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Sample records for exposure limits scoel

  1. Approaches for the development of occupational exposure limits for man-made mineral fibres (MMMFs)

    International Nuclear Information System (INIS)

    Ziegler-Skylakakis, Kyriakoula

    2004-01-01

    Occupational exposure limits (OELs) are an essential tool in the control of exposure to hazardous chemical agents, and serve to minimise the occurrence of occupational diseases associated with such exposure. The setting of OELs, together with other associated measures, forms an essential part of the European Community's strategy on health and safety at work, upon which the legislative framework for the protection of workers from risks related to chemical agents is based. The European Commission is assisted by the Scientific Committee on Occupational Exposure Limits (SCOEL) in its work of setting OELs for hazardous chemical agents. The procedure for setting OELs requires information on the toxic mechanisms of an agent that should allow to differentiate between thresholded and non-thresholded mechanisms. In the first case, a no-observed adverse effect level (NOAEL) can be defined, which can be the basis for a derivation of an OEL. In the latter case, any exposure is correlated with a certain risk. If adequate scientific data are available, SCOEL estimates the risk associated with a series of exposure levels. This can then be used for guidance, when setting OELs at European level. Man-made mineral fibres (MMMFs) are widely used at different worksites. MMMF products can release airborne respirable fibres during their production, use and removal. According to the classification of the EU system, all MMMF fibres are considered to be irritants and are classified for carcinogenicity. EU legislation foresees the use of limit values as one of the provisions for the protection of workers from the risks related to exposure to carcinogens. In the following paper, the research requirements identified by SCOEL for the development of OELs for MMMFs will be presented

  2. Electromagnetic Fields Exposure Limits

    Science.gov (United States)

    2018-01-01

    Mr. T.P. (Tjerk) KUIPERS Senior Adviser Health Physics Military Healthcare & Occupational Health Expertise Co-ordination Centre Support...Test of Biological Integrity in Dogs Exposed to an Electromagnetic Pulse Environment”, Health Physics 36:159-165, 1979. [11] Baum, S.J., Ekstrom, M.E...Electromagnetic Radiation”, Health Physics 30:161-166, 1976. [12] Baum, S., Skidmore, W. and Ekstrom, M., “Continuous Exposure of Rodents to 108 Pulses

  3. Microdosimetric basis for exposure limits

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; Braby, L.A.

    1986-10-01

    The new organ-weighted effective dose equivalents should provide a much more accurate estimation of the degree of hazard for a worker's exposure to ionizing radiations. The method involves the microdosimetric concept of lineal energy to help establish exposure limits and will provide a unified system applicable to all types of ionizing radiation. Rather than being only calculated values, the effective dose equivalents and quality factors will be experimentally measured using tissue equivalent proportional counters. The measurement may be difficult to perform at various depths in an anthropomorphic phantom. Operational health physicists will be concerned about the lack of survey instruments and personnel dosimeters that measure lineal energy distributions. Their possible objections may be mitigated by the commercial introduction of instruments based upon tissue equivalent proportional counters or related devices containing inexpensive microprocessors. The many potential benefits include providing a uniform method for implementing the proposed increases in quality factors for neutrons and photons, providing a more unified approach for combining external and internal exposures, and potentially resolving questions about dosimeter placement and dose assessment for nonuniform exposures to mixed radiations. 16 refs., 3 figs

  4. Occupational Exposures and Chronic Airflow Limitation

    Directory of Open Access Journals (Sweden)

    Helen Dimich-Ward

    1996-01-01

    Full Text Available The recent literature was reviewed to evaluate whether chronic airflow limitation is associated with occupational exposures to dusts. Only those studies that controlled for the effects of smoking were included. There is compelling evidence that exposure to inorganic dusts, such as from coal and hardrock mining or asbestos, are associated with the development of chronic airflow limitation, independently of pneumoconiosis. Nonsmoking gold miners are particularly at high risk of airflow obstruction and emphysema. Findings from studies of organic dusts, such as exposures to wood, cotton, grain or other agricultural dusts, or to mixed dust exposures, were less consistent but tended to show positive dose-response associations. In the majority of studies, no statistical interaction was shown between dust exposures and smoking; however, the effects of the dust exposures were often more pronounced. An occupational history should be considered, in addition to a smoking history, as an integral part of an investigation of chronic airflow limitation in a patient.

  5. [Nanosilver--Occupational exposure limits].

    Science.gov (United States)

    Świdwińska-Gajewska, Anna Maria; Czerczak, Sławomir

    2015-01-01

    Historically, nanosilver has been known as colloidal silver composed of particles with a size below 100 nm. Silver nanoparticles are used in many technologies, creating a wide range of products. Due to antibacterial properties nanosilver is used, among others, in medical devices (wound dressings), textiles (sport clothes, socks), plastics and building materials (paints). Colloidal silver is considered by many as an ideal agent in the fight against pathogenic microorganisms, unlike antibiotics, without side effects. However, in light of toxicological research, nanosilver is not inert to the body. The inhalation of silver nanoparticles have an adverse effect mainly on the liver and lung of rats. The oxidative stress caused by reactive oxygen species is responsible for the toxicity of nanoparticles, contributing to cytotoxic and genotoxic effects. The activity of the readily oxidized nanosilver surface underlies the molecular mechanism of toxicity. This leads to the release of silver ions, a known harmful agent. Occupational exposure to silver nanoparticles may occur in the process of its manufacture, formulation and also usage during spraying, in particular. In Poland, as well as in other countries of the world, there is no separate hygiene standards applicable to nanomaterials. The present study attempts to estimate the value of MAC-TWA (maximum admissible concentration--the time-weighted average) for silver--a nano-objects fraction, which amounted to 0.01 mg/m3. The authors are of the opinion that the current value of the MAC-TWA for silver metallic--inhalable fraction (0.05 mg/m3) does not provide sufficient protection against the harmful effects of silver in the form of nano-objects. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  6. Nanosilver – Occupational exposure limits

    Directory of Open Access Journals (Sweden)

    Anna Maria Świdwińska-Gajewska

    2015-07-01

    Full Text Available Historically, nanosilver has been known as colloidal silver composed of particles with a size below 100 nm. Silver nanoparticles are used in many technologies, creating a wide range of products. Due to antibacterial properties nanosilver is used, among others, in medical devices (wound dressings, textiles (sport clothes, socks, plastics and building materials (paints. Colloidal silver is considered by many as an ideal agent in the fight against pathogenic microorganisms, unlike antibiotics, without side effects. However, in light of toxicological research, nanosilver is not inert to the body. The inhalation of silver nanoparticles have an adverse effect mainly on the liver and lung of rats. The oxidative stress caused by reactive oxygen species is responsible for the toxicity of nanoparticles, contributing to cytotoxic and genotoxic effects. The activity of the readily oxidized nanosilver surface underlies the molecular mechanism of toxicity. This leads to the release of silver ions, a known harmful agent. Occupational exposure to silver nanoparticles may occur in the process of its manufacture, formulation and also usage during spraying, in particular. In Poland, as well as in other countries of the world, there is no separate hygiene standards applicable to nanomaterials. The present study attempts to estimate the value of MAC-TWA (maximum admissible concentration – the time-weighted average for silver – a nano-objects fraction, which amounted to 0.01 mg/m3. The authors are of the opinion that the current value of the MAC-TWA for silver metallic – inhalable fraction (0.05 mg/m3 does not provide sufficient protection against the harmful effects of silver in the form of nano-objects. Med Pr 2015;66(3:429–442

  7. Limit values for exposure to physical agents

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The limit values for exposure to thermal environments adopted by the French AFNOR and by the ISO Working Group (AFNOR Standard X 35-201 and ISO Standard 7243, and AFNOR Standard X 35-204). The limit values for exposure to other physical agents established by the American ACGIH for 1982. The following agents are covered: - laser radiation (ocular and skin exposure); - ultraviolet radiation; - visible and near-infrared radiation (retinal thermal and photochemical injury); - airborne and upper sonic and ultrasonic acoustic radiation; - radiofrequency radiation [fr

  8. Bases for establishing radiation exposure limits

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1977-01-01

    It is an essential requirement of good radiation protection that all unnecessary exposure of people should be avoided and that any necessary exposure, whether of workers or of members of the general public, should be minimised. It is, however, an additional requirement that such necessary exposures should not exceed certain stated limits. These principles are based on the possibility that even the smallest exposures may involve some risk of harm, that any risk of harm should be justifiable by the circumstances necessitating it, and that risk should always be limited to an appropriately low level. The bases for establishing exposure limits must therefore involve an assessment of the risk involved in any form of radiation exposure, and an opinion as to the degree of safety that should be ensured in circumstances which necessitate any occupational or public exposure to radiation. There is increasing quantitative evidence on the frequency on which harm, and particularly the induction of malignancies, may be caused in people exposed to radiation at high doses; and somewhat clearer bases than previously for inferring the possible frequencies at low doses. It is therefore easier to assess the degree of safety ensured by restricting radiation exposure to particular levels. The degree of safety which should be regarded as appropriate in different circumstances remains a matter for review, but suggestions are made as to levels which would be advocated by informed opinion, and the exposure limits which would correspond to these. It is clear also that a comparable degree of safety should be ensured whether the radiation exposure involves the whole body more of less uniformly, or individual tissues or organs selectively. Increasing epidemiological evidence is available on the relative sensitivity to radiation induction of malignancies in a number of organs, and to the apparently much lower sensitivity of other organs; and experimental evidence in animals allows a comparable

  9. Bases for establishing radiation exposure limits

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1977-01-01

    It is an essential requirement of good radiation protection that all unnecessary exposure of people should be avoided and that any necessary exposure, whether of workers or of members of the general public, should be minimized. It is, however, an additional requirement that such necessary exposures should not exceed certain stated limits. These principles are based on the possibility that even the smallest exposures may involve some risk of harm, that any risk of harm should be justifiable by the circumstances necessitating it, and that risk should always be limited to an appropriately low level. The bases for establishing exposure limits must therefore involve an assessment of the risk involved in any form of radiation exposure, and an opinion as to the degree of safety that should be ensured in circumstances which necessitate any occupational or public exposure to radiation. There is increasing quantitative evidence on the frequency on which harm, and particularly the induction of malignancies, may be caused in people exposed to radiation at high doses; and somewhat clearer bases than previously for inferring the possible frequencies at low doses. It is therefore easier to assess the degree of safety ensured by restricting radiation exposure to particular levels. It is clear also that a comparable degree of safety should be ensured whether the radiation exposure involves the whole body more of less uniformly, or individual tissues or organs selectively. The ''weighting'' factors appropriate to irradiation of particular tissues from internal emitters can thus be defined in terms of their likely individual contributions to the harm of whole-body irradiation. In this way the limits for different modes of exposure by external or internal radiation can be related so as to ensure that protection should be equally effective for different distributions of absorbed dose in the body. In particular, the over-simplified concept of a single critical organ determining the

  10. Establishing exposure limits for chemical pollutants

    International Nuclear Information System (INIS)

    Drosselmeyer, E.

    1979-05-01

    In addition to toxic effects, chemical pollutants may produce cancer and genetic damage as radiation does. Some of these effects have been known since a very long time. Inspite of this fact, the knowledge of the basic processes in damage formation, of dose-effect relationships, and of possible threshold values seem to be at least comparable in the field of radiation protection. The attempt is made to give an introduction into the problems by a literature survey of the effects on man of heavy metals, especially of lead. Subsequently the exposure limits for different groups of the population and the legal national and international standards are considered. Efforts to quantify the relationship existing between different pollutants by the definition of a 'radiation equivalent' dose for chemicals deserve particular interest. (orig.) [de

  11. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 57... Underground § 57.5001 Exposure limits for airborne contaminants. Except as permitted by § 57.5005— (a) Except as provided in paragraph (b), the exposure to airborne contaminants shall not exceed, on the basis of...

  12. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 56... Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... contaminants shall not exceed, on the basis of a time weighted average, the threshold limit values adopted by...

  13. Human exposure limits to hypergolic fuels

    Science.gov (United States)

    Garcia, H. D.; James, J. T.; Limero, T. F.

    1992-01-01

    Over the past four decades, many studies have been conducted on the toxicities of the rocket propellants hydrazine (HZ) and monomethylhydrazine (MH). Numerous technical challenges have made it difficult to unambiguously interpret the results of these studies, and there is considerable divergence between results obtained by different investigators on the inhalation concentrations (MAC's) for each toxic effect inducible by exposure to hypergolic fuels in spacecraft atmospheres, NASA undertook a critical review of published and unpublished investigations on the toxicities of these compounds. The current state of the art practices for similar studies. While many questions remain unanswered, MAC's were determined using the best available data for a variety of toxic endpoints for potential continuous exposure durations ranging from 1 hour to 180 days. Spacecraft MAC's (SMAC's) were set for each compound based on the most sensitive toxic endpoint at each exposure duration.

  14. Threshold limit values, permissible exposure limits, and feasibility: The bases for exposure limits in the United States

    International Nuclear Information System (INIS)

    Rappaport, S.M.

    1993-01-01

    The development of exposure limits in the United States has always relied heavily upon the threshold limit values (TLVs) developed by the American Conference of Governmental Industrial Hygienists (ACGIH). In fact, the TLVs were adopted as official exposure limits by the Occupational Safety and Health Administration (OSHA) in 1972 and 1989. Given the continuing importance of the ACGIH limits, this paper compares the basis of the TLVs with that employed by OSHA de novo in its 12 new permissible exposure limits (PELs). Using benzene as an example, it is shown that OSHA's new PELs have been established following a rigorous assessment of the inherent risks and the feasibility of instituting the limit. The TLVs, on the other hand, have been developed by ad hoc procedures and appear to have traditionally reflected levels thought to be achievable at the time. However, this might be changing. Analysis of the historical reductions of TLVs, for 27 substances on the 1991-1992 list of intended changes, indicates smaller reductions in the past (median reduction of 2.0-2.5-fold between 1946 and 1988) compared to those currently being observed (median reduction of 7.5-fold between 1989 and 1991). Further analysis suggests a more aggressive policy of the ACGIH regarding TLVs for carcinogens but not for substances that produce effects other than cancer. Regardless of whether the basis of the TLVs has changed recently, it would take a relatively long time for the impact of any change to be felt, since the median age of the 1991-1992 TLVs is 16.5 years, and 75% of these limits are more than 10 years old. The implications of OSHA's continued reliance on the TLVs as a means of updating its PELs are discussed, and four alternatives are presented to the ACGIH regarding the future of its activities related to exposure limits. It is concluded that new mechanisms are needed for OSHA to update its PELs in a timely fashion so that the TLVs will not be adopted by default in the future

  15. New radiation limits and air crew exposure

    International Nuclear Information System (INIS)

    Antic, D.

    1999-01-01

    Commercial aircraft have optimum cruising speed of 800 - 900 km/h and the cruising altitude near 13 km.The flight paths are assigned according to airway corridors and safety requirements.The relatively high dose-equivalent rates at cruising altitudes near 13 km (about 0.5-2 mSv/h, and the shielding effect of the atmosphere corresponds to about 2 M of water) can cause exposures greater than 5 mSv/y, for a crew with full-time flight (500-600 h/y).The radiation exposure of the crew in commercial air traffic has been studied for the associations of the crews and airline management and published, and regulatory authorities are slowly accepting the fact that there indeed is a problem which needs investigations and protective regulation

  16. ELRA: The exposure limiting robotic apparatus

    International Nuclear Information System (INIS)

    Knighton, G.C.; Rosenberg, K.E.; Henslee, S.P.; Michelbacher, J.A.; Wilkes, C.W.

    1992-09-01

    A problem situation involving the handling of radioactive material at Argonne National Laboratory -- West (ANL-W) was solved through the use of remote handling techniques, providing significant exposure reduction to personnel. Robotic devices can be useful, but the cost of a robot is often prohibitive for many jobs. A low cost, disposable robot was built which successfully removed a highly radioactive and potentially explosive system from a hot cell at ANL-W

  17. Radiofrequency fields: Bases for exposure limits

    Energy Technology Data Exchange (ETDEWEB)

    Paolo Vecchia [Department of Technologies and Health National Institute of Health, Rome (Italy)

    2006-07-01

    Several biological effects have been reported at exposure levels below the threshold for thermal effects, but most of them require independent confirmation before being accepted as established. However, no seems to have relevant implications for human health. Precautionary measures should be based on a cost/benefit analysis, and be proportionate on one side to the risk they aim at preventing and on the other side to actions taken in other areas to prevent comparable risks. (N.C.)

  18. Radiofrequency fields: Bases for exposure limits

    International Nuclear Information System (INIS)

    Paolo Vecchia

    2006-01-01

    Several biological effects have been reported at exposure levels below the threshold for thermal effects, but most of them require independent confirmation before being accepted as established. However, no seems to have relevant implications for human health. Precautionary measures should be based on a cost/benefit analysis, and be proportionate on one side to the risk they aim at preventing and on the other side to actions taken in other areas to prevent comparable risks. (N.C.)

  19. Basis for limiting exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Bush, W.R.

    1979-07-01

    In view of the uncertainty about the size of the risk from radiation, it is assumed that all doses are potentially harmful with the probability of harm proportional to the dose, without threshold. Canada participates in the work of UNSCEAR, and the Canadian Atomic Energy Control Board follows the recommendations of the International Commission on Radiological Protection in setting its dose limits, encouraging the application of the ALARA (as low as reasonably achievable) concept through its licensing and compliance activities

  20. Radon daughter exposure estimation and its relation to the exposure limit

    International Nuclear Information System (INIS)

    Stocker, H.

    1981-10-01

    Under current Atomic Energy Control Regulations, the annual limit for individual exposure to radon daughters is 4 WLM. The Regulations do not specify how the exposure is to be determined nor to what accuracy the measurements should be made. This paper discusses the historical and conventional grab-sampling and time-weighting methods for assigning exposures to radon daughters in uranium mines in Canada. As a further step in the evolution of exposure assignments, the system of personal radon daughter dosimetry is introduced as the more accurate means of assigning individual exposures and of adhering to the intent of the exposure limit

  1. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency radiation exposure limits. 1... Procedures Implementing the National Environmental Policy Act of 1969 § 1.1310 Radiofrequency radiation... exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except in the case of portable...

  2. The revision of dose limits for exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Hughes, D.

    1990-01-01

    The paper reviews the current dose limits for exposure to ionizing radiations and the risk factors on which they are based, and summarizes the revised risk factors and the draft proposals for new dose limits published by the International Commission on Radiological Protection. (author)

  3. Epistemological limitation for attributing health effects to natural radiation exposure

    International Nuclear Information System (INIS)

    González, Abel J.

    2010-01-01

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

  4. Secondary limits of exposure in facilities handling uranium

    International Nuclear Information System (INIS)

    Raghavayya, M.

    1999-08-01

    Annual limits of exposure and intake for radiation workers in nuclear installations have been recommended by the International Commission on Radiological Protection and the same have been adopted by the Indian Atomic Energy Regulatory Board for all the radionuclides of interest. The prescribed limits cannot be directly used for day to day radiation protection work. Hence secondary limits have to be derived for routine applications. The modeling steps may be simple in some situations and more complicated in some others. The limits recommended are for individual radionuclides. But in facilities handling natural or enriched uranium the radionuclides (isotopes of uranium and its decay products) generally occur together in specific ratios. Derivation of secondary limits has to take this into consideration. The present document is an attempt at deriving the secondary limits required for routine application in facilities handling uranium (Mine, mill, refineries and fuel fabrication etc.). Secondary limits of exposure have been derived in this document for air borne activity, activity in water, surface contamination and internal exposures. (author)

  5. Occupational exposure limits for nanomaterials: state of the art

    Science.gov (United States)

    Schulte, P. A.; Murashov, V.; Zumwalde, R.; Kuempel, E. D.; Geraci, C. L.

    2010-08-01

    Assessing the need for and effectiveness of controlling airborne exposures to engineered nanomaterials in the workplace is difficult in the absence of occupational exposure limits (OELs). At present, there are practically no OELs specific to nanomaterials that have been adopted or promulgated by authoritative standards and guidance organizations. The vast heterogeneity of nanomaterials limits the number of specific OELs that are likely to be developed in the near future, but OELs could be developed more expeditiously for nanomaterials by applying dose-response data generated from animal studies for specific nanoparticles across categories of nanomaterials with similar properties and modes of action. This article reviews the history, context, and approaches for developing OELs for particles in general and nanoparticles in particular. Examples of approaches for developing OELs for titanium dioxide and carbon nanotubes are presented and interim OELs from various organizations for some nanomaterials are discussed. When adequate dose-response data are available in animals or humans, quantitative risk assessment methods can provide estimates of adverse health risk of nanomaterials in workers and, in conjunction with workplace exposure and control data, provide a basis for determining appropriate exposure limits. In the absence of adequate quantitative data, qualitative approaches to hazard assessment, exposure control, and safe work practices are prudent measures to reduce hazards in workers.

  6. Occupational exposure limits for nanomaterials: state of the art

    International Nuclear Information System (INIS)

    Schulte, P. A.; Murashov, V.; Zumwalde, R.; Kuempel, E. D.; Geraci, C. L.

    2010-01-01

    Assessing the need for and effectiveness of controlling airborne exposures to engineered nanomaterials in the workplace is difficult in the absence of occupational exposure limits (OELs). At present, there are practically no OELs specific to nanomaterials that have been adopted or promulgated by authoritative standards and guidance organizations. The vast heterogeneity of nanomaterials limits the number of specific OELs that are likely to be developed in the near future, but OELs could be developed more expeditiously for nanomaterials by applying dose-response data generated from animal studies for specific nanoparticles across categories of nanomaterials with similar properties and modes of action. This article reviews the history, context, and approaches for developing OELs for particles in general and nanoparticles in particular. Examples of approaches for developing OELs for titanium dioxide and carbon nanotubes are presented and interim OELs from various organizations for some nanomaterials are discussed. When adequate dose-response data are available in animals or humans, quantitative risk assessment methods can provide estimates of adverse health risk of nanomaterials in workers and, in conjunction with workplace exposure and control data, provide a basis for determining appropriate exposure limits. In the absence of adequate quantitative data, qualitative approaches to hazard assessment, exposure control, and safe work practices are prudent measures to reduce hazards in workers.

  7. Ability to Discriminate Between Sustainable and Unsustainable Heat Stress Exposures-Part 1: WBGT Exposure Limits.

    Science.gov (United States)

    Garzón-Villalba, Ximena P; Wu, Yougui; Ashley, Candi D; Bernard, Thomas E

    2017-07-01

    Heat stress exposure limits based on wet-bulb globe temperature (WBGT) were designed to limit exposures to those that could be sustained for an 8-h day using limited data from Lind in the 1960s. In general, Sustainable exposures are heat stress levels at which thermal equilibrium can be achieved, and Unsustainable exposures occur when there is a steady increase in core temperature. This paper addresses the ability of the ACGIH® Threshold Limit Value (TLV®) to differentiate between Sustainable and Unsustainable heat exposures, to propose alternative occupational exposure limits, and ask whether an adjustment for body surface area improves the exposure decision. Two progressive heat stress studies provided data on 176 trials with 352 pairs of Sustainable and Unsustainable exposures over a range of relative humidities and metabolic rates using 29 participants wearing woven cotton clothing. To assess the discrimination ability of the TLV, the exposure metric was the difference between the observed WBGT and the TLV adjusted for metabolic rate. Conditional logistic regression models and receiver operating characteristic curves (ROC) along with ROC's area under the curve (AUC) were used. Four alternative models for an occupational exposure limit were also developed and compared to the TLV. For the TLV, the odds ratio (OR) for Unsustainable was 2.5 per 1°C-WBGT [confidence interval (CI) 2.12-2.88]. The AUC for the TLV was 0.85 (CI 0.81-0.89). For the alternative models, the ORs were also about 2.5/°C-WBGT, with AUCs between 0.84 and 0.88, which were significantly different from the TLV's AUC but have little practical difference. This study (1) confirmed that the TLV is appropriate for heat stress screening; (2) demonstrated the TLV's discrimination accuracy with an ROC AUC of 0.85; and (3) established the OR of 2.5/°C-WBGT for unsustainable exposures. The TLV has high sensitivity, but its specificity is very low, which is protective. There were no important

  8. Diesel Engine Exhaust: Basis for Occupational Exposure Limit Value.

    Science.gov (United States)

    Taxell, Piia; Santonen, Tiina

    2017-08-01

    Diesel engines are widely used in transport and power supply, making occupational exposure to diesel exhaust common. Both human and animal studies associate exposure to diesel exhaust with inflammatory lung effects, cardiovascular effects, and an increased risk of lung cancer. The International Agency for Research on Cancer has evaluated diesel exhaust as carcinogenic to humans. Yet national or regional limit values for controlling occupational exposure to diesel exhaust are rare. In recent decades, stricter emission regulations have led to diesel technologies evolving significantly, resulting in changes in exhaust emissions and composition. These changes are also expected to influence the health effects of diesel exhaust. This review provides an overview of the current knowledge on the health effects of diesel exhaust and the influence of new diesel technologies on the health risk. It discusses the relevant exposure indicators and perspectives for setting occupational exposure limit values for diesel exhaust, and outlines directions for future research. The review is based on a collaborative evaluation report by the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Safety. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  9. Consideration on a limit for lifetime occupational radiation exposure

    International Nuclear Information System (INIS)

    Kellerer, A.M.

    1998-01-01

    Annual dose limits in occupational radiation exposure are merely a secondary constraint in addition to the primary rule of dose reduction and justification. The limits may, therefore, be reached only in rare, special cases. However, in principle, there might be cases in which the annual limit is continuously exhausted throughout a working life; a high total dose of 0.8 Sv could then be reached. In view of this possibility, there have been considerations of an added restriction by limiting the lifetime occupational dose to 0.4 Sv. The implications of such lifetime doses are considered, and it is shown that an exposure up to the maximum of 0.8 Sv will lead to the need for compensation, if a leukaemia were to occur in the exposed worker. A lifetime dose of 0.4 Sv equally spread over a working life will not lead to the critical value of the probability of causation in excess of 0.5. Nevertheless, it could cause such critical values when it is accumulated during shorter periods. More decisive than the probabilities of causation are, however, the absolute numbers of excess cases of leukaemia due to the occupational exposure. It is seen that less than one excess case would be expected if a group of 100 workers were all exposed to the maximum of 0.8 Sv. Since lifetime doses of 0.8 or 0.4 Sv will be accumulated in very few cases and only with special justification, there appears to be little need to introduce a further limit of lifetime exposure in addition to the current annual limit. (orig.)

  10. The Occupational Exposure Limit for Fluid Aerosol Generated in Metalworking Operations: Limitations and Recommendations

    Directory of Open Access Journals (Sweden)

    Donguk Park

    2012-03-01

    Full Text Available The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF types. The OEL (time-weighted average; 5 mg/m3, short-term exposure limit ; 15 mg/m3 has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m3 would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

  11. The occupational exposure limit for fluid aerosol generated in metalworking operations: limitations and recommendations.

    Science.gov (United States)

    Park, Donguk

    2012-03-01

    The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m(3), short-term exposure limit ; 15 mg/m(3)) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m(3)) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

  12. Allowable exposure limits for carbon dioxide during extravehicular activity

    Science.gov (United States)

    Seter, Andrew J.

    1993-01-01

    The intent was to review the research pertaining to human exposure to carbon dioxide (CO2) and to recommend allowable exposure limits for extravehicular activity (EVA). Respiratory, renal, and gastrointestinal systems may be adversely affected by chronic low dose CO2 exposure. Ventilation was increased 15 percent with 1 percent CO2 and 50 percent with 2 percent CO2. Chronic exposure to less than 2 percent CO2 led to 20 day cycles of uncompensated and compensated respiratory acidosis. Acid-base changes were small. Histopathologic changes in guinea pig lungs have been noted with long term exposure to 1 percent CO2. No changes were seen with exposure to 0.5 percent CO2. Cycling of bone calcium stores with associated changes in blood and urinary calcium levels occurs with long term CO2 exposure. Histologic changes in bone have been noted in guinea pigs exposed to 1 percent CO2. Renal calcification has been noted in guinea pigs with exposure to as low as 0.5 percent CO2. An increase in gastric acidity was noted in subjects with long term exposure to 1 percent CO2. Cardiovascular and neurologic function were largely unaffected. A decrease in the incidence of respiratory, renal, and gastrointestinal disease was noted in submariners coincident with a decrease in ambient CO2 from 1.2 percent to 0.8-0.9 percent. Oxygen (O2) and CO2 stimulate respiration independently and cumulatively. The addition of CO2 to high dose O2 led to the faster onset of seizure activity in mice. Experiments evaluating the physiologic responses to intermittent, repetitive exposures to low dose CO2 and 100 percent O2 mixtures should be performed. A reduction in the current NASA standard for CO2 exposure during EVA of 1 percent (7.6 mmHg) for nominal and 2 percent (15.2 mmHg) for heavy exertion to 0.5 percent (3.8 mmHg) for nominal and 1 percent (7.6 mmHg) for heavy exertion may be prudent. At a minimum, the current NASA standard should not be liberalized.

  13. Occupational exposures and the case for reducing dose limits

    International Nuclear Information System (INIS)

    Gee, David

    1987-01-01

    This chapter describes the General, Municipal, Boilermakers and Allied Trades Union approach to all harmful agents encountered in either the workplace or the general environment; summarizes current radiation exposures in the UK and their arguments for a five-fold reduction in dose limits; and concludes with a summary of the only agreed compensation scheme in the world for radiation-induced cancer amongst workers. (author)

  14. The Limited Impact of Exposure Duration on Holistic Word Processing.

    Science.gov (United States)

    Chen, Changming; Abbasi, Najam Ul Hasan; Song, Shuang; Chen, Jie; Li, Hong

    2016-01-01

    The current study explored the impact of stimuli exposure duration on holistic word processing measured by the complete composite paradigm (CPc paradigm). The participants were asked to match the cued target parts of two characters which were presented for either a long (600 ms) or a short duration (170 ms). They were also tested by two popular versions of the CPc paradigm: the "early-fixed" task where the attention cue was visible from the beginning of each trial at a fixed position, and the "delayed-random" task where the cue showed up after the study character at random locations. The holistic word effect, as indexed by the alignment × congruency interaction, was identified in both tasks and was unaffected by the stimuli duration in both tasks. Meanwhile, the "delayed-random" task did not bring about larger holistic word effect than the "early-fixed" task. These results suggest the exposure duration (from around 150 to 600 ms) has a limited impact on the holistic word effect, and have methodological implications for experiment designs in this field.

  15. Airborne Isocyanate Exposures in the Collision Repair Industry and a Comparison to Occupational Exposure Limits

    Science.gov (United States)

    Reeb-Whitaker, Carolyn; Whittaker, Stephen G.; Ceballos, Diana M.; Weiland, Elisa C.; Flack, Sheila L.; Fent, Kenneth W.; Thomasen, Jennifer M.; Gaines, Linda G. Trelles; Nylander-French, Leena A.

    2014-01-01

    Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 μg/m3 for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 μg NCO/m3 for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UKHSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OROSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or

  16. Airborne isocyanate exposures in the collision repair industry and a comparison to occupational exposure limits.

    Science.gov (United States)

    Reeb-Whitaker, Carolyn; Whittaker, Stephen G; Ceballos, Diana M; Weiland, Elisa C; Flack, Sheila L; Fent, Kenneth W; Thomasen, Jennifer M; Trelles Gaines, Linda G; Nylander-French, Leena A

    2012-01-01

    Isocyanate exposure was evaluated in 33 spray painters from 25 Washington State autobody shops. Personal breathing zone samples (n = 228) were analyzed for isophorone diisocyanate (IPDI) monomer, 1,6-hexamethylene diisocyanate (HDI) monomer, IPDI polyisocyanate, and three polyisocyanate forms of HDI. The objective was to describe exposures to isocyanates while spray painting, compare them with short-term exposure limits (STELs), and describe the isocyanate composition in the samples. The composition of polyisocyanates (IPDI and HDI) in the samples varied greatly, with maximum amounts ranging from up to 58% for HDI biuret to 96% for HDI isocyanurate. There was a significant inverse relationship between the percentage composition of HDI isocyanurate to IPDI and to HDI uretdione. Two 15-min STELs were compared: (1) Oregon's Occupational Safety and Health Administration (OR-OSHA) STEL of 1000 μg/m(3) for HDI polyisocyanate, and (2) the United Kingdom's Health and Safety Executive (UK-HSE) STEL of 70 μg NCO/m(3) for all isocyanates. Eighty percent of samples containing HDI polyisocyanate exceeded the OR-OSHA STEL while 98% of samples exceeded the UK-HSE STEL. The majority of painters (67%) wore half-face air-purifying respirators while spray painting. Using the OR-OSHA and the UK-HSE STELs as benchmarks, 21% and 67% of painters, respectively, had at least one exposure that exceeded the respirator's OSHA-assigned protection factor. A critical review of the STELs revealed the following limitations: (1) the OR-OSHA STEL does not include all polyisocyanates, and (2) the UK-HSE STEL is derived from monomeric isocyanates, whereas the species present in typical spray coatings are polyisocyanates. In conclusion, the variable mixtures of isocyanates used by autobody painters suggest that an occupational exposure limit is required that includes all polyisocyanates. Despite the limitations of the STELs, we determined that a respirator with an assigned protection factor of 25 or

  17. The Global Landscape of Occupational Exposure Limits--Implementation of Harmonization Principles to Guide Limit Selection.

    Science.gov (United States)

    Deveau, M; Chen, C-P; Johanson, G; Krewski, D; Maier, A; Niven, K J; Ripple, S; Schulte, P A; Silk, J; Urbanus, J H; Zalk, D M; Niemeier, R W

    2015-01-01

    Occupational exposure limits (OELs) serve as health-based benchmarks against which measured or estimated workplace exposures can be compared. In the years since the introduction of OELs to public health practice, both developed and developing countries have established processes for deriving, setting, and using OELs to protect workers exposed to hazardous chemicals. These processes vary widely, however, and have thus resulted in a confusing international landscape for identifying and applying such limits in workplaces. The occupational hygienist will encounter significant overlap in coverage among organizations for many chemicals, while other important chemicals have OELs developed by few, if any, organizations. Where multiple organizations have published an OEL, the derived value often varies considerably-reflecting differences in both risk policy and risk assessment methodology as well as access to available pertinent data. This article explores the underlying reasons for variability in OELs, and recommends the harmonization of risk-based methods used by OEL-deriving organizations. A framework is also proposed for the identification and systematic evaluation of OEL resources, which occupational hygienists can use to support risk characterization and risk management decisions in situations where multiple potentially relevant OELs exist.

  18. The philosophy and assumptions underlying exposure limits for ionising radiation, inorganic lead, asbestos and noise

    International Nuclear Information System (INIS)

    Akber, R.

