field is discussed, and it is shown to be gauge (or rather Lie) independent. A detailed examination of the propagation of a free electromagnetic wave in a gravitational radiation field shows that no resonance phenomena can be expected. Thus, the results valid in the geometrical optics limit are also approximately valid for any gravitational radiation spectrum dominated by wavelengths large compared to that of the electromagnetic signal. The ''Doppler noise'' due to a stochastic background is evaluated, and it is shown to depend on the total energy density of the background and a parameter that is a characteristic of the aradiation spectrum and the detection system used. A background gravitational radiation with an energy density comparable to the electromagnetic (approx.3 K) background and a spectrum dominated by wavelengths > or approx. =1 AU may be detectable in the near future by the Doppler tracking of interplanetary spacecraft

Cosmic microwave background radiation

International Nuclear Information System (INIS)

Wilson, R.W.

1979-01-01

The 20-ft horn-reflector antenna at Bell Laboratories is discussed in detail with emphasis on the 7.35 cm radiometer. The circumstances leading to the detection of the cosmic microwave background radiation are explored

Evaluation of the natural background radiation in City Sopron

International Nuclear Information System (INIS)

Spaits, T.; Divos, F.; Kavasi, N.; Boka, Z.

2006-01-01

In the Postgraduate School of the Faculty of Forestry of the University of West Hungary a project with the topic Research of natural radioactive isotopes in our built and natural environs is being run. Preparing this map is an organic part of this PhD research. The measurements are being made in Sopron city and in its next surroundings, trying to estimate, which dose of radiation a citizen of Sopron is exposed, according to his age and lifestyle. The measurements completely cover the built-up area of Sopron, moreover they exceed the confines, so thus they provide information about the natural areas in the vicinity of the city. In figures, the detection carried out in an area of 24 square kilometres, working with a grid mesh of 200 metres. A sodium-iodide detector was used. We have faced several anomalies while mapping. These are the following: On Main Square (Foter), Ursulin Square (Orsolya ter), Paulites Square (Palosok tere, where a higher dose can be measured, due to granite cobbles, used to cover the pavements of the squares and streets. This was confirmed by the gamma spectrometric examination of the granite stones. In these areas, a triple of the mean dose-rate of 70-90 n Sv/h in Sopron was detected. The highest values of 400 n Sv/h were detected in the cinder-covered car-park of the paint store in Koszegi Street. The total gamma activity concentration of the cinder used in the car-park was nearly 2000 Bq/kg. A triple to a quadruple of the natural level was detected in the vicinity of the chimney of the former thermal power plant and the brick factory. The detection was carried out in four directions with raising range starting by the chimneys, which has spectacularly shown, that the sedimentation of the aerosols can be tracked is a function of distance. The measurements have also shown, that there is a significant difference between dose-levels of the natural areas beyond the eastern and western edge of the city, which can be explained with the different

Epidemiology of non-syndromic cleft lip/palate in the high level natural background radiation areas (HLNRA) of the South west coast of India

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

All consecutive births in selected government hospitals in and around the high level natural background radiation areas (HLNRA) of Kerala were monitored for congenital malformations observable at birth since 1995. The HLNR area, with natural deposits of monazite sand containing thorium (8-10%) and Uranium (0.3%), is a coastal strip of land about 55 km in length and 0.5 km in breadth from Purakkad in the north in Alleppey district to Sakthikulangara in the south of Quilon district and is one among the most prominent background radiation areas of the world. Patchy and non-uniform distribution of Monazite sand causes wide variation in dose ranging from <1 to 45 mGy/year. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. Areas with a mean radiation dose of more than 1.5 mGy/year were treated as HLNR areas and areas with a dose level of 1.5 mGy/year or less were treated as normal level radiation areas (NLNRA). A total of 134,178 newborns were monitored and non-syndromic cleft lip/palate (NSCLP) was detected in 143 newborns (1.07%). Cleft lip with cleft palate (59.4%) was more common than cleft lip (18.2%) or Cleft palate (22.4%) alone and 11.9% had other malformation(s) together with NSCLP. There was no evidence to suggest that NSFC was significantly associated with prevailing dose level of area of mother's residence, maternal age birth, gravida, ethnicity or consanguinity

Association of Radon Background and Total Background Ionizing Radiation with Alzheimer's Disease Deaths in U.S. States.

Science.gov (United States)

Lehrer, Steven; Rheinstein, Peter H; Rosenzweig, Kenneth E

2017-01-01

Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

Measurements of the cosmic background radiation

International Nuclear Information System (INIS)

Weiss, R.

1980-01-01

Measurements of the attributes of the 2.7-K microwave background radiation (CBR) are reviewed, with emphasis on the analytic phase of CBR studies. Methods for the direct measurement of the CBR spectrum are discussed. Attention is given to receivers, antennas, absolute receiver calibration, atmospheric emission and absorption, the galactic background contribution, the analysis of LF measurements, and recent HF observations of the CBR spectrum. Measurements of the large-angular-scale intensity distribution of the CBR (the most convincing evidence that the radiation is of cosmological origin) are examined, along with limits on the linear polarization of the CBR. A description is given of the NASA-sponsored Cosmic Background Explorer (COBE) satellite mission. The results of the COBE mission will be a set of sky maps showing, in the wave number range from 1 to 10,000 kaysers, the galactic background radiation due to synchrotron emission from galactic cosmic rays, to diffuse thermal emission from H II regions, and to diffuse thermal emission from interstellar and interplanetary dust, as well as a residue consisting of the CBR and whatever other cosmological background might exist

Distribution characteristics of natural gamma background levels around the capital city Shillong, Meghalaya (India)

International Nuclear Information System (INIS)

Kukreti, B.M.; Sharma, G.K.; Rao, M.S.; Ramabhadraih, T.; Bhaskar Rao, Arjun; Bhuphang, A.

2012-01-01

Onsite measurement of natural gamma radiation around the capital city Shillong in Meghalaya, has been carried out using GPS device and environmental survey meter. Each referenced insitu data point was validated at the site by means of simultaneous measurements of radiation levels (at 1.0 mts height) through handheld dosimeters. Collected data points on natural background levels, have been analysed and quantified in the context of preparing reference background levels in the city in order to deal with any radiological emergency that may arise in the public domain. Study reveals Gaussian distributed mean annual gamma dose of 0.77 mSv (n=53) in the range of 0.38 to 1.51 mSv. The study area, bound by the coordinates N (25.50°-25.66°, and E (91.82°-91.96°) indicates few pockets of higher average background levels, particularly towards the eastern side of study area, namely Nongmynsong, NEIGRIMS and Happy Valley. However, from the radiological safety aspects in public domain, all these reported levels are within the safety limits of prevailing environmental background. (author)

Measurement of natural background neutron

CERN Document Server

Li Jain, Ping; Tang Jin Hua; Tang, E S; Xie Yan Fong

1982-01-01

A high sensitive neutron monitor is described. It has an approximate counting rate of 20 cpm for natural background neutrons. The pulse amplitude resolution, sensitivity and direction dependence of the monitor were determined. This monitor has been used for natural background measurement in Beijing area. The yearly average dose is given and compared with the results of KEK and CERN.

Intercomparison of natural and technologically enhanced background radiation levels in Micronesia

International Nuclear Information System (INIS)

Greenhouse, N.A.; Miltenberger, R.P.

1982-01-01

The United States Pacific Nuclear Testing Program resulted in local and regional fallout contamination of islands in the central Pacific basin, in an area which is generically known as Micronesia. Since all of the Marshall Islands are low coral islands or atolls, the natural radioactivity content of their soil is among the lowest on earth. In contrast, the high islands of the Caroline groups, to the west of the Marshalls, are characterized by volcanic soils having a significant complement of radionuclides of the uranium and thorium chains. Several field trips between 1975 and 1980 have afforded opportunities to study the natural radiation environments of the coral atolls of the Marshalls and several high islands in the Carolines. The results of these studies have indicated that significant contributions from radioactive fallout can be evaluated in-situ with relative ease on coral islands. In contrast, the higher natural radioactivity content of high island soils, as well as the greater distance of these islands from the test areas, combine to make evaluations of local fallout contributions from US Pacific tests indistinguishable from the contributions of the world-wide fallout

Multiple chromosome aberrations among newborns from high level natural radiation area and normal level natural radiation area of south west coast of Kerala

International Nuclear Information System (INIS)

Soren, D.C.; Ramachandran, E.N.; Karuppasamy, C.V.; Cheriyan, V.D.; Anil Kumar, V.; Koya, P.K.M.; Seshadri, M.

2010-01-01

Cord blood samples were collected in heparin vials and microculture techniques employed to obtain good metaphase chromosome spreads. In cytogenetic studies on newborns cells with multiple aberrations were recorded in 57 from a total of 27285 newborns (1266972 cells). Of these 17294 newborns (964140 cells) were from High Level Natural Radiation Area (HLNRA) and 9991 newborns (302832 cells) from Normal Level Natural Radiation Area (NLNRA). Cells with multiple aberrations were observed in 38 and 19 newborns from High and Normal Level Natural Radiation Area respectively. On an average one cell with multiple aberrations was observed among 479 newborns. Cells with multiple aberrations were observed in newborns from HLNRA as well as NLNRA in both males and females. Gender difference of newborns, maternal age group and background radiation levels did not seem to have any influence in the occurrence of Multiple chromosome aberrations

Natural radioactivity in the Dutch outdoor environment. The explanation of uncomprehended variations in the background

International Nuclear Information System (INIS)

Blaauboer, R.O.; Smetsers, R.C.G.M.

1996-01-01

In the Netherlands and many other countries research in the field of natural radioactivity is focused on the prevention of radon in the indoor environment. However, also the occurrence of natural radioactivity in the outdoor environment is an interesting subject to be studied. The natural background radiation in the outdoor environment, in particular its variations, hinders the verification of radiation level standards, caused by human activities. An analysis of the data of the Dutch National Monitoring Network for Radioactivity (LMR) provided more insight into those variations. This article is a summary of the authors' thesis on the subject. 5 figs., 8 refs

Assessment of Natural Exposure From Some kinds of Egyptian Gypsum Using Low Background Spectrometer

International Nuclear Information System (INIS)

Sroor, A.

2006-01-01

Radioactivity of natural gypsum and gypsum derived products are examined investigated due to their importance as element of building materials and agricultural gypsum. the natural gypsum and its product may constitute an additional source of radiation exposure to workers and members of public from radiation produced by radioactive decaying. thirty natural gypsum samples from different quarries and 32 fabricated gypsum samples from commercial companies were analyzed using low background HPGe detector. the natural concentration of Ra-226, 232 Th and 40 K activities in all samples were determined in Bq/Kg dry weight. it was found that radioactivity of natural gypsum is less than the fabricated gypsum, so it can be used as agricultural gypsum. fabricated gypsum is suitable for use as an element of building material in egypt

Radioactivity in food crops from high background radiation area in southwest area

International Nuclear Information System (INIS)

Shanthi, G.; Maniyan, C.G.; Allan Gnana Raj, G.; Thampi Thanka Kumaran, J.

2009-01-01

The study was carried out to evaluate radioactive concentration in food crops grown in naturally high-background radiation areas in southwest India. Seventeen varieties of food crops were collected from different parts of Kanyakumari district. The gross alpha and beta activities of the collected samples were measured using alpha scintillation counter and low beta counter respectively. The alpha activity was maximum in tapioca (497± 72 Bq kg -1 ) and the beta activity was maximum in paddy grain (10,946±583 Bq kg -1 ). The gamma activity of the food samples was studied by measuring the activity concentration of the radionuclides ( 226 Ra, 228 Th, 238 U, 40 K) in the food crops. The radioactivity content of the food crops from high-background radiation area was higher when compared to similar samples collected from low-background radiation area. The daily radionuclide intake from the food crops grown and consumed by the public was 127.696 Bq and daily internal dose resulting from ingestion of radionuclides in food was 2.34 μSv. (author)

Diffuse Cosmic Infrared Background Radiation

Science.gov (United States)

Dwek, Eli

2002-01-01

The diffuse cosmic infrared background (CIB) consists of the cumulative radiant energy released in the processes of structure formation that have occurred since the decoupling of matter and radiation following the Big Bang. In this lecture I will review the observational data that provided the first detections and limits on the CIB, and the theoretical studies explaining the origin of this background. Finally, I will also discuss the relevance of this background to the universe as seen in high energy gamma-rays.

Spontaneous Radiation Background Calculation for LCLS

CERN Document Server

Reiche, Sven

2004-01-01

The intensity of undulator radiation, not amplified by the FEL interaction, can be larger than the maximum FEL signal in the case of an X-ray FEL. In the commissioning of a SASE FEL it is essential to extract an amplified signal early to diagnose eventual misalignment of undulator modules or errors in the undulator field strength. We developed a numerical code to calculate the radiation pattern at any position behind a multi-segmented undulator with arbitrary spacing and field profiles. The output can be run through numerical spatial and frequency filters to model the radiation beam transport and diagnostic. In this presentation we estimate the expected background signal for the FEL diagnostic and at what point along the undulator the FEL signal can be separated from the background. We also discusses how much information on the undulator field and alignment can be obtained from the incoherent radiation signal itself.

Car-borne survey of natural background gamma dose rate in Canakkale region (Turkey)

International Nuclear Information System (INIS)

Turhan, S.; Arikan, I. H.; Oquz, F.; Aezdemir, T.; Yuecel, B.; Varinlioqlu, A.; Koese, A.

2012-01-01

Natural background gamma radiation was measured along roads in the environs of Canakkale region by using a car-borne spectrometer system with a plastic gamma radiation detector. In addition, activity concentrations of 238 U, 226 Ra, 232 Th and 40 K in soil samples from the Canakkale region were determined by using a gamma spectrometer with an HPGe detector. A total of 92 856 data of the background gamma dose rate were collected for the Canakkale region. The background gamma dose rate of the Canakkale region was mapped using ArcGIS software, applying the geostatistical inverse distance-weighted method. The average and population-weighted average of the gamma dose are 55.4 and 40.6 nGy h -1 , respectively. The corresponding average annual effective dose to the public ranged from 26.6 to 96.8 μSv. (authors)

Origin of the diffuse background gamma radiation

International Nuclear Information System (INIS)

Stecker, F.W.; Puget, J.L.

1974-05-01

Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

Background compensation for a radiation level monitor

Science.gov (United States)

Keefe, D.J.

1975-12-01

Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

Electromagnetic wave collapse in a radiation background

International Nuclear Information System (INIS)

Marklund, Mattias; Brodin, Gert; Stenflo, Lennart

2003-01-01

The nonlinear interaction, due to quantum electrodynamical (QED) effects between an electromagnetic pulse and a radiation background, is investigated by combining the methods of radiation hydrodynamics with the QED theory for photon-photon scattering. For the case of a single coherent electromagnetic pulse, we obtain a Zakharov-like system, where the radiation pressure of the pulse acts as a driver of acoustic waves in the photon gas. For a sufficiently intense pulse and/or background energy density, there is focusing and the subsequent collapse of the pulse. The relevance of our results for various astrophysical applications are discussed

On background radiation gradients – the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry

International Nuclear Information System (INIS)

Kock, Peder; Rääf, Christopher; Samuelsson, Christer

2014-01-01

Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. -- Highlights: • We present a simple method to account for gradients in the natural background radiation. • Gradients in the natural radiation background can be modelled at the ground level using AGS data. • The number of false positives due to background gradients can be reduced by using airborne data

Monitoring of external background radiation level in Asa dam ...

African Journals Online (AJOL)

An external background ionizing radiation study has been carried out within the Asa Dam Industrial Layout of Ilorin in Kwara State. The study was carried out in 5 stations within the industrial area using two Digilert Nuclear Radiation Monitors. The study has revealed that the external background ionizing radiation is ...

Cosmic gamma-ray background radiation. Current understandings and problems

International Nuclear Information System (INIS)

Inoue, Yoshiyuki

2015-01-01

The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. (author)

Effects of background radiation

International Nuclear Information System (INIS)

Knox, E.G.; Stewart, A.M.; Gilman, E.A.; Kneale, G.W.

1987-01-01

The primary objective of this investigation is to measure the relationship between exposure to different levels of background gamma radiation in different parts of the country, and different Relative Risks for leukaemias and cancers in children. The investigation is linked to an earlier analysis of the effects of prenatal medical x-rays upon leukaemia and cancer risk; the prior hypothesis on which the background-study was based, is derived from the earlier results. In a third analysis, the authors attempted to measure varying potency of medical x-rays delivered at different stages of gestation and the results supply a link between the other two estimates. (author)

THE HIGH BACKGROUND RADIATION AREA IN RAMSAR IRAN: GEOLOGY, NORM, BIOLOGY, LNT, AND POSSIBLE REGULATORY FUN

Energy Technology Data Exchange (ETDEWEB)

Karam, P. A.

2002-02-25

The city of Ramsar Iran hosts some of the highest natural radiation levels on earth, and over 2000 people are exposed to radiation doses ranging from 1 to 26 rem per year. Curiously, inhabitants of this region seem to have no greater incidence of cancer than those in neighboring areas of normal background radiation levels, and preliminary studies suggest their blood cells experience fewer induced chromosomal abnormalities when exposed to 150 rem ''challenge'' doses of radiation than do the blood cells of their neighbors. This paper will briefly describe the unique geology that gives Ramsar its extraordinarily high background radiation levels. It will then summarize the studies performed to date and will conclude by suggesting ways to incorporate these findings (if they are borne out by further testing) into future radiation protection standards.

Proceedings of the 8. International symposium on the natural radiation environment (NRE-VIII). Book of abstracts

International Nuclear Information System (INIS)

2007-01-01

Theoretical and experimental papers are presented in these proceedings covering the following subjects: cosmic radiation, solar activity and cosmogenic radionuclides - natural radiation from space, high background areas - life in naturally elevated radiation areas, radon and thoron - indoors and outdoors, other terrestrial natural radionuclides - natural radioactivity, NORM/TENORM, including depleted uranium - technologically enhanced natural radioactivity, dosimetry and health risk assessment biological effects of natural radioactivity , exposures of biota to natural radioactivity, metrology, modelling and epidemiology, BSS and legal issues - regulating natural radioactivity, RDD (dirty bombs and terrorism - terrorism and natural radioactive material, non-ionising radiation (NIR) an the NRE 11), geochronology plus natural radioactivity and the theory of time

On the nature of low-energy background in instruments for rentgenoradiometric analysis

International Nuclear Information System (INIS)

Kokhov, E.D.; Mamikonyan, S.V.; Mel'ttser, L.V.; Mil'chakov, V.I.; Shchekin, K.I.

1972-01-01

A study of the background radiation nature and its attenuation are one of the main techniques to decrease the sensitivity threshold of a roentgen radiometric analysis. The reasons for low-energy ''tail'' occurence are investigated in the article. It has been concluded that the low-energy ''tail'' occurence within the energy range less than 25 keV depends on a proportional counter. It has been confirmed that one of the main reasons for the low-energy ''tail'' occurence lies in photoelectron leakage from the counter sensing volume. It is shown that while determining the concentrations close to the sensitivity threshold, the elimination of radiation of the sample incident on the counter surface at an inclination angle seems to be reasonable. The test results show that the use of a collimator makes it possible to decrease the background concentration or the sensitivity threshold about 1.5 times as much

Method and apparatus for determining accuracy of radiation measurements made in the presence of background radiation

International Nuclear Information System (INIS)

Horrocks, D.L.

1977-01-01

A radioactivity measuring instrument, and a method related to its use, for determining the radioactivity of a sample measured in the presence of significant background radiation, and for determining an error value relating to a specific probability of accuracy of the result are presented. Error values relating to the measurement of background radiation alone, and to the measurement of sample radiation and background radiation together, are combined to produce a true error value relating to the sample radiation alone

Influence of radiation damage on internal friction background

International Nuclear Information System (INIS)

Burbelo, R.M.; Grinik, Eh.U.; Paliokha, M.I.; Orlinskij, A.B.

1984-01-01

Influence of radiation damage on internal friction background in samples of polycrystalline nickel and iron irradiated by a fast neutron flux approximately 10 14 neutr/(cm 2 xs) at 350 deg C has been studied using the low-frequency unit of the reverse torsion pendulum type. It has been established experimentally that a high-temperature background of internal friction of iron and nickel samples decreases as accumulating radiation defects occurring under neutron irradiation. Assumptions on a possible mechanism of the effect have been proposed. Simple expression for the background magnitude evaluation has been suggested

Interpretation of observed cosmic microwave background radiation

International Nuclear Information System (INIS)

Alfven, H.; Mendis, A.

1977-01-01

It is stated that the observed cosmic microwave background radiation, which closely fits a 2.7 K black body spectrum, is generally claimed to be the strongest piece of evidence in support of hot big bang cosmologies by its proponents. It is here stated that the observed radiation corresponds to the distribution of dust in galaxies or protogalaxies with a temperature approximately 110 K at the epoch corresponding to Z approximately 40, and not to a plasma of temperature > approximately 3000 K at an earlier epoch (Z > approximately 1000), as indicated by the canonical model of big bang cosmologies. The claim that the latter lends strong support to hot big bang cosmologies is stated to be without foundation. It is concluded that the microwave background radiation must be explained not in terms of a coupling between matter and radiation at the present epoch, but in terms of a coupling in a previous epoch within the framework of an evolutionary cosmology. (U.K.)

Analysis of signal to background ratio in synchrotron radiation X-ray fluorescence

International Nuclear Information System (INIS)

Sakurai, Kenji; Gohshi, Yohichi; Iida, Atsuo.

1988-01-01

The signal to background (S/B) ratio in energy dispersive X-ray fluorescence using synchrotron radiation (SR) was quantitatively analyzed. The S/B ratio, which has been significantly improved by taking advantage of the polarized nature of SR, was found to be strongly dependent on geometrical factors of the measurement system. From the analysis on the origin of the scattered background, the dependence of the S/B ratio on the geometry was quantitatively explained, mainly by the polarization properties of SR. Experimental conditions could be optimized by adjusting the degree of polarization of the incident beam and the detector solid angle. (author)

measurement of indoor background ionizing radiation in some

African Journals Online (AJOL)

Administrator

Measurement of the background ionizing radiation profile within the. Chemistry Research Laboratory and Physics Laboratory III all of the. University of Jos and their immediate neighbourhood were carried out. These science laboratories also harbour a number of active radiation sources. The radiation levels were measured ...

Radiation stability of animate nature

International Nuclear Information System (INIS)

Romanov, G.N.; Spirin, D.A.

1990-01-01

The main principles of radiation safety for animate nature including provisions for biological species protection and main requirement for animate nature radiation protection, which is the guarantee of any ecosystem integrity, are discussed. Ecosystem should be taken as the objective unit for animate nature radiation protection. The maximum dose of biot irradiation may amount to 0.5 Gy/year, which is 20-fold lower than the main dose limit for animate nature and 40-fold lower than ecological dose limits for conifers as the weakest radiostable member in ecosystem, at environment radioactive contamination determined by radiation safety standards. The radiation protection of animate nature is guaranteed at such levels of environment radioactive contamination

Modeling background radiation using geochemical data: A case study in and around Cameron, Arizona.

Science.gov (United States)

Marsac, Kara E; Burnley, Pamela C; Adcock, Christopher T; Haber, Daniel A; Malchow, Russell L; Hausrath, Elisabeth M

2016-12-01

This study compares high resolution forward models of natural gamma-ray background with that measured by high resolution aerial gamma-ray surveys. The ability to predict variations in natural background radiation levels should prove useful for those engaged in measuring anthropogenic contributions to background radiation for the purpose of emergency response and homeland security operations. The forward models are based on geologic maps and remote sensing multi-spectral imagery combined with two different sources of data: 1) bedrock geochemical data (uranium, potassium and thorium concentrations) collected from national databases, the scientific literature and private companies, and 2) the low spatial resolution NURE (National Uranium Resource Evaluation) aerial gamma-ray survey. The study area near Cameron, Arizona, is located in an arid region with minimal vegetation and, due to the presence of abandoned uranium mines, was the subject of a previous high resolution gamma-ray survey. We found that, in general, geologic map units form a good basis for predicting the geographic distribution of the gamma-ray background. Predictions of background gamma-radiation levels based on bedrock geochemical analyses were not as successful as those based on the NURE aerial survey data sorted by geologic unit. The less successful result of the bedrock geochemical model is most likely due to a number of factors including the need to take into account the evolution of soil geochemistry during chemical weathering and the influence of aeolian addition. Refinements to the forward models were made using ASTER visualizations to create subunits of similar exposure rate within the Chinle Formation, which contains multiple lithologies and by grouping alluvial units by drainage basin rather than age. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Background outdoor radiation dose to inhabitants around Narwapahar mine

International Nuclear Information System (INIS)

Srivastava, V.S.; Jha, V.N.; Topno, R.; Dandpat, B.L.; Patnaik, R.I.; Kumar, R.; Tripathi, R.M.; Puranik, V.D.

2012-01-01

Mining of uranium ore due to their inherent radiological characteristics may lead to release radionuclides into the environment. Monitoring of radiological parameters in the villages surrounding the mining areas are of significant concern for the evaluation of public exposure. The monitoring objectives will include the natural distribution of radionuclides in the environment as well as contribution of the source (mine), if any. Radon and its short lived progeny present in the environment contributes maximum natural background radiation dose due to inhalation. Apart from this, terrestrial radionuclides ( 238 U, 232 Th series and 40 K) present in trace level in earth crust are significant contributor of external exposure in the environment. The variation in the levels of these radionuclides depends on the geological strata of the area. Measured radiological parameters are comparable to the global average variation of exposure level due to these natural sources. Statistical treatment of the database reveals that the variation in radon and gamma level is natural and contribution of mining activities at the site is insignificant. The same is attributed to natural uranium mineralization of Singhbhum shear zone. Apart from this, seasonal variation in radon profile is globally reported

Measurement of indoor background ionizing radiation in some ...

African Journals Online (AJOL)

Certain types of building materials are known to be radioactive. Exposure to indoor ionizing radiation like exposure to any other type of ionizing radiation results in critical health challenges. Measurement of the background ionizing radiation profile within the Chemistry Research Laboratory and Physics Laboratory III all of ...

The cosmic microwave background radiation

International Nuclear Information System (INIS)

Wilson, R.W.

1980-01-01

The history is described of the discovery of microwave radiation of the cosmic background using the 20-foot horn antenna at the Bell Laboratories back in 1965. Ruby masers with travelling wave were used, featuring the lowest noise in the world. The measurement proceeded on 7 cm. In measuring microwave radiation from the regions outside the Milky Way continuous noise was discovered whose temperature exceeded the calculated contributions of the individual detection system elements by 3 K. A comparison with the theory showed that relict radiation from the Big Bang period was the source of the noise. The discovery was verified by measurements on the 20.1 cm wavelength and by other authors' measurements on 0.5 mm to 74 cm, and by optical measurements of the interstellar molecule spectrum. (Ha)

Background radiation study of Offa industrial area of Kwara State ...

African Journals Online (AJOL)

A study of the external background radiation in Offa industrial area of Kwara State is hereby reported. An in-situ measurement using two Digilert radiation monitors at five different stations were carried out. A mean exposure rate of 0.0132mR/hr, which represents 20% elevation from the standard background radiation, was ...

TeV Blazars and Cosmic Infrared Background Radiation

OpenAIRE

Aharonian, F. A.

2001-01-01

The recent developments in studies of TeV radiation from blazars are highlighted and the implications of these results for derivation of cosmologically important information about the cosmic infrared background radiation are discussed.

Nature of gamma rays background radiation in new and old buildings of Qatar University

International Nuclear Information System (INIS)

Al-Houty, L.; Abou-Leila, H.; El-Kameesy, S.

1987-01-01

Measurements and analysis of gamma-background radiation spectrum in four different places of Qatar University campus were performed at the energy range 10 keV-3 MeV using hyper pure Ge-detector. The dependence of the detector absolute photopeak efficiency on gamma-ray energies was determined and correction of the data for that was also done. The absorbed dose for each gamma line was calculated and an estimation of the total absorbed dose for the detected gamma lines in the four different places was obtained. Comparison with other results was also performed

Radiation exposure map based on fuzzy logic for the representation of areas with high natural background

International Nuclear Information System (INIS)

Vasconcelos, Wagner Eustaquio de; Lira, Carlos Alberto Brayner de Oliveira

2009-01-01

The identification of areas with high concentrations of natural radionuclides is an important task in classifying these areas in relation to the health risk for residents in the region. The aim of this work is to identify areas of high exposure to nuclear radiation using a geographic representation based on the theory of fuzzy sets. Radiometric data obtained from previous works developed in a region of high concentrations in natural uranium were used to create a fuzzy map of the local radiation levels. During the image processing, a nonlinear filter was applied to eliminate noise i.e. to reduce isolated pixels that would eventually cause major uncertainties in the results. A resulting image was geographically positioned (WGS40) and obtained in gray scale. This image was fuzzified for membership functions that represent linguistic variables as low exposure, medium exposure and high exposure. After representing the membership grade in a RGB (red, green and blue) image it was possible to visualize the radiation level in the area of exposure. When compared to data from the region, results demonstrated the good efficiency of the technique here employed for the representation of areas with high radioactivity levels. The image obtained also provided important information about those areas where exposure to radiation is more pronounced. Hence, the fuzzy map can be applied in decision-making of experts when a risk situation is identified. (author)

Background radiation dose of dumpsites in Ota and Environs

Science.gov (United States)

Usikalu, M. R.; Ola, O. O.; Achuka, J. A.; Babarimisa, I. O.; Ayara, W. A.

2017-05-01

In-situ measurement of background radiation dose from selected dumpsites in Ota and its environs was done using Radialert Nuclear Radiation Monitor (Digilert 200). Ten measurements were taken from each dumpsite. The measured background radiation range between 0.015 mRhr-1 for AOD and 0.028 mRhr-1 for SUS dumpsites. The calculated annual equivalent doses vary between 1.31 mSvyr-1 for AOD and 2.28 mSv/yr for SUS dumpsites. The air absorbed dose calculated ranged from 150 nGyhr-1 to 280 nGy/hr for AOD and SUS dumpsites respectively with an average value of 217 nGyhr-1 for all the locations. All the estimated parameters were higher than permissible limit set for background radiation for the general public. Conclusively, the associated challenge and radiation burden posed by the wastes on the studied locations and scavengers is high. Therefore, there is need by the regulatory authorities to look into the way and how waste can be properly managed so as to alleviate the effects on the populace leaving and working in the dumpsites vicinity.

Effects of deprivation of background environmental radiation on cultured human cells

International Nuclear Information System (INIS)

Carbone, M.C.; Pinto, M.; Antonelli, F.; Balata, M.

