Assessment of nuclear power scenarios allowing for matrix behavior in radiological impact modeling of disposal scenarios

International Nuclear Information System (INIS)

Tronche, E.; Boussier, H.

2000-01-01

Under the provisions of the 1991 French radioactive waste management law, various fuel cycle scenarios will be assessed and compared in terms of feasibility, flexibility, cost, and ultimate waste radio-toxic inventory. The latter criterion may be further broken down into 'potential radio-toxic inventory' (the radio-toxic inventory of all the radionuclides produced) and 'residual radio-toxic inventory' (the radionuclide fraction reaching the biosphere after migration from the repository). The innovative scientific contribution of this study is to consider a third type of radio-toxic inventory: the potential radio-toxic inventory after conditioning, i.e. taking into account the containment capacity of the radionuclide conditioning matrices. The matrix fraction subjected to alteration over time determines the potential for radionuclide release, hence the notion of the potential radio-toxic inventory after conditioning. An initial comparison of possible scenarios is proposed by considering orders of magnitude for the radionuclide containment capacity of the disposal matrices and for their mobilization potential. All the scenarios investigated are normalized to the same annual electric power production so that a legitimate comparison can be established for the ultimate wasteform produced per year of operation. This approach reveals significant differences among the scenarios considered that do not appear when only the raw potential radio-toxic inventory is taken into account. The matrix containment performance has a decisive effect on the final impact of a given scenario or type of scenario. Pu recycling scenarios thus reduce the potential radio-toxicity by roughly a factor of 50 compared with an open cycle; the gain rises to a factor of about 300 for scenarios in which Pu and the minor actinides are recycled. Interestingly, the results obtained by the use of a dedicated containment matrix for the minor actinides in a scenario limited to Pu recycling were comparable to

The variation of health effects based on the scenarios considering release parameters and meteorological data

International Nuclear Information System (INIS)

Jeong, Jong Tae; Ha, Jae Joo

2000-01-01

The variation of health effects resulting from the severe accidents of the YGN 3 and 4 nuclear power plants was examined based on scenarios considering the release parameters and meteorological data. The release parameters and meteorological data considered in making basic scenarios are release height, heat content, release time, warning time, wind speed, rainfall rate, and atmospheric stability class. The seasonal scenarios were also made in order to estimate the seasonal variation of health effects by considering seasonal characteristics of Korea. According to the results, there are large differences in consequence analysis from scenario to although an equal amount of radioactive materials is released to the atmosphere. Also, there are large differences in health effects from season to season due to distinct seasonal characteristics of Korea. Therefore, it is necessary to consider seasonal characteristics in developing optimum emergency response strategies

2004 Toxic Release Inventory Sites in Louisiana, Geographic NAD83, EPA (2006) [toxic_release_inventory_site_LA_EPA_2004

Data.gov (United States)

Louisiana Geographic Information Center — Data extracted from the EPA Toxics Release Inventory (TRI) system for reporting year 2004. The dataset contains facility identification, submitted and/or preferred...

2015 TRI National Analysis: Toxics Release Inventory Releases at Various Summary Levels

Science.gov (United States)

The TRI National Analysis is EPA's annual interpretation of TRI data at various summary levels. It highlights how toxic chemical wastes were managed, where toxic chemicals were released and how the 2015 TRI data compare to data from previous years. This dataset reports US state, county, large aquatic ecosystem, metro/micropolitan statistical area, and facility level statistics from 2015 TRI releases, including information on: number of 2015 TRI facilities in the geographic area and their releases (total, water, air, land); population information, including populations living within 1 mile of TRI facilities (total, minority, in poverty); and Risk Screening Environmental Indicators (RSEI) model related pounds, toxicity-weighted pounds, and RSEI score. The source of administrative boundary data is the 2013 cartographic boundary shapefiles. Location of facilities is provided by EPA's Facility Registry Service (FRS). Large Aquatic Ecosystems boundaries were dissolved from the hydrologic unit boundaries and codes for the United States, Puerto Rico, and the U.S. Virgin Islands. It was revised for inclusion in the National Atlas of the United States of America (November 2002), and updated to match the streams file created by the USGS National Mapping Division (NMD) for the National Atlas of the United States of America.

76 FR 7841 - Agency Information Collection Activities; Proposed Collections; Toxic Chemical Release Reporting...

Science.gov (United States)

2011-02-11

... agencies, and others to promote reductions in toxic chemical releases. Industrial facilities use the TRI... Activities; Proposed Collections; Toxic Chemical Release Reporting; Request for Comments on Proposed Renewal... the individual listed in the preceding FOR FURTHER INFORMATION CONTACT section. Title: Toxic Chemical...

Sugeno integral ranking of release scenarios in a low and intermediate waste repository

International Nuclear Information System (INIS)

Kim, S. Ho; Kim, Tae Woon; Ha, Jae Joo

2004-01-01

In the present study, a multi criteria decision-making (MCDM) problem of ranking of important radionuclide release scenarios in a low and intermediate radioactive waste repository is to treat on the basis of λ-fuzzy measures and Sugeno integral. Ranking of important scenarios can lead to the provision of more effective safety measure in a design stage of the repository. The ranking is determined by a relative degree of appropriateness of scenario alternatives. To demonstrate a validation of the proposed approach to ranking of release scenarios, results of the previous AHP study are used and compared with them of the present SIAHP approach. Since the AHP approach uses importance weight based on additive probability measures, the interaction among criteria is ignored. The comparison of scenarios ranking obtained from these two approaches enables us to figure out the effect of different models for interaction among criteria

Long term safety assessment of geological waste disposal systems: issues on release scenarios

International Nuclear Information System (INIS)

Khan, S.A.; Qureshi, A.A.

1995-01-01

Geological insolation of high level nuclear waste is an attractive waste disposal concept. However, long term safety demonstration of this concept is a major challenge to the operators, regulators and the scientific community. Identification of the factors responsible for the release of radionuclides from geosphere to biosphere,is first step in this regard. Current understanding of the release scenarios indicates that faulting, ground after percolation, seismicity, volcanism and human intrusion are the dominating release factors for most of the candidate rock formations. The major source of uncertainties is the probability values of various release events due to random nature of catastrophic geological events and past poor historical records of the frequencies of such events. There is consensus among the experts that the waste release via human intrusion is the most unpredictable scenario at present state of the knowledge. (author)

Modelling of motorway tunnels scenario for utilization of conditionally released radioactive materials

International Nuclear Information System (INIS)

Hrncir, Tomas; Panik, Michal; Necas, Vladimir

2011-01-01

Considerable amount of solid radioactive waste with radioactivity slightly above the limits for unconditional release is generated during the decommissioning of the nuclear installations. Conditional release deals with precisely this type of materials with activity slightly above limits in order to save considerable financial resources, which would be otherwise spend on treatment, conditioning and disposal of these materials at appropriate repository. The basic principles of conditional release as well as possibilities of reusing of the conditionally released materials are described. One of these possibilities of the reusing was chosen and application proposal of conditional release of metal waste - steel reinforcement in the concrete, which could be used for construction of motorway tunnels, was created. The computer code Visiplan 4.0 3D ALARA planning tool software was used for the calculation of effective individual dose for personnel constructing the tunnel and for critical group related to scenario. Particular models for individual scenarios of conditional release have been developed within the scope of this software code. The aim of the paper is to determine a level of the radioactivity of conditional released materials to avoid over exceeding the value of annual individual effective dose 10μSv/year established by international recommendations. (author)

Topical report on release scenario analysis of long-term management of high-level defense waste at the Hanford Site

International Nuclear Information System (INIS)

Wallace, R.W.; Landstrom, D.K.; Blair, S.C.; Howes, B.W.; Robkin, M.A.; Benson, G.L.; Reisenauer, A.E.; Walters, W.H.; Zimmerman, M.G.

1980-11-01

Potential release scenarios for the defense high-level waste (HLW) on the Hanford Site are presented. Presented in this report are the three components necessary for evaluating the various alternatives under consideration for long-term management of Hanford defense HLW: identification of scenarios and events which might directly or indirectly disrupt radionuclide containment barriers; geotransport calculations of waste migration through the site media; and consequence (dose) analyses based on groundwater and air pathways calculations. The scenarios described in this report provide the necessary parameters for radionuclide transport and consequence analysis. Scenarios are categorized as either bounding or nonbounding. Bounding scenarios consider worst case or what if situations where an actual and significant release of waste material to the environment would happen if the scenario were to occur. Bounding scenarios include both near-term and long-term scenarios. Near-term scenarios are events which occur at 100 years from 1990. Long term scenarios are potential events considered to occur at 1000 and 10,000 years from 1990. Nonbounding scenarios consider events which result in insignificant releases or no release at all to the environment. Three release mechanisms are described in this report: (1) direct exposure of waste to the biosphere by a defined sequence of events (scenario) such as human intrusion by drilling; (2) radionuclides contacting an unconfined aquifer through downward percolation of groundwater or a rising water table; and (3) cataclysmic or explosive release of radionuclides by such mechanisms as meteorite impact, fire and explosion, criticality, or seismic events. Scenarios in this report present ways in which these release mechanisms could occur at a waste management facility. The scenarios are applied to the two in-tank waste management alternatives: in-situ disposal and continued present action

Showcasing Sustainability in Your Toxics Release Inventory Report

Science.gov (United States)

From a June 2012 webinar, these slides contain guidance for reporting Pollution Prevention and Source Reduction data on the Toxics Release Inventory Form R and a synopsis of EPA's use of this information.

76 FR 64022 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

Science.gov (United States)

2011-10-17

... Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Lifting of Administrative Stay for Hydrogen Sulfide. SUMMARY: EPA is announcing... (EPCRA) section 313 toxic chemical release reporting requirements for hydrogen sulfide (Chemical...

Scenario-targeted toxicity assessment through multiple endpoint bioassays in a soil posing unacceptable environmental risk according to regulatory screening values.

Science.gov (United States)

Rodriguez-Ruiz, A; Etxebarria, J; Boatti, L; Marigómez, I

2015-09-01

Lanestosa is a chronically polluted site (derelict mine) where the soil (Lanestosa (LA) soil) exceeds screening values (SVs) of regulatory policies in force (Basque Country; Europe) for Zn, Pb and Cd. A scenario-targeted toxicity assessment was carried out on the basis of a multi-endpoint bioassay approach. Acute and chronic toxicity bioassays were conducted with selected test species (Vibrio fischeri, Dictyostelium discoideum, Lactuca sativa, Raphanus sativus and Eisenia fetida) in combination with chemical analysis of soils and elutriates and with bioaccumulation studies in earthworms. Besides, the toxicity profile was compared with that of the mine runoff (RO) soil and of a fresh artificially polluted soil (LAAPS) resembling LA soil pollutant profile. Extractability studies in LA soil revealed that Pb, Zn and Cd were highly available for exchange and/or release into the environment. Indeed, Pb and Zn were accumulated in earthworms and LA soil resulted to be toxic. Soil respiration, V. fischeri, vegetative and developmental cycles of D. discoideum and survival and juvenile production of E. fetida were severely affected. These results confirmed that LA soil had unacceptable environmental risk and demanded intervention. In contrast, although Pb and Zn concentrations in RO soil revealed also unacceptable risk, both metal extractability and toxicity were much lower than in LA soil. Thus, within the polluted site, the need for intervention varied between areas that posed dissimilar risk. Besides, since LAAPS, with a high exchangeable metal fraction, was the most toxic, ageing under in situ natural conditions seemingly contributed to attenuate LA soil risk. As a whole, combining multi-endpoint bioassays with scenario-targeted analysis (including leaching and ageing) provides reliable risk assessment in soils posing unacceptable environmental risk according to SVs, which is useful to optimise the required intervention measures.

TOXRISK, Toxic Gas Release Accident Analysis

International Nuclear Information System (INIS)

Bennett, D.E.; Chanin, D.I.; Shiver, A.W.

1993-01-01

1 - Description of program or function: TOXRISK is an interactive program developed to aid in the evaluation of nuclear power plant control room habitability in the event of a nearby toxic material release. The program uses a model which is consistent with the approach described in the NRC Regulatory Guide 1.78. Release of the gas is treated as an initial puff followed by a continuous plume. The relative proportions of these as well as the plume release rate are supplied by the user. Transport of the gas is modeled as a Gaussian distribution and occurs through the action of a constant velocity, constant direction wind. Great flexibility is afforded the user in specifying the release description, meteorological conditions, relative geometry of the accident and plant, and the plant ventilation system characteristics. Two types of simulation can be performed: multiple case (parametric) studies and probabilistic analyses. Upon execution, TOXRISK presents a menu, and the user chooses between the Data Base Manager, the Multiple Case program, and the Probabilistic Study Program. The Data Base Manager provides a convenient means of storing, retrieving, and modifying blocks of data required by the analysis programs. The Multiple Case program calculates resultant gas concentrations inside the control room and presents a summary of information that describes the event for each set of conditions given. Optimally, a time history profile of inside and outside concentrations can also be produced. The Probabilistic Study program provides a means for estimating the annual probability of operator incapacitation due to toxic gas accidents on surrounding transportation routes and storage sites. 2 - Method of solution: Dispersion or diffusion of the gas during transport is described by modified Pasquill-Gifford dispersion coefficients

U.S./Mexico Border environmental study toxics release inventory data, 1988--1992

Energy Technology Data Exchange (ETDEWEB)

O`Brien, R.F.; LoPresti, C.A.

1996-02-01

This is a report on industrial toxic chemical releases and transfers based on information reported to the Toxics Release Inventory (TRI), a database maintained by the USEPA. This document discusses patterns of toxic chemical releases to the atmosphere, to water, to the land, and to underground injection; and transfers of toxic chemicals to Publicly Owned Treatment Works (POTW), and for disposal, treatment and other off-site transfers during the TRI reporting years 1988--1992. Geographic coverage is limited to the US side of the ``Border Area``, the geographic area situated within 100 km of the US/Mexico international boundary. A primary purpose of this study is to provide background information that can be used in the future development of potential ``indicator variables`` for tracking environmental and public health status in the Border Area in conjunction with the implementation of the North American Free Trade Agreement (NAFTA).

TURVA-2012: Assessment of radionuclide release scenarios for the repository system

International Nuclear Information System (INIS)

Smith, Paul; Poteri, Antti; Nordman, Henrik; Cormenzana, Jose Luis; Snellman, Margit; Marcos, Nuria; Hjerpe, Thomas; Koskinen, Lasse

2014-01-01

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This paper gives a summary of the analyses of the radionuclide release scenarios formulated in a companion paper, TURVA-2012: Formulation of Radionuclide Release Scenarios (Marcos, 2014). The scenarios and the analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in a further paper: TURVA-2012: Performance Assessment (Hellae, 2014). For each scenario, calculation cases are analysed to evaluate compliance of the proposed repository with regulatory requirements on radiological protection, as well as to illustrate the impact of specific uncertainties or combinations of uncertainties on the calculated results. Each case illustrates different possibilities for how the repository might evolve and perform over time, taking into account uncertainties in the models and parameter values used to represent radionuclide release, retention and transport and, for biosphere assessment calculation cases, radiation exposure. The calculation cases each address a single, failed canister, where three possible modes of failure are considered: - The presence of an initial defect in the copper overpack of the canister that penetrates the overpack completely (subsequent corrosion of the insert may then lead to an enlargement of the defect). - Corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion. - Shear movements on fractures intersecting the deposition holes. However, the likelihood and consequences of more than one canister failure occurring during the assessment time fame are also considered, generally based on the findings from the single canister calculations. Quantitative

Computer enhanced release scenario analysis for a nuclear waste repository

International Nuclear Information System (INIS)

Stottlemyre, J.A.; Petrie, G.M.; Mullen, M.F.

1979-01-01

An interactive (user-oriented) computer tool is being developed at PNL to assist in the analysis of release scenarios for long-term safety assessment of a continental geologic nuclear waste repository. Emphasis is on characterizing the various ways the geologic and hydrologic system surrounding a repository might vary over the 10 6 to 10 7 years subsequent to final closure of the cavern. The potential disruptive phenomena are categorized as natural geologic and man-caused and tend to be synergistic in nature. The computer tool is designed to permit simulation of the system response as a function of the ongoing disruptive phenomena and time. It is designed to be operated in a determinatic manner, i.e., user selection of the desired scenarios and associated rate, magnitude, and lag time data; or in a stochastic mode. The stochastic mode involves establishing distributions for individual phenomena occurrence probabilities, rates, magnitudes, and phase relationships. A Monte-Carlo technique is then employed to generate a multitude of disruptive event scenarios, scan for breaches of the repository isolation, and develop input to the release consequence analysis task. To date, only a simplified one-dimensional version of the code has been completed. Significant modification and development is required to expand its dimensionality and apply the tool to any specific site

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Formulation of radionuclide release scenarios 2012

International Nuclear Information System (INIS)

2013-04-01

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR) and application for a construction licence for a repository for disposal of spent nuclear fuel at the Olkiluoto site in south-western Finland. This report presents the radionuclide release scenarios and the methodology followed in formulating them. The formulation of scenarios takes into account the regulatory framework, the knowledge acquired in the present safety case as well as in previous safety assessments, the safety functions of the barriers of the repository system and the uncertainties in the features, events, and processes (FEPs) that may affect the entire disposal system (i.e. repository system plus the surface environment) from the emplacement of the first canister until the far future. In the report Performance Assessment, the performance of the engineered and natural barriers has been assessed against the loads expected during the evolution of the repository system and the site. Uncertainties have been identified and these are taken into account in the formulation of radionuclide release scenarios. The uncertainties in the FEPs affecting the characteristics and evolution of the surface environment are taken into account in formulating the surface environment scenarios used ultimately for assessing radiation exposure. Formulating radionuclide release scenarios for the repository system links the reports Performance Assessment and Assessment of Radionuclide Release Scenarios for the Repository System. The formulation of radionuclide release scenarios for the surface environment brings together Biosphere Description and the surface environment FEPs and is the link to the assessment of the surface environment scenarios analysed in Biosphere Assessment. (orig.)

2008 Toxic Chemical Release Inventory 2008 Toxic Chemical Release Inventory Community Right-to-Know Act of 1986, Title III, Section 313

Energy Technology Data Exchange (ETDEWEB)

Ecology and Air Quality Group

2009-10-01

For reporting year 2008, Los Alamos National Laboratory (LANL) submitted a Form R report for lead as required under the Emergency Planning and Community Right-to- Know Act (EPCRA) Section 313. No other EPCRA Section 313 chemicals were used in 2008 above the reportable thresholds. This document was prepared to provide a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2008, as well as to provide background information about data included on the Form R reports. Section 313 of EPCRA specifically requires facilities to submit a Toxic Chemical Release Inventory Report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. In 1999, EPA promulgated a final rule on persistent bioaccumulative toxics (PBTs). This rule added several chemicals to the EPCRA Section 313 list of toxic chemicals and established lower reporting thresholds for these and other PBT chemicals that were already reportable. These lower thresholds became applicable in reporting year 2000. In 2001, EPA expanded the PBT rule to include a lower reporting threshold for lead and lead compounds. Facilities that manufacture, process, or otherwise use more than 100 lb of lead or lead compounds must submit a Form R.

Emergency planning and preparedness for the deliberate release of toxic industrial chemicals.

Science.gov (United States)

Russell, David; Simpson, John

2010-03-01

Society in developed and developing countries is hugely dependent upon chemicals for health, wealth, and economic prosperity, with the chemical industry contributing significantly to the global economy. Many chemicals are synthesized, stored, and transported in vast quantities and classified as high production volume chemicals; some are recognized as being toxic industrial chemicals (TICs). Chemical accidents involving chemical installations and transportation are well recognized. Such chemical accidents occur with relative frequency and may result in large numbers of casualties with acute and chronic health effects as well as fatalities. The large-scale production of TICs, the potential for widespread exposure and significant public health impact, together with their relative ease of acquisition, makes deliberate release an area of potential concern. The large numbers of chemicals, together with the large number of potential release scenarios means that the number of possible forms of chemical incident are almost infinite. Therefore, prior to undertaking emergency planning and preparedness, it is necessary to prioritize risk and subsequently mitigate. This is a multi-faceted process, including implementation of industrial protection layers, substitution of hazardous chemicals, and relocation away from communities. Residual risk provides the basis for subsequent planning. Risk-prioritized emergency planning is a tool for identifying gaps, enhancing communication and collaboration, and for policy development. It also serves to enhance preparedness, a necessary prelude to preventing or mitigating the public health risk to deliberate release. Planning is an iterative and on-going process that requires multi-disciplinary agency input, culminating in the formation of a chemical incident plan complimentary to major incident planning. Preparedness is closely related and reflects a state of readiness. It is comprised of several components, including training and exercising

Scenarios and analytical methods for UF6 releases at NRC-licensed fuel cycle facilities

International Nuclear Information System (INIS)

Siman-Tov, M.; Dykstra, J.; Holt, D.D.; Huxtable, W.P.; Just, R.A.; Williams, W.R.

1984-06-01

This report identifies and discusses potential scenarios for the accidental release of UF 6 at NRC-licensed UF 6 production and fuel fabrication facilities based on a literature review, site visits, and DOE enrichment plant experience. Analytical tools needed for evaluating source terms for such releases are discussed, and the applicability of existing methods is reviewed. Accident scenarios are discussed under the broad headings of cylinder failures, UF 6 process system failures, nuclear criticality events, and operator errors and are categorized by location, release source, phase of UF 6 prior to release, release flow characteristics, release causes, initiating events, and UF 6 inventory at risk. At least three types of releases are identified for further examination: (1) a release from a liquid-filled cylinder outdoors, (2) a release from a pigtail or cylinder in a steam chest, (3) an indoor release from either (a) a pigtail or liquid-filled cylinder or (b) other indoor source depending on facility design and operating procedures. Indoor release phenomena may be analyzed to determine input terms for a ventilation model by using a time-dependent homogeneous compartment model or a more complex hydrodynamic model if time-dependent, spatial variations in concentrations, temperature, and pressure are important. Analytical tools for modeling directed jets and explosive releases are discussed as well as some of the complex phenomena to be considered in analyzing UF 6 releases both indoors and outdoors

Scenarios for 14C release to the atmosphere by the world nuclear industry and estimated radiological impacts

International Nuclear Information System (INIS)

Till, J.E.; Killough, G.G.

1978-01-01

This paper presents an assessment of the radiation dose to the world population and the associated potential health effects from three scenarios of 14 C releases by the nuclear industry between 1975 and 2020. Measures of health impact are derived from source terms through the use of a multicompartment model of the global carbon cycle, dose-rate factors based on 14 C specific activity in various organs of man, and health-effect incidence factors recently recommended by the International Commission on Radiological Protection. The scenarios for worldwide 14 C releases considered are (1) a pessimistic scenario in which all the 14 C projected to be produced in fuel cycles is released, (2) an optimistic scenario that assumes a decontamination factor of 100 for fuel reprocessing, and (3) an intermediate scenario that simulates a phased improvement in effluent treatment technology at reprocessing plants. The estimates of cumulative potential health effects are based on integrations over infinite time. Comparisons with estimated effects from naturally formed 14 C are shown

Cumulative toxicity of neonicotinoid insecticide mixtures to Chironomus dilutus under acute exposure scenarios.

Science.gov (United States)

Maloney, Erin M; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

2017-11-01

Extensive agricultural use of neonicotinoid insecticide products has resulted in the presence of neonicotinoid mixtures in surface waters worldwide. Although many aquatic insect species are known to be sensitive to neonicotinoids, the impact of neonicotinoid mixtures is poorly understood. In the present study, the cumulative toxicities of binary and ternary mixtures of select neonicotinoids (imidacloprid, clothianidin, and thiamethoxam) were characterized under acute (96-h) exposure scenarios using the larval midge Chironomus dilutus as a representative aquatic insect species. Using the MIXTOX approach, predictive parametric models were fitted and statistically compared with observed toxicity in subsequent mixture tests. Single-compound toxicity tests yielded median lethal concentration (LC50) values of 4.63, 5.93, and 55.34 μg/L for imidacloprid, clothianidin, and thiamethoxam, respectively. Because of the similar modes of action of neonicotinoids, concentration-additive cumulative mixture toxicity was the predicted model. However, we found that imidacloprid-clothianidin mixtures demonstrated response-additive dose-level-dependent synergism, clothianidin-thiamethoxam mixtures demonstrated concentration-additive synergism, and imidacloprid-thiamethoxam mixtures demonstrated response-additive dose-ratio-dependent synergism, with toxicity shifting from antagonism to synergism as the relative concentration of thiamethoxam increased. Imidacloprid-clothianidin-thiamethoxam ternary mixtures demonstrated response-additive synergism. These results indicate that, under acute exposure scenarios, the toxicity of neonicotinoid mixtures to C. dilutus cannot be predicted using the common assumption of additive joint activity. Indeed, the overarching trend of synergistic deviation emphasizes the need for further research into the ecotoxicological effects of neonicotinoid insecticide mixtures in field settings, the development of better toxicity models for neonicotinoid mixture

Formulation and evaluation of gas release scenarios for the silo in Swedish Final Repository for Radioactive Waste (SFR)

International Nuclear Information System (INIS)

Carlsson, J.; Moreno, L.

1992-01-01

The Swedish Final Repository for Radioactive Waste (SFR) has been in operation since 1988 and is located in the crystalline rock, 60 m below the Baltic Sea. In the licensing procedure for the SFR the safety assessment has been complemented with a detailed scenario analysis of the performance of the repository. The scenarios include the influence on radionuclide release by gas formation and gas transport processes in the silo. The overall conclusion is that the release of most radionuclides from the silo is only marginally affected by the formation and release of gas, even for scenarios considering unexpected events. The largest effects were found for short-lived radionuclides and radionuclides that have no or low sorption ability. Except for very extreme scenarios for the silo the overall impact from repository on the environment is by far dominated by the release of radionuclides from the rock vaults. 10 refs., 6 figs

Toxics Release Inventory Chemical Hazard Information Profiles (TRI-CHIP) Dataset

Data.gov (United States)

U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) Chemical Hazard Information Profiles (TRI-CHIP) dataset contains hazard information about the chemicals reported in TRI. Users can...

The Impact of Pollution Prevention on Toxic Environmental Releases from U.S. Manufacturing Facilities.

Science.gov (United States)

Ranson, Matthew; Cox, Brendan; Keenan, Cheryl; Teitelbaum, Daniel

2015-11-03

Between 1991 and 2012, the facilities that reported to the U.S. Environmental Protection Agency's Toxic Release Inventory (TRI) Program conducted 370,000 source reduction projects. We use this data set to conduct the first quasi-experimental retrospective evaluation of how implementing a source reduction (pollution prevention) project affects the quantity of toxic chemicals released to the environment by an average industrial facility. We use a differences-in-differences methodology, which measures how implementing a source reduction project affects a facility's releases of targeted chemicals, relative to releases of (a) other untargeted chemicals from the same facility, or (b) the same chemical from other facilities in the same industry. We find that the average source reduction project causes a 9-16% decrease in releases of targeted chemicals in the year of implementation. Source reduction techniques vary in effectiveness: for example, raw material modification causes a large decrease in releases, while inventory control has no detectable effect. Our analysis suggests that in aggregate, the source reduction projects carried out in the U.S. since 1991 have prevented between 5 and 14 billion pounds of toxic releases.

Reuse of conditional released materials from decommissioning; a review of approaches and scenarios with long-term constructions - 59149

International Nuclear Information System (INIS)

Daniska, Vladimir; Pritrsky, Jozef; Ondra, Frantisek; Zachar, Matej; Necas, Vladimir

2012-01-01

Paper presents the overall scope and actual results of the project for evaluation of representative scenarios for reuse of conditionally released materials from decommissioning. Aim of the project is to evaluate the possibilities of reuse of conditionally released steels and concrete in technical constructions which guarantee the long-term preservation of design properties over periods of 50-100 years. Interaction of conditionally released materials with public is limited and predictable due to design and purpose of selected constructions and due to fact that in many scenarios these materials are embedded in non-radioactive materials such as bars in reinforced concrete. Worker's scenarios for preparation, operation and maintenance of these constructions are analysed in detail including the manufacturing of elements for these constructions. Project aims to evaluate the scenarios of reuse of conditionally released materials in a complex way in order to develop the data for designers of scenarios and to evaluate the volumes of conditionally released materials based on facility (to be decommissioned) inventory data. The long-term constructions considered are bridges, tunnels, roads, railway constructions, industrial buildings, power industry equipment and others. Evaluation covers following areas: - Analysis of activities for manufacturing of reinforcement bars, rolled steel sheets and other steel elements and analysis of activities for construction of evaluated scenarios in order to evaluate the external exposure of professionals performing these activities; - Analysis of external exposure of professionals involved in operation and maintenance of the long-term constructions; analysis of external exposure of public groups which are exposed to evaluated constructions; - Analysis of internal exposure of public groups from the radionuclides released from the evaluated scenarios based on models for migration of radionuclides from the long-term constructions to critical

Proceedings of the workshop on radionuclide release scenarios for geologic repositories

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

The safety of radioactive waste disposal in geological formations cannot be verified experimentally. Safety analysis provides the only means to ensure that all risks associated with the waste repositories are acceptably low. The definition of radionuclide release scenarios, as discussed in these proceeedings, is the first step in the safety analysis of waste repositories.

2001 Toxic Chemical Release Inventory Emergency Planning and Community Right to Know Act SEC 313

International Nuclear Information System (INIS)

ZALOUDEK, D.E.

2002-01-01

Pursuant to section 313 of the Emergency Planning and Community Right-To-Know Act of 1986 (EPCRA), and Executive Order 13148, Greening the Government Through Leadership in Environmental Management, the US Department of Energy has prepared and submitted a Toxic Chemical Release Inventory for the Hanford Site covering activities performed during calendar year 2001. EPCRA Section 313 requires facilities that manufacture, process, or otherwise use listed toxic chemicals in quantities exceeding established threshold levels to report total annual releases of those chemicals. During calendar year 2001, Hanford Site activities resulted in one chemical used in amounts exceeding an activity threshold. Accordingly, the Hanford Site 2001 Toxic Chemical Release Inventory, DOE/RL-2002-37, includes total annual amount of lead released to the environment, transferred to offsite locations, and otherwise managed as waste

78 FR 52860 - Electronic Reporting of Toxics Release Inventory Data

Science.gov (United States)

2013-08-27

... only exception to this electronic reporting requirement is for the few facilities that submit trade... rulemaking process later to require the electronic reporting of trade secrets. The EPA recognizes the... Electronic Reporting of Toxics Release Inventory Data AGENCY: Environmental Protection Agency (EPA). ACTION...

Multi-objective evacuation routing optimization for toxic cloud releases

International Nuclear Information System (INIS)

Gai, Wen-mei; Deng, Yun-feng; Jiang, Zhong-an; Li, Jing; Du, Yan

2017-01-01

This paper develops a model for assessing the risks associated with the evacuation process in response to potential chemical accidents, based on which a multi-objective evacuation routing model for toxic cloud releases is proposed taking into account that the travel speed on each arc will be affected by disaster extension. The objectives of the evacuation routing model are to minimize travel time and individual evacuation risk along a path respectively. Two heuristic algorithms are proposed to solve the multi-objective evacuation routing model. Simulation results show the effectiveness and feasibility of the model and algorithms presented in this paper. And, the methodology with appropriate modification is suitable for supporting decisions in assessing emergency route selection in other cases (fires, nuclear accidents). - Highlights: • A model for assessing and visualizing the risks is developed. • A multi-objective evacuation routing model is proposed for toxic cloud releases. • A modified Dijkstra algorithm is designed to obtain an solution of the model. • Two heuristic algorithms have been developed as the optimization tool.

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Assessment of radionuclide release scenarios for the repository system 2012

International Nuclear Information System (INIS)

2012-12-01

Assessment of Radionuclide Release Scenarios sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of presenting an assessment of the repository system scenarios leading to radionuclide releases that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For each scenario, a range of calculation cases, also identified in Formulation of Radionuclide Release Scenarios, has been analysed, complemented by Monte Carlo simulations, a probabilistic sensitivity analysis and other supporting calculations. The calculation cases and analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in Performance Assessment. Quality control and assurance measures have been adopted to ensure transparency and traceability of the calculations performed and hence to promote confidence in the analysis of the calculation cases. The calculation cases each consider a single, failed canister, where three possible modes of failure are addressed: (1) the presence of an initial penetrating defect in the copper overpack of the canister, (2) corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion, (3) shear movement on a fracture intersecting a deposition hole. The likelihood and consequences of multiple canister failure occurring during the assessment time frame are also considered. In particular, the analyses consider: The likelihood and consequences of there being multiple canisters with initial penetrating defects; The consequences if canister failure due to corrosion following buffer erosion were to occur; and The low annual probability of there being an earthquake large enough to give rise to canister failure due to rock shear movements and the potential consequences of such an earthquake, taking into

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Assessment of radionuclide release scenarios for the repository system 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Assessment of Radionuclide Release Scenarios sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of presenting an assessment of the repository system scenarios leading to radionuclide releases that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For each scenario, a range of calculation cases, also identified in Formulation of Radionuclide Release Scenarios, has been analysed, complemented by Monte Carlo simulations, a probabilistic sensitivity analysis and other supporting calculations. The calculation cases and analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in Performance Assessment. Quality control and assurance measures have been adopted to ensure transparency and traceability of the calculations performed and hence to promote confidence in the analysis of the calculation cases. The calculation cases each consider a single, failed canister, where three possible modes of failure are addressed: (1) the presence of an initial penetrating defect in the copper overpack of the canister, (2) corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion, (3) shear movement on a fracture intersecting a deposition hole. The likelihood and consequences of multiple canister failure occurring during the assessment time frame are also considered. In particular, the analyses consider: The likelihood and consequences of there being multiple canisters with initial penetrating defects; The consequences if canister failure due to corrosion following buffer erosion were to occur; and The low annual probability of there being an earthquake large enough to give rise to canister failure due to rock shear movements and the potential consequences of such an earthquake

Preliminary scenarios for the release of radioactive waste from a hypothetical repository in basalt of the Columbia Plateau

International Nuclear Information System (INIS)

Hunter, R.L.

1983-10-01

Nine release phenomena - normal flow of water, tectonic disturbance of the fracture network, intersection of a new fault with the repository, glaciation, fluvia erosion, thermomechanical disturbances, subsidence, seal failure, and drilling - give rise to 318 preliminary scenarios for the release of waste from a hypothetical high-level-waste repository in basalt. The scenarios have relative probabilities that range over several orders of magnitude. The relative probabilities provide a means of screening the scenarios for the more limited set to be subjected to consequence analysis. Lack of data and of preliminary modeling, however, lead to great uncertainties in the highly conservative probabilities assigned here. As a result, the recommendations in this report are directed at resolution of the major uncertainties in the relative probabilities of the preliminary scenarios. The resolution of some of the uncertainties should help in the selection of the suite of scenarios for final consequence analysis. 38 references, 22 figures, 18 tables

Reuse of conditionally released steel; proposals and evaluation of processes for manufacturing of steel elements and processes for construction of selected scenarios - 59130

International Nuclear Information System (INIS)

Bezak, Peter; Ondra, Frantisek; Hajkova, Eva; Necas, Vladimir

2012-01-01

The project include systematic scenarios analysis of conditionally released materials from the decommissioning of nuclear installations and the creation of new knowledge in this field, which will be used for implementing projects for reuse of these materials. New knowledge includes data about materials from the decommissioning (types of materials and radiological data on the basis of analysis of various scenarios). Scenarios contain information about conditionally released materials, data of the external exposure of personnel who will assemble those structures and who will be use the constructions up to the target scenario. Scenarios assume guarantee that the final products will be placed on the current position for a very long period from 50 to 100 years. The paper presents the review of activities for manufacturing of various steel construction elements made of conditionally released steels and activities for realisation of selected scenarios for reuse of construction elements. The ingots after melting of decommissioned radioactive steel materials are as the starting material for manufacturing of steel components. Ingots from the controlled area will be melted into induction furnace and the mixture of liquid steel will be alloyed for achieve of required chemical parameters. Typical steel products suitable for established scenarios are steel rebar of concrete, steel profiles of various forms, railway rails and rolled steel sheets. Target scenarios include an analysis of staff exposure during installation of steel constructions as well as exposure of individual from critical groups of population during their exploitation. The various scenarios, provided within the scope of the CONRELMAT project are focused at the systematic analysis of the use of conditionally released steel from decommissioning of nuclear facilities. Scenarios are focused on research and development of model situations in constructions in the areas of transport, civil constructions, industry and

1997 toxic chemical release inventory. Emergency Planning and Community Right-To-Know Act, Section 313

International Nuclear Information System (INIS)

Zaloudek, D.E.

1998-01-01

Two listed toxic chemicals were used at the Hanford Site above established activity thresholds: phosphoric acid and chlorine. Because total combined quantities of chlorine released, disposed, treated, recovered through recycle operations, co-combusted for energy recovery, and transferred to off-site locations for the purpose of recycle, energy recovery, treatment, and/or disposal, amounted to less than 500 pounds, the Hanford Site qualified for the alternate one million pound threshold for chlorine. Accordingly, this Toxic Chemical Release Inventory includes a Form A for chlorine, and a Form B for phosphoric acid

Hot and toxic: Temperature regulates microcystin release from cyanobacteria.

Science.gov (United States)

Walls, Jeremy T; Wyatt, Kevin H; Doll, Jason C; Rubenstein, Eric M; Rober, Allison R

2018-01-01

The mechanisms regulating toxin release by cyanobacteria are poorly understood despite the threat cyanotoxins pose to water quality and human health globally. To determine the potential for temperature to regulate microcystin release by toxin-producing cyanobacteria, we evaluated seasonal patterns of water temperature, cyanobacteria biomass, and extracellular microcystin concentration in a eutrophic freshwater lake dominated by Planktothrix agardhii. We replicated seasonal variation in water temperature in a concurrent laboratory incubation experiment designed to evaluate cause-effect relationships between temperature and toxin release. Lake temperature ranged from 3 to 27°C and cyanobacteria biomass increased with warming up to 18°C, but declined rapidly thereafter with further increases in temperature. Extracellular microcystin concentration was tightly coupled with temperature and was most elevated between 20 and 25°C, which was concurrent with the decline in cyanobacteria biomass. A similar trend was observed in laboratory incubations where productivity-specific microcystin release was most elevated between 20 and 25°C and then declined sharply at 30°C. We applied generalized linear mixed modeling to evaluate the strength of water temperature as a predictor of cyanobacteria abundance and microcystin release, and determined that warming≥20°C would result in a 36% increase in microcystin release when Chlorophyll a was ≤50μgl -1 . These results show a temperature threshold for toxin release in P. agardhii, which demonstrates a potential to use water temperature to forecast bloom severity in eutrophic lakes where blooms can persist year-round with varying degrees of toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of release scenarios for a repository of radioactive waste in a salt dome in the Netherlands

International Nuclear Information System (INIS)

Glasbergen, P.; Hamstra, J.

1981-01-01

A review is presented of the long-term scenarios used in the safety analysis which was carried out for the disposal of radioactive waste in salt domes in the Netherlands. The long-term analysis involved the following natural processes or events: climatological and sea-level changes, glacial erosion, diapirism, subsidence, faulting and dissolution. The model calculations which were carried out showed the dominant parameters: the rate of diapirism and the rate of subsurface dissolution of rock salt. During the operational period the intrusion of water in the repository was considered to be the most hazardous event. Because the layout of the disposal mine, the disposal geometry and the disposal mining procedures were still under consideration, the first approach of a release scenario was made on a generic basis. A generic scenario is presented for the events during the flooding of the repository. The transport ways of water through the repository and its surroundings are indicated. It is concluded that release scenario analysis for long-term periods and for the operational period provides essential information to optimize the overall disposal system in an iterative process

Toxic Release Inventory (TRI) Facility Points, Region 9, 2012, US EPA Region 9

Data.gov (United States)

U.S. Environmental Protection Agency — A federal law called the Emergency Planning and Community Right to Know Act (EPCRA) gives the public the right to know about toxic chemicals being released into the...

Toxic Release Inventory (TRI) Facility Points, Region 9, 2014, US EPA Region 9

Data.gov (United States)

U.S. Environmental Protection Agency — A federal law called the Emergency Planning and Community Right to Know Act (EPCRA) gives the public the right to know about toxic chemicals being released into the...

Toxic Release Inventory (TRI) Facility Points, Region 9, 2011, US EPA Region 9

Data.gov (United States)

U.S. Environmental Protection Agency — A federal law called the Emergency Planning and Community Right to Know Act (EPCRA) gives the public the right to know about toxic chemicals being released into the...

Scenarios of 14C releases from the World Nuclear Power Industry from 1975 to 2020 and the estimated radiological impact

International Nuclear Information System (INIS)

Killough, G.G.; Till, J.E.

1978-01-01

This article presents an assessment of the radiation dose to the world population and the associated potential health effects from three scenarios of 14 C releases by the nuclear industry between 1975 and 2020. Measures of health impact are derived from source terms through the use of a multicompartment model of the global carbon cycle, dose-rate factors based on 14 C specific activity in various organs of man, and health-effect incidence factors recently recommended by the International Commission on Radiological Protection (ICRP). The three scenarios for worldwide 14 C releases considered are (1) a pessimistic scenario in which all the 14 C projected to be produced in fuel cycles is released (2) an optimistic scenario that assumes a decontamination factor of 100 for fuel reprocessing, and (3) an intermediate scenario that simulates a phased improvement in the effluent treatment technology at reprocessing plants. The estimates of cumulative potential health effects based on integration over infinite time (effectively 46,000 years or about 8 half-lives of 14 C) are as follows: 110,000 cancers and 75,000 genetic effects from the pessimistic scenario; 21,000 cancers and 14,000 genetic effects from the optimistic scenario; 22,000 cancers and 15,000 genetic effects from the intermediate scenario; 100,000 cancers and 68,000 genetic effects from the 14 C formed in nature between 1975 and 2020; and 380,000 cancers and 250,000 genetic effects from the 14 C formed by the detonation of nuclear explosives from 1945 to 1974. Comparable effects from the naturally formed 14 C in steady state in the environment, also integrated over 46,000 years, are approximately 66 million cancers and 43 million genetic effects. These estimates are based on a world population that is assumed to remain stationary at 12.2 billion after 2075

A Nuclide Release Model for a Deep Well Scenario near a Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jung, Jong Tae; Choi, Jong Won

2010-01-01

Recently several template programs ready for the safety assessment of a high-level radioactive waste repository (HLW) and a low- and intermediate level radioactive waste repository (LILW) systems, that are conceptually modeled, have been developed by utilizing GoldSim and AMBER at KAERI. During the last few years, such template programs have been utilized for the evaluation of nuclide transports in the nearand far-field of a repository as well as transport through the biosphere under various normal and disruptive release scenarios with assumed data. The GoldSim program, another template program by which influence due to a well located very near to the repository has been modeled and evaluated for an assumed case in order to simulate the worst exposure scenario. This seems very useful to evaluate an accidental event a long time after closure of the repository has been developed and illustrated

76 FR 69136 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting

Science.gov (United States)

2011-11-08

... Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting AGENCY: Environmental Protection Agency (EPA). ACTION: Lifting of Administrative Stay for Hydrogen Sulfide; Correction. SUMMARY: The... Administrative Stay of the reporting requirements for hydrogen sulfide. The Office of the Federal Register...

Childhood lead toxicity and impaired release of thyrotropin-stimulating hormone

International Nuclear Information System (INIS)

Huseman, C.A.; Moriarty, C.M.; Angle, C.R.

1987-01-01

Decreased stature of children is epidemiologically associated with increased blood lead independent of multiple socioeconomic and nutritional variables. Since endocrine dysfunction occurs in adult lead workers, they studied two girls, 2 years of age, before and after calcium disodium edetate chelation for blood leads (PbB) of 19-72 μg/dl. The height of both children had crossed from the 50th to below the 10th percentile during the course of chronic lead toxicity. Basal free T 4 , T 4 , T 3 , cortisol, somatomedin C, and sex steroids were normal. A decrease in the growth hormone response and elevation of basal prolcatin and gonadotropins were noted in one. Both children demonstrated blunted thyrotropin-stimulating hormone (TSH) responses to thyrotropin-releasing hormone (TRH) in six of seven challenges. This prompted in vitro studies of cultured cells from rat pituitarities. After incubation of pituitary cells with 0.1-10 μM Pb 2+ for 2 hr, followed by the addition of TRH, there was a dose-dependent inhibition of TSH release Lead did not interfere with the assay of TSH. To investigate the interaction of lead and calcium, 45 Ca 2+ kinetic analyses were done on rat pituitary slices after 1 hr incubation with 1.0 μM lead. The impaired late efflux was consistent with a decrease in the size and exchangeability of the tightly bound pool of intracellular microsomal or mitochondrial calcium. The rat pituitary cell model provides a model for the decreased TSH release of lead poisoning, supports the biological plausibility of a neuroendocrine effect on growth, and suggests that interference with calcium-mediated intracellular responses is a basic mechanism of lead toxicity

Radionuclide release calculations for selected severe accident scenarios. PWR, ice condenser design

Energy Technology Data Exchange (ETDEWEB)

Denning, R S; Gieseke, J A; Cybulskis, P; Lee, K W; Jordan, H; Curtis, L A; Kelly, R F; Kogan, V; Schumacher, P M

1986-07-01

This report presents results of analyses of the environmental releases of fission products (source terms) for severe accident scenarios in a pressurized water reactor with an ice-condenser containment. The analyses were performed to support the Severe Accident Risk Reduction/Risk Rebaselining Program (SARRP) which is being undertaken for the U.S. Nuclear Regulatory Commission by Sandia National Laboratories. In the SARRP program, risk estimates are being generated for a number of reference plant designs. The Sequoyah Plant has been used in this study as an example of a PWR ice-condenser plant. (author)

Do Industries Pollute More in Poorer Neighborhoods? Evidence From Toxic Releasing Plants in Mexico

OpenAIRE

Lopamudra Chakraborti; José Jaime Sainz Santamaría

2015-01-01

Studies on industrial pollution and community pressure in developing countries are rare. We employ previously unused, self-reported toxics pollution data from Mexico to show that there exists some evidence of environmental justice concerns and community pressure in explaining industrial pollution behavior. We obtain historical data on toxic releases into water and land for the time period 2004 to 2012. We focus on 7 major pollutants including heavy metals and cyanide. To address endogeneity c...

Analytical methodology for optimization of waste management scenarios in nuclear installation decommissioning process - 16148

International Nuclear Information System (INIS)

Zachar, Matej; Necas, Vladimir; Daniska, Vladimir; Rehak, Ivan; Vasko, Marek

2009-01-01

The nuclear installation decommissioning process is characterized by production of large amount of various radioactive and non-radioactive waste that has to be managed, taking into account its physical, chemical, toxic and radiological properties. Waste management is considered to be one of the key issues within the frame of the decommissioning process. During the decommissioning planning period, the scenarios covering possible routes of materials release into the environment and radioactive waste disposal, should be discussed and evaluated. Unconditional and conditional release to the environment, long-term storage at the nuclear site, near surface or deep geological disposal and relevant material management techniques for achieving the final status should be taken into account in the analysed scenarios. At the level of the final decommissioning plan, it is desirable to have the waste management scenario optimized for local specific facility conditions taking into account a national decommissioning background. The analytical methodology for the evaluation of decommissioning waste management scenarios, presented in the paper, is based on the materials and radioactivity flow modelling, which starts from waste generation activities like pre-dismantling decontamination, selected methods of dismantling, waste treatment and conditioning, up to materials release or conditioned radioactive waste disposal. The necessary input data for scenarios, e.g. nuclear installation inventory database (physical and radiological data), waste processing technologies parameters or material release and waste disposal limits, have to be considered. The analytical methodology principles are implemented into the standardised decommissioning parameters calculation code OMEGA, developed in the DECOM company. In the paper the examples of the methodology implementation for the scenarios optimization are presented and discussed. (authors)

1992 Toxic Chemical Release Inventory: Emergency Planning and Community Right-To-Know-Act of 1986 Section 313

International Nuclear Information System (INIS)

1993-07-01

Section 313 of the Emergency Planning and Community Right-To-Know Act of 1986 (EPCRA) requires the annual submittal of toxic chemical release information to the US Environmental Protection Agency (EPA). The following document is the July 1993 submittal of the EPCRA Toxic Chemical Release Inventory Report (Form R). Included is a Form R for chlorine and for lead, the two chemicals used in excess of the established regulatory thresholds at the Hanford Site by the US Department of Energy, Richland Operations Office and its contractors during calendar year 1992

Release, transport and toxicity of engineered nanoparticles.

Science.gov (United States)

Soni, Deepika; Naoghare, Pravin K; Saravanadevi, Sivanesan; Pandey, Ram Avatar

2015-01-01

Recent developments in nanotechnology have facilitated the synthesis of novel engineered nanoparticles (ENPs) that possess new and different physicochemical properties. These ENPs have been ex tensive ly used in various commercial sectors to achieve both social and economic benefits. However. the increasing production and consumption of ENPs by many different industries has raised concerns about their possible release and accumulation in the environment. Released EN Ps may either remain suspended in the atmosphere for several years or may accumulate and eventually be modified int o other substances. Settled nanoparticles can he easily washed away during ra in s. and therefore may easily enter the food chain via water and so il. Thus. EN Ps can contaminate air. water and soil and can subsequently pose adverse risks to the health of different organisms. Studies to date indicate that ENP transport to and within the ecosystem depend on their chemical and physical properties (viz .. size. shape and solubility) . Therefore. the EN Ps display variable behavior in the environment because of their individual properties th at affect their tendency for adsorption, absorption, diffusional and colloidal interaction. The transport of EN Ps also influences their fate and chemical transformation in ecosystems. The adsorption, absorption and colloidal interaction of ENPs affect their capacity to be degraded or transformed, whereas the tendency of ENPs to agglomerate fosters their sedimentation. How widely ENPs are transported and their environmental fate influence how tox ic they may become to environmental organisms. One barrier to fully understanding how EN Ps are transformed in the environment and how best to characterize their toxicity, is related to the nature of their ultrafine structure. Experiments with different animals, pl ants, and cell lines have revealed that ENPs induce toxicity via several cellular pathways that is linked to the size. shape. surface area

Toxic vapor concentrations in the control room following a postulated accidental release

International Nuclear Information System (INIS)

Wing, J.

1979-05-01

An acceptable method is presented for calculating the vapor concentrations in a control room as a function of time after a postulated accidental release. Included are the mathematical formulas for computing the rates of vaporization and evaporation of liquid spills, the vapor dispersion in air, and the control room air exchange. A list of toxic chemicals and their physical properties is also given

Release of copper from sintered tungsten-bronze shot under different pH conditions and its potential toxicity to aquatic organisms

International Nuclear Information System (INIS)

Thomas, Vernon G.; Santore, Robert C.; McGill, Ian

2007-01-01

Sintered tungsten-bronze is a new substitute for lead shot, and is about to be deposited in and around the wetlands of North America. This material contains copper in the alloyed form of bronze. This in vitro study was performed according to U.S. Fish and Wildlife Service criteria to determine the dissolution rate of copper from the shot, and to assess the toxic risk that it may present to aquatic organisms. The dissolution of copper from tungsten-bronze shot, pure copper shot, and glass beads was measured in a buffered, moderately hard, synthetic water of pH 5.5, 6.6, and 7.8 over a 28-day period. The dissolution of copper from both the control copper shot and the tungsten-bronze shot was affected significantly by the pH of the water and the duration of dissolution (all p values < 0.000). The rate of copper release from tungsten bronze shot was 30 to 50 times lower than that from the copper shot, depending on pH (p < 0.0000). The observed expected environmental concentration of copper released from tungsten-bronze shot after 28 days was 0.02 μg/L at pH 7.8, and 0.4 μg/L at pH 5.6, using a loading and exposure scenario specific in a U.S. Fish and Wildlife Service protocol. Ratio Quotient values derived from the highest EEC observed in this study (0.4 μg/L), and the copper toxic effect levels for all aquatic species listed in the U.S. Environmental Protection Agency ambient water quality criteria database, were all far less than the 0.1 criterion value. Given the conditions stipulated by the U.S. Fish and Wildlife Service and the U.S. Environmental Protection Agency, heavy loading from discharged tungsten-bronze shot would not pose a toxic risk to potable water, or to soil. Consequently, it would appear that no toxic risks to aquatic organisms will attend the use of tungsten-bronze shot of the approved composition. Given the likelihood that sintered tungsten-bronze of the same formula will be used for fishing weights, bullets, and wheel balance weights, it is

Scenarios for long-term release of radionuclides from a nuclear-waste repository in the Los Medanos region of New Mexico

International Nuclear Information System (INIS)

Bingham, F.W.; Barr, G.E.

1979-05-01

This report discusses hypothetical sequences of events that could conceivably release radionuclides from radioactive waste buried in the proposed WIPP repository. All the scenarios are described in terms specific to the WIPP site; they include only events whose occurrence is physically possible there. The report estimates the relative probabilities of the scenarios at times ranging from 1000 to 1 million years after the repository is sealed. Although none of the scenarios is judged likely, the report recommends several for detailed computer modeling and consequence analysis

Assessment of nanoparticle release and associated health effect of polymer-silicon composites

International Nuclear Information System (INIS)

Zhu, H; Irfan, A; Sachse, S; Njuguna, J

2012-01-01

Little information is currently available on possible release of nanomaterials or/and nanoparticles (NP) from conventional and novel products and associated health effect. This study aimed to assess the possible release of NP during the application stage of conventional and nanoproducts. NP release was monitored during physical processing of polymer-silicon composites, and the toxicity of both the released NP and the raw silica nanomaterials that were used as fillers in the nanocomposites was assessed in vitro using human lung epithelial A549 cells. This study suggests that 1) NP can be released from the conventional and novel polymer-silicon composites under certain application scenario; 2) the level of NP release from polymer composites could be altered by different reinforcement materials; e.g. nanostructured MMT could reduce the release while SiO2 NP could increase the release; 3) working with polymer composites under certain conditions could risk inhalation of high level of polymer NP; 4) raw nanomaterials appeared to be toxic in the chosen in vitro system. Further study of the effect of novel filler materials on NP release from final polymer products and the effect of released NP on environment and human health will inform design of safe materials and minimization of negative impact on the environment and human health.

1995 Toxic chemical release inventory: Emergency Planning and Community Right-to-Know Act of 1986, Section 313

International Nuclear Information System (INIS)

Mincey, S.L.

1996-08-01

Section 313 of the Emergency Planning and Community Right-To-Know Act (EPCRA) requires the annual submittal of toxic chemical release information to the U.S. Environmental Protection Agency.Executive Order 12856, 'Federal Compliance With Right-to-Know Laws and Pollution Prevention Requirements' extends the requirements of EPCRA to all Federal agencies. The following document is the August 1996 submittal of the Hanford Site Toxic Chemical Release Inventory report. Included is a Form R for ethylene glycol, the sole chemical used in excess of the established regulatory thresholds at the Hanford Site by the U.S. Department of Energy, Richland Operations Office and its contractors during Calendar Year 1995

14 CFR Appendix I to Part 417 - Methodologies for Toxic Release Hazard Analysis and Operational Procedures

Science.gov (United States)

2010-01-01

... Quotient/Hazard Index (HQ/HI) formulation to determine the toxic concentration threshold for mixtures of... cloud center of mass altitude. (vi) Worst case initial source term assuming instantaneous release of...

1998 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III

International Nuclear Information System (INIS)

Stockton, Marjorie B.

1999-01-01

The Emergency Planning and Community Right-to-Know Act (EPCRA) of 1986 [also known as the Superfund Amendment and Reauthorization Act (SARA), Title III], as modified by Executive Order 12856, requires that all federal facilities evaluate the need to submit an annual Toxic Chemical Release Inventory report as prescribed in Title III, Section 313 of this Act. This annual report is due every July for the preceding calendar year. Owners and operators who manufacture, process, or otherwise use certain toxic chemicals above listed threshold quantities are required to report their toxic chemical releases to all environmental mediums (air, water, soil, etc.). At Los Alamos National Laboratory (LANL), no EPCRA Section 313 chemicals were used in 1998 above the reportable threshold limits of 10,000 lb or 25,000 lb. Therefore LANL was not required to submit any Toxic Chemical Release Inventory reports (Form Rs) for 1998. This document was prepared to provide a detailed description of the evaluation on chemical usage and EPCRA Section 313 threshold determinations for LANL for 1998

Exploring Bioeconomy Growth through the Public Release of the Biomass Scenario Model

Energy Technology Data Exchange (ETDEWEB)

Newes, Emily K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Inman, Daniel J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vimmerstedt, Laura J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Peterson, Steve [Lexidyne, LLC

2017-08-02

The Biomass Scenario Model (BSM) is an important tool for exploring vibrant future bioeconomy scenarios that leverage domestic resources. Developed by NREL and BETO, this model of the domestic biofuels supply chain has been used to explore success strategies for BETO's activities towards bioeconomy growth. The BSM offers a robust test bed for detailed exploration of effects of BETO activities within the complex context of resource availability; physical, technological, and economic constraints; behavior; and policy. The public release of the model in 2017 will allow broad engagement with the theme of the conference as model users can analyze bioeconomy growth, domestic biomass resource use, and associated effects. The BSM is a carefully validated, state-of-the-art, dynamic model of the biomass to biofuels supply chain. Using a system dynamics simulation modeling approach, the model tracks long-term deployment of biofuels given technology development and investment, considering land availability, the competing oil market, consumer demand, and government policies over time. Sample outputs include biofuels production, feedstock use, capital investment, incentives, and costs of feedstocks and fuels. BSM scenarios reveal technological, economic, and policy challenges, as well as opportunities for dynamic growth of the bioeconomy with strategic public and private investment at key points in the system. The model logic and results have been reviewed extensively, through collaborative analysis, expert reviews and external publications (https://www.zotero.org/groups/bsm_publications/).

Scenarios for potential radionuclide release from marine reactors dumped in the Kara Sea

International Nuclear Information System (INIS)

Lynn, N.; Mount, M.; Gussgard, K.