    1996-01-01

    Full text: A review of the literature relating to exposure to, and exposure limits for, ionising radiation, inorganic lead, asbestos and noise was undertaken. The four hazards were chosen because they were insidious and ubiquitous, were potential hazards in both occupational and environmental settings and had early and late effects depending on dose and dose rate. For all four hazards, the effect of the hazard was enhanced by other exposures such as smoking or organic solvents. In the cases of inorganic lead and noise, there were documented health effects which affected a significant percentage of the exposed populations at or below the [effective] exposure limits. This was not the case for ionising radiation and asbestos. None of the exposure limits considered exposure to multiple mutagens/carcinogens in the calculation of risk. Ionising radiation was the only one of the hazards to have a model of all likely exposures, occupational, environmental and medical, as the basis for the exposure limits. The other three considered occupational exposure in isolation from environmental exposure. Inorganic lead and noise had economic considerations underlying the exposure limits and the exposure limits for asbestos were based on the current limit of detection. All four hazards had many variables associated with exposure, including idiosyncratic factors, that made modelling the risk very complex. The scientific idea of a time weighted average based on an eight hour day, and forty hour week on which the exposure limits for lead, asbestos and noise were based was underpinned by neither empirical evidence or scientific hypothesis. The methodology of the ACGIH in the setting of limits later brought into law, may have been unduly influenced by the industries most closely affected by those limits. Measuring exposure over part of an eight hour day and extrapolating to model exposure over the longer term is not the most effective way to model exposure. The statistical techniques used

  19. Multiple context mere exposure: Examining the limits of liking.

    Science.gov (United States)

    de Zilva, Daniel; Newell, Ben R; Mitchell, Chris J

    2016-01-01

    Recent evidence suggests that increased liking of exposed stimuli-a phenomenon known as the mere exposure effect-is dependent on experiencing the stimuli in the same context at exposure and test. Three experiments extended this work by examining the effect of presenting target stimuli in single and multiple exposure contexts. Target face stimuli were repeatedly paired with nonsense words, which took the role of contexts, across exposure. On test, the mere exposure effect was found only when the target face stimuli were presented with nonsense word cues (contexts) with which they had been repeatedly paired. The mere exposure effect was eliminated when exposure to target face stimuli with the nonsense word cues (contexts) was minimal, despite the overall number of exposures to the target face being equated across single- and multiple-context exposure conditions. The results suggest that familiarity of the relationship between stimuli and their context, not simply familiarity of the stimuli themselves, leads to liking. The finding supports a broader framework, which suggests that liking is partly a function of the consistency between past and present experiences with a target stimulus.

  20. Limiting criteria for human exposure to low humidity indoors

    DEFF Research Database (Denmark)

    Wyon, David; Fang, Lei; Meyer, H.

    2002-01-01

    Thirty subjects (17 female) were exposed for 5 hours to clean air at 5%, 15%, 25% and 35% RH at 22 deg.C. Another 30 subjects (15 female) were similarly exposed to air polluted by carpet and linoleum at 18, 22 and 26 deg.C with humidity 2.4 g/kg dry air (=15% RH at 22 deg.C), and at 22 deg.C, 35......% RH. The subjects performed simulated office work throughout each exposure. Building Related Symptom (BRS) intensity was reported on visual-analogue scales. Tests of eye, nose and skin function were applied. In these short exposures subjective discomfort, though significantly increased by low humidity......, was very moderate even at 5% RH. However, tear film quality as indicated by the Mucous Ferning Test deteriorated significantly at RH22 deg.C, significantly more rapid blink rates were observed at 5% than at 35% RH, and skin became significantly more dry at 15% than at 35% RH....

  1. Limitation of future radiation exposures from the present operation of nuclear fuel cycle installations

    International Nuclear Information System (INIS)

    Beninson, D.

    1982-01-01

    This paper reviews the bases and the formulation for limiting the doses in the future from the combined contribution of present and future practices causing radiation exposures. Local, regional and global contributions to the exposure of given population groups are discussed, and the use of the collective dose commitments for predicting future exposures from continuing practice is presented. The paper discusses the limitation of the dose commitment and of the collective dose commitment per unit practice as procedures for controlling future exposures. It also presents the bases used to assign upperbounds of exposure, which are fractions of the relevant dose limits, to exposures caused by a given source or practice. These considerations have been introduced in the regulatory requirements used in Argentina, and the paper examines the bases of the relevant provisions. (author)

  2. Degradation behavior of limestone concrete under limited time sodium exposure

    International Nuclear Information System (INIS)

    Das, S.K.; Sharma, A.K.; Ramesh, S.S.; Parida, F.C.; Kasinathan, N.; Chellapandi, P.

    2009-01-01

    Adequate safety measures are taken during design, fabrication, construction and operation of liquid sodium cooled fast breeder reactor (FBR). However, possibility of sodium leak from secondary heat transport circuits of FBR has not been completely ruled out. In the areas housing sodium pipelines such as Steam Generator Building (SGB), spilled liquid sodium not only reacts with air causing fire but also interacts with structural concrete resulting in its degradation. The structural concrete can be protected from sodium attack using sodium resistant sacrificial concrete layer or steel/refractory liners. Moreover, design and construction of sloping floor with sodium collection pit helps in minimizing the mass of sodium accumulated on the floor and exposure period. Sacrificial concrete layer on the structural concrete should meet key factors like economy, castability, easy removal of affected concrete in the event of a sodium fire and disposability of debris apart from its good resistance against hot burning sodium. Present study is directed towards testing of limestone concrete blocks (made out of 13% ordinary portland cement, 8% water, 48% coarse limestone and 31 % fine limestone aggregates)

  3. Patient-Provider Discussions About Strategies to Limit Air Pollution Exposures.

    Science.gov (United States)

    Mirabelli, Maria C; Damon, Scott A; Beavers, Suzanne F; Sircar, Kanta D

    2018-06-11

    Exposure to air pollution negatively affects respiratory and cardiovascular health. The objective of this study was to describe the extent to which health professionals report talking about how to limit exposure to air pollution during periods of poor air quality with their at-risk patients. In 2015, a total of 1,751 health professionals completed an online survey and reported whether they talk with their patients about limiting their exposure to air pollution. In 2017, these data were analyzed to assess the frequency that health professionals in primary care, pediatrics, obstetrics/gynecology, and nursing reported talking about limiting air pollution exposure with patients who have respiratory or cardiovascular diseases, were aged ≤18 years, were aged ≥65 years, or were pregnant women. Frequencies of positive responses were assessed across categories of provider- and practice-level characteristics. Overall, 714 (41%) respondents reported ever talking with their patients about limiting their exposure to air pollution. Thirty-four percent and 16% of providers specifically reported talking with their patients with respiratory or cardiovascular disease diagnoses, respectively. Percentages of health professionals who reported talking with their patients about limiting air pollution exposure were highest among respondents in pediatrics (56%) and lowest among respondents in obstetrics/gynecology (0%). Despite the well-described health effects of exposure to air pollution, the majority of respondents did not report talking with their patients about limiting their exposure to air pollution. These findings reveal clear opportunities to improve awareness about strategies to limit air pollution exposure among sensitive groups of patients and their health care providers. Published by Elsevier Inc.

  4. Recommendations concerning an interim annual individual exposure limit for respirable quartz

    International Nuclear Information System (INIS)

    Stocker, H.; Horvath, F.J.; Napier, W.

    1983-07-01

    This paper presents AECB staff recommendations on the desirability of an annual individual occupational exposure limit for respirable quartz and on the magnitude of this limit, for uranium miners. Justifications are presented for the magnitude of this suggested limit for respirable quartz, drawing on experience gained in Ontario uranium and non-uranium mines and on that in other countries. The suggestion is made that an exposure limit be set for an interim period in order that additional information on the adequacy of the magnitude of the limit may be acquired. To complement the suggested exposure limit, it is proposed that a co-existing control program of action levels, to be triggered at various respirable quartz concentrations, be set up. It is the contention of this paper that the degree of protection afforded to individuals by the suggested exposure limit would be equivalent to the time-weighted average threshold limit value derived from recommendations, based on group average exposures, of the American Conference of Governmental Industrial Hygienists

  5. The Impact of Different Permissible Exposure Limits on Hearing Threshold Levels Beyond 25 dBA

    OpenAIRE

    Sayapathi, Balachandar S; Su, Anselm Ting; Koh, David

    2014-01-01

    Background: Development of noise-induced hearing loss is reliant on a few factors such as frequency, intensity, and duration of noise exposure. The occurrence of this occupational malady has doubled from 120 million to 250 million in a decade. Countries such as Malaysia, India, and the US have adopted 90 dBA as the permissible exposure limit. According to the US Occupational Safety and Health Administration (OSHA), the exposure limit for noise is 90 dBA, while that of the US National Institut...

  6. NASA Space Radiation Protection Strategies: Risk Assessment and Permissible Exposure Limits

    Science.gov (United States)

    Huff, J. L.; Patel, Z. S.; Simonsen, L. C.

    2017-01-01

    Permissible exposure limits (PELs) for short-term and career astronaut exposures to space radiation have been set and approved by NASA with the goal of protecting astronauts against health risks associated with ionizing radiation exposure. Short term PELs are intended to prevent clinically significant deterministic health effects, including performance decrements, which could threaten astronaut health and jeopardize mission success. Career PELs are implemented to control late occurring health effects, including a 3% risk of exposure induced death (REID) from cancer, and dose limits are used to prevent cardiovascular and central nervous system diseases. For radiation protection, meeting the cancer PEL is currently the design driver for galactic cosmic ray and solar particle event shielding, mission duration, and crew certification (e.g., 1-year ISS missions). The risk of cancer development is the largest known long-term health consequence following radiation exposure, and current estimates for long-term health risks due to cardiovascular diseases are approximately 30% to 40% of the cancer risk for exposures above an estimated threshold (Deep Space one-year and Mars missions). Large uncertainties currently exist in estimating the health risks of space radiation exposure. Improved understanding through radiobiology and physics research allows increased accuracy in risk estimation and is essential for ensuring astronaut health as well as for controlling mission costs, optimization of mission operations, vehicle design, and countermeasure assessment. We will review the Space Radiation Program Element's research strategies to increase accuracy in risk models and to inform development and validation of the permissible exposure limits.

  7. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances

    International Nuclear Information System (INIS)

    Schieber, C.; Schneider, T.

    2002-08-01

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  8. Transuranium element toxicity: dose-response relationships at low exposure levels. Summary and speculative interpretation relative to exposure limits

    International Nuclear Information System (INIS)

    Thompson, R.C.

    1975-01-01

    A summary is given of information on transuranium element toxicity and the correlation of this information with current established exposure limits. It is difficult to calculate a biologically relevant radiation dose from deposited plutonium; it is exposure that must be controlled in order to prevent biological effect, and if the relationship between exposure and effect is known, then radiation dose is of no concern. There are extensive data on the effects of plutonium in bone. Results of studies at the University of Utah indicate that plutonium in beagles may be as much as ten times more toxic than radium. It has been suggested that this toxicity ratio may be even higher in man than in the beagle dog because of differences in surface-to-volume ratios and differences in the rate of burial of surface-deposited plutonium. The present capabilities for extrapolating dose-effect relationships seem to be limited to the setting of upper limits, based on assumptions of linearity and considerations related to natural background

  9. Proposal for the development of ICNIRP guidelines on limits for optical radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Siekmann, H. [Berufsgenossenschaftliches Institut fuer Arbeitsschutz - FIA, Sankt Augustin (Germany); Reidenbach, H.D. [Fachhochschule Koeln (Germany)

    2004-07-01

    Guidelines on limits of exposure to incoherent ultraviolet radiation, to incoherent visible and infrared radiation and to laser radiation have been published by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These guidelines are accepted globally and form the basis for risk assessment procedures for optical radiation in many countries. With the appearance of new scientific cognition the ICNIRP guidelines will be revised from time to time. A revision may also concern more formal aspects. Some proposals for the development of the ICNIRP limit value recommendations for optical radiation exposures follow. (orig.)

  10. The Impact of Different Permissible Exposure Limits on Hearing Threshold Levels Beyond 25 dBA.

    Science.gov (United States)

    Sayapathi, Balachandar S; Su, Anselm Ting; Koh, David

    2014-10-01

    Development of noise-induced hearing loss is reliant on a few factors such as frequency, intensity, and duration of noise exposure. The occurrence of this occupational malady has doubled from 120 million to 250 million in a decade. Countries such as Malaysia, India, and the US have adopted 90 dBA as the permissible exposure limit. According to the US Occupational Safety and Health Administration (OSHA), the exposure limit for noise is 90 dBA, while that of the US National Institute of Occupational Safety and Health (NIOSH) is 85 dBA for 8 hours of noise exposure. This study aimed to assess the development of hearing threshold levels beyond 25 dBA on adoption of 85 dBA as the permissible exposure limit compared to 90 dBA. This is an intervention study done on two automobile factories. There were 203 employees exposed to noise levels beyond the action level. Hearing protection devices were distributed to reduce noise levels to a level between the permissible exposure limit and action level. The permissible exposure limits were 90 and 85 dBA in factories 1 and 2, respectively, while the action levels were 85 and 80 dBA, respectively. The hearing threshold levels of participants were measured at baseline and at first month of postshift exposure of noise. The outcome was measured by a manual audiometer. McNemar and chi-square tests were used in the statistical analysis. We found that hearing threshold levels of more than 25 dBA has changed significantly from pre-intervention to post-intervention among participants from both factories (3000 Hz for the right ear and 2000 Hz for the left ear). There was a statistically significant association between participants at 3000 Hz on the right ear at 'deteriorated' level ( χ² (1) = 4.08, φ = - 0.142, P = 0.043), whereas there was worsening of hearing threshold beyond 25 dBA among those embraced 90 dBA. The adoption of 85 dBA as the permissible exposure limit has preserved hearing threshold level among participants at 3000 Hz

  11. Experiences from occupational exposure limits set on aerosols containing allergenic proteins

    DEFF Research Database (Denmark)

    Nielsen, Gunnar; Larsen, Søren; Hansen, Jitka S

    2012-01-01

    Occupational exposure limits (OELs) together with determined airborne exposures are used in risk assessment based managements of occupational exposures to prevent occupational diseases. In most countries, OELs have only been set for few protein-containing aerosols causing IgE-mediated allergies. ...... is available for setting OELs for proteins and protein-containing aerosols where the critical effect is IgE sensitization and IgE-mediated airway diseases.......Occupational exposure limits (OELs) together with determined airborne exposures are used in risk assessment based managements of occupational exposures to prevent occupational diseases. In most countries, OELs have only been set for few protein-containing aerosols causing IgE-mediated allergies...... for setting OELs. Our aim is to analyse prerequisites for setting OELs for the allergenic protein-containing aerosols. Opposite to the key effect of toxicological reactions, two thresholds, one for the sensitization phase and one for elicitation of IgE-mediated symptoms in sensitized individuals, are used...

  12. Assessment of new limit values for wind turbines. Influence of different limit values on exposure, annoyance and potential development locations

    International Nuclear Information System (INIS)

    Verheijen, E.; Jabben, J.; Schreurs, E.; Koeman, T.; Van Poll, R.; Du Pon, B.

    2009-01-01

    Approximately 1500 people living in the close vicinity of wind turbines in the Netherlands run the risk of suffering severe annoyance effects due to noise exposure. New guidelines that limit new wind turbines to a maximum noise level of 45 dB can minimize any further increase in noise health effects. Noise levels above 45 dB will likely result in a further increase in annoyance effects and sleep disturbances. Compared to other noise sources, noise emitted from a wind turbine causes annoyance at relatively low noise levels. The amount of available land for the placement of new wind turbines depends on the limit value that is chosen. A limit value of 40 dB would enable an additional 7000 megawatt of renewable energy to be obtained from new turbines. A limit value of 45 dB, however, would enable wind turbines to be constructed on additional land, resulting in the production of approximately 25,000 megawatt. A new noise regulation for wind turbines is currently being prepared that sets limits on the noise levels experienced by residents of nearby dwellings. The regulation aims at limiting the effects of noise annoyance caused by new wind turbines within the framework of policy targets for renewable energy. This new regulation will be in line with existing ones for road- and railway traffic in setting both a preferable and maximum allowable value for the noise level (Lden) in nearby residences. Below the preferred value, there will be no noise restriction; above the maximum value, local authorities will not be allowed to issue building permits. For noise levels that fall in between, the decision for/against construction will be based on the results of a public inquiry process involving the major stakeholders. The National Institute for Public Health and Environment (RIVM) has investigated the consequences of different choices for the preferred and maximum noise limits. Aspects of annoyance and health effects, amount of land available for new turbines within the

  13. The difficulties in establishing an occupational exposure limit for carbon nanotubes

    DEFF Research Database (Denmark)

    Ellenbecker, M.; Tsai, .S-J.; Jacobs, M.

    2018-01-01

    Concern over the health effects from the inhalation of carbon nanotubes (CNTs) has been building for some time, and adverse health effects found in animal studies include acute and chronic respiratory damage, cardiac inflammation, and cancer including mesothelioma, heretofore only associated...... with asbestos exposure. The strong animal evidence of toxicity requires that the occupational hygiene community develops strategies for reducing or eliminating worker exposures to CNTs; part of this strategy involves the setting of occupational exposure limits (OELs) for CNTs. A number of government agencies...... concerning the potential adverse health effects from CNT inhalation, the development of more nuanced OELs that reflect the complex nature of CNT exposure, a broader discussion of these issues among all interested parties, and further research into important unanswered questions including optimum methods...

  14. Proposed Occupational Exposure Limits for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals

    International Nuclear Information System (INIS)

    Poet, Torka S.; Timchalk, Chuck

    2006-01-01

    A large number of volatile chemicals have been identified in the headspaces of tanks used to store mixed chemical and radioactive waste at the U.S. Department of Energy (DOE) Hanford Site, and there is concern that vapor releases from the tanks may be hazardous to workers. Contractually established occupational exposure limits (OELs) established by the Occupational Safety and Health Administration (OSHA) and American Conference of Governmental Industrial Hygienists (ACGIH) do not exist for all chemicals of interest. To address the need for worker exposure guidelines for those chemicals that lack OSHA or ACGIH OELs, a procedure for assigning Acceptable Occupational Exposure Limits (AOELs) for Hanford Site tank farm workers has been developed and applied to a selected group of 57 headspace chemicals

  15. Proposed Occupational Exposure Limits for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Poet, Torka S.; Timchalk, Chuck

    2006-03-24

    A large number of volatile chemicals have been identified in the headspaces of tanks used to store mixed chemical and radioactive waste at the U.S. Department of Energy (DOE) Hanford Site, and there is concern that vapor releases from the tanks may be hazardous to workers. Contractually established occupational exposure limits (OELs) established by the Occupational Safety and Health Administration (OSHA) and American Conference of Governmental Industrial Hygienists (ACGIH) do not exist for all chemicals of interest. To address the need for worker exposure guidelines for those chemicals that lack OSHA or ACGIH OELs, a procedure for assigning Acceptable Occupational Exposure Limits (AOELs) for Hanford Site tank farm workers has been developed and applied to a selected group of 57 headspace chemicals.

  16. The difficulties in establishing an occupational exposure limit for carbon nanotubes

    Science.gov (United States)

    Ellenbecker, M.; Tsai, S.-J.; Jacobs, M.; Riediker, M.; Peters, T.; Liou, S.; Avila, A.; FossHansen, S.

    2018-05-01

    Concern over the health effects from the inhalation of carbon nanotubes (CNTs) has been building for some time, and adverse health effects found in animal studies include acute and chronic respiratory damage, cardiac inflammation, and cancer including mesothelioma, heretofore only associated with asbestos exposure. The strong animal evidence of toxicity requires that the occupational hygiene community develops strategies for reducing or eliminating worker exposures to CNTs; part of this strategy involves the setting of occupational exposure limits (OELs) for CNTs. A number of government agencies and private entities have established OELs for CNTs; some are mass-based, while others rely on number concentration. We review these various proposed standards and discuss the pros and cons of each approach. We recommend that specific action be taken, including intensified outreach to employers and employees concerning the potential adverse health effects from CNT inhalation, the development of more nuanced OELs that reflect the complex nature of CNT exposure, a broader discussion of these issues among all interested parties, and further research into important unanswered questions including optimum methods to evaluate CNT exposures. We conclude that current animal toxicity evidence suggests that strong action needs to be taken to minimize exposures to CNTs, and that any CNT OEL should be consistent with the need to minimize exposures.

  17. CUMEX: a cumulative hazard index for assessing limiting exposures to environmental pollutants

    International Nuclear Information System (INIS)

    Walsh, P.J.; Killough, G.G.; Parzyck, D.C.; Rohwer, P.S.; Rupp, e.M.; Whitfield, B.L.; Booth, R.S.; Raridon, R.J.

    1977-04-01

    A hazard index methodology called CUMEX has been developed for limiting human exposure to environmental pollutants. Hazard index is defined as Q/Q/sub L/ where Q is exposure or dose to total-body, organ or tissue from all environmental pathways and Q/sub L/ is a limit which should not be exceeded because of health risk to humans. Mathematical formulations for hazard indices are developed for each sampling medium corresponding to each effluent type. These hazard indices are accumulated into composite indices such that total human intake or dose would not exceed the health risk limit. Mathematical formulation for composite hazard indices or CUMEX indices for multiple pollutants are presented. An example CUMEX application to cadmium release from a smelter complex in East Helena, Montana demonstrates details of the methodology for a single pollutant where human intake occurs through inhalation and ingestion

  18. Experiences in limiting radiation exposure to the embryo/fetus in nuclear power plants

    International Nuclear Information System (INIS)

    Kelly, J.J.

    1991-01-01

    This paper presents the results of a survey of operating nuclear reactors and nuclear fuel fabrication facilities in the US. The survey obtained information on the number of women radiation workers in those plants over the last ten years and the number of workers potentially exposed to radiation while pregnant. Information on plant exposure limits for pregnant workers practiced at these plants and whether these limits comply with NCRP guidance and proposed NRC regulatory limits will also be presented. The discussion will include the effects of unions, labor arbitration, and legal actions on these policies. The unique problems of fuel manufacturers in addressing the proposed NRC regulations for embryo/fetus exposure will also be presented

  19. Limited inflammatory response in rats after acute exposure to a silicon carbide nanoaerosol

    Energy Technology Data Exchange (ETDEWEB)

    Laloy, J., E-mail: julie.laloy@unamur.be [University of Namur (UNamur), Department of Pharmacy, Namur Nanosafety Centre (NNC), Namur Research Institute for Life Sciences NARILIS (Belgium); Lozano, O. [University of Namur (UNamur), Research Centre in Physics of Matter and Radiation (PMR), Namur Nanosafety Centre NNC, Namur Research Institute for Life Sciences NARILIS (Belgium); Alpan, L.; Masereel, B. [University of Namur (UNamur), Department of Pharmacy, Namur Nanosafety Centre (NNC), Namur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, O. [University of Namur (UNamur), Laboratory of Cellular Biochemistry and Biology (URBC), Namur Nanosafety Centre NNC, Namur Research Institute for Life Sciences NARILIS (Belgium); Dogné, J. M. [University of Namur (UNamur), Department of Pharmacy, Namur Nanosafety Centre (NNC), Namur Research Institute for Life Sciences NARILIS (Belgium); Lucas, S. [University of Namur (UNamur), Research Centre in Physics of Matter and Radiation (PMR), Namur Nanosafety Centre NNC, Namur Research Institute for Life Sciences NARILIS (Belgium)

    2015-08-15

    Inhalation represents the major route of human exposure to manufactured nanomaterials (NMs). Assessments are needed about the potential risks of NMs from inhalation on different tissues and organs, especially the respiratory tract. The aim of this limited study is to determine the potential acute pulmonary toxicity in rats exposed to a dry nanoaerosol of silicon carbide (SiC) nanoparticles (NPs) in a whole-body exposure (WBE) model. The SiC nanoaerosol is composed of a bimodal size distribution of 92.8 and 480 nm. The exposure concentration was 4.91 mg/L, close to the highest recommended concentration of 5 mg/L by the Organisation for Economic Co-operation and Development. Rats were exposed for 6 h to a stable and reproducible SiC nanoaerosol under real-time measurement conditions. A control group was exposed to the filtered air used to create the nanoaerosol. Animals were sacrificed immediately, 24 or 72 h after exposure. The bronchoalveolar lavage fluid from rat lungs was recovered. Macrophages filled with SiC NPs were observed in the rat lungs. The greatest load of SiC and macrophages filled with SiC were observed on the rat lungs sacrificed 24 h after acute exposure. A limited acute inflammatory response was found up to 24 h after exposure characterized by a lactate dehydrogenase and total protein increase or presence of inflammatory cells in pulmonary lavage. For this study a WBE model has been developed, it allows the simultaneous exposure of six rats to a nanoaerosol and six rats to clean-filtered air. The nanoaerosol was generated using a rotating brush system (RBG-1000) and analyzed with an electrical low pressure impactor in real time.

  20. National Standard for Limiting Occupational Exposure to Ionizing Radiation. NOHSC:1013(1995)

    International Nuclear Information System (INIS)

    1995-06-01

    The objectives of The National Standard for Limiting Occupational Exposure to Ionizing Radiation are to limit the risk to health arising from exposure to ionizing radiation in the workplace and to optimize radiation protection by setting common essential requirements for the control of exposure to radiation, including the specification of employer duties and employee duties. It serves to identify the provisions which are to be made in the regulations of States, Territories and the Commonwealth for the control of occupational exposure to radiation. It is recognised that legislation, including regulations, may already exist which covers all or part of the scope of this Standard. It is also recognised that it may not be appropriate to take up this Standard verbatim because of differing legislative frameworks and drafting conventions in each State and Territory and in the Commonwealth. However, it is expected that the implementation of the provisions contained in this Standard will be nationally consistent. This Standard deals only with occupational health and safety matters related to exposure to ionizing radiation; the appropriate authority should be consulted about other radiation control requirements which may apply. The complementary 'Recommendations for Limiting Exposure to Ionizing Radiation' - Guidance note NOHSC:3022(1995)- Radiation Health series no. 39 - describes the principles and practice on which this Standard is based and provides interpretive and reference material. It supersedes earlier recommendations of the NHMRC: Recommended Radiation Protection Standards for Individuals Exposed to Ionising Radiation, adopted in 1980, Australia's Radiation Protection Standards (1989) and the Interim on Australia's Radiation Protection Standards (1991). These revised Recommendations for application in Australia take into account the most recent recommendations of the ICRP, which were adopted after careful review of all available scientific evidence concerning the

  1. Interim guidelines on limits of exposure to 50/60 Hz electric and magnetic fields (1989)

    International Nuclear Information System (INIS)

    1989-12-01

    Public concern is growing and in many countries regulatory and advisory agencies have been requested to evaluate possible adverse effects of extremely low frequency electromagnetic fields on human health (Grandolfo and Vecchia, 1989). From a review of the scientific literature it is apparent that gaps exist in our knowledge and more data need to be collected to answer unresolved questions concerning biological effects of exposure to these fields. On the other hand, analysis of the existing literature does not provide evidence that exposure at present day levels has a public health impact which would require corrective action. In several countries there is an ongoing controversy between proponents of restrictive protective measures and advocates of technological growth leading to an increase in exposure levels. It thus appeared that there was a need for guidelines on exposure limits based on a objective analysis of currently available knowledge. These guidelines are intended to protect the health of humans from the potentially harmful effects of exposure to electric and magnetic fields at frequencies of 50/60 Hz, and are primarily based on established or predicted effects. 43 refs., 1 tab

  2. Evaluation of exposure limits to toxic gases for nuclear reactor control room operators

    International Nuclear Information System (INIS)

    Mahlum, D.D.; Sasser, L.B.

    1991-07-01

    We have evaluated ammonia, chlorine, Halon (actually a generic name for several halogenated hydro-carbons), and sulfur dioxide for their possible effects during an acute two-minute exposure in order to derive recommendations for maximum exposure levels. To perform this evaluation, we conducted a search to find the most pertinent literature regarding toxicity in humans and in experimental animals. Much of the literature is at least a decade old, not an unexpected finding since acute exposures are less often performed now than they were a few years ago. In most cases, the studies did not specifically examine the effects of two-minute exposures; thus, extrapolations had to be made from studies of longer-exposure periods. Whenever possible, we gave the greatest weight to human data, with experimental animal data serving to strengthen the conclusion arrived at from consideration of the human data. Although certain individuals show hypersensitivity to materials like sulfur dioxide, we have not attempted to factor this information into the recommendations. After our evaluation of the data in the literature, we held a small workshop. Major participants in this workshop were three consultants, all of whom were Diplomates of the American Board of Toxicology, and staff from the Nuclear Regulatory Commission. Our preliminary recommendations for two-minute exposure limits and the rationale for them were discussed and consensus reached on final recommendations. These recommendations are: (1) ammonia-300 to 400-ppm; (2) chlorine-30 ppm; (3) Halon 1301-5%; Halon 1211-2%; and (4) sulfur dioxide-100 ppm. Control room operators should be able to tolerate two-minute exposures to these levels, don fresh-air masks, and continue to operate the reactor if the toxic material is eliminated, or safely shut down the reactor if the toxic gas remains. 96 refs., 9 tabs

  3. Radiation exposure of the Yugoslav Airlines crews according to new radiation limits

    International Nuclear Information System (INIS)

    Antic, D.

    1998-01-01

    Radiation exposure of the Yugoslav Airlines (JAT) crews in commercial air traffic has been studied according to the new radiation limits (ICRP 60). Selected pilots make the groups, for different types in use by JAT, and two groups of the co-pilots ('flight engineers' for B-727 and DC-10 aircraft's). Cabin crew members make three groups of pursers and two groups of STW/STD (they include both male and female workers). Annual doses and added risks have been assessed. (author)

  4. The beryllium quandary: will the lower exposure limits spur new developments in sampling and analysis?

    Energy Technology Data Exchange (ETDEWEB)

    Brisson, Michael

    2013-06-03

    At the time this article was written, new rulemakings were under consideration at OSHA and the U.S. Department of Energy (DOE) that would propose changes to occupational exposure limits for beryllium. Given these developments, it’s a good time to review the tools and methods available to IHs for assessing beryllium air and surface contamination in the workplace—what’s new and different, and what’s tried and true. The article discusses limit values and action levels for beryllium, problematic aspects of beryllium air sampling, sample preparation, sample analysis, and data evaluation.

  5. Rules and recent trends for setting health-based occupational exposure limits for chemicals

    Directory of Open Access Journals (Sweden)

    Jolanta Skowroń

    2015-04-01

    Full Text Available The working environment is the special case of the non-natural environment created by man in which the increased production activity brings about the concentration of stimulators particularly aggressive to the human organism, such as chemical hazards, noise, vibration, extreme temperatures, and finally, intensified psychological and emotional stress. Depending on the nature and intensity, working environment factors have been classified into dangerous, harmful and annoying. The workers are more and more frequently exposed to dangerous chemicals in the working environment. The chemicals cause many diseases including, in the 1st place, respiratory insufficiency, inflammatory skin conditions, psychoneurological disorders and neoplastic diseases. Occupational exposure limit values (OELs, the main criteria for occupational exposure assessment, constitute an important factor for the safe use of chemicals in the working environment. In Poland, to date there are 524 chemical substances and 19 dusts for which maximum admissible concentrations (MAC have been established.

  6. Principles for limiting exposure of the public to natural sources of radiation

    International Nuclear Information System (INIS)

    1984-01-01

    In a preliminary note a discussion is presented of the factors by which the values of Annual Limits on Intakes (ALI) and Derived Air Concentrations (DAC) recommended in ICRP Publication 30 for workers would differ from those that would be appropriate for members of the public. In Publication 39, the principles adopted distinguish between procedures for existing exposure situations, which can only be influenced by remedial action, and examples of future exposure situations which can be subject to administrative control (e.g. new house construction, reduction of ventilation in existing houses, production of building materials from new production facilities, water supplies from new facilities, burning natural gas from new wells, using fertiliser from new mills and factories). (U.K.)

  7. Risk ratios for use in establishing dose limits for occupational exposure to radiation

    International Nuclear Information System (INIS)

    Metcalf, P.E.; Winkler, B.C.

    1980-01-01

    Dose limits for occupational exposure to radiation may be established by comparing the associated mortality risk with apparently accepted levels of industrial mortality risk due to conventional hazards. Average levels of industrial mortality risk rates are frequently quoted and used in such comparisons. However, within particular occupations or industries certain groups of workers will be exposed to higher levels of risk than the average, again an apparently accepted situation. A study has been made of the ratios of maximum to average industrial mortality risk currently experienced in some South African industries. Such a ratio may be used to assess the acceptability of maximum individual-to-average exposures in particular groups of exposed individuals. (author)

  8. Nanomaterials – Proposals of occupational exposure limits in the world and hygiene standards in Poland

    Directory of Open Access Journals (Sweden)

    Anna Maria Świdwińska-Gajewska

    2013-12-01

    Full Text Available Currently, there are no legally binding workplace exposure limits for substances in the form of nanoobjects. There are different approaches to risk assessment and determination of occupational exposure limits. The purpose of this article is to compare exposure levels in the work environment proposed by international organizations and world experts, as well as the assumptions and methods used for their estimation. This paper presents the proposals of the National Institute for Public Health and the Environment in the Netherlands (RIVM, the New Energy and Industrial Technology Development Organization in Japan (NEDO and the National Institute for Occupational Safety and Health in the USA (NIOSH. The authors also discuss the reports on the levels for carbon nanotubes (Baytubes® and Nanocyl proposed by Pauluhn and Luizi, the derived no-effect levels (DNEL complying with the REACH Regulation, proposed by experts under the 7th Framework Programme of the European Commission, coordinated by Professor Vicki Stone (ENRHES, and alternative estimation levels for poorly soluble particles by Pauluhn. The issue was also raised whether the method of determining maximum admissible concentrations in the work environment, currently used in Poland, is adequate for nanoobjects. Moreover, the introduction of nanoreference values, as proposed by RIVM, the definition of a new fraction for particles of 1-100 nm, taking into account the surface area and activity of the particles, and an adequate estimation of uncertainty factors seem to be worth considering. Other important, if not key issues are the appropriate measurement (numerical concentration, surface concentration, particle size distribution, as well as the methodology and equipment accessibility to all employers responsible for a reliable risk assessment of exposure to nanoparticles in the work environment. Med Pr 2013;64(6:829–845

  9. Previous Repeated Exposure to Food Limitation Enables Rats to Spare Lipid Stores during Prolonged Starvation.

    Science.gov (United States)

    McCue, Marshall D; Albach, Audrey; Salazar, Giovanni

    The risk of food limitation and, ultimately, starvation dates back to the dawn of heterotrophy in animals, yet starvation remains a major factor in the regulation of modern animal populations. Researchers studying starvation more than a century ago suggested that animals subjected to sublethal periods of food limitation are somehow more tolerant of subsequent starvation events. This possibility has received little attention over the past decades, yet it is highly relevant to modern science for two reasons. First, animals in natural populations are likely to be exposed to bouts of food limitation once or more before they face prolonged starvation, during which the risk of mortality becomes imminent. Second, our current approach to studying starvation physiology in the laboratory focuses on nourished animals with no previous exposure to nutritional stress. We examined the relationship between previous exposure to food limitation and potentially adaptive physiological responses to starvation in adult rats and found several significant differences. On two occasions, rats were fasted until they lost 20% of their body mass maintained lower body temperatures, and had presumably lower energy requirements when subjected to prolonged starvation than their naive cohort that never experienced food limitation. These rats that were trained in starvation also had lower plasma glucose set -points and reduced their reliance on endogenous lipid oxidation. These findings underscore (1) the need for biologists to revisit the classic hypothesis that animals can become habituated to starvation, using a modern set of research tools; and (2) the need to design controlled experiments of starvation physiology that more closely resemble the dynamic nature of food availability.