2010-01-01

In this paper we present results from an experiment aimed at investigating whether living cells are influenced by background ionizing radiation. Parallel human cell cultures were set-up in two separate laboratories and maintained for several months under identical conditions but for a 80 x different level of background ionizing radiation. Periodically, the cell cultures were monitored for the onset of divergences in biochemical behavior, using two distinct cellular biology assays, namely micronuclei induction and activity of enzymes implicated in the management of oxidative stress. To reveal any subtle modifications, responses were also amplified by subjecting cell cultures to acute stress induced by exposure to moderately high doses of ionizing radiation. Compared to reference radiation background conditions, cultures maintained in a reduced background radiation environment handled the consequences of acute stress with diminished efficacy.

Management of radiation injuries by natural herbs and neutraceuticals

Energy Technology Data Exchange (ETDEWEB)

Goyal, P.K., E-mail: pkgoyal2002@gmail.com [Radiation and Cancer Biology Laboratory, Department of Zoology, University of Rajasthan, Jaipur (India)

2013-10-15

In the era of expanding nuclear energy program all over world, the role of radiation biology has acquired greater relevance and significance in addressing the health and environment issues. In view of constant human exposure to background radiation both naturally and man made e.g nuclear power plants and weapons testing, consumer products, medical X-ray, uranium mining and milling etc., the radiobiological research has been devoted to induction of cancer and evaluation of genetic effects. In the present time, nuclear terrorism and weapon related effects are raising much alarm and concern to public health. Obviously, radiation biology research has great potential in diagnosis, therapy and establishing standards for assessment risk from radiation exposure. The development of effective medical countermeasures to protect, mitigate, and treat normal tissue injury needs urgent investigation for basic molecular mechanisms and developing appropriate ready to-use kits using relevant cellular, animal model and clinical trails for practical purposes. Since the use of synthetic compounds is associated with the inherent toxicity, attention in recent years has been directed towards developing radiation countermeasure agents from the natural sources and/or nature-identical molecules. The rich biodiversity available in the Indian subcontinent has yielded several new drugs that find application in the modern medicine and there is a like hood of discovering many more, Over the last few years, interest in evaluating oriental medicinal herbs and edible phyto products for the use in anti-radiation strategies is encouraging and emerging as an acceptable approach for preventing the radiation induced lesions in many countries. Several Indian medicinal plants (Emblica officinalis, Rosemarinus officinalis, Trigonella foenum-graecum, Alstonia scholaris, Tinospora cordifolia, Phyllanthus niruri, Svzvgiumcumini, Aegle marmelos etc) and antioxidant vitamins (C and E) have been tested in this

Management of radiation injuries by natural herbs and neutraceuticals

International Nuclear Information System (INIS)

Goyal, P.K.

2013-01-01

In the era of expanding nuclear energy program all over world, the role of radiation biology has acquired greater relevance and significance in addressing the health and environment issues. In view of constant human exposure to background radiation both naturally and man made e.g nuclear power plants and weapons testing, consumer products, medical X-ray, uranium mining and milling etc., the radiobiological research has been devoted to induction of cancer and evaluation of genetic effects. In the present time, nuclear terrorism and weapon related effects are raising much alarm and concern to public health. Obviously, radiation biology research has great potential in diagnosis, therapy and establishing standards for assessment risk from radiation exposure. The development of effective medical countermeasures to protect, mitigate, and treat normal tissue injury needs urgent investigation for basic molecular mechanisms and developing appropriate ready to-use kits using relevant cellular, animal model and clinical trails for practical purposes. Since the use of synthetic compounds is associated with the inherent toxicity, attention in recent years has been directed towards developing radiation countermeasure agents from the natural sources and/or nature-identical molecules. The rich biodiversity available in the Indian subcontinent has yielded several new drugs that find application in the modern medicine and there is a like hood of discovering many more, Over the last few years, interest in evaluating oriental medicinal herbs and edible phyto products for the use in anti-radiation strategies is encouraging and emerging as an acceptable approach for preventing the radiation induced lesions in many countries. Several Indian medicinal plants (Emblica officinalis, Rosemarinus officinalis, Trigonella foenum-graecum, Alstonia scholaris, Tinospora cordifolia, Phyllanthus niruri, Svzvgiumcumini, Aegle marmelos etc) and antioxidant vitamins (C and E) have been tested in this

The world's high background natural radiation areas (HBNRAs) revisited: A broad overview of the dosimetric, epidemiological and radiobiological issues

International Nuclear Information System (INIS)

Aliyu, Abubakar Sadiq; Ramli, Ahmad Termizi

2015-01-01

The residents of the world's high background natural radiation areas (HBNRAs), such as Ramsar (in Iran), Guarapari (in Brazil), Orissa and Kerala (in India) and Yangjiang (in China) have lived in these areas for generations under extraordinary radiation fields. The failure of earlier epidemiological studies to report any substantial increase in cancer incidence in HBNRAs has raised some controversy regarding the validity of the linear no-threshold hypothesis. This paper reviews some of the most recent studies of HBNRAs with the intent of stimulating greater research interest in the dosimetric, epidemiological and radiobiological issues related to the world's HBNRAs and proposes solutions to the challenges facing HBNRA studies. This paper may serve as a useful reference for some of the harder-to-find literature. - Highlights: • Some of the challenging issues of HBNRAs have not been resolved. • A literature review of the most recent studies of HBNRAs has been conducted. • An overview of some of the challenging issues and viable solutions are presented

Electromagnetic radiation in a time-varying background medium

NARCIS (Netherlands)

Budko, N.V.

2009-01-01

Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the synchronous permittivity and permeability described by any positive

Can the anisotropy of microwave background radiation be discovered at present?

International Nuclear Information System (INIS)

Gurzadyan, V.G.; Kocharyan, A.A.

1990-10-01

An effect leading to a decrease of perturbations of Microwave Background Radiation after recombination epoch is investigated. Behaviour of correlation functions for null geodesics flow enables one to evaluate the role of this effect based purely on geometrical and topological properties of the Universe. Possible anisotropy of MwB in open Friedmannian Universe is shown to decrease due to this effect to a level far below present experimental accuracy. The fractal nature of the large scale structure of the Universe is also discussed. (author). 20 refs

MDS G(N) fast differentiation between natural and artificial gamma radiation with a new class of mobile instruments

International Nuclear Information System (INIS)

Katzung, W.; Bottcher, J.

2009-01-01

A State-of-the-Art tool used for detecting and tracking artificial gamma radiation out of a helicopter or a vehicle is the MDS G(N) - Mobile Detection System. A highly sensitive scintillation detector detects a significant artificial gamma radiation on the ground even if the helicopter is travelling at high speed. The GPS-aided system visualizes the measured values on a moveable map displayed on the screen of a notebook every second. The colours of the continuously entered points do represent adjustable alarm thresholds. This way, location and intensity of an unknown radioactive source or a radioactive contamination can be determined very quickly. The NBR-technology (Natural Background Rejection) which is used here leads to expressive measurement results differentiating between artificial and natural gamma radiation. Additional He-3 detectors allow simultaneously the detection of neutrons. The NBR principle - developed by Thermo Scientific - stands out for its very short response times. Thus, artificial radiation can be detected reliably within seconds - even when the unit is operated by untrained staff. Unlike traditional analytic measuring techniques, the NBR method is able to detect artificial radiation sources hidden or strongly shielded gamma sources clearly from the natural background radiation. The measuring range from 1 nSv/h to 20 ?Sv/h and is extended to 1 Sv/h with a Geiger Mueller counting tube. The sensitivity amounts to max. 20000 cps (referred to 1 ?Sv/h for Cs-137). The NBR- technique is well-proven and tested for: tracking hidden radiation sources, even such ones with low activity or which are shielded, detection of artificial radiation portions in the range of the natural background, reliably measuring the ambient equivalent dose rate in the range of the natural background, fast detection of artificial radioactivity out of helicopters and vehicles.(author)

Cosmic microwave background radiation of black hole universe

Science.gov (United States)

Zhang, T. X.

2010-11-01

Modifying slightly the big bang theory, the author has recently developed a new cosmological model called black hole universe. This new cosmological model is consistent with the Mach principle, Einsteinian general theory of relativity, and observations of the universe. The origin, structure, evolution, and expansion of the black hole universe have been presented in the recent sequence of American Astronomical Society (AAS) meetings and published recently in a scientific journal: Progress in Physics. This paper explains the observed 2.725 K cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present universe with hundred billion-trillions of solar masses. According to the black hole universe model, the observed cosmic microwave background radiation can be explained as the black body radiation of the black hole universe, which can be considered as an ideal black body. When a hot and dense star-like black hole accretes its ambient materials and merges with other black holes, it expands and cools down. A governing equation that expresses the possible thermal history of the black hole universe is derived from the Planck law of black body radiation and radiation energy conservation. The result obtained by solving the governing equation indicates that the radiation temperature of the present universe can be ˜2.725 K if the universe originated from a hot star-like black hole, and is therefore consistent with the observation of the cosmic microwave background radiation. A smaller or younger black hole universe usually cools down faster. The characteristics of the original star-like or supermassive black hole are not critical to the physical properties of the black hole universe at present, because matter and radiation are mainly from the outside space, i.e., the mother universe.

Radiation in the Einstein universe and the cosmic background

International Nuclear Information System (INIS)

Segal, I.E.

1983-01-01

It is shown that the cosmic background radiation is not at all uniquely or scientifically relatively economically indicative of a ''big bang.'' Specifically, essentially any temporally homogeneous theory in the Einstein universe is consistent with the existence of a cosmic background radiation (CBR) conforming to the Planck law; in particular, the chronometric cosmology is such. It is noted that the Einstein universe appears particularly natural as a habitat for photons by virtue of the absence of infrared divergences and of the absolute convergence of the trace for associated Gibbs-state density matrices. These features are connected with the closed character of space in the Einstein universe, and facilitate the use of the latter in modeling local phenomena, in place of Minkowski space with periodic boundary conditions or the like, with minimal loss of covariance or effect on the wave functions. In particular, the Einstein universe may be used in the analysis of the perturbation of a Planck-law spectrum due to a local nonvanishing isotropic angular momentum of the CBR, of whatever origin. The estimated distortion of the spectrum due to such a kinematically admissible effect is in very good agreement with that observed by Woody and Richards, which is opposite in direction to those earlier predicted by big-bang theories. The theoretical analysis involves a preliminary treatment of equilibria of linear quantum fields with supplementary quasilinear constraints

Exposure of the Bulgarian population from natural and manmade ionizing radiation sources in the mid 90-ies

International Nuclear Information System (INIS)

Vasilev, G.; Bajrakova, A.; Ingilizova, Kh.; Khristova, M.; Karadzhov, A.

1997-01-01

The main radiation sources the Bulgarian population is exposed to, e.g. natural radiation background and manmade exposure such as occupational, medical, nuclear power engineering and the like, are analyzed. The study covers the period 1991-1994 but it also contains a number of retrospective assessments concerning the last few decades. It is prepared with a special reference to the forthcoming report of the United Nations Scientific Committee on the effect of atomic radiation scheduled for publication in 1998/1999. The Bulgarian population exposure presented as average annual effective collective doses amounts to 20240 mSv/a from natural background, 6400 mSv/a from x-ray diagnostics, 400 mSv/a from nuclear medicine, 17 mSv/a from occupational exposure (uranium mining excluded) etc. Total exposure in excess to background irradiation is about 40% of the background one

CERN-derived analysis of lunar radiation backgrounds

Science.gov (United States)

Wilson, Thomas L.; Svoboda, Robert

1993-01-01

The Moon produces radiation which background-limits scientific experiments there. Early analyses of these backgrounds have either failed to take into consideration the effect of charm in particle physics (because they pre-dated its discovery), or have used branching ratios which are no longer strictly valid (due to new accelerator data). We are presently investigating an analytical program for deriving muon and neutrino spectra generated by the Moon, converting an existing CERN computer program known as GEANT which does the same for the Earth. In so doing, this will (1) determine an accurate prompt neutrino spectrum produced by the lunar surface; (2) determine the lunar subsurface particle flux; (3) determine the consequence of charm production physics upon the lunar background radiation environment; and (4) provide an analytical tool for the NASA astrophysics community with which to begin an assessment of the Moon as a scientific laboratory versus its particle radiation environment. This will be done on a recurring basis with the latest experimental results of the particle data groups at Earth-based high-energy accelerators, in particular with the latest branching ratios for charmed meson decay. This will be accomplished for the first time as a full 3-dimensional simulation.

Means of evaluation of population dose from the natural background of radiation for control of the exposure of environment of nuclear power plants

International Nuclear Information System (INIS)

Pensko, J.

1974-01-01

Given in this paper are the method and the results of calculation of the average value of the equivalent of the dose of the natural background of radiation, affecting the gonads and the bone marrow of the inhabitants of one of the regions of Poland, chosen as an example. These values weighed on a number of more important environmental factors, amounts to 78.0 mrem/years for gonads and 72.1 mrem/year for bone marrow. The value of the total population dose for the investigated region, from these sources of radiation, does not exceed 1.2 x 10 4 man-rem/year. Calculations were performed mainly on the base of the results of measurements of the exposure dose rate by a scintillation monitor from aboard an airplane, using also the numerous measurements of the dose at the height of 1 m over the earth's surface, done by means of a high-pressure ionization chamber, and the results of gamma spectrometric analysis of samples of soil. In calculations, coefficients of transformation of the exposure dose into the dose absorbed by various tissues, and the time spent indoors, were taken into consideration. For this purpose, using a proper coefficient of building screen has been suggested. This method can be used for estimating the average population dose, from the external radiation originating from natural and artificial radioactive sources, present in the environment of nuclear power plants. (author)

Incidence of neural tube defects in the natural radiation coastal areas of Kerala

International Nuclear Information System (INIS)

Jaikrishan, G.; Sudheer, K.R.; Andrews, V.J.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.

2010-01-01

All consecutive births in selected government hospitals in and around the high level natural background radiation areas (HLNRA) of Kerala were monitored for congenital malformations observable at birth since 1995. The HLNR area, a coastal strip of land about 55 km in length and 0.5 km in breadth from Purakkad in the north in Alleppey district to Sakthikulangara in the south of Quilon district, stands out among the most prominent background radiation areas of the world. Natural deposit of monazite sand, containing Thorium (8-10%), Uranium (0.3%) and corresponding decay products, is the source of elevated background radiation, ranging from < 1 to 45 mGy/year. Wide variation in dose, due to the patchy and non-uniform distribution of Monazite sand, enables in built controls. High population density, limited migration, ethnic diversity, good literacy, health awareness, institutionalized births and acceptance of small family norm are some of the key features of the population. Areas with a mean radiation dose of more than 1.5 mGy/year were treated as HLNR areas and areas with a dose level of 1.5 mGy/year or less were treated as normal level radiation (NLNR) areas. The study carried out since 1995 does not seem to implicate HLNR in the incidence of neural tube defects among newborns

Organization and operation of the Sixth International Symposium on the Natural Radiation Environment (NRE VI)

International Nuclear Information System (INIS)

Hopke, P.K.

1996-01-01

An important source of human exposure to radiation is the natural world including cosmic rays, cosmogenic radionuclides, natural terrestrial radionuclides, and radon isotopes and its decay products. Considerable effort is being expended on a worldwide basis to characterize the exposure to the natural radiation environment and determine the important pathways for the exposure to result in the dose to tissue that leads to injury and disease. The problem of background exposure to naturally occurring radioactivity has been the subject of research since the initial discovery of the radioactivity of uranium and thorium. However, with the advent of artificial sources of radiation with both benefits and harm the nature and magnitude of the natural radiation environment and the effects on various populations are important in the development of overall public health strategies as ALARA principles are applied to the situation

Safety of natural radiation exposure. A meta-analysis of epidemiological studies on natural radiation

International Nuclear Information System (INIS)

Osaki, S.

2000-01-01

People have been exposed every time and everywhere to natural radiation and ''intuitively'' know the safety of this radiation exposure. On the other hand the theory of no threshold value on radiological carcinogenesis is known widely, and many people feel danger with even a smallest dose of radiation exposure. The safety of natural radiation exposure can be used for the risk communication with the public. For this communication, the safety of natural radiation exposure should be proved ''scientifically''. Safety is often discussed scientifically as the risks of the mortality from many practices, and the absolute risks of safe practices on the public are 1E-5 to 1E-6. The risks based on the difference of natural radiation exposure on carcinogenesis have been analyzed by epidemiological studies. Much of the epidemiological studies have been focused on the relationship between radiation doses and cancer mortalities, and their results have been described as relative risks or correlation factors. In respect to the safety, however, absolute risks are necessary for the discussion. Cancer mortalities depend not only on radiation exposure, but also on ethnic groups, sexes, ages, social classes, foods, smoking, environmental chemicals, medical radiation, etc. In order to control these confounding factors, the data are collected from restricted groups or/and localities, but any these ecological studies can not perfectly compensate the confounding factors. So positive or negative values of relative risks or the meaningful correlation factors can not be confirmed that their values are derived originally from the difference of their exposure doses. The absolute risks on these epidemiological studies are also affected by many factors containing radiation exposure. The absolute risk or the upper value of the confidence limit obtained from the epidemiological study which is well regulated confounding factors is possible to be a maximum risk on the difference of the exposure doses

Correlation between natural radiation exposure and cancer mortality, (2)

International Nuclear Information System (INIS)

Noguchi, Kunikazu; Shimizu, Masami; Onishi, Masaaki; Sairenji, Eiko

1986-01-01

In the previous study, a statistically significant positive correlation between natural background radiation exposure rates and crude (non-age-adjusted) cancer mortality rates was observed in 46 Japanese prefectures over the period from 1968 until 1978. In the present investigation, however, the significance of this correlation mostly disappeared through age adjustment with only the two exceptions of female stomach and uterine cancers. Age adjusted male esophagus cancer mortality rate still showed a significant negative correlation. Female esophagus and pancreas cancers became negatively correlated with exposure rate through age adjustment. It was suggested that natural radiation levels are positively correlated with prefectural population component ratios older than 40, 50 and 65 years, which was considered to be one of the causes of apparent correlation between exposure rates and crude cancer mortality rates. (author)

Background radiation in the Sydney metropolitan area scientific reality and public perception

International Nuclear Information System (INIS)

Kemeny, L.G.

1988-01-01

Very little information if any, is available to the public about the ubiquitous nature of low-level background radiation -both from terrestrial and cosmic sources - in our highly urbanised or predominantly agrarnian societies. Public perception has naively accepted that the combustion of precious oxygen by air breathing engines is both natural and societally acceptable. Little thought has been given to the fact that on the one planet known to be able to sustain life based on oxygen, this is a recipe for disaster. On the other hand, since the evolution or creation of our universe, billions of tonnes of radioactive material within the crust of planet earth together with radiation from the thermonuclear powers station of the solar system, the sun, have sustained life, assisted in its evolution and, through photosynthesis and energy deposition, have ensured its propagation. In this on-going student project, employing wide-band, sensitive scintillation radiation detectors, careful statistical analysis and an understanding of the physics of radium-uranium decay chain and the production of radon gas and its daughter products, fluctuation in the radiation fields of large cities is clearly demonstrated. The work is usually carried out by the author and his final year thesis and students have great educational value for the public, civic authorities, school teachers, the media and political decision makers

Epidemiological studies in high background radiation areas

International Nuclear Information System (INIS)

Akiba, Suminori

2012-01-01

Below the doses of 100-200 mSv of radiation exposure, no acute health effect is observed, and the late health effects such as cancer are yet unclear. The problems making the risk evaluation of low dose radiation exposure difficult are the fact that the magnitude of expected health effects are small even if the risk is assumed to increase in proportion to radiation doses. As a result, studies need to be large particular when dealing with rare disease such as cancer. In addition, the expected health effects are so small that they can easily be masked by lifestyles and environmental factors including smoking. This paper will discuss cancer risk possibly associated with low-dose and low-dose rate radiation exposure, describing epidemiological studies on the residents in the high-background radiation areas. (author)

Background radiation measurements at the Waste Isolation Pilot Plant (WIPP) Site, Carlsbad, New Mexico

International Nuclear Information System (INIS)

Minnema, D.M.; Brewer, L.W.

1983-09-01

A series of background radiation measurements was performed at the Waste Isolation Pilot Plant (WIPP) Site, Carlsbad, New Mexico. The survey consisted of gross gamma and gamma spectral measurements of the radiation fields, soil and salt grab sample gamma analysis, and radon and working level measurements. The survey included locations at the surface and also within the mine itself. Background radiation levels on the surface were measured to average 7.65 microR/hour, and 0.7 microR/hour within the mine. Radon and working levels were at or below detection levels at all locations, and the radon concentration was estimated to be about 0.01 pCi/liter on the surface based on spectral measurements. The spectral measurements were performed using an intrinsic germanium spectrometer, and calculations from the spectra indicated that potassium-40 contributed about 28% to the surface level dose rates, natural uranium daughters contributed about 64%, and cesium-137 from weapons testing fallout contributed about 8%. In the mine potassium-40 was the only identifiable contributor to the dose rate

Spectral characterization of natural backgrounds

Science.gov (United States)

Winkelmann, Max

2017-10-01

As the distribution and use of hyperspectral sensors is constantly increasing, the exploitation of spectral features is a threat for camouflaged objects. To improve camouflage materials at first the spectral behavior of backgrounds has to be known to adjust and optimize the spectral reflectance of camouflage materials. In an international effort, the NATO CSO working group SCI-295 "Development of Methods for Measurements and Evaluation of Natural Background EO Signatures" is developing a method how this characterization of backgrounds has to be done. It is obvious that the spectral characterization of a background will be quite an effort. To compare and exchange data internationally the measurements will have to be done in a similar way. To test and further improve this method an international field trial has been performed in Storkow, Germany. In the following we present first impressions and lessons learned from this field campaign and describe the data that has been measured.

Exposure to natural radiation

International Nuclear Information System (INIS)

Green, B.M.R.

1985-01-01

A brief report is given of a seminar on the exposure to enhanced natural radiation and its regulatory implications held in 1985 at Maastricht, the Netherlands. The themes of the working sessions included sources of enhanced natural radiation, parameters influencing human exposure, measurement and survey programmes, technical countermeasures, risk and assessment studies, philosophies of dose limitations and national and international policies. (U.K.)

DNDO Report: Predicting Solar Modulation Potentials for Modeling Cosmic Background Radiation

Energy Technology Data Exchange (ETDEWEB)

Behne, Patrick Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-08-08

The modeling of the detectability of special nuclear material (SNM) at ports and border crossings requires accurate knowledge of the background radiation at those locations. Background radiation originates from two main sources, cosmic and terrestrial. Cosmic background is produced by high-energy galactic cosmic rays (GCR) entering the atmosphere and inducing a cascade of particles that eventually impact the earth’s surface. The solar modulation potential represents one of the primary inputs to modeling cosmic background radiation. Usosokin et al. formally define solar modulation potential as “the mean energy loss [per unit charge] of a cosmic ray particle inside the heliosphere…” Modulation potential, a function of elevation, location, and time, shares an inverse relationship with cosmic background radiation. As a result, radiation detector thresholds require adjustment to account for differing background levels, caused partly by differing solar modulations. Failure to do so can result in higher rates of false positives and failed detection of SNM for low and high levels of solar modulation potential, respectively. This study focuses on solar modulation’s time dependence, and seeks the best method to predict modulation for future dates using Python. To address the task of predicting future solar modulation, we utilize both non-linear least squares sinusoidal curve fitting and cubic spline interpolation. This material will be published in transactions of the ANS winter meeting of November, 2016.

Awareness for natural radiation potential zones in Archean Terrain of Chhattisgarh State

International Nuclear Information System (INIS)

Diwan, H.D.; Pande, S.K.

2015-01-01

In the environment, the natural radiations emitted by rocks and soils containing radioactive minerals, largely affected the human being in various aspects. The Chhattisgarh region characterized by the mineral of natural radiations with their relative distribution found in Granitic rocks of Archean age. Adjacent to Cratonic margins, exposures of outer fringes became suitable sites for radiation spread. It constituting towards the emission of radiation by the intrinsic content of minerals present in the host rock i.e. the terrestrial sources of radiation. The Archean terrain covers the surrounding areas of oval cup shaped sedimentary basin and it lies in the S.O.I. toposheet no. 64 G. H.I.K.L. To locate the marked potential zone for natural radiation, the investigation nearby aquatic component of main river and tributaries of Mahanadi river system is important. The presence of Granitic/ Pegmatite rocks at the boundaries of shield areas became promising areas for radiation generating mineral components. Occurrence in the potential zones expressed as lense shaped deposits or strips in dimension of IX1/2 with few hundred long belt. Presence of weathering of Uraninite minerals content remain yellow orange coloured impressions on the surface. In urban areas the background radiation in form of ionic radiation by the residential dwelling units accredates radiations. It needs awareness for Natural Radiation of under zones (NRPZ) in the region. To ensure the effective awareness programme, the area under consideration of natural radiation should take care of socially sustainable activities and spatio-temporal spread to motivate and implement various safety provisions. The model experiments can be sued from R and D point of view, also to alert the people to provide 'Safety, health and welfare of society'. (author)

Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

Science.gov (United States)

Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

2016-01-27

A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis.

Localities With Elevated Radiation Background in the High Karst Zone of Montenegro

International Nuclear Information System (INIS)

Vukotic, P.; Svrkota, R.; Andjelic, T.; Zekic, R.; Antovic, N.

2011-01-01

Research aimed to find localities in Montenegro with an elevated terrestrial gamma background was conducted during the period 2008-2009. For this purpose, 138 localities which have geological formations known to contain minerals with potentially high concentrations of U, Th and K, were selected throughout the country for a dosimetric survey. There are four distinctive geotectonic units in Montenegro: the Adriatic-Ionian Zone (JZ), the Budva-Cukali Zone (BZ), the High Karst Zone (VK), and the Durmitor Tectonic Unit (DTJ). The central and southern parts of Montenegro belong to the VK zone, whose geological structure is predominated by Mesozoic carbonate sediments, with occurrences of red and white bauxite formations, Triassic volcanic rocks, Paleogene flysch sediments and Quaternary sediments. In total, 38 localities belonging to the VK zone were selected for field investigations of terrestrial radiation. Knowing from earlier investigations that in Montenegro the average absorbed dose-rate in the air, 1 m above the ground, is 55 nGy/h, it was arbitrarily adopted that only localities with absorbed doses at least 50 % above this average value would be considered as having a relatively elevated radiation background. Field measurements have shown that 12 of the surveyed localities in the VK zone have such elevated dose values, five of them being with the highest dose rates in Montenegro. Among these five sites, the highest dose rate (192 nGy/h) was found at a locality which lies on andesite volcanic rock, while the other four localities (131 - 149 nGy/h) lie on bauxite deposits. Compared to the other areas in the world known to have a high natural radiation background, all of these localities in Montenegro have a moderately elevated radiation level. From the 12 localities with a relatively elevated radiation background, soil samples have been collected and analyzed by gamma spectrometry to determine activity concentrations of 40K, 232Th, 235U, 238U, 226Ra and 137Cs

Germline mutation rates in families residing in high level natural radiation areas of Kerala coast in southwest India

International Nuclear Information System (INIS)

Das, Birajalaxmi; Ghosh, Anu; Ahmad, Shazia; Saini, DivyaIakshmi; Chauhan, P.S.; Seshadri, M.

2010-01-01

For this study, 200 nuclear families have been analyzed using over 40 mini- and microsatellite markers. Cord blood samples for the child and peripheral blood samples for the parent(s) were collected in EDTA vacuutainers from the hospital units located in High Level Natural Radiation Areas (HLNRA) and Normal Level Natural Radiation Areas (NLNRA). Both the parents of the newborn were exposed to the background dose. The families were grouped into four distinct dose groups - NLNRA group 5.00 mGy/year. An overall mutation rate of 2.08 X 10 -3 per cell per generation was observed for NLNRA and 2.12 X 10 -3 per cell per generation for HLNRA families. No radiation induced dose response was observed for the stratified groups. Thus, this study shows that mutation rates at mini- and microsatellites in the off springs of the parents living in the high background radiation areas of Kerala does not vary with radiation exposure. This is the first report to understand germline mutation rates at hypervariable loci in families residing in high level natural radiation areas of the world

Research And Investigation To Establish The Database Of Environment Radiation Background For Vietnam (Phase 2009 -2011)

International Nuclear Information System (INIS)

Trinh Van Giap; Nguyen Huu Quyet; Nguyen Quang Long; Bui Dac Dung; Vuong Thu Bac; Le Dinh Cuong; Chu Vu Long; Le Ngoc Thiem; Truong Y; Nguyen Van Mai; Nguyen Ba Tien

2013-01-01

Setting up data base of natural radiation background serves for planning socio-economics development in a province as well as the whole country and estimating annual effective dose of population. Beside external irradiation dose caused by the natural radioisotopes in the series 238 U, 232 Th and 40 K in soil, population has been received internal dose caused by the above radioisotopes taken in the body from several ways. In order to complete the database of national radiation background and go to estimate annual effective radiation dose of population in the whole country, this project focus to carry out the works as following: (i) Setting up database of radiation background in the whole country: 150 soil samples that collected in the districts of 46 provinces have been analyzed. The average activity concentration of 238 U, 232 Th and 40 K are 37.86 Bq/kg, 58.88 Bq/kg and 462.78 Bq/kg, respectively. The outdoor, indoor and total annual effective doses are calculated: 0.087±0.036 mSv; 0.488±0.202 mSv and 0.576± 0.240 mSv, respectively. (ii) Setting up database of radiation background of province Ninh Thuan and Quang Nam: The detailed database of radiation background of all villages in Ninh Thuan and Quang Nam has been established. 84 soil samples in Ninh Thuan and 311 in Quang Nam were collected for analyze. The indoor and outdoor radon concentration at sampling positions has been measured. The average activities of 238 U, 232 Th, 40 K, and 222 Rn isotopes in Ninh Thuan are reported: 33.50 Bq/kg, 55.43 Bq/kg, 701.12 Bq/kg and 12.1 Bq/m 3 , 9.5 Bq/m 3 , respectively. The outdoor, indoor and total annual effective doses in Ninh Thuan are calculated: 0.095±0.029 mSv; 0.529±0.162 mSv and 0.624± 0.382 mSv, respectively. The average activities of 238 U, 232 Th, 40 K, and 222 Rn isotopes in Quang Nam are reported: 44.47 Bq/kg, 52.68 Bq/kg, 459.33 Bq/kg, 18.0 Bq/m 3 . The outdoor, indoor and total annual effective doses are calculated: 0.086±0.039 mSv; 0.482±0.216 m

Assessment of background gamma radiation and determination of excess lifetime cancer risk in Sabzevar City, Iran in 2014

Directory of Open Access Journals (Sweden)

Akbar Eslami

2016-01-01

Full Text Available Background: Background gamma radiation levels vary in different locations and depended on many factors such as radiation properties of soil, building materials as well as construction types which human lives on it. People are always exposed to ionizing radiation, which could badly influence their health. The aim of this study was to evaluate the background gamma-ray dose rate and the estimated annual effective dose equivalent and determination of excess lifetime cancer risk in Sabzevar City, Iran. Methods: The aim of this cross-sectional study was to determine the dose rate of background gamma radiation in outdoor an indoor areas, 26 stations were selected using the map of the Sabzevar City. The amount of gamma radiation was measured at 4 months (September to January in 2014 year. The dosimeter used in this study was a survey meter, that is designed for monitoring radiation of x, gamma and beta rays. Results: The obtained results show that there are significant differences between the indoor and outdoor exposures (P> 0.05. We did not observe significant differences between the time of sampling and sampling locations, (P<0.05. The minimum and maximum values of dose rate were found 66±20 nSvh-1 and 198±28 nSvh-1. The annual effective dose for Sabzevar residents was estimated to be 0.85 mSv and also the amount of excess lifetime cancer risk was estimated 3.39×10-3. Conclusion: According to the results, the excess lifetime cancer risk and the annual effective dose for the Sabzavar City residents due to the background gamma radiation was higher than the global average (0.5 mSv. The epidemiological studies have been proposed to evaluate the risk of chronic diseases associated with natural radiation exposure among residents.