1995-01-01

The largest inventory of radioactive materials dumped in the Kara Sea by the former Soviet Union comes from the spent nuclear fuel (SNF) of seven marine reactors, the current (1994) inventory of which makes a total of approximately 4.7x10 15 Bq. In progressing its work for the International Arctic Seas Assessment Project, under the auspices of the International Atomic Energy Agency, the Source Term Working Group has analysed the Source Term and subsequently developed a number of model scenarios for the potential release patterns of radionuclides into the Kara Sea from the SNF and activated components dumped within the marine reactors.These models are based on the present and future conditions of the barrier materials and their configuration within the dumped objects. They account for progressive corrosion of the outer and inner steel barriers, breakdown of the organic fillers, and degradation and leaching from the SNFs. Annual release rates are predicted to four thousand years into the future. 5 refs., 1 fig., 1 tab

Hazards study of environmental protection classified facilities. Scenarios analysis; Etude de dangers des ICPE. Analyse des scenarios

Energy Technology Data Exchange (ETDEWEB)

Seveque, J.L. [Cour d' Appel d' Amiens, 80 (France)

2006-04-15

This article describes the analysis and study of the possible impacts of accidents occurring at industrial facilities classified with respect to the environment protection. The operators of such facilities have to describe the possible risks and their consequences, the measures taken to prevent them and the level of residual risk. Therefore, it consists in calculating the consequences of all possible aggressions that a facility can undergo. The receptors are of 2 type: the human body (burns, asphyxia, intoxication, shock wave, projectile), and the surrounding equipments (fire, unconfined vapour cloud explosion (UVCE), boiling liquid expanding vapour explosion (BLEVE), fireball, dispersion of toxic gases). Content: 1 - fire-type scenario: description, modeling of thermal effects, conclusion; 2 - UVCE-type scenario: description, Lannoy method (TNT equivalent), multi-energy method, conclusion; 3 - BLEVE-type scenario: description, modeling of overpressure effects, thermal effects of the fireball; 4 - toxic cloud scenario: modeling of a toxic cloud dispersion, effects and consequences; 5 - conclusions. (J.S.)

Scenarios and methods that induce protruding or released CNTs after degradation of nanocomposite materials.

Science.gov (United States)

Hirth, Sabine; Cena, Lorenzo; Cox, Gerhard; Tomović, Zeljko; Peters, Thomas; Wohlleben, Wendel

2013-04-01

Nanocomposite materials may be considered as a low-risk application of nanotechnology, if the nanofillers remain embedded throughout the life-cycle of the products in which they are embedded. We hypothesize that release of free CNTs occurs by a combination of mechanical stress and chemical degradation of the polymer matrix. We experimentally address limiting cases: Mechanically released fragments may show tubular protrusions on their surface. Here we identify these protrusions unambiguously as naked CNTs by chemically resolved microscopy and a suitable preparation protocol. By size-selective quantification of fragments we establish as a lower limit that at least 95 % of the CNTs remain embedded. Contrary to classical fiber composite approaches, we link this phenomenon to matrix materials with only a few percent elongation at break, predicting which materials should still cover their CNT nanofillers after machining. Protruding networks of CNTs remain after photochemical degradation of the matrix, and we show that it takes the worst case combinations of weathering plus high-shear wear to release free CNTs in the order of mg/m 2 /year. Synergy of chemical degradation and mechanical energy input is identified as the priority scenario of CNT release, but its lab simulation by combined methods is still far from real-world validation.

Toxic releases and risk disparity: a spatiotemporal model of industrial ecology and social empowerment.

Science.gov (United States)

Aoyagi, Hannah; Ogunseitan, Oladele A

2015-06-02

Information-based regulations (IBRs) are founded on the theoretical premise that public participation in accomplishing policy goals is empowered by open access to information. Since its inception in 1988, the Toxics Release Inventory (TRI) has provided the framework and regulatory impetus for the compilation and distribution of data on toxic releases associated with industrial development, following the tenets of IBR. As TRI emissions are reputed to disproportionately affect low-income communities, we investigated how demographic characteristics are related to change in TRI emissions and toxicity risks between 1989 and 2002, and we sought to identify factors that predict these changes. We used local indicators of spatial association (LISA) maps and spatial regression techniques to study risk disparity in the Los Angeles urban area. We also surveyed 203 individuals in eight communities in the same region to measure the levels of awareness of TRI, attitudes towards air pollution, and general environmental risk. We discovered, through spatial lag models, that changes in gross and toxic emissions are related to community ethnic composition, poverty level, home ownership, and base 1989 emissions (R-square=0.034-0.083). We generated a structural equation model to explain the determinants of social empowerment to act on the basis of environmental information. Hierarchical confirmatory factor analysis (HCFA) supports the theoretical model that individual empowerment is predicted by risk perception, worry, and awareness (Chi-square=63.315, p=0.022, df=42). This study provides strong evidence that spatiotemporal changes in regional-scale environmental risks are influenced by individual-scale empowerment mediated by IBRs.

Toxic Releases and Risk Disparity: A Spatiotemporal Model of Industrial Ecology and Social Empowerment

Directory of Open Access Journals (Sweden)

Hannah Aoyagi

2015-06-01

Full Text Available Information-based regulations (IBRs are founded on the theoretical premise that public participation in accomplishing policy goals is empowered by open access to information. Since its inception in 1988, the Toxics Release Inventory (TRI has provided the framework and regulatory impetus for the compilation and distribution of data on toxic releases associated with industrial development, following the tenets of IBR. As TRI emissions are reputed to disproportionately affect low-income communities, we investigated how demographic characteristics are related to change in TRI emissions and toxicity risks between 1989 and 2002, and we sought to identify factors that predict these changes. We used local indicators of spatial association (LISA maps and spatial regression techniques to study risk disparity in the Los Angeles urban area. We also surveyed 203 individuals in eight communities in the same region to measure the levels of awareness of TRI, attitudes towards air pollution, and general environmental risk. We discovered, through spatial lag models, that changes in gross and toxic emissions are related to community ethnic composition, poverty level, home ownership, and base 1989 emissions (R-square = 0.034–0.083. We generated a structural equation model to explain the determinants of social empowerment to act on the basis of environmental information. Hierarchical confirmatory factor analysis (HCFA supports the theoretical model that individual empowerment is predicted by risk perception, worry, and awareness (Chi-square = 63.315, p = 0.022, df = 42. This study provides strong evidence that spatiotemporal changes in regional-scale environmental risks are influenced by individual-scale empowerment mediated by IBRs.

76 FR 60781 - Toxics Release Inventory (TRI) Reporting for Facilities Located in Indian Country and...

Science.gov (United States)

2011-09-30

... increase awareness of toxic releases within Tribal communities, thereby increasing the understanding of potential human health and ecological impacts from these hazardous chemicals. DATES: Comments must be... 212221, 212222, 212231, 212234, 212299 (correspond to SIC 10, Metal Mining (except 1011, 1081, and 1094...

Identifying Toxic Impacts of Metals Potentially Released during Deep-Sea Mining—A Synthesis of the Challenges to Quantifying Risk

Directory of Open Access Journals (Sweden)

Chris Hauton

2017-11-01

Full Text Available In January 2017, the International Seabed Authority released a discussion paper on the development of Environmental Regulations for deep-sea mining (DSM within the Area Beyond National Jurisdiction (the “Area”. With the release of this paper, the prospect for commercial mining in the Area within the next decade has become very real. Moreover, within nations' Exclusive Economic Zones, the exploitation of deep-sea mineral ore resources could take place on very much shorter time scales and, indeed, may have already started. However, potentially toxic metal mixtures may be released at sea during different stages of the mining process and in different physical phases (dissolved or particulate. As toxicants, metals can disrupt organism physiology and performance, and therefore may impact whole populations, leading to ecosystem scale effects. A challenge to the prediction of toxicity is that deep-sea ore deposits include complex mixtures of minerals, including potentially toxic metals such as copper, cadmium, zinc, and lead, as well as rare earth elements. Whereas the individual toxicity of some of these dissolved metals has been established in laboratory studies, the complex and variable mineral composition of seabed resources makes the a priori prediction of the toxic risk of DSM extremely challenging. Furthermore, although extensive data quantify the toxicity of metals in solution in shallow-water organisms, these may not be representative of the toxicity in deep-sea organisms, which may differ biochemically and physiologically and which will experience those toxicants under conditions of low temperature, high hydrostatic pressure, and potentially altered pH. In this synthesis, we present a summation of recent advances in our understanding of the potential toxic impacts of metal exposure to deep-sea meio- to megafauna at low temperature and high pressure, and consider the limitation of deriving lethal limits based on the paradigm of exposure to

Analysis of explosion-induced releases of toxic materials at an environmental restoration project

International Nuclear Information System (INIS)

Bloom, S.G.; Moon, W.H. Jr.

1993-01-01

Prior to 1988, a variety of materials were buried on the US DOE Oak Ridge Reservation. Records of the disposal operations are incomplete and toxic materials may have been placed adjacent to potential explosives. One of the safety concerns in conducting an environmental restoration project at the burial sites, is the possibility of an explosion which could release toxic materials to the atmosphere. A safety analysis examined the consequences of such releases by first postulating an upper bound for the strength of an explosive. A correlation, developed by Steindler and Seefeldt of Argonne National Laboratory, was then used to estimate the amount and particle-size distribution of the material that could become airborne from the explosion. The estimated amount of airborne material was the source term in an atmospheric dispersion model which was used to calculate infinite-time, concentration-time integrals and 5-minute, time- weighted average concentrations at locations down-wind from the explosion. The dispersion model includes particle deposition as a function of particle-size distribution class. The concentration-time integrals and average concentrations were compared to published guidelines to assess the consequences of an accidental explosion

Assessment of effectiveness of geologic isolation systems. A conceptual simulation model for release scenario analysis of a hypothetical site in Columbia Plateau Basalts

International Nuclear Information System (INIS)

Stottlemyre, J.A.; Petrie, G.M.; Benson, G.L.; Zellmer, J.T.

1981-01-01

This report is a status report for an evolving methodology for release scenario development for underground nuclear waste repositories. As such, it is intended for use as a reference point and a preliminary description of an evolving geoscience methodology. When completed this methodology will be used as a tool in developing disruptive release scenarios for analyzing the long-term safety of geological nuclear waste repositories. While a basalt environment is used as an example, this report is not intended to reflect an actual site safety assessment for a repository in a media. It is rather intended to present a methodology system framework and to provide discussions of the geological phenomena and parameters that must be addressed in order to develop a methodology for potential release scenarios. It is also important to note that the phenomena, their interrelationships, and their relative importance along with the overall current structure of the model will change as new geological information is gathered through additional peer review, geotechnical input, site specific field work, and related research efforts

Radionuclide release calculations for selected severe accident scenarios. Volume 3. PWR, subatmospheric containment design

International Nuclear Information System (INIS)

Denning, R.S.; Gieseke, J.A.; Cybulskis, P.; Lee, K.W.; Jordan, H.; Curtis, L.A.; Kelly, R.F.; Kogan, V.; Schumacher, P.M.

1986-07-01

This report presents results of analyses of the enviromental releases of fission products (source terms) for severe accident scenarios in a pressurized water reactor with a subatmospheric containment design. The analyses were performed to support the Severe Accident Risk Reduction/Risk Rebaselining Program (SARRP) which is being undertaken for the US Nuclear Regulatory Commission by Sandia National Laboratories. In the SARRP program, risk estimates are being generated for a number of reference plant designs. the Surry plant has been used in this study as the reference plant for a subatmospheric design

Toxic chemical hazard classification and risk acceptance guidelines for use in DOE facilities. Revision 2

International Nuclear Information System (INIS)

Craig, D.K.; Davis, J.S.; Prowse, J.; Hoffman, P.W.

1995-01-01

The concentration-limit guidelines presented in this document apply to airborne releases of chemicals evaluated with respect to human health effects for the purposes of hazard classification and categorization, risk assessment and safety analysis. They apply to all DOE facilities and operations involving the use of potentially hazardous chemicals. The guidelines do not address other nonradiological hazards such as fire, pressure releases (including explosions), and chemical reactivity, but the guidelines are applicable to hazardous chemical releases resulting from these events. This report presents the subcommittee's evaluation and recommendations regarding analyses of accidentally released toxic chemicals. The premise upon which these recommendations are based is that the mechanism of action of toxic chemicals is fundamentally different from that associated with radionuclides, with the exception of carcinogens. The recommendations reported herein are restricted to the airborne pathway because in an accident scenario this typically represents the most immediately significant route of public exposure. However, the subcommittee recognizes that exposure to chemicals through other pathways, in particular waterborne, can have significant impacts on human health and the environment. Although there are a number of chemicals for which absorption through the skin can contribute measurably to the total dose in chronic (e.g., occupational) exposure situations, this pathway has not been considered for the acute exposure scenarios considered in this report. Later studies. will address these issues if it appears desirable

The Relationship between Toxics Release Inventory Discharges and Mortality Rates in Rural and Urban Areas of the United States

Science.gov (United States)

Hendryx, Michael; Fedorko, Evan

2011-01-01

Background: Potential environmental exposures from chemical manufacturing or industrial sites have not been well studied for rural populations. The current study examines whether chemical releases from facilities monitored through the Toxics Release Inventory (TRI) program are associated with population mortality rates for both rural and urban…

Inventory of LCIA selection methods for assessing toxic releases. Methods and typology report part B

DEFF Research Database (Denmark)

Larsen, Henrik Fred; Birkved, Morten; Hauschild, Michael Zwicky

method(s) in Work package 8 (WP8) of the OMNIITOX project. The selection methods and the other CRS methods are described in detail, a set of evaluation criteria are developed and the methods are evaluated against these criteria. This report (Deliverable 11B (D11B)) gives the results from task 7.1d, 7.1e......This report describes an inventory of Life Cycle Impact Assessment (LCIA) selection methods for assessing toxic releases. It consists of an inventory of current selection methods and other Chemical Ranking and Scoring (CRS) methods assessed to be relevant for the development of (a) new selection...... and 7.1f of WP 7 for selection methods. The other part of D11 (D11A) is reported in another report and deals with characterisation methods. A selection method is a method for prioritising chemical emissions to be included in an LCIA characterisation of toxic releases, i.e. calculating indicator scores...

Evaluating Potential for Large Releases from CO2 Storage Reservoirs: Analogs, Scenarios, and Modeling Needs

International Nuclear Information System (INIS)

Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Tsang, Chin-Fu; Karimjee, Anhar

2005-01-01

While the purpose of geologic storage of CO 2 in deep saline formations is to trap greenhouse gases underground, the potential exists for CO 2 to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. Such discharge is not necessarily a serious concern, as CO 2 is a naturally abundant and relatively benign gas in low concentrations. However, there is a potential risk to health, safety and environment (HSE) in the event that large localized fluxes of CO 2 were to occur at the land surface, especially where CO 2 could accumulate. In this paper, we develop possible scenarios for large CO 2 fluxes based on the analysis of natural analogues, where large releases of gas have been observed. We are particularly interested in scenarios which could generate sudden, possibly self-enhancing, or even eruptive release events. The probability for such events may be low, but the circumstances under which they might occur and potential consequences need to be evaluated in order to design appropriate site selection and risk management strategies. Numerical modeling of hypothetical test cases is needed to determine critical conditions for such events, to evaluate whether such conditions may be possible at designated storage sites, and, if applicable, to evaluate the potential HSE impacts of such events and design appropriate mitigation strategies

Toxic chemical release inventory reporting form R and instructions. Revised 1992 version. Section 313 of the Emergency Planning and Community Right-to-Know Act

International Nuclear Information System (INIS)

1993-01-01

Reporting is required to provide the public with information on the releases of listed toxic chemicals in their communities and to provide EPA with release information to assist the Agency in determining the need for future regulations. Facilities must report the quantities of both routine and accidental releases of listed toxic chemicals, as well as the maximum amount of the listed toxic chemical on-site during the calendar year and the amount contained in wastes transferred off-site. These instructions supplement and elaborate on the requirements in the reporting rule (40 CFR Part 372). Together with the reporting rule, they constitute the reporting requirements. All references in these instructions are to sections in the reporting rule unless otherwise indicated

Toxics release inventory: List of toxic chemicals within the polychlorinated alkanes category and guidance for reporting

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-02-01

Section 313 of the Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA) requires certain facilities manufacturing, processing, or otherwise using listed toxic chemicals to report their environmental releases of such chemicals annually. On November 30, 1994 EPA added 286 chemicals and chemical categories. Six chemical categories (nicotine and salts, strychnine and salts, polycyclic aromatic compounds, water dissociable nitrate compounds, diisocyanates, and polychlorinated alkanes) are included in these additions. At the time of the addition, EPA indicated that the Agency would develop, as appropriate, interpretations and guidance that the Agency determines are necessary to facilitate accurate reporting for these categories. This document constitutes such guidance for the polychlorinated alkanes category.

The toxic and radiological risk equivalence approach in UF6 transport

International Nuclear Information System (INIS)

Ringot, C.; Hamard, J.

1988-12-01

After a brief description of the safety in transport of UF 6 , we discuss the equivalence of the radioactive and chemical risks in UF 6 transport regulations. As the concept of low specific activity appears to be ill-suited for a toxic gas, we propose a quantity of material limit designated T 2 (equivalent to A 2 for radioactive substances) for packagings unable to withstand accident conditions (9 m drop, 800 0 C fire environment for 30 minutes). It is proposed that this limit be chosen for the amount of release acceptable after AIEA tests. Different possible scenarios are described, with fire assumed to be the most severe toxic risk situation

75 FR 19319 - Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting; Extension of Comment...

Science.gov (United States)

2010-04-14

... Hydrogen Sulfide; Community Right-to-Know Toxic Chemical Release Reporting; Extension of Comment Period... reporting requirements for hydrogen sulfide (Chemical Abstracts Service Number (CAS No.) 7783-06-4) (75 FR... may be potentially affected by this action if you manufacture, process, or otherwise use hydrogen...

Executive Order 12898 and Social, Economic, and Sociopolitical Factors Influencing Toxic Release Inventory Facility Location in EPA Region 6: A Multi-Scale Spatial Assessment of Environmental Justice

Science.gov (United States)

Moore, Andrea Lisa

2013-01-01

Toxic Release Inventory facilities are among the many environmental hazards shown to create environmental inequities in the United States. This project examined four factors associated with Toxic Release Inventory, specifically, manufacturing facility location at multiple spatial scales using spatial analysis techniques (i.e., O-ring statistic and…

Examining the antimicrobial activity and toxicity to animal cells of different types of CO-releasing molecules.

Science.gov (United States)

Nobre, Lígia S; Jeremias, Hélia; Romão, Carlos C; Saraiva, Lígia M

2016-01-28

Transition metal carbonyl complexes used as CO-releasing molecules (CORMs) for biological and therapeutic applications may exhibit interesting antimicrobial activity. However, understanding the chemical traits and mechanisms of action that rule this activity is required to establish a rationale for the development of CORMs into useful antibiotics. In this work the bactericidal activity, the toxicity to eukaryotic cells, and the ability of CORMs to deliver CO to bacterial and eukaryotic cells were analysed for a set of seven CORMs that differ in the transition metal, ancillary ligands and the CO release profile. Most of these CORMs exhibited bactericidal properties that decrease in the following order: CORM-2 > CORM-3 > ALF062 > ALF850 > ALF186 > ALF153 > [Fe(SBPy3)(CO)](BF4)2. A similar yet not entirely coincident decreasing order was found for their induction of intracellular reactive oxygen species (ROS) in E. coli. In contrast, studies in model animal cells showed that for any given CORM, the level of intracellular ROS generated was negligible when compared with that measured inside bacteria. Importantly, these CORMs were in general not toxic to eukaryotic cells, namely murine macrophages, kidney LLC-PK1 epithelial cells, and liver cell line HepG2. CORM-2 and CORM-3 delivered CO to the intracellular space of both E. coli and the two types of tested eukaryotic cells, yet toxicity was only elicited in the case of E. coli. CO delivered by ALF186 into the intercellular space did not enter E. coli cells and the compound was not toxic to either bacteria or to eukaryotic cells. The Fe(ii) carbonyl complex [Fe(SBPy3)(CO)](2+) had the reverse, undesirable toxicity profile, being unexpectedly toxic to eukaryotic cells and non-toxic to E. coli. ALF153, the most stable complex in the whole set, was essentially devoid of toxicity or ROS induction ability in all cells. These results suggest that CORMs have a relevant therapeutic potential as antimicrobial drugs since (i) they

Scenario analysis for the postclosure assessment of the Canadian concept for nuclear fuel waste disposal

Energy Technology Data Exchange (ETDEWEB)

Goodwin, B W; Stephens, M E; Davison, C C; Johnson, L H; Zach, R

1994-12-01

AECL Research has developed and evaluated a concept for disposal of Canada`s nuclear fuel waste involving deep underground disposal of the waste in intrusive igneous rock of the Canadian Shield. The postclosure assessment of this concept focusses on the effects on human health and the environment due to potential contaminant releases into the biosphere after the disposal vault is closed. Both radiotoxic and chemically toxic contaminants are considered. One of the steps in the postclosure assessment process is scenario analysis. Scenario analysis identifies factors that could affect the performance of the disposal system and groups these factors into scenarios that require detailed quantitative evaluation. This report documents a systematic procedure for scenario analysis that was developed for the postclosure assessment and then applied to the study of a hypothetical disposal system. The application leads to a comprehensive list of factors and a set of scenarios that require further quantitative study. The application also identifies a number of other factors and potential scenarios that would not contribute significantly to environmental and safety impacts for the hypothetical disposal system. (author). 46 refs., 3 tabs., 3 figs., 2 appendices.

Scenario analysis for the postclosure assessment of the Canadian concept for nuclear fuel waste disposal

International Nuclear Information System (INIS)

Goodwin, B.W.; Stephens, M.E.; Davison, C.C.; Johnson, L.H.; Zach, R.

1994-12-01

AECL Research has developed and evaluated a concept for disposal of Canada's nuclear fuel waste involving deep underground disposal of the waste in intrusive igneous rock of the Canadian Shield. The postclosure assessment of this concept focusses on the effects on human health and the environment due to potential contaminant releases into the biosphere after the disposal vault is closed. Both radiotoxic and chemically toxic contaminants are considered. One of the steps in the postclosure assessment process is scenario analysis. Scenario analysis identifies factors that could affect the performance of the disposal system and groups these factors into scenarios that require detailed quantitative evaluation. This report documents a systematic procedure for scenario analysis that was developed for the postclosure assessment and then applied to the study of a hypothetical disposal system. The application leads to a comprehensive list of factors and a set of scenarios that require further quantitative study. The application also identifies a number of other factors and potential scenarios that would not contribute significantly to environmental and safety impacts for the hypothetical disposal system. (author). 46 refs., 3 tabs., 3 figs., 2 appendices

A comparison between the example reference biosphere model ERB 2B and a process-based model: simulation of a natural release scenario.

Science.gov (United States)

Almahayni, T

2014-12-01

The BIOMASS methodology was developed with the objective of constructing defensible assessment biospheres for assessing potential radiological impacts of radioactive waste repositories. To this end, a set of Example Reference Biospheres were developed to demonstrate the use of the methodology and to provide an international point of reference. In this paper, the performance of the Example Reference Biosphere model ERB 2B associated with the natural release scenario, discharge of contaminated groundwater to the surface environment, was evaluated by comparing its long-term projections of radionuclide dynamics and distribution in a soil-plant system to those of a process-based, transient advection-dispersion model (AD). The models were parametrised with data characteristic of a typical rainfed winter wheat crop grown on a sandy loam soil under temperate climate conditions. Three safety-relevant radionuclides, (99)Tc, (129)I and (237)Np with different degree of sorption were selected for the study. Although the models were driven by the same hydraulic (soil moisture content and water fluxes) and radiological (Kds) input data, their projections were remarkably different. On one hand, both models were able to capture short and long-term variation in activity concentration in the subsoil compartment. On the other hand, the Reference Biosphere model did not project any radionuclide accumulation in the topsoil and crop compartments. This behaviour would underestimate the radiological exposure under natural release scenarios. The results highlight the potential role deep roots play in soil-to-plant transfer under a natural release scenario where radionuclides are released into the subsoil. When considering the relative activity and root depth profiles within the soil column, much of the radioactivity was taken up into the crop from the subsoil compartment. Further improvements were suggested to address the limitations of the Reference Biosphere model presented in this paper

2015 TRI National Analysis: Toxics Release Inventory Releases at Various Summary Levels

Data.gov (United States)

U.S. Environmental Protection Agency — The TRI National Analysis is EPA's annual interpretation of TRI data at various summary levels. It highlights how toxic chemical wastes were managed, where toxic...

Cyclophosphamide-induced pulmonary toxicity

International Nuclear Information System (INIS)

Siemann, D.W.; Macler, L.; Penney, D.P.

1986-01-01

Unlike radiation effects, pulmonary toxicity following drug treatments may develop soon after exposure. The dose-response relationship between Cyclophosphamide and lung toxicity was investigated using increased breathing frequency assays used successfully for radiation induced injury. The data indicate that release of protein into the alveolus may play a significant role in Cy induced pulmonary toxicity. Although the mechanism responsible for the increased alveolar protein is as yet not identified, the present findings suggest that therapeutic intervention to inhibit protein release may be an approach to protect the lungs from toxic effects. (UK)

Hazards to nuclear plants from off-site release of toxic vapors

International Nuclear Information System (INIS)

Hornyik, K.

1976-01-01

A method for the assessment of risk involved in shipping toxic compounds past nuclear power plants uses a postulated chain of events, starting with a traffic accident causing instantaneous release of the compound as vapor, and leading to incapacitation of control operators in the nuclear plant, described by deterministic and statistical models as appropriate to the respective event. Statistical treatment of relevant atmospheric conditions is a major improvement over more conservative assumptions commonly made in current analyses of this problem. Consequently, one obtains a substantial reduction in the estimated risk expressed in usual terms of the annual probability of an unacceptable event, in spite of the fact that no credit is taken for protective measures other than potential control room isolation

Both released silver ions and particulate Ag contribute to the toxicity of AgNPs to earthworm Eisenia fetida

NARCIS (Netherlands)

Li, L.; , van, Gestel C.A.M.

2015-01-01

To disentangle the contribution of ionic and nanoparticulate Ag to the overall toxicity to the earthworm Eisenia fetida, a semi-permeable membrane strategy was used to separate Ag+ released from silver nanoparticles (AgNPs) in an aqueous exposure. Internal Ag fractionation, activities of antioxidant

The Atmospheric Release Advisory Capability Site Workstation System

International Nuclear Information System (INIS)

Foster, K.T.; Sumikawa, D.A.; Foster, C.S.; Baskett, R.L.

1993-01-01

The Atmospheric Release Advisory Capability (ARAC) is a centralized emergency response service that assesses the consequences that may result from an atmospheric release of toxic material. ARAC was developed by the Lawrence Livermore National Laboratory (LLNL) for the Departments of Energy (DOE) and Defense (DOD) and responds principally to radiological accidents. ARAC provides radiological health and safety guidance to decision makers in the form of computer-generated estimates of the effects of an actual, or potential release of radioactive material into the atmosphere. Upon receipt of the release scenario, the ARAC assessment staff extracts meteorological, topographic, and geographic data from resident world-wide databases for use in complex, three-dimensional transport and diffusion models. These dispersion models generate air concentration (or dose) and ground deposition contour plots showing estimates of the contamination patterns produced as the toxic material is carried by the prevailing winds. To facilitate the ARAC response to a release from specific DOE and DOD sites and to provide these sites with a local emergency response tool, a remote Site Workstation System (SWS) is being placed at various ARAC-supported facilities across the country.. This SWS replaces the existing antiquated ARAC Site System now installed at many of these sites. The new system gives users access to complex atmospheric dispersion models that may be run either by the ARAC staff at LLNL, or (in a later phase of the system) by site personnel using the computational resources of the SWS. Supporting this primary function are a variety of SWS-resident supplemental capabilities that include meteorological data acquisition, manipulation of release-specific databases, computer-based communications, and the use of a simpler Gaussian trajectory puff model that is based on Environmental Protection Agency's INPUFF code

iQOS: evidence of pyrolysis and release of a toxicant from plastic.

Science.gov (United States)

Davis, Barbara; Williams, Monique; Talbot, Prue

2018-03-13

To evaluate performance of the I quit original smoking (iQOS) heat-not-burn system as a function of cleaning and puffing topography, investigate the validity of manufacturer's claims that this device does not burn tobacco and determine if the polymer-film filter is potentially harmful. iQOS performance was evaluated using five running conditions incorporating two different cleaning protocols. Heatsticks were visually and stereomicroscopically inspected preuse and postuse to determine the extent of tobacco plug charring (from pyrolysis) and polymer-film filter melting, and to elucidate the effects of cleaning on charring. Gas chromatography-mass spectrometry headspace analysis was conducted on unused polymer-film filters to determine if potentially toxic chemicals are emitted from the filter during heating. For all testing protocols, pressure drop decreased as puff number increased. Changes in testing protocols did not affect aerosol density. Charring due to pyrolysis (a form of organic matter thermochemical decomposition) was observed in the tobacco plug after use. When the manufacturer's cleaning instructions were followed, both charring of the tobacco plug and melting of the polymer-film filter increased. Headspace analysis of the polymer-film filter revealed the release of formaldehyde cyanohydrin at 90°C, which is well below the maximum temperature reached during normal usage. Device usage limitations may contribute to decreases in interpuff intervals, potentially increasing user's intake of nicotine and other harmful chemicals. This study found that the tobacco plug does char and that charring increases when the device is not cleaned between heatsticks. Release of formaldehyde cyanohydrin is a concern as it is highly toxic at very low concentrations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Scenarios and innovative systems

International Nuclear Information System (INIS)

2001-11-01

The purpose of this workshop is to present to the GEDEON community the scenarios for the deployment of innovative nuclear solutions. Both steady state situations and possible transitions from the present to new reactors and fuel cycles are considered. Innovative systems that satisfy improved natural resource utilization and waste minimization criteria will be described as well as the R and D orientations of various partners. This document brings together the transparencies of 17 communications given at this workshop: general policy for transmutation and partitioning; Amster: a molten salt reactor (MSR) concept; MSR capabilities; potentials and capabilities of accelerator driven systems (ADS); ADS demonstrator interest as an experimental facility; innovative systems: gas coolant technologies; Pu management in EPR; scenarios with thorium fuel; scenarios at the equilibrium state; scenarios for transition; partitioning and specific conditioning; management of separated radio-toxic elements; European programs; DOE/AAA (Advanced Accelerator Applications) program; OECD scenario studies; CEA research programs and orientations; partitioning and transmutation: an industrial point of view. (J.S.)

Assessment of effectiveness of geologic isolation systems. Perspectives on the geological and hydrological aspects of long-term release scenario analyses

Energy Technology Data Exchange (ETDEWEB)

Stottlemyre, J.A.; Wallace, R.W.; Benson, G.L.; Zellmer, J.T.

1980-06-01

Information that may be relevant to individuals involved with analyzing long-term release scenarios of specific repositories for nuclear waste is presented. The bulk of the information is derived from recent studies in West Germany and the United States. Emphasis is on the specific geological and hydrological phenomena that, alone or in concert, could potentially perturb the area around specific repository sites. Research is continuing on most of the topics discussed within this report. Because research is ongoing, statements and conclusions described in this document are subject to change. The main topics of this report are: (1) fracturing, (2) geohydrology, (3) magmatic activity, and (4) geomorphology. Therefore, the site-specific nature of the problem cannot be overemphasized. As an example of how one might combine the many synergistic and time-dependent parameters into a concise format the reader is referred to A Conceputal Simulation Model for Release Scenario Analysis of a Hypothetical Site in Columbia Plateau Basalts, PNL-2892. For additional details on the topics in this report, the reader is referred to the Pacific Northwest Laboratory (PNL) consultant report listed in the bibliography.

Assessment of effectiveness of geologic isolation systems. Perspectives on the geological and hydrological aspects of long-term release scenario analyses

International Nuclear Information System (INIS)

Stottlemyre, J.A.; Wallace, R.W.; Benson, G.L.; Zellmer, J.T.

1980-06-01

Information that may be relevant to individuals involved with analyzing long-term release scenarios of specific repositories for nuclear waste is presented. The bulk of the information is derived from recent studies in West Germany and the United States. Emphasis is on the specific geological and hydrological phenomena that, alone or in concert, could potentially perturb the area around specific repository sites. Research is continuing on most of the topics discussed within this report. Because research is ongoing, statements and conclusions described in this document are subject to change. The main topics of this report are: (1) fracturing, (2) geohydrology, (3) magmatic activity, and (4) geomorphology. Therefore, the site-specific nature of the problem cannot be overemphasized. As an example of how one might combine the many synergistic and time-dependent parameters into a concise format the reader is referred to A Conceputal Simulation Model for Release Scenario Analysis of a Hypothetical Site in Columbia Plateau Basalts, PNL-2892. For additional details on the topics in this report, the reader is referred to the Pacific Northwest Laboratory (PNL) consultant report listed in the bibliography

Artificial saliva effect on toxic substances release from acrylic resins

Directory of Open Access Journals (Sweden)

Kostić Milena

2015-01-01

Full Text Available Background/Aim. Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS immediately upon polymerization and incubation in different types of artificial saliva. Methods. Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 ± 1°C. Analysis of the surface structure of samples was carried out using scanning electronic microscopy analysis immediately after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. Results. Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. Conclusion. In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard coldpolymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary. [Projekat Ministarstva nauke Republike Srbije, br. 41017

LCIA selection methods for assessing toxic releases

DEFF Research Database (Denmark)

Larsen, Henrik Fred; Birkved, Morten; Hauschild, Michael Zwicky

2002-01-01

the inventory that contribute significantly to the impact categories on ecotoxicity and human toxicity to focus the characterisation work. The reason why the selection methods are more important for the chemical-related impact categories than for other impact categories is the extremely high number......Characterization of toxic emissions in life cycle impact assessment (LCIA) is in many cases severely limited by the lack of characterization factors for the emissions mapped in the inventory. The number of substances assigned characterization factors for (eco)toxicity included in the dominating LCA....... The methods are evaluated against a set of pre-defined criteria (comprising consistency with characterization and data requirement) and applied to case studies and a test set of chemicals. The reported work is part of the EU-project OMNIITOX....

Dividing by four CO2 releases due to energy: the Negatep scenario

International Nuclear Information System (INIS)

Acket, C.; Bacher, P.

2011-01-01

The Negatep scenario aims at dividing CO 2 releases by 4, which means, more or less, dividing the consumption of fossil energies by the same factor, in order to comply with the French 2005 energy act. After a description of the situation in 2006, of trends, and a recall of the objectives defined by the 'Grenelle de l'Environnement' regarding energy savings and renewable energies, the authors show that reaching such a reduction requires to: decrease to nearly zero oil and gas in the residential and tertiary sectors, reduce significantly the use of oil in the transport sector, reduce significantly the use of fossil fuels in industry, increase massively the share of electricity in the energy mix, maintain the share of nuclear in the electricity generation and, as long as the storage of electricity is not developed, limit the share of intermittent energies to a level compatible with that of gas turbines. The study shows that the proposed measures can fulfill the objectives for 2020 proposed by the 'Grenelle de l'Environnement'

Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

OpenAIRE

Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

2009-01-01

An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

NC-6301, a polymeric micelle rationally optimized for effective release of docetaxel, is potent but is less toxic than native docetaxel in vivo

Directory of Open Access Journals (Sweden)

Harada M

2012-05-01

Full Text Available Mitsunori Harada,1 Caname Iwata,2 Hiroyuki Saito,1 Kenta Ishii,1 Tatsuyuki Hayashi,1 Masakazu Yashiro,3 Kosei Hirakawa,3 Kohei Miyazono,2 Yasuki Kato,1 Mitsunobu R Kano21Research Division, NanoCarrier Co, Ltd, Chiba, Japan; 2Department of Molecular Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan; 3Department of Surgical Oncology, Osaka City University, Osaka, JapanAbstract: Drug release rate is an important factor in determining efficacy and toxicity of nanoscale drug delivery systems. However, optimization of the release rate in polymeric micellar nanoscale drug delivery systems has not been fully investigated. In this study NC-6301, a poly(ethylene glycol-poly(aspartate block copolymer with docetaxel (DTX covalently bound via ester link, was synthesized with various numbers of DTX molecules bound to the polymer backbone. The number of DTX molecules was determined up to 14 to achieve an optimal release rate, based upon the authors' own pharmacokinetic model using known patient data. Efficacy and toxicity of the formulation was then tested in animals. When administered three times at 4-day intervals, the maximum tolerated doses of NC-6301 and native DTX were 50 and 10 mg/kg, respectively, in nude mice. Tissue distribution studies of NC-6301 in mice at 50 mg/kg revealed prolonged release of free DTX in the tumor for at least 120 hours, thus supporting its effectiveness. Furthermore, in cynomolgus monkeys, NC-6301 at 6 mg/kg three times at 2-week intervals showed marginal toxicity, whereas native DTX, at 3 mg/kg with the same schedule, induced significant decrease of food consumption and neutrophil count. NC-6301 at 50 mg/kg in mice also regressed a xenografted tumor of MDA-MB-231 human breast cancer. Native DTX, on the other hand, produced only transient and slight regression of the same tumor xenograft. NC-6301 also significantly inhibited growth of OCUM-2MLN human scirrhous gastric carcinoma in an orthotopic mouse

Potential Environmental and Environmental-Health Implications of the SAFRR Tsunami Scenario in California: Chapter F in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

Science.gov (United States)

Plumlee, Geoffrey S.; Morman, Suzette A.; San Juan, Carma

2013-01-01

The California Tsunami Scenario models the impacts of a hypothetical, yet plausible, tsunami caused by an earthquake offshore from the Alaska Peninsula. In this chapter, we interpret plausible tsunami-related contamination, environmental impacts, potential for human exposures to contaminants and hazardous materials, and implications for remediation and recovery. Inundation-related damages to major ports, boat yards, and many marinas could release complex debris, crude oil, various fuel types and other petroleum products, some liquid bulk cargo and dry bulk cargo, and diverse other pollutants into nearby coastal marine environments and onshore in the inundation zone. Tsunami-induced erosion of contaminated harbor bottom sediments could re-expose previously sequestered metal and organic pollutants (for example, organotin or DDT). Inundation-related damage to many older buildings could produce debris containing lead paint, asbestos, pesticides, and other legacy contaminants. Intermingled household debris and externally derived debris and sediments would be left in flooded buildings. Post tsunami, mold would likely develop in inundated houses, buildings, and debris piles. Tsunamigenic fires in spilled oil, debris, cargo, vehicles, vegetation, and residential, commercial, or industrial buildings and their contents would produce potentially toxic gases and smoke, airborne ash, and residual ash/debris containing caustic alkali solids, metal toxicants, asbestos, and various organic toxicants. Inundation of and damage to wastewater treatment plants in many coastal cities could release raw sewage containing fecal solids, pathogens, and waste chemicals, as well as chemicals used to treat wastewaters. Tsunami-related physical damages, debris, and contamination could have short- and longer-term impacts on the environment and the health of coastal marine and terrestrial ecosystems. Marine habitats in intertidal zones, marshes, sloughs, and lagoons could be damaged by erosion or

2004 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313

Energy Technology Data Exchange (ETDEWEB)

M. Stockton

2006-01-15

Section 313 of Emergency Planning and Community Right-to-Know Act (EPCRA) specifically requires facilities to submit a Toxic Chemical Release Inventory Report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. For reporting year 2004, Los Alamos National Laboratory (LANL or the Laboratory) submitted Form R reports for lead compounds, nitric acid, and nitrate compounds as required under the EPCRA Section 313. No other EPCRA Section 313 chemicals were used in 2004 above the reportable thresholds. This document provides a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2004, as well as background information about data included on the Form R reports.

Potential release scenarios for carbon nanotubes used in composites

Science.gov (United States)

The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limi...

Potential release scenarios for carbon nanotubes used in composites

NARCIS (Netherlands)

Nowack, B.; David, R.M.; Fissan, H.; Morris, H.; Shatkin, J.A.; Stintz, M.; Zepp, R.; Brouwer, D.

2013-01-01

The expected widespread use of carbon nanotube (CNT)-composites in consumer products calls for an assessment of the possible release and exposure to workers, consumers and the environment. Release of CNTs may occur at all steps in the life cycle of products, but to date only limited information is

Research study for extremely unlikely scenario of high level waste disposal: Part 3

International Nuclear Information System (INIS)

Ohkubo, Hiroo

1999-02-01

In this research, first, event and process relevant to the key words (or scenario initiator) such as volcanism have been identified and, especially a middle-scale eruption scenario including pyroclastic flows has been analyzed as the catastrophic scenario, which inspires ordinary people to have tremendous concern. Secondly, based upon the characteristic events and processes of each scenario considered in the above and through the research of existing model of such risk, quantitative concept (release amount magnitude, release mode, release form, frequency of release, probability etc.) and impact on repository system, facility and environment have been analyzed, defended and defined. Model which can assess and analyze such impact has been built. Using these models, risks directly or indirectly caused by HLW repository have been calculated. Finally, the process for assessing the consequence of volcanism scenario and its risk calculated by the model developed in the above have been visualized, and presented by comparing with other risks. (author)

The approach of toxic and radiological risk equivalence in UF6 transport

International Nuclear Information System (INIS)

Ringot, C.; Hamard, J.

1989-01-01

After a brief description of the present situation concerning the safety of the transport of UF6 and the new regulation project which is being developed under the behalf of IAEA, the equivalence of radioactive and chemical risks is considered for UF6 transport regulations. The concept of low specific activity appearing misfitting to toxic gas, it is proposed a quantity limit of material, T 2 (equivalent to A 2 for radioactive materials), for packagings which do not resist to accidental conditions, (9 m drop, 800 0 C, 30 minutes fire environment). It is proposed that this limit is chosen as the release rate which is acceptable after the IAEA tests for packages having a capacity higher than T 2 kilograms. The fire being considered as the most severe situation for the toxic risk, different possible scenarios are described. This approach of risk equivalence leads to impose that the packaging resists a 800 0 C - 30 minutes fire and that in this condition the release is less than T 2 . The problem of the behaviour of the shell and the openings (in particular the valve) is raised in this context [fr

Possibilities for the Reuse of Steel from Decommissioning. Selected Scenarios in the Process of Proposal and Evaluation of Manufacturing Processes for Conditional Released Steel and their Application in General and Nuclear Industry

International Nuclear Information System (INIS)

Bezak, P.; Daniska, V.; Ondra, F.; Necas, V.

2012-01-01

Conditional release of steels from NPP decommissioning enables controlled reuse of non-negligible volumes of steels. For proposal of scenarios for steel reuse, it is needed to identify and evaluate partial elementary activities of the whole process from conditional release of steels, manufacturing of various elements up to realisation of scenarios. For scenarios of reuse of conditionally released steel the products of steel, as steel reinforcements, rails, profiles and sheets for technical constructions such as bridges, tunnels, railways and other constructions which guarantee the long-term properties over the periods of 50-100 years are considered. The idea offers also the possibility for using this type of steel for particular technical constructions, directly usable in nuclear facilities. The paper presents the review of activities for manufacturing of various steel construction elements made from conditionally released steels and their use in general and also in the nuclear industry. As the starting material for manufacturing of steel elements ingots or just fragments of steel after dismantling in controlled area can be used. These input materials are re-melted in industrial facilities in order to achieve the required physical and chemical characteristics. Mostly used technique for manufacturing of the steel construction elements is rolling. As the products considered in scenarios for reuse of conditional released steels are bars for reinforcement concrete, rolled steel sheets and other rolled profiles. For use in the nuclear industry it offers the possibility for casting of thick-walled steel containers for long-term storage of high level radioactive components in integral storage and also assembly of stainless steel tanks for storing of liquid radioactive waste. Lists of elementary activities which are needed for manufacturing of selected steel elements are elaborated. These elementary activities are then the base for detailed safety evaluation of external

The Reference Scenarios for the Swiss Emergency Planning

International Nuclear Information System (INIS)

Hanspeter Isaak; Navert, Stephan B.; Ralph Schulz

2006-01-01

For the purpose of emergency planning and preparedness, realistic reference scenarios and corresponding accident source terms have been defined on the basis of common plant features. Three types of representative reference scenarios encompass the accident sequences expected to be the most probable. Accident source terms are assumed to be identical for all Swiss nuclear power plants, although the plants differ in reactor type and power. Plant-specific probabilistic safety analyses were used to justify the reference scenarios and the postulated accident source terms. From the full spectrum of release categories available, those categories were selected which would be covered by the releases and time frames assumed in the reference scenarios. For each nuclear power plant, the cumulative frequency of accident sequences not covered by the reference scenarios was determined. It was found that the cumulative frequency for such accident sequences does not exceed about 1 x 10 -6 per year. The Swiss Federal Nuclear Safety Inspectorate concludes that the postulated accident source terms for the reference scenarios are consistent with the current international approach in emergency planning, where one should concentrate on the most probable accident sequences. (N.C.)

Pediatric Toxic Shock Syndrome

Directory of Open Access Journals (Sweden)

Jennifer Yee

2017-09-01

Full Text Available Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management. If patients suffering from this condition are managed incorrectly, they may progress into multi-organ dysfunction and potentially death. Toxic shock syndrome has been associated with Streptococcus and Staphylococcus aureus (Staph. Approximately half of Staph cases are associated with menstruation, which was first described in the 1970s-1980s and was associated with the use of absorbent tampons.1 Group A Streptococcus may cause complications such as necrotizing fasciitis and gangrenous myositis.2 Pediatric patients may present critically ill from toxic shock syndrome. Providers need to perform a thorough history and physical exam to discern the source of infection. Management requires aggressive care with antibiotics and IV fluids. Objectives: By the end of this simulation session, the learner will be able to: 1 Recognize toxic shock syndrome. 2 Review the importance of a thorough physical exam. 3 Discuss management of toxic shock syndrome, including supportive care and the difference in antibiotic choices for streptococcal and staphylococcal toxic shock syndrome. 4 Appropriately disposition a patient suffering from toxic shock syndrome. 5 Communicate effectively with team members and nursing staff during a resuscitation of a critically ill patient. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on toxic shock syndrome.

Combining scenarios in a calculation of the overall probability distribution of cumulative releases of radioactivity from the Waste Isolation Pilot Plant, southeastern New Mexico

International Nuclear Information System (INIS)

Tierney, M.S.

1991-11-01

The Waste Isolation Pilot Plant (WIPP), in southeastern New Mexico, is a research and development facility to demonstrate safe disposal of defense-generated transuranic waste. The US Department of Energy will designate WIPP as a disposal facility if it meets the US Environmental Protection Agency's standard for disposal of such waste; the standard includes a requirement that estimates of cumulative releases of radioactivity to the accessible environment be incorporated in an overall probability distribution. The WIPP Project has chosen an approach to calculation of an overall probability distribution that employs the concept of scenarios for release and transport of radioactivity to the accessible environment. This report reviews the use of Monte Carlo methods in the calculation of an overall probability distribution and presents a logical and mathematical foundation for use of the scenario concept in such calculations. The report also draws preliminary conclusions regarding the shape of the probability distribution for the WIPP system; preliminary conclusions are based on the possible occurrence of three events and the presence of one feature: namely, the events ''attempted boreholes over rooms and drifts,'' ''mining alters ground-water regime,'' ''water-withdrawal wells provide alternate pathways,'' and the feature ''brine pocket below room or drift.'' Calculation of the WIPP systems's overall probability distributions for only five of sixteen possible scenario classes that can be obtained by combining the four postulated events or features

A dynamic approach for the impact of a toxic gas dispersion hazard considering human behaviour and dispersion modelling.

Science.gov (United States)

Lovreglio, Ruggiero; Ronchi, Enrico; Maragkos, Georgios; Beji, Tarek; Merci, Bart

2016-11-15

The release of toxic gases due to natural/industrial accidents or terrorist attacks in populated areas can have tragic consequences. To prevent and evaluate the effects of these disasters different approaches and modelling tools have been introduced in the literature. These instruments are valuable tools for risk managers doing risk assessment of threatened areas. Despite the significant improvements in hazard assessment in case of toxic gas dispersion, these analyses do not generally include the impact of human behaviour and people movement during emergencies. This work aims at providing an approach which considers both modelling of gas dispersion and evacuation movement in order to improve the accuracy of risk assessment for disasters involving toxic gases. The approach is applied to a hypothetical scenario including a ship releasing Nitrogen dioxide (NO2) on a crowd attending a music festival. The difference between the results obtained with existing static methods (people do not move) and a dynamic approach (people move away from the danger) which considers people movement with different degrees of sophistication (either a simple linear path or more complex behavioural modelling) is discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

A proposal for a test method for assessment of hazard property HP 12 (“Release of an acute toxic gas”) in hazardous waste classification - Experience from 49 waste

OpenAIRE

Hennebert , Pierre; Samaali , Ismahen; Molina , Pauline

2016-01-01

International audience; A stepwise method for assessment of the HP 12 is proposed and tested with 49 waste samples. The hazard property HP 12 is defined as “Release of an acute toxic gas”: waste which releases acute toxic gases (Acute Tox. 1, 2 or 3) in contact with water or an acid. When a waste contains a substance assigned to one of the following supplemental hazards EUH029, EUH031 and EUH032, it shall be classified as hazardous by HP 12 according to test methods or guidelines (EC, 2014a, ...

Emergency planning and the Control of Major Accident Hazards (COMAH/Seveso II) Directive: An approach to determine the public safety zone for toxic cloud releases

International Nuclear Information System (INIS)

O'Mahony, Mary T.; Doolan, Donal; O'Sullivan, Alice; Hession, Michael

2008-01-01

The EU Control of Major Accidents Hazards Directive (Seveso II) requires an external emergency plan for each top tier site. This paper sets out a method to build the protection of public health into emergency planning for Seveso sites in the EU. The method involves the review of Seveso site details prescribed under the directive. The site safety report sets out the potential accident scenarios. The safety report's worst-case scenario, and chemical involved, is used as the basis for the external emergency plan. A decision was needed on the appropriate threshold value to use as the level of concern to protect public health. The definitions of the regulatory standards (air quality standards and occupational standards) in use were studied, how they are derived and for what purpose. The 10 min acute exposure guideline level (AEGL) for a chemical is recommended as the threshold value to inform decisions taken to protect public health from toxic cloud releases. The area delimited by AEGL 1 defines the population who may be concerned about being exposed. They need information based on comprehensive risk assessment. The area delimited by AEGL 2 defines the population for long-term surveillance when indicated and may include first responders. The area delimited by AEGL 3 defines the population who may present acutely to the medical services. It ensures that the emergency responders site themselves safely. A standard methodology facilitates discussions with plant operators and concerned public. Examples show how the methodology can be adapted to suit explosive risk and response to fire

RELEASE OF DRIED RADIOACTIVE WASTE MATERIALS TECHNICAL BASIS DOCUMENT

International Nuclear Information System (INIS)

KOZLOWSKI, D.S.

2005-01-01

The body of this document analyzes scenarios involving releases of dried tank waste from the DBVS dried waste transfer system and OGTS HEPA filters. Analyses of dried waste release scenarios from the CH-TRUM WPU are included as Appendix D

Biosphere scenario development. An interim report of an SKI, SSI, SKB working group

International Nuclear Information System (INIS)

1989-11-01

The Swedish Nuclear Power Inspectorate and the Swedish Nuclear Fuel and Waste Management Co have initiated a project for the development of scenarios for the behaviour of radionuclides in high level waste following deep geological disposal. The main objective is to develop a general consensus of scenarios and conceptual models. Within the project a biosphere scenarios working group was initiated to consider specific questions of the biosphere. This report describes the results of the group's deliberations up to the end of July 1989. A methodology is presented for the development of biosphere scenarios which may be considered alongside scenarios for radionuclide behaviour in the near field and geosphere. Two major biosphere elements affecting processes in the surface environment have been recognised, climate and development. Alternative states for climate and level of development are suggested and each combination can be considered with one or more of a range of biosphere receptors, such as a river or a lake. The features, events and processes relevant to each receptor are presented. Consideration is then given to biosphere assumptions for both gradual and direct releases from the geosphere, as well as biosphere effects on the repository near field or geosphere. The amount of screening which can be done at this stage to limit the number of biosphere scenarios is small. However, considerable potential exists once more details are available for geosphere release scenarios. It may be appropriate to further develop biosphere scenarios, specific to each geosphere release scenario. It may also be appropriate to consider scenarios specifically in relation to the individual radionuclides which dominate geosphere releases. Both these possibilities could result in considerably reduced requirements for calculations

2002 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313

International Nuclear Information System (INIS)

Stockton, M.

2003-01-01

For reporting year 2002, Los Alamos National Laboratory (LANL or the Laboratory) submitted Form R reports for lead compounds and mercury as required under the Emergency Planning and Community Right-to-Know Act (EPCRA), Section 313. No other EPCRA Section 313 chemicals were used in 2002 above the reportable thresholds. This document was prepared to provide a description of the evaluation of EPCRA Section 313 chemical usage and threshold determinations for LANL for calendar year 2002 as well as provide background information about the data included on the Form R reports. Section 313 of EPCRA specifically requires facilities to submit a Toxic Chemical Release Inventory report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. In 1999 EPA promulgated a final rule on Persistent Bioaccumulative Toxics (PBTs). This rule added several chemicals to the EPCRA Section 313 list of toxic chemicals and established lower reporting thresholds for these and other PBT chemicals that were already reportable under EPCRA Section 313. These lower thresholds became applicable in reporting year 2000. In 2001, EPA expanded the PBT rule to include a lower reporting threshold for lead and lead compounds. Facilities that manufacture, process, or otherwise use more than 100 lb of lead or lead compounds must submit a Form R

2006 Toxic Chemical Release Inventory Report for the Emergency Planning and Community Right-to-Know Act of 1986, Title III, Section 313

Energy Technology Data Exchange (ETDEWEB)

Ecology and Air Quality Group (ENV-EAQ)

2007-12-12

For reporting year 2006, Los Alamos National Laboratory (LANL or the Laboratory) submitted Form R reports for lead as required under the Emergency Planning and Community Right-to-Know Act (EPCRA) Section 313. No other EPCRA Section 313 chemicals were used in 2006 above the reportable thresholds. This document was prepared to provide a description of the evaluation of EPCRA Section 313 chemical use and threshold determinations for LANL for calendar year 2006, as well as to provide background information about data included on the Form R reports. Section 313 of EPCRA specifically requires facilities to submit a Toxic Chemical Release Inventory Report (Form R) to the U.S. Environmental Protection Agency (EPA) and state agencies if the owners and operators manufacture, process, or otherwise use any of the listed toxic chemicals above listed threshold quantities. EPA compiles this data in the Toxic Release Inventory database. Form R reports for each chemical over threshold quantities must be submitted on or before July 1 each year and must cover activities that occurred at the facility during the previous year. In 1999, EPA promulgated a final rule on persistent bioaccumulative toxics (PBTs). This rule added several chemicals to the EPCRA Section 313 list of toxic chemicals and established lower reporting thresholds for these and other PBT chemicals that were already reportable. These lower thresholds became applicable in reporting year 2000. In 2001, EPA expanded the PBT rule to include a lower reporting threshold for lead and lead compounds. Facilities that manufacture, process, or otherwise use more than 100 lb of lead or lead compounds must submit a Form R.

Effect of surfactant in mitigating cadmium oxide nanoparticle toxicity: Implications for mitigating cadmium toxicity in environment

International Nuclear Information System (INIS)

Balmuri, Sricharani Rao; Selvaraj, Uthra; Kumar, Vadivel Vinod; Anthony, Savarimuthu Philip; Tsatsakis, Aristides Michael; Golokhvast, Kirill Sergeevich; Raman, Thiagarajan

2017-01-01

Cadmium (Cd), classified as human carcinogen, is an extremely toxic heavy metal pollutant, and there is an increasing environmental concern for cadmium exposure through anthropogenic sources including cigarette smoke. Though Cd based nanoparticles such as cadmium oxide (CdO) are being widely used in a variety of clinical and industrial applications, the toxicity of CdO nanoparticles has not been well characterized. Herein we report the toxicity of CdO nanoparticles employing zebrafish as a model. Two different CdO nanoparticles were prepared, calcination of Cd(OH) 2 without any organic molecule (CdO-1) and calcination of Cd-citrate coordination polymer (CdO-2), to evaluate and compare the toxicity of these two different CdO nanoparticles. Results show that zebrafish exposed to CdO-2 nanoparticles expressed reduced toxicity as judged by lower oxidative stress levels, rescue of liver carboxylesterases and reduction in metallothionein activity compared to CdO-1 nanoparticles. Histopathological observations also support our contention that CdO-1 nanoparticles showed higher toxicity relative to CdO-2 nanoparticles. The organic unit of Cd-citrate coordination polymer might have converted into carbon during calcination that might have covered the surface of CdO nanoparticles. This carbon surface coverage can control the release of Cd 2+ ions in CdO-2 compared to non-covered CdO-1 nanoparticles and hence mitigate the toxicity in the case of CdO-2. This was supported by atomic absorption spectrophotometer analyses of Cd 2+ ions release from CdO-1 and CdO-2 nanoparticles. Thus the present study clearly demonstrates the toxicity of CdO nanoparticles in an aquatic animal and also indicates that the toxicity could be substantially reduced by carbon coverage. This could have important implications in terms of anthropogenic release and environmental pollution caused by Cd and human exposure to Cd 2+ from sources such as cigarette smoke. - Highlights: • Toxicity of Cd

Effect of surfactant in mitigating cadmium oxide nanoparticle toxicity: Implications for mitigating cadmium toxicity in environment

Energy Technology Data Exchange (ETDEWEB)

Balmuri, Sricharani Rao [Department of Bioengineering, School of Chemical & Biotechnology, SASTRA University, Thanjavur 613401 (India); Selvaraj, Uthra [Department of Biotechnology, School of Chemical & Biotechnology, SASTRA University, Thanjavur 613401 (India); Kumar, Vadivel Vinod [Department of Chemistry, School of Chemical & Biotechnology, SASTRA University, Thanjavur 613401 (India); Anthony, Savarimuthu Philip, E-mail: philip@biotech.sastra.edu [Department of Chemistry, School of Chemical & Biotechnology, SASTRA University, Thanjavur 613401 (India); Tsatsakis, Aristides Michael [Department of Forensic Sciences and Toxicology, Medical School, University of Crete, Heraklion 71003 (Greece); Scientific Educational Center of Nanotechnology, Far Eastern Federal University, Vladivostok 690990 (Russian Federation); Golokhvast, Kirill Sergeevich [Scientific Educational Center of Nanotechnology, Far Eastern Federal University, Vladivostok 690990 (Russian Federation); Raman, Thiagarajan, E-mail: raman@biotech.sastra.edu [Department of Bioengineering, School of Chemical & Biotechnology, SASTRA University, Thanjavur 613401 (India); Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA University, Thanjavur 613401 (India)

2017-01-15

Cadmium (Cd), classified as human carcinogen, is an extremely toxic heavy metal pollutant, and there is an increasing environmental concern for cadmium exposure through anthropogenic sources including cigarette smoke. Though Cd based nanoparticles such as cadmium oxide (CdO) are being widely used in a variety of clinical and industrial applications, the toxicity of CdO nanoparticles has not been well characterized. Herein we report the toxicity of CdO nanoparticles employing zebrafish as a model. Two different CdO nanoparticles were prepared, calcination of Cd(OH){sub 2} without any organic molecule (CdO-1) and calcination of Cd-citrate coordination polymer (CdO-2), to evaluate and compare the toxicity of these two different CdO nanoparticles. Results show that zebrafish exposed to CdO-2 nanoparticles expressed reduced toxicity as judged by lower oxidative stress levels, rescue of liver carboxylesterases and reduction in metallothionein activity compared to CdO-1 nanoparticles. Histopathological observations also support our contention that CdO-1 nanoparticles showed higher toxicity relative to CdO-2 nanoparticles. The organic unit of Cd-citrate coordination polymer might have converted into carbon during calcination that might have covered the surface of CdO nanoparticles. This carbon surface coverage can control the release of Cd{sup 2+} ions in CdO-2 compared to non-covered CdO-1 nanoparticles and hence mitigate the toxicity in the case of CdO-2. This was supported by atomic absorption spectrophotometer analyses of Cd{sup 2+} ions release from CdO-1 and CdO-2 nanoparticles. Thus the present study clearly demonstrates the toxicity of CdO nanoparticles in an aquatic animal and also indicates that the toxicity could be substantially reduced by carbon coverage. This could have important implications in terms of anthropogenic release and environmental pollution caused by Cd and human exposure to Cd{sup 2+} from sources such as cigarette smoke. - Highlights: �

Barrier and operational risk analysis of hydrocarbon releases (BORA-Release)

International Nuclear Information System (INIS)

Sklet, Snorre; Vinnem, Jan Erik; Aven, Terje

2006-01-01

This paper presents results from a case study carried out on an offshore oil and gas production platform with the purpose to apply and test BORA-Release, a method for barrier and operational risk analysis of hydrocarbon releases. A description of the BORA-Release method is given in Part I of the paper. BORA-Release is applied to express the platform specific hydrocarbon release frequencies for three release scenarios for selected systems and activities on the platform. The case study demonstrated that the BORA-Release method is a useful tool for analysing the effect on the release frequency of safety barriers introduced to prevent hydrocarbon releases, and to study the effect on the barrier performance of platform specific conditions of technical, human, operational, and organisational risk influencing factors (RIFs). BORA-Release may also be used to analyse the effect on the release frequency of risk reducing measures

Acrolein and Human Disease: Untangling the Knotty Exposure Scenarios Accompanying Several Diverse Disorders.