  10. Evaluation of the toxicity data for peracetic acid in deriving occupational exposure limits: a minireview.

    Science.gov (United States)

    Pechacek, Nathan; Osorio, Magdalena; Caudill, Jeff; Peterson, Bridget

    2015-02-17

    Peracetic acid (PAA) is a peroxide-based chemistry that is highly reactive and can produce strong local effects upon direct contact with the eyes, skin and respiratory tract. Given its increasing prominence in industry, attention has focused on health hazards and associated risks for PAA in the workplace. Occupational exposure limits (OEL) are one means to mitigate risks associated with chemical hazards in the workplace. A mini-review of the toxicity data for PAA was conducted in order to determine if the data were sufficient to derive health-based OELs. The available data for PAA frequently come from unpublished studies that lack sufficient study details, suffer from gaps in available information and often follow unconventional testing methodology. Despite these limitations, animal and human data suggest sensory irritation as the most sensitive endpoint associated with inhalation of PAA. Rodent RD50 data (the concentration estimated to cause a 50% depression in respiratory rate) were selected as the critical studies in deriving OELs. Based on these data, a range of 0.36-0.51mg/m(3) (0.1-0.2ppm) was calculated for a time-weighted average (TWA), and 1.2-1.7mg/m(3) (0.4-0.5ppm) as a range for a short-term exposure limit (STEL). These ranges compare favorably to other published OELs for PAA. Considering the applicable health hazards for this chemistry, a joint TWA/STEL OEL approach for PAA is deemed the most appropriate in assessing workplace exposures to PAA, and the selection of specific values within these proposed ranges represents a risk management decision. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Limitations and problems in deriving risk estimates for low-level radiation exposure

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1981-01-01

    Some of the problems in determining the cancer risk of low-level radiation from studies of exposed groups are reviewed and applied to the study of Hanford workers by Mancuso, Stewart, and Kneale. Problems considered are statistical limitations, variation of cancer rates with geography and race, the ''healthy worker effect,'' calendar year and age variation of cancer mortality, choosing from long lists, use of proportional mortality rates, cigarette smoking-cancer correlations, use of averages to represent data distributions, ignoring other data, and correlations between radiation exposure and other factors that may cause cancer. The current status of studies of the Hanford workers is reviewed

  12. Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure

    Science.gov (United States)

    Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fallon, S. R.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Velan, V.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

    2017-06-01

    We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σn=1.6 ×10-41 cm2 (σp=5 ×10-40 cm2 ) at 35 GeV c-2 , almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

  13. Football Players' Head-Impact Exposure After Limiting of Full-Contact Practices.

    Science.gov (United States)

    Broglio, Steven P; Williams, Richelle M; O'Connor, Kathryn L; Goldstick, Jason

    2016-07-01

    Sporting organizations limit full-contact football practices to reduce concussion risk and based on speculation that repeated head impacts may result in long-term neurodegeneration. To directly compare head-impact exposure in high school football players before and after a statewide restriction on full-contact practices. Cross-sectional study. High school football field. Participants were varsity football athletes from a single high school. Before the rule change, 26 athletes (age = 16.2 ± 0.8 years, height = 179.6 ± 6.4 cm, weight = 81.9 ± 13.1 kg) participated. After the rule change, 24 athletes (age = 15.9 ± 0.8 years, height = 178.3 ± 6.5 cm, weight = 76.2 ± 11.6 kg) participated. Nine athletes participated in both years of the investigation. Head-impact exposure was monitored using the Head Impact Telemetry System while the athletes participated in football games and practices in the seasons before and after the rule change. Head-impact frequency, location, and magnitude (ie, linear acceleration, rotational acceleration, and Head Impact Telemetry severity profile [HITsp], respectively) were measured. A total of 15 398 impacts (592 impacts per player per season) were captured before the rule change and 8269 impacts (345 impacts per player per season) after the change. An average 42% decline in impact exposure occurred across all players, with practice-exposure declines occurring among linemen (46% decline); receivers, cornerbacks, and safeties (41% decline); and tight ends, running backs (including fullbacks), and linebackers (39% decline). Impact magnitudes remained largely unchanged between the years. A rule change limiting full-contact high school football practices appears to have been effective in reducing head-impact exposure across all players, with the largest reduction occurring among linemen. This finding is likely associated with the rule modification, particularly because the coaching staff and offensive scheme remained consistent, yet how

  14. Exposure to Non-Ionizing Radiation and Public Health: Basic Concepts and Safety Limits

    International Nuclear Information System (INIS)

    Ubeda-Maeso, A.; Vargas-Marcos, F.; Trillo-Ruiz, M.A.

    2003-01-01

    The potential health effects of exposure to non-ionizing electromagnetic radiation in public and residential environments are a source of increasing concern for both the public and authorities on environmental health. This work briefly summarizes the theoretical and experimental bases supporting the safety levels proposed by international committees. It also reviews the recent scientific literature on bioeffects on non-ionizing radiation that may prove potentially relevant to the validation or modification of present exposure limits. Because of their social interest, special consideration will be given to power frequency fields (50-60 Hz) and to the radio communication signals of mobile phones. We will also describe how interpretations of scientific evidence from sources other than international committees have generated some controversy and provided basis for more restrictive limits, such as those adopted in Europe by Switzerland and Italy. In addition, this work identifies some gaps in the present scientific knowledge of bioelectromagnetics. Such gaps are largely responsible for the existing controversy and differences in risk perception. This is why more research aimed at broadening and deepening our understanding of biological responses to non-ionizing radiation is urgently needed. (author)

  15. Study of anticipated impact on DOE programs from proposed reductions to the external occupational radiation exposure limit

    International Nuclear Information System (INIS)

    1978-01-01

    Many years of radiation exposure experience in all phases of nuclear energy applications were surveyed to evaluate the impact of reducing the present DOE limit of 5 rem/yr. Conclusions drawn are: (1) Reduction of the occupational exposure limit would result in significant increase in total accumulated exposure to the current radiation worker population and could require an increase in the work force with attending personnel and administrative problems. (2) Important programs/facilities would have to be abandoned. (3) Some engineering technology is not sufficiently developed to design or operate at the 0.5 rem/yr limit. (4) Exposure reduction to 2.5 rem/yr would significantly increase costs and would result in a small increase in total exposure to the work force. (5) Significant initial capital cost plus increased annual costs would result. (6) The major emphasis in controlling occupational exposure should be on continued work toward further reduction of total man-rem. This should involve continued development of ALAP programs along with improvements in dose measurement and recording methods, more sophisticated exposure records, and containment, handling and remote maintenance techniques. (7) Radiation protection practices at DOE facilities have maintained exposures of the bulk of the nuclear work force substantially below current limits for many years. (8) The current standards of 5 rem/yr is used only as a limit. For example, 97% of the employees receive less than 0.5 rem/yr

  16. Study of anticipated impact on DOE programs from proposed reductions to the external occupational radiation exposure limit

    International Nuclear Information System (INIS)

    1981-02-01

    A study of the impact of reducing the occupational radiation exposure limit from 5 rem/yr to 2.5, 1.0 and 0.5 rem/yr, respectively produced the following conclusions: reduction of the occupational exposure limit would result in significant increase in total accumulated exposure to the current radiation worker population and could require an increase in the work force; important programs would have to be abandoned at a planned exposure limit of 0.5 rem/yr; some engineering technology is not sufficiently developed to design or operate at the 0.5 rem/yr limit; even a factor of 2 reduction (2.5 rem/yr) would significantly increase costs and would result in an increase in total exposure to the work force; in addition to a significant one-time initial capital cost resulting from a 0.5 rem/yr limit, there would be a significant increase in annual costs; the major emphasis in controlling occupational exposure should be on further reduction of total man-rem; and current standards are used only as a limit. For example, 97% of the employees receive less than 0.5 rem/yr

  17. Precautionary limits of exposure to electromagnetic fields: can they be practically enforced?

    International Nuclear Information System (INIS)

    Vecchia, P.

    2002-01-01

    The first actions aimed at protecting from exposure to electromagnetic fields date back to the 50s of the past century. Over the years, protection standards have evolved to become real protection system, founded on solid scientific bases and structured in a logic and effective way. The most authoritative standards are guidelines developed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP 1998), the successor of the International Non Ionizing Radiation Committee of IRPA. Other internationally recognised standards, such as those developed by the Institute of Electrical and Electronics Engineers (IEEE 1999) or by the National Radiological Protection Board (NRPB 1993) in the UK, adopt the same basic approach of ICNIRP, although some differences exist in numerical values. In the last years, actions have been started aiming at a world-wide harmonisation of EMF standards. About 30 countries have adopted the ICNIRP guidelines as national regulations, and the Council of the European Union has issued a Recommendation to Member States to adopt a common frame of norms on exposure to electromagnetic fields (EU 1999). However, Italy has enforced national standards that diverge from international guidelines, both in the rationale and in the numerical values of the limits. The precautionary principle has been invoked to justify the Italian policy. While the applicability of the principle to electromagnetic fields has been questioned by bodies such as ICNIRP and the World Health Organization (WHO), even the possibility of practical implementation of precautionary regulations similar to the Italian is far from being proved

  18. Occupational exposure limits in Europe and Asia--continued divergence or global harmonization?

    Science.gov (United States)

    Ding, Qian; Schenk, Linda; Malkiewicz, Katarzyna; Hansson, Sven Ove

    2011-12-01

    Occupational exposure limits (OELs) are used as a risk management tool aiming at protecting against negative health effects of occupational exposure to harmful substances. The systems of OEL development have not been standardized and divergent outcomes have been reported. However some harmonization processes have been initiated, primarily in Europe. This study investigates the state of harmonization in a global context. The OEL systems of eight Asian and seventeen European organizations are analyzed with respect to similarities and differences in: (1) the system for determining OELs, (2) the selection of substances, and (3) the levels of the OELs. The majority of the investigated organizations declare themselves to have been influenced by the American Conference of Governmental Industrial Hygienists (ACGIH), and in many cases this can be empirically confirmed. The EU harmonization process is reflected in trends towards convergence within the EU. However, comparisons of Asian and European organizations provide no obvious evidence that OELs are becoming globally harmonized. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Rules and recent trends for setting health-based occupational exposure limits for chemicals.

    Science.gov (United States)

    Skowroń, Jolanta; Czerczak, Sławomir

    2015-01-01

    The working environment is the special case of the non-natural environment created by man in which the increased production activity brings about the concentration of stimulators particularly aggressive to the human organism, such as chemical hazards, noise, vibration, extreme temperatures, and finally, intensified psychological and emotional stress. Depending on the nature and intensity, working environment factors have been classified into dangerous, harmful and annoying. The workers are more and more frequently exposed to dangerous chemicals in the working environment. The chemicals cause many diseases including, in the 1st place, respiratory insufficiency, inflammatory skin conditions, psychoneurological disorders and neoplastic diseases. Occupational exposure limit values (OELs), the main criteria for occupational exposure assessment, constitute an important factor for the safe use of chemicals in the working environment. In Poland, to date there are 524 chemical substances and 19 dusts for which maximum admissible concentrations (MAC) have been established. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  20. Limited recovery of soil microbial activity after transient exposure to gasoline vapors

    DEFF Research Database (Denmark)

    Modrzyński, Jakub J.; Christensen, Jan H.; Mayer, Philipp

    2016-01-01

    During gasoline spills complex mixtures of toxic volatile organic compounds (VOCs) are released to terrestrial environments. Gasoline VOCs exert baseline toxicity (narcosis) and may thus broadly affect soil biota. We assessed the functional resilience (i.e. resistance and recovery of microbial...... functions) in soil microbial communities transiently exposed to gasoline vapors by passive dosing via headspace for 40 days followed by a recovery phase of 84 days. Chemical exposure was characterized with GC-MS, whereas microbial activity was monitored as soil respiration (CO2 release) and soil bacterial...... microbial activity indicating residual soil toxicity, which could not be attributed to BTEX, but rather to mixture toxicity of more persistent gasoline constituents or degradation products. Our results indicate a limited potential for functional recovery of soil microbial communities after transient...

  1. LIMITATIONS ON THE USES OF MULTIMEDIA EXPOSURE MEASUREMENTS FOR MULTIPATHWAY EXPOSURE ASSESSMENT - PART II: EFFECTS OF MISSING DATA AND IMPRECISION

    Science.gov (United States)

    Multimedia data from two probability-based exposure studies were investigated in terms of how missing data and measurement-error imprecision affected estimation of population parameters and associations. Missing data resulted mainly from individuals' refusing to participate in c...

  2. Derived limits for occupational exposure to uranium mine and mill dusts in the air and on surfaces

    International Nuclear Information System (INIS)

    Carter, M.W.

    1983-01-01

    Limits are derived for the concentration of uranium mine and mill dusts in the air based on ICRP30 and assumptions regarding the isotopic make up of the dusts. From these limits using a resuspension factor, limits for surface contamination are derived. Calculations are presented of the dose to the basal layer of the skin from mine and mill dusts on the skin. From these calculations limits for skin contamination are derived. A calculation of a limit based on direct ingestion is also presented. Exposure limits for the public are not considered

  3. Experiencing a probabilistic approach to clarify and disclose uncertainties when setting occupational exposure limits.

    Science.gov (United States)

    Vernez, David; Fraize-Frontier, Sandrine; Vincent, Raymond; Binet, Stéphane; Rousselle, Christophe

    2018-03-15

    Assessment factors (AFs) are commonly used for deriving reference concentrations for chemicals. These factors take into account variabilities as well as uncertainties in the dataset, such as inter-species and intra-species variabilities or exposure duration extrapolation or extrapolation from the lowest-observed-adverse-effect level (LOAEL) to the noobserved- adverse-effect level (NOAEL). In a deterministic approach, the value of an AF is the result of a debate among experts and, often a conservative value is used as a default choice. A probabilistic framework to better take into account uncertainties and/or variability when setting occupational exposure limits (OELs) is presented and discussed in this paper. Each AF is considered as a random variable with a probabilistic distribution. A short literature was conducted before setting default distributions ranges and shapes for each AF commonly used. A random sampling, using Monte Carlo techniques, is then used for propagating the identified uncertainties and computing the final OEL distribution. Starting from the broad default distributions obtained, experts narrow it to its most likely range, according to the scientific knowledge available for a specific chemical. Introducing distribution rather than single deterministic values allows disclosing and clarifying variability and/or uncertainties inherent to the OEL construction process. This probabilistic approach yields quantitative insight into both the possible range and the relative likelihood of values for model outputs. It thereby provides a better support in decision-making and improves transparency. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  4. 30 CFR 57.5060 - Limit on exposure to diesel particulate matter.

    Science.gov (United States)

    2010-07-01

    ... significant reductions in DPM exposures, controls must be used to reduce the miner's exposure to as low a... to the transfer. (ii) Increases in wages of the transferred miner must be based upon the new work...

  5. The development of criteria for limiting the non-stochastic effects of non-uniform skin exposure

    International Nuclear Information System (INIS)

    Charles, M.W.; Wells, J.

    1980-01-01

    The recent recommendations of the International Commission on Radiological Protection (ICRP, 1977) have underlined the lack of knowledge relating to small area skin exposures and have highlighted the difficulties of integrating stochastic and nonstochastic effects into a unified radiation protection philosophy. A system of limitation is suggested which should be appropriate to the wide range of skin irradiation modes which are met in practice. It is proposed for example, that for large area exposures, the probability of skin cancer induction should be considered as the limiting factor. For partial-body skin exposures the probability of the stochastic response will be reduced and late nonstochastic effects will become limiting as the area exposed is reduced. Highly non-uniform exposures such as from small sources or radioactive particulates should be limited on the basis of early rather than late effects. A survey of epidemiological and experimental work is used to show how detailed guidance for limitation in these cases can be provided. Due to the detailed morphology of the skin the biological response depends critically upon the depth dose. In the case of alpha and beta radiation this should be reflected in a less restrictive limitation system, particularly for non-stochastic effects. Up-to-date and on-going experimental studies are described which can provide guidance in this field. (author)

  6. The relationship between anatomically correct electric and magnetic field dosimetry and publishe delectric and magnetic field exposure limits.

    Science.gov (United States)

    Kavet, Robert; Dovan, Thanh; Reilly, J Patrick

    2012-12-01

    Electric and magnetic field exposure limits published by International Commission for Non-Ionizing Radiation Protection and Institute of Electrical and Electronics Engineers are aimed at protection against adverse electrostimulation, which may occur by direct coupling to excitable tissue and, in the case of electric fields, through indirect means associated with surface charge effects (e.g. hair vibration, skin sensations), spark discharge and contact current. For direct coupling, the basic restriction (BR) specifies the not-to-be-exceeded induced electric field. The key results of anatomically based electric and magnetic field dosimetry studies and the relevant characteristics of excitable tissue were first identified. This permitted us to assess the electric and magnetic field exposure levels that induce dose in tissue equal to the basic restrictions, and the relationships of those exposure levels to the limits now in effect. We identify scenarios in which direct coupling of electric fields to peripheral nerve could be a determining factor for electric field limits.

  7. Defining Occupational and Consumer Exposure Limits for Nanomaterials – First Experiences from REACH Registrations

    International Nuclear Information System (INIS)

    Aschberger, K; Christensen, F M; Klöslova, Z; Falck, G

    2013-01-01

    nanosized materials, they were not derived from hazard data for the nanoform. Different methods for deriving the DNELs were applied and few dossiers derived DNELs by applying the default assessment factors in the REACH guidance. Several DNELs were based on available Occupational Exposure Limits (OELs) for inhalable and respirable dust or the nuisance dust levels, which have not been established for nanosized materials. In general lower (i.e. less strict) assessment factors were applied with different types of justification. All DNELs were expressed in the mass metrics. It is important to note that submission, identification and selection of the dossiers addressed in this study was done before the adoption of the EC recommendation (2011/696/EU) on a definition of nanomaterial and before the publication of the revised ECHA guidance documents that include recommendations for nanomaterials.

  8. Limitations and information needs for engineered nanomaterial-specific exposure estimation and scenarios: recommendations for improved reporting practices

    Science.gov (United States)

    Clark, Katherine; van Tongeren, Martie; Christensen, Frans M.; Brouwer, Derk; Nowack, Bernd; Gottschalk, Fadri; Micheletti, Christian; Schmid, Kaspar; Gerritsen, Rianda; Aitken, Rob; Vaquero, Celina; Gkanis, Vasileios; Housiadas, Christos; de Ipiña, Jesús María López; Riediker, Michael

    2012-09-01

    The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO2), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.

  9. Limitations and information needs for engineered nanomaterial-specific exposure estimation and scenarios: recommendations for improved reporting practices

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Katherine, E-mail: katherine.clark@lkc-ltd.com [LKC (Switzerland); Tongeren, Martie van, E-mail: martie.vantongeren@iom-world.org [Institute of Occupational Medicine (IOM) (United Kingdom); Christensen, Frans M., E-mail: fmch@cowi.dk [COWI (Denmark); Brouwer, Derk, E-mail: dick.brouwer@tno.nl [TNO (Netherlands); Nowack, Bernd, E-mail: nowack@empa.ch; Gottschalk, Fadri, E-mail: Fadri.Gottschalk@empa.ch [EMPA-Swiss Federal Laboratories for Materials Science and Technology (Switzerland); Micheletti, Christian, E-mail: Christian.micheletti@gmail.com [Veneto NanoTech S.C.p.A (Italy); Schmid, Kaspar, E-mail: kasparschmid@alumni.ethz.ch [Institute of Occupational Medicine (IOM) (United Kingdom); Gerritsen, Rianda, E-mail: rianda.gerritsen@tno.nl [TNO (Netherlands); Aitken, Rob, E-mail: rob.aitken@iom-world.org [Institute of Occupational Medicine (IOM) (United Kingdom); Vaquero, Celina, E-mail: celina.vaquero@tecnalia.com [TECNALIA Research and Innovation (Spain); Gkanis, Vasileios, E-mail: v_gkanis@hotmail.com; Housiadas, Christos, E-mail: christos@ipta.demokritos.gr [National Center for Scientific Research ' Demokritos' (Greece); Ipina, Jesus Maria Lopez de, E-mail: jesus.lopezdeipina@tecnalia.com [TECNALIA Research and Innovation (Spain); Riediker, Michael, E-mail: michael.riediker@hospvd.ch [Institute for Work and Health (IST) (Switzerland)

    2012-09-15

    The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO{sub 2}), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.

  10. Testing the coherence between occupational exposure limits for inhalation and their biological limit values with a generalized PBPK-model: the case of 2-propanol and acetone.

    Science.gov (United States)

    Huizer, Daan; Huijbregts, Mark A J; van Rooij, Joost G M; Ragas, Ad M J

    2014-08-01

    The coherence between occupational exposure limits (OELs) and their corresponding biological limit values (BLVs) was evaluated for 2-propanol and acetone. A generic human PBPK model was used to predict internal concentrations after inhalation exposure at the level of the OEL. The fraction of workers with predicted internal concentrations lower than the BLV, i.e. the 'false negatives', was taken as a measure for incoherence. The impact of variability and uncertainty in input parameters was separated by means of nested Monte Carlo simulation. Depending on the exposure scenario considered, the median fraction of the population for which the limit values were incoherent ranged from 2% to 45%. Parameter importance analysis showed that body weight was the main factor contributing to interindividual variability in blood and urine concentrations and that the metabolic parameters Vmax and Km were the most important sources of uncertainty. This study demonstrates that the OELs and BLVs for 2-propanol and acetone are not fully coherent, i.e. enforcement of BLVs may result in OELs being violated. In order to assess the acceptability of this "incoherence", a maximum population fraction at risk of exceeding the OEL should be specified as well as a minimum level of certainty in predicting this fraction. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. The Role of Home Smoking Bans in Limiting Exposure to Secondhand Tobacco Smoke in Hungary

    Science.gov (United States)

    Paulik, Edit; Maroti-Nagy, A.; Nagymajtenyi, L.; Rogers, T.; Easterling, D.

    2013-01-01

    Our objective was to assess how exposure to secondhand tobacco smoke occurs in Hungarian homes, particularly among non-smokers, and to examine the effectiveness of home smoking bans in eliminating exposure to secondhand smoke at home. In 2009, 2286 non-smokers and smokers aged 16-70 years, who were selected randomly from a nationally…

  12. Development of an extended shift exposure limit adjustment factor for coal mine dusts

    Energy Technology Data Exchange (ETDEWEB)

    Tiernan, G; Van Zanten, D [SIMTARS (Australia)

    1999-12-31

    Four models for adjusting exposure standards for use during altered work shifts are reviewed. These are the absorbed dose adjustment model; the Brief and Scala model; the US Occupational Safety and Health Administration (OSHA) model; and the pharmacokinetic models of Hockey and Reist and of Stan Roach. The most appropriate model is selected for control of coal mine dusts exposure. 14 refs., 3 tabs.

  13. Cetacean noise criteria revisited in the light of proposed exposure limits for harbour porpoises

    DEFF Research Database (Denmark)

    Tougaard, Jakob; Wright, Andrew John; Madsen, Professor Peter Teglberg

    2015-01-01

    The impact of underwater noise on marine life calls for identification of exposure criteria to inform mitigation. Here we review recent experimental evidence with focus on the high-frequency cetaceans and discuss scientifically-based initial exposure criteria. A range of new TTS experiments sugge...

  14. Limited infection upon human exposure to a recombinant raccoon pox vaccine vector

    Science.gov (United States)

    Rocke, T.E.; Dein, F.J.; Fuchsberger, M.; Fox, B.C.; Stinchcomb, D.T.; Osorio, J.G.

    2004-01-01

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  15. Limited infection upon human exposure to a recombinant raccoon pox vaccine vector.

    Science.gov (United States)

    Rocke, Tonie E; Dein, F Joshua; Fuchsberger, Martina; Fox, Barry C; Stinchcomb, Dan T; Osorio, Jorge E

    2004-07-29

    A laboratory accident resulted in human exposure to a recombinant raccoon poxvirus (RCN) developed as a vaccine vector for antigens of Yersinia pestis for protection of wild rodents (and other animals) against plague. Within 9 days, the patient developed a small blister that healed within 4 weeks. Raccoon poxvirus was cultured from the lesion, and the patient developed antibody to plague antigen (F1) and RCN. This is the first documented case of human exposure to RCN.

  16. Comparison of the concepts used to develop and apply occupational exposure limits for ionizing radiation and hazardous chemical substances

    International Nuclear Information System (INIS)

    Halton, D.M.

    1988-01-01

    The rationales used by the American Conference of Governmental Industrial Hygienists (AC-GIH) to recommend exposure limits for 10 chemicals were reviewed. The 10 chemicals chosen were known to produce chronic disease after prolonged overexposure in the workplace. The chemicals were toluene diisocyanate, hydrogen fluoride, n-hexane, carbon disulfide, cadmium, inorganic mercury, cobalt, nitroglycerol, silica, and vinyl chloride. The rationales used by the International Commission on Radiological Protection (ICRP) to recommend limits for workplace exposure to ionizing radiation were reviewed. The rationales used in occupational health by ACGIH were then compared with those used by ICRP in health physics. The comparison revealed a significant divergence in the underlying concepts and philosophies of the two approaches. This divergence cannot be solely attributed to differences in scientific knowledge about toxicological and radiological effects. In areas of scientific uncertainty, exposure limits for ionizing radiation are based on worst case or conservative assumptions. This approach favors human safety. Parallel approaches could not be found for any of the 10 chemicals reviewed. Other factors such as the costs incurred by industry in meeting the proposed standards played a more significant role in establishing limits for workplace chemicals than for ionizing radiation

  17. Screening values for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals that Lack Established Occupational Exposure Limits

    Energy Technology Data Exchange (ETDEWEB)

    Poet, Torka S.; Mast, Terryl J.; Huckaby, James L.

    2006-02-06

    Over 1,500 different volatile chemicals have been reported in the headspaces of tanks used to store high-level radioactive waste at the U.S. Department of Energy's Hanford Site. Concern about potential exposure of tank farm workers to these chemicals has prompted efforts to evaluate their toxicity, identify chemicals that pose the greatest risk, and incorporate that information into the tank farms industrial hygiene worker protection program. Established occupation exposure limits for individual chemicals and petroleum hydrocarbon mixtures have been used elsewhere to evaluate about 900 of the chemicals. In this report headspace concentration screening values were established for the remaining 600 chemicals using available industrial hygiene and toxicological data. Screening values were intended to be more than an order of magnitude below concentrations that may cause adverse health effects in workers, assuming a 40-hour/week occupational exposure. Screening values were compared to the maximum reported headspace concentrations.

  18. Behavioral Flexibility and Response Selection Are Impaired after Limited Exposure to Oxycodone

    Science.gov (United States)

    Seip-Cammack, Katharine M.; Shapiro, Matthew L.

    2014-01-01

    Behavioral flexibility allows individuals to adapt to situations in which rewards and goals change. Potentially addictive drugs may impair flexible decision-making by altering brain mechanisms that compute reward expectancies, thereby facilitating maladaptive drug use. To investigate this hypothesis, we tested the effects of oxycodone exposure on…

  19. 78 FR 33654 - Reassessment of Exposure to Radiofrequency Electromagnetic Fields Limits and Policies

    Science.gov (United States)

    2013-06-04

    ... available for inspection and copying during normal business hours in the FCC Reference Center (Room CY-A257... and supported statements. I. Notice of Proposed Rulemaking (Further NPRM) A. Definition of Terms... definitions for ``power'' in its RF-exposure related rules, it is proposing explicit and consistent power...

  20. Exposure to a heat wave under food limitation makes an agricultural insecticide lethal: a mechanistic laboratory experiment

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Janssens, Lizanne; Stoks, Robby

    2016-01-01

    Extreme temperatures and exposure to agricultural pesticides are becoming more frequent and intense under global change. Their combination may be especially problematic when animals suffer food limitation. We exposed Coenagrion puella damselfly larvae to a simulated heat wave combined with food...... limitation and subsequently to a widespread agricultural pesticide (chlorpyrifos) in an indoor laboratory experiment designed to obtain mechanistic insights in the direct effects of these stressors in isolation and when combined. The heat wave reduced immune function (activity of phenoloxidase, PO...... variables. While the immediate effects of the heat wave were subtle, our results indicate the importance of delayed effects in shaping the total fitness impact of a heat wave when followed by pesticide exposure. Firstly, the combination of delayed negative effects of the heat wave and starvation...

  1. REQUIREMENTS TO THE LIMITATION OF POPULATION EXPO-SURE FROM THE NATIRAL IONIZING IRRADIATION SOURCES IN INDUSTRIAL CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2010-01-01

    Full Text Available The paper presents conceptually new requirements to the limitation of population exposure from the natural ionizing irradiation sources in industrial conditions, introduced into Basic Sanitary Rules of Radiation Safety (OSPORB-99/2010. It is shown that, first of all, introduction of these requirements is aimed at the resolution of variety of previously existing serious contradictions in organization of radiation safety control and supervision for the impact of natural ionizing irradiation sources in industry.

  2. Learning foreign labels from a foreign speaker: the role of (limited) exposure to a second language.

    Science.gov (United States)

    Akhtar, Nameera; Menjivar, Jennifer; Hoicka, Elena; Sabbagh, Mark A

    2012-11-01

    Three- and four-year-olds (N = 144) were introduced to novel labels by an English speaker and a foreign speaker (of Nordish, a made-up language), and were asked to endorse one of the speaker's labels. Monolingual English-speaking children were compared to bilingual children and English-speaking children who were regularly exposed to a language other than English. All children tended to endorse the English speaker's labels when asked 'What do you call this?', but when asked 'What do you call this in Nordish?', children with exposure to a second language were more likely to endorse the foreign label than monolingual and bilingual children. The findings suggest that, at this age, exposure to, but not necessarily immersion in, more than one language may promote the ability to learn foreign words from a foreign speaker.

  3. Evaluation of exposure in mammography: limitations of average glandular dose and proposal of a new quantity

    International Nuclear Information System (INIS)

    Geeraert, N.; Bosmans, H.; Klausz, R.; Muller, S.; Bloch, I.

    2015-01-01

    The radiation risk in mammography is traditionally evaluated using the average glandular dose. This quantity for the average breast has proven to be useful for population statistics and to compare exposure techniques and systems. However it is not indicating the individual radiation risk based on the individual glandular amount and distribution. Simulations of exposures were performed for six appropriate virtual phantoms with varying glandular amount and distribution. The individualised average glandular dose (iAGD), i.e. the individual glandular absorbed energy divided by the mass of the gland, and the glandular imparted energy (GIE), i.e. the glandular absorbed energy, were computed. Both quantities were evaluated for their capability to take into account the glandular amount and distribution. As expected, the results have demonstrated that iAGD reflects only the distribution, while GIE reflects both the glandular amount and distribution. Therefore GIE is a good candidate for individual radiation risk assessment. (authors)

  4. The relationship between anatomically correct electric and magnetic field dosimetry and published electric and magnetic field exposure limits

    International Nuclear Information System (INIS)

    Kavet, R.; Dovan, T.; Patrick Reilly, J.

    2012-01-01

    Electric and magnetic field exposure limits published by International Commission for Non-Ionizing Radiation Protection and Inst. of Electrical and Electronics Engineers are aimed at protection against adverse electro-stimulation, which may occur by direct coupling to excitable tissue and, in the case of electric fields, through indirect means associated with surface charge effects (e.g. hair vibration, skin sensations), spark discharge and contact current. For direct coupling, the basic restriction (BR) specifies the not-to-be-exceeded induced electric field. The key results of anatomically based electric and magnetic field dosimetry studies and the relevant characteristics of excitable tissue were first identified. This permitted us to assess the electric and magnetic field exposure levels that induce dose in tissue equal to the basic restrictions, and the relationships of those exposure levels to the limits now in effect. We identify scenarios in which direct coupling of electric fields to peripheral nerve could be a determining factor for electric field limits. (authors)

  5. MDI Biological Laboratory Arsenic Summit: Approaches to Limiting Human Exposure to Arsenic

    OpenAIRE

    Stanton, Bruce A.

    2015-01-01

    This report is the outcome of the meeting: “Environmental and Human Health Consequences of Arsenic”, held at the MDI Biological Laboratory in Salisbury Cove, Maine, August 13–15, 2014. Human exposure to arsenic represents a significant health problem worldwide that requires immediate attention according to the World Health Organization (WHO). One billion people are exposed to arsenic in food and more than 200 million people ingest arsenic via drinking water at concentrations greater than inte...

  6. The limits of two-year bioassay exposure regimens for identifying chemical carcinogens.

    Science.gov (United States)

    Huff, James; Jacobson, Michael F; Davis, Devra Lee

    2008-11-01

    Chemical carcinogenesis bioassays in animals have long been recognized and accepted as valid predictors of potential cancer hazards to humans. Most rodent bioassays begin several weeks after birth and expose animals to chemicals or other substances, including workplace and environmental pollutants, for 2 years. New findings indicate the need to extend the timing and duration of exposures used in the rodent bioassay. In this Commentary, we propose that the sensitivity of chemical carcinogenesis bio-assays would be enhanced by exposing rodents beginning in utero and continuing for 30 months (130 weeks) or until their natural deaths at up to about 3 years. Studies of three chemicals of different structures and uses-aspartame, cadmium, and toluene-suggest that exposing experimental animals in utero and continuing exposure for 30 months or until their natural deaths increase the sensitivity of bioassays, avoid false-negative results, and strengthen the value and validity of results for regulatory agencies. Government agencies, drug companies, and the chemical industry should conduct and compare the results of 2-year bioassays of known carcinogens or chemicals for which there is equivocal evidence of carcinogenicity with longer-term studies, with and without in utero exposure. If studies longer than 2 years and/or with in utero exposure are found to better identify potential human carcinogens, then regulatory agencies should promptly revise their testing guidelines, which were established in the 1960s and early 1970s. Changing the timing and dosing of the animal bioassay would enhance protection of workers and consumers who are exposed to potentially dangerous workplace or home contaminants, pollutants, drugs, food additives, and other chemicals throughout their lives.

  7. Derivation of an occupational exposure limit (OEL) for methylene chloride based on acute CNS effects and relative potency analysis.