Interstellar cyanogen and the temperature of the cosmic microwave background radiation

Science.gov (United States)

Roth, Katherine C.; Meyer, David M.; Hawkins, Isabel

1993-01-01

We present the results of a recently completed effort to determine the amount of CN rotational excitation in five diffuse interstellar clouds for the purpose of accurately measuring the temperature of the cosmic microwave background radiation (CMBR). In addition, we report a new detection of emission from the strongest hyperfine component of the 2.64 mm CN rotational transition (N = 1-0) in the direction toward HD 21483. We have used this result in combination with existing emission measurements toward our other stars to correct for local excitation effects within diffuse clouds which raise the measured CN rotational temperature above that of the CMBR. After making this correction, we find a weighted mean value of T(CMBR) = 2.729 (+0.023, -0.031) K. This temperature is in excellent agreement with the new COBE measurement of 2.726 +/- 0.010 K (Mather et al., 1993). Our result, which samples the CMBR far from the near-Earth environment, attests to the accuracy of the COBE measurement and reaffirms the cosmic nature of this background radiation. From the observed agreement between our CMBR temperature and the COBE result, we conclude that corrections for local CN excitation based on millimeter emission measurements provide an accurate adjustment to the measured rotational excitation.

Excess relative risk for solid cancer mortality during prolonged exposure to high-background natural radiation in Yangjiang area of China

International Nuclear Information System (INIS)

Sun Quanfu; Tao Zufan; Yuan Yongling; Zou Jianming; Cha Yongru; Jian Yuannu; Wei Luxin; Akiba, S.

2002-01-01

Objective: To estimate the excess relative risk for solid cancer associated with chronically exposure to high-background natural radiation in Yangjiang area of China. Methods: Based on hamlet-specific environmental doses and sex-and age-specific occupancy factors, the authors calculated cumulative doses for each cohort member. Assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995 and Poisson model, the authors estimated the excess relative risk (ERR) for solid cancer. Results: The ERR per Sv of all solid cancer is estimated to be -0.11 (95% CI, -0.67, 0.69 to 95%). The corresponding figures for cancers of liver, nasopharynx, lungs and stomach are -0.99 (-1.60, 0.10), 0.10 (-1.21, 3.28), -0.68 (-1.58, 1.66) and -0.27 (-1.37, 2.69) respectively. Conclusion: The association between ERR of solid cancer and dose can not be found

Natural radiation dose of small mammalians in beech forest of Rokkasho, Japan

International Nuclear Information System (INIS)

Ohtsuka, Yoshihito; Iyogi, Takashi; Takaku, Yuichi; Hisamatsu, Shun'ichi

2008-01-01

Full text: Protection of the environment itself from radiation hazards is recognized as important as that of humans. Actual data on the background natural radiation dose, which is necessary to evaluate the effect of radiation, are very few, especially in the terrestrial environment. Forests around the Japan's first large scale nuclear fuel reprocessing plant in Rokkasho were selected as the research field for evaluating the background natural radiation to the environment. Data observed will be used in future for the comparison with the radiation dose from radionuclides released from the plant. Small mammalians, mouse (Apodeums argentus) and mole (Urotrichus talpoides), were selected as representative animals of the forests in this study, and it was planned to measure their radiation doses from natural sources; environmental γ-rays, Rn and internal radionuclides. The forests around the plant were classified into three types: beech, oak and coniferous. We have been measuring the natural radiation to the mammalians in each of those forests one by one and report the data for the beech forest here. The mammalians caught in traps in the beech forest during June-October, 2006 were analyzed for their natural radionuclides burdens ( 210 Pb, 210 Po, 40 K, 87 Rb, 226 Ra, 238 U and 232 Th) in 11 organs and carcass. Radiation dose rates from environmental γ-rays and atmospheric concentration of Rn in the forest were also measured during August-December, 2006. Mean internal dose rates of mouse and mole caught in June, 2006 were estimated to be 0.036 μGy h -1 and 0.28 μGy h -1 , respectively, from mean concentrations of the nuclides in a total body and internal dose conversion coefficients by FASSET. The difference of the dose between the two mammalian species was attributed to higher contribution of 210 Po in mole, in which dose reached 0.25 μGy h -1 in contrast to that in mouse of 0.016 μGy h -1 . The concentration of 210 Po in kidney of mole (0.37 Bq g -1 wet) was

Radioactivity in the groundwater of a high background radiation area.

Science.gov (United States)

Shabana, E I; Kinsara, A A

2014-11-01

Natural radioactivity was measured in groundwater samples collected from 37 wells scattered in an inhabited area of high natural background radiation, in a purpose of radiation protection. The study area is adjacent to Aja heights of granitic composition in Hail province, Saudi Arabia. Initial screening for gross α and gross β activities showed levels exceeded the national regulation limits set out for gross α and gross β activities in drinking water. The gross α activity ranged from 0.17 to 5.41 Bq L(-)(1) with an average value of 2.15 Bq L(-)(1), whereas gross β activity ranged from 0.48 to 5.16 Bq L(-)(1), with an average value of 2.60 Bq L(-)(1). The detail analyses indicated that the groundwater of this province is contaminated with uranium and radium ((226)Ra and (228)Ra). The average activity concentrations of (238)U, (234)U, (226)Ra and (228)Ra were 0.40, 0.77, 0.29 and 0.46 Bq L(-)(1), respectively. The higher uranium content was found in the samples of granitic aquifers, whereas the higher radium content was found in the samples of sandstone aquifers. Based on the obtained results, mechanism of leaching of the predominant radionuclides has been discussed in detail. Copyright © 2014 Elsevier Ltd. All rights reserved.

SU-F-T-166: On the Nature of the Background Visible Light Observed in Fiber Optic Dosimetry of Proton Beams

Energy Technology Data Exchange (ETDEWEB)

Darafsheh, A; Kassaee, A; Finlay, J [University of Pennsylvania, Philadelphia, PA (United States); Taleei, R [UT Southwestern Medical Center, Dallas, TX (United States)

2016-06-15

Purpose: The nature of the background visible light observed during fiber optic dosimetry of proton beams, whether it is due to Cherenkov radiation or not, has been debated in the literature recently. In this work, experimentally and by means of Monte Carlo simulations, we shed light on this problem and investigated the nature of the background visible light observed in fiber optics irradiated with proton beams. Methods: A bare silica fiber optics was embedded in tissue-mimicking phantoms and irradiated with clinical proton beams with energies of 100–225 MeV at Roberts Proton Therapy Center. Luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze in detail the emission spectrum of the fiber tip across the visible range of 400–700 nm. Monte Carlo simulation was performed by using FLUKA Monte Carlo code to simulate Cherenkov light and ionizing radiation dose deposition in the fiber. Results: The experimental spectra of the irradiated silica fiber shows two distinct peaks at 450 and 650 nm, whose spectral shape is different from that of Cherenkov radiation. We believe that the nature of these peaks are connected to the point defects of silica including oxygen-deficiency center (ODC) and non-bridging oxygen hole center (NBOHC). Monte Carlo simulations confirmed the experimental observations that Cherenkov radiation cannot be solely responsible for such a signal. Conclusion: We showed that Cherenkov radiation is not the dominant visible signal observed in bare fiber optics irradiated with proton beams. We observed two distinct peaks at 450 and 650 nm whose nature is connected with the point defects of silica fiber including oxygen-deficiency center and non-bridging oxygen hole center.

THE EFFECTS OF THE IONIZING RADIATION BACKGROUND ON GALAXY EVOLUTION

International Nuclear Information System (INIS)

Hambrick, D. Clay; Ostriker, Jeremiah P.; Naab, Thorsten; Johansson, Peter H.

2009-01-01

We find that the amount and nature of the assumed ionizing background can strongly affect galaxy formation and evolution. Galaxy evolution simulations typically incorporate an ultraviolet background which falls off rapidly above z = 3; e.g., that of Haardt and Madau. However, this decline may be too steep to fit the Wilkinson Microwave Anistropy Probe constraints on electron scattering optical depth or observations of intermediate redshift (z ∼ 2-4) Lyα forest transmission. As an alternative, we present simulations of the cosmological formation of individual galaxies with UV backgrounds that decline more slowly at high redshift: both a simple intensity rescaling and the background recently derived by Faucher-Giguere, which softens the spectrum at higher redshifts. We also test an approximation of the X-ray background with a similar z dependence. We find for the test galaxies that an increase in either the intensity or hardness of ionizing radiation generically pushes star formation toward lower redshifts: although overall star formation in the simulation boxes is reduced by 10%-25%, the galaxies show a factor of ∼2 increase in the fraction of stars within a 30 kpc radius that are formed after z = 1. Other effects include late gas inflows enhanced up to 30 times, stellar half-mass radii decreased by up to 30%, central velocity dispersions increased up to 40%, and a strong reduction in substructure. The magnitude of the effects depends on the environmental/accretion properties of the particular galaxy.

Radiation education by means of the measurement of natural environmental radiation in Tono region, Gifu prefecture

International Nuclear Information System (INIS)

Maruyama, Haruo; Yoshida, Yasuo; Uda, Tatsuhiko; Obayashi, Haruo

1999-01-01

The Tono region is placed in the south-east of Gifu prefecture. In this region, there is a plan of construction of the Research and Education Park. As the center facility of the park, the National Institute for Fusion Science (NIFS) has started their research activities. The Plasma Research Committee of Toki-city has been organized by the board of education of Toki-city for about 20 years. The committee is mainly composed of science teachers of elementary school, junior high school and high school in the area. The committee has measured continuously the natural environmental background radiations in cooperation with NIFS. Its activities started before constructing the NIFS laboratory buildings. Now, the new measuring points in Tajimi-city and Mizunami-city are added to the points in Toki-city area, therefore, some teachers join as the new members of the committee. In this conference, we present. (1) Plasma Research Committee of Toki-city; its history, organization and activities. (2) Obtained data of the natural environmental radiation in Toki-city. (3) Example lecture taken in natural radiation, its results and the farther issues. (author)

On the omnipresent background gamma radiation of the continuous spectrum

Energy Technology Data Exchange (ETDEWEB)

Banjanac, R.; Maletić, D.; Joković, D., E-mail: yokovic@ipb.ac.rs; Veselinović, N.; Dragić, A.; Udovičić, V.; Aničin, I.

2014-05-01

The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere, is studied by means of absorption measurements, both in a ground level and in an underground laboratory. The low-energy continuous portion of this background spectrum that peaks at around 100 keV, which is its most intense component, is found to be of very similar shape at the two locations. It is established that it is mostly due to the radiations of the real continuous spectrum, which is quite similar to the instrumental one. The intensity of this radiation is in our cases estimated to about 8000 photons/(m{sup 2}s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m{sup 2}s·2π·srad) in the underground laboratory, at the depth of 25 m.w.e. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is predominantly of terrestrial origin, due to environmental gamma radiations scattered off the materials that surround the detector (the “skyshine radiation”), and to a far less extent to cosmic rays of degraded energy. - Highlights: • We studied the low-energy part of continuous background spectra of germanium detectors. • The study was performed at the ground level and at the shallow underground sites. • The instrumental spectrum is due to radiations of the similar continuous spectrum. • The low-energy radiation is of both terrestrial and cosmic-ray origin. • In our study, we find that this radiation is of predominantly terrestrial origin.

Natural radionuclide and radiological assessment of building materials in high background radiation areas of Ramsar, Iran.

Science.gov (United States)

Bavarnegin, Elham; Moghaddam, Masoud Vahabi; Fathabadi, Nasrin

2013-04-01

Building materials, collected from different sites in Ramsar, a northern coastal city in Iran, were analyzed for their natural radionuclide contents. The measurements were carried out using a high resolution high purity Germanium (HPGe) gamma-ray spectrometer system. The activity concentration of (226)Ra, (232)Th, and (40)K content varied from below the minimum detection limit up to 86,400 Bqkg(-1), 187 Bqkg(-1), and 1350 Bqkg(-1), respectively. The radiological hazards incurred from the use of these building materials were estimated through various radiation hazard indices. The result of this survey shows that values obtained for some samples are more than the internationally accepted maximum limits and as such, the use of them as a building material pose significant radiation hazard to individuals.

Radiation measurement practice for understanding statistical fluctuation of radiation count using natural radiation sources

International Nuclear Information System (INIS)

Kawano, Takao

2014-01-01

It is known that radiation is detected at random and the radiation counts fluctuate statistically. In the present study, a radiation measurement experiment was performed to understand the randomness and statistical fluctuation of radiation counts. In the measurement, three natural radiation sources were used. The sources were fabricated from potassium chloride chemicals, chemical fertilizers and kelps. These materials contain naturally occurring potassium-40 that is a radionuclide. From high schools, junior high schools and elementary schools, nine teachers participated to the radiation measurement experiment. Each participant measured the 1-min integration counts of radiation five times using GM survey meters, and 45 sets of data were obtained for the respective natural radiation sources. It was found that the frequency of occurrence of radiation counts was distributed according to a Gaussian distribution curve, although the obtained 45 data sets of radiation counts superficially looked to be fluctuating meaninglessly. (author)

Some characteristics and effects of natural radiation

International Nuclear Information System (INIS)

Mc Laughlin, J.P.

2015-01-01

Since life first appeared on the Earth, it has, in all its subsequent evolved forms including human, been exposed to natural radiation in the environment both from terrestrial and extra-terrestrial sources. Being an environmental mutagen, ionising natural radiation may have played a role of some significance in the evolution of early life forms on Earth. It has been estimated by United Nations Scientific Committee on the Effects of Atomic Radiation that at the present time, exposure to natural radiation globally results in an annual average individual effective dose of about 2.4 mSv. This represents about 80 % of the total dose from all sources. The three most important components of natural radiation exposure are cosmic radiation, terrestrial radioactivity and indoor radon. Each of these components exhibits both geographical and temporal variabilities with indoor radon exposure being the most variable and also the largest contributor to dose for most people. In this account, an overview is given of the characteristics of the main components of the natural radiation environment and some of their effects on humans. In the case of cosmic radiation, these range from radiation doses to aircrew and astronauts to the controversial topic of its possible effect on climate change. In the case of terrestrial natural radiation, accounts are given of a number of human exposure scenarios. (author)

Organization and operation of the sixth international symposium on the natural radiation environment (NRE VI). Final report

International Nuclear Information System (INIS)

Hopke, P.K.

1995-01-01

An important source of human exposure to radiation is the natural world including cosmic rays, cosmogonic radionuclides, natural terrestrial radionuclides, and radon isotopes and its decay products. Considerable effort is being expended on a worldwide basis to characterize the exposure to the natural radiation environment and determine the important pathways for the exposure to result in dose to tissue that leads to injury and disease. The problem of background exposure to naturally occurring radioactivity has been the subject of research since the initial discovery of the radioactivity of uranium and thorium. However, with the advent of artificial sources of radiation with both benefits (medical x-rays and nuclear medicine), and harm (Chernobyl fallout), the nature and magnitude of the natural radiation environment and the effects on various populations are important in the development of overall public health strategies as ALARA principles are applied. To facilitate the exchange of information and the review of uncertainties and scientific research priorities, a series of 5 international meetings on Natural Radiation Environment, 1963, 1987, 1991. This conference (Montreal, 1995) covers the range of natural radiation environments that give rise to human exposure and dose. This document is a program summary

Natural radiation environment III

International Nuclear Information System (INIS)

Gesell, T.F.; Lowder, W.M.

1980-01-01

Separate abstracts were prepared for the 52 research papers presented at this symposium in April 1978. The major topics in this volume deal with penetrating radiation measurements, radiation surveys and population exposure, radioactivity in the indoor environment, and technologically enhanced natural radioactivity

The impact of cosmic-origin background radiation on human survival in the Czech Republic

Czech Academy of Sciences Publication Activity Database

Podolská, Kateřina; Rychtaříková, J.

2017-01-01

Roč. 59, č. 2 (2017), s. 132-149 ISSN 0011-8265 Institutional support: RVO:68378289 Keywords : mortality * incidence * solid cancer * lifetime attributable risk * age at exposure * solar activity * natural background radiation dose Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences https://www.czso.cz/documents/10180/46203818/clanek+3_Podolska-Rychtarikova.pdf/1454147e-8a44-40ca-b76c-d1fe6e7b822c?version=1.0

Annual radiation background in Isfahan city

International Nuclear Information System (INIS)

Tavakoli, Mohammad B.

2002-01-01

Measurement of environmental exposure is very important from different points of view. It is especially important for human health. It has been measured accurately in many countries. In Iran, it is also measured in some cities especially in high background areas such as Ramsar, but there is not any measurement in Isfahan. Measurement of background radiation in this study is performed using TLD method. The TLDs used are made from CaSO 4 :Dy, which is very sensitive. The locations under investigations in this research were 52 health centers distributed all around Isfahan city. Each TLD badge was put in a special plastic bag and left over the roofs of the selected health center for a month. The procedure was repeated for all 12 months of the year 1379(21 st March 2000 to 20 th March 2001). The results were used to obtain mean and SD in each month and at different places. The maximum and the minimum of obtained results for dose equivalent in different months and locations were 15.9x10 -2 and 6.5x10 -2 mSv. Obtained maximum and minimum of the means between all the locations were 10.5x10 -2 and 8.6x10 2 mSv for the whole year. Monthly mean and SD for Isfahan city for the whole year were 9.7x10 -2 and 1.5x10 -2 respectively therefore mean annual dose equivalent in Isfahan city is 1.16mSv. The results do not show any high background radiation area

Natural radiation focused by power lines: new evidence

Energy Technology Data Exchange (ETDEWEB)

Hopwood, Anthony

1992-11-01

Scientists searching for a mechanism to explain increases in the incidence of cancer among those living in close proximity to power lines could have been looking in the wrong place. New evidence suggests that instead of trying to find an as yet unproven cellular reaction to the presence of the power-line's magnetic fields, researchers should investigate power lines as concentrators of potentially damaging natural sky radiation. If accepted, a clear link between a known biological cell damage mechanism and power lines will have been established, triggering a reassessment of the independent studies recording statistical increases in cancer incidence around power lines. The evidence stems from recordings showing concentrations of background solar radiation under power lines - a direction of enquiry prompted by a chance observation made during a British Astronomical Association experiment. (Author).

Measurement of Background Gamma Radiation Levels at Two ...

African Journals Online (AJOL)

MICHAEL

ABSTRACT: An in-situ measurement of the background radiation level was carried out at the vicinity of three ... Soil contains small quantities of radioactive elements along with their progeny. .... assessment for soil samples from Kestanbol.

Radioecology teaching: evaluation of the background radiation levels from areas with high concentrations of radionuclides in soil

International Nuclear Information System (INIS)

Anjos, R M; Okuno, E; Gomes, P R S; Veiga, R; Estellita, L; Mangia, L; Uzeda, D; Soares, T; Facure, A; Brage, J A P; Mosquera, B; Carvalho, C; Santos, A M A

2004-01-01

The study of environmental radioactivity is a topic which is not usually included in physics courses in Brazilian and Latin American universities. Consequently, high-school teachers are not able to show experimentally or discuss with their students the effects of exposure to terrestrial radiation. This paper presents a laboratory experiment in a teaching programme on the physics of ionizing radiation. It is based on the evaluation of the background radiation levels from areas with high concentrations of natural or artificial radionuclides in the soil. A brief analysis of the theory behind the technique and a description of some measurements, including their interpretations, are presented

An intercomparison of detectors for measurement of background radiation

International Nuclear Information System (INIS)

Nielsen, S.P.; Boetter-Jensen, L.

1981-04-01

Measurements of the background radiation were made in 1978 at 14 locations with a high-pressure ionization chamber, thermoluminiscence dosimeters (TLD's), two NaI(Tl) detectors, and a Ge(Li) spectrometer system. Simultaneous measurements with the ionization chamber and the spectrometer system provide reliable estimates of the total background exposure rate, of the individual contributors to the terrestrial exposure rate, and of the exposure rate from the secondary cosmic radiation. The TLD results agree with those of the ionization chamber. The NaI(Tl) detector results show that accurate estimates of the terrestrial exposure rate can be obtained if empirical corrections are applied. (author)

Report of the radiation group on radiation backgrounds and damage in the ISABELLE intersection regions

International Nuclear Information System (INIS)

Ludlam, T.; Kistiakowsky, V.; Toohig, T.E.

1976-01-01

The Radiation Group was charged to examine radiation aspects of the current ISABELLE design and the projected experimental arrangements. Some samples of questions to be addressed were: (1) how does the overall shielding design impact the experimental design, (2) what backgrounds might be expected from the proposed beam scraping, shaving, etc. schemes, (3) what are the radiation damage considerations for experimental electronics near the beam, and (4) what backgrounds might be expected in an experiment from operation of another experiment in the same or the adjacent intersection region. A review is given based on the ISABELLE Proposal, The Proceedings of the 1975 ISABELLE Summer Study, and the estimate of ISABELLE shielding requirements by Stevens and Thorndike

Assessment of background gamma radiation levels around Tummalapalle uranium mining and processing facility, Andhra Pradesh

International Nuclear Information System (INIS)

Rana, B.K.; Dhumale, M.R.; Molla, Samim; Rao, K.B.; Jha, S.K.; Tripathi, R.M.; Sahu, S.K.

2018-01-01

Natural environmental radioactivity and the associated external exposure due to gamma radiation depend primarily on the geological and geographical conditions, and appear at different levels in the soil of each region in the world. The dose received by the population in a region comprises of (i) external gamma radiation dose due to cosmic rays and primordial radionuclides; (ii) inhalation dose due to radon, thoron and their progeny, and (iii) ingestion dose due to the intake of radionuclides through the consumption of food, milk, water, etc. In this study, background gamma radiation level around Tummalapalle uranium mining and processing site was estimated by using radiation survey meter and deploying environmental TLDs. The generated data can be served as baseline for this area for future comparison for prolonged operation of the plant, for the upcoming adjacent projects and during decommissioning phase of the mine, mill and tailings pond

Cytogenetic study of stable chromosome aberrations in residents of a high background radiation area in China

International Nuclear Information System (INIS)

Zhang Wei; Wang Chunyan; Chen Deqing; Wei Lvxin

2004-01-01

Objective: To investigate the effect of high background radiation on the induction of stable chromosome aberrations. Methods: By fluorescence in situ hybridization (FISH) technique chromosome Nos. 1, 2 and 4 were painted using specific biotin-labeled whole chromosome painting probes. Peripheral blood specimens were taken from 31 individuals living in the high background radiation area (HRBA) and 29 individuals in the control area. Results: No significant difference was found in the frequencies of translocations between HBRA and the control (P>0.05, Mann-Whitney U test) for both children and elderly individuals. On the other hand, correlation between age and translocation frequencies was significant at the 1% level (r s =0.388 with 56DF). Conclusion: There are no differences in the frequencies of translocations between HBRA and the control area. The present result indicates that the contribution of an elevated level of natural radiation in HBRA in China to the induction rate of stable type aberrations (translocations) dose not have a significant effect compared with the contributions from all other sources such as chemical mutagens and(or) metabolic factors. (authors)

Anisotropy of the cosmic background radiation

International Nuclear Information System (INIS)

Silk, J.

1988-01-01

The characteristics of the cosmic microwave background radiation (CBR) are reviewed, focusing on intrinsic anisotropies caused by primordial matter fluctuations. The basic elements of the CBR are outlined and the contributions to anisotropy at different angular scales are discussed. Possible fluctuation spectra that can generate the observed large-scale structure of the universe through gravitational instability and nonlinear evolution are examined and compared with observational searches for cosmic microwave anisotropies. 21 refs

Natural sources of ionizing radiations

International Nuclear Information System (INIS)

Marej, A.N.

1984-01-01

Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed

Radiation processing of natural polymer

International Nuclear Information System (INIS)

Khairul Zaman; Kamaruddin Hashim; Zulkafli Ghazali; Mohd Hilmi Mahmood; Jamaliah Sharif

2006-01-01

Radiation processing of natural polymer has been the subject of interest of countries in this region in the past 5 ∼ 7 years. Although some of the output of the research have been commercialized in particular for the applications in the agriculture and healthcare sectors, the potential applications of radiation processing of natural polymers in the medical sector are yet to be fully understood and developed. (author)

Gravitational perturbation of the cosmic background radiation by density concentrations. [Swiss cheese model universe

Energy Technology Data Exchange (ETDEWEB)

Dyer, C C [Cambridge Univ. (UK). Inst. of Theoretical Astronomy

1976-05-01

The gravitational effect of density concentrations in the Universe on the temperature distribution of the cosmic blackbody background radiation is considered, using the Swiss cheese model universe, and supposing each hole to contain an expanding, homogeneous dust sphere at its centre. The temperature profile across such a hole differs in an essential way from that obtained earlier by Rees et al (Nature; 217:511 (1968)). The evolution of this effect with the expansion of the Universe is considered for 'relatively increasing' density contrasts emerging from the same initial singular state as the rest of the Universe. This effect becomes comparable to the bremsstrahlung and Compton effects on the isotropy of the background radiation for masses of about 10/sup 19/ times the mass of the sun, and exceeds these other effects as about Msup(2/3) for larger masses. If large-scale condensations of the Universe can be found for z approximately 1 to 5, delineated, maybe, by the clustering of quasars, etc., then this effect may be observable.

Epidemiological studies in high-background radiation areas its potential contribution to evaluating risk of low-level radiation

International Nuclear Information System (INIS)

Akiba, Suminori; Nair, R.K.; Nakamura, Seiichi; Mizuno, Shoich

2008-01-01

The health effect of low-level ionizing radiation is yet unclear. As pointed out by Upton in his review (Upton, 1989), low-level ionizing radiation seems to have different biological effects from what high-level radiation has. Its evaluation requires epidemiological studies of scale-large cohorts (ICRP 99, 2005) such of atomic bomb survivors and nuclear workers. Epidemiological studies in high-background radiation (HBR) areas are also expected to make a significant contribution toward this end. Among several HBR areas in the world, Yangjiang, Guangdong Province in China, Karunagappally in Kerala State of India, Manawalakurichi and Koodankulam in Tamil Nadu of India, and Ramsar in Iran are important areas where epidemiological studies are possible, because of their relatively high background radiation levels and large population sizes. (author)

Naturally occuring radiation in the Nordic countries - recommendations

International Nuclear Information System (INIS)

1986-01-01

In the publication ''Report on the Applicability of International Radiation Protection Recommendations in the Nordic Countries'', published in 1976, the radiation protection authorities in Denmark, Finland, Iceland, Norway and Sweden expessed their agreement on the main principles of radiation protection. The general aspects of radiation protection were covered in the recommendations with the exception of exposure of the public from natural sources of radiation. In 1983 a working group published the report ''Naturally Occurring radiation in the Nordic Countries, - Levels'' in the Radiation Protection Information-Series from the Nordic countries. In that report the present knowledge of the population exposure from natural sources of external gamma-radiation and from radon and thoron daughters in air was reviewed as a basis for the development of the radiation protection recommendations for natural radiation. During preparation of these recommendations due account has also been taken of ICRP publication no. 39: ''Principles for Limiting Exposure of the Public to Natural Sources of Radiation'', which was published in 1984 and in which ICRP for the first time has issued more specific recommendations for natural sources. The recommendations may serve as a basis for more formal rules and regulations within each country, if this is seemed necessary. However, no attempt has been made to formulate identical rules for all the five countries since the exposure levels from natural sources, methods of application and the legal frameworks differ between the countries. (EG)

Cosmic thermalization and the microwave background radiation

International Nuclear Information System (INIS)

Rana, N.C.

1981-01-01

A different origin of the microwave background radiation (MBR) is suggested in view of some of the difficulties associated with the standard interpretation. Extensive stellar-type nucleosynthesis could provide radiation with the requisite energy density of the MBR and its spectral features are guaranteed by adequate thermalization of the above radiation by an ambient intergalactic dust medium. This thermalization must have occurred in quite recent epochs, say around epochs of redshift z = 7. The model emerges with consistent limits on the cosmic abundance of helium, the general luminosity evolution of the extragalactic objects, the baryonic matter density in the Universe (or, equivalently the deceleration parameter) and the degree of isotropy of MBR. The model makes definite predictions on issues like the properties of the intergalactic thermalizers, the degree of isotropy of MBR at submillimetre wavelengths and cluster emission in the far infrared. (author)

Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation

International Nuclear Information System (INIS)

Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

1987-01-01

Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y

Radiation background with the CMS RPCs at the LHC

CERN Document Server

Costantini, Silvia; Cai, J.; Li, Q.; Liu, S.; Qian, S.; Wang, D.; Xu, Z.; Zhang, F.; Choi, Y.; Goh, J.; Kim, D.; Choi, S.; Hong, B.; Kang, J.W.; Kang, M.; Kwon, J.H.; Lee, K.S.; Lee, S.K.; Park, S.K.; Pant, L.M.; Mohanty, A.K.; Chudasama, R.; Singh, J.B.; Bhatnagar, V.; Mehta, A.; Kumar, R.; Cauwenbergh, S.; Cimmino, A.; Crucy, S.; Fagot, A.; Garcia, G.; Ocampo, A.; Poyraz, D.; Salva, S.; Thyssen, F.; Tytgat, M.; Zaganidis, N.; Doninck, W.V.; Cabrera, A.; Chaparro, L.; Gomez, J.P.; Gomez, B.; Sanabria, J.C.; Avila, C.; Ahmad, A.; Muhammad, S.; Shoaib, M.; Hoorani, H.; Awan, I.; Ali, I.; Ahmed, W.; Asghar, M.I.; Shahzad, H.; Sayed, A.; Ibrahim, A.; Aly, S.; Assran, Y.; Radi, A.; Elkafrawy, T.; Sharma, A.; Colafranceschi, S.; Abbrescia, M.; Calabria, C.; Colaleo, A.; Iaselli, G.; Loddo, F.; Maggi, M.; Nuzzo, S.; Pugliese, G.; Radogna, R.; Venditti, R.; Verwilligen, P.; Benussi, L.; Bianco, S.; Piccolo, D.; Paolucci, P.; Buontempo, S.; Cavallo, N.; Merola, M.; Fabozzi, F.; Iorio, O.M.; Braghieri, A.; Montagna, P.; Riccardi, C.; Salvini, P.; Vitulo, P.; Vai, I.; Magnani, A.; Dimitrov, A.; Litov, L.; Pavlov, B.; Petkov, P.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Rodozov, M.; Sultanov, G.; Vutova, M.; Stoykova, S.; Hadjiiska, R.; Ibargüen, H.S.; Morales, M.I.P.; Bernardino, S.C.; Bagaturia, I.; Tsamalaidze, Z.; Crotty, I.; Kim, M.S.