Science.gov (United States)

Burcham, Philip C

2017-01-17

Acrolein is a highly toxic electrophile that participates in many diseases, yet efforts to delineate its precise mechanistic contributions to specific conditions are complicated by its wide distribution within human environments. This Perspective develops the proposal that due to its mixed status as environmental pollutant, metabolic byproduct, and endotoxicant which forms via ubiquitous pathophysiological processes, many diseases likely involve acrolein released from multiple sources. Although the category boundaries are indistinct, at least four identifiable exposure scenarios are identifiable. First, in some syndromes, such as those accompanying chronic or acute intoxication with smoke, whatever role acrolein plays in disease pathogenesis mainly traces to exogenous sources such as the combustion of tobacco or other organic matter. A second exposure category involves xenobiotics that undergo metabolism within the body to release acrolein. Still other health conditions, however, involve acrolein that forms via several endogenous pathways, some of which are activated upon intoxication with xenobiotics (i.e., Exposure Category 3), while still others accompany direct physical trauma to body tissues (Exposure Category 4). Further complicating efforts to clarify the role of endogenous acrolein in human disease is the likelihood that many such syndromes are complex phenomena that resemble "chemical mixture exposures" by involving multiple toxic substances simultaneously. This Perspective contends that while recent decades have witnessed much progress in describing the deleterious effects of acrolein at the cellular and molecular levels, more work is needed to define the contributions of different acrolein sources to "real-world" health conditions in human subjects.

Radionuclide release calculations for SAR-08

International Nuclear Information System (INIS)

Thomson, Gavin; Miller, Alex; Smith, Graham; Jackson, Duncan

2008-04-01

Following a review by the Swedish regulatory authorities of the post-closure safety assessment of the SFR 1 disposal facility for low and intermediate waste (L/ILW), SAFE, the SKB has prepared an updated assessment called SAR-08. This report describes the radionuclide release calculations that have been undertaken as part of SAR-08. The information, assumptions and data used in the calculations are reported and the results are presented. The calculations address issues raised in the regulatory review, but also take account of new information including revised inventory data. The scenarios considered include the main case of expected behaviour of the system, with variants; low probability releases, and so-called residual scenarios. Apart from these scenario uncertainties, data uncertainties have been examined using a probabilistic approach. Calculations have been made using the AMBER software. This allows all the component features of the assessment model to be included in one place. AMBER has been previously used to reproduce results the corresponding calculations in the SAFE assessment. It is also used in demonstration of the IAEA's near surface disposal assessment methodology ISAM and has been subject to very substantial verification tests and has been used in verifying other assessment codes. Results are presented as a function of time for the release of radionuclides from the near field, and then from the far field into the biosphere. Radiological impacts of the releases are reported elsewhere. Consideration is given to each radionuclide and to each component part of the repository. The releases from the entire repository are also presented. The peak releases rates are, for most scenarios, due to organic C-14. Other radionuclides which contribute to peak release rates include inorganic C-14, Ni-59 and Ni-63. (author)

Radionuclide release calculations for SAR-08

Energy Technology Data Exchange (ETDEWEB)

Thomson, Gavin; Miller, Alex; Smith, Graham; Jackson, Duncan (Enviros Consulting Ltd, Wolverhampton (United Kingdom))

2008-04-15

Following a review by the Swedish regulatory authorities of the post-closure safety assessment of the SFR 1 disposal facility for low and intermediate waste (L/ILW), SAFE, the SKB has prepared an updated assessment called SAR-08. This report describes the radionuclide release calculations that have been undertaken as part of SAR-08. The information, assumptions and data used in the calculations are reported and the results are presented. The calculations address issues raised in the regulatory review, but also take account of new information including revised inventory data. The scenarios considered include the main case of expected behaviour of the system, with variants; low probability releases, and so-called residual scenarios. Apart from these scenario uncertainties, data uncertainties have been examined using a probabilistic approach. Calculations have been made using the AMBER software. This allows all the component features of the assessment model to be included in one place. AMBER has been previously used to reproduce results the corresponding calculations in the SAFE assessment. It is also used in demonstration of the IAEA's near surface disposal assessment methodology ISAM and has been subject to very substantial verification tests and has been used in verifying other assessment codes. Results are presented as a function of time for the release of radionuclides from the near field, and then from the far field into the biosphere. Radiological impacts of the releases are reported elsewhere. Consideration is given to each radionuclide and to each component part of the repository. The releases from the entire repository are also presented. The peak releases rates are, for most scenarios, due to organic C-14. Other radionuclides which contribute to peak release rates include inorganic C-14, Ni-59 and Ni-63. (author)

The Industrial Toxics Project: Targeting chemicals for environmental results

International Nuclear Information System (INIS)

Burch, W.M.

1991-01-01

In September, 1990, the Administrator of the US Environmental Protection Agency committed the Agency to a program of targeting chemicals for multi-media risk reduction activities through pollution prevention. The Industrial Toxics Project will place emphasis on obtaining voluntary commitments from industry to reduce releases of toxic chemicals to the air, water, and land with a goal of reducing releases nationwide by 33% by 1992 and 50% by 1995. An initial list of 18 chemicals have been selected based on recommendations from each Agency program. The chemicals selected are subject to reporting under the Toxic Chemical Release Inventory Program which will provide the basis for tracking progress. The chemicals are characterized by high production volume, toxicity and releases and present the potential for significant risk reduction through pollution prevention. This presentation will discuss the focus and direction of this new initiative

Studies on the toxic effects of periodontal sustained release drug containing ornidazole and pefloxacin mesylate on early embryonic development of SD rat

Directory of Open Access Journals (Sweden)

Zheng-mou DONG

2011-01-01

Full Text Available Objective To evaluate the toxic effects of periodontal sustained release drug containing ornidazole and pefloxacin mesylate on early embryonic development of SD rats.Methods A total of 100female SD rats were randomly divided into negative control,low-,medium-,high-dose group and intervention group(20each.Rats in low-,medium-and high-dose group were fed daily with the sustained release drug at 1,4,and 8g/kg respectively;those in negative control group were fed daily with distilled water from the 14th day before mating to the 7th day of pregnancy continuously,and those in intervention group received cyclophosphamide(40mg/kgby intraperitoneal injection for 5successive days.During this period,the general status,mating,pregnancy,coefficient of ovary and uterus,the numbers of corpus luteum,nidation,live births,stillbirths,absorbed embryo,prenidatory and postnidatory mortality,serum testosterone(Tand estradiol(E2were determined respectively.Histopathologic examination of the ovary and uterus,immunohistochemical observation of ovaries for proliferating cell nuclear antigen(PCNAand Bcl-2associated X protein(Baxwere also performed respectively.Results The general status of those rats was good except one in the low-dose group and one in the intervention group died on the 14th day of administration,and one in negative control and one in high dose group died on the 5th day of pregnancy,respectively.The body weight of animals decreased significantly(P 0.05.The serum T level in medium-and high-dose group and the E2level in high-dose group declined compared to that in negative control group(P < 0.05.Conclusions Although the periodontal sustained release drug containing ornidazole and pefloxacin mesylate shows no toxicity to the early embryonic development of SD rats,the high dose drug has certain toxicity to ovary.Declined serum concentrations of T and E2,reduced expression of PCNA,and increased Bax may be the causes of the toxicity.

Release behavior and toxicity profiles towards A549 cell lines of ciprofloxacin from its layered zinc hydroxide intercalation compound.

Science.gov (United States)

Abdul Latip, Ahmad Faiz; Hussein, Mohd Zobir; Stanslas, Johnson; Wong, Charng Choon; Adnan, Rohana

2013-01-01

Layered hydroxides salts (LHS), a layered inorganic compound is gaining attention in a wide range of applications, particularly due to its unique anion exchange properties. In this work, layered zinc hydroxide nitrate (LZH), a family member of LHS was intercalated with anionic ciprofloxacin (CFX), a broad spectrum antibiotic via ion exchange in a mixture solution of water:ethanol. Powder x-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) confirmed the drug anions were successfully intercalated in the interlayer space of LZH. Specific surface area of the obtained compound was increased compared to that of the host due to the different pore textures between the two materials. CFX anions were slowly released over 80 hours in phosphate-buffered saline (PBS) solution due to strong interactions that occurred between the intercalated anions and the host lattices. The intercalation compound demonstrated enhanced antiproliferative effects towards A549 cancer cells compared to the toxicity of CFX alone. Strong host-guest interactions between the LZH lattice and the CFX anion give rise to a new intercalation compound that demonstrates sustained release mode and enhanced toxicity effects towards A549 cell lines. These findings should serve as foundations towards further developments of the brucite-like host material in drug delivery systems.

Overview study of LNG release prevention and control systems

Energy Technology Data Exchange (ETDEWEB)

Pelto, P.J.; Baker, E.G.; Holter, G.M.; Powers, T.B.

1982-03-01

The liquefied natural gas (LNG) industry employs a variety of release prevention and control techniques to reduce the likelihood and the consequences of accidental LNG releases. A study of the effectiveness of these release prevention and control systems is being performed. Reference descriptions for the basic types of LNG facilities were developed. Then an overview study was performed to identify areas that merit subsequent and more detailed analyses. The specific objectives were to characterize the LNG facilities of interest and their release prevention and control systems, identify possible weak links and research needs, and provide an analytical framework for subsequent detailed analyses. The LNG facilities analyzed include a reference export terminal, marine vessel, import terminal, peakshaving facility, truck tanker, and satellite facility. A reference description for these facilities, a preliminary hazards analysis (PHA), and a list of representative release scenarios are included. The reference facility descriptions outline basic process flows, plant layouts, and safety features. The PHA identifies the important release prevention operations. Representative release scenarios provide a format for discussing potential initiating events, effects of the release prevention and control systems, information needs, and potential design changes. These scenarios range from relatively frequent but low consequence releases to unlikely but large releases and are the principal basis for the next stage of analysis.

Toxic effects and bioaccumulation of nano-, micron-, and ionic-Ag on the polychaete, Nereis diversicolor

DEFF Research Database (Denmark)

Cong, Yi; Banta, Gary Thomas; Selck, Henriette

2011-01-01

There is increasing concern about the toxicities and potential risks, both still poorly understood, of silver nanoparticles for the aquatic environment after their eventual release via wastewater discharges. In this study, the toxicities of sediment associated nano (...)- and ionic (AgNO3)- Ag on the sediment-dwelling polychaete, Nereis diversicolor, were compared after 10 days of sediment exposure, using survival, DNA damage (comet assay) and bioaccumulation as endpoints. The nominal concentrations used in all exposure scenarios were 0, 1, 5, 10, 25, and 50 g Ag/g dry...... weight (dw) sediment. Our results showed that Ag was able to cause DNA damage in Nereis coelomocytes, and that this effect was both concentration- and Ag form-related. There was significantly greater genotoxicity (higher tail moment and tail DNA intensities) at 25 and 50 g/g dw in nano- and micron-Ag...

Extreme scenarios for nuclear waste repositories

Energy Technology Data Exchange (ETDEWEB)

Brown, M J [Harvard Univ., Cambridge, MA (USA). Div. of Applied Sciences; Crouch, E [Harvard Univ., Cambridge, MA (USA). Energy and Environmental Policy Center

1982-09-01

Two extreme scenarios for release of radioactive waste have been constructed. In the first, a volcanic eruption releases 1 km/sup 2/ of an underground nuclear waste repository, while in the second, waste enters the drinking water reservoir of a major city. With pessimistic assumptions, upper bounds on the number of cancers due to radiation are calculated. In the volcano scenario, the effects of the waste are smaller than the effects of natural radioactivity in the volcanic dust if the delay between emplacement and eruption exceeds 2000 yr. The consequences of the waste in drinking water depend on the survival time of the canisters and the rate of leaching of the nuclides from the waste matrix. For a canister life of 400 yr and a leach time of 6300 yr the cancer rate in the affected area would increase by 25%.

Extreme scenarios for nuclear waste repositories

Energy Technology Data Exchange (ETDEWEB)

Brown, M J; Crouch, E

1982-09-01

Two extreme scenarios for release of radioactive waste have been constructed. In the first, a volcanic eruption releases 1 km2 of an underground nuclear waste repository, while in the second, waste enters the drinking water reservoir of a major city. With pessimistic assumptions, upper bounds on the number of cancers due to radiation are calculated. In the volcano scenario, the effects of the water are smaller than the effects of natural radioactivity in the volcanic dust if the delay between emplacement and eruption exceeds 2000 yr. The consequences of the waste in drinking water depend on the survival time of the canisters and the rate of leaching of the nuclides from the waste matrix. For a canister life of 400 yr and a leach time of 6300 yr the cancer rate in the affected area would increase by 25%.

Divide by 4 the emissions: the Negatep scenario; Diviser par 4 nos rejets: le scenario Negatep

Energy Technology Data Exchange (ETDEWEB)

Acket, C.; Bacher, P

2007-01-15

The Negatep scenario is proposed in the framework of the french energy policy, aiming to divide by 4 the CO{sub 2} emissions for 2050. After an evaluation of the today situation concerning the energy consumption and needs, the scenario proposes some ways of energy conservation in different sectors, other energy sources in place of the fossil fuels, the energy needs by sectors. The last part of the document provides the main consumption posts, the CO{sub 2} releases and the approach. (A.L.B.)

Scenarios constructed for basaltic igneous activity at Yucca Mountain and vicinity

International Nuclear Information System (INIS)

Barr, G.E.; Dunn, E.; Dockery, H.; Barnard, R.; Valentine, G.; Crowe, B.

1993-08-01

Basaltic volcanism has been identified as a possible future event initiating a release of radionuclides from a potential repository at the proposed Yucca Mountain high-level waste repository site. The performance assessment method set forth in the Site Characterization Plan (DOE, 1988) requires that a set of scenarios encompassing all significant radionuclide release paths to the accessible environment be described. This report attempts to catalogue the details of the interactions between the features and processes produced by basaltic volcanism in the presence of the presumed groundwater flow system and a repository structure, the engineered barrier system (EBS), and waste. This catalogue is developed in the form of scenarios. We define a scenario as a well-posed problem, starting from an initiating event or process and proceeding through a logically connected and physically possible combination or sequence of features, events, and processes (FEPs) to the release of contaminants

The importance of scenario development in meeting 40 CFR part 191

International Nuclear Information System (INIS)

Hunter, R.L.

1988-01-01

Scenario development and screening is a fundamental part of performance assessment, but its importance in satisfying 40 CFR Part 191 (the standard) is sometimes underestimated. The first step in scenario development in support of performance assessment for the standard's containment requirements is to identify a set of potentially disruptive events and processes. This set must be broad enough to allow the identification, as required by the standard, of those processes and events that might affect the disposal system; data can then be collected on the scenarios identified in this step. The standard also requires that releases be estimated for all significant processes and events; thus the final step in scenario development is systematically screening the scenarios, on the basis of their probabilities and consequences, to select those that are important enough to be modeled in detail. In general, a few hundred scenarios for the release of radionuclides from a nuclear-waste repository can be identified, but only a few of these can or should be modeled in detail

Acute aquatic toxicity of tire and road wear particles to alga, daphnid, and fish.

Science.gov (United States)

Marwood, Christopher; McAtee, Britt; Kreider, Marisa; Ogle, R Scott; Finley, Brent; Sweet, Len; Panko, Julie

2011-11-01

Previous studies have indicated that tire tread particles are toxic to aquatic species, but few studies have evaluated the toxicity of such particles using sediment, the likely reservoir of tire wear particles in the environment. In this study, the acute toxicity of tire and road wear particles (TRWP) was assessed in Pseudokirchneriella subcapita, Daphnia magna, and Pimephales promelas using a sediment elutriate (100, 500, 1000 or 10000 mg/l TRWP). Under standard test temperature conditions, no concentration response was observed and EC/LC(50) values were greater than 10,000 mg/l. Additional tests using D. magna were performed both with and without sediment in elutriates collected under heated conditions designed to promote the release of chemicals from the rubber matrix to understand what environmental factors may influence the toxicity of TRWP. Toxicity was only observed for elutriates generated from TRWP leached under high-temperature conditions and the lowest EC/LC(50) value was 5,000 mg/l. In an effort to identify potential toxic chemical constituent(s) in the heated leachates, toxicity identification evaluation (TIE) studies and chemical analysis of the leachate were conducted. The TIE coupled with chemical analysis (liquid chromatography/mass spectrometry/mass spectrometry [LC/MS/MS] and inductively coupled plasma/mass spectrometry [ICP/MS]) of the leachate identified zinc and aniline as candidate toxicants. However, based on the high EC/LC(50) values and the limited conditions under which toxicity was observed, TRWP should be considered a low risk to aquatic ecosystems under acute exposure scenarios.

Biodegradable chitosan and polylactic acid-based intraocular micro-implant for sustained release of methotrexate into vitreous: analysis of pharmacokinetics and toxicity in rabbit eyes.

Science.gov (United States)

Manna, Soumyarwit; Banerjee, Rupak K; Augsburger, James J; Al-Rjoub, Marwan F; Donnell, Anna; Correa, Zelia M

2015-08-01

The purpose of this study was to evaluate the pharmacokinetics and toxicity of a chitosan (CS) and polylactic acid (PLA) based methotrexate (MTX) intravitreal micro-implant in an animal model using rabbit eyes. CS- and PLA-based micro-implants containing 400 μg of MTX were fabricated using lyophilization and dip-coating techniques. The micro-implants were surgically implanted in the vitreous of eight New Zealand rabbits employing minimally invasive technique. The PLA-coated CS-MTX micro-implant was inserted in the right eye and the placebo micro-implant in the left eye of each rabbit. Two rabbits were euthanized at each pre-determined time point post-implantation (days 5, 12, 19, and 33) for pharmacokinetics and histopathology evaluation. A therapeutic concentration of MTX (0.1-1.0 μM) in the vitreous was detected in the rabbit eyes studied for 33 days. The MTX release from the coated micro-implants followed a first order kinetics (R (2) ~ 0.88), implying that MTX release depends on the concentration of MTX in the micro-implant. Histopathological analysis of the enucleated eyes failed to show any signs of infection or tissue toxicity in any of the specimens. The PLA-coated CS-MTX micro-implants were able to deliver therapeutic release of MTX for a period of more than 1 month without detectable toxicity in a rabbit model. The micro-implants can be further investigated as a prospective alternative to current treatment protocols of repeated intravitreal MTX injections in intraocular disorders such as primary intraocular lymphoma, and selected cases of non-microbial intraocular inflammation.

Beyond platinum: synthesis, characterization, and in vitro toxicity of Cu(II-releasing polymer nanoparticles for potential use as a drug delivery vector

Directory of Open Access Journals (Sweden)

Harris Alesha

2011-01-01

Full Text Available Abstract The field of drug delivery focuses primarily on delivering small organic molecules or DNA/RNA as therapeutics and has largely ignored the potential for delivering catalytically active transition metal ions and complexes. The delivery of a variety of transition metals has potential for inducing apoptosis in targeted cells. The chief aims of this work were the development of a suitable delivery vector for a prototypical transition metal, Cu2+, and demonstration of the ability to impact cancer cell viability via exposure to such a Cu-loaded vector. Carboxylate-functionalized nanoparticles were synthesized by free radical polymerization and were subsequently loaded with Cu2+ via binding to particle-bound carboxylate functional groups. Cu loading and release were characterized via ICP MS, EDX, XPS, and elemental analysis. Results demonstrated that Cu could be loaded in high weight percent (up to 16 wt.% and that Cu was released from the particles in a pH-dependent manner. Metal release was a function of both pH and the presence of competing ligands. The toxicity of the particles was measured in HeLa cells where reductions in cell viability greater than 95% were observed at high Cu loading. The combined pH sensitivity and significant toxicity make this copper delivery vector an excellent candidate for the targeted killing of disease cells when combined with an effective cellular targeting strategy.

A general mechanism for intracellular toxicity of metal-containing nanoparticles

Science.gov (United States)

Sabella, Stefania; Carney, Randy P.; Brunetti, Virgilio; Malvindi, Maria Ada; Al-Juffali, Noura; Vecchio, Giuseppe; Janes, Sam M.; Bakr, Osman M.; Cingolani, Roberto; Stellacci, Francesco; Pompa, Pier Paolo

2014-05-01

The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment - where particles are abundantly internalized - is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a ``lysosome-enhanced Trojan horse effect'' since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments.The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment - where

Toxic effects and bioaccumulation of nano-, micron- and ionic-Ag in the polychaete, Nereis diversicolor

DEFF Research Database (Denmark)

cong, Yi; Banta, Gary Thomas; Selck, Henriette

There is increasing concern about the toxicities and potential risks, both still poorly understood, of silver nanoparticles for the aquatic environment after their eventual release. In this study, the toxicities of nano (AgNO3)-Ag on the sediment......-dwelling polychaete, Nereis diversicolor, were compared after 10 d of sediment exposure, using growth, DNA damage (comet assay) and bioaccumulation as endpoints. The nominal concentrations used in all exposure scenarios were 0, 1, 5, 10, 25, 50 µg Ag/g dry weight (dw) sediment. Our results show that Ag is able...... to cause DNA damage in Nereis coelomocytes and that this effect is both concentration- and Ag form-related. There were significantly greater genotoxity (higher tail moment and tail DNA intensities) at 25 and 50 µg/g dw in nano- and micron-Ag treated groups and at 50 µg/g dw in ionic-Ag treated group...

Methodological studies for deriving release criteria for liquid effluents from medical installations

International Nuclear Information System (INIS)

Shu, Jane; Comissao Nacional de Energia Nuclear; Rochedo, Elaine R.R.; Heilbron Filho, Paulo F.L.; Crispim, Verginia R.

2009-01-01

This work aims to develop a methodology for the assessment of clearance limits for the release of liquid waste arising from medical installations using radionuclides for medical diagnostic purposes in the town of Rio de Janeiro. The results will be used to assess the need to justify or to revise the current clearance values as specified in regulation CNEN-NE-6.05 - Radioactive Waste Management in Radioactive Facilities. The proposed methodology is based on the mathematical model recommended by the International Atomic Energy Agency, adapted to the observed release conditions in the study area. In order to turn the assessment as realistic as possible, two scenarios are simulated. The first scenario simulates the release to the sewage system with access to a sewer treatment stations. The second scenario simulates the releases without passing a treatment station, with direct outflow to surface water. Probabilistic assessments were performed using the Crystal Ball software. Distributions were than compared to current IAEA clearance criteria that include specific values for average and low probability scenarios. The results will be used to derive adequate clearance levels for radionuclides used in nuclear diagnostic medicine in Brazil according to the specific relevant release scenario. (author)

Scenarios and innovative systems; Scenarii et systemes innovants

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-11-01

The purpose of this workshop is to present to the GEDEON community the scenarios for the deployment of innovative nuclear solutions. Both steady state situations and possible transitions from the present to new reactors and fuel cycles are considered. Innovative systems that satisfy improved natural resource utilization and waste minimization criteria will be described as well as the R and D orientations of various partners. This document brings together the transparencies of 17 communications given at this workshop: general policy for transmutation and partitioning; Amster: a molten salt reactor (MSR) concept; MSR capabilities; potentials and capabilities of accelerator driven systems (ADS); ADS demonstrator interest as an experimental facility; innovative systems: gas coolant technologies; Pu management in EPR; scenarios with thorium fuel; scenarios at the equilibrium state; scenarios for transition; partitioning and specific conditioning; management of separated radio-toxic elements; European programs; DOE/AAA (Advanced Accelerator Applications) program; OECD scenario studies; CEA research programs and orientations; partitioning and transmutation: an industrial point of view. (J.S.)

Disruption scenarios for a nuclear-waste repository on the Nevada Test Site

International Nuclear Information System (INIS)

Link, R.L.; Bingham, F.W.; Barr, G.E.

1981-01-01

Scenarios are being constructed for the release of radioactive maerial from hypothetical repositories in different types of rock at NTS. Deductive event trees are constructed; each path through an event tree is a scenario. The complete set of NTS event trees comprises about 340 scenarios, not counting the multiple paths through the subtrees made by expanding complex events. Each of these scenarios is being analyzed for 10 different types of rocks

Radionuclide toxicity

International Nuclear Information System (INIS)

Galle, P.

1982-01-01

The aim of this symposium was to review the radionuclide toxicity problems. Five topics were discussed: (1) natural and artificial radionuclides (origin, presence or emission in the environment, human irradiation); (2) environmental behaviour of radionuclides and transfer to man; (3) metabolism and toxicity of radionuclides (radioiodine, strontium, rare gas released from nuclear power plants, ruthenium-activation metals, rare earths, tritium, carbon 14, plutonium, americium, curium and einsteinium, neptunium, californium, uranium) cancerogenous effects of radon 222 and of its danghter products; (4) comparison of the hazards of various types of energy; (5) human epidemiology of radionuclide toxicity (bone cancer induction by radium, lung cancer induction by radon daughter products, liver cancer and leukaemia following the use of Thorotrast, thyroid cancer; other site of cancer induction by radionuclides) [fr

National Toxic Substance Incidents Program (NTSIP)

Centers for Disease Control (CDC) Podcasts

2011-02-03

This podcast gives an overview of the three components of the National Toxic Substance Incidents Program: state surveillance, national database, and response teams.  Created: 2/3/2011 by Agency for Toxic Substances and Disease Registry.   Date Released: 2/3/2011.

Persistent toxic substances released from uncontrolled e-waste recycling and actions for the future

International Nuclear Information System (INIS)

Man, Ming; Naidu, Ravi; Wong, Ming H.

2013-01-01

The Basel Convention on the Control of Transboundary Movement of Hazardous Wastes and their Disposal was adopted on March 22, 1989 and enforced on May 5, 1992. Since then, the USA, one of the world's largest e-waste producers, has not ratified this Convention or the Basel Ban Amendment. Communities are still debating the legal loophole, which permits the export of whole products to other countries provided it is not for recycling. In January 2011, China's WEEE Directive was implemented, providing stricter control over e-waste imports to China, including Hong Kong, while emphasizing that e-waste recycling is the producers' responsibility. China is expected to supersede the USA as the principal e-waste producer, by 2020, according to the UNEP. Uncontrolled e-waste recycling activities generate and release heavy metals and POPs into the environment, which may be re-distributed, bioaccumulated and biomagnified, with potentially adverse human health effects. Greater efforts and scientific approaches are needed for future e-product designs of minimal toxic metal and compound use, reaping greater benefits than debating the definition and handling responsibilities of e-waste recycling. - Highlights: ► We recommended to ban uses of deca-BDE in addition to penta- and octa-BDEs. ► We suggested to replace PVC in electronic products with non-chlorinated polymers. ► Spend less time on debating responsibilities and definition of e-waste and recycling. ► Proposed to work more on eliminating sources and potentials of toxic substances

Volatile organic compounds released from Microcystis flos-aquae under nitrogen sources and their toxic effects on Chlorella vulgaris.

Science.gov (United States)

Xu, Qinghuan; Yang, Lin; Yang, Wangting; Bai, Yan; Hou, Ping; Zhao, Jingxian; Zhou, Lv; Zuo, Zhaojiang

2017-01-01

Eutrophication promotes massive growth of cyanobacteria and algal blooms, which can poison other algae and reduce biodiversity. To investigate the differences in multiple nitrogen (N) sources in eutrophicated water on the emission of volatile organic compounds (VOCs) from cyanobacteria, and their toxic effects on other algal growth, we analyzed VOCs emitted from Microcystis flos-aquae with different types and concentrations of nitrogen, and determined the effects under Normal-N and Non-N conditions on Chlorella vulgaris. M. flos-aquae released 27, 22, 20, 27, 19, 25 and 17 compounds, respectively, with NaNO 3 , NaNO 2 , NH 4 Cl, urea, Ser, Lys and Arg as the sole N source. With the reduction in N amount, the emission of VOCs was increased markedly, and the most VOCs were found under Non-N condition. C. vulgaris cell propagation, photosynthetic pigment and Fv/Fm declined significantly following exposure to M. flos-aquae VOCs under Non-N condition, but not under Normal-N condition. When C. vulgaris cells were treated with two terpenoids, eucalyptol and limonene, the inhibitory effects were enhanced with increasing concentrations. Therefore, multiple N sources in eutrophicated water induce different VOC emissions from cyanobacteria, and reduction in N can cause nutrient competition, which can result in emissions of more VOCs. Those VOCs released from M. flos-aquae cells under Non-N for nutrient competition can inhibit other algal growth. Among those VOCs, eucalyptol and limonene are the major toxic agents. Copyright © 2016 Elsevier Inc. All rights reserved.

Hazardous substances releases associated with Hurricanes Katrina and Rita in industrial settings, Louisiana and Texas.

Science.gov (United States)

Ruckart, Perri Zeitz; Orr, Maureen F; Lanier, Kenneth; Koehler, Allison

2008-11-15

The scientific literature concerning the public health response to the unprecedented hurricanes striking the Gulf Coast in August and September 2005 has focused mainly on assessing health-related needs and surveillance of injuries, infectious diseases, and other illnesses. However, the hurricanes also resulted in unintended hazardous substances releases in the affected states. Data from two states (Louisiana and Texas) participating in the Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to describe the characteristics of hazardous substances releases in industrial settings associated with Hurricanes Katrina and Rita. HSEES is an active multi-state Web-based surveillance system maintained by the Agency for Toxic Substances and Disease Registry (ATSDR). In 2005, 166 hurricane-related hazardous substances events in industrial settings in Louisiana and Texas were reported. Most (72.3%) releases were due to emergency shut downs in preparation for the hurricanes and start-ups after the hurricanes. Emphasis is given to the contributing causal factors, hazardous substances released, and event scenarios. Recommendations are made to prevent or minimize acute releases of hazardous substances during future hurricanes, including installing backup power generation, securing equipment and piping to withstand high winds, establishing procedures to shutdown process operations safely, following established and up-to-date start-up procedures and checklists, and carefully performing pre-start-up safety reviews.

Hazardous substances releases associated with Hurricanes Katrina and Rita in industrial settings, Louisiana and Texas

International Nuclear Information System (INIS)

Ruckart, Perri Zeitz; Orr, Maureen F.; Lanier, Kenneth; Koehler, Allison

2008-01-01

The scientific literature concerning the public health response to the unprecedented hurricanes striking the Gulf Coast in August and September 2005 has focused mainly on assessing health-related needs and surveillance of injuries, infectious diseases, and other illnesses. However, the hurricanes also resulted in unintended hazardous substances releases in the affected states. Data from two states (Louisiana and Texas) participating in the Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to describe the characteristics of hazardous substances releases in industrial settings associated with Hurricanes Katrina and Rita. HSEES is an active multi-state Web-based surveillance system maintained by the Agency for Toxic Substances and Disease Registry (ATSDR). In 2005, 166 hurricane-related hazardous substances events in industrial settings in Louisiana and Texas were reported. Most (72.3%) releases were due to emergency shut downs in preparation for the hurricanes and start-ups after the hurricanes. Emphasis is given to the contributing causal factors, hazardous substances released, and event scenarios. Recommendations are made to prevent or minimize acute releases of hazardous substances during future hurricanes, including installing backup power generation, securing equipment and piping to withstand high winds, establishing procedures to shutdown process operations safely, following established and up-to-date start-up procedures and checklists, and carefully performing pre-start-up safety reviews

Hazardous substances releases associated with Hurricanes Katrina and Rita in industrial settings, Louisiana and Texas

Energy Technology Data Exchange (ETDEWEB)

Ruckart, Perri Zeitz [Division of Health Studies, Agency for Toxic Substances and Disease Registry, Atlanta, GA (United States)], E-mail: afp4@cdc.gov; Orr, Maureen F. [Division of Health Studies, Agency for Toxic Substances and Disease Registry, Atlanta, GA (United States); Lanier, Kenneth; Koehler, Allison [Louisiana Department of Health and Hospitals, Office of Public Health, New Orleans, LA (United States)

2008-11-15

The scientific literature concerning the public health response to the unprecedented hurricanes striking the Gulf Coast in August and September 2005 has focused mainly on assessing health-related needs and surveillance of injuries, infectious diseases, and other illnesses. However, the hurricanes also resulted in unintended hazardous substances releases in the affected states. Data from two states (Louisiana and Texas) participating in the Hazardous Substances Emergency Events Surveillance (HSEES) system were analyzed to describe the characteristics of hazardous substances releases in industrial settings associated with Hurricanes Katrina and Rita. HSEES is an active multi-state Web-based surveillance system maintained by the Agency for Toxic Substances and Disease Registry (ATSDR). In 2005, 166 hurricane-related hazardous substances events in industrial settings in Louisiana and Texas were reported. Most (72.3%) releases were due to emergency shut downs in preparation for the hurricanes and start-ups after the hurricanes. Emphasis is given to the contributing causal factors, hazardous substances released, and event scenarios. Recommendations are made to prevent or minimize acute releases of hazardous substances during future hurricanes, including installing backup power generation, securing equipment and piping to withstand high winds, establishing procedures to shutdown process operations safely, following established and up-to-date start-up procedures and checklists, and carefully performing pre-start-up safety reviews.

Safety barriers to prevent release of hydrocarbons during production of oil and gas

OpenAIRE

Sklet, Snorre; Hauge, Stein

2004-01-01

This report documents a set of scenarios related to release of hydrocarbons during production on oil and gas platforms. For each release scenario, initiating events, barrier functions aimed to prevent loss of containment, and barrier systems that realize these barrier functions are identified and described. Safety barriers to prevent release of hydrocarbons during production of oil and gas

Molecular toxicity mechanism of nanosilver

Directory of Open Access Journals (Sweden)

Danielle McShan

2014-03-01

Full Text Available Silver is an ancient antibiotic that has found many new uses due to its unique properties on the nanoscale. Due to its presence in many consumer products, the toxicity of nanosilver has become a hot topic. This review summarizes recent advances, particularly the molecular mechanism of nanosilver toxicity. The surface of nanosilver can easily be oxidized by O2 and other molecules in the environmental and biological systems leading to the release of Ag+, a known toxic ion. Therefore, nanosilver toxicity is closely related to the release of Ag+. In fact, it is difficult to determine what portion of the toxicity is from the nano-form and what is from the ionic form. The surface oxidation rate is closely related to the nanosilver surface coating, coexisting molecules, especially thiol-containing compounds, lighting conditions, and the interaction of nanosilver with nucleic acids, lipid molecules, and proteins in a biological system. Nanosilver has been shown to penetrate the cell and become internalized. Thus, nanosilver often acts as a source of Ag+ inside the cell. One of the main mechanisms of toxicity is that it causes oxidative stress through the generation of reactive oxygen species and causes damage to cellular components including DNA damage, activation of antioxidant enzymes, depletion of antioxidant molecules (e.g., glutathione, binding and disabling of proteins, and damage to the cell membrane. Several major questions remain to be answered: (1 the toxic contribution from the ionic form versus the nano-form; (2 key enzymes and signaling pathways responsible for the toxicity; and (3 effect of coexisting molecules on the toxicity and its relationship to surface coating.

A general mechanism for intracellular toxicity of metal-containing nanoparticles

KAUST Repository

Sabella, Stefania

2014-04-09

The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment-where particles are abundantly internalized-is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a "lysosome-enhanced Trojan horse effect" since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments. The Royal Society of Chemistry 2014.

A general mechanism for intracellular toxicity of metal-containing nanoparticles

KAUST Repository

Sabella, Stefania; Carney, Randy P.; Brunetti, Virgilio; Malvindi, Maria Ada; Al-Juffali, Noura; Vecchio, Giuseppe; Janes, Sam M.; Bakr, Osman; Cingolani, Roberto; Stellacci, Francesco; Pompa, Pier Paolo

2014-01-01

The assessment of the risks exerted by nanoparticles is a key challenge for academic, industrial, and regulatory communities worldwide. Experimental evidence points towards significant toxicity for a range of nanoparticles both in vitro and in vivo. Worldwide efforts aim at uncovering the underlying mechanisms for this toxicity. Here, we show that the intracellular ion release elicited by the acidic conditions of the lysosomal cellular compartment-where particles are abundantly internalized-is responsible for the cascading events associated with nanoparticles-induced intracellular toxicity. We call this mechanism a "lysosome-enhanced Trojan horse effect" since, in the case of nanoparticles, the protective cellular machinery designed to degrade foreign objects is actually responsible for their toxicity. To test our hypothesis, we compare the toxicity of similar gold particles whose main difference is in the internalization pathways. We show that particles known to pass directly through cell membranes become more toxic when modified so as to be mostly internalized by endocytosis. Furthermore, using experiments with chelating and lysosomotropic agents, we found that the toxicity mechanism for different metal containing NPs (such as metallic, metal oxide, and semiconductor NPs) is mainly associated with the release of the corresponding toxic ions. Finally, we show that particles unable to release toxic ions (such as stably coated NPs, or diamond and silica NPs) are not harmful to intracellular environments. The Royal Society of Chemistry 2014.

Preliminary analyses of scenarios for potential human interference for repositories in three salt formations

International Nuclear Information System (INIS)

1985-10-01

Preliminary analyses of scenarios for human interference with the performance of a radioactive waste repository in a deep salt formation are presented. The following scenarios are analyzed: (1) the U-Tube Connection Scenario involving multiple connections between the repository and the overlying aquifer system; (2) the Single Borehole Intrusion Scenario involving penetration of the repository by an exploratory borehole that simultaneously connects the repository with overlying and underlying aquifers; and (3) the Pressure Release Scenario involving inflow of water to saturate any void space in the repository prior to creep closure with subsequent release under near lithostatic pressures following creep closure. The methodology to evaluate repository performance in these scenarios is described and this methodology is applied to reference systems in three candidate formations: bedded salt in the Palo Duro Basin, Texas; bedded salt in the Paradox Basin, Utah; and the Richton Salt Dome, Mississippi, of the Gulf Coast Salt Dome Basin

TECHNICAL BASIS DOCUMENT FOR VENTILATION SYSTEM FILTRATION FAILURE LEADING TO AN UNFILTERED RELEASE

Energy Technology Data Exchange (ETDEWEB)

KOZLOWSKI, S.D.

2005-01-06

This document analyzed three scenarios involving failures of HEPA filtration systems leading to releases from liquid waste tanks. The scenarios are failure due to high temperature (fire), overpressure (filter blowout), and unfiltered release due to filter failure, improper installation. etc.

Determination of Radiological, Material and Organizational Measures for Reuse of Conditionally Released Materials from Decommissioning

International Nuclear Information System (INIS)

Ondra, F.; Vasko, M.; Necas, V.

2012-01-01

An important part of nuclear installation decommissioning is conditional release of materials. The mass of conditionally released materials can significantly influence radioactive waste management and capacity of radioactive waste repository. The influence on a total decommissioning cost is also not negligible. Several scenarios for reuse of conditionally released materials were developed within CONRELMAT project. Each scenario contains preparation phase, construction phase and operation phase. For each above mentioned phase is needed to determine radiological, material, organizational and other constraints for conditionally released materials reuse to not break exposure limits for staff and public. Constraints are determined on the basis of external and internal exposure calculations in created models for selected takes in particular scenarios phases. The paper presents a developed methodology for determination of part of above mentioned constraints concerning external exposure of staff or public. Values of staff external exposure are also presented in paper to ensure that staff or public exposure does not break the limits. The methodology comprises a proposal of following constraints: radionuclide limit concentration of conditionally released materials for specific scenarios and nuclide vectors, specific deployment of conditionally released materials eventually shielding materials, staff and public during the scenario's phases, organizational measures concerning time of staff's or public's stay in the vicinity of conditionally released materials for individual performed scenarios and nuclide vectors. The paper further describes VISIPLAN 3D ALARA calculation planning software tool used for calculation of staff's and public's external exposure for individual scenarios. Several other parallel papers proposed for HND2012 are presenting selected details of the project.(author).

Reservoir release patterns for hydropower operations at the Aspinall Unit on the Gunnison River, Colorado

International Nuclear Information System (INIS)

Yin, S.C.L.; Sedlacek, J.

1995-05-01

This report presents the development of reservoir release patterns for the Aspinall Unit, which includes Blue Mesa, Morrow Point, and Crystal Reservoirs on the Gunnison River in Colorado. Release patterns were assessed for two hydropower operational scenarios--seasonally adjusted steady flows and seasonally adjusted high fluctuating flows--and three representative hydrologic years--moderate (1987), dry (1989), and wet (1983). The release patterns for the operational scenarios were developed with the aid of monthly, daily, and hourly reservoir operational models, which simulate the linked operation of the three Aspinall Unit reservoirs. Also presented are reservoir fluctuations and downstream water surface elevations corresponding to the reservoir release patterns. Both of the hydropower operational scenarios evaluated are based on the ecological research flows proposed by the US Fish and Wildlife Service for the Aspinall Unit. The first operational scenario allows only seasonally adjusted steady flows (no hourly fluctuations at any dam within one day), whereas the second scenario permits high fluctuating flows from Blue Mesa and Morrow Point Reservoirs during certain times of the year. Crystal Reservoir would release a steady flow within each day under both operational scenarios

Scenario study on the FBR deployment

International Nuclear Information System (INIS)

Ono, Kiyoshi; Kofuji, Hirohide; Otaki, Akira; Yonezawa, Shigeaki; Shinoda, Yoshihiko; Hirao, Kazunori; Ikegami, Tetsuo

2000-12-01

This study on success scenarios for the Fast Breeder Reactor (FBR) deployment was performed taking account of future situation of fossil, renewable and nuclear energies in Japan as well as the world from the viewpoints of the following four items; economics, environment, energy security and restriction of natural uranium resources. In the economics scenario, if carbon tax is added to generating cost of LNG, coal and oil and the economics of FBR cycle is competitive with LWR cycle in the future, FBR cycle will be expected to introduce as the middle and base load power plant. In the environment scenario, there is also any possibility that FBR cycle which can burn and transmute minor actinide and fission product elements will be introduced in order to reduce the burden of deposit facility and the toxicity of high-level waste. In the uranium resources restriction scenario, FBR cycle needs to be deployed at the latest in the middle of 21st century from the viewpoint of the restriction of natural uranium resources. This study was carried out in a part of JNC's feasibility study on commercialized FBR cycle system. (author)

Persistent toxic substances released from uncontrolled e-waste recycling and actions for the future

Energy Technology Data Exchange (ETDEWEB)

Man, Ming [Croucher Institute for Environmental Sciences, Hong Kong Baptist University (Hong Kong); Naidu, Ravi [Cooperative Research Centre for Contamination Assessment and Remediation of Environments (CRC CARE), University of South Australia (Australia); Wong, Ming H., E-mail: mhwong@hkbu.edu.hk [Croucher Institute for Environmental Sciences, Hong Kong Baptist University (Hong Kong)

2013-10-01

The Basel Convention on the Control of Transboundary Movement of Hazardous Wastes and their Disposal was adopted on March 22, 1989 and enforced on May 5, 1992. Since then, the USA, one of the world's largest e-waste producers, has not ratified this Convention or the Basel Ban Amendment. Communities are still debating the legal loophole, which permits the export of whole products to other countries provided it is not for recycling. In January 2011, China's WEEE Directive was implemented, providing stricter control over e-waste imports to China, including Hong Kong, while emphasizing that e-waste recycling is the producers' responsibility. China is expected to supersede the USA as the principal e-waste producer, by 2020, according to the UNEP. Uncontrolled e-waste recycling activities generate and release heavy metals and POPs into the environment, which may be re-distributed, bioaccumulated and biomagnified, with potentially adverse human health effects. Greater efforts and scientific approaches are needed for future e-product designs of minimal toxic metal and compound use, reaping greater benefits than debating the definition and handling responsibilities of e-waste recycling. - Highlights: ► We recommended to ban uses of deca-BDE in addition to penta- and octa-BDEs. ► We suggested to replace PVC in electronic products with non-chlorinated polymers. ► Spend less time on debating responsibilities and definition of e-waste and recycling. ► Proposed to work more on eliminating sources and potentials of toxic substances.

Evaluation of the potential for significant ammonia releases from Hanford waste tanks

International Nuclear Information System (INIS)

Palmer, B.J.; Anderson, C.M.; Chen, G.; Cuta, J.M.; Ferryman, T.A.; Terrones, G.

1996-07-01

Ammonia is ubiquitous as a component of the waste stored in the Hanford Site single-shell tanks (SSTs) and double-shell tanks (DSTs). Because ammonia is both flammable and toxic, concerns have been raised about the amount of ammonia stored in the tanks and the possible mechanisms by which it could be released from the waste into the head space inside the tanks as well as into the surrounding atmosphere. Ammonia is a safety issue for three reasons. As already mentioned, ammonia is a flammable gas and may contribute to a flammability hazard either directly, if it reaches a high enough concentration in the tank head space, or by contributing to the flammability of other flammable gases such as hydrogen (LANL 1994). Ammonia is also toxic and at relatively low concentrations presents a hazard to human health. The level at which ammonia is considered Immediately Dangerous to Life or Health (IDLH) is 300 ppm (WHC 1993, 1995). Ammonia concentrations at or above this level have been measured inside the head space in a number of SSTs. Finally, unlike hydrogen and nitrous oxide, ammonia is highly soluble in aqueous solutions, and large amounts of ammonia can be stored in the waste as dissolved gas. Because of its high solubility, ammonia behaves in a qualitatively different manner from hydrogen or other insoluble gases. A broader range of scenarios must be considered in modeling ammonia storage and release

Divide by 4 the emissions: the Negatep scenario

International Nuclear Information System (INIS)

Acket, C.; Bacher, P.

2007-01-01

The Negatep scenario is proposed in the framework of the french energy policy, aiming to divide by 4 the CO 2 emissions for 2050. After an evaluation of the today situation concerning the energy consumption and needs, the scenario proposes some ways of energy conservation in different sectors, other energy sources in place of the fossil fuels, the energy needs by sectors. The last part of the document provides the main consumption posts, the CO 2 releases and the approach. (A.L.B.)

Detailed study of transmutation scenarios involving present day reactor technologies; Etude detaillee des scenarios de transmutation faisant appel aux technologies actuelles pour les reacteurs

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

This document makes a detailed technical evaluation of three families of separation-transmutation scenarios for the management of radioactive wastes. These scenarios are based on 2 parks of reactors which recycle plutonium and minor actinides in an homogeneous way. A first scenario considers the multi-recycling of Pu and Np and the mono-recycling of Am and Cm using both PWRs and FBRs. A second scenario is based on PWRs only, while a third one considers FBRs only. The mixed PWR+FBR scenario requires innovative options and gathers more technical difficulties due to the americium and curium management in a minimum flux of materials. A particular attention has been given to the different steps of the fuel cycle (fuels and targets fabrication, burnup, spent fuel processing, targets management). The feasibility of scenarios of homogeneous actinides recycling in PWRs-only and in FBRs-only has been evaluated according to the results of the first scenario: fluxes of materials, spent fuel reprocessing by advanced separation, impact of the presence of actinides on PWRs and FBRs operation. The efficiency of the different scenarios on the abatement of wastes radio-toxicity is presented in conclusion. (J.S.)

Release and Degradation of Microencapsulated Spinosad and Emamectin Benzoate.

Science.gov (United States)

Huang, Bin Bin; Zhang, Shao Fei; Chen, Peng Hao; Wu, Gang

2017-09-07

The dynamics of release and degradation of the microencapsulation formulation containing spinosad (SP) and emamectin benzoate (EM) were evaluated in the present study. SP and EM were microencapsulated using biodegradable poly-lactic acid (PLA) as the wall material. Their release from and degradation within the prepared SP and EM microspheres (SP-EM-microspheres) were studied. It was found that the encapsulation significantly prolonged the insecticide release. The release could be further extended if the external aqueous phase was pre-saturated with the insecticides and the microspheres were additionally coated with gelatin. On the other hand, increasing the water content of the emulsion or the hydrophilic polycaprolactone (PCL) content in the PLA/PCL mixture accelerated the release. Due to the photolysis and hydrolysis of SP and EM by sunlight, the toxicity of the non-encapsulated insecticides in water declined continuously from 0 through the 9 th day (d), and dissipated in 13 d. In contrast, an aqueous suspension containing 5% SP-EM-microspheres maintained a mostly constant toxicity to Plutella xylostella for 17 d. The biodegradable SP-EM-microspheres showed significantly higher long-term toxicity to P. xylostella due to lower release, reduced photolysis and hydrolysis of the encapsulated insecticides, which were affected by the varied preparation conditions.

Scenarios constructed for nominal flow in the presence of a repository at Yucca Mountain and vicinity

International Nuclear Information System (INIS)

Barr, G.E.; Hunter, R.L.; Dunn, E.; Flint, A.

1995-03-01

Scenario development for the system performance assessment of the Yucca Mountain Site Characterization Project defines a scenario as a well-posed problem connecting an initiating event with radionuclide release to the accessible environment by a logical and physically possible combination or sequence of features, events, and processes. Drawing on the advice and assistance of the Project's principal investigators (PIs), a collection of release scenarios initiated by the nominal ground-water flow occurring in the vicinity of the potential Yucca Mountain high-level-waste repository is developed and described in pictorial form. This collection of scenarios is intended to provide a framework to assist PIs in recognizing essential field and calculational analyses, to assist performance assessment in providing guidance to site characterization, and to continue the effort to exhaustively identify all features, events, and processes important to releases. It represents a step in the iterative process of identifying what details of the potential site are important for safe disposal. 67 refs

Detailed study of transmutation scenarios involving present day reactor technologies

International Nuclear Information System (INIS)

2003-01-01

This document makes a detailed technical evaluation of three families of separation-transmutation scenarios for the management of radioactive wastes. These scenarios are based on 2 parks of reactors which recycle plutonium and minor actinides in an homogeneous way. A first scenario considers the multi-recycling of Pu and Np and the mono-recycling of Am and Cm using both PWRs and FBRs. A second scenario is based on PWRs only, while a third one considers FBRs only. The mixed PWR+FBR scenario requires innovative options and gathers more technical difficulties due to the americium and curium management in a minimum flux of materials. A particular attention has been given to the different steps of the fuel cycle (fuels and targets fabrication, burnup, spent fuel processing, targets management). The feasibility of scenarios of homogeneous actinides recycling in PWRs-only and in FBRs-only has been evaluated according to the results of the first scenario: fluxes of materials, spent fuel reprocessing by advanced separation, impact of the presence of actinides on PWRs and FBRs operation. The efficiency of the different scenarios on the abatement of wastes radio-toxicity is presented in conclusion. (J.S.)

Food plant toxicants and safety - Risk assessment and regulation of inherent toxicants in plant foods

DEFF Research Database (Denmark)

Essers, A.J.A.; Alink, G.M.; Speijers, G.J.A.

1998-01-01

The ADI as a tool for risk management and regulation of food additives and pesticide residues is not readily applicable to inherent food plant toxicants: The margin between actual intake and potentially toxic levels is often small; application of the default uncertainty factors used to derive ADI...... values, particularly when extrapolating from animal data, would prohibit the utilisation of the food, which may have an overall beneficial health effect. Levels of inherent toxicants are difficult to control; their complete removal is not always wanted, due to their function for the plant or for human...... health. The health impact of the inherent toxicant is often modified by factors in the food, e.g. the bioavailability from the matrix and interaction with other inherent constituents. Risk-benefit analysis should be made for different consumption scenarios, without the use of uncertainty factors. Crucial...

Development, description and validation of a Tritium Environmental Release Model (TERM).

Science.gov (United States)

Jeffers, Rebecca S; Parker, Geoffrey T

2014-01-01

Tritium is a radioisotope of hydrogen that exists naturally in the environment and may also be released through anthropogenic activities. It bonds readily with hydrogen and oxygen atoms to form tritiated water, which then cycles through the hydrosphere. This paper seeks to model the migration of tritiated species throughout the environment - including atmospheric, river and coastal systems - more comprehensively and more consistently across release scenarios than is currently in the literature. A review of the features and underlying conceptual models of some existing tritium release models was conducted, and an underlying aggregated conceptual process model defined, which is presented. The new model, dubbed 'Tritium Environmental Release Model' (TERM), was then tested against multiple validation sets from literature, including experimental data and reference tests for tritium models. TERM has been shown to be capable of providing reasonable results which are broadly comparable with atmospheric HTO release models from the literature, spanning both continuous and discrete release conditions. TERM also performed well when compared with atmospheric data. TERM is believed to be a useful tool for examining discrete and continuous atmospheric releases or combinations thereof. TERM also includes further capabilities (e.g. river and coastal release scenarios) that may be applicable to certain scenarios that atmospheric models alone may not handle well. Copyright © 2013 Elsevier Ltd. All rights reserved.

Accidental Release of Chlorine from a Storage Facility and an On-Site Emergency Mock Drill: A Case Study

Directory of Open Access Journals (Sweden)

Ambalathumpara Raman Soman

2015-01-01

Full Text Available In the current industrial scenario there is a serious need for formulating strategies to handle hazardous substances in the safest way. Manufacture, storage, and use of hazardous substances pose a serious risk to industry, people, and the environment. Accidental release of toxic chemicals can lead to emergencies. An emergency response plan (ERP is inevitable to minimize the adverse effects of such releases. The on-site emergency plan is an integral component of any process safety and risk management system. This paper deals with an on-site emergency response plan for a chlorine manufacturing industry. It was developed on the basis of a previous study on chlorine release and a full scale mock drill has been conducted for testing the plan. Results indicated that properly trained personnel can effectively handle each level of incidents occurring in the process plant. As an extensive guideline to the district level government authorities for off-site emergency planning, risk zone has also been estimated with reference to a chlorine exposure threshold of 3 ppm.

TOXIC METAL EMISSIONS FROM INCINERATION: MECHANISMS AND CONTROL

Science.gov (United States)

Toxic metals appear in the effluents of many combustion processes, and their release into the environment has come under regulatory scrutiny. This paper reviews the nature of the problems associated with toxic metals in combustion processes, and describes where these problems occ...

Process Risk Assessment using Dynamic Simulation of Scenarios

DEFF Research Database (Denmark)

Markert, Frank; Kozin, Igor; Duijm, Nijs Jan

2016-01-01

identification, description of accident scenarios and using the conventional approach to develop static event trees for events following a loss of containment. Modelling the impacts and consequences needs models to describe the release, dispersion and effect of the hazardous material, as well as models...

Models for environmental impact assessments of releases of radioactive substances from CERN facilities

CERN Document Server

Vojtyla, P

2005-01-01

The document describes generic models for environmental impact assessments of releases of radioactive substances from CERN facilities. Except for few models developed in the Safety Commission, the models are based on the 1997 Swiss directive HSK-R-41 and on the 2001 IAEA Safety Report No. 19. The writing style is descriptive, facilitating the practical implementation of the models at CERN. There are four scenarios assumed for airborne releases: (1) short-term releases for release limit calculations, (2) actual short-term releases, (3) short-term releases during incidents/accidents, and (4) chronic long-term releases during the normal operation of a facility. For water releases, two scenarios are considered: (1) a release into a river, and (2) a release into a water treatment plant. The document shall be understood as a reference for specific environmental studies involving radioactive releases and as a recommendation of the Safety Commission.

In-vitro Release Study of Carvedilol Phosphate Matrix Tablets ...

African Journals Online (AJOL)

decreased while Starch 1500 and lactose monohydrate increased drug release. Drug release mechanism ... case of antihypertensive agents to maintain constant blood levels ... systems because of their low toxicity, pH- independent swelling ...