    Science.gov (United States)

    Storm, J E; Rozman, K K

    1998-06-01

    The Occupational Safety and Health Administration (OSHA) methylene chloride Permissible Exposure Level (PEL) or 25 ppm is quantitatively derived from mouse tumor results observed in a high-exposure National Toxicology Program bioassay. Because this approach depends on controversial interspecies and low-dose extrapolations, the PEL itself has stimulated heated debate. Here, an alternative safety assessment for methylene chloride is presented. It is based on an acute human lowest-observed-adverse-effect level (LOAEL) of 200 ppm for subtle central nervous system (CNS) depression. Steep, parallel exposure-response curves for anesthetic and subanesthetic CNS effects associated with compounds mechanistically and structurally related to methylene chloride are shown to support a safety factor of two to account for inter-individual variability in response. LOAEL/no-observed-adverse-effect ratios for subtle CNS effects associated with structurally related solvents are shown to support a safety factor range of two to four to account for uncertainty in identifying a subthreshold exposure level. Anesthetic relative potencies and anesthetic/subanesthetic effect level ratios are shown to be constant for the compounds evaluated, demonstrating that subanesthetic relative potencies are also constant. Relative potencies among similarly derived occupational exposure limits (OELs) for solvents structurally related to methylene chloride are therefore used to validate the derived methylene chloride OEL range of 25-50 ppm. Because this safety assessment is based on human (rather than rodent) data and empirical (rather than theoretical) exposure-response relationships and is supported by relative potency analysis, it is a defensible alternative to to the OSHA risk assessment and should positively contribute to the debate regarding the appropriate basis and value for a methylene chloride PEL.

  8. Exposure limits: the underestimation of absorbed cell phone radiation, especially in children.

    Science.gov (United States)

    Gandhi, Om P; Morgan, L Lloyd; de Salles, Alvaro Augusto; Han, Yueh-Ying; Herberman, Ronald B; Davis, Devra Lee

    2012-03-01

    The existing cell phone certification process uses a plastic model of the head called the Specific Anthropomorphic Mannequin (SAM), representing the top 10% of U.S. military recruits in 1989 and greatly underestimating the Specific Absorption Rate (SAR) for typical mobile phone users, especially children. A superior computer simulation certification process has been approved by the Federal Communications Commission (FCC) but is not employed to certify cell phones. In the United States, the FCC determines maximum allowed exposures. Many countries, especially European Union members, use the "guidelines" of International Commission on Non-Ionizing Radiation Protection (ICNIRP), a non governmental agency. Radiofrequency (RF) exposure to a head smaller than SAM will absorb a relatively higher SAR. Also, SAM uses a fluid having the average electrical properties of the head that cannot indicate differential absorption of specific brain tissue, nor absorption in children or smaller adults. The SAR for a 10-year old is up to 153% higher than the SAR for the SAM model. When electrical properties are considered, a child's head's absorption can be over two times greater, and absorption of the skull's bone marrow can be ten times greater than adults. Therefore, a new certification process is needed that incorporates different modes of use, head sizes, and tissue properties. Anatomically based models should be employed in revising safety standards for these ubiquitous modern devices and standards should be set by accountable, independent groups.

  9. Limited SHIV env diversification in macaques failing oral antiretroviral pre-exposure prophylaxis.

    Science.gov (United States)

    Zheng, Qi; Ruone, Susan; Switzer, William M; Heneine, Walid; García-Lerma, J Gerardo

    2012-05-09

    Pre-exposure prophylaxis (PrEP) with daily Truvada [a combination of emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF)] is a novel HIV prevention strategy recently found to prevent HIV transmission among men who have sex with men and heterosexual couples. Acute infection in adherent persons who fail PrEP will inevitably occur under concurrent antiretroviral therapy, thus raising questions regarding the potential impact of PrEP on early viral dynamics. We investigated viral evolution dynamics in a macaque model of PrEP consisting of repeated rectal exposures to SHIV162P3 in the presence of PrEP. Four macaques were infected during daily or intermittent PrEP with FTC or FTC/TDF, and five were untreated controls. SHIV env sequence evolution was monitored by single genome amplification with phylogenetic and sequence analysis. Mean nucleotide divergence from transmitted founder viruses calculated 17 weeks (range = 12-20) post peak viremia was significantly lower in PrEP failures than in control animals (7.2 × 10-3 compared to 1.6 × 10-2 nucleotide substitutions per site per year, respectively, p diversification during early infection might enhance immune control by slowing the selection of escape mutants.

  10. Commonly recommended daily intake of vitamin D is not sufficient if sunlight exposure is limited

    DEFF Research Database (Denmark)

    Glerup, H; Mikkelsen, K; Poulsen, L

    2000-01-01

    OBJECTIVES: Sunlight exposure of the skin is known to be the most important source of vitamin D. The aims of this study were: (i) to estimate vitamin D status amongst sunlight-deprived individuals (veiled Arab women, veiled ethnic Danish Moslem women and Danish controls); and (ii) through food...... intake analysis to estimate the oral intake of vitamin D necessary to keep a normal vitamin D status in sunlight-deprived individuals. DESIGN: Cross-sectional study amongst randomly selected Moslem women of Arab origin living in Denmark. Age-matched Danish women were included as controls. To control...... for racial differences, a group of veiled ethnic Danish Moslem women (all Caucasians) was included. SETTING: Primary Health Care Centre, City Vest and Department of Endocrinology and Metabolism C, University Hospital of Aarhus, Aarhus Amtssygehus, Aarhus, Denmark. SUBJECTS: Sixty-nine Arab women (60 veiled...

  11. Reassessment of data used in setting exposure limits for hot particles

    International Nuclear Information System (INIS)

    Baum, J.W.; Kaurin, D.G.

    1991-05-01

    A critical review and a reassessment of data reviewed in NCRP Report 106 on effects of ''hot particles'' on the skin of pigs, monkeys, and humans were made. Our analysis of the data of Forbes and Mikhail on effects from activated UC 2 particles, ranging in diameter from 144 μm to 328 μm, led to the formulation of a new model for prediction of both the threshold for acute ulceration and for ulcer diameter. A dose of 27 Gy at a depth of 1.33 mm in tissue in this model will result in an acute ulcer with a diameter determined by the radius over which this dose (at 1.33-mm depth) extends. Application of the model to the Forbes-Mikhail data yielded a ''threshold'' (5% probability) of 6 x 10 9 beta particles from a point source on skin of mixed fission product beta particles, or about 10 10 beta particles from Sr--Y-90, since few of the Sr-90 beta particles reach this depth. The data of Hopewell et al. for their 1 mm Sr-Y-90 exposures were also analyzed with the above model and yielded a predicted threshold of 2 x 10 10 Sr-Y-90 beta particles for a point source on skin. Dosimetry values were employed in this latter analysis that are 3.3 times higher than previously reported for this source. An alternate interpretation of the Forbes and Mikhail data, derived from linear plots of the data, is that the threshold depends strongly on particle size with the smaller particles yielding a much lower threshold and smaller minimum size ulcer. Additional animal exposures are planned to distinguish between the above explanations. 17 refs., 3 figs., 3 tabs

  12. Tinnitus and other auditory problems - occupational noise exposure below risk limits may cause inner ear dysfunction.

    Science.gov (United States)

    Lindblad, Ann-Cathrine; Rosenhall, Ulf; Olofsson, Åke; Hagerman, Björn

    2014-01-01

    The aim of the investigation was to study if dysfunctions associated to the cochlea or its regulatory system can be found, and possibly explain hearing problems in subjects with normal or near-normal audiograms. The design was a prospective study of subjects recruited from the general population. The included subjects were persons with auditory problems who had normal, or near-normal, pure tone hearing thresholds, who could be included in one of three subgroups: teachers, Education; people working with music, Music; and people with moderate or negligible noise exposure, Other. A fourth group included people with poorer pure tone hearing thresholds and a history of severe occupational noise, Industry. Ntotal = 193. The following hearing tests were used: - pure tone audiometry with Békésy technique, - transient evoked otoacoustic emissions and distortion product otoacoustic emissions, without and with contralateral noise; - psychoacoustical modulation transfer function, - forward masking, - speech recognition in noise, - tinnitus matching. A questionnaire about occupations, noise exposure, stress/anxiety, muscular problems, medication, and heredity, was addressed to the participants. Forward masking results were significantly worse for Education and Industry than for the other groups, possibly associated to the inner hair cell area. Forward masking results were significantly correlated to louder matched tinnitus. For many subjects speech recognition in noise, left ear, did not increase in a normal way when the listening level was increased. Subjects hypersensitive to loud sound had significantly better speech recognition in noise at the lower test level than subjects not hypersensitive. Self-reported stress/anxiety was similar for all groups. In conclusion, hearing dysfunctions were found in subjects with tinnitus and other auditory problems, combined with normal or near-normal pure tone thresholds. The teachers, mostly regarded as a group exposed to noise

  13. Tinnitus and other auditory problems - occupational noise exposure below risk limits may cause inner ear dysfunction.

    Directory of Open Access Journals (Sweden)

    Ann-Cathrine Lindblad

    Full Text Available The aim of the investigation was to study if dysfunctions associated to the cochlea or its regulatory system can be found, and possibly explain hearing problems in subjects with normal or near-normal audiograms. The design was a prospective study of subjects recruited from the general population. The included subjects were persons with auditory problems who had normal, or near-normal, pure tone hearing thresholds, who could be included in one of three subgroups: teachers, Education; people working with music, Music; and people with moderate or negligible noise exposure, Other. A fourth group included people with poorer pure tone hearing thresholds and a history of severe occupational noise, Industry. Ntotal = 193. The following hearing tests were used: - pure tone audiometry with Békésy technique, - transient evoked otoacoustic emissions and distortion product otoacoustic emissions, without and with contralateral noise; - psychoacoustical modulation transfer function, - forward masking, - speech recognition in noise, - tinnitus matching. A questionnaire about occupations, noise exposure, stress/anxiety, muscular problems, medication, and heredity, was addressed to the participants. Forward masking results were significantly worse for Education and Industry than for the other groups, possibly associated to the inner hair cell area. Forward masking results were significantly correlated to louder matched tinnitus. For many subjects speech recognition in noise, left ear, did not increase in a normal way when the listening level was increased. Subjects hypersensitive to loud sound had significantly better speech recognition in noise at the lower test level than subjects not hypersensitive. Self-reported stress/anxiety was similar for all groups. In conclusion, hearing dysfunctions were found in subjects with tinnitus and other auditory problems, combined with normal or near-normal pure tone thresholds. The teachers, mostly regarded as a group

  14. Emergency and Continuous Exposure Limits for Selected Airborne Contaminants. Volume 1

    Science.gov (United States)

    1984-04-01

    fuels, corn remover, drawing inks, fuel-system deicer, glue, nail-polish remover, paint-brush cleaners, paint and varnish removers, and china ,• ~ ~film...and fire hazards of butanone and acetone. Ind. Bull. (N.Y. State Dept. Labor) 23:173-176. Societa Italiana di Medicina del Lavoro. 1975. Associazione...Italiana di Medicina del Lavoro 1975. Associazione Italiana - -degli Igienisti Industriali. Valori Limite Ponderati degli Inquinanti Chimici e

  15. Evaluation of recommendations on limits of exposure to ultraviolet radiation on the basis of data from the Austrian population

    International Nuclear Information System (INIS)

    Keck, G.; Schauberger, G.; Cabaj, A.

    1996-01-01

    For the application of solaria at present the following international recommendations on limits of exposure exist, which differ strongly: 1. IRPA/INIRC (1991): 30 MED/a (i.e. 7.5 kJ/a). 2. IEC 335-2-27 (1978, 1989): 25 kJ/m 2 /a for each region of the body, that is 100 MED/a. On the basis of our data from the Austrian population we give an evaluation of these recommendations for the entire population. This evaluation shows that 100 MED/a is much too high, it seduces rather to use solaria than to restrict their application

  16. Irreversibility of a bad start: early exposure to osmotic stress limits growth and adaptive developmental plasticity.

    Science.gov (United States)

    Wu, Chi-Shiun; Gomez-Mestre, Ivan; Kam, Yeong-Choy

    2012-05-01

    Harsh environments experienced early in development have immediate effects and potentially long-lasting consequences throughout ontogeny. We examined how salinity fluctuations affected survival, growth and development of Fejervarya limnocharis tadpoles. Specifically, we tested whether initial salinity effects on growth and rates of development were reversible and whether they affected the tadpoles' ability to adaptively accelerate development in response to deteriorating conditions later in development. Tadpoles were initially assigned to either low or high salinity, and then some were switched between salinity levels upon reaching either Gosner stage 30 (early switch) or 38 (late switch). All tadpoles initially experiencing low salinity survived whereas those initially experiencing high salinity had poor survival, even if switched to low salinity. Growth and developmental rates of tadpoles initially assigned to high salinity did not increase after osmotic stress release. Initial low salinity conditions allowed tadpoles to attain a fast pace of development even if exposed to high salinity afterwards. Tadpoles experiencing high salinity only late in development metamorphosed faster and at a smaller size, indicating an adaptive acceleration of development to avoid osmotic stress. Nonetheless, early exposure to high salinity precluded adaptive acceleration of development, always causing delayed metamorphosis relative to those in initially low salinity. Our results thus show that stressful environments experienced early in development can critically impact life history traits, having long-lasting or irreversible effects, and restricting their ability to produce adaptive plastic responses.

  17. LIMITED ANTIBODY EVIDENCE OF EXPOSURE TO MYCOBACTERIUM BOVIS IN FERAL SWINE (SUS SCROFA) IN THE USA.

    Science.gov (United States)

    Pedersen, Kerri; Miller, Ryan S; Anderson, Theodore D; Pabilonia, Kristy L; Lewis, Jonathan R; Mihalco, Rebecca L; Gortázar, Christian; Gidlewski, Thomas

    2017-01-01

    Bovine tuberculosis is a chronic disease of cattle ( Bos taurus ) caused by the bacterium Mycobacterium bovis . Efforts have been made in the US to eradicate the disease in cattle, but spillover into wildlife and subsequent spillback have impeded progress in some states. In particular, infection in white-tailed deer ( Odocoileus virginianus ) has been followed by infection in cattle in some Midwestern states. Infection has also been documented in feral swine ( Sus scrofa ) on the Hawaiian island of Molokai and in various European countries, but no large-scale survey of antibody exposure to the bacteria has been conducted in feral swine in the US. We tested 488 sera from feral swine collected near previously documented outbreaks of bovine tuberculosis in cattle and captive cervids, in addition to 2,237 feral swine sera collected across the US from 1 October 2013 to 30 September 2014. While all but one of the samples were antibody negative, the results are important for establishing baseline negative data since feral swine are capable reservoirs and could be implicated in future outbreaks of the disease.

  18. Mast Cells Limit the Exacerbation of Chronic Allergic Contact Dermatitis in Response to Repeated Allergen Exposure.

    Science.gov (United States)

    Gimenez-Rivera, Vladimir-Andrey; Siebenhaar, Frank; Zimmermann, Carolin; Siiskonen, Hanna; Metz, Martin; Maurer, Marcus

    2016-12-01

    Allergic contact dermatitis is a chronic T cell-driven inflammatory skin disease that is caused by repeated exposure to contact allergens. Based on murine studies of acute contact hypersensitivity, mast cells (MCs) are believed to play a role in its pathogenesis. The role of MCs in chronic allergic contact dermatitis has not been investigated, in part because of the lack of murine models for chronic contact hypersensitivity. We developed and used a chronic contact hypersensitivity model in wild-type and MC-deficient mice and assessed skin inflammatory responses to identify and characterize the role of MCs in chronic allergic contact dermatitis. Ear swelling chronic contact hypersensitivity responses increased markedly, up to 4-fold, in MC-deficient Kit W-sh/W-sh (Sash) and MCPT5-Cre + iDTR + mice compared with wild-type mice. Local engraftment with MCs protected Sash mice from exacerbated ear swelling after repeated oxazolone challenge. Chronic contact hypersensitivity skin of Sash mice exhibited elevated levels of IFN-γ, IL-17α, and IL-23, as well as increased accumulation of Ag-specific IFN-γ-producing CD8 + tissue-resident memory T (T RM ) cells. The CD8 + T cell mitogen IL-15, which was increased in oxazolone-challenged skin of Sash mice during the accumulation of cutaneous T RM cells, was efficiently degraded by MCs in vitro. MCs protect from the exacerbated allergic skin inflammation induced by repeated allergen challenge, at least in part, via effects on CD8 + T RM cells. MCs may notably influence the course of chronic allergic contact dermatitis. A better understanding of their role and the underlying mechanisms may lead to better approaches for the treatment of this common, disabling, and costly condition. Copyright © 2016 by The American Association of Immunologists, Inc.

  19. Limited internal radiation exposure associated with resettlements to a radiation-contaminated homeland after the Fukushima Daiichi nuclear disaster.

    Directory of Open Access Journals (Sweden)

    Masaharu Tsubokura

    Full Text Available Resettlement to their radiation-contaminated hometown could be an option for people displaced at the time of a nuclear disaster; however, little information is available on the safety implications of these resettlement programs. Kawauchi village, located 12-30 km southwest of the Fukushima Daiichi nuclear power plant, was one of the 11 municipalities where mandatory evacuation was ordered by the central government. This village was also the first municipality to organize the return of the villagers. To assess the validity of the Kawauchi villagers' resettlement program, the levels of internal Cesium (Cs exposures were comparatively measured in returnees, commuters, and non-returnees among the Kawauchi villagers using a whole body counter. Of 149 individuals, 5 villagers had traceable levels of Cs exposure; the median detected level was 333 Bq/body (range, 309-1050 Bq/kg, and 5.3 Bq/kg (range, 5.1-18.2 Bq/kg. Median annual effective doses of villagers with traceable Cs were 1.1 x 10(-2 mSv/y (range, 1.0 x 10(-2-4.1 x 10(-2 mSv/y. Although returnees had higher chances of consuming locally produced vegetables, Cochran-Mantel-Haenszel test showed that their level of internal radiation exposure was not significantly higher than that in the other 2 groups (p=0.643. The present findings in Kawauchi village imply that it is possible to maintain internal radiation exposure at very low levels even in a highly radiation-contaminated region at the time of a nuclear disaster. Moreover, the risks for internal radiation exposure could be limited with a strict food control intervention after resettlement to the radiation-contaminated village. It is crucial to establish an adequate number of radio-contaminated testing sites within the village, to provide immediate test result feedback to the villagers, and to provide education regarding the importance of re-testing in reducing the risk of high internal radiation exposure.

  20. Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system

    Science.gov (United States)

    Johnson, Christine K.; Tinker, M. Tim; Estes, James A.; Conrad, Patricia A.; Staedler, Michelle M.; Miller, Melissa A.; Jessup, David A.; Mazet, Jonna A.K.

    2014-01-01

    The processes promoting disease in wild animal populations are highly complex, yet identifying these processes is critically important for conservation when disease is limiting a population. By combining field studies with epidemiologic tools, we evaluated the relationship between key factors impeding southern sea otter (Enhydra lutris nereis) population growth: disease and resource limitation. This threatened population has struggled to recover despite protection, so we followed radio-tagged sea otters and evaluated infection with 2 disease-causing protozoal pathogens, Toxoplasma gondii and Sarcocystis neurona, to reveal risks that increased the likelihood of pathogen exposure. We identified patterns of pathogen infection that are linked to individual animal behavior, prey choice, and habitat use. We detected a high-risk spatial cluster of S. neurona infections in otters with home ranges in southern Monterey Bay and a coastal segment near San Simeon and Cambria where otters had high levels of infection with T. gondii. We found that otters feeding on abalone, which is the preferred prey in a resource-abundant marine ecosystem, had a very low risk of infection with either pathogen, whereas otters consuming small marine snails were more likely to be infected with T. gondii. Individual dietary specialization in sea otters is an adaptive mechanism for coping with limited food resources along central coastal California. High levels of infection with protozoal pathogens may be an adverse consequence of dietary specialization in this threatened species, with both depleted resources and disease working synergistically to limit recovery.

  1. [Exposure to limited resources in the gastroenterology - results of a survey of hospital physicians].

    Science.gov (United States)

    Kerkemeyer, L; Reifferscheid, A; Pomorin, N; Wasem, J

    2016-11-01

    Background and research question: The hospital sector is currently characterized by a high economic pressure. As well the DRG system as the investment financing by the federal states imply financial limitations. Hospitals react to this situation by trying to reduce costs and to increase case volume. It is questionable whether and to what extent patient care and the working conditions of the physicians are affected by these circumstances. Especially, gastroenterological patients were considered to be insufficiently covered by the DRG system in the past. Therefore, this study focuses on the gastroenterology. Method: Based on prior studies and several semi-structured interviews with gastroenterologists working in hospitals a discipline-specific questionnaire was developed. Three versions of the questionnaire were differentiated to correspond to the respective experiences of the target population (chief physician, senior physician, assistant physician). All in all, 1751 members of the "Deutsche Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten" (DGVS) were addressed. The questionnaire was answered by 642 participants resulting in a response rate of 36.7 %. The answers were interpreted by using descriptive and multivariate analyses. Results: A significant economic pressure is perceived by the participating gastroenterologists. This pressure manifests itself primary in perceived deficits in nursing care and human attention towards the patients. Moreover, the work satisfaction is negatively affected. Identified difficulties in the personnel recruitment can only be partially attributed to economic reasons. However, rationing of services is relatively seldom. Also, a financially-oriented overprovision is not perceived as a primary concern. In general, assistant physicians were a bit more skeptical about the situation in the gastroenterology, e. g. patient care, than the chief physicians. Conclusions: In total, the situation in the

  2. Microbial Response to UV Exposure and Nitrogen Limitation in Desert Soil Crusts

    Science.gov (United States)

    Fulton, J. M.; Van Mooy, B. A.

    2016-12-01

    Microbiotic soil crusts have diverse biomarker distributions and C and N stable isotopic compositions that covary with soil type. Sparse plant cover and the relative lack of soil disturbance in arid/semi-arid landscapes allows populations of soil cyanobacteria to develop along with fungi and heterotrophic bacteria. Microbial communities in this extreme environment depend in part on the production of scytonemin, a UV protective pigment, by cyanobacteria near the top of the crust. N limitation of microbial growth also affects soil crust population dynamics, increasing the requirement of N2fixation by diazotrophic cyanobacteria. We collected 56 soil crust samples from 27 locations throughout the Great Salt Lake Desert, including four transects spanning high-elevation, erosion-dominated soils to lower elevation soils dominated by silt-accumulation. Erosion-dominated soil surfaces included rounded gravel and cobbles; in the interstices there were poorly-developed microbiotic crusts on sandy loam with low δ15N values near 0‰ that point toward microbial growth dependent on cyanobacterial N2 fixation. Nutrients regenerated by heterotrophic bacteria may have been eroded from the system, providing a positive feedback for N2 fixation. High scytonemin:chlorophyll a ratios suggest that cyanobacteria required enhanced protection from UV damage in these crusts. A similar increase in scytonemin:chlorophyll a ratio during soil crust rehydration experiments also points toward the importance of UV protection. Glycolipid:phospholipid ratios were lowest where N2 fixation was favored, however, suggesting that the cyanobacterial population was relatively small, possibly because of the metabolic cost of N2fixation. Microbiotic crusts on silt loam soils, on the other hand, had higher δ15N values between 3.5 and 7.8‰, consistent with heterotrophic growth and nutrient recycling. Lower scytonemin:chlorophyll a ratios suggest that relatively high photosynthetic activity was supported in

  3. Health Council of the Netherlands : No need to change from SAR to time-temperature relation in electromagnetic fields exposure limits

    NARCIS (Netherlands)

    van Rhoon, Gerard C.; Aleman, Andre; Kelfkens, Gert; Kromhout, Hans; Van Leeuwen, Flora E.; Savelkoul, Huub F. J.; Wadman, Wytse J.; Van De Weerdt, Rik D. H. J.; Zwamborn, A. Peter M.; Van Rongen, Eric

    2011-01-01

    During the workshop on Thermal Aspects of Radio Frequency Exposure on 11--12 January 2010 in Gaithersburg, Maryland, USA, the question was raised whether there would be a practical advantage in shifting from expressing the exposure limits in SAR to expressing them in terms of a maximum allowable

  4. Early Liver and Kidney Dysfunction Associated with Occupational Exposure to Sub-Threshold Limit Value Levels of Benzene, Toluene, and Xylenes in Unleaded Petrol

    Directory of Open Access Journals (Sweden)

    Masoud Neghab

    2015-12-01

    Conclusion: The average exposure of petrol station workers to BTX did not exceed the current threshold limit values (TLVs for these chemicals. However, evidence of subtle, subclinical and prepathologic early liver and kidney dysfunction was evident in exposed individuals.

  5. Multi-tissue analyses reveal limited inter-annual and seasonal variation in mercury exposure in an Antarctic penguin community.

    Science.gov (United States)

    Brasso, Rebecka L; Polito, Michael J; Emslie, Steven D

    2014-10-01

    Inter-annual variation in tissue mercury concentrations in birds can result from annual changes in the bioavailability of mercury or shifts in dietary composition and/or trophic level. We investigated potential annual variability in mercury dynamics in the Antarctic marine food web using Pygoscelis penguins as biomonitors. Eggshell membrane, chick down, and adult feathers were collected from three species of sympatrically breeding Pygoscelis penguins during the austral summers of 2006/2007-2010/2011. To evaluate the hypothesis that mercury concentrations in penguins exhibit significant inter-annual variation and to determine the potential source of such variation (dietary or environmental), we compared tissue mercury concentrations with trophic levels as indicated by δ(15)N values from all species and tissues. Overall, no inter-annual variation in mercury was observed in adult feathers suggesting that mercury exposure, on an annual scale, was consistent for Pygoscelis penguins. However, when examining tissues that reflected more discrete time periods (chick down and eggshell membrane) relative to adult feathers, we found some evidence of inter-annual variation in mercury exposure during penguins' pre-breeding and chick rearing periods. Evidence of inter-annual variation in penguin trophic level was also limited suggesting that foraging ecology and environmental factors related to the bioavailability of mercury may provide more explanatory power for mercury exposure compared to trophic level alone. Even so, the variable strength of relationships observed between trophic level and tissue mercury concentrations across and within Pygoscelis penguin species suggest that caution is required when selecting appropriate species and tissue combinations for environmental biomonitoring studies in Antarctica.

  6. Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz)

    International Nuclear Information System (INIS)

    Anon.

    2011-01-01

    This paper is the French translation of an article from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines, entitled 'Guidelines for Limiting Exposure to Time-Varying Electric and Magnetic Fields (1 Hz To 100 kHz)'. In This document, guidelines are established for the protection of humans exposed to electric and magnetic fields in the low-frequency range of the electromagnetic spectrum. The general principles for the development of ICNIRP guidelines are published elsewhere (ICNIRP 2002). For the purpose of this document, the low-frequency range extends from 1 Hz to 100 kHz. Above 100 kHz, effects such as heating need to be considered, which are covered by other ICNIRP guidelines. However, in the frequency range from 100 kHz up to approximately 10 MHz protection from both, low frequency effects on the nervous system as well as high frequency effects need to be considered depending on exposure conditions. Therefore, some guidance in this document is extended to 10 MHz to cover the nervous system effects in this frequency range. Guidelines for static magnetic fields have been issued in a separate document (ICNIRP 2009). Guidelines applicable to movement-induced electric fields or time-varying magnetic fields up to 1 Hz will be published separately. This publication replaces the low-frequency part of the 1998 guidelines (ICNIRP 1998). ICNIRP is currently revising the guidelines for the high-frequency portion of the spectrum (above 100 kHz). (authors)

  7. Ethical issues related to professional exposure of pregnant women in the medical field: Monitoring and limiting effective dose

    International Nuclear Information System (INIS)

    Santos, J. A. M.; Nunes, R.

    2011-01-01

    The International Commission on Radiological Protection recommendations for occupational exposed pregnant women do not imply necessarily the complete avoidance of work with radiation or radioactive materials. Instead, a careful review of the exposure conditions, once the pregnancy is declared, as part of the exercise of the ICRP optimisation principle (based in a teleological ethics point of view) is suggested. The dose limitation (following a deontological ethics point of view) of the fetus/embryo is, however, not clearly well established as happens in the case of workers or members of the public. Also, the justification of practices (to continue to work or not with radiation or radioactive materials) is not clearly addressed in most national or international recommendations. An analysis of this justification (bearing in mind both teleological and deontological ethics) is examined in this work having in mind the best interest of the child-to-be as well as other existing social and economical factors. (authors)

  8. Ethical issues related to professional exposure of pregnant women in the medical field: monitoring and limiting effective dose.

    Science.gov (United States)

    Santos, J A M; Nunes, R

    2011-03-01

    The International Commission on Radiological Protection recommendations for occupational exposed pregnant women do not imply necessarily the complete avoidance of work with radiation or radioactive materials. Instead, a careful review of the exposure conditions, once the pregnancy is declared, as part of the exercise of the ICRP optimisation principle (based in a teleological ethics point of view) is suggested. The dose limitation (following a deontological ethics point of view) of the fetus/embryo is, however, not clearly well established as happens in the case of workers or members of the public. Also, the justification of practices (to continue to work or not with radiation or radioactive materials) is not clearly addressed in most national or international recommendations. An analysis of this justification (bearing in mind both teleological and deontological ethics) is examined in this work having in mind the best interest of the child-to-be as well as other existing social and economical factors.

  9. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances; Analyse des modalites de fixation des valeurs limites d'exposition et d'emission pour les substances chimiques et radioactives

    Energy Technology Data Exchange (ETDEWEB)

    Schieber, C.; Schneider, T

    2002-08-01

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  10. Radio-frequency electromagnetic field (RF-EMF) exposure levels in different European outdoor urban environments in comparison with regulatory limits

    NARCIS (Netherlands)

    Urbinello, Damiano; Joseph, Wout; Huss, Anke|info:eu-repo/dai/nl/331385880; Verloock, Leen; Beekhuizen, Johan|info:eu-repo/dai/nl/34472641X; Vermeulen, Roel|info:eu-repo/dai/nl/216532620; Martens, Luc; Röösli, Martin

    Background: Concerns of the general public about potential adverse health effects caused by radio-frequency electromagnetic fields (RF-EMFs) led authorities to introduce precautionary exposure limits, which vary considerably between regions. It may be speculated that precautionary limits affect the

  11. Radio-frequency electromagnetic field (RF-EMF) exposure levels in different European outdoor urban environments in comparison with regulatory limits.

    Science.gov (United States)

    Urbinello, Damiano; Joseph, Wout; Huss, Anke; Verloock, Leen; Beekhuizen, Johan; Vermeulen, Roel; Martens, Luc; Röösli, Martin

    2014-07-01

    Concerns of the general public about potential adverse health effects caused by radio-frequency electromagnetic fields (RF-EMFs) led authorities to introduce precautionary exposure limits, which vary considerably between regions. It may be speculated that precautionary limits affect the base station network in a manner that mean population exposure unintentionally increases. The objectives of this multicentre study were to compare mean exposure levels in outdoor areas across four different European cities and to compare with regulatory RF-EMF exposure levels in the corresponding areas. We performed measurements in the cities of Amsterdam (the Netherlands, regulatory limits for mobile phone base station frequency bands: 41-61 V/m), Basel (Switzerland, 4-6 V/m), Ghent (Belgium, 3-4.5 V/m) and Brussels (Belgium, 2.9-4.3 V/m) using a portable measurement device. Measurements were conducted in three different types of outdoor areas (central and non-central residential areas and downtown), between 2011 and 2012 at 12 different days. On each day, measurements were taken every 4s for approximately 15 to 30 min per area. Measurements per urban environment were repeated 12 times during 1 year. Arithmetic mean values for mobile phone base station exposure ranged between 0.22 V/m (Basel) and 0.41 V/m (Amsterdam) in all outdoor areas combined. The 95th percentile for total RF-EMF exposure varied between 0.46 V/m (Basel) and 0.82 V/m (Amsterdam) and the 99th percentile between 0.81 V/m (Basel) and 1.20 V/m (Brussels). All exposure levels were far below international reference levels proposed by ICNIRP (International Commission on Non-Ionizing Radiation Protection). Our study did not find indications that lowering the regulatory limit results in higher mobile phone base station exposure levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Non-cancer health risk assessment from exposure to cyanide by resident adults from the mining operations of Bogoso Gold Limited in Ghana.

    Science.gov (United States)

    Obiri, S; Dodoo, D K; Okai-Sam, F; Essumang, D K

    2006-07-01

    Cyanide is a very toxic chemical that is used to extract gold from its ores. Wastewaters from gold mining companies such as Bogoso Gold Limited (BGL) contain cyanide and other potentially toxic chemicals that have adverse effects on human beings and aquatic organisms. This study was conducted to evaluate the human health risk assessment from exposure to free cyanide via oral and dermal contact of surface/underground water by resident adults within the concession of Bogoso Gold Limited. The chronic non-cancer health risk from exposure to cyanide in River Bogo Upstream is 230 and 43 (by Central Tendency Exposure (CTE) parameters respectively). This means that approximately 230 and 43 resident adults are likely to suffer diseases related to cyanide intoxication via oral and dermal contact respectively. For chronic exposure to River Bogo Downstream by resident adults, the non-cancer health risks are: 0.031 and 0.57 via oral and dermal contact for CTE parameters respectively, which also means that, the non-cancer health risks associated with cyanide intoxication is negligible as the hazard index is less than 1.0 via oral and dermal contacts respectively. The results showed that health risk for acute exposure to cyanide by the resident adults is very high. Hence the residents attribute most of the unexplained deaths in the communities to accidental ingestion and dermal contact of cyanide water.

  13. Minimum exposure limits and measured relationships between the vitamin D, erythema and international commission on non-ionizing radiation protection solar ultraviolet.

    Science.gov (United States)

    Downs, Nathan; Parisi, Alfio; Butler, Harry; Turner, Joanna; Wainwright, Lisa

    2015-01-01

    The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for exposure to ultraviolet radiation in outdoor occupational settings. Spectrally weighted ICNIRP ultraviolet exposures received by the skin or eye in an 8 h period are limited to 30 J m(-2). In this study, the time required to reach the ICNIRP exposure limit was measured daily in 10 min intervals upon a horizontal plane at a subtropical Australian latitude over a full year and compared with the effective Vitamin D dose received to one-quarter of the available skin surface area for all six Fitzpatrick skin types. The comparison of measured solar ultraviolet exposures for the full range of sky conditions in the 2009 measurement period, including a major September continental dust event, show a clear relationship between the weighted ICNIRP and the effective vitamin D dose. Our results show that the horizontal plane ICNIRP ultraviolet exposure may be used under these conditions to provide minimum guidelines for the healthy moderation of vitamin D, scalable to each of the six Fitzpatrick skin types. © 2014 The American Society of Photobiology.