2015-05-28

The Resistive Plate Chambers (RPCs) are employed in the CMS experiment at the LHC as dedicated trigger system both in the barrel and in the endcap. This note presents results of the radiation background measurements performed with the 2011 and 2012 proton-proton collision data collected by CMS. Emphasis is given to the measurements of the background distribution inside the RPCs. The expected background rates during the future running of the LHC are estimated both from extrapolated measurements and from simulation.

Noncommutative black-body radiation: Implications on cosmic microwave background

International Nuclear Information System (INIS)

Fatollahi, A.H.; Hajirahimi, M.

2006-01-01

Including loop corrections, black-body radiation in noncommutative space is anisotropic. A direct implication of possible space non-commutativity on the cosmic microwave background map is argued. (authors)

Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

Science.gov (United States)

Madau, Piero; Fragos, Tassos

2017-05-01

We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior to and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z ≲ 4. Together with an updated empirical determination of the cosmic history of star formation, recent modeling of the stellar mass-metallicity relation, and a scheme for absorption by the IGM that accounts for the presence of ionized H II bubbles during the epoch of reionization, our detailed calculations provide refined predictions of the X-ray volume emissivity and filtered radiation background from “normal” galaxies at z ≳ 6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. Because of the energy dependence of photoabsorption, soft X-ray photons are produced by local sources, while more energetic radiation arrives unattenuated from larger cosmological volumes. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct He I photoionizations are the main source of IGM heating, and the temperature of the largely neutral medium in between H II cavities increases above the temperature of the cosmic microwave background (CMB) only at z ≲ 10, when the volume filling factor of H II bubbles is already ≳0.1. Therefore, in this scenario, it is only at relatively late epochs that neutral intergalactic hydrogen

Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

Energy Technology Data Exchange (ETDEWEB)

Madau, Piero [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Fragos, Tassos [Geneva Observatory, University of Geneva, Chemin des Maillettes 51, 1290 Sauverny (Switzerland)

2017-05-01

We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior to and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z ≲ 4. Together with an updated empirical determination of the cosmic history of star formation, recent modeling of the stellar mass–metallicity relation, and a scheme for absorption by the IGM that accounts for the presence of ionized H ii bubbles during the epoch of reionization, our detailed calculations provide refined predictions of the X-ray volume emissivity and filtered radiation background from “normal” galaxies at z ≳ 6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. Because of the energy dependence of photoabsorption, soft X-ray photons are produced by local sources, while more energetic radiation arrives unattenuated from larger cosmological volumes. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct He i photoionizations are the main source of IGM heating, and the temperature of the largely neutral medium in between H ii cavities increases above the temperature of the cosmic microwave background (CMB) only at z ≲ 10, when the volume filling factor of H ii bubbles is already ≳0.1. Therefore, in this scenario, it is only at relatively late epochs that neutral intergalactic

Validity of the linear no-threshold (LNT) hypothesis in setting radiation protection regulations for the inhabitants in high level natural radiation areas of Ramsar, Iran

International Nuclear Information System (INIS)

Mortazavi, S.M.J.; Atefi, M.; Razi, Z.; Mortazavi Gh

2010-01-01

Some areas in Ramsar, a city in northern Iran, have long been known as inhabited areas with the highest levels of natural radiation. Despite the fact that the health effects of high doses of ionizing radiation are well documented, biological effects of above the background levels of natural radiation are still controversial and the validity of the LNT hypothesis in this area, has been criticized by many investigators around the world. The study of the health effects of high levels of natural radiation in areas such as Ramsar, help scientists to investigate the biological effects without the need for extrapolating the observations either from high doses of radiation to low dose region or from laboratory animals to humans. Considering the importance of these studies, National Radiation Protection Department (NRPD) of the Iranian Nuclear Regulatory Authority has started an integrative research project on the health effects of long-term exposure to high levels of natural radiation. This paper reviews findings of the studies conducted on the plants and humans living or laboratory animals kept in high level natural radiation areas of Ramsar. In human studies, different end points such as DNA damage, chromosome aberrations, blood cells and immunological alterations are discussed. This review comes to the conclusion that no reproducible detrimental health effect has been reported so far. In this paper the validity of LNT hypothesis in the assessment of the health effects of high levels of natural radiation is discussed. (author)

Childhood cancers in the UK and their relation to background radiation

International Nuclear Information System (INIS)

Kneale, G.W.; Stewart, A.M.

1987-01-01

This chapter shows the results of including two independent data sets in a study of several factors with cancer associations including background radiation. One data set came from the Oxford Survey of Childhood Cancers (OSCC); the other from the National Radiological Protection Board (NRPB) and findings are compatible with background radiation being the single most important cause of juvenile neoplasms. It also emerged that these neoplasms have a strongly clustered distribution. No obvious cause of clusters was found, but they had associations with prenatal and postnatal illnesses as well as background radiation. Therefore, since there is mounting sensitivity to infections during the latent phase of leukaemia, cancer clusters might be the result of competing causes of death having an epidemic distribution. The findings as a whole are compatible with all man-made additions to background (including leakages of radioactivity from a reprocessing plant) adding to risk of an early cancer death. Proof that certain leukaemia clusters in the vicinity of two reprocessing plants were caused in this way must await collection of data. (author)

Preliminary study on the measurement of background radiation dose at Antarctica during 32nd expedition

International Nuclear Information System (INIS)

Bakshi, A.K.; Pal, Rupali; Chougaonkar, M.P.; Dhar, Ajay

2013-01-01

A significant proportion (10%) of the natural background radiation is of cosmic origin. Cosmic ray consists of gamma, protons, electrons, pions, muons, neutrons and low Z nuclei. Due to the geomagnetic effect, cosmic radiation levels at poles are higher. As a consequence, personnel working in Antarctica (or Arctic) are subjected to high level of cosmic radiation. The present study gives the details of the estimation of background radiation (neutrons, gamma and electrons) dose rate around the Indian station at Antarctica named 'Bharati' measured during 32 nd Indian scientific expedition to Antarctica (32 nd INSEA). The measurement was carried out by passive dosimeters such as TLDs and CR-39 and active dosimeter such as RadEye G portable gamma survey meter. Gamma and electron components were measured using TLDs and survey meter, whereas CR-39 SSNTDs and neutron sensitive TLDs were used for neutron measurements. These detectors were deployed at few selected locations around Bharati station for about 2½ months during summer expedition. The neutron detectors used in the study were pre-calibrated with 241 Am-Be fast/thermal neutron source. The fast neutron dose rate measured based on CR-39 detector was found to about 140-420 nSv/h. The gamma dose rate evaluated by TLDs/survey meter are in the range of 290-400 nSv/h. (author)

Assessment of natural radioactivity and associated radiation indices in soil samples from the high background radiation area, Kanyakumari district, Tamil Nadu, India

Directory of Open Access Journals (Sweden)

A K Ajithra

2017-01-01

Full Text Available Assessment of natural radioactivity is very important from different points of view, especially for assessment of radiation exposure to human. In the present study, natural radionuclide concentrations of 238U, 232Th, and 40K were measured by gamma spectrometry using HPGe detector in soil samples collected from Southwest coast of Kanyakumari district, Tamil Nadu. The radiological index parameters due to natural radionuclides such as radium equivalent activity, absorbed dose rate, annual effective dose rate, external hazard index, internal hazard index, and gamma index were calculated for the soil samples. All the calculated radiological index values are higher than world average values and the recommended safety limits. Multivariate statistical techniques such as Pearson correlation, principal component analysis, and cluster analysis were applied to know the relation between radionuclides and radiological parameters and to study the spatial distribution of radionuclides.

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

Directory of Open Access Journals (Sweden)

Seyed Mohammad Javad Mortazavi

2017-04-01

Full Text Available Background: Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. Objective: To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium (S. typhimurium, Staphylococcus aureus, and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Methods: Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. Results: The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6 mm; it was 14.7 (SD 0.6 mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Conclusion: Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Chromosome translocation in residents of the high background radiation areas in southern China

International Nuclear Information System (INIS)

Hayata, Isamu; Minamihisamatsu, Masako; Wang Chunyan; Wei Zhang; Chen Deqing; Morishima, Hiroshige; Yuan Yongling; Wei Luxin; Sugahara, Tsutomu

2000-01-01

We performed a cytogenetical study using chromosome painting analysis on 9 residents of the naturally high background radiation areas (HBRA) and 8 residents of the control areas in southern China. The estimated dose (air kerma) of each resident measured by an electric pocket dosimeter showed 2.20-4.23 mGy/year in HBRA and 0.56-0.70 mGy/year in the control areas. A total of 14,096 cells (1,566 cells/case) in the former and 17,522 cells (2,190 cells/case) in the latter were analyzed. Children, both in HBRA and in the control areas, had translocations at low frequencies. The frequency of translocations among elder individuals varied widely and it was not possible to detect dose effect although it was detected in dicentrics. The effect of radiation on the induction of chromosome aberrations, which have a statistically potential risk of causing malignant or congenital diseases, seems to be less significant than those of metabolic factors and/or mutagenic agents (excluding radiation) even in HBRA in China. (author)

Effect of increased natural radiation background on glycogen content of peripheral blood leukocytes of microtus oeconomus Pall

International Nuclear Information System (INIS)

Materij, L.D.; Maslova, K.I.

1984-01-01

In experiments on Microtus oeconomus Pall, living in natural conditions with normal (0.72-1.08 pA/kg) and increased (3.6-1440 pA/kg) levels of external gamma-radiation and affected by numerous incorporated radionuclides, the differences were detected, by the cytochemical method, both in the total glycogen content of eucocytes and in the type of grouping of cells depending on the cegre of their saturation with polysaccharide

Natural and anthropogenic radiation exposure of humans in Germany

International Nuclear Information System (INIS)

Koelzer, Winfried

2016-12-01

The contribution on natural and anthropogenic radiation exposure in Germany covers the following issues: (1) natural radiation exposure: external radiation exposure - cosmic and terrestric radiation, internal radiation exposure - primordial and cosmogenic radionuclides; radiation exposure due to sola neutrinos and geo-neutrinos. (2) Anthropogenic radiation exposure: radiation exposure in medicine, radioactivity in industrial products, radiation exposure during flights, radiation exposure due to nuclear facilities, radiation exposure due to fossil energy carriers in power generation, radiation exposure due to nuclear explosions, radiation exposure due to nuclear accidents. (3) Occupational radiation exposure in Germany: radiation monitoring with personal dosimeters in medicine and industry, dose surveillance of the aviation personal, working places with increases radiation exposure by natural radiation sources.

Research on Paramecium aurelia sensitivity factors to natural ionizing radiations

International Nuclear Information System (INIS)

Croute, F.; Soleilhavoup, J.P.; Gros, N.; Planel, H.

1976-01-01

Previous results have demonstrated that the proliferative activity of Paramecium aurelia is linked to the level of natural ionizing radiations since this activity is decreased under radiation protection (lead cell) and increased under chronic exposure to very low dose of 60 Co gamma rays. The results of this investigation indicate that cell sensitivity in spite of variations in natural irradiation levels can be isolated; they are called 'radioresistant' in opposition to 'radiosensitive' cells which present the other response. These characters are being retained for 9 months after the strains have been isolated. On the other hand, in the case of radiosensitive strains, it has been demonstrated that autogamy affected the cell response to background irradiation; no response at all occured on the very day when autogamy took place, but it reached a maximum level 8 days approximately after autogamy. Moreover, it has been proved that the catalase activity of Paramecium aurelia is higher than those already studied in other cell varieties. This great amount of catalase, which seems to vary with the age of cultures after autogamy, could act on Paramecium sensitivity to very low radiation doses [fr

Natural radiation exposure modified by human activities

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1995-01-01

We are now living in the radiation environment modified by our technology. It is usually called 'Technologically Enhanced Natural Radiation' and have been discussed in the UNSCEAR Reports as an important source of exposure. The terrestrial radionuclide concentrations as well as the intensity of cosmic rays are considered to have been constant after our ancestors came down from trees and started walking on their two feet. However, we have been changing our environment to be more comfortable for our life and consequently ambient radiation levels are nomore what used to be. In this paper exposures due to natural radiation modified by our following activities are discussed: housing, balneology, cave excursion, mountain climbing, skiing, swimming, smoking and usage of mineral water, well water, coal, natural gas, phosphate rocks and minerals. In the ICRP Publication No. 39, it is clearly mentioned that even natural radiation should be controlled as far as it is controllable. We have to pay more attention to our activities not to enhance the exposure due to unnecessary, avoidable radiation. (author)

Natural radioactivity and associated radiation hazardous of main building materials in Yan'an, China

International Nuclear Information System (INIS)

Li Nan; Lu Xinwei; Yang Guang; Zhao Caifeng

2012-01-01

Background: With the rapidly economic development and urbanization in Yan'an city, more building materials were consumed in building construction. While the natural radioactivity level of building materials from Yan'an is limited in the literatures. Purpose: The main objective of this study is to determine the natural radioactivity level and to analyze the associated radiation hazards of building materials in Yan'an. Methods: The specific activities of natural radionuclides 226 Ra, 232 Th and 40 K in various building materials from Yan'an city were determined using low-background gamma-ray spectrometry, and their radiation hazards were evaluated according to the standard methods. Results: The results show that the specific activities of 226 Ra, 232 Th and 40 K in the building materials are 9.4-73.1, 11.5-86.9 and 258.9-1055.1 Bq/kg, respectively. The activities of 226 Ra and 232 Th, except for sand and gravel aggregate, in all other building materials are higher than the corresponding means of local soil, and the activities of 40 K in hollow brick, red-clay brick, sand and gravel aggregate exceed the means of 40 K in soil. However, the values of internal exposure index, external exposure index and gamma radiation index in all investigated building materials are less than 1. Conclusions: The radiation levels of all analyzed building materials are within the national safety standard, which indicates that all analyzed building materials can be used anywhere and they can't cause radiation hazard to the local residents. (authors)

The anisotropy of the cosmic background radiation from local dynamic density perturbations

International Nuclear Information System (INIS)

Dyer, C.C.; Ip, P.S.S.

1988-01-01

Contrary to the usual assumption, it is shown here that the anisotropy of the cosmic background radiation need not be dominated by perturbations at the last scattering surface. The results of computer simulations are shown in which local dynamic density perturbations, in the form of Swiss cheese holes with finite, uniform density central lumps, are the main source of anisotropy of the cosmic background radiation. (author)

Introduction to radiation backgrounds in a B factory

International Nuclear Information System (INIS)

Khan, S.

1992-08-01

Detector backgrounds in a B factory due to synchrotron radiation and beam-gas interactions are discussed and the computational tools to simulate these processes are outlined. As an example of their application, simulations and beam tests that preceded the installation of the ARGUS silicon vertex detector are described. (orig.)

Investigation of background radiation and associated anomalies in Rifle, Colorado

International Nuclear Information System (INIS)

Smuin, D.R.; Wilson, M.J.; Crutcher, J.W.

1988-02-01

In addition to examining anomalies and establishing the background gamma exposure rate range, the study presents a formula to convert thousand counts per minute (kcpm) from a gamma scintillator to microroentgen per hour (μRh) for the Rifle region. Also, a method is presented to identify contaminated areas containing excess 226 Ra, by using a GR-410 gamma spectrometer. This method is suggested to be applied to all property surveys in the Rifle area. The Wasatch Formation, which outcrops extensively in the Rifle area, was found to have a major influence on the background radiation. Varying potassium concentrations and naturally occurring uranium in this rock unit reveal varying gamma exposure rates. Examining RaTh ratios from laboratory analysis of soil samples or use of RaTh ratios from GR-410 gamma spectrometer readings on site allows discrimination between mill related contamination and naturally occuring radioactivity. Radioactive coal clinkers were found used as fill material throughout the Rifle region and have been determined to be a product of the mill and subject to remediation. Finally, windblown mill tailings contamination is addressed in some detail. Mill tailings redistributed from the Rifle uranium mill tailings piles by prevailing winds were detected extensively on vicinity properties in Rifle. Some radioactive components of the windblown tailings were found to have leached into the subsurface soil. The combination of Wasatch Formation, radioactive coal clinkers, and windblown tailings accounts for many of the anomalous gamma exposure rates observed by the radiological survey teams. 11 refs., 10 figs., 3 tabs

Evaluation of thyroid function in female subjects living in the high natural background radiation area of Karunagappally, Kerala

International Nuclear Information System (INIS)

Sreekumar, A.; Nair, Raghu Ram K.; Jayalakshmi, P.; Sebastian, P.; Akiba, S.

2010-01-01

Radiation exposure has been reported to cause non cancer thyroid abnormalities like diffuse goiter and thyroid nodules. The present study was undertaken to see if there are any morphological and functional changes taking place in the thyroid due to chronic low level radiation exposure. 257 female subjects living in the four high background radiation panchayats of Chavara, Neendakara, Alappad and Panmana were selected for the study after getting informed consent. 5 ml of blood was drawn from these subjects for assessing thyroid function. The subjects were all staying in the same area since their birth and had not moved out for more than one year at a stretch. The average age of the subjects was 40.5y with a range of 17-66y. The cumulative dose had a mean of 226.3 mGy and a range of 20.6-937.8 mGy. 95 subjects from the low background area of Oachira and Thevalakkara were selected as controls in the age group of 18-63y with a mean age of 47.1y. The mean cumulative dose of this group was 35.9 mGy with a minimum of 5.3 mGy and a maximum of 106.8 mGy. 5 ml blood was collected from these subjects for thyroid function studies. All the subjects underwent ultrasound examination of the thyroid using a 10 MHz frequency linear probe. The following parameters were studied to assess thyroid function: Free T4, TSH, Antithyroglobulin antibody (ATG), Parathyroid hormone. Ultrasound images showed the following common features: Normal - 171, Suggestive of Thyroiditis - 106, Multinodular Goitre - 63, Diffuse Goitre - 5, Solitary Nodule - 31. 73 subjects had elevated TSH and 190 subjects had raised ATG. A significant numbers of subjects had features of thyroiditis. A comparative evaluation with control subjects will be done to assess its significance with reference to cumulative dose

Assessment of Human Exposures to Natural Sources of Radiation in Kenya

International Nuclear Information System (INIS)

Mustapha, A.O.; Patel, J.P.

1999-01-01

Levels of exposures to different components of natural background radiation in Kenya were assessed from measured data and published conversion factors. Among them, the average annual per capital effective dose from terrestrial external radiation is 0.76 mSv and the annual per capital effective dose from external exposure to cosmic radiation at ground levels is 0.41 mSv. The total average annual effective dose is greater than the global average. Also among the measured data, concentrations of radon ( 222 Rn) vary from 5 to 1200 Bq m -3 in indoor air of dwellings, and from 1 to 410 KBq m -3 in drinking water. An unusual pathway to internal exposure was discovered among the female population who engage in consumption of some earth materials, some of which are rich in thorium

Transcriptome analysis reveals a stress response of Shewanella oneidensis deprived of background levels of ionizing radiation

Science.gov (United States)

Li, Xiaoping; Schilkey, Faye; Smith, Geoffrey B.

2018-01-01

Natural ionizing background radiation has exerted a constant pressure on organisms since the first forms of life appeared on Earth, so that cells have developed molecular mechanisms to avoid or repair damages caused directly by radiation or indirectly by radiation-induced reactive oxygen species (ROS). In the present study, we investigated the transcriptional effect of depriving Shewanella oneidensis cultures of background levels of radiation by growing the cells in a mine 655 m underground, thus reducing the dose rate from 72.1 to 0.9 nGy h-1 from control to treatment, respectively. RNASeq transcriptome analysis showed the differential expression of 4.6 and 7.6% of the S. oneidensis genome during early- and late-exponential phases of growth, respectively. The greatest change observed in the treatment was the downregulation of ribosomal proteins (21% of all annotated ribosomal protein genes during early- and 14% during late-exponential) and tRNA genes (14% of all annotated tRNA genes in early-exponential), indicating a marked decrease in protein translation. Other significant changes were the upregulation of membrane transporters, implying an increase in the traffic of substrates across the cell membrane, as well as the up and downregulation of genes related to respiration, which could be interpreted as a response to insufficient oxidants in the cells. In other reports, there is evidence in multiple species that some ROS not just lead to oxidative stress, but act as signaling molecules to control cellular metabolism at the transcriptional level. Consistent with these reports, several genes involved in the metabolism of carbon and biosynthesis of amino acids were also regulated, lending support to the idea of a wide metabolic response. Our results indicate that S. oneidensis is sensitive to the withdrawal of background levels of ionizing radiation and suggest that a transcriptional response is required to maintain homeostasis and retain normal growth. PMID:29768440

Position sensitive detection of neutrons in high radiation background field.

Science.gov (United States)

Vavrik, D; Jakubek, J; Pospisil, S; Vacik, J

2014-01-01

We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e(-) radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm(2)) spectroscopic Timepix detector adapted for neutron detection utilizing very thin (10)B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10(-4).

Angular anisotropy of the cosmic microwave background radiation

International Nuclear Information System (INIS)

Silk, J.

1982-01-01

The theory of fluctuations in the cosmic microwave background radiation is reviewed. Anisotropy on large-scale (dipole and quadrupole) and on small scales is discussed. The smoothing effects of secondary ionization (fractional ionization x) are found to be unimportant over an angular scale greater than approx.= 5(OMEGAx)sup(1/3) degrees. (author)

Health effects in residents of high background radiation regions

International Nuclear Information System (INIS)

Hanson, G.P.

1984-01-01

Although the health effects of radiation doses in occupationally exposed persons had received attention, it was not until the 1950s, when the atmospheric atom bomb tests of the United States and the Soviet Union had raised the level of environmental radioactivity, that the long-term effects of low-level radiation dosage became a matter of popular concern throughout the world. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was created, and the World Health Organization (WHO) appointed an expert committee to provide advice concerning radiation and human health. In its first report, the WHO expert committee identified several areas of high natural radiation where studies of the exposed population might possibly provide information concerning the effects of chromic low-level radiation dosage

Radiation processing of natural polymers: The IAEA contribution

Science.gov (United States)

Haji-Saeid, Mohammad; Safrany, Agnes; Sampa, Maria Helena de O.; Ramamoorthy, Natesan

2010-03-01

Radiation processing offers a clean and additive-free method for preparation of value-added novel materials based on renewable, non-toxic, and biodegradable natural polymers. Crosslinked natural polymers can be used as hydrogel wound dressings, face cleaning cosmetic masks, adsorbents of toxins, and non-bedsore mats; while low molecular weight products show antibiotic, antioxidant, and plant-growth promoting properties. Recognizing the potential benefits that radiation technology can offer for processing of natural polymers into useful products, the IAEA implemented a coordinated research project (CRP) on "Development of Radiation-processed products of Natural Polymers for application in Agriculture, Healthcare, Industry and Environment". This CRP was launched at the end of 2007 with participation of 16 MS to help connecting radiation technology and end-users to derive enhanced benefits from these new value-added products of radiation-processed natural materials. In this paper the results of activities in participating MS related to this work will be presented.

Radiation processing of natural polymers: The IAEA contribution

International Nuclear Information System (INIS)

Haji-Saeid, Mohammad; Safrany, Agnes; Sampa, Maria Helena de O.; Ramamoorthy, Natesan

2010-01-01

Radiation processing offers a clean and additive-free method for preparation of value-added novel materials based on renewable, non-toxic, and biodegradable natural polymers. Crosslinked natural polymers can be used as hydrogel wound dressings, face cleaning cosmetic masks, adsorbents of toxins, and non-bedsore mats; while low molecular weight products show antibiotic, antioxidant, and plant-growth promoting properties. Recognizing the potential benefits that radiation technology can offer for processing of natural polymers into useful products, the IAEA implemented a coordinated research project (CRP) on 'Development of Radiation-processed products of Natural Polymers for application in Agriculture, Healthcare, Industry and Environment'. This CRP was launched at the end of 2007 with participation of 16 MS to help connecting radiation technology and end-users to derive enhanced benefits from these new value-added products of radiation-processed natural materials. In this paper the results of activities in participating MS related to this work will be presented.

Criteria for radiological protection against exposure to natural radiation

International Nuclear Information System (INIS)

Cardenas Herrera, Juan

2012-01-01

Ionizing radiation includes natural radiation which has been part cosmic radiation. Radon in homes, irradiation, gamma, among others, they have also been part of ionizing radiation. The activities that have lead to natural radiation materials are: mining and processing of uranium, radio application and thorium, phosphate industry, mining and smelting of metals, oil and gas extraction, coal mining and power generation, rare earth industry and titanium, zirconium and ceramics, building materials, waste water purification. Therefore, different criteria for radiation protection have had to create against exposure to natural radiation. Distinct rules and regulations to control were created in that sense [es

Cosmic background radiation spectral distortion and radiative decays of relic neutral particles

International Nuclear Information System (INIS)

Berezhiani, Z.G.; Doroshkevich, A.G.; Khlopov, M.Yu.; Yurov, V.P.; Vysotskij, M.I.

1989-01-01

The recently observed excess of photons on a short wavelength side of the peak of a cosmic background radiation spectrum can be described by radiative decays of relic neutral particles. The lifetime and mass of a decaying particle must satisfy the following conditions: 2x10 9 s 14 s, 0.4 eV -9 -8x10 -8 ) μ b , and the interaction of new particles with the usual matter must be rather strong. The generalization of the standard SU(3)xSU(2)xU(1) model is presented which includes new particles with the desired properties. 18 refs.; 3 figs.; 2 tabs

Radiation processing of natural polymer in Malaysia

International Nuclear Information System (INIS)

Khairul Zaman; Kamaruddin Hashim; Zulkafli Ghazali; Mohd Hilmi Mahmood; Dahlan Hj. Mohd; Jamaliah Sharif

2007-01-01

Research on radiation processing of natural polymer has been carried out by Nuclear Malaysia since 10 years ago. The progress of the research is at various stages. Radiation processing of sago hydrogel has been commercialized. Meanwhile ago film for packaging is at the pilot scale trial. Palm oil products are ready to be further developed for commercialization with any interested industrial partner. On the other hand, some new materials are being developed based on natural rubber such as liquid natural as compatibilizer, natural rubber thermoplastic nanoclay composites and natural rubber magnetic nano particles composites. (author)

Excess relative risk of solid cancer mortality after prolonged exposure to naturally occurring high background radiation in Yangjiang, China

Energy Technology Data Exchange (ETDEWEB)

Sun Quanfu; Tao Zufan [Ministry of Health, Beijing (China). Lab. of Industrial Hygiene; Akiba, Suminori (and others)

2000-10-01

A study was made on cancer mortality in the high-background radiation areas of Yangjiang, China. Based on hamlet-specific environmental doses and sex- and age-specific occupancy factors, cumulative doses were calculated for each subject. In this article, we describe how the indirect estimation was made on individual dose and the methodology used to estimate radiation risk. Then, assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995, we estimate the excess relative risk per Sievert for solid cancer to be -0.11 (95% CI, -0.67, 0.69). Also, we estimate the excess relative risks of four leading cancers in the study areas, i.e., cancers of the liver, nasopharynx, lung and stomach. In addition, we evaluate the effects of possible bias on our risk estimation. (author)

Low environmental radiation background impairs biological defence of the yeast Saccharomyces cerevisiae to chemical radiomimetic agents

International Nuclear Information System (INIS)

Satta, L.; Augusti-Tocco, G.; Ceccarelli, R.; Paggi, P.; Scarsella, G.; Esposito, A.; Fiore, M.; Poggesi, I.; Ricordy, R.; Cundari, E.