CAirTOX: A compartment model for assessing the fate of and human exposure to toxic-chemical emissions to air

Energy Technology Data Exchange (ETDEWEB)

McKone, T.E.

1993-10-01

CAirTOX has been developed as a spreadsheet model to assist in making a risk assessment of toxic air emissions. With CAirTOX, one can address how contaminants released to an air basin can lead to contamination of soil, food, surface water, and sediments. The modeling effort includes a multimedia transport and transformation model, exposure scenario models, and efforts to quantify uncertainty in multimedia, multiple-pathway exposure assessments. The multimedia transport and transformation model is a steady-state, but non-equilibrium model that can be used to assess concentrations of contaminants released continuously to air. In Part 1, the authors describe the multimedia transport and transformation model used to determine the fate of air emissions. In Part 2, they describe inputs and data needs for CAirTOX and the development of a set of landscape factors, which can be used to represent regional air basin/water-shed systems in California. In Part 3, they describe the multiple-pathway exposure scenarios and exposure algorithms. In Part 4, they compare the HRA approach and results and the CAirTOX exposure equations. In Part 5, they consider model sensitivity and uncertainty to determine how variability and uncertainty in model inputs affects the precision, accuracy, and credibility of the model output.

Scenario of organophosphate pollution and toxicity in India: A review.

Science.gov (United States)

Kumar, Shardendu; Kaushik, Garima; Villarreal-Chiu, Juan Francisco

2016-05-01

The present study on organophosphate deals with the reports on pollution and toxicity cases throughout India. The use of pesticides was introduced in India during the 1960s which are now being used on a large scale and represents the common feature of Indian agriculture. Use of organophosphates as a pesticide came as an alternative to chlorinated hydrocarbons due to their easy degradability. Although these xenobiotics degrade under natural condition, their residues have been detected in soil, sediments, and water due to their non-regulated usage practice. The over-reliance on pesticides has not only threatened our environment but contaminations of organophosphate residues have been also detected in certain agricultural products like tea, sugars, vegetables, and fruits throughout India. This paper highlights many of the cases where different organophosphates have been detected exceeding their respective MRL values. Some organophosphates detected are so hazardous that even WHO has listed them in class 1a and class 1b hazardous group. Presence of their residues in blood, milk, honey, and tissues of human and animals revealed their excessive use and bioaccumulating capabilities. Their intentional or unintentional uptake is causing thousands of deaths and severity each year. Most of the toxicity cases presented here are due to their uptake during a suicidal attempt. This shows how easily these harmful substances are available in the market.

Comparing rankings of selected TRI organic chemicals for two environments using a level III fugacity model and toxicity

International Nuclear Information System (INIS)

Edwards, F.G.; Egemen, E.; Nirmalakhandan, N.

1998-01-01

The Toxics Release Inventory, TRI (USEPA, 1995) is a comprehensive listing of chemicals, mass released, source of releases, and other related information for chemicals which are released into the environment in the US. These chemicals are then ranked according to the mass released as a indication of their environmental impact. Industries have been encouraged to adopt production methods to decrease the release of chemicals which are ranked highly in the TRI. Clearly, this ranking of the chemicals based upon the mass released fails to take into account very important environmental aspects. The first and most obvious aspect is the wide range of toxicity's of the chemicals released. Numerous researchers have proposed systems to rank chemicals according to their toxicity. The second aspect, which a mass released based ranking does not take into account, is the fate and transport of each chemical within the environment. Cohen and Ryan (1985) and Mackay and Paterson (1991) have proposed models to evaluate the fate and transport of chemicals released into the environment. Some authors have incorporated the mass released and toxicity with some fate and transport aspects to rank the impact of released chemicals. But, due to the complexities of modeling the environment, the lack of published data on properties of chemicals, and the lack of information on the speciation of chemicals in complex systems, modeling the fate and transport of toxic chemicals in the environment remains difficult. To provide an indication of the need to rank chemicals according to their environmental impact instead of the mass released, the authors have utilized a subset of 45 organic chemicals from the TRI, modeled the fate and transport of the chemicals using a Level III fugacity model, and compared those equilibrium concentrations with toxicity data to yield a hazard value for each chemical

Sub-100 nm biodegradable nanoparticles: in vitro release features and toxicity testing in 2D and 3D cell cultures

International Nuclear Information System (INIS)

Biondi, Marco; Guarnieri, Daniela; Yu Hui; Belli, Valentina; Netti, Paolo Antonio

2013-01-01

A big challenge in tumor targeting by nanoparticles (NPs), taking advantage of the enhanced permeability and retention effect, is the fabrication of small size devices for enhanced tumor penetration, which is considered fundamental to improve chemotherapy efficacy. The purposes of this study are (i) to engineer the formulation of doxorubicin-loaded poly(d,l-lactic-co-glycolic acid) (PLGA)–block–poly(ethylene glycol) (PEG) NPs to obtain <100 nm devices and (ii) to translate standard 2D cytotoxicity studies to 3D collagen systems in which an initial step gradient of the NPs is present. Doxorubicin release can be prolonged for days to weeks depending on the NP formulation and the pH of the release medium. Sub-100 nm NPs are effectively internalized by HeLa cells in 2D and are less cytotoxic than free doxorubicin. In 3D, <100 nm NPs are significantly more toxic than larger ones towards HeLa cells, and the cell death rate is affected by the contributions of drug release and device transport through collagen. Thus, the reduction of NP size is a fundamental feature from both a technological and a biological point of view and must be properly engineered to optimize the tumor response to the NPs. (paper)

Benzo[a]pyrene exposure under future ocean acidification scenarios weakens the immune responses of blood clam, Tegillarca granosa.

Science.gov (United States)

Su, Wenhao; Zha, Shanjie; Wang, Yichen; Shi, Wei; Xiao, Guoqiang; Chai, Xueliang; Wu, Hongxi; Liu, Guangxu

2017-04-01

Persistent organic pollutants (POPs) are known to converge into the ocean and accumulate in the sediment, posing great threats to marine organisms such as the sessile bottom burrowing bivalves. However, the immune toxicity of POPs, such as B[a]P, under future ocean acidification scenarios remains poorly understood to date. Therefore, in the present study, the impacts of B[a]P exposure on the immune responses of a bivalve species, Tegillarca granosa, under present and future ocean acidification scenarios were investigated. Results obtained revealed an increased immune toxicity of B[a]P under future ocean acidification scenarios in terms of reduced THC, altered haemocyte composition, and hampered phagocytosis, which may attribute to the synergetic effects of B[a]P and ocean acidification. In addition, the gene expressions of pathogen pattern recognition receptors (TLR1, TLR2, TLR4, TLR6), pathway mediators (TRAF6, TAK1, TAB2, IKKα and Myd88), and effectors (NF-ĸB) of the important immune related pathways were significantly down-regulated upon exposure to B[a]P under future ocean acidification scenarios. Results of the present study suggested an increased immune toxicity of B[a]P under future ocean acidification scenarios, which will significantly hamper the immune responses of T. granosa and subsequently render individuals more susceptible to pathogens challenges. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protein alkylation, transcriptional responses and cytochrome c release during acrolein toxicity in A549 cells: influence of nucleophilic culture media constituents.

Science.gov (United States)

Thompson, Colin A; Burcham, Philip C

2008-06-01

Acrolein is a toxic combustion product that elicits apoptotic and/or necrotic cell death depending on the conditions under which exposure occurs. As a strong electrophile, side-reactions with nucleophilic media constituents seem likely to accompany study of its toxicity in vitro, but these reactions are poorly characterized. We have thus examined the effect of media composition on the toxicity of acrolein in A549 cells. Cells were exposed to acrolein in either Dulbecco's buffered saline (DBS) or F12 supplemented with various concentrations of fetal bovine serum. Cell viability was assessed using the MTT assay, while heme oxygenase-1 (HO-1) and cytoplasmic cytochrome c were measured as respective markers of transcriptional response and apoptosis. Protein damage was evaluated using the protein carbonyl assay. Compared to F12 media (with or without serum), maximal cell death as evaluated using the MTT assay, as well as adduction of intracellular proteins, occurred when cells were exposed to acrolein in DBS. In contrast, cytochrome c release was maximal in cells exposed to acrolein in serum-containing F12, conditions which inhibited protein modification and overt cell death. These findings highlight the need for careful attention to experimental conditions when conducting in vitro toxicological studies of reactive substances.

Time scales of solar microwave bursts and scenarios of flare enregy release

International Nuclear Information System (INIS)

Krueger, A.; Kliem, B.; Hildebrandt, J.

1989-01-01

Based on earlier observational evidence that characteristic time scales of different solar microwave burst types are distributed over a wide range (10 -3 -10 4 sec), different mechanisms of energy release have been considered to account for the impulsive flux increase (time scale 3 sec). Among different competing processes the coalescence instability is found to be a promising candidate to combine sufficiently short time scales with substantial energy release. (author). 20 refs.; 1 fig

NC-6301, a polymeric micelle rationally optimized for effective release of docetaxel, is potent but is less toxic than native docetaxel in vivo

OpenAIRE

Kano, Mitsunobu; Harada,; Iwata,; Saito,; Ishii,; Hayashi,; Yashiro,; Hirakawa,; Miyazono,Kohei; Kato,Yasuki; Kano,Mitsunobu

2012-01-01

Mitsunori Harada,1 Caname Iwata,2 Hiroyuki Saito,1 Kenta Ishii,1 Tatsuyuki Hayashi,1 Masakazu Yashiro,3 Kosei Hirakawa,3 Kohei Miyazono,2 Yasuki Kato,1 Mitsunobu R Kano21Research Division, NanoCarrier Co, Ltd, Chiba, Japan; 2Department of Molecular Pathology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan; 3Department of Surgical Oncology, Osaka City University, Osaka, JapanAbstract: Drug release rate is an important factor in determining efficacy and toxicity of nanoscale dru...

Environmental and Environmental-Health Implications of the USGS SAFRR California Tsunami Scenario

Science.gov (United States)

Plumlee, G. S.; Morman, S. A.; San Juan, C. A.

2013-12-01

The California Tsunami Scenario models the impacts of a hypothetical yet plausible tsunami caused by an earthquake offshore from the Alaskan Peninsula. Here, we interpret plausible tsunami-related contamination, environmental impacts, potential for human exposures to contaminants and hazardous materials, and implications for remediation and recovery. Inundation-related damages to major ports, boat yards, and many marinas could release complex debris, crude oil, various fuel types, other petroleum products, some liquid bulk cargo and dry bulk cargo, and diverse other pollutants into nearby coastal marine environments and onshore in the inundation zone. Tsunami-induced erosion of contaminated harbor bottom sediments could re-expose previously sequestered metal and organic pollutants (e.g., organotin, DDT). Inundation-related damage to many older buildings could produce complex debris containing lead paint, asbestos, pesticides, and other legacy contaminants. Intermingled household debris and externally derived debris and sediments would be left in flooded buildings. Post tsunami, mold would likely develop in inundated houses, buildings, and debris piles. Tsunamigenic fires in spilled oil, debris, cargo, vehicles, vegetation, and residential, commercial, or industrial buildings and their contents would produce potentially toxic gases and smoke, airborne ash, and residual ash/debris containing caustic alkali solids, metal toxicants, asbestos, and various organic toxicants. Inundation of and damage to wastewater treatment plants in many coastal cities could release raw sewage containing fecal solids, pathogens, and waste chemicals, as well as chemicals used to treat wastewaters. Tsunami-related physical damages, debris, and contamination could have short- and longer-term impacts on the environment and the health of coastal marine and terrestrial ecosystems. Marine habitats in intertidal zones, marshes, sloughs, and lagoons could be damaged by erosion or sedimentation

Toxicity of jet fuel aliphatic and aromatic hydrocarbon mixtures on human epidermal Keratinocytes: evaluation based on in vitro cytotoxicity and interleukin-8 release

Energy Technology Data Exchange (ETDEWEB)

Yang, Jen-Hung (Chung-Shan Medical University Hospital, Department of Dermatology, Taichung, Taiwan, R.O.C); Lee, Chia-Hue; Tsang, Chau-Loong [National Chung-Hsing University, College of Veterinary Medicine, Taichung (Taiwan); Monteiro-Riviere, Nancy A.; Riviere, Jim E. [North Carolina State University, Center for Chemical Toxicology Research and Pharmacokinetics (CCTRP), Raleigh, NC (United States); Chou, Chi-Chung [National Chung-Hsing University, College of Veterinary Medicine, Taichung (Taiwan); National Chung-Hsing University, College of Veterinary Medicine, Taichung (Taiwan)

2006-08-15

Jet fuels are complex mixtures of aliphatic (ALI) and aromatic (ARO) hydrocarbons that vary significantly in individual cytotoxicity and proinflammatory activity in human epidermal keratinocytes (HEK). In order to delineate the toxicological interactions among individual hydrocarbons in a mixture and their contributions to cutaneous toxicity, nine ALI and five ARO hydrocarbons were each divided into five (high/medium/low cytotoxic and strong/weak IL-8 induction) groups and intra/inter-mixed to assess for their mixture effects on HEK mortality and IL-8 release. Addition of single hydrocarbon to JP-8 fuel was also evaluated for their changes in fuel dermatotoxicity. The results indicated that when hydrocarbons were mixed, HEK mortality and IL-8 release were not all predictable by their individual ability affecting these two parameters. The lowest HEK mortality (7%) and the highest IL-8 production were induced with mixtures including high cytotoxic and weak IL-8 inductive ARO hydrocarbons. Antagonistic reactions not consistently correlated with ALI carbon chain length and ARO structure were evident and carried different weight in the overall mixture toxicities. Single addition of benzene, toluene, xylene or ethylbenzene for up to tenfold in JP-8 did not increase HEK mortality while single addition of ALI hydrocarbons exhibited dose-related differential response in IL-8. In an all ALI environment, no single hydrocarbon is the dominating factor in the determination of HEK cytotoxicity while deletion of hexadecane resulted in a 2.5-fold increase in IL-8 production. Overall, decane, undecane and dodecane were the major hydrocarbons associated with high cytotoxicity while tetradecane, pentadecane and hexadecane were those which had the greatest buffering effect attenuating dermatotoxicity. The mixture effects must be considered when evaluating jet fuel toxicity to HEK. (orig.)

Approach toward development of release standards for D and D cleanup

International Nuclear Information System (INIS)

Chen, S. Y.

1999-01-01

The release of materials containing residual radioactivity from a controlled environment in decontamination and decommissioning (D and D) activities has been problematic. The primary impediment to such a release is the lack of a suitable framework within which release standards can be developed. The concept of clearance for radioactive materials was recently introduced by the International Atomic Energy Agency (IAEA) (l). This concept is being evaluated by the international regulatory communities as a basis for setting standards for releasing from control solid materials containing residual radioactivity. Accordingly, both the IAEA (2) and the European Commission (EC) (3) have recently proposed clearance standards. In the US, the Nuclear Regulatory Commission (USNRC) has just begun its rule-making process on clearance. The term ''clearance'' was introduced as a regulatory process for releasing radioactive materials posing negligible risks. A trivial risk level has been determined to be a 10 -6 to 10 -7 annual risk to an exposed individual, and a population risk of no more than 0.1 for an annual practice. Under these strict constraints, exposure scenarios would be developed to estimate potential doses to affected individuals. Such scenarios may account for processing, disposal, and product end-use of materials. This paper discusses these scenarios and also describes the technical basis for deriving release levels under the suggested risk for dose constraints

Persistent toxic substances released from uncontrolled e-waste recycling and actions for the future.

Science.gov (United States)

Man, Ming; Naidu, Ravi; Wong, Ming H

2013-10-01

The Basel Convention on the Control of Transboundary Movement of Hazardous Wastes and their Disposal was adopted on March 22, 1989 and enforced on May 5, 1992. Since then, the USA, one of the world's largest e-waste producers, has not ratified this Convention or the Basel Ban Amendment. Communities are still debating the legal loophole, which permits the export of whole products to other countries provided it is not for recycling. In January 2011, China's WEEE Directive was implemented, providing stricter control over e-waste imports to China, including Hong Kong, while emphasizing that e-waste recycling is the producers' responsibility. China is expected to supersede the USA as the principal e-waste producer, by 2020, according to the UNEP. Uncontrolled e-waste recycling activities generate and release heavy metals and POPs into the environment, which may be re-distributed, bioaccumulated and biomagnified, with potentially adverse human health effects. Greater efforts and scientific approaches are needed for future e-product designs of minimal toxic metal and compound use, reaping greater benefits than debating the definition and handling responsibilities of e-waste recycling. Copyright © 2012 Elsevier B.V. All rights reserved.

Probabilistic consequence model of accidenal or intentional chemical releases.

Energy Technology Data Exchange (ETDEWEB)

Chang, Y.-S.; Samsa, M. E.; Folga, S. M.; Hartmann, H. M.

2008-06-02

In this work, general methodologies for evaluating the impacts of large-scale toxic chemical releases are proposed. The potential numbers of injuries and fatalities, the numbers of hospital beds, and the geographical areas rendered unusable during and some time after the occurrence and passage of a toxic plume are estimated on a probabilistic basis. To arrive at these estimates, historical accidental release data, maximum stored volumes, and meteorological data were used as inputs into the SLAB accidental chemical release model. Toxic gas footprints from the model were overlaid onto detailed population and hospital distribution data for a given region to estimate potential impacts. Output results are in the form of a generic statistical distribution of injuries and fatalities associated with specific toxic chemicals and regions of the United States. In addition, indoor hazards were estimated, so the model can provide contingency plans for either shelter-in-place or evacuation when an accident occurs. The stochastic distributions of injuries and fatalities are being used in a U.S. Department of Homeland Security-sponsored decision support system as source terms for a Monte Carlo simulation that evaluates potential measures for mitigating terrorist threats. This information can also be used to support the formulation of evacuation plans and to estimate damage and cleanup costs.

Analysis of accidental UF6 releases

International Nuclear Information System (INIS)

Fan Yumao; Tan Rui; Gao Qifa

2012-01-01

As interim substance in the nuclear fuel enrichment process, Uranium Hexafluoride (UF 6 ) is widely applied in nuclear processing, enrichment and fuel fabrication plants. Because of its vivid chemical characteristics and special radiological hazard and chemical toxicity, great attention must be paid to accident of UF 6 leakage. The chemical reactions involved in UF 6 release processes were introduced, therewith potential release styles, pathways and characteristics of diffusion were analyzed. The results indicated that the accidental release process of UF 6 is not a simple passive diffusion. So, specific atmospheric diffusion model related to UF 6 releases need be used in order to analyze and evaluate accurately the accidental consequences. (authors)

Methodology of external exposure calculation for reuse of conditional released materials from decommissioning - 59138

International Nuclear Information System (INIS)

Ondra, Frantisek; Vasko, Marek; Necas, Vladimir

2012-01-01

The article presents methodology of external exposure calculation for reuse of conditional released materials from decommissioning using VISIPLAN 3D ALARA planning tool. Production of rails has been used as an example application of proposed methodology within the CONRELMAT project. The article presents a methodology for determination of radiological, material, organizational and other conditions for conditionally released materials reuse to ensure that workers and public exposure does not breach the exposure limits during scenario's life cycle (preparation, construction and operation of scenario). The methodology comprises a proposal of following conditions in the view of workers and public exposure: - radionuclide limit concentration of conditionally released materials for specific scenarios and nuclide vectors, - specific deployment of conditionally released materials eventually shielding materials, workers and public during the scenario's life cycle, - organizational measures concerning time of workers or public stay in the vicinity on conditionally released materials for individual performed scenarios and nuclide vectors. The above mentioned steps of proposed methodology have been applied within the CONRELMAT project. Exposure evaluation of workers for rail production is introduced in the article as an example of this application. Exposure calculation using VISIPLAN 3D ALARA planning tool was done within several models. The most exposed profession for scenario was identified. On the basis of this result, an increase of radionuclide concentration in conditional released material was proposed more than two times to 681 Bq/kg without no additional safety or organizational measures being applied. After application of proposed safety and organizational measures (additional shielding, geometry changes and limitation of work duration) it is possible to increase concentration of radionuclide in conditional released material more than ten times to 3092 Bq/kg. Storage

Scenario evolution: Interaction between event tree construction and numerical analyses

International Nuclear Information System (INIS)

Barr, G.E.; Barnard, R.W.; Dockery, H.A.; Dunn, E.; MacIntyre, A.T.

1991-01-01

Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Even tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, we discuss the iterations used to develop numerical analyses for PACE-90 using basaltic igneous activity and human-intrusion event trees

Potential release scenario and radiological consequence evaluation of mineral resources at WIPP

International Nuclear Information System (INIS)

Little, M.S.

1982-05-01

This report has reviewed certain of the natural resources which may be found at the site of the nuclear waste repository being considered for southeastern New Mexico, and discussed the scenarios which have been used to estimate the radiological consequences from the mining of these resources several hundred years after the radioactive waste has been emplaced. It has been concluded that the radiological consequences of the mining of potash or hydrocarbons (mostly natural gas) are probably bounded by the consequences of hydrologic breach scenarios already considered by the US Department of Energy, and by reports of EEG. These studies conclude that the resultant doses would not constitute a significant threat to public health. This report also evaluates the radiological consequences of solution mining of halite at the WIPP site. Although such mining in the Delaware Basin and particularly at the WIPP site, is not likely at the present time, significant economic, social or climatic changes a few hundred years after emplacement may make these resources more attractive. The DOE did not consider such mining at the site credible

Comparison of Acute Toxicity of Algal Metabolites Using Bioluminescence Inhibition Assay

Directory of Open Access Journals (Sweden)

Hansa Jeswani

2015-01-01

Full Text Available Microalgae are reported to degrade hazardous compounds. However, algae, especially cyanobacteria are known to produce secondary metabolites which may be toxic to flora, fauna and human beings. The aim of this study was selection of an appropriate algal culture for biological treatment of biomass gasification wastewater based on acute toxicity considerations. The three algae that were selected were Spirulina sp., Scenedesmus abundans and a fresh water algal consortium. Acute toxicity of the metabolites produced by these algal cultures was tested at the end of log phase using the standard bioluminescence inhibition assay based on Vibrio fischeri NRRLB 11174. Scenedesmus abundans and a fresh water algal consortium dominated by cyanobacteria such as Phormidium, Chroococcus and Oscillatoria did not release much toxic metabolites at the end of log phase and caused only about 20% inhibition in bioluminescence. In comparison, Spirulina sp. released toxic metabolites and caused 50% bioluminescence inhibition at 3/5 times dilution of the culture supernatant (EC50.

TOXICITY TESTING IN THE 21ST CENTURY: A VISION AND A STRATEGY

DEFF Research Database (Denmark)

Krewski, D.; Acosta, D.; Andersen, M.

2010-01-01

With the release of the landmark report Toxicity Testing in the 21st Century: A Vision and a Strategy, the U. S. National Academy of Sciences, in 2007, precipitated a major change in the way toxicity testing is conducted. It envisions increased efficiency in toxicity testing and decreased animal ...

TOXIC LEADERSHIP: A SYSTEMIC APPROACH TO SHIFT FROM REACTIVE TO PROACTIVE SOLUTIONS

Science.gov (United States)

2017-03-01

AIR COMMAND AND STAFF COLLEGE AIR UNIVERSITY TOXIC LEADERSHIP: A SYSTEMIC APPROACH TO SHIFT FROM REACTIVE TO PROACTIVE SOLUTIONS...DISTRIBUTION A. Approved for public release: distribution unlimited. Toxic Leadership: A Systemic Approach to Shift From Reactive to Proactive Solutions 1...US military loses valuable personnel when it is too late to implement corrective action and after those toxic Toxic Leadership: A Systemic Approach

Development of nuclear spent fuel Maritime transportation scenario

International Nuclear Information System (INIS)

Yoo, Min; Kang, Hyun Gook

2014-01-01

Spent fuel transportation of South Korea is to be conducted through near sea because it is able to ship a large amount of the spent fuel far from the public comparing to overland transportation. The maritime transportation is expected to be increased and its risk has to be assessed. For the risk assessment, this study utilizes the probabilistic safety assessment (PSA) method and the notions of the combined event. Risk assessment of maritime transportation of spent fuel is not well developed in comparison with overland transportation. For the assessment, first, the transportation scenario should be developed and categorized. Categories are assorted into the locations, release aspects and exposure aspects. This study deals with accident that happens on voyage and concentrated on ship-ship collision. The collision accident scenario is generated with event tree analysis. The scenario will be exploited for the maritime transportation risk model which includes consequence and accident probability

Development of nuclear spent fuel Maritime transportation scenario

Energy Technology Data Exchange (ETDEWEB)

Yoo, Min; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

2014-08-15

Spent fuel transportation of South Korea is to be conducted through near sea because it is able to ship a large amount of the spent fuel far from the public comparing to overland transportation. The maritime transportation is expected to be increased and its risk has to be assessed. For the risk assessment, this study utilizes the probabilistic safety assessment (PSA) method and the notions of the combined event. Risk assessment of maritime transportation of spent fuel is not well developed in comparison with overland transportation. For the assessment, first, the transportation scenario should be developed and categorized. Categories are assorted into the locations, release aspects and exposure aspects. This study deals with accident that happens on voyage and concentrated on ship-ship collision. The collision accident scenario is generated with event tree analysis. The scenario will be exploited for the maritime transportation risk model which includes consequence and accident probability.

Impacts of select organic ligands on the colloidal stability, dissolution dynamics, and toxicity of silver nanoparticles.

Science.gov (United States)

Pokhrel, Lok R; Dubey, Brajesh; Scheuerman, Phillip R

2013-11-19

Key understanding of potential transformations that may occur on silver nanoparticle (AgNP) surface upon interaction with naturally ubiquitous organic ligands (e.g., -SH (thoil), humic acid, or -COO (carboxylate)) is limited. Herein we investigated how dissolved organic carbon (DOC), -SH (in cysteine, a well-known Ag(+) chelating agent), and -COO (in trolox, a well-known antioxidant) could alter the colloidal stability, dissolution rate, and toxicity of citrate-functionalized AgNPs (citrate-AgNPs) against a keystone crustacean Daphnia magna. Cysteine, DOC, or trolox amendment of citrate-AgNPs differentially modified particle size, surface properties (charge, plasmonic spectra), and ion release dynamics, thereby attenuating (with cysteine or trolox) or promoting (with DOC) AgNP toxicity. Except with DOC amendment, the combined toxicity of AgNPs and released Ag under cysteine or trolox amendment was lower than of AgNO3 alone. The results of this study show that citrate-AgNP toxicity can be associated with oxidative stress, ion release, and the organism biology. Our evidence suggests that specific organic ligands available in the receiving waters can differentially surface modify AgNPs and alter their environmental persistence (changing dissolution dynamics) and subsequently the toxicity; hence, we caveat to generalize that surface modified nanoparticles upon environmental release may not be toxic to receptor organisms.

Impaired ecosystem process despite little effects on populations: modeling combined effects of warming and toxicants.

Science.gov (United States)

Galic, Nika; Grimm, Volker; Forbes, Valery E

2017-08-01

Freshwater ecosystems are exposed to many stressors, including toxic chemicals and global warming, which can impair, separately or in combination, important processes in organisms and hence higher levels of organization. Investigating combined effects of warming and toxicants has been a topic of little research, but neglecting their combined effects may seriously misguide management efforts. To explore how toxic chemicals and warming, alone and in combination, propagate across levels of biological organization, including a key ecosystem process, we developed an individual-based model (IBM) of a freshwater amphipod detritivore, Gammarus pseudolimnaeus, feeding on leaf litter. In this IBM, life history emerges from the individuals' energy budgets. We quantified, in different warming scenarios (+1-+4 °C), the effects of hypothetical toxicants on suborganismal processes, including feeding, somatic and maturity maintenance, growth, and reproduction. Warming reduced mean adult body sizes and population abundance and biomass, but only in the warmest scenarios. Leaf litter processing, a key contributor to ecosystem functioning and service delivery in streams, was consistently enhanced by warming, through strengthened interaction between the detritivorous consumer and its resource. Toxicant effects on feeding and maintenance resulted in initially small adverse effects on consumers, but ultimately led to population extinction and loss of ecosystem process. Warming in combination with toxicants had little effect at the individual and population levels, but ecosystem process was impaired in the warmer scenarios. Our results suggest that exposure to the same amount of toxicants can disproportionately compromise ecosystem processing depending on global warming scenarios; for example, reducing organismal feeding rates by 50% will reduce resource processing by 50% in current temperature conditions, but by up to 200% with warming of 4 °C. Our study has implications for

Scenario evolution: Interaction between event tree construction and numerical analyses

International Nuclear Information System (INIS)

Barr, G.E.; Barnard, R.W.; Dockery, H.A.; Dunn, E.; MacIntyre, A.T.

1990-01-01

Construction of well-posed scenarios for the range of conditions possible at any proposed repository site is a critical first step to assessing total system performance. Event tree construction is the method that is being used to develop potential failure scenarios for the proposed nuclear waste repository at Yucca Mountain. An event tree begins with an initial event or condition. Subsequent events are listed in a sequence, leading eventually to release of radionuclides to the accessible environment. Ensuring the validity of the scenarios requires iteration between problems constructed using scenarios contained in the event tree sequence, experimental results, and numerical analyses. Details not adequately captured within the tree initially may become more apparent as a result of analyses. To illustrate this process, the authors discuss the iterations used to develop numerical analyses for PACE-90 (Performance Assessment Calculational Exercises) using basaltic igneous activity and human-intrusion event trees

Weather scenarios for dose calculations with incomplete meteorological data. V.IV

International Nuclear Information System (INIS)

Alp, E.; Lam, L.H.; Moran, M.D.

1985-09-01

This report documents a study to substantiate or modify the weather scenarios proposed by the Atomic Energy Control Board Staff Position Paper on meteorological acceptance criteria for estimating the potential radiological consequences of postulated accidents (AECB, 1982) for short-, prolonged-, and long-term releases from ground level and elevated sources. The study examined available meteorological data in Canada to determine whether the AECB-proposed scenarios are sufficiently general that they are appropriate and conservative for any potential nuclear power plant in Canada, but also realistic, i.e., not so conservative that the results of dose calculations using these scenarios would be wholly unrepresentative leading to incorrect design decisions. Three different sets of scenarios were derived using three site-specific data sets from weather stations that are representative of existing nuclear power plants in Canada. When compared, the scenarios for the three sites are not significantly different from each other, especially in terms of trends, considering that they have been based on data from widely differing meteorological regions in Canada. Conservative envelopes of the scenarios for the three sites were taken to give the recommended general weather scenario set. The recommended set was then compared with the AECB proposed scenarios. The recommended scenarios are, in general, conservative

Maximum forseeable accident analysis made by a sodium leak on the BN-800 primary circuit and the more constraining accident development scenario

International Nuclear Information System (INIS)

Ivanenko, V.N.; Zybin, V.A.

1988-01-01

In this paper the different ways of development for the BN-800 maximum credible accident in case of loss and fire of primary sodium are examined. The more constraining scenario is presented. During the scenario analysis the accidental release of radioactive materials in the environment has been studied. These releases are below the authorized values [fr

Modulatory effects of Zn2+ ions on the toxicity of citrate- and PVP-capped gold nanoparticles towards freshwater algae, Scenedesmus obliquus.

Science.gov (United States)

Iswarya, V; Johnson, J B; Parashar, Abhinav; Pulimi, Mrudula; Chandrasekaran, N; Mukherjee, Amitava

2017-02-01

Gold nanoparticles (GNPs) are widely used for medical purposes, both in diagnostics as well as drug delivery, and hence are prone to release and distribution in the environment. Thus, we have explored the effects of GNPs with two distinct surface capping (citrate and PVP), and three different sizes (16, 27, and 37 nm) at 0.01-, 0.1-, and 1-mg L -1 concentrations on a predominant freshwater alga Scenedesmus obliquus in the sterile freshwater matrix. We have also investigated how an abundant metal ion from freshwater, i.e., Zn 2+ ions may modulate the effects of the selected GNPs (40 nm, citrate, and PVP capped). Preliminary toxicity results revealed that gold nanoparticles were highly toxic in comparison to zinc ions alone. A significant modulation in the toxicity of Zn ions was not noticed in the presence of GNPs. In contrast, zinc ions minimized the toxicity produced by GNPs (both CIT-37 and PVP-37), despite its individual toxicity. Approximately, about 42, 33, and 25% toxicity reduction was noted at 0.05-, 0.5-, and 5-mg L -1 Zn ions, respectively, for CIT-37 GNPs, while 31% (0.05 mg L -1 ), 24% (0.5 mg L -1 ), and 9% (5 mg L -1 ) of toxicity reduction were noted for PVP-37 GNPs. Maximum toxicity reduction was seen at 0.05 mg L -1 of Zn ions. Abbott modeling substantiated antagonistic effects offered by Zn 2+ ions on GNPs. Stability and sedimentation data revealed that the addition of zinc ions gradually induced the aggregation of NPs and in turn significantly reduced the toxicity of GNPs. Thus, the naturally existing ions like Zn 2+ have an ability to modulate the toxicity of GNPs in a real-world environment scenario.

Toxicity and management in CAR T-cell therapy

Directory of Open Access Journals (Sweden)

Challice L Bonifant

2016-01-01

Full Text Available T cells can be genetically modified to target tumors through the expression of a chimeric antigen receptor (CAR. Most notably, CAR T cells have demonstrated clinical efficacy in hematologic malignancies with more modest responses when targeting solid tumors. However, CAR T cells also have the capacity to elicit expected and unexpected toxicities including: cytokine release syndrome, neurologic toxicity, “on target/off tumor” recognition, and anaphylaxis. Theoretical toxicities including clonal expansion secondary to insertional oncogenesis, graft versus host disease, and off-target antigen recognition have not been clinically evident. Abrogating toxicity has become a critical step in the successful application of this emerging technology. To this end, we review the reported and theoretical toxicities of CAR T cells and their management.

Scenarios for the assessment of urban exposures after radioactive contamination

International Nuclear Information System (INIS)

Silva, D.N.G.; Guimarães, J.R.D.; Rochedo, E.R.R.

2015-01-01

Accidents involving radioactive material are not frequent but may include releases of radionuclides to the air, land or waterways. These releases are usually uncontrollable and may lead to doses in the public in excess of the reference levels established by regulations defined by the national regulatory agencies of each country. Although they had occurred sporadically since the last century, it was observed that, after the emergency phase, the public concern is enhanced when they feel that there is an unpreparedness of authorities responsible for remediation actions, due to the lack of definition of strategies to be adopted in the long term after such events. The aim of this work is to describe reference urban scenarios, considering the characteristics observed in residential and free access areas of urban centers. These scenarios were developed based on the counties surrounding the Brazilian nuclear power plant. Considering the counties within 50 km from the nuclear power plant, nine belong to the state of Rio de Janeiro and seven belong to São Paulo state; the highest population densities were observed in five counties of Rio de Janeiro. Based on the different types of residences and outdoor areas observed in these 16 counties, six reference scenarios for urban areas were developed including areas comprised by four types of residential houses (with low, medium and high shielding building material and houses in a row), apartments in buildings, and park areas with lawn and trees. The characteristics of each of these scenarios were raised through Google Earth images considering 1 km 2 of different locations comprised by each type of area defined. In a next step, the information obtained in each scenario shall be used in computer simulations to characterize the effects and consequences on public exposure of the application of decontamination procedures. (authors)

Cooling methods of station blackout scenario for LWR plants

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

The objective of this study is to analyze the cooling method of station blackout scenario for both the BWR and PWR plants by RELAP5 code and to check the validity of the cooling method proposed by the utilities. In the BWR plant cooling scenario, the Reactor Core Isolation Cooling System (RCIC), which is operated with high pressure steam from the reactor, injects cooling water into the reactor to keep the core water level. The steam generated in the core is released into the suppression pool at containment vessel to condense. To restrict the containment vessel pressure rising, the ventilation from the wet-well is operated. The scenario is analyzed by RELAP5 code. In the PWR plant scenario, the primary pressure is decreased by the turbine-driven auxiliary feed water system operated with secondary side steam of the steam generators (SGs). And the core cooling is kept by the natural circulation flow at the primary loop. From the RELAP5 code analysis, it was shown that the primary system cooling was practicable by using the turbine-driven auxiliary feed water system. (author)

Cooling methods of station blackout scenario for LWR plants

International Nuclear Information System (INIS)

2012-01-01

The objective of this study is to analyze the cooling method of station blackout scenario for both the BWR and PWR plants by RELAP5 code and to check the validity of the cooling method proposed by the utilities. In the BWR plant cooling scenario, the Reactor Core Isolation Cooling System (RCIC), which is operated with high pressure steam from the reactor, injects cooling water into the reactor to keep the core water level. The steam generated in the core is released into the suppression pool at containment vessel to condense. To restrict the containment vessel pressure rising, the ventilation from the wet-well is operated. The scenario is analyzed by RELAP5 and CONTEMPT-LT code. In the PWR plant scenario, the primary pressure is decreased by the turbine-driven auxiliary feed water system operated with secondary side steam of the steam generators (SGs). And the core cooling is kept by the natural circulation flow at the primary loop. The analytical method of un-uniform flow behavior among the SG U-tubes, which affects the natural circulation flow rate, is developed. (author)

Relocation impacts of a major release from SRTC

International Nuclear Information System (INIS)

Blanchard, A.; Thompson, E.A.; Thompson, J.M.

1999-01-01

The relocation impacts of an accidental release, scenario 1-RD-3 , are evaluated for the Savannah River Technology Center. The extent of the area potentially contaminated to a level that would result in doses exceeding the relocation protective action guide(PAG)is calculated. The maximum calculated distance downwind from the accident at which the relocation PAG is exceeded is also determined. The consequences of the particulate portion of the release are evaluated using the HOTSPOT model and an EXCEL spreadsheet. The consequences of the tritium release are evaluated using UFOTRI

Application of the HGSYSTEM/UF6 model to simulate atmospheric dispersion of UF6 releases from uranium enrichment plants

International Nuclear Information System (INIS)

Goode, W.D. Jr.; Bloom, S.G.; Keith, K.D. Jr.

1995-01-01

Uranium hexafluoride is a dense, reactive gas used in Gaseous Diffusion Plants (GDPs) to make uranium enriched in the 235 U isotope. Large quantities of UF 6 exist at the GDPs in the form of in-process gas and as a solid in storage cylinders; smaller amounts exist as hot liquid during transfer operations. If liquid UF 6 is released to the environment, it immediately flashes to a solid and a dense gas that reacts rapidly with water vapor in the air to form solid particles of uranyl fluoride and hydrogen fluoride gas. Preliminary analyses were done on various accidental release scenarios to determine which scenarios must be considered in the safety analyses for the GDPS. These scenarios included gas releases due to failure of process equipment and liquid/gas releases resulting from a breach of transfer piping from a cylinder. A major goal of the calculations was to estimate the response time for mitigating actions in order to limit potential off-site consequences of these postulated releases. The HGSYSTEM/UF 6 code was used to assess the consequences of these release scenarios. Inputs were developed from release calculations which included two-phase, choked flow followed by expansion to atmospheric pressure. Adjustments were made to account for variable release rates and multiple release points. Superpositioning of outputs and adjustments for exposure time were required to evaluate consequences based on health effects due to exposures to uranium and HF at a specific location

Toxicity of tire wear particle leachate to the marine macroalga, Ulva lactuca

Energy Technology Data Exchange (ETDEWEB)

Turner, Andrew, E-mail: aturner@plymouth.ac.u [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Rice, Lynsey [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

2010-12-15

Tire wear particles filed from the treads of end-of-life vehicle tires have been added to sea water to examine the release of Zn and the toxicity of the resulting leachate and dilutions thereof to the marine macroalga, Ulva lactuca. Zinc release appeared to be diffusion-controlled, with a conditional rate constant of 5.4 {mu}g[L(h){sup 1/2}]{sup -1}, and about 1.6% of total Zn was released after 120 h incubation. Exposure to increasing concentrations of leachate resulted in a non-linear reduction in the efficiency of photochemical energy conversion of U. lactuca and, with the exception of the undiluted leachate, increasing accumulation of Zn. Phototoxicity was significantly lower on exposure to equivalent concentrations of Zn added as Zn(NO{sub 3}){sub 2}, suggesting that organic components of leachate are largely responsible for the overall toxicity to the alga. Given the ubiquity and abundance of TWP in urban coastal sediments, the generation, biogeochemistry and toxicity of tire leachate in the marine setting merit further attention. - Tire wear leachate is toxic to Ulva lactuca and zinc is a potential bioindicator of leachate contamination in urban marine systems.

Safety barriers on oil and gas platforms. Means to prevent hydrocarbon releases

Energy Technology Data Exchange (ETDEWEB)

Sklet, Snorre

2005-12-15

The main objective of the PhD project has been to develop concepts and methods that can be used to define, illustrate, analyse, and improve safety barriers in the operational phase of offshore oil and gas production platforms. The main contributions of this thesis are; Clarification of the term safety barrier with respect to definitions, classification, and relevant attributes for analysis of barrier performance Development and discussion of a representative set of hydrocarbon release scenarios Development and testing of a new method, BORA-Release, for qualitative and quantitative risk analysis of hydrocarbon releases Safety barriers are defined as physical and/or non-physical means planned to prevent, control, or mitigate undesired events or accidents. The means may range from a single technical unit or human actions, to a complex socio-technical system. It is useful to distinguish between barrier functions and barrier systems. Barrier functions describe the purpose of safety barriers or what the safety barriers shall do in order to prevent, control, or mitigate undesired events or accidents. Barrier systems describe how a barrier function is realized or executed. If the barrier system is functioning, the barrier function is performed. If a barrier function is performed successfully, it should have a direct and significant effect on the occurrence and/or consequences of an undesired event or accident. It is recommended to address the following attributes to characterize the performance of safety barriers; a) functionality/effectiveness, b) reliability/ availability, c) response time, d) robustness, and e) triggering event or condition. For some types of barriers, not all the attributes are relevant or necessary in order to describe the barrier performance. The presented hydrocarbon release scenarios include initiating events, barrier functions introduced to prevent hydrocarbon releases, and barrier systems realizing the barrier functions. Both technical and human

Role of Bioadsorbents in Reducing Toxic Metals

OpenAIRE

Mathew, Blessy Baby; Jaishankar, Monisha; Biju, Vinai George; Krishnamurthy Nideghatta Beeregowda

2016-01-01

Industrialization and urbanization have led to the release of increasing amounts of heavy metals into the environment. Metal ion contamination of drinking water and waste water is a serious ongoing problem especially with high toxic metals such as lead and cadmium and less toxic metals such as copper and zinc. Several biological materials have attracted many researchers and scientists as they offer both cheap and effective removal of heavy metals from waste water. Therefore it is urgent to st...

Zippered release from polymer-gated carbon nanotubes

KAUST Repository

Mashat, Afnan

2012-01-01

A thermosensitive drug delivery system based on polymer-gated carbon nanotubes (CNTs) that are loaded with the anticancer drug doxorubicin (DOX) is herein reported. The development of carbon nanotubes for various biomedical applications is the research focus of many research groups and holds great promise. The major drawback of these materials is the toxicity that is associated with conjugated carbon systems. Functionalization of CNTs with polymers has proved very successful in lowering the toxicity and improving the pharmacokinetic profile. In this work, CNTs are coated with polyethylenimine (PEI) and polyvinyl alcohol (PVA) via the "zipper effect" that provides both support and control over drug release. PEI/PVA provides excellent support to increase DOX loading on the nanocarrier. The system is controlled by changes in temperature due to the complexation (low temperature) and decomplexation (high temperature) of PEI and PVA via hydrogen bonding. The release of DOX was tested in three cell lines (Lung fibroblast (LF), Breast Adenocarcinoma (BA), and HeLa). It was further tested in primary cell lines (Human Dermal Fibroblast adult (HDFa) and Human Dermal Fibroblast neonatal (HDFn)). When the bonds between PEI and PVA are decomplexed at high temperature (≥40 °C), drug release was observed as verified by fluorescence microscopy. There was no drug release at room temperature (25 °C) and a slow release at normal body temperature (37 °C). This system represents a promising method for incorporating stimuli triggered polymer-gated CNTs in future controlled release applications. © 2012 The Royal Society of Chemistry.

Environmental hazards due to rupture of a liquefied propane pipeline

International Nuclear Information System (INIS)

Badr, O.A.; El-Sheikh, H.A.

1996-01-01

Accidental leakages of liquefied propane from high-pressure pipelines may occur despite the use of sophisticated safety equipment and following strict monitoring procedures. Environmental impact of steady and transient leakages were considered from toxicity and flammability viewpoints for two specific scenarios of full pipe ruptures. For each case, calculated mass flow rate, velocity, and temperature of leaking gas were utilized in an EPA-based dispersion model to predict the ground level concentration profiles in the downwind and crosswind directions. For the specific pipeline conditions considered here, the first scenario of a nonjet release (a cloud) produced steady toxic and flammable zones which were about 20 times bigger than those produced in the transient case. The second scenario of a free vertical jet resulted in the formation of a flammable vertical plume, while at ground level it did not produce flammable nor toxic zones. A parametric study of the first scenario confirmed the expected effects of both the gas release time and the atmospheric stability on the size of the dangerous zones. Within the typical range, the wind speed was found to have opposite effects for steady and transient releases. For a steady release, the dangerous zone was wider for slower winds and vice versa for a transient case. Moreover, the size of the dangerous zone was found to be an exponential function of the pipe diameter, while the effect of the initial pipe pressure was insignificant

Sensitivity of the global submarine hydrate inventory to scenarios of future climate change

Science.gov (United States)

Hunter, S. J.; Goldobin, D. S.; Haywood, A. M.; Ridgwell, A.; Rees, J. G.

2013-04-01

The global submarine inventory of methane hydrate is thought to be considerable. The stability of marine hydrates is sensitive to changes in temperature and pressure and once destabilised, hydrates release methane into sediments and ocean and potentially into the atmosphere, creating a positive feedback with climate change. Here we present results from a multi-model study investigating how the methane hydrate inventory dynamically responds to different scenarios of future climate and sea level change. The results indicate that a warming-induced reduction is dominant even when assuming rather extreme rates of sea level rise (up to 20 mm yr-1) under moderate warming scenarios (RCP 4.5). Over the next century modelled hydrate dissociation is focussed in the top ˜100m of Arctic and Subarctic sediments beneath business-as-usual scenario (RCP 8.5), upper estimates of resulting global sea-floor methane fluxes could exceed estimates of natural global fluxes by 2100 (>30-50TgCH4yr-1), although subsequent oxidation in the water column could reduce peak atmospheric release rates to 0.75-1.4 Tg CH4 yr-1.

Control of accidental releases of hydrogen selenide in vented storage cabinets

Science.gov (United States)

Fthenakis, V. M.; Moskowitz, P. D.; Sproull, R. D.

1988-07-01

Highly toxic hydrogen selenide and hydrogen sulfide gases are used in the production of copper-indium-diselenide photovoltaic cells by reactive sputtering. In the event of an accident, these gases may be released to the atmosphere and pose hazards to public and occupational safety and health. This paper outlines an approach for designing systems for the control of these releases given the uncertainty in release conditions and lack of data on the chemical systems involved. Accidental releases of these gases in storage cabinets can be controlled by either a venturi and packed-bed scrubber and carbon adsorption bed, or containment scrubbing equipment followed by carbon adsorption. These systems can effectively reduce toxic gas emissions to levels needed to protect public health. The costs of these controls (˜0.012/Wp) are samll in comparison with current (˜6/Wp) and projected (˜I/Wp) production costs.

LTE UE Energy Saving by Applying Carrier Aggregation in a HetNet Scenario

DEFF Research Database (Denmark)

Lauridsen, Mads; Wang, Hua; Mogensen, Preben

2013-01-01

In this work it is examined if downlink Carrier Aggregation (CA) can be used to save UE energy. A dual-receiver LTE release 10 UE is compared with a single-receiver LTE release 8 UE. The models are based on scaling of an existing LTE release 8 UE power model. The energy consumption of the UEs...... is examined in a Heterogeneous Network scenario consisting of macro and small cells. The unexpected conclusion is that CA UEs can save energy, compared to LTE release 8 UEs, if they, depending on cell load, experience a throughput gain of 20%. However if the UE throughput is unaltered the energy consumption...

Center for Integrated Nanotechnologies (CINT) Chemical Release Modeling Evaluation

Energy Technology Data Exchange (ETDEWEB)

Stirrup, Timothy Scott [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-12-20

This evaluation documents the methodology and results of chemical release modeling for operations at Building 518, Center for Integrated Nanotechnologies (CINT) Core Facility. This evaluation is intended to supplement an update to the CINT [Standalone] Hazards Analysis (SHA). This evaluation also updates the original [Design] Hazards Analysis (DHA) completed in 2003 during the design and construction of the facility; since the original DHA, additional toxic materials have been evaluated and modeled to confirm the continued low hazard classification of the CINT facility and operations. This evaluation addresses the potential catastrophic release of the current inventory of toxic chemicals at Building 518 based on a standard query in the Chemical Information System (CIS).

OSCAAR calculations for the Hanford dose reconstruction scenario of BIOMASS Theme 2

International Nuclear Information System (INIS)

Homma, Toshimitsu; Tomita, Kenichi

2000-10-01

This report presents the results obtained from the application of the accident consequence assessment code, called OSCAAR, developed in Japan Atomic Energy Research Institute to the Hanford dose reconstruction scenario of BIOMASS Theme 2 organized by International Atomic Energy Agency. The scenario relates to an inadvertent release of 131 I to atmosphere from the Hanford Purex Chemical Separations Plant on 2-5 September 1963. This exercise was used to test the atmospheric dispersion and deposition models and food chain transport models for 131 I in OSCAAR with actual measurements and to identify the most important sources of uncertainty with respect both to the part of the assessment and to the overall assessment. The OSCAAR food chain model performed relatively well, while the atmospheric dispersion and deposition calculations made using wind data at the release height and wind fields by simple interpolation of the surrounding surface wind data indicated limited capabilities. The Monte Carlo based uncertainty and sensitivity method linked with OSCAAR successfully demonstrated its usefulness in the scenario. The method presented here also allowed the determination of the parameters that have the most important impact in accident consequence assessments. (author)

OSCAAR calculations for the Hanford dose reconstruction scenario of BIOMASS Theme 2

Energy Technology Data Exchange (ETDEWEB)

Homma, Toshimitsu; Tomita, Kenichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Inoue, Yoshihisa [Visible Information Center Inc., Tokai, Ibaraki (Japan)

2000-10-01

This report presents the results obtained from the application of the accident consequence assessment code, called OSCAAR, developed in Japan Atomic Energy Research Institute to the Hanford dose reconstruction scenario of BIOMASS Theme 2 organized by International Atomic Energy Agency. The scenario relates to an inadvertent release of {sup 131}I to atmosphere from the Hanford Purex Chemical Separations Plant on 2-5 September 1963. This exercise was used to test the atmospheric dispersion and deposition models and food chain transport models for {sup 131}I in OSCAAR with actual measurements and to identify the most important sources of uncertainty with respect both to the part of the assessment and to the overall assessment. The OSCAAR food chain model performed relatively well, while the atmospheric dispersion and deposition calculations made using wind data at the release height and wind fields by simple interpolation of the surrounding surface wind data indicated limited capabilities. The Monte Carlo based uncertainty and sensitivity method linked with OSCAAR successfully demonstrated its usefulness in the scenario. The method presented here also allowed the determination of the parameters that have the most important impact in accident consequence assessments. (author)

A Risk Assessment Model for Water Resources: releases of dangerous and hazardous substances.

Science.gov (United States)

Rebelo, Anabela; Ferra, Isabel; Gonçalves, Isolina; Marques, Albertina M

2014-07-01

Many dangerous and hazardous substances are used, transported and handled daily in diverse situations, from domestic use to industrial processing, and during those operations, spills or other anomalous situations may occur that can lead to contaminant releases followed by contamination of surface water or groundwater through direct or indirect pathways. When dealing with this problem, rapid, technically sound decisions are desirable, and the use of complex methods may not be able to deliver information quickly. This work describes a simple conceptual model established on multi-criteria based analysis involving a strategic appraisal for contamination risk assessment to support local authorities on rapid technical decisions. The model involves a screening for environmental risk sources, focussing on persistent, bioaccumulative and toxic (PBT) substances that may be discharged into water resources. It is a simple tool that can be used to follow-up actual accident scenarios in real time and to support daily activities, such as site-inspections. Copyright © 2014 Elsevier Ltd. All rights reserved.

Defining Moments in MMWR History: Toxic-Shock Syndrome -- 1980

Centers for Disease Control (CDC) Podcasts

2017-11-03

In the late 1970s and early 1980s, an outbreak of a disease called Toxic Shock Syndrome made healthy women sick. CDC’s disease detectives helped unravel the link between Toxic Shock Syndrome and high-absorbency tampons. MMWR was the first scientific publication to break the news of these cases. In this podcast, Dr. Kathy Shands, former chief of CDC’s Toxic Shock Syndrome Task Force, recalls her experience working with state epidemiologists to identify the link between toxic shock syndrome and tampon use.  Created: 11/3/2017 by MMWR.   Date Released: 11/3/2017.

Trichothecenes: structure-toxic activity relationships.

Science.gov (United States)

Wu, Qinghua; Dohnal, Vlastimil; Kuca, Kamil; Yuan, Zonghui

2013-07-01

Trichothecenes comprise a large family of structurally related toxins mainly produced by fungi belonging to the genus Fusarium. Among trichothecenes, type A and type B are of the most concern due to their broad and highly toxic nature. In order to address structure-activity relationships (SAR) of trichothecenes, relationships between structural features and biological effects of trichothecene mycotoxins in mammalian systems are summarized in this paper. The double bond between C-9-C-10 and the 12,13-epoxide ring are essential structural features for trichothecene toxicity. Removal of these groups results in a complete loss of toxicity. A hydroxyl group at C-3 enhances trichothecene toxicity, while this activity decreases gradually when C-3 is substituted with either hydrogen or an acetoxy group. The presence of a hydroxyl group at C-4 promotes slightly lower toxicity than an acetoxy group at the same position. The toxicity for type B trichothecenes decreases if the substituent at C-4 is changed from acetoxy to hydroxyl or hydrogen at C-4 position. The presence of hydroxyl and hydrogen groups on C-15 decreases the trichothecene toxicity in comparison with an acetoxy group attached to this carbon. Trichothecenes toxicity increases when a macrocyclic ring exists between the C-4 and C-15. At C-8 position, an oxygenated substitution at C-8 is essential for trichothecene toxicity, indicating a decrease in the toxicity if substituent change from isovaleryloxy through hydrogen to the hydroxyl group. The presence of a second epoxy ring at C-7-C-8 reduces the toxicity, whereas epoxidation at C-9-C-10 of some macrocyclic trichothecenes increases the activity. Conjugated trichothecenes could release their toxic precursors after hydrolysis in animals, and present an additional potential risk. The SAR study of trichothecenes should provide some crucial information for a better understanding of trichothecene chemical and biological properties in food contamination.

European Union regulators and industry agree on improving specific environmental release categories: Report from the exchange network for exposure scenarios specific environmental release category workshop on May 13, 2016.

Science.gov (United States)

Ahrens, Andreas; Moilanen, Marianne; Martin, Sara; Garcia-John, Enrique; Sättler, Daniel; Bakker, Joost; Reihlen, Antonia; Wind, Thorsten; Tolls, Johannes

2017-09-01

Specific environmental release categories (SPERCs) are an instrument for lower-tier environmental emissions assessments. They support chemical safety assessments under the European Union (EU) regulation Registration, Evaluation, Authorisation, and Restriction of Chemicals. SPERCs have been developed by industry and subjected to regulatory review. Within the framework of the Chemical Safety Report/Exposure Scenario Roadmap, the EU Chemicals Agency (ECHA), the EU Member State authorities, and European industry sector associations collaborate to improve the quality of the SPERCs. Following up on the outcome of ECHA's SPERC Best Practice Project, industry, together with ECHA, developed an updated SPERC factsheet template and guidance on how to fill it out. In addition, industry developed 2 sets of SPERC factsheet examples and the corresponding SPERC background documents. These documents were submitted to a multistakeholder review process. The comments from the review were discussed at a workshop in spring 2016. The workshop participants acknowledged the revised factsheet format including the corresponding guidance, the 2 SPERC factsheets, and the 2 SPERC background documents as best practice examples. The package is expected to support further improvement of the quality of the SPERCs. A common understanding was achieved of the need to match the level of detail of the use conditions description with the risk to be controlled (i.e., the emission intensity and hazard profile of the substances) and with the level of conservatism of SPERC release factors. The complete and transparent documentation of the derivation of the release factors and of their conservatism is conceived as crucial for the credibility of the SPERCs, such that they can be trusted by partners in the chemicals supply chain and by regulators. To that end, background documents will include a dedicated section describing the conservatism of SPERCs. The workshop concluded with an outline of the practical way

Evaluation of metals, metalloids, and ash mixture toxicity using sediment toxicity testing.

Science.gov (United States)

Stojak, Amber; Bonnevie, Nancy L; Jones, Daniel S

2015-01-01

In December 2008, a release of 4.1 million m(3) of coal ash from the Tennessee Valley Authority Kingston Fossil Plant occurred. Ash washed into the Emory River and migrated downstream into the Clinch and Tennessee Rivers. A Baseline Ecological Risk Assessment evaluated risks to ecological receptors from ash in the river system post-dredging. This article describes the approach used and results from sediment toxicity tests, discussing any causal relationships between ash, metals, and toxicity. Literature is limited in the realm of aquatic coal combustion residue (CCR) exposures and the potential magnitude of effects on benthic invertebrates. Sediment samples along a spectrum of ash content were used in a tiered toxicity testing approach and included a combination of 10 day sediment toxicity acute tests and longer-term, partial life cycle "definitive" tests with 2 species (Hyalella azteca and Chironomus dilutus). Arsenic, and to a lesser extent Se, in the ash was the most likely toxicant causing observed effects in the laboratory toxicity tests. Sites in the Emory River with the greatest statistical and biologically significant effects had As concentrations in sediments twice the probable effects concentration of 33 mg/kg. These sites contained greater than 50% ash. Sites with less than approximately 50% ash in sediments exhibited fewer significant toxic responses relative to the reference sediment in the laboratory. The results discussed here present useful evidence of only limited effects occurring from a worst-case exposure pathway. These results provided a valuable line of evidence for the overall assessment of risks to benthic invertebrates and to other ecological receptors, and were crucial to risk management and development of project remediation goals. © 2014 SETAC.

