Sample records for atmosphere exposure analysis
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International Nuclear Information System (INIS)
Craig, D.K.; Baskett, R.L.; Powell, T.J.; Davis, J.S.; Dukes, L.L.; Hansen, D.J.; Petrocchi, A.J.; Sutherland, P.J.
1997-01-01
Safety analysis of Department of Energy (DOE) facilities requires consideration of potential exposures to mixtures of chemicals released to the atmosphere. Exposure to chemical mixtures may lead to additive, synergistic, or antagonistic health effects. In the past, the consequences of each chemical have been analyzed separately. This approach may not adequately protect the health of persons exposed to mixtures. However, considerable time would be required to evaluate all possible mixtures. The objective of this paper is to present reasonable default methodology developed by the EFCOG Safety Analysis Working Group Nonradiological Hazardous Material Subgroup (NHMS) for use in safety analysis within the DOE Complex
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Copper patinas formed in different atmospheres and exposure times
International Nuclear Information System (INIS)
Lobo, V.M.M.; Almeida, M.E.; Balmayor, M.; Tomas, H.M.L.R.
1998-01-01
Atmospheric corrosion products in copper samples, known as patinas, formed in industrial-marine, severe-marine and rural atmospheres exposed for 1,2,3, and 4 years, have been studied. The nature and structure of the products formed, characterized by X-ray diffraction (XRD) and infrared spectrometry (FTIR) depend on the time of exposure and the type of atmosphere. Copper patinas have been extensively mentioned in the literature, but the structural nature of their compounds, which vary according to the time of exposure and types of atmospheres, is still not adequately described in the literature. In order to give a contribution to this area, copper panels were exposed for 1,2,3, and 4 years in different types of atmospheres representing situations commonly observed, and subsequently the patinas were studied by XRD and FTIR 150 mm x 1 mm copper panels from commercial copper were exposed to three different atmospheric conditions in Portugal: industrial-marine (Leixoes, near Oporto, highly industrialized city close to the Ocean, subject to SO 2 from refineries); rural (Pego, small village in rural environment). The panels, attached to the appropriate stands, in accordance with ISO 8565 (1), were exposed for periods of 1,2,3 and 4 years, adequately collected for laboratory analysis by infrared spectrometry (FTIR). (Author)
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Atmospheric Ionizing Radiation and Human Exposure
Wilson, John W.; Mertens, Christopher J.; Goldhagen, Paul; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.
2005-01-01
Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes. especially along the coastal plain and interior low lands, and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.
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Atmospheric Ionizing Radiation and Human Exposure
Wilson, J. W.; Goldhagen, P.; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.
2004-01-01
Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes especially along the coastal plain and interior low lands and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.
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Zhang, Yang; Shen, Jing; Li, Yu
2018-01-13
Assessing and quantifying atmospheric vulnerability is a key issue in urban environmental protection and management. This paper integrated the Analytical hierarchy process (AHP), fuzzy synthesis evaluation and Geographic Information System (GIS) spatial analysis into an Exposure-Sensitivity-Adaptive capacity (ESA) framework to quantitatively assess atmospheric environment vulnerability in the Beijing-Tianjin-Hebei (BTH) region with spatial and temporal comparisons. The elaboration of the relationships between atmospheric environment vulnerability and indices of exposure, sensitivity, and adaptive capacity supports enable analysis of the atmospheric environment vulnerability. Our findings indicate that the atmospheric environment vulnerability of 13 cities in the BTH region exhibits obvious spatial heterogeneity, which is caused by regional diversity in exposure, sensitivity, and adaptive capacity indices. The results of atmospheric environment vulnerability assessment and the cause analysis can provide guidance to pick out key control regions and recognize vulnerable indicators for study sites. The framework developed in this paper can also be replicated at different spatial and temporal scales using context-specific datasets to support environmental management.
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Directory of Open Access Journals (Sweden)
Sofia Costanzini
2018-01-01
Full Text Available This work originates from an epidemiological study aimed to assess the correlation between population exposure to pesticides used in agriculture and adverse health effects. In support of the population exposure evaluation two models implemented by the authors were applied: a GIS-based proximity model and the CAREA atmospheric dispersion model. In this work, the results of the two models are presented and compared. Despite the proximity analysis is widely used for these kinds of studies, it was investigated how meteorology could affect the exposure assessment. Both models were applied to pesticides emitted by 1519 agricultural fields and considering 2584 receptors distributed over an area of 8430 km2. CAREA output shows a considerable enhancement in the percentage of exposed receptors, from the 4% of the proximity model to the 54% of the CAREA model. Moreover, the spatial analysis of the results on a specific test site showed that the effects of meteorology considered by CAREA led to an anisotropic exposure distribution that differs considerably from the symmetric distribution resulting by the proximity model. In addition, the results of a field campaign for the definition and planning of ground measurement of concentration for the validation of CAREA are presented. The preliminary results showed how, during treatments, pesticide concentrations distant from the fields are significantly higher than background values.
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Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing
Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.
2011-01-01
Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.
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Radiation exposure of airline crew members to the atmospheric ionizing radiation environment
International Nuclear Information System (INIS)
Angelis, G. De; Ballard, T.; Lagorio, S.; Verdecchia, A.
2000-01-01
All risk assessment techniques for possible health effects from low dose rate radiation exposure should combine knowledge both of the radiation environment and of the biological response, whose effects (e.g. carcinogenesis) are usually evaluated through mathematical models and/or animal and cell experiments. Data on human exposure to low dose rate radiation exposure and its effects are not readily available, especially with regards to stochastic effects, related to carcinogenesis and therefore to cancer risks, for which the event probability increases with increasing radiation exposure. The largest source of such data might be airline flight personnel, if enrolled for studies on health effects induced by the cosmic-ray generated atmospheric ionizing radiation, whose total dose, increasing over the years, might cause delayed radiation-induced health effects, with the high-LET and highly ionizing neutron component typical of atmospheric radiation. In 1990 flight personnel has been given the status of 'occupationally exposed to radiation' by the International Commission for Radiation Protection (ICRP), with a received radiation dose that is at least twice larger than that of the general population. The studies performed until now were limited in scope and cohort size, and moreover no information whatsoever on radiation occupational exposure (e.g. dose, flight hours, route haul, etc.) was used in the analysis, so no correlation has been until now possible between atmospheric ionizing radiation and (possibly radiation-induced) observed health effects. Our study addresses the issues, by considering all Italian civilian airline flight personnel, both cockpit and cabin crew members, with about 10,000 people selected, whose records on work history and actual flights (route, aircraft type, date, etc. for each individual flight for each person where possible) are considered. Data on actual flight routes and profiles have been obtained for the whole time frame. The actual dose
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Generation and characterization of gasoline engine exhaust inhalation exposure atmospheres.
McDonald, Jacob D; Barr, Edward B; White, Richard K; Kracko, Dean; Chow, Judith C; Zielinska, Barbara; Grosjean, Eric
2008-10-01
Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 4.3-L gasoline engine coupled to a dynamometer and operated on an adapted California Unified Driving Cycle. Exposure levels were maintained at three different dilution rates. One chamber at the lowest dilution had particles removed by filtration. Each exposure atmosphere was characterized for particle mass, particle number, particle size distribution, and detailed chemical speciation. The majority of the mass in the exposure atmospheres was gaseous carbon monoxide, nitrogen oxides, and volatile organics, with small amounts of particle-bound carbon/ions and metals. The atmospheres varied according to the cycle, with the largest spikes in volatile organic and inorganic species shown during the "cold start" portion of the cycle. Ammonia present from the exhaust and rodents interacted with the gasoline exhaust to form secondary inorganic particles, and an increase in exhaust resulted in higher proportions of secondary inorganics as a portion of the total particle mass. Particle size had a median of 10-20 nm by number and approximately 150 nm by mass. Volatile organics matched the composition of the fuel, with large proportions of aliphatic and aromatic hydrocarbons coupled to low amounts of oxygenated organics. A new measurement technique revealed organics reacting with nitrogen oxides have likely resulted in measurement bias in previous studies of combustion emissions. Identified and measured particle organic species accounted for about 10% of total organic particle mass and were mostly aliphatic acids and polycyclic aromatic hydrocarbons.
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International Nuclear Information System (INIS)
De Angelis, G.; Caldora, M.; Santaquilani, M.; Scipione, R.; Verdecchia, A.
2003-01-01
A study of the effects of high-LET, low-dose and low-dose-rate ionizing radiation and associated risk analysis is underway. This study involves analyzing the atmospheric ionizing radiation exposure (including high-energy neutrons) and associated effects for members of civilian aviation flight personnel, in an attempt to better understand low-dose long-term radiation effects on human subjects. The study population includes all Italian civilian airline flight personnel, both cockpit and cabin crew members, whose work history records and actual flights (route, aircraft type, and date for each individual flight for each person where possible) are available. The dose calculations are performed along specific flight legs, taking into account the actual flight profiles for all different routes and the variations with time of solar and geomagnetic parameters. Dose values for each flight are applied to the flight history of study participants in order to estimate the individual annual and lifetime occupational radiation dose. An update of the study of the physical atmospheric ionizing radiation exposure is given here, in terms of environmental modeling, flight routes, radiation dose evaluation along different flight paths, and exposure matrix construction. The exposure analysis is still in progress, and the first results are expected soon
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Energy Technology Data Exchange (ETDEWEB)
GRIGSBY KM
2011-04-07
This report presents the atmospheric dispersion coefficients used in Tank Farms safety analysis. The basis equations for calculating radiological and toxicological exposures are also included. In this revision, the time averaging for toxicological consequence evaluations is clarified based on a review of DOE complex guidance and a review of tank farm chemicals.
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Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing - Part 2
Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerome C.; Kolody, Mark R.
2012-01-01
Evaluation of metals to predict service life of metal-based structures in corrosive environments has long relied on atmospheric exposure test sites. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions similar to those of the corrosive environment. Their reliability to correlate to atmospheric exposure test results is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated corrosion testing has yet to be universally accepted as a useful tool in predicting the long-term service life of a metal, despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard, and their use is crucial, a method that correlates timescales from accelerated testing to atmospheric exposure would be very valuable. This paper presents work that began with the characterization of the atmospheric environment at the Kennedy Space Center (KSC) Beachside Corrosion Test Site. The chemical changes that occur on low carbon steel, during atmospheric and accelerated corrosion conditions, were investigated using surface chemistry analytical methods. The corrosion rates and behaviors of panels subjected to long-term and accelerated corrosion conditions, involving neutral salt fog and alternating seawater spray, were compared to identify possible timescale correlations between accelerated and long-term corrosion performance. The results, as well as preliminary findings on the correlation investigation, are presented.
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Energy Technology Data Exchange (ETDEWEB)
SANDGREN, K.R.
2005-03-03
This report presents the atmospheric dispersion coefficients used in Tank Farm safety analyses. The current revision also includes atmospheric dispersion coefficients used for analyses of the Demonstration Bulk Vitrification System. The basic equations for calculating radiological and toxicological exposures are also included.
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Ouidir, Marion; Lepeule, Johanna; Siroux, Valérie; Malherbe, Laure; Meleux, Frederik; Rivière, Emmanuel; Launay, Ludivine; Zaros, Cécile; Cheminat, Marie; Charles, Marie-Aline; Slama, Rémy
2017-10-01
Exposure to atmospheric pollutants is a danger for the health of pregnant mother and children. Our objective was to identify individual (socioeconomic and behavioural) and contextual factors associated with atmospheric pollution pregnancy exposure at the nationwide level. Among 14 921 women from the French nationwide ELFE (French Longitudinal Study of Children) mother-child cohort recruited in 2011, outdoor exposure levels of PM 2.5 , PM 10 (particulate matter atmospheric pollutants with individual (maternal age, body mass index, parity, education level, relationship status, smoking status) and contextual (European Deprivation Index, urbanisation level) factors. Patterns of associations were globally similar across pollutants. For the CART approach, the highest tertile of exposure included mainly women not in a relationship living in urban and socially deprived areas, with lower education level. Linear regression models identified different determinants of atmospheric pollutants exposure according to the residential urbanisation level. In urban areas, atmospheric pollutants exposure increased with social deprivation, while in rural areas a U-shaped relationship was observed. We highlighted social inequalities in atmospheric pollutants exposure according to contextual characteristics such as urbanisation level and social deprivation and also according to individual characteristics such as education, being in a relationship and smoking status. In French urban areas, pregnant women from the most deprived neighbourhoods were those most exposed to health-threatening atmospheric pollutants. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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Exposures to atmospheric effects in the entertainment industry.
Teschke, Kay; Chow, Yat; van Netten, Chris; Varughese, Sunil; Kennedy, Susan M; Brauer, Michael
2005-05-01
Theatrical fogs are commonly used in the entertainment industry to create special atmospheric effects during filming and live productions. We examined exposures to mineral oil-and glycol-based theatrical fogs to determine what fluids and effects were commonly used, to measure the size distributions of the aerosols, and to identify factors associated with personal exposure levels. In nonperformance jobs in a range of production types (television, film, live theater, and concerts),we measured airborne concentrations of inhalable aerosol,aldehydes, and polycyclic aromatic hydrocarbons, and collected observations about the sites and tasks performed. Both mineral oil and glycols were observed in use on about one-half the production days in the study. The most common effect produced was a generalized haze over the entire set. Mean personal inhalable aerosol concentrations were 0.70 mg/m3(range 0.02 to 4.1). The mean proportion of total aerosol mass less than 3.5 microns in aerodynamic diameter was 61%. Exposures were higher when mineral oils, rather than glycols, were used to generate fogs. Higher exposures were also associated with movie and television productions, with using more than one fog machine, with increased time spent in visible fog, and for those employed as "grips." Decreased exposures were associated with increasing room temperature, with increasing distance from fog machines, and for those employed as "sound technicians." Exposures to theatrical fogs are just beginning to be measured. It is important to consider these exposures in light of any health effects observed, since existing occupational exposure limits were developed in other industries where the aerosol composition differs from that of theatrical fogs.
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Germination of fungal conidia after exposure to low concentration ozone atmospheres.
The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...
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International Nuclear Information System (INIS)
Mmari, A.G.; Uiso, C.B.S.; Makundi, I.N.; Potgieter-Vermaak, S.S.; Potgieter, J.H.; Van Grieken, R.
2007-01-01
Air pollution studies in Africa are limited and the influence of ambient air quality on buildings and constructions have not been investigated in the larger part of Sub-Saharan Africa. The increasing burden of emission from industry, traffic and coal power plants on ambient air pollution in Sub-Saharan Africa necessitated reviewing previous and current studies. In South Africa a 20-year exposure program, focusing on the effect of ambient exposure on various metals and alloys, showed that the amount of rainfall, relative humidity, atmospheric pollution, wind speed, solar radiation and structural design are some of the factors controlling atmospheric corrosion. Tanzania, being among the Sub-Saharan African countries and partly bordered by Indian ocean, the main source of marine atmosphere, experiences corrosive degradation on metal roofing and cementitious materials. This paper describes the exposure site set-up and will report on some preliminary results of air quality and its relation with the meteorological conditions, as well as surface changes observed, for the year one of exposure. These will thereafter be compared to the completed European and Asian studies, as reported by CLRTAP and RAPIDC respectively. (author)
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International Nuclear Information System (INIS)
Boyer, C.
2009-01-01
This thesis has explored the mechanisms of tritium 'absorption and incorporation in a human-consumed plant, lettuce (Lactuca sativa L.), due to atmospheric exposure. Foliar uptake appears to play a key role in absorption of tritium as tissue free water tritium. Whatever the development stage and the light conditions, the specific activity in tissue free water reaches that of water vapour in air in several hours. The specific activity ratio is then about 0, 4. The time to reach equilibrium in soil is over 24 hours in most cases: the specific activity ratio ranges then 0, 01 to 0, 26. Incorporation rate of tissue free water tritium as organically-bound tritium has been estimated to 0, 13 to 0, 16 % h-l in average over the growing period of the plant, but marked variations are observed during growth. In particular, a significant increase appeared at the exponential growth stage. Deposition and diffusion of tritium in soil lead to significant OBT activities in soil. Results globally indicate equilibrium between the different environmental compartments (air, soil, plant). However, some experiments have revealed high OBT concentrations regarding atmospheric level exposure and ask for a possible phenomenon of local tritium accumulation in OBT for particular conditions of exposure. (author) [fr
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Light Emission Requires Exposure to the Atmosphere in Ex Vivo Bioluminescence Imaging
Directory of Open Access Journals (Sweden)
Yusuke Inoue
2006-04-01
Full Text Available The identification of organs bearing luciferase activity by in vivo bioluminescence imaging (BLI is often difficult, and ex vivo imaging of excised organs plays a complementary role. This study investigated the importance of exposure to the atmosphere in ex vivo BLI. Mice were inoculated with murine pro-B cell line Ba/F3 transduced with firefly luciferase and p190 BCR-ABL. They were killed following in vivo BLI, and whole-body imaging was done after death and then after intraperitoneal air injection. In addition, the right knee was exposed and imaged before and after the adjacent bones were cut. Extensive light signals were seen on in vivo imaging. The luminescence disappeared after the animal was killed, and air injection restored the light emission from the abdomen only, suggesting a critical role of atmospheric oxygen in luminescence after death. Although no substantial light signal at the right knee was seen before bone cutting, light emission was evident after cutting. In conclusion, in ex vivo BLI, light emission requires exposure to the atmosphere. Bone destruction is required to demonstrate luciferase activity in the bone marrow after death.
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Atmospheric pollutants monitoring by analysis of epiphytic lichens
International Nuclear Information System (INIS)
Fuga, Alessandra; Saiki, Mitiko; Marcelli, Marcelo P.; Saldiva, Paulo H.N.
2008-01-01
The Canoparmelia texana epiphytic lichenized fungi was used to monitor atmospheric pollution in the Sao Paulo metropolitan region, SP, Brazil. The cluster analysis applied to the element concentration values confirmed the site groups of different levels of pollution due to industrial and vehicular emissions. In the distribution maps of element concentrations, higher concentrations of Ba and Mn were observed in the vicinity of industries and of a petrochemical complex. The highest concentration of Co found in lichens from the Sao Miguel Paulista site is due to the emissions from a metallurgical processing plant that produces this element. For Br and Zn, the highest concentrations could be associated both to vehicular and industrial emissions. Exploratory analyses revealed that the accumulation of toxic elements in C. texana may be of use in evaluating the human risk of cardiopulmonary mortality due to prolonged exposure to ambient levels of air pollution. - Canoparmelia texana lichenized fungi is a valuable biomonitor for atmospheric pollution
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Radiation exposure of airline crew members to the atmospheric ionizing radiation environment
Energy Technology Data Exchange (ETDEWEB)
De Angelis, G. E-mail: gianni.deangelis@iol.it; Caldora, M.; Santaquilani, M.; Scipione, R.; Verdecchia, A
2001-06-01
A study of radiation exposures in the ionizing radiation environment of the atmosphere is currently in progress for the Italian civil aviation flight personnel. After a description of the considered data sources/ the philosophy of the study is presented/ and an overview is given of the data processing with regard to flight routes/ the computational techniques for radiation dose evaluation along the flight paths and for the exposure matrix building/ along with an indication of the results that the study should provide.
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SHORT-TERM EXPOSURE TO ATMOSPHERIC AMMONIA DOES NOT AFFECT LOW-TEMPERATURE HARDENING OF WINTER-WHEAT
CLEMENT, JMAM; VENEMA, JH; VANHASSELT, PR
The effect of atmospheric NH3 on low-temperature hardening of winter wheat (Triticum aestivum L. cv. Urban) was investigated. Growth and photosynthesis were stimulated by ammonia exposure. After a 14 d exposure at moderate temperatures (day/night 18.5/16 degrees C) total nitrogen content was
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Lin, Hai-tao; Li, Qi-lu; Zhang, Gan; Li, Jun
2016-01-15
The gas and particle samples of eight cities were collected by high flow active air sampler in the Eastern and Western China and eight congeners of polybrominated diphenyl ethers were analyzed. The results showed that the concentration of BDE-28 (tri-BDE) in the gas-phase (three bromide components) was the highest, which was different from previous studies where BDE-99 and-47 were the predominant homologues in the gas-phase while the concentration of BDE-209 [(25.4 ± 124) pg · m⁻³] in particle-phase was the highest. The atmospheric concentrations of PBDEs in Beijing and Guangzhou were relatively higher, especially the BDE-209 concentration in particle phases of Guangzhou was two orders higher than those of other cities. However, the atmospheric concentrations of PBDEs declined significantly when compared with the data from previous studies. Meanwhile, the results indicated that the gas-phase concentrations decreased slowly and the particle-phase concentrations decreased rapidly. Combined with the results of correlation analysis, this phenomenon might be ascribed to the ceased commercial production of penta- and octa-BDE, the light degradation of high bromide components and reduced concentrations of atmospheric particles in urban area. Inhalation exposure for infants was about 2-3 times higher than that of adults. This reflected that the potential health risk of atmospheric PBDEs in city for residents, especially infants and young children, should not be ignored.
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Air exposure of coral is a significant source of dimethylsulfide (DMS) to the atmosphere.
Hopkins, Frances E; Bell, Thomas G; Yang, Mingxi; Suggett, David J; Steinke, Michael
2016-10-31
Corals are prolific producers of dimethylsulfoniopropionate (DMSP). High atmospheric concentrations of the DMSP breakdown product dimethylsulfide (DMS) have been linked to coral reefs during low tides. DMS is a potentially key sulfur source to the tropical atmosphere, but DMS emission from corals during tidal exposure is not well quantified. Here we show that gas phase DMS concentrations (DMS gas ) increased by an order of magnitude when three Indo-Pacific corals were exposed to air in laboratory experiments. Upon re-submersion, an additional rapid rise in DMS gas was observed, reflecting increased production by the coral and/or dissolution of DMS-rich mucus formed by the coral during air exposure. Depletion in DMS following re-submersion was likely due to biologically-driven conversion of DMS to dimethylsulfoxide (DMSO). Fast Repetition Rate fluorometry showed downregulated photosynthesis during air exposure but rapid recovery upon re-submersion, suggesting that DMS enhances coral tolerance to oxidative stress during a process that can induce photoinhibition. We estimate that DMS emission from exposed coral reefs may be comparable in magnitude to emissions from other marine DMS hotspots. Coral DMS emission likely comprises a regular and significant source of sulfur to the tropical marine atmosphere, which is currently unrecognised in global DMS emission estimates and Earth System Models.
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Energy Technology Data Exchange (ETDEWEB)
Rufner, J.; Gannon, P.; White, P.; Deibert, M.; Teintze, S. [Chemical and Biological Engineering, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59717-3920 (United States); Smith, R.; Chen, H. [Physics, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59717-3920 (United States)
2008-02-15
Intermediate temperature ({proportional_to}800 {sup o}C) planar solid oxide fuel cells (SOFCs) allow the use of ferritic stainless steel (FSS) interconnects. SOFC FSS interconnects are used to stack individual cells into series, and are simultaneously exposed to air on the cathode side and fuel on the anode side, creating a 'dual atmosphere' exposure. The thermally grown oxide (TGO) layers on the air side of FSSs 430 and 441 were analyzed as a function of simulated dual atmosphere exposures (moist air/moist hydrogen) for up to 300 h. FSS 430 showed some changes in oxidation behavior, with a slight Fe concentration increase and localized Fe{sub 2}O{sub 3} nodule formation observed in the dual atmosphere TGO layer relative to its single atmosphere (air/air) counterpart. Significantly accelerated and anomalous oxidation was observed with FSS 441 subjected to dual atmosphere exposures compared with air/air exposures. The TGO layer formed on the 441 exposed to air/air was comprised of Mn-rich, Cr and Fe-containing isomorphic spinel surface crystallites, with a Cr{sub 2}O{sub 3} (eskolaite)-based bottom layer, having a total TGO layer thickness of <2{mu} m after 300 h. In contrast, the TGO layer formed on 441 during dual atmosphere exposure was much faster-growing (>6{mu} m in 20 h) and exhibited a continuous, porous Fe{sub 2}O{sub 3}-rich surface layer with a relatively thin (<2{mu} m) sublayer of similar composition to the TGO layer formed during the air/air exposure. Spontaneous TGO layer spallation was also observed for the air side of 441 exposed to dual atmosphere for >100h. The observed oxidation behavior and TGO layer evolution of 441 in both air/air and dual atmosphere are presented, with possible mechanisms and implications discussed. (author)
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Sampling of Atmospheric Precipitation and Deposits for Analysis of Atmospheric Pollution
Skarżyńska, K.; Polkowska, Ż; Namieśnik, J.
2006-01-01
This paper reviews techniques and equipment for collecting precipitation samples from the atmosphere (fog and cloud water) and from atmospheric deposits (dew, hoarfrost, and rime) that are suitable for the evaluation of atmospheric pollution. It discusses the storage and preparation of samples for analysis and also presents bibliographic information on the concentration ranges of inorganic and organic compounds in the precipitation and atmospheric deposit samples.
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Energy Technology Data Exchange (ETDEWEB)
Wang, Rong
2015-06-01
This thesis presents research focusing on the improvement of high-resolution global black carbon (BC) emission inventory and application in assessing the population exposure to ambient BC. A particular focus of the thesis is on the construction of a high-resolution (both spatial and sectorial) fuel consumption database, which is used to develop the emission inventory of black carbon. Above all, the author updates the global emission inventory of black carbon, a resource subsequently used to study the atmospheric transport of black carbon over Asia with the help of a high-resolution nested model. The thesis demonstrates that spatial bias in fuel consumption and BC emissions can be reduced by means of the sub-national disaggregation approach. Using the inventory and nested model, ambient BC concentrations can be better validated against observations. Lastly, it provides a complete uncertainty analysis of global black carbon emissions, and this uncertainty is taken into account in the atmospheric modeling, helping to better understand the role of black carbon in regional and global air pollution.
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Application of PIXE analysis to atmospheric environmental studies
International Nuclear Information System (INIS)
Kasahara, Mikio
1997-01-01
Physical and chemical properties of the atmospheric aerosols is a fundamental to understand the behavior of aerosols in the atmosphere. The analysis of atmospheric aerosols is the most preferable fields of the PIXE. In this paper, the characteristics of atmospheric aerosols are reviewed at first, and the sampling method of atmospheric aerosols for the PIXE samples and the characterization of atmospheric aerosols using the PIXE analysis are discussed. (author)
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Characterization of corrosion products formed on steels in the first months of atmospheric exposure
Antunes Renato Altobelli; Costa Isolda; Faria Dalva Lúcia Araújo de
2003-01-01
The corrosion products of carbon steel and weathering steel exposed to three different types of atmospheres, at times ranging from one to three months, have been identified. The steels were exposed in an industrial site, an urban site (São Paulo City, Brazil), and a humid site. The effect of the steel type on the corrosion products formed in the early stages of atmospheric corrosion has been evaluated. The corrosion products formed at the various exposure locations were characterized by Raman...
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International Nuclear Information System (INIS)
Natesan, M.; Venkatachari, G.; Palaniswamy, N.
2006-01-01
As a part of updating Corrosion Map of India project, atmospheric corrosion behaviour of commercially available engineering materials such as mild steel, galvanized iron, zinc and aluminium metals was studied in marine, industrial, urban, and rural environments by weight loss method at 10 exposure stations in India over a period of 5 years. The results of these studies demonstrated that galvanized iron, zinc and aluminium metals were several times more durable than mild steel. Compared to galvanized iron and zinc, aluminium provided superior protection in industrial and marine environment except at Mormugao Port Trust (MPT). It also offered much better resistance to corrosion in rural environments. At certain places, galvanized iron proved to be more durable than aluminium. The results obeyed well with the empirical kinetics equation of the form C = Kt n , where K and C are the corrosion losses in μm after 1 and 't' years of the exposure, respectively, and 'n' is a constant. Based on 'n' values, the corrosion mechanisms of these metals are predicted. The corrosion products formed on the metal samples in Chennai marine atmosphere were identified by X-ray diffraction analysis
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Energy Technology Data Exchange (ETDEWEB)
COWLEY, W.L.
2005-01-31
This report presents the atmospheric dispersion coefficients used for Tank Farms safety analyses. The report also contains the necessary documentation for meeting Software QA requirements for the GXQ software. The basic equations for calculating radiological doses and chemical exposures are also included. Revision 3 adds information about Building Wakes and calculates dispersion coefficients that incorporate building wake for 222-S and 242-A.
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Elemental analysis of atmospheric aerosols in Gaborone
African Journals Online (AJOL)
ELO
amount more than 90% were copper, lead, nickel and gold. Key words: Atmospheric particles, elements, ... Selebi-Phikwe area, gold and nickel in Francis town and soda ash in Sowa. Gaborone is the capital of ... a stub three times a week with an exposure time of four hours. The exposed stubs were collected and kept ...
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Analysis on the atmospheric dispersion of radioactive materials
International Nuclear Information System (INIS)
Nagai, Haruyasu
2012-01-01
JAEA has been developing a new prediction system of comprehensive movement, SPEEDI-MP (SPEEDI Multi-model Package), which can treat continuously and strictly with the migration behavior of radioactive materials at atmosphere, sea, and land region. JAEA has been further promoting the detail analysis of atmospheric migration of radioactive materials dispersed by an accident. Then, using a part of this system, the atmospheric-diversion prediction system, WSPEEDI-II, the atmospheric diversion mass and the atmospheric diffusion analysis were carried out. This issue reports the summary. (M.H.)
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Energy Technology Data Exchange (ETDEWEB)
Pillinger, W.L.
2001-05-17
This report describes the AXAIR computer code which is available to terminal users for evaluating the doses to man from exposure to the atmospheric plume from postulated stack or building-vent releases at the Savannah River Plant. The emphasis herein is on documentation of the methodology only. The total-body doses evaluated are those that would be exceeded only 0.5 percent of the time based on worst-sector, worst-case meteorological probability analysis. The associated doses to other body organs are given in the dose breakdowns by radionuclide, body organ and pathway.
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International Nuclear Information System (INIS)
Lan, Tran Thi Ngoc; Nishimura, Rokuro; Tsujino, Yoshio; Satoh, Yukihiro; Thi Phuong Thoa, Nguyen; Yokoi, Masayuki; Maeda, Yasuaki
2005-01-01
The atmospheric corrosion of marble was evaluated in terms of SO 2 concentration as air pollution and climatic factors such as rainfall, relative humidity, temperature and so on under the field exposure. Marble of calcite type (CaCO 3 ) was exposed to outdoor atmospheric environment with and without a rain shelter at four test sites in the southern part of Vietnam for 3-month, 1- and 2-year periods from July 2001 to September 2003. The thickness loss of marble was investigated gravimetrically. X-ray diffraction and X-ray fluorescent methods were applied to study corrosion products on marble. The corrosion product of marble was only gypsum (CaSO 4 . 2H 2 O) and was washed out by rain under the unsheltered exposure condition. It was found that the most substantial factors influencing the corrosion of marble were rainfall, SO 2 concentration in the air and relative humidity. Based on the results obtained, we estimated the dose-response functions for the atmospheric corrosion of marble in the southern part of Vietnam
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Radionuclide dispersion in the atmosphere
International Nuclear Information System (INIS)
Moura Neto, C. de; Amorim, E.S. do; Panetta, J.
1979-05-01
The instantaneous liberation of radionuclides in the atmosphere is studied in three dimensions, according to the formalism of the diffusion theory. The analytical solution, expose to gravitational and an atmospherical effects, is combined with the discretization of space and time in the calculation of levels of exposure. A typical inventory (for a PWR) was considered in the calculation of immersion doses, and the results permitted a comparative analysis among the different existing models. (Author) [pt
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Chen, Yuanyuan; Wang, Jun; Shi, Guitao; Sun, Xiaojing; Chen, Zhenlou; Xu, Shiyuan
2011-12-01
The lead (Pb) content in atmospheric deposition was determined at 42 sampling sites in Baoshan District of Shanghai, China. Based on exposure and dose-response assessments, the health risk caused by Pb exposure in atmospheric deposition was investigated. The results indicated that Pb was significantly accumulated in atmospheric deposition. The spatial distribution of Pb was mapped by geostatistical analysis, and the results showed that pollution hotspots were present at traffic and industrial zones. Ingestion was the main route of Pb exposure in both adults and children. For children the risk value was above 1, whereas it was below 1 for the adult group. Therefore, children belong to the high-risk group for Pb exposure from atmospheric deposition in the observed area of Shanghai, China.
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Raoof, Sana A; Agaku, Israel T; Vardavas, Constantine I
2015-05-01
Exposure to secondhand smoke (SHS) has been linked to disease, disability, and premature death. While several countries have enacted smoke-free legislations, exposure to SHS may still occur in unregulated private environments, such as in the family car. We performed a systematic review of peer-reviewed literature in PubMed and Web of Science up to May 2013. Articles were selected if they provided a quantitative measure of SHS exposure (biological or atmospheric markers); the study was conducted inside a car; and the assessed exposure was attributable to cigarette combustion. From 202 articles identified, 12 met the inclusion criteria. Among all studies that assessed smoking in cars with at least one window partially open, the particulate matter 2.5 μm or less in diameter (PM2.5) concentrations ranged from 47 μg/m(3) to 12,150 μg/m(3). For studies with all windows closed, PM2.5 ranged from 203.6 μg/m(3) to 13,150 μg/m(3). SHS concentration in a car was mediated by air-conditioning status, extent of airflow, and driving speed. Smoking in cars leads to extremely high exposure to SHS and increased concentration of atmospheric markers of exposure-even in the presence of air-conditioning or increased airflow from open windows. This clearly shows that the only way to protect nonsmokers, especially children, from SHS within cars is by eliminating tobacco smoking. © The Author(s) 2015.
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International Nuclear Information System (INIS)
Bonnard, R.
2001-12-01
Risk assessment and environmental impacts studies are realized to preserve the public health. Today one of the most used approach is the use of an atmospheric dispersion model to assess the risks. The data are then injected in a calculation software of exposure bond to polluted soils, to evaluate the risks of non direct exposure. This report details and evaluates the models corresponding to the need: the methodology for assessing Health Risks associated with multiple pathways of exposure to combustor, human health risk assessment proto col for hazardous waste combustion facilities, EUSES, CALTOX, MEPAS, MEND-TOX, RESRAD, MMSOILS, FRAMES-HWIR, PC-GEMS and TRIM. (A.L.B.)
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Zhou, Bin; Zhao, Bin
2014-01-01
It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs), a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF) and potential impact fraction (PIF) of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making.
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Directory of Open Access Journals (Sweden)
Bin Zhou
Full Text Available It is difficult to evaluate and compare interventions for reducing exposure to air pollutants, including polycyclic aromatic hydrocarbons (PAHs, a widely found air pollutant in both indoor and outdoor air. This study presents the first application of the Monte Carlo population exposure assessment model to quantify the effects of different intervention strategies on inhalation exposure to PAHs and the associated lung cancer risk. The method was applied to the population in Beijing, China, in the year 2006. Several intervention strategies were designed and studied, including atmospheric cleaning, smoking prohibition indoors, use of clean fuel for cooking, enhancing ventilation while cooking and use of indoor cleaners. Their performances were quantified by population attributable fraction (PAF and potential impact fraction (PIF of lung cancer risk, and the changes in indoor PAH concentrations and annual inhalation doses were also calculated and compared. The results showed that atmospheric cleaning and use of indoor cleaners were the two most effective interventions. The sensitivity analysis showed that several input parameters had major influence on the modeled PAH inhalation exposure and the rankings of different interventions. The ranking was reasonably robust for the remaining majority of parameters. The method itself can be extended to other pollutants and in different places. It enables the quantitative comparison of different intervention strategies and would benefit intervention design and relevant policy making.
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International Nuclear Information System (INIS)
Bouville, A.; Wachholz, B.W.; Dreicer, M.
1991-01-01
The National Cancer Institute (NCI) is conducting an assessment of the exposure to 131 I that the American people received from the fallout resulting from the atmospheric bomb tests carried out at the Nevada Test Site (NTS). It is estimated that about 5 EBq of 131 I were released into the atmosphere as a result of approximately 100 tests carried out mainly in the 1950s. The most important source of human exposure from fallout 131 I was due to the ingestion of cows' milk but other routes of exposure (ingestion of goats' milk, leafy vegetables, eggs, and cottage cheese as well as inhalation) are also considered. The exposure to 131 I are assessed on a test-by-test and county-by-county basis. In order to make these estimates for locations throughout the United States, it is necessary to determine: The activities of 131 I deposited on soil and vegetation, the amount of 131 I consumed by dairy cows and the resulting 131 I concentrations in cow's milk, and the 131 I ingested by people. The overall methodology currently used in the assessment of the 131 I exposures is presented. Particular attention is devoted to the methodology developed to estimate the intake of contaminated pasture by dairy cows, milk production, and milk distribution for each county of the continental United States during the 1950s
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Analysis of atmospheric particulate samples via instrumental neutron activation analysis
International Nuclear Information System (INIS)
Greenberg, R.R.
1990-01-01
Instrumental neutron activation analysis (INAA) is a powerful analytical technique for the elemental characterization of atmospheric particulate samples. It is a true multielement technique with adequate sensitivity to determine 30 to 40 elements in a sample of atmospheric particulate material. Its nondestructive nature allows sample reanalysis by the same or a different analytical technique. In this paper as an example of the applicability of INAA to the study of atmospheric particulate material, a study of the emissions from municipal incinerators is described
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Galeriu, D; Melintescu, A; Strack, S; Atarashi-Andoh, M; Kim, S B
2013-04-01
The need for a less conservative, but reliable risk assessment of accidental tritium releases is emphasized in the present debate on the nuclear energy future. The development of a standard conceptual model for accidental tritium releases must be based on the process level analysis and the appropriate experimental database. Tritium transfer from atmosphere to plants and the subsequent conversion into organically bound tritium (OBT) strongly depends on the plant characteristics, seasons, and meteorological conditions, which have a large variability. The present study presents an overview of the relevant experimental data for the short term exposure, including the unpublished information, also. Plenty of experimental data is provided for wheat, rice, and soybean and some for potato, bean, cherry tomato, radish, cabbage, and tangerine as well. Tritiated water (HTO) uptake by plants during the daytime and nighttime has an important role in further OBT synthesis. OBT formation in crops depends on the development stage, length, and condition of exposure. OBT translocation to the edible plant parts differs between the crops analyzed. OBT formation during the nighttime is comparable with that during the daytime. The present study is a preliminary step for the development of a robust model of crop contamination after an HTO accidental release. Copyright © 2012 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Röttger, Annette; Honig, Anja; Schrammel, Dieter; Strauss, Heinrich F.
2016-01-01
Closed nuclear track detectors are widely used for the determination of Rn-222 exposures. There are also partial open systems available, which are specially designed for the determination of the exposure to Rn-220, which is a relevant exposure in special workplaces or in specific regions of the world. This paper presents data and a detail analysis of how to determine the cross-correlation by calibration in pure Rn-222 and pure Rn-220 atm. By these means calibration coefficients for the analysis of real mixed atmospheres can be obtained. The respective decision threshold, detection limit and limits of the confidence interval were determined according to ISO 11929 (ISO 11929:2010, 2010). The exposure of detectors was performed at the radon reference chamber and the thoron progeny chamber of the Physikalisch-Technische Bundesanstalt (PTB). The analysis of track response was done at Parc RGM, while the analytical routines were developed in the Leibniz University Hanover, Institute Radioökologie und Strahlenschutz IRS at the working Group AK SIGMA (Arbeitskreis Nachweisgrenzen). - Highlights: • Analysis of exposure in reference atmospheres according ISO 11929. • Calibration of nuclear track detectors for 222 Rn and 220 Rn. • Calculation of cross-correlation by calibration in pure 222 Rn and 220 Rn atmospheres. • Thoron activity concentration should not be omitted in radon exposure determinations.
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[Prolonged exposure to atmospheric air pollution and mortality from respiratory causes].
Eilstein, D
2009-12-01
Different designs can be used to analyze the relationships between respiratory mortality and long term exposure to atmospheric pollution: epidemiological studies (cohort, prevalence study) demonstrate the reality of the relationship and toxicological studies explain it. Cohort studies have the advantage of being able to take into account many confounding factors and thus avoid biases (which is not the case with prevalence studies), but require significant human and financial resources. They were first adopted in the US, but are now more often applied in Europe. The results are relatively consistent, as they all show a statistically significant association between an increase in particulate pollution and cardiopulmonary mortality. Mortality from lung cancer is also associated with long term exposition to particles and sometimes to ozone or nitrogen oxides. Cerebrovascular diseases and sudden death of young children have also been associated with particulate pollution. The relationships are more powerful for long term than short term exposure but are also linear and without threshold. In order to explain these effects (today the causality of the relationship is certain) there are many possible factors, particularly regarding particulate exposures: an increase in cardiovascular risk biomarkers (fibrinogen, white blood cells, and platelets), atherosclerosis, chronic inflammation of lung tissues increased by acute exposure, etc. More and more studies address the interaction between gene and environment and even epigenetic phenomena which could be responsible of these effects. Public Health impact could be quantified. The European E&H surveillance program Apheis, for example, estimated that if PM2.5 levels remained below 15 microg/m(3), a 30 year old person could see his life expectancy increased by 1 month to 2 years, depending on the studied city. Finally, mortality is not the only relevant indicator for health effects of air pollution. ISAAC studies address asthma
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Titan atmospheric composition by hypervelocity shock layer analysis
International Nuclear Information System (INIS)
Nelson, H.F.; Park, C.; Whiting, E.E.
1989-01-01
The Cassini Mission, a NASA/ESA cooperative project which includes a deployment of probe into the atmosphere of Titan, is described, with particular attention given to the shock radiometer experiment planned for the Titan probe for the analysis of Titan's atmosphere. Results from a shock layer analysis are presented, demonstrating that the mole fractions of the major species (N2, CH4, and, possibly Ar) in the Titan atmosphere can be successfully determined by the Titan-probe radiometer, by measuring the intensity of the CN(violet) radiation emitted in the shock layer during the high velocity portion of the probe entry between 200 and 400 km altitude. It is shown that the sensitivity of the CN(violet) radiation makes it possible to determine the mole fractions of N2, CH4, and Ar to about 0.015, 0.003, and 0.01, respectively, i.e., much better than the present uncertainties in the composition of Titan atmosphere. 29 refs
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Energy Technology Data Exchange (ETDEWEB)
Shan, Xi; Payer, Joe H. [Corrosion and Reliability Engineering, Department of Chemical and Biomolecular Engineering, University of Akron, 302 Buchtel Common, Akron, OH 44325 (United States); Wainright, Jesse S.; Dudik, Laurie [Department of Chemical Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States)
2011-01-15
The objective of this work was to develop a hydrogen storage module for onboard electrical power sources suitable for use in micro-power systems and micro-electro-mechanical systems (MEMS). Hydrogen storage materials were developed as thin-film inks to be compatible with an integrated manufacturing process. Important design aspects were (a) ready activation at sub-atmospheric hydrogen pressure and room temperature and (b) durability, i.e. capable of hundreds of absorption/desorption cycles and resistance to deactivation on exposure to air. Inks with palladium-treated intermetallic hydrogen storage alloys were developed and are shown here to be compatible with a thin-film micro-fabrication process. These hydrogen storage modules absorb hydrogen readily at atmospheric pressure, and the absorption/desorption rates remained fast even after the ink was exposed to air for 47 weeks. (author)
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Piver, W T
1991-12-01
Increasing concentrations of CO2 and other greenhouse gases in the atmosphere can be directly related to global warming. In terms of human health, because a major cause of increasing atmospheric concentrations of CO2 is the increased combustion of fossil fuels, global warming also may result in increases in air pollutants, acid deposition, and exposure to ultraviolet (UV) radiation. To understand better the impacts of global warming phenomena on human health, this review emphasizes the processes that are responsible for the greenhouse effect, air pollution, acid deposition, and increased exposure to UV radiation.
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Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout
Energy Technology Data Exchange (ETDEWEB)
Censi, P., E-mail: censi@unipa.it [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); En.Bio.Tech. - Via Aquileia, 35 90100 Palermo (Italy); Tamburo, E. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); Speziale, S. [Deutsches GeoForschungsZentrum, Telegrafenberg, Potsdam, 14473 (Germany); Zuddas, P. [Institut Genie de l' Environnement et Ecodeveloppement and Departement Sciences de la Terre, UMR 5125, Universite Claude Bernard Lyon 1, 2 rue R. Dubois, Bat GEODE 69622 Villeurbanne Cedex (France); Randazzo, L.A. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy); I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); En.Bio.Tech. - Via Aquileia, 35 90100 Palermo (Italy); Institut Genie de l' Environnement et Ecodeveloppement and Departement Sciences de la Terre, UMR 5125, Universite Claude Bernard Lyon 1, 2 rue R. Dubois, Bat GEODE 69622 Villeurbanne Cedex (France); Punturo, R. [Dipartimento di Scienze Geologiche, Universita di Catania, Corso Italia, 55 - 95129 Catania (Italy); Cuttitta, A. [I.A.M.C.-CNR - UOS di Capo Granitola, Via faro, 1 - 91026 Torretta Granitola, Campobello di Mazara (TP) (Italy); Arico, P. [Dipartimento C.F.T.A., Universita di Palermo, Via Archirafi, 36 90123 - Palermo (Italy)
2011-02-28
Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corresponding to the depletion of elements from Nd to Tb when compared to the variable enrichments of heavy lanthanides, Y, La and Ce. These features and concurrent thermodynamic simulations suggest that phosphate precipitation can occur in lungs due to interactions between volcanic particles and fluids. We propose that patterns of yttrium and lanthanides can represent a viable explanation of some pathology observed in patients after prolonged exposure to atmospheric fallout and are suitable to become a diagnostic parameter of chemical environmental stresses.
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Evaluation of environmental radiation exposure
International Nuclear Information System (INIS)
Imai, Kazuhiko
1974-01-01
The environmental radiation exposure due to radioactive rare gases is most important both at the time of reactor accidents and also in the long-term normal operation of reactor plants. The exposure dose is usually calculated by means of computers. The procedure of the calculation on environmental exposure dose is divided in several consecutive steps. The calculational formulae frequently used and those proposed recently are given with the explanation on released radionuclides, release to the atmosphere, concentration in the atmosphere, β-ray exposure, γ-ray exposure, and calculation of long-term exposure dose. (Mori, K.)
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Neutron activation analysis of atmospheric aerosol
International Nuclear Information System (INIS)
Obrusnik, I.
1986-01-01
Neutron activation analysis (NAA) is a modern analytical method well suited for the analysis of atmospheric aerosols. Particular steps of the NAA procedure and especially different types of aerosol sampling and sample preparation for analysis are discussed in detail. Several possible NAA techniques are described and the advantages of a purely instrumental technique with short and long irradiation are pointed out. Important performance characteristics of the NAA method such as precision, accuracy, sensitivity and detection limits are also discussed. Different applications of NAA in environmental studies are reviewed. (author)
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Parshintsev, Jevgeni; Vaikkinen, Anu; Lipponen, Katriina; Vrkoslav, Vladimir; Cvačka, Josef; Kostiainen, Risto; Kotiaho, Tapio; Hartonen, Kari; Riekkola, Marja-Liisa; Kauppila, Tiina J
2015-07-15
On-line chemical characterization methods of atmospheric aerosols are essential to increase our understanding of physicochemical processes in the atmosphere, and to study biosphere-atmosphere interactions. Several techniques, including aerosol mass spectrometry, are nowadays available, but they all suffer from some disadvantages. In this research, desorption atmospheric pressure photoionization high-resolution (Orbitrap) mass spectrometry (DAPPI-HRMS) is introduced as a complementary technique for the fast analysis of aerosol chemical composition without the need for sample preparation. Atmospheric aerosols from city air were collected on a filter, desorbed in a DAPPI source with a hot stream of toluene and nitrogen, and ionized using a vacuum ultraviolet lamp at atmospheric pressure. To study the applicability of the technique for ambient aerosol analysis, several samples were collected onto filters and analyzed, with the focus being on selected organic acids. To compare the DAPPI-HRMS data with results obtained by an established method, each filter sample was divided into two equal parts, and the second half of the filter was extracted and analyzed by liquid chromatography/mass spectrometry (LC/MS). The DAPPI results agreed with the measured aerosol particle number. In addition to the targeted acids, the LC/MS and DAPPI-HRMS methods were found to detect different compounds, thus providing complementary information about the aerosol samples. DAPPI-HRMS showed several important oxidation products of terpenes, and numerous compounds were tentatively identified. Thanks to the soft ionization, high mass resolution, fast analysis, simplicity and on-line applicability, the proposed methodology has high potential in the field of atmospheric research. Copyright © 2015 John Wiley & Sons, Ltd.
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Forecasting human exposure to atmospheric pollutants in Portugal - A modelling approach
Borrego, C.; Sá, E.; Monteiro, A.; Ferreira, J.; Miranda, A. I.
2009-12-01
Air pollution has become one main environmental concern because of its known impact on human health. Aiming to inform the population about the air they are breathing, several air quality modelling systems have been developed and tested allowing the assessment and forecast of air pollution ambient levels in many countries. However, every day, an individual is exposed to different concentrations of atmospheric pollutants as he/she moves from and to different outdoor and indoor places (the so-called microenvironments). Therefore, a more efficient way to prevent the population from the health risks caused by air pollution should be based on exposure rather than air concentrations estimations. The objective of the present study is to develop a methodology to forecast the human exposure of the Portuguese population based on the air quality forecasting system available and validated for Portugal since 2005. Besides that, a long-term evaluation of human exposure estimates aims to be obtained using one-year of this forecasting system application. Additionally, a hypothetical 50% emission reduction scenario has been designed and studied as a contribution to study emission reduction strategies impact on human exposure. To estimate the population exposure the forecasting results of the air quality modelling system MM5-CHIMERE have been combined with the population spatial distribution over Portugal and their time-activity patterns, i.e. the fraction of the day time spent in specific indoor and outdoor places. The population characterization concerning age, work, type of occupation and related time spent was obtained from national census and available enquiries performed by the National Institute of Statistics. A daily exposure estimation module has been developed gathering all these data and considering empirical indoor/outdoor relations from literature to calculate the indoor concentrations in each one of the microenvironments considered, namely home, office/school, and other
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Cost benefit analysis for occupational radiation exposure
International Nuclear Information System (INIS)
Caruthers, G.F.; Rodgers, R.C.; Donohue, J.P.; Swartz, H.M.
1978-01-01
In the course of system design, many decisions must be made concerning different aspects of that particular system. The design of systems and components in a nuclear power plant has the added faction of occupational exposure experienced as a result of that design. This paper will deal with the different methods available to factor occupational exposure into design decisions. The ultimate goal is to have exposures related to the design 'As Low As Reasonably Achievable' or ALARA. To do this an analysis should be performed to show that the cost of reducing exposures any further cannot be justified in a cost-benefit analysis. In this paper examples will be given that will show that it is possible to change to a design which would increase occupational exposure somewhat but would increase the benefit over the cost of the extra exposure received. It will also be shown that some changes in design or additional equipment could be justified due to a reduction in exposure while some changes could not be justified on a reduction in exposure aspect alone but are justified on a time saving aspect such as during a refueling outage. (author)
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Health effects from exposure to atmospheric mineral dust near Las Vegas, NV, USA
Directory of Open Access Journals (Sweden)
Deborah E. Keil
Full Text Available Desert areas are usually characterized by a continuous deposition of fine airborne particles. Over time, this process results in the accumulation of silt and clay on desert surfaces. We evaluated health effects associated with regional atmospheric dust, or geogenic dust, deposited on surfaces in the Nellis Dunes Recreation Area (NDRA in Clark County, Nevada, a popular off-road vehicle (ORV recreational site frequented daily by riders, families, and day campers. Because of atmospheric mixing and the mostly regional origin of the accumulated particles, the re-suspended airborne dust is composed of a complex mixture of minerals and metals including aluminum, vanadium, chromium, manganese, iron, cobalt, copper, zinc, arsenic, strontium, cesium, lead, uranium, and others. Geogenic dust with a median diameter of 4.1 μm was administered via oropharyngeal aspiration to female B6C3F1 mice at doses of 0.01 to 100 mg dust/kg body weight, four times, a week apart, for 28-days. Immuno- and neurotoxicological outcomes 24 h following the last exposure were evaluated. Antigen-specific IgM responses were dose-responsively suppressed at 0.1, 1.0, 10 and 100 mg/kg/day. Splenic and thymic lymphocytic subpopulations and natural killer cell activity also were significantly reduced. Antibodies against MBP, NF-68, and GFAP were not affected, while brain CD3+ T cells were decreased in number. A lowest observed adverse effect level (LOAEL of 0.1 mg/kg/day and a no observed adverse effect level (NOAEL of 0.01 mg/kg/day were derived based on the antigen-specific IgM responses. Keywords: Geogenic dust, Heavy metals, Minerals, Lung exposure, Immunotoxicity, Neurotoxicity
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Preliminary analysis of a membrane-based atmosphere-control subsystem
Mccray, Scott B.; Newbold, David D.; Ray, Rod; Ogle, Kathryn
1993-01-01
Controlled ecological life supprot systems will require subsystems for maintaining the consentrations of atmospheric gases within acceptable ranges in human habitat chambers and plant growth chambers. The goal of this work was to develop a membrane-based atmosphere comntrol (MBAC) subsystem that allows the controlled exchange of atmospheric componets (e.g., oxygen, carbon dioxide, and water vapor) between these chambers. The MBAC subsystem promises to offer a simple, nonenergy intensive method to separate, store and exchange atmospheric components, producing optimal concentrations of components in each chamber. In this paper, the results of a preliminary analysis of the MBAC subsystem for control of oxygen and nitrogen are presented. Additionally, the MBAC subsystem and its operation are described.
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Long-term atmospheric corrosion of mild steel
International Nuclear Information System (INIS)
Fuente, D. de la; Diaz, I.; Simancas, J.; Chico, B.; Morcillo, M.
2011-01-01
Research highlights: → Atmospheric corrosion rate stabilises after the first 4-6 years of exposure. → Great compaction of the rust layers in rural and urban atmospheres. → Corrosion (in rural and urban) deviates from common behaviour of bilogarithmic law. → Typical structures of lepidocrocite, goethite and akaganeite are identified. → Formation of hematite (industrial atmosphere) and ferrihydrite (marine atmosphere). - Abstract: A great deal of information is available on the atmospheric corrosion of mild steel in the short, mid and even long term, but studies of the structure and morphology of corrosion layers are less abundant and generally deal with those formed in just a few years. The present study assesses the structure and morphology of corrosion product layers formed on mild steel after 13 years of exposure in five Spanish atmospheres of different types: rural, urban, industrial and marine (mild and severe). The corrosion layers have been characterised by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Long-term corrosion is seen to be more severe in the industrial and marine atmospheres, and less so in the rural and urban atmospheres. In all cases the corrosion rate is seen to decrease with exposure time, stabilising after the first 4-6 years of exposure. The most relevant aspects to be noted are (a) the great compaction of the rust layers formed in the rural and urban atmospheres, (b) the formation of hematite and ferrihydrite phases (not commonly found) in the industrial and marine atmospheres, respectively and (c) identification of the typical morphological structures of lepidocrocite (sandy crystals and flowery plates), goethite (cotton balls structures) and akaganeite (cotton balls structures and cigar-shaped crystals).
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Space Weather Nowcasting of Atmospheric Ionizing Radiation for Aviation Safety
Mertens, Christopher J.; Wilson, John W.; Blattnig, Steve R.; Solomon, Stan C.; Wiltberger, J.; Kunches, Joseph; Kress, Brian T.; Murray, John J.
2007-01-01
There is a growing concern for the health and safety of commercial aircrew and passengers due to their exposure to ionizing radiation with high linear energy transfer (LET), particularly at high latitudes. The International Commission of Radiobiological Protection (ICRP), the EPA, and the FAA consider the crews of commercial aircraft as radiation workers. During solar energetic particle (SEP) events, radiation exposure can exceed annual limits, and the number of serious health effects is expected to be quite high if precautions are not taken. There is a need for a capability to monitor the real-time, global background radiations levels, from galactic cosmic rays (GCR), at commercial airline altitudes and to provide analytical input for airline operations decisions for altering flight paths and altitudes for the mitigation and reduction of radiation exposure levels during a SEP event. The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model is new initiative to provide a global, real-time radiation dosimetry package for archiving and assessing the biologically harmful radiation exposure levels at commercial airline altitudes. The NAIRAS model brings to bear the best available suite of Sun-Earth observations and models for simulating the atmospheric ionizing radiation environment. Observations are utilized from ground (neutron monitors), from the atmosphere (the METO analysis), and from space (NASA/ACE and NOAA/GOES). Atmospheric observations provide the overhead shielding information and the ground- and space-based observations provide boundary conditions on the GCR and SEP energy flux distributions for transport and dosimetry simulations. Dose rates are calculated using the parametric AIR (Atmospheric Ionizing Radiation) model and the physics-based HZETRN (High Charge and Energy Transport) code. Empirical models of the near-Earth radiation environment (GCR/SEP energy flux distributions and geomagnetic cut-off rigidity) are benchmarked
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Overview of Atmospheric Ionizing Radiation (AIR)
Wilson, J. W.; Maiden, D. L.; Goldhagen, P.; Tai, H.; Shinn, J. L.
2003-01-01
The SuperSonic Transport (SST) development program within the US was based at the Langley Research Center as was the Apollo radiation testing facility (Space Radiation Effects Laboratory) with associated radiation research groups. It was natural for the issues of the SST to be first recognized by this unique combination of research programs. With a re-examination of the technologies for commercial supersonic flight and the possible development of a High Speed Civil Transport (HSCT), the remaining issues of the SST required resolution. It was the progress of SST radiation exposure research program founded by T. Foelsche at the Langley Research Center and the identified remaining issues after that project over twenty-five years ago which became the launch point of the current atmospheric ionizing radiation (AIR) research project. Added emphasis to the need for reassessment of atmospheric radiation resulted from the major lowering of the recommended occupational exposure limits, the inclusion of aircrew as radiation workers, and the recognition of civil aircrew as a major source of occupational exposures. Furthermore, the work of Ferenc Hajnal of the Environmental Measurements Laboratory brought greater focus to the uncertainties in the neutron flux at high altitudes. A re-examination of the issues involved was committed at the Langley Research Center and by the National Council on Radiation Protection (NCRP). As a result of the NCRP review, a new flight package was assembled and flown during solar minimum at which time the galactic cosmic radiation is at a maximum (June 1997). The present workshop is the initial analysis of the new data from that flight. The present paper is an overview of the status of knowledge of atmospheric ionizing radiations. We will re-examine the exposures of the world population and examine the context of aircrew exposures with implications for the results of the present research. A condensed version of this report was given at the 1998
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GEOSPATIAL ANALYSIS OF ATMOSPHERIC HAZE EFFECT BY SOURCE AND SINK LANDSCAPE
Directory of Open Access Journals (Sweden)
T. Yu
2017-09-01
Full Text Available Based on geospatial analysis model, this paper analyzes the relationship between the landscape patterns of source and sink in urban areas and atmospheric haze pollution. Firstly, the classification result and aerosol optical thickness (AOD of Wuhan are divided into a number of square grids with the side length of 6 km, and the category level landscape indices (PLAND, PD, COHESION, LPI, FRAC_MN and AOD of each grid are calculated. Then the source and sink landscapes of atmospheric haze pollution are selected based on the analysis of the correlation between landscape indices and AOD. Next, to make the following analysis more efficient, the indices selected before should be determined through the correlation coefficient between them. Finally, due to the spatial dependency and spatial heterogeneity of the data used in this paper, spatial autoregressive model and geo-weighted regression model are used to analyze atmospheric haze effect by source and sink landscape from the global and local level. The results show that the source landscape of atmospheric haze pollution is the building, and the sink landscapes are shrub and woodland. PLAND, PD and COHESION are suitable for describing the atmospheric haze effect by source and sink landscape. Comparing these models, the fitting effect of SLM, SEM and GWR is significantly better than that of OLS model. The SLM model is superior to the SEM model in this paper. Although the fitting effect of GWR model is more unsuited than that of SLM, the influence degree of influencing factors on atmospheric haze of different geography can be expressed clearer. Through the analysis results of these models, following conclusions can be summarized: Reducing the proportion of source landscape area and increasing the degree of fragmentation could cut down aerosol optical thickness; And distributing the source and sink landscape evenly and interspersedly could effectively reduce aerosol optical thickness which represents
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Geospatial Analysis of Atmospheric Haze Effect by Source and Sink Landscape
Yu, T.; Xu, K.; Yuan, Z.
2017-09-01
Based on geospatial analysis model, this paper analyzes the relationship between the landscape patterns of source and sink in urban areas and atmospheric haze pollution. Firstly, the classification result and aerosol optical thickness (AOD) of Wuhan are divided into a number of square grids with the side length of 6 km, and the category level landscape indices (PLAND, PD, COHESION, LPI, FRAC_MN) and AOD of each grid are calculated. Then the source and sink landscapes of atmospheric haze pollution are selected based on the analysis of the correlation between landscape indices and AOD. Next, to make the following analysis more efficient, the indices selected before should be determined through the correlation coefficient between them. Finally, due to the spatial dependency and spatial heterogeneity of the data used in this paper, spatial autoregressive model and geo-weighted regression model are used to analyze atmospheric haze effect by source and sink landscape from the global and local level. The results show that the source landscape of atmospheric haze pollution is the building, and the sink landscapes are shrub and woodland. PLAND, PD and COHESION are suitable for describing the atmospheric haze effect by source and sink landscape. Comparing these models, the fitting effect of SLM, SEM and GWR is significantly better than that of OLS model. The SLM model is superior to the SEM model in this paper. Although the fitting effect of GWR model is more unsuited than that of SLM, the influence degree of influencing factors on atmospheric haze of different geography can be expressed clearer. Through the analysis results of these models, following conclusions can be summarized: Reducing the proportion of source landscape area and increasing the degree of fragmentation could cut down aerosol optical thickness; And distributing the source and sink landscape evenly and interspersedly could effectively reduce aerosol optical thickness which represents atmospheric haze
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Ivan P. Edwards; Donald R. Zak
2011-01-01
The long-term effects of rising atmospheric carbon dioxide (CO2) and tropospheric O3 concentrations on fungal communities in soil are not well understood. Here, we examine fungal community composition and the activities of cellobiohydrolase and N-acetylglucosaminidase (NAG) after 10 years of exposure to 1...
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Kurylo, M. J.; DeCola, P. L.; Kaye, J. A.
2000-01-01
Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology development, and monitoring of the Earth's upper atmosphere, with emphasis on the upper troposphere and stratosphere. This program aims at expanding our chemical and physical understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Research Division in the Office of Earth Science at NASA. Significant contributions to this effort have also been provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aero-Space Technology. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper troposphere and the stratosphere and their control on the distribution of atmospheric chemical species such as ozone; assess possible perturbations to the composition of the atmosphere caused by human activities and natural phenomena (with a specific emphasis on trace gas geographical distributions, sources, and sinks and the role of trace gases in defining the chemical composition of the upper atmosphere); understand the processes affecting the distributions of radiatively active species in the atmosphere, and the importance of chemical-radiative-dynamical feedbacks on the meteorology and climatology of the stratosphere and troposphere; and understand ozone production, loss, and recovery in an atmosphere with increasing abundances of greenhouse gases. The current report is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported
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Atmospheric Data Package for the Composite Analysis
Energy Technology Data Exchange (ETDEWEB)
Napier, Bruce A.; Ramsdell, James V.
2005-09-01
The purpose of this data package is to summarize our conceptual understanding of atmospheric transport and deposition, describe how this understanding will be simplified for numerical simulation as part of the Composite Analysis (i.e., implementation model), and finally to provide the input parameters needed for the simulations.
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Radiation exposure analysis of female nuclear medicine radiation workers
Energy Technology Data Exchange (ETDEWEB)
Lee, Ju Young [Dept. of Biomedical Engineering Graduate School, Chungbuk National University, Cheongju (Korea, Republic of); Park, Hoon Hee [Dept. of Radiological Technologist, Shingu College, Sungnam (Korea, Republic of)
2016-06-15
In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus
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Radiation exposure analysis of female nuclear medicine radiation workers
International Nuclear Information System (INIS)
Lee, Ju Young; Park, Hoon Hee
2016-01-01
In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus
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Mass spectroscopic analysis of atmospheric particulate matter
International Nuclear Information System (INIS)
Wippel, R.
1997-02-01
Particulate matter (PM) in the atmosphere vary greatly in origin, in their physical and chemical properties and their effects on climate, atmospheric chemistry and health. Aerosol particles with an aerodynamic diameter less than two μm can enter the respiratory tract of humans when inhaled. Bulk analysis of ambient dust particles was performed using an inductively coupled plasma mass spectrometer (ICP-MS). The size-fractionated collected samples were analyzed after a leaching procedure that simulates the solution reactions occurring in the lungs. A disadvantage of bulk analysis is that it gives no information about the distribution of a certain element within the particles under investigation. A Laser-Microprobe-Mass-Analyzer (LAMMA-500) was used to obtain this information. At sampling sites in Austria and in Zimbabwe, Africa, single particles were sampled using a self-made impactor. One of the final aims in environmental analysis is to successfully apply receptor models that relate the chemical and physical properties of a receptor site to a source. The knowledge of the sources of atmospheric particulate matter is essential for environmental policy makers as well as for epidemiological studies. Artificial neural networks (ANN) have a remarkable ability to handle LAMMA-data. Three ANNs were used as a pattern recognition tool for LAMMA mass spectral data: a back-propagation net, a Kohonen network,and a counter-propagation net. Standard source profiles from the United States Environmental Protection Agency were used as training and test data of the different nets. The elemental patterns of the sum of 100 mass spectra of fine dust particles were presented to the trained nets and satisfactory recognition (> 80 %) was obtained. (author)
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International Nuclear Information System (INIS)
Knoefell, T.M.J.; Silva Estrada, J.J. da; Tavares, O.A.P.; Martins, J.B.