1995-01-01

Background radiation is likely to constitute one of the factors involved in biological evolution since radiations are able to affect biological processes. Therefore, it is possible to hypothesize that organisms are adapted to environmental background radiation and that this adaptation could increase their ability to respond to the harmful effects of ionizing radiations. In fact, adaptive responses to alkylating agents and to low doses of ionizing radiation have been found in many organisms. In order to test for effects of adaptation, cell susceptibility to treatments with high doses of radiomimetic chemical agents has been studied by growing them in a reduced environmental radiation background. The experiment has been performed by culturing yeast cells (Saccharomyces cerevisiae D7) in parallel in a standard background environment and in the underground Gran Sasso National Laboratory, with reduced environmental background radiation. After a conditioning period, yeast cells were exposed to recombinogenic doses of methyl methanesulfonate. The yeast cells grown in the Gran Sasso Laboratory showed a higher frequency of radiomimetic induced recombination as compared to those grown in the standard environment. This suggests that environmental radiation may act as a conditioning agent

Background radiation and childhood cancer mortality

International Nuclear Information System (INIS)

Sakka, Masatoshi

1979-01-01

Oxford Survey of Childhood Cancer estimated an ''extra'' cancer risk of 572 per million man-rad of juvenile cancer deaths under 10 years of age. In Hiroshima and Nagasaki 36.9 juvenile cancers were expected out of 64,490 man-rad of exposed mothers. Observed cancer was, however, only one. The discrepancy was explained partly by possible overlapping of confidence intervals of two samples and partly by excessive doses received by exposed fetuses in Japan. If A-bomb radiation sterilized preleukemic cells induced in fetuses, it must also killed those cells in irradiated adults. Leukemogenic efficiency in adults, about 2.10 -5 per rad, is not different either in A-bomb survivors or in irradiated patients. We examined a dose-effect relationship in childhood cancer mortality (0 - 4 yrs) in Miyagi Prefecture Japan. Ninety two cancers were detected out of 1,214,157 children from 1968 to 1975. They were allocated to 8 districts with different background levels. Population at risk was calculated every year for every district. About 4 deaths occurred every 10,000 man-rad, which is comparable with 572 per million man-rad in Oxford Survey. One out of one thousand infants died from severe malformation in every year when they received 9.8 rad in embryonic stage, the doubling dose is estimated as 20 rad. Clinical and biological significance of the statistical data must be examined in future. Fetal death decreased significantly from 110/1,000 in 1962 to 55/1,000 in 1975. Background radiation plays no role in fetal death in Miyagi Prefecture. (author)

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

Energy Technology Data Exchange (ETDEWEB)

Koga, Taeko; Morishima, Hiroshige [Kinki Univ., Atomic Energy Research Institute, Osaka (Japan); Tatsumi, Kusuo [Kinki Univ., Life Science Research Institute, Osaka (Japan); Nakai, Sayaka; Sugahara, Tsutomu [Health Research Foundation, Kyoto (Japan); Yuan Yongling [Labor Hygiene Institute of Hunan Prov. (China); Wei Luxin [Laboratory of Industorial Hygiene, Ministry of Health (China)

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: (1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. (2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

International Nuclear Information System (INIS)

Koga, Taeko; Morishima, Hiroshige; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: 1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. 2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

On the radiative and thermodynamic properties of the cosmic radiations using COBE FIRAS instrument data: I. Cosmic microwave background radiation

Science.gov (United States)

Fisenko, Anatoliy I.; Lemberg, Vladimir

2014-07-01

Using the explicit form of the functions to describe the monopole and dipole spectra of the Cosmic Microwave Background (CMB) radiation, the exact expressions for the temperature dependences of the radiative and thermodynamic functions, such as the total radiation power per unit area, total energy density, number density of photons, Helmholtz free energy density, entropy density, heat capacity at constant volume, and pressure in the finite range of frequencies v 1≤ v≤ v 2 are obtained. Since the dependence of temperature upon the redshift z is known, the obtained expressions can be simply presented in z representation. Utilizing experimental data for the monopole and dipole spectra measured by the COBE FIRAS instrument in the 60-600 GHz frequency interval at the temperature T=2.72548 K, the values of the radiative and thermodynamic functions, as well as the radiation density constant a and the Stefan-Boltzmann constant σ are calculated. In the case of the dipole spectrum, the constants a and σ, and the radiative and thermodynamic properties of the CMB radiation are obtained using the mean amplitude T amp=3.358 mK. It is shown that the Doppler shift leads to a renormalization of the radiation density constant a, the Stefan-Boltzmann constant σ, and the corresponding constants for the thermodynamic functions. The expressions for new astrophysical parameters, such as the entropy density/Boltzmann constant, and number density of CMB photons are obtained. The radiative and thermodynamic properties of the Cosmic Microwave Background radiation for the monopole and dipole spectra at redshift z≈1089 are calculated.

Cosmic microwave background radiation anisotropies in brane worlds.

Science.gov (United States)

Koyama, Kazuya

2003-11-28

We propose a new formulation to calculate the cosmic microwave background (CMB) spectrum in the Randall-Sundrum two-brane model based on recent progress in solving the bulk geometry using a low energy approximation. The evolution of the anisotropic stress imprinted on the brane by the 5D Weyl tensor is calculated. An impact of the dark radiation perturbation on the CMB spectrum is investigated in a simple model assuming an initially scale-invariant adiabatic perturbation. The dark radiation perturbation induces isocurvature perturbations, but the resultant spectrum can be quite different from the prediction of simple mixtures of adiabatic and isocurvature perturbations due to Weyl anisotropic stress.

Investigation on Down's syndrome in the children living in high background radiation area

International Nuclear Information System (INIS)

Zha Yongru

1989-01-01

After the survey in 1975 and 1979 of Down's syndrome in the children living in high background radiation area, we made a follow-up investigation in 1985 and 1986. All the obtained data are analysed. 25258 children in high background radiation area were examined and 22 children with Down's syndrome were identified, the morbidity rate being 0.87%. 21837 children in control area were examined and four children with Down's syndrome were identified, the morbidity being 0.18%. There was a statistically significant difference between the two groups. It was noted that the occurrence of Down's syndrome was related to the maternal age but there was no evidence suggesting a close relationship between high background radiation and the development of Down's syndrome

Sister chromatid exchanges (SCEs) in lymphocytes of inhabitants in high background radiation area

International Nuclear Information System (INIS)

Li Jinsheng; Zheng Qiaoling

1985-01-01

Blood samples were taken from 126 students of 15-16 years old, living in the high background radiation area, and from 124 controls of the same age range, living in the normal background radiation area. All students were interviewed for evaluation of their health status. Whole blood cultures were done with RPMI 1640 medium supplemented with 20% fetal calf serum and antibiotics, The culture were incubated for 54-56 h in the presence of BrdU (10 μg/ml). Metaphases were stained for SCE using a modified techniqu of perry and Wolff. From each person 20 second division metaphases were analysed for SCEs. The average frequencies of SCEs observed in the high background group and the control group are presented. More SCEs were observed in the high background group than in the control with a statistically signigicant difference. In regard to the sex factor, it was found that the SCE frequencies in both sexes of the high background group were slightly higher than those in the control group. These findings suggest that continuous low-level irradiation by the high background radiation may induce increased frequency of SCEs

Role of natural radiation environment in earth sciences

International Nuclear Information System (INIS)

Vohra, K.G.

1980-01-01

Natural ionizing radiations play an important role in a wide spectrum of earth sciences, including meteorology, geophysics, hydrology, atmospheric physics, and atmospheric chemistry. The nature and distribution of ionizing radiation sources and natural radionuclides in the atmospheric environment are summarized. The present status of the use of natural radioactive tracers for atmospheric studies is discussed. The effect of ionization produced by natural radiation sources on atmospheric electricity, the relationship of electrical and meteorological variables, and the possible effects of man-made releases of 85 Kr are considered. Experimental evidence is presented for the production of condensation nuclei by the combined effects of radon and sulfur dioxide

The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

Energy Technology Data Exchange (ETDEWEB)

Karam, P. Andrew [Univ. of Rochester, Rochester, NY (United States); Mortazavi, S.M. Javad [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). Medical Physics Dept.

2001-07-01

Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of {sup 226}Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from

The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

International Nuclear Information System (INIS)

Karam, P. Andrew; Mortazavi, S.M. Javad

2001-01-01

Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of 226 Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from leukemia, breast and

Natural radiation in the environment

International Nuclear Information System (INIS)

Moeller, D.W.

1990-01-01

The speaker discusses natural radiation in the environment. He outlines the external sources of exposure (cosmic and terrestrial), as well as the internal sources (ingestion and inhalation). He states that a clear understanding of these sources and their impacts is necessary in order to properly evaluate both the environment and human radiation exposure

Development of advanced natural polymer using radiation technology

International Nuclear Information System (INIS)

Kang, Phil Hyun; Nho, Young Chang; Jeon, Jun Pyo

2012-01-01

This project was performed to develop the environment-friendly and higher value-added materials using natural polymers derivatives from biotic-resources by radiation technology. To study for structural change of natural polymer by radiation, the effect of electron beam and Gamma ray into four kinds of plants such as Kenaf core, kenaf bast, ock and cornhusk was investigated. As results of analysis about structural change of natural polymer by radiation, efficiently separating process of Lignin was developed by improved decomposition of Lignin with increasing power of radiation. Environ-friendly separating process of Cellulose and Lignin using radiation and water-cook was developed without toxically chemical treatment. Papers were fabricated by cellulose and tensile strength of pulp fabricated by radiation was invested properties of pulp depending on power of radiation. High purity cellulose was fabricated by reduced chemical ratio between hemi-cellulose and Lignin with control of radiative power. Manufacturing process of natural paper highly containing cellulose content was developed using efficient separation of cellulose from ock tree, kenaf core and kenaf bast through radiation technique. Cellulose fiber was fabricated using separated cellulose by radiation through the drying and wetting spinning with methanol and water. Also nano-fiber with Lignin was made by electro-spinning with different ratio between PAN and Lignin. Effect of thermal treatment and carbonization of fabricated nano-fiber was invested. Carbon fiber with Lignin was applied to high value-added a secondary battery used as a cathode in half cell type. The secondary battery with carbon fiber with Lignin used as a cathode showed very efficient performance, which revealed capacity-preservation with 100% during 100 cycles. This project could significantly contribute to national competitiveness with radiation technology and Low-carbon and green-growth industrial technology, based on securement of

Search for the Cosmic Infrared Background Radiation using COBE Data

Science.gov (United States)

Hauser, Michael

2001-01-01

This project was initiated to allow completion of the primary investigation of the Diffuse Infrared Background Experiment (DIRBE) on NASA's Cosmic Background Explorer (CORE) mission, and to study the implications of those findings. The Principal Investigator (PI) on this grant was also the Principal Investigator on the DIRBE team. The project had two specific goals: Goal 1: Seek improved limits upon, or detections of, the cosmic infrared background radiation using data from the COBE Diffuse Infrared Background Experiment (DIRBE). Goal 2: Explore the implications of the limits and measured values of the cosmic infrared background for energy releases in the Universe since the formation of the first luminous sources. Both of these goals have been successfully accomplished.

Natural radiation external exposures levels in Chilean Sub-Antarctic and country stations

International Nuclear Information System (INIS)

Stuardo, E.

1988-01-01

Since 1983 gamma exposures levels, at 1,5 m above the soil are being investigated using TLD detectors. A network of 12 stations have been established from ARICA (18 deg 20' S latitude) in Northern Chile to YELCHO (64 deg 52' S latitude) in Antartic territory. One year monitoring period was used at Antartic stations and a four months period in the country. The main subject of this study is to assess the average background radiation levels along the territory which is relevant to get a reference level and specially an estimate of the average natural radiation contribution to the population dose in Southern Chile

Cosmogenic radioberyllium and background radiation dose to the general public

International Nuclear Information System (INIS)

Poeschl, M.; Ohera, M.

2008-01-01

To discover the causes of the presence of abnormal Be concentrations (anthropogenic or natural or cosmogenic source) in the area of the Kralicky Sneznik mountain massive (in the northeast of the Czech Republic, altitude of about 800 m), concentrations of 7 Be and 10 Be were also assayed in selected environmental components in the years of 2005 - 2007. The 10 Be concentrations in soils (80.39x10 6 - 210.45x10 6 atom g -1 ) and activity concentrations of 7 Be in soils and wet deposition were very low (1.3 - 5.3 Bq kg -1 and 0.6 - 4.5 Bq l -1 , resp.). However, activities of 7 Be in birch leaves and grass (dry matter) reached relatively high values (up to 1000 Bq kg -1 ) and, in addition, showed out their significant seasonal growth. In the work the probable contribution of the cosmogenic 7 Be activities to background radiation dose to the general public is discussed. (authors)

Setting up a station to monitor the background radiation

International Nuclear Information System (INIS)

Douglas, J.A.

1980-12-01

This paper gives a brief review of the sources of external background from nuclear radiations and presents methods of measurement that can be conveniently used to determine the components. The methods of calibration are considered in detail and some discussion of meteorological effects is included. (author)

High background radiation area: an important source of exploring the health effects of low dose ionizing radiation

International Nuclear Information System (INIS)

Wei Luxin

1997-01-01

Objective: For obtaining more effective data from epidemiological investigation in high background radiation areas, it is necessary to analyze the advantages, disadvantages, weak points and problems of this kind of radiation research. Methods: For epidemiological investigation of population health effects of high background radiation, the author selected high background radiation areas of Yangjiang (HBRA) and a nearby control area (CA) as an instance for analysis. The investigation included classification of dose groups, comparison of the confounding factors in the incidence of mutation related diseases, cancer mortalities and the frequencies of chromosomal aberrations between HBRA and CA. This research program has become a China-Japan cooperative research since 1991. Results: The confounding factors above-mentioned were comparable between HBRA and CA, and within the dose groups in HBRA, based on a systematic study for many years. The frequencies of chromosomal aberrations increased with the increase of cumulative dose, but not for children around or below 10 years of age. The relative risks (RR) of total and site-specific cancer mortalities for HBRA were lower or around 1.00, compared with CA. The incidence of hereditary diseases and congenital deformities in HBRA were in normal range. The results were interpreted preliminarily by the modified 'dual radiation action' theory and the 'benefit-detriment competition' hypothesis. Conclusions: The author emphasizes the necessity for continuing epidemiological research in HBRA, especially for international cooperation. He also emphasizes the importance of combination of epidemiology and radiobiology

Natural radiation exposure indoors

International Nuclear Information System (INIS)

Brown, L.; Cliff, K.D.; Wrixon, A.D.

1981-01-01

A brief review is presented of the state of knowledge of indoor natural radiation exposure in the U.K. and the current survey work the N.R.P.B. is carrying out in this field. Discussion is limited in this instance to the improvement in estimation of population exposure and the identification of areas and circumstances in which high exposure occur, rather than the study of properties of a building and methods of building affecting exposure to radiation. (U.K.)

A measurement of the low frequency spectrum of the cosmic microwave background radiation

International Nuclear Information System (INIS)

Levin, S.M.

1987-04-01

As part of a larger effort to measure the spectrum of the Cosmic Background Radiation (CBR) at low frequencies, the intensity of the CBR has been measured at a frequency of 1.410 GHz. The measurement was made by comparing the power received from the sky with the power received from a specially designed cooled calibration target with known properties. Sources of radiation other than the CBR were then identified and subtracted to calculate the antenna temperature of the CBR at 1.410 GHz. The instrument used to measure the CBR was a total-power microwave radiometer with a 25 MHz bandwidth centered at 1.410 GHz. The radiometer had a noise temperature of 80 K, and sufficient data were taken that radiometer noise did not contribute significantly to the total measurement error. The sources of error were predominantly systematic in nature, and the largest error was due to uncertainty in the reflection characteristics of the cold-load calibrator. Identification and subtraction of signals from the Galaxy (0.7 K) and the Earth's atmosphere (0.8 K) were also significant parts of the data reduction and error analysis. The brightness temperature of the Cosmic Background Radiation at 1.410 GHz is 222. +- 0.55 Kelvin. The spectrum of the CBR, as determined by this measurement and other published results, is consistent with a blackbody spectrum of temperature 2.741 +- 0.016. Constraints on the amount by which the CBR spectrum deviates from Planck spectrum are used to place limits on energy releases early in the history of the universe. 55 refs., 25 figs., 8 tabs

The use of gamma ray data to define the natural radiation environment

International Nuclear Information System (INIS)

1990-09-01

The natural radiation environment is the major source of radiation exposure to man and consists of both internal and external sources. The most significant internal sources are the radioactive elements 40 K and 222 Rn which are taken into the body. The external sources are cosmic rays and naturally occurring radioactive isotopes of the 40 K, 238 U, and 232 Th decay series, some or all of which can be found in the ground, in construction materials, and in the air. This report has been prepared to provide a guide for the use of existing gamma ray survey data to define the natural radiation environment, but will only be concerned with the gamma ray exposure resulting from radiation originating in geological materials. The type of data needed to produce maps are available as a result of airborne, carborne, and ground gamma ray surveys in many parts of the world. Although most of these data were acquired for uranium and other mineral exploration and geological mapping purposes, they can be used to provide background radioactivity information. Standardized survey data can be compiled to produce regional maps of gamma ray air dose rates as well as single radioelement maps. Compilation procedures may use either manual or computer techniques. Although this work will primarily be done as national compilations, it will open the possibility of the compilation of radioelement geochemical maps on a regional and global scale. 48 refs, figs and tabs

Natural radiation, nuclear wastes and chemical pollutants

International Nuclear Information System (INIS)

Christensen, T.; Ehdwall, H.; Stranden, E.

1990-01-01

Doses from natural radiation to the population in the Nordic Countries are summarized and man made modifications of the natural radiation environment are discussed. An account is given of the radiological consequences of energy conservation by reduced ventilation. Risks from possible future releases of radioactivity from final repositories of spent nuclear fuel are compared to the risks from present natural radioactivity in the environment. The possibilities for comparison between chemical and radiological risks are discussed. (author) 13 refs

Project Marna Natural Gamma Radiation MAP

International Nuclear Information System (INIS)

Suarez, E.; Fernandez, J.A.

1997-01-01

The confusion created by the accident that occurred in one of the Chernobyl reactors in April of 1986 made the general public and governments aware of the need for improved monitoring of environmental radiation levels. The levels of total gamma radiation or total gamma exposure rate over large areas reached values as high as 400 micro Roentgen/hour (mu R/h) and at points exceeded 1000 mu R/h. It should be borne in mind that, depending on the type of geological formations, normal values range from 5 to 30 mu R/h. The IAEA recommended to all countries that natural gamma radiation maps be made available to evaluate the levels of natural gamma radiation and possible increases, and it also indicated its concern that information be standardized. In addition, it stressed the advisability of using data obtained from uranium prospecting. (Author)

Infrared radiation scene generation of stars and planets in celestial background

Science.gov (United States)

Guo, Feng; Hong, Yaohui; Xu, Xiaojian

2014-10-01

An infrared (IR) radiation generation model of stars and planets in celestial background is proposed in this paper. Cohen's spectral template1 is modified for high spectral resolution and accuracy. Based on the improved spectral template for stars and the blackbody assumption for planets, an IR radiation model is developed which is able to generate the celestial IR background for stars and planets appearing in sensor's field of view (FOV) for specified observing date and time, location, viewpoint and spectral band over 1.2μm ~ 35μm. In the current model, the initial locations of stars are calculated based on midcourse space experiment (MSX) IR astronomical catalogue (MSX-IRAC) 2 , while the initial locations of planets are calculated using secular variations of the planetary orbits (VSOP) theory. Simulation results show that the new IR radiation model has higher resolution and accuracy than common model.

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-01-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

Energy Technology Data Exchange (ETDEWEB)

Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-10-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Natural radiation environment III. [Lead Abstract

Energy Technology Data Exchange (ETDEWEB)

Gesell, T.F.; Lowder, W.M. (eds.)

1980-01-01

Separate abstracts were prepared for the 52 research papers presented at this symposium in April 1978. The major topics in this volume deal with penetrating radiation measurements, radiation surveys and population exposure, radioactivity in the indoor environment, and technologically enhanced natural radioactivity. (KRM)

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran.

Science.gov (United States)

Mortazavi, Seyed Mohammad Javad; Zarei, Samira; Taheri, Mohammad; Tajbakhsh, Saeed; Mortazavi, Seyed Alireza; Ranjbar, Sahar; Momeni, Fatemeh; Masoomi, Samaneh; Ansari, Leila; Movahedi, Mohammad Mehdi; Taeb, Shahram; Zarei, Sina; Haghani, Masood

2017-04-01

Over the past several years our laboratories have investigated different aspects of the challenging issue of the alterations in bacterial susceptibility to antibiotics induced by physical stresses. To explore the bacterial susceptibility to antibiotics in samples of Salmonella enterica subsp. enterica serovar Typhimurium ( S. typhimurium ), Staphylococcus aureus , and Klebsiella pneumoniae after exposure to gamma radiation emitted from the soil samples taken from the high background radiation areas of Ramsar, northern Iran. Standard Kirby-Bauer test, which evaluates the size of the zone of inhibition as an indicator of the susceptibility of different bacteria to antibiotics, was used in this study. The maximum alteration of the diameter of inhibition zone was found for K. pneumoniae when tested for ciprofloxacin. In this case, the mean diameter of no growth zone in non-irradiated control samples of K. pneumoniae was 20.3 (SD 0.6) mm; it was 14.7 (SD 0.6) mm in irradiated samples. On the other hand, the minimum changes in the diameter of inhibition zone were found for S. typhimurium and S. aureus when these bacteria were tested for nitrofurantoin and cephalexin, respectively. Gamma rays were capable of making significant alterations in bacterial susceptibility to antibiotics. It can be hypothesized that high levels of natural background radiation can induce adaptive phenomena that help microorganisms better cope with lethal effects of antibiotics.

Assessment of Radiation Background Variation for Moving Detection Systems

Energy Technology Data Exchange (ETDEWEB)

Miller, James Christopher [Los Alamos National Laboratory; Rennie, John Alan [Los Alamos National Laboratory; Toevs, James Waldo [Los Alamos National Laboratory; Wallace, Darrin J. [Los Alamos National Laboratory; Abhold, Mark Edward [Los Alamos National Laboratory

2015-07-13

The introduction points out that radiation backgrounds fluctuate across very short distances: factors include geology, soil composition, altitude, building structures, topography, and other manmade structures; and asphalt and concrete can vary significantly over short distances. Brief descriptions are given of the detection system, experimental setup, and background variation measurements. It is concluded that positive and negative gradients can greatly reduce the detection sensitivity of an MDS: negative gradients create opportunities for false negatives (nondetection), and positive gradients create a potentially unacceptable FAR (above 1%); the location of use for mobile detection is important to understand; spectroscopic systems provide more information for screening out false alarms and may be preferred for mobile use; and mobile monitor testing at LANL accounts for expected variations in the background.

Final report and evaluation of the SAWORA research program on background radiation levels from natural origin in The Netherlands

International Nuclear Information System (INIS)

Hogeweg, B.

1986-09-01

In order to study the various factors which determine the dose resulting from background radiation, in particular for the indoor situation, the SAMORA-programme was initiated in 1982. The various aspects studied were: 1) a determination of the current background radiation level, for the indoor as well as the outdoor situation; 2) an inventory of the radioactivity of the building materials; 3) the radioecological aspects from fly-ash and gypsum deposits; 4) a risk estimation of lung tumour induction at low doses and for low dose rates; 5) technical factors determining the effective dose equivalent. In this report the connection of the results derived in the different studies will be discussed. From the study on radioconcentration it became clear that the indoor concentration is strongly determined by the concentration in the crawl space. On the basis of the results of the programme an estimation of the lung tumour risk for the Dutch population is presented. For the current levels it is calculated that the risk is approximately 2.1 lung tumours per 100.000 persons. Since in 1982 the mean lung tumour death rate for the Dutch population was 56.8 per 100.000, this result demonstrates that the calculated contribution is relatively low (4%). Furthermore it is calculated that the maximum increase of this contribution as a result of the introduction of active gypsum building materials will be of the order of 1%. (Auth.)

Background radiation in inelastic X-ray scattering and X-ray emission spectroscopy. A study for Johann-type spectrometers

Science.gov (United States)

Paredes Mellone, O. A.; Bianco, L. M.; Ceppi, S. A.; Goncalves Honnicke, M.; Stutz, G. E.

2018-06-01

A study of the background radiation in inelastic X-ray scattering (IXS) and X-ray emission spectroscopy (XES) based on an analytical model is presented. The calculation model considers spurious radiation originated from elastic and inelastic scattering processes along the beam paths of a Johann-type spectrometer. The dependence of the background radiation intensity on the medium of the beam paths (air and helium), analysed energy and radius of the Rowland circle was studied. The present study shows that both for IXS and XES experiments the background radiation is dominated by spurious radiation owing to scattering processes along the sample-analyser beam path. For IXS experiments the spectral distribution of the main component of the background radiation shows a weak linear dependence on the energy for the most cases. In the case of XES, a strong non-linear behaviour of the background radiation intensity was predicted for energy analysis very close to the backdiffraction condition, with a rapid increase in intensity as the analyser Bragg angle approaches π / 2. The contribution of the analyser-detector beam path is significantly weaker and resembles the spectral distribution of the measured spectra. Present results show that for usual experimental conditions no appreciable structures are introduced by the background radiation into the measured spectra, both in IXS and XES experiments. The usefulness of properly calculating the background profile is demonstrated in a background subtraction procedure for a real experimental situation. The calculation model was able to simulate with high accuracy the energy dependence of the background radiation intensity measured in a particular XES experiment with air beam paths.

Investigation of background radiation levels and geologic unit profiles in Durango, Colorado

International Nuclear Information System (INIS)

Triplett, G.H.; Foutz, W.L.; Lesperance, L.R.

1989-11-01

As part of the Uranium Mill Tailings Remedial Action (UMTRA) Project, Oak Ridge National Laboratory (ORNL) has performed radiological surveys on 435 vicinity properties (VPs) in the Durango area. This study was undertaken to establish the background radiation levels and geologic unit profiles in the Durango VP area. During the months of May through June, 1986, extensive radiometric measurements and surface soil samples were collected in the Durango VP area by personnel from ORNL's Grand Junction Office. A majority of the Durango VP surveys were conducted at sites underlain by Quaternary alluvium, older Quaternary gravels, and Cretaceous Lewis and Mancos shales. These four geologic units were selected to be evaluated. The data indicated no formation anomalies and established regional background radiation levels. Durango background radionuclide concentrations in surface soil were determined to be 20.3 ± 3.4 pCi/g for 40 K, 1.6 ± 0.5 pCi/g for 226 Ra, and 1.2 ± 0.3 pCi/g for 232 Th. The Durango background gamma exposure rate was found to be 16.5 ± 1.3 μR/h. Average gamma spectral count rate measurements for 40 K, 226 Ra and 232 Th were determined to be 553, 150, and 98 counts per minute (cpm), respectively. Geologic unit profiles and Durango background radiation measurements are presented and compared with other areas. 19 refs., 15 figs., 5 tabs

Natural radiation dose to Gammarus from Hudson river

International Nuclear Information System (INIS)

Paschoa, A.S.; Wrenn, M.E.; Eisenbud, M.

1979-01-01

The purpose of this investigation is to evaluate the natural radiation dose rate to whole body and components of the Gammarus species, a zooplankton which occurs in the Hudson River among other places, and to compare the results with the upper limits of dose rates from man-made sources. The alpha dose rates to the exoskeleton and soft tissues are about 10 times the average alpha dose rate to the whole body, assuming uniform distribution of 226 Ra. The natural alpha radiation dose rate to Gammarus represents only about 5% of the total natural dose to the organism, i.e., 492 mrad/yr. The external dose rate due to 40 K, 238 U plus daughters and 232 Th plus daughters accumulated in the sediments comprise 91% of that total natural dose rate, the remaining percentage being due to natural internal beta emitters and cosmic radiation. Man-made sources can cause an external dose rate up to 224 mrad/yr, which comprises roughly 1/3 of the total dose rate (up to 716 mrad/yr; natural plus man-made) to the Gammarus of Hudson River in front of Indian Point Nuclear Power Station. However, in terms of dose-equivalent the natural sources of radiation would contribute more than 75% of the total dose to Gammarus

Review of radiation processing of natural polymer

International Nuclear Information System (INIS)

Khairul Zaman

2007-01-01

In recent years, natural polymers are being investigated with renewed interest because of their abundant quantity and unique characteristics such as inherent biocompatibility, biodegradability and renewable. It is also known as green polymer. Natural polymers such as carrageen, alginate, chitin/chitosan and starch are traditionally used in food-based industry. But now, the applications of natural polymers are being sought in knowledge-driven areas such as healthcare, agro-technology and industry. Radiation degraded alginates, carrangeenan and chitosan as plant growth promoter and protector have been developed. Radiation degraded chitosan, carraneenan and starch have also been used together with synthetic polymers for hydrogel production to be used for wound dressing, skin moisturization and for biodegradable packaging films and foams. Radiation crosslinking of natural polymer derivatives such as carboxymethyl chitosan, carboxymethyl starch have been successfully developed in Japan and used for various applications such as removal of pollutants, removal of waters from liverstock excrete as well as for bedsores protection mat. (author)

Assessment of immune surveillance among inhabitants of high natural background radiation areas in Ramsar-Iran

International Nuclear Information System (INIS)

Sileh, Sajad Borzouei; Monfared, Ali Shabestani; Mostafazade, Amrollah; Abedian, Said

2010-01-01

In this study by Multi-parameter flow cytometry, immunologic analyze is performed on peripheral blood, NK cells, most effective cells in innate immune and the proportion of TCD8/TCD4 cells that is effective in cellular immune system will be determined. Lysosomal-associated membrane protein-1 (LAMP-1 or CD107a) is used as a functional marker for the identification of natural killer cell activity. Immune surveillance and immune system role in tumoral defense in Ramsar inhabitants will be determined. Radiation dose rate in Talesh mahalle is very high and was many times greater than Chaparsar (another region in Ramsar). Immune surveillance and immune system role in tumoral defense in Talesh mahalle inhabitants will be compared to Chaparsar inhabitants. If this doesn't have significant difference, we should think about some other aspects such as free radical scavengers that will study later

Technologically modified exposures to natural radiation. Annex C

International Nuclear Information System (INIS)

1982-01-01

This Annex deals with some examples of technologically modified exposures to natural radiation. Radiation exposures due to coal-fired power plants, geothermal energy production, exploitation of phosphate rock, aircraft travel, and consumer products are discussed. The present state of knowledge does not allow an accurate estimate of the collective effective dose equivalent from technologically modified exposures to natural radiation to be made. This annex has an extensive bibliography with at least 200 references.

Natural radiation and radon concentration in buildings

International Nuclear Information System (INIS)

Ito, Kazuo; Asano, Kenji

1985-01-01

The purpose of this subject is to investigate the actual conditions of natural radiation levels in various types of buildings. This study is indispensable for the accurate evaluation of population dose of external and internal exposures from natural radiation. Concentrations of K-40, Ra-226 and Th-232 in building materials such as Portland cement, gypsum boards and its raw materials were measured with Ge gamma spectrometer. (author)

Concerns on the health effects of low-dose ionizing radiations from naturally occurring radioactive materials (NORM)

International Nuclear Information System (INIS)

Mohankumar, Mary N.