Protein Nanoscaffolds for Delivering Toxic Inorganic Cargo to Cancer Cells

Science.gov (United States)

Cioloboc, Daniela

Targeted delivery of anticancer drugs or prodrugs to tumors can minimize systemic toxicity and side effects. This study develops platforms for targeted delivery of two potentially less systemically toxic prodrugs by exploiting the native and/or bioinorganic properties of two ferritins, both of which function naturally as iron storage proteins. Two delivery approaches were investigated. The first system was designed to serve as either an enhancement or alternative to traditional photodynamic therapy by generating hydroxyl radical in addition to singlet oxygen as the toxic reactive oxygen species. This system used Escherichia coli bacterioferritin (Bfr) loaded with 2,500 irons and multiple zinc-porphyrin (ZnP) photosensitizers. Ferrous iron was released by photoreduction of ferric iron stored within the Bfr protein shell. Hydroxyl radicals were generated via the Fenton reaction between hydrogen peroxide and the released ferrous iron. The outer surface of the Bfr protein shell was coated with peptides that specifically bind to a receptor known to be overexpressed in many tumor cells and tumor vasculature. The iron-loaded peptide-ZnP-Bfr was endocytosed by melanoma cells, where it showed photo-triggered release of iron and light-dependent cytotoxicity. The second system, built around human heavy chain ferritin (HFn), was loaded with arsenate as a less toxic "prodrug" and designed to release arsenic in its toxic, therapeutically effective reduced form, arsenic trioxide (ATO). The Hfn shell was coated with peptides targeting receptors that are hyperexpressed in triple negative breast cancers. The arsenate/iron-loaded-Hfn was endocytosed by a breast cancer cell line and showed cytotoxicity equivalent to that of free ATO on an arsenic basis, whereas the "empty" or iron-only loaded Hfn showed no cytotoxicity. Although HFn has previously been used to deliver organic drugs and imaging agents, these new results demonstrate that both Bfr and HFn can be manipulated to function

Towards a user's guide to scenarios - a report on scenario types and scenario techniques

Energy Technology Data Exchange (ETDEWEB)

Boerjeson, Lena; Hoejer, Mattias; Dreborg, Karl-Henrik; Finnveden, Goeran [Royal Inst. of Technology, Stockholm (Sweden). Environmental Strategies Research - fms; Ekvall, Tomas [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy and Environment

2005-11-01

Futures studies consist of a vast variation of studies and approaches. The aim of this paper is to contribute to the understanding of for what purposes scenarios are useful and what methods and procedures are useful for furthering these purposes. We present a scenario typology with an aim to better suit the context in which the scenarios are used. The scenario typology is combined with a new way of looking at scenario techniques, i.e. practical methods and procedures for scenario development. Finally, we look at the usefulness of scenarios in the light of the scenario typology and the scenario techniques. As a start, we distinguish between three main categories of scenario studies. The classification is based on the principal questions we believe a user may want to pose about the future. The resolution is then increased by letting each category contain two different scenario types. These are distinguished by different angles of approach of the questions defining the categories. The first question, What will happen?, is responded to by Predictive scenarios. In fact, the response to a question like this will always be conditional, e.g. of a stable and peaceful world, or by a certain continuous development of some kind. We have utilized this fact when defining the two predictive scenario types, Forecasts and What-if scenarios. The second question, What can happen?, is responded to by Explorative scenarios. The scenarios are thus explorations of what might happen in the future, regardless of beliefs of what is likely to happen or opinions of what is desirable. This category is further divided into external and strategic scenarios. The final question, How can a specific target be reached?, is responded to by Normative scenarios. Such studies are explicitly normative, since they take a target as a starting point. They are often directed towards how the target could be reached. This category is divided into preserving and transforming scenarios. If the user wants to

75 FR 5261 - Waybill Data Reporting for Toxic Inhalation Hazards

Science.gov (United States)

2010-02-02

... monitor traffic flows and rate trends in the industry, and to develop evidence in Board proceedings. The... humans as to pose a hazard to health in the event of a release during transportation. These materials... so toxic to humans as to pose a hazard to health in the event of a release during transportation...

The sea urchin, a versatile model for eco-toxicity studies and ecological experimental research

Directory of Open Access Journals (Sweden)

D. Privitera

2011-01-01

Full Text Available Echinoderm early developmental stages represent a good tool for toxicity testing in different fields, ranging from environment to food contamination, and in full respect of the 3Rs objectives (Reduction, Refinement, Replacement of animal experiments, that will lead to the reduction of vertebrate use for toxicity testing. Further, sea urchins are key species in a wide range of marine habitats, as they are able to structure algal community. Experiments and observations aiming at the  characterization of anthropogenic or climate changes effects on their settlement, population structure, feeding behaviour and reproductive condition, may be useful to describe future scenarios regarding the whole marine community. The present paper represents a short review of the possible applications of eco-toxicity bioassays using Paracentrotus lividus gametes and embryos. Further, examples of ecological researches, involving sea urchins, aiming at the definition of future scenarios will be preserved.

Estimating the threshold levels of uranium and fluorine for the development of pulmonitis and toxic lung edema resultant from accidents involving uranium hexafluoride release

International Nuclear Information System (INIS)

Gasteva, G.N.; Antipin, E.B.; Bad'in, V.I.; Molokanov, A.A.; Mordasheva, V.V.; Mirkhajdarov, A.Kh.; Sorokin, A.V.; Savinova, I.A.

1999-01-01

Threshold doses of uranium and fluorine for the development of pulmonitis and toxic edema of the lung with lethal outcome are estimated. The levels of UF 6 entry under emergency conditions are evaluated and bronchopulmonary disease is described in subjects involved in three accidents with UF 6 release which occurred in the seventies and eighties, as shown by records. The results deny the previous assumption on the leading role of uranium in a single exposure to uranium hexafluoride. Fluorine ion triggering the mechanism of reactions in systems which determine the disease outcome is vitally important [ru

BIOMOVS test scenario model comparison using BIOPATH

International Nuclear Information System (INIS)

Grogan, H.A.; Van Dorp, F.

1986-07-01

This report presents the results of the irrigation test scenario, presented in the BIOMOVS intercomparison study, calculated by the computer code BIOPATH. This scenario defines a constant release of Tc-99 and Np-237 into groundwater that is used for irrigation. The system of compartments used to model the biosphere is based upon an area in northern Switzerland and is essentially the same as that used in Projekt Gewaehr to assess the radiological impact of a high level waste repository. Two separate irrigation methods are considered, namely ditch and overhead irrigation. Their influence on the resultant activities calculated in the groundwater, soil and different foodproducts, as a function of time, is evaluated. The sensitivity of the model to parameter variations is analysed which allows a deeper understanding of the model chain. These results are assessed subjectively in a first effort to realistically quantify the uncertainty associated with each calculated activity. (author)

Weather scenarios for dose calculations with incomplete meteorological data. V.I.(rev.1)

International Nuclear Information System (INIS)

Alp, E.; Lam, L.H.; Moran, M.D.

1985-09-01

This report documents a study to substantiate or modify the weather scenarios proposed by the Atomic Energy Control Board Staff Position Paper on meteorological acceptance criteria for estimating the potential radiological consequences of postulated accidents (AECB, 1982) for short-, prolonged-, and long-term releases from ground level and elevated sources. The study examined available meteorological data in Canada to determine whether the AECB-proposed scenarios are sufficiently general that they are appropriate and conservative for any potential nuclear power plant in Canada, but also realistic, i.e., not so conservative that the results of dose calculations using these scenarios would be wholly unrepresentative leading to incorrect design decisions. Three different sets of scenarios were derived using three site-specific data sets from weather stations that are representative of existing nuclear power plants in Canada. When compared, the scenarios for the three sites are not significantly different from each other, especially in terms of trends, considering that they have been based on data from widely differing meteorological regions in Canada. Conservative envelopes of the scenarios for the three sites were taken to give the recommended general weather scenario set. The recommended set was then compared with the AECB proposed scenarios. The recommended scenarios are, in general, conservative

Environmental Assessment of Possible Future Waste Management Scenarios

Directory of Open Access Journals (Sweden)

Yevgeniya Arushanyan

2017-02-01

Full Text Available Waste management has developed in many countries and will continue to do so. Changes towards increased recovery of resources in order to meet climate targets and for society to transition to a circular economy are important driving forces. Scenarios are important tools for planning and assessing possible future developments and policies. This paper presents a comprehensive life cycle assessment (LCA model for environmental assessments of scenarios and waste management policy instruments. It is unique by including almost all waste flows in a country and also allow for including waste prevention. The results show that the environmental impacts from future waste management scenarios in Sweden can differ a lot. Waste management will continue to contribute with environmental benefits, but less so in the more sustainable future scenarios, since the surrounding energy and transportation systems will be less polluting and also because less waste will be produced. Valuation results indicate that climate change, human toxicity and resource depletion are the most important environmental impact categories for the Swedish waste management system. Emissions of fossil CO2 from waste incineration will continue to be a major source of environmental impacts in these scenarios. The model is used for analyzing environmental impacts of several policy instruments including weight based collection fee, incineration tax, a resource tax and inclusion of waste in a green electricity certification system. The effect of the studied policy instruments in isolation are in most cases limited, suggesting that stronger policy instruments as well as combinations are necessary to reach policy goals as set out in for example the EU action plan on circular economy.

Comparative toxicity of leachates from 52 textiles to Daphnia magna.

Science.gov (United States)

Dave, Göran; Aspegren, Pia

2010-10-01

The environmental aspects of textiles are very complex and include production, processing, transport, usage, and recycling. Textiles are made from a variety of materials and can contain a large number of chemicals. Chemicals are used during production of fibres, for preservation and colouring and they are released during normal wear and during washing. The aim of this study was to investigate the release to water of toxic chemicals from various textiles. Altogether 52 samples of textiles made from cotton (21), linen (4), cotton and linen (7), cellulose (3), synthetic fibres (7), cotton and synthetic fibres (8) and wool (2). Seven were eco-labelled. All textiles were cut into squares and placed into Petri dishes with 50 ml ISO test medium in a concentration series (4-256 cm(2)/50 ml) and tested for acute toxicity to Daphnia magna. Estimated EC50s were converted into weight/volume, and 48-h EC50s ranged between 182 g/L. It was not possible to detect any difference between fibre type and toxicity (ANOVA), but a significantly higher toxicity was found for printed versus unprinted cotton and cotton/linen textiles, while the opposite was found for synthetic textiles. Eco-labelled products were evenly distributed on a toxicity scale, which means that eco-labelling in its present form does not necessarily protect users or the environment from exposure to toxic chemicals. Therefore, the results from the present study suggest that bioassays and toxicity tests should become an integrated part of textile environmental quality control programs. Copyright © 2010 Elsevier Inc. All rights reserved.

Air toxic emissions from burning of biomass globally-preliminary results

International Nuclear Information System (INIS)

Ward, D.E.; Hao, W.M.

1992-01-01

Emissions of trace gases, particles, and air toxic substances in the smoke plumes from biomass fires are of importance to global climate change. The potential impact of the air toxic emissions on the human population of specific regions globally is another major concern. The toxic materials are produced in high concentrations in areas of heavy biomass burning, e.g., Amazon Basin and Central/southern Africa. We provide new estimates of air toxics based on the combustion efficiency (percent of total carbon released as CO 2 ) for fires burning in different ecosystems on a global basis. Estimates of total biomass consumed on a global basis range from 2 to 10 Pg (1 petagram = 10 15 g) per year. We apply emission factors for various air toxics (g of emission released per kg of fuel consumed) to the estimate of global biomass consumption of 6.4 Pg per year. The principal air toxics analyzed in this paper include: Total particulate matter, CO, formaldehyde, acetaldehyde, acrolein, benzene, toluene, o-xylene, m, p-xylene, benzo[a]pyrene, and polycyclic organic material. The total emissions calculated for these materials on a yearly global basis are: 75, 362, 4.9, 1.5, 1.5, 2.1, 2.1, 0.3, 0.6, 0.001, 0.026, Tg (1 teragram = 10 12 g) per year, respectively. Biomass burning in the United States contributes less than 3% to the total global emissions

Canadian pollutant releases and transfers : NPRI data 1998

International Nuclear Information System (INIS)

2001-03-01

A large, two-sided fold-out poster showing pollution hotspots throughout Canada, has been released by the Canadian Institute for Environmental Law and Policy (CIELAP). The poster is based on the maps and tables of the National Pollutant Release Inventory (NPRI) 1998. It presents the top on-site releases and off-site transfers of pollutants by facilities across Canada, and provides a summary of releases, transfers and recycling of pollutants by province. The map depicts the facilities with the five largest quantities of individual pollutants released to each medium, i. e. water, air, land, underground. The crude oil and gas, other utilities, primary metal, paper and chemical industrial sectors are responsible for the largest on-site releases, while the business services, fabricated metal. primary metal and chemical industrial sectors account for the largest off-site transfers. Twenty-five of the 176 substances whose releases and transfers are reported under the NPRI are classified as 'toxic' or 'carcinogenic'. tabs., maps

The Dose Assessment in the Vault Test Case of Near-Surface Disposal Facility for Drinking Water Scenario

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Hyoung; Choi, Byung Seon; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Jae Woo [Jeju National University, Jeju (Korea, Republic of)

2012-05-15

It is generally accepted that the radionuclides contained in the radioactive wastes will be eventually released and these will be transported to the accessible environment (near-field, far-field, biosphere). Therefore, the long-term safety assessment of near-surface radioactive waste disposal should be required by modeling the expected release of radionuclides from the repository, far-field area, and biosphere. Finally, the effective dose rate should be estimated through the released radionuclides. In this study, the radiological dose was evaluated for the reference near-surface radioactive waste disposal facility in Vaalputs, South Africa, which has been selected as a part of IAEA coordinated research program on improvement of safety assessment methodologies(ISAM). The assessment of radiological dose was performed for drinking water scenario from a well. The release and transport of radionuclides in disposal system were simulated by GoldSim. This approach suggested the time variation of effective dose over long-term period. And the results from this approach were compared with another approach method for the same facility and scenario

The Dose Assessment in the Vault Test Case of Near-Surface Disposal Facility for Drinking Water Scenario

International Nuclear Information System (INIS)

Kim, Tae Hyoung; Choi, Byung Seon; Moon, Jei Kwon; Park, Jae Woo

2012-01-01

It is generally accepted that the radionuclides contained in the radioactive wastes will be eventually released and these will be transported to the accessible environment (near-field, far-field, biosphere). Therefore, the long-term safety assessment of near-surface radioactive waste disposal should be required by modeling the expected release of radionuclides from the repository, far-field area, and biosphere. Finally, the effective dose rate should be estimated through the released radionuclides. In this study, the radiological dose was evaluated for the reference near-surface radioactive waste disposal facility in Vaalputs, South Africa, which has been selected as a part of IAEA coordinated research program on improvement of safety assessment methodologies(ISAM). The assessment of radiological dose was performed for drinking water scenario from a well. The release and transport of radionuclides in disposal system were simulated by GoldSim. This approach suggested the time variation of effective dose over long-term period. And the results from this approach were compared with another approach method for the same facility and scenario

Comparison of Dissolved Nickel and Nickel Nanoparticles Toxicity in Larval Zebrafish in Terms of Gene Expression and DNA Damage.

Science.gov (United States)

Boran, Halis; Şaffak, Savaş

2018-01-01

With the use of nanoparticles (NPs) in many industrial activities and consumer products, it is important to evaluate the effects of their release into the environment. Metal NPs (e.g., Ni-NPs or Cu-NPs) can release metal ions that are toxic to aquatic organisms; however, whether the toxicity is from metal ions rather than unique "nano-scale" effects of the NPs is unresolved. This research investigated Ni-NP toxicity in zebrafish Danio rerio larvae to clarify whether toxic effects are attributable to release of Ni ions. First, the acute (96-h lethal) toxicity of Ni-NPs was determined in comparison to aqueous Ni in fish exposed to Ni(II) by water-soluble NiCl 2 . Subsequently, sublethal experiments with Ni-NPs and Ni(II) were conducted to assess changes in expression of stress-related genes (mt2, rad51, and p53) by quantitative PCR. Acute toxicity of Ni in fish exposed to Ni(II) was higher (96-h LC 50  = 32.6 mg/L) than for fish exposed to Ni-NPs (96-h LC 50  = 122.2 mg/L). Also, DNA strand breaks were higher in Ni(II)- than Ni-NPs-exposed larvae. Induction of stress-related genes in larvae was complex and was not directly related to Ni-NPs and Ni(II) concentration, although there was a significant induction in the mt2 and p53 gene of the larvae exposed to Ni-NPs and Ni(II) relative to controls. Results indicated that while Ni-NPs induced gene expression (presumably by the release of Ni ions), the differences in concentration relationships of gene expression between Ni-NPs and Ni(II) suggest that factors in addition to the release of Ni ions from Ni-NPs influence acute toxicity of Ni-NPs.

Financial analysis of experimental releases conducted at Glen Canyon Dam during water years 1997 through 2005.

Energy Technology Data Exchange (ETDEWEB)

Veselka, T. D.; Poch, L. A.; Palmer, C. S.; Loftin, S.; Osiek, B.; Decision and Information Sciences; Western Area Power Administration

2010-04-21

Because of concerns about the impact that Glen Canyon Dam (GCD) operations were having on downstream ecosystems and endangered species, the Bureau of Reclamation (Reclamation) conducted an Environmental Impact Statement (EIS) on dam operations (DOE 1996). New operating rules and management goals for GCD that had been specified in the Record of Decision (ROD) (Reclamation 1996) were adopted in February 1997. In addition to issuing new operating criteria, the ROD mandated experimental releases for the purpose of conducting scientific studies. This paper examines the financial implications of the experimental flows that were conducted at the GCD from 1997 to 2005. An experimental release may have either a positive or negative impact on the financial value of energy production. This study estimates the financial costs of experimental releases, identifies the main factors that contribute to these costs, and compares the interdependencies among these factors. An integrated set of tools was used to compute the financial impacts of the experimental releases by simulating the operation of the GCD under two scenarios, namely, (1) a baseline scenario that assumes operations comply with the ROD operating criteria and experimental releases that actually took place during the study period, and (2) a ''without experiments'' scenario that is identical to the baseline scenario of operations that comply with the GCD ROD, except it assumes that experimental releases did not occur. The Generation and Transmission Maximization (GTMax) model was the main simulation tool used to dispatch GCD and other hydropower plants that comprise the Salt Lake City Area Integrated Projects (SLCA/IP). Extensive data sets and historical information on SLCA/IP power plant characteristics, hydrologic conditions, and Western Area Power Administration's (Western's) power purchase prices were used for the simulation. In addition to estimating the financial impact of experimental

Investigation of Appropriate Applications for Reuse of Conditionally Released Materials from Decommissioning

International Nuclear Information System (INIS)

Daniska, V.; Vasko, M.; Necas, V.

2012-01-01

During the decommissioning (D and D) phase of nuclear facility life cycle a lot of original facility materials are generated as a primary decommissioning waste. One portion of these materials is unconditionally releasable, i.e. their radioactivity content is below the stipulated concentration limits for clearance thus they can be further recycled or dumped without any constraints as a conventional waste. Second portion of generated waste is waste with radioactivity content higher than limits for free release and it has to be handled and disposed of as the radioactive waste (RAW) within special RAW repositories. Disposal of RAW is quite expensive therefore it seems to be reasonable to reduce amount of waste destined for disposal and to identify RAW with radioactivity content slightly higher than stipulated concentration limits for unconditional release which could be released with some constraints for further recycling and reuse while stipulated safety requirements are observed, i.e. conditional release of RAW. The most perspective materials from decommissioning for such material reuse are steel and concrete. These materials can be reused within the long term robust constructions for applications with infrequent or only short time presence of personnel/public, minimum interaction of human with materials and controllable interaction of materials with environment. Ideal applications for deployment of such materials are steel reinforcement in pylons for highways, tunnel linings, industry prefabricates, big tanks or linings in nuclear applications, for concrete debris it can be filling material for road construction. Presented paper deals with preconditions for reuse of conditionally released materials. It maps legal pre-requisites in the Slovak Republic, appropriate material application scenarios, methodology of assessment of impact on human health and environment - external and internal exposure assessment, possible optimisation of scenarios and estimation of

Gossypol Toxicity from Cottonseed Products

Directory of Open Access Journals (Sweden)

Ivana Cristina N. Gadelha

2014-01-01

Full Text Available Gossypol is a phenolic compound produced by pigment glands in cotton stems, leaves, seeds, and flower buds (Gossypium spp.. Cottonseed meal is a by-product of cotton that is used for animal feeding because it is rich in oil and proteins. However, gossypol toxicity limits cottonseed use in animal feed. High concentrations of free gossypol may be responsible for acute clinical signs of gossypol poisoning which include respiratory distress, impaired body weight gain, anorexia, weakness, apathy, and death after several days. However, the most common toxic effects is the impairment of male and female reproduction. Another important toxic effect of gossypol is its interference with immune function, reducing an animal’s resistance to infections and impairing the efficiency of vaccines. Preventive procedures to limit gossypol toxicity involve treatment of the cottonseed product to reduce the concentration of free gossypol with the most common treatment being exposure to heat. However, free gossypol can be released from the bound form during digestion. Agronomic selection has produced cotton varieties devoid of glands producing gossypol, but these varieties are not normally grown because they are less productive and are more vulnerable to attacks by insects.

Diagnostic health risk assessment of electronic waste on the general population in developing countries' scenarios

International Nuclear Information System (INIS)

Frazzoli, Chiara; Orisakwe, Orish Ebere; Dragone, Roberto; Mantovani, Alberto

2010-01-01

E-waste is the generic name for technological waste. Even though aspects related to e-waste environmental pollution and human exposure are known, scientific assessments are missing so far on the actual risks for health sustainability of the general population exposed to e-waste scenarios, such as illicit dumping, crude recycling and improper treatment and disposal. In fact, further to occupational and direct local exposure, e-waste scenarios may impact on the environment-to-food chain, thus eliciting a widespread and repeated exposure of the general population to mixtures of toxicants, mainly toxic chemical elements, polycyclic aromatic hydrocarbons and persistent organic pollutants. In the absence of any clear policy on e-waste flow management, the situation in the e-waste receiver countries may become quite scary; accordingly, here we address a diagnostic risk assessment of health issues potentially elicited by e-waste related mixtures of toxicants. Scientific evidence available so far (mainly from China) is discussed with special attention to the concept of health sustainability, i.e. the poor health burden heritage perpetuated through the mother-to-child dyad. Endocrine disruption and neurotoxicity are specifically considered as examples of main health burden issues relevant to perpetuation through life cycle and across generations; toxicological information are considered along with available data on environmental and food contamination and human internal exposure. The risk from exposure to e-waste related mixtures of toxicants of vulnerable subpopulation like breast-fed infants is given special attention. The diagnostic risk assessment demonstrates how e-waste exposure poses an actual public health emergency, as it may entrain significant health risks also for generations to come. Exposure scenarios as well as specific chemicals of major concern may vary in different contexts; for instance, only limited information is available on e-waste related exposures in

Life cycle assessment and residue leaching: The importance of parameter, scenario and leaching data selection

Energy Technology Data Exchange (ETDEWEB)

Allegrini, E., E-mail: elia@env.dtu.dk [Technical University of Denmark, Department of Environmental Engineering, Building 115, 2800 Lyngby (Denmark); Butera, S. [Technical University of Denmark, Department of Environmental Engineering, Building 115, 2800 Lyngby (Denmark); Kosson, D.S. [Vanderbilt University, Department of Civil and Environmental Engineering, Box 1831 Station B, Nashville, TN 37235 (United States); Van Zomeren, A. [Energy Research Centre of the Netherlands (ECN), Department of Environmental Risk Assessment, P.O. Box 1, 1755 ZG Petten (Netherlands); Van der Sloot, H.A. [Hans van der Sloot Consultancy, Dorpsstraat 216, 1721 BV Langedijk (Netherlands); Astrup, T.F. [Technical University of Denmark, Department of Environmental Engineering, Building 115, 2800 Lyngby (Denmark)

2015-04-15

Highlights: • Relevance of metal leaching in waste management system LCAs was assessed. • Toxic impacts from leaching could not be disregarded. • Uncertainty of toxicity, due to background activities, determines LCA outcomes. • Parameters such as pH and L/S affect LCA results. • Data modelling consistency and coverage within an LCA are crucial. - Abstract: Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products and can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results

Conditions for the formation and atmospheric dispersion of a toxic, heavy gas layer during thermal metamorphism of coal and evaporite deposits by sill intrusion

Science.gov (United States)

Storey, Michael; Hankin, Robin K. S.

2010-05-01

There is compelling evidence for massive discharge of volatiles, including toxic species, into the atmosphere at the end of the Permian. It has been argued that most of the gases were produced during thermal metamorphism of coal and evaporite deposits in the East Siberia Tunguska basin following sill intrusion (Retallack and Jahren, 2008; Svensen et al., 2009). The release of the volatiles has been proposed as a major cause of environmental and extinction events at the end of the Permian, with venting of carbon gases and halocarbons to the atmosphere leading to global warming and atmospheric ozone depletion (Svensen et al., 2009) Here we consider the conditions required for the formation and dispersion of toxic, heavier than air, gas plumes, made up of a mixture of CO2, CH4, H2S and SO2 and formed during the thermal metamorphism of C- and S- rich sediments. Dispersion models and density considerations within a range of CO2/CH4 ratios and volatile fluxes and temperatures, for gas discharge by both seepage and from vents, allow the possibility that following sill emplacement much of the vast East Siberia Tunguska basin was - at least intermittently - covered by a heavy, toxic gas layer that was unfavorable for life. Dispersion scenarios for a heavy gas layer beyond the Siberian region during end-Permian times will be presented. REFERENCES G. J. Retallack and A. H. Jahren, Methane release from igneous intrusion of coal during Late Permian extinction events, Journal of Geology, volume 116, 1-20, 2008 H. Svensen et al., Siberian gas venting and the end-Permian environmental crisis, Earth and Planetary Science Letters, volume 277, 490-500, 2009

Projecting the environmental profile of Singapore's landfill activities: Comparisons of present and future scenarios based on LCA.

Science.gov (United States)

Khoo, Hsien H; Tan, Lester L Z; Tan, Reginald B H

2012-05-01

This article aims to generate the environmental profile of Singapore's Semakau landfill by comparing three different operational options associated with the life cycle stages of landfilling activities, against a 'business as usual' scenario. Before life cycle assessment or LCA is used to quantify the potential impacts from landfilling activities, an attempt to incorporate localized and empirical information into the amounts of ash and MSW sent to the landfill was made. A linear regression representation of the relationship between the mass of waste disposed and the mass of incineration ash generated was modeled from waste statistics between years 2004 and 2009. Next, the mass of individual MSW components was projected from 2010 to 2030. The LCA results highlighted that in a 'business as usual' scenario the normalized total impacts of global warming, acidification and human toxicity increased by about 2% annually from 2011 to 2030. By replacing the 8000-tonne barge with a 10000-tonne coastal bulk carrier or freighter (in scenario 2) a grand total reduction of 48% of both global warming potential and acidification can be realized by year 2030. Scenario 3 explored the importance of having a Waste Water Treatment Plant in place to reduce human toxicity levels - however, the overall long-term benefits were not as significant as scenario 2. It is shown in scenario 4 that the option of increased recycling championed over all other three scenarios in the long run, resulting in a total 58% reduction in year 2030 for the total normalized results. A separate comparison of scenarios 1-4 is also carried out for energy utilization and land use in terms of volume of waste occupied. Along with the predicted reductions in environmental burdens, an additional bonus is found in the expanded lifespan of Semakau landfill from year 2032 (base case) to year 2039. Model limitations and suggestions for improvements were also discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Human toxicity as a criterion in the environmental assessment of products

DEFF Research Database (Denmark)

Hauschild, Michael Zwicky; Olsen, Stig Irving; Wenzel, Henrik

1998-01-01

. The assessment proceeds through the steps of classification, characterization, normalization and valuation. In the classification step attention is focused on intrinsic toxicity, low biodegradability and potential for bioconcentration as properties that predicpose a substance for ecotoxicity. No concrete values...... references derived for each of these scenarios are presented as personal equivalents for citizens in the considered region. Valuation Applying the "distance to target principle to the present Danish political reduction targets for toxicity a weighting factor is derived to be used in the quantitative weighing...

Scenario development for the Waste Isolation Pilot Plant compliance certification application

International Nuclear Information System (INIS)

GALSON, D.A.; SWIFT, PETER N.; ANDERSON, D. RICHARD; BENNETT, D.G.

1998-01-01

Demonstrating compliance with the applicable regulations for the Waste Isolation Pilot Plant (WIPP) requires an assessment of the long-term performance of the disposal system. Scenario development is one starting point of this assessment, and generates inquiry about the present state and future evolution of the disposal system. Scenario development consists of four tasks: (1) identifying and classifying features, events and processes (FEPs), (2) screening FEPs according to well-defined criteria, (3) forming scenarios (combinations of FEPs) in the context of regulatory performance criteria and (4) specifying of scenarios for consequence analysis. The development and screening of a comprehensive FEP list provides assurance that the identification of significant processes and events is complete, that potential interactions between FEPs are not overlooked, and that responses to possible questions are available and well documented. Two basic scenarios have been identified for the WIPP: undisturbed performance (UP) and disturbed performance (DP). The UP scenario is used to evaluate compliance with the Environmental Protection Agency's (EPA's) Individual Dose (40 CFR Section 191-15) and Groundwater Protection (40 CFR Section 191-24) standards and accounts for all natural-, waste- and repository-induced FEPs that survive the screening process. The DP scenario is required for assessment calculations for the EPA's cumulative release standard (Containment Requirements, 40 CFR Section 191-13) and accounts for disruptive future human events, which have an uncertain probability of occurrence, in addition to the UP FEPs

The Chernobyl I-131 Release: Model Validation and Assessment of the Countermeasure Effectiveness. Report of the Chernobyl 131I Release Working Group of EMRAS Theme 1

International Nuclear Information System (INIS)

2012-01-01

The Chernobyl 131 I Release Working Group (IWG) which was established within the framework of the EMRAS Programme continues some of the more traditional work of previous international programmes that were aimed at increasing confidence in methods and models for the assessment of radiation exposure related to the environmental releases. There is still very little information regarding the quantitative relationship between radiation dose to the thyroid from Chernobyl and the risk of thyroid cancer. The uncertainty combined with individual estimates of radiation dose constitutes a crucial point in establishing this relationship, since, any release of radioiodine into environment creates wide range of uncertainty for internal dose assessments. The 131 I scenarios provide an excellent opportunity to compare a number of modelling approaches to a single assessment problem, in a dose reconstruction context. Nine experts in environmental modelling participated in the Plavsk Scenario dealing with areas of assessment modelling for which the capabilities are not yet well established. One could observes the remarkably improvement in models performance comparing with previous radioiodine scenarios. Predictions of the various models were within a factor of three of the observations, discrepancies between the estimates of average doses to thyroid produced by most participant not exceeded a factor of ten. The process of testing independent model calculations against independent data set also provided useful information to the originators of the test data.

Ethoprophos fate on soil-water interface and effects on non-target terrestrial and aquatic biota under Mediterranean crop-based scenarios.

Science.gov (United States)

Leitão, Sara; Moreira-Santos, Matilde; Van den Brink, Paul J; Ribeiro, Rui; José Cerejeira, M; Sousa, José Paulo

2014-05-01

The present study aimed to assess the environmental fate of the insecticide and nematicide ethoprophos in the soil-water interface following the pesticide application in simulated maize and potato crops under Mediterranean agricultural conditions, particularly of irrigation. Focus was given to the soil-water transfer pathways (leaching and runoff), to the pesticide transport in soil between pesticide application (crop row) and non-application areas (between crop rows), as well as to toxic effects of the various matrices on terrestrial and aquatic biota. A semi-field methodology mimicking a "worst-case" ethoprophos application (twice the recommended dosage for maize and potato crops: 100% concentration v/v) in agricultural field situations was used, in order to mimic a possible misuse by the farmer under realistic conditions. A rainfall was simulated under a slope of 20° for both crop-based scenarios. Soil and water samples were collected for the analysis of pesticide residues. Ecotoxicity of soil and aquatic samples was assessed by performing lethal and sublethal bioassays with organisms from different trophic levels: the collembolan Folsomia candida, the earthworm Eisenia andrei and the cladoceran Daphnia magna. Although the majority of ethoprophos sorbed to the soil application area, pesticide concentrations were detected in all water matrices illustrating pesticide transfer pathways of water contamination between environmental compartments. Leaching to groundwater proved to be an important transfer pathway of ethoprophos under both crop-based scenarios, as it resulted in high pesticide concentration in leachates from Maize (130µgL(-1)) and Potato (630µgL(-1)) crop scenarios, respectively. Ethoprophos application at the Potato crop scenario caused more toxic effects on terrestrial and aquatic biota than at the Maize scenario at the recommended dosage and lower concentrations. In both crop-based scenarios, ethoprophos moved with the irrigation water flow to the

Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

Energy Technology Data Exchange (ETDEWEB)

Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

2014-04-01

Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

Improving toxicity assessment of pesticide mixtures: the use of polar passive sampling devices extracts in microalgae toxicity tests

Directory of Open Access Journals (Sweden)

Sandra KIM TIAM

2016-09-01

Full Text Available Complexity of contaminants exposure needs to be taking in account for an appropriate evaluation of risks related to mixtures of pesticides released in the ecosystems. Toxicity assessment of such mixtures can be made through a variety of toxicity tests reflecting different level of biological complexity. This paper reviews the recent developments of passive sampling techniques for polar compounds, especially Polar Organic Chemical Integrative Samplers (POCIS and Chemcatcher® and the principal assessment techniques using microalgae in laboratory experiments. The progresses permitted by the coupled use of such passive samplers and ecotoxicology testing as well as their limitations are presented. Case studies combining passive sampling devices (PSD extracts and toxicity assessment toward microorganisms at different biological scales from single organisms to communities level are presented. These case studies, respectively aimed i at characterizing the toxic potential of waters using dose-response curves, and ii at performing microcosm experiments with increased environmental realism in the toxicant exposure in term of cocktail composition and concentration. Finally perspectives and limitations of such approaches for future applications in the area of environmental risk assessment are discussed.

Financial analysis of experimental releases conducted at Glen Canyon Dam during water years 2006 through 2010.

Energy Technology Data Exchange (ETDEWEB)

Poch, L. A.; Veselka, T. D.; Palmer, C. S.; Loftin, S.; Osiek, B. (Decision and Information Sciences); (Western Area Power Administration, Colorado River Storage Project Management Center)

2011-08-22

Because of concerns about the impact that Glen Canyon Dam (GCD) operations were having on downstream ecosystems and endangered species, the Bureau of Reclamation (Reclamation) conducted an Environmental Impact Statement (EIS) on dam operations (DOE 1996). New operating rules and management goals for GCD that had been specified in the Record of Decision (ROD) (Reclamation 1996) were adopted in February 1997. In addition to issuing new operating criteria, the ROD mandated experimental releases for the purpose of conducting scientific studies. A report released in January 2011 examined the financial implications of the experimental flows that were conducted at the GCD from 1997 to 2005. This report continues the analysis and examines the financial implications of the experimental flows conducted at the GCD from 2006 to 2010. An experimental release may have either a positive or negative impact on the financial value of energy production. This study estimates the financial costs of experimental releases, identifies the main factors that contribute to these costs, and compares the interdependencies among these factors. An integrated set of tools was used to compute the financial impacts of the experimental releases by simulating the operation of the GCD under two scenarios, namely, (1) a baseline scenario that assumes both that operations comply with the ROD operating criteria and the experimental releases that actually took place during the study period, and (2) a 'without experiments' scenario that is identical to the baseline scenario of operations that comply with the GCD ROD, except it assumes that experimental releases did not occur. The Generation and Transmission Maximization (GTMax) model was the main simulation tool used to dispatch GCD and other hydropower plants that comprise the Salt Lake City Area Integrated Projects (SLCA/IP). Extensive data sets and historical information on SLCA/IP powerplant characteristics, hydrologic conditions, and Western

Releases of UF6 to the atmosphere after a potential fire in a cylinder storage yard

International Nuclear Information System (INIS)

Lombardi, D.A.; Williams, W.R.; Anderson, J.C.

1997-01-01

Uranium hexafluoride (UF 6 ), a toxic material, is stored in just over 6200 cylinders at the K-25 site in Oak Ridge, Tennessee. The safety analysis report (SAR) for cylinder yard storage operations at the plant required the development of accident scenarios for the potential release of UF 6 to the atmosphere. In accordance with DOE standards and guidance, the general approach taken in this SAR was to examine the functions and contents of the cylinder storage yards to determine whether safety-significant hazards were present for workers in the immediate vicinity, workers on-site, the general public off-site, or the environment. and to evaluate the significance of any hazards that were found. A detailed accident analysis was performed to determine a set of limiting accidents that have potential for off-site consequences. One of the limiting accidents identified in the SAR was the rupture of a cylinder engulfed in a fire

Revised financial analysis of experimental releases conducted at Glen Canyon Dam during water years 1997 through 2005.

Energy Technology Data Exchange (ETDEWEB)

Veselka, T. D.; Poch, L. A.; Palmer, C. S.; Loftin, S.; Osiek, B.; Decision and Information Sciences; Western Area Power Administration, Colorado River Storage Project Management Center

2011-01-11

Because of concerns about the impact that Glen Canyon Dam (GCD) operations were having on downstream ecosystems and endangered species, the Bureau of Reclamation (Reclamation) conducted an Environmental Impact Statement (EIS) on dam operations (DOE 1996). New operating rules and management goals for GCD that had been specified in the Record of Decision (ROD) (Reclamation 1996) were adopted in February 1997. In addition to issuing new operating criteria, the ROD mandated experimental releases for the purpose of conducting scientific studies. This paper examines the financial implications of the experimental flows that were conducted at the GCD from 1997 to 2005. An experimental release may have either a positive or negative impact on the financial value of energy production. This study estimates the financial costs of experimental releases, identifies the main factors that contribute to these costs, and compares the interdependencies among these factors. An integrated set of tools was used to compute the financial impacts of the experimental releases by simulating the operation of the GCD under two scenarios, namely, (1) a baseline scenario that assumes operations comply with the ROD operating criteria and experimental releases that actually took place during the study period, and (2) a 'without experiments' scenario that is identical to the baseline scenario of operations that comply with the GCD ROD, except it assumes that experimental releases did not occur. The Generation and Transmission Maximization (GTMax) model was the main simulation tool used to dispatch GCD and other hydropower plants that comprise the Salt Lake City Area Integrated Projects (SLCA/IP). Extensive data sets and historical information on SLCA/IP power plant characteristics, hydrologic conditions, and Western Area Power Administration's (Western's) power purchase prices were used for the simulation. In addition to estimating the financial impact of experimental releases

Release of volatile and semi-volatile toxicants during house fires.

Science.gov (United States)

Hewitt, Fiona; Christou, Antonis; Dickens, Kathryn; Walker, Richard; Stec, Anna A

2017-04-01

Qualitative results are presented from analysis of volatile and semi-volatile organic compounds (VOCs/SVOCs) obtained through sampling of gaseous effluent and condensed particulates during a series of experimental house fires conducted in a real house. Particular emphasis is given to the 16 polycyclic aromatic hydrocarbons (PAHs) listed by the Environmental Protection Agency due to their potentially carcinogenic effects. The initial fuel packages were either cooking oil or a single sofa; these were burned both alone, and in furnished surroundings. Experiments were performed at different ventilation conditions. Qualitative Gas Chromatography-Mass Spectrometry (GC-MS) analysis found VOC/SVOC releases in the developing stages of the fires, and benzo(a)pyrene - the most carcinogenic PAH - was found in at least one sampling interval in the majority of fires. A number of phosphorus fire retardants were detected, in both the gaseous effluent and particulates, from fires where the initial fuel source was a sofa. Their release during the fire is significant as they pose toxicological concerns separate from those presented by the PAHs. Copyright © 2016. Published by Elsevier Ltd.

Radionuclide release calculations for selected severe accident scenarios

International Nuclear Information System (INIS)

Denning, R.S.; Leonard, M.T.; Cybulskis, P.; Lee, K.W.; Kelly, R.F.; Jordan, H.; Schumacher, P.M.; Curtis, L.A.

1990-08-01

This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. ''Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs

Characterization of Airborne Particles in an Electronic Waste Recycling Facility and Their Toxicity Assessment

Science.gov (United States)

Improper disposal of electronic waste (e-waste) can lead to release of toxic chemicals into the environment and also may pose health risks. Thus, recycling e-waste, instead of landfilling, is considered to be an effective way to reduce pollutant release and exposure. However, lit...

Scenario planning.

Science.gov (United States)

Enzmann, Dieter R; Beauchamp, Norman J; Norbash, Alexander

2011-03-01

In facing future developments in health care, scenario planning offers a complementary approach to traditional strategic planning. Whereas traditional strategic planning typically consists of predicting the future at a single point on a chosen time horizon and mapping the preferred plans to address such a future, scenario planning creates stories about multiple likely potential futures on a given time horizon and maps the preferred plans to address the multiple described potential futures. Each scenario is purposefully different and specifically not a consensus worst-case, average, or best-case forecast; nor is scenario planning a process in probabilistic prediction. Scenario planning focuses on high-impact, uncertain driving forces that in the authors' example affect the field of radiology. Uncertainty is the key concept as these forces are mapped onto axes of uncertainty, the poles of which have opposed effects on radiology. One chosen axis was "market focus," with poles of centralized health care (government control) vs a decentralized private market. Another axis was "radiology's business model," with one pole being a unified, single specialty vs a splintered, disaggregated subspecialty. The third axis was "technology and science," with one pole representing technology enabling to radiology vs technology threatening to radiology. Selected poles of these axes were then combined to create 3 scenarios. One scenario, termed "entrepreneurialism," consisted of a decentralized private market, a disaggregated business model, and threatening technology and science. A second scenario, termed "socialized medicine," had a centralized market focus, a unified specialty business model, and enabling technology and science. A third scenario, termed "freefall," had a centralized market focus, a disaggregated business model, and threatening technology and science. These scenarios provide a range of futures that ultimately allow the identification of defined "signposts" that can

A review and perspective of existing research on the release of nanomaterials from solid nanocomposites.

Science.gov (United States)

Froggett, Stephan J; Clancy, Shaun F; Boverhof, Darrell R; Canady, Richard A

2014-04-07

Advances in adding nanomaterials to various matrices have occurred in tandem with the identification of potential hazards associated with exposure to pure forms of nanomaterials. We searched multiple research publication databases and found that, relative to data generated on potential nanomaterial hazards or exposures, very little attention has focused on understanding the potential and conditions for release of nanomaterials from nanocomposites. However, as a prerequisite to exposure studying release is necessary to inform risk assessments. We identified fifty-four studies that specifically investigated the release of nanomaterials, and review them in the following release scenario groupings: machining, weathering, washing, contact and incineration. While all of the identified studies provided useful information, only half were controlled experiments. Based on these data, the debris released from solid, non-food nanocomposites contains in varying frequencies, a mixture of four types of debris. Most frequently identified are (1) particles of matrix alone, and slightly less often, the (2) matrix particles exhibit the nanomaterial partially or fully embedded; far less frequently is (3) the added nanomaterial entirely dissociated from the matrix identified: and most rare are (4) dissolved ionic forms of the added nanomaterial. The occurrence of specific debris types appeared to be dependent on the specific release scenario and environment. These data highlight that release from nanocomposites can take multiple forms and that additional research and guidance would be beneficial, allowing for more consistent characterization of the release potential of nanomaterials. In addition, these data support calls for method validation and standardization, as well as understanding how laboratory release scenarios relate to real-world conditions. Importantly, as risk is considered to be a function of the inherent hazards of a substance and the actual potential for exposure, data

Probabilistic consequence assessment of hydrogen sulphide releases from a heavy water plant

International Nuclear Information System (INIS)

Baynes, C.J.

1986-05-01

This report provides a summary of work carried out on behalf of the Atomic Energy Control Board, concerned with the consequences of accidental releases to the atmosphere of hydrogen sulphide (H 2 S) at a heavy water plant. In this study, assessments of consequences are made in terms of the probabilities of a range of possible outcomes, i.e., numbers of fatalities, given a certain release scenario. The report describes the major features of a computer model which was developed to calculate the consequences and their associated probabilities, and the major input data used in applying the model to a consequence assessment of the Bruce heavy water plant (HWP) in Ontario. The results of the sensitivity analyses of the model are summarized. Finally, the results of the consequence assessments of 43 accidental release scenarios at the Bruce HWP are summarized, together with a number of conclusions which were drawn from these results regarding the predicted consequences and the factors which influence them

Advice concerning radionuclide release of nuclear power plants and public health

International Nuclear Information System (INIS)

1984-01-01

Amongst the severe accidents with nuclear power plants, a number of scenario's is theoretically possible. These scenario's lead to more or less serious consequences for the environment. Characteristics for the category of accidents was the early breakdown of the containment of the reactor. In recent years more and more doubt has risen with regard to the most serious scenario KE. In the Netherlands the Committee for Reactor Safety (CRV) has reported on this subject (annex 1). According to the CRV the release of a number of important radionuclides, in the case of scenario KE, will be very much less than was supposed in the past. Also, the nuclides will be released much later than was supposed before. A committee of the Dutch Health Council, starting from the CRV-report, has made calculations on the radiological consequences of the KE-scenario, corrected in accordance with these new developments (KEH). As could be expected, this category KEH proves to be considerably less dangerous than was supposed before. Irradiation of the surrounding population with a lethal dose would not occur anymore. The number of somatic and genetic effects would be very small. The conclusions drawn from these calculations are given. These results are compared with calculated consequences of an accident of the KM-category. The CRV has defined a maximised accident from this category (KMM). The report includes the report of the Dutch Commission on Reactor Safety (CR-82-71) as an appendix. (Auth.)

78 FR 73787 - Chlorsulfuron; Community Right-to-Know Toxic Chemical Release Reporting

Science.gov (United States)

2013-12-09

... identified as the minor metabolic pathway. No additional information on the absorption, distribution... aquatic plants the toxicity of chlorsulfuron is very high. (Ref. 3). Duckweed (Lemna gibba) was the most... (cell density); 120 hr capricornutum). NOEC = 0.0094 mg/L (cell density). Lemna gibba Freshwater...

Accidental release of chlorine in Chicago: Coupling of an exposure model with a Computational Fluid Dynamics model

Science.gov (United States)

Sanchez, E. Y.; Colman Lerner, J. E.; Porta, A.; Jacovkis, P. M.

2013-01-01

The adverse health effects of the release of hazardous substances into the atmosphere continue being a matter of concern, especially in densely populated urban regions. Emergency responders need to have estimates of these adverse health effects in the local population to aid planning, emergency response, and recovery efforts. For this purpose, models that predict the transport and dispersion of hazardous materials are as necessary as those that estimate the adverse health effects in the population. In this paper, we present the results obtained by coupling a Computational Fluid Dynamics model, FLACS (FLame ACceleration Simulator), with an exposure model, DDC (Damage Differential Coupling). This coupled model system is applied to a scenario of hypothetical release of chlorine with obstacles, such as buildings, and the results show how it is capable of predicting the atmospheric dispersion of hazardous chemicals, and the adverse health effects in the exposed population, to support decision makers both in charge of emergency planning and in charge of real-time response. The results obtained show how knowing the influence of obstacles in the trajectory of the toxic cloud and in the diffusion of the pollutants transported, and obtaining dynamic information of the potentially affected population and of associated symptoms, contribute to improve the planning of the protection and response measures.

An advanced model for spreading and evaporation of accidentally released hazardous liquids on land

NARCIS (Netherlands)

Trijssenaar-Buhre, I.J.M.; Sterkenburg, R.P.; Wijnant-Timmerman, S.I.

2009-01-01

Pool evaporation modelling is an important element in consequence assessment of accidentally released hazardous liquids. The evaporation rate determines the amount of toxic or flammable gas released into the atmosphere and is an important factor for the size of a pool fire. In this paper a

An advanced model for spreading and evaporation of accidentally released hazardous liquids on land

NARCIS (Netherlands)

Trijssenaar-Buhre, I.J.M.; Wijnant-Timmerman, S.L.

2008-01-01

Pool evaporation modelling is an important element in consequence assessment of accidentally released hazardous liquids. The evaporation rate determines the amount of toxic or flammable gas released into the atmosphere and is an important factor for the size of a pool fire. In this paper a

The MARS simulation of the nuclear weapons preparedness LOTTA scenario

International Nuclear Information System (INIS)

Tovedal, H.

2001-03-01

The simulation method MARS, Mathematical Radiac Simulation, is primarily intended for preparedness exercises in nuclear fallout areas and simulates the ionizing radiation dose rates from fission products deposited on the ground, i.e. fallout from a nuclear weapons explosion or from a release of radioactive material from a nuclear reactor. MARS gives at any time after the fictitious explosion or reactor release the dose rates at any position in the fallout area. MARS has been used for simulation of an exercise scenario called LOTTA, designed for training and test of a radiac preparedness group in the Dept. of Nuclear Protection at FOI. The group is a member of a national preparedness organisation under the Swedish Radiation Protection Institute, SSI. This MARS application was a simulation of the entire course of events following a fictitious nuclear weapons explosion, including the fission product deposition process and the ultimate activity and dose rate distribution in the fallout area. The simulation was based on deposition and fallout prognoses worked out by FOI, using the prognosis model PELLO. This report presents a short description of the simulation of the LOTTA scenario. A more detailed presentation of the general MARS method can be found in the report 'Mathematical Radiac Simulation, MARS'

Justice in the Air: Tracking Toxic Pollution from America's Industries and Companies to Our States, Cities, and Neighborhoods

OpenAIRE

Michael Ash; James Boyce; Grace Chang; Justin Scoggins; Manuel Pastor

2009-01-01

This new environmental justice study, (co-authored by PERI’s James Boyce, Michael Ash, & Grace Chang, along with Manuel Pastor, Justin Scoggins, & Jennifer Tran of the Program for Environmental and Regional Equity at the University of Southern California) examines not only who receives the disproportionate share of toxic air releases -- low-income communities and people of color -- but who is releasing them. Justice in the Air: Tracking Toxic Pollution from America's Industries and Companies ...

Release fractions for Rocky Flats specific accidents

International Nuclear Information System (INIS)

Weiss, R.C.

1992-01-01

As Rocky Flats and other DOE facilities begin the transition process towards decommissioning, the nature of the scenarios to be studied in safety analysis will change. Whereas the previous emphasis in safety accidents related to production, now the emphasis is shifting to accidents related tc decommissioning and waste management. Accident scenarios of concern at Rocky Flats now include situations of a different nature and different scale than are represented by most of the existing experimental accident data. This presentation will discuss approaches at sign to use for applying the existing body of release fraction data to this new emphasis. Mention will also be made of ongoing efforts to produce new data and improve the understanding of physical mechanisms involved

Attributes Of Quality Scenarios/Scenario Sets Used In Software Requirements Elicitation

National Research Council Canada - National Science Library

Braun, Kimberly

1997-01-01

.... This thesis examines scenarios used in software requirements elicitation. Many different definitions, formats, and ideas exist on scenarios, but no thorough work has been done on what makes a good, quality scenario and scenario set...

Dispersion of dissolved tracers released at the seafloor

International Nuclear Information System (INIS)

Kupferman, S.L.; Moore, D.E.

1983-01-01

The authors present scenarios that describe the temporal and spatial development of a concentration field of a dissolved tracer released at the seafloor for one Pacific and two Atlantic study areas. The scenarios are closely tied to available data by means of simple analytical models, and they proceed in stages from short time and space scales in the immediate vicinity of a release point to those scales characteristic of entire ocean basins. They introduce and discuss the concepts of internal mixing time and residence time in the benthic mixed layer, which are useful for developing an intuitive feeling for the behavior of a tracer. They also introduce the concept of domain of occupation, which is useful in drawing distinctions between mixing and stirring in the ocean. From this study it is apparent that reliable estimation of mixing will require careful consideration of the dynamics of the eddy fields in the ocean. In addition they urgently need more information that relates isopycnal structure and bottom topography to local near-bottom circulation

Evaluation of the impact and the releases of operating nuclear facilities

International Nuclear Information System (INIS)

2005-01-01

The monitoring of nuclear installations releases, the associated impacts evaluation and the radiation monitoring of the environment are of an increase interest since the last ten years. Theses two days, organized by the environment section of the SFRP (French Society of Radiation Protection), aim to discuss the following topics: the development of the methods to improve radioactive elements and toxic substances releases in the environment; the structure of the environment control and the objectives of this control; the association of the local actors to the releases monitoring and to the environment control; the perspectives of evolution in matter of nuclear facilities releases management. (A.L.B.)

Characteristics of debris in the lower head of a BWR in different severe accident scenarios

International Nuclear Information System (INIS)

Phung, Viet-Anh; Galushin, Sergey; Raub, Sebastian; Goronovski, Andrei; Villanueva, Walter; Kööp, Kaspar; Grishchenko, Dmitry; Kudinov, Pavel

2016-01-01

Highlights: • Station blackout scenario with delayed recovery of safety systems in a Nordic BWR is considered. • Genetic algorithm and random sampling methods are used to explore accident scenario domain. • Main groups of scenarios are identified. • Ranges and distributions of characteristics of debris bed in the lower head are determined. - Abstract: Nordic boiling water reactors (BWRs) adopt ex-vessel debris cooling to terminate severe accident progression. Core melt released from the vessel into a deep pool of water is expected to fragment and form a coolable debris bed. Characteristics of corium melt ejection from the vessel determine conditions for molten fuel–coolant interactions (FCI) and debris bed formation. Non-coolable debris bed or steam explosion can threaten containment integrity. Vessel failure and melt ejection mode are determined by the in-vessel accident progression. Characteristics (such as mass, composition, thermal properties, timing of relocation, and decay heat) of the debris bed formed in the process of core relocation into the vessel lower plenum define conditions for the debris reheating, remelting, melt-vessel structure interactions, vessel failure and melt release. Thus core degradation and relocation are important sources of uncertainty for the success of the ex-vessel accident mitigation strategy. The goal of this work is improve understanding how accident scenario parameters, such as timing of failure and recovery of different safety systems can affect characteristics of the debris in the lower plenum. Station blackout scenario with delayed power recovery in a Nordic BWR is considered using MELCOR code. The recovery timing and capacity of safety systems were varied using genetic algorithm (GA) and random sampling methods to identify two main groups of scenarios: with relatively small ( 100 tons) amount of relocated debris. The domains are separated by the transition regions, in which relatively small variations of the input

Characteristics of debris in the lower head of a BWR in different severe accident scenarios

Energy Technology Data Exchange (ETDEWEB)

Phung, Viet-Anh, E-mail: vaphung@kth.se; Galushin, Sergey, E-mail: galushin@kth.se; Raub, Sebastian, E-mail: raub@kth.se; Goronovski, Andrei, E-mail: andreig@kth.se; Villanueva, Walter, E-mail: walterv@kth.se; Kööp, Kaspar, E-mail: kaspar@safety.sci.kth.se; Grishchenko, Dmitry, E-mail: dmitry@safety.sci.kth.se; Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se

2016-08-15

Highlights: • Station blackout scenario with delayed recovery of safety systems in a Nordic BWR is considered. • Genetic algorithm and random sampling methods are used to explore accident scenario domain. • Main groups of scenarios are identified. • Ranges and distributions of characteristics of debris bed in the lower head are determined. - Abstract: Nordic boiling water reactors (BWRs) adopt ex-vessel debris cooling to terminate severe accident progression. Core melt released from the vessel into a deep pool of water is expected to fragment and form a coolable debris bed. Characteristics of corium melt ejection from the vessel determine conditions for molten fuel–coolant interactions (FCI) and debris bed formation. Non-coolable debris bed or steam explosion can threaten containment integrity. Vessel failure and melt ejection mode are determined by the in-vessel accident progression. Characteristics (such as mass, composition, thermal properties, timing of relocation, and decay heat) of the debris bed formed in the process of core relocation into the vessel lower plenum define conditions for the debris reheating, remelting, melt-vessel structure interactions, vessel failure and melt release. Thus core degradation and relocation are important sources of uncertainty for the success of the ex-vessel accident mitigation strategy. The goal of this work is improve understanding how accident scenario parameters, such as timing of failure and recovery of different safety systems can affect characteristics of the debris in the lower plenum. Station blackout scenario with delayed power recovery in a Nordic BWR is considered using MELCOR code. The recovery timing and capacity of safety systems were varied using genetic algorithm (GA) and random sampling methods to identify two main groups of scenarios: with relatively small (<20 tons) and large (>100 tons) amount of relocated debris. The domains are separated by the transition regions, in which relatively small

User needs for climate change scenarios in Switzerland

Science.gov (United States)

Fischer, Andreas; Liniger, Mark; Flückiger Knutti, Jacqueline

2017-04-01

In the framework of the recently founded National Center for Climate Services (NCCS) new climate change scenarios for Switzerland are currently under development that will be released in 2018 ("CH2018 scenarios"). An important component herein is the consideration of user needs in order to ensure that the new scenarios are user tailored and hence find a wide applicability in different sectors in Switzerland. A comprehensive market research was conducted to get a better overview of who the users of climate scenarios are and what they need. The survey targeted the most climate relevant sectors, and involved representatives from administration, research and private companies across Switzerland. The survey comprised several qualitative group interviews with key stakeholders, a written questionaire, answered by more than one hundred users and two specific workshops gathering the needs in dissemination. Additionally, the survey results were consolidated at a national symposium with around 150 participants from research, administration and practice. The results of the survey show the necessity to classify the users of climate scenarios according to their level of usage and according to the different sectors. It turns out that the less intensive the usage of the climate scenarios is, the more important becomes the need of comprehensibility, clarity and support when disseminating new climate scenarios. According to the survey it is especially the non-experts that should be better addressed in the new cycle of national climate scenarios. In terms of content, the survey reveals strongest needs for quantitative information on changes in extremes, an aspect that was handled in a qualitative way only in the predecessor climate scenario suite CH2011. Another cross-sectoral need are physically consistent data in time, space and between several variables. For instance, in agriculture the combination of heat and dryness is an important aspect, while the same is true in the energy

Evaluating release alternatives for a long-lived bird species under uncertainty about long-term demographic rates

Science.gov (United States)

Moore, Clinton T.; Converse, Sarah J.; Folk, Martin J.; Runge, Michael C.; Nesbitt, Stephen A.