1981-01-01
The use of cellulose nitrate films LR-115 type II (Kodak-Pathe) as a practical, exposure integrating device to measure the level of exposure to alpha particles in atmospheres which contain radon and radon-daughter products is investigated. The analysis of a number of cellulose nitrate films that have been exposed to calibrated radon test-chamber atmospheres has indicated good correlations between through-etched track density p and integrated alpha-particle exposure Σa (Working-Level-Hour). It is shown that the response of the cellulose nitrate detector to radon-daughter alpha-particle exposures is linear, and that reliable conservative estimations of the Working-Level-Hour can be obtained from Σa = 3.0(p-b), where p is expressed in tracks/mm 2 (b is the background level). These results recommend the use of the special red cellulose nitrate films as a convenient dosimeter for monitoring radioactive contaminants in mine atmospheres. (Author) [pt
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International Nuclear Information System (INIS)
Kim, Byung Woo; Lee, Young Bok; Han, Moon Hee; Kim, Eun Han; Suh, Kyung Suk; Hwang, Won Tae
1992-12-01
Atmospheric diffusion and exposure strongly dependent on the environment were firstly considered in the full spectrum of accident consequence assessment to establish based on Korean conditions. An optimum weather category based on Korean climate and site-specific meteorology of Kori region was established by statistical analysis of measured data for 10 years. And a trajectory model was selected as the optimal one in the ACA by reviewing several existing diffusion models. Following aspects were considered in this selection as availability of meteorological data, ability to treat the change to wind direction, easy applicability of the model, and restriction of CPU time and core memory in current computers. Numerical integration method of our own was selected as the optimal dose assessment tool of external exposure. Unit dose rate was firstly computed with this method as the function of energy level of radionuclide, size of lattice, and distance between source and receptor, and then the results were rearranged as the data library for the rapid access to the ACA run. Dynamic ecosystem modelling has been done in order to estimate the seasonal variation of radioactivity for the assessment of ingestion exposure, considering Korean ingestion behavior, agricultural practice and the transportation. There is a lot of uncertainty in a countermeasure model due to the assumed values of parameters such as fraction of population with different shielding factor and driving speed. A new countermeasure model was developed using the concept of fuzzy set theory, since it provided the mathematical tools which could characterize the uncertainty involved in countermeasure modelling. (Author)
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Hinson, E. W.
1981-01-01
The preliminary analysis and data analysis system development for the shuttle upper atmosphere mass spectrometer (SUMS) experiment are discussed. The SUMS experiment is designed to provide free stream atmospheric density, pressure, temperature, and mean molecular weight for the high altitude, high Mach number region.
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Directory of Open Access Journals (Sweden)
Masamichi Oura
2018-03-01
Full Text Available For more than fifty years, atmospheric dispersion predictions based on the joint use of a Gaussian plume model and wind tunnel experiments have been applied in both Japan and the U.K. for the evaluation of public radiation exposure in nuclear safety analysis. The effective source height used in the Gaussian model is determined from ground-level concentration data obtained by a wind tunnel experiment using a scaled terrain and site model. In the present paper, the concentrations calculated by this method are compared with data observed over complex terrain in the field, under a number of meteorological conditions. Good agreement was confirmed in near-neutral and unstable stabilities. However, it was found to be necessary to reduce the effective source height by 50% in order to achieve a conservative estimation of the field observations in a stable atmosphere.
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Studies on tritium incorporation into wheat plants after short-term exposure to atmospheric tritium
International Nuclear Information System (INIS)
Diabate, S.; Strack, S.; Raskob, W.
1996-01-01
The paper summarizes the results of a series of laboratory experiments to study the uptake, loss, conversion and translocation of tritium in wheat plants following a short-term exposure to atmospheric tritiated water vapour (HTO) under laboratory conditions. The experiments were accompanied by the development of a Plant-OBT-Model to calculate the tritium behaviour in wheat. Exposures of potted plants were carried out between anthesis and maturity, under day conditions at two different light intensities (900 μmol m -2 s -1 and 120 μmol m -2 s -1 photosynthetic active radiation) and under night conditions. In leaves, the tritium uptake into tissue water tritium (TWT) was about four times lower under night conditions than day conditions. Organically bound tritium (OBT) was generated in leaves, stems and ears under day as well as under night conditions. The initial relative OBT concentrations in leaves observed under night conditions were about 50% of those under day conditions. OBT was translocated into the grain in dependence on the growth rate of the grain. Due to incorporation of new organic matter with lower OBT concentration into the grain, the specific OBT concentrations decreased slightly until harvest but the total OBT was rather constant. Once translocation to grain has taken place, OBT is lost only slowly. The growth of the plants has been calibrated with the measured growth data of winter wheat and spring wheat. Subsequently, the tritium incorporation was calibrated using the results of the exposure experiments in the same year. The final OBT concentration in the grain can be predicted with sufficient precision. However, the modelling of the OBT formation and turnover processes right after exposure to tritium needs improvement. A comprehensive validation of the model with independent data sets is still necessary. (J.P.N.)
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Ono-Ogasawara, Mariko; Serita, Fumio; Takaya, Mitsutoshi
2009-10-01
As the production of engineered nanomaterials quantitatively expands, the chance that workers involved in the manufacturing process will be exposed to nanoparticles also increases. A risk management system is needed for workplaces in the nanomaterial industry based on the precautionary principle. One of the problems in the risk management system is difficulty of exposure assessment. In this article, examples of exposure assessment in nanomaterial industries are reviewed with a focus on distinguishing engineered nanomaterial particles from background nanoparticles in workplace atmosphere. An approach by JNIOSH (Japan National Institute of Occupational Safety and Health) to quantitatively measure exposure to carbonaceous nanomaterials is also introduced. In addition to real-time measurements and qualitative analysis by electron microscopy, quantitative chemical analysis is necessary for quantitatively assessing exposure to nanomaterials. Chemical analysis is suitable for quantitative exposure measurement especially at facilities with high levels of background NPs.
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Long-life mission reliability for outer planet atmospheric entry probes
Mccall, M. T.; Rouch, L.; Maycock, J. N.
1976-01-01
The results of a literature analysis on the effects of prolonged exposure to deep space environment on the properties of outer planet atmospheric entry probe components are presented. Materials considered included elastomers and plastics, pyrotechnic devices, thermal control components, metal springs and electronic components. The rates of degradation of each component were determined and extrapolation techniques were used to predict the effects of exposure for up to eight years to deep space. Pyrotechnic devices were aged under accelerated conditions to an equivalent of eight years in space and functionally tested. Results of the literature analysis of the selected components and testing of the devices indicated that no severe degradation should be expected during an eight year space mission.
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International Nuclear Information System (INIS)
Lambrozo, J.; Guillossou, G.
2008-01-01
The atmosphere is the reservoir of numerous pollutants (nitrogen oxides, sulfur oxides, carbon oxides, particulates, volatile organic compounds, polycyclic aromatic hydrocarbons) from natural origin or anthropogenic origin ( industry, transport, agriculture, district heating). With epidemiologic studies the atmospheric pollution is associated with an increase of respiratory and cardiovascular diseases. At the european level, the technological progress, the legislation have allowed a reduction of pollutant emissions, however these efforts have to be continued because the sanitary impact of atmospheric pollution must not be underestimated, even if the risks appear less important that these ones in relation with tobacco, inside pollution or others factors of cardiovascular risks. Indeed, on these last factors an individual action is possible for the exposure to air pollution people have no control. (N.C.)
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Piver, W T
1991-01-01
Increasing concentrations of CO2 and other greenhouse gases in the atmosphere can be directly related to global warming. In terms of human health, because a major cause of increasing atmospheric concentrations of CO2 is the increased combustion of fossil fuels, global warming also may result in increases in air pollutants, acid deposition, and exposure to ultraviolet (UV) radiation. To understand better the impacts of global warming phenomena on human health, this review emphasizes the proces...
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Atmospheric aerosol dispersion models and their applications to environmental risk assessment
Directory of Open Access Journals (Sweden)
Andrzej Mazur
2014-03-01
Full Text Available Introduction. Numerical models of dispersion of atmospheric pollutants are widely used to forecast the spread of contaminants in the air and to analyze the effects of this phenomenon. The aim of the study is to investigate the possibilities and the quality of diagnosis and prediction of atmospheric transport of aerosols in the air using the dispersion model of atmospheric pollutants, developed at the Institute of Meteorology and Water Management (IMWM in Warsaw. Material and methods. A model of the dispersion of atmospheric pollutants, linked with meteorological models in a diagnostic mode, was used to simulate the transport of the cloud of aerosols released during the crash near the town of Ożydiw (Ukraine and of volcanic ash – during the volcanic eruption of Eyjafjallajökull in Iceland. Results. Possible directions of dispersion of pollutants in the air and its concentration in the atmosphere and deposition to the soil were assessed. The analysis of temporal variability of concentrations of aerosols in the atmosphere confirmed that the model developed at IMWM is an effective tool for diagnosis of air quality in the area of Poland as well as for determination of exposure duration to the aerosol clouds for different weather scenarios. Conclusions. The results are a confirmation of the thesis, that because in the environmental risk assessment, an important element is not only current information on the level of pollution concentrations, but also the time of exposure to pollution and forecast of these elements, and consequently the predicted effects on man or the environment in general; so it is necessary to use forecasting tools, similar to presented application. The dispersion model described in the paper is an operational tool for description, analysis and forecasting of emergency situations in case of emissions of hazardous substances.
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Estimation of atmospheric fluoride by limed filter papers
International Nuclear Information System (INIS)
Smith, D.R.
1988-09-01
The limed filter paper method of static sampling of atmospheric fluoride is reviewed in this report. Use of the technique, in conjunction with precise measurement of the absorbed fluoride and calibration with dynamic air sampling techniques, to estimate atmospheric fluoride levels, is considered to give only qualitative data (± 50%). The limed filter paper method is site specific due to variations in meteorological conditions. Its main value is to indicate seasonal and annual trends in fluoride exposure of vegetation. Subject to these considerations, the lower and upper limits of atmospheric fluoride exposure and the applicability to atmospheric fluoride estimation under routine or emergency fluoride release conditions are discussed, with special emphasis on the limiting factors
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Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures
Riedel, Theran P.; DeMarini, David M.; Zavala, Jose; Warren, Sarah H.; Corse, Eric W.; Offenberg, John H.; Kleindienst, Tadeusz E.; Lewandowski, Michael
2018-04-01
Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state atmospheric simulation chamber by irradiating mixtures of single aromatic VOCs, NOx, and ammonium sulfate seed aerosol in air. The 10 VOCs examined were benzene; toluene; ethylbenzene; o-, m-, and p-xylene; 1,2,4- and 1,3,5-trimethylbenzene; m-cresol; and naphthalene. Salmonella were exposed at the air-agar interface to the generated atmospheres for 1, 2, 4, 8, or 16 h. Dark-control exposures produced non-mutagenic atmospheres, illustrating that the gas-phase precursor VOCs were not mutagenic at the concentrations tested. Under irradiation, all but m-cresol and naphthalene produced mutagenic atmospheres, with potencies ranging from 2.0 (p-xylene) to 11.4 (ethylbenzene) revertants m3 mgC-1 h-1. The mutagenicity was due exclusively to direct-acting late-generation products of the photooxidation reactions. Gas-phase chemical analysis showed that a number of oxidized organic chemical species enhanced during the irradiated exposure experiments correlated (r ≥ 0.81) with the mutagenic potencies of the atmospheres. Molecular formulas assigned to these species indicated that they likely contained peroxy acid, aldehyde, alcohol, and other functionalities.
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Atmospheric corrosion tests along the Norwegian-Russian border. Part II
Energy Technology Data Exchange (ETDEWEB)
Henriksen, J.F.; Mikhailov, A.A.
1997-12-31
A bilateral exposure programme was carried out along the Norwegian-Russian border in 1990-1991, 1992-1993 and 1993-1994 to evaluate quantitatively the effect of sulphur pollutants on the atmospheric corrosion of important materials in sub-arctic climate. The first part of the programme demonstrated that also in subarctic climate do metals corrode depending on the atmospheric corrosivity, and dose-response functions were derived which combined the effects of SO{sub 2} and time of wetness. The second part of the programme, which is described in this report, involved exposures of carbon steel, zinc and copper at two sites in Norway and three sites in Russia. It is concluded that the accelerated atmospheric corrosion of metals in regions along the border is mainly due to dry deposition of sulphur. At some sites, dry deposition of Cl contributes because of sea-salt aerosols. The corrosivity of acid precipitation is certain but could not be represented as a function because of the small differences observed in the pH values at the different sites. At all test sites the kinetics of corrosion of steel, zinc and copper are characterized by a reduced corrosion rate after one year of exposure. Time of wetness is an important parameter in predicting atmospheric corrosion of metals even on a regional scale. Hence, for monitoring and for trend-effect analysis, it is very important to determine the corrosivity of SO{sub 2} with time of wetness. In accordance with dose-response functions obtained, the yearly corrosion rate for steel and zinc are higher for the areas with higher amounts of dry deposition of Cl than for areas with analogous but only SO{sub 2}-containing atmosphere. 6 refs., 8 figs., 15 tabs.
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PIXE analysis of atmospheric aerosol and hydrometeor particles
International Nuclear Information System (INIS)
Groeneveld, K.O.; Hofmann, D.; Georgii, H.W.
1993-01-01
Atmospheric aerosol and hydrometeor particles act decisively on our weather, climate and thereby on all living conditions on Earth. Particle induced X-ray emission (PIXE) analysis has been demonstrated to be an extremely valuable tool for quantitative and qualitative elemental analysis of aerosol particles and hydrometeors. Reliability and detection limits of PIXE are determined, including comparison with other techniques. Aerosol particles are collected on a global scale in ground stations, or by ships and by planes. Correlation between wind direction and elemental composition of atmospheric aerosols, elemental particle size distributions of the tropospheric aerosol, aerosol elemental composition in particle size fractions in the case of long range transport, transport pathways of pollution aerosol, and trace element content precipitation are discussed. Hydrometeors were studied in the form of rain, snow, fog, dew and frost. The time dependence of the melting process of snow was studied in detail, in particular the washout phenomena of impurity ions. (orig.)
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Hydrocarbon solvent exposure data: compilation and analysis of the literature.
Caldwell, D J; Armstrong, T W; Barone, N J; Suder, J A; Evans, M J
2000-01-01
An occupational exposure database for hydrocarbon solvent end-use applications was constructed from the published literature. The database provides exposure assessment information for such purposes as regulatory risk assessments, support of industry product stewardship initiatives, and identification of applications in which limited exposure data are available. It is quantitative, documented, and based on credible data. Approximately 350 articles containing quantitative hydrocarbon solvent exposure data were identified using a search of computer databases of published literature. Many articles did not report sufficient details of the exposure data for inclusion in the database (e.g., full-shift exposure or task-based exposure data). Others were excluded because only limited summary statistics were provided, which precluded statistical analysis of the data (e.g., arithmetic mean concentration presented, but no sample number). Following evaluation, 16,880 hydrocarbon solvent exposure measurements from 99 articles were entered into a database for analysis. Methods used to identify and evaluate published solvent exposure data are described along with more detailed analysis of worker exposure to hydrocarbon solvents in three major end-use applications: painting and coating, printing, and adhesives. Solvent exposures were evaluated against current ACGIH threshold limit values (TLVs) and trends were identified. Limited quantitative data are available prior to 1970. In general, reported hydrocarbon solvent exposures decreased fourfold from 1960 to 1998, were below the TLVs applicable to specific hydrocarbon solvents at the time, and on average have been below 40% of the TLV since 1980. The database already has proved valuable; however, the utility of published exposure data could be further improved if authors consistently reported essential data elements and supporting information.
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PIXE analysis: an option for the study of atmospheric pollutants
International Nuclear Information System (INIS)
Aldape, U.F.
1989-01-01
Several techniques have been utilized in studying atmospheric contamination samples. However, each lack some characteristics required for these studies. Spectroscopy of X-rays particularly where excitation models are produced using charged particles (Particle Induced X-ray Emission, PIXE), for its high sensitivity, is the one that best fitting itself to the scheme of analysis required. In this paper we report some qualitative results of the atmospheric aerosol samples collected in Mexico City. (Author)
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International Nuclear Information System (INIS)
Hiergesell, Robert A.; Swingle, Robert F.
2005-01-01
The proposed action of disposing of 52 moderator deionizer vessels within the ILV was evaluated in this SA. In particular, a detailed analysis of the release of 14 C via the atmospheric pathway was conducted for these vessels since the major concern has been the nearly 20 Ci of 14 C that is associated with each vessel. The more rigorous evaluation of the atmospheric pathway for 14 C included incorporation of new information about the chemical availability of 14 C when disposed in a grout/cement encapsulation environment, as will be the case in the ILV. This information was utilized to establish the source term for a 1-D numerical model to simulate the diffusion of 14 CO 2 from the ILV Waste Zone to the land surface. The results indicate a peak surface emanation rate from the entire ILV of 1.42E-08 Ci/yr with an associated dose of only 3.83E-05 mrem/yr to the Maximally Exposed Individual (MEI) at 100m. The fact that the atmospheric pathway exposure for 14 C is controlled by chemical solubility limits for 14 C between the solid waste, pore water and pore vapor within the disposal environment rather than the absolute inventory suggests that the establishment of specific facility limits is inappropriate. With the relaxation of the atmospheric pathway restriction, the groundwater pathway becomes the more restrictive in terms of disposing 14 C or 14 C KB within the ILV. Since the resin-based 14 C of the 52 moderator deionizer vessels is highly similar to the 14 C KB waste form, the inventory from the 52 deionizer vessels is compared against the groundwater limits for that waste form. The small groundwater pathway fraction (1.14E-05) calculated for the proposed inventory of the 52 moderator deionizer vessels indicates that the proposed action will have an insignificant impact with respect to possible exposures via the groundwater pathway. This investigation recommends that there be no ILV Atmospheric pathway limit for 14 C and 14 C KB . Further, in the absence of an
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Non-thermal Plasma Exposure Rapidly Attenuates Bacterial AHL-Dependent Quorum Sensing and Virulence
Flynn, Padrig B.; Busetti, Alessandro; Wielogorska, Ewa; Chevallier, Olivier P.; Elliott, Christopher T.; Laverty, Garry; Gorman, Sean P.; Graham, William G.; Gilmore, Brendan F.
2016-01-01
The antimicrobial activity of atmospheric pressure non-thermal plasma has been exhaustively characterised, however elucidation of the interactions between biomolecules produced and utilised by bacteria and short plasma exposures are required for optimisation and clinical translation of cold plasma technology. This study characterizes the effects of non-thermal plasma exposure on acyl homoserine lactone (AHL)-dependent quorum sensing (QS). Plasma exposure of AHLs reduced the ability of such molecules to elicit a QS response in bacterial reporter strains in a dose-dependent manner. Short exposures (30–60 s) produce of a series of secondary compounds capable of eliciting a QS response, followed by the complete loss of AHL-dependent signalling following longer exposures. UPLC-MS analysis confirmed the time-dependent degradation of AHL molecules and their conversion into a series of by-products. FT-IR analysis of plasma-exposed AHLs highlighted the appearance of an OH group. In vivo assessment of the exposure of AHLs to plasma was examined using a standard in vivo model. Lettuce leaves injected with the rhlI/lasI mutant PAO-MW1 alongside plasma treated N-butyryl-homoserine lactone and n-(3-oxo-dodecanoyl)-homoserine lactone, exhibited marked attenuation of virulence. This study highlights the capacity of atmospheric pressure non-thermal plasma to modify and degrade AHL autoinducers thereby attenuating QS-dependent virulence in P. aeruginosa. PMID:27242335
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Airborne exposure to laboratory animal allergens
Directory of Open Access Journals (Sweden)
Howard J Mason
2017-09-01
Full Text Available Exposure to laboratory animal allergens remains a significant cause of IgE-mediated occupational allergy and asthma. Since 2005, we have measured the major mouse and rat allergens (mus m 1 and rat n 1 collected on filters from air sampling in a range of UK and non-UK animal facilities. Supplied core data allowed us to construct an anonymized database of atmospheric results in ng m–3 containing 3080 mouse and 1392 rat analyses. Roughly twice as many static samples compared to personal samples had been sent for analysis. The medians (90th percentiles for the mouse and rat allergens employing personal atmospheric sampling were 2.6 (60.6 and 0.4 (12.4 ng m–3 respectively; for static samples the equivalent values were 0.2 (3.7 and 0.1 (1.4 ng m–3. Where unequivocal sample descriptors were provided with samples, results were categorised to activities/areas. Medians and 90th percentiles in these categories suggest that staff undertaking cleaning out, dumping of soiled bedding and cleaning cages can still have very substantial potential exposures in some facilities. The move to filtered cages appears to reduce general exposure, but filter changing and/or cleaning can lead to high exposures. In some facilities, animal receipt can cause significant exposures, as well as activities such as bleeding, culling and dosing; all activities involving the handling of animals outside of cages. We believe that the data presented may help those using air measurements in such facilities to improve their control of exposure to such aeroallergens, and thus reduce the risk of both sensitisation and subsequent allergic health problems, including the development of allergic asthma.
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Energy Technology Data Exchange (ETDEWEB)
Mosqueron, L.; Momas, I. [Universite Rene Descartes, Faculte des Sciences Pharmaceutiques et Biologiques, Lab. d' Hygiene et de Sante Publique, 75 - Paris (France); Le Moullec, Y. [Laboratoire d' Hygiene de la Ville de Paris, 75 (France); Momas, I. [Direction de l' Action Sociale, de l' Enfance et de la Sante, Cellule Epidemiologie, 75 - Paris (France)
2001-02-01
There are few studies of individual exposure to atmospheric particles, because of the relatively bulky and noisy sampling devices. These personalized measurements, generally associated with micro-environmental measurements, are aimed at studying the distribution of individual exposure and identifying its main determinants. Methods: A synopsis of the methods implemented in such studies (populations studied, measurements strategies, questionnaires on time-activity patterns, residences and work place) was detailed. The major results are presented and discussed from an epidemiological point of view. Results: The individual exposure measured with portable devices generally were generally found to be higher than the estimations made by combining micro-environmental (outdoor and indoor) measurements and data from time-activity diaries. The difference between results of these two approaches, known as 'personal cloud', remains poorly understood. Correlations between individual measurements and outdoor concentrations are weak; nevertheless, day to day variations of these two series of measurements are better related. The main determinants of individual exposure to particles are identified but a quantification of their contribution remains difficult, except for passive smoking. Conclusion: Personal measurements cannot be used to estimate particle exposure in large scale epidemiological studies. This exposure needs to be modeled. (authors)
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International Nuclear Information System (INIS)
Lovett, D.B.
1976-01-01
The work described in this report was directed toward identifying and devising methods to minimize the previously observed variability between working level hour exposures and the alpha particle track densities resulting on Track Etch films exposed to mine atmospheres containing radon and radon daughters. The disequilibrium between radon and its daughters was shown to directly affect the Track Etch film calibration factor. The wide range of disequilibrium states possible in mine situations amply explains the variability in the previous tests. A file of published mine atmosphere composition data was compiled and was used, along with atmospheric compositions derived from several theoretical models of the atmospheric behavior, to evaluate the variability of several dosimeter configurations and concepts
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Analysis of the atmospheric 7Be radioactivity by neural network
International Nuclear Information System (INIS)
Moroz, Z.; Myslek-Laurikainen, B.; Matul, M.; Mikolajewski, S.; Preibisz, Z.; Trzaskowaka, H.; Kownacki, C.
2002-01-01
Computational methods of artificial intelligence (neural networks) and modern signal processing (wavelet decomposition were applied for the analysis of atmospheric 7 Be radioactivity data. Measurements were performed each week during 1994-2001 in the sampling station placed at Swider Geophysical Observatory. Raw data as well as those averaged over 4 and 10 weeks were used. Ability of the neural networks for the purpose of representation, interpolation and prediction was tested. The corresponding relative errors are calculated. Next, the time sequences were decomposed using the wavelet method and eight components of different time scales were obtained. Neural networks were applied separately to each of those components. Application of such analysis and their possible extensions useful for the construction of phenomeno-logical models of atmospheric radioactivity are discussed. (author)
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Atmospheric conditions important for the assessment of population exposure
International Nuclear Information System (INIS)
Vidic, S.
2005-01-01
Atmospheric distribution of a pollutant can be predicted using numerical weather prediction models and atmospheric dispersion models. The first provides prediction on the evaluation of the meteorological fields for specified time period and the second uses this information to determine the evolution of the dispersing cloud in time and space. There is a number of conditions and features that limit the performance of both models, as they contain a degree of parametrisation that may be a source of error. This paper discusses influential parameters and conditions.(author)
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Viking Lander image analysis of Martian atmospheric dust
Pollack, James B.; Ockert-Bell, Maureen E.; Shepard, Michael K.
1995-01-01
We have reanalyzed three sets of Viking Lander 1 and 2 (VL1 and VL2) images of the Martian atmosphere to better evaluate the radiative properties of the atmospheric dust particles. The properties of interest are the first two moments of the size distribution, the single-scattering albedo, the dust single-scattering phase function, and the imaginary index of refraction. These properties provide a good definition of the influence that the atmospheric dust has on heating of the atmosphere. Our analysis represents a significant improvement over past analyses (Pollack et al. 1977,1979) by deriving more accurate brightnesses closer to the sun, by carrying out more precise analyses of the data to acquire the quantities of interest, and by using a better representation of scattering by nonspherical particles. The improvements allow us to better define the diffraction peak and hence the size distribution of the particles. For a lognormal particle size distribution, the first two moments of the size distribution, weighted by the geometric cross section, are found. The geometric cross-section weighted mean radius (r(sub eff)) is found to be 1.85 +/- 0.3 microns at VL2 during northern summer when dust loading was low and 1.52 +/- 0.3 microns at VL1 during the first dust storm. In both cases the best cross-section weighted mean variance (nu(eff)) of the size distribution is equal to 0.5 +/- 0.2 microns. The changes in size distribution, and thus radiative properties, do not represent a substantial change in solar energy deposition in the atmosphere over the Pollack et al. (1977,1979) estimates.
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Applications of stable isotope analysis to atmospheric trace gas budgets
Directory of Open Access Journals (Sweden)
Brenninkmeijer C. A.M.
2009-02-01
Full Text Available Stable isotope analysis has become established as a useful method for tracing the budgets of atmospheric trace gases and even atmospheric oxygen. Several new developments are briefly discussed in a systematic way to give a practical guide to the scope of recent work. Emphasis is on applications and not on instrumental developments. Processes and reactions are less considered than applications to resolve trace gas budgets. Several new developments are promising and applications hitherto not considered to be possible may allow new uses.
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Zn-10.2% Fe coating over carbon steel atmospheric corrosion resistance. Comparison with zinc coating
International Nuclear Information System (INIS)
Arnau, G.; Gimenez, E.; Rubio, M.V.; Saura, J.J.; Suay, J.J.
1998-01-01
Zn-10.2% Fe galvanized coating versus hot galvanized coating over carbon steel corrosion performance has been studied. Different periods of atmospheric exposures in various Valencia Community sites, and salt spray accelerated test have been done. Carbon steel test samples have been used simultaneously in order to classify exposure atmosphere corrosivity, and environmental exposure atmosphere characteristics have been analyzed. Corrosion Velocity versus environmental parameters has been obtained. (Author) 17 refs
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Energy Technology Data Exchange (ETDEWEB)
Singh, Prabhakar [Univ. of Connecticut, Storrs, CT (United States); Mahapatra, Manoj [Univ. of Connecticut, Storrs, CT (United States); Ramprasad, Rampi [Univ. of Connecticut, Storrs, CT (United States); Minh, Nguyen [Univ. of California, San Diego, CA (United States); Misture, Scott [Alfred Univ., NY (United States)
2014-11-30
The overall objective of the program is to develop and validate mechanisms responsible for the overall structural and chemical degradation of lanthanum manganite as well as lanthanum ferrite cobaltite based cathode when exposed to “real world” air atmosphere exposure conditions during SOFC systems operation. Of particular interest are the evaluation and analysis of degradation phenomena related to and responsible for (a) products formation and interactions with air contaminants, (b) dopant segregation and oxide exolution at free surfaces, (c) cation interdiffusion and reaction products formation at the buried interfaces, (d) interface morphology changes, lattice transformation and the development of interfacial porosity and (e) micro-cracking and delamination from the stack repeat units. Reaction processes have been studied using electrochemical and high temperature materials compatibility tests followed by structural and chemical characterization. Degradation hypothesis has been proposed and validated through further experimentation and computational simulation.
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Use of neutron activation analysis at the IBR-2 reactor for atmospheric monitoring
International Nuclear Information System (INIS)
Peresedov, V.F.; Ostrovnaya, T.M.; Strelkova, L.P.; Chinaeva, V.P.; Gundorina, S.F.
1999-01-01
The object of this work was the study of the possibilities of neutron activation analysis (NAA) for determination of elemental content of atmospheric aerosol. On examples of three Siberian regions it was shown that methodics of analysis allow to estimate the average level of suburban background (ALSB), scale of its regional, season and annual changes. Analysis of enrichment factors allows one to convince in presence of increased content of a row of heavy metals in atmospheric air of background regions what is the consequence of a global growing of technogenic impact
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An Analysis of Cassini Observations Regarding the Structure of Jupiter's Equatorial Atmosphere
Choi, David S.; Simon-Miller, Amy A.
2012-01-01
A variety of intriguing atmospheric phenomena reside on both sides of Jupiter's equator. 5-micron bright hot spots and opaque plumes prominently exhibit dynamic behavior to the north, whereas compact, dark chevron-shaped features and isolated anticyclonic disturbances periodically occupy the southern equatorial latitudes. All of these phenomena are associated with the vertical and meridional perturbations of Rossby waves disturbing the mean atmospheric state. As previous observational analysis and numerical simulations have investigated the dynamics of the region, an examination of the atmosphere's vertical structure though radiative transfer analysis is necessary for improved understanding of this unique environment. Here we present preliminary analysis of a multispectral Cassini imaging data set acquired during the spacecraft's flyby of Jupiter in 2000. We evaluated multiple methane and continuum spectral channels at available viewing angles to improve constraints on the vertical structure of the haze and cloud layers comprising these interesting features. Our preliminary results indicate distinct differences in the structure for both hemispheres. Upper troposphere hazes and cloud layers are prevalent in the northern equatorial latitudes, but are not present in corresponding southern latitudes. Continued analysis will further constrain the precise structure present in these phenomena and the differences between them.
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Cao, Ying; Rajan, Suja S; Wei, Peng
2016-12-01
A Mendelian randomization (MR) analysis is performed to analyze the causal effect of an exposure variable on a disease outcome in observational studies, by using genetic variants that affect the disease outcome only through the exposure variable. This method has recently gained popularity among epidemiologists given the success of genetic association studies. Many exposure variables of interest in epidemiological studies are time varying, for example, body mass index (BMI). Although longitudinal data have been collected in many cohort studies, current MR studies only use one measurement of a time-varying exposure variable, which cannot adequately capture the long-term time-varying information. We propose using the functional principal component analysis method to recover the underlying individual trajectory of the time-varying exposure from the sparsely and irregularly observed longitudinal data, and then conduct MR analysis using the recovered curves. We further propose two MR analysis methods. The first assumes a cumulative effect of the time-varying exposure variable on the disease risk, while the second assumes a time-varying genetic effect and employs functional regression models. We focus on statistical testing for a causal effect. Our simulation studies mimicking the real data show that the proposed functional data analysis based methods incorporating longitudinal data have substantial power gains compared to standard MR analysis using only one measurement. We used the Framingham Heart Study data to demonstrate the promising performance of the new methods as well as inconsistent results produced by the standard MR analysis that relies on a single measurement of the exposure at some arbitrary time point. © 2016 WILEY PERIODICALS, INC.
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This dedicated issue of the Journal of the Air & Waste Management Association contains 17 peer-reviewed scientific papers that were presented at the specialty conference, “Particulate Matter: Atmospheric Sciences, Exposure and the Fourth Colloquium on PM and Human Health,” that w...
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The global atmospheric environment for the next generation
Dentener, F.; Stevenson, D.; Ellingsen, K.; Noije, van T.; Schultz, M.; Amann, M.; Atherton, C.; Bell, N.; Bergmann, D.; Bey, I.; Bouwman, L.; Butler, T.; Cofala, J.; Collins, B.; Drevet, J.; Doherty, R.; Eickhout, B.; Eskes, H.; Fiore, A.; Gauss, M.; Hauglustaine, D.; Horowitz, L.; Isaksen, I.S.A.; Josse, B.; Lawrence, M.; Krol, M.C.; Lamarque, J.F.; Montanaro, V.; Müller, J.F.; Peuch, V.H.; Pitari, G.; Pyle, J.; Rast, S.; Rodriguez, J.; Sanderson, M.; Savage, N.H.; Shindell, D.; Strahan, S.; Szopa, S.; Sudo, K.; Dingenen, van R.; Wild, O.; Zeng, G.
2006-01-01
Air quality, ecosystem exposure to nitrogen deposition, and climate change are intimately coupled problems: we assess changes in the global atmospheric environment between 2000 and 2030 using 26 state-of-the-art global atmospheric chemistry models and three different emissions scenarios. The first
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Martin, Craig E; Rux, Guido; Herppich, Werner B
2013-01-01
It has been well-established that many epiphytic bromeliads of the atmospheric-type morphology, i.e., with leaf surfaces completely covered by large, overlapping, multicellular trichomes, are capable of absorbing water vapor from the atmosphere when air humidity increases. It is much less clear, however, whether this absorption of water vapor can hydrate the living cells of the leaves and, as a consequence, enhance physiological processes in such cells. The goal of this research was to determine if the absorption of atmospheric water vapor by the atmospheric epiphyte Tillandsia usneoides results in an increase in turgor pressure in leaf epidermal cells that subtend the large trichomes, and, by using chlorophyll fluorescence techniques, to determine if the absorption of atmospheric water vapor by leaves of this epiphyte results in increased photosynthetic activity. Results of measurements on living cells of attached leaves of this epiphytic bromeliad, using a pressure probe and of whole-shoot fluorescence imaging analyses clearly illustrated that the turgor pressure of leaf epidermal cells did not increase, and the photosynthetic activity of leaves did not increase, following exposure of the leaves to high humidity air. These results experimentally demonstrate, for the first time, that the absorption of water vapor following increases in atmospheric humidity in atmospheric epiphytic bromeliads is mostly likely a physical phenomenon resulting from hydration of non-living leaf structures, e.g., trichomes, and has no physiological significance for the plant's living tissues. Copyright © 2012 Elsevier GmbH. All rights reserved.
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Mediation analysis with time varying exposures and mediators.
VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J
2017-06-01
In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.
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Thermal Analysis of the Decomposition of Ammonium Uranyl Carbonate (AUC) in Different Atmospheres
DEFF Research Database (Denmark)
Hälldahl, L.; Sørensen, Ole Toft
1979-01-01
The intermediate products formed during thermal decomposition of ammonium uranyl carbonate (AUC) in different atmospheres, (air, helium and hydrogen) have been determined by thermal analysis, (TG, and DTA) and X-ray analysis. The endproducts observed are U3O8 and UO2 in air/He and hydrogen, respe......, respectively. The following intermediate products were observed in all atmospheres: http://www.sciencedirect.com.globalproxy.cvt.dk/cache/MiamiImageURL/B6THV-44K80TV-FB-1/0?wchp=dGLzVlz-zSkWW X-ray diffraction analysis showed that these phases were amorphous....
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Hardt, Daniel J; James, R Arden; Gut, Chester P; McInturf, Shawn M; Sweeney, Lisa M; Erickson, Richard P; Gargas, Michael L
2015-02-01
The inhalation toxicity of submarine contaminants is of concern to ensure the health of men and women aboard submarines during operational deployments. Due to a lack of adequate prior studies, potential general, neurobehavioral, reproductive and developmental toxicity was evaluated in male and female rats exposed to mixtures of three critical submarine atmospheric components: carbon monoxide (CO) and carbon dioxide (CO2; levels elevated above ambient), and oxygen (O2; levels decreased below ambient). In a 14-day, 23 h/day, whole-body inhalation study of exposure to clean air (0.4 ppm CO, 0.1% CO2 and 20.6% O2), low-dose, mid-dose and high-dose gas mixtures (high dose of 88.4 ppm CO, 2.5% CO2 and 15.0% O2), no adverse effects on survival, body weight or histopathology were observed. Reproductive, developmental and neurobehavioral performance were evaluated after a 28-day exposure in similar atmospheres. No adverse effects on estrus phase, mating, gestation or parturition were observed. No developmental or functional deficits were observed in either exposed parents or offspring related to motor activity, exploratory behavior or higher-level cognitive functions (learning and memory). Only minimal effects were discovered in parent-offspring emotionality tests. While statistically significant increases in hematological parameters were observed in the offspring of exposed parents compared to controls, these parameters remained within normal clinical ranges for blood cells and components and were not considered adverse. In summary, subacute exposures to elevated concentrations of the submarine atmosphere gases did not affect the ability of rats to reproduce and did not appear to have any significant adverse health effects.
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Model Titan atmospheric hydrocarbon analysis by Ion Mobility Spectrometry in dry helium
International Nuclear Information System (INIS)
Kojiro, D.R.; Stimac, R.M.; Wernlund, R.F.; Cohen, M.J.
1990-01-01
Ion Mobility Spectrometry (IMS) is one analytical technique being investigated for the in situ analysis of the atmosphere of Titan. Any hydrocarbon ions that may form react immediately, in microseconds, with the high concentration of water vapor normally present in conventional IMS. By reducing the water concentration to the parts-per-billion range, the lifetime of the hydrocarbon ions may be increased to the milliseconds required for measurement. At low water level concentrations, other species may become the reactant ion. This study focuses on IMS analysis of expected Titan atmospheric hydrocarbons under very dry, low water concentration conditions
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KNOW YOUR NEIGHBORHOOD: A DETAILED MODEL ATMOSPHERE ANALYSIS OF NEARBY WHITE DWARFS
Energy Technology Data Exchange (ETDEWEB)
Giammichele, N.; Bergeron, P. [Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under cooperative agreement with the National Science Foundation (United States); Dufour, P., E-mail: noemi.giammichele@astro.umontreal.ca, E-mail: pierre.bergeron@astro.umontreal.ca, E-mail: patrick.dufour@astro.umontreal.ca [Departement de Physique, Universite de Montreal, C.P. 6128, Succ. Centre-Ville, Montreal, Quebec H3C 3J7 (Canada)
2012-04-01
We present improved atmospheric parameters of nearby white dwarfs lying within 20 pc of the Sun. The aim of the current study is to obtain the best statistical model of the least-biased sample of the white dwarf population. A homogeneous analysis of the local population is performed combining detailed spectroscopic and photometric analyses based on improved model atmosphere calculations for various spectral types including DA, DB, DC, DQ, and DZ stars. The spectroscopic technique is applied to all stars in our sample for which optical spectra are available. Photometric energy distributions, when available, are also combined to trigonometric parallax measurements to derive effective temperatures, stellar radii, as well as atmospheric compositions. A revised catalog of white dwarfs in the solar neighborhood is presented. We provide, for the first time, a comprehensive analysis of the mass distribution and the chemical distribution of white dwarf stars in a volume-limited sample.
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A simulation of the OMEGA/Mars Express observations: Analysis of the atmospheric contribution
Melchiorri, R.; Drossart, P.; Fouchet, T.; Bézard, B.; Forget, F.; Gendrin, A.; Bibring, J. P.; Manaud, N.; OMEGA Team; Berthé, M.; Bibring, J.-P.; Langevin, Y.; Forni, O.; Gendrin, A.; Gondet, B.; Manaud, N.; Poulet, F.; Poulleau, G.; Soufflot, A.; Mangold, N.; Bonello, G.; Forget, F.; Bezard, B.; Combes, M.; Drossart, P.; Encrenaz, T.; Fouchet, T.; Melchiorri, R.; Erard, S.; Bellucci, G.; Altieri, F.; Formisano, V.; Fonti, S.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Kottsov, V.; Ignatiev, N.; Moroz, V.; Titov, D.; Zasova, L.; Pinet, P.; Schmitt, B.; Sotin, C.; Hauber, E.; Hoffmann, H.; Jaumann, R.; Keller, U.; Arvidson, R.; Mustard, J.; Duxbary, T.
2006-08-01
Spectral images of Mars obtained by the Mars Express/OMEGA experiment in the near infrared are the result of a complex combination of atmospheric, aerosol and ground features. Retrieving the atmospheric information from the data is important, not only to decorrelate mineralogical against atmospheric features, but also to retrieve the atmospheric variability. Once the illumination conditions have been taken into account, the main source of variation on the CO2 absorption is due to the altitude of the surface, which governs atmospheric pressure variation by more than an order of magnitude between the summit of Olympus Mons down to the bottom of Valles Marineris. In this article we present a simplified atmospheric spectral model without scattering, specially developed for the OMEGA observations, which is used to retrieve the local topography through the analysis of the 2.0μmCO2 band. OMEGA atmospheric observations increase the horizontal resolution compared to MOLA altimetry measurements, and therefore complement the mineralogical studies from the same instrument. Finally, residual variations of the pressure can be related to atmospheric structure variation.
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To the exposure of air crew members to cosmic radiation
International Nuclear Information System (INIS)
Spurny, F.; Kovar, I.; Bottollier-Depois, J.F.; Plawinski, L.
1998-01-01
According to an ICRP recommendation, the exposure of jet aircraft crew to radiation should be considered as occupational exposure when the annual equivalent doses are liable to exceed 1 mSv. Many new data on this type of exposure collected since 1991 are presented and analyzed. The dose equivalent rates established are fitted as a function of flight altitude. An analysis of data from cosmic ray monitors has shown that the presence of cosmic rays in the Earth's atmosphere is rather stable since early 1992. An estimation was therefore made of the possible influence of the solar cycle phase by means of a transport code. The results obtained are compared with experimental data
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Final safety analysis report for the atmospheric protection system
International Nuclear Information System (INIS)
1976-06-01
An Atmospheric Protection System (APS) has been constructed at the Idaho Chemical Processing Plant to minimize the release of radioactive particulate material to the atmosphere from nonroutine occurrences. Existing off-gas cleanup systems remove radioactive particulates to well below allowable limits for controlled areas before release to the plant stack. Previously all ventilation air from process cells was discharged to the stack without treatment. The APS provides continuous filtration of all ventilation air from process cells and backup filtration of all process off gases before they are released to the atmosphere. A safety analysis of the potential hazards associated with the APS has been completed. The review indicates that the system is capable of withstanding design basis natural phenomena including a flood, tornado, and earthquake without releasing unacceptable amounts of radioactive particulate from the filters to the environment. An in-cell explosion, fire, mechanical damage, and other postulated accident situations were investigated. From these, the design basis accident postulated for the facility is complete release of the maximum amount of radioactive particulate collected on the 104 ventilation air HEPA filters to the atmosphere via the 250-foot high stack. Even though the release of all the radioactive particulate contained on the filters is hardly credible, it would not present an unacceptable hazard to personnel on or offsite
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EXPOSURE ANALYSIS MODELING SYSTEM (EXAMS): USER MANUAL AND SYSTEM DOCUMENTATION
The Exposure Analysis Modeling System, first published in 1982 (EPA-600/3-82-023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals - pesticides, ...
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Determination of the Atmospheric Neutrino Fluxes from Atmospheric Neutrino Data
Gonzalez-Garcia, M. C.; Maltoni, M.; Rojo, J.
2006-01-01
The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard atmospheric neutrino data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based
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Surface analysis of 316 stainless steel treated with cold atmospheric plasma
Energy Technology Data Exchange (ETDEWEB)
Williams, David F., E-mail: david.williams@surrey.ac.uk [Department of Mechanical Engineering Sciences, University Of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); TWI Ltd Granta Park Great Abington, Cambridge CB21 6AL (United Kingdom); Kellar, Ewen J.C. [TWI Ltd Granta Park Great Abington, Cambridge CB21 6AL (United Kingdom); Jesson, David A.; Watts, John F. [Department of Mechanical Engineering Sciences, University Of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)
2017-05-01
Highlights: • Reduction in carbon contamination from ∼80 at.% to 40 at.% after 15 s treatment. • Associated carbon thickness reduction from 4.5 nm to 0.5 nm. • Area treated by torch has a diameter of 11 mm measured using imaging XPS. - Abstract: The surface of 316 stainless steel has been modified using cold atmospheric plasma (CAP) to increase the surface free energy (by cleaning the and chemically activating the surface)IN preparation for subsequent processes such as painting, coating or adhesive bonding. The analyses carried out, on CAP treated 316 stainless steel surfaces, includes X-ray photoelectron spectroscopy (XPS), imaging XPS (iXPS), and surface free energy (SFE) analysis using contact angle measurements. The CAP treatment is shown to increase the SFE of as-received 316 stainless steel from ∼39 mJ m{sup −1} to >72 mJ m{sup −1} after a short exposure to the plasma torch. This was found to correlate to a reduction in adventitious carbon, as determined by XPS analysis of the surface. The reduction from ∼90 at% to ∼30% and ∼39 at%, after being plasma treated for 5 min and 15 s respectively, shows that the process is relatively quick at changing the surface. It is suggested that the mechanism that causes the increase in surface free energy is chain scission of the hydrocarbon contamination triggered by free electrons in the plasma plume followed by chemical functionalisation of the metal oxide surface and some of the remaining carbon contamination layer.
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Technical Overview of Ecological Risk Assessment - Analysis Phase: Exposure Characterization
Exposure Characterization is the second major component of the analysis phase of a risk assessment. For a pesticide risk assessment, the exposure characterization describes the potential or actual contact of a pesticide with a plant, animal, or media.
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Li, Yingjie; Wang, Jiahui; Ren, Bainian; Wang, Hongli; Qiao, Liping; Zhu, Jiping; Li, Li
2018-04-01
While phthalates in indoor environments are extensively studied, reports on phthalates in outdoor air, particularly their associations with haze weather events are rare. Phthalates, especially dimethyl phthalate, are known to react with criteria air pollutants contributing to the formation of secondary organic aerosols. This study investigated phthalates levels in the atmosphere in Shanghai with a focus on their associations with different air quality weather events. The air quality during the study period was classified into three levels: non-haze, light pollution and moderate pollution. Phthalates levels were found to be lower in non-haze weather events (236 ng/m3) and higher in moderate pollution weather events (up to 700 ng/m3). Meteorological factors of relative humidity and wind speed had an inverse relationship with phthalates levels. Particulate matter had a positive correlation with phthalates levels. Hydroxyl radical initiated photo-reaction of dimethyl phthalate was evident by its inverse relationship with total atmospheric oxidant (O3 + NO2), indicating that dimethyl phthalate could be one of the precursors of secondary organic aerosol causing haze weather events. Daily intake of phthalates through exposure to outdoor air is estimated to be relatively minor; children intake remains higher on a body weight basis. This is the first study demonstrating the relationship of phthalates and different air quality conditions in haze weather events. The knowledge contributes to our understanding on the cause of haze weather events in China and elsewhere.
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Wilson, J. W. (Editor); Jones, I. W. (Editor); Maiden, D. L. (Editor); Goldhagen, P. (Editor)
2003-01-01
The United States initiated a program to assess the technology required for an environmentally safe and operationally efficient High Speed Civil Transport (HSCT) for entrance on the world market after the turn of the century. Due to the changing regulations on radiation exposures and the growing concerns over uncertainty in our knowledge of atmospheric radiations, the NASA High Speed Research Project Office (HSRPO) commissioned a review of "Radiation Exposure and High-Altitude Flight" by the National Council on Radiation Protection and Measurements (NCRP). On the basis of the NCRP recommendations, the HSRPO funded a flight experiment to resolve the environmental uncertainty in the atmospheric ionizing radiation levels as a step in developing an approach to minimize the radiation impact on HSCT operations. To minimize costs in this project, an international investigator approach was taken to assure coverage with instrument sensitivity across the range of particle types and energies to allow unique characterization of the diverse radiation components. The present workshop is a result of the flight measurements made at the maximum intensity of the solar cycle modulated background radiation levels during the month of June 1997.
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Analysis of wave-like oscillations in parameters of sporadic E layer and neutral atmosphere
Mošna, Z.; Koucká Knížová, P.
2012-12-01
The present study mainly concerns the wave-like activity in the ionospheric sporadic E layer (Es) and in the lower lying stratosphere. The proposed analysis involves parameters describing the state of plasma in the sporadic E layer. Critical frequencies foEs and layer heights hEs were measured at the Pruhonice station (50°N, 14.5°E) during summer campaigns 2004, 2006 and 2008. Further, we use neutral atmosphere (temperature data at 10 hPa) data from the same time interval. The analysis concentrates on vertically propagating wave-like structures within distant atmospheric regions. By means of continuous wavelet transform (CWT) we have detected significant wave-like oscillation at periods covering tidal and planetary oscillation domains both in the Es layer parameters (some of them were reported earlier, for instance in works of Abdu et al., 2003; Pancheva and Mitchel, 2004; Pancheva et al., 2003; Šauli and Bourdillon, 2008) and in stratospheric temperature variations. Further analyses using cross wavelet transform (XWT) and wavelet coherence analysis (WTC) show that despite high wave-like activity in a wide period range, there are only limited coherent wave-like bursts present in both spectra. Such common coherent wave bursts occur on periods close to eigen-periods of the terrestrial atmosphere. We suppose that vertical coupling between atmospheric regions realized by vertically propagating planetary waves occurs predominantly on periods close to those of Rossby modes. Analysis of the phase shift between data from distant atmospheric regions reveals high variability and very likely supports the non-linear scenario of the vertical coupling provided by planetary waves.
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Characterization of population exposure to organochlorines: A cluster analysis application
R.M. Guimarães (Raphael Mendonça); S. Asmus (Sven); A. Burdorf (Alex)
2013-01-01
textabstractThis study aimed to show the results from a cluster analysis application in the characterization of population exposure to organochlorines through variables related to time and exposure dose. Characteristics of 354 subjects in a population exposed to organochlorine pesticides residues
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Perry, J. L.; James, J. T.; Cole, H. E.; Limero, T. F.; Beck, S. W.
1997-01-01
Collection and analysis of spacecraft cabin air samples are necessary to assess the cabin air quality with respect to crew health. Both toxicology and engineering disciplines work together to achieve an acceptably clean cabin atmosphere. Toxicology is concerned with limiting the risk to crew health from chemical sources, setting exposure limits, and analyzing air samples to determine how well these limits are met. Engineering provides the means for minimizing the contribution of the various contaminant generating sources by providing active contamination control equipment on board spacecraft and adhering to a rigorous material selection and control program during the design and construction of the spacecraft. A review of the rationale and objectives for sampling spacecraft cabin atmospheres is provided. The presently-available sampling equipment and methods are reviewed along with the analytical chemistry methods employed to determine trace contaminant concentrations. These methods are compared and assessed with respect to actual cabin air quality monitoring needs. Recommendations are presented with respect to the basic sampling program necessary to ensure an acceptably clean spacecraft cabin atmosphere. Also, rationale and recommendations for expanding the scope of the basic monitoring program are discussed.
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Annual Book of ASTM Standards, Part 23: Water; Atmospheric Analysis.
American Society for Testing and Materials, Philadelphia, PA.
Standards for water and atmospheric analysis are compiled in this segment, Part 23, of the American Society for Testing and Materials (ASTM) annual book of standards. It contains all current formally approved ASTM standard and tentative test methods, definitions, recommended practices, proposed methods, classifications, and specifications. One…
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Virtual reality exposure therapy for anxiety disorders: A meta-analysis
Powers, M.B.; Emmelkamp, P.M.G.
2008-01-01
There is now a substantial literature investigating virtual reality exposure therapy (VRET) as a viable treatment option for anxiety disorders. In this meta-analysis we provide effect size estimates for virtual reality treatment in comparison to in vivo exposure and control conditions (waitlist,
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Variability of benzene exposure among filling station attendants
International Nuclear Information System (INIS)
Carere, A.; Iacovella, N.; Turrio Baldassarri, L.; Fuselli, S.; Iavarone, I.; Lagorio, S.; Proietto, A.R.
1996-12-01
A monitoring survey of filling station attendants aimed at identifying sources of variability of exposure to benzene and other aromatics was carried out. Concurrent samples of the worker's breathing zone air, atmospheric air in the service station proximity, and gasoline were collected, along with information about daily workloads and other exposure-related factors. Benzene personal exposure was characterised by a small between-worker variability and a predominant within-worker variance component. Such elevated day-to-day variability yields to imprecise estimates of mean personal exposure. Almost 70% of the overall personal exposure variance was explained by a model including daily benzene from dispensed fuel, presence of a shelter over the refueling area, amount of fuel supplied to the station if a delivery occurred, and background atmospheric benzene concentration
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[Regional atmospheric environment risk source identification and assessment].
Zhang, Xiao-Chun; Chen, Wei-Ping; Ma, Chun; Zhan, Shui-Fen; Jiao, Wen-Tao
2012-12-01
Identification and assessment for atmospheric environment risk source plays an important role in regional atmospheric risk assessment and regional atmospheric pollution prevention and control. The likelihood exposure and consequence assessment method (LEC method) and the Delphi method were employed to build a fast and effective method for identification and assessment of regional atmospheric environment risk sources. This method was applied to the case study of a large coal transportation port in North China. The assessment results showed that the risk characteristics and the harm degree of regional atmospheric environment risk source were in line with the actual situation. Fast and effective identification and assessment of risk source has laid an important foundation for the regional atmospheric environmental risk assessment and regional atmospheric pollution prevention and control.
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Nuraini, Lutviasari; Prifiharni, Siska; Priyotomo, Gadang; Sundjono, Gunawan, Hadi; Purawiardi, Ibrahim
2018-05-01
The performance of carbon steel, galvanized steel and aluminium after one month exposed in the atmospheric coastal area, which is in Limbangan and Karangsong Beach, West Java, Indonesia was evaluated. The corrosion rate was determined by weight loss method and the morphology of the steel after exposed was observed by Scanning Electron Microscopy(SEM)/Energy Dispersive X-Ray Analysis(EDX). The site was monitored to determine the chloride content in the marine atmosphere. Then, the corrosion products formed at carbon steel were characterized by X-Ray diffraction (XRD). The result showed the aggressively corrosion in Karangsong beach, indicated from the corrosion rate of carbon steel, galvanized steel and aluminium were 38.514 mpy; 4.7860 mpy and 0.5181 mpy, respectively. While in Limbangan Beach the corrosion rate of specimen carbon steel, galvanized steel and aluminium were 3.339; 0.219 and 0.166 mpy, respectively. The chloride content was found to be the main factor that influences in the atmospheric corrosion process in this area. Chloride content accumulated in Karangsong and Limbangan was 497 mg/m2.day and 117 mg/m2.day, respectively. The XRD Analysis on each carbon steel led to the characterization of a complex mixture of iron oxides phases.
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DEFF Research Database (Denmark)
Bergh, Jan-Erik; Hansen, Lise Stengaard; Nielsen, Per Væggemose
1999-01-01
Based on surveys of species of museum pest insects commonly found in Fennoscandia, a number of important species were selected for a study of mortality caused by exposure to modified atmosphere (>99.7 % nitrogen). In most of the species 100 % mortality was obtained within 72 hours of exposure....... Preliminary analysis of the results revealed that the larval and pupal stages were most tolerant to the anoxic treatment....
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Atmospheric Pathway Screening Analysis for Saltstone Disposal Facility Vault 4
International Nuclear Information System (INIS)
COOK, JAMES
2004-01-01
A sequential screening process using a methodology developed by the National Council on Radiation Protection and Measurements, professional judgment and process knowledge has been used to produce a list of radionuclides requiring detailed analysis to derive disposal limits for the Saltstone Disposal Facility based on the atmospheric pathway
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Analysis and application of Fourier transform spectroscopy in atmospheric remote sensing
Park, J. H.
1984-01-01
An analysis method for Fourier transform spectroscopy is summarized with applications to various types of distortion in atmospheric absorption spectra. This analysis method includes the fast Fourier transform method for simulating the interferometric spectrum and the nonlinear least-squares method for retrieving the information from a measured spectrum. It is shown that spectral distortions can be simulated quite well and that the correct information can be retrieved from a distorted spectrum by this analysis technique.
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International Nuclear Information System (INIS)
Xia Zhonghuan; Duan Xiaoli; Tao Shu; Qiu Weixun; Liu Di; Wang Yilong; Wei Siye; Wang Bin; Jiang Qiujing; Lu Bin; Song Yunxue; Hu Xinxin
2013-01-01
Passive air samplers were deployed to collect both gas and particulate phase polycyclic aromatic hydrocarbons in Taiyuan between 2009 and 2010. Annual average concentrations of BaP equivalent concentration (B[a]P eq ) in background, rural and urban areas were 2.90 ± 0.29, 23.2 ± 30.8 and 27.4 ± 28.1 ng/m 3 , respectively, with higher concentration in the winter than in other seasons. The median B[a]P eq concentrations of annual inhalation exposure were estimated to be in the range of 103–347 ng/d for all population groups in rural as well as in urban areas. The median values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure for all groups were basically larger than 10 −6 , with higher values in winter than in other seasons and in urban than in rural area. In the same season and area, the ILCR of adults was larger than other age groups and that of females was a little higher than males. - Highlights: ► The median values of ILCR were higher in winter than in other seasons. ► The median values of ILCR were higher in urban than in rural area. ► In the same season and area, the ILCR of adults was larger than other age groups. ► In the same season and area, the ILCR of females was a little higher than males. ► Exposure level and the cancer slope factor influenced the ILCR greatly. - The inhalation exposure and lung cancer risk of ambient atmospheric PAHs changed for different seasons, areas and population groups in Taiyuan, China.
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Regression analysis with categorized regression calibrated exposure: some interesting findings
Directory of Open Access Journals (Sweden)
Hjartåker Anette
2006-07-01
Full Text Available Abstract Background Regression calibration as a method for handling measurement error is becoming increasingly well-known and used in epidemiologic research. However, the standard version of the method is not appropriate for exposure analyzed on a categorical (e.g. quintile scale, an approach commonly used in epidemiologic studies. A tempting solution could then be to use the predicted continuous exposure obtained through the regression calibration method and treat it as an approximation to the true exposure, that is, include the categorized calibrated exposure in the main regression analysis. Methods We use semi-analytical calculations and simulations to evaluate the performance of the proposed approach compared to the naive approach of not correcting for measurement error, in situations where analyses are performed on quintile scale and when incorporating the original scale into the categorical variables, respectively. We also present analyses of real data, containing measures of folate intake and depression, from the Norwegian Women and Cancer study (NOWAC. Results In cases where extra information is available through replicated measurements and not validation data, regression calibration does not maintain important qualities of the true exposure distribution, thus estimates of variance and percentiles can be severely biased. We show that the outlined approach maintains much, in some cases all, of the misclassification found in the observed exposure. For that reason, regression analysis with the corrected variable included on a categorical scale is still biased. In some cases the corrected estimates are analytically equal to those obtained by the naive approach. Regression calibration is however vastly superior to the naive method when applying the medians of each category in the analysis. Conclusion Regression calibration in its most well-known form is not appropriate for measurement error correction when the exposure is analyzed on a
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[Role of biometric analysis in the retrospective assessment of exposure to asbestos].
Pairon, J C; Dumortier, P
1999-12-01
Despite intrinsic limitations due to differences in the bio-persistence of the various asbestos types, in the definition of control populations and in analytical techniques used by the laboratories, mineralogical analysis of biological samples is useful in the assessment of past exposure to asbestos. It provides additional information to occupational and environmental questionnaires, particularly when exposure to asbestos is doubtful, unknown or forgotten by a subject. Results should be interpreted taking into account clinical information. A positive result does not mean existence of asbestos-related disease. A negative result does not exclude previous significant asbestos exposure, clearly identified by an occupational questionnaire (particularly for exposure to chrysotile). Threshold values indicative of a high probability of previous asbestos exposure have been established for bronchoalveolar lavage fluid (BALF) samples and lung tissue samples. Quantification of asbestos bodies by light microscopy is easy to perform. Sensitivity and specificity of this analysis towards the total pulmonary asbestos fiber burden is good. Therefore this analysis should be performed first. Mineralogical analysis in BALF or lung tissue should be considered only when sampling is supported by diagnostic or therapeutic implications.
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Radomyski, Artur; Giubilato, Elisa; Ciffroy, Philippe; Critto, Andrea; Brochot, Céline; Marcomini, Antonio
2016-11-01
The study is focused on applying uncertainty and sensitivity analysis to support the application and evaluation of large exposure models where a significant number of parameters and complex exposure scenarios might be involved. The recently developed MERLIN-Expo exposure modelling tool was applied to probabilistically assess the ecological and human exposure to PCB 126 and 2,3,7,8-TCDD in the Venice lagoon (Italy). The 'Phytoplankton', 'Aquatic Invertebrate', 'Fish', 'Human intake' and PBPK models available in MERLIN-Expo library were integrated to create a specific food web to dynamically simulate bioaccumulation in various aquatic species and in the human body over individual lifetimes from 1932 until 1998. MERLIN-Expo is a high tier exposure modelling tool allowing propagation of uncertainty on the model predictions through Monte Carlo simulation. Uncertainty in model output can be further apportioned between parameters by applying built-in sensitivity analysis tools. In this study, uncertainty has been extensively addressed in the distribution functions to describe the data input and the effect on model results by applying sensitivity analysis techniques (screening Morris method, regression analysis, and variance-based method EFAST). In the exposure scenario developed for the Lagoon of Venice, the concentrations of 2,3,7,8-TCDD and PCB 126 in human blood turned out to be mainly influenced by a combination of parameters (half-lives of the chemicals, body weight variability, lipid fraction, food assimilation efficiency), physiological processes (uptake/elimination rates), environmental exposure concentrations (sediment, water, food) and eating behaviours (amount of food eaten). In conclusion, this case study demonstrated feasibility of MERLIN-Expo to be successfully employed in integrated, high tier exposure assessment. Copyright © 2016 Elsevier B.V. All rights reserved.
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Considerations for the design and technical setup of a human whole-body exposure chamber.
Monsé, Christian; Sucker, Kirsten; van Thriel, Christoph; Broding, Horst Christoph; Jettkant, Birger; Berresheim, Hans; Wiethege, Thorsten; Käfferlein, Heiko; Merget, Rolf; Bünger, Jürgen; Brüning, Thomas
2012-01-01
Exposures to air contaminants, such as chemical vapors and particulate matter, pose important health hazards at workplaces. Short-term experimental exposures to chemical vapors and particles in humans are a promising attempt to investigate acute effects of such hazards. However, a significant challenge in this field is the determination of effects of co-exposures to more than one chemical or mixtures of chemical vapors and/or particles. To overcome such a challenge, studies have to be conducted under standardized exposure characterization and real time measurements, if possible. A new exposure laboratory (ExpoLab) was installed at IPA, combining sophisticated engineering designs with new analytical techniques, to fulfill these requirements. Low-dose as well as high-dose exposure scenarios are achieved by means of a calibration-gas-generator. Exposure monitoring can be carried out with a high performance real time mass spectrometer and other suitable analyzers (e.g. gas chromatograph). Numerous automated security facilities guarantee the physical integrity of the volunteers, and the waste atmosphere is removed using either charcoal filtration or catalytic post-combustion. Measurements of sulfur hexafluoride, carbon dioxide, aniline and carbon black are presented to demonstrate the performance of the exposure unit with respect to the temporal and spatial stability of generated atmospheres. The variations of generated contents in the atmospheres at steady state are slightly higher than the measurement precision of the analyzers (the typical standard deviation of generated atmospheres is standards in validity and reliability of generating and measuring exposure atmospheres.
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International Nuclear Information System (INIS)
Ladislav Tomasek; Agnes Rogel; Margot Tirmarche; Dominique Laurier
2006-01-01
The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)
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Energy Technology Data Exchange (ETDEWEB)
Ladislav Tomasek [National Radiation Protection Institute, Prague (Czech Republic); Agnes Rogel; Margot Tirmarche; Dominique Laurier [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)
2006-07-01
The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)
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Alteration of municipal and industrial slags under atmospheric conditions
Rafał Kowalski, Piotr; Michalik, Marek
2014-05-01
The Waste Management System in Poland is being consequently built since 1998. After important changes in legislation, local governments have taken over the duty of waste collection. New points of selective collection of wastes have been opened and new sorting and composting plants were built. The last stage of introducing the Waste Management System is construction of waste incineration power plants. From nine installations which were planned, six are now under construction and they will start operating within the next two years. It is assumed that the consumption of raw wastes for these installations will reach 974 thousand tons per year. These investments will result in increased slags and ashes production. Now in Poland several local waste incinerators are operating and predominant amount of produced incineration residues is landfilled. These materials are exposed to atmospheric conditions in time of short term storage (just after incineration) and afterwards for a longer period of time on the landfill site. During the storage of slags low temperature mineral transformations and chemical changes may occur and also some components can be washed out. These materials are stored wet because of the technological processes. The aim of this study is to investigate the influence of storage in atmospheric conditions on slags from incineration of industrial and municipal wastes. The experiment started in January 2013. During this period slag samples from incineration of industrial and municipal wastes were exposed to atmospheric conditions. Samples were collected after 6 and 12 months. Within this time the pH value was measured monthly, and during the experimental period remained constant on the level of 9.5. After 6 months of exposure only slight changes in mineral compositions were observed in slags. The results of XRD analysis of municipal slags showed increase in content of carbonate minerals in comparison to the raw slag samples. In industrial slags, a decrease in
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Vulnerability assessment of atmospheric environment driven by human impacts.
Zhang, Yang; Shen, Jing; Ding, Feng; Li, Yu; He, Li
2016-11-15
Atmospheric environment quality worsening is a substantial threat to public health worldwide, and in many places, air pollution due to the intensification of the human activity is increasing dramatically. However, no studies have been investigated the integration of vulnerability assessment and atmospheric environment driven by human impacts. The objective of this study was to identify and prioritize the undesirable environmental changes as an early warning system for environment managers and decision makers in term of human, atmospheric environment, and social economic elements. We conduct a vulnerability assessment method of atmospheric environment associated with human impact, this method integrates spatial context of Geographic Information System (GIS) tool, multi-criteria decision analysis (MCDA) method, ordered weighted averaging (OWA) operators under the Exposure-Sensitivity- Adaptive Capacity (ESA) framework. Decision makers can find out relevant vulnerability assessment results with different vulnerable attitudes. In the Beijing-Tianjin-Hebei (BTH) region, China, we further applied this developed method and proved it to be reliable and consistent with the China Environmental Status Bulletin. Results indicate that the vulnerability of atmospheric environment in the BTH region is not optimistic, and environment managers should do more about air pollution. Thus, the most appropriate strategic decision and development program of city or state can be picked out assisting by the vulnerable results. Copyright © 2016 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Filipiak, B.; Nowicki, K.