  14. Occupational exposure to vapor, gas, dust, or fumes and chronic airflow limitation, COPD, and emphysema: the Swedish CArdioPulmonary BioImage Study (SCAPIS pilot

    Directory of Open Access Journals (Sweden)

    Torén K

    2017-11-01

    Full Text Available Kjell Torén,1 Jenny Vikgren,2 Anna-Carin Olin,1 Annika Rosengren,3 Göran Bergström,3 John Brandberg2 1Section of Occupational and Environmental Medicine, Institute of Medicine, Sahlgrenska Academy, 2Department of Radiology, Institute of Clinical Sciences, 3Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Background: The aim of this study was to estimate the occupational burden of airflow limitation, chronic airflow limitation, COPD, and emphysema.Materials and methods: Subjects aged 50–64 years (n=1,050 were investigated with forced expiratory volume in 1 s (FEV1 and forced vital capacity (FVC. Airflow limitation was defined as FEV1/FVC <0.7 before bronchodilation. Chronic airflow limitation was defined after bronchodilation either according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD as FEV1/FVC <0.7 or according to the lower limit of normal (LLN approach as FEV1/FVC < LLN. COPD was defined as chronic airflow limitation (GOLD in combination with dyspnea, wheezing, or chronic bronchitis. Emphysema was classified according to findings from computed tomography of the lungs. Occupational exposure was defined as self-reported occupational exposure to vapor, gas, dust, or fumes (VGDF. Odds ratios (OR were calculated in models adjusted for age, gender, and smoking; population-attributable fractions and 95% CI were also calculated.Results: There were significant associations between occupational exposure to VGDF and COPD (OR 2.7, 95% CI 1.4–51, airflow limitation (OR 1.8, 95% CI 1.3–2.5, and emphysema (OR 1.8, 95% CI 1.1–3.1. The associations between occupational exposure to VGDF and chronic airflow limitation were weaker, and for the OR, the CIs included unity. The population-attributable fraction for occupational exposure to VGDF was 0.37 (95% CI 0.23–0.47 for COPD and 0.23 (95% CI 0.05–0.35 for emphysema.Conclusion: The

  15. Early Liver and Kidney Dysfunction Associated with Occupational Exposure to Sub-Threshold Limit Value Levels of Benzene, Toluene, and Xylenes in Unleaded Petrol.

    Science.gov (United States)

    Neghab, Masoud; Hosseinzadeh, Kiamars; Hassanzadeh, Jafar

    2015-12-01

    Unleaded petrol contains significant amounts of monocyclic aromatic hydrocarbons such as benzene, toluene, and xylenes (BTX). Toxic responses following occupational exposure to unleaded petrol have been evaluated only in limited studies. The main purpose of this study was to ascertain whether (or not) exposure to unleaded petrol, under normal working conditions, is associated with any hepatotoxic or nephrotoxic response. This was a cross-sectional study in which 200 employees of Shiraz petrol stations with current exposure to unleaded petrol, as well as 200 unexposed employees, were investigated. Atmospheric concentrations of BTX were measured using standard methods. Additionally, urine and fasting blood samples were taken from individuals for urinalysis and routine biochemical tests of kidney and liver function. The geometric means of airborne concentrations of BTX were found to be 0.8 mg m(-3), 1.4 mg m(-3), and 2.8 mg m(-3), respectively. Additionally, means of direct bilirubin, alanine aminotransferase, aspartate aminotransferase, blood urea and plasma creatinine were significantly higher in exposed individuals than in unexposed employees. Conversely, serum albumin, total protein, and serum concentrations of calcium and sodium were significantly lower in petrol station workers than in their unexposed counterparts. The average exposure of petrol station workers to BTX did not exceed the current threshold limit values (TLVs) for these chemicals. However, evidence of subtle, subclinical and prepathologic early liver and kidney dysfunction was evident in exposed individuals.

  16. Human responses to carbon dioxide, a follow-up study at recommended exposure limits in non-industrial environments

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2016-01-01

    To extend the results of a previous study on the effects of carbon dioxide (CO2) and bioeffluents on humans, the new study reported in this paper was carried out. The purpose of this study was to examine, whether exposure to CO2 at 5000 ppm would cause sensory discomfort, evoke acute health...... no effect on perceived air quality or physiological responses except for end-tidal CO2 (ETCO2), which increased more (to 5.3 kPa) than it was in the reference condition (5.1 kPa). Other results indicate additionally that a 2.5-h exposure to CO2 up to 5000 ppm did not increase intensity of health symptoms...

  17. A comparison of important international and national standards for limiting exposure to EMF including the scientific rationale.

    Science.gov (United States)

    Roy, Colin R; Martin, Lindsay J

    2007-06-01

    A comparison of Eastern (from Russia, Hungary, Bulgaria, Poland, and the Czech Republic) and Western (represented by the International Commission on Non-Ionizing Radiation Protection guidelines and the Institute of Electrical and Electronic Engineers standards) radiofrequency standards reveals key differences. The Eastern approach is to protect against non-thermal effects caused by chronic exposure to low level exposure, and the occupational basic restriction is power load (the product of intensity and exposure duration). In contrast, the Western approach is to protect against established acute biological effects that could signal an adverse health effect, and the principal basic restriction is the specific absorption rate to protect against thermal effects. All of the standards are science-based, but a fundamental difference arises from a lack of agreement on the composition of the reference scientific database and of which adverse effect needs to be protected against. However, differences also exist between the ICNIRP and IEEE standards. An additional complication arises when standards are derived or modified using a precautionary approach. For ELF the differences between ICNIRP and IEEE are more fundamental; namely, differences in the basic restriction used (induced current; in-situ electric field) and the location of breakpoints in the strength-frequency curves result in large differences. In 2006, ICNIRP will initiate the review of their ELF and radiofrequency guidelines, and this will provide an opportunity to address differences in standards and the move towards harmonization of EMF standards and guidelines.

  18. The recommended Threshold Limit Values for heat exposure fail to maintain body core temperature within safe limits in older working adults.

    Science.gov (United States)

    Lamarche, Dallon T; Meade, Robert D; D'Souza, Andrew W; Flouris, Andreas D; Hardcastle, Stephen G; Sigal, Ronald J; Boulay, Pierre; Kenny, Glen P

    2017-09-01

    The American Conference of Governmental and Industrial Hygienists (ACGIH®) Threshold Limit Values (TLV® guidelines) for work in the heat consist of work-rest (WR) allocations designed to ensure a stable core temperature that does not exceed 38°C. However, the TLV® guidelines have not been validated in older workers. This is an important shortcoming given that adults as young as 40 years demonstrate impairments in their ability to dissipate heat. We therefore evaluated body temperature responses in older adults during work performed in accordance to the TLV® recommended guidelines. On three occasions, 9 healthy older (58 ± 5 years) males performed a 120-min work-simulated protocol in accordance with the TLV® guidelines for moderate-to-heavy intensity work (360 W fixed rate of heat production) in different wet-bulb globe temperatures (WBGT). The first was 120 min of continuous (CON) cycling at 28.0°C WBGT (CON[28°C]). The other two protocols were 15-min intermittent work bouts performed with different WR cycles and WBGT: (i) WR of 3:1 at 29.0°C (WR3:1[29°C]) and (ii) WR of 1:1 at 30.0°C (WR1:1[30°C]). Rectal temperature was measured continuously. The rate of change in mean body temperature was determined via thermometry (weighting coefficients: rectal, 0.9; mean skin temperature, 0.1) and direct calorimetry. Rectal temperature exceeded 38°C in all participants in CON[28°C] and WR3:1[29°C] whereas a statistically similar proportion of workers exceeded 38°C in WR1:1[30°C] (χ 2 ; P = 0.32). The average time for rectal temperature to reach 38°C was: CON[28°C], 53 ± 7; WR3:1[29°C], 79 ± 11; and WR1:1[30°C], 100 ± 29 min. Finally, while a stable mean body temperature was not achieved in any work condition as measured by thermometry (i.e., >0°C·min -1 ; all Pheat balance as determined by direct calorimetry was achieved in WR3:1[29°C] and WR1:1[30°C] (both P ≥ 0.08). Our findings indicate that the TLV® guidelines do not prevent body core

  19. Use of environmental TLD data at a nuclear power station to estimate detection limits for radiation exposure due to station operation

    International Nuclear Information System (INIS)

    Lang, E.; Hardeman, J.; Kahn, B.

    1987-01-01

    The environmental radiation monitoring network maintained by the Georgia Department of Natural Resources at the Hatch Nuclear Plant, Baxley, GA, was used to determine the variability in measured background exposures in order to estimate the detection limits for radiation due to station operation. Data were obtained from LiF thermoluminescent dosimeters (TLDs) exposed in sets of four at 46 locations for 16 consecutive quarters from 1982 to 1985. The average exposure for 695 values was 11.8 microC kg-1 y-1 (mR/quarter). At individual locations, the averages of quarterly exposures ranged from 9.3 to 14.3 microC kg-1 y-1 and had standard deviations from 0.8 to 2.2 microC kg-1 y-1 with a typical standard deviation of 1.5 microC kg-1 y-1. The standard deviation due to reading the TLDs and subtracting the transit plus storage exposure, estimated as 0.4 microC kg-1 y-1, contributed only a small fraction of the uncertainty of the mean background; the greater contribution is from temporal fluctuations. There is a spatial pattern of higher background along the Altamaha River but no distinct seasonal pattern. The observation that exposure values at most locations rose and fell in unison suggested a calculational model that adjusts the average exposure level at a location by an increment determined each quarter at control locations. This model reduced the standard deviation for a predicted quarterly background exposure to 0.9 microC kg-1 y-1, with a range of 0.5 to 1.3 microC kg-1 y-1. If the standard deviation of the net value is multiplied by an error probability constant of 3.3 (type I and II errors not greater than 5%), the detection limits range from 2 to 5 microC kg-1 y-1 at the individual locations, with an average of 3 microC kg-1 y-1. This approach or two similar ones described earlier are recommended for improving the detection limit where needed

  20. Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey J [Los Alamos National Laboratory; Mcnaughton, Michael W [Los Alamos National Laboratory

    2009-01-01

    Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr-! versus 0.3 mSv yr-!). The estimated effective dose rate for a more homebound person was about 3 mSv yr-!. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-!, which is similar to the 1 mSv yr-! threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf! from radon background exposure in homes stands in

  1. Work to save dose: contrasting effective dose rates from radon exposure in workplaces and residences against the backdrop of public and occupational limits

    International Nuclear Information System (INIS)

    Whicker, Jeffrey J.; Mcnaughton, Michael W.

    2009-01-01

    Office workers are exposed to radon while at work and at home. Though there has been a multitude of studies reporting the measurements of radon concentrations and potential lung and effective doses associated with radon and progeny exposure in homes, similar studies on the concentrations and subsequent effective dose rates in the non-mine workplaces are lacking. Additionally, there are few, if any, comparative analyses of radon exposures at more 'typical' workplace with residential exposures within the same county. The purposes of this study were to measure radon concentrations in office and residential spaces in the same county and explore the radiation dose implications. Sixty-five track-etch detectors were deployed in office spaces and 47 were deployed in residences, all within Los Alamos County, New Mexico, USA. The sampling periods for these measurements were generally about three months. The measured concentrations were used to calculate and compare effective dose rates resulting from exposure while at work and at home. Results showed that full-time office workers receive on average about 8 times greater exposure at home than while in the office (2.3 mSv yr- versus 0.3 mSv yr-). The estimated effective dose rate for a more homebound person was about 3 mSv yr-. Estimating effective doses from background radon exposure in the same county as Los Alamos National Laboratory, with thousands of'radiological workers,' highlights interesting contrasts in radiation protection standards that span public and occupational settings. For example, the effective dose rate from background radon exposure in unregulated office spaces ranged up to 1.1 mSv yr-, which is similar to the 1 mSv yr- threshold for regulation ofa 'radiological worker,' as defined in the Department of Energy regulations for occupational exposure. Additionally, the estimated average effective dose total of> 3 mSv yf from radon background exposure in homes stands in contrast to the 0.1 mSv yr- air pathway

  2. Effect of exposure to sunlight and phosphorus-limitation on bacterial degradation of coloured dissolved organic matter (CDOM) in freshwater

    DEFF Research Database (Denmark)

    Kragh, Theis; Søndergaard, Morten; Tranvik, Lars

    2008-01-01

    This study reports on the interacting effect of photochemical conditioning of dissolved organic matter and inorganic phosphorus on the metabolic activity of bacteria in freshwater. Batch cultures with lake-water bacteria and dissolved organic carbon (DOC) extracted from a humic boreal river were...... arranged in an experimental matrix of three levels of exposure to simulated sunlight and three levels of phosphorus concentration. We measured an increase in bacterial biomass, a decrease in DOC and bacterial respiration as CO(2) production and O(2) consumption over 450 h. These measurements were used...

  3. Effect of exposure to sunlight and phosphorus-limitation on bacterial degradation of coloured dissolved organic matter (CDOM) in freshwater.

    Science.gov (United States)

    Kragh, Theis; Søndergaard, Morten; Tranvik, Lars

    2008-05-01

    This study reports on the interacting effect of photochemical conditioning of dissolved organic matter and inorganic phosphorus on the metabolic activity of bacteria in freshwater. Batch cultures with lake-water bacteria and dissolved organic carbon (DOC) extracted from a humic boreal river were arranged in an experimental matrix of three levels of exposure to simulated sunlight and three levels of phosphorus concentration. We measured an increase in bacterial biomass, a decrease in DOC and bacterial respiration as CO(2) production and O(2) consumption over 450 h. These measurements were used to calculate bacterial growth efficiency (BGE). Bacterial degradation of DOC increased with increasing exposure to simulated sunlight and availability of phosphorus and no detectable growth occurred on DOC that was not pre-exposed to simulated sunlight. The outcome of photochemical degradation of DOC changed with increasing availability of phosphorus, resulting in an increase in BGE from about 5% to 30%. Thus, the availability of phosphorus has major implications for the quantitative transfer of carbon in microbial food webs.

  4. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario

    International Nuclear Information System (INIS)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-01-01

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates. (paper)

  5. Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

    Science.gov (United States)

    Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

    2017-07-24

    Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

  6. Theoretical assessment of the maximum obtainable power in wireless power transfer constrained by human body exposure limits in a typical room scenario.

    Science.gov (United States)

    Chen, Xi Lin; De Santis, Valerio; Umenei, Aghuinyue Esai

    2014-07-07

    In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.

  7. Proposal to regulate human exposure limits to electromagnetic fields produced by cellular telephony systems in Costa Rica

    International Nuclear Information System (INIS)

    Gomez Lizano, Cristian; Calvo Horth, Gustavo; Dompe Gamboa, Pablo; Ramirez Rodriguez, David; Retana Duran, Elias; Gutierrez Chinchilla, Jose Alcides

    2008-01-01

    Modern society has presented an epic technology development in recent years, driven strongly by communications networks: from micro environments such as personal area networks passing by cell phone to the global Internet network. The communications established in real-time are increasingly, a necessary input. However, the growing demand for communications services and in particularly mobile phone, has meant that the environment is altered by the large number of signals generated by electromagnetic fields that transmit high volumes of energy, which saturate the electromagnetic spectrum, these waves of energy called no ionizing energy. The World Health Organization, through the International Energy Agency Nonionizing (ICNIRP for its acronym in English), has conducted in recent years researches on the effects of the health of people exposed to nonionizing energy; also, have existed proposals regulating these exposure levels. Nonionizing electromagnetic fields are investigated, focusing on transmitting equipment for mobile phone systems in Costa Rica and electromagnetic safety criteria of exposure, both occupational as of general public. The electromagnetism basic concepts and parameters related with nonionizing radiations research are referenced, among them can be mentioned the relationship between the electric field E, the magnetic field H and the power density S. Other concepts such as near-field region, far-field region, exposure zones and specified absorption rate SAR, are also defined. A mathematical fundament is presented showing the relationships between the concepts explained. Guidelines for calculating the power density are provided by means of a theoretical estimate from parameters of transmitting equipment. Also, the procedures for calculating the spatial and temporal averaging are set out and a brief overview is made of epidemiological and biological effects caused by radio frequency radiation. The existing rules at the international level are analyzed to

  8. Interest and limits of microwaves thermographic measurements for the diagnosis and pronostic of local acute exposure in the pig

    International Nuclear Information System (INIS)

    Daburon, F.; Lefaix, J.L.; Remy, J.; Fayart, G.; Tricaud, Y.

    1985-01-01

    Microwaves thermographic measurements were carried out on 30 pigs following local exposure of the thigh by a collimated source of iridium 192 at doses ranging between 30 and 84 Gy (2 cm depth dose). Measurement and data processing methods were developed both qualitatively (thermographic images vs anatomo-clinical evolution of the lesions) and quantitatively (by means of indexes calculated from the rough thermographic data to evaluate the relations between the intensity of the local thermic reaction and the applied dose or dose rate). Beside the diagnostic value of the method, which accounts for the global radiological injuries better than the physical dose really distributed, its pronostic value -much more reliable- makes it possible to estimate the severity of the injuries and their later evolution very early (between 10 and 15 days) [fr

  9. Exposure of Human CD8+ T Cells to Type-2 Cytokines Impairs Division and Differentiation and Induces Limited Polarization

    Directory of Open Access Journals (Sweden)

    Annette Fox

    2018-05-01

    Full Text Available Effector CD8+ T cells generally produce type-1 cytokines and mediators of the perforin/granzyme cytolytic pathway, yet type-2-polarized CD8+ cells (Tc2 are detected in type-2 (T2 cytokine-driven diseases such as asthma. It is unclear whether T2 cytokine exposure during activation is sufficient to polarize human CD8+ T cells. To address this question, a protocol was developed for high-efficiency activation of human CD8+ T cells in which purified single cells or populations were stimulated with plate-bound anti-CD3 and anti-CD11a mAb for up to 8 days in T2 polarizing or neutral conditions, before functional analysis. Activation of CD8+ naïve T cells (TN in T2 compared with neutral conditions decreased the size of single-cell clones, although early division kinetics were equivalent, indicating an effect on overall division number. Activation of TN in T2 conditions followed by brief anti-CD3 mAb restimulation favored expression of T2 cytokines, GATA3 and Eomes, and lowered expression of type-1 cytokines, Prf1, Gzmb, T-BET, and Prdm1. However, IL-4 was only weakly expressed, and PMA and ionomycin restimulation favored IFN-γ over IL-4 expression. Activation of TN in T2 compared with neutral conditions prevented downregulation of costimulatory (CD27, CD28 and lymph-node homing receptors (CCR7 and CD95 acquisition, which typically occur during differentiation into effector phenotypes. CD3 was rapidly and substantially induced after activation in neutral, but not T2 conditions, potentially contributing to greater division and differentiation in neutral conditions. CD8+ central memory T cells (TCM were less able to enter division upon reactivation in T2 compared with neutral conditions, and were more refractory to modulating IFN-γ and IL-4 production than CD8+ TN. In summary, while activation of TN in T2 conditions can generate T2 cytokine-biased cells, IL-4 expression is weak, T2 bias is lost upon strong restimulation, differentiation, and division

  10. Reduction in exposure to arsenic from drinking well-water in Bangladesh limited by insufficient testing and awareness.

    Science.gov (United States)

    Pfaff, A; Schoenfeld, A; Ahmed, K M; van Geen, A

    2017-01-01

    This study considers potential policy responses to the still very high levels of exposure to arsenic (As) caused by drinking water from shallow tubewells in rural Bangladesh. It examines a survey of 4,109 households in 76 villages of Araihazar upazila conducted two years after a national testing campaign swept through the area. The area is adjacent to the region where a long-term study was initiated in 2000 and where households are periodically reminded of health risks associated with well-water elevated in As. Results confirm that testing spurs switching away from unsafe wells, although the 27% fraction who switched was only about half of that in the long-term study area. By village, the fraction of households that switched varied with the availability of safe wells and the distance from the long-term study area. Lacking follow-up testing, two years only after the campaign 21% of households did not know the status of their well and 21% of households with an unsafe well that switched did so to an untested well. Well testing is again urgently needed in Bangladesh and should be paired with better ways to raise awareness and the installation of additional deep community wells.

  11. Does attenuated skin blood flow lower sweat rate and the critical environmental limit for heat balance during severe heat exposure?

    Science.gov (United States)

    Cramer, Matthew N; Gagnon, Daniel; Crandall, Craig G; Jay, Ollie

    2017-02-01

    What is the central question of this study? Does attenuated skin blood flow diminish sweating and reduce the critical environmental limit for heat balance, which indicates maximal heat loss potential, during severe heat stress? What is the main finding and its importance? Isosmotic hypovolaemia attenuated skin blood flow by ∼20% but did not result in different sweating rates, mean skin temperatures or critical environmental limits for heat balance compared with control and volume-infusion treatments, suggesting that the lower levels of skin blood flow commonly observed in aged and diseased populations may not diminish maximal whole-body heat dissipation. Attenuated skin blood flow (SkBF) is often assumed to impair core temperature (T c ) regulation. Profound pharmacologically induced reductions in SkBF (∼85%) lead to impaired sweating, but whether the smaller attenuations in SkBF (∼20%) more often associated with ageing and certain diseases lead to decrements in sweating and maximal heat loss potential is unknown. Seven healthy men (28 ± 4 years old) completed a 30 min equilibration period at 41°C and a vapour pressure (P a ) of 2.57 kPa followed by incremental steps in P a of 0.17 kPa every 6 min to 5.95 kPa. Differences in heat loss potential were assessed by identifying the critical vapour pressure (P crit ) at which an upward inflection in T c occurred. The following three separate treatments elicited changes in plasma volume to achieve three distinct levels of SkBF: control (CON); diuretic-induced isosmotic dehydration to lower SkBF (DEH); and continuous saline infusion to maintain SkBF (SAL). The T c , mean skin temperature (T sk ), heart rate, mean laser-Doppler flux (forearm and thigh; LDF mean ), mean local sweat rate (forearm and thigh; LSR mean ) and metabolic rate were measured. In DEH, a 14.2 ± 5.7% lower plasma volume resulted in a ∼20% lower LDF mean in perfusion units (PU) (DEH, 139 ± 23 PU; CON, 176 ± 22 PU; and SAL

  12. Limited Sampling Strategy for Accurate Prediction of Pharmacokinetics of Saroglitazar: A 3-point Linear Regression Model Development and Successful Prediction of Human Exposure.

    Science.gov (United States)

    Joshi, Shuchi N; Srinivas, Nuggehally R; Parmar, Deven V

    2018-03-01

    Our aim was to develop and validate the extrapolative performance of a regression model using a limited sampling strategy for accurate estimation of the area under the plasma concentration versus time curve for saroglitazar. Healthy subject pharmacokinetic data from a well-powered food-effect study (fasted vs fed treatments; n = 50) was used in this work. The first 25 subjects' serial plasma concentration data up to 72 hours and corresponding AUC 0-t (ie, 72 hours) from the fasting group comprised a training dataset to develop the limited sampling model. The internal datasets for prediction included the remaining 25 subjects from the fasting group and all 50 subjects from the fed condition of the same study. The external datasets included pharmacokinetic data for saroglitazar from previous single-dose clinical studies. Limited sampling models were composed of 1-, 2-, and 3-concentration-time points' correlation with AUC 0-t of saroglitazar. Only models with regression coefficients (R 2 ) >0.90 were screened for further evaluation. The best R 2 model was validated for its utility based on mean prediction error, mean absolute prediction error, and root mean square error. Both correlations between predicted and observed AUC 0-t of saroglitazar and verification of precision and bias using Bland-Altman plot were carried out. None of the evaluated 1- and 2-concentration-time points models achieved R 2 > 0.90. Among the various 3-concentration-time points models, only 4 equations passed the predefined criterion of R 2 > 0.90. Limited sampling models with time points 0.5, 2, and 8 hours (R 2 = 0.9323) and 0.75, 2, and 8 hours (R 2 = 0.9375) were validated. Mean prediction error, mean absolute prediction error, and root mean square error were prediction of saroglitazar. The same models, when applied to the AUC 0-t prediction of saroglitazar sulfoxide, showed mean prediction error, mean absolute prediction error, and root mean square error model predicts the exposure of

  13. Safe limit of arsenic in soil in relation to dietary exposure of arsenicosis patients from Malda district, West Bengal- A case study.

    Science.gov (United States)

    Golui, Debasis; Guha Mazumder, D N; Sanyal, S K; Datta, S P; Ray, P; Patra, P K; Sarkar, S; Bhattacharya, K

    2017-10-01

    Safe limit of arsenic in soil in relation to dietary exposure of arsenicosis patients was established in Malda district of West Bengal. Out of 182 participants examined, 80 (43.9%) participants showed clinical features of arsenicosis, characterized by arsenical skin lesion (pigmentation and keratosis), while 102 participants did not have any such lesion (control). Experimental results of the twenty eight soils (own field) of the participants showed the mean Olsen extractable and total arsenic concentration of 0.206 and 6.70mgkg -1 , respectively. Arsenic concentration in rice grain ranged from 2.00 to 1260μgkg -1 with the mean value of 146μgkg -1 . The hazard quotient (HQ) for intake of As by human through consumption of rice varied from 0.03 to 3.52. HQ exceeds 1.0 for drinking water and rice grain grown in the study area in many cases. As high as 77.6% variation in As content in rice grain could be explained by the solubility-free ion activity model. Toxic limit of extractable As in soil for rice in relation to soil properties and human health hazard, associated with consumption of rice grain by human, was established. For example, the permissible limit of Olsen extractable As in soil would be 0.43mgkg -1 for rice cultivation, if soil pH and organic carbon content were 7.5% and 0.50%, respectively. However, the critical limit of Olsen extractable As in soil would be 0.54mgkg -1 , if soil pH and organic carbon were 8.5% and 0.75%, respectively. The conceptual framework of fixing the toxic limit of arsenic in soils with respect to soil properties and human health under modeling-framework was established. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. An isotope dilution gas chromatography/mass spectrometry method for trace analysis of xylene and its metabolites in tissues following threshold limit value exposures

    Energy Technology Data Exchange (ETDEWEB)

    Pyon, K.H.; Kracko, D.A.; Strunk, M.R. [and others

    1995-12-01

    The existence of a nose-brain barrier that functions to protect the central nervous system (CNS) from inhaled toxicants has been postulated. Just as a blood-brain barrier protects the CNS from systemic toxicants, the nose-brain barrier may have similar characteristic functions. One component of interest is nasal xenobiotic metabolism and its effect on the transport of pollutants into the CNS at environmentally plausible levels of exposure. Previous results have shown that inhaled xylene are dimethyl phenol (DMP) and methyl benzyl alcohol (MBA), and the nonvolatile metabolites are toluic acid (TA) and methyl hippuric acid (MHA). The nonvolatile metabolites of xylene, along with a small quantity of volatiles, representing either parent xylene or volatile metabolites, are transported via the olfactory epithelium to the glomeruli within the olfactory bulbs of the brain. Further work will be done to establish the linearity for each analyte at the actual highest detection limit of the GC/MS.

  15. An isotope dilution gas chromatography/mass spectrometry method for trace analysis of xylene and its metabolites in tissues following threshold limit value exposures

    International Nuclear Information System (INIS)

    Pyon, K.H.; Kracko, D.A.; Strunk, M.R.

    1995-01-01

    The existence of a nose-brain barrier that functions to protect the central nervous system (CNS) from inhaled toxicants has been postulated. Just as a blood-brain barrier protects the CNS from systemic toxicants, the nose-brain barrier may have similar characteristic functions. One component of interest is nasal xenobiotic metabolism and its effect on the transport of pollutants into the CNS at environmentally plausible levels of exposure. Previous results have shown that inhaled xylene are dimethyl phenol (DMP) and methyl benzyl alcohol (MBA), and the nonvolatile metabolites are toluic acid (TA) and methyl hippuric acid (MHA). The nonvolatile metabolites of xylene, along with a small quantity of volatiles, representing either parent xylene or volatile metabolites, are transported via the olfactory epithelium to the glomeruli within the olfactory bulbs of the brain. Further work will be done to establish the linearity for each analyte at the actual highest detection limit of the GC/MS

  16. Particle size distributions of lead measured in battery manufacturing and secondary smelter facilities and implications in setting workplace lead exposure limits.

    Science.gov (United States)

    Petito Boyce, Catherine; Sax, Sonja N; Cohen, Joel M

    2017-08-01

    Inhalation plays an important role in exposures to lead in airborne particulate matter in occupational settings, and particle size determines where and how much of airborne lead is deposited in the respiratory tract and how much is subsequently absorbed into the body. Although some occupational airborne lead particle size data have been published, limited information is available reflecting current workplace conditions in the U.S. To address this data gap, the Battery Council International (BCI) conducted workplace monitoring studies at nine lead acid battery manufacturing facilities (BMFs) and five secondary smelter facilities (SSFs) across the U.S. This article presents the results of the BCI studies focusing on the particle size distributions calculated from Personal Marple Impactor sampling data and particle deposition estimates in each of the three major respiratory tract regions derived using the Multiple-Path Particle Dosimetry model. The BCI data showed the presence of predominantly larger-sized particles in the work environments evaluated, with average mass median aerodynamic diameters (MMADs) ranging from 21-32 µm for the three BMF job categories and from 15-25 µm for the five SSF job categories tested. The BCI data also indicated that the percentage of lead mass measured at the sampled facilities in the submicron range (i.e., lead) was generally small. The estimated average percentages of lead mass in the submicron range for the tested job categories ranged from 0.8-3.3% at the BMFs and from 0.44-6.1% at the SSFs. Variability was observed in the particle size distributions across job categories and facilities, and sensitivity analyses were conducted to explore this variability. The BCI results were compared with results reported in the scientific literature. Screening-level analyses were also conducted to explore the overall degree of lead absorption potentially associated with the observed particle size distributions and to identify key issues

  17. Nanosilver – Occupational exposure limits

    OpenAIRE

    Anna Maria Świdwińska-Gajewska; Sławomir Czerczak

    2015-01-01

    Historically, nanosilver has been known as colloidal silver composed of particles with a size below 100 nm. Silver nanoparticles are used in many technologies, creating a wide range of products. Due to antibacterial properties nanosilver is used, among others, in medical devices (wound dressings), textiles (sport clothes, socks), plastics and building materials (paints). Colloidal silver is considered by many as an ideal agent in the fight against pathogenic microorganisms, unlike antibiotics...

  18. The role of reported tobacco-specific media exposure on adult attitudes towards proposed policies to limit the portrayal of smoking in movies.

    Science.gov (United States)

    Blake, Kelly D; Viswanath, K; Blendon, Robert J; Vallone, Donna

    2010-06-01

    To assess the relative, independent contribution of reported tobacco-specific media exposure (pro-tobacco advertising, anti-tobacco advertising, and news coverage of tobacco issues) to US adults' support for policy efforts that aim to regulate the portrayal of smoking in movies. Using the American Legacy Foundation's 2003 American Smoking and Health Survey (ASHES-2), multivariable logistic regression was used to model the predicted probability that US adults support movie-specific tobacco control policies, by reported exposure to tobacco-specific media messages, controlling for smoking status, education, income, race/ethnicity, age, sex, knowledge of the negative effects of tobacco and state. Across most outcome variables under study, findings reveal that reported exposure to tobacco-specific media messages is associated with adult attitudes towards movie-specific policy measures. Most exposure to tobacco information in the media (with the exception of pro-tobacco advertising on the internet) contributes independently to the prediction of adult support for movie-specific policies. The direction of effect follows an expected pattern, with reported exposure to anti-tobacco advertising and news coverage of tobacco predicting supportive attitudes towards movie policies, and reported exposure to pro-tobacco advertising lessening support for some movie policies, though the medium of delivery makes a difference. Media campaigns to prevent tobacco use and exposure to secondhand smoke have had value beyond the intended impact of single-issue campaigns; exposure to anti-tobacco campaigns and public dialogue about the dangers of tobacco seem also to be associated with shaping perceptions of the social world related to norms about tobacco, and ideas about regulating the portrayal of smoking in movies.

  19. Evaluation of Pharmacokinetic Models for the Disposition of Lead (Pb) in Humans, in Support of Application to Occupational Exposure Limit Derivation

    Science.gov (United States)

    2015-11-09

    The subjects ranged in age from 16-47, with a mean age of 29 years, with an average number of 3 pregnancies ; on average, blood was collected...presented by Vork et al. (2013), Table B-3, a plot of BLL vs. workplace air Pb predictions for the Leggett+ (MATLAB) model could be constructed, and was...excluded subjects all had the highest estimated exposures as well, but this was not the case; 6 of the excluded subjects had workplace air exposures

  20. Pre-exposure to simultaneous, but not individual, climate change stressors limits acclimation capacity of Irukandji jellyfish polyps to predicted climate scenarios

    KAUST Repository

    Klein, Shannon G.; Pitt, Kylie A.; Carroll, Anthony R.

    2017-01-01

    Researchers have investigated the immediate effects of end-of-century climate change scenarios on many marine species, yet it remains unclear whether we can reliably predict how marine species may respond to future conditions because biota may become either more or less resistant over time. Here, we examined the role of pre-exposure to elevated temperature and reduced pH in mitigating the potential negative effects of future ocean conditions on polyps of a dangerous Irukandji jellyfish Alatina alata. We pre-exposed polyps to elevated temperature (28 °C) and reduced pH (7.6), in a full factorial experiment that ran for 14 d. We secondarily exposed original polyps and their daughter polyps to either current (pH 8.0, 25 °C) or future conditions (pH 7.6, 28 °C) for a further 34 d to assess potential phenotypic plastic responses and whether asexual offspring could benefit from parental pre-exposure. Polyp fitness was characterised as asexual reproduction, respiration, feeding, and protein concentrations. Pre-exposure to elevated temperature alone partially mitigated the negative effects of future conditions on polyp fitness, while pre-exposure to reduced pH in isolation completely mitigated the negative effects of future conditions on polyp fitness. Pre-exposure to the dual stressors, however, reduced fitness under future conditions relative to those in the control treatment. Under future conditions, polyps had higher respiration rates regardless of the conditions they were pre-exposed to, suggesting that metabolic rates will be higher under future conditions. Parent and daughter polyps responded similarly to the various treatments tested, demonstrating that parental pre-exposure did not confer any benefit to asexual offspring under future conditions. Importantly, we demonstrate that while pre-exposure to the stressors individually may allow Irukandji polyps to acclimate over short timescales, the stressors are unlikely to occur in isolation in the long term, and

  1. Pre-exposure to simultaneous, but not individual, climate change stressors limits acclimation capacity of Irukandji jellyfish polyps to predicted climate scenarios

    KAUST Repository

    Klein, Shannon G.