2012-01-01

The release of animals to reestablish an extirpated population is a decision problem that is often attended by considerable uncertainty about the probability of success. Annual releases of captive-reared juvenile Whooping Cranes (Grus americana) were begun in 1993 in central Florida, USA, to establish a breeding, non-migratory population. Over a 12-year period, 286 birds were released, but by 2004, the introduced flock had produced only four wild-fledged birds. Consequently, releases were halted over managers' concerns about the performance of the released flock and uncertainty about the efficacy of further releases. We used data on marked, released birds to develop predictive models for addressing whether releases should be resumed, and if so, under what schedule. To examine the outcome of different release scenarios, we simulated the survival and productivity of individual female birds under a baseline model that recognized age and breeding-class structure and which incorporated empirically estimated stochastic elements. As data on wild-fledged birds from captive-reared parents were sparse, a key uncertainty that confronts release decision-making is whether captive-reared birds and their offspring share the same vital rates. Therefore, we used data on the only population of wild Whooping Cranes in existence to construct two alternatives to the baseline model. The probability of population persistence was highly sensitive to the choice of these three models. Under the baseline model, extirpation of the population was nearly certain under any scenario of resumed releases. In contrast, the model based on estimates from wild birds projected a high probability of persistence under any release scenario, including cessation of releases. Therefore, belief in either of these models suggests that further releases are an ineffective use of resources. In the third model, which simulated a population Allee effect, population persistence was sensitive to the release decision

Development of a database: DACTARI for a radio-toxic element ranking methodology

International Nuclear Information System (INIS)

Ansoborlo, E.; Santucci, C.; Grouiller, J.P.; Boucher, L.; Fluery-Herard, A.; Menetrier, F.; Comte, A.; Cook, E.; Moulin, V.

2007-01-01

Dosimetric impact studies aim at evaluating potential radiological effects of chronic or acute releases from nuclear facilities. A methodology for ranking radionuclides (RN) in terms of their health-related impact on the human population was first developed at CEA with specific criteria for each RN that could be applied to a variety of situations. It is based, in particular, on applying physico-chemical criteria to the complete RN inventory (present in the release or in the source term) and on applying norms related to radiation protection and chemical toxicology. The initial step consisted in identifying and collecting data necessary to apply the methodology, with reference to a previous database of long-lived radionuclides (LLRN, with half-lives ranging from 30 to 10 14 y) containing 95 radionuclides. The initial results have allowed us to identify missing data and revealed the need to complete the study for both toxic and radio-toxic aspects. This led us to the next step, developing a specific database, Database for Chemical Toxicity and Radiotoxicity Assessment of RadIonuclides (DACTARI), to collect data on chemical toxicity and radiotoxicity, including acute or chronic toxicity, the chemical form of the compounds, the contamination route (ingestion, inhalation), lethal doses, target organs, intestinal and maternal-foetal transfer, drinking water guidelines and the mutagenic and carcinogenic properties. (authors)

A proposal for a test method for assessment of hazard property HP 12 ("Release of an acute toxic gas") in hazardous waste classification - Experience from 49 waste.

Science.gov (United States)

Hennebert, Pierre; Samaali, Ismahen; Molina, Pauline

2016-12-01

A stepwise method for assessment of the HP 12 is proposed and tested with 49 waste samples. The hazard property HP 12 is defined as "Release of an acute toxic gas": waste which releases acute toxic gases (Acute Tox. 1, 2 or 3) in contact with water or an acid. When a waste contains a substance assigned to one of the following supplemental hazards EUH029, EUH031 and EUH032, it shall be classified as hazardous by HP 12 according to test methods or guidelines (EC, 2014a, 2014b). When the substances with the cited hazard statement codes react with water or an acid, they can release HCl, Cl 2 , HF, HCN, PH 3 , H 2 S, SO 2 (and two other gases very unlikely to be emitted, hydrazoic acid HN 3 and selenium oxide SeO 2 - a solid with low vapor pressure). Hence, a method is proposed:For a set of 49 waste, water addition did not produce gas. Nearly all the solid waste produced a gas in contact with hydrochloric acid in 5 min in an automated calcimeter with a volume >0.1L of gas per kg of waste. Since a plateau of pressure is reached only for half of the samples in 5 min, 6 h trial with calorimetric bombs or glass flasks were done and confirmed the results. Identification of the gases by portable probes showed that most of the tested samples emit mainly CO 2 . Toxic gases are emitted by four waste: metallic dust from the aluminum industry (CO), two air pollution control residue of industrial waste incinerator (H 2 S) and a halogenated solvent (organic volatile(s) compound(s)). HF has not been measured in these trials started before the present definition of HP 12. According to the definition of HP 12, only the H 2 S emission of substances with hazard statement EUH031 is accounted for. In view of the calcium content of the two air pollution control residue, the presence of calcium sulphide (EUH031) can be assumed. These two waste are therefore classified potentially hazardous for HP 12, from a total of 49 waste. They are also classified as hazardous for other properties (HP 7

Analysis of metal ion release from biomedical implants

Directory of Open Access Journals (Sweden)

Ivana Dimić

2013-06-01

Full Text Available Metallic biomaterials are commonly used for fixation or replacement of damaged bones in the human body due to their good combination of mechanical properties. The disadvantage of metals as implant materials is their susceptibility to corrosion and metal ion release, which can cause serious health problems. In certain concentrations metals and metal ions are toxic and their presence can cause diverse inflammatory reactions, genetic mutations or even cancer. In this paper, different approaches to metal ion release examination, from biometallic materials sample preparation to research results interpretation, will be presented. An overview of the analytical techniques, used for determination of the type and concentration of released ions from implants in simulated biofluids, is also given in the paper.

Nanoscale Coloristic Pigments: Upper Limits on Releases from Pigmented Plastic during Environmental Aging, In Food Contact, and by Leaching.

Science.gov (United States)

Neubauer, Nicole; Scifo, Lorette; Navratilova, Jana; Gondikas, Andreas; Mackevica, Aiga; Borschneck, Daniel; Chaurand, Perrine; Vidal, Vladimir; Rose, Jerome; von der Kammer, Frank; Wohlleben, Wendel

2017-10-17

The life cycle of nanoscale pigments in plastics may cause environmental or human exposure by various release scenarios. We investigated spontaneous and induced release with mechanical stress during/after simulated sunlight and rain degradation of polyethylene (PE) with organic and inorganic pigments. Additionally, primary leaching in food contact and secondary leaching from nanocomposite fragments with an increased surface into environmental media was examined. Standardized protocols/methods for release sampling, detection, and characterization of release rate and form were applied: Transformation of the bulk material was analyzed by Scanning Electron Microscopy (SEM), X-ray-tomography and Fourier-Transform Infrared spectroscopy (FTIR); releases were quantified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), single-particle-ICP-MS (sp-ICP-MS), Transmission Electron Microscopy (TEM), Analytical Ultracentrifugation (AUC), and UV/Vis spectroscopy. In all scenarios, the detectable particulate releases were attributed primarily to contaminations from handling and machining of the plastics, and were not identified with the pigments, although the contamination of 4 mg/kg (Fe) was dwarfed by the intentional content of 5800 mg/kg (Fe as Fe 2 O 3 pigment). We observed modulations (which were at least partially preventable by UV stabilizers) when comparing as-produced and aged nanocomposites, but no significant increase of releases. Release of pigments was negligible within the experimental error for all investigated scenarios, with upper limits of 10 mg/m 2 or 1600 particles/mL. This is the first holistic confirmation that pigment nanomaterials remain strongly contained in a plastic that has low diffusion and high persistence such as the polyolefin High Density Polyethylene (HDPE).

Chemical toxicity approach for emergency response

International Nuclear Information System (INIS)

Bauer, T.

2009-01-01

In the event of an airborne release of chemical agent or toxic industrial chemical by accidental or intentional means, emergency responders must have a reasonable estimate of the location and size of the resulting hazard area. Emergency responders are responsible for warning persons downwind of the hazard to evacuate or shelter-in-place and must know where to look for casualties after the hazard has passed or dissipated. Given the same source characterization, modern hazard assessment models provide comparable concentration versus location and time estimates. Even urban hazard assessment models often provide similar predictions. There is a major shortcoming, though, in applying model output to estimating human toxicity effects. There exist a variety of toxicity values for non-lethal effects ranging from short-term to occupational to lifetime exposures. For health and safety purposes, these estimates are all safe-sided in converting animal data to human effects and in addressing the most sensitive subset of the population. In addition, these values are usually based on an assumed 1 hour exposure duration at constant concentration and do not reflect either a passing clouds concentration profile or duration. Emergency responders need expected value toxicity parameters rather than the existing safe-sided ones. This presentation will specify the types of toxicity values needed to provide appropriate chemical hazard estimates to emergency responders and will demonstrate how dramatically their use changes the hazard area.(author)

Toxic effects of extracellular histones and their neutralization by vitreous in retinal detachment.

Science.gov (United States)

Kawano, Hiroki; Ito, Takashi; Yamada, Shingo; Hashiguchi, Teruto; Maruyama, Ikuro; Hisatomi, Toshio; Nakamura, Makoto; Sakamoto, Taiji

2014-05-01

Histones are DNA-binding proteins and are involved in chromatin remodeling and regulation of gene expression. Histones can be released after tissue injuries, and the extracellular histones cause cellular damage and organ dysfunction. Regardless of their clinical significance, the role and relevance of histones in ocular diseases are unknown. We studied the role of histones in eyes with retinal detachment (RD). Vitreous samples were collected during vitrectomy, and the concentration of histone H3 was measured by enzyme-linked immunosorbent assay. The location of the histones and related molecules was examined in a rat RD model. The release of histones and their effects on rat retinal progenitor cells R28 and ARPE-19 were evaluated in vitro. In addition, the protective role of the vitreous body against histones was tested. The intravitreal concentration of histones was higher in eyes with RD (mean, 30.9 ± 9.8 ng/ml) than in control eyes (below the limit of detection, Phistone H3 was observed on the outer side of the detached retina and was associated with photoreceptor death. Histone H3 was released from cultured R28 by oxidative stress. Histones at a concentration 10 μg/ml induced the production of interleukin-8 in ARPE-19 cells (2.5-fold increase, PHistones were toxic to cells at concentrations of ≥ 20 μg/ml. Vitreous body or hyaluronan decreased toxicity of histones by inhibiting diffusion of histones. These results indicate that histones are released from retinas with RD and may modulate the subretinal microenvironment by functioning as damage-associated molecular pattern molecules, thereby inducing proinflammatory cytokines or cell toxicity. In addition, the important role of the vitreous body and hyaluronan in protecting the retina from these toxic effects is suggested.

The joint SKI/SKB scenario development project

International Nuclear Information System (INIS)

Andersson, Johan

1989-12-01

The Swedish Nuclear Power and Swedish Nuclear Waste Management Co. have carried through a joint scenario development exercise of a hypothetical repository for spent fuel and high level waste based on the KBS-3 concept as disposal method. The starting point has been the 'Sandia methodology', but the actual implementation of the steps in this method has required new strategy development. The work started with a relatively large internationally composed group meeting, which identified an extensive list of features, events and processes (FEPs) that might influence the long term performance of a repository. All these FEPs as well as its possible causes and consequences have been entered into a computer database. The next step in the development was to remove from the list approximately 30 FEPs of low probability or negligible consequence. In a following step a large number of the FEPs on the original list were assigned to the 'PROCESS SYSTEM', comprising the complete set of 'deterministic' chemical and physical processes that might influence the release from the repository to the biosphere. A scenario is defined by a set of external conditions which will influence the processes in the PROCESS SYSTEM. Approximately 50 FEPs were left representing external conditions. The remaining FEPs could all be combined to form scenarios, but it is concluded that it is not meaningful to discuss combinations without first analysing the consequence and probability of the individual conditions. An important aspect of the work is that the developed strategy includes a framework for the documentation of the complete chain of scenario development. Such a transparent documentation makes possible an extensive review and updating of the set of scenarios. A reviewing process, open to very broad groups in the society, is probably the best means of assuring reasonable completeness and of building up a general consensus on what are the critical issues for the safe disposal of radioactive waste

Controlled release system for ametryn using polymer microspheres: Preparation, characterization and release kinetics in water

International Nuclear Information System (INIS)

Grillo, Renato; Pereira, Anderson do Espirito Santo; Ferreira Silva de Melo, Nathalie; Porto, Raquel Martins; Feitosa, Leandro Oliveira; Tonello, Paulo Sergio; Dias Filho, Newton L.; Rosa, Andre Henrique; Lima, Renata; Fraceto, Leonardo Fernandes

2011-01-01

The purpose of this work was to develop a modified release system for the herbicide ametryn by encapsulating the active substance in biodegradable polymer microparticles produced using the polymers poly(hydroxybutyrate) (PHB) or poly(hydroxybutyrate-valerate) (PHBV), in order to both improve the herbicidal action and reduce environmental toxicity. PHB or PHBV microparticles containing ametryn were prepared and the efficiencies of herbicide association and loading were evaluated, presenting similar values of approximately 40%. The microparticles were characterized by scanning electron microscopy (SEM), which showed that the average sizes of the PHB and PHBV microparticles were 5.92 ± 0.74 μm and 5.63 ± 0.68 μm, respectively. The ametryn release profile was modified when it was encapsulated in the microparticles, with slower and more sustained release compared to the release profile of pure ametryn. When ametryn was associated with the PHB and PHBV microparticles, the amount of herbicide released in the same period of time was significantly reduced, declining to 75% and 87%, respectively. For both types of microparticle (PHB and PHBV) the release of ametryn was by diffusion processes due to anomalous transport (governed by diffusion and relaxation of the polymer chains), which did not follow Fick's laws of diffusion. The results presented in this paper are promising, in view of the successful encapsulation of ametryn in PHB or PHBV polymer microparticles, and indications that this system may help reduce the impacts caused by the herbicide, making it an environmentally safer alternative.

Analysis of core degradation and relocation phenomena and scenarios in a Nordic-type BWR

Energy Technology Data Exchange (ETDEWEB)

Galushin, Sergey, E-mail: galushin@kth.se; Kudinov, Pavel, E-mail: pkudinov@kth.se

2016-12-15

Highlights: • A data base of the debris properties in lower plenum generated using MELCOR code. • The timing of safety systems has significant effect on the relocated debris properties. • Loose coupling between core relocation and vessel failure analyses was established. - Abstract: Severe Accident Management (SAM) in Nordic Boiling Water Reactors (BWR) employs ex-vessel cooling of core melt debris. The melt is released from the failed vessel and poured into a deep pool of water located under the reactor. The melt is expected to fragment, quench, and form a debris bed, coolable by a natural circulation and evaporation of water. Success of the strategy is contingent upon melt release conditions from the vessel and melt-coolant interaction that determine (i) properties of the debris bed and its coolability (ii) potential for energetic melt-coolant interactions (steam explosions). Risk Oriented Accident Analysis Methodology (ROAAM+) framework is currently under development for quantification of the risks associated with formation of non-coolable debris bed and occurrence of steam explosions, both presenting a credible threats to containment integrity. The ROAAM+ framework consist of loosely coupled models that describe each stage of the accident progression. Core relocation analysis framework provides initial conditions for melt vessel interaction, vessel failure and melt release frameworks. The properties of relocated debris and melt release conditions, including in-vessel and ex-vessel pressure, lower drywell pool depth and temperature, are sensitive to the accident scenarios and timing of safety systems recovery and operator actions. This paper illustrates a methodological approach and relevant data for establishing a connection between core relocation and vessel failure analysis in ROAAM+ approach. MELCOR code is used for analysis of core degradation and relocation phenomena. Properties of relocated debris are obtained as functions of the accident scenario

Critical analysis of accident scenario and consequences modelling applied to light-water reactor power plants for accident categories beyond the design basis accident (DBA)

International Nuclear Information System (INIS)

Brofferio, C.; Cagnetti, P.; Ferrara, V.; Manilia, E.; Pietrangeli, G.; Sennis, C.

1985-01-01

A critical analysis and sensitivity study of the modelling of accident scenarios and environmental consequences are presented, for light-water reactor accident categories beyond the standard design-basis-accident category. The first chapter, on ''source term'' deals with the release of fission products from a damaged core inventory and their migration within the primary circuit and the reactor containment. Particular attention is given to the influence of engineering safeguards intervention and of the chemical forms of the released fission products. The second chapter deals with their release to the atmosphere, transport and wet or dry deposition, outlining relevant partial effects and confronting short-duration or prolonged releases. The third chapter presents a variability analysis, for environmental contamination levels, for two extreme hypothetical scenarios, evidencing the importance of plume rise. A numerical plume rise model is outlined

Acute toxicity of Headline® fungicide to Blanchard's cricket frogs (Acris blanchardi).

Science.gov (United States)

Cusaac, J Patrick W; Morrison, Shane A; Belden, Jason B; Smith, Loren M; McMurry, Scott T

2016-04-01

Previous laboratory studies have suggested that pyraclostrobin-containing fungicide formulations are toxic to amphibians at environmentally relevant concentrations. However, it is unknown if all pyraclostrobin formulations have similar toxicity and if toxicity occurs in different amphibian species. We investigated the acute toxicity of two formulations, Headline(®) fungicide and Headline AMP(®) fungicide, to Blanchard's cricket frogs (Acris blanchardi) based on a direct overspray scenario. In addition, we examined body residues of fungicide active ingredients in A. blanchardi following direct exposure to Headline AMP fungicide. Headline fungicide and Headline AMP fungicide had similar toxicity to A. blanchardi with calculated median lethal doses of 2.1 and 1.7 µg pyraclostrobin/cm(2), respectively, which are similar to the suggested maximum label rate in North American corn (2.2 and 1.52 µg pyraclostrobin/cm(2), respectively). Tissue concentrations of pyraclostrobin were lower than predicted based on full uptake of a direct dose, and did not drop during the first 24 h after exposure. Headline fungicides at corn application rates are acutely toxic to cricket frogs, but acute toxicity in the field will depend on worst-case exposure.

Safety assessment of VHTR hydrogen production system against fire, explosion and acute toxicity

International Nuclear Information System (INIS)

Murakami, Tomoyuki; Nishihara, Tetsuo; Kunitomi, Kazuhiko

2008-01-01

The Japan Atomic Energy Agency has been developing a nuclear hydrogen production system by using heat from the Very High Temperature Reactor (VHTR). This system will handle a large amount of combustible gas and toxic gas. The risk from fire, explosion and acute toxic exposure caused by an accident involving chemical material release in a hydrogen production system is assessed. It is important to ensure the safety of the nuclear plant, and the risks for public health should be sufficiently small. This report provides the basic policy for the safety evaluation in cases of accident involving fire, explosion and toxic material release in a hydrogen production system. Preliminary safety analysis of a commercial-sized VHTR hydrogen production system, GTHTR300C, is performed. This analysis provides us with useful information on the separation distance between a nuclear plant and a hydrogen production system and a prospect that an accident in a hydrogen production system does not significantly increase the risks of the public. (author)

Prevention and mitigation of groundwater contamination from radioactive releases

International Nuclear Information System (INIS)

1988-10-01

This document gives basic information on potential pathways and mechanisms, by which radioactive materials from releases can reach man, and on modelling considerations to predict the behaviour of radioactive materials in the ground. The main objective is to present an overview of existing techniques for preventing the offsite releases of contaminants into the groundwater systems and techniques for mitigation of effects of such releases should they occur. The recommended techniques are fully applicable to any hazardous materials, such as organic liquids, and toxic materials or otherwise dangerous materials, the presence of which in the accessible biosphere can represent health risks as well as economic losses to the general public. 11 refs, 2 figs, 8 tabs

Toxicity of carbon nanotubes to freshwater aquatic invertebrates

Science.gov (United States)

Mwangi, Joseph N.; Wang, Ning; Ingersoll, Christopher G.; Hardesty, Doug K.; Brunson, Eric L.; Li, Hao; Deng, Baolin

2012-01-01

Carbon nanotubes (CNTs) are hydrophobic in nature and thus tend to accumulate in sediments if released into aquatic environments. As part of our overall effort to examine the toxicity of carbon-based nanomaterials to sediment-dwelling invertebrates, we have evaluated the toxicity of different types of CNTs in 14-d water-only exposures to an amphipod (Hyalella azteca), a midge (Chironomus dilutus), an oligochaete (Lumbriculus variegatus), and a mussel (Villosa iris) in advance of conducting whole-sediment toxicity tests with CNTs. The results of these toxicity tests conducted with CNTs added to water showed that 1.00g/L (dry wt) of commercial sources of CNTs significantly reduced the survival or growth of the invertebrates. Toxicity was influenced by the type and source of the CNTs, by whether the materials were precleaned by acid, by whether sonication was used to disperse the materials, and by species of the test organisms. Light and electron microscope imaging of the surviving test organisms showed the presence of CNTs in the gut as well as on the outer surface of the test organisms, although no evidence was observed to show penetration of CNTs through cell membranes. The present study demonstrated that both the metals solubilized from CNTs such as nickel and the "metal-free" CNTs contributed to the toxicity.

The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

Energy Technology Data Exchange (ETDEWEB)

O' Neill, Brian C.; Tebaldi, Claudia; van Vuuren, Detlef P.; Eyring, Veronika; Friedlingstein, Pierre; Hurtt, George; Knutti, Reto; Kriegler, Elmar; Lamarque, Jean-Francois; Lowe, Jason; Meehl, Gerald A.; Moss, Richard; Riahi, Keywan; Sanderson, Benjamin M.

2016-01-01

Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially

Suitability of a Saccharomyces cerevisiae-based assay to assess the toxicity of pyrimethanil sprayed soils via surface runoff: comparison with standard aquatic and soil toxicity assays.

Science.gov (United States)

Gil, Fátima N; Moreira-Santos, Matilde; Chelinho, Sónia; Pereira, Carla; Feliciano, Joana R; Leitão, Jorge H; Sousa, José P; Ribeiro, Rui; Viegas, Cristina A

2015-02-01

The present study is aimed at evaluating whether a gene expression assay with the microbial eukaryotic model Saccharomyces cerevisiae could be used as a suitable warning tool for the rapid preliminary screening of potential toxic effects on organisms due to scenarios of soil and water contamination with pyrimethanil. The assay consisted of measuring changes in the expression of the selected pyrimethanil-responsive genes ARG3 and ARG5,6 in a standardized yeast population. Evaluation was held by assessing the toxicity of surface runoff, a major route of pesticide exposure in aquatic systems due to non-point-source pollution, which was simulated with a pyrimethanil formulation at a semifield scale mimicking worst-case scenarios of soil contamination (e.g. accident or improper disposal). Yeast cells 2-h exposure to the runoff samples led to a significant 2-fold increase in the expression of both indicator genes. These results were compared with those from assays with organisms relevant for the aquatic and soil compartments, namely the nematode Caenorhabditis elegans (reproduction), the freshwater cladoceran Daphnia magna (survival and reproduction), the benthic midge Chironomus riparius (growth), and the soil invertebrates Folsomia candida and Enchytraeus crypticus (survival and reproduction). Under the experimental conditions used to simulate accidental discharges into soil, runoff waters were highly toxic to the standard test organisms, except for C. elegans. Overall, results point out the usefulness of the yeast assay to provide a rapid preview of the toxicity level in preliminary screenings of environmental samples in situations of inadvertent high pesticide contamination. Advantages and limitations of this novel method are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Methodology Using MELCOR Code to Model Proposed Hazard Scenario

Energy Technology Data Exchange (ETDEWEB)

Gavin Hawkley

2010-07-01

This study demonstrates a methodology for using the MELCOR code to model a proposed hazard scenario within a building containing radioactive powder, and the subsequent evaluation of a leak path factor (LPF) (or the amount of respirable material which that escapes a facility into the outside environment), implicit in the scenario. This LPF evaluation will analyzes the basis and applicability of an assumed standard multiplication of 0.5 × 0.5 (in which 0.5 represents the amount of material assumed to leave one area and enter another), for calculating an LPF value. The outside release is dependsent upon the ventilation/filtration system, both filtered and un-filtered, and from other pathways from the building, such as doorways (, both open and closed). This study is presents ed to show how the multiple leak path factorsLPFs from the interior building can be evaluated in a combinatory process in which a total leak path factorLPF is calculated, thus addressing the assumed multiplication, and allowing for the designation and assessment of a respirable source term (ST) for later consequence analysis, in which: the propagation of material released into the environmental atmosphere can be modeled and the dose received by a receptor placed downwind can be estimated and the distance adjusted to maintains such exposures as low as reasonably achievableALARA.. Also, this study will briefly addresses particle characteristics thatwhich affect atmospheric particle dispersion, and compares this dispersion with leak path factorLPF methodology.

Silicon Impurity Release and Surface Transformation of TiO2 Anatase and Rutile Nanoparticles in Water Environments

Science.gov (United States)

Surface transformation can affect the stability, reactivity, and toxicity of titanium dioxide (TiO2) nanoparticles (NPs) when released to water environments. Herein, we investigated the release kinetics of Si impurity frequently introduced during NP synthesis and the resulting ef...

Making use of scenarios : supporting scenario use in product design

NARCIS (Netherlands)

Anggreeni, Irene

2010-01-01

The discipline of Scenario-Based Product Design (SBPD) guides the use of scenarios in a product design process. As concrete narratives, scenarios could facilitate making explicit how users would use the designed product in their activities, allowing usability studies to be an integrated part of the

Pyrethroid insecticides evoke neurotransmitter release from rabbit striatal slices

International Nuclear Information System (INIS)

Eells, J.T.; Dubocovich, M.L.

1988-01-01

The effects of the synthetic pyrethroid insecticide fenvalerate ([R,S]-alpha-cyano-3-phenoxybenzyl[R,S]-2-(4-chlorophenyl)-3- methylbutyrate) on neurotransmitter release in rabbit brain slices were investigated. Fenvalerate evoked a calcium-dependent release of [ 3 H]dopamine and [ 3 H]acetylcholine from rabbit striatal slices that was concentration-dependent and specific for the toxic stereoisomer of the insecticide. The release of [ 3 H]dopamine and [ 3 H]acetylcholine by fenvalerate was modulated by D2 dopamine receptor activation and antagonized completely by the sodium channel blocker, tetrodotoxin. These findings are consistent with an action of fenvalerate on the voltage-dependent sodium channels of the presynaptic membrane resulting in membrane depolarization, and the release of dopamine and acetylcholine by a calcium-dependent exocytotic process. In contrast to results obtained in striatal slices, fenvalerate did not elicit the release of [ 3 H]norepinephrine or [ 3 H]acetylcholine from rabbit hippocampal slices indicative of regional differences in sensitivity to type II pyrethroid actions

Nanoscale Coloristic Pigments: Upper Limits on Releases from Pigmented Plastic during Environmental Aging, In Food Contact, and by Leaching

DEFF Research Database (Denmark)

Neubauer, Nicole; Scifo, Lorette; Navratilova, Jana

2017-01-01

The life cycle of nanoscale pigments in plastics may cause environmental or human exposure by various release scenarios. We investigated spontaneous and induced release with mechanical stress during/after simulated sunlight and rain degradation of polyethylene (PE) with organic and inorganic pigm...... investigated scenarios, with upper limits of 10 mg/m2 or 1600 particles/mL. This is the first holistic confirmation that pigment nanomaterials remain strongly contained in a plastic that has low diffusion and high persistence such as the polyolefin High Density Polyethylene (HDPE)....

Conductive plastics: comparing alternative nanotechnologies by performance and life cycle release probability

Energy Technology Data Exchange (ETDEWEB)

Neubauer, Nicole; Wohlleben, Wendel, E-mail: wendel.wohlleben@basf.com [Material Physics, GMC/R, BASF SE (Germany); Tomović, Željko, E-mail: zeljko.tomovic@basf.com [BASF Polyurethanes GmbH, GMP/LS (Germany)

2017-03-15

Nanocomposites can be considered safe during their life cycle as long as the nanofillers remain embedded in the matrix. Therefore, a possible release of nanofillers has to be assessed before commercialization. This report addresses possible life cycle release scenarios for carbon nanotubes (CNT), graphene, and carbon black (CB) from a thermoplastic polyurethane (TPU) matrix. The content of each nanofiller was adjusted to achieve the same conductivity level. The nanofillers reduced the rate of nanoscale releases during mechanical processing with decreasing release in the order neat TPU, TPU-CNT, TPU-graphene, and TPU-CB. Released fragments were dominated by the polymer matrix with embedded or surface-protruding nanofillers. During electron microscopy analysis, free CB was observed, however, there was no free CNT or graphene. Quantitatively, the presence of free nanofillers remained below the detection limit of <0.01% of generated dust. Further, both the production process and type of mechanical processing showed a significant impact with higher release rates for injection-molded compared to extruded and sanded compared to drilled materials. Due to its optimal performance for further development, extruded TPU-CNT was investigated in a combined, stepwise worst case scenario (mechanical processing after weathering). After weathering by simulated sunlight and rain, CNT were visible at the surface of the nanocomposite; after additional sanding, fragments showed protruding CNT, but free CNT were not detected. In summary, this preliminary exposure assessment showed no indication that recommended occupational exposure limits for carbonaceous nanomaterials can be exceeded during the life cycle of the specific TPU nanocomposites and conditions investigated in this study.

Measuring Nanomaterial Release from Carbon Nanotube Composites: Review of the State of the Science

International Nuclear Information System (INIS)

Harper, Stacey; Wohlleben, Wendel; Doa, Maria; Nowack, Bernd; Clancy, Shaun; Canady, Richard; Maynard, Andrew

2015-01-01

Hazard studies of “as-produced” nanomaterials are increasingly available, yet a critical gap exists in exposure science that may impede safe development of nanomaterials. The gap is that we do not understand what is actually released because nanomaterials can change when released in ways that are not understood. We also generally do not have methods capable of quantitatively measuring what is released to support dose assessment. This review presents a case study of multi-walled carbon nanotubes (MWCNTs) for the measurement challenge to bridge this gap. As the use and value of MWCNTs increases, methods to measure what is released in ways relevant to risk evaluation are critically needed if products containing these materials are to be economically, environmentally, and socially sustainable. This review draws on the input of over 50 experts engaged in a program of workshops and technical report writing to address the release of MWCNTs from nanocomposite materials across their life cycle. The expert analyses reveals that new and sophisticated methods are required to measure and assess MWCNT exposures for realistic exposure scenarios. Furthermore, method requirements vary with the materials and conditions of release across life cycle stages of products. While review shows that the likelihood of significant release of MWCNTs appears to be low for many stages of composite life cycle, measurement methods are needed so that exposures from MWCNT-composites are understood and managed. In addition, there is an immediate need to refocus attention from study of “as-produced” nanomaterials to coordinated research on actual release scenarios. (paper)

Dying scenarios improve recall as much as survival scenarios.

Science.gov (United States)

Burns, Daniel J; Hart, Joshua; Kramer, Melanie E

2014-01-01

Merely contemplating one's death improves retention for entirely unrelated material learned subsequently. This "dying to remember" effect seems conceptually related to the survival processing effect, whereby processing items for their relevance to being stranded in the grasslands leads to recall superior to that of other deep processing control conditions. The present experiments directly compared survival processing scenarios with "death processing" scenarios. Results showed that when the survival and dying scenarios are closely matched on key dimensions, and possible congruency effects are controlled, the dying and survival scenarios produced equivalently high recall levels. We conclude that the available evidence (cf. Bell, Roer, & Buchner, 2013; Klein, 2012), while not definitive, is consistent with the possibility of overlapping mechanisms.

Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor

International Nuclear Information System (INIS)

Rodriguez Castillo, Alfredo Santiago; Guihéneuf, Solène; Le Guével, Rémy; Biard, Pierre-François

2016-01-01

Highlights: • Description of a VOC depollution system suitable with industrial processes, TPPB. • Novel association of TPPB and hydrophobic ionic liquids. • Synthesis of several hydrophobic ionic liquids designed to fit desired properties. • Toxicity evaluation of these ILs towards cells, animals and bacteria. - Abstract: Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF_6"−, NTf_2"− and NfO"−. Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD_2_8 of aqueous samples (compound concentration,1 mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation.

Scenario design : adaptive architecture for command and control experiment eight

OpenAIRE

Clark, Frankie J.

2002-01-01

Approved for public release; distribution is unlimited. The Adaptive Architectures for Command and Control (A2C2) project is an ongoing research effort sponsored by the Office of Naval Research to explore adaptation in joint command and control. The objective of the project's eighth experiment is to study the adjustments that organizations make when they are confronted with a scenario for which their organizational is ill-suited. To accomplish this, teams will each be in one of two fundame...

Monitoring the effectiveness of remediation techniques using sediment toxicity tests with the amphipod Eohaustorius estuarius

International Nuclear Information System (INIS)

Doe, K.G.; Jackman, P.M.; Lee, K.

2002-01-01

The results of a controlled oil release experiment of weathered crude oil was presented. The released oil was applied to a tidal saltwater marsh at Conrod's Beach, Nova Scotia, Canada. The study included 3 replicate blocks which included 2 unoiled treatments and 4 oiled treatments for each block. One unoiled site had no treatment, the second unoiled site had nutrient addition to examine the effect of nutrients. The oiled treatments included natural attenuation, nutrient addition, nutrient addition with plants, and nutrient addition with a garden aerator to introduce oxygen. A standard lab procedure was used to analyze the sediments to determine the effectiveness of the technique as well as the toxic effects on the survival of the amphipod Eohaustorius estuarius. Test results indicated that the unoiled sites were non-toxic, with a slight decrease in survival in the treatment with nutrient addition. All the oiled sites were very toxic at first, but toxicity decreased gradually with time. Treatment with nutrient addition with a garden aerator proved to be the most complete and fastest detoxification method. 8 refs., 4 tabs., 2 figs

Assessing bio-available silver released from silver nanoparticles embedded in silica layers using the green algae Chlamydomonas reinhardtii as bio-sensors

Energy Technology Data Exchange (ETDEWEB)

Pugliara, Alessandro [nMat group-CEMES (Centre d' Elaboration de Matériaux et d' Etudes Structurales)-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4 (France); LAPLACE (LAboratoire PLAsma et Conversion d' Energie), Université de Toulouse, CNRS, UPS, INPT, 118 route de Narbonne, F-31062 Toulouse (France); Makasheva, Kremena; Despax, Bernard [LAPLACE (LAboratoire PLAsma et Conversion d' Energie), Université de Toulouse, CNRS, UPS, INPT, 118 route de Narbonne, F-31062 Toulouse (France); Bayle, Maxime; Carles, Robert; Benzo, Patrizio; BenAssayag, Gérard; Pécassou, Béatrice [nMat group-CEMES (Centre d' Elaboration de Matériaux et d' Etudes Structurales)-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4 (France); Sancho, Maria Carmen; Navarro, Enrique [IPE (Instituto Pirenaico de Ecología)-CSIC, Avda. Montañana 1005, Zaragoza 50059 (Spain); Echegoyen, Yolanda [I3A, Department of Analytical Chemistry, University of Zaragoza, C/ María de Luna 3, 50018, Zaragoza (Spain); Bonafos, Caroline, E-mail: bonafos@cemes.fr [nMat group-CEMES (Centre d' Elaboration de Matériaux et d' Etudes Structurales)-CNRS, Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse Cedex 4 (France)

2016-09-15

Silver nanoparticles (AgNPs) because of their strong antibacterial activity are widely used in health-care sector and industrial applications. Their huge surface-volume ratio enhances the silver release compared to the bulk material, leading to an increased toxicity for microorganisms sensitive to this element. This work presents an assessment of the toxic effect on algal photosynthesis due to small (size < 20 nm) AgNPs embedded in silica layers. Two physical approaches were originally used to elaborate the nanocomposite structures: (i) low energy ion beam synthesis and (ii) combined silver sputtering and plasma polymerization. These techniques allow elaboration of a single layer of AgNPs embedded in silica films at defined nanometer distances (from 0 to 7 nm) beneath the free surface. The structural and optical properties of the nanostructures were studied by transmission electron microscopy and optical reflectance. The silver release from the nanostructures after 20 h of immersion in buffered water was measured by inductively coupled plasma mass spectrometry and ranges between 0.02 and 0.49 μM. The short-term toxicity of Ag to photosynthesis of Chlamydomonas reinhardtii was assessed by fluorometry. The obtained results show that embedding AgNPs reduces the interactions with the buffered water free media, protecting the AgNPs from fast oxidation. The release of bio-available silver (impacting on the algal photosynthesis) is controlled by the depth at which AgNPs are located for a given host matrix. This provides a procedure to tailor the toxicity of nanocomposites containing AgNPs. - Highlights: • Controlled synthesis of 2D arrays of silver nanoparticles embedded in silica. • Assessing bio-available silver release using the green algae as bio-sensors. • The Ag release can be controlled by the distance nanoparticles/dielectric surface. • All the Ag released in solution is in the form of Ag{sup +} ions. • Toxicity comparable to similar concentrations of

Photolabile ruthenium complexes to cage and release a highly cytotoxic anticancer agent.

Science.gov (United States)

Wei, Jianhua; Renfrew, Anna K

2018-02-01

CHS-828 (N-(6-(4-chlorophenoxy)hexyl)-N'-cyano-N″-4-pyridyl guanidine) is an anticancer agent with low bioavailability and high systemic toxicity. Here we present an approach to improve the therapeutic profile of the drug using photolabile ruthenium complexes to generate light-activated prodrugs of CHS-828. Both prodrug complexes are stable in the dark but release CHS-828 when irradiated with visible light. The complexes are water-soluble and accumulate in tumour cells in very high concentrations, predominantly in the mitochondria. Both prodrug complexes are significantly less cyototoxic than free CHS-828 in the dark but their toxicity increases up to 10-fold in combination with visible light. The cellular responses to light treatment are consistent with release of the cytotoxic CHS-828 ligand. Copyright © 2017 Elsevier Inc. All rights reserved.

Glucose deprivation stimulates Cu(2+) toxicity in cultured cerebellar granule neurons and Cu(2+)-dependent zinc release.

Science.gov (United States)

Isaev, Nickolay K; Genrikhs, Elisaveta E; Aleksandrova, Olga P; Zelenova, Elena A; Stelmashook, Elena V

2016-05-27

Copper chloride (0.01mM, 2h) did not have significant influence on the survival of cerebellar granule neurons (CGNs) incubated in balanced salt solution. However, CuCl2 caused severe neuronal damage by glucose deprivation (GD). The glutamate NMDA-receptors blocker MK-801 partially and antioxidant N-acetyl-l-cysteine (NAC) or Zn(2+) chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) almost entirely protected CGNs from this toxic effect. Measurements of intracellular calcium ions using Fluo-4 AM, or zinc ions with FluoZin-3 AM demonstrated that 1 h-exposure to GD induced intensive increase of Fluo-4 but not FluoZin-3 fluorescence in neurons. The supplementation of solution with CuCl2 caused an increase of FluoZin-3, Fluo-4 and CellROX Green (reactive oxygen species probe) fluorescence by GD. The stimulation of Fluo-4 but not FluoZin-3 fluorescence by copper could be prevented partially by MK-801 and as well as CellROX Green fluorescence by NAC at GD. This data imply that during GD copper ions induce intense displacement zinc ions from intracellular stores, in addition free radical production, glutamate release and Ca(2+) overload of CGNs, that causes death of neurons as a result. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Aqueous humor tyrosinase activity is indicative of iris melanocyte toxicity.

Science.gov (United States)

Mahanty, Sarmistha; Kawali, Ankush A; Dakappa, Shruthi Shirur; Mahendradas, Padmamalini; Kurian, Mathew; Kharbanda, Varun; Shetty, Rohit; Setty, Subba Rao Gangi

2017-09-01

Antibiotics such as fluoroquinolones (FQLs) are commonly used to treat ocular infections but are also known to cause dermal melanocyte toxicity. The release of dispersed pigments from the iris into the aqueous humor has been considered a possible ocular side effect of the systemic administration of FQLs such as Moxifloxacin, and this condition is known as bilateral acute iris transillumination (BAIT). Bilateral acute depigmentation of iris (BADI) is a similar condition, with iris pigment released into the aqueous, but it has not been reported as a side effect of FQL. Iris pigments are synthesized by the melanogenic enzyme tyrosinase (TYR) and can be detected but not quantified by using slit-lamp biomicroscopy. The correlation between dispersed pigments in the aqueous and the extent of melanocyte toxicity due to topical antibiotics in vivo is not well studied. Here, we aimed to study the effect of topical FQLs on iris tissue, the pigment release in the aqueous humor and the development of clinically evident iris atrophic changes. We evaluated this process by measuring the activity of TYR in the aqueous humor of 82 healthy eyes undergoing cataract surgery following topical application of FQLs such as Moxifloxacin (27 eyes, preservative-free) or Ciprofloxacin (29 eyes, with preservative) or the application of non-FQL Tobramycin (26 eyes, with preservative) as a control. In addition, the patients were questioned and examined for ocular side effects in pre- and post-operative periods. Our data showed a significantly higher mean TYR activity in the aqueous humor of Ciprofloxacin-treated eyes compared to Moxifloxacin- (preservative free, p iris melanocytes. However, the reduced TYR activity in the aqueous of Moxifloxacin-treated eyes was possibly due to the presence of a higher drug concentration, which inhibits TYR activity. Consistently, immunoblotting analysis of the aqueous humor from both Ciprofloxacin- and Moxifloxacin-treated eyes showed the presence of soluble

Influences of use activities and waste management on environmental releases of engineered nanomaterials

International Nuclear Information System (INIS)

Wigger, Henning; Hackmann, Stephan; Zimmermann, Till; Köser, Jan; Thöming, Jorg; Gleich, Arnim von

2015-01-01

Engineered nanomaterials (ENM) offer enhanced or new functionalities and properties that are used in various products. This also entails potential environmental risks in terms of hazard and exposure. However, hazard and exposure assessment for ENM still suffer from insufficient knowledge particularly for product-related releases and environmental fate and behavior. This study therefore analyzes the multiple impacts of the product use, the properties of the matrix material, and the related waste management system (WMS) on the predicted environmental concentration (PEC) by applying nine prospective life cycle release scenarios based on reasonable assumptions. The products studied here are clothing textiles treated with silver nanoparticles (AgNPs), since they constitute a controversial application. Surprisingly, the results show counter-intuitive increases by a factor of 2.6 in PEC values for the air compartment in minimal AgNP release scenarios. Also, air releases can shift from washing to wearing activity; their associated release points may shift accordingly, potentially altering release hot spots. Additionally, at end-of-life, the fraction of AgNP-residues contained on exported textiles can be increased by 350% when assuming short product lifespans and globalized WMS. It becomes evident that certain combinations of use activities, matrix material characteristics, and WMS can influence the regional PEC by several orders of magnitude. Thus, in the light of the findings and expected ENM market potential, future assessments should consider these aspects to derive precautionary design alternatives and to enable prospective global and regional risk assessments. - Highlights: • Textile use activities and two waste management systems (WMSs) are investigated. • Matrix material and use activities determine the ENM release. • Counter-intuitive shifts of releases to air can happen during usage. • WMS export can increase by 350% in case of short service life and

Influences of use activities and waste management on environmental releases of engineered nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Wigger, Henning, E-mail: hwigger@uni-bremen.de [Faculty of Production Engineering, Department of Technological Design and Development, University of Bremen, Badgasteiner Str. 1, 28359 Bremen (Germany); Hackmann, Stephan [UFT Center for Environmental Research and Sustainable Technology, Department of General and Theoretical Ecology, University of Bremen, Leobener Str., 28359 Bremen (Germany); Zimmermann, Till [Faculty of Production Engineering, Department of Technological Design and Development, University of Bremen, Badgasteiner Str. 1, 28359 Bremen (Germany); ARTEC — Research Center for Sustainability Studies, Enrique-Schmidt-Str. 7, 28359 Bremen (Germany); Köser, Jan [UFT Center for Environmental Research and Sustainable Technology, Department of Sustainable Chemistry, University of Bremen, Leobener Str., 28359 Bremen (Germany); Thöming, Jorg [UFT Center for Environmental Research and Sustainable Technology, Department of Sustainable Chemical Engineering, University of Bremen, Leobener Str., 28359 Bremen (Germany); Gleich, Arnim von [Faculty of Production Engineering, Department of Technological Design and Development, University of Bremen, Badgasteiner Str. 1, 28359 Bremen (Germany); ARTEC — Research Center for Sustainability Studies, Enrique-Schmidt-Str. 7, 28359 Bremen (Germany)

2015-12-01

Engineered nanomaterials (ENM) offer enhanced or new functionalities and properties that are used in various products. This also entails potential environmental risks in terms of hazard and exposure. However, hazard and exposure assessment for ENM still suffer from insufficient knowledge particularly for product-related releases and environmental fate and behavior. This study therefore analyzes the multiple impacts of the product use, the properties of the matrix material, and the related waste management system (WMS) on the predicted environmental concentration (PEC) by applying nine prospective life cycle release scenarios based on reasonable assumptions. The products studied here are clothing textiles treated with silver nanoparticles (AgNPs), since they constitute a controversial application. Surprisingly, the results show counter-intuitive increases by a factor of 2.6 in PEC values for the air compartment in minimal AgNP release scenarios. Also, air releases can shift from washing to wearing activity; their associated release points may shift accordingly, potentially altering release hot spots. Additionally, at end-of-life, the fraction of AgNP-residues contained on exported textiles can be increased by 350% when assuming short product lifespans and globalized WMS. It becomes evident that certain combinations of use activities, matrix material characteristics, and WMS can influence the regional PEC by several orders of magnitude. Thus, in the light of the findings and expected ENM market potential, future assessments should consider these aspects to derive precautionary design alternatives and to enable prospective global and regional risk assessments. - Highlights: • Textile use activities and two waste management systems (WMSs) are investigated. • Matrix material and use activities determine the ENM release. • Counter-intuitive shifts of releases to air can happen during usage. • WMS export can increase by 350% in case of short service life and

Simulating post-wildfire forest trajectories under alternative climate and management scenarios.

Science.gov (United States)

Tarancón, Alicia Azpeleta; Fulé, Peter Z; Shive, Kristen L; Sieg, Carolyn H; Meador, Andrew Sánchez; Strom, Barbara

Post-fire predictions of forest recovery under future climate change and management actions are necessary for forest managers to make decisions about treatments. We applied the Climate-Forest Vegetation Simulator (Climate-FVS), a new version of a widely used forest management model, to compare alternative climate and management scenarios in a severely burned multispecies forest of Arizona, USA. The incorporation of seven combinations of General Circulation Models (GCM) and emissions scenarios altered long-term (100 years) predictions of future forest condition compared to a No Climate Change (NCC) scenario, which forecast a gradual increase to high levels of forest density and carbon stock. In contrast, emissions scenarios that included continued high greenhouse gas releases led to near-complete deforestation by 2111. GCM-emissions scenario combinations that were less severe reduced forest structure and carbon stock relative to NCC. Fuel reduction treatments that had been applied prior to the severe wildfire did have persistent effects, especially under NCC, but were overwhelmed by increasingly severe climate change. We tested six management strategies aimed at sustaining future forests: prescribed burning at 5, 10, or 20-year intervals, thinning 40% or 60% of stand basal area, and no treatment. Severe climate change led to deforestation under all management regimes, but important differences emerged under the moderate scenarios: treatments that included regular prescribed burning fostered low density, wildfire-resistant forests composed of the naturally dominant species, ponderosa pine. Non-fire treatments under moderate climate change were forecast to become dense and susceptible to severe wildfire, with a shift to dominance by sprouting species. Current U.S. forest management requires modeling of future scenarios but does not mandate consideration of climate change effects. However, this study showed substantial differences in model outputs depending on climate

Acute toxicity of uranium hexafluoride, uranyl fluoride and hydrogen fluoride

International Nuclear Information System (INIS)

Just, R.A.

1988-01-01

Uranium hexafluoride (UF 6 ) released into the atmosphere will react rapidly with moisture in the air to form the hydrolysis products uranyl fluoride (UO 2 F 2 ) and hydrogen fluoride (HF). Uranium compounds such as UF 6 and UO 2 F 2 exhibit both chemical toxicity and radiological effects, while HF exhibits only chemical toxicity. This paper describes the development of a methodology for assessing the human health consequences of a known acute exposure to a mixture of UF 6 , UO 2 F 2 , and HF. 4 refs., 2 figs., 5 tabs

Evaluating Weathering of Food Packaging Polyethylene-Nano-clay Composites: Release of Nanoparticles and their Impacts.

Science.gov (United States)

Han, Changseok; Zhao, Amy; Varughese, Eunice; Sahle-Demessie, E

2018-01-01

Nano-fillers are increasingly incorporated into polymeric materials to improve the mechanical, barrier or other matrix properties of nanocomposites used for consumer and industrial applications. However, over the life cycle, these nanocomposites could degrade due to exposure to environmental conditions, resulting in the release of embedded nanomaterials from the polymer matrix into the environment. This paper presents a rigorous study on the degradation and the release of nanomaterials from food packaging composites. Films of nano-clay-loaded low-density polyethylene (LDPE) composite for food packaging applications were prepared with the spherilene technology and exposed to accelerated weathering of ultraviolet (UV) irradiation or low concentration of ozone at 40 °C. The changes in the structural, surface morphology, chemical and physical properties of the films during accelerated weathering were investigated. Qualitative and quantitative changes in properties of pristine and aged materials and the release of nano-clay proceeded slowly until 130 hr irradiation and then accelerated afterward resulting complete degradation. Although nano-clay increased the stability of LDPE and improved thermal and barrier properties, they accelerated the UV oxidation of LDPE. With increasing exposure to UV, the surface roughness, chemiluminescence index, and carbonyl index of the samples increased while decreasing the intensity of the wide-angle X-ray diffraction pattern. Nano-clay particles with sizes ranging from 2-8 nm were released from UV and ozone weathered composite. The concentrations of released nanoparticles increased with an increase in aging time. Various toxicity tests, including reactive oxygen species generation and cell activity/viability were also performed on the released nano-clay and clay polymer. The released nano-clays basically did not show toxicity. Our combined results demonstrated the degradation properties of nano-clay particle-embedded LDPE composites

EDITORIAL: Where next with global environmental scenarios? Where next with global environmental scenarios?

Science.gov (United States)

O'Neill, Brian; Pulver, Simone; Van Deveer, Stacy; Garb, Yaakov

2008-12-01

Scenarios have become a standard tool in the portfolio of techniques that scientists and policy-makers use to envision and plan for the future. Defined as plausible, challenging and relevant stories about how the future might unfold that integrate quantitative models with qualitative assessments of social and political trends, scenarios are a central component in assessment processes for a range of global issues, including climate change, biodiversity, agriculture, and energy. Yet, despite their prevalence, systematic analysis of scenarios is in its beginning stages. Fundamental questions remain about both the epistemology and scientific credibility of scenarios and their roles in policymaking and social change. Answers to these questions have the potential to determine the future of scenario analyses. Is scenario analysis moving in the direction of earth system governance informed by global scenarios generated through increasingly complex and comprehensive models integrating socio-economic and earth systems? Or will global environmental scenario analyses lose favour compared to more focused, policy-driven, regionally specific modelling? These questions come at an important time for the climate change issue, given that the scenario community, catalyzed by the Intergovernmental Panel on Climate Change (IPCC), is currently preparing to embark on a new round of scenario development processes aimed at coordinating research and assessment, and informing policy, over the next five to ten years. These and related questions about where next to go with global environmental scenarios animated a workshop held at Brown University (Note1) that brought together leading practitioners and scholars of global environmental change scenarios from research, policy-making, advocacy, and business settings. The workshop aimed to provide an overview of current practices/best practices in scenario production and scenario use across a range of global environmental change arenas. Participants

Taking inventory on VOC releases from Amoco's Yorktown refinery

International Nuclear Information System (INIS)

Klee, H.H. Jr.; Schmitt, R.E.; Harrass, M.C.; Podar, M.K.

1996-01-01

Amoco's Yorktown, Virginia, refinery is a 35-year-old, 53,000 bbl/day facility that manufacturers gasoline, heating oil, liquid petroleum gas, sulfur, and coke. In a cooperative and voluntary effort, Amoco Corporation and the US Environmental Protection Agency conducted a joint project to study pollution prevention opportunities at an operating industrial facility. Source reduction efforts--key to pollution prevention strategies--require knowledge of specific sources of releases. However, data on releases from individual process units are limited in favor of data to monitor existing end-of-pipe pollution control requirements. The study's sampling program sought to portray the distribution of releases within the refinery, their management within the refinery, and ultimate releases leaving the refinery. Subsequent tests of blowdown stack and fugitive emissions further improved total release estimates. The initial study estimated that the refinery generates about 25,000 metric tons (t)/year of potential pollutants. Of these, about half are released from the refinery as airborne, waterborne, or land-disposed releases. Airborne releases comprise the majority of releases by mass, about 12,000 t/year. Most of the airborne releases are volatile organic compound hydrocarbons. The inventory sampling project and subsequent work identified differences with Toxic Release Inventory (TRI) values and standard emission factors (AP-42). The inventory and other data provided an opportunity to consider options for, and limitations of, specific pollution prevention or source reduction strategies

Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam during Water Year 2015

Energy Technology Data Exchange (ETDEWEB)

Graziano, D. J. [Argonne National Lab. (ANL), Argonne, IL (United States); Poch, L. A. [Argonne National Lab. (ANL), Argonne, IL (United States); Veselka, T. D. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-11-01

This report examines the financial implications of experimental flows conducted at the Glen Canyon Dam (GCD) in water year (WY) 2015. It is the seventh report in a series examining the financial implications of experimental flows conducted since the Record of Decision (ROD) was adopted in February 1997 (Reclamation 1996). A report released in January 2011 examined WYs 1997 to 2005 (Veselka et al. 2011); a report released in August 2011 examined WYs 2006 to 2010 (Poch et al. 2011); a report released June 2012 examined WY 2011 (Poch et al. 2012); a report released April 2013 examined WY 2012 (Poch et al. 2013); a report released June 2014 examined WY 2013 (Graziano et al. 2014); and a report released September 2015 examined WY 2014 (Graziano et al. 2015). An experimental release may have either a positive or negative impact on the financial value of energy production. Only one experimental release was conducted at GCD in WY 2015; specifically, a high flow experimental (HFE) release conducted in November 2014. For this experimental release, financial costs of approximately $2.1 million were incurred because the HFE required sustained water releases that exceeded the powerplant’s maximum flow rate. In addition, during the month of the experiment, operators were not allowed to shape GCD power production to either follow firm power customer loads or to respond to market prices. This study identifies the main factors that contribute to HFE costs and examines the interdependencies among these factors. It applies an integrated set of tools to estimate financial impacts by simulating the GCD operations under two scenarios: (1) a baseline scenario that mimics both HFE operations during the experiment and during the rest of the year when it complies with the 1996 ROD operating criteria, and (2) a “without experiments” scenario that is identical to the baseline except it assumes that the HFE did not occur. The Generation and Transmission Maximization (GTMax) model was the

Investigation of zero-release cycle using fast breeder reactor

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-11-01

The task force was organized for the main purpose of offering quantitative basic data to the study group on nuclear fuel cycle in February, 1997. The effect of so-called frontier technologies such as the isotope separation by laser method, the FP annihilation with electron beam accelerators and so on in the FBR cycle based on MOX fuel and PUREX reprocessing method was expected. It is aimed at to recycle the total amount of minor actinides. The object of recycling is the nuclides which contribute largely to toxicity, namely 11 elements, 12 nuclides. The preconditions and the target to be attained of the investigation are explained. As the results of investigation, the amount of reloading MA and FP into a reactor, squeezing the recycling scenario, the effect of reducing toxicity and the subject of the countermeasures to the nuclides with long half-life which cannot be reloaded are reported. As the technical evaluation required for realizing the concept, the concept of the core which excludes recriticality, the advance of reprocessing technology, isotope separation, the fabrication into the optimal form for recycling and so on are discussed. The economical efficiency of the recycling based on MOX and PUREX and the proposal of the development scenario are described. (K.I.)

One Health and Toxic Cyanobacteria | Science Inventory | US ...

Science.gov (United States)

One Health and toxic cyanobacteria Blooms of toxic freshwater blue-green algae or cyanobacteria (HABs) have been in the news after HABs associated with human and animal health problems have been reported in Florida, California and Utah during 2016. HABs occur in warm, slow moving or stagnant surface waters that are enriched with nutrients such as nitrogen and phosphorous. People are exposed to potentially toxic HABs during recreation in contaminated water, after exposure to contaminated drinking water or to blue-green algae supplements. Animals may be exposed to toxic HABs after drinking contaminated surface waters or coming into contact with HABs then ingesting cyanobacteria from their bodies during self-grooming activities. As HABs are being reported more frequently in the US, it is important for veterinarians to secure good exposure histories and to recognize the potential signs and health consequences of HAB exposures. We will review the current knowledge about human and animal health effects associated with freshwater HABs and scenarios that pose the highest risks for illnesses and deaths. This abstract does not necessarily reflect EPA policy. This is a summary of One Health and Cyanobacteria for public health and public practice veterinarians at the American Veterinary Medical Association annual convention. This product is associated with SSWR 4.01B

Safety distance assessment of industrial toxic releases based on frequency and consequence: A case study in Shanghai, China

International Nuclear Information System (INIS)

Yu, Q.; Zhang, Y.; Wang, X.; Ma, W.C.; Chen, L.M.

2009-01-01

A case study on the safety distance assessment of a chemical industry park in Shanghai, China, is presented in this paper. Toxic releases were taken into consideration. A safety criterion based on frequency and consequence of major hazard accidents was set up for consequence analysis. The exposure limits for the accidents with the frequency of more than 10 -4 , 10 -5 -10 -4 and 10 -6 -10 -5 per year were mortalities of 1% (or SLOT), 50% (SLOD) and 75% (twice of SLOD) respectively. Accidents with the frequency of less than 10 -6 per year were considered incredible and ignored in the consequence analysis. Taking the safety distance of all the hazard installations in a chemical plant into consideration, the results based on the new criterion were almost smaller than those based on LC50 or SLOD. The combination of the consequence and risk based results indicated that the hazard installations in two of the chemical plants may be dangerous to the protection targets and measurements had to be taken to reduce the risk. The case study showed that taking account of the frequency of occurrence in the consequence analysis would give more feasible safety distances for major hazard accidents and the results were more comparable to those calculated by risk assessment.