1995-01-01
The exposure of particular persons, living in the near surroundings of Nuclear Centre - Swierk near Warsaw, Poland, to radioactive substances removed to the atmosphere during the period 1987-1992 has been assessed. The effective dose equivalent for statistically critical groups of persons has been estimated. The results have been compared with maximum permitted dose limits. 17 refs, 12 tabs
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Non-LTE model atmosphere analysis of Nova Cygni 1992
Hauschildt, P. H.; Starrfield, S.; Austin, S.; Wagner, R. M.; Shore, S. N.; Sonneborn, G.
1994-01-01
We use spherically symmetric non-local thermodynamic equilibrium (non-LTE), line-blanketed, expanding model atmospheres to analyze the International Ultraviolet Explorer (IUE) and optical spectra of Nova Cygni 1992 during the early phases of its outburst. We find that the first IUE spectrum obtained just after discovery on 1992 February 20, is best reproduced by a model atmosphere with a steep density gradient and homologous expansion, whereas the IUE and optical spectra obtained on February 24 show an extended, optically thick, wind structure. Therefore, we distinguish two phases of the early evolution of the nova photosphere: the initial, rapid, 'fireball' phase and the subsequent, much longer, optically thick 'wind' phase. The importance of line-blanketing in nova spectra is demonstrated. Our preliminary abundance analysis implies that hydrogen is depeleted in the ejecta, corresponding to abundance enhancements of Fe by a factor of approximately 2 and of CNO by more than a factor of 10 when compared to solar abundances. The synthetic spectra reproduce both the observed pseudo-continua as well as most of the observed features from the UV to the optical spectral range and demonstrate the importance of obtaining nearly simultaneous UV and optical spectra for performing accurate analyses of expanding stellar atmospheres (for both novae and supernovae).
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Agudelo-Castañeda, Dayana M; Teixeira, Elba C; Schneider, Ismael L; Lara, Sheila Rincón; Silva, Luis F O
2017-05-01
We investigated the carcinogenic and mutagenic respiratory health risks related to the exposure to atmospheric PAHs in an urban area. Our study focused in the association of these pollutants and their possible effect in human health, principally respiratory and circulatory diseases. Also, we determined a relationship between the inhalation risk of PAHs and meteorological conditions. We validated the hypothesis that in winter PAHs with high molecular weight associated to submicron particles (PM 1 ) may increase exposure risk, especially for respiratory diseases, bronchitis and pneumonia diseases. Moreover, in our study we verified the relationship between diseases and several carcinogenic PAHs (Ind, BbkF, DahA, BaP, and BghiP). These individual PAHs contributed the most to the potential risk of exposure for inhalation of PM 1.0 . Even at lower ambient concentrations of BaP and DahA in comparison with individual concentrations of other PAHs associated to PM 1.0 . Mainly, research suggests to include carcinogenic and mutagenic PAHs in future studies of environmental health risk due to their capacity to associate to PM 10 . Such carcinogenic and mutagenic PAHs are likely to provide the majority of the human exposure, since they originate from dense traffic urban areas were humans congregate. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Atmospheric dispersion and environmental consequences
International Nuclear Information System (INIS)
Hedemann Jensen, P.
1992-11-01
Methods are described for assessing early radiation doses due to atmospheric releases of radionuclides, i.e. inhalation and external exposure from the plume and from deposited activity. Data to be used in these assessments are presented. The purpose of the present work is to evaluate methods and data that could be used in emergency situations as well as for emergency planning purposes. The most important direct pathways following a release of airborne radionuclides to the atmosphere are the inhalation pathway and the external exposure pathway from ground-deposited activity. For long-lived radionuclides like 134 Cs and 137 Cs the committed effective external dose from deposited acitivity is 1-2 orders of magnitude larger than the committed effective dose from inhalation. Similarly, the committed effective dose from inhalation is 1-2 orders of magnitude larger than the external γ-dose originating directly from the plume. (au) (21 tabs., 2 ills., 37 refs.)
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New analysis indicates no thermal inversion in the atmosphere of HD 209458b
International Nuclear Information System (INIS)
Diamond-Lowe, Hannah; Stevenson, Kevin B.; Bean, Jacob L.; Line, Michael R.; Fortney, Jonathan J.
2014-01-01
An important focus of exoplanet research is the determination of the atmospheric temperature structure of strongly irradiated gas giant planets, or hot Jupiters. HD 209458b is the prototypical exoplanet for atmospheric thermal inversions, but this assertion does not take into account recently obtained data or newer data reduction techniques. We reexamine this claim by investigating all publicly available Spitzer Space Telescope secondary-eclipse photometric data of HD 209458b and performing a self-consistent analysis. We employ data reduction techniques that minimize stellar centroid variations, apply sophisticated models to known Spitzer systematics, and account for time-correlated noise in the data. We derive new secondary-eclipse depths of 0.119% ± 0.007%, 0.123% ± 0.006%, 0.134% ± 0.035%, and 0.215% ± 0.008% in the 3.6, 4.5, 5.8, and 8.0 μm bandpasses, respectively. We feed these results into a Bayesian atmospheric retrieval analysis and determine that it is unnecessary to invoke a thermal inversion to explain our secondary-eclipse depths. The data are well fitted by a temperature model that decreases monotonically between pressure levels of 1 and 0.01 bars. We conclude that there is no evidence for a thermal inversion in the atmosphere of HD 209458b.
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Instrumental neutron activation analysis of dry atmospheric fall-out and rain-water
International Nuclear Information System (INIS)
Schutyser, P.; Maenhaut, W.; Dams, R.
1978-01-01
An automated precipitation sampler and an instrumental neutron activation analysis (i.n.a.a.) method for the determination of some major and trace elements in dry atmospheric fall-out and rain-water are presented. The sampler features a rain detector which makes separate collections of dry atmospheric fall-out and rain-water possible. The sampler is equipped with u.v. lamps in order to avoid algal growth during extended collection periods. After collection, the samples are separated into water-soluble and insoluble fractions. The soluble fraction is preconcentrated before analysis by freeze-drying. The i.n.a.a. method involves the measurement of both short- and long-lived radioactivities so that a total of 35 elements can be determined. The possibility of losses during freeze-drying and the accuracy of the i.n.a.a. method were investigated for 7 elements by analysis of a soluble fraction with an independent method, viz. inductively coupled plasma atomic emission spectrometry. (Auth.)
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Atmospheric neutrino oscillation analysis with external constraints in Super-Kamiokande I-IV
Abe, K.; Bronner, C.; Haga, Y.; Hayato, Y.; Ikeda, M.; Iyogi, K.; Kameda, J.; Kato, Y.; Kishimoto, Y.; Marti, Ll.; Miura, M.; Moriyama, S.; Nakahata, M.; Nakajima, T.; Nakano, Y.; Nakayama, S.; Okajima, Y.; Orii, A.; Pronost, G.; Sekiya, H.; Shiozawa, M.; Sonoda, Y.; Takeda, A.; Takenaka, A.; Tanaka, H.; Tasaka, S.; Tomura, T.; Akutsu, R.; Irvine, T.; Kajita, T.; Kametani, I.; Kaneyuki, K.; Nishimura, Y.; Okumura, K.; Richard, E.; Tsui, K. M.; Labarga, L.; Fernandez, P.; Blaszczyk, F. d. M.; Gustafson, J.; Kachulis, C.; Kearns, E.; Raaf, J. L.; Stone, J. L.; Sulak, L. R.; Berkman, S.; Tobayama, S.; Goldhaber, M.; Carminati, G.; Elnimr, M.; Kropp, W. R.; Mine, S.; Locke, S.; Renshaw, A.; Smy, M. B.; Sobel, H. W.; Takhistov, V.; Weatherly, P.; Ganezer, K. S.; Hartfiel, B. L.; Hill, J.; Hong, N.; Kim, J. Y.; Lim, I. T.; Park, R. G.; Akiri, T.; Himmel, A.; Li, Z.; O'Sullivan, E.; Scholberg, K.; Walter, C. W.; Wongjirad, T.; Ishizuka, T.; Nakamura, T.; Jang, J. S.; Choi, K.; Learned, J. G.; Matsuno, S.; Smith, S. N.; Amey, J.; Litchfield, R. P.; Ma, W. Y.; Uchida, Y.; Wascko, M. O.; Cao, S.; Friend, M.; Hasegawa, T.; Ishida, T.; Ishii, T.; Kobayashi, T.; Nakadaira, T.; Nakamura, K.; Oyama, Y.; Sakashita, K.; Sekiguchi, T.; Tsukamoto, T.; Abe, KE.; Hasegawa, M.; Suzuki, A. T.; Takeuchi, Y.; Yano, T.; Hayashino, T.; Hirota, S.; Huang, K.; Ieki, K.; Jiang, M.; Kikawa, T.; Nakamura, KE.; Nakaya, T.; Patel, N. D.; Suzuki, K.; Takahashi, S.; Wendell, R. A.; Anthony, L. H. V.; McCauley, N.; Pritchard, A.; Fukuda, Y.; Itow, Y.; Mitsuka, G.; Murase, M.; Muto, F.; Suzuki, T.; Mijakowski, P.; Frankiewicz, K.; Hignight, J.; Imber, J.; Jung, C. K.; Li, X.; Palomino, J. L.; Santucci, G.; Vilela, C.; Wilking, M. J.; Yanagisawa, C.; Ito, S.; Fukuda, D.; Ishino, H.; Kayano, T.; Kibayashi, A.; Koshio, Y.; Mori, T.; Nagata, H.; Sakuda, M.; Xu, C.; Kuno, Y.; Wark, D.; Di Lodovico, F.; Richards, B.; Tacik, R.; Kim, S. B.; Cole, A.; Thompson, L.; Okazawa, H.; Choi, Y.; Ito, K.; Nishijima, K.; Koshiba, M.; Totsuka, Y.; Suda, Y.; Yokoyama, M.; Calland, R. G.; Hartz, M.; Martens, K.; Quilain, B.; Simpson, C.; Suzuki, Y.; Vagins, M. R.; Hamabe, D.; Kuze, M.; Yoshida, T.; Ishitsuka, M.; Martin, J. F.; Nantais, C. M.; de Perio, P.; Tanaka, H. A.; Konaka, A.; Chen, S.; Wan, L.; Zhang, Y.; Wilkes, R. J.; Minamino, A.; Super-Kamiokande Collaboration
2018-04-01
An analysis of atmospheric neutrino data from all four run periods of Super-Kamiokande optimized for sensitivity to the neutrino mass hierarchy is presented. Confidence intervals for Δ m322 , sin2θ23, sin2θ13 and δC P are presented for normal neutrino mass hierarchy and inverted neutrino mass hierarchy hypotheses, based on atmospheric neutrino data alone. Additional constraints from reactor data on θ13 and from published binned T2K data on muon neutrino disappearance and electron neutrino appearance are added to the atmospheric neutrino fit to give enhanced constraints on the above parameters. Over the range of parameters allowed at 90% confidence level, the normal mass hierarchy is favored by between 91.9% and 94.5% based on the combined Super-Kamiokande plus T2K result.
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The Consistency of Isotopologues of Ambient Atmospheric Nitric Acid in Passively Collected Samples
Bell, M. D.; Sickman, J. O.; Bytnerowicz, A.; Padgett, P.; Allen, E. B.
2012-12-01
Anthropogenic sources of nitrogen oxides have previously been shown to have distinctive isotopic signatures of oxygen and nitrogen. Nylon filters are currently used in passive sampling arrays to measure ambient atmospheric nitric acid concentrations and estimate deposition rates. This experiment measured the ability of nylon filters to consistently collect isotopologues of atmospheric nitric acid in the same ratios as they are present in the atmosphere. Samplers were deployed in continuous stirred tank reactors (CSTR) and at field sites across a nitrogen deposition gradient in Southern California. Filters were exposed over a four week period with individual filters being subjected to 1-4 week exposure times. Extracted nitric acid were measured for δ18O and δ15N ratios and compared for consistency based on length of exposure and amount of HNO3 collected. Filters within the CSTRs collected HNO3 at a consistent rate in both high and low concentration chambers. After two weeks of exposure, the mean δ18O values were within 0.5‰ of the δ18O of the source HNO3 solution. The mean of all weekly exposures were within 0.5‰ of the δ15N of the source solution, but after three weeks, the mean δ15N of adsorbed HNO3 was within 0.2‰. As the length of the exposure increased, the variability of measured delta values decreased for both elements. The field samplers collected HNO3 consistent with previously measured values along a deposition gradient. The mean δ18O at high deposition sites was 52.2‰ compared to 35.7‰ at the low deposition sites. Mean δ15N values were similar at all sites across the deposition gradient. Due to precipitation events occurring during the exposure period, the δ15N and δ18O of nitric acid were highly variable at all field sites. At single sites, changes in δ15N and δ18O were negatively correlated, consistent with two-sourcing mixing dynamics, but the slope of the regressions differed between high and low deposition sites. Anthropogenic
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Exergy analysis of a crude oil atmospheric distillation unit
International Nuclear Information System (INIS)
Rivero, R.; Gonzalez, G.V.; Garcia, V.H.; Pulido, R.; Escarcega, C.A.
1989-01-01
This paper deals with the application of an exergy analysis to an existing and operating crude oil atmospheric distillation unit. The objective of such an analysis is to fully understand where energy inefficiencies and real energy losses are located and where modifications should be implemented to improve the overall utilization of energy in the plant. First, the description of the process and the block diagram are presented. After that, the calculating procedure to obtain the exergy balance, the exergy losses, the effectiveness and the improvement potential for each plant component is described and the corresponding results are shown. Finally, the component and overall evaluations are discussed
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Monitoring of contamination of atmospheric environment by radiation
International Nuclear Information System (INIS)
Ise, Hiroaki
1995-01-01
Atmospheric pollution has become a worldwide problem regardless of developed industrial nations and developing countries. In particular, the pollution due to automobile exhaust gas, the carcinogenic particles in diesel exhaust and their relation to various respiratory diseases are the problems. Nitrogen oxides and sulfur oxides in exhaust gas become the cause of acid rain. Radiation began to be utilized for the measurement of the concentration of floating particles and the amount of fallout dust, the forecast of the generation and diffusion of pollutants, the elucidation of the contribution of generation sources in wide areas and so on. In this report, the circumstances that radiation became to be utilized for monitoring atmospheric environment and the present status and the perspective of the radiation utilization in the field of the preservation of atmospheric environment are described. The progress of the method of measuring floating particles in Japan is explained. The automatic measurement of floating particles by β-ray absorption method and the application of β-ray absorption method to the measurement of the amount of fallout dust, generation source particles and the exposure to floating particles of individuals for health control are described. The utilization of radiation for real time monitoring, the investigation of the generation of blown-up dust, atmospheric diffusion experiment and the elucidation of the contribution of generation sources by PIXE radioactivation analysis are reported. (K.I.)
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Exploring atmospheric radon with airborne gamma-ray spectroscopy
Baldoncini, Marica; Albéri, Matteo; Bottardi, Carlo; Minty, Brian; Raptis, Kassandra G. C.; Strati, Virginia; Mantovani, Fabio
2017-12-01
222Rn is a noble radioactive gas produced along the 238U decay chain, which is present in the majority of soils and rocks. As 222Rn is the most relevant source of natural background radiation, understanding its distribution in the environment is of great concern for investigating the health impacts of low-level radioactivity and for supporting regulation of human exposure to ionizing radiation in modern society. At the same time, 222Rn is a widespread atmospheric tracer whose spatial distribution is generally used as a proxy for climate and pollution studies. Airborne gamma-ray spectroscopy (AGRS) always treated 222Rn as a source of background since it affects the indirect estimate of equivalent 238U concentration. In this work the AGRS method is used for the first time for quantifying the presence of 222Rn in the atmosphere and assessing its vertical profile. High statistics radiometric data acquired during an offshore survey are fitted as a superposition of a constant component due to the experimental setup background radioactivity plus a height dependent contribution due to cosmic radiation and atmospheric 222Rn. The refined statistical analysis provides not only a conclusive evidence of AGRS 222Rn detection but also a (0.96 ± 0.07) Bq/m3 222Rn concentration and a (1318 ± 22) m atmospheric layer depth fully compatible with literature data.
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Atmospheric Pressure Plasma Induced Sterilization and Chemical Neutralization
Garate, Eusebio; Evans, Kirk; Gornostaeva, Olga; Alexeff, Igor; Lock Kang, Weng; Wood, Thomas K.
1998-11-01
We are studying chemical neutralization and surface decontamination using atmospheric pressure plasma discharges. The plasma is produced by corona discharge from an array of pins and a ground plane. The array is constructed so that various gases, like argon or helium, can be flowed past the pins where the discharge is initiated. The pin array can be biased using either DC, AC or pulsed discharges. Results indicate that the atmospheric plasma is effective in sterilizing surfaces with biological contaminants like E-coli and bacillus subtilus cells. Exposure times of less than four minutes in an air plasma result in a decrease in live colony counts by six orders of magnitude. Greater exposure times result in a decrease of live colony counts of up to ten orders of magnitude. The atmospheric pressure discharge is also effective in decomposing organic phosphate compounds that are simulants for chemical warfare agents. Details of the decomposition chemistry, by-product formation, and electrical energy consumption of the system will be discussed.
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Radiation exposure usage accountability and impact with respect to ALAP (ALARA) analysis
International Nuclear Information System (INIS)
Williams, M.C.
1978-01-01
A unique method has been developed for radiation exposure usage accounting at the N Reactor. This method accounts for exposure usage by specific job and working crafts. The accounting system provides information for use in job planning, exposure resource management, and ALAP (ALARA) analysis. It provides justification for ALAP expenditures, documentation of the effectiveness of exposure reduction efforts, and can be used to establish priorities for ALAP efforts
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Pesticide Flow Analysis to Assess Human Exposure in Greenhouse Flower Production in Colombia
Directory of Open Access Journals (Sweden)
Claudia R. Binder
2013-03-01
Full Text Available Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.
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Neutron activation analysis of the atmosphere content in the Central Asia south regions
International Nuclear Information System (INIS)
Niyazova, O.A.; Turaev, Eh.Yu.
2001-01-01
By the method of neutron activation analysis a atmospheric air elementary content of south regions of Uzbekistan and Turkmenistan during the 'Afghan' dust-storm were studied. Comparison with data for atmospheric air before nad after this phenomenon was carried out.It shown, that during the 'Afghan' dust-storm the elements concentration of Au, La, Na, Sm, Hg, Cs, Zn, Co is increased in to 3-4 times. Concentration of Sc and Fe is increasing into 8-9 times. In the atmosphere with the storm beginning the Ce and Cr elements are appealing, its are absent before the 'Afghan' dust-storm. The surprise result, that Br element in air during the dust storm is disappearing
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Exploratory analysis of atmospheric pollution in a coastal forest ecosystem in central Italy
Directory of Open Access Journals (Sweden)
Rita Aromolo
2015-02-01
Full Text Available Exploratory analysis of atmospheric pollution in a coastal forest ecosystem in central Italy - The study of spatial and temporal distribution of heavy metals in the atmosphere through the continuous assessment of deposition is of great interest for the analysis of anthropogenic pressure on the environment and the potential toxicity to humans and other living organisms. Information based on reliable estimates of heavy metals is therefore crucial for the evaluation of environmental quality. Trends in heavy metal concentration in atmospheric depositions on a coastal forest ecosystem (Castelporziano, Rome are analyzed in the present study based on a three-year monitoring field survey over three sites representative of different woodland characteristics in the area. Our results highlight both the influence of transportation processes in the short and medium distance based on the human pressure reflecting urban expansion and infrastructure development on the fringe of Castelporziano pristine forest. Further studies investigating the latent correlation with meteorological variables at various temporal scales are needed to provide a comprehensive picture of environmental conditions in a forest ecosystem subjected to increasing human pressure. Analysis of runoff water quality and the determination of other heavy metals, such as arsenic, may identify additional sources of pollution impacting soil and forest ecosystem.
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Atmospheric corrosion of mild steel in Oman
International Nuclear Information System (INIS)
Gismelseed, Abbasher; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K.
2006-01-01
A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.
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Atmospheric corrosion of mild steel in Oman
Energy Technology Data Exchange (ETDEWEB)
Gismelseed, Abbasher, E-mail: abbasher@squ.edu.om; Al-Harthi, S. H.; Elzain, M.; Al-Rawas, A. D.; Yousif, A.; Al-Saadi, S.; Al-Omari, I.; Widatallah, H.; Bouziane, K. [College of Science, Department of Physics (Oman)
2006-01-15
A systematic study has been made of the initial corrosion products which form on mild steel capons exposed near the coastal region of Oman and at some industrial areas. The phases and compositions of the products formed at different periods of exposure were examined by using Moessbauer spectroscopy (295 and 78 K) and X-ray diffraction (XRD) techniques. The results show that lepidocorcite and maghemite are early corrosion products and goethite starts to form after 2 months of metal exposure to the atmosphere. Akaganeite is an early corrosion product but it forms in marine environments only, which reflects the role of chlorine effect in the atmosphere. The 12 months coupons showed the presence of goethite, lepidocorcite and maghemite, but no akaganeite being seen in the products of one of the studied areas.
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Fetal cocaine exposure: analysis of vernix caseosa.
Moore, C; Dempsey, D; Deitermann, D; Lewis, D; Leikin, J
1996-10-01
Preliminary data regarding the use of vernix caseosa (VC) as an alternative to other biological specimens for the determination of fetal cocaine exposure are presented. Advantages of VC analysis include its presence on all newborn babies, historical record of drug exposure, and ease of collection and storage. Fifteen samples of vernix caseosa-five from babies known to be cocaine-exposed because of a positive benzoylecgonine result from the urine and umbilical cord blood and ten from nonexposed neonates-were analyzed for the presence of cocaine and metabolites. VC samples from three of the five neonates known to be cocaine-exposed were positive for cocaine or its metabolites, the other two had little or no remaining specimen. The remaining ten were negative.
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Nighttime exposure to electromagnetic fields and childhood leukemia: an extended pooled analysis
DEFF Research Database (Denmark)
Schüz, Joachim; Svendsen, Anne Louise; Linet, Martha S
2007-01-01
analysis of case-control studies on ELF EMF exposure and risk of childhood leukemia to examine nighttime residential exposures. Data from four countries (Canada, Germany, the United Kingdom, and the United States) were included in the analysis, comprising 1,842 children diagnosed with leukemia and 3......,099 controls (diagnosis dates ranged from 1988 to 1996). The odds ratios for nighttime ELF EMF exposure for categories of 0.1-or=0.4 microT as compared with ... that nighttime measures are more appropriate; hence, the observed association between ELF EMF and childhood leukemia still lacks a plausible explanation....
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Virtual reality exposure therapy in anxiety disorders: a quantitative meta-analysis.
Opriş, David; Pintea, Sebastian; García-Palacios, Azucena; Botella, Cristina; Szamosközi, Ştefan; David, Daniel
2012-02-01
Virtual reality exposure therapy (VRET) is a promising intervention for the treatment of the anxiety disorders. The main objective of this meta-analysis is to compare the efficacy of VRET, used in a behavioral or cognitive-behavioral framework, with that of the classical evidence-based treatments, in anxiety disorders. A comprehensive search of the literature identified 23 studies (n = 608) that were included in the final analysis. The results show that in the case of anxiety disorders, (1) VRET does far better than the waitlist control; (2) the post-treatment results show similar efficacy between the behavioral and the cognitive behavioral interventions incorporating a virtual reality exposure component and the classical evidence-based interventions, with no virtual reality exposure component; (3) VRET has a powerful real-life impact, similar to that of the classical evidence-based treatments; (4) VRET has a good stability of results over time, similar to that of the classical evidence-based treatments; (5) there is a dose-response relationship for VRET; and (6) there is no difference in the dropout rate between the virtual reality exposure and the in vivo exposure. Implications are discussed. © 2011 Wiley Periodicals, Inc.
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Penning de Vries, Bas B L; Kolkert, Joé L P; Meerwaldt, Robbert; Groenwold, Rolf H H
2017-10-01
Associations between atmospheric pressure and abdominal aortic aneurysm (AAA) rupture risk have been reported, but empirical evidence is inconclusive and largely derived from studies that did not account for possible nonlinearity, seasonality, and confounding by temperature. Associations between atmospheric pressure and AAA rupture risk were investigated using local meteorological data and a case series of 358 patients admitted to hospital for ruptured AAA during the study period, January 2002 to December 2012. Two analyses were performed-a time series analysis and a case-crossover study. Results from the 2 analyses were similar; neither the time series analysis nor the case-crossover study showed a significant association between atmospheric pressure ( P = .627 and P = .625, respectively, for mean daily atmospheric pressure) or atmospheric pressure variation ( P = .464 and P = .816, respectively, for 24-hour change in mean daily atmospheric pressure) and AAA rupture risk. This study failed to support claims that atmospheric pressure causally affects AAA rupture risk. In interpreting our results, one should be aware that the range of atmospheric pressure observed in this study is not representative of the atmospheric pressure to which patients with AAA may be exposed, for example, during air travel or travel to high altitudes in the mountains. Making firm claims regarding these conditions in relation to AAA rupture risk is difficult at best. Furthermore, despite the fact that we used one of the largest case series to date to investigate the effect of atmospheric pressure on AAA rupture risk, it is possible that this study is simply too small to demonstrate a causal link.
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International Nuclear Information System (INIS)
Kojo, Katja; Jansen, Christer T.; Nybom, Pia; Huurto, Laura; Laihia, Jarmo; Ilus, Taina; Auvinen, Anssi
2006-01-01
Ultraviolet radiation (UVR) is the principal cause of cutaneous malignant melanoma (CMM). However, the relation between CMM and UVR exposure is not clear. We present the trends of population exposure to UVR and conduct a time-series analysis of the relation between UVR exposure and incidence of CMM. Data on CMM incidence were obtained from the Finnish Cancer Registry. Clothing coverage of the body was scored from archival photographs and the proportion of uncovered skin was used as a measure of solar exposure. Information on the number of sunny resort holidays, duration of annual holidays, and sunscreen sales were obtained from various sources. Exposed skin area doubled from 1920 to 1985. The average duration of annual holidays increased 30-fold. The number of sunny resort holidays and the sales of sunscreens increased rapidly from 1980. CMM was most strongly associated with solar exposure of 5-19 years earlier. There is a considerable decrease in clothing coverage during the 20th century. UVR exposure preceding CMM occurrence 4 years or less does not appear relevant, whereas the period 5-19 years prior to CMM occurrence might be the most relevant period. However, findings of ecological studies may not be applicable at the individual level
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Sensor-triggered sampling to determine instantaneous airborne vapor exposure concentrations.
Smith, Philip A; Simmons, Michael K; Toone, Phillip
2018-06-01
It is difficult to measure transient airborne exposure peaks by means of integrated sampling for organic chemical vapors, even with very short-duration sampling. Selection of an appropriate time to measure an exposure peak through integrated sampling is problematic, and short-duration time-weighted average (TWA) values obtained with integrated sampling are not likely to accurately determine actual peak concentrations attained when concentrations fluctuate rapidly. Laboratory analysis for integrated exposure samples is preferred from a certainty standpoint over results derived in the field from a sensor, as a sensor user typically must overcome specificity issues and a number of potential interfering factors to obtain similarly reliable data. However, sensors are currently needed to measure intra-exposure period concentration variations (i.e., exposure peaks). In this article, the digitized signal from a photoionization detector (PID) sensor triggered collection of whole-air samples when toluene or trichloroethylene vapors attained pre-determined levels in a laboratory atmosphere generation system. Analysis by gas chromatography-mass spectrometry of whole-air samples (with both 37 and 80% relative humidity) collected using the triggering mechanism with rapidly increasing vapor concentrations showed good agreement with the triggering set point values. Whole-air samples (80% relative humidity) in canisters demonstrated acceptable 17-day storage recoveries, and acceptable precision and bias were obtained. The ability to determine exceedance of a ceiling or peak exposure standard by laboratory analysis of an instantaneously collected sample, and to simultaneously provide a calibration point to verify the correct operation of a sensor was demonstrated. This latter detail may increase the confidence in reliability of sensor data obtained across an entire exposure period.
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Caudeville, Julien; Bonnard, Roseline; Boudet, Céline; Denys, Sébastien; Govaert, Gérard; Cicolella, André
2012-08-15
Analyzing the relationship between the environment and health has become a major focus of public health efforts in France, as evidenced by the national action plans for health and the environment. These plans have identified the following two priorities: - identify and manage geographic areas where hotspot exposures are a potential risk to human health; and - reduce exposure inequalities. The aim of this study is to develop a spatial stochastic multimedia exposure model for detecting vulnerable populations and analyzing exposure determinants at a fine resolution and regional scale. A multimedia exposure model was developed by INERIS to assess the transfer of substances from the environment to humans through inhalation and ingestion pathways. The RESPIR project adds a spatial dimension by linking GIS (Geographic Information System) to the model. Tools are developed using modeling, spatial analysis and geostatistic methods to build and discretize interesting variables and indicators from different supports and resolutions on a 1-km(2) regular grid. We applied this model to the risk assessment of exposure to metals (cadmium, lead and nickel) using data from a region in France (Nord-Pas-de-Calais). The considered exposure pathways include the atmospheric contaminant inhalation and ingestion of soil, vegetation, meat, egg, milk, fish and drinking water. Exposure scenarios are defined for different reference groups (age, dietary properties, and the fraction of food produced locally). The two largest risks correspond to an ancient industrial site (Metaleurop) and the Lille agglomeration. In these areas, cadmium, vegetation ingestion and soil contamination are the principal determinants of the computed risk. Copyright © 2012 Elsevier B.V. All rights reserved.
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Verrier, A; Souques, M; Wallet, F
2005-05-01
Our lack of knowledge about the biological mechanisms of 50 Hz magnetic fields makes it hard to improve exposure assessment. To provide better information about these exposure measures, we use multidimensional analysis techniques to examine the relations between different exposure metrics for a group of subjects. We used a combination of a two stage Principal Component Analysis (PCA) followed by an ascending hierarchical classification (AHC) to identify a set of measures that would capture the characteristics of the total exposure. This analysis gives an indication of the aspects of the exposure that are important to capture to get a complete picture of the magnetic field environment. We calculated 44 metrics of exposure measures from 16 exposed EDF employees and 15 control subjects, containing approximately 20,000 recordings of magnetic field measurements, taken every 30 s for 7 days with an EMDEX II dosimeter. These metrics included parameters used routinely or occasionally and some that were new. To eliminate those that expressed the least variability and that were most highly correlated to one another, we began with an initial Principal Component Analysis (PCA). A second PCA of the remaining 12 metrics enabled us to identify from the foreground 82.7% of the variance: the first component (62.0%) was characterized by central tendency metrics, and the second (20.7%) by dispersion characteristics. We were able to use AHC to divide the entire sample (of individuals) into four groups according to the axes that emerged from the PCA. Finally, discriminant analysis tested the discriminant power of the variables in the exposed/control classification as well as those from the AHC classification. The first showed that two subjects had been incorrectly classified, while no classification error was observed in the second. This exploratory study underscores the need to improve exposure measures by using at least two dimensions: intensity and dispersion. It also indicates the
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Development of a phoswich detector for neutron dose rate measurements in the Earth's atmosphere
International Nuclear Information System (INIS)
Doensdorf, Esther Miriam
2014-01-01
The Earth is constantly exposed to a stream of energetic particles from outer space. Through the interaction of this radiation with the Earth's magnetosphere and atmosphere a complex radiation field is formed which varies with the location inside the Earth's atmosphere. This radiation field consists of charged and uncharged particles leading to the constant exposure of human beings to radiation. As this ionizing radiation can be harmful for humans, it is necessary to perform dose rate measurements in different altitudes in the Earth's atmosphere. Due to their higher biological effectiveness the exposure to neutrons is more harmful than the exposure to γ-rays and charged particles, which is why the determination of neutron dose rates is the focus of this work. In this work the prototype of a Phoswich detector called PING (Phoswich Instrument for Neutrons and Gammas) is developed to determine dose rates caused by neutrons in the Earth's atmosphere and to distinguish these from γ-rays. The instrument is composed of two different scintillators optically coupled to each other and read out by one common photomultiplier tube. The scintillator package consists of an inner plastic scintillator made of the material BC-412 and a surrounding anti-coincidence made of sodium doped caesium iodide (CsI(Na)). In this work the instrument is calibrated, tested and flown and a procedure for a pulse shape analysis for this instrument is developed. With this analysis it is possible to distinguish pulses from the plastic scintillator and pulses from the CsI(Na). The pulses from the plastic scintillator are mainly due to the interaction of neutrons but there is an energy-dependent contribution of γ-rays to these events. Measurements performed on board an airplane show that the dose rates measured with the developed detector are in the same order of magnitude as results of other instruments. During measurements on board stratospheric balloons the altitude dependence of count rates and
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Sulphur and nitrogen in the atmosphere
International Nuclear Information System (INIS)
Legge, A.H.
1990-01-01
The author discusses sulfur and nitrogen compounds in the atmosphere. Both dry and wet deposition of these compounds are reported on. Characteristics of air pollutant exposure dynamics are described. Environmental responses to the deposition of sulfur and nitrogen compounds, as well as to other pollutants, are detailed
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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)
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International Nuclear Information System (INIS)
Wan, Haojiang; Wei, Guanghui; Cui, Yaozhong; Chen, Yazhou
2013-01-01
Monitoring of atmospheric electric field near ground plays a critical role in atmospheric environment detecting and lightning warning. Different environmental conditions (e.g. buildings, plants, weather, etc.) have different influences on the data's coherence in an atmospheric electric field detection network. In order to study the main influence factors of atmospheric electric field monitoring under different weather conditions, with the combination of theoretical analysis and experiments, the electric field monitoring data on the ground and on the top of a building are compared in fair weather and thunderstorm weather respectively in this paper. The results show that: In fair weather, the field distortion due to the buildings is the main influence factor on the electric field monitoring. In thunderstorm weather, the corona ions produced from the ground, besides the field distortion due to the buildings, can also influence the electric field monitoring results.
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DEFF Research Database (Denmark)
Poulsen, T.G.; Christophersen, Mette; Moldrup, P.
2003-01-01
were applied: (I) State-space analysis was used to identify relations between gas flux and short-term (hourly) variations in atmospheric pressure. (II) A numerical gas transport model was fitted to the data and used to quantify short-term impacts of variations in atmospheric pressure, volumetric soil......-water content, soil gas permeability, soil gas diffusion coefficients, and biological CH4 degradation rate upon landfill gas concentration and fluxes in the soil. Fluxes and concentrations were found to be most sensitive to variations in volumetric soil water content, atmospheric pressure variations and gas...... permeability whereas variations in CH4 oxidation rate and molecular coefficients had less influence. Fluxes appeared to be most sensitive to atmospheric pressure at intermediate distances from the landfill edge. Also overall CH4 fluxes out of the soil over longer periods (years) were largest during periods...
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Selenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression
Cai, Xianlei; Wang, Chen; Yu, Wanqi; Fan, Wenjie; Wang, Shan; Shen, Ning; Wu, Pengcheng; Li, Xiuyang; Wang, Fudi
2016-01-01
The objective of this study was to investigate the associations between selenium exposure and cancer risk. We identified 69 studies and applied meta-analysis, meta-regression and dose-response analysis to obtain available evidence. The results indicated that high selenium exposure had a protective effect on cancer risk (pooled OR = 0.78; 95%CI: 0.73–0.83). The results of linear and nonlinear dose-response analysis indicated that high serum/plasma selenium and toenail selenium had the efficacy on cancer prevention. However, we did not find a protective efficacy of selenium supplement. High selenium exposure may have different effects on specific types of cancer. It decreased the risk of breast cancer, lung cancer, esophageal cancer, gastric cancer, and prostate cancer, but it was not associated with colorectal cancer, bladder cancer, and skin cancer. PMID:26786590
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Sousa, Raquel; Duque, Laura; Duarte, Abel J; Gomes, Carlos R; Ribeiro, Helena; Cruz, Ana; Esteves da Silva, Joaquim C G; Abreu, Ilda
2012-02-21
In the last years, a rising trend of pollen allergies in urban areas has been attributed to atmospheric pollution. In this work, we investigated the effects of SO(2) and NO(2) on the protein content, allergenicity, and germination rate of Acer negundo pollen. A novel environmental chamber was assembled to exposure pollen samples with SO(2) or NO(2) at two different levels: just below and two times the atmospheric hour-limit value acceptable for human health protection in Europe. Results showed that protein content was lower in SO(2)-exposed pollen samples and slightly higher in NO(2)-exposed pollen compared to the control sample. No different polypeptide profiles were revealed by SDS-PAGE between exposed and nonexposed pollen, but the immunodetection assays indicated higher IgE recognition by all sera of sensitized patients to Acer negundo pollen extracts in all exposed samples in comparison to the nonexposed samples. A decrease in the germination rate of exposed in contrast to nonexposed pollen was verified, which was more pronounced for NO(2)-exposed samples. Our results indicated that in urban areas, concentrations of SO(2) and NO(2) below the limits established for human protection can indirectly aggravate pollen allergy on predisposed individuals and affect plant reproduction.
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Eustachian tube function and middle ear barotrauma associated with extremes in atmospheric pressure.
Miyazawa, T; Ueda, H; Yanagita, N
1996-11-01
Eustachian tube (ET) function was studied by means of sonotubometry and tubotympano-aerodynamography (TTAG) prior to and following exposure to hypobaric or hyperbaric conditions. Forty normal adults were subjected to hypobaric pressure. Fifty adults who underwent hyperbaric oxygen (HBO) therapy also were studied. Following hypobaric exposure, 14 of 80 ears (17.5%) exhibited middle ear barotrauma. Following hyperbaric exposure, 34 of 100 ears (34%) exhibited middle ear barotrauma. Dysfunction of the ET, characterized by altered active and passive opening capacity, was more prevalent following exposure to extremes in atmospheric pressure compared to baseline. The ET function, which was impaired after the first HBO treatment, improved gradually over the next 2 hours. Overall, however, ET function was worse after the seventh treatment. The patients who developed barotrauma exhibited worse ET function prior to hypobaric or hyperbaric exposure. Thus, abnormal ET function can be used to predict middle ear barotrauma prior to exposure to hypobaric or hyperbaric atmospheric pressure.
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Radiation dosimetry for crewmember exposure to cosmic radiation during astronaut training operations
International Nuclear Information System (INIS)
Shavers, M.R.; Gersey, B.B.; Wilkins, R.T.; Semones, E.J.; Cucinotta, F.A.
2003-01-01
'Atmospheric exposures' of astronauts to cosmic ions and secondary particles during air-flight training are being measured and analytically modeled for inclusion in the astronaut medical records database. For many of the ∼170 astronauts currently in the astronaut corps, their occupational radiation exposure history will be dominated by cosmic ion exposures during air-travel rather than short-duration spaceflight. Relatively low (usually <10 μSv hr -1 ) and uniform organ dose rates result from the penetrating mix of cosmic particles during atmospheric exposures at all altitudes, but at rates that vary greatly due to differences in flight profiles and the geomagnetic conditions at the time of flight. The precision and accuracy to which possible deleterious effects of the exposures can be assessed suffers from limitations that similarly impact assessment of human exposures in low-Earth orbit: uncertainties associated with the environmental measurements and their interpretation, uncertainties associated with the analytical tools that transport the cosmic radiation environment, and uncertain biological responses to low-dose-rate exposures to radiation fields of mixed radiation 'quality'. Lineal energy spectra will be measured using a Tissue Equivalent Proportional Counter designed for training and operational sorties frequently flown in T-38, Space Shuttle Trainer, and high altitude WB-57 aircraft. Linear energy spectra will be measured over multiple flights using CR-39 plastic nuclear track detectors, as well. Flight records are available for nearly 200,000 sorties flown in NASA aircraft by astronauts and flight officers in the Johnson Space Center Aircraft Operations Division over the past 25 years, yet this database only partially documents the complete exposure histories. Age-dependent risk analysis indicates significant impact, particularly to young women who anticipate lengthy on-orbit careers
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Morino, Yu; Ohara, Toshimasa; Yumimoto, Keiya
2014-05-01
than particles. Analysis of 131I deposition gives us better constraint for the atmospheric simulation of 131I, which is important in assessing public radiation exposure.
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Atmospheric corrosion of metals in industrial city environment
Kusmierek, Elzbieta; Chrzescijanska, Ewa
2015-01-01
Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the s...
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EFFECTS OF TRITIUM GAS EXPOSURE ON EPDM ELASTOMER
Energy Technology Data Exchange (ETDEWEB)
Clark, E.
2009-12-11
Samples of four formulations of ethylene-propylene diene monomer (EPDM) elastomer were exposed to initially pure tritium gas at one atmosphere and ambient temperature for various times up to about 420 days in closed containers. Two formulations were carbon-black-filled commercial formulations, and two were the equivalent formulations without filler synthesized for this work. Tritium effects on the samples were characterized by measuring the sample volume, mass, flexibility, and dynamic mechanical properties and by noting changes in appearance. The glass transition temperature was determined by analysis of the dynamic mechanical properties. The glass transition temperature increased significantly with tritium exposure, and the unfilled formulations ceased to behave as elastomers after the longest tritium exposure. The filled formulations were more resistant to tritium exposure. Tritium exposure made all samples significantly stiffer and therefore much less able to form a reliable seal when employed as O-rings. No consistent change of volume or density was observed; there was a systematic lowering of sample mass with tritium exposure. In addition, the significant radiolytic production of gas, mainly protium (H{sub 2}) and HT, by the samples when exposed to tritium was characterized by measuring total pressure in the container at the end of each exposure and by mass spectroscopy of a gas sample at the end of each exposure. The total pressure in the containers more than doubled after {approx}420 days tritium exposure.
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The tempo-spatially modulated polarization atmosphere Michelson interferometer.
Zhang, ChunMin; Zhu, HuaChun; Zhao, Baochang
2011-05-09
A space-based tempo-spatially modulated polarization atmosphere Michelson interferometer (TSMPAMI) is described. It uses the relative movement between the TSMPAMI and the measured target to change optical path difference. The acquisition method of interferogram is presented. The atmospheric temperatures and horizontal winds can be derived from the optical observations. The measurement errors of the winds and temperatures are discussed through simulations. In the presence of small-scale structures of the atmospheric fields, the errors are found to be significantly influenced by the mismatch of the scenes observed by the adjacent CCD sub-areas aligned along the orbiter's track during successive measurements due to the orbital velocity and the exposure time. For most realistic conditions of the orbit and atmosphere, however, the instrument is proven suitable for measuring the atmospheric parameters. © 2011 Optical Society of America
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International Nuclear Information System (INIS)
An Taicheng; Zhang Delin; Li Guiying; Mai Bixian; Fu Jiamo
2011-01-01
Gas samples and total suspended particle during work and off work time were investigated on-site and off-site electronic waste dismantling workshop (I- and O-EWDW), then compared with plastic recycling workshop (PRW) and waste incineration plant (WIP). TSP concentrations and total PBDE were 0.36-2.21 mg/m 3 and 27-2975 ng/m 3 at different workshops, respectively. BDE-47, -99, and -209 were major ΣPBDE congeners at I-EWDW and WIP, while BDE-209 was only dominant congener in PRW and control sites during work time and all sites during off work time. The gas-particle partitioning result was well correlated with the subcooled liquid vapor pressure for all samples, except for WIP and I-EDWD, at park during work time, and residential area during off work time. The predicted urban curve fitted well with measured φ values at O-DEWD during work time, whereas it was slightly overestimated or underestimated for others. Exposure assessment revealed the highest exposure site was I-EDWD. - Highlights: → On- and off-site atmospheric PBDEs was monitored in e-waste dismantling workshops in south China. → The gas-particle partitioning result was well correlated with the subcooled liquid vapor pressure for some samples. → Exposure assessment revealed that workers in I-EDWD were the highest exposure population. - The findings of this study may serve as a valuable reference for future risk assessment and environmental management in Guiyu, South China.
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Impacts of heterogeneous reactions to atmospheric peroxides: Observations and budget analysis study
Qin, Mengru; Chen, Zhongming; Shen, Hengqing; Li, Huan; Wu, Huihui; Wang, Yin
2018-06-01
Atmospheric peroxides play important roles in atmospheric chemistry, acting as reactive oxidants and reservoirs of HOX and ROX radicals. Field measurements of atmospheric peroxides were conducted over urban Beijing from 2015 to 2016, including dust storm days, haze days and different seasons. We employed a box model based on RACM2 mechanism to conduct concentration simulation and budget analysis of hydrogen peroxide (H2O2) and peroxyacetic acid (PAA). In this study, heterogeneous reaction is found to be a significant sink for atmospheric H2O2 and PAA in urban Beijing. Here, we recommend a suitable uptake coefficient formula considering the water effect for model research of peroxides. It is found that H2O2 and PAA unexpectedly maintained considerable concentrations on haze days, even higher than that on non-haze days. This phenomenon is mainly ascribed to relatively high levels of volatile organic compounds and ozone on haze days. In addition, high levels of water vapor in pollution episode can promote not only the heterogeneous uptake to aerosol phase but also the production of H2O2. Atmospheric PAA formation is suggested to be sensitive to alkenes and NOX in urban Beijing. In particular, with the help of peroxides, sulfate formation rate from heterogeneous uptake could increase by ∼4 times on haze days, indicating the potential effect of peroxides on enhancement of aerosol oxidative property and secondary sulfate formation.
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Pesticide exposure and risk of Alzheimer’s disease: a systematic review and meta-analysis
Yan, Dandan; Zhang, Yunjian; Liu, Liegang; Yan, Hong
2016-09-01
Evidence suggests that lifelong cumulative exposure to pesticides may generate lasting toxic effects on the central nervous system and contribute to the development of Alzheimer’s disease (AD). A number of reports indicate a potential association between long-term/low-dose pesticide exposure and AD, but the results are inconsistent. Therefore, we conducted a meta-analysis to clarify this association. Relevant studies were identified according to inclusion criteria. Summary odds ratios (ORs) were calculated using fixed-effects models. A total of seven studies were included in our meta-analysis. A positive association was observed between pesticide exposure and AD (OR = 1.34 95% confidence interval [CI] = 1.08, 1.67; n = 7). The summary ORs with 95% CIs from the crude and adjusted effect size studies were 1.14 (95% CI = 0.94, 1.38; n = 7) and 1.37 (95% CI = 1.09, 1.71; n = 5), respectively. The sensitivity analyses of the present meta-analysis did not substantially modify the association between pesticide exposure and AD. Subgroup analyses revealed that high-quality studies tended to show significant relationships. The present meta-analysis suggested a positive association between pesticide exposure and AD, confirming the hypothesis that pesticide exposure is a risk factor for AD. Further high-quality cohort and case-control studies are required to validate a causal relationship.
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Energy Technology Data Exchange (ETDEWEB)
Bonnard, R
2001-12-15
Risk assessment and environmental impacts studies are realized to preserve the public health. Today one of the most used approach is the use of an atmospheric dispersion model to assess the risks. The data are then injected in a calculation software of exposure bond to polluted soils, to evaluate the risks of non direct exposure. This report details and evaluates the models corresponding to the need: the methodology for assessing Health Risks associated with multiple pathways of exposure to combustor, human health risk assessment proto col for hazardous waste combustion facilities, EUSES, CALTOX, MEPAS, MEND-TOX, RESRAD, MMSOILS, FRAMES-HWIR, PC-GEMS and TRIM. (A.L.B.)
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Inhalation Exposure Input Parameters for the Biosphere Model
Energy Technology Data Exchange (ETDEWEB)
M. Wasiolek
2006-06-05
This analysis is one of the technical reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), referred to in this report as the biosphere model. ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. ''Inhalation Exposure Input Parameters for the Biosphere Model'' is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the biosphere model is presented in Figure 1-1 (based on BSC 2006 [DIRS 176938]). This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and how this analysis report contributes to biosphere modeling. This analysis report defines and justifies values of atmospheric mass loading for the biosphere model. Mass loading is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Mass loading values are used in the air submodel of the biosphere model to calculate concentrations of radionuclides in air inhaled by a receptor and concentrations in air surrounding crops. Concentrations in air to which the receptor is exposed are then used in the inhalation submodel to calculate the dose contribution to the receptor from inhalation of contaminated airborne particles. Concentrations in air surrounding plants are used in the plant submodel to calculate the concentrations of radionuclides in foodstuffs contributed from uptake by foliar interception. This
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Inhalation Exposure Input Parameters for the Biosphere Model
International Nuclear Information System (INIS)
M. Wasiolek
2006-01-01
This analysis is one of the technical reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), referred to in this report as the biosphere model. ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. ''Inhalation Exposure Input Parameters for the Biosphere Model'' is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the biosphere model is presented in Figure 1-1 (based on BSC 2006 [DIRS 176938]). This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and how this analysis report contributes to biosphere modeling. This analysis report defines and justifies values of atmospheric mass loading for the biosphere model. Mass loading is the total mass concentration of resuspended particles (e.g., dust, ash) in a volume of air. Mass loading values are used in the air submodel of the biosphere model to calculate concentrations of radionuclides in air inhaled by a receptor and concentrations in air surrounding crops. Concentrations in air to which the receptor is exposed are then used in the inhalation submodel to calculate the dose contribution to the receptor from inhalation of contaminated airborne particles. Concentrations in air surrounding plants are used in the plant submodel to calculate the concentrations of radionuclides in foodstuffs contributed from uptake by foliar interception. This report is concerned primarily with the
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International Nuclear Information System (INIS)
Avakyan, K.; Chilingarian, A.; Karapetyan, T.; Chilingaryan, S.
2017-01-01
To make transformational scientific progress in Space science and geophysics, the Sun, heliosphere, magnetosphere and different layers of the atmosphere must be studied as a coupled system. Presented paper describes how information on complicated physical processes on Sun, in the heliosphere, magnetosphere and atmosphere can be made immediately assessable for researchers via advanced multivariate visualization system with simple statistical analysis package. Research of the high-energy phenomena in the atmosphere and the atmospheric discharges is of special importance. The relationship between thundercloud electrification, lightning activity, wideband radio emission and particle fluxes have not been yet unambiguously established. One of most intriguing opportunities opening by observation of the high-energy processes in the atmosphere is their relation to lightning initiation. Investigations of the accelerated structures in the geospace plasmas can as well shed light on particle acceleration up to much higher energies in the similar structures of space plasmas in the distant objects of the Universe. (author)
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International Nuclear Information System (INIS)
Savolainen, Ilkka
1980-01-01
A presentation is made of probabilistic evaluation schemes for nuclear power plant siting. Effects on health attributable to ionizing radiation are reviewed, for the purpose of assessment of the numbers of the most important health effect cases in light-water reactor accidents. The atmospheric dispersion of radioactive releases from nuclear power plants is discussed, and there is presented an environmental consequence assessment model in which the radioactive releases and atmospheric dispersion of the releases are treated by the application of probabilistic methods. In the model, the environmental effects arising from exposure to radiation are expressed as cumulative probability distributions and expectation values. The probabilistic environmental consequence assessment model has been applied to nuclear power plant site evaluation, including risk-benefit and cost-benefit analyses, and the comparison of various alternative sites. (author)
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Atmospheric radiation flight dose rates
Tobiska, W. K.
2015-12-01
Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.
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Energy Technology Data Exchange (ETDEWEB)
Caudeville, Julien, E-mail: Julien.CAUDEVILLE@ineris.fr [INERIS (French National Institute for Industrial Environment and Risks), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Joint research unit UMR 6599, Heudiasyc (Heuristic and Diagnoses of Complex Systems), University of Technology of Compiegne and CNRS, Rue du Dr Schweitzer, 60200 Compiegne (France); Bonnard, Roseline, E-mail: Roseline.BONNARD@ineris.fr [INERIS (French National Institute for Industrial Environment and Risks), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Boudet, Celine, E-mail: Celine.BOUDET@ineris.fr [INERIS (French National Institute for Industrial Environment and Risks), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Denys, Sebastien, E-mail: Sebastien.DENYS@ineris.fr [INERIS (French National Institute for Industrial Environment and Risks), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Govaert, Gerard, E-mail: gerard.govaert@utc.fr [Joint research unit UMR 6599, Heudiasyc (Heuristic and Diagnoses of Complex Systems), University of Technology of Compiegne and CNRS, Rue du Dr Schweitzer, 60200 Compiegne (France); Cicolella, Andre, E-mail: Andre.CICOLELLA@ineris.fr [INERIS (French National Institute for Industrial Environment and Risks), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France)
2012-08-15
Analyzing the relationship between the environment and health has become a major focus of public health efforts in France, as evidenced by the national action plans for health and the environment. These plans have identified the following two priorities: -identify and manage geographic areas where hotspot exposures are a potential risk to human health; and -reduce exposure inequalities. The aim of this study is to develop a spatial stochastic multimedia exposure model for detecting vulnerable populations and analyzing exposure determinants at a fine resolution and regional scale. A multimedia exposure model was developed by INERIS to assess the transfer of substances from the environment to humans through inhalation and ingestion pathways. The RESPIR project adds a spatial dimension by linking GIS (Geographic Information System) to the model. Tools are developed using modeling, spatial analysis and geostatistic methods to build and discretize interesting variables and indicators from different supports and resolutions on a 1-km{sup 2} regular grid. We applied this model to the risk assessment of exposure to metals (cadmium, lead and nickel) using data from a region in France (Nord-Pas-de-Calais). The considered exposure pathways include the atmospheric contaminant inhalation and ingestion of soil, vegetation, meat, egg, milk, fish and drinking water. Exposure scenarios are defined for different reference groups (age, dietary properties, and the fraction of food produced locally). The two largest risks correspond to an ancient industrial site (Metaleurop) and the Lille agglomeration. In these areas, cadmium, vegetation ingestion and soil contamination are the principal determinants of the computed risk. -- Highlights: Black-Right-Pointing-Pointer We present a multimedia exposure model for mapping environmental disparities. Black-Right-Pointing-Pointer We perform a risk assessment on a region of France at a fine scale for three metals. Black-Right-Pointing-Pointer We
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International Nuclear Information System (INIS)
Caudeville, Julien; Bonnard, Roseline; Boudet, Céline; Denys, Sébastien; Govaert, Gérard; Cicolella, André
2012-01-01
Analyzing the relationship between the environment and health has become a major focus of public health efforts in France, as evidenced by the national action plans for health and the environment. These plans have identified the following two priorities: -identify and manage geographic areas where hotspot exposures are a potential risk to human health; and -reduce exposure inequalities. The aim of this study is to develop a spatial stochastic multimedia exposure model for detecting vulnerable populations and analyzing exposure determinants at a fine resolution and regional scale. A multimedia exposure model was developed by INERIS to assess the transfer of substances from the environment to humans through inhalation and ingestion pathways. The RESPIR project adds a spatial dimension by linking GIS (Geographic Information System) to the model. Tools are developed using modeling, spatial analysis and geostatistic methods to build and discretize interesting variables and indicators from different supports and resolutions on a 1-km 2 regular grid. We applied this model to the risk assessment of exposure to metals (cadmium, lead and nickel) using data from a region in France (Nord-Pas-de-Calais). The considered exposure pathways include the atmospheric contaminant inhalation and ingestion of soil, vegetation, meat, egg, milk, fish and drinking water. Exposure scenarios are defined for different reference groups (age, dietary properties, and the fraction of food produced locally). The two largest risks correspond to an ancient industrial site (Metaleurop) and the Lille agglomeration. In these areas, cadmium, vegetation ingestion and soil contamination are the principal determinants of the computed risk. -- Highlights: ► We present a multimedia exposure model for mapping environmental disparities. ► We perform a risk assessment on a region of France at a fine scale for three metals. ► We examine exposure determinants and detect vulnerable population. ► The largest
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Mosely, Jackie A; Stokes, Peter; Parker, David; Dyer, Philip W; Messinis, Antonis M
2018-02-01
A novel method has been developed that enables chemical compounds to be transferred from an inert atmosphere glove box and into the atmospheric pressure ion source of a mass spectrometer whilst retaining a controlled chemical environment. This innovative method is simple and cheap to implement on some commercially available mass spectrometers. We have termed this approach inert atmospheric pressure solids analysis probe ( iASAP) and demonstrate the benefit of this methodology for two air-/moisture-sensitive chemical compounds whose characterisation by mass spectrometry is now possible and easily achieved. The simplicity of the design means that moving between iASAP and standard ASAP is straightforward and quick, providing a highly flexible platform with rapid sample turnaround.
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Multichannel singular spectrum analysis of the axial atmospheric angular momentum
Directory of Open Access Journals (Sweden)
Leonid Zotov
2017-11-01
Full Text Available Earth's variable rotation is mainly produced by the variability of the AAM (atmospheric angular momentum. In particular, the axial AAM component χ3, which undergoes especially strong variations, induces changes in the Earth's rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD (length of day were described. We applied MSSA (Multichannel Singular Spectrum Analysis jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-month, quasi-biennial, 5-year, and low-frequency oscillations. PCs (Principal components strongly related to ENSO (El Nino southern oscillation were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.
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Kendall, Rose (Compiler); Wolfe, Kathy (Compiler)
1997-01-01
Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology, and monitoring of the Earth's upper atmosphere, with emphasis on the stratosphere. This program aims at expanding our understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Science Division in the Office of Mission to Planet Earth at NASA. Significant contributions to this effort are also provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aeronautics. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper atmosphere and their effect on the distribution of chemical species in the stratosphere, such as ozone; understand the relationship of the trace constituent composition of the lower stratosphere and the lower troposphere to the radiative balance and temperature distribution of the Earth's atmosphere; and accurately assess possible perturbations of the upper atmosphere caused by human activities as well as by natural phenomena. In compliance with the Clean Air Act Amendments of 1990, Public Law 101-549, NASA has prepared a report on the state of our knowledge of the Earth's upper atmosphere, particularly the stratosphere, and on the progress of UARP and ACMAP. The report for the year 1996 is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported under NASA UARP and ACMAP in a document entitled, Research Summary 1994-1996. Part 2 is entitled Present State of Knowledge of the Upper Atmosphere
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Analysis of tritium releases to the atmosphere by a CTR
International Nuclear Information System (INIS)
Renne, D.S.; Sandusky, W.F.; Dana, M.T.
1975-08-01
Removal by atmospheric processes of routinely and accidentally released tritium from a controlled thermonuclear reactor (CTR) was investigated. Based on previous studies, the assumed form of the tritium for this analysis was HTO or tritiated water vapor. Assuming a CTR operation in Morris, Illinois, surface water and ground-level air concentration values of tritium were computed for three space (or time) scales: local (50 Km of a plant), regional (up to 1000 Km of the plant), and global
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The exposure assessment of Rn-222 gas in the atmosphere(II)
International Nuclear Information System (INIS)
Ha, Chung Wo; Chang, Si Young; Seo, Kyung Won; Yoon, Yeo Chang; Kim, Jang Lyul; Yoon, Suk Chul; Chung, Rae Ik; Kim, Jong Soo; Park, Young Woong
1991-01-01
Dose assessment to inhalation exposure of indoor 222 Rn daughters in 12 residential areas in Korea has been performed by long term averaged radon concentrations measured with passive CR-39 radon cups. A simple mathematical lung dosimetry model based on the ICRP-30 was derived to estimate the indoor radon daughters exposure. The long term average indoor 222 Rn concentrations and corresponding equilibrium equivalent radon concentrations (EEC Rn ) in 12 areas showed a range of 33.82 ∼ 61.42 Bq.m -3 (median : 48.90 Bq.m -3 ) and of 13.53 ∼ 24.57 Bq.m -3 (median: 19.55 Bq.m -3 ), respectively. Reference dose conversion functions for evaluation of regional lung dose and effective dose equivalent for unit exposure to EEC Rn have been derived for an adult. The effective dose equivalent conversion factor was estimated to be 1.07 x 10 -5 mSv/Bq.h.m -3 and this conversion factor agreed well with that recommended by the ICRP and UNSCEAR report. The annual average dose equivalents(H) to Tracheo-Bronchial and Pulmonary region of the lung, and total lung from exposure to measured EEC Rn were estimated to be 17.52 mSv.y -l , 3.35 mSv.y -l and 20.90 mSv.y -1 , respectively, and the resulting effective dose equivalent(H E ) was estimated to be 1.25 mSv.y -l , which is almost 50% of the natural radiation exposure of 2.40 mSv.y -l reported by the UNSCEAR. (Author)
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The sources of radiation exposure
International Nuclear Information System (INIS)
Bennett, B.G.
1992-01-01
Radiation protection of workers and of members of the public requires an assessment of the various sources of exposure, their variations in time or under specific conditions or circumstances, and the possibilities for control or limitation. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has evaluated the various components of natural and man-made sources in some detail. Natural exposures form the largest component of radiation exposure of man. Variability in exposures depends on elevation, the concentrations of radionuclides in soil, food and water, the composition of building materials and the susceptibility of indoor spaces to radon build-up. Man-made sources have included exposures to fallout from atmospheric nuclear testing and discharged from nuclear fuel cycle installations in routine operations or in accidents. The other main source of radiation exposures of individuals is in medical diagnostic examinations and therapeutic treatments. (author)
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Liu, Li-xin; Zhou, Ling-xi; Xia, Ling-jun; Wang, Hong-yang; Fang, Shuang-xi
2014-12-01
To strengthen scientific management and sharing of greenhouse gas data obtained from atmospheric background stations in China, it is important to ensure the standardization of quality assurance and quality control method for background CO2 sampling and analysis. Based on the greenhouse gas sampling and observation experience of CMA, using portable sampling observation and WS-CRDS analysis technique as an example, the quality assurance measures for atmospheric CO,sampling and observation in the Waliguan station (Qinghai), the glass bottle quality assurance measures and the systematic quality control method during sample analysis, the correction method during data processing, as well as the data grading quality markers and data fitting interpolation method were systematically introduced. Finally, using this research method, the CO2 sampling and observation data at the atmospheric background stations in 3 typical regions were processed and the concentration variation characteristics were analyzed, indicating that this research method could well catch the influences of the regional and local environmental factors on the observation results, and reflect the characteristics of natural and human activities in an objective and accurate way.
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Nature of activities and natural, artificial, accidental exposures. Magnitude of these exposures
International Nuclear Information System (INIS)
Aurengo, A.
2009-01-01
The exposure to ionizing radiation (I.R.) is linked to radioelements of organism (9%), earth (12%), cosmic radiation (10%), radon (37%), atmospheric fallout ( nuclear tests 2.5% and industry 0.5%) and to medical procedures (29%). The natural exposure varies in France from 2.5 to 5 mSv by year. In some areas in the world it reaches several tens of mSv by year. The medical exposure is very heterogeneous and concerns particularly old people. For a same examination, the patients exposure varies in an important way ( sometimes from 1 to 10) according to the country, even in France. In France, 250 000 persons are occupationally exposed to ionizing radiation. Among these ones, the most of cases exceeded regulatory limits for exposure to IR concern the health sector. The accidental exposures are in relation with industrial activities (51%) research (20%) civil nuclear (13%) or military (5%) and medical activities (11%). The exposures and then the consequences are very variable, ranging from death to unapparent consequences. in the most of cases a human error is involved and these accidents could have been avoided through measures of prevention and training. (N.C.)
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Applying Authentic Data Analysis in Learning Earth Atmosphere
Johan, H.; Suhandi, A.; Samsudin, A.; Wulan, A. R.
2017-09-01
The aim of this research was to develop earth science learning material especially earth atmosphere supported by science research with authentic data analysis to enhance reasoning through. Various earth and space science phenomenon require reasoning. This research used experimental research with one group pre test-post test design. 23 pre-service physics teacher participated in this research. Essay test was conducted to get data about reason ability. Essay test was analyzed quantitatively. Observation sheet was used to capture phenomena during learning process. The results showed that student’s reasoning ability improved from unidentified and no reasoning to evidence based reasoning and inductive/deductive rule-based reasoning. Authentic data was considered using Grid Analysis Display System (GrADS). Visualization from GrADS facilitated students to correlate the concepts and bring out real condition of nature in classroom activity. It also helped student to reason the phenomena related to earth and space science concept. It can be concluded that applying authentic data analysis in learning process can help to enhance students reasoning. This study is expected to help lecture to bring out result of geoscience research in learning process and facilitate student understand concepts.
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Annual and long-term prediction of the atmospheric corrosion of metals
International Nuclear Information System (INIS)
Morcillo, M.
1998-01-01
The atmospheric corrosion of metals is known to be a discontinuous electrochemical process which takes place only when the metallic surface is wet or moistened by different meteorological phenomena (rain, humidity condensation, fog, etc.) The magnitude of atmospheric corrosion would be relatively low if it were not for the presence of certain pollutants in the atmosphere, mainly sulphur dioxide (anthropogenic pollutant) and marine chlorides (natural pollutant). The literature contains different models for predicting the atmospheric metals over short periods (generally one year) and long periods (15, 20 or more years) of atmospheric exposure. In addition to the different meteorological factors (volume of precipitation, days of rain, relative humidity (RH), T, etc.), atmospheric SO 2 deposition rate and atmospheric salinity (Cl - ) appear as independent variables in all of these models. (Author)
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Development of a phoswich detector for neutron dose rate measurements in the Earth's atmosphere
Energy Technology Data Exchange (ETDEWEB)
Doensdorf, Esther Miriam
2014-04-30
The Earth is constantly exposed to a stream of energetic particles from outer space. Through the interaction of this radiation with the Earth's magnetosphere and atmosphere a complex radiation field is formed which varies with the location inside the Earth's atmosphere. This radiation field consists of charged and uncharged particles leading to the constant exposure of human beings to radiation. As this ionizing radiation can be harmful for humans, it is necessary to perform dose rate measurements in different altitudes in the Earth's atmosphere. Due to their higher biological effectiveness the exposure to neutrons is more harmful than the exposure to γ-rays and charged particles, which is why the determination of neutron dose rates is the focus of this work. In this work the prototype of a Phoswich detector called PING (Phoswich Instrument for Neutrons and Gammas) is developed to determine dose rates caused by neutrons in the Earth's atmosphere and to distinguish these from γ-rays. The instrument is composed of two different scintillators optically coupled to each other and read out by one common photomultiplier tube. The scintillator package consists of an inner plastic scintillator made of the material BC-412 and a surrounding anti-coincidence made of sodium doped caesium iodide (CsI(Na)). In this work the instrument is calibrated, tested and flown and a procedure for a pulse shape analysis for this instrument is developed. With this analysis it is possible to distinguish pulses from the plastic scintillator and pulses from the CsI(Na). The pulses from the plastic scintillator are mainly due to the interaction of neutrons but there is an energy-dependent contribution of γ-rays to these events. Measurements performed on board an airplane show that the dose rates measured with the developed detector are in the same order of magnitude as results of other instruments. During measurements on board stratospheric balloons the altitude dependence
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Spatial Analysis of Human Exposure and Vulnerability to Coastal ...