2005-01-01

It is a widely known fact that man evolved in a naturally radioactive environment. Even today life exists in an atmosphere of cosmic and terrestrial radiation. Radionuclides are found naturally in air, water and soil. They are even found in us, we being the products of our environment. Every day, we ingest and inhale radionuclides in our air and food and the water. Natural radioactivity is common in the rocks and soil that makes up our planet, in water and oceans, and in our building materials and homes. There is nowhere on earth that one cannot find natural radioactivity. Radioactive materials which occur naturally and expose people to radiation occur widely, and are known by the acronym 'NORM' (Naturally Occurring Radioactive Materials). Besides, around the globe there are some areas with an elevated background radiation. These areas include parts of Brazil, Iran, India and China. The sources of radiation in these areas include monazite containing beach sands and radium from hot springs. On the southwest coast of India, there are large deposits of thorium bearing monazite sands that contribute to an external radiation dose of about 5 - 6 mGy/yr, but in some parts doses up to 32.6 mGy/yr have been reported. Nevertheless, most general public associate ionising radiations only with the nuclear industry. Antinuclear activists often fail to accept the fact that coal-fired power stations and the oil and gas exploration operations may emit more radioactivity than an operating nuclear reactor. Another NORM issue relates to radon exposure in homes, particularly those built on granite grounds. The solid airborne Rn-222 progeny, particularly Po-218, Pb-214 and Bi-214 are of health importance because they can be inspired and retained in the lung causing cancer. Man-made operations like oil and gas production and processing operations result in technologically enhanced naturally occurring radioactive materials (TENORM) to accumulate at elevated concentrations in by

The local contribution to the microwave background radiation

International Nuclear Information System (INIS)

Pecker, Jean-Claude; Narlikar, Jayant V.; Ochsenbein, Francois; Wickramasinghe, Chandra

2015-01-01

The observed microwave background radiation (MBR) is commonly interpreted as the relic of an early hot universe, and its observed features (spectrum and anisotropy) are explained in terms of properties of the early universe. Here we describe a complementary, even possibly alternative, interpretation of MBR, first proposed in the early 20 th century, and adapt it to modern observations. For example, the stellar Hipparcos data show that the energy density of starlight from the Milky Way, if suitably thermalized, yields a temperature of ∼2.81 K. This and other arguments given here strongly suggest that the origin of MBR may lie, at least in a very large part, in re-radiation of thermalized galactic starlight. The strengths and weaknesses of this alternative radical explanation are discussed. (paper)

Dose assessment on natural radiation, natural radionuclide, and artificial radionuclide released by Fukushima nuclear accident

International Nuclear Information System (INIS)

Hosoda, Masahiro; Tokonami, Shinji; Furukawa, Masahide

2012-01-01

Various radionuclides are distributed in environmental materials such as soil, rock, and water. People are exposed every day to natural radiation. According to the UNSCEAR 2008 report, Sources of Ionizing Radiation, natural radiation sources are categorized as terrestrial gamma-rays, radon, cosmic rays and food. The effective dose from radon, thoron and its decay products is about 50% of all natural radiation exposure. Consciousness of the Japanese public toward radiation exposure has significantly increased since the start of the Fukushima Dai-ichi Nuclear Power Station accident. In this paper, the nationwide survey and dose estimation for terrestrial gamma-rays and radon are summarized. External dose from artificial radionuclides released by the Fukushima accident are also reported. (author)

Natural radiation, protection against its effects and maintaining safe natural environment

International Nuclear Information System (INIS)

Alhassan, Muhammad

2015-01-01

Exposure to naturally occurring radioactivity and its consequences is an issue that needs the global concern, as practices bringing such radioactive materials closer to human environment through mining, building, industrial applications and food production and preservation is continuously increasing, in addition to the daily consumption in foods such as banana, carrot, potato and drinking water. Although it has direct and indirect impacts affecting human health that in some cases lead to the loss of lives and polluting natural environment, it is an inevitable task that necessitates devising some means of its minimization and protection against its hazardous effects. This could be achieved by the use of expertise ideas and by the creation of awareness and sharing related information with the people concerned and the general public. This paper gives an overview on the radiation present in natural environment, its sources, mechanism of its effects. The paper compares the radiation dose limits with the average doses from these sources in order to raise the challenges facing researchers, governments and the general individuals with regard to this issue. The paper also proposed applicable solutions to reduce the risks due to the exposure to natural radiation to ground level. (author)

Investigation of environmental natural penetrating radiation in Hunan province

International Nuclear Information System (INIS)

1991-01-01

The methods and results of the investigation of natural penetrating radiation level in Hunan Province are presented. 309 25 x 25 km-netted measuring points were set up uniformly all over the province, with 1007 densely measuring points of different type added. The results showed that: (1) the point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate over field was 7.11, 6.90 and 7.07 x 10 -8 Gy · h -1 , respectively; (2) The point-weighted and population-weighted average value of natural γ radiation dose rate over road was 7.05 x 10 -8 Gy · h -1 ; (3) The point-weighted and population-weighted average value of natural γ radiation dose rate inside buildings was 10.43 and 10.56 x 10 -8 Gy · h -1 ; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray was 2.67 and 2.66 x 10 -8 Gy · h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings was 13.1 and 13.2 x 10 -8 Gy · h -1 , and outside buildings was 10.1 and 9.88 x 10 -8 Gy · h -1 , respectively; (6) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation was 0.58, 0.24 and 0.82 mSv, respectively, and correspondingly, the annual collective effective dose equivalent was 3.1, 1.3 and 4.4 x 10 4 man · Sv, respectively

Assessment of impact of urbanisation on background radiation exposure and human health risk estimation in Kuala Lumpur, Malaysia.

Science.gov (United States)

Sanusi, M S M; Ramli, A T; Hassan, W M S W; Lee, M H; Izham, A; Said, M N; Wagiran, H; Heryanshah, A

2017-07-01

Kuala Lumpur has been undergoing rapid urbanisation process, mainly in infrastructure development. The opening of new township and residential in former tin mining areas, particularly in the heavy mineral- or tin-bearing alluvial soil in Kuala Lumpur, is a contentious subject in land-use regulation. Construction practices, i.e. reclamation and dredging in these areas are potential to enhance the radioactivity levels of soil and subsequently, increase the existing background gamma radiation levels. This situation is worsened with the utilisation of tin tailings as construction materials apart from unavoidable soil pollutions due to naturally occurring radioactive materials in construction materials, e.g. granitic aggregate, cement and red clay brick. This study was conducted to assess the urbanisation impacts on background gamma radiation in Kuala Lumpur. The study found that the mean value of measured dose rate was 251±6nGyh -1 (156-392nGyh -1 ) and 4 times higher than the world average value. High radioactivity levels of 238 U (95±12Bqkg -1 ), 232 Th (191±23Bqkg -1 ,) and 40 K (727±130Bqkg -1 ) in soil were identified as the major source of high radiation exposure. Based on statistical ANOVA, t-test, and analyses of cumulative probability distribution, this study has statistically verified the dose enhancements in the background radiation. The effective dose was estimated to be 0.31±0.01mSvy -1 per man. The recommended ICRP reference level (1-20mSvy -1 ) is applicable to the involved existing exposure situation in this study. The estimated effective dose in this study is lower than the ICRP reference level and too low to cause deterministic radiation effects. Nevertheless based on estimations of lifetime radiation exposure risks, this study found that there was small probability for individual in Kuala Lumpur being diagnosed with cancer and dying of cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimation of background radiation doses for the Peninsular Malaysia's population by ESR dosimetry of tooth enamel.

Science.gov (United States)

Rodzi, Mohd; Zhumadilov, Kassym; Ohtaki, Megu; Ivannikov, Alexander; Bhattacharjee, Deborshi; Fukumura, Akifumi; Hoshi, Masaharu

2011-08-01

Background radiation dose is used in dosimetry for estimating occupational doses of radiation workers or determining radiation dose of an individual following accidental exposure. In the present study, the absorbed dose and the background radiation level are determined using the electron spin resonance (ESR) method on tooth samples. The effect of using different tooth surfaces and teeth exposed with single medical X-rays on the absorbed dose are also evaluated. A total of 48 molars of position 6-8 were collected from 13 district hospitals in Peninsular Malaysia. Thirty-six teeth had not been exposed to any excessive radiation, and 12 teeth had been directly exposed to a single X-ray dose during medical treatment prior to extraction. There was no significant effect of tooth surfaces and exposure with single X-rays on the measured absorbed dose of an individual. The mean measured absorbed dose of the population is 34 ± 6.2 mGy, with an average tooth enamel age of 39 years. From the slope of a regression line, the estimated annual background dose for Peninsular Malaysia is 0.6 ± 0.3 mGy y(-1). This value is slightly lower than the yearly background dose for Malaysia, and the radiation background dose is established by ESR tooth measurements on samples from India and Russia.

Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia

Directory of Open Access Journals (Sweden)

G. C. Edwards

2013-05-01

Full Text Available This paper presents the first gaseous elemental mercury (GEM air-surface exchange measurements obtained over naturally enriched and background (−1 Hg terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m−2 h−1 to 113 ± 6 ng m−2 h−1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m−2 h−1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s−1 to 0.0083 cm s−1 with an average of 0.0041 ± 0.00018 cm s−1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.

Hybrid radiation background monitoring in operational control and forecasting of environmental contamination by nuclear power station discharges

International Nuclear Information System (INIS)

Ermeev, I.S.; Eremenko, V.A.; Makarov, Y.A.; Matueev, V.V.; Zhernov, V.S.

1986-01-01

Rapid developments in nuclear power have stimulated research on monitoring and forecasting environmental radiation pollution (ERP), and in particular the amounts, compositions, and distributions of radionuclides in the environment. A conceptual model is presented for hybrid environmental radiation pollution monitoring. When there is an emergency, the model operates in a fashion most closely corresponding to the actual meteorological conditions, and the ERP data given by the model enable one to distinguish changes due to the man-made component from random fluctuations in the natural background. The measurement system in general includes mobile and stationary data-acquisition facilities linked by wire or radio to the central point. The system also accumulates and stores data on the radiation environment, which are edited on the basis of radioactive, chemical, and other transformations. The purpose of hybrid monitoring is ultimately to analyze trends in order to detect elevated discharges and thus to output data to the regional monitoring system

Epistemological limitation for attributing health effects to natural radiation exposure

International Nuclear Information System (INIS)

González, Abel J.

2010-01-01

The attribution of health effects to prolonged radiation exposure situations, such as those experienced in nature, is a challenging problem. The paper describes the epistemological limitations for such attribution it demonstrate that in most natural exposure situations, the theory of radiation-related sciences is not capable to provide the scientific evidence that health effects actually occur (or do not occur) and, therefore, that radiation effects are attributable to natural exposure situations and imputable to nature. Radiation exposure at high levels is known to provoke health effects as tissue reactions. If individuals experience these effects they can be attributed to the specific exposure with a high degree of confidence under the following conditions: the dose incurred have been higher that the relevant dose-threshold for the specific effect; and an unequivocal pathological diagnosis is attainable ensuring that possible competing causes have been eliminated. Only under these conditions, the occurrence of the effect may be properly attested and attributed to the exposure. However, even high levels of natural radiation exposure are lower than relevant dose-thresholds for tissue reactions and, therefore, natural radiation exposure is generally unable to cause these type of effects. One exception to this general rule could be situations of high levels of natural radiation exposure that might be sufficient to induce opacities in the lens of the eyes (which could be considered a tissue-reaction type of effect)

Fluctuations in the cosmic microwave background

International Nuclear Information System (INIS)

Banday, A.J.; Wolfendale, A.W.

1990-01-01

In view of the importance to contemporary cosmology, and to our understanding of the Universe, of the precise nature of the Cosmic Microwave Background (CMB) spectrum, we consider the effects on this spectrum of contamination by other radiation fields of both galactic and extragalactic origin. Particular attention is given to the significance of measurements of the fluctuations in the 'background' radiation detected at 10.46 GHz and we conclude that these fluctuations are of the same magnitude as those expected from galactic cosmic-ray effects. A more detailed study of the cosmic-ray induced fluctuations and measurements at higher frequencies will be needed before genuine CMB fluctuations can be claimed. (author)

Natural occurring radioactivity in Palmyra and its surrounding

International Nuclear Information System (INIS)

Al-Masri, M. S.; Shwekani, R.; Raja, G.; Hushari, M.; Al-Hent, R.; Issa, M.

2006-06-01

In this work, the natural radiation background has been carried out for Palmyra city and its surroundings area. The study has covered gamma radiation measurements, indoor radon gas concentration and radionuclides levels in environmental samples (soil, water, plat). The results showed that indoor radon gas concentrations and radiation exposure rates are within the background levels. Also, the results showed that there is no artificial radiation in the area and there is no correlation between the natural radiation levels and the reported cancer cases. Therefore, the reported cancer cases in this area may be due to non-radiation cases, which must be investigated, or they are within the natural levels in Syria unless accurate statistics proves the opposite. (author)

Review of epidemiological and cytogenetic studies on high background radiation area residents

International Nuclear Information System (INIS)

Iwasaki, Toshiyasu

2008-01-01

Emerging scientific knowledge in the field of radiation biology has put into question the generic use of a simple linear extrapolation of radiation effects from high to low dose or dose rate. Though the direct information of biological effects at low dose or low dose rate has been accumulated, it is still immature to mention health effects as the consequence of biological effects. As epidemiological data have been the main sources of direct information on human health effects, studies of the health of population exposed by low dose or low dose rate ionizing radiation will help to improve our understanding. In this meaning, the epidemiological studies of residents in high background radiation areas (HBRA), which are supported by us, will provide important direct information on the biological and health effects of chronic low dose rate ionizing radiation. The epidemiological results in HBRA in China showed there are no significant increases of cancer risks caused by the high background levels of ionizing radiation. From the results which come from cytogeneticl studies, the frequencies of unstable chromosomal aberrations have shown good correlation with cumulative doses in their lifetimes, which indicated it is a sensitive and informative biomarker. On the other hand, the frequencies of stable chromosomal aberrations have shown no significant difference and the frequency was much higher than that of unstable type aberrations. It suggests that mutagenic factors other than radiation contribute more than the elevated level of radiation to the induction of DNA rearrangements which could lead to the increase of cancer risk in HBRA in China. (author)

Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

International Nuclear Information System (INIS)

Ramola, R. C.; Gusain, G. S.; Rautela, B. S.; Sagar, D. V.; Prasad, G.; Shahoo, S. K.; Ishikawa, T.; Omori, Y.; Janik, M.; Sorimachi, A.; Tokonami, S.

2012-01-01

Exposure to radon, 222 Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, 220 Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to 220 Rn and its progeny can equal or several time exceed that of 220 Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

Levels of thoron and progeny in high background radiation area of southeastern coast of Odisha (India))

Energy Technology Data Exchange (ETDEWEB)

Ramola, R C; Gusain, G S; Rautela, B S [Dept. of Physics, H.N.B. Garhwal Univ., Badshahi Thaul Campus, Tehri Garhwal 249199 (India); Sagar, D V [Health Physics Unit EAD, BARC, IRE, OSCOM, Matikhalo, Ganjam, Odisha 761 045 (India); Prasad, G; Shahoo, S K; Ishikawa, T; Omori, Y; Janik, M [National Inst. of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555 (Japan); Sorimachi, A; Tokonami, S [Inst. of Radiation Emergency Medicine, Hirosaki Univ., Aomori 036-8564 (Japan)

2012-07-01

Exposure to radon, {sup 222}Rn, is assumed to be the most significant source of natural radiation to human beings in most cases. It is thought that radon and its progeny are major factors that cause cancer. The presence of thoron, {sup 220}Rn, was often neglected because it was considered that the quantity of thoron in the environment is less than that of radon. However, recent studies have shown that a high thoron concentration was found in some regions and the exposure to {sup 220}Rn and its progeny can equal or several time exceed that of {sup 220}Rn and its progeny. The results of thoron and its progeny measurements in the houses of high background radiation area (HBRA) of the southeastern coast of Odisha (India)) presented here. This area is one of the high background radiation areas in India with a large deposit of monazite sand which is the probable source of thoron. Both active and passive methods were employed for the measurement of thoron and its progeny in cement, brick and mud houses in the study area. Thoron concentration was measured using RAD-7 and Raduet. A CR-39 track detector was employed for the measurement of environmental thoron progeny, both in active and passive modes. Thoron and its progeny concentrations were found to be comparatively high in the area. A comparison between the results obtained with various techniques is presented in this paper. (authors)

Radiation risk from natural radioactivity in oil and gas production industry. Vol. 4

Energy Technology Data Exchange (ETDEWEB)

Eid, M A [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo, (Egypt)

1996-03-01

This paper throws light on the natural radioactive materials as well as the radiation background level in Egypt and other global areas. It also describes the deposition of naturally occurring radioactivity as well as the gamma-ray exposure rate primarily due to {sub 226} Ra and daughters which concentrate as scale or sludge in oil field piping and equipment. The potential hazards arising during normal operation, maintenance, and cleaning are considered. Occupational annual personnel doses are estimated and examined relative to work function. The measures to reduce occupational radiation exposure and radioactive contamination were investigated. The data indicated that relatively higher exposure rates are associated with areas around water discharge system, separator and descaling operations where the dose rates varying between 0.02-6 m R/h. The annual collective effective dose equivalent was estimated about 4.58 man-Rem, and the mean annual dose equivalent of about 120 mrem were measured. 3 tabs.

Investigation of environmental natural penetrating radiation in Shanxi Province

International Nuclear Information System (INIS)

Li Junshan; Chen Baotian; Zhang Runrun; He Zeyong; Li Jinfu

1990-01-01

The methods and results of the investigation on natural penetrating radiation level in Shanxi Province are presented. 262 25 x 25 km-netted measuring points were set unformly up all over the province, with 255 densely measuring points of different types added. The results showed that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate over field was 5.39, 5.41 and 5.43 x 10 -8 Gy·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate over road was 4.84 x 10 -8 Gy·h -1 ; (3) The point-weighted and population-weighted average value of natural γ radiation dose rate inside buildings was 8.09 and 8.24 x 10 -8 Gy·h -1 ; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray was 3.46 and 3.36 x 10 -8 Gy·h -1 , and outside buildings was 3.85 and 3.73 x 10 -8 Gy·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings was 11.55 and 11.60 x 10 -8 Gy·h -1 and outside buildidngs was 8.97 and 8.42 x 10 -8 Gy·h -1 , respectively; (6) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation was 0.46, 0.30 and 0.76 mSv, respectively, and correspondingly, the annual collective effective dose equivalent was 1.2, 0.77 and 2.0 x 10 4 man·Sv, respectively

Natural ionizing radiation and human health in Serbia

Directory of Open Access Journals (Sweden)

Obradović-Arsić Danijela R.

2010-01-01

Full Text Available This paper provides information about potential effects of natural ionizing radiation on general population health. Natural radionuclides are particularly stressed, as well as health effects of high and lower doses. Radio-ecological areals have been presented for Serbia, while radiation risk has been assessed for the population of Serbia according to census years.

Technologically enhanced natural radiation (TENR II). Proceedings of an international symposium

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-02-01

Natural radiation is ubiquitous. In recent decades, there has been a developing interest in fully documenting exposure of human beings to radiation of natural origin. Radiation experts have recognized that natural sources of radiation can cause exposure of members of the general public and workers to levels that warrant consideration of whether controls should be applied. The second International Symposium on Technologically Enhanced Natural Radiation (TENR II) was held in Rio de Janeiro from 12 to 17 September 1999. The objective of the symposium was to provide a forum for the international exchange of information on the scientific and technical aspects of those components of exposure to natural radiation that warrant consideration. These components were examined under the headings: the technological enhancement of natural radiation in mining and non-nuclear industries; radon indoors and outdoors; mobility and transfer of natural radionuclides; natural radiation and health effects; analytical techniques and methodologies; the remediation of contaminated sites; and regulatory and legal aspects. The symposium found that exposures to natural sources of radiation should be considered from the point of view of their amenability to control. This approach is reflected in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) and the associated IAEA documents on occupational exposure and rehabilitation of contaminated lands. The concepts of exclusion and intervention are particularly relevant to the amenability to control of natural sources of radiation. Indeed, the BSS specify that any exposure whose magnitude is essentially unamenable to control through the requirements of the BSS is out of the scope of the BSS. The BSS further indicate that protective or remedial actions shall be undertaken whenever they are justified in terms of the benefit to be obtained. Following their deliberations, the

Mode shape and natural frequency identification for seismic analysis from background vibration

International Nuclear Information System (INIS)

Bhan, S.; Wozniak, Z.

1986-02-01

The feasibility of calculating natural frequencies and mode shapes of major equipment in a CANDU reactor from the measurements of their response to background excitation has been studied. A review of vibration data measured at various locations in CANDU plants shows that structures responded to a combination of random and harmonic background excitation. Amplitude of measured vibration is sufficient to allow meaningful data analysis. Frequency content in the 0 to 50-Hz range, which is of interest for earthquake response, is present in some of the vibration measurements studied. Spectral techniques have been developed for determining the response function of structures from measured vibration response to background excitation. The natural frequencies and mode shapes are then evaluated graphically from the frequency function plots. The methodology has been tested on a simple cantilever beam with known natural frequencies and mode shapes. The comparison between the theoretical and the computed natural frequencies and mode shapes is good for the lower modes. However, better curve-fitting techniques will be required in future, especially for higher modes. Readily available equipment necessary for the measurement of background vibration in a CANDU plant (which is commercially available) has been identified. An experimental program has been proposed to verify the methodology developed in this study. Recommendations are also made to study methods to improve the accuracy of the mode shape and natural frequency prediction

Experimental study of variations in background radiation and the effect on Nuclear Car Wash sensitivity

International Nuclear Information System (INIS)

Church, J; Slaughter, D; Norman, E; Asztalos, S; Biltoft, P

2007-01-01

Error rates in a cargo screening system such as the Nuclear Car Wash [1-7] depend on the standard deviation of the background radiation count rate. Because the Nuclear Car Wash is an active interrogation technique, the radiation signal for fissile material must be detected above a background count rate consisting of cosmic, ambient, and neutron-activated radiations. It was suggested previously [1,6] that the Corresponding negative repercussions for the sensitivity of the system were shown. Therefore, to assure the most accurate estimation of the variation, experiments have been performed to quantify components of the actual variance in the background count rate, including variations in generator power, irradiation time, and container contents. The background variance is determined by these experiments to be a factor of 2 smaller than values assumed in previous analyses, resulting in substantially improved projections of system performance for the Nuclear Car Wash

Cosmic background radiation anisotropy in an open inflation, cold dark matter cosmogony

Science.gov (United States)

Kamionkowski, Marc; Ratra, Bharat; Spergel, David N.; Sugiyama, Naoshi

1994-01-01

We compute the cosmic background radiation anisotropy, produced by energy-density fluctuations generated during an early epoch of inflation, in an open cosmological model based on the cold dark matter scenario. At Omega(sub 0) is approximately 0.3-0.4, the Cosmic Background Explorer (COBE) normalized open model appears to be consistent with most observations.

Cytogenetic findings from inhabitants of different ages in high background radiation areas of Yangjiang

International Nuclear Information System (INIS)

Chen Deqing; Yao Suyan; Zhang Chaoyang

1997-01-01

Objective: To explore the relationship between high background radiation and injurious effect on inhabitants. Method: Peripheral blood samples were collected from the inhabitants of 10, 40, 55 and 70 years old in high background radiation areas (HBRA) of Yangjiang, Chromosome preparations were carried out with conventional whole-blood microculture. Results: The percentage of dicentric chromosome with fragments in inhabitants of HBRA was significantly higher than that in control areas (CA) (0.469% vs. 0.315%, P<0.01), and there was an increase in the aberration frequencies with age (or accumulated doses). Conclusion: Chromosome aberration is an extremely sensitive indicator of radiation damage and a good radio-biodosimeter

Investigation of environmental natural penetrating radiation level in Beijing

International Nuclear Information System (INIS)

Wu Zengxin; Zhang Wenying; Zheng Rukuan; Wei Shujun; Ding Huiqiu

1992-01-01

The authors report the methods and results of investigation of environmental natural penetrating radiation level in Beijing. There were 83 measurement points selected, which were located at the vertexes of 1 x 1 km square meshes and uniformly distributed over the urban district. 173 net grid measuring points selected with grid spacing of 10 x 10 km and uniformly distributed over the suburban district. Another 131 more densely distributed points were added over some special areas. The results show that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate over field is 56.2, 56.4 and 50.1 nGy · h -1 respectively. The γ radiation dose rate is higher in west and north area than in southeast area. (2) The point-weighted average value of natural γ radiation dose rate over roads was 49.3 nGy · h -1 . (3) The point weighted and population-weighted average value of natural γ radiation dose inside buildings was 83.5 and 77.1 nGy · h -1 respectively. (4) The weighted average of air absorbed dose rate from the ionizing components of cosmic rays (except for neutron) over point number and population was respectively 29.0 and 27.5 nGy · h -1 indoors, and 32.3 and 30.8 nGy · h -1 outdoors. (5) The point and population-weighted means of natural penetrating radiation dose rate (the contribution from neutron is not included) are 112.8 and 104.5 nGy · h -1 indoors, respectively; 88.7 and 81.3 nGy · h -1 outdoors, respectively. (6) The annual effective dose equivalent per capital people natural γ radiation, cosmic ray and natural penetrating radiation was 0.43, 0.25 and 0.68 mSv respectively, and the annual collective effective dose equivalent was 4.0, 2.3 and 6.3 x 10 3 man · Sv, respectively

Natural radiation sources fabricated from potassic chemical fertilizers and application to radiation education

International Nuclear Information System (INIS)

Kawano, Takao

2010-01-01

Potassic chemical fertilizers contain potassium, a small part of which is potassium-40. Since potassium-40 is a naturally occurring radioisotope, potassic chemical fertilizers are often used for demonstrations of the existence of natural radioisotopes and radiation. To fabricate radiation sources as educational tools, the compression and formation method developed by our previous study was applied to 13 brands of commercially available chemical fertilizers containing different amounts of potassium. The suitability (size, weight, and solidness) of thus fabricated sources was examined and 12 of them were selected as easy-to-use radiation sources at radiation educational courses. The radiation strength (radiation count rate measured by a GM survey meter) and potassium content of the 12 sources were examined. It was found that the count rate was wholly proportional to the percentage of potassium, and a new educational application was proposed and discussed for understanding that the substance emitting radiation must be the potassium present in the raw fertilizers. (author)

Natural radiation, radioactive waste and chemical risk determinants

International Nuclear Information System (INIS)

Christensen, T.; Mustonen, R.; Edhwall, H.; Hansen, H.; Soerensen, A.; Stranden, E.

1990-01-01

Doses from natural radiation to the population in the Nordic countries are summarized, and man-made modifications of the natural radiation environment are discussed. An account is given for the radiological concequences of energy concervation by reduced ventilation. Risks from possible future releases of radioactivity from final depositories of spent nuclear fuel are compared to the risks from present natural radioactivity in the environment. The possibilities for comparison between chemical and radiological risks are discussed. 104 refs., 36 figs., 47 tabs

Natural radiation environment III

International Nuclear Information System (INIS)

Gesell, T.F.; Lowder, W.M.

1980-01-01

Separate abstracts were prepared for the 57 research papers presented at this symposium in April 1978 at Houston, Texas. This symposium provided a common forum for scientists in several disciplines that deal with natural radiation because there is an increasing interest in the environment as it pertains to human health and the competition for scarce energy and material resources

Natural indoor gamma background in Coonoor environment of South India

International Nuclear Information System (INIS)

Sivakumar, R.; Selvasekarapandian, S.; Mugunthamanikand, N.; Raghunath, V.M.

2002-01-01

Indoor natural radiation dose existing in dwellings of Coonoor have been estimated using thermoluminescent dosimeters. TLDs are displayed in indoors and are replaced after three-month period. The seasonal averages of the dose rate and the annual effective dose equivalent are calculated from the measured results. Geographical and seasonal variations as well as the differences between indoor to outdoor dose rates have also been studied. Very good correlation exists between the indoor dose rates measured by LTD and environmental radiation dosimeter with correlation coefficient of 0.91. The annual effective dose equivalent to the Coonoor population due to indoor gamma radiation was estimated to be 970 μSv/y for the period of 1997-1998. (author)

Radiological impact of natural and artificial sources of ionizing radiation. Report UNSCEAR 2000

International Nuclear Information System (INIS)

Cancio, D.

2001-01-01

The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was established by the General Assembly in 1995. It has the mandate to assess the levels and effects of ionizing radiation. During the last years UNSCEAR has undertaken a broad review of the natural and artificial sources of ionizing radiation. The results of these evaluations have been presented in a Report to the General Assembly with Scientific Annexes including extensive data for the world community (Report UNSCEAR 2000). The greatest contribution to radiation exposure comes from natural background sources. There are considerable variation in the exposures of the population depending on the altitude and latitude, characteristics of the soil and diet and the construction and ventilation features of houses. The global annual average per caput is 2.4 mSv with typical range 1 to 10 mSv. The next largest component comes from medical radiation examinations and treatments with an annual average of 0.4 mSv ranging from 0.04 to 1.0 mSv depending on the level o f medical care. The man-made practices, activities, and events in which radionuclides are released to the environment are always of much concern, but usually they contribute quite low to radiation exposure to humans. Atmospheric testing caused the greatest releases but nowadays very low residual annual levels of exposures persist (0.005 mSv). Nuclear Power production is responsible for only very low exposure and may reach in the future an average annual level of 0.0002 mSv. (Author)

Background radiation in two locations in Deaf Smith and Swisher Counties within the Palo Duro Basin

International Nuclear Information System (INIS)

1984-10-01

Data on external background radiation doses resulting from cosmic, terrestrial, and fallout sources and on concentrations of radioactivity in environmental media are presented and discussed. Doses to individuals located at the approximate centers of two locations in Texas, one in Deaf Smith County and the other in Swisher County, are given, as are the population doses to people residing within 50 miles of each of the approximate centers. No adjustments have been made for the effects of buildings on radiation doses - that is, the shielding from external radiation afforded by the buildings and radiation from building materials are not accounted for. Concentrations of radioactivity in air, water, and milk in the region are also given. Because of the lack of specific information on background radiation at the locations, the external-dose rates to people and the radioactivity levels in environmental media for the region have been taken from the literature. A background radiation survey will be conducted in the Palo Duro Basin to obtain additional data. 26 references, 3 figures, 15 tables

Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation.

Science.gov (United States)

Castillo, Hugo; Schoderbek, Donald; Dulal, Santosh; Escobar, Gabriela; Wood, Jeffrey; Nelson, Roger; Smith, Geoffrey

2015-01-01

The 'Linear no-threshold' (LNT) model predicts that any amount of radiation increases the risk of organisms to accumulate negative effects. Several studies at below background radiation levels (4.5-11.4 nGy h(-1)) show decreased growth rates and an increased susceptibility to oxidative stress. The purpose of our study is to obtain molecular evidence of a stress response in Shewanella oneidensis and Deinococcus radiodurans grown at a gamma dose rate of 0.16 nGy h(-1), about 400 times less than normal background radiation. Bacteria cultures were grown at a dose rate of 0.16 or 71.3 nGy h(-1) gamma irradiation. Total RNA was extracted from samples at early-exponential and stationary phases for the rt-PCR relative quantification (radiation-deprived treatment/background radiation control) of the stress-related genes katB (catalase), recA (recombinase), oxyR (oxidative stress transcriptional regulator), lexA (SOS regulon transcriptional repressor), dnaK (heat shock protein 70) and SOA0154 (putative heavy metal efflux pump). Deprivation of normal levels of radiation caused a reduction in growth of both bacterial species, accompanied by the upregulation of katB, recA, SOA0154 genes in S. oneidensis and the upregulation of dnaK in D. radiodurans. When cells were returned to background radiation levels, growth rates recovered and the stress response dissipated. Our results indicate that below-background levels of radiation inhibited growth and elicited a stress response in two species of bacteria, contrary to the LNT model prediction.