The HayWired Earthquake Scenario

Science.gov (United States)

Detweiler, Shane T.; Wein, Anne M.

2017-04-24

interconnectedness of infrastructure, society, and our economy. How would this earthquake scenario, striking close to Silicon Valley, impact our interconnected world in ways and at a scale we have not experienced in any previous domestic earthquake?The area of present-day Contra Costa, Alameda, and Santa Clara Counties contended with a magnitude-6.8 earthquake in 1868 on the Hayward Fault. Although sparsely populated then, about 30 people were killed and extensive property damage resulted. The question of what an earthquake like that would do today has been examined before and is now revisited in the HayWired scenario. Scientists have documented a series of prehistoric earthquakes on the Hayward Fault and are confident that the threat of a future earthquake, like that modeled in the HayWired scenario, is real and could happen at any time. The team assembled to build this scenario has brought innovative new approaches to examining the natural hazards, impacts, and consequences of such an event. Such an earthquake would also be accompanied by widespread liquefaction and landslides, which are treated in greater detail than ever before. The team also considers how the now-prototype ShakeAlert earthquake early warning system could provide useful public alerts and automatic actions.Scientific Investigations Report 2017–5013 and accompanying data releases are the products of an effort led by the USGS, but this body of work was created through the combined efforts of a large team including partners who have come together to form the HayWired Coalition (see chapter A). Use of the HayWired scenario has already begun. More than a full year of intensive partner engagement, beginning in April 2017, is being directed toward producing the most in-depth look ever at the impacts and consequences of a large earthquake on the Hayward Fault. With the HayWired scenario, our hope is to encourage and support the active ongoing engagement of the entire community of the San Francisco Bay region by

Consequence assessment for Airborne Releases of SO2 from the Y-12 Pilot Dechlorination Facility

International Nuclear Information System (INIS)

Pendergrass, W.R.

1992-06-01

The Atmospheric Turbulence and Diffusion Division was requested by the Department of Energy's Oak Ridge Operations Office to conduct a consequence assessment for potential atmospheric releases of SO 2 from the Y-12 Pilot Dechlorination Facility. The focus of the assessment was to identify ''worst'' case meteorology which posed the highest concentration exposure potential for both on-site as well as off-site populations. A series of plausible SO 2 release scenarios were provided by Y-12 for the consequence assessment. Each scenario was evaluated for predictions of downwind concentration, estimates of a five-minute time weighted average, and estimate of the dimension of the puff. The highest hazard potential was associated with Scenario 1, in which a total of eight SO 2 cylinders are released internally to the Pilot Facility and exhausted through the emergency venting system. A companion effort was also conducted to evaluate the potential for impact of releases of SO 2 from the Pilot Facility on the population of Oak Ridge. While specific transport trajectory data is not available for the Pilot Facility, extrapolations based on the Oak Ridge Site Survey and climatological records from the Y-12 meteorological program does not indicate the potential for impact on the city of Oak Ridge. Steering by the local topographical features severely limits the potential impact ares. Due to the lack of specific observational data, both tracer and meteorological, only inferences can be made concerning impact zones. It is recommended tat the Department of Energy Oak Ridge Operations examine the potential for off-site impact and develop the background data to prepare impact zones for releases of hazardous materials from the Y-12 facility

Experimental evaluation of mercury release from molten lead

International Nuclear Information System (INIS)

Tutu, N.K.; Greene, G.A.; Van Tuyle, G.J.

1994-01-01

In order to assess the worst impact of an extremely improbable accident in an accelerator target for producing tritium, an event scenario was developed and analyzed, and an experiment was Performed to resolve an important question raised by the analysis. The target, known as SILC for ''Spallation Induced Lithium Conversion,'' contains approximately 22 metric tons of Pb, with small inventories of potentially hazardous radionuclides which continue to accumulate as the production cycle continues. Analysis of a scenario involving several failures in the normal, backup, and emergency cooling systems is presented, including event simulation by BNL indicating when and how long the Pb continues to melt, and a summary of SNL estimates of the releases of potentially hazardous spallation products is given. Finally, a recent experiment is described in which it was shown that virtually no mercury is likely to escape from the molten Pb, a result having significant impact on the potential risk of such worst-case scenarios

Synthesis and Characterization of Stimuli-Responsive Poly(2-dimethylamino-ethylmethacrylate-Grafted Chitosan Microcapsule for Controlled Pyraclostrobin Release

Directory of Open Access Journals (Sweden)

Chunli Xu

2018-03-01

Full Text Available Controllable pesticide release in response to environmental stimuli is highly desirable for better efficacy and fewer adverse effects. Combining the merits of natural and synthetic polymers, pH and temperature dual-responsive chitosan copolymer (CS-g-PDMAEMA was facilely prepared through free radical graft copolymerization with 2-(dimethylamino ethyl 2-methacrylate (DMAEMA as the vinyl monomer. An emulsion chemical cross-linking method was used to expediently fabricate pyraclostrobin microcapsules in situ entrapping the pesticide. The loading content and encapsulation efficiency were 18.79% and 64.51%, respectively. The pyraclostrobin-loaded microcapsules showed pH-and thermo responsive release. Microcapsulation can address the inherent limitation of pyraclostrobin that is photo unstable and highly toxic on aquatic organisms. Compared to free pyraclostrobin, microcapsulation could dramatically improve its photostability under ultraviolet light irradiation. Lower acute toxicity against zebra fish on the first day and gradually similar toxicity over time with that of pyraclostrobin technical concentrate were in accordance with the release profiles of pyraclostrobin microcapsules. This stimuli-responsive pesticide delivery system may find promising application potential in sustainable plant protection.

Synthesis and Characterization of Stimuli-Responsive Poly(2-dimethylamino-ethylmethacrylate)-Grafted Chitosan Microcapsule for Controlled Pyraclostrobin Release.

Science.gov (United States)

Xu, Chunli; Cao, Lidong; Zhao, Pengyue; Zhou, Zhaolu; Cao, Chong; Zhu, Feng; Li, Fengmin; Huang, Qiliang

2018-03-14

Controllable pesticide release in response to environmental stimuli is highly desirable for better efficacy and fewer adverse effects. Combining the merits of natural and synthetic polymers, pH and temperature dual-responsive chitosan copolymer (CS- g -PDMAEMA) was facilely prepared through free radical graft copolymerization with 2-(dimethylamino) ethyl 2-methacrylate (DMAEMA) as the vinyl monomer. An emulsion chemical cross-linking method was used to expediently fabricate pyraclostrobin microcapsules in situ entrapping the pesticide. The loading content and encapsulation efficiency were 18.79% and 64.51%, respectively. The pyraclostrobin-loaded microcapsules showed pH-and thermo responsive release. Microcapsulation can address the inherent limitation of pyraclostrobin that is photo unstable and highly toxic on aquatic organisms. Compared to free pyraclostrobin, microcapsulation could dramatically improve its photostability under ultraviolet light irradiation. Lower acute toxicity against zebra fish on the first day and gradually similar toxicity over time with that of pyraclostrobin technical concentrate were in accordance with the release profiles of pyraclostrobin microcapsules. This stimuli-responsive pesticide delivery system may find promising application potential in sustainable plant protection.

The world in scenarios

International Nuclear Information System (INIS)

De Jong, A.; Roodenburg, H.

1992-01-01

As an introduction to this special issue 'Worlds of difference: Scenarios's for the economy, energy and the environment 1990-2015', an outline is given of the future of the world and the Netherlands, based on four scenarios. These scenarios are published in 'Scanning the future' in May 1992 by the CPB, the Dutch Central Planning Bureau. The Global Shift (GS) scenario is characterized by a very dynamic technological development, the free market perspective, strong economic growth in the Asian economies, and a relative economic regression in Western Europe. In the European Renaissance (ER) scenario the technological development is less dynamic and more gradual than in the GS scenario. The Balanced Growth (BG) scenario is dominated by a sustainable economic development and a strong technological dynamic development. The Global Crisis (GC) scenario shows a downward spiral in many areas, stagnating developments and fragile economies as results of the trends in the eighties. The first three scenarios are elaborated for the Netherlands. Also attention is paid to the aims and meaning of long-term scenarios. 2 figs., 2 tabs., 3 refs

Biological treatment of concentrated hazardous, toxic, andradionuclide mixed wastes without dilution

Energy Technology Data Exchange (ETDEWEB)

Stringfellow, William T.; Komada, Tatsuyuki; Chang, Li-Yang

2004-06-15

Approximately 10 percent of all radioactive wastes produced in the U. S. are mixed with hazardous or toxic chemicals and therefore can not be placed in secure land disposal facilities. Mixed wastes containing hazardous organic chemicals are often incinerated, but volatile radioactive elements are released directly into the biosphere. Some mixed wastes do not currently have any identified disposal option and are stored locally awaiting new developments. Biological treatment has been proposed as a potentially safer alternative to incineration for the treatment of hazardous organic mixed wastes, since biological treatment would not release volatile radioisotopes and the residual low-level radioactive waste would no longer be restricted from land disposal. Prior studies have shown that toxicity associated with acetonitrile is a significant limiting factor for the application of biotreatment to mixed wastes and excessive dilution was required to avoid inhibition of biological treatment. In this study, we demonstrate that a novel reactor configuration, where the concentrated toxic waste is drip-fed into a complete-mix bioreactor containing a pre-concentrated active microbial population, can be used to treat a surrogate acetonitrile mixed waste stream without excessive dilution. Using a drip-feed bioreactor, we were able to treat a 90,000 mg/L acetonitrile solution to less than 0.1 mg/L final concentration using a dilution factor of only 3.4. It was determined that the acetonitrile degradation reaction was inhibited at a pH above 7.2 and that the reactor could be modeled using conventional kinetic and mass balance approaches. Using a drip-feed reactor configuration addresses a major limiting factor (toxic inhibition) for the biological treatment of toxic, hazardous, or radioactive mixed wastes and suggests that drip-feed bioreactors could be used to treat other concentrated toxic waste streams, such as chemical warfare materiel.

The influence of lysosomal stability of silver nanomaterials on their toxicity to human cells.

Science.gov (United States)

Setyawati, Magdiel Inggrid; Yuan, Xun; Xie, Jianping; Leong, David Tai

2014-08-01

How silver nanomaterials (Ag NMs) could induce toxicity has been debated heatedly by many researchers. We utilized Ag nanoclusters (Ag NCs) with the same size and ligand protection but different core surface speciation. Ag(+)-rich NCs (Ag(+)-R NCs) and their counterpart, the reduced Ag(0)-rich NCs (Ag(0)-R NCs) are synthesized to represent possible dichotomous stages in silver nanomaterial degradation process. Here we show Ag(0)-R NCs induce higher cellular toxicity when compared to Ag(+)-R NCs. This cellular toxicity is brought about via the modulation of reactive oxygen species (ROS) in cells as a result of the more rapid release of Ag species from Ag(0)-R NCs and subsequent oxidation into Ag(+) in the lysosomal compartment. The weaker Ag(0)-R bond greatly potentiated the release of Ag species in the acidic and enzymatic processes within the lysosomes. Since lysosomes are absent in bacteria, increasing silver nanomaterials stability may lower toxicity in mammalian cells whilst not reducing their efficacy to fight bacteria; this redesign can result in a safer silver nanomaterial. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modelling and assessment of accidental oil release from damaged subsea pipelines.

Science.gov (United States)

Li, Xinhong; Chen, Guoming; Zhu, Hongwei

2017-10-15

This paper develops a 3D, transient, mathematical model to estimate the oil release rate and simulate the oil dispersion behavior. The Euler-Euler method is used to estimate the subsea oil release rate, while the Eulerian-Lagrangian method is employed to track the migration trajectory of oil droplets. This model accounts for the quantitative effect of backpressure and hole size on oil release rate, and the influence of oil release rate, oil density, current speed, water depth and leakage position on oil migration is also investigated in this paper. Eventually, the results, e.g. transient release rate of oil, the rise time of oil and dispersion distance are determined by above-mentioned model, and the oil release and dispersion behavior under different scenarios is revealed. Essentially, the assessment results could provide a useful guidance for detection of leakage positon and placement of oil containment boom. Copyright © 2017 Elsevier Ltd. All rights reserved.

Toxicity of zinc oxide nanoparticles to zebrafish embryo: a physicochemical study of toxicity mechanism

International Nuclear Information System (INIS)

Bai Wei; Zhang Zhiyong; Tian Wenjing; He Xiao; Ma Yuhui; Zhao Yuliang; Chai Zhifang

2010-01-01

The biological impact of engineered nanomaterials released into the aquatic environment is a major concern. In this work, the properties of ZnO nanoparticles (nano-ZnO, 30 nm) were characterized in a water suspension (E3 medium), and a zebrafish 96-h post fertilization (hpf) embryo-larval test was performed to assess the toxicity of nano-ZnO suspension. Nano-ZnO was found to readily form aggregates with different sizes; small aggregates (142.4-517.7 nm) were still suspended in E3 medium, but large aggregates (>1 μm) quickly deposited on the bottom of 24-well plates; nano-ZnO was partially dissolved to Zn species (Zn (dis) ) in E3 medium. In the nano-ZnO suspension, small aggregates, Zn (dis) , and large aggregates might jointly exert influence on the development of zebrafish embryos. The embryo toxicity test revealed that nano-ZnO killed zebrafish embryos (50 and 100 mg/L), retarded the embryo hatching (1-25 mg/L), reduced the body length of larvae, and caused tail malformation after the 96 hpf exposure. Zn (dis) only partially contributed to the toxicity of nano-ZnO. This research highlights the need to further investigate the ecotoxicity of nano-ZnO in the water environment.

Effects of synthetic and natural toxicants on livestock.

Science.gov (United States)

Shull, L R; Cheeke, P R

1983-07-01

Synthetic and natural toxicants are constituents of soil, air, water and foodstuffs. Their impact on animal agriculture has resulted from acute and chronic intoxication and residues transferred into meat, dairy and poultry products. Recent advances in analytical chemistry and the sciences associated with toxicology have allowed better assessment of the hazard of toxicants on animals including man. Historically, natural toxicants (phytotoxins, mycotoxins and minerals) that are associated with many common feedstuffs accounted for toxicity episodes of epidemic proportions. Most synthetic chemicals (pesticides, nonpesticidal organic chemicals and drugs) have been introduced in increasing numbers since the 1940's. In the 1960's and '70's, recognition of the need to control their environmental distribution stimulated the introduction of numerous laws and regulations. In the last decade, several problematic synthetic chemicals have been banned, particularly those found to persist in the environment or those confirmed or suspected as carcinogens in humans. At the farm level, the development of various preventative management strategies has decreased the exposure of livestock to natural toxicants. In the future, the impact of natural toxicants on animal agriculture is expected to lessen as their existence, etiology and toxicology are determined. On the other hand, synthetic chemicals will continue to threaten animal health as greater numbers and quantities are released into the environment. These challenges should stimulate a greater involvement of animal scientists in toxicology.

Exposure of Cleft Lip and Palate Patients to Toxic Elements Released during Orthodontic Treatment in the Study of Non-Invasive Matrices.

Directory of Open Access Journals (Sweden)

Marcin Mikulewicz

Full Text Available The aim of the study was evaluation of metal ions (nickel and chromium released from orthodontic appliances in cleft lip and palate patients and the usefulness of non-invasive matrices (saliva and hair.The material studied consisted of 100 individuals, including 59 females and 41 males of 5 to 16 years of age, which were divided into 3 groups: experimental-patients with cleft lip and palate (36 individuals, the average treatment time 5.74 years; control group-patients without cleft lip and palate, during orthodontic treatment (32 individuals, the average treatment time 1.78 years and the control group patients without cleft lip and palate, without any orthodontic appliances (32 individuals. Samples (saliva, hair were collected and subjects underwent a survey by questionnaire. Multi-elemental analyses of the composition of non-invasive matrices was conducted in an accredited laboratory by inductively coupled plasma spectrometry technique ICP-OES. The results were reported as mean contents of particular elements (Cd, Cr, Cu, Fe, Mn, Mo, Ni, Si in hair and in saliva.The concentration of Cr, Ni, Fe and Cu ions in saliva of cleft lip and palate patients were several times higher as compared with not treated orthodontically control groups and higher than in the group with orthodontic appliances. Among the assessed matrices, hair of cleft lip and palate patients seem to be not a meaningful biomarker.It was found that orthodontic appliances used in long-term treatment of cleft lip and palate patients do not release toxic levels of Cr and Ni ions.

The Toxicity of Nitroguanidine and Photolyzed Nitroguandine to Freshwater Aquatic Organisms

Science.gov (United States)

1985-03-01

presently stored in lagoons and holding ponds; release of Wu could result from leakage, overflows, or leaching from the storage facilities. 2...111-112. *16. American Society for Testing and Materials. 1980. Standard practice for conducting acute toxicity tests with fishes, macroinvertebrates

Life cycle assessment of municipal solid waste management scenarios on the small island of Mauritius.

Science.gov (United States)

Rajcoomar, Avinash; Ramjeawon, Toolseeram

2017-03-01

The aim of this study was to use the life cycle assessment tool to assess, from an environmental point of view, the different possible municipal solid waste (MSW) management scenarios for the island of Mauritius. The scenarios include landfilling with energy recovery (S1), incineration with energy recovery (S2), composting, incineration and landfilling (S3) and finally composting, recycling, incineration and landfilling (S4). The MSW generated in 2010 was selected as the functional unit. Foreground data were collected through surveys and literature. Background data were obtained from ecoinvent data in SimaPro 8 libraries. The scenarios were compared both through the CML-IA baseline-midpoint method and the ReCiPe end-point method. From the midpoint method, the results obtained indicates that landfilling (S1) has the greatest impact in all the analyzed impact categories except ozone layer depletion and human toxicity, while incineration (S2) has the least impact on almost all the analyzed damage categories except in global warming potential and human toxicity. The collection and transportation of waste has a significant impact on the environment. From the end-point method, S4 reduces the damage impact categories on Human Health, Ecosystems and Resources due to the recycling process. S3 is not favorable due to the impact caused by the composting process. However, it is also very important to emphasize that for incineration, the best available technology with energy recovery shall be considered. It is recommended that S2 and S4 are considered for strategic planning.

Normal and Abnormal Scenario Modeling with GoldSim for Radioactive Waste Disposal System

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2010-08-01

A modeling study and development of a total system performance assessment (TSPA) template program, by which an assessment of safety and performance for the radioactive waste repository with normal and/or abnormal nuclide release cases could be assessed has been carried out by utilizing a commercial development tool program, GoldSim. Scenarios associated with the various FEPs and involved in the performance of the proposed repository in view of nuclide transport and transfer both in the geosphere and biosphere has been also carried out. Selected normal and abnormal scenarios that could alter groundwater flow scheme and then nuclide transport are modeled with the template program. To this end in-depth system models for the normal and abnormal well and earthquake scenarios that are conceptually and rather practically described and then ready for implementing into a GoldSim TSPA template program are introduced with conceptual schemes for each repository system. Illustrative evaluations with data currently available are also shown

Biomimetics approach for methods to release microobjects from the gripping tool

DEFF Research Database (Denmark)

Gegeckaite, Asta; Moon, Jack; Hansen, Hans Nørgaard

2005-01-01

of handling can be found in for example insect everyday life, cells, enzymes etc. To find out these principles we need special tools, like BioDlab database, which is created specially to find the examples form the biology in order to solve engineering problems. In this report different principles of handling...... at the micro and nano level are presented as well as solutions for micro assembly principles are introduced, concentrating on the adhesion and releasing during the picking and releasing stages of the handling scenario....

Radiological risk associated with a fire scenario in a radioactive waste deposit

Energy Technology Data Exchange (ETDEWEB)

Domingos, E.N.; Lima, Z.R. de, E-mail: erica.ndomingos@gmail.com, E-mail: zelmolima@yahoo.com.br [Instituto de Engenharia Nuclear (PPGIEN/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Aguiar, L.A., E-mail: aguiar.lais@gmail.com [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro-RJ (Brazil)

2017-07-01

A fire at the disposal of radioactive waste can result in significant damage, as well as serious risks to the environment and the health of the general public. The norms of CNEN (Comissão Nacional de Energia Nuclear), CNEN 2.03; CNEN 2.04 and CNEN 8.02 include fire protection regulations and have criteria and requirements that aim to prevent the occurrence, neutralize the action and minimize the effects of the fire on the radioactive and/or toxic mate-rial present in the installations. For decision making due to a fire scenario containing radioactive material, it is fundamental to have information that can allow the estimate of the dose to which the population will be submitted. This work proposes to identify the radiological risk of cancer in the respiratory system using the BEIR V model, associated with a fire scenario containing radioactive material generated in the Hotspot code. (author)

Life cycle of petroleum biodegradation metabolite plumes, and implications for risk management at fuel release sites.

Science.gov (United States)

Zemo, Dawn A; O'Reilly, Kirk T; Mohler, Rachel E; Magaw, Renae I; Espino Devine, Catalina; Ahn, Sungwoo; Tiwary, Asheesh K

2017-07-01

This paper summarizes the results of a 5-y research study of the nature and toxicity of petroleum biodegradation metabolites in groundwater at fuel release sites that are quantified as diesel-range "Total Petroleum Hydrocarbons" (TPH; also known as TPHd, diesel-range organics (DRO), etc.), unless a silica gel cleanup (SGC) step is used on the sample extract prior to the TPH analysis. This issue is important for site risk management in regulatory jurisdictions that use TPH as a metric; the presence of these metabolites may preclude site closure even if all other factors can be considered "low-risk." Previous work has shown that up to 100% of the extractable organics in groundwater at petroleum release sites can be biodegradation metabolites. The metabolites can be separated from the hydrocarbons by incorporating an SGC step; however, regulatory agency acceptance of SGC has been inconsistent because of questions about the nature and toxicity of the metabolites. The present study was conducted to answer these specific questions. Groundwater samples collected from source and downgradient wells at fuel release sites were extracted and subjected to targeted gas chromatography-mass spectrometry (GC-MS) and nontargeted two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-MS) analyses, and the metabolites identified in each sample were classified according to molecular structural classes and assigned an oral reference dose (RfD)-based toxicity ranking. Our work demonstrates that the metabolites identified in groundwater at biodegrading fuel release sites are in classes ranked as low toxicity to humans and are not expected to pose significant risk to human health. The identified metabolites naturally attenuate in a predictable manner, with an overall trend to an increasingly higher proportion of organic acids and esters, and a lower human toxicity profile, and a life cycle that is consistent with the low-risk natural attenuation paradigm adopted

Lake level fluctuations boost toxic cyanobacterial "oligotrophic blooms".

Directory of Open Access Journals (Sweden)

Cristiana Callieri

Full Text Available Global warming has been shown to strongly influence inland water systems, producing noticeable increases in water temperatures. Rising temperatures, especially when combined with widespread nutrient pollution, directly favour the growth of toxic cyanobacteria. Climate changes have also altered natural water level fluctuations increasing the probability of extreme events as dry periods followed by heavy rains. The massive appearance of Dolichospermum lemmermannii ( = planktonic Anabaena, a toxic species absent from the pelagic zone of the subalpine oligotrophic Lake Maggiore before 2005, could be a consequence of the unusual fluctuations of lake level in recent years. We hypothesized that these fluctuations may favour the cyanobacterium as result of nutrient pulses from the biofilms formed in the littoral zone when the lake level is high. To help verify this, we exposed artificial substrates in the lake, and evaluated their nutrient enrichment and release after desiccation, together with measurements of fluctuations in lake level, precipitation and D. lemmermannii population. The highest percentage of P release and the lowest C:P molar ratio of released nutrients coincided with the summer appearance of the D. lemmermannii bloom. The P pulse indicates that fluctuations in level counteract nutrient limitation in this lake and it is suggested that this may apply more widely to other oligotrophic lakes. In view of the predicted increase in water level fluctuations due to climate change, it is important to try to minimize such fluctuations in order to mitigate the occurrence of cyanobacterial blooms.

Synthesis and toxicity evaluation of hydrophobic ionic liquids for volatile organic compounds biodegradation in a two-phase partitioning bioreactor

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Castillo, Alfredo Santiago [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); Guihéneuf, Solène, E-mail: solene.guiheneuf@wanadoo.fr [Université européenne de Bretagne, Université de Rennes 1, Sciences Chimiques de Rennes, UMR, CNRS 6226, Groupe Ingénierie Chimique & Molécules Pour le Vivant (ICMV), Bât. 10A, Campus de Beaulieu, Avenue du Général Leclerc, CS 74205, 35042 Rennes cedex (France); Le Guével, Rémy [Plate-forme ImPACcell Structure Fédérative de Recherche BIOSIT Université de Rennes 1, Bat. 8, Campus de Villejean, 2 Avenue du Pr. Leon Bernard, CS 34317, 35043 Rennes Cedex (France); Biard, Pierre-François [Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7 (France); Université européenne de Bretagne (France); and others

2016-04-15

Highlights: • Description of a VOC depollution system suitable with industrial processes, TPPB. • Novel association of TPPB and hydrophobic ionic liquids. • Synthesis of several hydrophobic ionic liquids designed to fit desired properties. • Toxicity evaluation of these ILs towards cells, animals and bacteria. - Abstract: Synthesis of several hydrophobic ionic liquids (ILs), which might be selected as good candidates for degradation of hydrophobic volatile organic compounds in a two-phase partitioning bioreactor (TPPB), were carried out. Several bioassays were also realized, such as toxicity evaluation on activated sludge and zebrafish, cytotoxicity, fluoride release in aqueous phase and biodegradability in order to verify their possible effects in case of discharge in the aquatic environment and/or human contact during industrial manipulation. The synthesized compounds consist of alkylimidazoliums, functionalized imidazoliums, isoqinoliniums, triazoliums, sulfoniums, pyrrolidiniums and morpholiniums and various counter-ions such as: PF{sub 6}{sup −}, NTf{sub 2}{sup −} and NfO{sup −}. Toxicity evaluation on activated sludge of each compound (5% v/v of IL) was assessed by using a glucose uptake inhibition test. Toxicity against zebrafish and cytotoxicity were evaluated by the ImPACCell platform of Rennes (France). Fluoride release in water was estimated by regular measurements using ion chromatography equipment. IL biodegradability was determined by measuring BOD{sub 28} of aqueous samples (compound concentration,1 mM). All ILs tested were not biodegradable; while some of them were toxic toward activated sludge. Isoquinolinium ILs were toxic to human cancerous cell lines. Nevertheless no toxicity was found against zebrafish Danio rerio. Only one IL released fluoride after long-time agitation.

Assessement of user needs for climate change scenarios in Switzerland

Science.gov (United States)

Fischer, Andreas; Liniger, Mark; Flückiger-Knutti, Jacqueline

2016-04-01

There is a growing demand to assess and inform about future climate change and its impacts on society and ecosystems and to deduce appropriate adaptation strategies. The basis for such assessments are reliable and up-to-date climate change scenarios on the local to regional scale. In Switzerland, an important step has been accomplished by the release of the climate scenarios in 2011 ("CH2011"). New climate model simulations, an improved scientific understanding and new statistical downscaling tools make an update of these scenarios necessary. An important component toward the new national scenarios "CH2018" are the consideration of user needs in order to ensure that the new scenarios are user-tailored and hence find a wide applicability. The new CH2018 scenarios are developed in the framework of the recently founded National Center for Climate Services (NCCS). To get a better overview of who the users of climate scenarios are and what they need, a comprehensive market research was undertaken. The survey targeted the most climate-relevant sectors, and considered representatives from administration, research and private companies across Switzerland. The survey comprised several qualitative group interviews with key stakeholders, as well as a written questionaire, answered by more than one hundred users. Additionally, two workshops were organized to gather the needs in dissemination of climate scenarios. The results of the survey show the necessity to classify the user needs according to the level of usage: "intensive users" are mainly researchers who handle large climate scenario data for further use in subsequent impact studies; "extensive users" are usually from administrations or consulting companies and perform simple calculations for specific questions or use provided graphics and tables; "facilitators" are usually from media, NGOs or schools and process and disseminate scenario information for a specific target group. The less intensive the usage of climate

Prediction of toxic metals concentration using artificial intelligence techniques

Science.gov (United States)

Gholami, R.; Kamkar-Rouhani, A.; Doulati Ardejani, F.; Maleki, Sh.

2011-12-01

Groundwater and soil pollution are noted to be the worst environmental problem related to the mining industry because of the pyrite oxidation, and hence acid mine drainage generation, release and transport of the toxic metals. The aim of this paper is to predict the concentration of Ni and Fe using a robust algorithm named support vector machine (SVM). Comparison of the obtained results of SVM with those of the back-propagation neural network (BPNN) indicates that the SVM can be regarded as a proper algorithm for the prediction of toxic metals concentration due to its relative high correlation coefficient and the associated running time. As a matter of fact, the SVM method has provided a better prediction of the toxic metals Fe and Ni and resulted the running time faster compared with that of the BPNN.

In vitro and in vivo evidence of the cytotoxic and genotoxic effects of metal ions released by orthodontic appliances: A review.

Science.gov (United States)

Martín-Cameán, Ana; Jos, Ángeles; Mellado-García, Pilar; Iglesias-Linares, Alejandro; Solano, Enrique; Cameán, Ana M

2015-07-01

Intraoral fixed orthodontic appliances are frequently used in the clinical practice of dentistry. They are made from alloys containing different metals at various percentages. The use of these appliances leads to the long-term exposure of patients to these materials, and the potential toxic effects of this exposure raises concerns about patient safety. Thus, the biocompatibility (corrosion behaviour and toxicity) of these materials has to be evaluated prior to clinical use. In the present report, the most recent studies in the scientific literature examining metal ion release from orthodontic appliances and the toxic effects of these ions have been reviewed with a special focus on cytotoxicity and genotoxicity. Previous studies suggest that a case-by-case safety evaluation is required to take into account the increasing variability of materials, their composition and the manufacturing processes. Moreover, in vivo toxicity studies in regard to metal release, cytotoxicity and genotoxicity are still scarce. Therefore, in vitro and in vivo monitoring studies are needed to establish cause-effect relationships between metal ion release and biomarkers of cytotoxicity and genotoxicity. Further investigations could be performed to elucidate the toxic mechanisms involved in the observed effects with a special emphasis on oxidative damage. Copyright © 2015 Elsevier B.V. All rights reserved.

Food scenarios 2025

DEFF Research Database (Denmark)

Sundbo, Jon

2016-01-01

This article presents the results of a future study of the food sector. Two scenarios have been developed using a combination of: 1) a summary of the relevant scientific knowledge, 2) systematic scenario writing, 3) an expert-based Delphi technique, and 4) an expert seminar assessment. The two...... scenarios present possible futures at global, national (Denmark) and regional (Zealand, Denmark) levels. The main scenario is called ‘Food for ordinary days and celebrations’ (a combination of ‘High-technological food production − The functional society’ and ‘High-gastronomic food − The experience society...

Interpreting energy scenarios

Science.gov (United States)

Iyer, Gokul; Edmonds, James

2018-05-01

Quantitative scenarios from energy-economic models inform decision-making about uncertain futures. Now, research shows the different ways these scenarios are subsequently used by users not involved in their initial development. In the absence of clear guidance from modellers, users may place too much or too little confidence in scenario assumptions and results.

A review of slow-release fluoride devices.

Science.gov (United States)

Toumba, K J; Al-Ibrahim, N S; Curzon, M E J

2009-09-01

Fluoride has been used to combat dental caries using a number of different clinical approaches. An exciting relatively new development is fluoride slow-releasing devices that consistently elevate intra-oral fluoride levels of plaque and saliva for prolonged periods of up to two years. The literature on the use of slow-releasing fluoride devices in dentistry were reviewed. A Medline search on key words was carried out. All papers in English were individually reviewed. Slow-releasing fluoride devices have been shown to be effective in elevating salivary fluoride levels in both animals and human studies and to enhance the remineralisation of dental enamel. They have been demonstrated to be safe to use and without the risk of fluoride toxicity. A double blind randomised clinical trial demonstrated 76% fewer new carious surface increment in high caries-risk children after two years. These devices have a number of potential uses in dentistry and in particular have great potential for caries prevention of non-compliant high caries-risk groups.

Resveratrol prevents ammonia toxicity in astroglial cells.

Directory of Open Access Journals (Sweden)

Larissa Daniele Bobermin

Full Text Available Ammonia is implicated as a neurotoxin in brain metabolic disorders associated with hyperammonemia. Acute ammonia toxicity can be mediated by an excitotoxic mechanism, oxidative stress and nitric oxide (NO production. Astrocytes interact with neurons, providing metabolic support and protecting against oxidative stress and excitotoxicity. Astrocytes also convert excess ammonia and glutamate into glutamine via glutamine synthetase (GS. Resveratrol, a polyphenol found in grapes and red wines, exhibits antioxidant and anti-inflammatory properties and modulates glial functions, such as glutamate metabolism. We investigated the effect of resveratrol on the production of reactive oxygen species (ROS, GS activity, S100B secretion, TNF-α, IL-1β and IL-6 levels in astroglial cells exposed to ammonia. Ammonia induced oxidative stress, decreased GS activity and increased cytokines release, probably by a mechanism dependent on protein kinase A (PKA and extracellular signal-regulated kinase (ERK pathways. Resveratrol prevented ammonia toxicity by modulating oxidative stress, glial and inflammatory responses. The ERK and nuclear factor-κB (NF-κB are involved in the protective effect of resveratrol on cytokines proinflammatory release. In contrast, other antioxidants (e.g., ascorbic acid and trolox were not effective against hyperammonemia. Thus, resveratrol could be used to protect against ammonia-induced neurotoxicity.

Resveratrol Prevents Ammonia Toxicity in Astroglial Cells

Science.gov (United States)

Guerra, Maria Cristina; Leite, Marina Concli; Souza, Diogo Onofre; Gonçalves, Carlos-Alberto; Gottfried, Carmem

2012-01-01

Ammonia is implicated as a neurotoxin in brain metabolic disorders associated with hyperammonemia. Acute ammonia toxicity can be mediated by an excitotoxic mechanism, oxidative stress and nitric oxide (NO) production. Astrocytes interact with neurons, providing metabolic support and protecting against oxidative stress and excitotoxicity. Astrocytes also convert excess ammonia and glutamate into glutamine via glutamine synthetase (GS). Resveratrol, a polyphenol found in grapes and red wines, exhibits antioxidant and anti-inflammatory properties and modulates glial functions, such as glutamate metabolism. We investigated the effect of resveratrol on the production of reactive oxygen species (ROS), GS activity, S100B secretion, TNF-α, IL-1β and IL-6 levels in astroglial cells exposed to ammonia. Ammonia induced oxidative stress, decreased GS activity and increased cytokines release, probably by a mechanism dependent on protein kinase A (PKA) and extracellular signal-regulated kinase (ERK) pathways. Resveratrol prevented ammonia toxicity by modulating oxidative stress, glial and inflammatory responses. The ERK and nuclear factor-κB (NF-κB) are involved in the protective effect of resveratrol on cytokines proinflammatory release. In contrast, other antioxidants (e.g., ascorbic acid and trolox) were not effective against hyperammonemia. Thus, resveratrol could be used to protect against ammonia-induced neurotoxicity. PMID:23284918

Compliance of the Vaalputs national radioactive waste disposal facility to a frequency-magnitude release criterion as required for licensing

International Nuclear Information System (INIS)

Adrian, H.W.W.; Gerber, H.H.; Kruger, J.; Weygand, J.

1986-01-01

Accidental releases of radioactivity from the Vaalputs nuclear waste repository have been quantified and release frequencies have been attached to a number of accident scenarios of human or natural origin. These have then been compared to a frequency-magnitude release criterion according to South African licensing requirements. It was shown that the criterion was applicable in three release bands. In two of these the criterion was met by some orders of magnitude. In the third band the permitted release frequency was a factor 55 below the limit in spite of pessimistic release assumptions

Effect of phenolic compounds released during degradation of Coir ...

African Journals Online (AJOL)

MICHAEL

www.bioline.org.br/ja. Effect of phenolic compounds released during degradation of Coir pith by ... of the culture filtrate appears to be non toxic in the tested animals @ JASEM. Coir pith is a highly ... degradation of coir pith by fungi and bacteria were already reported, ... no.1 filter paper and used as feed for the experimental ...

Effect of RCIC Operating Conditions on the Accident Scenario in Fukushima Unit 2

International Nuclear Information System (INIS)

Kim, Sung Il; Park, Jong Hwa; Ha, Kwang Soon

2015-01-01

This study was conducted by using MELCOR 1.8.6. Fukushima unit 2 accident was analyzed using MELCOR in this study, and best estimate scenario with considering RCIC operating conditions was presented. Researches on the boiling water reactor (BWR) plant with reactor core isolation cooling (RCIC) system have been conducted. Research on the RCIC operation in Fukushima unit 2 was also conducted by Sandia National Laboratory. MELCOR analysis of the Fukushima unit 2 accident was conducted in the report and energy balance in wetwell was described by considering RCIC operation. However, the effect of RCIC operation condition on the accident scenario has not been studied. The operating conditions of RCIC system affect the pressures in wetwell and drywell, and the high pressure can make leakage path of fission product from PCV to reactor building. Thus it can be directly related with the amount of fission product which released to environment. In this study, severe accident on Fukushima unit 2 was analyzed considering the operating condition of RCIC system, and best estimated scenario was presented. In addition, the effect of RCIC turbine efficiency on the accident progression was examined. Energy balance in suppression chamber was also considered with discussion on the effect of torus room flooding level. It was found that the operating condition of RCIC turbine not only affects the variation of drywell pressure but also the amount of released fission products to environment. It was also confirmed that the RCIC turbine efficiency in the accident would be less than normal operating condition

An integrated Riverine Environmental Flow Decision Support System (REFDSS) to evaluate the ecological effects of alternative flow scenarios on river ecosystems

Science.gov (United States)

Maloney, Kelly O.; Talbert, Colin B.; Cole, Jeffrey C.; Galbraith, Heather S.; Blakeslee, Carrie J.; Hanson, Leanne; Holmquist-Johnson, Christopher L.

2015-01-01

In regulated rivers, managers must evaluate competing flow release scenarios that attempt to balance both human and natural needs. Meeting these natural flow needs is complex due to the myriad of interacting physical and hydrological factors that affect ecosystems. Tools that synthesize the voluminous scientific data and models on these factors will facilitate management of these systems. Here, we present the Riverine Environmental Flow Decision Support System (REFDSS), a tool that enables evaluation of competing flow scenarios and other variables on instream habitat. We developed a REFDSS for the Upper Delaware River, USA, a system that is regulated by three headwater reservoirs. This version of the REFDSS has the ability to integrate any set of spatially explicit data and synthesizes modeled discharge for three competing management scenarios, flow-specific 2-D hydrodynamic modeled estimates of local hydrologic conditions (e.g., depth, velocity, shear stress, etc.) at a fine pixel-scale (1 m2), and habitat suitability criteria (HSC) for a variety of taxa. It contains all individual model outputs, computationally integrates these data, and outputs the amount of potentially available habitat for a suite of species of interest under each flow release scenario. Users have the flexibility to change the time period of interest and vary the HSC. The REFDSS was developed to enable side-by-side evaluation of different flow management scenarios and their effects on potential habitat availability, allowing managers to make informed decisions on the best flow scenarios. An exercise comparing two alternative flow scenarios to a baseline scenario for several key species is presented. The Upper Delaware REFDSS was robust to minor changes in HSC (± 10 %). The general REFDSS platform was developed as a user-friendly Windows desktop application that was designed to include other potential parameters of interest (e.g., temperature) and for transferability to other riverine systems.

Formaldehyde-releasers: relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde-releasers

DEFF Research Database (Denmark)

de Groot, Anton C; Flyvholm, Mari-Ann; Lensen, Gerda

2009-01-01

in the literature as formaldehyde-releasers, data are inadequate to consider them as such beyond doubt. Several (nomenclature) mistakes and outdated information are discussed. Formaldehyde and formaldehyde allergy are reviewed: applications, exposure scenarios, legislation, patch testing problems, frequency....... The frequency of contact allergy to formaldehyde is consistently higher in the USA (8-9%) than in Europe (2-3%). Patch testing with formaldehyde is problematic; the currently used 1% solution may result in both false-positive and false-negative (up to 40%) reactions. Determining the relevance of patch test...

Factors affecting toxicity and efficacy of polymeric nanomedicines

International Nuclear Information System (INIS)

Igarashi, Eiki

2008-01-01

Nanomedicine is the application of nanotechnology to medicine. The purpose of this article is to review common characteristics of polymeric nanomedicines with respect to passive targeting. We consider several biodegradable polymeric nanomedicines that are between 1 and 100 nm in size, and discuss the impact of this technology on efficacy, pharmacokinetics, toxicity and targeting. The degree of toxicity of polymeric nanomedicines is strongly influenced by the biological conditions of the local environment, which influence the rate of degradation or release of polymeric nanomedicines. The dissemination of polymeric nanomedicines in vivo depends on the capillary network, which can provide differential access to normal and tumor cells. The accumulation of nanomedicines in the microlymphatics depends upon retention time in the blood and extracellular compartments, as well as the type of capillary endothelium surrounding specific tissues. Finally, the toxicity or efficacy of intact nanomedicines is also dependent upon tissue type, i.e., non-endocrine or endocrine tissue, spleen, or lymphatics, as well as tumor type

The antibacterial activity and toxicity of enrofloxacin are decreased by nanocellulose conjugated with aminobenzyl purin.

Science.gov (United States)

Yasini, Seyed Ali; Zadeh, Mohammad Hossein Balal; Shahdadi, Hossein

2015-11-01

The first aim of this study was to synthesize nanocellulose conjugated with aminobenzyl purin (NCABP), and the second aim was to evaluate the effect of NCABP on both toxicity and antibacterial activity of enrofloxacin. Here, the adsorption of enrofloxacin by NCABP was first modeled by molecular dynamic (MD) simulation. In the next step, NCABP was synthesized, and was exposed to enrofloxacin, 1000 μg mL(-1), at various conditions. Then, the quantity of adsorption and release was separately measured. Furthermore, both toxicity and antibacterial activity of NCABP, enrofloxacin, and (NCABP+enrofloxacin) were separately evaluated. In this study, MD simulation clearly showed the adsorption after 50 picoseconds. The adsorption tests revealed that the increase of incubation time and NCABP concentration, at range of 50-200 μg mL(-1), led to increase of adsorption. Moreover, the decrease of pH led to increase of adsorption. Interestingly, NCABP could adsorb enrofloxacin, up to 1000 μg mL(-1), in different types of meat. Moreover, the increase of incubation time and temperature did not release enrofloxacin, but the increase of pH increased release. This study showed that both toxicity and antibacterial activity of enrofloxacin were decreased when exposed together with NCABP. Copyright © 2015 Elsevier B.V. All rights reserved.

Minimum Release of Tributyltin to Prevent Macrofouling

Science.gov (United States)

1990-10-01

Thain, J.E., M.J. Waldock, and M.E. Wait, Toxicity and degradation studies of Tributyltin ( TBT ) and Dibutyltin (DBT) in the aquatic environment, in...MATERIALS AND METHODS The test system used was designed to pump a known volume of a tributyltin ( TBT ) solution of known concentration through a porous...ELEMENT NO NO NO ACCESSION NO 11 TITLE (Include Security Classification) nimum Release of Tributyltin to Prevent Macrofoulinq 12 PERSONAL AUTHOR(S

Cellular toxicity and bioaccumulationof silver nanoparticles in the marine polychaete, Nereis diversicolor

DEFF Research Database (Denmark)

cong, Yi; Banta, Gary Thomas; Selck, Henriette

(comet assay) and bioaccumulation as endpoints. Prior to the toxicity experiment, the physical-chemical properties of Ag NPs were fully characterized. The nominal concentrations used in all exposure scenarios were 0, 5, 10, 25, 50 and 100 µg Ag/g dry weight (dw) sediment. Lysosomal membrane stability...... of Nereis coelomocytes, which was measured by neutral red retention time (NRRT), decreased in a concentration-dependent manner in all Ag treatments, indicating increased permeability of lysosomal membranes. Comet assay results showed that Ag was able to cause DNA damage in Nereis coelomocytes regardless......In this study, the toxicities of commercial silver nanoparticles (Ag NPs, 20 and 80 nm) were compared with the toxicities of Ag+ ions in the marine sediment-dwelling polychaete, Nereis diversicolor, after 10 d of sediment exposure, using lysosomal membrane stability (neutral red assay), DNA damage...

NAPL migration and ecotoxicity of conventional and renewable fuels in accidental spill scenarios.

Science.gov (United States)

Malk, Vuokko; Barreto Tejera, Eduardo; Simpanen, Suvi; Dahl, Mari; Mäkelä, Riikka; Häkkinen, Jani; Kiiski, Anna; Penttinen, Olli-Pekka

2014-01-01

Fuels derived from non-petroleum renewable resources have raised interest due to their potential in replacing petroleum-based fuels, but information on their fate and effects in the terrestrial and aquatic environments in accidental spill scenario is limited. In this study, migration of four fuels (conventional diesel, conventional gasoline, renewable diesel NExBTL, and ethanol-blended gasoline RE85 containing maximum 85% ethanol) as non-aqueous phase liquids (NAPL) in soil was demonstrated in a laboratory-scale experiment. Ecotoxicity data was produced for the same fuels. There was no significant difference in migration of conventional and renewable diesel, but gasoline migrated 1.5 times deeper and 7-9 times faster in sand than diesel. RE85 spread horizontally wider but not as deep (p gasoline. Conventional gasoline was the most toxic (lethal concentration [LC50] 20 mg/kg total hydrocarbon content [THC]) among the studied fuels in soil toxicity test with earthworm Eisenia fetida followed by ethanol-blended gasoline (LC50 1,643 mg/kg THC) and conventional diesel (LC50 2,432 mg/kg THC), although gasoline evaporated fast from soil. For comparison, the toxicity of the water-accommodated fractions (WAF) of the fuels was tested with water flea Daphnia magna and Vibrio fischeri, also demonstrating groundwater toxicity. The WAF of conventional gasoline and RE85 showed almost similar toxicity to both the aquatic test species. EC50 values of 1:10 (by volume) WAF were 9.9 %WAF (gasoline) and 9.3 %WAF (RE85) to D. magna and 9.3 %WAF (gasoline) and 12.3 %WAF (RE85) to V. fischeri. Low solubility decreased toxicity potential of conventional diesel in aquatic environment, but direct physical effects of oil phase pose a threat to organisms in nature. Renewable diesel NExBTL did not show clear toxicity to any test species.

Removal of soluble toxic metals from water

International Nuclear Information System (INIS)

Buckley, L.P.; Vijayan, S.; McConeghy, G.J.; Maves, S.R.; Martin, J.F.

1990-05-01

The removal of selected, soluble toxic metals from aqueous solutions has been accomplished using a combination of chemical treatment and ultrafiltration. The process has been evaluated at the bench-scale and is undergoing pilot-scale testing. Removal efficiencies in excess of 95-99% have been realized. The test program at the bench-scale investigated the limitations and established the optimum range of operating parameters for the process, while the tests conducted with the pilot-scale process equipment are providing information on longer-term process efficiencies, effective processing rates, and fouling potential of the membranes. With the typically found average concentrations of the toxic metals in groundwaters at Superfund sites used as the feed solution, the process has decreased levels up to 100-fold or more. Experiments were also conducted with concentrated solutions to determine their release from silica-based matrices. The solidified wastes were subjected to EP Toxicity test procedures and met the criteria successfully. The final phase of the program involving a field demonstration at a uranium tailings site will be outlined

Radiological accidents, scenarios, planning and answers

International Nuclear Information System (INIS)

Solis Delgado, Alexander.

2008-01-01

Radiological accidents, scenarios and the importance of a good planning to prevent and control these types of accidents are presented. The radiation can be only one of the risks in an accident, most of dominant radiological risks are not radiological (fire, toxic gases, etc.). The common causes of radiological accidents, potential risks such as external irradiation, internal contamination and the environment pollution are highlighted. In addition, why accidents happen and how they evolve is explained. It describes some incidents with the radiation occurred in Costa Rica from 1993 to 2007. The coordination of emergency management in Costa Rica in relation to a radiological accident, and some mechanisms of action that have practiced in other places are focuses. Among the final considerations are the need to finalize the national plan for radiological emergencies as a tool of empowerment for the teams of emergency care and the availability of information. Likewise the processes of communication, coordination and cooperation to avoid chaos, confusion and crisis are also highlighted [es

Environmental Impacts by Fragments Released from Nanoenabled Products: A Multiassay, Multimaterial Exploration by the SUN Approach.

Science.gov (United States)

Amorim, Mónica J B; Lin, Sijie; Schlich, Karsten; Navas, José M; Brunelli, Andrea; Neubauer, Nicole; Vilsmeier, Klaus; Costa, Anna L; Gondikas, Andreas; Xia, Tian; Galbis, Liliana; Badetti, Elena; Marcomini, Antonio; Hristozov, Danail; Kammer, Frank von der; Hund-Rinke, Kerstin; Scott-Fordsmand, Janeck J; Nel, André; Wohlleben, Wendel

2018-02-06

Nanoenabled products (NEPs) have numerous outdoor uses in construction, transportation or consumer scenarios, and there is evidence that their fragments are released in the environment at low rates. We hypothesized that the lower surface availability of NEPs fragment reduced their environmental effects with respect to pristine nanomaterials. This hypothesis was explored by testing fragments generated by intentional micronisation ("the SUN approach"; Nowack et al. Meeting the Needs for Released Nanomaterials Required for Further Testing: The SUN Approach. Environmental Science & Technology, 2016 (50), 2747). The NEPs were composed of four matrices (epoxy, polyolefin, polyoxymethylene, and cement) with up to 5% content of three nanomaterials (carbon nanotubes, iron oxide, and organic pigment). Regardless of the type of nanomaterial or matrix used, it was observed that nanomaterials were only partially exposed at the NEP fragment surface, indicating that mostly the intrinsic and extrinsic properties of the matrix drove the NEP fragment toxicity. Ecotoxicity in multiple assays was done covering relevant media from terrestrial to aquatic, including sewage treatment plant (biological activity), soil worms (Enchytraeus crypticus), and fish (zebrafish embryo and larvae and trout cell lines). We designed the studies to explore the possible modulation of ecotoxicity by nanomaterial additives in plastics/polymer/cement, finding none. The results support NEPs grouping by the matrix material regarding ecotoxicological effect during the use phase. Furthermore, control results on nanomaterial-free polymer fragments representing microplastic had no significant adverse effects up to the highest concentration tested.

Biological treatment of concentrated hazardous, toxic, and radionuclide mixed wastes without dilution

International Nuclear Information System (INIS)

Stringfellow, William T.; Komada, Tatsuyuki; Chang, Li-Yang

2004-01-01

Approximately 10 percent of all radioactive wastes produced in the U. S. are mixed with hazardous or toxic chemicals and therefore can not be placed in secure land disposal facilities. Mixed wastes containing hazardous organic chemicals are often incinerated, but volatile radioactive elements are released directly into the biosphere. Some mixed wastes do not currently have any identified disposal option and are stored locally awaiting new developments. Biological treatment has been proposed as a potentially safer alternative to incineration for the treatment of hazardous organic mixed wastes, since biological treatment would not release volatile radioisotopes and the residual low-level radioactive waste would no longer be restricted from land disposal. Prior studies have shown that toxicity associated with acetonitrile is a significant limiting factor for the application of biotreatment to mixed wastes and excessive dilution was required to avoid inhibition of biological treatment. In this study, we demonstrate that a novel reactor configuration, where the concentrated toxic waste is drip-fed into a complete-mix bioreactor containing a pre-concentrated active microbial population, can be used to treat a surrogate acetonitrile mixed waste stream without excessive dilution. Using a drip-feed bioreactor, we were able to treat a 90,000 mg/L acetonitrile solution to less than 0.1 mg/L final concentration using a dilution factor of only 3.4. It was determined that the acetonitrile degradation reaction was inhibited at a pH above 7.2 and that the reactor could be modeled using conventional kinetic and mass balance approaches. Using a drip-feed reactor configuration addresses a major limiting factor (toxic inhibition) for the biological treatment of toxic, hazardous, or radioactive mixed wastes and suggests that drip-feed bioreactors could be used to treat other concentrated toxic waste streams, such as chemical warfare materiel

Up the stack : coal-fired electricity's toxic impact : an OCAA air quality report

International Nuclear Information System (INIS)

Rang, S.

2002-07-01

Ontario Power Generation (OPG) must report annually its releases and transfers of 268 chemicals to the federal National Pollutant Release Inventory (NPRI). Each OPG facility reports the amount of chemicals released to the air, land, water and injected under ground at the facility site. The facilities must also report the amount of chemicals that are transferred off-site for treatment, sewage, disposal, recycling or energy recovery. In 1999 and 2000, atmospheric releases from OPG's coal-fired plants accounted for a significant percentage of the total pollutants released for Ontario and Canada. OPG's facilities are often in the top 5 in Ontario and Canada for releases of various chemicals, including persistent toxic chemicals. In 1999, the Nanticoke coal-fired power plant on Lake Erie was ranked first in Canada for releases to the air. Data reported for the 1999 and 2000 reporting period for dioxins and furans, hexachlorobenzene, mercury, metals (chromium, nickel and arsenic), and acid gases such as hydrochloric acid, hydrogen fluoride, and sulphuric acid clearly indicates that OPG coal-fired plants are a leading source of air pollution in Canada and Ontario. The Ontario Clean Air Alliance suggests the data is sufficient to phase-out the use of coal for power generation in Ontario. It recommends conserving energy and replacing coal-fired power with renewable energy sources such as wind and water power. Converting coal facilities to high-efficiency natural gas units would also reduce the toxic impacts of OPG's coal-fired power plants. As an immediate first step, it was recommended that the government should ban non-emergency exports of coal-fired electricity during smog-alert periods in Ontario. 11 tabs

Synthesis, characterization, release kinetics and toxicity profile of drug-loaded starch nanoparticles.

Science.gov (United States)

El-Naggar, Mehrez E; El-Rafie, M H; El-sheikh, M A; El-Feky, Gina S; Hebeish, A

2015-11-01

The current research work focuses on the medical application of the cost-effective cross-linked starch nanoparticles, for the transdermal delivery using Diclofenac sodium (DS) as a model drug. The prepared DS-cross-linked starch nanoparticles were synthesized using nanoprecipitation technique at different concentrations of sodium tripolyphosphate (STPP) in the presence of Tween 80 as a surfactant. The resultant cross-linked starch nanoparticles loaded with DS were characterized using world-class facilities such as TEM, DLS, FT-IR, XRD, and DSc. The efficiency of DS loading was also evaluated via entrapment efficiency as well as in vitro release and histopathological study on rat skin. The optimum nanoparticles formulation selected by the JMP(®) software was the formula that composed of 5% maize starch, 57.7mg DS and 0.5% STPP and 0.4% Tween 80, with particle diameter of about 21.04nm, polydispersity index of 0.2 and zeta potential of -35.3mV. It is also worth noting that this selected formula shows an average entrapment efficiency of 95.01 and sustained DS release up to 6h. The histophathological studies using the best formula on rat skin advocate the use of designed transdermal DS loaded cross-linked starch nanoparticles as it is safe and non-irritant to rat skin. The overall results indicate that, the starch nanoparticles could be considered as a good carrier for DS drug regarding the enhancement in its controlled release and successful permeation, thus, offering a promising nanoparticulate system for the transdermal delivery non-steroidal anti-inflammatory drug (NSAID). Copyright © 2015 Elsevier B.V. All rights reserved.

Supercritical carbon dioxide extraction as a predictor of polycyclic aromatic hydrocarbon bioaccumulation and toxicity by earthworms in manufactured-gas plant site soils.

Science.gov (United States)

Kreitinger, Joseph P; Quiñones-Rivera, Antonio; Neuhauser, Edward F; Alexander, Martin; Hawthorne, Steven B

2007-09-01

The toxicity and uptake of polycyclic aromatic hydrocarbons (PAHs) by earthworms were measured in soil samples collected from manufactured-gas plant sites having a wide range in PAH concentrations (170-42,000 mg/kg) and soil characteristics. Samples varied from vegetated soils to pure lampblack soot and had total organic carbon contents ranging from 3 to 87%. The biota-soil accumulation factors (BSAFs) observed for individual PAHs in field-collected earthworms (Aporrectodea caliginosa) were up to 50-fold lower than the BSAFs predicted using equilibrium-partitioning theory. Acute toxicity to the earthworm Eisenia fetida was unrelated to total PAH concentration: Mortality was not observed in some soils having high concentrations of total PAHs (>42,000 mg/kg), whereas 100% mortality was observed in other soils having much lower concentrations of total PAHs (1,520 mg/kg). Instead, toxicity appeared to be related to the rapidly released fraction of PAHs determined by mild supercritical CO2 extraction (SFE). The results demonstrate that soils having approximately 16,000 mg rapidly released total PAH/kg organic carbon can be acutely toxic to earthworms and that the concentration of PAHs in soil that is rapidly released by SFE can estimate toxicity to soil invertebrates.

In-vitro evaluation of ion-exchange microspheres for the sustained release of liposomal-adenoviral conjugates.

Science.gov (United States)

Steel, Jason C; Cavanagh, Heather M A; Burton, Mark A; Dingwall, Daniel; Kalle, Wouter H J

2004-03-24

This study looks at the development of a novel combination vector consisting of adenovirus conjugated to liposomes (AL complexes) bound to cation-exchanging microspheres (MAL complexes). With adenovirus having a net negative charge and the liposomes a net positive charge it was possible to modify the net charge of the AL complexes by varying the concentrations of adenovirus to liposomes. The modification of the net charge resulted in altered binding and release characteristics. Of the complexes tested, the 5:1 and 2:1 ratio AL complexes were able to be efficiently bound by the microspheres and exhibited sustained release over 24 h. The 1:1 and 1:2 AL complexes, however, bound poorly to the microspheres and were rapidly released. In addition the MAL complexes also were able to reduce the toxicity of the AL complexes, which was seen with the 10:1 ratio. The AL complexes showed considerably more toxicity alone than in combination with microspheres, highlighting a potential benefit of this vector.