African Journals Online (AJOL)
Disasters in coastal cities have shown an ever-increasing frequency of occurrence. Population growth and urbanisation have increased the vulnerability of properties and societies in coastal flood-prone areas. Analysis of human exposure and vulnerability is one of the main strategies used to determine the necessary ...
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International Nuclear Information System (INIS)
Abbas, Imane; Garcon, Guillaume; Billet, Sylvain; Shirali, Pirouz; Andre, Veronique; Le Goff, Jeremie; Sichel, Francois; Roy Saint-Georges, Francoise; Mulliez, Philippe
2012-01-01
Because of their deep penetration in human lungs, fine airborne particulate matter were described as mainly responsible for the deleterious effects of exposure to air pollution on health. Organic constituents are adsorbed on particles surface and, after inhalation, some (polycyclic aromatic hydrocarbons, PAHs) can be activated into reactive metabolites and can bind to DNA. The formation of bulky DNA adducts has been researched after exposure of mono-and co-cultures of alveolar macrophages (AM) and human embryonic human lung epithelial (L132), to fine air pollution particulate matter Air samples have been collected with cascade impactor and characterized: size distribution (92.15% 2 /g), inorganic (Fe, AI, Ca, Na, K, Mg, Pb, etc.) and organic compounds (PAHs, etc.). 32 P post-labeling method was applied to detect bulky DNA adducts in AM and L132, in mono-and co-cultures, 72 h after their exposure to atmospheric particles at their Lethals and Effects concentrations or (LC or CE) to 50% (i.e. MA: EC 50 = 74.63 μg/mL and L132: LC-5-0 = 75.36 μg/mL). Exposure to desorbed particles (MA: C1= 61.11 μg/mL and L132 : C2 = 61.71 μg/mL) and B[a]P (1 μM) were included. Bulky PAH-DNA adducts were detected in AM in mono-culture after exposure to total particles (Pt), to B[a]P and desorbed particles (Pd). Whatever the exposure, no DNA adduct was detected in L132 in mono-culture. These results are coherent with the enzymatic activities of cytochrome P450 l Al in AM and L132. Exposure of co-culture to Pt, or Pd induced bulky adducts to DNA in AM but not in L132. Exposure to B[a]P alone has altered the DNA of AM and L132, in co-culture. Exposure to Pt is closer to the environmental conditions, but conferred an exposure to amounts of genotoxic agents compared to studies using organic extracts. The formation of bulky DNA adducts was nevertheless observed in AM exposed to Pt, in mono- or co-culture, indicating that they were competent in terms of metabolic activation of PAHs. The
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International Nuclear Information System (INIS)
Fu, J.
1991-01-01
Atmospheric nutrient input to the Apalachicola Bay estuary was studied because it has been demonstrated that atmospheric deposition can be a major source of nutrients to eastern U.S. estuaries. Besides the Apalachicola River, the Sopchoppy and the Ochlockonee were also selected for a comparative analysis. Receptor model, absolute principal of component analysis (APCA), and mass balance methods were applied in the study. The results of the study show that nitrogen is probably not a limiting nutrient in the three rivers because their N:P mole ratios are nearly 3 times higher than the Redfield ratio for photosynthesis. The total atmospheric nitrogen depositions in the three river watershed are at least as great as their river fluxes. In the Apalachicola River, the atmospheric source of nitrogen is found to be several times higher than the largest possible input of urban sewage. Atmospheric deposition, therefore, might be the dominant nitrogen source entering the estuary. The results of APCA show that Apalachicola River water is mainly a mixture of components that correspond in their compositions to aged rain, ground water, and fresh rain. Atmospheric nitrate deposition is the result of the air pollution, i.e., acid rain. The studies also show that the annual average deposition of nitrate has a narrow range, mainly from 5.8 to 11.5 kg/ha/yr in most of the NADP sites in the 8 southeastern states. Since all the software and data sets employed in the study are accessible nationwide, the methods could be applied in other watersheds
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Atmospheric characteristics essential for health effects modeling
International Nuclear Information System (INIS)
Nelson, N.S.
1977-01-01
Factors to be considered in evaluating the possible consequences of exposure of human populations to radioactive aerosols are reviewed. Mathematical models of the mechanisms of radioinduced carcinogenesis, tissue deposition and lung clearance of radioactive aerosols, and meteorological parameters affecting the diffusion of radioactive aerosols in the atmosphere are discussed
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High-Temperature, Dual-Atmosphere Corrosion of Solid-Oxide Fuel Cell Interconnects
Gannon, Paul; Amendola, Roberta
2012-12-01
High-temperature corrosion of ferritic stainless steel (FSS) surfaces can be accelerated and anomalous when it is simultaneously subjected to different gaseous environments, e.g., when separating fuel (hydrogen) and oxidant (air) streams, in comparison with single-atmosphere exposures, e.g., air only. This so-called "dual-atmosphere" exposure is realized in many energy-conversion systems including turbines, boilers, gasifiers, heat exchangers, and particularly in intermediate temperature (600-800°C) planar solid-oxide fuel cell (SOFC) stacks. It is generally accepted that hydrogen transport through the FSS (plate or tube) and its subsequent integration into the growing air-side surface oxide layer can promote accelerated and anomalous corrosion—relative to single-atmosphere exposure—via defect chemistry changes, such as increased cation vacancy concentrations, decreased oxygen activity, and steam formation within the growing surface oxide layers. Establishment of a continuous and dense surface oxide layer on the fuel side of the FSS can inhibit hydrogen transport and the associated effects on the air side. Minor differences in FSS composition, microstructure, and surface conditions can all have dramatic influences on dual-atmosphere corrosion behaviors. This article reviews high-temperature, dual-atmosphere corrosion phenomena and discusses implications for SOFC stacks, related applications, and future research.
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Urban planning and interactions with atmospheric pollution in Arve valley
Langlois de Septenville, William; Cossart, Étienne
2017-04-01
Atmospheric pollution is a major concern of urbanised areas and territory managers have to conduct efficient policies to decrease population exposure and vulnerability. Even if pollution peaks are subject to an important mediatisation and to a large part of preventive actions, background pollution remains responsible of the largest sanitary effects. They depend on (1) the concentration and the duration of the exposure and (2) to the kind of pollutants considered. Many sources of pollutants can be identified in urban areas as heating, industry or traffic; and each of them generates specific particles. Currently, the major part of pollution risk studies focuses on modelling particle emissions and their dissemination in the environment. These kinds of studies highlight the hazard intensity and its spatiality, commonly named the hazard exposure. Another part of risk studies, less frequent, considers the vulnerability. Vulnerability is a complex concept that involves a wide range of scales and objects ranging from biophysical parameters to social characteristics. They notably concern accessibility to information, knowledge and perceptions about the risk. The Arve valley (south-east of France) is subject to heavy pollution concentrations. High levels recording in this area have imposed the implementation of an Atmosphere Protection Plan. This type of plan is triggered if a peak occurs and enforces provisional binding measures for polluters, such as highway speed limitation for traffic emissions. These measures are only focused on emissions and have no effect for reducing vulnerability and exposition, for a long- and short-term time scales. An opportunity to ensure this objective is to consider how local urban morphologies can combine exposition and vulnerability situations. Indeed, cities have been planned without taking into account atmospheric pollution and morphologies. This context may conduct to the increase in both of these two risk components and producing
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Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres
Energy Technology Data Exchange (ETDEWEB)
Hopke, P.K.
1992-07-01
This report covers the second year of the 28 month grant current grant to Clarkson University to study the chemical and physical behavior of the polonium 218 atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical process that affect the progeny's atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. This report describes the progress toward achieving these objectives.
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Effect of atmosphere composition on the oxidation behavior of MCrAlY coatings
Energy Technology Data Exchange (ETDEWEB)
Song, P.; Subanovic, M.; Toscano, J.; Naumenko, D.; Quadakkers, W.J. [Forschungszentrum Juelich GmbH, Institute for Energy Research (IEF-2), 52425 Juelich (Germany)
2011-07-15
In the present work the effect of atmosphere composition on the growth rate and adherence of the alumina scales was studied using free-standing MCrAlY-coatings and TBC-specimens with MCrAlY-bondcoats. The exposures comprised isothermal and cyclic exposures in laboratory air and Ar-H{sub 2}-H{sub 2}O at 1100 C. It is shown that minor Zr-addition to the bondcoat results in enhanced scale growth and internal oxidation. This effect is independent of the atmosphere composition. As a consequence of the rapid oxide formation the times to TBC failure on the Zr-containing bondcoat in both atmospheres were much shorter compared to those with Zr-free bondcoat. In the latter case the formation of a thin compact alumina TGO was slower in H{sub 2}/H{sub 2}O than in air resulting in significantly longer TBC-lifetime in the former atmosphere. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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International Nuclear Information System (INIS)
Beck, P.; Latocha, M.; Dorman, L.; Pelliccioni, M.; Rollet, S.
2007-01-01
As required by the European Directive 96/29/Euratom, radiation exposure due to natural ionizing radiation has to be taken into account at workplaces if the effective dose could become more than 1 mSv per year. An example of workers concerned by this directive is aircraft crew due to cosmic radiation exposure in the atmosphere. Extensive measurement campaigns on board aircraft have been carried out to assess ambient dose equivalent. A consortium of European dosimetry institutes within EURADOS WG5 summarized experimental data and results of calculations, together with detailed descriptions of the methods for measurements and calculations. The radiation protection quantity of interest is the effective dose, E (ISO). The comparison of results by measurements and calculations is done in terms of the operational quantity ambient dose equivalent, H*(10). This paper gives an overview of the EURADOS Aircraft Crew In-Flight Database and it presents a new empirical model describing fitting functions for this data. Furthermore, it describes numerical simulations performed with the Monte Carlo code FLUKA-2005 using an updated version of the cosmic radiation primary spectra. The ratio between ambient dose equivalent and effective dose at commercial flight altitudes, calculated with FLUKA-2005, is discussed. Finally, it presents the aviation dosimetry model AVIDOS based on FLUKA-2005 simulations for routine dose assessment. The code has been developed by Austrian Research Centers (ARC) for the public usage (http://avidos.healthphysics.at. (authors)
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International Nuclear Information System (INIS)
Akata, N.; Kawabata, H.; Hasegawa, H.; Kondo, K.; Chikuchi, Y.; Hisamatsu, S.; Inaba, J.; Sato, T.
2009-01-01
Atmospheric concentrations of 210 Pb change with various factors such as meso-scale meteorological conditions. We have already reported the biweekly atmospheric 210 Pb concentrations in Rokkasho, Japan for 5 years and found that they had clear seasonal variations: low concentrations in summer and high values in winter to spring. To study the reasons for the seasonal variations, the origins of the air mass flowing to Rokkasho were analyzed by 3-D backward air mass trajectory analysis. Routes of the calculated trajectories were classified into four regions: northeastern and southeastern Asian Continent, sea and other regions. The atmospheric 210 Pb concentrations were well correlated with the frequency of the routes through the northeastern Asian Continent. A non-linear multiple regression analysis of the 210 Pb concentrations and the relative frequencies of the four routes showed good fitting of the predicted values to the observed ones, and indicated that the atmospheric 210 Pb concentrations in Rokkasho depended on the frequency of the air mass from the northeastern Asian Continent. (author)
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Lehmann, Edouard; Oltramare, Christelle; Nfon Dibié, Jean-Jacques; Konaté, Yacouba; de Alencastro, Luiz Felippe
2018-02-01
The present work assesses human exposure to pesticides in vegetable-producing areas in Burkina Faso, using hair as an indicator. The study design includes a comparison between operators who are occupationally exposed while working in the fields and a reference population (i.e. not occupationally exposed) to evaluate both occupational and indirect exposures. Hair samples from volunteers (n=101) were positive for 17 pesticides (38 analyzed). Acetamiprid, desethylatrazine, carbofuran, and deltamethrin were detected for the first time in field samples. With a maximum of 9 residues per sample, pesticide exposure was ubiquitous in both populations. Contamination by acetamiprid, cypermethrin, and lambda-cyhalothrin (used in vegetable production) prevailed in operator samples. For other pesticides, such as imidacloprid and deltamethrin, no significant difference was found. This indicates a potentially large environmental exposure (dietary intake or atmospheric contamination) or the prevalence of other contamination sources. The present findings are concerning, as detected levels are globally higher than those previously reported, and indicate exposure to endocrine disrupting chemicals and probable carcinogens. Hair was found to be a suitable matrix for biomonitoring human exposure to pesticides and assessing dominant factors (i.e. sex, age, and protective equipment) in subgroups, as well as identifying geographical contamination patterns. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Analysis of monoterpene hydrocarbons in rural atmospheres
International Nuclear Information System (INIS)
Holdren, M.W.; Westberg, H.H.; Zimmerman, P.R.
1979-01-01
Gas chromatographic/mass spectrometric analysis of monoterpenes from a rural forested site in the northwestern United States is described. Use of a glass capillary column provided excellent resolution of the hydrocarbons. Increased sensitivity and specificity of the mass spectrometer detector over the flame ionization detector were demonstrated for trace (parts per trillion) atmospheric hydrocarbons. As little as 10 ppt of compound was detectable in 100-cc air samples. Two analytical methods (cryogenic and solid adsorbent--Tenax-GC) were used in the collection of ambient air. Analytical results from the two techniques compared very well. Rural concentrations of the monoterpenes varied considerably depending upon location within the forest canopy. The concentration of individual species never exceeded 1 ppb of compound during a 10-month sampling period. The monoterpene total for all samples fell in the range of 0.5- to 16-ppb compound for C 10 terpene
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The Human Exposure Potential from Propylene Releases to the Environment
Directory of Open Access Journals (Sweden)
David A. Morgott
2018-01-01
Full Text Available A detailed literature search was performed to assess the sources, magnitudes and extent of human inhalation exposure to propylene. Exposure evaluations were performed at both the community and occupational levels for those living or working in different environments. The results revealed a multitude of pyrogenic, biogenic and anthropogenic emission sources. Pyrogenic sources, including biomass burning and fossil fuel combustion, appear to be the primary contributors to atmospheric propylene. Despite a very short atmospheric lifetime, measurable levels could be detected in highly remote locations as a result of biogenic release. The indoor/outdoor ratio for propylene has been shown to range from about 2 to 3 in non-smoking homes, which indicates that residential sources may be the largest contributor to the overall exposure for those not occupationally exposed. In homes where smoking takes place, the levels may be up to thirty times higher than non-smoking residences. Atmospheric levels in most rural regions are typically below 2 ppbv, whereas the values in urban levels are much more variable ranging as high as 10 ppbv. Somewhat elevated propylene exposures may also occur in the workplace; especially for firefighters or refinery plant operators who may encounter levels up to about 10 ppmv.
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Pervez, S.; Koshle, A.; Pervez, Y.
2010-06-01
Mercury release by coal combustion has been significantly increased in India. Mercury content in coal has been analyzed to 0.272 ppm by Central Pollution Control Board. Toxicological effects of elemental Hg (Hg0) exposure include respiratory and renal failures, cardiac arrest, and cerebral oedema, while subclinical exposure may induce kidney, behavioral, and cognitive dysfunctions. The present work is focused on dispersion pattern and inter-phase exchange phenomena of ambient mercury between air-particulate matter evaluations of alongwith dominance of various major routes of human exposure-dose response using regression analysis around an integrated steel plant in central India. Source-downwind type stratified random sampling plan using longitudinal study design has been adopted for ambient monitoring of total mercury, while representative sampling plant has been adopted for persona exposure-dose response study In space-time framework. Control sites and subjects have been chosen from uncontaminated area (100 km away from any industrial activities). 06 ambient air monitoring stations and 17 subjects from workers, non-workers but local residents' categories and from controlled sites have been chosen for the study. Samples of mercury biomarkers (blood, breast milk and urine) have also been collected from same subjects in each month during sampling period. The sampling period was March 2005 to February 2006 . Samples of 30% acidified KMnO4 for air-Hg absorption, PM10, RPM and biological samples were analyzed for total mercury by ICP-AES using standard methods. Local soils and ground water were also monitored for total mercury content during the sampling period. Results have shown that mercury concentration is very high compared to prescribed limits in all receptors. Results of exchange phenomenon have shown the higher transfer of mercury from air to particulate during combustion in steel plant environment due to presence of huge amount of iron particles, in contrast to
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Development of acute exposure guideline levels for airborne exposures to hazardous substances.
Krewski, Daniel; Bakshi, Kulbir; Garrett, Roger; Falke, Ernest; Rusch, George; Gaylor, David
2004-04-01
Hazardous substances can be released into the atmosphere due to industrial and transportation accidents, fires, tornadoes, earthquakes, and terrorists, thereby exposing workers and the nearby public to potential adverse health effects. Various enforceable guidelines have been set by regulatory agencies for worker and ambient air quality. However, these exposure levels generally are not applicable to rare lifetime acute exposures, which possibly could occur at high concentrations. Acute exposure guideline levels (AEGLs) provide estimates of concentrations for airborne exposures for an array of short durations that possibly could cause mild (AEGL-1), severe, irreversible, potentially disabling adverse health effects (AEGL-2), or life threatening effects (AEGL-3). These levels can be useful for emergency responders and planners in reducing or eliminating potential risks to the public. Procedures and methodologies for deriving AEGLs are reviewed in this paper that have been developed in the United States, with direct input from international representatives of OECD member-countries, by the National Advisory Committee for Acute Exposure Guidelines for Hazardous Substances and reviewed by the National Research Council. Techniques are discussed for the extrapolation of effects across different exposure durations. AEGLs provide a viable approach for assisting in the prevention, planning, and response to acute airborne exposures to toxic agents.
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Exposure to pesticides and diabetes: A systematic review and meta-analysis.
Evangelou, Evangelos; Ntritsos, Georgios; Chondrogiorgi, Maria; Kavvoura, Fotini K; Hernández, Antonio F; Ntzani, Evangelia E; Tzoulaki, Ioanna
2016-05-01
Diabetes mellitus has a multifactorial pathogenesis with a strong genetic component as well as many environmental and lifestyle influences. Emerging evidence suggests that environmental contaminants, including pesticides, might play an important role in the pathogenesis of diabetes. We performed a systematic review and meta-analysis of observational studies that assessed the association between exposure to pesticides and diabetes and we examined the presence of heterogeneity and biases across available studies. A comprehensive literature search of peer-reviewed original research pertaining to pesticide exposure and diabetes, published until 30st May 2015, with no language restriction, was conducted. Eligible studies were those that investigated potential associations between pesticides and diabetes without restrictions on diabetes type. We included cohort studies, case-control studies and cross-sectional studies. We extracted information on study characteristics, type of pesticide assessed, exposure assessment, outcome definition, effect estimate and sample size. We identified 22 studies assessing the association between pesticides and diabetes. The summary OR for the association of top vs. bottom tertile of exposure to any type of pesticide and diabetes was 1.58 (95% CI: 1.32-1.90, p=1.21×10(-6)), with large heterogeneity (I(2)=66.8%). Studies evaluating Type 2 diabetes in particular (n=13 studies), showed a similar summary effect comparing top vs. bottom tertiles of exposure: 1.61 (95% CI 1.37-1.88, p=3.51×10(-9)) with no heterogeneity (I(2)=0%). Analysis by type of pesticide yielded an increased risk of diabetes for DDE, heptachlor, HCB, DDT, and trans-nonachlor or chlordane. The epidemiological evidence, supported by mechanistic studies, suggests an association between exposure to organochlorine pesticides and Type 2 diabetes. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Impact of assimilation window length on diurnal features in a Mars atmospheric analysis
Directory of Open Access Journals (Sweden)
Yongjing Zhao
2015-05-01
Full Text Available Effective simulation of diurnal variability is an important aspect of many geophysical data assimilation systems. For the Martian atmosphere, thermal tides are particularly prominent and contribute much to the Martian atmospheric circulation, dynamics and dust transport. To study the Mars diurnal variability and Mars thermal tides, the Geophysical Fluid Dynamics Laboratory Mars Global Climate Model with the 4D-local ensemble transform Kalman filter (4D-LETKF is used to perform an analysis assimilating spacecraft temperature retrievals. We find that the use of a ‘traditional’ 6-hr assimilation cycle induces spurious forcing of a resonantly enhanced semi-diurnal Kelvin waves represented in both surface pressure and mid-level temperature by forming a wave 4 pattern in the diurnal averaged analysis increment that acts as a ‘topographic’ stationary forcing. Different assimilation window lengths in the 4D-LETKF are introduced to remove the artificially induced resonance. It is found that short assimilation window lengths not only remove the spurious resonance, but also push the migrating semi-diurnal temperature variation at 50 Pa closer to the estimated ‘true’ tides even in the absence of a radiatively active water ice cloud parameterisation. In order to compare the performance of different assimilation window lengths, short-term to mid-range forecasts based on the hour 00 and 12 assimilation are evaluated and compared. Results show that during Northern Hemisphere summer, it is not the assimilation window length, but the radiatively active water ice clouds that influence the model prediction. A ‘diurnal bias correction’ that includes bias correction fields dependent on the local time is shown to effectively reduce the forecast root mean square differences between forecasts and observations, compensate for the absence of water ice cloud parameterisation and enhance Martian atmosphere prediction. The implications of these results for
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Atmospheric pressure plasma jet treatment of Salmonella Enteritidis inoculated eggshells.
Moritz, Maike; Wiacek, Claudia; Koethe, Martin; Braun, Peggy G
2017-03-20
Contamination of eggshells with Salmonella Enteritidis remains a food safety concern. In many cases human salmonellosis within the EU can be traced back to raw or undercooked eggs and egg products. Atmospheric pressure plasma is a novel decontamination method that can reduce a wide range of pathogens. The aim of this work was to evaluate the possibility of using an effective short time cold plasma treatment to inactivate Salmonella Enteritidis on the eggshell. Therefore, artificially contaminated eggshells were treated with an atmospheric pressure plasma jet under different experimental settings with various exposure times (15-300s), distances from the plasma jet nozzle to the eggshell surface (5, 8 or 12mm), feed gas compositions (Ar, Ar with 0.2, 0.5 or 1.0% O 2 ), gas flow rates (5 and 7slm) and different inoculations of Salmonella Enteritidis (10 1 -10 6 CFU/cm 2 ). Atmospheric pressure plasma could reduce Salmonella Enteritidis on eggshells significantly. Reduction factors ranged between 0.22 and 2.27 log CFU (colony-forming units). Exposure time and, particularly at 10 4 CFU/cm 2 inoculation, feed gas had a major impact on Salmonella reduction. Precisely, longer exposure times led to higher reductions and Ar as feed gas was more effective than ArO 2 mixtures. Copyright © 2017 Elsevier B.V. All rights reserved.
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Gebauer, S; Grenfell, J L; Stock, J W; Lehmann, R; Godolt, M; von Paris, P; Rauer, H
2017-01-01
Understanding the evolution of Earth and potentially habitable Earth-like worlds is essential to fathom our origin in the Universe. The search for Earth-like planets in the habitable zone and investigation of their atmospheres with climate and photochemical models is a central focus in exoplanetary science. Taking the evolution of Earth as a reference for Earth-like planets, a central scientific goal is to understand what the interactions were between atmosphere, geology, and biology on early Earth. The Great Oxidation Event in Earth's history was certainly caused by their interplay, but the origin and controlling processes of this occurrence are not well understood, the study of which will require interdisciplinary, coupled models. In this work, we present results from our newly developed Coupled Atmosphere Biogeochemistry model in which atmospheric O 2 concentrations are fixed to values inferred by geological evidence. Applying a unique tool (Pathway Analysis Program), ours is the first quantitative analysis of catalytic cycles that governed O 2 in early Earth's atmosphere near the Great Oxidation Event. Complicated oxidation pathways play a key role in destroying O 2 , whereas in the upper atmosphere, most O 2 is formed abiotically via CO 2 photolysis. The O 2 bistability found by Goldblatt et al. ( 2006 ) is not observed in our calculations likely due to our detailed CH 4 oxidation scheme. We calculate increased CH 4 with increasing O 2 during the Great Oxidation Event. For a given atmospheric surface flux, different atmospheric states are possible; however, the net primary productivity of the biosphere that produces O 2 is unique. Mixing, CH 4 fluxes, ocean solubility, and mantle/crust properties strongly affect net primary productivity and surface O 2 fluxes. Regarding exoplanets, different "states" of O 2 could exist for similar biomass output. Strong geological activity could lead to false negatives for life (since our analysis suggests that reducing gases
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Insight into the product film formed on Ni-advanced weathering steel in a tropical marine atmosphere
Wu, Wei; Cheng, Xuequn; Hou, Huaxing; Liu, Bo; Li, Xiaogang
2018-04-01
The product film formed on Ni-advanced weathering steel in a tropical marine environment was investigated in detail through outdoor exposure by using diverse surface analysis techniques combined with electrochemical impedance spectroscopy and scanning kelvin probe measurements. The results showed that the product film was mainly composed of nanophasic goethite in the inner layer and maghemite, akaganeite, and hematite in the outer layer. Moreover, the resistance to atmospheric corrosion gradually increased from the outermost product film to the innermost film. Ni was significantly enriched in the inner layer in the form of the spinel phase NiFe2O4, which transformed lepidocrocite to fine-grained goethite, withstood the invasion of chloridion, and improved the corrosion potential of the product film in a tropical marine atmosphere.
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Determination of the atmospheric neutrino fluxes from atmospheric neutrino data
International Nuclear Information System (INIS)
Gonzalez-Garcia, C.; Maltoni, M.; Rojo, J.
2006-06-01
The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based on the convolution of the primary cosmic ray spectrum with the expected yield of neutrinos per incident cosmic ray. In this work we present an alternative approach to the determination of the atmospheric neutrino fluxes based on the direct extraction from the experimental data on neutrino event rates. The extraction is achieved by means of a combination of artificial neural networks as interpolants and Monte Carlo methods for faithful error estimation. (author)
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Determination of the atmospheric neutrino fluxes from atmospheric neutrino data
International Nuclear Information System (INIS)
Gonzalez-Garcia, Concepcion; Maltoni, Michele; Rojo, Joan
2006-01-01
The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations based on the convolution of the primary cosmic ray spectrum with the expected yield of neutrinos per incident cosmic ray. In this work we present an alternative approach to the determination of the atmospheric neutrino fluxes based on the direct extraction from the experimental data on neutrino event rates. The extraction is achieved by means of a combination of artificial neural networks as interpolants and Monte Carlo methods for faithful error estimation
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Energy Technology Data Exchange (ETDEWEB)
Ota, Masakazu, E-mail: ohta.masakazu@jaea.go.jp [Research Group for Environmental Science, Division of Environment and Radiation, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (Japan); Nagai, Haruyasu [Research Group for Environmental Science, Division of Environment and Radiation, Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency (Japan)
2011-09-15
A numerical model simulating transport of tritiated water (HTO) in atmosphere-soil-vegetation system, and, accumulation of organically bound tritium (OBT) in vegetative leaves was developed. Characteristic of the model is, for calculating tritium transport, it incorporates a dynamical atmosphere-soil-vegetation model (SOLVEG-II) that calculates transport of heat and water, and, exchange of CO{sub 2}. The processes included for calculating tissue free water tritium (TFWT) in leaves are HTO exchange between canopy air and leaf cellular water, root uptake of aqueous HTO in soil, photosynthetic assimilation of TFWT into OBT, and, TFWT formation from OBT through respiration. Tritium fluxes at the last two processes are input to a carbohydrate compartment model in leaves that calculates OBT translocation from leaves and allocation in them, by using photosynthesis and respiration rate in leaves. The developed model was then validated through a simulation of an existing experiment of acute exposure of grape plants to atmospheric HTO. Calculated TFWT concentration in leaves increased soon after the start of HTO exposure, reaching to equilibrium with the atmospheric HTO within a few hours, and then rapidly decreased after the end of the exposure. Calculated non-exchangeable OBT amount in leaves linearly increased during the exposure, and after the exposure, rapidly decreased in daytime, and, moderately nighttime. These variations in the calculated TFWT concentrations and OBT amounts, each mainly controlled by HTO exchange between canopy air and leaf cellular water and by carbohydrates translocation from leaves, fairly agreed with the observations within average errors of a factor of two. - Highlights: > TFWT retention and OBT formation in leaves were modeled > The model fairly well calculates TFWT concentration after an acute HTO exposure > The model well assesses OBT formation and attenuation of OBT amount in leaves.
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Analysis of Δ14C variations in atmosphere
International Nuclear Information System (INIS)
Simon, J.; Sivo, A.; Richtarikova, M.; Holy, K.; Polaskova, A.; Bulko, M.; Hola, O.
2005-01-01
The Δ 14 C in the atmosphere have been measured and studied in two localities of Slovakia. The accomplished analysis proved the existence of the annual variations of the Δ 14 C with the attenuating amplitude and decreasing mean value. It seems to be logical and physically correct to describe the Δ 14 C time-dependence by the equation: y = Ae -at + Be -bt cos(ω 1 t + (φ)). The coefficients A, a, B, b, (φ) are listed in the table for both the localities. The observed variations of the Δ 14 C have a maximum in summer and minimum in winter .Probably it is caused by the higher requirement of the heat supply in winter season which is connected directly with the fossil CO 2 emissions and more intensive Suess effect. Summer maximum could be explained by the combination of the lower CO 2 emission rate and higher turbulent transport of the stratospheric 14 C to the troposphere. Using the Fourier harmonic analysis the amplitude spectra of the average annual variations were plotted. The obtained result shows that the variations have the high degree of symmetry. Furthermore, the obtained basic frequency ω 1 = 2π/12 [month -1 ] proves that the cyclic processes with the period of T = 12 [month] have a major influence on the 14 C amount in the troposphere. The presence of some higher-order harmonics is significant, but a physical interpretation has not yet been clear. In addition to the main frequency there are presented also 2ω 1 and 3ω 1 in Bratislava and 4ω 1 in Zlkovce data-set. The long-time average of the Δ 14 C in Zlkovce during years 1995-2004 is higher of about 6.6 o / oo than in Bratislava. It represents an unique evidence that the local CO 2 pollution affects the 14 C activity . The correlation on the level R 2 = 0,43 was found between Bratislava and Zlkovce atmospheric Δ 14 C data. (authors)
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Directory of Open Access Journals (Sweden)
V. P. Veiko
2013-03-01
Full Text Available The article deals with computational thermodynamic method for determination of phase chemical composition of metal alloys surface formed under laser action in the atmosphere, depending on its volume components, conditions of laser exposure and atmosphere composition. By giving an example of laser heating of complex alloy (alloyed steel in the air it is demonstrated that from a set of various possible reactions of interaction between iron, nickel or chrome with air components (oxygen, nitrogen, carbon, their compounds, atmospheric moisture, etc., only strictly defined reactions are realized. Primarily, these are metal oxidation processes with the formation of an oxide film, whose phase and chemical composition is determined by temperature and heating time. Calculation data are confirmed by the experimental data provided by energy-dispersive X-ray spectroscopy.
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Personal exposure to grass pollen: relating inhaled dose to background concentration
DEFF Research Database (Denmark)
Peel, Robert George; Hertel, Ole; Smith, Matt
2013-01-01
Background: Very few studies on human exposure to allergenic pollen have been conducted using direct methods, with background concentrations measured at city center monitoring stations typically taken as a proxy for exposure despite the inhomogeneous nature of atmospheric pollen concentrations. A...
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The bibliometrics of atmospheric environment
Brimblecombe, Peter; Grossi, Carlota M.
Bibliometric analysis is an important tool in the management of a journal. SCOPUS output is used to assess the increase in the quantity of material in Atmospheric Environment and stylistic changes in the way authors choose words and punctuation in titles and assemble their reference lists. Citation analysis is used to consider the impact factor of the journal, but perhaps more importantly the way in which it reflects the importance authors give to papers published in Atmospheric Environment. The impact factor of Atmospheric Environment (2.549 for 2007) from the Journal Citation Reports suggests it performs well within the atmospheric sciences, but it conceals the long term value authors place on papers appearing in the journal. Reference lists show that a fifth come through citing papers more than a decade old.
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Analysis of the atmospheric upward radiation in low latitude area
Li, Haiying; Wu, Zhensen; Lin, Leke; Lu, Changsheng
2016-10-01
Remote sensing using THz wave has irreplaceable advantage comparing to the microwave and the infrared waves, and study on the THz remote sensing become more and more popular in recent years. The major applications of the remote sensing in THz wavelengths are the retrieval of the atmospheric parameters and the microphysical information of the ice cloud. The remote sensing of the atmosphere is based on the radiation of THz wave along the earth-space path of which the most significant part is the upward radiation of the atmosphere. The upward radiation of the atmosphere in sunny day in the low latitude area is computed and analyzed in this paper. The absorption of THz wave by the atmosphere is calculated using the formulations illustrated in the Recommendation ITU-R P.676 to save machine hour, the frequency range is then restricted below 1THz. The frequencies used for the retrieval of atmospheric parameters such as temperature and water content are usually a few hundred GHz, at the lower end of THz wavelengths, so this frequency range is sufficient. The radiation contribution of every atmospheric layer for typical frequencies such as absorption window frequencies and peak frequencies are analyzed. Results show that at frequencies which absorption is severe, information about lower atmosphere cannot reach the receiver onboard a satellite or other high platforms due to the strong absorption along the path.
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Atmospheric neutrinos in Soudan 2.
Energy Technology Data Exchange (ETDEWEB)
Goodman, M. C.; Soudan 2 Collaboration
1999-03-30
Soudan 2 has measured the atmospheric neutrino flavor ratio with 4.2 fiducial kiloton-years of exposure. It measures a flavor ratio of 0.66 {+-} 0.11(stat), inconsistent with the expected ratio but consistent with the hypothesis of neutrino oscillations and the Super-Kamiokande data. In a sample of events with good angular resolution, fits to the L/E distribution suggest that {Delta}m{sup 2} > 10{sup {minus}3} eV{sup 2}.
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International Nuclear Information System (INIS)
Boyarchuk, K A; Karelin, A V; Shirokov, R V
2003-01-01
The outlook for using narrow-band spontaneous emission sources for purification of smoke gases from sulphur and nitrogen oxides is demonstrated by calculations based on a nonstationary kinetic model of the N 2 - O 2 - H 2 O - CO 2 - SO 2 mixture. The dependences of the mixture purification efficiency on the UV source power at different wavelengths, the exposure time, and the mixture temperature are calculated. It is shown that the radiation sources proposed in the paper will provide better purification of waste gases in the atmosphere. The most promising is a KrCl* lamp emitting an average power of no less than 100 W at 222 nm. (laser applications and other topics in quantum electronics)
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Causal mediation analysis for longitudinal data with exogenous exposure.
Bind, M-A C; Vanderweele, T J; Coull, B A; Schwartz, J D
2016-01-01
Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Triton: Scattering models and surface/atmosphere constraints
International Nuclear Information System (INIS)
Thompson, W.R.
1989-01-01
Modeling of Triton's spectrum indicates a bright scattering layer of optical depth τ≅3 overlying an optically deep layer of CH 4 with high absorption and little scattering. UV absorption in the spectrum indicates τ≅0.3 of red-yellow haze, although some color may also arise from complex organics partially visible on the surface. An analysis of this and other (spectro)photometric evidence indicates that Triton most likely has a bright surface, which was partially visible in 1977-1980. Geometric albedo p=0.62 +0.18 -0.12 , radius r = 1480 ± 180 km, and temperature T = 48 ± 6 K. With scattering optical depths of 0.3-3 and ∼1-10 mb of N 2 , a Mars-like atmospheric density and surface visibility pertain. Imaging with the 0.62μm CH 4 filter of the Voyager 2 wide angle camera could show ∼20% contrast between the average surface and clean exposures of CH 4 ice (which is not limited to the polar caps). Low far-infrared atmospheric opacity will in principle allow the detection of thermal gradients in the surface caused by optically transmitting but infrared opaque CH 4 and N 2 ice
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Transfer of atmospheric tritiated water to foliage and fruit of crops
International Nuclear Information System (INIS)
Fellows, R.J.; Cataldo, D.A.; Ligotke, M.W.; Napier, B.A.
1993-01-01
Tritiated water (THO) released to the environment from the effluent streams of nuclear reactors may be easily assimilated by organisms through metabolic fixation following foliar interception of THO vapor. This study was initiated to characterize atmospheric THO exchange parameters in two crops agronomically important to eastern Washington, grape (Vitus vinifera) and alfalfa (Medicago sativa). Short-term exposures using atmospheric THO concentrations ranging from 458 to 1,300,900 pCi/m 3 indicated no statistically significant concentration influences on THO exchange into the leaf tissue free-water (TFW) and organically bound tritium (OBT) of the leaves of either species. Long-term exposures indicated that equilibration of the leaf TFW with atmospheric THO concentrations occurred within 24 to 48 h for both species while equilibration of grape TFW appeared to take over 20 days. The rate of THO saturation of the foliage TFW appeared to be directly related to the stomatal resistance of the leaves and fruit. Desorption rates from both leaves and fruit were greater in the light than in the dark, again correlating with stomatal resistance. More than 90% of the absorbed THO was lost from the leaf TFW pool within 24 h following cessation of exposure for both species, while loss of THO from grape TFW and OBT pools was minimal. It appeared that more than 95 to 98% of the THO found in the TFW and OBT pools of the grape fruit was of atmospheric origin and not from transport from other parts of the plant
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Atmospheric Processing of Volcanic Glass: Effects on Iron Solubility and Redox Speciation.
Maters, Elena C; Delmelle, Pierre; Bonneville, Steeve
2016-05-17
Volcanic ash from explosive eruptions can provide iron (Fe) to oceanic regions where this micronutrient limits primary production. Controls on the soluble Fe fraction in ash remain poorly understood but Fe solubility is likely influenced during atmospheric transport by condensation-evaporation cycles which induce large pH fluctuations. Using glass powder as surrogate for ash, we experimentally simulate its atmospheric processing via cycles of pH 2 and 5 exposure. Glass fractional Fe solubility (maximum 0.4%) is governed by the pH 2 exposure duration rather than by the pH fluctuations, however; pH 5 exposure induces precipitation of Fe-bearing nanoparticles which (re)dissolve at pH 2. Glass leaching/dissolution release Fe(II) and Fe(III) which are differentially affected by changes in pH; the average dissolved Fe(II)/Fetot ratio is ∼0.09 at pH 2 versus ∼0.18 at pH 5. Iron release at pH 2 from glass with a relatively high bulk Fe(II)/Fetot ratio (0.5), limited aqueous Fe(II) oxidation at pH 5, and possibly glass-mediated aqueous Fe(III) reduction may render atmospherically processed ash a significant source of Fe(II) for phytoplankton. By providing new insight into the form(s) of Fe associated with ash as wet aerosol versus cloud droplet, we improve knowledge of atmospheric controls on volcanogenic Fe delivery to the ocean.
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Human Exposure to Dynamic Air Pollutants: Ozone in Airplanes and Ultrafine Particles in Homes
2010-01-01
original source of my love of learning. All her grandchildren have had to tolerate, at least temporarily, being ignored while she was immersed in a book ...Indoor Air 17, 372-383. Klepeis NE, Nazaroff WW, 2006a. Modeling residential exposure to secondhand tobacco smoke. Atmospheric Environment 40, 4393...4407. Klepeis NE, Nazaroff WW, 2006b. Mitigating residential exposure to secondhand tobacco smoke. Atmospheric Environment 40, 4408-4422. 84
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Wood dust exposure and lung cancer risk: a meta-analysis.
Hancock, David G; Langley, Mary E; Chia, Kwan Leung; Woodman, Richard J; Shanahan, E Michael
2015-12-01
Occupational lung cancers represent a major health burden due to their increasing prevalence and poor long-term outcomes. While wood dust is a confirmed human carcinogen, its association with lung cancer remains unclear due to inconsistent findings in the literature. We aimed to clarify this association using meta-analysis. We performed a search of 10 databases to identify studies published until June 2014. We assessed the lung cancer risk associated with wood dust exposure as the primary outcome and with wood dust-related occupations as a secondary outcome. Random-effects models were used to pool summary risk estimates. 85 publications were included in the meta-analysis. A significantly increased risk for developing lung cancer was observed among studies that directly assessed wood dust exposure (RR 1.21, 95% CI 1.05 to 1.39, n=33) and that assessed wood dust-related occupations (RR 1.15, 95% CI 1.07 to 1.23, n=59). In contrast, a reduced risk for lung cancer was observed among wood dust (RR 0.63, 95% CI 0.39 to 0.99, n=5) and occupation (RR 0.96, 95% CI 0.95 to 0.98, n=1) studies originating in Nordic countries, where softwood dust is the primary exposure. These results were independent of the presence of adjustment for smoking and exposure classification methods. Only minor differences in risk between the histological subtypes were identified. This meta-analysis provides strong evidence for an association between wood dust and lung cancer, which is critically influenced by the geographic region of the study. The reasons for this region-specific effect estimates remain to be clarified, but may suggest a differential effect for hardwood and softwood dusts. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
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Nuclear microprobe analysis and source apportionment of individual atmospheric aerosol particles
International Nuclear Information System (INIS)
Artaxo, P.; Rabello, M.L.C.; Watt, F.; Grime, G.; Swietlicki, E.
1993-01-01
In atmospheric aerosol reserach, one key issue is to determine the sources of the airborne particles. Bulk PIXE analysis coupled with receptor modeling provides a useful, but limited view of the aerosol sources influencing one particular site or sample. The scanning nuclear microprobe (SNM) technique is a microanalytical technique that gives unique information on individual aerosol particles. In the SNM analyses a 1.0 μm size 2.4 MeV proton beam from the Oxford SNM was used. The trace elements with Z>11 were measured by the particle induced X-ray emission (PIXE) method with detection limits in the 1-10 ppm range. Carbon, nitrogen and oxygen are measured simultaneously using Rutherford backscattering spectrometry (RBS). Atmospheric aerosol particles were collected at the Brazilian Antarctic Station and at biomass burning sites in the Amazon basin tropical rain forest in Brazil. In the Antarctic samples, the sea-salt aerosol particles were clearly predominating, with NaCl and CaSO 4 as major compounds with several trace elements as Al, Si, P, K, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb. Factor analysis of the elemental data showed the presence of four components: 1) Soil dust particles; 2) NaCl particles; 3) CaSO 4 with Sr; and 4) Br and Mg. Strontium, observed at 20-100 ppm levels, was always present in the CaSO 4 particles. The hierarchical cluster procedure gave results similar to the ones obtained through factor analysis. For the tropical rain forest biomass burning aerosol emissions, biogenic particles with a high organic content dominate the particle population, while K, P, Ca, Mg, Zn, and Si are the dominant elements. Zinc at 10-200 ppm is present in biogenic particles rich in P and K. The quantitative aspects and excellent detection limits make SNM analysis of individual aerosol particles a very powerful analytical tool. (orig.)
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Nonlinear phased analysis of reinforced concrete tunnels under fire exposure
Lilliu, G.; Meda, A.
2013-01-01
Fire analysis of precast segmental tunnels involves several problems, mainly related to the soil-structure interaction during fire exposure, coupled with material degradation. Temperature increase in the tunnel is the cause of thermal expansion of the lining, which is resisted by the soil pressure.
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The atmospheric inventory of Xenon and noble cases in shales The plastic bag experiment
Bernatowicz, T. J.; Podosek, F. A.; Honda, M.; Kramer, F. E.
1984-01-01
A novel trapped gas analysis protocol is applied to five shales in which the samples are sealed in air to eliminate the possibility of gas loss in the preanalysis laboratory vacuum exposure of a conventional protocol. The test is aimed at a determination concerning the hypothesis that atmospheric noble gases occur in the same proportion as planetary gases in meteorites, and that the factor-of-23 deficiency of air Xe relative to planetary Xe is made up by Xe stored in shales or other sedimentary rocks. The results obtained do not support the shale hypothesis.
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Oscillations in stellar atmospheres
International Nuclear Information System (INIS)
Costa, A.; Ringuelet, A.E.; Fontenla, J.M.
1989-01-01
Atmospheric excitation and propagation of oscillations are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of oscillations, the minimum frequencies are obtained for radially propagating waves. The comparison of the minimum frequencies obtained for a variety of stellar types is in good agreement with the observed periods of the oscillations. The role of the atmosphere in the globar stellar pulsations is thus emphasized. 7 refs
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Space Shuttle and Space Station Radio Frequency (RF) Exposure Analysis
Hwu, Shian U.; Loh, Yin-Chung; Sham, Catherine C.; Kroll, Quin D.
2005-01-01
This paper outlines the modeling techniques and important parameters to define a rigorous but practical procedure that can verify the compliance of RF exposure to the NASA standards for astronauts and electronic equipment. The electromagnetic modeling techniques are applied to analyze RF exposure in Space Shuttle and Space Station environments with reasonable computing time and resources. The modeling techniques are capable of taking into account the field interactions with Space Shuttle and Space Station structures. The obtained results illustrate the multipath effects due to the presence of the space vehicle structures. It's necessary to include the field interactions with the space vehicle in the analysis for an accurate assessment of the RF exposure. Based on the obtained results, the RF keep out zones are identified for appropriate operational scenarios, flight rules and necessary RF transmitter constraints to ensure a safe operating environment and mission success.
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Development and evaluation of an instantaneous atmospheric corrosion rate monitor
Mansfeld, F.; Jeanjaquet, S. L.; Kendig, M. W.; Roe, D. K.
1985-06-01
A research program was carried out in which a new instantaneous atmospheric corrosion rate monitor (ACRM) was developed and evaluated, and equipment was constructed which will allow the use of many sensors in an economical way in outdoor exposures. In the first task, the ACRM was developed and tested in flow chambers in which relative humidity and gaseous and particulate pollutant levels can be controlled. Diurnal cycles and periods of rain were simulated. The effects of aerosols were studied. A computerized system was used for collection, storage, and analysis of the electrochemical data. In the second task, a relatively inexpensive electronics system for control of the ACRM and measurement of atmospheric corrosion rates was designed and built. In the third task, calibration of deterioration rates of various metallic and nonmetallic materials with the response of the ACRMs attached to these materials was carried out under controlled environmental conditions using the system developed in the second task. A Quality Assurance project plan was prepared with inputs from the Rockwell International Environmental Monitoring and Service Center and Quality Assurance System audits were performed.
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Exposure to atmospheric pms, pahs, pcdd/fs and metals near an open air waste burning site in Beirut
Directory of Open Access Journals (Sweden)
Rima Baalbaki
2016-12-01
Full Text Available Baalbaki, R., El Hage, R., Nassar, J., Gerard, J., Saliba, N.B., Zaarour, R., Abboud, M., Wehbeh, F., Khalaf, L.K., Shihadeh, A.L., Saliba, N.A. 2016. Exposure to atmospheric PMS, PAHS, PCDD/FS and metals near an open air waste burning site in Beirut. Lebanese Science Journal, 17(2: 91-103. Since July 2015, Lebanon has experienced the worst solid waste management crisis in its history. Consequently, open-air waste burning in the vicinity of highly populated areas in Beirut has become a common practice. This study evaluates the effects of open-air dumping and burning on local air quality and public health. The levels of particulate matter (PM10, PM2.5, gaseous and particle-bound polycyclic aromatic hydrocarbons (PAHs, polychlorinated dibenzo-dioxins and furans (PCDD/Fs, and particle-bound metals at a residence close to waste burning are reported. Concentrations, determined between October 2 and December 2, 2015, were compared either to previous measurements or to measurements taken away from a nearby burning incident, and after it had rained. Subsequently, the cancer risk due to exposure to these chemicals was assessed. Results showed alarming increases in pollutant concentrations which was translated into an increase in short-term cancer risk from about 1 to 20 people per million on the days when waste was being burned. Findings were shared with the public to warn the community against the dangers of waste mismanagement, and underline the obvious need for solid waste management at the governmental and municipal levels.
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Scientific Visualization for Atmospheric Data Analysis in Collaborative Virtual Environments
Engelke, Wito; Flatken, Markus; Garcia, Arturo S.; Bar, Christian; Gerndt, Andreas
2016-04-01
1 INTRODUCTION The three year European research project CROSS DRIVE (Collaborative Rover Operations and Planetary Science Analysis System based on Distributed Remote and Interactive Virtual Environments) started in January 2014. The research and development within this project is motivated by three use case studies: landing site characterization, atmospheric science and rover target selection [1]. Currently the implementation for the second use case is in its final phase [2]. Here, the requirements were generated based on the domain experts input and lead to development and integration of appropriate methods for visualization and analysis of atmospheric data. The methods range from volume rendering, interactive slicing, iso-surface techniques to interactive probing. All visualization methods are integrated in DLR's Terrain Rendering application. With this, the high resolution surface data visualization can be enriched with additional methods appropriate for atmospheric data sets. This results in an integrated virtual environment where the scientist has the possibility to interactively explore his data sets directly within the correct context. The data sets include volumetric data of the martian atmosphere, precomputed two dimensional maps and vertical profiles. In most cases the surface data as well as the atmospheric data has global coverage and is of time dependent nature. Furthermore, all interaction is synchronized between different connected application instances, allowing for collaborative sessions between distant experts. 2 VISUALIZATION TECHNIQUES Also the application is currently used for visualization of data sets related to Mars the techniques can be used for other data sets as well. Currently the prototype is capable of handling 2 and 2.5D surface data as well as 4D atmospheric data. Specifically, the surface data is presented using an LoD approach which is based on the HEALPix tessellation of a sphere [3, 4, 5] and can handle data sets in the order of
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Behaviour of unprotected and anodized aluminium in atmospheres with very different pollution degrees
International Nuclear Information System (INIS)
Bautista, A.; Morcillo, M.; Gonzalez, J.A.; Simancas, J.; Otero, E.
1998-01-01
In the present research, the responses of unprotected and anodized aluminium specimens are compared after they have been exposed to 12 different atmospheres. The significance of the anodizing and the sealing on the atmospheric corrosion behaviour is analysed. The results show that the anodizing and sealing of aluminium exclude the risk of pitting corrosion in marine atmospheres and that the oxide thickness is not determining, at least during the first year of exposure. (Author) 8 refs
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Hupe, Patrick; Ceranna, Lars; Pilger, Christoph
2018-04-01
The International Monitoring System (IMS) has been established to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty and comprises four technologies, one of which is infrasound. When fully established, the IMS infrasound network consists of 60 sites uniformly distributed around the globe. Besides its primary purpose of determining explosions in the atmosphere, the recorded data reveal information on other anthropogenic and natural infrasound sources. Furthermore, the almost continuous multi-year recordings of differential and absolute air pressure allow for analysing the atmospheric conditions. In this paper, spectral analysis tools are applied to derive atmospheric dynamics from barometric time series. Based on the solar atmospheric tides, a methodology for performing geographic and temporal variability analyses is presented, which is supposed to serve for upcoming studies related to atmospheric dynamics. The surplus value of using the IMS infrasound network data for such purposes is demonstrated by comparing the findings on the thermal tides with previous studies and the Modern-Era Retrospective analysis for Research and Applications Version 2 (MERRA-2), which represents the solar tides well in its surface pressure fields. Absolute air pressure recordings reveal geographical characteristics of atmospheric tides related to the solar day and even to the lunar day. We therefore claim the chosen methodology of using the IMS infrasound network to be applicable for global and temporal studies on specific atmospheric dynamics. Given the accuracy and high temporal resolution of the barometric data from the IMS infrasound network, interactions with gravity waves and planetary waves can be examined in future for refining the knowledge of atmospheric dynamics, e.g. the origin of tidal harmonics up to 9 cycles per day as found in the barometric data sets. Data assimilation in empirical models of solar tides would be a valuable application of the IMS infrasound
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Mercury exposure: are we at risk?
CSIR Research Space (South Africa)
Matooane, M
2010-03-01
Full Text Available South Africa is considered one of the major contributors to global Hg emissions into the atmosphere mainly due to coal-based power generation. Exposure to Hg occurs through the inhalation of Hg vapours, or ingestion of Hg-contaminated food or water...
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Atmospheric Ionizing Radiation and the High Speed Civil Transport. Chapter 1
Maiden, D. L.; Wilson, J. W.; Jones, I. W.; Goldhagen, P.
2003-01-01
Atmospheric ionizing radiation is produced by extraterrestrial radiations incident on the Earth's atmosphere. These extraterrestrial radiations are of two sources: ever present galactic cosmic rays with origin outside the solar system and transient solar particle events that are at times very intense events associated with solar activity lasting several hours to a few days. Although the galactic radiation penetrating through the atmosphere to the ground is low in intensity, the intensity is more than two orders of magnitude greater at commercial aircraft altitudes. The radiation levels at the higher altitudes of the High Speed Civil Transport (HSCT) are an additional factor of two higher. Ionizing radiation produces chemically active radicals in biological tissues that alter the cell function or result in cell death. Protection standards against low levels of ionizing radiation are based on limitation of excess cancer mortality or limitation of developmental injury resulting in permanent damage to the offspring during pregnancy. The crews of commercial air transport operations are considered as radiation workers by the EPA, the FAA, and the International Commission on Radiological Protection (ICRP). The annual exposures of aircrews depend on the latitudes and altitudes of operation and flight time. Flight hours have significantly increased since deregulation of the airline industry in the 1980's. The FAA estimates annual subsonic aircrew exposures to range from 0.2 to 9.1 mSv compared to 0.5 mSv exposure of the average nuclear power plant worker in the nuclear industry. The commercial aircrews of the HSCT may receive exposures above recently recommended allowable limits for even radiation workers if flying their allowable number of flight hours. An adequate protection philosophy for background exposures in HSCT commercial airtraffic cannot be developed at this time due to current uncertainty in environmental levels. In addition, if a large solar particle event
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Ashworth, Danielle C.; Fuller, Gary W.; Toledano, Mireille B.; Font, Anna; Elliott, Paul; Hansell, Anna L.; de Hoogh, Kees
2013-01-01
Background. Research to date on health effects associated with incineration has found limited evidence of health risks, but many previous studies have been constrained by poor exposure assessment. This paper provides a comparative assessment of atmospheric dispersion modelling and distance from source (a commonly used proxy for exposure) as exposure assessment methods for pollutants released from incinerators. Methods. Distance from source and the atmospheric dispersion model ADMS-Urban were used to characterise ambient exposures to particulates from two municipal solid waste incinerators (MSWIs) in the UK. Additionally an exploration of the sensitivity of the dispersion model simulations to input parameters was performed. Results. The model output indicated extremely low ground level concentrations of PM10, with maximum concentrations of incinerator characteristics, magnitude of emissions, and surrounding meteorological and topographical conditions are considered. Reducing exposure misclassification is particularly important in environmental epidemiology to aid detection of low-level risks. PMID:23935644
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Delayed effects of cold atmospheric plasma on vascular cells
Stoffels, Eva; Roks, Anton J. M.; Deelmm, Leo E.
2008-01-01
We investigated the long-term behaviour of vascular cells (endothelial and smooth muscle) after exposure to a cold atmospheric plasma source. The cells were treated through a gas-permeable membrane, in order to simulate intravenous treatment with a gas plasma-filled catheter. Such indirect treatment
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Complexities of sibling analysis when exposures and outcomes change with time and birth order
Sudan, M; Kheifets, LI; Arah, OA; Divan, HA; Olsen, J
2014-01-01
In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were included. We examined differences in exposures and behavioral problems between siblings and non-siblings and by birth order and birth year. We estimated associations between cell phone exposures and b...
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Takagi, H; Watanabe, T; Mizuno, Y; Kawai, N; Umemoto, T
2014-12-01
The aim of this paper was to determine whether weather factors including atmospheric pressure are associated with the occurrence of ruptured abdominal aortic aneurysm (RAAA). We investigated our institutional experiences of RAAA in more than 150 patients during 8 years. Further, we performed a meta-analysis of published studies reporting the influence of atmospheric pressure on RAAA. We retrospectively evaluated 152 patients who underwent surgery for RAAA (including ruptured iliac arterial aneurysm) at our institute between 1 January 2006 and 31 December 2013. Daily regional meteorological data (in the nearest weather station located 3.5 km from the hospital) were obtained online from Japan Meteorological Agency. To identify comparative studies of mean atmospheric pressure on the day with RAAA versus that on the day without RAAA, MEDLINE and EMBASE were searched through January 2014 using Web-based search engines (PubMed and OVID). Mean sea level atmospheric pressure, delta mean atmospheric pressure (difference between mean sea level atmospheric pressure on the day and that on the previous day), and sunshine duration on the day with RAAA were significantly lower than those on the day without RAAA: 1012.43±7.44 versus 1013.71±6.49 hPa, P=0.039, -1.18±5.15 versus 0.05±5.62 hPa, P=0.005; and 4.76±3.76 versus 5.47±3.88 h, P=0.026; respectively. A pooled analysis of 8 studies (including our institutional study) demonstrated that mean atmospheric pressure on the day with RAAA was significantly lower than that on the day without RAAA: standardized mean difference, -0.09; 95% confidence interval, -0.14 to -0.04; P=0.0009. Atmospheric pressure on the day with RAAA appears lower than that on the day without RAAA. Atmospheric pressure may be associated with the occurrence of RAAA.
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Effects of 108 Days Tritium Exposure on UHMW-PE, PTFE, and Vespel(R)
International Nuclear Information System (INIS)
Clark, E.A.
2003-01-01
Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), also known as Teflon(R), and Vespel(R) polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for 108 days. Sample mass and size measurements to calculate density, spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of this exposure on these samples. This technical report is the first report from this research program
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Badjagbo, Koffi; Picard, Pierre; Moore, Serge; Sauvé, Sébastien
2009-05-01
Real-time monitoring of benzene, toluene, ethylbenzene, and xylenes (BTEX) in ambient air is essential for the early warning detection associated with the release of these hazardous chemicals and in estimating the potential exposure risks to humans and the environment. We have developed a tandem mass spectrometry (MS/MS) method for continuous real-time determination of ambient trace levels of BTEX. The technique is based on the sampling of air via an atmospheric pressure inlet directly into the atmospheric pressure chemical ionization (APCI) source. The method is linear over four orders of magnitude, with correlation coefficients greater than 0.996. Low limits of detection in the range 1-2 microg/m(3) are achieved for BTEX. The reliability of the method was confirmed through the evaluation of quality parameters such as repeatability and reproducibility (relative standard deviation below 8% and 10%, respectively) and accuracy (over 95%). The applicability of this method to real-world samples was evaluated through measurements of BTEX levels in real ambient air samples and results were compared with a reference GC-FID method. This direct APCI-MS/MS method is suitable for real-time analysis of BTEX in ambient air during regulation surveys as well as for the monitoring of industrial processes or emergency situations.
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International Nuclear Information System (INIS)
1977-01-01
The report deals with development of methodology for the health benefit-cost analysis of activities that result in radiation exposure to humans. It attempts to frame the problems and to communicate the necessary elements of the complex technical process required for this method of analysis. The main thrust of the report is to develop a methodology for analyzing the benefits and costs of these activities. Application of the methodology is demonstrated for nuclear power production and medical uses of radiation, but no definitive analysis is attempted. The report concludes that benefit-cost analysis can be effectively applied to these applications and that it provides a basis for more informed governmental decision-making and for public participation in evaluating the issues of radiation exposure. It notes, however, that for cases where national policy is involved, decisions must inevitably be made on the basis of value judgements to which such analyses can make only limited contributions. An important conclusion is that a significant reduction in radiation exposure to the population is apparently achievable by development of methods for eliminating unproductive medical X-ray exposure
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Arnault, Joel; Kunstmann, Harald; Knoche, Hans-Richard
2015-04-01
Many numerical studies have shown that the West African monsoon is highly sensitive to the state of the land surface. It is however questionable to which extend a local change of land surface properties would affect the local climate, especially with respect to precipitation. This issue is traditionally addressed with the concept of precipitation recycling, defined as the contribution of local surface evaporation to local precipitation. For this study the West African monsoon has been simulated with the Weather Research and Forecasting (WRF) model using explicit convection, for the domain (1°S-21°N, 18°W-14°E) at a spatial resolution of 10 km, for the period January-October 2013, and using ERA-Interim reanalyses as driving data. This WRF configuration has been selected for its ability to simulate monthly precipitation amounts and daily histograms close to TRMM (Tropical Rainfall Measuring Mission) data. In order to investigate precipitation recycling in this WRF simulation, surface evaporation tagging has been implemented in the WRF source code as well as the budget of total and tagged atmospheric water. Surface evaporation tagging consists in duplicating all water species and the respective prognostic equations in the source code. Then, tagged water species are set to zero at the lateral boundaries of the simulated domain (no inflow of tagged water vapor), and tagged surface evaporation is considered only in a specified region. All the source terms of the prognostic equations of total and tagged water species are finally saved in the outputs for the budget analysis. This allows quantifying the respective contribution of total and tagged atmospheric water to atmospheric precipitation processes. The WRF simulation with surface evaporation tagging and budgets has been conducted two times, first with a 100 km2 tagged region (11-12°N, 1-2°W), and second with a 1000 km2 tagged region (7-16°N, 6°W -3°E). In this presentation we will investigate hydro-atmospheric
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Self-protection of unsealed anodised aluminium exposed to atmosphere
International Nuclear Information System (INIS)
Escudero, E.; Bartolome, M. J.; Lopez, V.; Simancas, J.; Gonalez, J. A.; Morcillo, M.; Otero, E.
2005-01-01
To confirm or refute the widely held idea that the sealing operation is vital to guarantee the good resistance of anodised aluminium to atmospheric corrosion, unsealed, anodised specimens with three different film thick messes were exposed in 9 atmospheres in Ibero america with salinity values of between 3.9 and 684 mg m''2 day ''-1 of chlorides. Using a wide variety of techniques, from scanning and transmission electron microscopy to direct measurements by gravimetry, and including indirect measurements by electrochemical techniques as well as standard sealing quality control tests, the self-sealing capacity of unsealed anodic coating during atmospheric exposure is demonstrated. Surprisingly, unlike other types of protective coatings, the quality of anodic films improves with ageing. (Author) 15 refs
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Intermediate range atmospheric transport and technology assessments: nuclear pollutants
International Nuclear Information System (INIS)
Rohwer, P.S.; Hoffman, F.O.; Miller, C.W.
1981-01-01
Mathematical models have been used to assess potential impacts of radioactivity releases during all phases of our country's development of nuclear power. Experience to date has shown that in terms of potential dose to man, the most significant releases of radioactivity from nuclear fuel cycle facilities are those to the atmosphere. Our ability to predict atmospheric dispersion will, therefore, ultimately affect our capability to understand and assess the significance of both routine and accidental discharges of radionuclides. Assessment of potential radiological exposures from postulated routine and accidental releases of radionuclides from the fast-breeder reactor will require the use of atmospheric dispersion models, and the design, siting, and licensing of breeder reactor fuel cycle facilities will be influenced by the predictions made by these models
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A Database of Herbaceous Vegetation Responses to Elevated Atmospheric CO{sub 2}
Energy Technology Data Exchange (ETDEWEB)
Jones, M.H.
1999-11-24
To perform a statistically rigorous meta-analysis of research results on the response by herbaceous vegetation to increased atmospheric CO{sub 2} levels, a multiparameter database of responses was compiled from the published literature. Seventy-eight independent CO{sub 2}-enrichment studies, covering 53 species and 26 response parameters, reported mean response, sample size, and variance of the response (either as standard deviation or standard error). An additional 43 studies, covering 25 species and 6 response parameters, did not report variances. This numeric data package accompanies the Carbon Dioxide Information Analysis Center's (CDIAC's) NDP-072, which provides similar information for woody vegetation. This numeric data package contains a 30-field data set of CO{sub 2}-exposure experiment responses by herbaceous plants (as both a flat ASCII file and a spreadsheet file), files listing the references to the CO{sub 2}-exposure experiments and specific comments relevant to the data in the data sets, and this documentation file (which includes SAS{reg_sign} and Fortran codes to read the ASCII data file). The data files and this documentation are available without charge on a variety of media and via the Internet from CDIAC.
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International Nuclear Information System (INIS)
Kobayashi, Hideo; Yabuta, Hajimu; Katagiri, Hiroshi; Obata, Kazuichi; Kokubu, Morinobu
1982-03-01
Various calculations are made to estimate the distributions of concentration and γ-exposure rate due to a radioactive cloud released from a point source to the atmosphere. In this report, the isopleths of concentration and γ-exposure rate which were calculated are given in graphs to enable rapid prediction of the influence of released radioactive material in the emergency situation. Recently there are facilities which are equipped with a system to display the calculation results on CRT; but such practice is rather rare. By placing the calculated isopleths of reduction scale 1/25000 or 1/50000 on the usual map, any facilities without the CRT system can readily estimate the influence of an accidental release. The graphs of isopleths are given with the release height (11 values of 0 to 200 m at about 20 m intervals) and the atmospheric stability (6 classes) as parameters. Calculations of γ-exposure rates were made using the computer code GAMPUL developed by T. Hayashi and T. Shiraishi. In the calculation of radioactive concentrations and γ-exposure rates, the vertical diffusion depths, σsub(z), exceeding 1000 m are taken to be 1000 m according to the Meteorological Guide for the Safety Analysis of Power Reactor (J.AEC). The comparison between with and without this limitation in σsub(z) is made in the case of downwind axial surface distributions. (author)
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Standard practice for conducting atmospheric corrosion tests on metals
American Society for Testing and Materials. Philadelphia
2010-01-01
1.1 This practice covers and defines conditions for exposure of metals and alloys to the weather. It sets forth the general procedures that should be followed in any atmospheric test. It is presented as an aid in conducting atmospheric corrosion tests so that some of the pitfalls of such testing may be avoided. As such, it is concerned mainly with panel exposures to obtain data for comparison purposes. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Symbolic Analysis of Heart Rate Variability During Exposure to Musical Auditory Stimulation.