    2017-05-20

    Researchers have investigated the immediate effects of end-of-century climate change scenarios on many marine species, yet it remains unclear whether we can reliably predict how marine species may respond to future conditions because biota may become either more or less resistant over time. Here, we examined the role of pre-exposure to elevated temperature and reduced pH in mitigating the potential negative effects of future ocean conditions on polyps of a dangerous Irukandji jellyfish Alatina alata. We pre-exposed polyps to elevated temperature (28 °C) and reduced pH (7.6), in a full factorial experiment that ran for 14 d. We secondarily exposed original polyps and their daughter polyps to either current (pH 8.0, 25 °C) or future conditions (pH 7.6, 28 °C) for a further 34 d to assess potential phenotypic plastic responses and whether asexual offspring could benefit from parental pre-exposure. Polyp fitness was characterised as asexual reproduction, respiration, feeding, and protein concentrations. Pre-exposure to elevated temperature alone partially mitigated the negative effects of future conditions on polyp fitness, while pre-exposure to reduced pH in isolation completely mitigated the negative effects of future conditions on polyp fitness. Pre-exposure to the dual stressors, however, reduced fitness under future conditions relative to those in the control treatment. Under future conditions, polyps had higher respiration rates regardless of the conditions they were pre-exposed to, suggesting that metabolic rates will be higher under future conditions. Parent and daughter polyps responded similarly to the various treatments tested, demonstrating that parental pre-exposure did not confer any benefit to asexual offspring under future conditions. Importantly, we demonstrate that while pre-exposure to the stressors individually may allow Irukandji polyps to acclimate over short timescales, the stressors are unlikely to occur in isolation in the long term, and

  2. Pre-exposure to simultaneous, but not individual, climate change stressors limits acclimation capacity of Irukandji jellyfish polyps to predicted climate scenarios

    Science.gov (United States)

    Klein, Shannon G.; Pitt, Kylie A.; Carroll, Anthony R.

    2017-09-01

    Researchers have investigated the immediate effects of end-of-century climate change scenarios on many marine species, yet it remains unclear whether we can reliably predict how marine species may respond to future conditions because biota may become either more or less resistant over time. Here, we examined the role of pre-exposure to elevated temperature and reduced pH in mitigating the potential negative effects of future ocean conditions on polyps of a dangerous Irukandji jellyfish Alatina alata. We pre-exposed polyps to elevated temperature (28 °C) and reduced pH (7.6), in a full factorial experiment that ran for 14 d. We secondarily exposed original polyps and their daughter polyps to either current (pH 8.0, 25 °C) or future conditions (pH 7.6, 28 °C) for a further 34 d to assess potential phenotypic plastic responses and whether asexual offspring could benefit from parental pre-exposure. Polyp fitness was characterised as asexual reproduction, respiration, feeding, and protein concentrations. Pre-exposure to elevated temperature alone partially mitigated the negative effects of future conditions on polyp fitness, while pre-exposure to reduced pH in isolation completely mitigated the negative effects of future conditions on polyp fitness. Pre-exposure to the dual stressors, however, reduced fitness under future conditions relative to those in the control treatment. Under future conditions, polyps had higher respiration rates regardless of the conditions they were pre-exposed to, suggesting that metabolic rates will be higher under future conditions. Parent and daughter polyps responded similarly to the various treatments tested, demonstrating that parental pre-exposure did not confer any benefit to asexual offspring under future conditions. Importantly, we demonstrate that while pre-exposure to the stressors individually may allow Irukandji polyps to acclimate over short timescales, the stressors are unlikely to occur in isolation in the long term, and

  3. IWGT report on quantitative approaches to genotoxicity risk assessment II. Use of point-of-departure (PoD) metrics in defining acceptable exposure limits and assessing human risk.

    Science.gov (United States)

    MacGregor, James T; Frötschl, Roland; White, Paul A; Crump, Kenny S; Eastmond, David A; Fukushima, Shoji; Guérard, Melanie; Hayashi, Makoto; Soeteman-Hernández, Lya G; Johnson, George E; Kasamatsu, Toshio; Levy, Dan D; Morita, Takeshi; Müller, Lutz; Schoeny, Rita; Schuler, Maik J; Thybaud, Véronique

    2015-05-01

    This is the second of two reports from the International Workshops on Genotoxicity Testing (IWGT) Working Group on Quantitative Approaches to Genetic Toxicology Risk Assessment (the QWG). The first report summarized the discussions and recommendations of the QWG related to the need for quantitative dose-response analysis of genetic toxicology data, the existence and appropriate evaluation of threshold responses, and methods to analyze exposure-response relationships and derive points of departure (PoDs) from which acceptable exposure levels could be determined. This report summarizes the QWG discussions and recommendations regarding appropriate approaches to evaluate exposure-related risks of genotoxic damage, including extrapolation below identified PoDs and across test systems and species. Recommendations include the selection of appropriate genetic endpoints and target tissues, uncertainty factors and extrapolation methods to be considered, the importance and use of information on mode of action, toxicokinetics, metabolism, and exposure biomarkers when using quantitative exposure-response data to determine acceptable exposure levels in human populations or to assess the risk associated with known or anticipated exposures. The empirical relationship between genetic damage (mutation and chromosomal aberration) and cancer in animal models was also examined. It was concluded that there is a general correlation between cancer induction and mutagenic and/or clastogenic damage for agents thought to act via a genotoxic mechanism, but that the correlation is limited due to an inadequate number of cases in which mutation and cancer can be compared at a sufficient number of doses in the same target tissues of the same species and strain exposed under directly comparable routes and experimental protocols. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Ex vivo exposure of bone marrow from chronic kidney disease donor rats to pravastatin limits renal damage in recipient rats with chronic kidney disease

    NARCIS (Netherlands)

    Koppen, A. van; Papazova, D.A.; Oosterhuis, N.R.; Gremmels, H.; Giles, R.H.; Fledderus, J.O.; Joles, J.A.; Verhaar, M.C.

    2015-01-01

    Introduction: Healthy bone marrow cell (BMC) infusion improves renal function and limits renal injury in a model of chronic kidney disease (CKD) in rats. However, BMCs derived from rats with CKD fail to retain beneficial effects, demonstrating limited therapeutic efficacy. Statins have been reported

  5. Ex vivo exposure of bone marrow from chronic kidney disease donor rats to pravastatin limits renal damage in recipient rats with chronic kidney disease

    NARCIS (Netherlands)

    van Koppen, Arianne; Papazova, Diana A.; Oosterhuis, Nynke R.; Gremmels, Hendrik; Giles, Rachel H.; Fledderus, Joost O.; Joles, Jaap A.; Verhaar, Marianne C.

    2015-01-01

    INTRODUCTION: Healthy bone marrow cell (BMC) infusion improves renal function and limits renal injury in a model of chronic kidney disease (CKD) in rats. However, BMCs derived from rats with CKD fail to retain beneficial effects, demonstrating limited therapeutic efficacy. Statins have been reported

  6. High-dose vitamin D3 reduces deficiency caused by low UVB exposure and limits HIV-1 replication in urban Southern Africans

    Science.gov (United States)

    Coussens, Anna K.; Naude, Celeste E.; Goliath, Rene; Chaplin, George; Wilkinson, Robert J.; Jablonski, Nina G.

    2015-06-01

    Cape Town, South Africa, has a seasonal pattern of UVB radiation and a predominantly dark-skinned urban population who suffer high HIV-1 prevalence. This coexistent environmental and phenotypic scenario puts residents at risk for vitamin D deficiency, which may potentiate HIV-1 disease progression. We conducted a longitudinal study in two ethnically distinct groups of healthy young adults in Cape Town, supplemented with vitamin D3 in winter, to determine whether vitamin D status modifies the response to HIV-1 infection and to identify the major determinants of vitamin D status (UVB exposure, diet, pigmentation, and genetics). Vitamin D deficiency was observed in the majority of subjects in winter and in a proportion of individuals in summer, was highly correlated with UVB exposure, and was associated with greater HIV-1 replication in peripheral blood cells. High-dosage oral vitamin D3 supplementation attenuated HIV-1 replication, increased circulating leukocytes, and reversed winter-associated anemia. Vitamin D3 therefore presents as a low-cost supplementation to improve HIV-associated immunity.

  7. Occupational dose equivalent limits

    International Nuclear Information System (INIS)

    Goldfinch, E.P.

    1980-01-01

    This paper considers methods of limiting individual radiation risks by recognizing the variation of risk with age at exposure, taking into account both somatic and genetic risks and proposes a simple formula for controlling individual cumulative exposure and hence risk. (Author)

  8. On the use of advanced numerical models for the evaluation of dosimetric parameters and the verification of exposure limits at workplaces.

    Science.gov (United States)

    Catarinucci, L; Tarricone, L

    2009-12-01

    With the next transposition of the 2004/40/EC Directive, employers will become responsible for the electromagnetic field level at the workplace. To make this task easier, the scientific community is compiling practical guidelines to be followed. This work aims at enriching such guidelines, especially for the dosimetric issues. More specifically, some critical aspects related to the application of numerical dosimetric techniques for the verification of the safety limit compliance have been highlighted. In particular, three different aspects have been considered: the dosimetric parameter dependence on the shape and the inner characterisation of the exposed subject as well as on the numerical algorithm used, and the correlation between reference limits and basic restriction. Results and discussions demonstrate how, even by using sophisticated numerical techniques, in some cases a complex interpretation of the result is mandatory.

  9. On the use of advanced numerical models for the evaluation of dosimetric parameters and the verification of exposure limits at workplaces

    International Nuclear Information System (INIS)

    Catarinucci, L.; Tarricone, L.

    2009-01-01

    With the next transposition of the 2004/40/EC Directive, employers will become responsible for the electromagnetic field level at the workplace. To make this task easier, the scientific community is compiling practical guidelines to be followed. This work aims at enriching such guidelines, especially for the dosimetric issues. More specifically, some critical aspects related to the application of numerical dosimetric techniques for the verification of the safety limit compliance have been highlighted. In particular, three different aspects have been considered: the dosimetric parameter dependence on the shape and the inner characterisation of the exposed subject as well as on the numerical algorithm used, and the correlation between reference limits and basic restriction. Results and discussions demonstrate how, even by using sophisticated numerical techniques, in some cases a complex interpretation of the result is mandatory. (authors)

  10. Smoke exposure at western wildfires.

    Science.gov (United States)

    Timothy E. Reinhardt; Roger D. Ottmar

    2000-01-01

    Smoke exposure measurements among firefighters at wildfires in the Western United States between 1992 and 1995 showed that altogether most exposures were not significant, between 3 and 5 percent of the shift-average exposures exceeded occupational exposure limits for carbon monoxide and respiratory irritants. Exposure to benzene and total suspended particulate was not...

  11. Systematic study on the radiation exposure of flora and fauna in case of compliance with the dose limits of the StrlSchV (radiation protection regulation) for men. Final report

    International Nuclear Information System (INIS)

    Kueppers, Christian; Ustohalova, Veronika; Ulanovsky, Alexander

    2012-01-01

    Dose limits for members of the public exposed to the discharge of radioactive substances into the air or water bodies are defined in the German Radiation Protection Ordinance. This study tested whether non-human species are protected within the human dose limits for all 750 radionuclides as compared to a set of reference biota. External and, where possible, internal doses were calculated for the reference biota. In addition new exposure pathways such as submersion and inhalation (for rat and deer) were incorporated. The upper limit as ordered for adequate biota protection is 10 μGy/h. This study found that radionuclide discharges into the air never exceeded the reference dose rate limit. However, violations were detected for discharges of some very short-lived radionuclides into freshwater or seawater, if the maximum water contamination is assumed. Protection of non-human species is guaranteed for more realistic emission and immission situations. This means that damage to populations living in small water volumes cannot be excluded solely on the basis of regulations for the human dose limit. Therefore, it is necessary to judge the individual case in very unfavourable immission situations. (orig.)

  12. Petrol filling workers as biomonitor of PAH exposure and functional health capacity in resource-limited settings of city Rawalpindi, Pakistan.

    Science.gov (United States)

    Rashid, Audil; Tao, Shu; Uddin, Ikhtiar; Kamal, Atif

    2017-07-01

    This is the first study from Pakistan to report the exposure of petrol filling workers (n = 120) to naphthalene (Nap) and pyrene (Pyr) in relation to their functional capacities and health outcome. A group of non-exposed subjects (controls n = 46) was also recruited for comparison. The perceived health risk of the exposed workers was monitored using a questionnaire based on the self-reporting survey. The observed physical anomalies related to the health disorder included the acidity after meals, eye redness, appetite loss, skin lesions, and dryness of oral cavity, while those related to neurasthenic symptoms included the body aches, energy loss, twitching, fatigue, sleeplessness, fainting, and irritability. Mean Nap level observed in the exposed group (106 μg L -1 ) was significantly correlated (r = 0.49; p Workers exposed for 6 h per day or more had significantly high prevalence of physical disorders (OR = 2.79, 95% CI = 1.28-6.09). Neurasthenic symptoms were found in 65% of the subjects and were associated with years of involvement in job. Ten years or more work duration at petrol pumps could be associated with a substantial development of neurasthenic effects (OR = 2.80, 95% CI = 1.23-6.34). In conclusion, the subjects ascribed the disturbances in physical and neurological behavior to their occupation (petrol filling) and also rated their overall health and functional capacity as poor. To promote health of petrol pump workers, reduction in work hours and provision of masks and gloves could be introduced as occupational health interventions.

  13. Exposure to non-ionizing electromagnetic radiation and public health : review of safety levels; Exposicion a radiaciones no ionizantes ambientales y salud publica: Una revision de las bases biomedicas de los limites de seguridad

    Energy Technology Data Exchange (ETDEWEB)

    Ubeda, A.; Trillo, M. A.

    2005-07-01

    The potential health effects of the exposure to non-ionizing electromagnetic radiation are a source of increasing interest on the part of the public and the authorities. This article summarizes the theoretical-experimental basis supporting the safety levels proposed by international committees, and reviews the recent scientific literature on non-ionizing radiation's bioeffects that are relevant to the validation or modification of the present exposure limits. Because of its social interest, special consideration is given to power frequency fields (50-60Hz) and to the radio communication signals of mobile telephony. The paper also describes how interpretations of the scientific evidence, other than those of the international committees, have generated some controversy and have provided a basis for more restrictive limits, like those adopted in Europe by Switzerland and Italy. The article also identifies some gaps in the present scientific knowledge on the bioelectromagnetics discipline and proposes that additional research is needed to complete our present knowledge on the biological responses to non-ionizing radiation. (Author) 80 refs.

  14. Natural radiation exposure indoors

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  15. Limitation of exposure to ionizing radiation

    International Nuclear Information System (INIS)

    1983-01-01

    The Atomic Energy Control Board (AECB) proposes to amend the Atomic Energy Control Regulations in the light of the latest recommendations of the International Commission on Radiological Protection (ICRP). Guidance on how the AECB would apply its proposed amended regulations is provided in this document, which also explains the more important changes from the present regulations. The most basic change is the introduction of the concept of effective dose equivalent. Another is a requirement to keep doses of radiation as low as reasonably achievable. (L.L.)

  16. Exposure to natural radiation

    International Nuclear Information System (INIS)

    Green, B.M.R.

    1985-01-01

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

  17. Radiation protection: occupational exposure

    International Nuclear Information System (INIS)

    Shah, G.A.

    1990-01-01

    The basis of the occupational exposure limit of 50 mSv recommended by the ICRP is questioned. New dosimetry at Hiroshima and Nagasaki, the fact that the dose-response curve may be non-linear and that the relative risk model may be applicable, are some of the arguments advanced to support a reduction in the occupational exposure dose limits. 5 refs., 2 tabs., 3 figs

  18. Occupational exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1985-01-01

    An overview of occupational exposure is presented. Concepts and quantities used for radiation protection are explained as well as the ICRP system of dose limitation. The risks correlated to the limits are discussed. However, the actual exposure are often much lower than the limits and the average risk in radiation work is comparable with the average risk in other safe occupations. Actual exposures in various occupations are presented and discussed. (author)

  19. Exposure Forecaster

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Exposure Forecaster Database (ExpoCastDB) is EPA's database for aggregating chemical exposure information and can be used to help with chemical exposure...

  20. Radiation exposure from incorporated isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Beleznay, F [Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics

    1985-01-01

    Recommendations for the limitation of the burden of the human body from radiation exposure were developed to avoid direct radiation health damage such that the occurrence of stochastic damage can be held below a resonable risk level. The recommendations, published under ICRP 26 and ICRP 30, contain several guidelines and concepts which are discussed here. They include the primary internal dose exposure limits, secondary and implied limits for the monitoring of internal radiation exposure (Annual Limit of Intake, Derived Air Concentrations). Methods are presented for inspection and monitoring of internal exposure in medical laboratories, inspection of incorporation of sup(131)I and sup(99m)Tc.

  1. Focal exposure of limited lung volumes to high-dose irradiation down-regulated organ development-related functions and up-regulated the immune response in mouse pulmonary tissues.

    Science.gov (United States)

    Kim, Bu-Yeo; Jin, Hee; Lee, Yoon-Jin; Kang, Ga-Young; Cho, Jaeho; Lee, Yun-Sil

    2016-01-27

    Despite the emergence of stereotactic body radiotherapy (SBRT) for treatment of medically inoperable early-stage non-small-cell lung cancer patients, the molecular effects of focal exposure of limited lung volumes to high-dose radiation have not been fully characterized. This study was designed to identify molecular changes induced by focal high-dose irradiation using a mouse model of SBRT. Central areas of the mouse left lung were focally-irradiated (3 mm in diameter) with a single high-dose of radiation (90 Gy). Temporal changes in gene expression in the irradiated and non-irradiated neighboring lung regions were analyzed by microarray. For comparison, the long-term effect (12 months) of 20 Gy radiation on a diffuse region of lung was also measured. The majority of genes were down-regulated in the focally-irradiated lung areas at 2 to 3 weeks after irradiation. This pattern of gene expression was clearly different than gene expression in the diffuse region of lungs exposed to low-dose radiation. Ontological and pathway analyses indicated these down-regulated genes were mainly associated with organ development. Although the number was small, genes that were up-regulated after focal irradiation were associated with immune-related functions. The temporal patterns of gene expression and the associated biological functions were also similar in non-irradiated neighboring lung regions, although statistical significance was greatly reduced when compared with those from focally-irradiated areas of the lung. From network analysis of temporally regulated genes, we identified inter-related modules associated with diverse functions, including organ development and the immune response, in both the focally-irradiated regions and non-irradiated neighboring lung regions. Focal exposure of lung tissue to high-dose radiation induced expression of genes associated with organ development and the immune response. This pattern of gene expression was also observed in non

  2. Current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

    1996-09-01

    The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

  3. Quench limits

    International Nuclear Information System (INIS)

    Sapinski, M.

    2012-01-01

    With thirteen beam induced quenches and numerous Machine Development tests, the current knowledge of LHC magnets quench limits still contains a lot of unknowns. Various approaches to determine the quench limits are reviewed and results of the tests are presented. Attempt to reconstruct a coherent picture emerging from these results is taken. The available methods of computation of the quench levels are presented together with dedicated particle shower simulations which are necessary to understand the tests. The future experiments, needed to reach better understanding of quench limits as well as limits for the machine operation are investigated. The possible strategies to set BLM (Beam Loss Monitor) thresholds are discussed. (author)

  4. Dose limits

    International Nuclear Information System (INIS)

    Fitoussi, L.

    1987-12-01

    The dose limit is defined to be the level of harmfulness which must not be exceeded, so that an activity can be exercised in a regular manner without running a risk unacceptable to man and the society. The paper examines the effects of radiation categorised into stochastic and non-stochastic. Dose limits for workers and the public are discussed

  5. Inverse Limits

    CERN Document Server

    Ingram, WT

    2012-01-01

    Inverse limits provide a powerful tool for constructing complicated spaces from simple ones. They also turn the study of a dynamical system consisting of a space and a self-map into a study of a (likely more complicated) space and a self-homeomorphism. In four chapters along with an appendix containing background material the authors develop the theory of inverse limits. The book begins with an introduction through inverse limits on [0,1] before moving to a general treatment of the subject. Special topics in continuum theory complete the book. Although it is not a book on dynamics, the influen

  6. Dose limits for ionising radiation

    International Nuclear Information System (INIS)

    Gifford, D.

    1989-01-01

    Dose limits for exposure to ionising radiation are assessed to see if they give sufficient protection both for the occupationally exposed and for the general public. It is concluded that current limits give a level of safety that satisfies the necessary criteria in the light of present knowledge and further reductions would be unlikely to improve standards of safety. (author)

  7. Contaminant exposure in terrestrial vertebrates

    International Nuclear Information System (INIS)

    Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.

    2007-01-01

    Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

  8. Hazards of radiation exposure

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1982-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risks to health from exposure to low levels of radiation. There is scant data on somatic and genetic risks at environmental and occupational levels of radiation exposure. The available data on radiation induced carcinogenesis and mutagenesis are for high doses and high dose rates of radiation. Risk assessments for low level radiation are obtained using these data, assuming a linear dose-response relationship. During uranium mining the chief source of radiation hazard is inhalation of radon daughters. The correlation between radon daughter exposure and the increased incidence of lung cancer has been well documented. For radiation exposures at and below occupational limits, the associated risk of radiation induced cancers and genetic abnormalities is small and should not lead to a detectable increase over naturally occurring rates

  9. Justification of medical exposures

    International Nuclear Information System (INIS)

    Ditto, M.

    2009-01-01

    Justification of practices using ionising radiation is one of the principles of radiation protection, in addition to optimisation and limitation of dose. This contribution overviews the legal und practical implementation of the principle of justification of medical exposures taking into account the Austrian situation in particular. (orig.)

  10. Automatic Exposure Control Devices for Digital Mammography

    National Research Council Canada - National Science Library

    Fajardo, Laurie

    2000-01-01

    Purpose: The broad, long-term objective of this IDEA proposal is to achieve optimized image quality for DM within acceptable limits of radiation exposure by developing innovative approaches for controlling DM exposures. Scope...

  11. Occupational radiation exposure in Germany: many monitored persons = high exposure?

    International Nuclear Information System (INIS)

    Nitschke, J.

    1996-01-01

    Natural radiation affects the entire population in Germany, and most of Germany's inhabitants are exposed to medical radiation in their lifetime. Occupational radiation exposure, however, is a kind of exposure affecting only a limited and well-defined group of the population, and this radiation exposure has been recorded and monitored as precisely as technically possible ever since the radiation protection laws made occupational radiation exposure monitoring a mandatory obligation. Official personal dosimetry applying passive dosemeters in fact does not offer direct protection against the effects of ionizing radiation, as dosemeter read-out and dose calculation is a post-exposure process. But it nevertheless is a rewarding monitoring duty under radiation protection law, as is shown by the radiation exposure statistics accumulated over decades: in spite of the number of monitored persons having been increasing over the years, the total exposure did not, due to the corresponding improvements in occupational radiation protection. (orig.) [de

  12. Radiation protection limits and review procedure

    International Nuclear Information System (INIS)

    Dafauti, Sunita; Gopalakrishnan, R.K.; Pradeepkumar, K.S.

    2017-01-01

    The primary means of controlling radiation exposure in planned exposure situations in nuclear facilities/radiological laboratories are by good design of facilities, equipment, operating procedures and by ensuring appropriate training to all plant occupational workers. In planned exposure situations, exposure at some level can be expected to occur. For planned exposure situations, exposures are subject to control for ensuring that the specified dose limits for occupational exposure and those for public exposure are not exceeded and optimization is applied to attain the desired level of protection and safety. The person or organization responsible for any facility or activity that gives rise to radiation exposure should have the prime responsibility for protection and safety, which cannot be delegated

  13. Dose. Detriment. Limit assessment

    International Nuclear Information System (INIS)

    Breckow, J.

    2015-01-01

    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  14. Occupational risk and lifetime exposure

    International Nuclear Information System (INIS)

    Lapp, R.E.

    1991-01-01

    Any lowering of annual radiation limits for occupational exposure should be based on industry experience with lifetime doses and not on a worst case career exposure of 47 years. Two decades of experience show a lifetime accumulation of less than 1.5 rem for workers with measurable exposure. This is 5% of the normal lifetime exposure of Americans to natural and medical radiation. Any epidemiology of the US nuclear power workforce's two decade long exposure would have to focus on excess leukemia. Application of the Hiroshima and Nagasaki cancer mortality shows that too few leukemias would be expressed to permit a feasible epidemiology. Ionizing radiation appears to be a mild carcinogen as compared to physical and chemical agents presented in the occupational environment. A realistic factor in determining any change in occupational exposure limits for ionizing radiation should take into account the past performance of the licensee and potential health effects applicable to the workplace. Specifically, the lifetime exposure data for workers at nuclear power plants and naval shipyards should be considered. The nuclear industry and the US Navy have detailed data on the annual exposure of workers with a combined collective exposure approaching 1 million worker-rem. The lifetime dose for naval personnel and shipyard workers averages 1.1 rem J 1990. Shipyard workers have an annual dose of 0.28 rem per work-year and a mean exposure time of 4.4 years. The data apply to workers with measurable dose

  15. Exposure to radon

    International Nuclear Information System (INIS)

    1988-01-01

    Part 3 is given of the Code of Practice approved by the UK Health and Safety Commission with the consent of the Secretary of State for the purpose of providing practical guidance with respect to the provisions of the Ionising Radiations Regulations 1985. Part 3 gives specific guidance on the application of the Regulations to certain work involving exposure to isotopes of radon and their decay products. Aspects covered in the Regulations include restriction of exposure, dose limits, controlled areas, radiation protection advisers and supervisors, dosimetry and area monitoring. (U.K.)

  16. Industrial chemical exposure: guidelines for biological monitoring

    National Research Council Canada - National Science Library

    Lauwerys, Robert R; Hoet, Perrine

    2001-01-01

    .... With Third Edition of Industrial Chemical Exposure you will understand the objectives of biological monitoring, the types of biological monitoring methods, their advantages and limitations, as well...

  17. INFLUENCE OF EXPOSURE ASSESSMENT METHOD IN AN EPIDEMIOLOGIC STUDY OF TRIHALOMETHANE EXPOSURE AND SPONTANEOUS ABORTION

    Science.gov (United States)

    Trihalomethanes are common contaminants of chlorinated drinking water. Studies of their health effects have been hampered by exposure misclassification, due in part to limitations inherent in using utility sampling records. We used two exposure assessment methods, one based on ut...

  18. 'PrEP is not ready for our community, and our community is not ready for PrEP': pre-exposure prophylaxis for HIV for people who inject drugs and limits to the HIV prevention response.

    Science.gov (United States)

    Guise, Andy; Albers, Eliot Ross; Strathdee, Steffanie A

    2017-04-01

    Pre-exposure prophylaxis for HIV, or 'PrEP', is the use of antiretroviral medicines by people who are HIV-negative to protect themselves against acquiring HIV. PrEP has shown efficacy for preventing HIV acquisition. Despite the potential, many concerns have been voiced by people who inject drugs (PWID) and their organizations. There is a need to engage with these views and ensure their integration in to policy and strategy. This paper presents PWID views on PrEP to foster the uptake of these opinions into scientific and policy debate around PrEP METHODS: Critical analysis of a report of a community consultation led by the International Network of People who Use Drugs (INPUD). The INPUD report highlights enthusiasm from PWID for PrEP, but also three main concerns: the feasibility and ethics of PrEP, its potential use as a substitute for other harm reduction strategies and how a focus on PrEP heralds a re-medicalization of HIV. Each concern relates to evidenced gaps in essential services or opposition to harm reduction and PWID human rights. People who use drugs have fundamental concerns about the potential impacts of pre-exposure prophylaxis for HIV which reflect a 'fault line' in HIV prevention: a predominance of biomedical approaches over community perspectives. Greater community engagement in HIV prevention strategy is needed, or we risk continuing to ignore the need for action on the underlying structural drivers and social context of the HIV epidemic. © 2016 Society for the Study of Addiction.

  19. The sources of radiation exposure

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1992-01-01

    Radiation protection of workers and of members of the public requires an assessment of the various sources of exposure, their variations in time or under specific conditions or circumstances, and the possibilities for control or limitation. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has evaluated the various components of natural and man-made sources in some detail. Natural exposures form the largest component of radiation exposure of man. Variability in exposures depends on elevation, the concentrations of radionuclides in soil, food and water, the composition of building materials and the susceptibility of indoor spaces to radon build-up. Man-made sources have included exposures to fallout from atmospheric nuclear testing and discharged from nuclear fuel cycle installations in routine operations or in accidents. The other main source of radiation exposures of individuals is in medical diagnostic examinations and therapeutic treatments. (author)

  20. Neutron exposure

    International Nuclear Information System (INIS)

    Prillinger, G.; Konynenburg, R.A. van

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. In chapter 6, LWR-PV neutron transport calculations and dosimetry methods and how they are combined to evaluate the neutron exposure of the steel of pressure vessels are discussed. An effort to correlate neutron exposure parameters with damage is made

  1. Asbestos Exposure Assessment Database

    Science.gov (United States)

    Arcot, Divya K.

    2010-01-01

    Exposure to particular hazardous materials in a work environment is dangerous to the employees who work directly with or around the materials as well as those who come in contact with them indirectly. In order to maintain a national standard for safe working environments and protect worker health, the Occupational Safety and Health Administration (OSHA) has set forth numerous precautionary regulations. NASA has been proactive in adhering to these regulations by implementing standards which are often stricter than regulation limits and administering frequent health risk assessments. The primary objective of this project is to create the infrastructure for an Asbestos Exposure Assessment Database specific to NASA Johnson Space Center (JSC) which will compile all of the exposure assessment data into a well-organized, navigable format. The data includes Sample Types, Samples Durations, Crafts of those from whom samples were collected, Job Performance Requirements (JPR) numbers, Phased Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM) results and qualifiers, Personal Protective Equipment (PPE), and names of industrial hygienists who performed the monitoring. This database will allow NASA to provide OSHA with specific information demonstrating that JSC s work procedures are protective enough to minimize the risk of future disease from the exposures. The data has been collected by the NASA contractors Computer Sciences Corporation (CSC) and Wyle Laboratories. The personal exposure samples were collected from devices worn by laborers working at JSC and by building occupants located in asbestos-containing buildings.

  2. Pesticide Exposure in Children

    Science.gov (United States)

    Roberts, James R.; Karr, Catherine J.

    2018-01-01

    outcomes including physical birth defects, low birth weight, and fetal death, although the data are less robust than for cancer and neurodevelopmental effects. Children’s exposures to pesticides should be limited as much as possible. PMID:23184105

  3. Exposure Prophylaxis

    African Journals Online (AJOL)

    opsig

    health care workers who report exposure to HIV at work whether given PEP or not ... breast milk, amniotic fluid, cerebrospinal fluid, pericardial fluid ... or skin lesions [1]. Other body fluid like sweat, tears, saliva, urine and stool do not contain significant quantities of HIV unless there is blood mixed with them[1,2]. HIV is not ...

  4. Compliance with public dose limits

    International Nuclear Information System (INIS)

    Mason, G.C.

    1991-01-01

    Radiation, in various forms, is ubiquitous in the environment. Natural background radiation leads to an average radiation exposure for the general population of about 2 mSv per year. The mining and milling of radioactive ores - uranium and mineral sands - may cause a small increase in radiation exposure for some members of the public. Because any such increment in exposure is small compared with a natural exposure that is variable and difficult to quantify accurately, it is not easy to determine what proportion of the total dose received by a member of the public can be attributed to mining and milling activities. Consequently, because public dose limits apply and to those doses caused by human activity, such as mining and milling, the task of demonstrating compliance can be hampered by uncertainty. Some strategies for handling this situation are discussed. While the discussion concentrates on public dose limits, much of it may also be applicable, or adaptable, to occupational exposure. 4 refs., 2 figs

  5. Exposures series

    OpenAIRE

    Stimson, Blake

    2011-01-01

    Reaktion Books’ Exposures series, edited by Peter Hamilton and Mark Haworth-Booth, is comprised of 13 volumes and counting, each less than 200 pages with 80 high-quality illustrations in color and black and white. Currently available titles include Photography and Australia, Photography and Spirit, Photography and Cinema, Photography and Literature, Photography and Flight, Photography and Egypt, Photography and Science, Photography and Africa, Photography and Italy, Photography and the USA, P...

  6. Measuring exposure to organochlorinated pesticides

    Directory of Open Access Journals (Sweden)

    Gulnar Azevedo e Silva Mendonça

    1998-01-01

    Full Text Available Environmental epidemiological investigations in cancer remain, with rare exceptions, inconclusive. The difficulties of establishing patterns of measurements of exposure in the human body is one of the limitations of these studies. The findings of six recent epidemiological studies that analyzed the association between organochlorinated compounds and breast cancer are reviewed in considering the problems of measuring environmental exposure through biological markers. The epidemiological evidence based on these studies do not indicate a risk of breast cancer related to organochlorines. Some aspects that may partially explain this absence of risk are discussed regarding the investigation of environmental carcinogenic agents in populations with low but homogeneously sprayed levels of exposure.

  7. Past exposure

    International Nuclear Information System (INIS)

    Dropkin, G.; Clark, D.

    1992-01-01

    Past Exposure uses confidential company documents, obtained by the Namibia Support Committee over several years, to draw attention to risks to workers' health and the environment at Roessing Uranium mine. Particular reference is made to discussion of dust levels, radiation hazards, uranium poisoning, environmental leaks, especially from the tailings dam, and the lack of monitoring of thorium. In relation to agreements between trades unions and mines, agreements reached by RTZ-owned Canadian in Canada, and British Nuclear Fuels in the UK, are discussed. (UK)

  8. Medical exposure and the effects of radiation

    International Nuclear Information System (INIS)

    Okuyama, Chio

    2011-01-01

    Radiation gives cracks to genes. The influence is divided into deterministic effect with a threshold value, and the stochastic effect (tumor and genetic effect) which increases according to the exposure amount. Although we are put to various non-artificial radiations, which we cannot be avoided, on the earth, the contamination by artificial radiation can be defended. Artificial radioactive exposure includes medical exposure and non-medical exposure for example by nuclear power plant. As to medical examinations using radiation, the inquiry about the radiation exposure is increasing after the occurrence of the first nuclear power plant disaster of Fukushima. While concern about non-medical radioactive exposure increases, the uneasiness to medical irradiation is also increasing. The dose limit by artificial radioactive exposure other than medical exposure is set up in order to prevent the influence on the health. While the dose limit of the public exposure is set to the lower value than the total dose of non-artificial exposure concerning of a safety margin for all people, the dose limit of medical exposure is not defined, since it is thought that medical irradiation has a benefit for those who receive irradiation. Making an effort to decrease the radiation dose in performing the best medical treatment is the responsibility with which we are burdened. (author)

  9. Environmental radiation standards and risk limitation

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1987-01-01

    The Environmental Protection Agency and Nuclear Regulatory Commission have established environmental radiation standards for specific practices which correspond to limits on risk to the public that vary by several orders of magnitude and often are much less than radiation risks that are essentially unregulated, e.g., risks from radon in homes. This paper discusses a proposed framework for environmental radiation standards that would improve the correspondence with limitation of risk. This framework includes the use of limits on annual effective dose equivalent averaged over a lifetime, rather than limits on dose equivalent to whole body or any organ for each year of exposure, and consideration of exposures of younger age groups as well as adults; limits on annual effective dose equivalent averaged over a lifetime no lower than 0.25 mSv (25 mrem) per practice; maintenance of all exposures as low as reasonably achievable (ALARA); and establishment of a generally applicable de minimis dose for public exposures. Implications of the proposed regulatory framework for the current system of standards for limiting public exposures are discussed. 20 refs

  10. A critical review of biomarkers used for monitoring human exposure to lead: advantages, limitations and future needs Uma avaliação crítica sobre biomarcadores utilizados para o monitoramento biológico de exposição ao chumbo: vantagens, limitações e perspectivas futuras

    Directory of Open Access Journals (Sweden)

    Fernando Barbosa Jr

    2006-03-01

    Full Text Available Lead concentration in whole blood (Blood-Pb is the primary biomarker used to monitor exposure to this metallic element. However, the difficulty in assessing the exact nature of Pb exposure is dependent not so much on problems with current analytical methodologies, but rather on the complex toxicokinetics of Pb within various body compartments. If we are to differentiate more effectively between Pb that is stored in the body for years and Pb from recent exposure, information on other biomarkers of exposure may be needed. None of the current biomarkers of internal Pb dose has yet been accepted by the scientific community as a reliable substitute for a Blood-Pb measurement. This review focuses on the limitations of biomarkers of Pb exposure, and the need to improve the accuracy of their measurement. We present here only the traditional analytical protocols in current use and we attempt to assess the influence of confounding variables on Blood-Pb levels. Finally, we discuss the interpretation of Blood-Pb data with respect to both external and endogenous Pb exposure, past or recent exposure, as well as the significance of lead determinations in human specimens including hair, nails, saliva, bone, blood, urine, feces, and exfoliated teeth.A concentração de chumbo (Pb no sangue total (Pb-B vem sendo comumente utilizada para monitorar a exposição a este elemento químico. Entretanto, a dificuldade em avaliar a natureza exata da exposição ao Pb é dependente não só de problemas inerentes a metodologias analíticas inapropriadas, bem como da toxicocinética complexa do Pb em compartimentos de nosso corpo. Se quisermos diferenciar mais efetivamente entre o Pb que está estocado no corpo por anos daquele proveniente de uma exposição recente, deverão ser obtidas informações pela análise de outros biomarcadores de exposição. Entretanto, nenhum dos biomarcadores de dose interna para Pb é aceito pela comunidade científica como substituto ao Pb

  11. DOE 2010 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-11-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The DOE 2010 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  12. DOE 2012 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-10-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site.