Occupational exposure to natural sources of radiation

International Nuclear Information System (INIS)

Ortiz, T.; Sciocchetti, G.; Rannou, A.

1993-01-01

The most important natural sources of radiation are analyzed. The situation in France, Italy, and Spain concerning protection against natural radiation is described, including the identification of sources, and defined practices, organizations charged of national surveys and the responsibility of regulatory bodies and the role of operating management. The activities of the international organizations (ICRP, CEC and IAEA) are presented and discussed, and existing actions toward harmonization in the CEC, IAEA and other international programs is also discussed. (R.P.) 23 refs., 2 tabs

Current Status of Radiation Processing of Natural Polymers in India

International Nuclear Information System (INIS)

Ramnani, S.P.

2010-01-01

Radiation processing is being used on commercial basis in India since 1974 with the operation of ISOMED plant for radiation sterilization of medical products and Electron beam machine (ILU-6) in 1986. Since then many new products and processes have been investigated and some of them have culminated into useful applications. Many Indian industries produce and process natural polymers for local consumption and export. India exports about 120,000 tons of polysaccharides every year. Natural polysaccharides like guar gum, gum acacia, gum tora, agar, psylium husk etc are treated with gamma radiation mainly for controlling microbial contamination and sterilization. Radiation processing has also been used to reduce molecular weight of the polysaccharides in some applications. Recently, a few new applications have emerged where natural polysaccharides are used as additives and which play important role in controlling basic radiation chemistry reactions to produce useful products. Developed at BARC, radiation processed wound dressings, superabsorbent materials and low molecular weight chitosan are the products which have been used and could find potential applications in health care and agriculture sector. Radiation processed hydrogel wound dressings containing natural polysaccharides have already been commercialized. Some of the applications recently developed at BARC using natural polymers are briefly described below

Natural products as radiation response modifiers

International Nuclear Information System (INIS)

Colin Seymour; Carmel Mothersill

2007-01-01

Complete text of publication follows. Protection of cells and organisms against low doses of radiation is a complex issue which must be considered at the level of cells, tissues and organisms. 'Protection' at one level, for example, prevention of cell death, may be adverse at another level, if it allows a damaged cell to survive and form a malignant tumour. Conversely, death of a cell carrying damage can be protective for the organism if it eliminates a damaged cell. Thus, it is important to understand the mechanisms involved in protection against radiation damage at several hierarchical levels. The use of natural products as radiation response modifiers is very attractive. Many of these compounds are readily available and their function and pharmacology is well understood. Some derive from venoms or natural defenses and are currently used in medicine, others include vitamins, antioxidants or cofactors, which are tried and tested nutritional supplements. Radiation effects may be targeted or untargeted. Radiation may interact directly within a cell causing a direct DNA lesion or it may elicit a bystander response from the irradiated cell. A bystander effect is produced when the irradiated cell apparently exhibits no damage from the radiation, but passes on a biochemical signal which induces neighbouring cells to apoptose or undergo a number of other responses usually associated with irradiation such as mutation induction, transformation, induction of ROS responses etc.. Effects induced in progeny of non-targeted cells in receipt of bystander signals include genetic instability, mini and microsatellite mutations and carcinogenesis. A key characteristic of these non targeted effects is that they occur at very low acute doses (of the order of 5mGy) and saturate so that effective prevention requires an agent which can effectively shut off the mechanism. While the mechanism is not fully known, it is thought to involve signals from irradiated cells communicating via

Investigation of environmental natural penetrating radiation level in Anhui province

International Nuclear Information System (INIS)

Zhu Jingqiu; Chen Shuping; Jiang Shan; Zhu Xingsheng; Huang Jiangbin; Wu Chuanyong; Wang Weining

1992-01-01

The methods and results of the investigation on natural penetrating radiation level in Anhui Province in 1987 are presented. The results show that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate for field is 5.67, 5.62 and 5.55 x 10 -8 Gy· -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 5.38 x 10 -8 Gy·h -1 ; (3) The point-weighted and population-weighted average value of natural γ radiation dose rate inside buildings is 9.59 and 9.36 x 10 -8 Gy·h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 2.64 and 2.62 x 10 -8 ·h -1 , and outside buildings is 2.95 and 2.94 x 10 -8 ·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 12.23 and 11.99 x 10 -8 Gy·h -1 , outside buildings is 8.62 and 8.49 x 10 -8 ·h -1 , respectively; (6) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation is 0.51, 0.24, and 0.75 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 2.5, 1.2 and 3.7 x 10 4 man·Sv, respectively

Human genetic studies in areas of high natural radiation

International Nuclear Information System (INIS)

Freire-Maia, A.; Krieger, H.

1978-01-01

Data have been obtained by a genetic-epidemiological survey of a population living in the State of Espirito Santo (Brazil), and subjected to mean levels of natural radiation, per locality, ranging from 7 to 133 μrad/hr. Multiple regression models have been applied to the data, and the results showed no detectable effect of natural radiation on the sex ratio at birth, on the occurrence of congenital anomalies, and on the numbers of pregnancy terminations, stillbirths, livebirths, and post-infant mortality in the children, as well as fecundity and fertility of the couples (these observations contradict some data from the literature, based on official records and without analyses of the concomitant effects of other variables). However, nonsignificant results cannot be considered as disproving harmful effects of natural radiation on mortality and morbidity. These results may simply mean that other causes of mortality and morbidity are so important, under the conditions of the study, that the contribution of low-level, chronic natural radiation is made negligible. (author)

Radioactive background of Granito Madeira, north Amazonas, Brazil

Energy Technology Data Exchange (ETDEWEB)

Moura, Vanderlei; Pereira, Claubia; Martins, Agnaldo Kenji, E-mail: vandermoura@gmail.com, E-mail: claubia@nuclear.ufmg.br, E-mail: amartins@mtaboca.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Mineracao Taboca S.A., Presidente Figueiredo, AM (Brazil)

2017-11-01

Naturally occurring radionuclides, such as the uranium and thorium decay chains, are present in rocks and soils. But its distribution is not homogeneous: it depends on the type of rock being that those of volcanic origin have higher concentrations of uranium and thorium. These are NORM. Locations with NORM present higher dose rates than the world average. Thus, the determination of the natural radioactivity of a NORM region is of extreme importance since it provides data for the estimation of human exposure to natural radiation. In addition, if there is a mining company exploring NORM, the background radiation estimation should be considered in the decommissioning and future planning. There are places in Brazil, such as Granito Madeira in the state of Amazonas, in the north of Brazil, where NORM is present. It is an extremely remote area located within the Amazon Forest currently in the process of open cast mining. In this study, the iodide scintillator detector was used to measure and map the natural background radiation of the Granito Madeira using a scintillator detector of sodium iodide that was transported in tracks within the forest. The data obtained were georeferenced, classified and used to obtain the annual dose related to gamma radiation. The results are presented in frequency histograms and maps. The annual average was (6.0 ± 3.0) mSv.y{sup -1}. These data were compared to those available from other regions with NORM in Brazil and the 2010 UNSCEAR report. (author)

Radioactive background of Granito Madeira, north Amazonas, Brazil

International Nuclear Information System (INIS)

Moura, Vanderlei; Pereira, Claubia; Martins, Agnaldo Kenji

2017-01-01

Naturally occurring radionuclides, such as the uranium and thorium decay chains, are present in rocks and soils. But its distribution is not homogeneous: it depends on the type of rock being that those of volcanic origin have higher concentrations of uranium and thorium. These are NORM. Locations with NORM present higher dose rates than the world average. Thus, the determination of the natural radioactivity of a NORM region is of extreme importance since it provides data for the estimation of human exposure to natural radiation. In addition, if there is a mining company exploring NORM, the background radiation estimation should be considered in the decommissioning and future planning. There are places in Brazil, such as Granito Madeira in the state of Amazonas, in the north of Brazil, where NORM is present. It is an extremely remote area located within the Amazon Forest currently in the process of open cast mining. In this study, the iodide scintillator detector was used to measure and map the natural background radiation of the Granito Madeira using a scintillator detector of sodium iodide that was transported in tracks within the forest. The data obtained were georeferenced, classified and used to obtain the annual dose related to gamma radiation. The results are presented in frequency histograms and maps. The annual average was (6.0 ± 3.0) mSv.y"-"1. These data were compared to those available from other regions with NORM in Brazil and the 2010 UNSCEAR report. (author)

Propagation of Polarized Cosmic Microwave Background Radiation in an Anisotropic Magnetized Plasma

International Nuclear Information System (INIS)

Moskaliuk, S. S.

2010-01-01

The polarization plane of the cosmic microwave background radiation (CMBR) can be rotated either in a space-time with metric of anisotropic type and in a magnetized plasma or in the presence of a quintessential background with pseudoscalar coupling to electromagnetism. A unified treatment of these three phenomena is presented for cold anisotropic plasma at the pre-recombination epoch. It is argued that the generalized expressions derived in the present study may be relevant for direct searches of a possible rotation of the cosmic microwave background polarization.

Speech recognition in natural background noise.

Directory of Open Access Journals (Sweden)

Julien Meyer

Full Text Available In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR. Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A, reference at 1 meter at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (-8.8 dB to -18.4 dB. Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda. Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for

Speech recognition in natural background noise.

Science.gov (United States)

Meyer, Julien; Dentel, Laure; Meunier, Fanny

2013-01-01

In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR). Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A), reference at 1 meter) at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (-8.8 dB to -18.4 dB). Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda). Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for future studies.

Thyroid nodularity and chromosome aberrations among women in areas of high background radiation in China

International Nuclear Information System (INIS)

Wang, Z.Y.; Boice, J.D. Jr.; Wei, L.X.; Beebe, G.W.; Zha, Y.R.; Kaplan, M.M.; Tao, Z.F.; Maxon, H.R. III; Zhang, S.Z.; Schneider, A.B.

1990-01-01

Thyroid nodularity following continuous low-dose radiation exposure in China was determined in 1,001 women aged 50-65 years who resided in areas of high background radiation (330 mR/yr) their entire lives, and in 1,005 comparison subjects exposed to normal levels of radiation (114 mR/yr). Cumulative doses to the thyroid were estimated to be of the order of 14 cGy and 5 cGy, respectively. Personal interviews and physical examinations were conducted, and measurements were made of serum thyroid hormone levels, urinary iodine concentrations, and chromosome aberrations in circulating lymphocytes. For all nodular disease, the prevalences in the high background and control areas were 9.5% and 9.3%, respectively. For single nodules, the prevalences were 7.4% in the high background area and 6.6% in the control area (prevalence ratio = 1.13; 95% confidence interval = 0.82-1.55). There were no differences found in serum levels of thyroid hormones. Women in the high background region, however, had significantly lower concentrations of urinary iodine and significantly higher frequencies of stable and unstable chromosome aberrations. Increased intake of allium vegetables such as garlic and onions was associated with a decreased risk of nodular disease, which seems consistent with experimental studies suggesting that allium compounds can inhibit tumor growth and proliferation. The prevalence of mild diffuse goiter was higher in the high background radiation region, perhaps related to a low dietary intake of iodine. These data suggest that continuous exposure to low-level radiation throughout life is unlikely to appreciably increase the risk of thyroid cancer. However, such exposure may cause chromosomal damage

Acute myeloid leukaemia in relation to background radiation in houses

International Nuclear Information System (INIS)

Axelson, O.; Flodin, U.

1993-01-01

A review is presented on the results of several studies performed since the late 1970s to elucidate the role of background gamma radiation in houses and the incidence of cancer, especially leukemia. The influence of exposure time is discussed and the age dependence of the latency period is outlined. Estimation of dose-response relationships are presented. (MG)

Natural and man-made radiation: is there a distinction

International Nuclear Information System (INIS)

Moghissi, A.A.; Carter, M.W.

1976-01-01

The Atomic Energy Act of 1954 and its subsequent amdenments separate radioactive materials and ionizing radiation into two categories. The one category, man-made, which is covered by that Act has received considerable care and attention and thus causes a small population exposure and dose. However, the second category, natural, has received very little care and attention and, in many cases, has been neglected. Ironically, natural radiation causes the major fraction of the population exposure. This paper describes the exposure from these categories, identifies laws covering each category, and attempts a risk-benefit analysis of the subject. It also discusses the difficulties associated with differentiating between natural and man-made radiation

Investigation of environmental natural penetrating radiation level in Hubei Province

International Nuclear Information System (INIS)

Zhang Sihui; Zhang Jiaxian

1992-01-01

The methods and results of the investigation on natural penetrating radiation level in Hubei Province are presented, 290 measuring points of 25 x 25 km-grid were set uniformly up all over the province, with 385 densely measuring points of different types added. The results show that: (1) The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 60.8, 58.5 and 60.9 nGy ·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 55.3 nGy·h -1 ; (3) The population-weighted and point-weighed average value of natural γ radiation dose rate inside buildings is 94.5 and 93.2 x 10 nGy·h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 27.8 and 26.3 nGy·h -1 , and outside buildings is 31.8 and 30.4 nGy·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside building is 121.0 and 120.7 nGy·h -1 , outside buildings is 92.8 and 88.9 nGy·h -1 , respectively; (6) The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.24, 0.52 and 0.76 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 1.2, 2.5 and 3.7 x 10 4 man·Sv, respectively

Investigation of environmental natural penetrating radiation level in Heilongjiang Province

International Nuclear Information System (INIS)

Liu Yuncheng; Wu Chengxiang; Zhang Juling; Zhao Defeng

1994-01-01

The methods and results of the investigation on natural penetrating radiation level in Heilongjiang Province are presented. 221 25 km x 25 km-grid measuring points were set uniformly up all over the province, with 555 densely measuring points of different types added. The results show that: (1)The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 53.5, 58.5 and 54.2 nGy·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 58.4 nGy·h -1 ; (3) The population-weighted and point-weighted average value of natural γ radiation dose rate inside buildings is 85.2 and 78.9 nGy·h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 28.6 and 28.1 nGy·h -1 , and outside buildings is 32.4 and 32.2 nGy·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 109.7 and 112.8 nGy·h -1 , outside buildings is 84.8 and 91.0 nGy·h -1 , respectively; (6) The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.26, 0.48 and 0.73 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 0.8 x 10 4 , 1.6 x 10 4 and 2.4 x 10 4 man·Sv, respectively

Investigation of environmental natural penetrating radiation level in Jiangsu province

International Nuclear Information System (INIS)

Liu Ming; Wang Chengbao.

1993-01-01

The methods and results of in investigation on natural penetrating radiation level in Jiangsu Province are presented. 182 25 km x 25 km-grid measuring points were set up uniformly all over the province, with 236 densely measuring points of different types added. The results show that: (1) The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 50.3, 50.6 and 50.4 nGy · h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 47.1 nGy · h -1 ; (3) The population-weighted and point-weighted average value of natural γ radiation dose rate inside buildings is 89.7 and 89.2 nGy · h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 26.0 and 25.8 nGy · h -1 , and outside buildings is 29.2 and 29.1 nGy · h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 115.1 and 115.5 nGy · h -1 , outside buildings is 79.5 and 79.7 nGy · h -1 , respectively; (6) The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.23, 0.48 and 0.71 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 3.0, 1.5 and 4.5 x 10 4 man · Sv, respectively

Investigation of environmental natural penetrating radiation level in Shaanxi Province

International Nuclear Information System (INIS)

Zhang Chunfang; Li Jiyin

1994-01-01

The methods and results of the investigation on natural penetrating radiation level in Shaanxi Province are presented. 359 25 km x 25 km-grid measuring points were set uniformly up all over the province, with 433 densely measuring points of different types added. The results show that: (1) The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 62.0, 63.0 and 61.0 nGy·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 63.0 nGy · h -1 ; (3)The population-weighted and point-weighted average value of natural γ radiation dose rate inside buildings is 100.0 and 98.0 nGy·h -1 , respectively; (4)The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 32.0 and 31.0 nGy·h -1 , and outside buildings is 37.0 and 36.0 nGy·h -1 , respectively; (5)The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 130.0 and 131.0 nGy·h -1 , outside buildings is 130.0 and 130.0 nGy·h -1 , respectively; (6)The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.55, 0.28 and 0.83 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 1.63, 0.83 and 2.46 x 10 4 man·Sv, respectively

Indoor exposure to natural radiation in Denmark

International Nuclear Information System (INIS)

Ulbak, K.; Stenum, B.; Soerensen, A.; Majborn, B.; Boetter-Jensen, L.; Nielsen, S.P.

1988-01-01

Assessment of the exposures to the Danish population from different natural radiation sources including building materials, drinking water, fly ash etc. has been performed from 1975 and up till now. In 1987 a comprehensive nationwide investigation of the gamma exposures and radon levels in 500 randomly selected Danish dwellings will be concluded by the National Institute of Radiation Hygiene. At the same time the Danish authorities will publish a control strategy for limiting the exposure of the Danish population from natural sources, especially from radon daughter exposure in dwellings. The presentation will outline the main results of the nationwide survey in Danish dwellings together with the main principles behind and the consequences of the initiated control strategy for limiting the exposures from natural radioactive sources

Measurement of background gamma radiation in the northern Marshall Islands.

Science.gov (United States)

Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

2016-06-21

We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered.

Radiation vulcanization of natural rubber latex sensitized with commercial gases

International Nuclear Information System (INIS)

Chirinos, H.; Lugao, A.

2002-01-01

The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

Radiation vulcanization of natural rubber latex sensitized with commercial gases

Energy Technology Data Exchange (ETDEWEB)

Chirinos, H.; Lugao, A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

2002-07-01

The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

Perception of radiation hazards

International Nuclear Information System (INIS)

Sorenson, J.A.

1986-01-01

The health risks of radiation have been carefully studied and are relatively well understood in comparison with other risks to the human environment. Public perception of these risks often is distorted, due in part to lack of familiarity with the actual risk levels involved. There is a need for dissemination to the public of accurate information on radiation risks as well as to patients and volunteer subjects for studies involving radiation exposures. Often such information can be presented meaningfully by comparing the risks of radiation exposure with other, more familiar risks. Natural background radiation is a universally present and generally accepted source of risk, and thus serves as one reference against which to compare the risks of other radiation exposures. Natural background radiation averages about 100 mrem/yr, but much higher levels are encountered in some parts of the US (400 mrem/yr) and worldwide (2000 mrem/yr). These variations are due primarily to differences in cosmic ray intensity with altitude and in terrestrial radiation originating from soil and rocks. Radiation risks also may be compared with the risks of other human activities, both voluntary and involuntary. The former are useful for comparisons with the risks of voluntary radiation exposures such as occupational exposure and participation in medical or research procedures involving radiation. Involuntary radiation exposure, such as might result from the transportation and disposal of radioactive waste, poses a more complicated issue. Comparisons of such exposures to natural background radiation levels and their variations are helpful. Two other concepts that have been proposed for assessing the relative risk of low-level radiation exposure are de minimus risk and probability of causation. 28 references

The Local Contribution to the Microwave Background Radiation(MBR)

Science.gov (United States)

Narlikar, Jayant V.; Pecker, Jean-Claude; Wickramasinghe, N. Ch.

2010-11-01

In the early fifties, from the early theories of the big bang universe, Gamow, Alpher & Herman have predicted the existence of a "cosmological" microwave background radiation, corresponding to a black body of a few Kelvins. When, in 1964, Penzias & Wilson, observed a radiation at 2.7K, the scientific world concluded quickly it was a proof, a final proof, of the big bang type cosmologies. But it should be realized that, in the beginning of the XX-th century, several authors, from Guillaume to Eddington, have predicted the same thing in a static Universe. We have redone the calculations of Eddington, and based them on the recent and very accurate photometric results from the satellite Hipparcos. In the absence of any expansion, of any big bang type behaviour, we compute the local temperature induced by the reradiation by local matter of stellar radiation, and we found it to be in excellent agreement with the observations. This result, completed by a careful discussion, could lead to a dramatic revision of the classical cosmological concepts.

Could unstable relic particles distort the microwave background radiation?

International Nuclear Information System (INIS)

Dar, A.; Loeb, A.; Nussinov, S.

1989-01-01

Three general classes of possible scenarios for the recently reported distortion of the microwave background radiation (MBR) via decaying relic weakly interacting particles are analyzed. The analysis shows that such particles could not reheat the universe and cause the spectral distortion of the MBR. Gravitational processes such as the early formation of massive black holes may still be plausible energy sources for producing the reported spectral distortion of the MBR at an early cosmological epoch. 24 references

Thermal annealing of natural, radiation-damaged pyrochlore

Energy Technology Data Exchange (ETDEWEB)

Zietlow, Peter; Beirau, Tobias; Mihailova, Boriana; Groat, Lee A.; Chudy, Thomas; Shelyug, Anna; Navrotsky, Alexandra; Ewing, Rodney C.; Schlüter, Jochen; Škoda, Radek; Bismayer, Ulrich

2017-01-01

Radiation damage in minerals is caused by the α-decay of incorporated radionuclides, such as U and Th and their decay products. The effect of thermal annealing (400–1000 K) on radiation-damaged pyrochlores has been investigated by Raman scattering, X-ray powder diffraction (XRD), and combined differential scanning calorimetry/thermogravimetry (DSC/TG). The analysis of three natural radiation-damaged pyrochlore samples from Miass/Russia [6.4 wt% Th, 23.1·10

Concentrations of radionuclides in cassava growing in high background radiation area and their transfer

International Nuclear Information System (INIS)

Huang Jialin; Zha Yongru; Guo Yicao

1985-01-01

The concentrations of several natural radionuclides in common cassava (Manihot esculenta Crantz) growing in Yangjiang County, a high background radiation area in Guangdong Province, and their uptake from soil and distribution in the plant were investigated. The results show that the concentrations of natural uranium and thorium in cassava root are of the order of 10 -6 g/kg, and those of radium-226, radium-228, lead-210 and polonium-210 are of the order of 10 -11 Ci/kg. The highest level is 9.30 +- 0.30 x 10 -11 Ci/kg (lead-210), and the lowest is 3.99 +- 0.20 x 10 -11 Ci/kg (radium-226). The levels of natural uranium, thorium, radium-226 and polonium-210 in cassava are below the limits stipulated by the regulations for food hygiene in China, while the lead-210 level approaches the limit. It is noticeable that the highest level of radium-228 is 7.28 +- 1.03 x 10 -11 Ci/kg, 10.4 times higher than the limit. The transfer of all he nuclides from soil to different parts of cassava shows a pattern contrary to that of he nuclides in the other regions where uranium-and radium-containing waste water and phosphate fertilizer are used in agriculture

Cytogenetic investigation in a population living in the high background radiation area in China

Energy Technology Data Exchange (ETDEWEB)

Deqing, C.

1980-04-01

On the basis of the previous investigation, 24,000 metaphases of the lymphocytes of 120 inhabitants from Tongyou region, where the highest individual cummulative exposure per year of 372 mR in weighted average was recorded in the high background radiation area selected, have been analysed with the method recommended by WHO in 1973, in order to determine the extent of human chromosome aberrations induced by the high background radiation of various levels. The results show that the difference between the total number of chromosome breakages in the individuals living in the high background radiation area and that in the control area (0.32x10/sup -2/ and 0.27x10/sup -2/ per cell respectively) is not significant whereas that between the numbers of two-hite aberrations (mainly dicentric) in the same two groups (0.042x10/sup -2/ and 0.0048x10/sup -2/ per cell) is significant (X/sup 2/ = 6.1475, P<0.05). In addition, the normal value of the chromosome aberrations of human lymphocytes was analyzed.

Acceptable level of radiation risk and its perception

International Nuclear Information System (INIS)

Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

1987-01-01

The acceptable level of radiation risk for public members, that is 10 -5 /y, was proposed by ICRP and other international organizations. We studied to survey basic procedures of deriving this value and to derive an acceptable risk value in Japan by using similar procedures. The basic procedures to derive 10 -5 /y were found as follows; (1) 0.1 percent of annual mortality from all diseases, (2) 0.1 percent of life time risk, (3) one percent of mortality from all causes in each age cohort and (4) corresponding value to 1 mSv annual radiation exposure. From these bases we derived the value of 10 -5 /y as acceptable risk level in Japan. The perception to risk level of 10 -5 /y in conventional life was investigated by means of questionnaires for 1,095 college students living in Tokyo. The risks considered in this study were natural background radiation, coffee, skiing, X-ray diagnosis, spontaneous cancer, passive smoking and air pollution. The most acceptable risk was the risk related with natural background radiation. And the risk of natural background radiation was more easily accepted by the students who had knowledges on natural background radiation. On the other hand, the risk from air pollution or passive smoking was the most adverse one. (author)

The contribution of accreting black holes to the background radiation density

International Nuclear Information System (INIS)

Carr, B.J.

1979-01-01

Black holes could generate radiation as a result of accretion. The requirement that this radiation should not have a density exceeding the observed background density places an interesting limit on the number of black holes, depending on the wavelength at which the radiation is generated and the efficiency with which it is produced from accreted material. Consideration of the radiation produced in the present epoch already constrains the mass range in which black holes could have a significant cosmological density. For pregalactic black holes, which may have been accreting more rapidly in the past, the constraint could be even stronger. However, because pregalactic accretion will in general increase the matter temperature of the Universe, it is a self-limiting process. For this reason the pregalactic accretion limit is not as strong as one might naively expect and it is generally weaker than the present epoch limit. (author)

Nature and magnitude of the problem of spent radiation sources

International Nuclear Information System (INIS)

1991-09-01

Various types of sealed radiation sources are widely used in industry, medicine and research. Virtually all countries have some sealed sources. The activity in the sources varies from kilobecquerels in consumer products to hundreds of pentabecquerels in facilities for food irradiation. Loss or misuse of sealed sources can give rise to accidents resulting in radiation exposure of workers and members of the general public, and can also give rise to extensive contamination of land, equipment and buildings. In extreme cases the exposure can be lethal. Problems of safety relating to spent radiation sources have been under consideration within the Agency for some years. The first objective of the project has been to prepare a comprehensive report reviewing the nature and background of the problem, also giving an overview of existing practices for the management of spent radiation sources. This report is the fulfilment of this first objective. The safe management of spent radiation sources cannot be studied in isolation from their normal use, so it has been necessary to include some details which are relevant to the use of radiation sources in general, although that area is outside the scope of this report. The report is limited to radiation sources made up of radioactive material. The Agency is implementing a comprehensive action plan for assistance to Member States, especially the developing countries, in all aspects of the safe management of spent radiation sources. The Agency is further seeking to establish regional or global solutions to the problems of long-term storage of spent radiation sources, as well as finding routes for the disposal of sources when it is not feasible to set up safe national solutions. The cost of remedial actions after an accident with radiation sources can be very high indeed: millions of dollars. If the Agency can help to prevent even one such single accident, the cost of its whole programme in this field would be more than covered. Refs

COMPARISON OF NATURAL BACKGROUND DOSE RATES FOR RESIDENTS OF THE AMARGOSA VALLEY, NV, TO THOSE IN LEADVILLE, CO, AND THE STATES OF COLORADO AND NEVADA

International Nuclear Information System (INIS)

D. Moeller and L. C. Sun

2006-01-01

In the latter half of 2005, the U.S. Environmental Protection Agency (USEPA) published a Proposed Rule (40 CFR Part 197) for establishing a dose rate standard for limiting radionuclide releases from the proposed Yucca Mountain high-level radioactive waste repository during the time period from 10 4 to 10 6 years after closure. The proposed standard was based on the difference in the estimated total dose rate from natural background in the Amargosa Valley and the ''average annual background radiation'' for the State of Colorado. As defined by the USEPA, ''natural background radiation consists of external exposures from cosmic and terrestrial sources, and internal exposures from indoor exposures to naturally-occurring radon''. On the basis of its assessments, the USEPA estimated that the difference in the dose rate in the two identified areas was 3.5 mSv y -1 . The purpose of this review was to provide an independent evaluation and review of this estimate. One of the first observations was that, because site-specific dose rate measurements for the Amargosa Valley ''were not available'', the dose rates for various sources of natural background in that area, used by the USEPA in its assessment, were based on modifications of the average values for the State of Nevada. A second observation was that the conversion factor applied in estimating the dose rates due to exposures to indoor radon and its decay products was a factor of 2 higher than the currently accepted value. Further review revealed that site-specific data for many natural background sources in the Amargosa Valley were available. One particularly important observation was that about 91% of the residents of that area live in mobile homes which, due to their construction and design, have indoor radon concentrations comparable to, or less than, those outdoors. For that reason, alone, the USEPA estimate of the average dose rate for residents of the Amargosa Valley, due to indoor radon, was not valid. For purposes

The background of external γ radiation in the proportional counters in SAGE experiment

International Nuclear Information System (INIS)

Gavrin, V.N.; Gorbachev, V.V.

2003-01-01

The influence of external γ radiation on the process of 71 Ge-decay counting in proportional counters in SAGE experiment of solar neutrino flux measurement is examined. One determines the systematic error of SAGE result, connected with radon decays inside the air volume surrounding the counters, and the background counting rate of proportional counters from γ radiation of passive and active shield [ru

Doses from Medical Radiation Sources

Science.gov (United States)

... Medical Radiation Sources Michael G. Stabin, PhD, CHP Introduction Radiation exposures from diagnostic medical examinations are generally ... of exposure annually to natural background radiation. Plain Film X Rays Single Radiographs Effective Dose, mSv Skull ( ...

Areas with increased natural radioactivity. Pt. 7

International Nuclear Information System (INIS)

Soman, S.D.; Nambi, K.S.V.

1990-03-01

When studying possible health effects of environmental radioactivity to man, areas of high natural radiation background are especially valuable. The classical and most investigated areas with this respect in the world are the monazite sand regions on the beaches of the States of Kerala and Tamil Nadu in South-India. Indian scientists from the Bhabha Atomic Research Center (BARC) have investigated possible health effects to man by the high natural background radiation in this area since about thirty years. As a remarkable result of the epidemiological studies, no significant genetical radiation damage effects within a collective of about seventythousand investigated persons could be observed. When studying lung cancer risks as a function of natural radiation exposure in the region of relatively low doses, the central problem is, how to extrapolate from the high doses of uranium miners to zero doses. Since the relative number of lung cancer is too small and does not exceed the statistical noise level, no significant experimental approval could be made until today. Therefore, one has to rely mainly on three different hypothesis, among which one cannot make an experimental decision at the moment. Hypothesis I (linear extrapolation) is the most pessimistic one, which denies the existence of repair mechanisms. Hypethesis II (threshold behaviour) is more realistic and considers repair mechanisms. Hypothesis III (hormesis effect) assumes positive health effects at lower radiation doses because of the proved existence of repair mechanisms in the living human cell and their stimulation by irradiation. In possible agreement with hypothesis III, within the last few years several authors in different areas of the world with higher natural radiation background have observed a significant decrease of lung cancer risk with increasing natural radiation background. The authors of this report are demonstrating this behaviour for India with their sets of data. (orig./MG)

Measurement of the cosmic background radiation temperature at 6.3 cm

International Nuclear Information System (INIS)

Mandolesi, N.; Calzolari, P.; Cortiglioni, S.; Morigi, G.