Vanderlei, Franciele Marques; de Abreu, Luiz Carlos; Garner, David Matthew; Valenti, Vitor Engrácia
2016-01-01
In recent years, the application of nonlinear methods for analysis of heart rate variability (HRV) has increased. However, studies on the influence of music on cardiac autonomic modulation in those circumstances are rare. The research team aimed to evaluate the acute effects on HRV of selected auditory stimulation by 2 musical styles, measuring the results using nonlinear methods of analysis: Shannon entropy, symbolic analysis, and correlation-dimension analysis. Prospective control study in which the volunteers were exposed to music and variables were compared between control (no auditory stimulation) and during exposure to music. All procedures were performed in a sound-proofed room at the Faculty of Science and Technology at São Paulo State University (UNESP), São Paulo, Brazil. Participants were 22 healthy female students, aged between 18 and 30 y. Prior to the actual intervention, the participants remained at rest for 20 min, and then they were exposed to one of the selected types of music, either classical baroque (64-84 dB) or heavy-metal (75-84 dB). Each musical session lasted a total of 5 min and 15 s. At a point occurring up to 1 wk after that day, the participants listened to the second type of music. The 2 types of music were delivered in a random sequence that depended on the group to which the participant was assigned. The study analyzed the following HRV indices through Shannon entropy; symbolic analysis-0V%, 1V%, 2LV%, and 2ULV%; and correlation-dimension analysis. During exposure to auditory stimulation by heavy-metal or classical baroque music, the study established no statistically significant variations regarding the indices for the Shannon entropy; the symbolic analysis-0V%, 1V%, and 2ULV%; and the correlation-dimension analysis. However, during heavy-metal music, the 2LV% index in the symbolic analysis was reduced compared with the controls. Auditory stimulation with the heavy-metal music reduced the parasympathetic modulation of HRV
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Shulgina, T.; Genina, E.; Gordov, E.; Nikitchuk, K.
2009-04-01
At present numerous data archives which include meteorological observations as well as climate processes modeling data are available for Earth Science specialists. Methods of mathematical statistics are widely used for their processing and analysis. In many cases they represent the only way of quantitative assessment of the meteorological and climatic information. Unified set of analysis methods allows us to compare climatic characteristics calculated on the basis of different datasets with the purpose of performing more detailed analysis of climate dynamics for both regional and global levels. The report presents the results of comparative analysis of atmosphere temperature behavior for the Northern Eurasia territory for the period from 1979 to 2004 based on the NCEP/NCAR Reanalysis, NCEP/DOE Reanalysis AMIP II, JMA/CRIEPI JRA-25 Reanalysis, ECMWF ERA-40 Reanalysis data and observation data obtained from meteorological stations of the former Soviet Union. Statistical processing of atmosphere temperature data included analysis of time series homogeneity of climate indices approved by WMO, such as "Number of frost days", "Number of summer days", "Number of icing days", "Number of tropical nights", etc. by means of parametric methods of mathematical statistics (Fisher and Student tests). That allowed conducting comprehensive research of spatio-temporal features of the atmosphere temperature. Analysis of the atmosphere temperature dynamics revealed inhomogeneity of the data obtained for large observation intervals. Particularly, analysis performed for the period 1979 - 2004 showed the significant increase of the number of frost and icing days approximately by 1 day for every 2 years and decrease roughly by 1 day for 2 years for the number of summer days. Also it should be mentioned that the growth period mean temperature have increased by 1.5 - 2° C for the time period being considered. The usage of different Reanalysis datasets in conjunction with in-situ observed
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Exposure to organochlorine pollutants and type 2 diabetes: a systematic review and meta-analysis.
Directory of Open Access Journals (Sweden)
Mengling Tang
Full Text Available OBJECTIVE: Though exposure to organochlorine pollutants (OCPs is considered a risk factor for type 2 diabetes (T2DM, epidemiological evidence for the association remains controversial. A systematic review and meta-analysis was applied to quantitatively evaluate the association between exposure to OCPs and incidence of T2DM and pool the inconsistent evidence. DESIGN AND METHODS: Publications in English were searched in MEDLINE and WEB OF SCIENCE databases and related reference lists up to August 2013. Quantitative estimates and information regarding study characteristics were extracted from 23 original studies. Quality assessments of external validity, bias, exposure measurement and confounding were performed, and subgroup analyses were conducted to examine the heterogeneity sources. RESULTS: We retrieved 23 eligible articles to conduct this meta-analysis. OR (odds ratio or RR (risk ratio estimates in each subgroup were discussed, and the strong associations were observed in PCB-153 (OR, 1.52; 95% CI, 1.19-1.94, PCBs (OR, 2.14; 95% CI, 1.53-2.99, and p,p'-DDE (OR, 1.33; 95% CI, 1.15-1.54 based on a random-effects model. CONCLUSIONS: This meta-analysis provides quantitative evidence supporting the conclusion that exposure to organochlorine pollutants is associated with an increased risk of incidence of T2DM.
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A model for radiological consequences of nuclear power plant operational atmospheric releases
International Nuclear Information System (INIS)
Kocar, Cemil; Soekmen, Cemal Niyazi
2009-01-01
A dynamic dose and risk assessment model is developed to estimate radiological consequences of atmospheric emissions from nuclear power plants. Internal exposure via inhalation and ingestion, external exposure from clouds and radioactivity deposited on the ground are included in the model. The model allows to simulate interregional moves of people and multi-location food supply in the computational domain. Any long-range atmospheric dispersion model which yields radionuclide concentrations in air and on the ground at predetermined time intervals can easily be integrated into the model. The software developed is validated against radionuclide concentrations measured in different environmental media and dose values estimated after the Chernobyl accident. Results obtained using the model compare well with dose estimates and activities measured in foodstuffs and feedstuffs
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Optical monitoring of CH3NH3PbI3 thin films upon atmospheric exposure
International Nuclear Information System (INIS)
Ghimire, Kiran; Zhao, Dewei; Cimaroli, Alex; Ke, Weijun; Yan, Yanfa; Podraza, Nikolas J
2016-01-01
CH 3 NH 3 PbI 3 perovskite films of interest for photovoltaic (PV) devices have been prepared by (i) vapor deposition and (ii) solution processing. Complex dielectric function ( ε = ε 1 + i ε 2 ) spectra and structural parameters of the films have been extracted using near infrared to ultraviolet spectroscopic ellipsometry. In situ real time spectroscopic ellipsometry (RTSE) over a 48 h period has been performed on vapor deposited CH 3 NH 3 PbI 3 after the deposition in normal atmospheric laboratory ambient conditions. Analysis of RTSE data for vapor deposited CH 3 NH 3 PbI 3 film prepared under un-optimized conditions identifies phase segregated PbI 2 and CH 3 NH 3 I at the substrate/film interface and unreacted PbI 2 and CH 3 NH 3 I on the film surface. This analysis also provides the time dependence of the effective thicknesses of perovskite film, unreacted components, and phase segregated layers to track CH 3 NH 3 PbI 3 decomposition. (paper)
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Atmospheric corrosion of metals in industrial city environment.
Kusmierek, Elzbieta; Chrzescijanska, Ewa
2015-06-01
Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust.
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An assessment of worldwide energy-related atmospheric pollution
International Nuclear Information System (INIS)
1989-01-01
Energy-related emissions of atmospheric pollutants are currently suspected as the source of a number of major environmental problems. Early concerns about local and regional air quality and respiratory health risks, greatly alleviated in the case of sulfur dioxide (SO 2 ) emissions by the use of tall stacks, have been superseded by ''global problems,'' such as acidification of the biosphere, increase in tropospheric ozone (O 3 ), visibility impairment, long-term exposure to toxic pollutants, and buildup of ''greenhouse gases''. Chapter 1 assesses the sources and physical/chemical atmospheric processes of energy-related atmospheric pollution (ERAP). It is not an exhaustive review but rather a documented statement of the state-of-art knowledge on issues critical to effective environmental decision-making. Chapter 2 looks at the effects on man, the environment and materials, and chapter 3 presents an overview and policy options. (author)
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A brief review on the atmospheric corrosion of mild steel in Iran
Directory of Open Access Journals (Sweden)
E. Shafiei
2014-12-01
Full Text Available This paper presents a review on the atmospheric corrosion of steel, at three sites, in Iran. Corrosion rate values, time of wetness, and the level of pollutants, namely of SO2 and chlorides were determined for the first year of exposure in order to establish the aggressiveness of the atmospheres. The results obeyed well with the empirical kinetics equation of the form C = Ktn.
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Occupational exposure to HDI: progress and challenges in biomarker analysis.
Flack, Sheila L; Ball, Louise M; Nylander-French, Leena A
2010-10-01
1,6-Hexamethylene diisocyanate (HDI) is extensively used in the automotive repair industry and is a commonly reported cause of occupational asthma in industrialized populations. However, the exact pathological mechanism remains uncertain. Characterization and quantification of biomarkers resulting from HDI exposure can fill important knowledge gaps between exposure, susceptibility, and the rise of immunological reactions and sensitization leading to asthma. Here, we discuss existing challenges in HDI biomarker analysis including the quantification of N-acetyl-1,6-hexamethylene diamine (monoacetyl-HDA) and N,N'-diacetyl-1,6-hexamethylene diamine (diacetyl-HDA) in urine samples based on previously established methods for HDA analysis. In addition, we describe the optimization of reaction conditions for the synthesis of monoacetyl-HDA and diacetyl-HDA, and utilize these standards for the quantification of these metabolites in the urine of three occupationally exposed workers. Diacetyl-HDA was present in untreated urine at 0.015-0.060 μg/l. Using base hydrolysis, the concentration range of monoacetyl-HDA in urine was 0.19-2.2 μg/l, 60-fold higher than in the untreated samples on average. HDA was detected only in one sample after base hydrolysis (0.026 μg/l). In contrast, acid hydrolysis yielded HDA concentrations ranging from 0.36 to 10.1 μg/l in these three samples. These findings demonstrate HDI metabolism via N-acetylation metabolic pathway and protein adduct formation resulting from occupational exposure to HDI. Copyright © 2010 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Panikov, N.S.; Paduraru, S.; Crowe, R.; Ricatto, P.J.; Christodoulatos, C.; Becker, K.
2002-01-01
The results of experiments aimed at the investigation of the destruction of spore-forming bacteria, which are believed to be among the most resistant microorganisms, using a novel atmospheric-pressure dielectric capillary electrode discharge plasma are reported. Various well-characterized cultures of Bacillus subtilis were prepared, subjected to atmospheric-pressure plasma jets emanating from a plasma shower reactor operated either in He or in air (N 2 /O 2 mixture) at various power levels and exposure times, and analyzed after plasma treatment. Reductions in colony-forming units ranged from 10 4 (He plasma) to 10 8 (air plasma) for plasma exposure times of less than 10 minutes. (author)
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Smith, Philip A; Lockhart, Bonnie; Besser, Brett W; Michalski, Michael A R
2014-01-01
Hazardous atmospheres in confined spaces may be obvious when a source of air contamination or oxygen (O2) deficiency is recognized. Such is often the case in general industry settings, especially with work processes which create hazardous atmospheres that may be anticipated. Hazards present in active sewers are also well recognized; but the possibility that O2 deficiency or high airborne contaminant concentrations may exist in new construction sewers or storm drains has been repeatedly ignored with deadly results. Low O2 and high carbon dioxide (CO2) concentrations may exist in new construction manholes that have not yet been connected to an active sewer or drain system, and these concentrations have been shown to vary over time. A recent incident is described where workers repeatedly entered such a confined space without incident, but subsequent entry resulted in a fatality and a near-miss for a co-worker rescuer. Additional cases are discussed, with an emphasis placed on elevated CO2 concentrations as a causative factor. A description is provided for the adsorptive gas chromatography whole-air analysis methodology used to quantitatively determine atmospheric conditions present at this type of fatality site or others after an incident, and for the gas chromatography-mass spectrometry method used to provide confirmation of analyte identity with high certainty. Many types of confined spaces may be encountered in addition to the underground varieties discussed, and many possible atmospheric hazards are possible. The definitive whole-air analysis approach described here may be of use and should be considered to investigate many confined space fatality and near-miss cases, and to better understand the causes of dangerous atmosphere conditions that may arise in confined spaces.
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International Nuclear Information System (INIS)
Espinosa, A.; Miranda, J.; Pineda, J. C.
2010-01-01
One of the aspects that are frequently overlooked in the evaluation of uncertainty in experimental data is the possibility that the involved quantities are correlated among them, due to different causes. An example in the elemental analysis of atmospheric aerosols using techniques like X-ray Fluorescence (X RF) or Particle Induced X-ray Emission (PIXE). In these cases, the measured elemental concentrations are highly correlated, and then are used to obtain information about other variables, such as the contribution from emitting sources related to soil, sulfate, non-soil potassium or organic matter. This work describes, as an example, the method required to evaluate the uncertainty in variables determined from correlated quantities from a set of atmospheric aerosol samples collected in the Metropolitan Area of the Mexico Valley and analyzed with PIXE. The work is based on the recommendations of the Guide for the Evaluation of Uncertainty published by the International Organization for Standardization. (Author)
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Causal mediation analysis for longitudinal data with exogenous exposure
Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.
2015-01-01
Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different type...
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Directory of Open Access Journals (Sweden)
Jingwen Zhang
Full Text Available Association between polychlorinated biphenyl (PCB exposure and breast cancer risk has been widely studied, but the results remain controversial. We performed a meta-analysis to evaluate the evidences from observational studies on PCB exposure and breast cancer risk.Relevant studies with data on internal PCB dose were identified from PubMed, EMBASE, CBM and CNKI databases through November 2014. Multivariable-adjusted odds ratio (OR with 95% confidence intervals (CIs were applied to assess the association between PCB exposure and breast cancer risk. Heterogeneity test, sensitivity analysis, subgroup analysis and publication bias test were also performed. To further explore the association between specific groups of PCB congeners and breast cancer, we examined the PCB congeners classified, according to their structural, biological and pharmacokinetics properties, as group I (potentially estrogenic, group II (potentially anti-estrogenic and immunotoxic, dioxin-like, and group III (phenobarbital, CYP1A and CYP2B inducers, biologically persistent.Of 660 studies screened, 25 studies which met criteria were selected, involving a total of 12866 participants (6088 cases and 6778 controls from eight countries. The results showed that the risk of breast cancer was associated with group II (OR = 1.23, 95% CI: 1.08-1.40 and group III (OR = 1.25, 95% CI: 1.09-1.43 PCBs, but not with group I (OR = 1.10, 95%CI: 0.97-1.24 PCBs or total PCB exposure (OR = 1.09, 95%CI: 0.97-1.22.Our meta-analysis based on the selected studies found group II and group III PCB exposure might contribute to the risk of breast cancer. More studies in developing countries with higher PCB levels are needed, as well as studies to explore the relationships between mixtures of organochlorine compounds and breast cancer risk.
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Relative significance of natural irradiation vs all human exposures
International Nuclear Information System (INIS)
Jammet, H.
1985-01-01
A review is made of the fundamentals allowing to quantitatively express the importance of the various sources of human exposure by an individual or collective approach. Following a summary of the components of normal exposure to natural sources, the various human actions at the origin of enhanced exposure are studied: 1) those modifying the relationship between natural sources and man (dwelling conditions, coal burning, geothermal energy production, exploitation of phosphate rock); 2) those creating new artificial sources (nuclear explosions in the atmosphere, nuclear power production, medical use of radiation and radionuclides). The effective dose equivalent commitments for these sources are compared with those necessarily involved by continuous normal exposure to the natural sources of exposure [fr
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Energy Technology Data Exchange (ETDEWEB)
Mastalerz, M.; Glikson, M.; Simpson, R.W. [Indiana University, Bloomington, IN (United States). Indiana Geological Survey
1998-09-01
An increase in particulate matter in the atmosphere has been shown to be linked to increased mortality but this relationship is poorly understood. Light microscopy, electron microscopy, electron microprobe, and micro-FTIR techniques have been applied to study atmospheric particulates in Brisbane, Australia as a part of a study on asthma. The particulate matter samples were collected daily from April to August 1992, and the sampling covered the autumn period which is typically a time of high asthma incidence in Brisbane. Volumetrically, most atmospheric particulate matter is less than 2{mu}m in size. The microscopic analysis reveals that this material is composed mainly of combusted and incompletely burned hydrocarbons from motor vehicle exhaust emissions, quiescent spores of Mucorales, soil bacteria, and inorganic matter in the form of quartz and other silicates. Elemental and functional group analyses confirm microscope identification, documenting carbon-rich, aromatic exhaust material, more aliphatic pollen and spore material and inorganic matter. Fungal spores dominate bioaerosol and are very abundant from the end of April through May to mid-June. The cytoplasmic content of pollens or fungaonly regarded as allergenic. Particulates from the exhaust emissions and crustal material in a sub-micrometer size range may act as carriers or dispersive mechanisms for cytoplasmic material from fungal spores and pollens, perhaps causing periods of the highest exhaust emission to be the most allergenic. 25 refs., 4 figs., 1 tab.
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Corrosion and protection of metals in the rural atmosphere of El Pardo Spain (PATINA/CYTED project)
International Nuclear Information System (INIS)
Simancas, J.; Castano, J. G.; Morcillo, M.
2003-01-01
Atmospheric corrosion tests of metallic and organic coatings on steel, zinc and aluminium have been conducted in el Pardo (Spain) as part of the PATINA/CYTED project Anticorrosive Protection of Metals in the Atmosphere. This is a rural atmosphere with the following ISO corrosivity categories: C2 (Fe), C'' (Zn), Cu (Cu) and C1 (Al). Its average temperature and relative humidity is 13 degree centigrade and 62.8, respectively, and it has low SO 2 and C1''- contents. Results of 42 months exposure are discussed. Atmospheric exposure tests were carried out for the following types of coatings: conventional paint coatings for steel and hot-dip galvanized steel (group 1), new painting technologies for steel and galvanized steel (group 2), zinc-base metallic coatings (group 3), aluminium-base metallic coatings (group 4), coatings on aluminium (group 5) and coil-coatings on steel, hot-dip galvanized steel and 55% Al-Zn coated steel (group 6). (Author) 9 refs
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Non-destructive neutron activation analysis of atmospheric pollutants
International Nuclear Information System (INIS)
Owlya, A.; Kasrai, M.; Massoumi, R.
1976-01-01
The concentration of elements in atmospheric particulate in an urban area were determined by means of a Ge(Li) detector. Samples were collected on a Millipore filter at a single location during three seasons of the year and the results compared. These results are compared with results for the same elements in other cities. It was concluded that in a dry climate, at least two parameters are related to seasonal changes in trace element concentration in the atmosphere-rain and snowfall, and the reducation of vertical diffusion of airborne particulates (author)
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Energy Technology Data Exchange (ETDEWEB)
Cushman, R.M.
2003-08-28
The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including atmospheric concentrations and atmospheric emissions of carbon dioxide (CO{sub 2}) and other radiatively active gases; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.
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Bos, Peter Martinus Jozef; Zeilmaker, Marco Jacob; Eijkeren, Jan Cornelis Henri van
2006-01-01
Acute exposure guideline levels (AEGLs) are derived to protect the human population from adverse health effects in case of single exposure due to an accidental release of chemicals into the atmosphere. AEGLs are set at three different levels of increasing toxicity for exposure durations ranging from
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Swider, Paweł; Lewtak, Jan P; Gryko, Daniel T; Danikiewicz, Witold
2013-10-01
The porphyrinoids chemistry is greatly dependent on the data obtained in mass spectrometry. For this reason, it is essential to determine the range of applicability of mass spectrometry ionization methods. In this study, the sensitivity of three different atmospheric pressure ionization techniques, electrospray ionization, atmospheric pressure chemical ionization and atmospheric pressure photoionization, was tested for several porphyrinods and their metallocomplexes. Electrospray ionization method was shown to be the best ionization technique because of its high sensitivity for derivatives of cyanocobalamin, free-base corroles and porphyrins. In the case of metallocorroles and metalloporphyrins, atmospheric pressure photoionization with dopant proved to be the most sensitive ionization method. It was also shown that for relatively acidic compounds, particularly for corroles, the negative ion mode provides better sensitivity than the positive ion mode. The results supply a lot of relevant information on the methodology of porphyrinoids analysis carried out by mass spectrometry. The information can be useful in designing future MS or liquid chromatography-MS experiments. Copyright © 2013 John Wiley & Sons, Ltd.
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On the 485-day Mode in the Atmospheric Angular Momentum: Spectral Analysis of IERS Data
Tsurkis, I. Ya.; Kuchai, M. S.
2018-05-01
The modification of spectral analysis especially intended for studying the disturbing functions of the atmosphere and ocean, as well as the observed polar motion (Wiener-Liouville spectrum), is used. The time series of the atmospheric disturbing functions obtained by the U.S. National Centers for Environmental Prediction (NCEP) of the International Earth Rotation and Reference Systems Service (IERS) for the period from January 1, 1980 to June 20, 2014 (http://www.iers.org/.cs1?pid=43-1100116) are analyzed. It is shown that the baric disturbing function contains a regular mode with a period of 16 months; the contribution of this mode in the polar motion is estimated.
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Analysis of Radio Frequency Blackout for a Blunt-Body Capsule in Atmospheric Reentry Missions
Directory of Open Access Journals (Sweden)
Yusuke Takahashi
2016-01-01
Full Text Available A numerical analysis of electromagnetic waves around the atmospheric reentry demonstrator (ARD of the European Space Agency (ESA in an atmospheric reentry mission was conducted. During the ARD mission, which involves a 70% scaled-down configuration capsule of the Apollo command module, radio frequency blackout and strong plasma attenuation of radio waves in communications with data relay satellites and air planes were observed. The electromagnetic interference was caused by highly dense plasma derived from a strong shock wave generated in front of the capsule because of orbital speed during reentry. In this study, the physical properties of the plasma flow in the shock layer and wake region of the ESA ARD were obtained using a computational fluid dynamics technique. Then, electromagnetic waves were expressed using a frequency-dependent finite-difference time-domain method using the plasma properties. The analysis model was validated based on experimental flight data. A comparison of the measured and predicted results showed good agreement. The distribution of charged particles around the ESA ARD and the complicated behavior of electromagnetic waves, with attenuation and reflection, are clarified in detail. It is suggested that the analysis model could be an effective tool for investigating radio frequency blackout and plasma attenuation in radio wave communication.
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Study plan for the sensitivity analysis of the Terrain-Responsive Atmospheric Code (TRAC)
International Nuclear Information System (INIS)
Restrepo, L.F.; Deitesfeld, C.A.
1987-01-01
Rocky Flats Plant, Golden, Colorado is presently developing a computer code to model the dispersion of potential or actual releases of radioactive or toxic materials to the environment, along with the public consequences from these releases. The model, the Terrain-Responsive Atmospheric Code (TRAC), considers several complex features which could affect the overall dispersion and consequences. To help validate TRAC, a sensitivity analysis is being planned to determine how sensitive the model's solutions are to input variables. This report contains a brief description of the code, along with a list of tasks and resources needed to complete the sensitivity analysis
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Atmospheric dispersion and individual exposure of hazardous materials
International Nuclear Information System (INIS)
Efthimiou, G.C.; Bartzis, J.G.
2011-01-01
In this work a new approach for CFD RANS modelling of dispersion of airborne point source releases is presented. The key feature of this approach is the model capability to predict concentration time scales that are functions not only of the flow turbulence scales but also of the pollutant travel time. This approach has been implemented for the calculation of the concentration fluctuation dissipation time scale and the maximum individual exposure at short time intervals. For the estimation of travel time in the Eulerian grid the new 'radioactive tracer method' is introduced. The new approaches were incorporated in the CFD code ADREA. The capabilities of the new approaches are validated against the Mock Urban Setting Trial field experiment data under neutral conditions. The comparisons of model and observations gave quite satisfactory results.
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Electron microscopy of atmospheric particles
Huang, Po-Fu
Electron microscopy coupled with energy dispersive spectrometry (EM/EDS) is a powerful tool for single particle analysis. However, the accuracy with which atmospheric particle compositions can be quantitatively determined by EDS is often hampered by substrate-particle interactions, volatilization losses in the low pressure microscope chamber, electron beam irradiation and use of inaccurate quantitation factors. A pseudo-analytical solution was derived to calculate the temperature rise due to the dissipation of the electron energy on a particle-substrate system. Evaporative mass loss for a spherical cap-shaped sulfuric acid particle resting on a thin film supported by a TEM grid during electron beam impingement has been studied. Measured volatilization rates were found to be in very good agreement with theoretical predictions. The method proposed can also be used to estimate the vapor pressure of a species by measuring the decay of X-ray intensities. Several types of substrates were studied. We found that silver-coated silicon monoxide substrates give carbon detection limits comparable to commercially available substrates. An advantage of these substrates is that the high thermal conductivity of the silver reduces heating due to electron beam impingement. In addition, exposure of sulfuric acid samples to ammonia overnight substantially reduces sulfur loss in the electron beam. Use of size-dependent k-factors determined from particles of known compositions shows promise for improving the accuracy of atmospheric particle compositions measured by EM/EDS. Knowledge accumulated during the course of this thesis has been used to analyze atmospheric particles (Minneapolis, MN) selected by the TDMA and collected by an aerodynamic focusing impactor. 'Less' hygroscopic particles, which do not grow to any measurable extent when humidified to ~90% relative humidity, included chain agglomerates, spheres, flakes, and irregular shapes. Carbon was the predominant element detected in
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Performance Analysis of M-atmospheric FSO Links
DEFF Research Database (Denmark)
Lopez-Gonzalez, Francisco J.; Garrido-Balsellss, José María; Jurado-Navas, Antonio
2016-01-01
In this paper, a generalization of the Málaga atmospheric optical communications links treated as a finite number of Generalized-K distributed sub-channels is analyzed in terms of the average bit error rate and outage probability....
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Appenzeller, Brice M R; Hardy, Emilie M; Grova, Nathalie; Chata, Caroline; Faÿs, François; Briand, Olivier; Schroeder, Henri; Duca, Radu-Corneliu
2017-08-01
Urine and plasma have been used to date for the biomonitoring of exposure to pollutants and are still the preferred fluids for this purpose; however, these fluids mainly provide information on the short term and may present a high level of variability regarding pesticide concentrations, especially for nonpersistent compounds. Hair analysis may provide information about chronic exposure that is averaged over several months; therefore, this method has been proposed as an alternative to solely relying on these fluids. Although the possibility of detecting pesticides in hair has been demonstrated over the past few years, the unknown linkage between exposure and pesticides concentration in hair has limited the recognition of this matrix as a relevant tool for assessing human exposure. Based on a rat model in which there was controlled exposure to a mixture of pesticides composed of lindane, β-hexachlorocyclohexane, β-endosulfan, p,p'-DDT, p,p'-DDE, dieldrin, pentachlorophenol, diazinon, chlorpyrifos, cyhalothrin, permethrin, cypermethrin, propiconazole, fipronil, oxadiazon, diflufenican, trifluralin, carbofuran, and propoxur, the current work demonstrates the association between exposure intensity and resulting pesticide concentration in hair. We also compared the results obtained from a hair analysis to urine and plasma collected from the same rats. Hair, blood, and urine were collected from rats submitted to 90-day exposure by gavage to the aforementioned mixture of common pesticides at different levels. We observed a linear relationship between exposure intensity and the concentration of pesticides in the rats' hair (R Pearson 0.453-0.978, p pesticide concentrations in the matrix. Therefore, this study strongly supports hair analysis as a reliable tool to be used during epidemiological studies to investigate exposure-associated adverse health effects.
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Irreversible adsorption of atmospheric helium on olivine: A lobster pot analogy
Protin, Marie; Blard, Pierre-Henri; Marrocchi, Yves; Mathon, François
2016-04-01
This study reports new experimental results that demonstrate that large amounts of atmospheric helium may be adsorbed onto the surfaces of olivine grains. This behavior is surface-area-related in that this contamination preferentially affects grains that are smaller than 125 μm in size. One of the most striking results of our study is that in vacuo heating at 900 °C for 15 min is not sufficient to completely remove the atmospheric contamination. This suggests that the adsorption of helium may involve high-energy trapping of helium through irreversible anomalous adsorption. This trapping process of helium can thus be compared to a ;lobster pot; adsorption: atmospheric helium easily gets in, but hardly gets out. While this type of behavior has previously been reported for heavy noble gases (Ar, Kr, Xe), this is the first time that it has been observed for helium. Adsorption of helium has, until now, generally been considered to be negligible on silicate surfaces. Our findings have significant implications for helium and noble gas analysis of natural silicate samples, such as for cosmic-ray exposure dating or noble gas characterization of extraterrestrial material. Analytical procedures in future studies should be adapted in order to avoid this contamination. The results of this study also allow us to propose an alternative explanation for previously described matrix loss of cosmogenic 3He.
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Pujol, M.; Marty, B.; Burnard, P.; Hofmann, A.
2012-12-01
The initial atmospheric xenon isotopic composition has been much debated over the last 4 decades. A Non radiogenic Earth Atmospheric xenon (NEA-Xe) composition has been proposed to be the best estimate of the initial signature ([1]). NEA-Xe consists of modern atmospheric Xe without fission (131-136Xe) or radioactive decay (129Xe) products. However, the isotope composition of such non-radiogenic xenon is very different to that of potential cosmochemical precursors such as solar or meteoritic Xe, as it is mass-fractionated by up to 3-4 % per amu relative to the potential precursors, and it is also elementally depleted relative to other noble gases. Because the Xe isotopic composition of the Archean appears to be intermediate between that of these cosmochemical end-members and that of the modern atmosphere, we argued that isotopic fractionation of atmospheric xenon did not occur early in Earth's history by hydrodynamic escape, as postulated by all other models ([1], [2], [3]), but instead was a continuous, long term process that lasted during at least the Hadean and Archean eons. Taken at face value, the decrease of the Xe isotopic fractionation from 1.6-2.1 % amu-1 3.5 Ga ago ([4]) to 1 % amu-1 3.0 Ga ago (Ar-Ar age in fluid inclusions trapped in quartz from the same Dresser Formation, [5]) could reflect a secular variation of the atmospheric Xe signature. Nevertheless, up until now, all data showing an isotopic mass fractionation have been measured in rocks and fluids from the same formation (Dresser Formation, Western Australia, aged 3.5 Ga), and have yet to be confirmed in rocks from different locations. In order to better constrain xenon isotopic fractionation of the atmosphere through time, we decided to analyze barites from different ages, geological environments and metamorphism grade. We started this study with barite from the Fig Tree Formation (South Africa, aged 3.26 Ga). This barite was sampled in old mines so have negligible modern exposure time. It is
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Atmospheric corrosion of metals in industrial city environment
Directory of Open Access Journals (Sweden)
Elzbieta Kusmierek
2015-06-01
Full Text Available Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust.
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Study on influence of native oxide and corrosion products on atmospheric corrosion of pure Al
International Nuclear Information System (INIS)
Liu, Yanjie; Wang, Zhenyao; Ke, Wei
2014-01-01
Highlights: •Corrosion products layer is only formed in coastal atmosphere. •In coastal atmosphere, rate controlling step is diffusion process. •In rural atmosphere, rate controlling step is charge transfer process. •Pitting area increases greatly in coastal site, but slightly in rural site. -- Abstract: Effects of native oxide and corrosion products on atmospheric corrosion of aluminium in rural and coastal sites were studied by electrochemical impedance spectroscopy (EIS), open-circuit potential (OCP) and scanning electron microscope (SEM) techniques after outdoor exposure. In the rural atmosphere, only the compact, adhesive native oxide layer exists, and the rate controlling step is diffusion process, while in the coastal atmosphere, another loose, inadhesive corrosion products layer exists, and a charge transfer process controls the corrosion process. The pitting area in the coastal atmosphere increases over time more obviously than that in the rural atmosphere
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Mastalerz, Maria; Glikson, M.; Simpson, R.W.
1999-01-01
An increase in participate matter in the atmosphere has been shown to be linked to increased mortality but this relationship is poorly understood. Light microscopy, electron microscopy, electron microprobe, and micro-FTIR techniques have been applied to study atmospheric particulates in Brisbane, Australia as a part of a study on asthma. The particulate matter samples were collected daily from April to August 1992, and the sampling covered the autumn period which is typically a time of high asthma incidence in Brisbane. Volumetrically, most atmospheric particulate matter is less than 2 ??m in size. The microscopic analysis reveals that this material is composed mainly of combusted and incompletely burned hydrocarbons from motor vehicle exhaust emissions, quiescent spores of Mucorales, soil bacteria, and inorganic matter in the form of quartz and other silicates. Elemental and functional group analyses confirm microscope identification, documenting carbon-rich, aromatic exhaust material, more aliphatic pollen and spore material and inorganic matter. Fungal spores dominate bioaerosol and are very abundant from the end of April through May to mid-June. The cytoplasmic content of pollens or fungal spores is commonly regarded as allergenic. Particulates from the exhaust emissions and crustal material in a sub-micrometer size range may act as carriers or dispersive mechanisms for cytoplasmic material from fungal spores and pollens, perhaps causing periods of the highest exhaust emission to be the most allergenic. ?? 1998 Elsevier Science B.V. All rights reserved.
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Ustinov, E.
1999-01-01
Sensitivity analysis based on using of the adjoint equation of radiative transfer is applied to the case of atmospheric remote sensing in the thermal spectral region with non-negligeable atmospheric scattering.
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Real-Time Aircraft Cosmic Ray Radiation Exposure Predictions from the NAIRAS Model
Mertens, C. J.; Tobiska, W.; Kress, B. T.; Xu, X.
2012-12-01
The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. There is also interest in extending NAIRAS to the LEO environment to address radiation hazard issues for the emerging commercial spaceflight industry. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. Real-time observations are required at a variety of locations within the geospace environment. The NAIRAS model is driven by real-time input data from ground-, atmospheric-, and space-based platforms. During the development of the NAIRAS model, new science questions and observational data gaps were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. The focus of this talk is to present the current capabilities of the NAIRAS model, discuss future developments in aviation radiation modeling and instrumentation, and propose strategies and methodologies of bridging known gaps in current modeling and observational capabilities.
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Buying atmosphere in the selected retail unit
GOLKOVÁ, Iveta
2013-01-01
Diploma thesis deals with analysis of the shopping atmosphere of selected retail unit depending on its main objective. In the first part of the thesis - literary research - the theoretical background of the issue is processed. The second part - own work - already deals with the analysis. Retail unit Tesco České Budějovice was chosen for the analysis and a description of its shopping atmosphere is included in the work. The main method of analysis was an on-line questionnaire survey which was c...
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Valentin, J. R.
1989-01-01
-Cassini entry probe, which is being jointly planned by NASA and the European Space Agency (ESA), might be launched as early as 1994. As in the Pioneer mission, limited time--perhaps only 3-4 h--will be available for the completion of all analyses while the probe descends through the atmosphere. A conventional GC or GC-MS system would be able to analyze no more than two aerosol and two gas samples during the probe's descent. Conventional GC also is limited by the sensitivity of the detector and by the sample volume. For the Titan mission, the sensitivity problems will be worse because the atmospheric pressure at the time of instrument deployment is expected to be of such limitations, alternative GC analysis techniques have been investigated for future NASA missions. Multiplex gas chromatography has been investigated as a possible candidate for chemical analysis within a spacecraft or other restricted environment, and chemical modulators have been developed and used when needed with this technique to reduce the size and weight of the instrumentation. Also, several new multiplex techniques have been developed for use in specific applications.
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FAULT TREE ANALYSIS FOR EXPOSURE TO REFRIGERANTS USED FOR AUTOMOTIVE AIR CONDITIONING IN THE U.S.
A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servic...
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Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers.
Chang, Ellen T; Delzell, Elizabeth
2016-01-01
This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0-1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0-1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7-1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6-1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC.
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Energy Technology Data Exchange (ETDEWEB)
Frome, EL
2005-09-20
Environmental exposure measurements are, in general, positive and may be subject to left censoring; i.e,. the measured value is less than a ''detection limit''. In occupational monitoring, strategies for assessing workplace exposures typically focus on the mean exposure level or the probability that any measurement exceeds a limit. Parametric methods used to determine acceptable levels of exposure, are often based on a two parameter lognormal distribution. The mean exposure level, an upper percentile, and the exceedance fraction are used to characterize exposure levels, and confidence limits are used to describe the uncertainty in these estimates. Statistical methods for random samples (without non-detects) from the lognormal distribution are well known for each of these situations. In this report, methods for estimating these quantities based on the maximum likelihood method for randomly left censored lognormal data are described and graphical methods are used to evaluate the lognormal assumption. If the lognormal model is in doubt and an alternative distribution for the exposure profile of a similar exposure group is not available, then nonparametric methods for left censored data are used. The mean exposure level, along with the upper confidence limit, is obtained using the product limit estimate, and the upper confidence limit on an upper percentile (i.e., the upper tolerance limit) is obtained using a nonparametric approach. All of these methods are well known but computational complexity has limited their use in routine data analysis with left censored data. The recent development of the R environment for statistical data analysis and graphics has greatly enhanced the availability of high-quality nonproprietary (open source) software that serves as the basis for implementing the methods in this paper.
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International Nuclear Information System (INIS)
Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin; Choi, Eun Jin
2015-01-01
Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y -1 ). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of
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Energy Technology Data Exchange (ETDEWEB)
Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of); Choi, Eun Jin [Dept. of Public Health and Medicine, Dongshin University, Naju (Korea, Republic of)
2015-02-15
Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y{sup -1}). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of
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Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth
International Nuclear Information System (INIS)
Shepherd, Thomas J.; Dirks, Wendy; Roberts, Nick M.W.; Patel, Jaiminkumar G.; Hodgson, Susan; Pless-Mulloli, Tanja; Walton, Pamela; Parrish, Randall R.
2016-01-01
We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and 208 Pb/ 206 Pb, 207 Pb/ 206 Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5–8 years, living in NE England. By integrating the isotope data with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2–3 years for molars, first 1–2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2 µg Pb/g) with 208 Pb/ 206 Pb (mean ±2σ: 2.126–2.079) 208 Pb/ 206 Pb (mean ±2σ: 0.879–0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM 10 , PM 2.5 ) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4 µgPb/g) with 208 Pb/ 206 Pb (mean ±2σ: 2.145–2.117) 208 Pb/ 206 Pb (mean ±2σ: 0.898–0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1–2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood changes in the isotope composition of blood Pb. Our pilot
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International Nuclear Information System (INIS)
Yoshida, Tomio; Yoneyama, Tadakatsu.
1980-01-01
Atmospheric nitrogen fixation in the rice rhizosphere was determined under in situ conditions of growing flooded rice using the N-15 isotope method. The whole plant growing in a pot at a reproductive stage was placed in a specially designed glass container and exposed to a 15 N 2 atmosphere. The amounts of total nitrogen fixed in the rice rhizosphere under the experimental conditions were 1366, 592, 878, and 698 μg per pot containing 0.4 kg of soil during 15 N 2 exposure for 7 to 13 days in the four experiments conducted in this study. It was also found that the nitrogen fixed in the rice rhizosphere was translocated into other plant parts. Nineteen to 25% of the total atmospheric nitrogen fixed in the rice rhizosphere was found in the roots, leaves and stems, and ears of the rice plants during the 15 N 2 exposure period. (author)
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International Nuclear Information System (INIS)
Gonzalez, J. A.; Escudero, E.; Lopez, V.; Simancas, J.; Morcillo, M.
2004-01-01
The behaviour of bare aluminium is studied in atmospheric exposure at 11 natural testing stations with salinity levels ranging between 2.1 and 684 mg Cl''- m''-2 d''-1. In atmospheres of low or moderate aggressivity aluminium behaves as a passive material, though the insignificant corrosion that is produced is sufficient to spoil its appearance. In contrast, at salinity levels of 50 mg Cl''- m''-2 ''-1 or above, aluminium is susceptible to pitting corrosion even in the first year of atmospheric exposure, or in the second year at salinities of ≤ 10 mg Cl''- m''-2 d''-1. For comparative purposes, results are included for aluminium protected with an anodic film of 28 μm thickness exposed at the same testing stations. A 28 μm anodic film, correctly sealed, prevents the risk of localised corrosion even in the most unfavourable situations. (Author) 23 refs
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Atmospheric pollution and human reproduction: Report on the Munich International Workshop
Czech Academy of Sciences Publication Activity Database
Slama, R.; Darrow, L.; Parker, J.; Woodruff, T.J.; Strickland, M.; Nieuwenhuijsen, M.; Glinianaia, S.; Hoggatt, J.; Kannan, S.; Hurley, K.; Kalinka, J.; Šrám, Radim; Brauer, M.; Wilhelm, M.; Heinrich, J.; Ritz, B.
2008-01-01
Roč. 116, č. 6 (2008), s. 791-798 ISSN 0091-6765 Institutional research plan: CEZ:AV0Z50390512 Keywords : Atmospheric pollution * Birth weight * Exposure assessment Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 6.123, year: 2008
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International Nuclear Information System (INIS)
Wang, Y.; Rawat, R.S.; Bisht, A.
2013-01-01
A pre-annealing atmospheric pulsed laser exposure was applied to decrease the phase transition (from chemically disordered A1 phase to chemically ordered L1 0 phase) temperature of FePt nano-particles on a Si (100) substrate. Different pre-annealing laser energy densities of 0.024 and 0.079 J/cm2 were utilized to expose the pulsed laser deposition (PLD) FePt thin film samples under atmospheric conditions. Subsequently, FePt thin film samples were annealed at different temperatures of 300 and 400 ºC to observe the influence of laser exposure on the phase transition temperature. The phase transition temperature was decreased from conventional 600 ºC to 400 ºC by one shot pre-annealing atmospheric pulsed laser exposure. (author)
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International Nuclear Information System (INIS)
Gudiksen, P.H.; Sullivan, T.J.; Harvey, T.F.
1986-10-01
The Atmospheric Release Advisory Capability (ARAC) project, developed by the Lawrence Livermore National Laboratory (LLNL), provides real-time dose assessments and estimates of the extent of surface contamination that may result from an atmospheric release of radioactivity. It utilizes advanced computer-based data communication and processing systems to acquire the meteorological and source term information needed by the three-dimensional atmospheric dispersion models to derive the consequence assessments. The ARAC responded to the recent Chernobyl reactor accident in the Soviet Union by estimating the source term and the radiation dose distribution due to exposure to the radioactive cloud over Europe and the Northern Hemisphere. This analysis revealed that approximately 50% of the estimated core inventories of I-131 and Cs-137 were released. The estimated committed effective dose equivalent due to inhalation of radioactivty during cloud passage is of the order of 10 mrem within parts of Scandinavia and eastern Europe, while most of the populations within central Europe were exposed to levels ranging from 1 to 10 mrem. The amount of Cs-137 released by the Chernobyl accident far exceeds that released by previous reactor accidents, but is only about 6% of the Cs-137 produced by the atmospheric weapon testing programs. 9 refs., 4 figs., 2 tabs
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Noble gases in Mars atmosphere: new precise analysis with Paloma
Sarda, Ph.; Paloma Team
2003-04-01
The Viking mission embarked a mass spectrometer designed by Alfred O. Nier that yielded the first determination of the elemental and isotopic composition of noble gases in Mars atmosphere. For example, the 40Ar/36Ar ratio in martian air is roughly 10 fold that in terrestrial air. This extraordinary accomplishment, however, has furnished only partial results with large analytical uncertainties. For example, we do not know the isotopic composition of helium, and only very poorly that of Ne, Kr and Xe. In planetary science, it is fundamental to have a good knowledge of the atmosphere because this serves as a reference for all further studies of volatiles. In addition, part of our present knowledge of Mars atmosphere is based on the SNC meteorites, and again points to important differences between the atmospheres of Earth and Mars. For example the 129Xe/132Xe ratio of martian atmosphere would be twice that of terrestrial air and the 36Ar/38Ar ratio strongly different from the terrestrial or solar value. There is a need for confirming that the atmospheric components found in SNC meteorites actually represents the atmosphere of Mars, or to determine how different they are. Paloma is an instrument designed to generate elemental and isotopic data for He, Ne, Ar, Kr and Xe (and other gases) using a mass spectrometer with a purification and separation line. Gas purification and separation did not exist on the Vicking instrument. Because Paloma includes purification and separation, we expect strong improvement in precision. Ne, Ar and Xe isotope ratios should be obtained with an accuracy of better than 1%. Determination of the presently unknown ^3He/^4He ratio is also awaited from this experiment. Knowledge of noble gas isotopes in Mars atmosphere will allow some insight into major planetary processes such as degassing (^3He/^4He, 40Ar/36Ar, 129Xe/130Xe, 136Xe/130Xe), gravitational escape to space (^3He/^4He, 20Ne/22Ne), hydrodynamic escape and/or impact erosion of the
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Hayashi, H.; Tanaka, Y.; Hori, T.; Koyama, Y.; Shinbori, A.; Abe, S.; Kagitani, M.; Kouno, T.; Yoshida, D.; Ueno, S.; Kaneda, N.; Yoneda, M.; Tadokoro, H.; Motoba, T.; Umemura, N.; Iugonet Project Team
2011-12-01
The Inter-university Upper atmosphere Global Observation NETwork (IUGONET) is a Japanese inter-university project by the National Institute of Polar Research (NIPR), Tohoku University, Nagoya University, Kyoto University, and Kyushu University to build a database of metadata for ground-based observations of the upper atmosphere. The IUGONET institutes/universities have been collecting various types of data by radars, magnetometers, photometers, radio telescopes, helioscopes, etc. at various locations all over the world and at various altitude layers from the Earth's surface to the Sun. The metadata database will be of great help to researchers in efficiently finding and obtaining these observational data spread over the institutes/universities. This should also facilitate synthetic analysis of multi-disciplinary data, which will lead to new types of research in the upper atmosphere. The project has also been developing a software to help researchers download, visualize, and analyze the data provided from the IUGONET institutes/universities. The metadata database system is built on the platform of DSpace, which is an open source software for digital repositories. The data analysis software is written in the IDL language with the TDAS (THEMIS Data Analysis Software suite) library. These products have been just released for beta-testing.
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The effect of meteorological data on atmospheric pressure loading corrections in VLBI data analysis
Balidakis, Kyriakos; Glaser, Susanne; Karbon, Maria; Soja, Benedikt; Nilsson, Tobias; Lu, Cuixian; Anderson, James; Liu, Li; Andres Mora-Diaz, Julian; Raposo-Pulido, Virginia; Xu, Minghui; Heinkelmann, Robert; Schuh, Harald
2015-04-01
Earth's crustal deformation is a manifestation of numerous geophysical processes, which entail the atmosphere and ocean general circulation and tidal attraction, climate change, and the hydrological circle. The present study deals with the elastic deformations induced by atmospheric pressure variations. At geodetic sites, APL (Atmospheric Pressure Loading) results in displacements covering a wide range of temporal scales which is undesirable when rigorous geodetic/geophysical analysis is intended. Hence, it is of paramount importance that the APL signal are removed at the observation level in the space geodetic data analysis. In this study, elastic non-tidal components of loading displacements were calculated in the local topocentric frame for all VLBI (Very Long Baseline Interferometry) stations with respect to the center-of-figure of the solid Earth surface and the center-of-mass of the total Earth system. The response of the Earth to the load variation at the surface was computed by convolving Farrell Green's function with the homogenized in situ surface pressure observations (in the time span 1979-2014) after the subtraction of the reference pressure and the S1, S2 and S3 thermal tidal signals. The reference pressure was calculated through a hypsometric adjustment of the absolute pressure level determined from World Meteorological Organization stations in the vicinity of each VLBI observatory. The tidal contribution was calculated following the 2010 International Earth Rotation and Reference Systems Service conventions. Afterwards, this approach was implemented into the VLBI software VieVS@GFZ and the entirety of available VLBI sessions was analyzed. We rationalize our new approach on the basis that the potential error budget is substantially reduced, since several common errors are not applicable in our approach, e.g. those due to the finite resolution of NWM (Numerical Weather Models), the accuracy of the orography model necessary for adjusting the former as
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Atmosphere Processing Module Automation and Catalyst Durability Analysis for Mars ISRU Pathfinder
Petersen, Elspeth M.
2016-01-01
The Mars In-Situ Resource Utilization Pathfinder was designed to create fuel using components found in the planet’s atmosphere and regolith for an ascension vehicle to return a potential sample return or crew return vehicle from Mars. The Atmosphere Processing Module (APM), a subunit of the pathfinder, uses cryocoolers to isolate and collect carbon dioxide from Mars simulant gas. The carbon dioxide is fed with hydrogen into a Sabatier reactor where methane is produced. The APM is currently undergoing the final stages of testing at Kennedy Space Center prior to process integration testing with the other subunits of the pathfinder. The automation software for the APM cryocoolers was tested and found to perform nominally. The catalyst used for the Sabatier reactor was investigated to determine the factors contributing to catalyst failure. The results from the catalyst testing require further analysis, but it appears that the rapid change in temperature during reactor start up or the elevated operating temperature is responsible for the changes observed in the catalyst.
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Atmospheric mercury dispersion modelling from two nearest hypothetical point sources
Energy Technology Data Exchange (ETDEWEB)
Al Razi, Khandakar Md Habib; Hiroshi, Moritomi; Shinji, Kambara [Environmental and Renewable Energy System (ERES), Graduate School of Engineering, Gifu University, Yanagido, Gifu City, 501-1193 (Japan)
2012-07-01
The Japan coastal areas are still environmentally friendly, though there are multiple air emission sources originating as a consequence of several developmental activities such as automobile industries, operation of thermal power plants, and mobile-source pollution. Mercury is known to be a potential air pollutant in the region apart from SOX, NOX, CO and Ozone. Mercury contamination in water bodies and other ecosystems due to deposition of atmospheric mercury is considered a serious environmental concern. Identification of sources contributing to the high atmospheric mercury levels will be useful for formulating pollution control and mitigation strategies in the region. In Japan, mercury and its compounds were categorized as hazardous air pollutants in 1996 and are on the list of 'Substances Requiring Priority Action' published by the Central Environmental Council of Japan. The Air Quality Management Division of the Environmental Bureau, Ministry of the Environment, Japan, selected the current annual mean environmental air quality standard for mercury and its compounds of 0.04 ?g/m3. Long-term exposure to mercury and its compounds can have a carcinogenic effect, inducing eg, Minamata disease. This study evaluates the impact of mercury emissions on air quality in the coastal area of Japan. Average yearly emission of mercury from an elevated point source in this area with background concentration and one-year meteorological data were used to predict the ground level concentration of mercury. To estimate the concentration of mercury and its compounds in air of the local area, two different simulation models have been used. The first is the National Institute of Advanced Science and Technology Atmospheric Dispersion Model for Exposure and Risk Assessment (AIST-ADMER) that estimates regional atmospheric concentration and distribution. The second is the Hybrid Single Particle Lagrangian Integrated trajectory Model (HYSPLIT) that estimates the atmospheric
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Energy Technology Data Exchange (ETDEWEB)
Cushman, R.M.
2001-11-15
The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO{sub 2}) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO{sub 2} and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO{sub 2} on vegetation; and the vulnerability of coastal areas to rising sea levels.
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The use of caffeine to assess high dose exposures to ionising radiation by dicentric analysis
International Nuclear Information System (INIS)
Pujol, M.; Puig, R.; Caballin, M. R.; Barrios, L.; Barquinero, J. F.
2012-01-01
Dicentric analysis is considered as a 'gold standard' method for biological dosimetry. However, due to the radiation-induced mitotic delay or inability to reach mitosis of heavily damaged cells, the analysis of dicentrics is restricted to doses up to 4-5 Gy. For higher doses, the analysis by premature chromosome condensation technique has been proposed. Here, it is presented a preliminary study is presented in which an alternative method to analyse dicentrics after high dose exposures to ionising radiation (IR) is evaluated. The method is based on the effect of caffeine in preventing the G2/M checkpoint allowing damaged cells to reach mitosis. The results obtained indicate that the co-treatment with Colcemide and caffeine increases significantly increases the mitotic index, and hence allows a more feasible analysis of dicentrics. Moreover in the dose range analysed, from 0 to 15 Gy, the dicentric cell distribution followed the Poisson distribution, and a simulated partial-body exposure has been clearly detected. Overall, the results presented here suggest that caffeine has a great potential to be used for dose-assessment after high dose exposure to IR. (authors)
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Manganese in exhaled breath condensate: a new marker of exposure to welding fumes.
Hulo, Sébastien; Chérot-Kornobis, Nathalie; Howsam, Mike; Crucq, Sébastien; de Broucker, Virginie; Sobaszek, Annie; Edme, Jean-Louis
2014-04-07
To evaluate manganese in exhaled breath condensate (Mn-EBC) as an indicator of exposure to fumes from metal inert gas welding process. We collected EBC and urine from 17 welders and 16 unexposed control subjects after 5 days exposure. Concentrations of manganese (Mn), nickel (Ni), iron (Fe) and chromium (Cr) were measured in EBC and urine samples and correlated with cumulative exposure indices for the working week (CIW) and for the total welding years (WY), based on duration of welding activity and atmospheric metal measurements. Concentrations of Mn and Ni in EBC were significantly higher among welders than controls whereas this difference was not significant for Mn in urine. Levels of Mn and Ni in EBC were not correlated with their respective levels in urine. The linear regressions found significant positive coefficients between Mn-EBC, Ni-EBC, Ni-U and Cr-U concentrations and the cumulative exposure indices. Taking into account tobacco use, statistical analysis showed the same trends except for the relationship between Mn-U and CIW. This pilot study showed that Mn-EBC, as well as Ni-EBC, can serve as reliable indices of occupational exposure to welding fumes and provide complimentary toxicokinetic information to that provided by urine analyses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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Atmospheric stability analysis and its relationship with the atmospheric pollution in Salamanca
International Nuclear Information System (INIS)
Fidalgo, M.R.; Garmendia, J.
1989-01-01
In this paper we have studied the relationship between the sulphur dioxide and suspended particulate matter concentrations and the atmospheric stability in Salamanca over 4 year (1978-1982). Of the various indices cited in the bibliography for estimating stratification stability, two were used. First, the Pasquill categories and later a method based on Montgomery's potential, which was the one that gave the best results. (Author)
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Sampling Ozone Exposure of Canadian Forests at Different Scales: Some Case Studies
Directory of Open Access Journals (Sweden)
R.M. Cox
2001-01-01
Full Text Available The use of passive samplers in extensive monitoring, such as that used in national forest health monitoring plots, indicates that these devices are able to determine both spatial and temporal differences in ozone exposure of the plots. This allows for categorisation of the plots and the potential for cause-effect analysis of certain forest health responses. Forest exposure along a gradient of air pollution deposition demonstrates large variation in accumulated exposures. The efficacy of using passive samplers for in situ monitoring of forest canopy exposure was also demonstrated. The sampler data produced weak relationships with ozone values from the nearest �continuous� monitor, even though data from colocated samplers showed strong relationships. This spatial variation and the apparent effect of elevation on ozone exposure demonstrate the importance of topography and tree canopy characteristics in plant exposure on a regional scale. In addition, passive sampling may identify the effects of local pollutant gases, such as NO, which may scavenge ozone locally only to increase the production of this secondary pollutant downwind, as atmospheric reactions redress the equilibrium between concentrations of this precursor and those of the generated ozone. The use of passive samplers at the stand level is able to resolve vertical profiles within the stand and edge effects that are important in exposure of understorey and ground flora. Recent case studies using passive samplers to determine forest exposure to ozone indicate a great potential for the development of spatial models on a regional, landscape, and stand level scale.
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Naphthalene and Naphthoquinone: Distributions and Human Exposure in the Los Angeles Basin
Lu, R.; Wu, J.; Turco, R.; Winer, A. M.; Atkinson, R.; Paulson, S.; Arey, J.; Lurmann, F.
2003-12-01
Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons (PAHs). Naphthalene is found primarily in the gas-phase and has been detected in both outdoor and indoor samples. Evaporation from naphthalene-containing products (including gasoline), and during refining operations, are important sources of naphthalene in air. Naphthalene is also emitted during the combustion of fossil fuels and wood, and is a component of vehicle exhaust. Exposure to high concentrations of naphthalene can damage or destroy red blood cells, causing hemolytic anemia. If inhaled over a long period of time, naphthalene may cause kidney and liver damage, skin allergy and dermatitis, cataracts and retinal damage, as well as attack the central nervous system. Naphthalene has been found to cause cancer as a result of inhalation in animal tests. Naphthoquinones are photooxidation products of naphthalene and the potential health effects of exposure to these quinones are a current focus of research. We are developing and applying models that can be used to assess human exposure to naphthalene and its photooxidation products in major air basins such as California South Coast Air Basin (SoCAB). The work utilizes the Surface Meteorology and Ozone Generation (SMOG) airshed model, and the REgional Human EXposure (REHEX) model, including an analysis of individual exposure. We will present and discuss simulations of basin-wide distributions of, and human exposures to, naphthalene and naphthoquinone, with emphasis on the uncertainties in these estimates of atmospheric concentrations and human exposure. Regional modeling of pollutant sources and exposures can lead to cost-effective and optimally health-protective emission control strategies.
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Alif, Sheikh M; Dharmage, Shyamali C; Bowatte, Gayan; Karahalios, Amalia; Benke, Geza; Dennekamp, Martine; Mehta, Amar J; Miedinger, David; Künzli, Nino; Probst-Hensch, Nicole; Matheson, Melanie C
2016-08-01
Due to contradictory literature we have performed a systematic review and meta-analyse of population-based studies that have used Job Exposure Matrices to assess occupational exposure and risk of Chronic Obstructive Pulmonary Disease (COPD). Two researchers independently searched databases for published articles using predefined inclusion criteria. Study quality was assessed, and results pooled for COPD and chronic bronchitis for exposure to biological dust, mineral dust, and gases/fumes using a fixed and random effect model. Five studies met predetermined inclusion criteria. The meta-analysis showed low exposure to mineral dust, and high exposure to gases/fumes were associated with an increased risk of COPD. We also found significantly increased the risk of chronic bronchitis for low and high exposure to biological dust and mineral dust. Expert commentary: The relationship between occupational exposure assessed by the JEM and the risk of COPD and chronic bronchitis shows significant association with occupational exposure. However, the heterogeneity of the meta-analyses suggests more wide population-based studies with older age groups and longitudinal phenotype assessment of COPD to clarify the role of occupational exposure to COPD risk.
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Directory of Open Access Journals (Sweden)
Myrna J. Simpson
2013-08-01
Full Text Available 1H NMR-based metabolomics was used to measure the response of Eisenia fetida earthworms after exposure to sub-lethal concentrations of perfluorooctane sulfonate (PFOS in soil. Earthworms were exposed to a range of PFOS concentrations (five, 10, 25, 50, 100 or 150 mg/kg for two, seven and fourteen days. Earthworm tissues were extracted and analyzed by 1H NMR. Multivariate statistical analysis of the metabolic response of E. fetida to PFOS exposure identified time-dependent responses that were comprised of two separate modes of action: a non-polar narcosis type mechanism after two days of exposure and increased fatty acid oxidation after seven and fourteen days of exposure. Univariate statistical analysis revealed that 2-hexyl-5-ethyl-3-furansulfonate (HEFS, betaine, leucine, arginine, glutamate, maltose and ATP are potential indicators of PFOS exposure, as the concentrations of these metabolites fluctuated significantly. Overall, NMR-based metabolomic analysis suggests elevated fatty acid oxidation, disruption in energy metabolism and biological membrane structure and a possible interruption of ATP synthesis. These conclusions obtained from analysis of the metabolic profile in response to sub-lethal PFOS exposure indicates that NMR-based metabolomics is an excellent discovery tool when the mode of action (MOA of contaminants is not clearly defined.
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Tong, Shu-Hui; Liu, Yi-Ting; Liu, Yang
2013-02-01
To investigate the association between paternal exposure to occupational electromagnetic radiation and the sex ratio of the offspring. We searched various databases, including PubMed, Embase, Cochrane Library, OVID, Bioscience Information Service (BIOSIS), China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals and Wanfang Database, for the literature relevant to the association of paternal exposure to occupational electromagnetic radiation with the sex ratio of the offspring. We conducted a meta-analysis on their correlation using Stata 11.0. There was no statistically significant difference in the sex ratio between the offspring with paternal exposure to occupational electromagnetic radiation and those without (pooled OR = 1.00 [95% CI: 0.95 -1.05], P = 0.875). Subgroup analysis of both case-control and cohort studies revealed no significant difference (pooled OR = 1.03 [95% CI: 0.99 -1.08], P = 0.104 and pooled OR = 0.98 [95% CI: 0.99 -1.08], P = 0.186, respectively). Paternal exposure to occupational electromagnetic radiation is not correlated with the sex ratio of the offspring.
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Improvement of the CULTEX® exposure technology by radial distribution of the test aerosol.
Aufderheide, Michaela; Heller, Wolf-Dieter; Krischenowski, Olaf; Möhle, Niklas; Hochrainer, Dieter
2017-07-05
The exposure of cellular based systems cultivated on microporous membranes at the air-liquid interface (ALI) has been accepted as an appropriate approach to simulate the exposure of cells of the respiratory tract to native airborne substances. The efficiency of such an exposure procedure with regard to stability and reproducibility depends on the optimal design at the interface between the cellular test system and the exposure technique. The actual exposure systems favor the dynamic guidance of the airborne substances to the surface of the cells in specially designed exposure devices. Two module types, based on a linear or radial feed of the test atmosphere to the test system, were used for these studies. In our technical history, the development started with the linear designed version, the CULTEX ® glass modules, fulfilling basic requirements for running ALI exposure studies (Mohr and Durst, 2005). The instability in the distribution of different atmospheres to the cells caused us to create a new exposure module, characterized by a stable and reproducible radial guidance of the aerosol to the cells. The outcome was the CULTEX ® RFS (Mohr et al., 2010). In this study, we describe the differences between the two systems with regard to particle distribution and deposition clarifying the advantages and disadvantages of a radial to a linear aerosol distribution concept. Copyright © 2017 Elsevier GmbH. All rights reserved.
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PIXE Analysis of Atmospheric Aerosol Samples Collected in the Adirondack Mountains
Yoskowitz, Josh; Ali, Salina; Nadareski, Benjamin; Safiq, Alexandrea; Smith, Jeremy; Labrake, Scott; Vineyard, Michael
2013-10-01
We have performed an elemental analysis of atmospheric aerosol samples collected at Piseco Lake in Upstate New York using proton induced x-ray emission spectroscopy (PIXE). This work is part of a systematic study of airborne pollution in the Adirondack Mountains. Of particular interest is the sulfur content that can contribute to acid rain, a well-documented problem in the Adirondacks. We used a nine-stage cascade impactor to collect the samples and distribute the particulate matter onto Kapton foils by particle size. The PIXE experiments were performed with 2.2-MeV proton beams from the 1.1-MV pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. X-Ray energy spectra were measured with a silicon drift detector and analyzed with GUPIX software to determine the elemental concentrations of the aerosols. A broad range of elements from silicon to zinc were detected with significant sulfur concentrations measured for particulate matter between 0.25 and 0.5 μm in size. The PIXE analysis will be described and preliminary results will be presented.
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Lung cancer mortality among European rock/slag wool workers: exposure-response analysis.
Consonni, D; Boffetta, P; Andersen, A; Chang-Claude, J; Cherrie, J W; Ferro, G; Frentzel-Beyme, R; Hansen, J; Olsen, J; Plato, N; Westerholm, P; Saracci, R
1998-08-01
The purpose was to analyze the relationship between semi-quantitative indices of exposure to manmade vitreous fibers and lung cancer mortality among European rock/slag wool (RSW) workers. The study population comprised 9,603 male workers employed in RSW production in seven factories in Denmark, Norway, Sweden, and Germany, followed up for mortality as of 1990-91. Estimates of past exposure to respirable fibers were used to calculate cumulative exposure with a 15-year lag and maximum annual exposure based on employment history up to 1977. Rate ratios were estimated via multivariate Poisson regression, adjusting for country, age, calendar year, time since first employment, and employment status. A total of 159 lung cancer deaths were included in the analysis of which 97 among workers with more than one year of employment. We found nonstatistically significant trends in lung cancer risk according to cumulative exposure. Relative risks (RR) in the four quartiles were 1.0 (reference), 1.3 (95 percent confidence interval [CI] = 0.8-2.4), 1.2 (CI = 0.7-2.1), and 1.5 (CI = 0.7-3.0, P test for trend = 0.4). When workers with less than one year of employment were excluded, there was no increased risk; the RRs in the four quartiles were 1.0, 0.9 (CI = 0.4-2.0), 0.8 (CI = 0.3-1.9), and 1.0 (CI = 0.4-2.7). No trend was present according to maximum annual exposure. The results were not consistent among countries. We found a positive association between exposure to respirable fibers and lung cancer mortality. However, the lack of statistical significance, the dependence of the results on inclusion of short-term workers, the lack of consistency among countries, and the possible correlation between exposure to respirable fibers and to other agents reduce the weight of such evidence.
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International Nuclear Information System (INIS)
Rancitelli, L.A.; Tanner, T.M.