  13. DOE 2011 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-12-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2011 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past five years.

  14. Effects after prenatal radiation exposures

    International Nuclear Information System (INIS)

    Streffer, C.

    2001-01-01

    The mammalian organism is highly radiosensitive during all prenatal developmental periods. For most effects a dose relationship with a threshold is observed. These threshold doses are generally above the exposures from medical diagnostic procedures. The quality and extent of radiation effects are very much dependent on the developmental stage during which an exposure takes place and on the radiation dose. An exposure during the preimplantation period will cause lethality. Malformations are usually induced after exposures during the major organogenesis. Growth retardation is also possible during the late organogenesis and foetal periods. The lower limits of threshold doses for these effects are in the range of 100 mGy. A radiation exposure during the early foetal period can lead to severe mental retardation and impairment of intelligence. There are very serious effects with radiation doses above 0.3 Gy. Carcinogenesis can apparently occur after radiation exposures during the total prenatal development period. The radiation risk factor up to now has not been clear, but it seems that it is in the range of risk factors for cancer that are observed after exposures during childhood. For radiation doses that are used in radiological diagnostics the risk is zero or very low. A termination of pregnancy after doses below 100 mGy should not be considered. (author)

  15. Mercury Report-Children's exposure to elemental mercury

    Science.gov (United States)

    ... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

  16. Derived limits for surface contamination

    CERN Document Server

    Wrixon, A D; Linsley, G S; White, D F

    1979-01-01

    Derived limits (DLs) for surface contamination were first established for use in the nuclear energy industry where a wide variety of radionuclides is encountered. They were later used in factories, hospitals, and universities, where the radionuclides used are normally fewer in number, either known or readily identifiable, and often of low toxicity. In these situations the current limits are frequently over-restrictive. This report describes a reassessment of the values in the light of more recent information on the possible pathways of exposure and the dose equivalent limits given in ICRP Publication 26. The reassessment is prompted also by the introduction of SI units. The results of the reassessment are used to produce a classification of DLs for all radionuclides for active and inactive area surfaces and for skin.

  17. Effluent release limits, sources and control

    International Nuclear Information System (INIS)

    Swindell, G.E.

    1977-01-01

    Objectives of radiation protection in relation to releases. Environmental transfer models for radionuclides. Relationship between releases, environmental levels and doses to persons. Establishment of release limits: Limits based on critical population group concept critical pathway analysis and identification of critical group. Limits based on optimization of radiation protection individual dose limits, collective doses and dose commitments 1) differential cost benefit analysis 2) authorized and operational limits taking account of future exposures. Monitoring of releases to the environment: Objectives of effluent monitoring. Typical sources and composition of effluents; design and operation of monitoring programmes; recording and reporting of monitoring results; complementary environmental monitoring. (orig.) [de

  18. Application of human volunteer studies in setting exposure limits

    International Nuclear Information System (INIS)

    Bailey, M.R.

    1989-01-01

    Human volunteer studies can provide many of the quantitative data on human radionuclide biokinetics needed to relate organ doses to intakes. They are best suited to characterising parameters that apply to a wide range of compounds, e.g. particle deposition in the respiratory tract, and the retention and excretion of elements after injection into the blood. Their application to quantifying particle clearance from the respiratory tract is discussed, with particular reference to recent findings and the NRPB's programme of volunteer investigations. Evidence to support the view that particle clearance rates are similar for different materials is summarised. Rates of particle clearance from the human lung to the GI tract are calculated from the results of two recent studies. The fraction of the remaining lung content cleared per day is estimated to decrease from ∼ 3 x 10 -3 d -1 at 25 days to ∼ 5 x 10 -4 d -1 at 350 days. There is a large degree of inter-subject variation, with most results conforming to a log-normal distribution with σ g of 1.6. There remains considerable uncertainty about subsequent clearance, and about sites of long-term lung retention. (author)

  19. Occupational Exposure Limits and classification of 25 carcinogens

    NARCIS (Netherlands)

    van Kesteren PCE; Palmen NGM; Dekkers S; SIR; vgc

    2012-01-01

    Grenswaarden voor beroepsmatige blootstelling aan stoffen helpen de blootstelling aan gevaarlijke stoffen op de werkplek te beheersen door de maximale concentratie van een stof (in de lucht) vast te stellen die nog veilig wordt geacht. Deze grenswaarden kunnen worden vastgelegd op Europees niveau,

  20. Limiting hazardous noise exposure from noisy toys: simple, sticky solutions.

    Science.gov (United States)

    Weinreich, Heather M; Jabbour, Noel; Levine, Samuel; Yueh, Bevan

    2013-09-01

    To assess noise levels of toys from the Sight & Hearing Association (SHA) 2010 Noisy Toys List and evaluate the change in noise of these toys after covering the speakers with tape or glue. One Group Pretest-Posttest Design. SHA 2010 Toys List (n = 18) toys were tested at distances of 0 and 25 cm from sound source in a soundproof booth using a digital sound-level meter. The dBA level of sound produced by toy was obtained. Toys with speakers (n = 16) were tested before and after altering speakers with plastic packing tape or nontoxic glue. Mean noise level for non-taped toys at 0 and 25 cm was 107.6 dBA (SD ± 8.5) and 82.5 dBA (SD ± 8.8), respectively. With tape, there was a statistically significant decrease in noise level at 0 and 25 cm: 84.2 dBA and 68.2 dBA (P toys. However, there was no significant difference between tape or glue. Overall, altering the toy can significantly decrease the sound a child may experience when playing with toys. However, some toys, even after altering, still produce sound levels that may be considered dangerous. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  1. Assessing landslide exposure in areas with limited landslide information

    NARCIS (Netherlands)

    Pellicani, R.; van Westen, C.J.; Spilotro, G.

    2014-01-01

    Landslide risk assessment is often a difficult task due to the lack of temporal data on landslides and triggering events (frequency), run-out distance, landslide magnitude and vulnerability. The probability of occurrence of landslides is often very difficult to predict, as well as the expected

  2. The historical development of radiation protection limits

    International Nuclear Information System (INIS)

    Schuettmann, W.

    1976-01-01

    The present internationally largely corresponding radiation protection limits are based on recommendations given by the ICRP in 1965. In order to better understand the underlying concepts, a historical sketch of the development is presented including actual discussions of trends to be excepted. Although exposure of healthy individuals by man-made sources up to these maximum levels is legally permissible, it should be emphasized again and again that any unavoidable exposure must be justified by the need for its associated cause. (author)

  3. Relevance of protection quantities in medical exposures

    International Nuclear Information System (INIS)

    Pradhan, A.S.

    2008-01-01

    International Commission on Radiological Protection (ICRP) continues to classify the exposures to radiation in three categories; namely 1- occupational exposure, 2- public exposure, and 3- medical exposure. Protection quantities are primarily meant for the regulatory purpose in radiological protection for controlling and limiting stochastic risks in occupational and public exposures. These are based on two basic assumptions of 1- linear no-threshold dose-effect relationship (LNT) at low doses and 2- long-term additivity of low doses. Medical exposure are predominantly delivered to individuals (patients) undergoing diagnostic examinations, interventional procedures and radiation therapy but also include individual caring for or comforting patients incurring exposure and the volunteers of biomedical medical research programmes. Radiation protection is as relevant to occupational and public exposure as to medical exposures except that the dose limits set for the formers are not applicable to medical exposure but reference levels and dose constrains are recommended for diagnostic and interventional medical procedures. In medical institutions, both the occupational and medical exposure takes place. Since the doses in diagnostic examinations are low, it has been observed that not only the protection quantities are often used in such cases but these are extended to estimate the number of cancer deaths due to such practices. One of the striking features of the new ICRP recommendations has been to elaborate the concepts of the dosimetric quantities. The limitation of protection quantities ((Effective dose, E=Σ RT D TR .W T .W R and Equivalent Dose H T =Σ RT D TR .W R ) have been brought out and this has raised a great concern and initiated debates on the use of these quantities in medical exposures. Consequently, ICRP has set a task group to provide more details and the recommendations. It has, therefore, became important to draw the attention of medical physics community

  4. Cadmium and children: Exposure and health effects.

    NARCIS (Netherlands)

    Schoeters, G.; Hond, E. Den; Zuurbier, M.; Naginiene, R.; Hazel, P.J. van den; Stilianakis, N.; Ronchetti, R.; Koppe, J.G.

    2006-01-01

    Cadmium exposure and accumulation in the body start at young age. Exposure routes in children are mainly via food, environmental tobacco smoke and house dust. Excretion from the body is limited. Cadmium accumulation in the kidney is responsible for effects such as nephrotoxicity and osteoporosis

  5. Scenarios identified internationally for occupational and public exposure to naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Lopez Bejarano, Gladys

    2012-01-01

    A study was conducted to determine the exposure of workers; exposure limits, and the delegation of responsibilities and special measures of compensation, protection and security. Likewise, monitoring, personal exposure assessments, externally and internally, are analyzed [es

  6. Partnerships – Limited partnerships and limited liability limited partnerships

    OpenAIRE

    Henning, Johan J.

    2000-01-01

    Consideration of the Limited Liability Partnership Act 2000 which introduced a new corporate entity, carrying the designations “partnership” and “limited” which allow members to limit their liability whilst organising themselves internally as a partnership. Article by Professor Johan Henning (Director of the Centre for Corporate Law and Practice, IALS and Dean of the Faculty of Law, University of the Free State, South Africa). Published in Amicus Curiae - Journal of the Institute of Advanced ...

  7. Radiation exposure during equine radiography

    International Nuclear Information System (INIS)

    Ackerman, N.; Spencer, C.P.; Hager, D.A.; Poulos, P.W. Jr.

    1988-01-01

    All personnel present in the X-ray examination room during equine radiography were monitored using low energy direct reading ionization chambers (pockets dosimeters) worn outside the lead apron at neck level. The individuals' task and dosimeter readings were recorded after each examination. Average doses ranged from 0 to 6 mrad per study. The greatest exposures were associated with radiography of the shoulder and averaged less than 4 mrad. The individual extending the horse's limb was at greatest risk although the individual holding the horse's halter and the one making the X-ray exposure received similar exposures. A survey of the overhead tube assembly used for some of the X-ray examinations also was performed. Meter readings obtained indicated an asymetric dose distribution around the tube assembly, with the highest dose occurring on the side to which the exposure cord was attached. Although the exposures observed were within acceptable limits for occupational workers, we have altered our protocol and no longer radiograph the equine shoulder unless the horse is anesthetized. Continued use of the pocket dosimeters and maintenance of a case record of radiation exposure appears to make the technologists more aware of radiation hazards

  8. The philosophy of dose limitation

    International Nuclear Information System (INIS)

    Recht, P.

    1981-01-01

    The evolution of concepts and terms appearing in the European Rules of 15 July 1980 is briefly described. After a period where ''tolerance doses'' represent definite limits which should be respected, appears the concept of a ''as low as possible'' and ''as low as practicable'' level. The hypothesis that any exposure represents a risk which should be avoided is taken into account in the later evolution. As a consequence one has to examine the advantages and disadvantages in other words to make a cost-benefit analysis. This evolution leads to the concepts of justification and optimization used at the present time. (author)

  9. HOME Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — HOME Income Limits are calculated using the same methodology that HUD uses for calculating the income limits for the Section 8 program. These limits are based on HUD...

  10. DOE Occupational Radiation Exposure, 2001 report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2001-12-31

    The goal of the U.S. Department of Energy (DOE) is to conduct its operations, including radiological, to ensure the safety and health of all DOE employees, contractors, and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures to levels that are “As Low As Reasonably Achievable” (ALARA). The 2001 DOE Occupational Radiation Exposure Report provides a summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE, and energy research.

  11. Indoor exposure to natural radiation in Denmark

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  12. Designing exposure registries for improved tracking of occupational exposure and disease.

    Science.gov (United States)

    Arrandale, Victoria H; Bornstein, Stephen; King, Andrew; Takaro, Timothy K; Demers, Paul A

    2016-06-27

    Registries are one strategy for collecting information on occupational exposure and disease in populations. Recently leaders in the Canadian occupational health and safety community have shown an interest in the use of occupational exposure registries. The primary goal of this study was to review a series of Canadian exposure registries to identify their strengths and weaknesses as a tool for tracking occupational exposure and disease in Canada. A secondary goal was to identify the features of an exposure registry needed to specifically contribute to prevention, including the identification of new exposure-disease relationships. A documentary review of five exposure registries from Canada was completed. Strengths and limitations of the registries were compared and key considerations for designing new registries were identified. The goals and structure of the exposure registries varied considerably. Most of the reviewed registries had voluntary registration, which presents challenges for the use of the data for either surveillance or epidemiology. It is recommended that eight key issues be addressed when planning new registries: clear registry goal(s), a definition of exposure, data to be collected (and how it will be used), whether enrolment will be mandatory, as well as ethical, privacy and logistical considerations. When well constructed, an exposure registry can be a valuable tool for surveillance, epidemiology and ultimately the prevention of occupational disease. However, exposure registries also have a number of actual and potential limitations that need to be considered.

  13. Problems associated with localised skin exposures

    International Nuclear Information System (INIS)

    Wells, J.

    1986-01-01

    The possible sources of localised skin exposure include small commercial sources (for radiotherapy, for example), radiopharmaceuticals, collimated microbeams, and both fission and activation products from nuclear reactors, neutron generators and associated facilities. Each of these sources has its own particular characteristics and associated problems. Recommendations and regulations relating to limits on skin dose for such exposures have been constrained by inadequate radiobiological data and the limitations inherent in personal dosimetric techniques. A growing body of data is now available for beta-emitters which allows a preliminary reassessment of some aspects of the currently recommended dose limits for localised skin exposures. How the skin dose is measured is particularly important for such exposures, as doses often have to be averaged over a specific area. The area chosen for dose measurement and the depth at which the measurement is made are crucial to understanding the possible biological consequences and for formulating appropriate protection criteria. (author)

  14. Limits on fundamental limits to computation.

    Science.gov (United States)

    Markov, Igor L

    2014-08-14

    An indispensable part of our personal and working lives, computing has also become essential to industries and governments. Steady improvements in computer hardware have been supported by periodic doubling of transistor densities in integrated circuits over the past fifty years. Such Moore scaling now requires ever-increasing efforts, stimulating research in alternative hardware and stirring controversy. To help evaluate emerging technologies and increase our understanding of integrated-circuit scaling, here I review fundamental limits to computation in the areas of manufacturing, energy, physical space, design and verification effort, and algorithms. To outline what is achievable in principle and in practice, I recapitulate how some limits were circumvented, and compare loose and tight limits. Engineering difficulties encountered by emerging technologies may indicate yet unknown limits.

  15. Limiting values for radioactive materials in food

    International Nuclear Information System (INIS)

    Steiner, Martin

    2014-01-01

    The contribution describes the fundamentals of radiation protection: LNT (linear, no threshold) hypotheses, ALARA (a slow as reasonably achievable), limiting values. Using the example the nuclear accident in Chernobyl the differences in contamination development in different foodstuffs in Germany is demonstrated including recommended limiting values and the radiation exposures after 30 years due to consumption of contaminated food. The natural radioactivity is about 0.3 mSv/year.

  16. Medium wave exposure characterisation using exposure quotients.

    Science.gov (United States)

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Pinar, Iván

    2010-06-01

    One of the aspects considered in the International Commission on Non-Ionizing Radiation Protection guidelines is that, in situations of simultaneous exposure to fields of different frequencies, exposure quotients for thermal and electrical stimulation effects should be examined. The aim of the present work was to analyse the electromagnetic radiation levels and exposure quotients for exposure to multiple-frequency sources in the vicinity of medium wave radio broadcasting antennas. The measurements were made with a spectrum analyser and a monopole antenna. Kriging interpolation was used to prepare contour maps and to estimate the levels in the towns and villages of the zone. The results showed that the exposure quotient criterion based on electrical stimulation effects to be more stringent than those based on thermal effects or power density levels. Improvement of dosimetry evaluations requires the spectral components of the radiation to be quantified, followed by application of the criteria for exposure to multiple-frequency sources.

  17. Personal exposure control system

    International Nuclear Information System (INIS)

    Tanabe, Ken-ichi; Akashi, Michio

    1994-01-01

    Nuclear power stations are under strict radiation control. Exposure control for nuclear workers is the most important operation, and so carefully thought out measures are taken. This paper introduces Fuji Electric's personal exposure control system that meets strict exposure control and rationalizes control operations. The system has a merit that it can provide required information in an optimum form using the interconnection of a super minicomputer and exposure control facilities and realizes sophisticated exposure control operations. (author)

  18. Prior Trauma Exposure for Youth in Treatment Foster Care

    Science.gov (United States)

    Dorsey, Shannon; Burns, Barbara J.; Southerland, Dannia G.; Cox, Julia Revillion; Wagner, H. Ryan; Farmer, Elizabeth M. Z.

    2012-01-01

    Very little research has focused on rates of trauma exposure for youth in treatment foster care (TFC). Available research has utilized record review for assessing exposure, which presents limitations for the range of trauma types examined, as records are predominantly focused on abuse and neglect. The current study examines exposure rates and…

  19. Noise Exposure Estimates of Urban MP3 Player Users

    Science.gov (United States)

    Levey, Sandra; Levey, Tania; Fligor, Brian J.

    2011-01-01

    Purpose: To examine the sound level and duration of use of personal listening devices (PLDs) by 189 college students, ages 18-53 years, as they entered a New York City college campus, to determine whether noise exposure from PLDs was in excess of recommended exposure limits and what factors might influence exposure. Method: Free-field equivalent…

  20. 1976 Hanford americium exposure incident: overview and perspective

    International Nuclear Information System (INIS)

    Thompson, R.C.

    1982-01-01

    Salient features of the 1976 Hanford americium exposure incident are discussed. Comparisons are made with previous human and animal exposure data, and conclusions drawn relative to the injured workman, to health physics practices, and to the adequacy of current exposure limits

  1. Ethical issues in medico-legal exposures

    International Nuclear Information System (INIS)

    O'Reilly, G.; Malone, J. F.

    2008-01-01

    The Medical Exposure Directive (MED) 97/43/Euratom defines medico-legal procedures as 'procedures performed for insurance or legal purposes without a medical indication'. The term 'medico-legal exposures' covers a wide range of possible types of exposures, very different in nature, for which the only feature in common is the fact that the main reason for performing them does not relate directly to the health of the individual being exposed to ionising radiation. The key issue in medico-legal exposures is justification. Balancing the advantages and disadvantages of such exposures is complex because not only can these be difficult to quantify and hence compare, but often the advantage may be to society whereas the disadvantage is usually to an individual. This adds an additional layer of ethical complexity to the problem and one, which requires input from a number of sources beyond the established radiation protection community. Because medico-legal exposures are considered to be medical exposures, they are not subject to dose limits. In medico-legal exposures where the benefit is not necessarily to the individual undergoing the exposure, the question must be asked as to whether or not this is an appropriate framework within which to conduct such exposures. This paper looks at the current situation in Europe, highlighting some of the particular problems that have arisen, and tries to identify the areas, which require further clarification and guidance. (authors)

  2. Use of dose constraints in medical exposure

    International Nuclear Information System (INIS)

    Mutanga, N. V. T.

    2013-04-01

    Medical-related radiation is the largest source of controllable radiation exposure to humans and it accounts for more than 95% of radiation exposure from man-made sources. Medical exposure to radiation is exposure incurred by patients as part of their own medical or dental diagnosis or treatment; by persons, other than those occupationally exposed, knowingly, while voluntarily helping in the support and comfort of patients; and by volunteers in a programme of biomedical research involving their exposure. Because it is planned exposure, medical exposure has to conform to a set of principles of protection that apply equally to all controllable exposure situations: the principle of justification, the principle of optimisation of protection, and the principle of application of limits on maximum doses in planned situations. In this study the concept of dose constraints is being scrutinized to see if it can be applied in medical exposures and the benefits of such restrictions. Dose constraints can only be applied to exposure to persons voluntary helping in the support and comfort of patients as well as volunteers in the programme of biomedical research. There are no dose constraints for patients but the concept of reference levels applies. (au)

  3. Radon exposures in the UK

    International Nuclear Information System (INIS)

    O'Riordan, M.C.

    1992-01-01

    Public and occupational health protection against radon is provided in the UK. Protection is advised where geological conditions cause high concentrations in domestic and commercial buildings. These circumstances are described and the resulting exposures reviewed. An account is given of the limitation scheme for radon in the home and the regulatory scheme for radon at work, the manner in which they are implemented, and the degree to which they are successful. (author)

  4. Occupational standard for exposure to ultraviolet radiation (1989)

    International Nuclear Information System (INIS)

    1989-12-01

    The exposure limit (EL) values in this standard refer to ultraviolet radiation (UVR) in the spectral region between 180 and 400 nm and represents conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect. The EL values for exposure of the eye or the skin may be used to evaluate potentially hazardous exposure from UVR. The limits do not apply to ultraviolet lasers. The values should be used as guides in the control of exposure to both pulsed and continuous sources of UVR where the exposure duration is not less than 0.1 μsec. The ELs are below levels used for UV exposures of patients as a part of medical treatment or for elective cosmetic purposes. They are intended as upper limits for non therapeutic and non cosmetic exposure. 2 refs., 2 tabs

  5. Approach to DOE threshold guidance limits

    International Nuclear Information System (INIS)

    Shuman, R.D.; Wickham, L.E.

    1984-01-01

    The need for less restrictive criteria governing disposal of extremely low-level radioactive waste has long been recognized. The Low-Level Waste Management Program has been directed by the Department of Energy (DOE) to aid in the development of a threshold guidance limit for DOE low-level waste facilities. Project objectives are concernd with the definition of a threshold limit dose and pathway analysis of radionuclide transport within selected exposure scenarios at DOE sites. Results of the pathway analysis will be used to determine waste radionuclide concentration guidelines that meet the defined threshold limit dose. Methods of measurement and verification of concentration limits round out the project's goals. Work on defining a threshold limit dose is nearing completion. Pathway analysis of sanitary landfill operations at the Savannah River Plant and the Idaho National Engineering Laboratory is in progress using the DOSTOMAN computer code. Concentration limit calculations and determination of implementation procedures shall follow completion of the pathways work. 4 references

  6. Robust test limits

    NARCIS (Netherlands)

    Albers, Willem/Wim; Kallenberg, W.C.M.; Otten, G.D.

    1997-01-01

    Because of inaccuracies of the measurement process inspection of manufactured parts requires test limits which are more strict than the given specification limits. Test limits derived under the assumption of normality for product characteristics turn out to violate the prescribed bound on the

  7. Head and neck cancer due to heavy metal exposure via tobacco smoking and professional exposure: A review

    International Nuclear Information System (INIS)

    Khlifi, Rim; Hamza-Chaffai, Amel

    2010-01-01

    Chronic exposures to heavy metals via tobacco smoking and professional exposure may increase the risk of head and neck cancer, although the epidemiologic evidence is limited by problems of low study power and inadequate adjustment for tobacco and professional exposure use. Numerous scientific reviews have examined the association of various heavy metals exposure with respiratory cancer as well as other cancer types, but few have been published on head and neck cancer. The purpose of this paper, therefore, is to review the head and neck tract cancer-related data on exposure to heavy metals via smoking and working exposure and to study the major mechanisms underlying some toxic metals carcinogenesis.

  8. LANSCE beam current limiter

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1996-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

  9. Human Exposure Assessment for Air Pollution.

    Science.gov (United States)

    Han, Bin; Hu, Li-Wen; Bai, Zhipeng

    2017-01-01

    Assessment of human exposure to air pollution is a fundamental part of the more general process of health risk assessment. The measurement methods for exposure assessment now include personal exposure monitoring, indoor-outdoor sampling, mobile monitoring, and exposure assessment modeling (such as proximity models, interpolation model, air dispersion models, and land-use regression (LUR) models). Among these methods, personal exposure measurement is considered to be the most accurate method of pollutant exposure assessment until now, since it can better quantify observed differences and better reflect exposure among smaller groups of people at ground level. And since the great differences of geographical environment, source distribution, pollution characteristics, economic conditions, and living habits, there is a wide range of differences between indoor, outdoor, and individual air pollution exposure in different regions of China. In general, the indoor particles in most Chinese families comprise infiltrated outdoor particles, particles generated indoors, and a few secondary organic aerosol particles, and in most cases, outdoor particle pollution concentrations are a major contributor to indoor concentrations in China. Furthermore, since the time, energy, and expense are limited, it is difficult to measure the concentration of pollutants for each individual. In recent years, obtaining the concentration of air pollutants by using a variety of exposure assessment models is becoming a main method which could solve the problem of the increasing number of individuals in epidemiology studies.

  10. Application of maximum radiation exposure values and monitoring of radiation exposure

    International Nuclear Information System (INIS)

    1993-01-01

    According to the Section 32 of the Radiation Act (592/91) the Finnish Centre for Radiation and Nuclear Safety gives instructions concerning the monitoring of the radiation exposure and the application of the dose limits in Finland. The principles to be applied to calculating the equivalent and the effective doses are presented in the guide. Also the detailed instructions on the application of the maximum exposure values for the radiation work and for the natural radiation as well as the instructions on the monitoring of the exposures are given. Quantities and units for assessing radiation exposure are presented in the appendix of the guide

  11. Dioxin Exposure Initiative

    Science.gov (United States)

    The Dioxin Exposure Initiative (DEI) is no longer active. This page contains a summary of the dioxin exposure initiative with illustrations, contact and background information.Originally supported by scientist Matthew Lorber, who retired in Mar 2017.

  12. Exposure scenarios for workers

    NARCIS (Netherlands)

    Marquart, H.; Northage, C.; Money, C.

    2007-01-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate

  13. Tetrachloroethylene exposure and bladder cancer risk

    DEFF Research Database (Denmark)

    Vlaanderen, Jelle; Straif, Kurt; Ruder, Avima

    2014-01-01

    BACKGROUND: In 2012, the International Agency for Research on Cancer classified tetrachloroethylene, used in the production of chemicals and the primary solvent used in dry cleaning, as "probably carcinogenic to humans" based on limited evidence of an increased risk of bladder cancer in dry...... cleaners. OBJECTIVES: We assessed the epidemiological evidence for the association between tetrachloroethylene exposure and bladder cancer from published studies estimating occupational exposure to tetrachloroethylene or in workers in the dry-cleaning industry. METHODS: Random-effects meta-analyses were...... carried out separately for occupational exposure to tetrachloroethylene and employment as a dry cleaner. We qualitatively summarized exposure-response data because of the limited number of studies available. RESULTS: The meta-relative risk (mRR) among tetrachloroethylene-exposed workers was 1.08 (95% CI...

  14. Virtual reality exposure therapy

    OpenAIRE

    Rothbaum, BO; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

  15. Occupational exposures. Annex H

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex focuses on significant changes in the pattern of occupational exposure which have appeared since the 1972 and 1962 reports, and presents information on trends or particular causes of high exposures. A further objective is to clarify the reasons for which the Committee requires data on occupational exposure, and to suggest areas in which better data collection or analysis may be performed. Data are also reviewed on accidents involving the exposure of workers to substantial radiation doses.

  16. A Technique: Exposure Therapy

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-07-01

    Full Text Available Introduction: Exposure with response prevention is an effective treatment for all anxiety disorders. According to the behavioral learning theories, fears which are conditioned via classical conditioning are reinforced by respondent conditioning. Avoidance and safety seeking behaviors prevent disconfirmation of anxious beliefs. In exposure client faces stimulates or cues that elicit fear or distress, by this avoidance is inhibited. Clients are also encouraged to resists performing safety seeking behaviors or rituals that they utilize to reduce fear or distress. Accomplishing these habituation or extinction is achieved. In addition to this clients learn that feared consequences does not realize or not harmful as they believed by experiencing. Emotional processing is believed to be the mechanism of change in exposure.Objective: The aim of this review is to provide a definition of exposure and its effectiveness briefly, and describe how to implement exposure, its steps and remarkable aspects using. Exposure therapies and treatments that involve exposure are proved to be effective in all anxiety disorders. Exposure therapy can be divided in three parts: Assessment and providing a treatment rationale, creating an exposure hierarchy and response prevention plan, implementing exposure sessions. Clients must also continue to perform exposure between sessions. Therapy transcripts are also provided to exemplify these parts. Conclusion: Exposure with response prevention is a basic and effective technique. Every cognitive behavior therapist must be able to implement this technique and be cognizant of pearls of this procedure.

  17. Radiation exposure records management

    International Nuclear Information System (INIS)

    Boiter, H.P.

    1975-12-01

    Management of individual radiation exposure records begins at employment with the accumulation of data pertinent to the individual and any previous occupational radiation exposure. Appropriate radiation monitorinng badges or devices are issued and accountability established. A computer master file is initiated to include the individual's name, payroll number, social security number, birth date, assigned department, and location. From this base, a radiation exposure history is accumulated to include external ionizing radiation exposure to skin and whole body, contributing neutron exposure, contributing tritium exposure, and extremity exposure. It is used also to schedule bioassay sampling and in-vivo counts and to provide other pertinent information. The file is used as a basis for providing periodic reports to management and monthly exposure summaries to departmental line supervision to assist in planning work so that individual annual exposures are kept as low as practical. Radiation exposure records management also includes documentation of radiation surveys performed by the health physicist to establish working rates and the individual estimating and recording his estimated exposure on a day-to-day basis. Exposure information is also available to contribute to Energy Research and Development Administration statistics and to the National Transuranium Registry

  18. Assessment of human exposures

    Energy Technology Data Exchange (ETDEWEB)

    Lebret, E [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

    1996-12-31

    This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

  19. Assessment of human exposures

    Energy Technology Data Exchange (ETDEWEB)

    Lebret, E. [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

    1995-12-31

    This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

  20. 7 CFR 1400.204 - Limited partnerships, limited liability partnerships, limited liability companies, corporations...

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Limited partnerships, limited liability partnerships..., limited liability partnerships, limited liability companies, corporations, and other similar legal entities. (a) A limited partnership, limited liability partnership, limited liability company, corporation...

  1. DOE 2013 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-11-01

    The Office of Analysis within the U.S. Department of Energy (DOE) Office of Environment, Health, Safety and Security (EHSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2013 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past five-year period, the occupational radiation exposure information has been analyzed in terms of aggregate data, dose to individuals, and dose by site.

  2. Techniques for controlling radiation exposure

    International Nuclear Information System (INIS)

    Ocken, H.; Wood, C.J.

    1993-01-01

    The US nuclear power industry has been remarkably successful in reducing worker radiation exposure over the past 10 years. There has been more than a fourfold reduction in person-rem per MW-year of electric power generated: from 1.8 person-rems in 1980 to only 0.4 person-rems in 1991. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in the 1990 Recommendations of the International Commission on Radiological Protection, ICRP Publication 60, and there will be more requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the 1995 industry goals for unit median collective exposure. No one method will suffice, but implementing suitable combinations from this compendium will help utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: Outages are shorter, staffing requirements are reduced, and work quality is improved. Despite up-front costs, the benefits over the following one to three years typically outweigh the expenses

  3. JET pump limiter

    International Nuclear Information System (INIS)

    Sonnenberg, K.; Deksnis, E.; Shaw, R.; Reiter, D.

    1988-01-01

    JET plans to install two pump limiter modules which can be used for belt-limiter, inner-wall and X-point discharges and, also, for 1-2s as the main limiter. A design is presented which is compatible with two diagnostic systems, and which allows partial removal of the pump limiter to provide access for remote-handling operations. The high heat-flux components are initially cooled during a pulse. Heat is removed between discharges by radiation and pressure contacts to a water-cooled support structure. The pumping edge will be made of annealed pyrolytic graphite. Exhaust efficiency has been estimated, for a 1-d edge model, using a Monte-Carlo calculation of neutral gas transport. When the pump limiter is operated together with other wall components we expect an efficiency of ≅ 5% (2.5 x 10 21 part/s). As a main limiter the efficiency increases to about 10%. (author)

  4. Aircrew radiation exposure assessment for Yugoslav airlines

    Energy Technology Data Exchange (ETDEWEB)

    Antic, Dragoljub [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Petrovic, Zika [Yugoslav Airlines, JAT, Bulevar umetnosti 16, 11001 Belgrade (Yugoslavia)

    1997-12-31

    The presented study shows that the crews of the intercontinental flights can receive significant annual effective doses (1.5-2.0 mSv). The exposure of the crews is comparable with natural radiation level on the ground level (it can be up to 5 times higher for some air crew members in the intercontinental flights), but smaller than maximum permissible dose for general population. The annual exposures of the passengers are generally smaller than the exposures of tile air crews. because the passengers have a limited number of flights per year compared with the members of the air-crews. (author).

  5. Reactor limit control system

    International Nuclear Information System (INIS)

    Rubbel, F.E.

    1982-01-01

    The very extensive use of limitations in the operational field between protection system and closed-loop controls is an important feature of German understanding of operational safety. The design of limitations is based on very large activities in the computational field but mostly on the high level of the plant-wide own commissioning experience of a turnkey contractor. Limitations combine intelligence features of closed-loop controls with the high availability of protection systems. (orig.)