1984-01-01

We present results of a measurement of the cosmic background radiation temperature at a wavelength of 6.3 cm. We obtained the value T/sub CBR/ = 2.71 +- 0.20 K. This is in good agreement with, and has a smaller error than, any previous measurement at equal or longer wavelengths

Analysis of population dosimetry data in the high level natural radiation areas, Kerala, India

International Nuclear Information System (INIS)

Chougaonkar, M.P.; Mayya, Y.S.; Koya, P.K.M.; Cheriyan, V.D.; Seshadri, M.; Eappen, K.P.; Ramachandran, T.V.; Jojo, P.J.; Predeep, P.

2010-01-01

In the Indian scenario, Kerala has huge monazite bearing sand deposits on the west coast thereby having high natural background radiation levels. Extensive studies on the radiation dosimetry as well as effects on the human health are therefore being carried out in the region. We have recently completed a dosimetric survey aimed for epidemiological studies using case control methodology. This study, in collaboration with two local colleges in Kollam, Kerala, was taken up to study the relationship of congenital malformations and radiation exposures, if any. The two conditions that were selected were mental retardation and cleft lip-palate. Stringent selection criteria were set in selecting the cases and suitable controls. A ratio of 1:3 for case:control was selected for getting the optimum statistical significance from the data generated. The paper describes the methodology of dosimetric survey and the analysis of dose data based on case and controls

Radiological Protection Experience with natural sources of radiation

International Nuclear Information System (INIS)

Quindos, L. S.; Fernandez, P. L.; Vinuela, J.; Arteche, J.; Sainz, G.; Gomez, J.; Matarranz

2003-01-01

During the last twenty five years the research Radon Group of the Medical Physics Unit of the University of Cantabria has been involved in projects concerning the measurement of natural radiation, in special that coming from radon gas. At this moment we have available for this field a lot of information in different formats, as paper, video and CD, interesting not only for public in general but also for professionals interested in the evaluation of doses coming from natural sources of radiation. (Author)

Americans' Average Radiation Exposure

International Nuclear Information System (INIS)

2000-01-01

We live with radiation every day. We receive radiation exposures from cosmic rays, from outer space, from radon gas, and from other naturally radioactive elements in the earth. This is called natural background radiation. It includes the radiation we get from plants, animals, and from our own bodies. We also are exposed to man-made sources of radiation, including medical and dental treatments, television sets and emission from coal-fired power plants. Generally, radiation exposures from man-made sources are only a fraction of those received from natural sources. One exception is high exposures used by doctors to treat cancer patients. Each year in the United States, the average dose to people from natural and man-made radiation sources is about 360 millirem. A millirem is an extremely tiny amount of energy absorbed by tissues in the body

Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

Energy Technology Data Exchange (ETDEWEB)

Kulisek, J.A., E-mail: Jonathan.Kulisek@pnnl.gov; Schweppe, J.E.; Stave, S.C.; Bernacki, B.E.; Jordan, D.V.; Stewart, T.N.; Seifert, C.E.; Kernan, W.J.

2015-06-01

Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, {sup 60}Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

Distortions in the Rayleigh-Jeans region of the cosmic background radiation spectrum

International Nuclear Information System (INIS)

De Zotti, G.

1982-01-01

The theory of the origin and evolution of distortions in the Rayleigh-Jeans region of the cosmic background radiation spectrum is reviewed. Some proposed experiments, designed to substantially improve our knowledge of that portion of the spectrum, are briefly described. (author)

Radiation vulcanization of natural rubber latex

International Nuclear Information System (INIS)

Wan Manshol bin Wan Zin; Norjanah binti Mohid

1994-01-01

This paper describes the experimental techniques and the results of radiation vulcanization of natural rubber latex carried out on several high ammonia latices available in the country. The efficiency of various sensitisers and stabilisers used were evaluated in terms of the gamma radiation dose required to produce the maximum tensile strengths. The extent of crosslinking of RVNRL sample films were estimated by equilibrium swelling ratio measurements. The stability of pre-irradiated and post-irradiated samples were monitored using viscosity measurements as the parameter

Determination of exposure rates from natural background radiation in Khartoum using LiF:Mg,Cu,P (GR-200) and CaSo4: Mn TLD chips

International Nuclear Information System (INIS)

Suliman, I.I.; Khangi, F.A.; Shaddad, I.A.; Suliman, I.A.; El Amin, O.I.

2002-01-01

The exposure rates from natural background radiation - including terrestrial gamma radiation and the ionizing component of cosmic rays - were measured for the first time in the city of khartoum using two types of TLD materials: LiF:Mg,Cu,P (GR-200) and CaSo 4 :Mn TLD chips. Measurements were performed at two sites simultaneously, one site was selected on land in the vicinity of the Sudan Atomic Energy Commission, for the purposes of the measurement of the total exposure rate outdoors, while the other site was located on a buoy anchored in the Blue Nile, and was selected to measure the exposure rate due to the ionizing component of cosmic rays. The investigations were conducted for periods of between 5 and 28 days. Calibration was performed on a selected number of dosimeters to determine the exposure rates at each site. The exposure rates from the ionizing component of cosmic rays in Khartoum were found to be respectively 33 nGy.h -1 and 30 nGy.h -1 , in the measurements performed within the scope of this work using GR-200 and CaSo 4 :Mn dosimeters, while the total values for exposure on land were found to be 45 nGy.h -1 and 42 nGy.h -1 respectively. These values compare reasonably well with other national averages reported in the UNSCEAR publication. The comparison of the results for the two dosimetric materials demonstrates both the sensitivity and suitability of GR-200 for the purposes of environmental monitoring (orig.)

On the contribution of a stochastic background of gravitational radiation to the timing noise of pulsars

Science.gov (United States)

Mashhoon, B.

1982-01-01

The influence of a stochastic and isotropic background of gravitational radiation on timing measurements of pulsars is investigated, and it is shown that pulsar timing noise may be used to establish a significant upper limit of about 10 to the -10th on the total energy density of very long-wavelength stochastic gravitational waves. This places restriction on the strength of very long wavelength gravitational waves in the Friedmann model, and such a background is expected to have no significant effect on the approximately 3 K electromagnetic background radiation or on the dynamics of a cluster of galaxies.

Environments with elevated radiation levels from natural radioactive substances

International Nuclear Information System (INIS)

Sohrabi, M.

2000-01-01

Some areas in the world have elevated levels of radioactive substances in the environment forming elevated radiation areas (ERAs) where public potential annual effective doses can exceed even the dose limit of radiation workers. Such radioactive substances are either terrestrial natural radioactivity added naturally in the soil or natural and/or man-made radioactivity from human activities added into the environment. If radioactivity is added naturally, elevated natural radiation areas (ENRAs) are formed. Based on the classification criteria introduced by the author, such regions are divided into static and dynamic areas. They are also classified in accordance with their level of potential effective dose to the public. Some main ENRAs are classified. Highlights are presented of the results of activity studies carried out in selected areas. The concepts discussed can also be applied to areas formed by human activities. The author suggests some guidelines for future studies, regulatory control and decision making, bearing in mind the need for harmonization of policies for regulatory control and remedial actions at sites to protect the public from environmental chronic exposures. (author)

Some perspectives on radiation protection

International Nuclear Information System (INIS)

Sinclair, W.K.

1979-01-01

A brief review of the history and organizational structure of the NCRP is given. Summaries are given of a number of NCRP radiation protection guides dealing with hazards from 85 Kr, radiation exposures from consumer products, basic radiation protection criteria, and doses from natural background radiation

Gamma background irradiation. Standards and reality

International Nuclear Information System (INIS)

Miloslavov, V.

1998-01-01

The systematic deviation of the results of measuring the power of air dose absorbed from the natural gamma background radiation in Bulgaria is inadmissibly large and variable. This in turn augments the dispersion of results as well as the mean value relative to worldwide data, to an implausible level, hardly attributable to the variegated geographical relief of the country. Thus in practice local anthropogenic increases hardly lend themselves to detection and demonstration. In the Radiation Protection Standards (RPS-92) in effect in Bulgaria, and in other documents concerning the same radiation factors as well, the maximum allowable limits for the population as a whole are clearly specified on the basis of worldwide expertise along this line. As a rule these limits are being exceeded by the actually measured values, and for this reason the cited documents contain a clause stipulating that these limits do not refer to the natural radiation background and therefore the latter may be virtually ignored. Thus the basic risk factor for the population goes beyond control at levels commensurable with the officially established limits, its twofold increase inclusive. The maximum allowable limit becomes undefinable. Bearing in mind the fact that in compliance with the cited RPS-92 elimination of the technogenic ionizing radiation sources incorporated in the environment prior to 1992 is 'freezed', it is evident that exposure of the population to anthropogenic radiation becomes legally allowable in a much wider range than the one specified by world legislators. One may anticipate radiation induced health noxae for the population directly or by anthropogenic radiation stress on biocenosis. A relatively large part of the population is susceptible to the effect of low radiation doses. Presumably this contingent will augment as a result of eventual fluctuations. The casual relationship which is difficult to establish should be given due consideration in the analysis of the causes

Acceptable level of radiation risk and its perception

Energy Technology Data Exchange (ETDEWEB)

Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

1987-03-01

The acceptable level of radiation risk for public members, that is 10/sup -5//y, was proposed by ICRP and other international organizations. We studied to survey basic procedures of deriving this value and to derive an acceptable risk value in Japan by using similar procedures. The basic procedures to derive 10/sup -5//y were found as follows; (1) 0.1 percent of annual mortality from all diseases, (2) 0.1 percent of life time risk, (3) one percent of mortality from all causes in each age cohort and (4) corresponding value to 1 mSv annual radiation exposure. From these bases we derived the value of 10/sup -5//y as acceptable risk level in Japan. The perception to risk level of 10/sup -5//y in conventional life was investigated by means of questionnaires for 1,095 college students living in Tokyo. The risks considered in this study were natural background radiation, coffee, skiing, X-ray diagnosis, spontaneous cancer, passive smoking and air pollution. The most acceptable risk was the risk related with natural background radiation. And the risk of natural background radiation was more easily accepted by the students who had knowledges on natural background radiation. On the other hand, the risk from air pollution or passive smoking was the most adverse one.

Background of external γ radiation in the proportional counters of the SAGE experiment

International Nuclear Information System (INIS)

Gavrin, V.N.; Gorbachev, V.V.

2003-01-01

The effect of external γ radiation on the process of counting 71 Ge decays in the proportional counters of the SAGE experiment measuring the solar-neutrino flux is considered. The systematic uncertainty in the SAGE result due to radon decays inside the air volume surrounding the counters is estimated. The background counting rate in the proportional counters that is caused by γ radiation from the enclosing shield is also determined

Does exposure to very high levels of natural radiation induce hematological alterations in humans?

International Nuclear Information System (INIS)

Ghiassi-Nejad, M.

2003-01-01

Full text: It has long been known that total body exposure to moderate doses decrease the number of circulating erythrocytes, platelets, granulocytes, and lymphocytes. However, data on hematopoietic effects of exposure to very low doses of ionizing radiation in humans are scarce. Recently it has been reported that hematological parameters have significant positive associations with the radiation dose received by residents lived near a nuclear power plant. Ramsar, a city in northern Iran, has some inhabited areas with the highest levels of natural radiation studied so far. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy y -1 and the highest recorded external gamma dose rates are about 130 mGy y -1 . In this study, hematological parameters such as counts of leukocytes, lymphocytes, monocytes, granulocytes, red blood cells, hemoglobin, hematocrit, MCV, MCH, MCHC, RDW, PLT, and MPV were measured in the inhabitants. The results of this study indicated that there was no any statistically significant alteration in hematological parameters of the inhabitants of very high background radiation areas of Ramsar compared to those of a neighboring control area

Study of thorium uptake by inhabitants of a high background radiation area

International Nuclear Information System (INIS)

Melo, D.R.; Lipsztein, J.L.; Juliao, L.M.Q.C.; Lourenco, M.C.; Lauria, D.

2002-01-01

Buena, located in the North of Rio de Janeiro, is characterized by its high natural radiation background, due to large deposits of monazite sand. The foodstuffs consumed by the population are basically composed of local products, which contain significant amounts of thorium. The analysis of complete cooked meals have shown an average daily intake of 18 mBq.d -1 of 232 Th and 189 mBq.d -1 of 228 Th. The average urine to feces ratio of 232 Th from samples of volunteers was found equal to 7.5x10 -2 . The comparison of the experimental data with the predicted urine to feces ratios derived using the biokinetic model for thorium described by the ICRP publication 69 and simulating inhalation and ingestion separately, lead to the conclusion that the thorium intake is a combination of inhalation and ingestion. The clearance rate of thorium of monazite in lungs has apparently behaved as Type M compound. Inhalation is the biggest contributor for the committed effective dose due to thorium internal exposure. (author)

Distribution of Radiation Exposure from Natural Radiation in Big Cities

International Nuclear Information System (INIS)

Udiyani, P.M.; Ahmad, Yus R.

2000-01-01

The measurement of radiation exposure from the natural radiation in the big city in Java such as Jakarta, Bandung, Semarang, Yogyakarta, and Surabaya have be done. Based on radiation dose and population at the sample location, the dose collective and risk probability will be know. The maximal exposure at Yogyakarta is 0.291 mSv/year and the minimal exposure at Surabaya is 0.216 mSv/year. Collective dose at Jakarta is 1.649.526 men mSv/year; Bandung 124.844 men mSv/year; Semarang : 64.558 men mSv/year; Yogyakarta 136.188 men mSv/year; and Surabaya 145.152 men mSv/year. The person probability of radiation disease at jakarta is 16.49 person/year, Bandung is 1.24 person/year, Semarang 1.64 person/year, Yogyakarta is 1.36 person/year, and Surabaya is 1.45 person/year

Radiation exposures: risks and realities

International Nuclear Information System (INIS)

Ganesh, G.

2010-01-01

Discovery of radioactivity in 1869 by Henry Becquerel and artificial radioactivity by Irene Curie in 1934 led to the development of nuclear field and nuclear materials in 20th century. They are widely used for man-kind across the globe in electricity production, carbon dating, treatment and diagnosis of diseases etc. While deriving benefits and utilizing nuclear resources for the benefit of man-kind, it is inevitable that exposure to radiation can not be avoided. Radiation exists all around us either natural or man-made which can not be totally eliminated or avoided. Radiation exposures from natural background contribute 2.4 to 3.6 mSv in a year. Radiation exposures incurred by a member of public due to nuclear industries constitute less than one hundredth of annual dose due to natural background. Hence it is important to understand the risk posed by radiation and comparison of radiation risk with various risks arising due to other sources. Studies have indicated that risks due to environmental pollution, cigarette smoking, alcohol consumption, heart diseases are far higher in magnitude compared to radiation risks from man made sources. This paper brings about the details and awareness regarding radiation exposures, radiation risk, various risks associated with other industries and benefits of radiation exposures. (author)

Investigation of environmental natural penetrating radiation level in Hebei province

International Nuclear Information System (INIS)

Zheng Deliang; Wang Shuming; Yang Huanfeng

1990-01-01

The methods and results of the investigation on natural penetrating radiation level in Hebei Province from 1985 to 1987 are presented. 285 25 x 25 km-netted measuring points were set unformly up all over the porvince, with 204 densely measuring points of different types added. The results show that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate for field is 5.59, 5.51 and 5.31 x 10 -8 Gy·h -1 , respectively; (2) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 3.05 and 2.80 x 10 -8 Gy·h -1 , and outside buildings is 3.38 and 3.11 x 10 -8 Gy·h -1 , respectively; (3) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 12.44 and 11.97 x 10 -8 Gy·h -1 , outside buildings is 8.97 and 8.42 x 10 -8 Gy·h -1 , respectively; (4) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation is 0.50, 0.25, and 0.75 mSv, respectively; and correspondingly, the annual collective effectiv dose equivalent is 2.7, 1.3 and 4.0 x 10 4 man·Sv, respectively

Down's syndrome and related abnormalities in an area of high background radiation in coastal Kerala

International Nuclear Information System (INIS)

Kochupillai, N.; Verma, I.C.; Grewal, M.S.; Ramalingaswami, V.

1976-01-01

It is stated that in a coastal area of Kerala, Southern India, the background radiation is between 1500 and 3000 mR/yr, this being due to the presence of Th-containing monazite mineral in the soil. During an epidemiological study of modular lesions of the thyroid in this area an apparently high prevalence of Down's syndrome and other forms of severe mental retardation was observed. A house-to-house survey of relevant abnormalities in this area was made, and also in a comparable control area without high background radiation. The frequency of chromosome aberrations in a sample of the population in the study and control areas was also investigated. The observations support the view that radiation induces genetic anomalies occur with above average frequency in the population living in the area with high background radiation. Only gross abnormalities evident in clinical examination were recorded. The study and control populations were similar in age and sex structure and general sociologic conditions. Severe mental retardation was the commonest abnormality encountered, and 85% of the abnormalities detected in the study population were genetic in origin, compared with 56% in the control population. Prevalence of Down's syndrome was 0.93 per 1000 in the study population. (U.K.)

Radiation microbiology relevant to radiation processing

International Nuclear Information System (INIS)

Tallentire, A.

1979-01-01

The subject is discussed under the following headings: typical background studies involving laboratory models (measurement of radiation responses of different organisms, alone or on or in products; isolation of radiation resistant organisms from products and product environments; measurement of levels of preirradiation microbial contamination ('bioburden')); supplementary studies involving naturally occurring microbial contaminants (unit medical products; microbiological quality assurance; products in bulk; animal diet study). (U.K.)

Concentrations of radionuclides in cassava growing in high background radiation area and their transfer

Energy Technology Data Exchange (ETDEWEB)

Jialin, Huang; Yongru, Zha; Yicao, Guo

1985-04-01

The concentrations of several natural radionuclides in common cassava (Manihot esculenta Crantz) growing in Yangjiang County, a high background radiation area in Guangdong Province, and their uptake from soil and distribution in the plant were investigated. The results show that the concentrations of natural uranium and thorium in cassava root are of the order of 10/sup -6/ g/kg, and those of radium-226, radium-228, lead-210 and polonium-210 are of the order of 10/sup -11/ Ci/kg. The highest level is 9.30 +- 0.30 x 10/sup -11/ Ci/kg (lead-210), and the lowest is 3.99 +- 0.20 x 10/sup -11/ Ci/kg (radium-226). The levels of natural uranium, thorium, radium-226 and polonium-210 in cassava are below the limits stipulated by the regulations for food hygiene in China, while the lead-210 level approaches the limit. It is noticeable that the highest level of radium-228 is 7.28 +- 1.03 x 10/sup -11/ Ci/kg, 10.4 times higher than the limit. The transfer of all the nuclides from soil to different parts of cassava shows a pattern contrary to that of he nuclides in the other regions where uranium-and radium-containing waste water and phosphate fertilizer are used in agriculture.

Naturally occurring 32 Si and low-background silicon dark matter detectors

Energy Technology Data Exchange (ETDEWEB)

Orrell, John L.; Arnquist, Isaac J.; Bliss, Mary; Bunker, Raymond; Finch, Zachary S.

2018-05-01

The naturally occurring radioisotope Si-32 represents a potentially limiting background in future dark matter direct-detection experiments. We investigate sources of Si-32 and the vectors by which it comes to reside in silicon crystals used for fabrication of radiation detectors. We infer that the Si-32 concentration in commercial single-crystal silicon is likely variable, dependent upon the specific geologic and hydrologic history of the source (or sources) of silicon “ore” and the details of the silicon-refinement process. The silicon production industry is large, highly segmented by refining step, and multifaceted in terms of final product type, from which we conclude that production of Si-32-mitigated crystals requires both targeted silicon material selection and a dedicated refinement-through-crystal-production process. We review options for source material selection, including quartz from an underground source and silicon isotopically reduced in Si-32. To quantitatively evaluate the Si-32 content in silicon metal and precursor materials, we propose analytic methods employing chemical processing and radiometric measurements. Ultimately, it appears feasible to produce silicon-based detectors with low levels of Si-32, though significant assay method development is required to validate this claim and thereby enable a quality assurance program during an actual controlled silicon-detector production cycle.

Naturally occurring 32Si and low-background silicon dark matter detectors

Science.gov (United States)

Orrell, John L.; Arnquist, Isaac J.; Bliss, Mary; Bunker, Raymond; Finch, Zachary S.

2018-05-01

The naturally occurring radioisotope 32Si represents a potentially limiting background in future dark matter direct-detection experiments. We investigate sources of 32Si and the vectors by which it comes to reside in silicon crystals used for fabrication of radiation detectors. We infer that the 32Si concentration in commercial single-crystal silicon is likely variable, dependent upon the specific geologic and hydrologic history of the source (or sources) of silicon "ore" and the details of the silicon-refinement process. The silicon production industry is large, highly segmented by refining step, and multifaceted in terms of final product type, from which we conclude that production of 32Si-mitigated crystals requires both targeted silicon material selection and a dedicated refinement-through-crystal-production process. We review options for source material selection, including quartz from an underground source and silicon isotopically reduced in 32Si. To quantitatively evaluate the 32Si content in silicon metal and precursor materials, we propose analytic methods employing chemical processing and radiometric measurements. Ultimately, it appears feasible to produce silicon detectors with low levels of 32Si, though significant assay method development is required to validate this claim and thereby enable a quality assurance program during an actual controlled silicon-detector production cycle.

Environmental radiation measurements and remedial actions (Hantepe/Ezine/Canakkale)

International Nuclear Information System (INIS)

2009-01-01

There are some regions in the world that are known as high background radiation areas. Intensive scientific investigations in the field of radiation dose and health effects, risk estimates, radiation protection, environmental transportation routes and ecological effects related with natural radiation have been carried out in these regions. Also natural radiation dosimetry, in vitro and in vivo biological studies which take into account the measurements in the field of low level radiation, radon, thoron and cosmic rays have been carried out, again in these regions. The well-known high natural background radiation areas in the world are Guarapari in Brazil, Ramsar in Iran, Kerala in India and Yangjiang in China. In addition to above mentioned areas, other relatively lower high background radiation areas are exist. Since 1960s, radiological, geological, epidemiological and ecological studies have been carried out in order to determine the risks and possible health effects of long-term low level natural radiation exposure. In the framework of surveying the background radiation of Turkey, the background radiation measurements were carried out in 56 different points around the area of Canakkale city. The radiation levels at Hantepe beach of Geyikli which is located in Ezine town of Canakkale was found higher than the mean background radiation level of the region. The radiation dose rates were measured in between 0.20 and 10.88 Gy h-1 in contact and 0.27 and 3.11 Gy h-1 above 1 meter of the ground level where the thorium-containing sand is dense. After the rehabilitation studies, the radiation dose rate were measured in between 0.15 and 8.09 Gy h-1 in contact and 0.17 and 2.88 Gy h-1 above 1 meter of the ground level. It was observed that the radiation dose rates were decreased seriously after the rehabilitation studies when the arithmetic mean value of the dose rates was taken into account. The effective dose calculations were performed by taking into account the

Generalized Chaplygin gas and cosmic microwave background radiation constraints

International Nuclear Information System (INIS)

Bento, M.C.; Bertolami, O.; Sen, A.A.

2003-01-01

We study the dependence of the location of the cosmic microwave background radiation peaks on the parameters of the generalized Chaplygin gas model, whose equation of state is given by p=-A/ρ α , where A is a positive constant and 0<α≤1. We find, in particular, that observational data arising from Archeops, BOOMERANG, supernova and high-redshift observations allow constraining significantly the parameter space of the model. Our analysis indicates that the emerging model is clearly distinguishable from the α=1 Chaplygin case and the ΛCDM model

Pilot study for natural radiation survey

International Nuclear Information System (INIS)

Brown, L.; Driscoll, C.M.H.; Green, B.M.R.; Miles, J.C.H.

1983-01-01

NRPB's national survey of natural radiation exposure in homes commenced in 1982 and will run until 1984. A pilot survey was undertaken in over 100 homes for one year, using passive thermoluminescent dosemeters to measure external radiation from terrestrial and cosmic sources and passive radon dosemeters to measure the radon-222 gas concentration. A preliminary analysis of the results obtained from the pilot survey is given. The main value of the pilot survey was in providing experience and various administrative and scientific procedures have been simplified or automated for the national survey. (U.K.)

Prospects of detecting gravitational background radiation by Doppler tracking interplanetary spacecraft

International Nuclear Information System (INIS)

Bertotti, B.; Carr, B.J.

1980-01-01

We examine the theoretical and experimental prospects of detecting a low-frequency, continuous, stochastic background of gravitational waves by Doppler tracking interplanetary spacecraft. From a theoretical standpoint, such a background may have been generated by various postgalactic processes or by pregalactic black hole formation; there could also exist a primordial background which goes back to the beginning of the universe. We review the characteristic frequency and density ranges which one might anticipate for these backgrounds. From an experimental standpoint, one's ability to detect a background is limited by the finite length of the record available and by an imperfect knowledge of the spectrum of various sources of noise. The fundamental contribution to the noise comes from the clock which regulates the frequency of the tracking waves. If one uses a hydrogen maser clock, this noise becomes progressively less important with decreasing frequency: one might hope to detect a critical density of background radiation at frequencies below 10 -2 Hz and a background with 10 -4 times the critical density at frequencies below 10 -5 Hz. It is encouraging that some of the sorts of background which we anticipate from theoretical considerations fall within the observable regime. We discuss the extent to which other sources of noise may exceed the clock noise and the degree to which they can be eliminated

On the anisotropies of cosmic microwave background radiation

International Nuclear Information System (INIS)

Molnar, Z.

1996-01-01

The work gives a brief overview of the topic of cosmic microwave background radiation anisotropies. Then is deals with the so-called Rees-Sciama affect; i.e. with the anisotropies arising between the last scattering surface and us due to transparent huge irregularities. Using the formulas of Special Theory of Relativity it is proven that in the neighbourhood of expanding spherical body the Meszaros calculation (Meszaros 1994) are correct; the inaccuracy is maximally of order 10 -12 . Then the profile of the blue shift of expansion caused by an expanding sphere is calculated for the case, when the radius of this sphere is much smaller that the relevant Hubble radius. Hence the profiles of the shifts of light periods through a void and through a supercluster are given in the most general cases. These cases contain all the three Friedmannian models and both the synchronous and asynchronous clusters. Then the obtained profiles are explicitly decomposed into the sum of the multipole terms, and it is shown that the observed difference between the measured direction of the maximum of dipole anisotropy of cosmic microwave background radiation and the result of Lauer and Postman (1994) is not explainable by the Rees-Sciama effect. This means that no alternative exists to the two possibilities for the explanation of the data of Lauer and Postman; either the either the huge system of Abell clusters is streaming, or the Friedmannian model is queried. The third possibility is, of course, that the data of observations of Lauer and Postman are incorrect. However, any of these three possibilities seem to be strange enough; hence, the problems coming from data of Lauer and Postman further holds. This is the key result of paper. As a further technical result it is also shown that in principle there is no upper limit of Rees-Sciama effect. (author)

Demonstration of a stimulating effect of natural ionizing radiation and of very low radiation doses on cell multiplication

International Nuclear Information System (INIS)

Planel, G.; Soleilhavoup, J.P.; Tixador, R.; Croute, F.; Richoilley, G.

1976-01-01

Experiments have been carried out to demonstrate a possible effect of natural ionizing radiation. Using lead shielding devices or an underground laboratory, it was shown that a decrease in background irradiation induces a decrease in cell growth rate (experiments carried out on Paramecia). On the other hand, the recovery of a normal irradiation level in shielding devices induces a quite normal cell proliferation. Moreover, small doses of γ rays from 60 Co exhibit a stimulating effect. Variations in cell radiosensitivity to these low doses are reported. Experiments carried out in the underground laboratory and at high altitude show that both telluric radioactivity and cosmic rays contribute to this stimulating effect on cell multiplication. (author)

Public health aspects of radiation

International Nuclear Information System (INIS)

Newcombe, H.B.

1978-12-01

The sources and levels of natural and manmade radiation are discussed in this report, and the resulting risks of radiation-induced cancer and hereditary diseases are estimated. The medical uses of X-rays currently increase the average population exposure by something like 35 per cent above natural background radiation. At a future time when nuclear generators will produce one kilowatt of electricity per person it is expected that the additional exposure from this source will not exceed 6 per cent of that from natural background. Acceptability of the risks that these exposures represent must depend upon the benefits with which they are associated, and upon the risks associated with other options open to society including alternative ways of obtaining similar benefits. The public health impact of the radiation from nuclear power generation, for example, is believed to be considerably less than that from the combustion products associated with the production of an equivalent amount of electrical power by conventional coal-fired stations. (author)

Public health aspects of radiation

International Nuclear Information System (INIS)

Newcombe, H.B.

1977-01-01

The sources and levels of natural and manmade radiation are discussed in this report, and the resulting risks of radiation-induced cancer and hereditary diseases are estimated. The medical uses of X-rays currently increase the average population exposure by something like 35 per cent above natural background radiation. At a future time when nuclear generators will produce one kilowatt of electricity per person it is expected that the additional exposure from this source will not exceed 6 per cent of that from natural background. Acceptability of the risks that these exposures represent must depend upon the benefits with which they are associated, and upon the risks associated with other options open to society including alternative ways of obtaining similar benefits. The public health impact of the radiation from nuclear power generation, for example, is believed to be considerably less than that from the combustion products associated with the production of an equivalent amount of electrical power by conventional coal-fired stations. (author)

Radiation energy devaluation in diffusion combusting flows of natural gas

International Nuclear Information System (INIS)

Makhanlall, Deodat; Munda, Josiah L.; Jiang, Peixue

2013-01-01

Abstract: CFD (Computational fluid dynamics) is used to evaluate the thermodynamic second-law effects of thermal radiation in turbulent diffusion natural gas flames. Radiative heat transfer processes in gas and at solid walls are identified as important causes of energy devaluation in the combusting flows. The thermodynamic role of thermal radiation cannot be neglected when compared to that of heat conduction and convection, mass diffusion, chemical reactions, and viscous dissipation. An energy devaluation number is also defined, with which the optimum fuel–air equivalence for combusting flows can be determined. The optimum fuel–air equivalence ratio for a natural gas flame is determined to be 0.7. The CFD model is validated against experimental measurements. - Highlights: • Thermodynamic effects of thermal radiation in combusting flows analyzed. • General equation for second-law analyses of combusting flows extended. • Optimum fuel–air equivalence ratio determined for natural gas flame