1976-01-01
The simultaneous measurement of a wide spectrum of elements in aerosols collected on air filters and in rainwater can yield information on the origin, transport, and removal of atmospheric pollutants. In order to determine the elemental content of these aerosols, a pair of highly sensitive, precise and complementing instrumental techniques, x-ray fluorescence and neutron activation analysis, have been developed and employed. Data are presented on the results of combined x-ray fluorescence and activation analysis of aerosols collected in a number of urban areas of the USA and from the 80th median sampling network in March 1972. From a comparison of these ratios in granite and diabase with those of filters placed in urban areas, it is evident that Zn, Se, Sb, Hg, and Pb levels have been increased by as much as several orders of magnitude. Al, Co, La, Fe, Eu, Sm, Tb, Ta, Hf, and Th appear to exist at levels compatible with an earth's crust origin
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Measurement of atmospheric neutrino composition with the IMB-3 detector
International Nuclear Information System (INIS)
Casper, D.; Becker-Szendy, R.; Bratton, C.B.; Cady, D.R.; Claus, R.; Dye, S.T.; Gajewski, W.; Goldhaber, M.; Haines, T.J.; Halverson, P.G.; Jones, T.W.; Kielczewska, D.; Kropp, W.R.; Learned, J.G.; LoSecco, J.M.; McGrew, C.; Matsuno, S.; Matthews, J.; Mudan, M.S.; Price, L.; Reines, F.; Schultz, J.; Sinclair, D.; Sobel, H.W.; Stone, J.L.; Sulak, L.R.; Svoboda, R.; Thornton, G.; van der Velde, J.C.; The University of Michigan, Ann Arbor, Michigan 48109 Brookhaven National; Laboratory, Upton, New York 11973; Boston University, Boston, Massachusetts 02215; The University of Hawaii, Honolulu, Hawaii 96822 University College, London, WC1E F6BT, United Kingdom; Warsaw University, Warsaw, Poland; Cleveland State University, Cleveland, Ohio 44115; The University of Notre Dame, Notre Dame, Indiana 46556; Lousiana State University, Baton Rouge, Lousisiana 70803; The University of Maryland, College Park, Maryland 20742)
1991-01-01
The atmospheric neutrino flux is measured using a 3.4-kt yr exposure of the IMB-3 detector. Single-ring events are classified as showering or nonshowering using the geometry of the Cerenkov pattern. A simulation of neutrino interactions and three models of atmospheric neutrino production are used to predict the composition of the sample. Showering-nonshowering character is strongly correlated with the flavor of the neutrino parent. In the lepton momentum range p<1500 MeV/c, we find that nonshowering events comprise [41±3±2syst]% of the total. The fraction expected is [51±5(syst)]%
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Energy Technology Data Exchange (ETDEWEB)
Halsey, D.P.; Dews, J.; Harris, F.C. [Wolverhampton Univ. (United Kingdom). School of Construction, Engineering and Technology; Mitchell, D.J. [Wolverhampton Univ. (United Kingdom). School of Applied Sciences
1995-12-31
Due to the urbanisation and industrialisation of the West Midlands, UK, historic sandstone buildings are exposed to atmospheric pollution. In order to assess the impact of this pollution upon their deterioration, chemical analysis of runoff water, from sandstone and control surfaces, has been carried out. The amount of stone affected by atmospheric pollution has been quantified by surveying selected sandstone buildings. (author)
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Energy Technology Data Exchange (ETDEWEB)
Halsey, D P; Dews, J; Harris, F C [Wolverhampton Univ. (United Kingdom). School of Construction, Engineering and Technology; Mitchell, D J [Wolverhampton Univ. (United Kingdom). School of Applied Sciences
1996-12-31
Due to the urbanisation and industrialisation of the West Midlands, UK, historic sandstone buildings are exposed to atmospheric pollution. In order to assess the impact of this pollution upon their deterioration, chemical analysis of runoff water, from sandstone and control surfaces, has been carried out. The amount of stone affected by atmospheric pollution has been quantified by surveying selected sandstone buildings. (author)
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International Nuclear Information System (INIS)
Lunguya, J. M.
2013-06-01
This work presents the environmental impact analysis of some selected radionuclides released from the Ghana Research Reactor- 1 (GHARR-1) after a hypothetical postulated accidents scenario. The source term was identified and generated from an inventory of radioisotopes released during the accident. Atmospheric transport model was then applied to calculate the total effective dose and how it would be distributed to different organs of the human body as a function of distance downwind. All accident scenarios were selected from GHARR-1 Safety Analysis Report. After the source term was identified the MCNPX code was used to perform the core burnup/depletion analysis. The assumption was made that the activities were released to the atmosphere under a horse design basis accident scenario. The gaussian dose calculation method was applied, coded in Hotspot, a Healthy Physics computer code. This served as the computational tool to perform the atmospheric dispersion modeling and was used to calculate radionuclide concentration at downwind location. Based upon predominant meteorological conditions at the site, the adopted strategy was to use site-specific meteorological data and dispersion modeling to analyze the hypothetical release to the environment of radionuclides and evaluate to what extent such a release may have radiological effects on the public. Final data were processed and presented as Total Effective Dose Equivalent as a function of time and distance of deposition. The results indicate that all the values of Effective dose obtained are far below the regulatory limits, making the use of the reactor safe, even in the case of worst accident scenario where all the fission products were released into the atmosphere. (au)
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International Nuclear Information System (INIS)
Palm, Linda Maud Naa-Dedei
2016-07-01
In the pursuit to improve man’s livelihood, human activities which include emission of heavy metals from various industries and sectors, as well as the past use of chemicals such as pesticides, polychlorinated biphenyls and flame retardants have often mobilized and redistributed natural substances and anthropogenic pollutants into the atmosphere, predisposing it to relatively high concentrations of such pollutants even in pristine areas in the environment. This study assessed the level of atmospheric pollution, contributing sources and human health exposure risk of persistent organic pollutants (POPs) along with selected heavy metals with focus on Abetifi, one of the highest altitude environments in Ghana. Passive sampling with polyurethane foam (PUF) as adsorbent was employed. Samplers were deployed every 84 days for two years. A total of 65 polyurethane foams were deployed and twelve (12) groups of analytes were considered together with their various isomers. High resolution gas chromatographic technique coupled with high resolution mass spectrometry (HRGC-HRMS) and electron capture detectors (ECD) were used in the analysis of the POPs. Besides, high performance liquid chromatography (HPLC) coupled with MS was employed in analysing the perfluorinated compounds (PFCs) while the heavy metals were analysed using Atomic Absorption Spectrometer (AAS). Principal Component Analysis (PCA) and UNMIX model were used to group pollution source contribution of all analytes (POPs and heavy metals) in this study. Diagnostic isomer and other predictive ratios were also employed for source apportionment of various individual analyte groups. Results revealed that polychlorinated dibenzo-furans gave with the least total mean concentration (0.074 pg/m"3) for the sampling period and polybrominated biphenyls gave the highest (55 pg/m"3). The pesticide group gave values in the order of DRINs (53 pg/m"3) > DDT (41 pg/m"3) > HCHs (28 pg/m"3). Data for perflourinated compounds (PFCs) in
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Recovering of images degraded by atmosphere
Lin, Guang; Feng, Huajun; Xu, Zhihai; Li, Qi; Chen, Yueting
2017-08-01
Remote sensing images are seriously degraded by multiple scattering and bad weather. Through the analysis of the radiative transfer procedure in atmosphere, an image atmospheric degradation model considering the influence of atmospheric absorption multiple scattering and non-uniform distribution is proposed in this paper. Based on the proposed model, a novel recovering method is presented to eliminate atmospheric degradation. Mean-shift image segmentation and block-wise deconvolution are used to reduce time cost, retaining a good result. The recovering results indicate that the proposed method can significantly remove atmospheric degradation and effectively improve contrast compared with other removal methods. The results also illustrate that our method is suitable for various degraded remote sensing, including images with large field of view (FOV), images taken in side-glance situations, image degraded by atmospheric non-uniform distribution and images with various forms of clouds.
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International Nuclear Information System (INIS)
Peng Shujing; Liu Xiulan; Sun Jie; Gao Zhiqiang; Yao Lan; Qiu Yiping
2010-01-01
This paper studies the influence of moisture absorption of cotton fabrics on the effectiveness of atmospheric pressure plasma jet (APPJ) on desizing of polyvinyl alcohol (PVA). Cotton fabrics with three different moisture regains (MR), namely 1.8%, 7.3%, and 28.4% corresponding to 10%, 65%, and 98% of relative humidity respectively, are treated for 16 s, 32 s, 48 s, and 64 s. X-ray photoelectron spectroscopy analysis indicates that the plasma treated PVA has higher oxygen concentration than the control. Mass loss results show that the fabric with the highest MR has the largest mass loss after 64 s plasma exposure. Solubility measurement reveals that the sample with the lowest MR has the highest desizing efficacy and the percent desizing ratio reaches 96% after 64 s exposure plus a 20 min hot wash, which is shown as clean as the unsized sample through scanning electron microscopy analysis. The yarn tensile strength test results show that APPJ has no negative effect on fabric tensile strength.
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Tritium uptake in cultivated plants after short-term exposure to atmospheric tritium
International Nuclear Information System (INIS)
Diabate, S.; Strack, S.; Paunescu, N.
1998-01-01
The tritium behavior in crop plants is of particular interest for the prediction of doses to humans due to ingestion. Tritium is present in plants in two forms: tritium free water tissue (TWT) and organically bound tritium (OBT). The both forms are to be considered in models calculating the ingestion dose. Potato plants belong to the major food crops in many countries and were chosen as representatives of crops whose edible parts grow under ground. Green bean were chosen as representatives of vegetables relevant in human diet. This vegetable may be consumed as green pod and it may be conserved over a long period of time. Green bean and potato plants were exposed to tritiated water vapor in the atmosphere during their generative phase of development. The uptake of tritium and the conversion into organic matter was studied under laboratory conditions at two different light intensities. The tritium concentrations in plants were followed until harvest. In leaves, the tritium uptake into tissue water under night conditions was 5-6 times lower than under day-time conditions. The initial incorporation into organic matter under night conditions was 0.7% of the tissue water concentration in leaves of both plant species. However, under light irradiation, this value increased to only 1.8% in bean leaves and 0.9% in potato leaves, which indicates a participation of processes other than photosynthesis in tritium incorporation into organic material. Organically bound tritium (OBT) was translocated into pods and tubers which represented a high percentage of the total organically bound tritium at harvest. The behavior of total OBT in all plants under study showed that OBT, once generated, is lost very slowly until harvest, in particular when storage organs of plants were in their phase of development at the time of exposure. OBT is translocated into the storage organs which may be used in the human diet and thus may contribute to the ingestion dose for a long time after the
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Song, Rongjing; Lin, Hepu; Chen, Yue; Zhang, Xiuying
2017-01-01
Objective The aim of this study was to determine the effect of exposure to different antithyroid drugs during pregnancy on the incidence of neonatal congenital malformations. Methods A meta-analysis was performed to compare the incidence of neonatal congenital malformations after exposure to different antithyroid drugs during pregnancy. Twelve studies that met the inclusion criteria were included in this meta-analysis. PubMed, Embase, and CENTRAL databases were searched from inception until January 2017. Study designs included case–control studies, prospective cohort studies, and retrospective cohort studies. Results Twelve studies involving 8028 participants with exposure to different antithyroid drugs during pregnancy were included in this study; however, only 10 studies involving 5059 participants involved exposure to different antithyroid drugs exactly during pregnancy. Our results indicated that exposure to methimazole (MMI)/carbimazole (CMZ) only during pregnancy significantly increased the risk of neonatal congenital malformations compared to no antithyroid drug exposure (OR 1.88; 95%CI 1.33 to 2.65; P = 0.0004). No differences were observed between propylthiouracil (PTU) exposure and no antithyroid drug exposure only during pregnancy (OR 0.81; 95%CI 0.58 to 1.15; P = 0.24). Exposure to MMI/CMZ only during pregnancy significantly increased the risk of neonatal congenital malformations compared to that associated with exposure to PTU (OR 1.90; 95%CI 1.30 to 2.78; P = 0.001). Conclusion For pregnant women with hyperthyroidism, exposure to MMI/CMZ significantly increased the incidence of neonatal congenital malformations compared to exposure to PTU and no antithyroid drug exposure; however, no differences were observed between PTU exposure and no antithyroid drug exposure. PMID:28671971
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Directory of Open Access Journals (Sweden)
Rongjing Song
Full Text Available The aim of this study was to determine the effect of exposure to different antithyroid drugs during pregnancy on the incidence of neonatal congenital malformations.A meta-analysis was performed to compare the incidence of neonatal congenital malformations after exposure to different antithyroid drugs during pregnancy. Twelve studies that met the inclusion criteria were included in this meta-analysis. PubMed, Embase, and CENTRAL databases were searched from inception until January 2017. Study designs included case-control studies, prospective cohort studies, and retrospective cohort studies.Twelve studies involving 8028 participants with exposure to different antithyroid drugs during pregnancy were included in this study; however, only 10 studies involving 5059 participants involved exposure to different antithyroid drugs exactly during pregnancy. Our results indicated that exposure to methimazole (MMI/carbimazole (CMZ only during pregnancy significantly increased the risk of neonatal congenital malformations compared to no antithyroid drug exposure (OR 1.88; 95%CI 1.33 to 2.65; P = 0.0004. No differences were observed between propylthiouracil (PTU exposure and no antithyroid drug exposure only during pregnancy (OR 0.81; 95%CI 0.58 to 1.15; P = 0.24. Exposure to MMI/CMZ only during pregnancy significantly increased the risk of neonatal congenital malformations compared to that associated with exposure to PTU (OR 1.90; 95%CI 1.30 to 2.78; P = 0.001.For pregnant women with hyperthyroidism, exposure to MMI/CMZ significantly increased the incidence of neonatal congenital malformations compared to exposure to PTU and no antithyroid drug exposure; however, no differences were observed between PTU exposure and no antithyroid drug exposure.
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Atmospheric NH3 as plant nutrient: A case study with Brassica oleracea
International Nuclear Information System (INIS)
Castro, Ana; Stulen, Ineke; De Kok, Luit J.
2008-01-01
Nutrient-sufficient and nitrate- or sulfate-deprived plants of Brassica oleracea L. were exposed to 4 μl l -1 NH 3 (2.8 mg m -3 ), and effects on biomass production and allocation, N-compounds and root morphology investigated. Nitrate-deprived plants were able to transfer to atmospheric NH 3 as nitrogen source, but biomass allocation in favor of the root was not changed by exposure to NH 3 . NH 3 reduced the difference in total root length between nitrate-sufficient and nitrate-deprived plants, and increased the specific root length in the latter. The internal N status, therefore, might be involved in controlling root length in B. oleracea. Root surface area, volume and diameter were unaffected by both nitrate deprivation and NH 3 exposure. In sulfate-deprived plants an inhibitory effect of NH 3 on root morphological parameters was observed. These plants, therefore, might be more susceptible to atmospheric NH 3 than nitrate-deprived plants. The relevance of the present data under field conditions is discussed. - Atmospheric NH 3 can serve as sole N source for Brassica oleracea, but does not change root biomass allocation in nitrate-deprived plants
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Arbuscular mycorrhiza formation and its function under elevated atmospheric O3: A meta-analysis.
Wang, Shuguang; Augé, Robert M; Toler, Heather D
2017-07-01
We quantitatively evaluated the effects of elevated O 3 on arbuscular mycorrhiza (AM) formation and on AM role in promoting plant growth in regard to several moderating variables (O 3 levels, O 3 exposure duration, plant types, AM fungi family, and additional stress) by means of meta-analysis of published data. The analysis consisted of 117 trials representing 20 peer-reviewed articles and 16 unpublished trials. Relative to non-mycorrhizal controls, AM inoculation did not significantly alter plant growth (shoot biomass, root biomass, total biomass and plant height) when O 3 concentration was less than 80 ppb, but at concentrations above 80 ppb symbiosis was associated with increases of 68% in shoot biomass and 131% in root biomass. AM effects on plant growth were affected by the duration of O 3 exposure but did not differ much with AM fungi taxa or plant type. AM symbiosis has also led to higher yields under O 3 stress, relative to the non-mycorrhizal plants, and the AM effects have been more pronounced as O 3 concentration increases. As with biomass, AM effects on yield have been affected by the duration of O 3 exposure, with the greatest increase (100%) occurring at 61-90 d. AM-induced promotion of yield differed with fungal species but not with plant type or other abiotic stress. Colonization of roots by AM fungi has been negatively affected by elevated O 3 compared to ambient O 3 ; total mycorrhizal colonization rate (MCR), arbuscular MCR, vesicular MCR and hyphal coil MCR declined as O 3 levels rose. AM colonization rates were affected by duration of O 3 exposure, plant type, AM fungal taxa and other concurrent stresses in most cases. The analysis showed that AM inoculation has the potential to ameliorate detrimental effects of elevated O 3 on plant growth and productivity, despite colonization rates being negatively affected by elevated O 3 . Copyright © 2017. Published by Elsevier Ltd.
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Study of the impact of atmospheric emissions (41AR) during operation of a nuclear reactor research
International Nuclear Information System (INIS)
Alves, Simone F.; Barreto, Alberto A.; Jacomino, Vanusa Maria F.; Rodrigues, Paulo Cesar H.
2013-01-01
The knowledge of the atmosphere dispersion of radionuclides, resulting from a nuclear reactor emissions during normal operation, is an important step in the process of nuclear licensing and environmental. This step requires a study to evaluate the radiological environmental impact. The results of this study are used by radiation protection agents to control the exposure of public to radiation during the operation of nuclear facilities. The elaboration of environmental impact assessment due to atmospheric emissions is based on a study of atmospheric dispersion. The aim of this study is estimate the concentrations of radionuclides in different compartments of the ecosystem and calculate the dose received by man as a result of radiation exposure in different scenarios of interest. This paper deals with the case study of the impact of atmospheric emissions of 41 Ar during operation of a nuclear research reactor. This study was accomplished with the application of the dispersion model ARTM (Radionuclide Transport Atmospheric Model), along with the geoprocessing resources. Among the results are: the spatial distribution of population by age; topography of the region, local wind rose, atmospheric stability and the estimate of the concentration of radionuclide 41 Ar and of dose. The results indicate that the dose, by external irradiation due to immersion in the cloud, was below the limits established by regulatory agencies. (author)
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#2 - An Empirical Assessment of Exposure Measurement Error ...
Background• Differing degrees of exposure error acrosspollutants• Previous focus on quantifying and accounting forexposure error in single-pollutant models• Examine exposure errors for multiple pollutantsand provide insights on the potential for bias andattenuation of effect estimates in single and bipollutantepidemiological models The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
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Space weather effects measured in atmospheric radiation on aircraft
Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Wieman, S. R.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, L. D.; Mertens, C. J.; Xu, X.; Wiltberger, M. J.; Wiley, S.; Teets, E.; Shea, M. A.; Smart, D. F.; Jones, J. B. L.; Crowley, G.; Azeem, S. I.; Halford, A. J.
2016-12-01
Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Since 2013 Space Environment Technologies (SET) has been conducting observations of the atmospheric radiation environment at aviation altitudes using a small fleet of six instruments. The objective of this work is to improve radiation risk management in air traffic operations. Under the auspices of the Automated Radiation Measurements for Aerospace Safety (ARMAS) and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) projects our team is making dose rate measurements on multiple aircraft flying global routes. Over 174 ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the radiation environment resulting from Galactic Cosmic Rays (GCRs), Solar Energetic Protons (SEPs), and outer radiation belt energetic electrons. The real-time radiation exposure is measured as an absorbed dose rate in silicon and then computed as an ambient dose equivalent rate for reporting dose relevant to radiative-sensitive organs and tissue in units of microsieverts per hour. ARMAS total ionizing absorbed dose is captured on the aircraft, downlinked in real-time, processed on the ground into ambient dose equivalent rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users. Dose rates from flight altitudes up to 56,700 ft. are shown for flights across the planet under a variety of space weather conditions. We discuss several space weather
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Surface modification of polylactic acid films by atmospheric pressure plasma treatment
Kudryavtseva, V. L.; Zhuravlev, M. V.; Tverdokhlebov, S. I.
2017-09-01
A new approach for the modification of polylactic acid (PLA) materials using atmospheric pressure plasma (APP) is described. PLA films plasma exposure time was 20, 60, 120 s. The surface morphology and wettability of the obtained PLA films were investigated by atomic force microscopy (AFM) and the sitting drop method. The atmospheric pressure plasma increased the roughness and surface energy of PLA film. The wettability of PLA has been improved with the application of an atmospheric plasma surface treatment. It was shown that it is possible to obtain PLA films with various surface relief and tunable wettability. Additionally, we demonstrated that the use of cold atmospheric pressure plasma for surface activation allows for the immobilization of bioactive compounds like hyaluronic acid (HA) on the surface of obtained films. It was shown that composite PLA-HA films have an increased long-term hydrophilicity of the films surface.
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Tracing fetal and childhood exposure to lead using isotope analysis of deciduous teeth
Energy Technology Data Exchange (ETDEWEB)
Shepherd, Thomas J. [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne (United Kingdom); British Geological Survey, Keyworth, Nottingham (United Kingdom); Dirks, Wendy [Department of Anthropology, Durham University, Durham (United Kingdom); Roberts, Nick M.W. [NERC Isotope Geosciences Laboratory, British Geological Survey, Nottingham (United Kingdom); Patel, Jaiminkumar G. [Leeds Dental Institute, University Leeds, Leeds (United Kingdom); Hodgson, Susan [MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College London (United Kingdom); Pless-Mulloli, Tanja [Institute of Health and Society, Newcastle University, Newcastle upon Tyne (United Kingdom); Walton, Pamela [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne (United Kingdom); Parrish, Randall R. [British Geological Survey, Keyworth, Nottingham (United Kingdom)
2016-04-15
We report progress in using the isotopic composition and concentration of Pb in the dentine and enamel of deciduous teeth to provide a high resolution time frame of exposure to Pb during fetal development and early childhood. Isotope measurements (total Pb and {sup 208}Pb/{sup 206}Pb, {sup 207}Pb/{sup 206}Pb ratios) were acquired by laser ablation inductively coupled mass spectrometry at contiguous 100 micron intervals across thin sections of the teeth; from the outer enamel surface to the pulp cavity. Teeth samples (n=10) were selected from two cohorts of children, aged 5–8 years, living in NE England. By integrating the isotope data with histological analysis of the teeth, using the daily incremental lines in dentine, we were able to assign true estimated ages to each ablation point (first 2–3 years for molars, first 1–2 years for incisors+pre-natal growth). Significant differences were observed in the isotope composition and concentration of Pb between children, reflecting differences in the timing and sources of exposure during early childhood. Those born in 2000, after the withdrawal of leaded petrol in 1999, have the lowest dentine Pb levels (<0.2 µg Pb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.126–2.079) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.879–0.856) ratios that correlate very closely with modern day Western European industrial aerosols (PM{sub 10}, PM{sub 2.5}) suggesting that diffuse airborne pollution was probably the primary source and exposure pathway. Legacy lead, if present, is insignificant. For those born in 1997, dentine lead levels are typically higher (>0.4 µgPb/g) with {sup 208}Pb/{sup 206}Pb (mean ±2σ: 2.145–2.117) {sup 208}Pb/{sup 206}Pb (mean ±2σ: 0.898–0.882) ratios that can be modelled as a binary mix between industrial aerosols and leaded petrol emissions. Short duration, high intensity exposure events (1–2 months) were readily identified, together with evidence that dentine provides a good proxy for childhood
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How Analysis Informs Regulation:Success and Failure of ...
How Analysis Informs Regulation:Success and Failure of Evolving Approaches to Polyfluoroalkyl Acid Contamination The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
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Characterization of regional atmospheric aerosols over Hungary by PIXE elemental analysis
International Nuclear Information System (INIS)
Koltay, E.; Szabo, G.; Borbely Kiss, I.; Somorjai, E.; Kiss, A.Z.
1994-01-01
Studying the characteristic features of atmospheric aerosols emitted by natural and anthropogenic sources is of basic importance for a detailed understanding of the physics and chemistry of the atmosphere. Environmental pollution by atmospheric aerosols and their impact can be tested in the same way, too. The separation of natural and anthropogenic components of the aerosol can be done through enrichment factors and size distribution curves deduced from analytical information. The Particle Induced X-ray Emission (PIXE) technique has been applied in aerosol studies by the authors. Results obtained on atmospheric aerosols collected over Hungary and presented in terms of concentrations, enrichment factors, regional signatures, deposition velocities, transport properties and apportionment of sources illustrate the scope and proportions of the potential contribution of PIXE to the methodology of atmospheric aerosol studies. Continued activity planned in the framework of the present CRP may widen the scope of the investigations mainly in the field of size-fractioned sampling and - possibly - in the direction of individual characterization of aerosol particles. (author). 14 refs
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Composition of atmospheric precipitation. I. Nitrogen compounds
Energy Technology Data Exchange (ETDEWEB)
Eriksson, E
1952-01-01
The purpose of this paper is to present a survey of published data on chemical analysis of atmospheric precipitation to discuss different cycles proposed for inorganic compounds in atmospheric precipitation and, finally, to assess the importance of these compounds from different points of view. Investigations of rainwater with a view to determine atmospheric pollution in industrial areas are mentioned incidentally but no results are detailed.
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Accurate assessment of chronic human exposure to atmospheric criteria pollutants, such as ozone, is critical for understanding human health risks associated with living in environments with elevated ambient pollutant concentrations. In this study, we analyzed a data set from a...
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Yuan, Jun; Sera, Koichiro; Takatsuji, Toshihiro
2015-01-01
To investigate human health effects of radiation exposure due to possible future nuclear accidents in distant places and other various findings of analysis of the radioactive materials contaminating the atmosphere of Nagasaki due to the Fukushima Daiichi Nuclear Power Plant accident. The concentrations of radioactive materials in aerosols in the atmosphere of Nagasaki were measured using a germanium semiconductor detector from March 2011 to March 2013. Internal exposure dose was calculated in accordance with ICRP Publ. 72. Air trajectories were analyzed using NOAA and METEX web-based systems. (134)Cs and (137)Cs were repeatedly detected. The air trajectory analysis showed that (134)Cs and (137)Cs flew directly from the Fukushima Daiichi Nuclear Power Plant from March to April 2011. However, the direct air trajectories were rarely detected after this period even when (134)Cs and (137)Cs were detected after this period. The activity ratios ((134)Cs/(137)Cs) of almost all the samples converted to those in March 2011 were about unity. This strongly suggests that the (134)Cs and (137)Cs detected mainly originated from the Fukushima Daiichi Nuclear Power Plant accident in March 2011. Although the (134)Cs and (137)Cs concentrations per air volume were very low and the human health effects of internal exposure via inhalation is expected to be negligible, the specific activities (concentrations per aerosol mass) were relatively high. It was found that possible future nuclear accidents may cause severe radioactive contaminations, which may require radiation exposure control of farm goods to more than 1000 km from places of nuclear accidents.
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International Nuclear Information System (INIS)
Saveleva, E. I.; Koryagina, N. L.; Radilov, A. S.; Khlebnikova, N. S.; Khrustaleva, V. S.; Feld, V. E.
2007-01-01
Reliable chemical analytical procedures for revealing an exposure to toxic chemicals, identifying the active substance, and assessing the degree of exposure are necessary as a component of medical and forensic activities in cases of the possible use of highly toxic chemicals in war conflicts and terrorism acts, as well as emergency situations in chemical industry, specifically at chemical weapons storage and destruction facilities. According to Chemical Weapons Convention, Part XI, Appendix 4, e-17, 'samples of importance in the investigation of alleged use include biomedical samples from human or animal sources (blood, urine, excreta, tissue etc.)'. Urinary metabolites, O-alkyl esters of methylphosphic acid, offer one of the simplest means of confirming an exposure to organophosphorus warfare agents (OPWA). Urine, unlike blood or tissues, does not require invasive collection demanding in terms of sterility. Excretion with urine is the major route of elimination of OPWA from an organism. According to published data, 90% of OPWA metabolites are excreted within 48-72 h after intoxication. We developed an SPME-GCMS procedure for the determination of O-alkyl esters methylphosphonic acid in urine, with the following detection limits,: isopropyl and isobutyl esters 5 ng/ml and pinacolyl ester 1 ng/ml. The procedure involves derivatization of the target compounds directly on the microfiber. The total analysis time is 1-1.5 h. In animal experiments in vivo we could establish the exposure to OPWA at a half-LD50 level within no less than 48 h after intoxication. In principle, OPWA metabolites could be detected in urine within two weeks after intoxication but at higher doses. Retrospective analysis of urinary metabolites in cases of the exposure to low doses of OPWA requires lower detection limits (0.1-1 ng/ml). Optimal objects for the retrospective analysis of OPWA in an organism are long-lived blood protein adducts. We developed a procedure for revealing an exposure to
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Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping
2015-01-01
Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.
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Directory of Open Access Journals (Sweden)
Xin-Hai Yin
Full Text Available Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk.PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs with corresponding 95% confidence intervals (CIs were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed.Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15. Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed.The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.
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Analysis of medical occupational exposure to ionizing radiation on Taiwan during past two decades
International Nuclear Information System (INIS)
Weng, P.-S.; Li, S.-Y.
1980-01-01
From the time of inception of the centralized laboratory for personnel dosimetry service operated by the National Tsing Hua University on Taiwan of the Republic of China in 1960 till 1979 the data obtained was analyzed to find the yearly occupational exposure to ionizing radiation. During the 20 year monitoring period, analysis was performed with reference to (1) medical occupational exposure, (2) maximum and average yearly dose-equivalent, (3) range of dose-equivalent, (4) percentage of maximum permissible dose-equivalent, (5) number of workers, including sex and age, (6) detailed quarterly analysis for the years 1977 to 1979, (7) types of radiation sources, and (8) estimation of the genetically significant dose-equivalent. (H.K.)
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Human exposure limits to hypergolic fuels
Garcia, H. D.; James, J. T.; Limero, T. F.
1992-01-01
Over the past four decades, many studies have been conducted on the toxicities of the rocket propellants hydrazine (HZ) and monomethylhydrazine (MH). Numerous technical challenges have made it difficult to unambiguously interpret the results of these studies, and there is considerable divergence between results obtained by different investigators on the inhalation concentrations (MAC's) for each toxic effect inducible by exposure to hypergolic fuels in spacecraft atmospheres, NASA undertook a critical review of published and unpublished investigations on the toxicities of these compounds. The current state of the art practices for similar studies. While many questions remain unanswered, MAC's were determined using the best available data for a variety of toxic endpoints for potential continuous exposure durations ranging from 1 hour to 180 days. Spacecraft MAC's (SMAC's) were set for each compound based on the most sensitive toxic endpoint at each exposure duration.
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Air crew exposure to cosmic radiation. New analysis, recommendations EURADOS
Energy Technology Data Exchange (ETDEWEB)
Spurny, F; Votockova, I [Academy of the Sciences of Czech Republic, Prague (Czech Republic). Nuclear Physics Institute, Department of Radiation Dosimetry
1996-12-31
Cosmic radiation on the board of an aircraft consist of two components: directly ionizing radiation (electron, proton - low LET) and neutrons (high LET). Neither composition nor the energy spectrum of usual on-Earth calibration sources ({sup 60}Co, {sup 252}Cf) do not correspond to the field on a board. Therefore high energy reference fields behind shielding high energy accelerator at CERN and Dubna have been created and intensively studied. Their typical characteristics following from the results of our measurements were obtained. In-flight measurements on the board of commercial aircraft have been realized since 1991 during about 20 flights, Flight routes extended from the 1.3 grad N up to about 65 grad N, flying altitudes varied from 8.2 km to 12.5 km. The exposure level due to galactic cosmic radiation is inversely proportional to the solar activity. Some radiation protection aspects were concluded: (a) The usual limits of annual air crew flight hours correspond at 11.3 km to about 4 mSv per year, with new ICRP conversion factors to about 5 mSv per year; (b) Monthly flight hours limit does not exclude that the exposure of a pregnant women can exceed 1 mSv during this period; (c) The air crew exposure should therefore be checked, controlled a nd administered as conscientiously as for any other group of occupationally exposed persons. A Working group 11 of EURADOS `Exposure of air crew to cosmic radiation` has been formed (1992-1995) to prepare basic analysis and recommendations concerning the topics. (Abstract Truncated)
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Accelerated atmospheric corrosion testing using a cyclic wet/dry exposure test
International Nuclear Information System (INIS)
Lyon, S.B.; Thompson, G.E.; Johnson, J.E.; Wood, G.C.
1989-01-01
Aluminum corrosion is important in overhead electrical conductors constructed from aluminum wire centrally reinforced by galvanized steel strands. Inspection of conductor after long service has implicated rubber bushing material, on the outside, and the galvanized strands, on the inside, as providing potential galvanic sites for the initiation of rapid aluminum corrosion. Therefore, the galvanic corrosion of aluminum in contact with graphite-loaded neoprene rubber, hot-dip galvanized steel and steel was assessed in a cyclic wet/dry exposure test using mixed-salts spray solutions containing appropriate ratios of sulfate and chloride ion. Aluminum was found to corrode at between 3 to 6 times its uncoupled rate when associated with the rubber material. While the eta-phase, relatively pure Zn, galvanized layer remained intact, galvanic corrosion of aluminum was slow. However, on exposure of the zeta-phase, Zn/Fe intermetallic layer, aluminum corroded about 35 times faster than expected in a solution with a high level of Cl - ion. The importance of these data to conductor lifetime is discussed
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A Meta-Analysis Summarizing the Effects of Pornography II: Aggression after Exposure.
Allen, Mike; And Others
1995-01-01
Examines by meta-analysis the effect that exposure to pornography produces on aggressive behavior under laboratory conditions considering a variety of possible moderating conditions. Demonstrates a homogeneous set of results showing that pictorial nudity reduces subsequent violent behavior, but that depictions of nonviolent sexual behavior and…
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Zendehdel, Rezvan; Tayefeh-Rahimian, Raana; Kabir, Ali
2014-01-01
Chlorophenols (CPs) and related phenoxyacetic acids (PAs) are pesticide groups contaminated with highly toxic 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) during production. PAs and CPs exposure is associated with risk of cancer, but the situation regarding lung cancer has not been clearly defined. We proposed a meta-analysis of published researches to evaluate relationship between chronic exposure to PAs and CPs in pesticide production workplaces and the risk of lung cancer. After searching PubMed, Scopus, Scholar Google, Web of Sciences until August 2013, the association between chronic PAs and CPs exposure in production workplace and lung cancer was studied in 15 cohort studies. The standardized mortality rate (SMR) and 95% confidence intervals (CI) were collected from the papers. We used random or fixed-effects models, Egger test, funnel plot and meta regression in our analysis. Five papers with six reports were included in the final analysis. The standardized mortality rate for lung cancer from the random model was 1.18 (95% CI: 1.03-1.35, p=0.014) with moderate heterogeneity. Publication bias was not found for included studies in meta-analysis (p=0.9). Our findings has strengthen the evidence of lung cancer from chronic exposure to chlorophenol related compounds (PAs, CPs).
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Effectiveness of Emission Controls to Reduce the Atmospheric Concentrations of Mercury.
Castro, Mark S; Sherwell, John
2015-12-15
Coal-fired power plants in the United States are required to reduce their emissions of mercury (Hg) into the atmosphere to lower the exposure of Hg to humans. The effectiveness of power-plant emission controls on the atmospheric concentrations of Hg in the United States is largely unknown because there are few long-term high-quality atmospheric Hg data sets. Here, we present the atmospheric concentrations of Hg and sulfur dioxide (SO2) measured from 2006 to 2015 at a relatively pristine location in western Maryland that is several (>50 km) kilometers downwind of power plants in Ohio, Pennsylvania, and West Virginia. Annual average atmospheric concentrations of gaseous oxidized mercury (GOM), SO2, fine particulate mercury (PBM2.5), and gaseous elemental mercury (GEM) declined by 75%, 75%, 43%, and 13%, respectively, and were strongly correlated with power-plant Hg emissions from the upwind states. These results provide compelling evidence that reductions in Hg emissions from power plants in the United States had their intended impact to reduce regional Hg pollution.
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Processes analysis of ocean-atmosphere interaction in Colombian marine areas
International Nuclear Information System (INIS)
Melo, Jeimmy; Pabon Caicedo, Jose Daniel
2002-01-01
This document shows the importance to understanding the processes of interaction ocean-atmosphere by means of the knowledge of the behavior of the physical and biological processes in the Colombian marine areas. For such aim, it was studied the production of the pigment concentration (chlorophyll-a) by means the state of the sea surface temperature and the atmospheric dynamics for year 2001
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Chang, Howard H; Peng, Roger D; Dominici, Francesca
2011-10-01
In air pollution epidemiology, there is a growing interest in estimating the health effects of coarse particulate matter (PM) with aerodynamic diameter between 2.5 and 10 μm. Coarse PM concentrations can exhibit considerable spatial heterogeneity because the particles travel shorter distances and do not remain suspended in the atmosphere for an extended period of time. In this paper, we develop a modeling approach for estimating the short-term effects of air pollution in time series analysis when the ambient concentrations vary spatially within the study region. Specifically, our approach quantifies the error in the exposure variable by characterizing, on any given day, the disagreement in ambient concentrations measured across monitoring stations. This is accomplished by viewing monitor-level measurements as error-prone repeated measurements of the unobserved population average exposure. Inference is carried out in a Bayesian framework to fully account for uncertainty in the estimation of model parameters. Finally, by using different exposure indicators, we investigate the sensitivity of the association between coarse PM and daily hospital admissions based on a recent national multisite time series analysis. Among Medicare enrollees from 59 US counties between the period 1999 and 2005, we find a consistent positive association between coarse PM and same-day admission for cardiovascular diseases.
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International Nuclear Information System (INIS)
Pacansky, J.; Schneider, S.
1990-01-01
Thin films of poly(vinyl alcohol) (PVA) were exposed to a 25-kV electron beam under high vacuum conditions and to a 175-kV electron beam at atmospheric pressures of N 2 . The decomposition of PVA by the electron beam sequentially formed materials that had polyketone- and polyethylene-like structures, respectively. Contrary to previous reports we show that the ketone groups formed as a result of the electron beam exposure are not due to an oxidation step by molecular oxygen. Damage cross sections for the electron beam decomposition (at 25 kV) were determined for PVA and the polyketone, and G values were determined for decomposition of -OH groups and formation of ketone functional groups
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Work environments and exposure to hazardous substances in korean tire manufacturing.
Lee, Naroo; Lee, Byung-Kyu; Jeong, Sijeong; Yi, Gwang Yong; Shin, Jungah
2012-06-01
The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. Workers were exposed to rubber fume that exceeded 0.6 mg/m(3), the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1℃ (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7℃ (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended.
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The atmospheric parameters of FGK stars using wavelet analysis of CORALIE spectra
Gill, S.; Maxted, P. F. L.; Smalley, B.
2018-05-01
Context. Atmospheric properties of F-, G- and K-type stars can be measured by spectral model fitting or with the analysis of equivalent width (EW) measurements. These methods require data with good signal-to-noise ratios (S/Ns) and reliable continuum normalisation. This is particularly challenging for the spectra we have obtained with the CORALIE échelle spectrograph for FGK stars with transiting M-dwarf companions. The spectra tend to have low S/Ns, which makes it difficult to analyse them using existing methods. Aims: Our aim is to create a reliable automated spectral analysis routine to determine Teff, [Fe/H], V sini from the CORALIE spectra of FGK stars. Methods: We use wavelet decomposition to distinguish between noise, continuum trends, and stellar spectral features in the CORALIE spectra. A subset of wavelet coefficients from the target spectrum are compared to those from a grid of models in a Bayesian framework to determine the posterior probability distributions of the atmospheric parameters. Results: By testing our method using synthetic spectra we found that our method converges on the best fitting atmospheric parameters. We test the wavelet method on 20 FGK exoplanet host stars for which higher-quality data have been independently analysed using EW measurements. We find that we can determine Teff to a precision of 85 K, [Fe/H] to a precision of 0.06 dex and V sini to a precision of 1.35 km s-1 for stars with V sini ≥ 5 km s-1. We find an offset in metallicity ≈- 0.18 dex relative to the EW fitting method. We can determine log g to a precision of 0.13 dex but find systematic trends with Teff. Measurements of log g are only reliable enough to confirm dwarf-like surface gravity (log g ≈ 4.5). Conclusions: The wavelet method can be used to determine Teff, [Fe/H], and V sini for FGK stars from CORALIE échelle spectra. Measurements of log g are unreliable but can confirm dwarf-like surface gravity. We find that our method is self consistent, and
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Does D-cycloserine enhance exposure therapy for anxiety disorders in humans? A meta-analysis.
Directory of Open Access Journals (Sweden)
Helga Rodrigues
Full Text Available The treatment of anxiety is on the edge of a new era of combinations of pharmacologic and psychosocial interventions. A new wave of translational research has focused on the use of pharmacological agents as psychotherapy adjuvants using neurobiological insights into the mechanism of the action of certain psychological treatments such as exposure therapy. Recently, d-cycloserine (DCS an antibiotic used to treat tuberculosis has been applied to enhance exposure-based treatment for anxiety and has proved to be a promising, but as yet unproven intervention. The present study aimed to evaluate the efficacy of DCS in the enhancement of exposure therapy in anxiety disorders. A systematic review/meta-analysis was conducted. Electronic searches were conducted in the databases ISI-Web of Science, Pubmed and PsycINFO. We included only randomized, double-blind, placebo-controlled trials with humans, focusing on the role of DCS in enhancing the action of exposure therapy for anxiety disorders. We identified 328 references, 13 studies were included in our final sample: 4 on obsessive-compulsive disorder, 2 on panic disorder, 2 on social anxiety disorder, 2 on posttraumatic stress disorder, one on acrophobia, and 2 on snake phobia. The results of the present meta-analysis show that DCS enhances exposure therapy in the treatment of anxiety disorders (Cohen d = -0.34; CI: -0.54 to -0.14, facilitating the specific process of extinction of fear. DCS seems to be effective when administered at a time close to the exposure therapy, at low doses and a limited number of times. DCS emerges as a potential new therapeutic approach for patients with refractory anxiety disorders that are unresponsive to the conventional treatments available. When administered correctly, DCS is a promising strategy for augmentation of CBT and could reduce health care costs, drop-out rates and bring faster relief to patients.
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Surzhikov, V D; Surzhikov, D V
2014-01-01
The search and measurement of causal relationships between exposure to air pollution and health state of the population is based on the system analysis and risk assessment to improve the quality of research. With this purpose there is applied the modern statistical analysis with the use of criteria of independence, principal component analysis and discriminate function analysis. As a result of analysis out of all atmospheric pollutants there were separated four main components: for diseases of the circulatory system main principal component is implied with concentrations of suspended solids, nitrogen dioxide, carbon monoxide, hydrogen fluoride, for the respiratory diseases the main c principal component is closely associated with suspended solids, sulfur dioxide and nitrogen dioxide, charcoal black. The discriminant function was shown to be used as a measure of the level of air pollution.
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PERSPECTIVES ON A DOE CONSEQUENCE INPUTS FOR ACCIDENT ANALYSIS APPLICATIONS
International Nuclear Information System (INIS)
O'Kula, K.R.; Thoman, D.C.; Lowrie, J.; Keller, A.
2008-01-01
Department of Energy (DOE) accident analysis for establishing the required control sets for nuclear facility safety applies a series of simplifying, reasonably conservative assumptions regarding inputs and methodologies for quantifying dose consequences. Most of the analytical practices are conservative, have a technical basis, and are based on regulatory precedent. However, others are judgmental and based on older understanding of phenomenology. The latter type of practices can be found in modeling hypothetical releases into the atmosphere and the subsequent exposure. Often the judgments applied are not based on current technical understanding but on work that has been superseded. The objective of this paper is to review the technical basis for the major inputs and assumptions in the quantification of consequence estimates supporting DOE accident analysis, and to identify those that could be reassessed in light of current understanding of atmospheric dispersion and radiological exposure. Inputs and assumptions of interest include: Meteorological data basis; Breathing rate; and Inhalation dose conversion factor. A simple dose calculation is provided to show the relative difference achieved by improving the technical bases
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International Nuclear Information System (INIS)
Halfa, I.K.I
2008-01-01
This thesis contains four chapters and list of references:In chapter 1, we introduce a brief survey about the atmospheric concepts and the topological methods for data analysis.In section 1.1, we give introduce a general introduction. We recall some of atmospheric fundamentals in Section 1.2. Section 1.3, shows the concepts of modern topological methods for data analysis.In chapter 2, we have studied the properties of atmosphere and focus on concept of Rough set and its properties. This concepts of rough set has been applied to analyze the atmospheric data.In section 2.1, we introduce a general introduction about concept of rough set and properties of atmosphere. Section 2.2 focuses on the concept of rough set and its properties and generalization of approximation of rough set theory by using topological space. In section 2.3 we have studied the stabilities of atmosphere for Inshas location for all seasons using different schemes and compared these schemes using statistical and rough set methods. In section 2.4, we introduce mixing height of plume for all seasons. Section 2.5 introduced seasonal surface layer turbulence processes for Inshas location. Section 2.6 gives a comparison between the seasonal surface layer turbulence processes for Inshas location and for different locations using rough set theory.In chapter 3 we focus on the concept of variable precision rough set (VPRS) and its properties and using it to compare, between the estimated and observed data of the concentration of air pollution for Inshas location. In Section 3.1 we introduce a general introduction about VPRS and air pollution. In Section 3.2 we have focused on the concept and properties of VPRS. In Section 3.3 we have introduced a method to estimate the concentration of air pollution for Inshas location using Gaussian plume model. Section 3.4 has showed the experimental data. The estimated data have been compared with the observed data using statistical methods in Section 3.5. In Section 3
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Quantitative plasma biomarker analysis in HDI exposure assessment.
Flack, Sheila L; Fent, Kenneth W; Trelles Gaines, Linda G; Thomasen, Jennifer M; Whittaker, Steve; Ball, Louise M; Nylander-French, Leena A
2010-01-01
Quantification of amines in biological samples is important for evaluating occupational exposure to diisocyanates. In this study, we describe the quantification of 1,6-hexamethylene diamine (HDA) levels in hydrolyzed plasma of 46 spray painters applying 1,6-hexamethylene diisocyanate (HDI)-containing paint in vehicle repair shops collected during repeated visits to their workplace and their relationship with dermal and inhalation exposure to HDI monomer. HDA was detected in 76% of plasma samples, as heptafluorobutyryl derivatives, and the range of HDA concentrations was HDA levels and HDI inhalation exposure measured on the same workday was low (N = 108, r = 0.22, P = 0.026) compared with the correlation between plasma HDA levels and inhalation exposure occurring approximately 20 to 60 days before blood collection (N = 29, r = 0.57, P = 0.0014). The correlation between plasma HDA levels and HDI dermal exposure measured on the same workday, although statistically significant, was low (N = 108, r = 0.22, P = 0.040) while the correlation between HDA and dermal exposure occurring approximately 20 to 60 days before blood collection was slightly improved (N = 29, r = 0.36, P = 0.053). We evaluated various workplace factors and controls (i.e. location, personal protective equipment use and paint booth type) as modifiers of plasma HDA levels. Workers using a downdraft-ventilated booth had significantly lower plasma HDA levels relative to semi-downdraft and crossdraft booth types (P = 0.0108); this trend was comparable to HDI inhalation and dermal exposure levels stratified by booth type. These findings indicate that HDA concentration in hydrolyzed plasma may be used as a biomarker of cumulative inhalation and dermal exposure to HDI and for investigating the effectiveness of exposure controls in the workplace.
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International Nuclear Information System (INIS)
Cushman, R.M.
2001-01-01
The Carbon Dioxide Information Analysis Center (CDIAC), which includes the World Data Center (WDC) for Atmospheric Trace Gases, is the primary global change data and information analysis center of the U.S. Department of Energy (DOE). More than just an archive of data sets and publications, CDIAC has, since its inception in 1982, enhanced the value of its holdings through intensive quality assurance, documentation, and integration. Whereas many traditional data centers are discipline-based (for example, meteorology or oceanography), CDIAC's scope includes potentially anything and everything that would be of value to users concerned with the greenhouse effect and global climate change, including concentrations of carbon dioxide (CO(sub 2)) and other radiatively active gases in the atmosphere; the role of the terrestrial biosphere and the oceans in the biogeochemical cycles of greenhouse gases; emissions of CO(sub 2) and other trace gases to the atmosphere; long-term climate trends; the effects of elevated CO(sub 2) on vegetation; and the vulnerability of coastal areas to rising sea levels
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International Nuclear Information System (INIS)
Ali, A.E.; Bacso, J.
1996-01-01
Different atmospheric aerosol samples were collected on three types of filters. Disks of both loaded and clean areas of each kind of filter were investigated by XRF, PIXE and Scanning Electron Microscope (SEM) methods. The blank concentration values of the elements Al, Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br and Pb in the three types of filters are discussed. It is found that for trace elemental analysis, the Nuclepore membrane filters are the most suitable for sampling. These have much lower blank element concentration values than the glass fibres and ash free filters. It was found also that the PIXE method is a more reliable analytical technique for atmospheric aerosol particles than the other methods. (author). 20 refs., 3 figs., 3 tabs
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Analysis of atmospheric concentrations of radon and thoron using beta counting technique
International Nuclear Information System (INIS)
Islam, G.S.; Basunia, S.M.
1995-05-01
This paper presents a detailed theory and experimental procedure for measurement and analysis of mixed radon and thoron in the environment. The technique has been successfully applied to the study of seasonal variations of radon and thoron in Rajshahi atmosphere during the years 1989-1991. The maximum radon concentration in outdoor air was observed in the winter from December to January while the indoor radon concentration was found to be maximum during the monsoon months of July and August. The implication of results is briefly discussed in the paper. (author). 4 refs, 6 figs, 2 tabs
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Observation and analysis of speciated atmospheric mercury in Shangri-La, Tibetan Plateau, China
Zhang, H.; Fu, X. W.; Lin, C.-J.; Wang, X.; Feng, X. B.
2015-01-01
This study reports the concentrations and potential sources of speciated atmospheric mercury at the Shangri-La Atmosphere Watch Regional Station (SAWRS), a pristine high-altitude site (3580 m a.s.l.) in Tibetan Plateau, China. Total gaseous mercury (TGM, defined as the sum of gaseous elemental mercury, GEM, and gaseous oxidized mercury, GOM), GOM and particulate-bound mercury (PBM) were monitored from November 2009 to November 2010 to investigate the characteristics and potential influence of the Indian summer monsoon (ISM) and the Westerlies on atmospheric transport of mercury. The mean concentrations (± standard deviation) of TGM, PBM and GOM were 2.55 ± 0.73 ng m-3, 38.82 ± 31.26 pg m-3 and 8.22 ± 7.90 pg m-3, respectively. A notable seasonal pattern of TGM concentrations was observed with higher concentrations at the beginning and the end of the ISM season. High TGM concentrations (> 2.5 ng m-3) were associated with the transport of dry air that carried regional anthropogenic emissions from both Chinese domestic and foreign (e.g., Myanmar, Bay of Bengal, and northern India) sources based on analysis of HYSPLIT4 back trajectories. Somewhat lower PBM and GOM levels during the ISM period were attributed to the enhanced wet scavenging. The high GOM and PBM were likely caused by local photo-chemical transformation under low RH and the domestic biofuel burning in cold seasons.
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Sensitivity Analysis of Onsite Atmospheric Dispersion Factor in Westinghouse type NPP in KOREA
International Nuclear Information System (INIS)
Lee, Seung Chan; Yoon, Duk Joo; Song, Dong Soo
2016-01-01
ARCON96 is a NRC licensed air dispersion model to evaluate onsite atmospheric relative concentration X/Q. The purpose of this paper is to provide some results for checking and testing the functionalities of ARCON96. Specially, this code is optimized to estimate a habitability of control room. Since NUREG 0737 issue, the control room habitability has been studied for a FSAR (Final Safety Analysis Report). Some assumptions and methodology is used in this paper. Some methodology is introduced in this paper. The reason of the selection of 2-loop Westinghouse NPP is because of carrying out the study project for the 2-loop Westinghouse NPP in the condition of the defueled NPP condition. Onsite atmospheric dispersion factor sensitivity is performed. Key impact factor is reviewed. Some results are below: a. Time averaged effect of X/Q is timely increased. b. ARCON96 code is more conservative at the low wind speed conditions. c. Building wake impact is significant in the condition of unstable atmospheric class with more than 7m/sec of wind speed. d. Plume meander effect is strong when the distance from the release point is small. e. The other plume meander effect is strong when the meander duration time is accumulated Finally, these results show that the appropriate conservation of ARCON96 is appeared in some conditions. Also these results seem to be in good agreement with NRC Regulatory Guide and positions
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Sensitivity Analysis of Onsite Atmospheric Dispersion Factor in Westinghouse type NPP in KOREA
Energy Technology Data Exchange (ETDEWEB)
Lee, Seung Chan; Yoon, Duk Joo; Song, Dong Soo [KHNP CRI, Daejeon (Korea, Republic of)
2016-10-15
ARCON96 is a NRC licensed air dispersion model to evaluate onsite atmospheric relative concentration X/Q. The purpose of this paper is to provide some results for checking and testing the functionalities of ARCON96. Specially, this code is optimized to estimate a habitability of control room. Since NUREG 0737 issue, the control room habitability has been studied for a FSAR (Final Safety Analysis Report). Some assumptions and methodology is used in this paper. Some methodology is introduced in this paper. The reason of the selection of 2-loop Westinghouse NPP is because of carrying out the study project for the 2-loop Westinghouse NPP in the condition of the defueled NPP condition. Onsite atmospheric dispersion factor sensitivity is performed. Key impact factor is reviewed. Some results are below: a. Time averaged effect of X/Q is timely increased. b. ARCON96 code is more conservative at the low wind speed conditions. c. Building wake impact is significant in the condition of unstable atmospheric class with more than 7m/sec of wind speed. d. Plume meander effect is strong when the distance from the release point is small. e. The other plume meander effect is strong when the meander duration time is accumulated Finally, these results show that the appropriate conservation of ARCON96 is appeared in some conditions. Also these results seem to be in good agreement with NRC Regulatory Guide and positions.
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Directory of Open Access Journals (Sweden)
Jie Jin
Full Text Available Pesticide exposure has been linked to increased risk of cancer at several sites, but its association with risk of myelodysplastic syndromes (MDS is still unclear. A meta-analysis of studies published through April, 2014 was performed to investigate the association of pesticide exposure with the risk of MDS.Studies were identified by searching the Web of Science, Cochrane Library and PubMed databases. Summary odds ratios (ORs with corresponding 95% confidence intervals (CIs were calculated using random- or fixed-effect models.This meta-analysis included 11 case-control studies, all of which demonstrated a correlation between pesticide exposure and a statistically significant increased risk of MDS (OR=1.95, 95% CI 1.23-3.09. In subgroup analyses, patients with pesticide exposure had increased risk of developing MDS if they were living in the Europe or Asia and had refractory anemia (RA or RA with ringed sideroblasts (RARS. Moreover, in the analysis by specific pesticides, increased risk was associated with exposure to insecticides (OR=1.71, 95% CI 1.22-2.40 but not exposure to herbicides or fungicides.This meta-analysis supports the hypothesis that exposure to pesticides increases the risk of developing MDS. Further prospective cohort studies are warranted to verify the association and guide clinical practice in MDS prevention.
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Application of PIXE analysis to study urban atmospheric aerosols from downtown Havana City
International Nuclear Information System (INIS)
Perez Zayas, Grizel; Pinnera Hernandez, Ibrahin; Ramos Aruca, Maridelin; Guibert Gala, Rolando; Molina Esquivel, Enrique; Martinez Varona, Miriam; Fernandez Arocha, Ariadna; Aldape Ugalde, Francisca; Flores Maldonado, Javier
2010-01-01
The present work reports, the results of a first study of elemental composition in airborne particulate matter (in fine and coarse particle size fractions) collected at the Atmospheric Monitoring Station in the Municipality of Centro Habana, using the Particle-Induced X-ray Emission (PIXE) technique. At present, there is not information available about elements contents in airborne particulate matter from this region. For this study, we carried out a sampling campaign during five months (November 14, 2006 to April 19, 2007). The samples were collected every second day during 24 h under an air flux of 20 l/min. The air sampler used was a Gent Sampler equipped with a Stacked Filter Unit (SFU) system which allows the aerosol collection in both size fractions simultaneously. A total of 144 aerosol samples were collected (72 correspond to the fine mass particle and 72 to the coarse mass particle). For PIXE analysis, the samples were irradiated by 2.5 MeV energy protons from the 2MV Van de Graff Tandetron Accelerator from the Laboratory of PIXE analysis at ININ, Mexico. A total of 14 elements (S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb) were consistently detected in both particle size fractions with minimum detection limits in the range of 1-10 ng/m3. The quantitative results obtained from PIXE elemental analysis for mass of particles in both fractions have revealed important information that has been used in a first attempt to understand and to characterize the atmospheric pollution of this area. A general discussion about these results is presented in this paper. (author)
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Application of PIXE analysis to study urban atmospheric aerosols from downtown Havana City
International Nuclear Information System (INIS)
Perez Zayas, Grizel; Pinnera Hernandez, Ibrahin; Ramos Aruca, Maridelin; Guibert Gala, Rolando; Molina Esquivel, Enrique; Martinez Varona, Miriam; Fernandez Arocha, Ariadna; Aldape Ugalde, Francisca; Flores Maldonado, Javier
2009-01-01
The present work reports, the results of a first study of elemental composition in airborne particulate matter (in fine and coarse particle size fractions) collected at the Atmospheric Monitoring Station in the Municipality of Centro Habana, using the Particle-Induced X-ray Emission (PIXE) technique. At present, there is not information available about elements contents in airborne particulate matter from this region. For this study, we carried out a sampling campaign during five months (November 14, 2006 to April 19, 2007). The samples were collected every second day during 24 h under an air flux of 20 l/min. The air sampler used was a Gent Sampler equipped with a Stacked Filter Unit (SFU) system which allows the aerosol collection in both size fractions simultaneously. A total of 144 aerosol samples were collected (72 correspond to the fine mass particle and 72 to the coarse mass particle). For PIXE analysis, the samples were irradiated by 2.5 MeV energy protons from the 2MV Van de Graff Tandetron Accelerator from the Laboratory of PIXE analysis at ININ, Mexico. A total of 14 elements (S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb) were consistently detected in both particle size fractions with minimum detection limits in the range of 1-10 ng/m3. The quantitative results obtained from PIXE elemental analysis for mass of particles in both fractions have revealed important information that has been used in a first attempt to understand and to characterize the atmospheric pollution of this area. A general discussion about these results is presented in this paper. (author)
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Colloquium:exposure to radon in houses: evaluation and risk management
International Nuclear Information System (INIS)
Anon.
1998-01-01
In this article, one intends to develop elements describing the behaviour of radon and its daughters in atmosphere, while pointing out the physical parameters allowing to characterize the personal natural exposure ( alpha potential energy, equilibrium fraction). (N.C.)
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NASA/MSFC FY90 Global Scale Atmospheric Processes Research Program Review
Leslie, Fred W. (Editor)
1990-01-01
Research supported by the Global Atmospheric Research Program at the Marshall Space Flight Center on atmospheric remote sensing, meteorology, numerical weather forecasting, satellite data analysis, cloud precipitation, atmospheric circulation, atmospheric models and related topics is discussed.
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Chen, Lee Chuin; Ninomiya, Satoshi; Hiraoka, Kenzo
2016-06-01
Ion source pressure plays a significant role in the process of ionization and the subsequent ion transmission inside a mass spectrometer. Pressurizing the ion source to a gas pressure greater than atmospheric pressure is a relatively new approach that aims to further improve the performance of atmospheric pressure ionization sources. For example, under a super-atmospheric pressure environment, a stable electrospray can be sustained for liquid with high surface tension such as pure water, because of the suppression of electric discharge. Even for nano-electrospray ionization (nano-ESI), which is known to work with aqueous solution, its stability and sensitivity can also be enhanced, particularly in the negative mode when the ion source is pressurized. A brief review on the development of super-atmospheric pressure ion sources, including high-pressure electrospray, field desorption and superheated ESI, and the strategies to interface these ion sources to a mass spectrometer will be given. Using a recent ESI prototype with an operating temperature at 220 °C under 27 atm, we also demonstrate that it is possible to achieve an online Asp-specific protein digestion analysis in which the whole processes of digestion, ionization and MS acquisition could be completed on the order of a few seconds. This method is fast, and the reaction can even be monitored on a near-real-time basis. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
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Held, D W; Potter, D A; Gates, R S; Anderson, R G
2001-04-01
Incidental transport of arthropods on plant material can be a significant mode of pest entry into greenhouses. We evaluated the use of controlled atmosphere treatments as a potential way to eliminate arthropod pests on plant propagules (i.e., cuttings or small rooted plants). Lethal exposures to CO2 or N2 were determined for common greenhouse pests including fungus gnat larvae, Bradysia sp.; green peach aphid, Myzus persicae (Sulzer); sweetpotato whitefly, Bemisia sp.; twospotted spider mite, Tetranychus urticae Koch; and western flower thrips, Frankliniella occidentalis (Pergande). We also studied the effect of pest species, life stage, and presence or absence of plants on efficacy of modified atmosphere treatments. Finally, effects of modified atmospheres on plant quality were evaluated for several bedding plant species including begonia, Begonia semperflorens-cultorum Hort. 'Cocktail Series', chrysanthemum, Dendranthema grandiflora Tzvelev., geranium, Pelargonium X hortorum L.H. Bailey, and impatiens, Impatiens wallerana Hook f., and among cultivars of geranium and chrysanthemum. Exposure for 12-18 h to >99% N2 or CO2 caused complete mortality of aphids, mites, thrips, and whiteflies. Fungus gnat larvae were more tolerant of hypoxic conditions. Adult mites and eggs were equally susceptible. For most pests, there was no difference in response to atmospheres modified by CO2 or N2. However, there was variation in response among plant species and cultivars, with effects ranging from delayed flowering to mortality. Despite the possibility of adverse effects on some plants, this work indicates that use of modified atmospheres has potential to eliminate arthropod pests on plant propagules before they are introduced into greenhouses.
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Flores-Pajot, Marie-Claire; Ofner, Marianna; Do, Minh T; Lavigne, Eric; Villeneuve, Paul J
2016-11-01
Genetic and environmental factors have been recognized to play an important role in autism. The possibility that exposure to outdoor air pollution increases the risk of autism spectrum disorder (ASD) has been an emerging area of research. Herein, we present a systematic review, and meta-analysis of published epidemiological studies that have investigated these associations. We undertook a comprehensive search strategy to identify studies that investigated outdoor air pollution and autism in children. Overall, seven cohorts and five case-control studies met our inclusion criteria for the meta-analysis. We summarized the associations between exposure to air pollution and ASD based on the following critical exposure windows: (i) first, second and third trimester of pregnancy, (ii) entire pregnancy, and (iii) postnatal period. Random effects meta-analysis modeling was undertaken to derive pooled risk estimates for these exposures across the studies. The meta-estimates for the change in ASD associated with a 10μg/m 3 increase in exposure in PM 2.5 and 10 ppb increase in NO 2 during pregnancy were 1.34 (95% CI:0.83, 2.17) and 1.05 (95% CI:0.99, 1.11), respectively. Stronger associations were observed for exposures received after birth, but these estimates were unstable as they were based on only two studies. O 3 exposure was weakly associated with ASD during the third trimester of pregnancy and during the entire pregnancy, however, these estimates were also based on only two studies. Our meta-analysis support the hypothesis that exposure to ambient air pollution is associated with an increased risk of autism. Our findings should be interpreted cautiously due to relatively small number of studies, and several studies were unable to control for other key risk factors. Copyright © 2016 Elsevier Inc. All rights reserved.
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Biswas, H. M.; Boral, M. C.
1986-06-01
Three groups of adult male toads were exposed intermittently in a decompression chamber for a daily period of 4 and 8 hours at a time for 6 consecutive days to an “altitude” of 12,000; 18,000 and 24,000 feet (3658; 5486; 7315 m) respectively. Most of the exposed animals were sacrificed immediately after the last exposure, but only a few animals experiencing 8 hours of exposure were sacrificed after a further 16 hours of exposure at normal atmospheric pressure. Eight hours of daily exposure for 6 days causes a decrease of body fluids and an increase of hematological parameters in all the altitude exposed animals compared with to the changes noted in the animals having 4 hours of daily exposure for 6 days at the same altitude levels. The animals that were exposed to pressures equivalent to altitudes of 12,000 and 18,000 feet daily for 8 hours were found to return nearly to their normal body fluids and hematological balance after 16 hours of exposure to normal atmospheric pressure, whereas the animals exposed for a similar period at an equivalent 24,000 feet failed to get back their normal balance of body fluids and hematology after 16 hours of exposure at normal atmospheric pressure. The present experiment shows that the body weight loss and changes of body fluid and hematological parameters in the toad after exposure to simulated high altitude are due not only to dehydration, but suggest that hypoxia may also have a role.
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Energy Technology Data Exchange (ETDEWEB)
Hopke, P.K.
1992-07-01
This report covers the second year of the 28 month grant current grant to Clarkson University to study the chemical and physical behavior of the polonium 218 atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical process that affect the progeny`s atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. This report describes the progress toward achieving these objectives.
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Complexities of sibling analysis when exposures and outcomes change with time and birth order.
Sudan, Madhuri; Kheifets, Leeka I; Arah, Onyebuchi A; Divan, Hozefa A; Olsen, Jørn
2014-01-01
In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were included. We examined differences in exposures and behavioral problems between siblings and non-siblings and by birth order and birth year. We estimated associations between cell phone exposures and behavioral problems while accounting for the random family effect among siblings. The association of behavioral problems with both prenatal and postnatal exposure differed between siblings (odds ratio (OR): 1.07; 95% confidence interval (CI): 0.69-1.66) and non-siblings (OR: 1.54; 95% CI: 1.36-1.74) and within siblings by birth order; the association was strongest for first-born siblings (OR: 1.72; 95% CI: 0.86-3.42) and negative for later-born siblings (OR: 0.63; 95% CI: 0.31-1.25), which may be because of increases in cell phone use with later birth year. Sibling analysis can be a powerful tool for (partially) accounting for confounding by invariant unmeasured within-family factors, but it cannot account for uncontrolled confounding by varying family-level factors, such as those that vary with time and birth order.