Integrative Scenario Development

Directory of Open Access Journals (Sweden)

Joerg A. Priess

2014-03-01

Full Text Available Scenarios are employed to address a large number of future environmental and socioeconomic challenges. We present a conceptual framework for the development of scenarios to integrate the objectives of different stakeholder groups. Based on the framework, land-use scenarios were developed to provide a common base for further research. At the same time, these scenarios assisted regional stakeholders to bring forward their concerns and arrive at a shared understanding of challenges between scientific and regional stakeholders, which allowed them to eventually support regional decision making. The focus on the integration of views and knowledge domains of different stakeholder groups, such as scientists and practitioners, required rigorous and repeated measures of quality control. The application of the integrative concept provided products for both stakeholder groups, and the process of scenario development facilitated cooperation and learning within both the scientist and practitioner groups as well as between the two groups.

Summary of four release consequence analyses for hypothetical nuclear waste repositories in salt and granite

International Nuclear Information System (INIS)

Cole, C.R.; Bond, F.W.

1980-12-01

Release consequence methology developed under the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) program has now been applied to four hypothetical repository sites. This paper summarizes the results of these four studies in order to demonstrate that the far-field methodology developed under the AEGIS program offers a practical approach to the post-closure safety assessment of nuclear waste repositories sited in deep continental geologic formations. The four studies are briefly described and compared according to the following general categories: physical description of the repository (size, inventory, emplacement depth); geologic and hydrologic description of the site and the conceptual hydrologic model for the site; description of release scenario; hydrologic model implementation and results; engineered barriers and leach rate modeling; transport model implementation and results; and dose model implementation and results. These studies indicate the following: numerical modeling is a practical approach to post-closure safety assessment analysis for nuclear waste repositories; near-field modeling capability needs improvement to permit assessment of the consequences of human intrusion and pumping well scenarios; engineered barrier systems can be useful in mitigating consequences for postulated release scenarios that short-circuit the geohydrologic system; geohydrologic systems separating a repository from the natural biosphere discharge sites act to mitigate the consequences of postulated breaches in containment; and engineered barriers of types other than the containment or absorptive type may be useful

HD271791: dynamical versus binary-supernova ejection scenario

Science.gov (United States)

Gvaramadze, V. V.

2009-05-01

The atmosphere of the extremely high-velocity (530-920kms-1) early B-type star HD271791 is enriched in α-process elements, which suggests that this star is a former secondary component of a massive tight binary system and that its surface was polluted by the nucleosynthetic products after the primary star exploded in a supernova. It was proposed that the (asymmetric) supernova explosion unbind the system and that the secondary star (HD271791) was released at its orbital velocity in the direction of Galactic rotation. In this Letter, we show that to explain the Galactic rest-frame velocity of HD271791 within the framework of the binary-supernova scenario, the stellar remnant of the supernova explosion (a =750-1200kms-1. We therefore consider the binary-supernova scenario as highly unlikely and instead propose that HD271791 attained its peculiar velocity in the course of a strong dynamical three- or four-body encounter in the dense core of the parent star cluster. Our proposal implies that by the moment of encounter HD271791 was a member of a massive post-supernova binary.

The future of scenarios: issues in developing new climate change scenarios

International Nuclear Information System (INIS)

Pitcher, Hugh M

2009-01-01

In September, 2007, the IPCC convened a workshop to discuss how a new set of scenarios to support climate model runs, mitigation analyses, and impact, adaptation and vulnerability research might be developed. The first phase of the suggested new approach is now approaching completion. This article discusses some of the issues raised by scenario relevant research and analysis since the last set of IPCC scenarios were created (IPCC SRES, 2000) that will need to be addressed as new scenarios are developed by the research community during the second phase. These include (1) providing a logic for how societies manage to transition from historical paths to the various future development paths foreseen in the scenarios, (2) long-term economic growth issues, (3) the appropriate GDP metric to use (purchasing power parity or market exchange rates), (4) ongoing issues with moving from the broad geographic and time scales of the emission scenarios to the finer scales needed for impacts, adaptation and vulnerability analyses and (5) some possible ways to handle the urgent request from the policy community for some guidance on scenario likelihoods. The challenges involved in addressing these issues are manifold; the reward is greater credibility and deeper understanding of an analytic tool that does much to form the context within which many issues in addition to the climate problem will need to be addressed.

The future of scenarios: issues in developing new climate change scenarios

Science.gov (United States)

Pitcher, Hugh M.

2009-04-01

In September, 2007, the IPCC convened a workshop to discuss how a new set of scenarios to support climate model runs, mitigation analyses, and impact, adaptation and vulnerability research might be developed. The first phase of the suggested new approach is now approaching completion. This article discusses some of the issues raised by scenario relevant research and analysis since the last set of IPCC scenarios were created (IPCC SRES, 2000) that will need to be addressed as new scenarios are developed by the research community during the second phase. These include (1) providing a logic for how societies manage to transition from historical paths to the various future development paths foreseen in the scenarios, (2) long-term economic growth issues, (3) the appropriate GDP metric to use (purchasing power parity or market exchange rates), (4) ongoing issues with moving from the broad geographic and time scales of the emission scenarios to the finer scales needed for impacts, adaptation and vulnerability analyses and (5) some possible ways to handle the urgent request from the policy community for some guidance on scenario likelihoods. The challenges involved in addressing these issues are manifold; the reward is greater credibility and deeper understanding of an analytic tool that does much to form the context within which many issues in addition to the climate problem will need to be addressed.

Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

Energy Technology Data Exchange (ETDEWEB)

Lombi, E., E-mail: enzo.lombi@unisa.edu.a [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, Mawson Lakes, SA 5095 (Australia); CRC CARE, PO Box 486, Salisbury, SA 5106 (Australia); Stevens, D.P. [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Arris Pty Ltd, PO Box 5143, Burnley, Victoria 3121 (Australia); McLaughlin, M.J. [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Soil and Land Systems, University of Adelaide, PMB 1, Glen Osmond, SA 5064 (Australia)

2010-06-15

Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. - The effect of water treatment residue application to soil was investigated in relation to phosphorus availability, and copper and aluminium phytotoxicity.

Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

International Nuclear Information System (INIS)

Lombi, E.; Stevens, D.P.; McLaughlin, M.J.

2010-01-01

Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. - The effect of water treatment residue application to soil was investigated in relation to phosphorus availability, and copper and aluminium phytotoxicity.

Multiscale numerical modeling of Ce3+-inhibitor release from novel corrosion protection coatings

International Nuclear Information System (INIS)

Trenado, Carlos; Wittmar, Matthias; Veith, Michael; Strauss, Daniel J; Rosero-Navarro, Nataly C; Aparicio, Mario; Durán, Alicia; Castro, Yolanda

2011-01-01

A novel hybrid sol–gel coating has recently been introduced as an alternative to high toxic chromate-based corrosion protection systems. In this paper, we propose a multiscale computational model to estimate the amount and time scale of inhibitor release of the active corrosion protection coating. Moreover, we study the release rate under the influence of parameters such as porosity and viscosity, which have recently been implicated in the stability of the coating. Numerical simulations obtained with the model predicted experimental release tests and recent findings on the compromise between inhibitor concentration and the stability of the coating

Approach on environmental risk assessment of nanosilver released from textiles

Energy Technology Data Exchange (ETDEWEB)

Voelker, Doris, E-mail: doris.voelker@uba.de [Federal Environment Agency Germany, Section IV 2.2, Wörlitzer Platz 1, 06844 Dessau-Rosslau (Germany); Schlich, Karsten [Fraunhofer Institute for Molecular Biology and Applied Ecology, Department of Ecotoxicology, Auf dem Aberg 1, 57392 Schmallenberg (Germany); Hohndorf, Lars; Koch, Wolfgang; Kuehnen, Ute [Federal Environment Agency Germany, Section IV 2.2, Wörlitzer Platz 1, 06844 Dessau-Rosslau (Germany); Polleichtner, Christian; Kussatz, Carola [Federal Environment Agency Germany, Section IV 2.4, Schichauweg 58, 12307 Berlin (Germany); Hund-Rinke, Kerstin [Fraunhofer Institute for Molecular Biology and Applied Ecology, Department of Ecotoxicology, Auf dem Aberg 1, 57392 Schmallenberg (Germany)

2015-07-15

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure scenarios (via municipal sewage treatment plant (STP)) with wastewater supply from domestic homes) were developed for three different types of textiles equipped with AgNM. Based on these scenarios predicted environmental concentrations (PECs) were deduced for STPs and for the environmental compartments surface water, sediment as well as soil. These PECs were related to PNECs (predicted no effect concentrations). PNECs were deduced from results of ecotoxicity tests of a selected AgNM (NM-300K). Data on ecotoxicology were derived from various tests with activated sludge, cyanobacteria, algae, daphnids, fish, duckweed, macrophytes, chironomids, earthworms, terrestrial plants as well as soil microorganisms. Emission data for the AgNM NM-300K from textiles were derived from washing experiments. The performed ERA was based on the specifications defined in the ECHA Guidances on information requirements and chemical safety assessment. Based on the chosen scenarios and preconditions, no environmental risk of the AgNM NM-300K released from textiles was detected. Under conservative assumptions a risk quotient for surface water close to 1 indicated that the aquatic compartment may be affected by an increased emission of AgNM to the environment due to the high sensitivity of aquatic organisms to silver. Based on the successful retention of AgNM in the sewage sludge and the still ongoing continual application of sewage sludge on farmland it is recommended to introduce a threshold for total silver content in sewage sludge into the respective regulations. Regarding potential risk mitigation measures, it is emphasized to preferably directly

Approach on environmental risk assessment of nanosilver released from textiles

International Nuclear Information System (INIS)

Voelker, Doris; Schlich, Karsten; Hohndorf, Lars; Koch, Wolfgang; Kuehnen, Ute; Polleichtner, Christian; Kussatz, Carola; Hund-Rinke, Kerstin

2015-01-01

Based on the increased utilization of nanosilver (silver nanomaterials=AgNM) as antibacterial agent, there is the strong need to assess the potential environmental implication associated with its new application areas. In this study an exemplary environmental risk assessment (ERA) of AgNM applied in textiles was performed. Environmental exposure scenarios (via municipal sewage treatment plant (STP)) with wastewater supply from domestic homes) were developed for three different types of textiles equipped with AgNM. Based on these scenarios predicted environmental concentrations (PECs) were deduced for STPs and for the environmental compartments surface water, sediment as well as soil. These PECs were related to PNECs (predicted no effect concentrations). PNECs were deduced from results of ecotoxicity tests of a selected AgNM (NM-300K). Data on ecotoxicology were derived from various tests with activated sludge, cyanobacteria, algae, daphnids, fish, duckweed, macrophytes, chironomids, earthworms, terrestrial plants as well as soil microorganisms. Emission data for the AgNM NM-300K from textiles were derived from washing experiments. The performed ERA was based on the specifications defined in the ECHA Guidances on information requirements and chemical safety assessment. Based on the chosen scenarios and preconditions, no environmental risk of the AgNM NM-300K released from textiles was detected. Under conservative assumptions a risk quotient for surface water close to 1 indicated that the aquatic compartment may be affected by an increased emission of AgNM to the environment due to the high sensitivity of aquatic organisms to silver. Based on the successful retention of AgNM in the sewage sludge and the still ongoing continual application of sewage sludge on farmland it is recommended to introduce a threshold for total silver content in sewage sludge into the respective regulations. Regarding potential risk mitigation measures, it is emphasized to preferably directly

Antibiotic-Releasing Silk Biomaterials for Infection Prevention and Treatment

OpenAIRE

Pritchard, Eleanor M.; Valentin, Thomas; Panilaitis, Bruce; Omenetto, Fiorenzo; Kaplan, David L.

2012-01-01

Effective treatment of infections in avascular and necrotic tissues can be challenging due to limited penetration into the target tissue and systemic toxicities. Controlled release polymer implants have the potential to achieve the high local concentrations needed while also minimizing systemic exposure. Silk biomaterials possess unique characteristics for antibiotic delivery including biocompatibility, tunable biodegradation, stabilizing effects, water-based processing and diverse material f...

Life cycle assessment and residue leaching: the importance of parameter, scenario and leaching data selection.

Science.gov (United States)

Allegrini, E; Butera, S; Kosson, D S; Van Zomeren, A; Van der Sloot, H A; Astrup, T F

2015-04-01

Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products and can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Toxicity of indium arsenide, gallium arsenide, and aluminium gallium arsenide

International Nuclear Information System (INIS)

Tanaka, Akiyo

2004-01-01

Gallium arsenide (GaAs), indium arsenide (InAs), and aluminium gallium arsenide (AlGaAs) are semiconductor applications. Although the increased use of these materials has raised concerns about occupational exposure to them, there is little information regarding the adverse health effects to workers arising from exposure to these particles. However, available data indicate these semiconductor materials can be toxic in animals. Although acute and chronic toxicity of the lung, reproductive organs, and kidney are associated with exposure to these semiconductor materials, in particular, chronic toxicity should pay much attention owing to low solubility of these materials. Between InAs, GaAs, and AlGaAs, InAs was the most toxic material to the lung followed by GaAs and AlGaAs when given intratracheally. This was probably due to difference in the toxicity of the counter-element of arsenic in semiconductor materials, such as indium, gallium, or aluminium, and not arsenic itself. It appeared that indium, gallium, or aluminium was toxic when released from the particles, though the physical character of the particles also contributes to toxic effect. Although there is no evidence of the carcinogenicity of InAs or AlGaAs, GaAs and InP, which are semiconductor materials, showed the clear evidence of carcinogenic potential. It is necessary to pay much greater attention to the human exposure of semiconductor materials

Preliminary analysis of public dose from CFETR gaseous tritium release

Energy Technology Data Exchange (ETDEWEB)

Nie, Baojie [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei, Anhui 230027 (China); Ni, Muyi, E-mail: muyi.ni@fds.org.cn [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Lian, Chao; Jiang, Jieqiong [Key Laboratory of Neutronics and Radiation Safety, Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

2015-02-15

Highlights: • Present the amounts and limit dose of tritium release to the environment for CFETR. • Perform a preliminary simulation of radiation dose for gaseous tritium release. • Key parameters about soil types, wind speed, stability class, effective release height and age were sensitivity analyzed. • Tritium release amount is recalculated consistently with dose limit in Chinese regulation for CFETR. - Abstract: To demonstrate tritium self-sufficiency and other engineering issues, the scientific conception of Chinese Fusion Engineering Test Reactor (CFETR) has been proposed in China parallel with ITER and before DEMO reactor. Tritium environmental safety for CFETR is an important issue and must be evaluated because of the huge amounts of tritium cycling in reactor. In this work, different tritium release scenarios of CFETR and dose limit regulations in China are introduced. And the public dose is preliminarily analyzed under normal and accidental events. Furthermore, after finishing the sensitivity analysis of key input parameters, the public dose is reevaluated based on extreme parameters. Finally, tritium release amount is recalculated consistently with the dose limit in Chinese regulation for CFETR, which would provide a reference for tritium system design of CFETR.

Potential Use of Chemoprotectants against the Toxic Effects of Cyanotoxins: A Review.

Science.gov (United States)

Guzmán-Guillén, Remedios; Puerto, María; Gutiérrez-Praena, Daniel; Prieto, Ana I; Pichardo, Silvia; Jos, Ángeles; Campos, Alexandre; Vasconcelos, Vitor; Cameán, Ana M

2017-05-23

Cyanobacterial toxins, particularly microcystins (MCs) and cylindrospermopsin (CYN), are responsible for toxic effects in humans and wildlife. In order to counteract or prevent their toxicity, various strategies have been followed, such as the potential application of chemoprotectants. A review of the main substances evaluated for this aim, as well as the doses and their influence on cyanotoxin-induced toxicity, has been performed. A search of the literature shows that research on MCs is much more abundant than research on CYN. Among chemoprotectants, antioxidant compounds are the most extensively studied, probably because it is well known that oxidative stress is one of the toxic mechanisms common to both toxins. In this group, vitamin E seems to have the strongest protectant effect for both cyanotoxins. Transport inhibitors have also been studied in the case of MCs, as CYN cellular uptake is not yet fully elucidated. Further research is needed because systematic studies are lacking. Moreover, more realistic exposure scenarios, including cyanotoxin mixtures and the concomitant use of chemoprotectants, should be considered.

Toxicity and mutagenicity of low-metallic automotive brake pad materials.

Science.gov (United States)

Malachova, Katerina; Kukutschova, Jana; Rybkova, Zuzana; Sezimova, Hana; Placha, Daniela; Cabanova, Kristina; Filip, Peter

2016-09-01

Organic friction materials are standardly used in brakes of small planes, railroad vehicles, trucks and passenger cars. The growing transportation sector requires a better understanding of the negative impact related to the release of potentially hazardous materials into the environment. This includes brakes which can release enormous quantities of wear particulates. This paper addresses in vitro detection of toxic and mutagenic potency of one model and two commercially available low-metallic automotive brake pads used in passenger cars sold in the EU market. The model pad made in the laboratory was also subjected to a standardized brake dynamometer test and the generated non-airborne wear particles were also investigated. Qualitative "organic composition" was determined by GC/MS screening of dichloromethane extracts. Acute toxicity and mutagenicity of four investigated sample types were assessed in vitro by bioluminescence assay using marine bacteria Vibrio fischeri and by two bacterial bioassays i) Ames test on Salmonella typhimurium His(-) and ii) SOS Chromotest using Escherichia coli PQ37 strain. Screening of organic composition revealed a high variety of organic compounds present in the initial brake pads and also in the generated non-airborne wear debris. Several detected compounds are classified by IARC as possibly carcinogenic to humans, e. g. benzene derivatives. Acute toxicity bioassay revealed a response of bacterial cells after exposure to all samples used. Phenolic resin and wear debris were found to be acutely toxic; however in term of mutagenicity the response was negative. All non-friction exposed brake pad samples (a model pad and two commercial pad samples) were mutagenic with metabolic activation in vitro. Copyright © 2016 Elsevier Inc. All rights reserved.

Documentation and evaluation of model validation data used in scenario S

International Nuclear Information System (INIS)

Rantavaara, A.; Arvela, H.; Suomela, M.

1996-01-01

Most radioactive fallout received in Finland after the Chernobyl nuclear accident originated in the first major release and spread over the test region between April 27 and 29, 1986. Most radioactive material was deposited with heavy showers which caused an uneven areal distribution. Deposition continued with varying intensity until May 12. At the end of April the growing season had not yet begun in Finland. Estimation of the mean deposition density was one of the modelling tasks. To avoid a biased starting point for foodchain assessments due to modellers' own deposition estimates, the mean deposition density of 137 Cs in each subregion used in the scenario was given as input information. The model validation test was started as a blind test. All regional information in the scenario description was coded, and the first maps of subregions were schematic to hide the actual test area. The blind test idea was gradually cancelled in the course of the exercise. The geographical region S was revealed after deposition estimates were made. At the same time, sources of information in the open literature became available to the modellers. After the blind test phase, communication was encouraged between modellers and the compiler of the scenario description at the Finnish Centre for Radiation and Nuclear Safety (STUK) to avoid unnecessary misinterpretations of input information. Clarifications and additional information provided in the course of model calculations are included in the present scenario description. 100 refs, 31 figs, 67 tabs

Optimizing Decision Preparedness by Adapting Scenario Complexity and Automating Scenario Generation

Science.gov (United States)

Dunne, Rob; Schatz, Sae; Flore, Stephen M.; Nicholson, Denise

2011-01-01

Klein's recognition-primed decision (RPD) framework proposes that experts make decisions by recognizing similarities between current decision situations and previous decision experiences. Unfortunately, military personnel arQ often presented with situations that they have not experienced before. Scenario-based training (S8T) can help mitigate this gap. However, SBT remains a challenging and inefficient training approach. To address these limitations, the authors present an innovative formulation of scenario complexity that contributes to the larger research goal of developing an automated scenario generation system. This system will enable trainees to effectively advance through a variety of increasingly complex decision situations and experiences. By adapting scenario complexities and automating generation, trainees will be provided with a greater variety of appropriately calibrated training events, thus broadening their repositories of experience. Preliminary results from empirical testing (N=24) of the proof-of-concept formula are presented, and future avenues of scenario complexity research are also discussed.

Investigation of Local Hydrogen Risk in the RDT Compartment of OPR1000 under SBO Scenario

International Nuclear Information System (INIS)

Kim, Nam Kyung; Jeon, Joon Goo; Choi, Won Jun; Song, Kyu Sang; Jeun, Gyoo Dong; Kim, Sung Joong

2016-01-01

As TMI-2 and Fukushima accidents revealed, a high concentration of hydrogen in a nuclear power plant (NPP) could cause hydrogen combustion. In order to take follow-up measures, an average and local hydrogen concentration in the NPP containment are regulated below 0.1 using hydrogen mitigation system such as igniter and/or passive autocatalytic recombiner (PAR). During a severe accident, some compartments of the NPP containment temporarily may show peaks of the local hydrogen concentration over 0.1 depending on the geometry of the containment structure and hydrogen transportation path. For example, the compartment of a reactor drain tank (RDT) is connected to the pressurizer nozzle and if the relieved pressure drives the significant amount of steam and hydrogen, then substantial peaks of the hydrogen concentration can occur. Before the RPV failure under SBO scenario, the RDT compartment was the main region for hydrogen release due to the RDT break. Therefore, confirming the local hydrogen risk in the RDT compartment is very important to verify the integrity of the NPP containment. In this study, the local hydrogen risk in the RDT compartment of OPR1000 under SBO scenario was evaluated using MELCOR 1.8.6 code in terms of the hydrogen volume fraction and the Shapiro diagram. (1) The RDT compartment showed the peaks of the hydrogen volume fraction over 0.1. As a future work, the local hydrogen risk of the compartment of a steam generator (SG) needs to be analyzed under SBLOCA scenario. Because the SG compartment is also a main region of hydrogen release under SBLOCA scenario. In the long run, the analysis for the detailed hydrogen distribution, based on detailed modeling of the whole OPR1000 containment, needs to be performed.

Runaway chemical reaction exposes community to highly toxic chemicals

International Nuclear Information System (INIS)

Kaszniak, Mark; Vorderbrueggen, John

2008-01-01

The U.S. Chemical Safety and Hazard Investigation Board (CSB) conducted a comprehensive investigation of a runaway chemical reaction at MFG Chemical (MFG) in Dalton, Georgia on April 12, 2004 that resulted in the uncontrolled release of a large quantity of highly toxic and flammable allyl alcohol and allyl chloride into the community. Five people were hospitalized and 154 people required decontamination and treatment for exposure to the chemicals. This included police officers attempting to evacuate the community and ambulance personnel who responded to 911 calls from residents exposed to the chemicals. This paper presents the findings of the CSB report (U.S. Chemical Safety and Hazard Investigation Board (CSB), Investigation Report: Toxic Chemical Vapor Cloud Release, Report No. 2004-09-I-GA, Washington DC, April 2006) including a discussion on tolling practices; scale-up of batch reaction processes; Process Safety Management (PSM) and Risk Management Plan (RMP) implementation; emergency planning by the company, county and the city; and emergency response and mitigation actions taken during the incident. The reactive chemical testing and atmospheric dispersion modeling conducted by CSB after the incident and recommendations adopted by the Board are also discussed

Experience of soil rehabilitation in the scenario of Chernobyl

International Nuclear Information System (INIS)

Millan Gomez, R.; Ronero, L.; Jouve, A.

1996-01-01

The Chernobyl post-accident scenario became nowadays a natural radioecology laboratory, where a wide range of decontamination methods can be applied, validated or developed. This paper presents the application of a soil rehabilitation technique, the removal of vegetation and associated soil, in the experimental fields of Bourakovka and Chistogalovka surrounding the Chernobyl NPP. The results obtained have shown soil decontamination factors higher than 90% for caesium and strontium. This technique involves the removal of deposited hot particles released at the accident, and the experience allowed a detailed study of one of them corresponding to a nuclear fuel fragment, probably generated at the beginning of the breakdown. 16 refs. (Author)

Toxic fluoride gas emissions from lithium-ion battery fires.

Science.gov (United States)

Larsson, Fredrik; Andersson, Petra; Blomqvist, Per; Mellander, Bengt-Erik

2017-08-30

Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15-22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF 3 ), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

Environmental Mercury and Its Toxic Effects

Directory of Open Access Journals (Sweden)

Kevin M. Rice

2014-03-01

Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

Fact Sheet: Clean Air Act Section 112(r): Accidental Release Prevention / Risk Management Plan Rule

Science.gov (United States)

EPA is required to publish regulations and guidance for chemical accident prevention at facilities that pose the greatest risk of harm from accidental releases of regulated flammable and toxic substances above threshold quantities.

A Relational Learning Approach to Structure-Activity Relationships in Drug Design Toxicity Studies

Directory of Open Access Journals (Sweden)

Camacho Rui

2011-12-01

Full Text Available It has been recognized that the development of new therapeutic drugs is a complex and expensive process. A large number of factors affect the activity in vivo of putative candidate molecules and the propensity for causing adverse and toxic effects is recognized as one of the major hurdles behind the current “target-rich, lead-poor” scenario.

Intracellular uptake: a possible mechanism for silver engineered nanoparticle toxicity to a freshwater alga Ochromonas danica.

Directory of Open Access Journals (Sweden)

Ai-Jun Miao

2010-12-01

Full Text Available The behavior and toxicity of silver engineered nanoparticles (Ag-ENs to the mixotrophic freshwater alga Ochromonas danica were examined in the present study to determine whether any other mechanisms are involved in their algal toxicity besides Ag(+ liberation outside the cells. Despite their good dispersability, the Ag-ENs were found to continuously aggregate and dissolve rapidly. When the initial nanoparticle concentration was lower than 10 µM, the total dissolved Ag(+ concentration ([Ag(+](T in the suspending media reached its maximum after 1 d and then decreased suggesting that Ag(+ release might be limited by the nanoparticle surface area under these conditions. Furthermore, Ag-EN dissolution extent remarkably increased in the presence of glutathione. In the Ag-EN toxicity experiment, glutathione was also used to eliminate the indirect effects of Ag(+ that was released. However, remarkable toxicity was still observed although the free Ag(+ concentration in the media was orders of magnitude lower than the non-observed effect concentration of Ag(+ itself. Such inhibitive effects were mitigated when more glutathione was added, but could never be completely eliminated. Most importantly, we demonstrate, for the first time, that Ag-ENs can be taken in and accumulated inside the algal cells, where they exerted their toxic effects. Therefore, nanoparticle internalization may be an alternative pathway through which algal growth can be influenced.

Oral Chromium Exposure and Toxicity

Science.gov (United States)

Sun, Hong; Brocato, Jason

2015-01-01

Hexavalent chromium [Cr(VI)] is a known carcinogen when inhaled. However, inhalational exposure to Cr(VI) affects only a small portion of the population, mainly by occupational exposures. In contrast, oral exposure to Cr(VI) is widespread and affects many people throughout the globe. In 2008, the National Toxicology Program (NTP) released a 2-year study demonstrating that ingested Cr(VI) was carcinogenic in rats and mice. The effects of Cr(VI) oral exposure is mitigated by reduction in the gut, however a portion evades the reductive detoxification and reaches target tissues. Once Cr(VI) enters the cell, it ultimately gets reduced to Cr(III), which mediates its toxicity via induction of oxidative stress during the reduction while Cr intermediates react with protein and DNA. Cr(III) can form adducts with DNA that may lead to mutations. This review will discuss the potential adverse effects of oral exposure to Cr(VI) by presenting up-to-date human and animal studies, examining the underlying mechanisms that mediate Cr(VI) toxicity, as well as highlighting opportunities for future research. PMID:26231506

Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

Directory of Open Access Journals (Sweden)

Ghada Bassioni

2010-10-01

Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

Toxicity of copper nanoparticles and CuCl2 salt to Enchytraeus albidus worms: Survival, reproduction and avoidance responses

International Nuclear Information System (INIS)

Amorim, Mónica João Barros; Scott-Fordsmand, Janeck James

2012-01-01

Environmental effects of copper nanoparticles are little studied in terrestrial ecosystems. In the present article, the toxicity of copper nanoparticles (Cu-NP) on the enchytraeid Enchytraeus albidus is compared to the toxicity of a copper-salt (CuCl 2 ). The effect parameters studied were survival, reproductive output and avoidance behaviour. The results show that Cu-NP were more toxic to E. albidus than the same concentrations of the CuCl 2 -salt. The physic-chemical analysis of the particles indicated that only a small fraction was released as ions. Hence, the results indicated a nanoparticle-specific effect – lower reproductive output and higher avoidance. This was observed as 2–8 fold (significant) lower ECx values for Cu-NP (EC 50-reprod = 95 mg Cu/kg; EC 50-avoid = 241 mg Cu/kg) exposed organisms compared to CuCl 2 (EC 50-reprod = 251 mg Cu/kg; EC 50-avoid = 475 mg Cu/kg) exposed organisms. These results corroborate with a nanoparticle-specific effect. - Highlights: ► Enchytraeus albidus were exposed to Cu-salt and Cu nanoparticles (80 nm) in soil. ► Survival, reproduction and avoidance behaviour were assessed. ► Particles characterization indicated very small ion release. ► Cu nanoparticles toxicity was higher than Cu-salt for reproduction and avoidance. - Toxicity of Cu chloride salt and Cu nanoparticles to Enchytraeus albidus indicated higher toxicity of Cu-NP.

Modeling the effects of reformulated gasoline usages on ambient concentrations of ozone and five air toxics

International Nuclear Information System (INIS)

Ligocki, M.P.; Schulhof, R.R.; Jackson, R.E.; Jimenez, M.M.; Atkinson, D.

1993-01-01

The use of reformulated gasolines to reduce motor-vehicle-related hydrocarbon emissions has been mandated by the 1990 Clean Air Act Amendments for nine severely polluted urban areas. Using a version of the Urban Airshed Model that includes explicit representation of five motor-vehicle-related air toxics, the effects of reformulated gasoline usage on ambient ozone and toxics concentrations were simulated. Simulations were conducted for two urban areas. Baltimore-Washington and Houston, for the year 1995. Additional simulation were conducted for Baltimore-Washington including winter and 1999 scenarios. In the Baltimore-Washington areas, the 1995 Federal reformulated gasoline scenario produce reductions of 1.1 percent in simulated peak ozone and 2.7 percent in the areal extent of simulated ozone exceedances. Simulated ozone reductions were much smaller in Houston. In the reformulated gasoline simulations, secondary formulation of formaldehyde and acetaldehyde was reduced, and decreases in ambient benzene and polycyclic organic matter (POM) concentrations were simulated. Larger reductions in ozone and toxics concentrations were simulated for reformulated gasolines meeting California Phase II standards than for those meeting Federal standards. The effects of reductions in motor-vehicle-related nitrogen oxides (NO x ) emissions, alone and in combination with hydrocarbon reductions, were also examined

Consequence Analysis of Release from KN-18 Cask during a Severe Transportation Accident

International Nuclear Information System (INIS)

Lim, Heoksoon; Bhang, Giin; Na, Janghwan; Ban, Jaeha; Kim, Myungsu

2015-01-01

Korea Hydro and Nuclear Power (KHNP) has launched a project entitled 'Development of APR1400 Physical Protection System Design' and conducting a new conceptual physical protection system(PPS) design. One of mayor contents is consequence analysis for spent nuclear fuel cask. Proper design of physical protection system for facilities and storage and transformation involving nuclear and radioactive material requires the quantification of potential consequence from prescribed sabotage and theft scenarios in order to properly understand the level of PPS needed for specific facilities and materials. An important aspect of the regulation of the nuclear industry is assessing the risk to the public and the environment from a release of radioactive material produced by accidental or intentional scenarios. This paper describes the consequence analysis methodology, structural analysis for KN-18 cask and results of release from the cask during a severe transportation accident. Accident during spent fuel cask transportation was numerically calculated for KN-18, and showed the integrity of the fuel assemblies and cask itself was unharmed on a scenario that is comparable to state of art NRC research. Even assumption of leakage as a size of 1 x 10''2 mm''2 does not exceed for a certain criteria at any distance

Consequence Analysis of Release from KN-18 Cask during a Severe Transportation Accident

Energy Technology Data Exchange (ETDEWEB)

Lim, Heoksoon; Bhang, Giin; Na, Janghwan; Ban, Jaeha; Kim, Myungsu [KAERI, Daejeon (Korea, Republic of)

2015-05-15

Korea Hydro and Nuclear Power (KHNP) has launched a project entitled 'Development of APR1400 Physical Protection System Design' and conducting a new conceptual physical protection system(PPS) design. One of mayor contents is consequence analysis for spent nuclear fuel cask. Proper design of physical protection system for facilities and storage and transformation involving nuclear and radioactive material requires the quantification of potential consequence from prescribed sabotage and theft scenarios in order to properly understand the level of PPS needed for specific facilities and materials. An important aspect of the regulation of the nuclear industry is assessing the risk to the public and the environment from a release of radioactive material produced by accidental or intentional scenarios. This paper describes the consequence analysis methodology, structural analysis for KN-18 cask and results of release from the cask during a severe transportation accident. Accident during spent fuel cask transportation was numerically calculated for KN-18, and showed the integrity of the fuel assemblies and cask itself was unharmed on a scenario that is comparable to state of art NRC research. Even assumption of leakage as a size of 1 x 10''2 mm''2 does not exceed for a certain criteria at any distance.

Classifying Scenarios in a Product Design Process: a study to achieve automated scenario generation

NARCIS (Netherlands)

Anggreeni, Irene; van der Voort, Mascha C.; van Houten, F.J.A.M.; Miedema, J.; Lutters, D.

2008-01-01

This paper explains the possible uses of scenarios in product design. A scenario classification is proposed as a framework to create, use and reuse different types of scenarios in a product design process. Our aims are three-fold: (1) to obtain a better view on the extent to which scenarios can be

Consequences in Norway of a hypothetical accident at Sellafield: Potential release - transport and fallout

International Nuclear Information System (INIS)

Ytre-Eide, M. A.; Standring, W.J.F.; Amundsen, I.; Sickel, M.; Liland, A.; Saltbones, J.; Bartnicki, J.; Haakenstad, H.; Salbu, B.

2009-03-01

This report focuses on transport and fallout from 'worst-case' scenarios based on a hypothetical accident at the B215 facility for storing Highly Active Liquors (HAL) at Sellafield. The scenarios involve an atmospheric release of between 0.1-10 % of the total HAL inventory; only transport and fallout of 137 Cs is considered in this case study. Simulations resulted in between 0.1-50 times the maximum 137 Cs fallout experienced in the most contaminated areas in Norway after the Chernobyl accident. (Author)

"The blood pressure and dermal sensitivity effects of Nylon hollow fiber releasing Glycerin Trinitrate in vivo "

Directory of Open Access Journals (Sweden)

"Ostad SN

2002-09-01

Full Text Available In order to improve patient's compliance in taking glycerine trinitrate (GTN nylon hollow fiber which has been successfully used for release of chlorhexidine diacetate and levonorgestrel was employed to make nylon hollow fiber releasing GTN. Hollow nylon fibres of external diameter 0.63 mm, 75 mm long with an internal capacity of 16 μl, were filled with GTN (190 mg/ml in 70% ethanol (v/v or vehicle alone and the ends were heat-sealed. The fibers were then immersed in 10 ml of 0.9% (w/v saline in a separating funnel. The GTN release pattern from fiber, the effect of the product on blood pressure and its potential dermal toxicity were assessed. The release of GTN from the fibres was approximately 2.7 μg/min when the fibres contained 16 mg of drug. The results showed that the amount of GTN within the single fibre was enough to reduce blood pressure significantly, while it did not show significant dermal toxicity. It is concluded that GTN fiber, if used as monofilament, is not an alternative method for GTN delivery.

Transcriptome of extracellular vesicles released by hepatocytes.

Directory of Open Access Journals (Sweden)

Felix Royo

Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

Modelling of oceanic gas hydrate instability and methane release in response to climate change

International Nuclear Information System (INIS)

Reagan, M.T.; Moridis, G.J.

2008-01-01

Methane releases from oceanic hydrates are thought to have played a significant role in climatic changes that have occurred in the past. In this study, gas hydrate accumulations subjected to temperature changes were modelled in order to assess their potential for future methane releases into the ocean. Recent ocean and atmospheric chemistry studies were used to model 2 climate scenarios. Two types of hydrate accumulations were used to represent dispersed, low-saturation deposits. The 1-D multiphase thermodynamic-hydrological model considered the properties of benthic sediments; ocean depth; sea floor temperature; the saturation and distribution of the hydrates; and the effect of benthic biogeochemical activity. Results of the simulations showed that shallow deposits undergo rapid dissociation and are capable of producing methane fluxes of 2 to 13 mol m 3 per year over a period of decades. The fluxes exceed the ability of the anaerobic sea floor environment to sequester or consume the methane. A large proportion of the methane released in the scenarios emerged in the gas phase. Arctic hydrates may pose a threat to regional and global ecological systems. It was concluded that results of the study will be coupled with global climate models in order to assess the impact of the methane releases in relation to global climatic change. 39 refs., 5 figs

Improved worst-case and liely accident definition in complex facilities for 40 CFR 68 compliance

International Nuclear Information System (INIS)

O'Kula, K.R., Taylor, Robert P., Jr; Hang, P.

1997-04-01

Many DOE facilities potentially subject to compliance with offsite consequence criteria under the 40 CFR 68 Risk Management Program house significant inventories of toxic and flammable chemicals. The accident progression event tree methodology is suggested as a useful technical basis to define Worst-Case and Alternative Release Scenarios in facilities performing operations beyond simple storage and/or having several barriers between the chemical hazard and the environment. For multiple chemical release scenarios, a chemical mixture methodology should be applied to conservatively define concentration isopleths. In some instances, the region requiring emergency response planning is larger under this approach than if chemicals are treated individually

Release strategies for rehabilitated sea otters

Science.gov (United States)

DeGange, Anthony R.; Ballachey, Brenda E.; Bayha, Keith; Williams, Terrie M.; Davis, Randall W.

1995-01-01

According to the U.S. Fish and Wildlife Services’ (USFWS) Response Plan for sea otters (USFWS, in preparation), in the event of an oil spill, the decision to release sea otters from rehabilitation centers following treatment will be linked to the decision on whether to capture sea otters for treatment. Assuming a scenario similar to the Exxon Valdez oil spill (EVOS), once the decision to capture sea otters is made, the ultimate goal is to return as many sea otters to the wild as possible, even though the rescue may not be expected to produce results significant at the population level. The decision by the USFWS to proceed with capture, rehabilitation, and release will be made on a case-by-case basis (USFWS, in preparation). Many factors will influence the decision. Perhaps the most important factors in deciding when and where to release sea otters are the location and availability of suitable release sites and verification that the otters are free of diseases that might be transmitted to the wild population.Alternative release strategies for sea otters will be contained in the sea otter response portion of the USFWS’s oil spill contingency plans for Alaska and California that are being developed as required by the Oil Pollution Act of 1990. Public review of these plans before they are implemented will help to reduce public concern about the survival of rehabilitated otters, their biological effect on the release area, and the potential introduction or spread of disease into the wild sea otter population.The objective of this chapter is to review alternative strategies for the disposition of rehabilitated sea otters. Our assumption is that returning as many animals to the wild as possible, whether it be for humanitarian or biological reasons, is the ultimate goal of this effort (Figure 10.1).

Shippingport Station Decommissioning Project site release protocol

International Nuclear Information System (INIS)

Handy, J.W.

1988-01-01

The Richland, Washington field office of the DOE and its Remedial Actions Contractor, GE, took possession of the SSDP site in September 1984. In February of the following year, DOE-HQ issued generic, site independent guidelines taken from existing radiation protection standards. Basic generic dose limits were English equivalents of 1 mSv (100 mrem) per year averaged over the lifetime of any individual member of the general public. Hot spot limits were given. Occupied or habitable structures were limited to 5.2 x 10 -9 C/Kg h (20mR/h). Surface contamination was limited to standards plus average and maximum contact dose rates of 2 microGy (0.2 mrad) per hour and 10 microGy (1 mrad) per hour respectively. In addition, ''all exposures ... were to be limited to levels that (were) as low as reasonably achievable (ALARA).'' Authorized limits higher than these guidelines were allowed under given exceptional circumstances. GE determined the allowable radionuclide concentrations that could remain in soil and included rubble, and not dose the resident farmer to more than 1 mSv (100 mrem) per year. Under more conservative scenarios, however, exposures were controlled for buried, potentially occupationally occupiable, concrete substructures, to souvenir items, or to buried, but potentially exposed, concrete slabs. GE incorporated the scenario's pathways into a document implementing specific site release criteria which cannot be exceeded if the site is to be released unconditionally. 3 refs., 1 fig

Correlations in metal release profiles following sorption by Lemna minor.

Science.gov (United States)

Üçüncü Tunca, Esra; Ölmez, Tolga T; Özkan, Alper D; Altındağ, Ahmet; Tunca, Evren; Tekinay, Turgay

2016-08-02

Following the rapid uptake of contaminants in the first few hours of exposure, plants typically attempt to cope with the toxic burden by releasing part of the sorbed material back into the environment. The present study investigates the general trends in the release profiles of different metal(loid)s in the aquatic macrophyte Lemna minor and details the correlations that exist between the release of metal(loid) species. Water samples with distinct contamination profiles were taken from Nilüfer River (Bursa, Turkey), Yeniçağa Lake (Bolu, Turkey), and Beyşehir Lake (Konya, Turkey) and used for release studies; 36 samples were tested in total. Accumulation and release profiles were monitored over five days for 11 metals and a metalloid ((208)Pb, (111)Cd, (52)Cr,(53)Cr,(60)Ni,(63)Cu,(65)Cu,(75)As,(55)Mn, (137)Ba, (27)Al, (57)Fe, (66)Zn,(68)Zn) and correlation, cluster and principal component analyses were employed to determine the factors that affect the release of these elements. Release profiles of the tested metal(loid)s were largely observed to be distinct; however, strong correlations have been observed between certain metal pairs (Cr/Ni, Cr/Cu, Zn/Ni) and principal component analysis was able to separate the metal(loid)s into three well-resolved groups based on their release.

Scenario planning and nanotechnological futures

International Nuclear Information System (INIS)

Farber, Darryl; Lakhtakia, Akhlesh

2009-01-01

Scenario planning may assist us in harnessing the benefits of nanotechnology and managing the associated risks for the good of the society. Scenario planning is a way to describe the present state of the world and develop several hypotheses about the future of the world, thereby enabling discussions about how the world ought to be. Scenario planning thus is not only a tool for learning and foresight, but also for leadership. Informed decision making by experts and political leaders becomes possible, while simultaneously allaying the public's perception of the risks of new and emerging technologies such as nanotechnology. Two scenarios of the societal impact of nanotechnology are the mixed-signals scenario and the confluence scenario. Technoscientists have major roles to play in both scenarios.

Land-Use Scenarios: National-Scale Housing-Density Scenarios Consistent with Climate Change Storylines (Final Report)

Science.gov (United States)

EPA announced the availability of the final report, Land-Use Scenarios: National-Scale Housing-Density Scenarios Consistent with Climate Change Storylines. This report describes the scenarios and models used to generate national-scale housing density scenarios for the con...

Hazard analysis in uranium hexafluoride production facility

International Nuclear Information System (INIS)

Marin, Maristhela Passoni de Araujo

1999-01-01

The present work provides a method for preliminary hazard analysis of nuclear fuel cycle facilities. The proposed method identify both chemical and radiological hazards, as well as the consequences associated with accident scenarios. To illustrate the application of the method, a uranium hexafluoride production facility was selected. The main hazards are identified and the potential consequences are quantified. It was found that, although the facility handles radioactive material, the main hazards as associated with releases of toxic chemical substances such as hydrogen fluoride, anhydrous ammonia and nitric acid. It was shown that a contention bung can effectively reduce the consequences of atmospheric release of toxic materials. (author)

Seed production scenario in Maharashtra with special reference to mutant crop varieties

International Nuclear Information System (INIS)

Raut, R.S.

2001-01-01

Several mutant varieties of different crops have been developed by the Bhabha Atomic Research Centre, Mumbai during last two decades and released for cultivation for Maharashtra and other states of the country. The Maharashtra State Seed Corporation (MSSC) has undertaken the seed production of the mutant varieties released for the Maharashtra state. There has been a growing demand of some mutant varieties especially TAU-1 of black gram and TAG-24 of ground nut by the farmers of various states. The MSSC has been meeting the demand of the farmers of Maharashtra as well as of other states of the country for these varieties for last several years. The demand for TAU-1 in Maharashtra has reached the level of 27525 quintals of certified seed during the current year. The total seed production scenario of mutant varieties is indicative of their popularity. (author)

The 2017-2050 NegaWatt Scenario. Executive Summary

International Nuclear Information System (INIS)

2017-01-01

The NegaWatt Association has released a new version of its 2050 energy outlook. Using improved and updated data, as well as refined tools and calculations, it confirms that France can reach 100% renewable energy by 2050 while phasing-out nuclear. The NegaWatt approach leads to achieving the energy transition, meeting the objectives of the Paris Climate Deal, and generating net benefits for the French economy, as confirmed by a financial and job assessment. First issued in 2003, and updated several times since then, our 2050 energy scenario for France is now a well acknowledged and recognised thorough piece of work to discuss the country's energy future, and options to engage in a sustainable energy transition. The scenario is supported by a large number of civil society organisations, and has been considered in official assessment studies and national energy debates. Covering all sectors (buildings, transport, industry, agriculture...) through thousands of parameters and sophisticated details, it shows how France could shift to a climate-friendly, nuclear-free, and sustainable energy future through an approach based on: energy sufficiency (favouring low energy services and lifestyles); energy efficiency (ensuring that energy is used in the most productive way); renewables (developing first the greenest forms of energy for our supply)

Transient toxicity of 2-Deoxy-2-[18F] fluoro-D-Glucose in mammalian cells: concise communication

International Nuclear Information System (INIS)

Kassis, A.I.; Adelstein, S.J.; Wolf, A.P.; Fowler, J.G.; Shiue, C.Y.

1983-01-01

The kinetics of uptake and toxicity of the positron emitter F-18 have been examined in a cultured cell line. 2-Deoxy-2[ 18 F]fluoro-D-glucose ( 18 FDG) concentrated rapidly within Chinese hamster V79 cells, and the uptake was linear with the extracellular radioactive concentrations. Whereas 18 FDG sythesized 2 hr before the incubation did not appear to be toxic, that synthesized 5 hr previously was highly toxic. Toxicity was transient and independent of both the extracellular/intracellular radioactive concentration and the energy released from the decay of fluorine-18. Similarly synthesized nonradioactive FDG and Na 18 F were not toxic under comparable experimental conditions. The authors conclude that this transient toxicity is due to an unidentified chemical species that is cytocidal following intracellular localization. These toxic levels are not likely to be achieved in the clinical use of 18 FDG due to dilution factors that are orders of magnitude greater than those used in these in vitro studies

The toxic effects of chlorophenols and associated mechanisms in fish

International Nuclear Information System (INIS)

Ge, Tingting; Han, Jiangyuan; Qi, Yongmei; Gu, Xueyan; Ma, Lin; Zhang, Chen; Naeem, Sajid; Huang, Dejun

2017-01-01

Highlights: • We review the toxic effects of chlorophenols (CPs) and underlying mechanisms in fish. • CPs induce lethal effects, oxidative stress, endocrine disruption, reproductive toxicity and apoptosis in fish. • CPs exhibit toxicity through multiple signaling pathways in fish and different pathways co-exist under the same conditions. • Studies on DNA methylation provide new insights into our understanding of epigenetic mechanisms of CPs-induced toxicity. • Mechanisms studies on CPs toxicity performed under environmental concentrations need more attentions. - Abstract: Chlorophenols (CPs) are ubiquitous contaminants in the environment primarily released from agricultural and industrial wastewater. These compounds are not readily degraded naturally, and easily accumulate in organs, tissues and cells via food chains, further leading to acute and chronic toxic effects on aquatic organisms. Herein, we review the available literature regarding CP toxicity in fish, with special emphasis on the potential toxic mechanisms. CPs cause oxidative stress via generation of reactive oxygen species, induction of lipid peroxidation and/or oxidative DNA damage along with inhibition of antioxidant systems. CPs affect immune system by altering the number of mature B cells and macrophages, while suppressing phagocytosis and down-regulating the expression of immune factors. CPs also disrupt endocrine function by affecting hormone levels, or inducing abnormal gene expression and interference with hormone receptors. CPs at relatively higher concentrations induce apoptosis via mitochondria-mediated pathway, cell death receptor-mediated pathway, and/or DNA damage-mediated pathway. CPs at relatively lower concentrations promote cell proliferation, and foster cancers-prone environment by increasing the rate of point mutations and oxidative DNA lesions. These toxic effects in fish are induced directly by CPs per se or indirectly by their metabolic products. In addition, recent

The toxic effects of chlorophenols and associated mechanisms in fish

Energy Technology Data Exchange (ETDEWEB)

Ge, Tingting; Han, Jiangyuan; Qi, Yongmei; Gu, Xueyan; Ma, Lin; Zhang, Chen; Naeem, Sajid; Huang, Dejun, E-mail: huangdj@lzu.edu.cn

2017-03-15

Highlights: • We review the toxic effects of chlorophenols (CPs) and underlying mechanisms in fish. • CPs induce lethal effects, oxidative stress, endocrine disruption, reproductive toxicity and apoptosis in fish. • CPs exhibit toxicity through multiple signaling pathways in fish and different pathways co-exist under the same conditions. • Studies on DNA methylation provide new insights into our understanding of epigenetic mechanisms of CPs-induced toxicity. • Mechanisms studies on CPs toxicity performed under environmental concentrations need more attentions. - Abstract: Chlorophenols (CPs) are ubiquitous contaminants in the environment primarily released from agricultural and industrial wastewater. These compounds are not readily degraded naturally, and easily accumulate in organs, tissues and cells via food chains, further leading to acute and chronic toxic effects on aquatic organisms. Herein, we review the available literature regarding CP toxicity in fish, with special emphasis on the potential toxic mechanisms. CPs cause oxidative stress via generation of reactive oxygen species, induction of lipid peroxidation and/or oxidative DNA damage along with inhibition of antioxidant systems. CPs affect immune system by altering the number of mature B cells and macrophages, while suppressing phagocytosis and down-regulating the expression of immune factors. CPs also disrupt endocrine function by affecting hormone levels, or inducing abnormal gene expression and interference with hormone receptors. CPs at relatively higher concentrations induce apoptosis via mitochondria-mediated pathway, cell death receptor-mediated pathway, and/or DNA damage-mediated pathway. CPs at relatively lower concentrations promote cell proliferation, and foster cancers-prone environment by increasing the rate of point mutations and oxidative DNA lesions. These toxic effects in fish are induced directly by CPs per se or indirectly by their metabolic products. In addition, recent

Exposure to potentially toxic hydrocarbons and halocarbons released from the dialyzer and tubing set during hemodialysis.

Science.gov (United States)

Lee, Hyun Ji Julie; Meinardi, Simone; Pahl, Madeleine V; Vaziri, Nostratola D; Blake, Donald R

2012-10-01

Although much is known about the effect of chronic kidney failure and dialysis on the composition of solutes in plasma, little is known about their impact on the composition of gaseous compounds in exhaled breath. This study was designed to explore the effect of uremia and the hemodialysis (HD) procedure on the composition of exhaled breath. Breath samples were collected from 10 dialysis patients immediately before, during, and after a dialysis session. To determine the potential introduction of gaseous compounds from dialysis components, gasses emitted from dialyzers, tubing set, dialysate, and water supplies were collected. Prospective cohort study. 10 HD patients and 10 age-matched healthy individuals. Predictors include the dialyzers, tubing set, dialysate, and water supplies before, during, and after dialysis. Changes in the composition of exhaled breath. A 5-column/detector gas chromatography system was used to measure hydrocarbon, halocarbon, oxygenate, and alkyl nitrate compounds. Concentrations of 14 hydrocarbons and halocarbons in patients' breath rapidly increased after the onset of the HD treatment. All 14 compounds and 5 others not found in patients' breath were emitted from the dialyzers and tubing sets. Contrary to earlier reports, exhaled breath ethane concentrations in our dialysis patients were virtually unchanged during the HD treatment. Single-center study with a small sample size may limit the generalizability of the findings. The study documented the release of several potentially toxic hydrocarbons and halocarbons to patients from the dialyzer and tubing sets during the HD procedure. Because long-term exposure to these compounds may contribute to the morbidity and mortality in dialysis population, this issue should be considered in the manufacturing of the new generation of dialyzers and dialysis tubing sets. Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Ecological risk assessment on a cadmium contaminated soil landfill-a preliminary evaluation based on toxicity tests on local species and site-specific information

International Nuclear Information System (INIS)

Chen, C.-M.; Liu, M.-C.

2006-01-01

the PECs based on the maximum initial concentrations. The Cd and Pb's PNECs for three aquatic animals were 0.01∼0.1 mg l -1 , higher than their PECs in coastal water, resulting in HQs less than 1 for the scenario described. We concluded that if a leakage does occur, the ecological impact would be minimal because a majority of the metals will be retained in the soil phase and the remaining, if released into the aquatic system, cannot reach high enough concentrations to produce toxicity to marine animals

Influence of Postprandial Intragastric Pressures on Drug Release from Gastroretentive Dosage Forms.

Science.gov (United States)

Schneider, Felix; Hoppe, Melanie; Koziolek, Mirko; Weitschies, Werner

2018-05-29

Despite extensive research in the field of gastroretentive dosage forms, this "holy grail" of oral drug delivery yet remained an unmet goal. Especially under fasting conditions, the reproducible retention of dosage forms in the stomach seems to be an impossible task. This is why such systems are often advised to be taken together with food. But also the postprandial motility can contribute significantly to the failure of gastroretentive dosage forms. To investigate the influence of postprandial pressure conditions on drug release from such systems, we used a novel in vitro dissolution tool, the dissolution stress test device. With the aid of this device, we simulated three different intragastric pressure profiles that may occur after postprandial intake. These transit scenarios were based on recently obtained, postprandial SmartPill® data. The tested systems, Glumetza® 1000 and Madopar® HBS 125, are marketed dosage forms that are based on different approaches to achieve proper gastric retention. All three transit scenarios revealed a highly pressure-sensitive drug release behavior, for both drugs. For Madopar® HBS 125, nearly complete drug release was observed even after early occurring pressures. Glumetza® 1000 seemed to be more resistant to these, most likely due to incomplete wetting of the system. On the contrary to these findings, data from standard dissolution tests using the paddle apparatus displayed controlled drug release for both systems for about 6 h. Based on these results, it can be doubted that established gastroretentive systems stay intact over a longer period of time, even under postprandial conditions.

Using random event simulation to evaluate the effectiveness of indoor sheltering during a sour gas release

International Nuclear Information System (INIS)

Wilson, D.

2003-01-01

In the event of sour gas releases to the atmosphere, there is a strong bias toward evacuation rather than sheltering-in-place. This paper described the critical factors in decision-making for shelter-in-place versus evacuation. These include: delay time expected before release begins; size of potential release, explosion or fire; expected duration; direction to safety for evacuation; the air tightness of the building; and, the number of people in the emergency response zone. A shelter-in-place decision chart developed by the Canadian Association of Fire Chiefs was presented. It shows the usual bias toward evacuation as the default position. It also shows the greatest drawbacks of sheltering-in-place. The main factor in maintaining the effectiveness of the building shelter is the rate of air infiltration into the building. Other issues to consider include: reactive versus passive chemicals in the release; light versus heavy gas releases; building type (houses, high-rise apartments, office buildings, or warehouses); tightness of building construction; whether to turn the house heating and air conditioning on or off during shelter; daytime versus nighttime conditions; and, cost factors. Equations for calculating indoor and outdoor toxic exposure to decide on shelter versus evacuation were also presented. It was concluded that the absence of peak concentrations dramatically reduce the risk of fatality to people sheltering indoors. Keeping people indoors is the best way to assure their safety for the first hour following a toxic release. 8 refs., 6 figs

Airborne uranium, its concentration and toxicity in uranium enrichment facilities

International Nuclear Information System (INIS)

Thomas, J.; Mauro, J.; Ryniker, J.; Fellman, R.

1979-02-01

The release of uranium hexafluoride and its hydrolysis products into the work environment of a plant for enriching uranium by means of gas centrifuges is discussed. The maximum permissible mass and curie concentration of airborne uranium (U) is identified as a function of the enrichment level (i.e., U-235/total U), and chemical and physical form. A discussion of the chemical and radiological toxicity of uranium as a function of enrichment and chemical form is included. The toxicity of products of UF 6 hydrolysis in the atmosphere, namely, UO 2 F 2 and HF, the particle size of toxic particulate material produced from this hydrolysis, and the toxic effects of HF and other potential fluoride compounds are also discussed. Results of an investigation of known effects of humidity and temperature on particle size of UO 2 F 2 produced by the reaction of UF 6 with water vapor in the air are reported. The relationship of the solubility of uranium compounds to their toxic effects was studied. Identification and discussion of the standards potentially applicable to airborne uranium compounds in the working environment are presented. The effectiveness of High Efficiency Particulate (HEPA) filters subjected to the corrosive environment imposed by the presence of hydrogen fluoride is discussed

Preparation and toxicity evaluation of a novel nattokinase-tauroursodeoxycholate complex

Directory of Open Access Journals (Sweden)

Rui Feng

2018-03-01

Full Text Available Nattokinase (NK, which has been identified as a potent fibrinolytic protease, has remarkable potential in treatment of thrombolysis, and even has the ability to ameliorate chronic vein thrombosis. To reduce the hemorrhagic risk from an intravenous injection of NK, nattokinase-tauroursodeoxycholate (NK-TUDCA complex was prepared at different pH values and with different ratios of NK and TUDCA. When assessing survival time, survival state, tail injury, and the body weight of mice, it was found that the NK-TUDCA complex (NK: 10 kIU/ml; TUDCA: 10 mg/ml; pH 5.0 had a lower toxicity when administered at an NK dosage of 130 kIU/kg in the acute toxicity test and 13 kIU/kg in the repeated low-dose challenge. From the results of the in vitro thrombolytic test and characterization of NK-TUDCA, we speculated that the delayed release of NK-TUDCA might be the main cause of toxicity reduction by the complex. This study described the preparation of an NK complex with low toxicity following intravenous administration, which could be utilized for further clinical study of NK. Keywords: Nattokinase, Tauroursodeoxycholate, Complex, Toxicity test, In vitro thrombolytic test