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Ratier, Aude; Dron, Julien; Revenko, Gautier; Austruy, Annabelle; Dauphin, Charles-Enzo; Chaspoul, Florence; Wafo, Emmanuel
2018-03-01
Lichen samples from contrasted environments, influenced by various anthropic activities, were investigated focusing on the contaminant signatures according to the atmospheric exposure typologies. Most of the contaminant concentrations measured in the 27 lichen samples, collected around the industrial harbor of Fos-sur-Mer (France), were moderate in rural and urban environments, and reached extreme levels in industrial areas and neighboring cities (Al up to 6567 mg kg -1 , Fe 42,398 mg kg -1 , or ΣPAH 1417 μg kg -1 for example). At the same time, a strong heterogeneity was noticed in industrial samples while urban and rural ones were relatively homogeneous. Several metals could be associated to steel industry (Fe, Mn, Cd), road traffic, and agriculture (Sb, Cu, Sn), or to a distinct chemical installation (Mo). As well, PCDFs dominated in industrial samples while PCDDs prevailed in urban areas. The particularities observed supported the purpose of this work and discriminated the contributions of various atmospheric pollution emission sources in lichen samples. A statistical approach based on principal component analysis (PCA) was applied and resolved these potential singularities into specific component factors. Even if a certain degree of mixing of the factors is pointed out, relevant relationships were observed with several atmospheric emission sources. By this methodology, the contribution of industrial emissions to the atmospheric metal, PAH, PCB, and PCDD/F levels was roughly estimated to be 60.2%, before biomass burning (10.2%) and road traffic (3.8%). These results demonstrate that lichen biomonitoring offers an encouraging perspective of spatially resolved source apportionment studies.
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Uranus atmospheric dynamics and circulation
Allison, Michael; Beebe, Reta F.; Conrath, Barney J.; Hinson, David P.; Ingersoll, Andrew P.
1991-01-01
The observations, models, and theories relevant to the atmospheric dynamics and meteorology of Uranus are discussed. The available models for the large-scale heat transport and atmospheric dynamics as well as diagnostic interpretations of the Voyager data are reviewed. Some pertinent ideas and questions regarding the global circulation balance are considered, partly in comparison with other planetary atmospheres. The available data indicate atmospheric rotation at midlatitudes nearly 200 m/s faster than that of the planetary magnetic field. Analysis of the dynamical deformation of the shape and size of isobaric surfaces measured by the Voyager radio-occultation experiment suggests a subrotating equator at comparable altitudes. Infrared temperature retrievals above the cloud deck indicate a smaller equator-to-pole contrast than expected for purely radiative-convective equilibrium, but show local variations implying a latitudinally correlated decrease with altitude in the cloud-tracked wind.
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Morrison, Lucas M; Unger, Kirk A; Watterson, James H
2017-07-01
Analysis of dextromethorphan (DXM) and its metabolite dextrorphan (DXT) in skeletal remains of rats following acute (ACU, 75 mg/kg, IP, n = 10) or three repeated (REP, 25 mg/kg, IP, n = 10, 40-min interval) doses of DXM is described. Following dosing and euthanasia, rats decomposed outdoors to skeleton in two different microclimate environments (n = 5 ACU and n = 5 REP at each site): Site A (shaded forest microenvironment) and Site B (rocky substrate exposed to direct sunlight, 600 m from Site A). Two drug-free rats at each site served as negative controls. Skeletal elements (vertebrae, ribs, pelvic girdles, femora, tibiae, skulls and scapulae) were recovered, pulverized and underwent methanolic microwave assisted extraction (MAE). Extracts were analyzed by GC-MS following clean-up by solid-phase extraction (SPE). Drug levels, expressed as mass-normalized response ratios and the ratios of DXT and DXM levels (RRDXT/RRDXM) were compared between drug exposures, microclimate sites, and across skeletal elements. DXM levels differed significantly (P < 0.05) between corresponding bone elements across exposure groups (5/7-site A; 4/7-site B), but no significant differences in DXT levels were observed between corresponding elements. RRDXT/RRDXM differed significantly (P < 0.05) between corresponding bone elements across exposure groups (6/7-site A; 5/7-site B). No significant differences were observed in levels of DXM, DXT or RRDXT/RRDXM between corresponding elements from either group between sites. When data from all bone elements was pooled, levels of DXM and RRDXT/RRDXM differed significantly between exposure groups at each site, while those of DXT did not. For both exposure groups, comparison of pooled data between sites showed no significant differences in levels of DXM, DXT or RRDXT/RRDXM. Different decomposition microclimates did not impede the discrimination of DXM exposure patterns from the analyses of DXM, DXT and RRDXT/RRDXM in bone samples. © The Author 2017
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International Nuclear Information System (INIS)
Villegas Gonzalez, Nicole
2014-01-01
The risk of disease associated with arsenic exposure is analyzed in water supply systems for human consumption, as well as the control of pollution and effects on health, in the community known as Barrio Hotel of Canas in comparison with the community of San Miguel in Canas, Guanacaste, Costa Rica. A spatial analysis, temporal and classification are realized by an ecological design of the country in the following zones of exposure: without exposure, low (≥3 μg/L and ≤10 μg/L) and medium to high (≥11 μg/L and ≤187 μg/L). The transversal design is tackled through the perceived morbidity. Spatial analysis has found in the districts of Bebedero, Los Chiles, Bagaces and Canas with Standardized Morbidity Index (EMI) by age in the the greatest national range of chronic renal failure (CRF). The protection of skin cancer risk is observed in the communities of Bagaces, Canas, El Amparo and La Cruz. A temporal trend of increase in IME of CRF and skin cancer is identified in Los Chiles. The classification by zone of exposure, the unexposed areas have been protected of kidney cancer, lung and bronchus, bladder and skin. The of low exposure have presented excess risk of CRF and have been protected of skin cancer. The of medium to high are protected of bladder cancer and have maintained the trend of excess in CRF and protection of skin cancer. The transversal design has found in the exposed community the risk to suffer kidneys diseases. Arsenic exposure has increased in men the risk of renal failure and anemia, in women the decrease of vision, and age groups under of 10 years and of 40-69 years of hypopigmentation and keratoses respectively. Multivariate analysis has showed a weak association of arsenic exposure time with the risk of hypertension [es
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A simplified model of the Martian atmosphere - Part 2: a POD-Galerkin analysis
Directory of Open Access Journals (Sweden)
S. G. Whitehouse
2005-01-01
Full Text Available In Part I of this study Whitehouse et al. (2005 performed a diagnostic analysis of a simplied model of the Martian atmosphere, in which topography was absent and in which heating was modelled as Newtonian relaxation towards a zonally symmetric equilibrium temperature field. There we derived a reduced-order approximation to the vertical and the horizonal structure of the baroclinically unstable Martian atmosphere, retaining only the barotropic mode and the leading order baroclinic modes. Our objectives in Part II of the study are to incorporate these approximations into a Proper Orthogonal Decomposition-Galerkin expansion of the spherical quasi-geostrophic model in order to derive hierarchies of nonlinear ordinary differential equations for the time-varying coefficients of the spatial structures. Two different vertical truncations are considered, as well as three different norms and 3 different Galerkin truncations. We investigate each in turn, using tools from bifurcation theory, to determine which of the systems most closely resembles the data for which the original diagnostics were performed.
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ANALYTICAL MODELS OF EXOPLANETARY ATMOSPHERES. I. ATMOSPHERIC DYNAMICS VIA THE SHALLOW WATER SYSTEM
Energy Technology Data Exchange (ETDEWEB)
Heng, Kevin [Center for Space and Habitability, University of Bern, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Workman, Jared, E-mail: kevin.heng@csh.unibe.ch, E-mail: jworkman@coloradomesa.edu [Colorado Mesa University, 1260 Kennedy Avenue, Grand Junction, CO 81501 (United States)
2014-08-01
Within the context of exoplanetary atmospheres, we present a comprehensive linear analysis of forced, damped, magnetized shallow water systems, exploring the effects of dimensionality, geometry (Cartesian, pseudo-spherical, and spherical), rotation, magnetic tension, and hydrodynamic and magnetic sources of friction. Across a broad range of conditions, we find that the key governing equation for atmospheres and quantum harmonic oscillators are identical, even when forcing (stellar irradiation), sources of friction (molecular viscosity, Rayleigh drag, and magnetic drag), and magnetic tension are included. The global atmospheric structure is largely controlled by a single key parameter that involves the Rossby and Prandtl numbers. This near-universality breaks down when either molecular viscosity or magnetic drag acts non-uniformly across latitude or a poloidal magnetic field is present, suggesting that these effects will introduce qualitative changes to the familiar chevron-shaped feature witnessed in simulations of atmospheric circulation. We also find that hydrodynamic and magnetic sources of friction have dissimilar phase signatures and affect the flow in fundamentally different ways, implying that using Rayleigh drag to mimic magnetic drag is inaccurate. We exhaustively lay down the theoretical formalism (dispersion relations, governing equations, and time-dependent wave solutions) for a broad suite of models. In all situations, we derive the steady state of an atmosphere, which is relevant to interpreting infrared phase and eclipse maps of exoplanetary atmospheres. We elucidate a pinching effect that confines the atmospheric structure to be near the equator. Our suite of analytical models may be used to develop decisively physical intuition and as a reference point for three-dimensional magnetohydrodynamic simulations of atmospheric circulation.
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Hintikka, Laura; Haapala, Markus; Franssila, Sami; Kuuranne, Tiia; Leinonen, Antti; Kostiainen, Risto
2010-12-24
Mass spectrometers equipped with atmospheric pressure ion sources (API-MS) have been designed to be interfaced with liquid chromatographs (LC) and have rarely been connected to gas chromatographs (GC). Recently, we introduced a heated nebulizer microchip and showed its potential to interface liquid microseparation techniques and GC with API-MS. This study demonstrates the feasibility of GC-microchip atmospheric pressure photoionization-tandem mass spectrometry (GC-μAPPI-MS/MS) in the analysis of underivatized anabolic steroids in urine. The APPI microchip provides high ionization efficiency and produces abundant protonated molecules or molecular ions with minimal fragmentation. The feasibility of GC-μAPPI-MS/MS in the analysis of six selected anabolic steroids in urine samples was studied with respect to intra-batch repeatability, linearity, linear range, and limit of detection (LOD). The method showed good sensitivity (LODs 0.2-1 ng/mL), repeatability (relative standard deviationanabolic steroids. Quantitative performance of the method was tested with two authentic urine samples, and the results were in good agreement with those obtained with conventional GC-electron ionization-MS after derivatization. Copyright © 2010 Elsevier B.V. All rights reserved.
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Natural radionuclides from the coal in atmospheric environment of the coal fired power plants
International Nuclear Information System (INIS)
Antic, D.; Kostic-Soskic, M.; Milovanovic, S.; Telenta, B.
1995-01-01
The inhalation radiation exposure of the public in the vicinity of the selected coal fired power plants near from Belgrade (30-50 km) has been studied, using a set of data for natural radionuclides from the analysed power plants. A generalised model for analysis of radiological impact of an energy source, that includes the two-dimensional version of the cloud model, has been used for simulation of the transport of radionuclides released to the atmosphere. The inhalation dose rates for an adult are assessed and analysed during fast changeable meteorological conditions. A set of realistic meteorological conditions (wind, radiosonde sounding temperature, pressure, and humidity data) has been used for the numerical simulations. (author)
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Unusual neurological syndrome induced by atmospheric pressure change.
Ptak, Judy A; Yazinski, Nancy A; Block, Clay A; Buckey, Jay C
2013-05-01
We describe a case of a 46-yr-old female who developed hypertension, tachycardia, dysarthria, and leg weakness provoked by pressure changes associated with flying. Typically during the landing phase of flight, she would feel dizzy and note that she had difficulty with speech and leg weakness. After the flight the leg weakness persisted for several days. The symptoms were mitigated when she took a combined alpha-beta blocker (labetalol) prior to the flight. To determine if these symptoms were related to atmospheric pressure change, she was referred for testing in a hyperbaric chamber. She was exposed to elevated atmospheric pressure (maximum 1.2 ATA) while her heart rate and blood pressure were monitored. Within 1 min she developed tachycardia and hypertension. She also quickly developed slurred speech, left arm and leg weakness, and sensory changes in her left leg. She was returned to sea level pressure and her symptoms gradually improved. A full neurological workup has revealed no explanation for these findings. She has no air collections, cysts, or other anatomic findings that could be sensitive to atmospheric pressure change. The pattern is most consistent with a vascular event stimulated by altitude exposure. This case suggests that atmospheric pressure change can produce neurological symptoms, although the mechanism is unknown.
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Computational Exposure Science: An Emerging Discipline to ...
Background: Computational exposure science represents a frontier of environmental science that is emerging and quickly evolving.Objectives: In this commentary, we define this burgeoning discipline, describe a framework for implementation, and review some key ongoing research elements that are advancing the science with respect to exposure to chemicals in consumer products.Discussion: The fundamental elements of computational exposure science include the development of reliable, computationally efficient predictive exposure models; the identification, acquisition, and application of data to support and evaluate these models; and generation of improved methods for extrapolating across chemicals. We describe our efforts in each of these areas and provide examples that demonstrate both progress and potential.Conclusions: Computational exposure science, linked with comparable efforts in toxicology, is ushering in a new era of risk assessment that greatly expands our ability to evaluate chemical safety and sustainability and to protect public health. The National Exposure Research Laboratory’s (NERL’s) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA’s mission to protect human health and the environment. HEASD’s research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA’s strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source
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Prototype Operational Advances for Atmospheric Radiation Dose Rate Specification
Tobiska, W. K.; Bouwer, D.; Bailey, J. J.; Didkovsky, L. V.; Judge, K.; Garrett, H. B.; Atwell, W.; Gersey, B.; Wilkins, R.; Rice, D.; Schunk, R. W.; Bell, D.; Mertens, C. J.; Xu, X.; Crowley, G.; Reynolds, A.; Azeem, I.; Wiltberger, M. J.; Wiley, S.; Bacon, S.; Teets, E.; Sim, A.; Dominik, L.
2014-12-01
Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. The coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has developed innovative, new space weather observations that will become part of the toolset that is transitioned into operational use. One prototype operational system for providing timely information about the effects of space weather is SET's Automated Radiation Measurements for Aerospace Safety (ARMAS) system. ARMAS will provide the "weather" of the radiation environment to improve aircraft crew and passenger safety. Through several dozen flights the ARMAS project has successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time via Iridium satellites, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. We are extending the dose measurement domain above commercial aviation altitudes into the stratosphere with a collaborative project organized by NASA's Armstrong Flight Research Center (AFRC) called Upper-atmospheric Space and Earth Weather eXperiment (USEWX). In USEWX we will be flying on the ER-2 high altitude aircraft a micro dosimeter for
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A.B. Graves; C.M. van Duijn (Cornelia); V. Chandra; L. Fratiglioni (Laura); A. Heyman; A.F. Jorm; E. Kokmen (Emre); K. Kondo; J.A. Mortimer; W.A. Rocca; S.L. Shalat; H. Soininen; A. Hofman (Albert)
1991-01-01
textabstractA meta-analysis, involving the secondary analysis of original data from 11 case-control studies of Alzheimer's disease, is presented for occupational exposures to solvents and lead. Three studies had data on occupational exposure to solvents. Among cases, 21.3% were reported to have been
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Mertens, C. J.; Kress, B. T.; Wiltberger, M. J.; Tobiska, W.; Xu, X.
2011-12-01
The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. During the development of the NAIRAS model, new science questions were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. Addressing these science questions require improvements in both space weather modeling and observations. The focus of this talk is to present these science questions, the proposed methodologies for addressing these science questions, and the anticipated improvements to the operational predictions of atmospheric radiation exposure. The overarching goal of this work is to provide a decision support tool for the aviation industry that will enable an optimal balance to be achieved between minimizing health risks to passengers and aircrew while simultaneously minimizing costs to the airline companies.
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Pelucchi, Claudio; Galeone, Carlotta; Bach, Jean-François; La Vecchia, Carlo; Chatenoud, Liliane
2013-09-01
Findings on pet exposure and the risk of atopic dermatitis (AD) in children are inconsistent. With the aim to summarize the results of exposure to different pets on AD, we undertook a meta-analysis of epidemiologic studies on this issue. In August 2012, we conducted a systematic literature search in Medline and Embase. We included analytic studies considering exposure to dogs, cats, other pets, or pets overall during pregnancy, infancy, and/or childhood, with AD assessment performed during infancy or childhood. We calculated summary relative risks and 95% CIs using both fixed- and random-effects models. We computed summary estimates across selected subgroups. Twenty-six publications from 21 birth cohort studies were used in the meta-analyses. The pooled relative risks of AD for exposure versus no exposure were 0.72 (95% CI, 0.61-0.85; I(2) = 46%; results based on 15 studies) for exposure to dogs, 0.94 (95% CI, 0.76-1.16; I(2) = 54%; results based on 13 studies) for exposure to cats, and 0.75 (95% CI, 0.67-0.85; I(2) = 54%; results based on 11 studies) for exposure to pets overall. No heterogeneity emerged across the subgroups examined, except for geographic area. This meta-analysis reported a favorable effect of exposure to dogs and pets on the risk of AD in infants or children, whereas no association emerged with exposure to cats. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.
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Photosynthesis and growth response of almond to increased atmospheric ozone partial pressures
International Nuclear Information System (INIS)
Retzlaff, W.A.; Williams, L.E.; DeJong, T.M.
1992-01-01
Uniform nursery stock of five almond cultivars [Prunus dulcis (Mill) D.A. Webb syn. P. amygdalus Batsch, cv. Butte, Carmel, Mission, Nonpareil, and Sonora] propagated on peach (P. domstica L. Batsch.) rootstock were exposed to three different atmospheric ozone (O 3 ) partial pressures. The trees were planted in open-top fumigation chambers on 19 Apr. 1989 at the University of California Kearny Agricultural Center located in the San Joaquin Valley of California. Exposures of the trees to three atmospheric O 3 partial pressures lasted from 1 June to 2 Nov. 1989. The mean 12-h [0800-2000 h Pacific Daylight Time (PDT)] O 3 partial pressures measured in the open-top chambers during the experimental period were 0.038, 0.060, and 0.112 μPa Pa -1 O 3 in the charcoal filtered, ambient, and ambient + O 3 treatments, respectively. Leaf net CO 2 assimilation, trunk cross-sectional area growth, and root, trunk, foliage, and total dry weight of Nonpareil were reduced by increased atmospheric O 3 partial pressures. Mission was unaffected by O 3 and Butte, Carmel, and Sonora were intermediate in their responses. Foliage of Nonpareil also abscised prematurely in the ambient and ambient + O 3 treatments. The results indicate that there are almond cultivars that are sensitive to O 3 exposure
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Directory of Open Access Journals (Sweden)
Xiaoqing Shao
2017-07-01
Full Text Available A number of studies have previously assessed the impact of antibiotic exposure in early life on the risk of childhood obesity, but no systematic assessment is currently available. A systematic review and meta-analysis was performed to comprehensively and quantitatively elucidate the risk of childhood obesity caused by antibiotic exposure in early life. Literature search was performed in PubMed, Embase, and Web of Science. Random-effect meta-analysis was used to pool the statistical estimates. Fifteen cohort studies involving 445,880 participants were finally included, and all those studies were performed in developed countries. Antibiotic exposure in early life significantly increased risk of childhood overweight [relative risk (RR = 1.23, 95% confidence interval (CI 1.13–1.35, P < 0.001] and childhood obesity (RR = 1.21, 95% CI 1.13–1.30, P < 0.001. Antibiotic exposure in early life also significantly increased the z-score of childhood body mass index (mean difference: 0.07, 95% CI 0.05–0.09, P < 0.00001. Importantly, there was an obvious dose–response relationship between antibiotic exposure in early life and childhood adiposity, with a 7% increment in the risk of overweight (RR = 1.07, 95% CI 1.01–1.15, P = 0.03 and a 6% increment in the risk of obesity (RR = 1.06, 95% CI 1.02–1.09, P < 0.001 for each additional course of antibiotic exposure. In conclusion, antibiotic exposure in early life significantly increases risk of childhood obesity. Moreover, current analyses are mainly taken from developed countries, and therefore the impact of antibiotic exposure on risk of childhood obesity in vulnerable populations or developing countries still needs to be evaluated in future studies.
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[Respiratory symptoms and atmospheric pollution and respiratory symptoms in the general population].
Simon, I; Charpin, D
2010-06-01
Epidemiological studies on air pollution have mainly been interested in the effects of short- or long-term exposure on patients suffering from respiratory illnesses. Fewer studies have addressed the acute effects of air pollution on respiratory symptoms in the general population. We conducted a review of the literature over the last 16years that has addressed the impact of atmospheric pollution on respiratory symptoms in the general population to estimate the magnitude of effect. The majority of studies demonstrated a significant association between exposure to air pollutants and the occurrence of respiratory symptoms, without any threshold. Although a link between atmospheric pollution and respiratory symptoms has been demonstrated, knowledge of the effects of specific air pollutants and the effect of pollution on particular vulnerable groups (infants, young children, the elderly) is still limited. There is a need for further studies in this area. Copyright 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.
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Prenatal exposure to polychlorinated biphenyls: a neuropsychologic analysis.
Boucher, Olivier; Muckle, Gina; Bastien, Célyne H
2009-01-01
A large body of literature documents the effects of prenatal exposure to polychlorinated biphenyls (PCBs) on cognitive development of children. Despite this fact, no integrative synthesis has been published yet to identify the cognitive functions that are particularly affected. Our aim is to review this literature in an attempt to identify the cognitive profile associated with prenatal PCB exposure. Studies were identified by searching the PubMed database for articles published before June 2008. We reviewed data from nine prospective longitudinal birth cohorts for different aspects of cognition. Associations between indicators of prenatal PCB exposure and performance on cognitive tasks reported in the selected studies are summarized and classified as general cognitive abilities, verbal or visual-spatial skills, memory, attention, and executive functions. The most consistent effects observed across studies are impaired executive functioning related to increased prenatal PCB exposure. Negative effects on processing speed, verbal abilities, and visual recognition memory are also reported by most studies. Converging results from different cohort studies in which exposure arises from different sources make it unlikely that co-exposure with another associated contaminant is responsible for the observed effects. Prenatal PCB exposure appears to be related to a relatively specific cognitive profile of impairments. Failure to assess functions that are specifically impaired may explain the absence of effects found in some studies. Our findings have implications in the selection of cognitive assessment methods in future studies.
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A technique is described where an atmospheric pressure-thermal desorption (AP-TD) device and electrospray ionization (ESI)-mass spectrometry are coupled and used for the rapid analysis of Bacillus spores in complex matrices. The resulting AP-TD/ESI-MS technique combines the generation of volatile co...
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Charakopoulos, A. K.; Katsouli, G. A.; Karakasidis, T. E.
2018-04-01
Understanding the underlying processes and extracting detailed characteristics of spatiotemporal dynamics of ocean and atmosphere as well as their interaction is of significant interest and has not been well thoroughly established. The purpose of this study was to examine the performance of two main additional methodologies for the identification of spatiotemporal underlying dynamic characteristics and patterns among atmospheric and oceanic variables from Seawatch buoys from Aegean and Ionian Sea, provided by the Hellenic Center for Marine Research (HCMR). The first approach involves the estimation of cross correlation analysis in an attempt to investigate time-lagged relationships, and further in order to identify the direction of interactions between the variables we performed the Granger causality method. According to the second approach the time series are converted into complex networks and then the main topological network properties such as degree distribution, average path length, diameter, modularity and clustering coefficient are evaluated. Our results show that the proposed analysis of complex network analysis of time series can lead to the extraction of hidden spatiotemporal characteristics. Also our findings indicate high level of positive and negative correlations and causalities among variables, both from the same buoy and also between buoys from different stations, which cannot be determined from the use of simple statistical measures.
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Torres, Craig; Jones, Rachael; Boelter, Fred; Poole, James; Dell, Linda; Harper, Paul
2014-01-01
Bayesian Decision Analysis (BDA) uses Bayesian statistics to integrate multiple types of exposure information and classify exposures within the exposure rating categorization scheme promoted in American Industrial Hygiene Association (AIHA) publications. Prior distributions for BDA may be developed from existing monitoring data, mathematical models, or professional judgment. Professional judgments may misclassify exposures. We suggest that a structured qualitative risk assessment (QLRA) method can provide consistency and transparency in professional judgments. In this analysis, we use a structured QLRA method to define prior distributions (priors) for BDA. We applied this approach at three semiconductor facilities in South Korea, and present an evaluation of the performance of structured QLRA for determination of priors, and an evaluation of occupational exposures using BDA. Specifically, the structured QLRA was applied to chemical agents in similar exposure groups to identify provisional risk ratings. Standard priors were developed for each risk rating before review of historical monitoring data. Newly collected monitoring data were used to update priors informed by QLRA or historical monitoring data, and determine the posterior distribution. Exposure ratings were defined by the rating category with the highest probability--i.e., the most likely. We found the most likely exposure rating in the QLRA-informed priors to be consistent with historical and newly collected monitoring data, and the posterior exposure ratings developed with QLRA-informed priors to be equal to or greater than those developed with data-informed priors in 94% of comparisons. Overall, exposures at these facilities are consistent with well-controlled work environments. That is, the 95th percentile of exposure distributions are ≤50% of the occupational exposure limit (OEL) for all chemical-SEG combinations evaluated; and are ≤10% of the limit for 94% of chemical-SEG combinations evaluated.
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Gohil, B. S.; Hariharan, T. A.; Sharma, A. K.; Pandey, P. C.
1982-01-01
The 19.35 GHz and 22.235 GHz passive microwave radiometers (SAMIR) on board the Indian satellite Bhaskara have provided very useful data. From these data has been demonstrated the feasibility of deriving atmospheric and ocean surface parameters such as water vapor content, liquid water content, rainfall rate and ocean surface winds. Different approaches have been tried for deriving the atmospheric water content. The statistical and empirical methods have been used by others for the analysis of the Nimbus data. A simulation technique has been attempted for the first time for 19.35 GHz and 22.235 GHz radiometer data. The results obtained from three different methods are compared with radiosonde data. A case study of a tropical depression has been undertaken to demonstrate the capability of Bhaskara SAMIR data to show the variation of total water vapor and liquid water contents.
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Yang, Liang
2014-04-01
Free-space optical (FSO) communication has become a cost-effective method to provide high data rates. However, the turbulence-induced fading limits its application to short-range applications. To address this, we propose a multiuser diversity (MD) FSO scheme in which the Nth best user is selected and the channel fluctuations can be effectively exploited to produce a selection diversity gain. More specifically, we first present the statistics analysis for the considered system over both weak and strong atmospheric turbulence channels. Based on these statistics, the outage probability, bit-error rate performance, average capacity, diversity order, and coverage are analyzed. Results show that the diversity order for the gamma-gamma fading is N min{α, β}/2, where N is the number of users, and α and β are the channel fading parameters related to the effective atmospheric conditions of the link.
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Control of occupational exposure to cosmic radiation outside the atmosphere
International Nuclear Information System (INIS)
Katoh, Kazuaki; Kaneko, Masahito
2000-01-01
Japan is participating in the project of constructing ISS, International Space Station, and taking part of constructing JEM, Japan Experimental Module. It is expected that people working in this module upon completion should be controlled their exposure to cosmic radiation according to Japanese laws. Hence, the issue has been studied by a committee in NASDA, National Space Development Agency of Japan. In 1999, its interim report was released and public comments had been invited. In this presentation, following the introduction of the gist of the interim report as well as comments by the authors, countermeasures are proposed. (author)
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Paternal exposure to Agent Orange and spina bifida: a meta-analysis
International Nuclear Information System (INIS)
Ngo, Anh Duc; Taylor, Richard; Roberts, Christine L.
2010-01-01
The objective of this study is to conduct a meta-analysis of published and unpublished studies that examine the association between Agent Orange (AO) exposure and the risk of spina bifida. Relevant studies were identified through a computerized literature search of Medline and Embase from 1966 to 2008; a review of the reference list of retrieved articles and conference proceedings; and by contacting researchers for unpublished studies. Both fixed-effects and random-effects models were used to pool the results of individual studies. The Cochrane Q test and index of heterogeneity (I 2 ) were used to evaluate heterogeneity, and a funnel plot and Egger's test were used to evaluate publication bias. Seven studies, including two Vietnamese and five non-Vietnamese studies, involving 330 cases and 134,884 non-cases were included in the meta-analysis. The overall relative risk (RR) for spina bifida associated with paternal exposure to AO was 2.02 (95% confidence interval [CI]: 1.48-2.74), with no statistical evidence of heterogeneity across studies. Non-Vietnamese studies showed a slightly higher summary RR (RR = 2.22; 95% CI: 1.38-3.56) than Vietnamese studies (RR = 1.92 95% CI: 1.29-2.86). When analyzed separately, the overall association was statistically significant for the three case-control studies (Summary Odds Ratio = 2.25, 95% CI: 1.31-3.86) and the cross sectional study (RR = 1.97, 95% CI: 1.31-2.96), but not for the three cohort studies (RR: 2.11; 95% CI: 0.78-5.73). Paternal exposure to AO appears to be associated with a statistically increased risk of spina bifida.
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Avissar, Roni; Chen, Fei
1993-01-01
Generated by landscape discontinuities (e.g., sea breezes) mesoscale circulation processes are not represented in large-scale atmospheric models (e.g., general circulation models), which have an inappropiate grid-scale resolution. With the assumption that atmospheric variables can be separated into large scale, mesoscale, and turbulent scale, a set of prognostic equations applicable in large-scale atmospheric models for momentum, temperature, moisture, and any other gaseous or aerosol material, which includes both mesoscale and turbulent fluxes is developed. Prognostic equations are also developed for these mesoscale fluxes, which indicate a closure problem and, therefore, require a parameterization. For this purpose, the mean mesoscale kinetic energy (MKE) per unit of mass is used, defined as E-tilde = 0.5 (the mean value of u'(sub i exp 2), where u'(sub i) represents the three Cartesian components of a mesoscale circulation (the angle bracket symbol is the grid-scale, horizontal averaging operator in the large-scale model, and a tilde indicates a corresponding large-scale mean value). A prognostic equation is developed for E-tilde, and an analysis of the different terms of this equation indicates that the mesoscale vertical heat flux, the mesoscale pressure correlation, and the interaction between turbulence and mesoscale perturbations are the major terms that affect the time tendency of E-tilde. A-state-of-the-art mesoscale atmospheric model is used to investigate the relationship between MKE, landscape discontinuities (as characterized by the spatial distribution of heat fluxes at the earth's surface), and mesoscale sensible and latent heat fluxes in the atmosphere. MKE is compared with turbulence kinetic energy to illustrate the importance of mesoscale processes as compared to turbulent processes. This analysis emphasizes the potential use of MKE to bridge between landscape discontinuities and mesoscale fluxes and, therefore, to parameterize mesoscale fluxes
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Atmospheric metal deposition in France: Estimation based on moss analysis. First results
International Nuclear Information System (INIS)
Galsomies, L.; Letrouit-Galinou, M.A.; Avnaim, M.; Duclaux, G.; Deschamps, C.; Savanne, D.
2000-01-01
The aim of this programme set up by University Pierre and Marie Curie-Paris VI and ADEME (French Agency for the Environment and Energy Management) is to obtain information on the atmospheric deposition of 36 elements (most being heavy metals) all over France, using 5 common mosses as bioaccumulators: Pleurozium schreberi, Hylocomium splendens, Hypnum cupressiforme, Scleropodium purum and Thuidium tamariscinum. Sampling was performed in 1996 from April to November thanks to 43 collectors. One sample of moss at least has been collected in 512 sites distributed over France, with an average density of one site each 1000 km 2 . Procedures for sampling, drying, cleaning, sorting are strictly codified based on Scandinavian guidelines. Analyses are performed according to two procedures: ICP-MS (Inductively Coupled Plasma, Mass Spectrometry) for Pb, Ni specialty and INAA (instrumental Neutron Activation Analysis for other elements. Data concerning As, Cd, Cr, Cu, Fe, Hg, Pb. Ni, V, Zn will be incorporated into the 1995-1996 European Programme 'Atmospheric Heavy Metal Deposition in Europe - estimation based on moss analysis' coordinated by the Nordic Council. The analyses are in progress, but preliminary results from Ile-de-France have been achieved for 34 elements in INAA. A preliminary study has shown that interspecies calibration could be possible for some heavy metals and that saturation effects in one species could be present when the intercalibration between species is not possible. Such a programme is made possible thanks to the financial support of the French Ministry of Environment and ADEME and with the active cooperation of several national organisations, especially the Laboratory Pierre Sue (CNRS-CEA). (author)
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Energy Technology Data Exchange (ETDEWEB)
Teschke, K.; Netten, C. van; Kennedy, S. [British Columbia Univ., Vancouver, BC (Canada)
2003-03-27
The University of British Columbia was asked by the Safety and Health in Arts Production and Entertainment to assist in investigating a number of issues concerning the safety of theatrical smokes and fogs. Specifically, the study strove to answer the following: (1) what products and equipment are used in the British Columbia (BC) entertainment industry, the chemicals that are used, and does the composition of the chemicals change once they are heated during use?, (2) what measuring equipment can be used for on-site monitoring by production staff?, (3) what levels of smokes and fogs are present in the air, the sizes of the airborne fog droplets, the type of exposure of employees?, (4) and are employees suffering ill health effects as a result of exposure? In the course of the study, 23 members of the International Alliance of Theatrical Stage Employees (IATSE) Local 891 were interviewed concerning their jobs, including the materials and equipment they use to create atmospheric effects. In addition, laboratory investigations of the constituents of the glycol fluids and their potential for pyrolysis under normal operating conditions were performed, as well as field tests of measurement methods to allow industry personnel to check exposure levels easily. The authors also performed a cross-sectional study of exposures to theatrical employees in the industry. The results showed that several technicians formulated their own fluids. Bulk samples were obtained of 15 glycol-based fluids and were found to have the same proportions of specific glycols as specified on their Material Safety Data Sheets. Three commercially available real-time direct-reading monitors were evaluated as simple monitoring methods. The preferred method was found to be the DataRAM which is easy to use, can be worn as a personal monitor and is silent. The drawback is the price (8000 dollars). Several recommendations were made. refs., tabs., figs.
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Environmental consequences of atmospheric krypton-85
International Nuclear Information System (INIS)
Boeck, W.L.
1978-01-01
This project examines the thesis that atmospheric background ionization is relevant to the understanding of weather. Projections of future world-wide use of nuclear energy imply that sufficient krypton-85 will be produced and may be released to significantly alter the natural ionization background. The scope of the project includes an assessment of krypton-85 on the electrical aspects of the atmosphere as well as the consequences of an altered electrical state of the atmosphere. The results of a first approximation model for the effects of krypton-85 on the atmosphere show that the electric field at the surface of the ocean would be reduced by about 25 percent and at a continental station by about 15 percent. At about two kilometers altitude, the electric field would be reduced by about 14 percent over the oceans and 16 percent over the land. The effects decrease quickly with increasing altitude. Analytical studies of the equations for fair weather atmospheric electricity yield solutions suitable for the interpretation of time dependent phenomena with periods longer than a few seconds. A brief analysis shows that a perfect assessment is not necessary to make an error-free decision regarding krypton-85 control measures. From the viewpoint of a decision-maker, those aspects that could swing the decision from one alternative to another are priority areas for analysis
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Chromosomal analysis and application of biological dosimetry in two cases of apparent over exposure
International Nuclear Information System (INIS)
Guerrero C, C.; Brena V, M.
2002-01-01
The gamma radiation calibration curve of 60 Co is used which was generated in the ININ Laboratory of Biology to calculate the exposure dose of two workers whose dosemeters marked values above of the limit allowed. The analysis indicates that in a first case, the aberrations frequency corresponded to the basal value, therefore there is not over exposure. The aberrations frequency of the second case is lightly above to the basal value and therefore the probability favors to what the physical dosimetry indicates. (Author)
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Children's Lead Exposure: A Multimedia Modeling Analysis to Guide Public Health Decision-Making.
Zartarian, Valerie; Xue, Jianping; Tornero-Velez, Rogelio; Brown, James
2017-09-12
Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)'s National Drinking Water Advisory Council (NDWAC) recommended establishment of a "health-based, household action level" for lead in drinking water based on children's exposure. The primary objective was to develop a coupled exposure-dose modeling approach that can be used to determine what drinking water lead concentrations keep children's blood lead levels (BLLs) below specified values, considering exposures from water, soil, dust, food, and air. Related objectives were to evaluate the coupled model estimates using real-world blood lead data, to quantify relative contributions by the various media, and to identify key model inputs. A modeling approach using the EPA's Stochastic Human Exposure and Dose Simulation (SHEDS)-Multimedia and Integrated Exposure Uptake and Biokinetic (IEUBK) models was developed using available data. This analysis for the U.S. population of young children probabilistically simulated multimedia exposures and estimated relative contributions of media to BLLs across all population percentiles for several age groups. Modeled BLLs compared well with nationally representative BLLs (0-23% relative error). Analyses revealed relative importance of soil and dust ingestion exposure pathways and associated Pb intake rates; water ingestion was also a main pathway, especially for infants. This methodology advances scientific understanding of the relationship between lead concentrations in drinking water and BLLs in children. It can guide national health-based benchmarks for lead and related community public health decisions. https://doi.org/10.1289/EHP1605.
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Study on atmosphere pollution by PIXE analysis combining with statistical method
International Nuclear Information System (INIS)
Zhu Guanghua
1994-06-01
Atmospheric aerosol samples were collected using an 8-stage cascade impactor or an automatic time sequence step sampler at Jomo Langma, Zhangye at the edge of Gobi Desert and Beijing. Element concentration were analyzed by PIXE (proton induced X-ray emission) technique. The data were analyzed by APCA (absolute principal component analysis) to determine the principal components. The sources and contribution to the aerosol in the above three regions were discussed. The result shows that the PIXE has high sensitivity, multi-element capability, high speed and non-destruction advantages. APCA analytical method can effectively determine the aerosol components in urban area, and it also can distinguish between local components and remote components in the area far from the pollution resources
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Analysis of Nerve Agent Metabolites from Hair for Long-Term Verification of Nerve Agent Exposure
2016-05-09
rats. The exposed hair samples were received from USAMRICD early in method development and required storage until the method was developed and validated...Because the storage of hair samples after an exposure has not been studied, it was unclear as to whether the analyte would be stable in the stored...biological matrixes typically used for analysis (i.e., blood, urine , and tissues), limiting the amount of time after an exposure that verification is
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Energy Technology Data Exchange (ETDEWEB)
Li, Fang [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Jin, Jing [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); Sun, Xiaoli [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Xueli; Li, Yun; Shah, Syed Mazhar [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); Chen, Jiping, E-mail: chenjp@dicp.ac.cn [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China)
2014-09-15
Highlights: • Atmospheric PCNs were detected by isotope-dilution GC–MS/MS. • The pollution levels of PCNs covering from mono- to octa-CNs were investigated comprehensively in air samples. • The dioxin-like toxicity and human exposure levels of PCNs in air samples were estimated. - Abstract: Atmospheric polychlorinated naphthalenes (PCNs) ranging from mono-CNs to octa-CNs were detected using isotope-dilution gas chromatography coupled with triple quadrupole mass spectrometry (GC–MS/MS). The developed instrumental method was successfully applied to the determination of PCNs in technical products. It was observed that there were significant differences in concentrations, homologue profiles, chlorinated contents and total toxic equivalents (∑TEQs) of PCNs for four Halowax products. Subsequently, the validation of the analytical method was evaluated for the determination of PCNs in air samples in terms of method detection limit (MDL), recovery and matrix effect. The results demonstrated that this method could provide satisfactory sensitivity and adequate selectivity with lower cost. It was conducted to comprehensively evaluate the levels, composition patterns, ∑TEQs, and daily intake exposure of PCNs in indoor and outdoor air samples. Concentrations and ∑TEQs of PCNs in air samples ranged 47.7–832.7 pg m{sup −3} and 1.31–5.99 fg m{sup −3}, respectively, and the predominant homologues were di- and tri-CNs in the gas phase. The results indicated that this analytical method was useful for the accurate and specific evaluation of dioxin-like toxicity and human exposure levels of PCNs in the atmosphere.
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Surface Exposure Geochronology Using Cosmogenic Nuclides: Applications in Antarctic Glacial Geology
1994-02-01
in rocks, are particularly promising for directly dating 1 geological surfaces . In 1934, Grosse et al. first suggested that cosmic rays produce rare...and muons produced by cosmic ray irteractions in the atmosphere and in rocks, and spallation by I neutrons produced in muon capture reactions (Kurz...stable isotopes are useful for surface 3 exposure studies because they can act as integrators of cosmic ray exposure on long time scales, potentially up
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Atmospheric heavy metal deposition in Europe estimated by moss analysis
Energy Technology Data Exchange (ETDEWEB)
Ruehling, Aa. [Swedish Environmental Research Inst., Lund (Sweden). Dept. of Ecology
1995-12-31
Atmospheric heavy metal deposition in Europe including 21 countries was monitored in 1990-1992 by the moss technique. This technique is based on the fact that the concentrations of heavy metals in moss are closely correlated to atmospheric deposition. This was the first attempt to map heavy metal deposition in this large area. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicate the location of important heavy metal pollution sources and to allow retrospective comparisons with similar studies. The present survey is a follow-up of a joint Danish and Swedish project in 1980 and an extended survey in 1985 within the framework of the Nordic Council of Ministers. In Sweden, heavy-metal deposition was first mapped on a nation-wide scale in 1968-1971 and 1975. (author)
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Atmospheric heavy metal deposition in Europe estimated by moss analysis
Energy Technology Data Exchange (ETDEWEB)
Ruehling, Aa [Swedish Environmental Research Inst., Lund (Sweden). Dept. of Ecology
1996-12-31
Atmospheric heavy metal deposition in Europe including 21 countries was monitored in 1990-1992 by the moss technique. This technique is based on the fact that the concentrations of heavy metals in moss are closely correlated to atmospheric deposition. This was the first attempt to map heavy metal deposition in this large area. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicate the location of important heavy metal pollution sources and to allow retrospective comparisons with similar studies. The present survey is a follow-up of a joint Danish and Swedish project in 1980 and an extended survey in 1985 within the framework of the Nordic Council of Ministers. In Sweden, heavy-metal deposition was first mapped on a nation-wide scale in 1968-1971 and 1975. (author)
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International Nuclear Information System (INIS)
Stenner, Robert D.; Bowers, Harold N.; Kenoyer, Judson L.; Strenge, Dennis L.; Brady, William H.; Ladue, Buffi; Samuels, Joseph K.
2001-01-01
The Department of Energy (DOE) has the responsibility to understand the ''big picture'' of worker health and safety which includes fully recognizing the vulnerabilities and associated programs necessary to protect workers at the various DOE sites across the complex. Exposure analysis and medical surveillance are key aspects for understanding this big picture, as is understanding current health and safety practices and how they may need to change to relate to future health and safety management needs. The exposure-based health issues project was initiated to assemble the components necessary to understand potential exposure situations and their medical surveillance and clinical aspects. Phase I focused only on current Hanford tank farm operations and serves as a starting point for the overall project. It is also anticipated that once the pilot is fully developed for Hanford HLW (i.e., current operations, retrieval, pretreatment, vitrification, and disposal), the process and analysis methods developed will be available and applicable for other DOE operations and sites. The purpose of this Phase I project report is to present the health impact information collected regarding ongoing tank waste maintenance operations, show the various aspects of health and safety involved in protecting workers, introduce the reader to the kinds of information that will need to be analyzed in order to effectively manage worker safety
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Nanoparticle exposure biomonitoring: exposure/effect indicator development approaches
Marie-Desvergne, C.; Dubosson, M.; Lacombe, M.; Brun, V.; Mossuz, V.
2015-05-01
The use of engineered nanoparticles (NP) is more and more widespread in various industrial sectors. The inhalation route of exposure is a matter of concern (adverse effects of air pollution by ultrafine particles and asbestos). No NP biomonitoring recommendations or standards are available so far. The LBM laboratory is currently studying several approaches to develop bioindicators for occupational health applications. As regards exposure indicators, new tools are being implemented to assess potentially inhaled NP in non-invasive respiratory sampling (nasal sampling and exhaled breath condensates (EBC)). Diverse NP analytical characterization methods are used (ICP-MS, dynamic light scattering and electron microscopy coupled to energy-dispersive X-ray analysis). As regards effect indicators, a methodology has been developed to assess a range of 29 cytokines in EBCs (potential respiratory inflammation due to NP exposure). Secondly, collaboration between the LBM laboratory and the EDyp team has allowed the EBC proteome to be characterized by means of an LC-MS/MS process. These projects are expected to facilitate the development of individual NP exposure biomonitoring tools and the analysis of early potential impacts on health. Innovative techniques such as field-flow fractionation combined with ICP-MS and single particle-ICPMS are currently being explored. These tools are directly intended to assist occupational physicians in the identification of exposure situations.
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Nanoparticle exposure biomonitoring: exposure/effect indicator development approaches
International Nuclear Information System (INIS)
Marie-Desvergne, C; Dubosson, M; Mossuz, V; Lacombe, M; Brun, V
2015-01-01
The use of engineered nanoparticles (NP) is more and more widespread in various industrial sectors. The inhalation route of exposure is a matter of concern (adverse effects of air pollution by ultrafine particles and asbestos). No NP biomonitoring recommendations or standards are available so far. The LBM laboratory is currently studying several approaches to develop bioindicators for occupational health applications. As regards exposure indicators, new tools are being implemented to assess potentially inhaled NP in non-invasive respiratory sampling (nasal sampling and exhaled breath condensates (EBC)). Diverse NP analytical characterization methods are used (ICP-MS, dynamic light scattering and electron microscopy coupled to energy-dispersive X-ray analysis). As regards effect indicators, a methodology has been developed to assess a range of 29 cytokines in EBCs (potential respiratory inflammation due to NP exposure). Secondly, collaboration between the LBM laboratory and the EDyp team has allowed the EBC proteome to be characterized by means of an LC-MS/MS process. These projects are expected to facilitate the development of individual NP exposure biomonitoring tools and the analysis of early potential impacts on health. Innovative techniques such as field-flow fractionation combined with ICP-MS and single particle-ICPMS are currently being explored. These tools are directly intended to assist occupational physicians in the identification of exposure situations. (paper)
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Rising atmospheric CO{sub 2} and crops: Research methodology and direct effects
Energy Technology Data Exchange (ETDEWEB)
Rogers, H. [National Soil Dynamics Laboratory, Auburn, AL (United States); Acock, B. [Systems Research Laboratory, Beltsville, MD (United States)
1993-12-31
Carbon dioxide is the food of trees and grass. Our relentless pursuit of a better life has taken us down a traffic jammed road, past smoking factories and forests. This pursuit is forcing a rise in the atmospheric CO{sub 2} level, and no one know when and if flood stage will be reached. Some thinkers have suggested that this increase of CO{sub 2} in the atmosphere will cause warming. No matter whether this prediction is realized or not, more CO{sub 2} will directly affect plants. Data from controlled observations have usually, but not always, shown benefits. Our choices of scientific equipment for gathering CO{sub 2} response data are critical since we must see what is happening through the eye of the instrument. The signals derived from our sensors will ultimately determine the truth of our conclusions, conclusion which will profoundly influence our policy decisions. Experimental gear is selected on the basis of scale of interest and problem to be addressed. Our imaginations and our budgets interact to set bounds on our objectives and approaches. Techniques run the gamut from cellular microprobes through whole-plant controlled environment chambers to field-scale exposure systems. Trade-offs exist among the various CO{sub 2} exposure techniques, and many factors impinge on the choice of a method. All exposure chambers are derivatives of three primary types--batch, plug flow, and continuous stirred tank reactor. Systems for the generation of controlled test atmospheres of CO{sub 2} vary in two basic ways--size and degree of control. Among the newest is free-air CO{sub 2} enrichment which allows tens of square meters of cropland to be studied.
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Romano, F.; Massuti-Ballester, B.; Binder, T.; Herdrich, G.; Fasoulas, S.; Schönherr, T.
2018-06-01
Challenging space mission scenarios include those in low altitude orbits, where the atmosphere creates significant drag to the S/C and forces their orbit to an early decay. For drag compensation, propulsion systems are needed, requiring propellant to be carried on-board. An atmosphere-breathing electric propulsion system (ABEP) ingests the residual atmosphere particles through an intake and uses them as propellant for an electric thruster. Theoretically applicable to any planet with atmosphere, the system might allow to orbit for unlimited time without carrying propellant. A new range of altitudes for continuous operation would become accessible, enabling new scientific missions while reducing costs. Preliminary studies have shown that the collectible propellant flow for an ion thruster (in LEO) might not be enough, and that electrode erosion due to aggressive gases, such as atomic oxygen, will limit the thruster lifetime. In this paper an inductive plasma thruster (IPT) is considered for the ABEP system. The starting point is a small scale inductively heated plasma generator IPG6-S. These devices are electrodeless and have already shown high electric-to-thermal coupling efficiencies using O2 and CO2 . The system analysis is integrated with IPG6-S tests to assess mean mass-specific energies of the plasma plume and estimate exhaust velocities.
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An atmospheric muon neutrino disappearance measurement with the MINOS far detector
Energy Technology Data Exchange (ETDEWEB)
Gogos, Jeremy Peter [Univ. of Minnesota, Minneapolis, MN (United States)
2007-12-01
It is now widely accepted that the Standard Model assumption of massless neutrinos is wrong, due primarily to the observation of solar and atmospheric neutrino flavor oscillations by a small number of convincing experiments. The MINOS Far Detector, capable of observing both the outgoing lepton and associated showering products of a neutrino interaction, provides an excellent opportunity to independently search for an oscillation signature in atmospheric neutrinos. To this end, a MINOS data set from an 883 live day, 13.1 kt-yr exposure collected between July, 2003 and April, 2007 has been analyzed. 105 candidate charged current muon neutrino interactions were observed, with 120.5 ± 1.3 (statistical error only) expected in the absence of oscillation. A maximum likelihood analysis of the observed log(L/E) spectrum shows that the null oscillation hypothesis is excluded at over 96% confidence and that the best fit oscillation parameters are sin2 2θ23 = 0.95 -0.32 and Δm$2\\atop{23}$ = 0.93$+3.94\\atop{ -0.44}$ x 10-3 eV2. This measurement of oscillation parameters is consistent with the best fit values from the Super-Kamiokande experiment at 68% confidence.
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[Assessment of a risk from exposure to atmosphere bus industrial emissions].
Stepkin, Iu I; Kuzmichev, M K
2009-01-01
The carcinogenic and noncarcinogenic risks to health were estimated in accordance with the requirements stated in the guide P 2.1.10.1920-04 "Guidelines for assessing the health risk in the population exposed to the chemicals polluting the environment" (approved by G. G. Onishchenko, state sanitary inspector on March 5, 2004) and comprised four successive steps: 1) identification of a hazard; 2) estimation of a dose-response relationship; 3) evaluation of exposure of the population to chemical substances; 4) characterization of a risk, by calculating the individual carcinogenic risk, hazard coefficients and indices characterizing the noncarcinogenic risk. The performed assessment of the health risk to the population living in the area exposed to the ambient air pollutant emissions by the AOA "Shinnyi Kompleks Amtel-Chenozymye" (Amtel-Chernozem Tyre Complex) allowed determination of priority pollutants, by taking into account their effect on human health. The individual carcinogenic risk to health has been found to be higher than the acceptable (safe) level (10-4) was due to the probable exposure to a 2-heptane fraction (nefras ChS 94/99) and hexavalent chromium. The highest non-carcinogenic risk to human was also due to the heptane fraction (nefras ChS 94/99) (hazard coefficient > 1).
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DEFF Research Database (Denmark)
Poulsen, Lis Hentze; Osler, M; Roberts, C
2002-01-01
OBJECTIVE: To determine whether adolescent smoking behaviour is associated with their perceived exposure to teachers or other pupils smoking at school, after adjustment for exposure to smoking at home, in school, and best friends smoking. DESIGN: Logistic regression analysis of cross sectional data...... from students in Denmark. SUBJECTS: 1515 grade 9 students (mean age 15.8) from 90 classes in 48 Danish schools. Outcome measure: Self reported smoking behaviour; daily smoking and heavy smoking, defined as those smoking more than 20 cigarettes per week. RESULTS: Of the students in this study, 62...... that they had seen other students smoking outdoors on the school premises. Adolescents' perceived exposure to teachers smoking outdoors on the school premises was significantly associated with daily smoking, having adjusted for sex, exposure to teachers smoking indoors at school and pupils smoking outdoors...
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Hao, Liang; Wu, Dapeng; Guan, Yafeng
2014-09-01
The determination of organic composition in atmospheric particulate matter (PM) is of great importance in understanding how PM affects human health, environment, climate, and ecosystem. Organic components are also the scientific basis for emission source tracking, PM regulation and risk management. Therefore, the molecular characterization of the organic fraction of PM has become one of the priority research issues in the field of environmental analysis. Due to the extreme complexity of PM samples, chromatographic methods have been the chief selection. The common procedure for the analysis of organic components in PM includes several steps: sample collection on the fiber filters, sample preparation (transform the sample into a form suitable for chromatographic analysis), analysis by chromatographic methods. Among these steps, the sample preparation methods will largely determine the throughput and the data quality. Solvent extraction methods followed by sample pretreatment (e. g. pre-separation, derivatization, pre-concentration) have long been used for PM sample analysis, and thermal desorption methods have also mainly focused on the non-polar organic component analysis in PM. In this paper, the sample preparation methods prior to chromatographic analysis of organic components in PM are reviewed comprehensively, and the corresponding merits and limitations of each method are also briefly discussed.
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Non-equilibrium atmospheric pressure microplasma jet: An approach to endoscopic therapies
Energy Technology Data Exchange (ETDEWEB)
Zuo, Xiao; Wei, Yu; Wei Chen, Long; Dong Meng, Yue [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Collaboration: Plasma Medicine Team
2013-08-15
Atmospheric pressure microplasma jet generated in a long hollow core optical fiber is studied to verify the potential feasibility of endoscopic therapies. Thermal damage and electric shock to the human body were suppressed by two technical methods, i.e., the high-voltage resistant flexible tube wrapped on the optical fiber and a power resistor of 100 kΩ connected between the power supply and the copper foil electrode. Optical emission spectra analysis indicated that many kinds of active radicals like excited atomic O and OH, were generated in the microplasma jet. In addition, the applications of the microplasma jet on sterilization and lung cancer cell apoptosis were presented. After 5 min of exposures to the microplasma jet, the cell viability and the bacillus subtilis replication decreased to about 3% and zero, respectively. More investigations are needed to improve the plasma-aided endoscopic therapies.
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Exposure to violent video games and aggression in German adolescents: a longitudinal analysis.
Möller, Ingrid; Krahé, Barbara
2009-01-01
The relationship between exposure to violent electronic games and aggressive cognitions and behavior was examined in a longitudinal study. A total of 295 German adolescents completed the measures of violent video game usage, endorsement of aggressive norms, hostile attribution bias, and physical as well as indirect/relational aggression cross-sectionally, and a subsample of N=143 was measured again 30 months later. Cross-sectional results at T1 showed a direct relationship between violent game usage and aggressive norms, and an indirect link to hostile attribution bias through aggressive norms. In combination, exposure to game violence, normative beliefs, and hostile attribution bias predicted physical and indirect/relational aggression. Longitudinal analyses using path analysis showed that violence exposure at T1 predicted physical (but not indirect/relational) aggression 30 months later, whereas aggression at T1 was unrelated to later video game use. Exposure to violent games at T1 influenced physical (but not indirect/relational) aggression at T2 via an increase of aggressive norms and hostile attribution bias. The findings are discussed in relation to social-cognitive explanations of long-term effects of media violence on aggression. Copyright 2008 Wiley-Liss, Inc.
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Analysis of smoke trailers at individual classes of atmosphere stability
International Nuclear Information System (INIS)
Carach, V.; Macala, J.
2007-01-01
At the present most endangered element of the environment is currently atmosphere and its pollution that rapidly accrue. Pollutants are emitted from air pollution sources. The output of pollutant from air pollution source is creating so-called smoke screen. Smoke screens can be observed from point sources of air pollution - smokestacks, up-cast. The purpose of this article was to build theoretical models of smoke screens rise from point source at different meteorological conditions characterized with fifth classes of atmosphere stability. (authors)
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International Nuclear Information System (INIS)
Benneke, Bjoern; Seager, Sara
2012-01-01
We present a retrieval method based on Bayesian analysis to infer the atmospheric compositions and surface or cloud-top pressures from transmission spectra of exoplanets with general compositions. In this study, we identify what can unambiguously be determined about the atmospheres of exoplanets from their transmission spectra by applying the retrieval method to synthetic observations of the super-Earth GJ 1214b. Our approach to inferring constraints on atmospheric parameters is to compute their joint and marginal posterior probability distributions using the Markov Chain Monte Carlo technique in a parallel tempering scheme. A new atmospheric parameterization is introduced that is applicable to general atmospheres in which the main constituent is not known a priori and clouds may be present. Our main finding is that a unique constraint of the mixing ratios of the absorbers and two spectrally inactive gases (such as N 2 and primordial H 2 + He) is possible if the observations are sufficient to quantify both (1) the broadband transit depths in at least one absorption feature for each absorber and (2) the slope and strength of the molecular Rayleigh scattering signature. A second finding is that the surface pressure or cloud-top pressure can be quantified if a surface or cloud deck is present at low optical depth. A third finding is that the mean molecular mass can be constrained by measuring either the Rayleigh scattering slope or the shapes of the absorption features, thus enabling one to distinguish between cloudy hydrogen-rich atmospheres and high mean molecular mass atmospheres. We conclude, however, that without the signature of molecular Rayleigh scattering—even with robustly detected infrared absorption features (>10σ)—there is no reliable way to tell from the transmission spectrum whether the absorber is a main constituent of the atmosphere or just a minor species with a mixing ratio of X abs < 0.1%. The retrieval method leads us to a conceptual picture
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Atmospheric science and power production
Energy Technology Data Exchange (ETDEWEB)
Randerson, D. (ed.)
1984-07-01
This is the third in a series of scientific publications sponsored by the US Atomic Energy Commission and the two later organizations, the US Energy Research and Development Adminstration, and the US Department of Energy. The first book, Meteorology and Atomic Energy, was published in 1955; the second, in 1968. The present volume is designed to update and to expand upon many of the important concepts presented previously. However, the present edition draws heavily on recent contributions made by atmospheric science to the analysis of air quality and on results originating from research conducted and completed in the 1970s. Special emphasis is placed on how atmospheric science can contribute to solving problems relating to the fate of combustion products released into the atmosphere. The framework of this book is built around the concept of air-quality modeling. Fundamentals are addressed first to equip the reader with basic background information and to focus on available meteorological instrumentation and to emphasize the importance of data management procedures. Atmospheric physics and field experiments are described in detail to provide an overview of atmospheric boundary layer processes, of how air flows around obstacles, and of the mechanism of plume rise. Atmospheric chemistry and removal processes are also detailed to provide fundamental knowledge on how gases and particulate matter can be transformed while in the atmosphere and how they can be removed from the atmosphere. The book closes with a review of how air-quality models are being applied to solve a wide variety of problems. Separate analytics have been prepared for each chapter.
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Modelling of aircrew radiation exposure during solar particle events
Al Anid, Hani Khaled
show a very different response during anisotropic events, leading to variations in aircrew radiation doses that may be significant for dose assessment. To estimate the additional exposure due to solar flares, a model was developed using a Monte-Carlo radiation transport code, MCNPX. The model transports an extrapolated particle spectrum based on satellite measurements through the atmosphere using the MCNPX analysis. This code produces the estimated flux at a specific altitude where radiation dose conversion coefficients are applied to convert the particle flux into effective and ambient dose-equivalent rates. A cut-off rigidity model accounts for the shielding effects of the Earth's magnetic field. Comparisons were made between the model predictions and actual flight measurements taken with various types of instruments used to measure the mixed radiation field during Ground Level Enhancements 60 and 65. An anisotropy analysis that uses neutron monitor responses and the pitch angle distribution of energetic solar particles was used to identify particle anisotropy for a solar event in December 2006. In anticipation of future commercial use, a computer code has been developed to implement the radiation dose assessment model for routine analysis. Keywords: Radiation Dosimetry, Radiation Protection, Space Physics.
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Occupational Radiation Exposure Analysis of US ITER DCLL TBM
Energy Technology Data Exchange (ETDEWEB)
Merrill, Brad J; Cadwallader, Lee C; Dagher, Mohamad
2007-08-01
This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.
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Enhanced UV exposure on a ski-field compared with exposures at sea level.
Allen, Martin; McKenzie, Richard
2005-05-01
Personal erythemal UV monitoring badges, which were developed to monitor the UV exposure of school children, were used to measure UV exposures received by one of the authors (MA) at the Mt Hutt ski-field, in New Zealand. These were then compared with measurements taken at the same times from a nearby sea level site in Christchurch city. The badges were designed to give instantaneous readings of erythemally-weighted (i.e., "sun burning") UV radiation and were cross-calibrated against meteorological grade UV instruments maintained by the National Institute of Water & Atmospheric Research (NIWA). All skiing and calibration days were clear and almost exclusively cloud free. It was found that the UV maxima for horizontal surfaces at the ski-field (altitude approximately 2 km) were 20-30% greater than at the low altitude site. Larger differences between the sites were observed when the sensor was oriented perpendicular to the sun. The personal doses of UV received by a sensor on the skier's lapel during two days of skiing activity were less than those received by a stationary detector on a horizontal surface near sea level. The exposures depended strongly on the time of year, and in mid-October the maximum UV intensity on the ski-field was 60% greater than in mid-September. The UV exposure levels experienced during skiing were smaller than the summer maxima at low altitudes.
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Analysis Of The 2009 July Impact Debris In Jupiter'S Atmosphere
Sanchez-Lavega, Agustin; Hueso, R.; Legarreta, J.; Pérez-Hoyos, S.; García-Melendo, E.; Gómez, J. M.; Rojas, J. F.; Orton, G. S.; Wesley, A.; IOPW International Outer Planet Watch Team
2009-09-01
We report the analysis of images obtained by the contributors to the International Outer Planet Watch (IOPW) of the debris left in the atmosphere of Jupiter by the object that impacted the planet between 18 and 19 July 2009. The discovery images by Anthony Wesley in July 19.625 and the first two days of its tracking, shows a dark debris spot (continuum wavelength) located at planetocentric latitude -55.1 deg and 304.5 deg System III longitude. The imaging survey indicates that the spot was not present in July 18.375, so the impact occurred during a window between both dates. The main spot had a size of about 4,500 km and to its Northwest a thin debris halo of similar size was initially observed. Methane band images at a wavelength of 890 nm shows the spot to be bright indicating that the debris aerosols are highly placed in the atmosphere relative to surrounding clouds. At the central latitude of the impact, the Jovian flow has nearly zero speed but anticyclonic vorticity bounded by jets at -51.5 deg (directed westward with velocity -10 m/s) and at -57.5 deg (directed eastward with velocity 25 m/s). The morphology in the continuum and the spot brightness in the methane band strongly suggest that the feature was caused by a cometary or asteroidal impact, similar in behaviour to the SL9 impacts of 1994. This work has been funded by Spanish MEC AYA2006-07735 with FEDER support and Grupos Gobierno Vasco IT-464-07. RH acknowledges a "Ramón y Cajal” contract from MEC.
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International Nuclear Information System (INIS)
Amiro, B.D.; Dormuth, K.W.
1996-02-01
AECL has submitted an environmental impact statement (EIS) describing its proposal for geological disposal of Canada's nuclear fuel waste. The EIS presents a detailed analysis of potential radiation exposure of an individual of a critical group of people in a hypothetical case. In this report, we provide a simpler analysis of potential exposure in the hope that the inherent safety of the disposal will be more readily evident from the analysis. A key to the simplification is the elimination from the analysis of the complex transport processes through disposal vault sealing materials and the geosphere. We also eliminate the relatively complex function describing the failure of the thin-walled titanium containers in the case study presented in the EIS. We therefore conceptually replace the thin-walled titanium containers with thicker-walled copper containers, are expected to remain intact much longer than 10,000 a, the period for which a quantitative estimate of individual exposure is made. However, about 1 in 5000 containers could have small defects that were undetected during manufacture. Our analysis applies only to the case of an undisrupted vault. We assume that the vault and geosphere barriers remain intact and prevent immobile radionuclides from reaching the biosphere. However, we also assume that the three most important mobile radionuclides can escape through an undected manufacturing defect in the container wall, and that the flux of these radionuclides is diluted by well water being used by people. We have focused on 129 I, 36 Cl and 14 C, because these nuclides are found to be the dominant source of exposure in more complex analyses. If a single container released radionuclides to well water, we estimate dose rates of about 1 μSv.a -1 from drinking water and 29 μSv.a -1 , which the Atomic Eenrgy Control Board has adopted as a de minimis dose rate, i.e., a dose rate so small as to not warrant institutional control. We believe that the dose rates are
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Sampling atmospheric pesticides with SPME: Laboratory developments and field study
International Nuclear Information System (INIS)
Wang Junxia; Tuduri, Ludovic; Mercury, Maud; Millet, Maurice; Briand, Olivier; Montury, Michel
2009-01-01
To estimate the atmospheric exposure of the greenhouse workers to pesticides, solid phase microextraction (SPME) was used under non-equilibrium conditions. Using Fick's law of diffusion, the concentrations of pesticides in the greenhouse can be calculated using pre-determined sampling rates (SRs). Thus the sampling rates (SRs) of two modes of SPME in the lab and in the field were determined and compared. The SRs for six pesticides in the lab were 20.4-48.3 mL min -1 for the exposed fiber and 0.166-0.929 mL min -1 for the retracted fiber. In field sampling, two pesticides, dichlorvos and cyprodinil were detected with exposed SPME. SR with exposed SPME for dichlorvos in the field (32.4 mL min -1 ) was consistent with that in the lab (34.5 mL min -1 ). SR for dichlorvos in the field (32.4 mL min -1 ) was consistent with that in the lab (34.5 mL min -1 ). The trends of temporal concentration and the inhalation exposure were also obtained. - SPME was proved to be a powerful and simple tool for determining pesticides' atmospheric concentration
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Control of radon and its progeny concentration in indoor atmosphere
International Nuclear Information System (INIS)
Ramachandran, T.V.; Subbaramu, M.C.
1986-01-01
Exposure to radon daughter concentration in indoor atmosphere can result in a significant risk to the general public. There are two generally used methods for the control of radon and progeny concentration in the indoor atmosphere, namely restriction of radon entry and reduction of indoor radon and its progeny concentration by ventilation or by air cleaning. Predominant radon entry process in most of the dwellings appears to be by pressure driven flow of soil gas through cracks or other openings in the basement slab or subfloors. Sealing these openings or ventilation of the subslab or subfloor space are the methods for reducing the radon entry rates. Indoor radon concentration can also be reduced by increasing the ventilation and by using charcoal filters for the removal of radon gas in indoor air by absorption. Concentration of radon progeny, which are responsible for most of the health risks associatd with radon exposure can also be controlled by the use of electrostatic or mechanical filters. This study describes briefly the above control strategies used for reducing the inhalation doses to persons in dwellings. (author). 9 refs., 2 tables
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Descatha, Alexis; Albo, Francesco; Leclerc, Annette; Carton, Matthieu; Godeau, Diane; Roquelaure, Yves; Petit, Audrey; Aublet-Cuvelier, Agnès
2016-11-01
In view of recent published studies, a meta-analysis was undertaken on prospective studies in order to assess any association between lateral epicondylitis and physical exposure at work. Using the key words "lateral epicondylitis" AND "occupational" AND ("cohort" OR "longitudinal," OR "incidence") without limitations on the language or year of publication, original prospective studies were selected from 4 databases (PubMed, Scopus, Web of Science, and Base de Données de Santé Publique) after 2 rounds (valid design, valid association reported, and valid work exposure). Relevant associations between physical exposure at work and incident lateral epicondylitis were extracted from the articles, and a meta-risk was calculated using the generic variance approach (meta-odds ratios [meta-ORs]). From 2001 to 2014, 5 prospective studies were included. Among 6,922 included subjects (and 3,449 who were followed), 256 cases of incident lateral epicondylitis were diagnosed 2.5-6 years after baseline. All the published studies found a significant estimation of relative risk for a positive association between combined biomechanic exposure involving the wrist and/or elbow and incidence of lateral epicondylitis. The overall meta-OR was 2.6 (95% confidence interval 1.9-3.5), with a low heterogeneity (Q = 1.4, P > 0.05). Funnel plots and Egger's test did not suggest major publication bias. The results of this meta-analysis strongly support the hypothesis of an association between biomechanic exposure involving the wrist and/or elbow at work and incidence of lateral epicondylitis. © 2016, American College of Rheumatology.
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The FLUKA atmospheric neutrino flux calculation
Battistoni, G.; Montaruli, T.; Sala, P.R.
2003-01-01
The 3-dimensional (3-D) calculation of the atmospheric neutrino flux by means of the FLUKA Monte Carlo model is here described in all details, starting from the latest data on primary cosmic ray spectra. The importance of a 3-D calculation and of its consequences have been already debated in a previous paper. Here instead the focus is on the absolute flux. We stress the relevant aspects of the hadronic interaction model of FLUKA in the atmospheric neutrino flux calculation. This model is constructed and maintained so to provide a high degree of accuracy in the description of particle production. The accuracy achieved in the comparison with data from accelerators and cross checked with data on particle production in atmosphere certifies the reliability of shower calculation in atmosphere. The results presented here can be already used for analysis by current experiments on atmospheric neutrinos. However they represent an intermediate step towards a final release, since this calculation does not yet include the...
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A tool model for predicting atmospheric kinetics with sensitivity analysis
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
A package( a tool model) for program of predicting atmospheric chemical kinetics with sensitivity analysis is presented. The new direct method of calculating the first order sensitivity coefficients using sparse matrix technology to chemical kinetics is included in the tool model, it is only necessary to triangularize the matrix related to the Jacobian matrix of the model equation. The Gear type procedure is used to integrate amodel equation and its coupled auxiliary sensitivity coefficient equations. The FORTRAN subroutines of the model equation, the sensitivity coefficient equations, and their Jacobian analytical expressions are generated automatically from a chemical mechanism. The kinetic representation for the model equation and its sensitivity coefficient equations, and their Jacobian matrix is presented. Various FORTRAN subroutines in packages, such as SLODE, modified MA28, Gear package, with which the program runs in conjunction are recommended.The photo-oxidation of dimethyl disulfide is used for illustration.
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Emissions and air exposure of carcinogens and co-carcinogens in four Nordic countries
DEFF Research Database (Denmark)
Fauser, Patrik; Plejdrup, Marlene Schmidt; Ketzel, Matthias
This project (KoL 12-08) was performed for the Climate and Air Quality Group (KlimaogLuftgruppen, KoL), Nordic Council of Ministers by atmospheric emission, exposureand epidemiology experts from Denmark, Finland, Norway and Sweden. Emission inventory methods and exposure models were presented...... to 2010 were compiled and discussed, and modelled andmeasured atmospheric concentrations for 2010 were compiled on regional, urbanand local scales. Nordic maps of emissions and air concentrations of PM2.5, PM10, NOx,NMVOC, benzene, BaP, dioxin, cadmium and nickel were compiled for allaggregated main...... sources, traffic and residential wood combustion. An overview of local studies on exposure for cities or communities with emphasis on wood combustion and traffic and a discussion of existing epidemiological studies on cancer and environment were given...
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Thermal Analysis of Solid Fuels in an Inert Atmosphere
Kijo-Kleczkowska, Agnieszka; Szumera, Magdalena; Środa, Katarzyna
2017-12-01
The paper takes the analysis of thermal studies of different types of fuels. It allowed diversification of fuels depending on their composition and origin. Consideration of coal, biomass and waste (coal mule, sewage sludge) as fuel is nowadays an important aspect of energy in our country. It should be emphasized that Poland power engineering is based up to 95% on coal - the primary fuel. Mining industry, forced to deliver power engineering more and better fuel, must however, use a deeper cleaning of coal. This results in a continuous increase waste in the form of mule flotation. The best method of disposing these mule is combustion and co-combustion with other fuels. On the other hand, commonly increasing awareness state of the environment and the need to reduce CO2 emissions energy industry have committed to implement alternative solutions in order to gain power, through, i.a.: development technologies use of biomass, which is one of the most promising renewable energy sources in Poland. The paper presents the results of research TG-DTA fuels made in an inert atmosphere.
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International Nuclear Information System (INIS)
2000-06-01
Some organisms accumulate atmospheric contaminants over certain periods of time and concentrate them, thus allowing reliable analytical measurements if the organisms are suitably chosen. Measurements of contaminants accumulated by such organisms (biomonitors) provide information on the integrated exposure over an extended period of time. They may also be present in remote areas, and no expensive technical equipment is involved in collecting them. Therefore, biomonitoring can be an effective tool for pollutant mapping and trend monitoring by real time and retrospective analysis. The IAEA is making concerted efforts to promote the practical use of nuclear and related analytical techniques in studies of non-radioactive environmental pollutants that may impact human health, and one of the main emphases is on studying air contaminants. The idea of organizing a workshop on biomonitoring atmospheric pollution arose during an IAEA Technical Co-operation Project on Monitoring of Trace Element Air Pollution, carried out at the Instituto Tecnologico e Nuclear (ITN), Portugal, with substantial technical support by the Interfaculty Reactor Institute (IRI) of the Delft University of Technology (TUDelft), Netherlands. The International Workshop on Biomonitoring of Atmospheric Pollution (With Emphasis on Trace Elements) - BioMAP, was held in Lisbon, Portugal, from 21 to 24 September 1997. The meeting was organized in co-operation with the Instituto Tecnologico e Nuclear
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Energy Technology Data Exchange (ETDEWEB)
NONE
2000-06-01
Some organisms accumulate atmospheric contaminants over certain periods of time and concentrate them, thus allowing reliable analytical measurements if the organisms are suitably chosen. Measurements of contaminants accumulated by such organisms (biomonitors) provide information on the integrated exposure over an extended period of time. They may also be present in remote areas, and no expensive technical equipment is involved in collecting them. Therefore, biomonitoring can be an effective tool for pollutant mapping and trend monitoring by real time and retrospective analysis. The IAEA is making concerted efforts to promote the practicaluse of nuclear and related analytical techniques in studies of non-radioactive environmental pollutants that may impact human health, and one of the main emphases is on studying air contaminants. The idea of organizing a workshop on biomonitoring atmospheric pollution arose during an IAEA Technical Co-operation Project on Monitoring of Trace Element Air Pollution, carried out at the Instituto Tecnologico e Nuclear (ITN), Portugal, with substantial technical support by the Interfaculty Reactor Institute (IRI) of the Delft University of Technology (TUDelft), Netherlands. The International Workshop on Biomonitoring of Atmospheric Pollution (With Emphasis on Trace Elements) - BioMAP, was held in Lisbon, Portugal, from 21 to 24 September 1997. The meeting was organized in co-operation with the Instituto Tecnologico e Nuclear.
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Bórnez, R; Linares, M B; Vergara, H
2010-04-01
Forty-nine Manchega breed male suckling lambs were used in this experiment. The effect of CO(2) concentration and exposure time at stunning [80% CO(2) for 90 s (G1); 90% CO(2) for 90 s (G2); 90% CO(2) for 60 s (G3); 80% CO(2) for 60 s (G4)] plus an electrically stunned control group (G5) was assessed for pH, colour (L(*), a(*), b(*), C(*) and h(*)), water holding capacity (WHC), drip loss (DL), cooking loss (CL) and shear force (SF) in samples packed under two different types of modified atmospheres (MA: MA A: 70%O(2)+30%CO(2); MA B: 69.3%N(2)+30%CO(2)+0.7%CO) at 7, 14 and 21 d post-packaging. The lowest pH was found in G4 and in G5. The highest WHC and the lowest CL were found in G2 and G3 groups (P<0.05). Modified atmospheres did not affect on pH, WHC, CL and DL, although a significant effect (P<0.001) on colour was found at all the analysis times. Both the type of stunning and the modified atmosphere affected SF values. 2009 Elsevier Ltd. All rights reserved.
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Analysis of Atmospheric Nitrate Deposition in Lake Tahoe Using Multiple Oxygen Isotopes
McCabe, J. R.; Michalski, G. M.; Hernandez, L. P.; Thiemens, M. H.; Taylor, K.; Kendall, C.; Wankel, S. D.
2002-12-01
Lake Tahoe in the Sierra Nevada Mountain Range is world renown for its depth and water clarity bringing 2.2 million visitors per year resulting in annual revenue of \\1.6 billion from tourism. In past decades the lake has suffered from decreased water clarity (from 32 m plate depth to less than 20), which is believed to be largely the result of algae growth initiated by increased nutrient loading. Lake nutrients have also seen a shift from a nitrogen limited to a phosphorous limited system indicating a large increase in the flux of fixed nitrogen. Several sources of fixed nitrogen of have been suggested including surface runoff, septic tank seepage from ground water and deposition from the atmosphere. Bio-available nitrogen in the form of nitrate (NO_{3}$-) is a main component of this system. Recent studies have estimated that approximately 50% of the nitrogen input into the lake is of atmospheric origin (Allison et al. 2000). However, the impact and magnitude of atmospheric deposition is still one of the least understood aspects of the relationship between air and water quality in the Basin (TRPA Threshold Assessment 2002). The utility of stable isotopes as tracers of nitrate reservoirs has been shown in several studies (Bohlke et al. 1997, Kendall and McDonnell 1998, Durka et al. 1994). Stable nitrogen (δ15N) and oxygen (δ18O) isotopes have been implemented in a dual isotope approach to characterize the various nitrate sources to an ecosystem. While δ18O distinguishes between atmospheric and soil sources of nitrate, processes such as denitrification can enrich the residual nitrate in δ18O leaving a misleading atmospheric signature. The benefit of δ15N as a tracer for NO3- sources is the ability to differentiate natural soil, fertilizer, and animal or septic waste, which contain equivalent δ18O values. The recent implementation of multiple oxygen isotopes to measure Δ17O in nitrate has proven to be a more sensitive tracer of atmospheric deposition. The
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Childhood lead exposure and uptake in teeth in the Cleveland area during the era of leaded gasoline
International Nuclear Information System (INIS)
Robbins, Norman; Zhang, Zhong-Fa; Sun, Jiayang; Ketterer, Michael E.; Lalumandier, James A.; Shulze, Richard A.
2010-01-01
Childhood uptake of lead from exposure to atmospheric leaded gasoline in the United States has been studied using mainly blood lead levels. Since reliable blood lead techniques were used only after the peak use of leaded gasoline, the prior exposure history is unclear. The well-documented decline in blood lead levels after the mid-1970s could represent the continuation of a historic steady decline in exposure from many sources. Alternatively, the post-1970s decline might represent the declining phase of a unimodal rise and fall corresponding closely to usage of leaded gasoline. To assess these possibilities, lead concentration and 207Pb/206Pb isotope ratios were measured in the enamel of permanent molar teeth formed between 1936 and 1993 in mainly African-American donors who grew up in the Cleveland area. Tooth enamel preserves the lead concentration and isotope ratio that prevails during tooth formation. Historical trends in enamel lead concentration were significantly correlated with surrogates of atmospheric lead exposure: lead in sediments of two dated Lake Erie cores, and lead consumed in gasoline. About two-thirds of the total lead uptake into enamel in this period was attributable to leaded gasoline, and the remainder to other sources (e.g. paint). Enamel 207Pb/206Pb isotope ratios were similar to those of one lake sediment. Multivariate analysis revealed significant correlation in neighborhoods with higher levels of traffic, and including lake sediment data, accounted for 53% of the variation in enamel lead levels. Enamel lead concentration was highly correlated with reported African-American childhood blood levels. The extrapolated peak level of 48 μg/dL (range 40 to 63) is associated with clinical and behavioral impairments, which may have implications for adults who were children during the peak gasoline lead exposure. In sum, leaded gasoline emission was the predominant source of lead exposure of African-American Cleveland children during the latter
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Directory of Open Access Journals (Sweden)
Xue Y
2016-05-01
Full Text Available Yingbo Xue, Ying Jiang, Shan Jin, Yong Li Department of Oncology, Guizhou Provincial People’s Hospital, Guiyang, Guizhou, People’s Republic of China Abstract: Lung cancer has been the main cause of cancer death around the world. Cigarette smoking has been identified as a risk factor for lung cancer in males. However, the etiological factors in nonsmoking women remain elusive. A meta-analysis was conducted to evaluate the relationship between cooking oil fume exposure and lung cancer among Chinese nonsmoking women. Thirteen articles containing three population-based case–control and ten hospital-based case–control studies were included in this meta-analysis. These studies with a total of 3,596 lung cancer women and 6,082 healthy controls were analyzed by RevMan 5.3. Fixed effects model or random effects model was used to obtain pooled estimates of risk ratio. The risk ratios with a 95% CI were 1.74 (95% CI =1.57–1.94 and 2.11 (95% CI =1.54–2.89, respectively. Cooking oil fume exposure as well as not using a kitchen ventilator when cooking was significantly associated with lung cancer among nonsmoking women (Z=10.07, P<0.00001; Z=4.65, P<0.00001. Cooking oil fume exposure, especially lacking a fume extractor, may increase the risk of lung cancer among Chinese nonsmoking women. Keywords: cooking oil fume exposure, lung cancer, meta-analysis, nonsmoking women
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Wang, Lingqing; Zhong, Buqing; Liang, Tao; Xing, Baoshan; Zhu, Yifang
2016-12-01
Exposure to radionuclide thorium (Th) has generated widespread public concerns, mainly because of its radiological effects on human health. Activity levels of airborne 232 Th in total suspended particulate (TSP) were measured in the vicinity of the largest rare earth mine in China in August 2012 and March 2013. The mean activity concentrations of 232 Th in TSP ranged from 820μBqm -3 in a mining area in August 2012 to 39,720μBqm -3 in a smelting area in March 2013, much higher than the world reference of 0.5μBqm -3 . Multistatistical analysis and Kohonen's self-organizing maps suggested that 232 Th in TSP was mainly derived from rare earth mining and smelting practices. In addition, personal inhalation exposures to 232 Th associated with respirable particulate (PM 10 ) were also measured among local dwellers via personal monitoring. The mean dose values for different age groups in the smelting and mining areas ranged from 97.86 to 417μSvyear - 1 and from 101.03 to 430.83μSvyear -1 , respectively. These results indicate that people living in the study areas are exposed to high levels of widespread 232 Th. Copyright © 2016 Elsevier B.V. All rights reserved.
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Assessing the Levels and Health Risk of Atmospheric Formaldehyde in Makkah, Saudi Arabia
Atef M.F. Mohammed; Essam A. Morsy; Turki M. Habeebullah; Said Munir
2015-01-01
Atmospheric Formaldehyde (HCHO) was monitored in four sites on the Holy Mosque of Makkah, Saudi Arabia during August, 2013. The daily mean concentrations of HCHO were ranged from 1.09-18.92 g/m3. The levels of HCHO were significantly higher than the permissible exposure limit (0.042 μg/m3) of the Occupational Safety and Health Administration (OSHA). However, it were not exceeded the recommended exposure limit of the National Institute for Occupational Safety and Health (20 μg/m3) and Egyptian...
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International Nuclear Information System (INIS)
Querol, X.; Alastuey, A.; Lopez-Soler, A.; Boix, A.; Sanfeliu, T.; Martynov, V.V.; Piven, P.I.; Kabina, L.P.; Souschov, P.A.
1997-01-01
This study focuses on the determination of trace element concentrations in total suspended particles by instrumental neutron activation analysis (INAA) in two different areas in Northeastern Spain (a rural area influenced by the emissions of a large coal-fired power station, and the urban and industrial areas of Castellon). Total suspended particles were sampled by means of standard MCV high- and medium-volume captors, using cellulose membrane filters of 0.8 and 0.45 μm pore size. Preliminary research was performed on the homogeneous distribution of elements in the sample filters and on the study of blank filters for the calculations of the background average element contents. The results obtained allowed to distinguish different major anthropogenic sources of trace elements in the atmosphere at the sampling sites: (a) Zr, Hf, Sc, U and Th are related to atmospheric pollution derived from the ceramic industry of the Castellon area; (b) As, Cr, Cs, Rb, Sb, Se, Zn are related to traffic and other industrial emission in the Castellon area, and As, Cr, Sb and Zn to power generation emissions in the rural area. (orig.). With 3 figs., 5 tabs
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Paschalidou, A K; Kassomenos, P A
2016-01-01
Wildfire management is closely linked to robust forecasts of changes in wildfire risk related to meteorological conditions. This link can be bridged either through fire weather indices or through statistical techniques that directly relate atmospheric patterns to wildfire activity. In the present work the COST-733 classification schemes are applied in order to link wildfires in Greece with synoptic circulation patterns. The analysis reveals that the majority of wildfire events can be explained by a small number of specific synoptic circulations, hence reflecting the synoptic climatology of wildfires. All 8 classification schemes used, prove that the most fire-dangerous conditions in Greece are characterized by a combination of high atmospheric pressure systems located N to NW of Greece, coupled with lower pressures located over the very Eastern part of the Mediterranean, an atmospheric pressure pattern closely linked to the local Etesian winds over the Aegean Sea. During these events, the atmospheric pressure has been reported to be anomalously high, while anomalously low 500hPa geopotential heights and negative total water column anomalies were also observed. Among the various classification schemes used, the 2 Principal Component Analysis-based classifications, namely the PCT and the PXE, as well as the Leader Algorithm classification LND proved to be the best options, in terms of being capable to isolate the vast amount of fire events in a small number of classes with increased frequency of occurrence. It is estimated that these 3 schemes, in combination with medium-range to seasonal climate forecasts, could be used by wildfire risk managers to provide increased wildfire prediction accuracy. Copyright © 2015 Elsevier B.V. All rights reserved.
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International Nuclear Information System (INIS)
Rizzio, Enrico; Gallorini, Mario
2002-01-01
The Neutron Activation Analysis (NAA) owns these requirements and is universally accepted as one of the most reliable analytical tools for trace and ultratrace elements determination. Its use in trace elements atmospheric pollution related studies has been and is still extensive as can be demonstrate by several specific works and detailed reviews. In this work, the application of this nuclear technique, in solving a series of different analytical problems related to trace elements in air pollution processes is reported. Examples and results are given on the following topics: characterization of urban and rural airborne particulate samples; particles size distribution in the different inhalable and respirable fractions (PM10 and PM 2.5); certification of related Standard Reference Materials for data quality assurance. (author)
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Gritsevich, M. I.
2008-10-01
To date, several meteorites have been found for which their flight in the atmosphere was recorded by special fireball camera networks. Because of this, a thorough analysis of the instrumentally registered falls is of current importance. For such fireballs, not only the high-quality photo images of the motion in the atmosphere exist, but also the density and the shape of the meteor body fragments reached the Earth’s surface are known for sure. In the present study, for the Innisfree, Lost City, and Pribram fireballs, new models of the entry to the atmosphere have been built. The values of the ballistic coefficient and the mass-loss parameter providing the best approximation for the observations of the luminous trajectory segment with the analytical solution of the meteor physics equations have been obtained. From recent results of the numerical experiments on the supersonic airflow of bodies of various shapes, the preatmospheric masses of the fireballs, as well as the dynamic estimates of the mass at the other trajectory points, were obtained. In particular, the terminal mass of the fireballs in the lower segment of the analyzed trajectories is in good agreement with the total mass of the meteorite material recovered in all of the cases considered. Moreover, to calculate the acceleration of the meteor bodies, a new analytical formula has been suggested, which allows the obtained theoretical time dependencies of the velocity and altitude to be compared with the observational data.
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International Nuclear Information System (INIS)
Dixon, E.; Holton, G.A.
1984-01-01
Ingestion of contaminated food due to the airborne release of radionuclides or chemical pollutants is a particularly difficult human exposure pathway to quantify. There are a number of important physical and biological processes such as atmospheric deposition and plant uptake to consider. These processes are approximate by techniques encoded in the computer program TEREX. Once estimates of pollutant concentrations are made, the problem can be reduced to computing exposure from ingestion of the food. Some assessments do not account for where the contaminated food is eaten, while others limit consumption to meat and vegetables produced within the affected area. While those approaches lead to an upper bound of exposure, a more realistic assumption is that if locally produced food is not sufficient to meet the dietary needs of the local populace, then uncontaminated food will be imported. This is the approach taken by the computer model FOODCHAIN. Exposures via ingestion of six basic types of food are modeled: beef, milk, grains, leafy vegetables, exposed produce (edible parts are exposed to atmospheric deposition), and protected produce (edible parts are protected from atmospheric deposition). Intake requirements for these six foods are based on a standard diet. Using TEREX-produced site-specific crop production values and food contamination values, FOODCHAIN randomly samples pollutant concentrations in each of the six foodstuffs in an inerative manner. Consumption of a particular food is weighted by a factor proportional to the total production of that food within the area studied. The exposures due to consumption of each of the six foodstuffs are summed to produce the total exposure for each randomly calculated diet
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The analysis of radiation exposure of hospital radiation workers
International Nuclear Information System (INIS)
Jeong, Tae Sik; Shin, Byung Chul; Moon, Chang Woo; Cho, Yeong Duk; Lee, Yong Hwan; Yum, Ha Yong
2000-01-01
This investigation was performed in order to improve the health care of radiation workers, to predict a risk, to minimize the radiation exposure hazard to them and for them to realize radiation exposure danger when they work in radiation area in hospital. The documentations checked regularly for personal radiation exposure in four university hospitals in Pusan city in Korea between January 1, 1993 and December 31, 1997 were analyz ed. There were 458 persons in this documented but 111 persons who worked less then one year were excluded and only 347 persons were included in this study. The average of yearly radiation exposure of 347 persons was 1.52±1.35 mSv. Though it was less than 5OmSv, the limitaion of radiation in law but 125 (36%) people received higher radiation exposure than non-radiation workers. Radiation workers under 30 year old have received radiation exposure of mean 1.87±1.01 mSv/year, mean 1.22±0.69 mSv between 31 and 40 year old and mean 0.97±0.43 mSv/year over, 41year old (p<0.001). Men received mean 1.67±1.54 mSv/year were higher than women who received mean 1.13±0.61 mSv/year (p<0.01). Radiation exposure in the department of nuclear medicine department in spite of low energy sources is higher than other departments that use radiations in hospital (p<0.05). And the workers who received mean 3.69±1.81 mSv/year in parts of management of radiation sources and injection of sources to patient receive high radiation exposure in nuclear medicine department (0<0.01). In department of diagnostic radiology high radiation exposure is in barium enema rooms where workers received mean 3.74±1.74 mSv/year and other parts where they all use fluoroscopy such as angiography room of mean 1.17±0.35 mSv/year and upper gastrointestinal room of mean 1.74±1.34 mSv/year represented higher radiation exposure than average radiation exposure in diagnostic radiology (p<0.01). Doctors and radiation technologists received higher radiation exposure of each mean 1.75±1
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International Nuclear Information System (INIS)
Lucaciu, Adriana
1997-01-01
This research is the direct result of a protocol between NIPNE-HH Bucharest, Romania and JINR-Dubna, Russia on one side, and NIPNE-HH Bucharest, Romania and the University of Trondheim, Norway on the other side. Since the summer of 1995, a systematic sampling of bio-indicators has been carried out. The bio-indicators are represented by three species of bryophytes with an endemic development in the Romanian area: Hylocomium splendens, Hypnum cupresiforme and Pleurozium schreberi. A large area of 45,000 km 2 , including the Carpathian Arch between the Olt River Gorge (Southern Carpathian Mountains) and the northern Romanian border (Eastern Carpathian Mountains) was covered. Some of the samples were prepared in the laboratory and analyzed by nuclear analysis methods of a high sensitivity and accuracy i.e., neutron activation analysis and atomic absorption spectrometry. Other samples are to be prepared and analyzed. The results will be shown as distribution maps for heavy metal concentrations in the studied area. The analysis were carried out at NIPNE-HH-Bucharest, JINR-Dubna and Trondheim University. Part of the results have already been included in the European Atlas of the Heavy Metal Atmospheric Depositions, published by the Northern Countries Council. The distribution maps of atmospheric depositions in Romania will also be included in the above mentioned Atlas. (author)
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Methods for conduct of atmospheric tracer studies at ANSTO
Energy Technology Data Exchange (ETDEWEB)
Clark, G H; Stone, D J.M.; Pascoe, J H [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Environment Division
2000-07-01
A perfluorocarbon atmospheric tracer system has been developed to investigate atmospheric dispersion processes in the region surrounding the Lucas Heights Science and Technology Centre. This report discusses the tracer release, sampling and analysis methods.
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Rodriguez, Delphy; Valari, Myrto; Markakis, Konstantinos; Payan, Sébastien
2016-04-01
Currently, ambient pollutant concentrations at monitoring sites are routinely measured by local networks, such as AIRPARIF in Paris, France. Pollutant concentration fields are also simulated with regional-scale chemistry transport models such as CHIMERE (http://www.lmd.polytechnique.fr/chimere) under air-quality forecasting platforms (e.g. Prev'Air http://www.prevair.org) or research projects. These data may be combined with more or less sophisticated techniques to provide a fairly good representation of pollutant concentration spatial gradients over urban areas. Here we focus on human exposure to atmospheric contaminants. Based on census data on population dynamics and demographics, modeled outdoor concentrations and infiltration of outdoor air-pollution indoors we have developed a population exposure model for ozone and PM2.5. A critical challenge in the field of population exposure modeling is model validation since personal exposure data are expensive and therefore, rare. However, recent research has made low cost mobile sensors fairly common and therefore personal exposure data should become more and more accessible. In view of planned cohort field-campaigns where such data will be available over the Paris region, we propose in the present study a statistical framework that makes the comparison between modeled and measured exposures meaningful. Our ultimate goal is to evaluate the exposure model by comparing modeled exposures to monitor data. The scientific question we address here is how to downscale modeled data that are estimated on the county population scale at the individual scale which is appropriate to the available measurements. To assess this question we developed a Bayesian hierarchical framework that assimilates actual individual data into population statistics and updates the probability estimate.
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Atmospheric monitoring in H.E.S.S.
Directory of Open Access Journals (Sweden)
Hahn J.
2015-01-01
Full Text Available Instruments applying the IACT method, such as H.E.S.S. (High Energy Stereoscopic System, observe VHE (very high energy, E > 100 GeV photons indirectly, using the Earth's atmosphere as a calorimeter. In the H.E.S.S. data reconstruction, the properties of this component are estimated by Monte Carlo simulations of a yearly averaged atmosphere density profile. Deviations of the real atmospheric conditions from this assumed atmospheric model will result in a biased reconstruction of the primary gamma-ray energy and thus the resulting source spectrum. In order to keep the corresponding systematic effects to a minimum, H.E.S.S. operates a set of atmospheric monitoring devices that allows it to characterise the atmospheric conditions during data taking. This information in turn is then used in data selection. Here, a short overview with respect to their usage during source observation and a posteriori analysis data selection will be presented.
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Research of chemical structure of atmospheric precipitation
International Nuclear Information System (INIS)
Korenyak, D.
2001-01-01
The structure of atmospheric precipitation changes in its passing through the air medium. Thus, the atmospheric precipitation is one of the ecological factors, acting regularly. The research of chemical structure of atmospheric precipitation is closely connected with the problems of turnover of elements, with sanitary - ecological conditions of regions, with the matters of agricultural equipment and of salt balance of the soils. In paper the author for the first time represents the data on chemical structure of precipitation in the town. The data of chemical analysis of 18 samples are given. Obtained results permitted, to a certain extent, to determine the mechanisms of formation of atmospheric precipitation in the region investigated and its genesis. (authors)
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Esbrí, José M; López-Berdonces, Miguel Angel; Fernández-Calderón, Sergio; Higueras, Pablo; Díez, Sergi
2015-04-01
An integrated analysis approach has been applied to a mercury (Hg) case study on a chlor-alkali plant located in the Ebro River basin, close to the town of Flix (NE Spain). The study focused on atmospheric Hg and its incorporation in soils and lichens close to a mercury cell chlor-alkali plant (CAP), which has been operating since the end of the 19th century. Atmospheric Hg present in the area was characterized by means of seven total gaseous mercury (TGM) surveys carried out from 2007 to 2012. Surveys were carried out by car, walking, and at fixed locations, and covered an area of some 12 km(2) (including the CAP area, the village in which workers live, Flix town, and the Sebes Wildlife Reserve). Finally, an atmospheric Hg dispersion model was developed with ISC-AERMOD software validated by a lichen survey of the area. The results for the atmospheric compartment seem to indicate that the Flix area currently has the highest levels of Hg pollution in Spain on the basis of the extremely high average concentrations in the vicinity of the CAP (229 ng m(-3)). Moreover, the Hg(0) plume affects Flix town center to some extent, with values well above the international thresholds for residential areas. Wet and dry Hg deposition reached its highest values on the banks of the Ebro River, and this contributes to increased soil contamination (range 44-12,900 ng g(-1), average 775 ng g(-1)). A good fit was obtained between anomalous areas indicated by lichens and the dispersion model for 1 year.
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Directory of Open Access Journals (Sweden)
Sheng Zhang
2018-06-01
Full Text Available The atmospheric corrosion of epoxy prime coated aluminum alloy 7075-T6 exposed for 7, 12 and 20 years was investigated. The remaining thicknesses of epoxy prime coatings for macroscopically intact coating areas followed a normal distribution and decreased linearly. EIS results demonstrated that the corrosion resistance of the coating decreased with exposure time. After 20 years of exposure, the epoxy coating had lost its protection as cracks existed within the coating and exfoliation corrosion had occurred on the substrate. The substrate was sensitive to exfoliation corrosion through metallographic and TEM analysis. The corrosion products were mainly hydroxides of aluminum. The morphology and chemical compositions of the coating bubbling area and propagation characterizations of exfoliation corrosion were analyzed by SEM, EPMA and EDS. Cracks between the lumps of corrosion products provided the channels for the transmission of corrosion mediums. Furthermore, the mechanical model was proposed to analyze the propagation characterization of exfoliation corrosion.
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Assessing population exposures to motor vehicle exhaust.
Van Atten, Chris; Brauer, Michael; Funk, Tami; Gilbert, Nicolas L; Graham, Lisa; Kaden, Debra; Miller, Paul J; Bracho, Leonora Rojas; Wheeler, Amanda; White, Ronald H
2005-01-01
The need is growing for a better assessment of population exposures to motor vehicle exhaust in proximity to major roads and highways. This need is driven in part by emerging scientific evidence of adverse health effects from such exposures and policy requirements for a more targeted assessment of localized public health impacts related to road expansions and increasing commercial transportation. The momentum for improved methods in measuring local exposures is also growing in the scientific community, as well as for discerning which constituents of the vehicle exhaust mixture may exert greater public health risks for those who are exposed to a disproportionate share of roadway pollution. To help elucidate the current state-of-the-science in exposure assessments along major roadways and to help inform decision makers of research needs and trends, we provide an overview of the emerging policy requirements, along with a conceptual framework for assessing exposure to motor-vehicle exhaust that can help inform policy decisions. The framework includes the pathway from the emission of a single vehicle, traffic emissions from multiple vehicles, atmospheric transformation of emissions and interaction with topographic and meteorologic features, and contact with humans resulting in exposure that can result in adverse health impacts. We describe the individual elements within the conceptual framework for exposure assessment and discuss the strengths and weaknesses of various approaches that have been used to assess public exposures to motor vehicle exhaust.
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Brandt, Annette; Posthoff, Eva; de Vera, Jean-Pierre; Onofri, Silvano; Ott, Sieglinde
2016-06-01
The lichen Xanthoria elegans has been exposed to space and simulated Mars-analogue environment in the Lichen and Fungi Experiment (LIFE) on the EXPOSE-E facility at the International Space Station (ISS). This long-term exposure of 559 days tested the ability of various organisms to cope with either low earth orbit (LEO) or Mars-analogue conditions, such as vacuum, Mars-analogue atmosphere, rapid temperature cycling, cosmic radiation of up to 215 ± 16 mGy, and insolation of accumulated doses up to 4.87 GJm-2, including up to 0.314 GJm-2 of UV irradiation. In a previous study, X. elegans demonstrated considerable resistance towards these conditions by means of photosynthetic activity as well as by post-exposure metabolic activity of 50-80 % in the algal and 60-90 % in the fungal symbiont (Brandt et al. Int J Astrobiol 14(3):411-425, 2015). The two objectives of the present study were complementary: First, to verify the high post-exposure viability by using a qualitative cultivation assay. Second, to characterise the cellular damages by transmission electron microscopy (TEM) which were caused by the space and Mars-analogue exposure conditions of LIFE. Since the algal symbiont of lichens is considered as the more susceptible partner (de Vera and Ott 2010), the analyses focused on the photobiont. The study demonstrated growth and proliferation of the isolated photobiont after all exposure conditions of LIFE. The ultrastructural analysis of the algal cells provided an insight to cellular damages caused by long-term exposure and highlighted that desiccation-induced breakdown of cellular integrity is more pronounced under the more severe space vacuum than under Mars-analogue atmospheric conditions. In conclusion, desiccation-induced damages were identified as a major threat to the photobiont of X. elegans. Nonetheless, a fraction of the photobiont cells remained cultivable after all exposure conditions tested in LIFE.
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Energy Technology Data Exchange (ETDEWEB)
Clark, E; Marie Kane, M
2008-12-12
Four formulations of EPDM (ethylene-propylene diene monomer) elastomer were exposed to tritium gas initially at one atmosphere and ambient temperature for between three and four months in closed containers. Material properties that were characterized include density, volume, mass, appearance, flexibility, and dynamic mechanical properties. The glass transition temperature was determined by analysis of the dynamic mechanical property data per ASTM standards. EPDM samples released significant amounts of gas when exposed to tritium, and the glass transition temperature increased by about 3 C. during the exposure. Effects of ultraviolet and gamma irradiation on the surface electrical conductivity of two types of polyaniline films are also documented as complementary results to planned tritium exposures. Future work will determine the effects of tritium gas exposure on the electrical conductivity of polyaniline films, to demonstrate whether such films can be used as a sensor to detect tritium. Surface conductivity was significantly reduced by irradiation with both gamma rays and ultraviolet light. The results of the gamma and UV experiments will be correlated with the tritium exposure results.
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Photosynthesis and growth response of almond to increased atmospheric ozone partial pressures
Energy Technology Data Exchange (ETDEWEB)
Retzlaff, W.A.; Williams, L.E. (Univ. of California, Davis (United States) Kearney Agricultural Center, Parlier, CA (United States)); DeJong, T.M. (Univ. of California, Davis (United States))
Uniform nursery stock of five almond cultivars [Prunus dulcis (Mill) D.A. Webb syn. P. amygdalus Batsch, cv. Butte, Carmel, Mission, Nonpareil, and Sonora] propagated on peach (P. domstica L. Batsch.) rootstock were exposed to three different atmospheric ozone (O[sub 3]) partial pressures. The trees were planted in open-top fumigation chambers on 19 Apr. 1989 at the University of California Kearny Agricultural Center located in the San Joaquin Valley of California. Exposures of the trees to three atmospheric O[sub 3] partial pressures lasted from 1 June to 2 Nov. 1989. The mean 12-h [0800-2000 h Pacific Daylight Time (PDT)] O[sub 3] partial pressures measured in the open-top chambers during the experimental period were 0.038, 0.060, and 0.112 [mu]Pa Pa[sup [minus]1] O[sub 3] in the charcoal filtered, ambient, and ambient + O[sub 3] treatments, respectively. Leaf net CO[sub 2] assimilation, trunk cross-sectional area growth, and root, trunk, foliage, and total dry weight of Nonpareil were reduced by increased atmospheric O[sub 3] partial pressures. Mission was unaffected by O[sub 3] and Butte, Carmel, and Sonora were intermediate in their responses. Foliage of Nonpareil also abscised prematurely in the ambient and ambient + O[sub 3] treatments. The results indicate that there are almond cultivars that are sensitive to O[sub 3] exposure.
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Bader, M; Van Weyenbergh, T; Verwerft, E; Van Pul, J; Lang, S; Oberlinner, C
2014-12-15
Human biomonitoring (HBM) is frequently used for the analysis and assessment of exposure to chemicals under routine working conditions. In recent years, HBM has also been applied to monitor the exposure of the general population, and of emergency responders in the aftermath of chemical incidents. Two examples of targeted HBM programs in the chemical industry are described and discussed in this paper: (1) analysis and assessment of the exposure of firefighters and chemical workers after the spill of p-chloroaniline from a burning chemical barrel, and (2) biomonitoring of maintenance workers potentially exposed to benzene during regular turnarounds. The results of these investigations underline that human biomonitoring contributes substantially to comprehensive exposure analyses, human health risk assessments and communication. In addition, regular HBM surveillance and feedback can assist in the continuous improvement of workplace safety measures and exposure control. In conclusion, data on accidental or short-term exposure to hazardous chemicals are an important source of information for the further development of limit and assessment values, the validation of biomarkers and of targeted HBM programs for both routine monitoring and disaster management. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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McNabola, Aonghus; Broderick, Brian M; Gill, Laurence W
2009-10-01
Principal component analysis was used to examine air pollution personal exposure data of four urban commuter transport modes for their interrelationships between pollutants and relationships with traffic and meteorological data. Air quality samples of PM2.5 and VOCs were recorded during peak traffic congestion for the car, bus, cyclist and pedestrian between January 2005 and June 2006 on a busy route in Dublin, Ireland. In total, 200 personal exposure samples were recorded each comprising 17 variables describing the personal exposure concentrations, meteorological conditions and traffic conditions. The data reduction technique, principal component analysis (PCA), was used to create weighted linear combinations of the data and these were subsequently examined for interrelationships between the many variables recorded. The results of the PCA found that personal exposure concentrations in non-motorised forms of transport were influenced to a higher degree by wind speed, whereas personal exposure concentrations in motorised forms of transport were influenced to a higher degree by traffic congestion. The findings of the investigation show that the most effective mechanisms of personal exposure reduction differ between motorised and non-motorised modes of commuter transport.
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Chiba, Yasutaka
2014-01-01
Questions of mediation are often of interest in reasoning about mechanisms, and methods have been developed to address these questions. However, these methods make strong assumptions about the absence of confounding. Even if exposure is randomized, there may be mediator-outcome confounding variables. Inference about direct and indirect effects is particularly challenging if these mediator-outcome confounders are affected by the exposure because in this case these effects are not identified irrespective of whether data is available on these exposure-induced mediator-outcome confounders. In this paper, we provide a sensitivity analysis technique for natural direct and indirect effects that is applicable even if there are mediator-outcome confounders affected by the exposure. We give techniques for both the difference and risk ratio scales and compare the technique to other possible approaches. PMID:25580387
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Thermal degradation of CR-39 polymer in an inert atmosphere
International Nuclear Information System (INIS)
Kalsi, P.C.; Pandey, A.K.; Iyer, R.H.; Singh Mudher, K.D.
1995-01-01
The thermal degradation of CR-39 (allyl diglycol carbonate), a polymer widely used in nuclear science and technology, in an inert atmosphere has been studied using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) techniques. The results are compared with the thermal degradation data of the polymer in an air atmosphere. The present studies showed that the thermal degradation of the polymer proceeds in two steps in an argon atmosphere as compared to three steps in air atmosphere. The mass losses in air are higher than that in argon due to the oxidative decomposition of the residue. The kinetics of the different stages of degradation were also evaluated from the TG curves. (author). 7 refs., 1 tab
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Research on the surface chemical behavior of uranium metal in hydrogen atmosphere by XPS
International Nuclear Information System (INIS)
Fu Xiaoguo; Wang Xiaolin; Yu Yong; Zhao Zhengping
2001-01-01
The surface chemical behavior clean uranium metal in hydrogen atmosphere at 100 and 200 degree C is studied by X-ray photoelectron spectroscopy (XPS), respectively. It leads to hydriding reaction when the hydrogen exposure is 12.0 Pa·s, and the U4f 7/2 binding energy of UH 3 is found to be 378.7 eV. The higher temperature (200 degree C) is beneficial to UH 3 formation at the same hydrogen exposures. XPS elemental depth profiles indicate that the distribution of uranium surface layer is UO 2 , UH 3 and U after exposure to 174.2 Pa·s hydrogen
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International Nuclear Information System (INIS)
Ji Meng; Bell, Michelle L; Cohan, Daniel S
2011-01-01
Ozone is associated with health impacts including respiratory outcomes; however, results differ across studies. Meta-analysis is an increasingly important approach to synthesizing evidence across studies. We conducted meta-analysis of short-term ozone exposure and respiratory hospitalizations to evaluate variation across studies and explore some of the challenges in meta-analysis. We identified 136 estimates from 96 studies and investigated how estimates differed by age, ozone metric, season, lag, region, disease category, and hospitalization type. Overall results indicate associations between ozone and various kinds of respiratory hospitalizations; however, study characteristics affected risk estimates. Estimates were similar, but higher, for the elderly compared to all ages and for previous day exposure compared to same day exposure. Comparison across studies was hindered by variation in definitions of disease categories, as some (e.g., asthma) were identified through ≥ 3 different sets of ICD codes. Although not all analyses exhibited evidence of publication bias, adjustment for publication bias generally lowered overall estimates. Emergency hospitalizations for total respiratory disease increased by 4.47% (95% interval: 2.48, 6.50%) per 10 ppb 24 h ozone among the elderly without adjustment for publication bias and 2.97% (1.05, 4.94%) with adjustment. Comparison of multi-city study results and meta-analysis based on single-city studies further suggested publication bias.
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International Nuclear Information System (INIS)
Esch, D.; Wittwer, C.
2014-01-01
Between 1967 and 1978 125.787 packages filled with low-level and intermediate-level radioactive waste were emplaced in the mining plant Asse II. Volatile radioactive substances like H-3, C-14 and Rn-222 are released from the emplaced waste. These substances reach the ventilated parts of the mine and are released with the discharge air. The potential radiation exposure of the population caused by deduction of radioactive substances with the discharge air in the normal operation is determined by the ''Atmospheric Radionuclide-Transport-Model'' (ARTM). As result the maximal deductions of volatile radioactive substances with the discharge air in the normal operation of the Asse II mine lead to radiation exposure of the population, which is considerably lower than the permissible values of application rate.
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Radiation exposure of uranium mill workers
International Nuclear Information System (INIS)
Jha, Giridhar; Saha, S.C.
1982-01-01
The uranium mill workers at Jaduguda were covered by a regular film badge service from 1969 onwards. Since the log normal plot is useful in interpreting occupational exposure, a statistical analysis of the radiation exposure data was attempted. Exposure data for each year has been plotted as cumulative percentage and worker's population with exposure levels in different class intervals. The plot for each of the year under investigation shows an occupational exposure distribution more or less consistent with the log normal distribution function. The analysis shows that more than 98% of radiation workers received less than 200 mrem (2 mSv). (author)
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Möhner, Matthias; Pohrt, Anne; Gellissen, Johannes
2017-10-01
While occupational exposure to respirable silica is known to lead to lung disease, most notably silicosis, its association with chronic kidney disease is unclear. This review explores the association between occupational exposure to respirable silica and chronic non-malignant renal disease such as glomerulonephritis. The evidence has been collected and compiled. Possible sources of bias are thoroughly discussed. Cohort studies with silica exposure and case-control studies of renal disease were searched in PubMed until January 2015. Two authors independently abstracted data; any disagreement was resolved by consulting a third reviewer. A meta-analysis was performed to evaluate the association to silica exposure. A total of 23 cohort and four case-control studies were included in the analysis. The meta-analysis of cohort studies yielded elevated overall SMRs for renal disease. Some studies, however, included dose-response analyses, most of which did not show a positive trend. The approaches and results of the case-control studies were very heterogeneous. While the studies of cohorts exposed to silica found elevated SMRs for renal disease, no clear evidence of a dose-response relationship emerged. The elevated risk may be attributed to diagnostic and methodological issues. In order to permit a reliable estimation of a possible causal link, exposed cohorts should be monitored for renal disease, as the information from mortality studies is hardly reliable in this field.
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Roy Tilla; Bopp Laurent; Gehlen Marion; Schneider Birgitt; Cadule Patricia; Frölicher Thomas; Segschneider Jochen; Tijputra Jerry; Heinze Christoph; Joos Fortunat
2011-01-01
The increase in atmospheric CO2 over this century depends on the evolution of the oceanic air–sea CO2 uptake which will be driven by the combined response to rising atmospheric CO2 itself and climate change. Here the future oceanic CO2 uptake is simulated using an ensemble of coupled climate–carbon cycle models. The models are driven by CO2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high emission scenario. A linear feedback analysis successfully sep...
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Differentiation between exposures to high or low ionizing radiation by means of Triage type analysis
International Nuclear Information System (INIS)
Guerrero C, C.; Arceo M, C.; Martinez A, J.; Cortina R, E.
2016-09-01
According to a culture of disaster prevention, in this case a radiological emergency, in which a large number of people are exposed to high doses of ionizing radiation, is necessary to make urgent decisions regarding the appropriate treatment, which for each case is required. In this regard, chromosomal analysis may provide additional information to that obtained from clinical observations confirming cases that suffered severe partial exposure and at the same time discriminating against false positives attributable to previous infections or hysterical behavior. The ionizing radiation causes different types of aberrations in the chromosomes, but one of the most characteristic is dicentric. The analysis of these in lymphocytes is a good indicator of the degree of exposure, because apart from being easily recognizable, the basal frequency in the population is low (1 x 10 3 cells) and increases in proportion to the dose. In order to establish the exposure dose, is usually necessary to analyze 1000 cells, a procedure that in an emergency, is very slow since is necessary to make rapid decisions to apply the appropriate treatment to the patient. The results of this intercalibration exercise demonstrate that the analysis of 20, 30 or 50 metaphases is sufficient to separate the cases of overexposure from the non-radio exposed ones and to the first ones by gravity category. (Author)
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Laser spectroscopic analysis in atmospheric pollution research
CSIR Research Space (South Africa)
Forbes, PBC
2008-01-01
Full Text Available stream_source_info ForbesP_2008.pdf.txt stream_content_type text/plain stream_size 3174 Content-Encoding ISO-8859-1 stream_name ForbesP_2008.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Laser spectroscopic... Department and a CSIR National Laser Centre rental pool programme grant-holder, is involved in research into a novel method of monitoring atmospheric PAHs. The rental pool programme gives South African tertiary education institutions access to an array...
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International Nuclear Information System (INIS)
Allison, M.; Travis, L.D.
1986-10-01
A conference on the atmosphere of Jupiter produced papers in the areas of thermal and ortho-para hydrogen structure, clouds and chemistry, atmospheric structure, global dynamics, synoptic features and processes, atmospheric dynamics, and future spaceflight opportunities. A session on the atmospheres of Uranus and Neptune was included, and the atmosphere of Saturn was discussed in several papers
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Vardavas, Constantine I.; Girvalaki, Charis; Filippidis, Filippos T; Oder, Mare; Kastanje, Ruth; de Vries, Irma; Scholtens, Lies; Annas, Anita; Plackova, Silvia; Turk, Rajka; Gruzdyte, Laima; Rato, F?tima; Genser, Dieter; Schiel, Helmut; Bal?zs, Andrea
2017-01-01
BACKGROUND: The use of e-cigarettes has increased during the past few years. Exposure to e-cigarette liquids, whether intentional or accidental, may lead to adverse events our aim was to assess factors associated with e-cigarette exposures across European Union Member States (EU MS). METHODS: A retrospective analysis of exposures associated with e-cigarettes reported to national poison centers was performed covering incidents from 2012 to March 2015 from 10 EU MS. De-identified and anonymous ...
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Overview on Analysis of Free Metabolites for Detection of Exposure to Chemical Warfare Agents
Directory of Open Access Journals (Sweden)
Grigoriu Nicoleta
2015-06-01
Full Text Available Chemical warfare agents (CWA’s induce complex toxicological effects with major adverse consequences for those exposed. For many chemical agents there is a need for research and development of analytical toxicological methods for a rapid and certain confirmation of those exposures. The certain methods will help for establishing the laboratory diagnosis for applying the proper therapy; the treatment of only contaminated people, decreasing the stress level in the medical community in management of crisis situations, increasing the survival rate of the population exposed to the contamination, supervision of professional exposure, judicial analysis in case of suspicious terrorist activities.
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Sangpenchan, R.
2011-12-01
This research explores the vulnerability of Thai rice production to simultaneous exposure by climate and socioeconomic change -- so-called "double exposure." Both processes influence Thailand's rice production system, but the vulnerabilities associated with their interactions are unknown. To understand this double exposure, I adopts a mixed-method, qualitative-quantitative analytical approach consisting of three phases of analysis involving a Vulnerability Scoping Diagram, a Principal Component Analysis, and the EPIC crop model using proxy datasets collected from secondary data sources at provincial scales.The first and second phases identify key variables representing each of the three dimensions of vulnerability -- exposure, sensitivity, and adaptive capacity indicating that the greatest vulnerability in the rice production system occurs in households and areas with high exposure to climate change, high sensitivity to climate and socioeconomic stress, and low adaptive capacity. In the third phase, the EPIC crop model simulates rice yields associated with future climate change projected by CSIRO and MIROC climate models. Climate change-only scenarios project the decrease in yields by 10% from the current productivity during 2016-2025 and 30% during 2045-2054. Scenarios applying both climate change and improved technology and management practices show that a 50% increase in rice production is possible, but requires strong collaboration between sectors to advance agricultural research and technology and requires strong adaptive capacity in the rice production system characterized by well-developed social capital, social networks, financial capacity, and infrastructure and household mobility at the local scale. The vulnerability assessment and climate and crop adaptation simulations used here provide useful information to decision makers developing vulnerability reduction plans in the face of concurrent climate and socioeconomic change.
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Extraction of the atmospheric neutrino fluxes from experimental event rate data
Gonzalez-Garcia, M. C.; Maltoni, M.; Rojo, J.
2007-01-01
The precise knowledge of the atmospheric neutrino fluxes is a key ingredient in the interpretation of the results from any atmospheric neutrino experiment. In the standard atmospheric neutrino data analysis, these fluxes are theoretical inputs obtained from sophisticated numerical calculations. In
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International Nuclear Information System (INIS)
Osaki, S.
2000-01-01
. Furthermore, the combine of these studies, a meta-analysis, is expected to decrease the confidence limit and to countervail the confounding factors. This study reviewed the epidemiological studies on natural radiation exposure and tried to combine their results to prove the safety of natural radiation exposure. (author)
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Gas fired boilers and atmospheric pollution
International Nuclear Information System (INIS)
Chiaranello, J.M.
1991-01-01
A general analysis concerning atmospheric pollution is presented: chemical composition and vertical distribution of atmosphere and pollutants, chemical reactions, ozone destruction and production cycles, COx, NOx and SOx pollutions. The gas fired boiler number and repartition in France are presented and the associated pollution is analyzed (CO2, CO, NOx) and quantified. Various pollution control technics concerning gas fired boiler pollutants are described and a pollution criterion for clean gas fired generators is proposed
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Improved conductivity of ZnO thin films by exposure to an atmospheric hydrogen plasma
Illiberi, A.; Kniknie, B.; Deelen, J. van; Steijvers, H.L.A.H.; Habets, D.; Simons, P.J.P.M.; Janssen, A.C.; Beckers, E.H.A.
2012-01-01
Aluminum-doped zinc oxide (ZnOx:Al) films have been deposited on a moving glass substrate by a high throughput metalorganic chemical vapor deposition process at atmospheric pressure. Thin (< 250 nm) ZnOx:Al films have a poor crystalline quality, due to a small grain size and the presence of
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Analysis of Patients' X-ray Exposure in 146 Percutaneous Radiologic Gastrostomies.
Petersen, Tim-Ole; Reinhardt, Martin; Fuchs, Jochen; Gosch, Dieter; Surov, Alexey; Stumpp, Patrick; Kahn, Thomas; Moche, Michael
2017-09-01
Purpose Analysis of patient´s X-ray exposure during percutaneous radiologic gastrostomies (PRG) in a larger population. Materials and Methods Data of primary successful PRG-procedures, performed between 2004 and 2015 in 146 patients, were analyzed regarding the exposition to X-ray. Dose-area-product (DAP), dose-length-product (DLP) respectively, and fluoroscopy time (FT) were correlated with the used x-ray systems (Flatpanel Detector (FD) vs. Image Itensifier (BV)) and the necessity for periprocedural placement of a nasogastric tube. Additionally, the effective X-ray dose for PRG placement using fluoroscopy (DL), computed tomography (CT), and cone beam CT (CBCT) was estimated using a conversion factor. Results The median DFP of PRG-placements under fluoroscopy was 163 cGy*cm 2 (flat panel detector systems: 155 cGy*cm 2 ; X-ray image intensifier: 175 cGy*cm 2 ). The median DLZ was 2.2 min. Intraprocedural placement of a naso- or orogastric probe (n = 68) resulted in a significant prolongation of the median DLZ to 2.5 min versus 2 min in patients with an already existing probe. In addition, dose values were analyzed in smaller samples of patients in which the PRG was placed under CBCT (n = 7, median DFP = 2635 cGy*cm 2 ), or using CT (n = 4, median DLP = 657 mGy*cm). Estimates of the median DFP and DLP showed effective doses of 0.3 mSv for DL-assisted placements (flat panel detector 0.3 mSv, X-ray image converter 0.4 mSv), 7.9 mSv using a CBCT - flat detector, and 9.9 mSv using CT. This corresponds to a factor 26 of DL versus CBCT, or a factor 33 of DL versus CT. Conclusion In order to minimize X-ray exposure during PRG-procedures for patients and staff, fluoroscopically-guided interventions should employ flat detector systems with short transmittance sequences in low dose mode and with slow image frequency. Series recordings can be dispensed with. The intraprocedural placement of a naso- or orogastric probe
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International Nuclear Information System (INIS)
1987-01-01
This report contains 6 separately documented lectures about the following topics of the meeting: 1) Radiation exposure of plants caused by the reactor accident of Chernobyl; 2) Tritium and radiocarbon concentrations in trees; 3) Energetics of the atmospheric trace materials cycle; 4) Phenomenology of formation and decomposition of ozone in the lower atmosphere, and 5) Comparison of radioactivity levels and trace materials in the air. (PW)
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Occupational exposures. Annex H
International Nuclear Information System (INIS)
1982-01-01
This Annex focuses on significant changes in the pattern of occupational exposure which have appeared since the 1972 and 1962 reports, and presents information on trends or particular causes of high exposures. A further objective is to clarify the reasons for which the Committee requires data on occupational exposure, and to suggest areas in which better data collection or analysis may be performed. Data are also reviewed on accidents involving the exposure of workers to substantial radiation doses.
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Ruiz-Jiménez, José; Hautala, Sanna; Parshintsev, Jevgeni; Laitinen, Totti; Hartonen, Kari; Petäjä, Tuukka; Kulmala, Markku; Riekkola, Marja-Liisa
2013-01-01
A complete methodology based on LC-anisole-toluene dopant-assisted atmospheric pressure photoionization-IT-MS was developed for the determination of aldehydes in atmospheric aerosol particles. For the derivatization, ultrasound was used to accelerate the reaction between the target analytes and 2,4-dinitrophenylhydrazine. The developed methodology was validated for three different samples, gas phase, ultrafine (Dp = 30 ± 4 nm; where Dp stands for particle diameter) and all-sized particles, collected on Teflon filters. The method quantitation limits ranged from 5 to 227 pg. The accuracy and the potential matrix effects were evaluated using standard addition methodology. Recoveries ranged between 91.7 and 109.9%, and the repeatability and the reproducibility of the method developed between 0.5 and 8.0% and between 2.9 and 11.1%, respectively. The results obtained by the developed methodology compared to those provided by the previously validated method revealed no statistical differences. The method developed was applied to the determination of aldehydes in 16 atmospheric aerosol samples (30 nm and all-sized samples) collected at the Station for Measuring Forest Ecosystem-Atmosphere Relations II during spring 2011. The mean concentrations of aldehydes, and oxidation products of terpenes were between 0.05 and 82.70 ng/m(3). © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Investigation of atmospheric waves on Neptune
Eshleman, Von R.; Hinson, David P.
1994-01-01
This document constitutes the final report for grant NAGW-2442 of the Neptune Data Analysis Program, which supported research concerning atmospheric dynamics on Neptune. Professor Von R. Eshleman was the principal investigator. David P. Hinson was a Co-Investigator. The grant covered the period 1 March 1991 through 31 August 1994, including a six month no-cost extension. Funding from this grant resulted in publication of one journal article and one book chapter as well as presentation of results at two conferences and in numerous seminars. A complete bibliography is given below. A copy of the journal article is attached along with abstracts from the book chapter and the conference presentations. With support from this grant we extended our analysis and interpretation of the Voyager Project. This research contributed to an improvement in our basic understanding of atmospheric dynamics on Neptune. The highlight was the discovery and characterization of inertio-gravity waves in the troposphere and stratosphere. Results include measures of basic wave properties, such as amplitudes and vertical wavelengths, as well as estimates of the effect of the waves on the photochemistry and momentum balance of the stratosphere. This investigation also yielded a better understanding of the potential of radio occultation experiments for studies of atmospheric waves. At the same time we developed new methods of data analysis for exploiting these capabilities. These are currently being applied to radio occultation data obtained with the Magellan spacecraft to study waves in the atmosphere of Venus. Future planetary missions, such as Mars Global Surveyor and Cassini, will benefit from these accomplishments.
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Analysis of Microbial Activity Under a Supercritical CO{sub 2} Atmosphere
Energy Technology Data Exchange (ETDEWEB)
Thompson, Janelle
2012-11-30
Because the extent and impact of microbial activity in deep saline aquifers during geologic sequestration is unknown, the objectives of this proposal were to: (1) characterize the growth requirements and optima of a biofilm-producing supercritical CO{sub 2}-tolerant microbial consortium (labeled MIT0212) isolated from hydrocarbons recovered from the Frio Ridge, TX carbon sequestration site; (2) evaluate the ability of this consortium to grow under simulated reservoir conditions associated with supercritical CO{sub 2} injection; (3) isolate and characterize individual microbial strains from this consortium; and (4) investigate the mechanisms of supercritical CO{sub 2} tolerance in isolated strains and the consortium through genome-enabled studies. Molecular analysis of genetic diversity in the consortium MIT0212 revealed a predominance of sequences closely related to species of the spore-forming genus Bacillus. Strain MIT0214 was isolated from this consortium and characterized by physiological profiling and genomic analysis. We have shown that the strain MIT0214 is an aerobic spore-former and capable of facultative anaerobic growth under both reducing N{sub 2} and CO{sub 2} atmospheres by fermentation and possibly anaerobic respiration. Strain MIT0214 is best adapted to anaerobic growth at pressures of 1 atm but is able to growth at elevated pressures After 1 week growth was observed at pressures as high as 27 atm (N{sub 2}) or 9 atm (CO{sub 2}) and after 26-30 days growth can be observed under supercritical CO{sub 2}. In addition, we have determined that spores of strain B. cereus MIT0214 are tolerant of both direct and indirect exposure to supercritical CO{sub 2}. Additional physiological characterization under aerobic conditions have revealed MIT0214 is able to grow from temperature of 21 to 45 °C and salinities 0.01 to 40 g/L NaCl with optimal growth occurring at 30°C and from 1 - 5 g NaCl/L. The genome sequence of B. cereus MIT0214 shared 89 to 91% of genes
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International Nuclear Information System (INIS)
Hu, Liqin; Luo, Dan; Zhou, Tingting; Tao, Yun; Feng, Jingwen; Mei, Surong
2017-01-01
Several epidemiological studies show the association between organophosphate pesticides (OPs) and the risk of non-Hodgkin lymphoma (NHL), yet various research results remain controversial. To explore the hazard of OPs exposure to human health, three kinds of OPs (Terbufos, Malathion, and Diazinon) that are non-halogenated aliphatic compounds were included in the meta-analysis. We searched PubMed and Web of Science Databases for articles published from 1985 to February 2017. The databases were also searched for eligible studies through a manual references search. The random-effect model was utilized to compute the odds ratios (ORs) and 95% confident intervals (CIs). A total of ten observational studies (five cohort, four case-control, and one nested case-control) were included in our meta-analysis, with a pooled OR of 1.22 (95% CI 1.04 to 1.43) of Malathion, Terbufos and Diazinion. The general heterogeneity for OR was moderate (P h = 0.032, I 2 = 41.2%). The OR estimates in the subset analyses were utilized to compare the association between the three kinds of OPs and NHL; Terbufos (OR = 1.07, 95% CI 0.85 to 1.36) and Malathion (OR = 1.17, 95% CI 0.82 to 1.67) had a statistically non-significant relationship, whereas Diazinon (OR = 1.39, 95% CI 1.11 to 1.73) was significantly associated with an increased NHL risk. Because immune dysfunction was thought to increase NHL risk, the toxicity levels in the immune system of the three types of OPs were compared. Malathion attacked immune cells via a direct effect and Diazinon disrupted the neuro-immune system, which involves the cholinergic system of lymphocytes via indirect immune damage, whereas an immunotoxic effect involving Terbufos was not reported. Overall, the present meta-analysis indicated a statistically significant association between Diazinon exposure and NHL risk. - Highlights: • The present meta-analysis indicated a significantly positive association between Diazinon exposure and NHL risk.
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International Nuclear Information System (INIS)
Asai, Kiyoshi; Shinozawa, Naohisa; Ishikawa, Hirohiko; Chino, Masamichi; Hayashi, Takashi
1983-02-01
Three computer codes MATHEW, ADPIC of LLNL and GAMPUL of JAERI for prediction of wind field, concentration and external exposure rate of airborne radioactive materials are vectorized and the results are presented. Using the continuous equation of incompressible flow as a constraint, the MATHEW calculates the three dimensional wind field by a variational method. Using the particle-in -cell method, the ADPIC calculates the advection and diffusion of radioactive materials in three dimensional wind field and terrain, and gives the concentration of the materials in each cell of the domain. The GAMPUL calculates the external exposure rate assuming Gaussian plume type distribution of concentration. The vectorized code MATHEW attained 7.8 times speedup by a vector processor FACOM230-75 APU. The ADPIC and GAMPUL are estimated to attain 1.5 and 4 times speedup respectively on CRAY-1 type vector processor. (author)
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Analysis of the corrosion products formed on Ti and a Ti-Pd alloy during exposure in hot water
International Nuclear Information System (INIS)
Olefjord, I.; Mattsson, H.
1982-01-01
This is a preliminary report dealing with the surface analysis of reaction products formed on Ti and a Ti-Pd alloy during their exposure in hot water. The compositions of the aqueous media were varied with respect to the dissolved oxygen and the content of chloride ions. The temperature was 60 0 C and the exposure times were 10 min. and 6 months. Work is in progress in which samples are exposed at 80 0 C and 95 0 C in the aqueous solutions. Surface analysis was also performed on a sample which had been exposed in water-saturated bentonite. It appears from te ESCA spectra that the oxide products formed on the surface consist of TiO 2 . The results also indicate that the thickness of the film formed at 60 0 C in water is in the range 50 A to 100 A. This is somewhat more than that obtained after exposure in water at room temperature. Exposure for 6 months increases the thickness of the oxide two to three times compared to that obtained during the short exposure at 60 0 C. The analyses of the samples that had been embedded in bentonite indicate that the surface reaction products are thinner than those found on the surface after exposure in an open vessel
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Energy Technology Data Exchange (ETDEWEB)
Grandjean, P
1984-01-01
In order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. Thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. Occupational exposures may lead to the retention of 100 micrograms of nickel per day. Environmental nickel levels depend particularly on natural sources, pollution from nickel-manufacturing industries and airborne particles from combustion of fossil fuels. Absorption from atmospheric nickel pollution is of minor concern. Vegetables usually contain more nickel than do other food items. Certain products, such as baking powder and cocoa powder, have been found to contain excessive amounts of nickel, perhaps related to nickel leaching during the manufacturing process. Soft drinking-water and acid beverages may dissolve nickel from pipes and containers. Scattered studies indicate a highly variable dietary intake of nickel, but most averages are about 200-300 micrograms/day. In addition, skin contact to a multitude of metal objects may be of significance to the large number of individuals suffering from contact dermatitis and nickel allergy. Finally, nickel alloys are often used in nails and prostheses for orthopaedic surgery, and various sources may contaminate intravenous fluids. Thus, human nickel exposure originates from a variety of sources and is highly variable. Occupational nickel exposure is of major significance, and leaching of nickel may add to dietary intakes and to cutaneous exposures. 79 references.