  6. Detector limitations, STAR

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, D. G.

    1998-07-13

    Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

  7. Performance limitations at ISABELLE

    International Nuclear Information System (INIS)

    Keil, E.

    1975-01-01

    The transverse stability of coasting beams in the planned ISABELLE storage rings was studied. The beam--beam tune shift limitation at 0.005 can be avoided, and a computer simulation seems to show 0.005 is a pessimistic limit. For beams of reasonable smoothness on the edge, the actual limit should be somewhat higher. Some coupling effects due to the beam--beam interaction are also examined

  8. Limit loads in nozzles

    International Nuclear Information System (INIS)

    Zouain, N.

    1983-01-01

    The static method for the evaluation of the limit loads of a perfectly elasto-plastic structure is presented. Using the static theorem of Limit Analysis and the Finite Element Method, a lower bound for the colapso load can be obtained through a linear programming problem. This formulation if then applied to symmetrically loaded shells of revolution and some numerical results of limit loads in nozzles are also presented. (Author) [pt

  9. Limit analysis via creep

    International Nuclear Information System (INIS)

    Taroco, E.; Feijoo, R.A.

    1981-07-01

    In this paper it is presented a variational method for the limit analysis of an ideal plastic solid. This method has been denominated as Modified Secundary Creep and enables to find the collapse loads through a minimization of a functional and a limit process. Given an ideal plastic material it is shown how to determinate the associated secundary creep constitutive equation. Finally, as an application, it is found the limit load in an pressurized von Mises rigid plastic sphere. (Author) [pt

  10. OCCUPATIONAL EXPOSURE AND COPD

    DEFF Research Database (Denmark)

    Würtz, Else Toft

    Chronic Obstructive Pulmonary Disease (COPD) is a common disease. The main risk factor is smoking although 15% of the COPD cases are expected to be preventable if the occupational exposures from vapour, gas, dust, and fume were eliminated; the population attributable fraction (PAF). The thesis...... addresses the association between occupational exposure and COPD in a population-based cohort of Danes aged 45-84-years. 4717 participants were included at baseline and 2624 at the four year follow-up. COPD was defined by spirometry and the occupational exposure was based on specialist defined jobs...... and questionnaires. The main occupational exposure was organic dust and 49% reported no lifetime occupational exposure. The results suggest occupational exposures to be associated to COPD also in never smokers and women. We found an exposure-response relation in the cross sectional analyses. The results...

  11. Internal emitter limits for iodine, radium and radon daughters

    Energy Technology Data Exchange (ETDEWEB)

    Schlenker, R.A.

    1984-08-15

    This paper identifies some of the issues which arise in the consideration of the derivation of new limits on exposure to internal emitters. Basic and secondary radiation protection limits are discussed. Terms are defined and applied to the limitation of risk from stochastic effects. Non-stochastic data for specific internal emitters (/sup 131/I and the radium isotopes) are presented. Emphasis is placed on the quantitative aspects of the limit setting problem. 65 references, 2 figures, 12 tables.

  12. Internal emitter limits for iodine, radium and radon daughters

    International Nuclear Information System (INIS)

    Schlenker, R.A.

    1984-01-01

    This paper identifies some of the issues which arise in the consideration of the derivation of new limits on exposure to internal emitters. Basic and secondary radiation protection limits are discussed. Terms are defined and applied to the limitation of risk from stochastic effects. Non-stochastic data for specific internal emitters ( 131 I and the radium isotopes) are presented. Emphasis is placed on the quantitative aspects of the limit setting problem. 65 references, 2 figures, 12 tables

  13. Numerical Limit Analysis:

    DEFF Research Database (Denmark)

    Damkilde, Lars

    2007-01-01

    Limit State analysis has a long history and many prominent researchers have contributed. The theoretical foundation is based on the upper- and lower-bound theorems which give a very comprehensive and elegant formulation on complicated physical problems. In the pre-computer age Limit State analysis...... also enabled engineers to solve practical problems within reinforced concrete, steel structures and geotechnics....

  14. Advanced limiters for ISX

    International Nuclear Information System (INIS)

    Mioduszewski, P.K.; Edmonds, P.H.; Sheffield, J.

    1982-01-01

    Continuous removal of heat and particles becomes a vital necessity in future steady-state fusion devices. The pump limiter seems to be an attractive concept to combine these two tasks. On ISX, various schemes of pump limiters are being explored with the final goal to furnish the ISX--C device with a pump limiter to handle heat removal and particle control in steady state. The emphasis of the present paper is on pump limiters based on ballistic particle collection. If this concept turns out to be successful in supplying sufficient pumping efficiency, it may be possible to design pump limiters without a leading edge. Analytical calculations of the particle collection efficiency are given for various limiter configurations. Pumping efficiencies of approximately 4--10%, depending on the specific configuration, seem to be feasible and should be sufficient for steady-state operation. Initial experimental results on pump limiter studies in ISX--B confirm the calculated collection efficiencies. By measuring the ion saturation current to the limiter blade and the pressure buildup simultaneously, we found a correlation between the incident particle flux and the pressure rise that agrees well with a simple model

  15. Limits to Inclusion

    Science.gov (United States)

    Hansen, Janne Hedegaard

    2012-01-01

    In this article, I will argue that a theoretical identification of the limit to inclusion is needed in the conceptual identification of inclusion. On the one hand, inclusion is formulated as a vision that is, in principle, limitless. On the other hand, there seems to be an agreement that inclusion has a limit in the pedagogical practice. However,…

  16. Mitigating greenhouse: Limited time, limited options

    International Nuclear Information System (INIS)

    Moriarty, Patrick; Honnery, Damon

    2008-01-01

    Most human-caused climate change comes from fossil fuel combustion emissions. To avoid the risk of serious climate change, very recent research suggests that emission reductions will need to be both large and rapidly implemented. We argue that technical solutions-improving energy efficiency, use of renewable and nuclear energy, and carbon capture and sequestration-can only be of minor importance, mainly given the limited time available to take effective climate action. Only curbing energy use, perhaps through 'social efficiency' gains, particularly in the high-energy consumption countries, can provide the rapid emissions reductions needed. The social efficiency approach requires a basic rethinking in how we can satisfy our human needs with low environmental impacts. Large cuts in emissions could then occur rapidly, but only if resistance to such changes can be overcome. Particularly in transport, there are also serious potential conflicts between the technical and the social efficiency approaches, requiring a choice to be made

  17. Modeling Complex Time Limits

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2013-01-01

    Full Text Available In this paper we analyze complexity of time limits we can find especially in regulated processes of public administration. First we review the most popular process modeling languages. There is defined an example scenario based on the current Czech legislature which is then captured in discussed process modeling languages. Analysis shows that the contemporary process modeling languages support capturing of the time limit only partially. This causes troubles to analysts and unnecessary complexity of the models. Upon unsatisfying results of the contemporary process modeling languages we analyze the complexity of the time limits in greater detail and outline lifecycles of a time limit using the multiple dynamic generalizations pattern. As an alternative to the popular process modeling languages there is presented PSD process modeling language, which supports the defined lifecycles of a time limit natively and therefore allows keeping the models simple and easy to understand.

  18. Moving toroidal limiter

    International Nuclear Information System (INIS)

    Ikuta, Kazunari; Miyahara, Akira.

    1983-06-01

    The concept of the limiter-divertor proposed by Mirnov is extended to a toroidal limiter-divertor (which we call moving toroidal limiter) using the stream of ferromagnetic balls coated with a low Z materials such as plastics, graphite and ceramics. An important advantage of the use of the ferromagnetic materials would be possible soft landing of the balls on a catcher, provided that the temperature of the balls is below Curie point. Moreover, moving toroidal limiter would work as a protector of the first wall not only against the vertical movement of plasma ring but also against the violent inward motion driven by major disruption because the orbit of the ball in the case of moving toroidal limiter distributes over the small major radius side of the toroidal plasma. (author)

  19. Epidemic gasoline exposures following Hurricane Sandy.

    Science.gov (United States)

    Kim, Hong K; Takematsu, Mai; Biary, Rana; Williams, Nicholas; Hoffman, Robert S; Smith, Silas W

    2013-12-01

    Major adverse climatic events (MACEs) in heavily-populated areas can inflict severe damage to infrastructure, disrupting essential municipal and commercial services. Compromised health care delivery systems and limited utilities such as electricity, heating, potable water, sanitation, and housing, place populations in disaster areas at risk of toxic exposures. Hurricane Sandy made landfall on October 29, 2012 and caused severe infrastructure damage in heavily-populated areas. The prolonged electrical outage and damage to oil refineries caused a gasoline shortage and rationing unseen in the USA since the 1970s. This study explored gasoline exposures and clinical outcomes in the aftermath of Hurricane Sandy. Prospectively collected, regional poison control center (PCC) data regarding gasoline exposure cases from October 29, 2012 (hurricane landfall) through November 28, 2012 were reviewed and compared to the previous four years. The trends of gasoline exposures, exposure type, severity of clinical outcome, and hospital referral rates were assessed. Two-hundred and eighty-three gasoline exposures were identified, representing an 18 to 283-fold increase over the previous four years. The leading exposure route was siphoning (53.4%). Men comprised 83.0% of exposures; 91.9% were older than 20 years of age. Of 273 home-based calls, 88.7% were managed on site. Asymptomatic exposures occurred in 61.5% of the cases. However, minor and moderate toxic effects occurred in 12.4% and 3.5% of cases, respectively. Gastrointestinal (24.4%) and pulmonary (8.4%) symptoms predominated. No major outcomes or deaths were reported. Hurricane Sandy significantly increased gasoline exposures. While the majority of exposures were managed at home with minimum clinical toxicity, some patients experienced more severe symptoms. Disaster plans should incorporate public health messaging and regional PCCs for public health promotion and toxicological surveillance.

  20. Task-based dermal exposure models for regulatory risk assessment.

    Science.gov (United States)

    Warren, Nicholas D; Marquart, Hans; Christopher, Yvette; Laitinen, Juha; VAN Hemmen, Joop J

    2006-07-01

    The regulatory risk assessment of chemicals requires the estimation of occupational dermal exposure. Until recently, the models used were either based on limited data or were specific to a particular class of chemical or application. The EU project RISKOFDERM has gathered a considerable number of new measurements of dermal exposure together with detailed contextual information. This article describes the development of a set of generic task-based models capable of predicting potential dermal exposure to both solids and liquids in a wide range of situations. To facilitate modelling of the wide variety of dermal exposure situations six separate models were made for groupings of exposure scenarios called Dermal Exposure Operation units (DEO units). These task-based groupings cluster exposure scenarios with regard to the expected routes of dermal exposure and the expected influence of exposure determinants. Within these groupings linear mixed effect models were used to estimate the influence of various exposure determinants and to estimate components of variance. The models predict median potential dermal exposure rates for the hands and the rest of the body from the values of relevant exposure determinants. These rates are expressed as mg or microl product per minute. Using these median potential dermal exposure rates and an accompanying geometric standard deviation allows a range of exposure percentiles to be calculated.

  1. From fundamental limits to radioprotection practice

    International Nuclear Information System (INIS)

    Henry, P.; Chassany, J.

    1980-01-01

    The individual dose limits fixed by present French legislation for different categories of people refer to dose equivalents received by or delivered to the whole body or to certain tissues or organs over given periods of time. The values concerning personnel engaged directly in work under radiations are summed up in a table. These are the limits which radioprotection authorities must impose, while ensuring that exposure levels are kept as low as possible. With the means available in practical radioprotection it is not possible to measure dose equivalents directly, but information may be obtained on dose rates, absorbed doses, particle fluxes, activities per unit volume and per surface area. An interpretation of these measurements is necessary if an efficient supervision of worker exposure is to be achieved [fr

  2. Tokamak pump limiters

    International Nuclear Information System (INIS)

    Conn, R.W.

    1984-05-01

    Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6MW of auxiliary neutral beam heating. Experiments have also been done with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a region may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this Z-mode of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described

  3. Tokamak pump limiters

    International Nuclear Information System (INIS)

    Conn, R.W.; California Univ., Los Angeles

    1984-01-01

    Recent experiments with a scoop limiter without active internal pumping have been carried out in the PDX tokamak with up to 6 MW of auxiliary neutral beam heating. Experiments have also been performed with a rotating head pump limiter in the PLT tokamak in conjunction with RF plasma heating. Extensive experiments have been done in the ISX-B tokamak and first experiments have been completed with the ALT-I limiter in TEXTOR. The pump limiter modules in these latter two machines have internal getter pumping. Experiments in ISX-B are with ohmic and auxiliary neutral beam heating. The results in ISX-B and TEXTOR show that active density control and particle removal is achieved with pump limiters. In ISX-B, the boundary layer (or scrape-off layer) plasma partially screens the core plasma from gas injection. In both ISX-B and TEXTOR, the pressure internal to the module scales linearly with plasma density but in ISX-B, with neutral beam injection, a nonlinear increase is observed at the highest densities studied. Plasma plugging is the suspected cause. Results from PDX suggest that a regime may exist in which core plasma energy confinement improves using a pump limiter during neutral beam injection. Asymmetric radial profiles and an increased edge electron temperature are observed in discharges with improved confinement. The injection of small amounts of neon into ISX-B has more clearly shown an improved electron core energy confinement during neutral beam injection. While carried out with a regular limiter, this 'Z-mode' of operation is ideal for use with pump limiters and should be a way to achieve energy confinement times similar to values for H-mode tokamak plasmas. The implication of all these results for the design of a reactor pump limiter is described. (orig.)

  4. The exposure data landscape for manufactured chemicals.

    Science.gov (United States)

    Egeghy, Peter P; Judson, Richard; Gangwal, Sumit; Mosher, Shad; Smith, Doris; Vail, James; Cohen Hubal, Elaine A

    2012-01-01

    The U.S. Environmental Protection Agency is developing chemical screening and prioritization programs to evaluate environmental chemicals for potential risk to human health in a rapid and efficient manner. As part of these efforts, it is important to catalog available information on chemical toxicity and exposure from widely dispersed sources. The main objective of this analysis is to define important aspects of the exposure space and to catalog the available exposure information for chemicals being considered for analysis as part of the U.S. EPA ToxCast™ screening and prioritization program. Publicly available exposure data have been extracted into ACToR (Aggregated Computational Toxicology Resource), which combines information for hundreds of thousands of chemicals from >600 public sources. We use data from ACToR to assess the exposure data landscape for environmental chemicals. Of the roughly 100,000 chemicals that have at least limited toxicity information available, less than one-fifth also have exposure information - and for most of these the information is of limited utility (e.g., production volume). Readily accessible data on concentrations in exposure-related media are only available for a much smaller fraction. Among these, the largest number of chemicals is measured in water with over 1150 unique compounds, followed by 788 substances measured in soil, and 670 in air. These small numbers clearly reflect a focus of resources on those substances previously identified as possibly posing a hazard to human health. Exposure to a much broader number of chemicals will need to be measured in order to fully realize the envisioned goal of using exposure information to guide toxicity testing. Published by Elsevier B.V.

  5. Novel limiter pump topologies

    International Nuclear Information System (INIS)

    Schultz, J.H.

    1981-01-01

    The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure

  6. Novel limiter pump topologies

    International Nuclear Information System (INIS)

    Schultz, J.H.

    1981-01-01

    The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topologies are suggested which allow high erosion without limiter failure

  7. HUD Program Income Limits

    Data.gov (United States)

    Department of Housing and Urban Development — Income limits used to determine the income eligibility of applicants for assistance under three programs authorized by the National Housing Act. These programs are...

  8. Limited Income and Resources

    Data.gov (United States)

    U.S. Department of Health & Human Services — Information for those with limited income and resources (those who may qualify for or already have the Low Income Subsidy to lower their prescription drug coverage...

  9. SIS - Annual Catch Limit

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Annual Catch Limit (ACL) dataset within the Species Information System (SIS) contains information and data related to management reference points and catch data.

  10. Limited Denial of Participation

    Data.gov (United States)

    Department of Housing and Urban Development — A Limited Denial of Participation (LDP) is an action taken by a HUD Field Office or the Deputy Assistant Secretary for Single Family (DASSF) or Multifamily (DASMF)...

  11. Towards Improved Optical Limiters

    National Research Council Canada - National Science Library

    Huffman, Peter

    2002-01-01

    .... The first approach was to synthesize and study soluble thallium phthalocyanines. Thallium, due to its proximity to lead and indium on the periodic table, should exhibit favorable optical limiting properties...

  12. ACA Federal Upper Limits

    Data.gov (United States)

    U.S. Department of Health & Human Services — Affordable Care Act Federal Upper Limits (FUL) based on the weighted average of the most recently reported monthly average manufacturer price (AMP) for...

  13. HOME Rent Limits

    Data.gov (United States)

    Department of Housing and Urban Development — In accordance with 24 CFR Part 92.252, HUD provides maximum HOME rent limits. The maximum HOME rents are the lesser of: The fair market rent for existing housing for...

  14. Limit lines for risk

    International Nuclear Information System (INIS)

    Cox, D.C.; Baybutt, P.

    1982-01-01

    Approaches to the regulation of risk from technological systems, such as nuclear power plants or chemical process plants, in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, accidents posing high relative risks, the rate at which accident probability decreases with increasing accident consequences, and the impact of high frequency, low consequence accidents. A hypothetical complementary cumulative distribution function (CCDF), with appropriately chosen parametric form, meets all these requirements. The Farmer limit line, by contrast, places limits on the risks due to individual accident sequences, and cannot adequately account for overall risk. This reduces its usefulness as a regulatory tool. In practice, the CCDF is used in the Canadian nuclear licensing process, while the Farmer limit line approach, supplemented by separate qualitative limits on overall risk, is employed in the United Kingdom

  15. Adjusting estimative prediction limits

    OpenAIRE

    Masao Ueki; Kaoru Fueda

    2007-01-01

    This note presents a direct adjustment of the estimative prediction limit to reduce the coverage error from a target value to third-order accuracy. The adjustment is asymptotically equivalent to those of Barndorff-Nielsen & Cox (1994, 1996) and Vidoni (1998). It has a simpler form with a plug-in estimator of the coverage probability of the estimative limit at the target value. Copyright 2007, Oxford University Press.

  16. Smoothness of limit functors

    Indian Academy of Sciences (India)

    Abstract. Let S be a scheme. Assume that we are given an action of the one dimen- sional split torus Gm,S on a smooth affine S-scheme X. We consider the limit (also called attractor) subfunctor Xλ consisting of points whose orbit under the given action. 'admits a limit at 0'. We show that Xλ is representable by a smooth ...

  17. Safety and design limits

    International Nuclear Information System (INIS)

    Shishkov, L. K.; Gorbaev, V. A.; Tsyganov, S. V.

    2007-01-01

    The paper touches upon the issues of NPP safety ensuring at the stage of fuel load design and operation by applying special limitations for a series of parameters, that is, design limits. Two following approaches are compared: the one used by west specialists for the PWR reactor and the Russian approach employed for the WWER reactor. The closeness of approaches is established, differences that are mainly peculiarities of terms are noted (Authors)

  18. Monitoring of radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service.

  19. Monitoring of radiation exposure

    International Nuclear Information System (INIS)

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service

  20. Altruism and Reproductive Limitations

    Directory of Open Access Journals (Sweden)

    Carey J. Fitzgerald

    2009-04-01

    Full Text Available We examined how different types of reproductive limitations — functional (schizoid personality disorder and schizophrenia, physical (malnutrition, and sexual (bisexuality and homosexuality — influenced altruistic intentions toward hypothetical target individuals of differing degrees of relatedness (r = 0, .25, and .50. Participants were 312 undergraduate students who completed a questionnaire on altruism toward hypothetical friends, half-siblings, and siblings with these different types of reproductive limitations. Genetic relatedness and reproductive limitations did not influence altruistic decision-making when the cost of altruism was low but did as the cost of altruism increased, with participants being more likely to help a sibling over a half-sibling and a half-sibling over a friend. Participants also indicated they were more likely to help a healthy (control person over people with a reproductive limitation. Of the three types of reproductive limitations, functional limitations had the strongest effect on altruistic decision-making, indicating that people were less likely to help those who exhibit abnormal social behavior.

  1. Hydrocarbon solvent exposure data: compilation and analysis of the literature.

    Science.gov (United States)

    Caldwell, D J; Armstrong, T W; Barone, N J; Suder, J A; Evans, M J

    2000-01-01

    An occupational exposure database for hydrocarbon solvent end-use applications was constructed from the published literature. The database provides exposure assessment information for such purposes as regulatory risk assessments, support of industry product stewardship initiatives, and identification of applications in which limited exposure data are available. It is quantitative, documented, and based on credible data. Approximately 350 articles containing quantitative hydrocarbon solvent exposure data were identified using a search of computer databases of published literature. Many articles did not report sufficient details of the exposure data for inclusion in the database (e.g., full-shift exposure or task-based exposure data). Others were excluded because only limited summary statistics were provided, which precluded statistical analysis of the data (e.g., arithmetic mean concentration presented, but no sample number). Following evaluation, 16,880 hydrocarbon solvent exposure measurements from 99 articles were entered into a database for analysis. Methods used to identify and evaluate published solvent exposure data are described along with more detailed analysis of worker exposure to hydrocarbon solvents in three major end-use applications: painting and coating, printing, and adhesives. Solvent exposures were evaluated against current ACGIH threshold limit values (TLVs) and trends were identified. Limited quantitative data are available prior to 1970. In general, reported hydrocarbon solvent exposures decreased fourfold from 1960 to 1998, were below the TLVs applicable to specific hydrocarbon solvents at the time, and on average have been below 40% of the TLV since 1980. The database already has proved valuable; however, the utility of published exposure data could be further improved if authors consistently reported essential data elements and supporting information.

  2. Exposure of croatian population to radiopharmaceuticals

    International Nuclear Information System (INIS)

    Prlic, I.; Suric Mihic, M.; Marovic, G.; Mestrovic, T.; Mrcela, I.; Cerovac, Z.; Golubovic, D.; Hajdinjak, M.

    2010-01-01

    The aim of this paper is to call attention to the exposure of Croatian population to open sources of ionising radiation used in medical diagnostics, radiopharmaceuticals in particular, whose initial activity is very high. Without proper exposure monitoring, it is not possible to establish the effective dose per capita, but we have estimated it to be between 6.8 μSv and 7.0 μSv for this type of internal exposure, based on a very loose assumption that about 35,000 diagnostic procedures with radiopharmaceuticals are performed in Croatia every year. This calls for further research that would eventually lead to limiting the doses received through exposure to radiopharmaceuticals. (authors)

  3. Exposure to Mebendazole and Pyrvinium during Pregnancy

    DEFF Research Database (Denmark)

    Torp-Pedersen, A; Jimenez-Solem, E; Andersen, J T

    2012-01-01

    or mebendazole was used to identify exposure. Results. 4715 women redeemed a prescription for pyrvinium or mebendazole during pregnancy; 1606 for pyrvinium, 2575 for mebendazole, and 534 for both drugs. Having >2 children compared to having no previous children was associated with exposure to pyrvinium (OR: 7......Purpose. Families with children are frequently exposed to pinworm infection and treatment involves the whole family. Information on consequences of exposure during, pregnancy is limited. The aim of this study was to investigate the exposure to pyrvinium and mebendazole before, during, and after...... pregnancy in a Danish nationwide cohort. Methods. From nationwide administrative registers, we identified 718, 900 births in Denmark between January 1997 and December 2007 as well as maternal prescription data of anthelmintics and maternal characteristics. Redemption of a prescription for pyrvinium...

  4. Spatiotemporal aspects of flood exposure in Switzerland

    Directory of Open Access Journals (Sweden)

    Röthlisberger Veronika

    2016-01-01

    Full Text Available While flood hazard mapping in Switzerland is close to completion, only a limited number of studies have been specifically conducted on exposure and vulnerability. We fill this knowledge gap by conducting a nation-wide study of flood exposure of buildings in Switzerland. Therefore, we generate a country-wide comprehensive and homogenous data set of polygons of residential buildings and their period of construction and overlay these building polygons with compiled and harmonized flood hazard maps provided by the Swiss cantons. In this paper we present first results of spatiotemporal analyses, namely the evolution of exposure from 1919 to 2012. Surprising is the increase in the share of exposure of new constructed buildings since the 1980s which contradicts the indented effects of the Swiss flood risk management strategies and calls for further investigations.

  5. Paternal Exposures and Pregnancy

    Science.gov (United States)

    ... increased risk for birth defects. Can the father’s workplace exposures affect my pregnancy? There have been a number of studies looking ... else could a father’s work exposure affect a pregnancy? Men exposed to ... chemicals in the workplace may carry these agents on their clothes and ...

  6. Exposures of the elbow.

    Science.gov (United States)

    Axelrod, Terry S

    2014-11-01

    This article describes the basic bony, ligamentous, and neurologic anatomy of the structures about the elbow. The surgical exposures of the elbow joint are described, providing details of the various posterior, lateral, and medial approaches to the articular segments. Clinical applications describing the potential benefits of each surgical exposure are provided as examples. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Force Limit System

    Science.gov (United States)

    Pawlik, Ralph; Krause, David; Bremenour, Frank

    2011-01-01

    The Force Limit System (FLS) was developed to protect test specimens from inadvertent overload. The load limit value is fully adjustable by the operator and works independently of the test system control as a mechanical (non-electrical) device. When a test specimen is loaded via an electromechanical or hydraulic test system, a chance of an overload condition exists. An overload applied to a specimen could result in irreparable damage to the specimen and/or fixturing. The FLS restricts the maximum load that an actuator can apply to a test specimen. When testing limited-run test articles or using very expensive fixtures, the use of such a device is highly recommended. Test setups typically use electronic peak protection, which can be the source of overload due to malfunctioning components or the inability to react quickly enough to load spikes. The FLS works independently of the electronic overload protection.

  8. Theory of limit cycles

    CERN Document Server

    Ye, Yan-Qian; Lo, Chi Y

    1986-01-01

    Over the past two decades the theory of limit cycles, especially for quadratic differential systems, has progressed dramatically in China as well as in other countries. This monograph, updating the 1964 first edition, includes these recent developments, as revised by eight of the author's colleagues in their own areas of expertise. The first part of the book deals with limit cycles of general plane stationary systems, including their existence, nonexistence, stability, and uniqueness. The second section discusses the global topological structure of limit cycles and phase-portraits of quadratic systems. Finally, the last section collects important results that could not be included under the subject matter of the previous two sections or that have appeared in the literature very recently. The book as a whole serves as a reference for college seniors, graduate students, and researchers in mathematics and physics.

  9. Radiation camera exposure control

    International Nuclear Information System (INIS)

    Martone, R.J.; Yarsawich, M.; Wolczek, W.

    1976-01-01

    A system and method for governing the exposure of an image generated by a radiation camera to an image sensing camera is disclosed. The exposure is terminated in response to the accumulation of a predetermined quantity of radiation, defining a radiation density, occurring in a predetermined area. An index is produced which represents the value of that quantity of radiation whose accumulation causes the exposure termination. The value of the predetermined radiation quantity represented by the index is sensed so that the radiation camera image intensity can be calibrated to compensate for changes in exposure amounts due to desired variations in radiation density of the exposure, to maintain the detectability of the image by the image sensing camera notwithstanding such variations. Provision is also made for calibrating the image intensity in accordance with the sensitivity of the image sensing camera, and for locating the index for maintaining its detectability and causing the proper centering of the radiation camera image

  10. Health risk assessment of exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu

    2011-01-01

    Risk assessment is an essential process for evaluating the human health effects of exposure to ionizing radiation and for determining acceptable levels of exposure. There are two major components of radiation risk assessment: a measure of exposure level and a measure of disease occurrence. For quantitative estimation of health risks, it is important to evaluate the association between exposure and disease occurrence using epidemiological or experimental data. In these approaches, statistical risk models are used particularly for estimating cancer risks related to exposure to low levels of radiation. This paper presents a summary of basic models and methods of risk assessment for studying exposure-risk relationships. Moreover, quantitative risk estimates are subject to several sources of uncertainty due to inherent limitations in risk assessment studies. This paper also discusses the limitations of radiation risk assessment. (author)

  11. Hadron collider luminosity limitations

    CERN Document Server

    Evans, Lyndon R

    1992-01-01

    The three colliders operated to date have taught us a great deal about the behaviour of both bunched and debunched beams in storage rings. The main luminosity limitations are now well enough understood that most of them can be stronglu attenuated or eliminated by approriate design precautions. Experience with the beam-beam interaction in both the SPS and the Tevatron allow us to predict the performance of the new generation of colliders with some degree of confidence. One of the main challenges that the accelerator physicist faces is the problem of the dynamic aperture limitations due to the lower field quality expected, imposed by economic and other constraints.

  12. SLC kicker magnet limitations

    International Nuclear Information System (INIS)

    Cassel, R.; Donaldson, A.; Mattison, T.; Bowden, G.; Weaver, J.; Bulos, F.; Fiander, D.

    1991-01-01

    The SLC Damping Ring kicker magnets requires a fast magnetic field rise time of 58 nsec, a peak field of 800 gauss, a pulse amplitude stability of 0.01%, and a reasonable operational lifetime. The original kicker magnets designed by SLAC and at Fermi were not able to fulfill the SLC kicker requirements. Extensive studies were conducted to determine the limitation in the magnets, response of the ferrite in kicker magnet, and the modifications needed to improve the kicker magnet performance. The paper details the SLAC and Fermi kicker magnets limitation of performance

  13. Some comments on space flight and radiation limits

    International Nuclear Information System (INIS)

    Thornton, W.E.

    1997-01-01

    Setting limits on human exposure to space-related radiation involves two very different processes - the appropriate hard science, and certain emotional aspects and expectations of the groups involved. These groups include the general public and their elected politicians, the astronauts and flight crews, and NASA managers, each group with different expectations and concerns. Public and political views of human space flight and human radiation exposures are often poorly informed and are often based on emotional reactions to current events which may be distorted by 'experts' and the media. Career astronauts' and cosmonauts' views are much more realistic about the risks involved and there is a willingness on their part to accept increased necessary risks. However, there is a concern on their part about career-threatening dose limits, the potential for overexposures, and the health effects from all sources of radiation. There is special concern over radiation from medical studies. This last concern continues to raise the question of 'voluntary' participation in studies involving radiation exposure. There is greatly diversity in spaceflight crews and their expectations; and 'official' Astronaut Office positions will reflect strong management direction. NASA management has its own priorities and concerns and this fact will be reflected in their crucial influence on radiation limits. NASA, and especially spaceflight crews, might be best served by exposure limits which address all sources of spaceflight radiation and all potential effects from such exposure. radiation and all potential effects from such exposure

  14. Kiln emissions and potters' exposures.

    Science.gov (United States)

    Hirtle, B; Teschke, K; van Netten, C; Brauer, M

    1998-10-01

    Some ten thousand British Columbia potters work in small private studios, cooperative facilities, educational institutions, or recreation centers. There has been considerable concern that this diffuse, largely unregulated activity may involve exposures to unacceptable levels of kiln emissions. Pottery kiln emissions were measured at 50 sites--10 from each of 5 categories: professional studios, recreation centers, elementary schools, secondary schools, and colleges. Area monitoring was done 76 cm from firing kilns and 1.6 m above the floor to assess breathing zone concentrations of nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes, aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, gold, iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium, silver, vanadium, and zinc. Personal exposures to the same metals were measured at 24 sites. Almost all measured values were well below permissible concentrations for British Columbia work sites and American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) with the following two exceptions. A single firing duration (495 minute) acrolein measurement adjacent to an electric kiln (0.109 ppm) exceeded these guidelines. One 15-minute sulfur dioxide measurement collected adjacent to a gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The fact that concentrations in small, ventilated kiln rooms ranked among the highest measured gives rise to concern that unacceptable levels of contamination may exist where small kiln rooms remain unventilated. Custom designed exhaust hoods and industrial heating, ventilating, and air-conditioning systems were the most effective ventilation strategies. Passive diffusion and wall/window fans were least effective.

  15. Activation analysis. Detection limits

    International Nuclear Information System (INIS)

    Revel, G.

    1999-01-01

    Numerical data and limits of detection related to the four irradiation modes, often used in activation analysis (reactor neutrons, 14 MeV neutrons, photon gamma and charged particles) are presented here. The technical presentation of the activation analysis is detailed in the paper P 2565 of Techniques de l'Ingenieur. (A.L.B.)

  16. Thermal background noise limitations

    Science.gov (United States)

    Gulkis, S.

    1982-01-01

    Modern detection systems are increasingly limited in sensitivity by the background thermal photons which enter the receiving system. Expressions for the fluctuations of detected thermal radiation are derived. Incoherent and heterodyne detection processes are considered. References to the subject of photon detection statistics are given.

  17. The Copyright Agency Limited.

    Science.gov (United States)

    Morgan, Caroline

    1993-01-01

    The evolution and functions of Australia's Copyright Agency Limited are described. The agency is a copyright collecting organization which collectively administers the rights of authors and publishers whose works are copied in education, and enters into blanket agreements with educational authorities outside the existing statutory license. Some…

  18. The Limits of Accountability.

    Science.gov (United States)

    Bailey, Stephen K.

    This discussion, presented at the Regent's Trustees' Conference, February 1973, reviews the limits of accountability in higher education. Managerial efficiency is suggested to assist in eliminating educational and financial waste. This, however, is the secondary concept emphasized. The primary emphasis indicates the legitimacy of the claims that a…

  19. Predictors of radiation exposure to providers during percutaneous nephrolithotomy

    OpenAIRE

    David L Wenzler; Joel E Abbott; Jeannie J Su; William Shi; Richard Slater; Daniel Miller; Michelle J Siemens; Roger L Sur

    2017-01-01

    Background: Limited studies have reported on radiation risks of increased ionizing radiation exposure to medical personnel in the urologic community. Fluoroscopy is readily used in many urologic surgical procedures. The aim of this study was to determine radiation exposure to all operating room personnel during percutaneous nephrolithotomy (PNL), commonly performed for large renal or complex stones. Materials and Methods: We prospectively collected personnel exposure data for all PNL cases at...

  20. Exposure to magnetic field and brain cancer among child

    International Nuclear Information System (INIS)

    Mir, L.

    2008-01-01

    The risk of childhood brain cancer as a function of magnetic field exposure has been studied less than the risk of leukemia. this updated meta-analysis of thirteen epidemiologic studies thus provides an important contribution to the literature. No increased risk of brain cancer was found, and there were no differences by method of exposure assessment. Doubt remains only for the highest exposure levels, for which very limited data are available. (author)

  1. Limitations on blanket performance

    International Nuclear Information System (INIS)

    Malang, S.

    1999-01-01

    The limitations on the performance of breeding blankets in a fusion power plant are evaluated. The breeding blankets will be key components of a plant and their limitations with regard to power density, thermal efficiency and lifetime could determine to a large degree the attractiveness of a power plant. The performance of two rather well known blanket concepts under development in the frame of the European Blanket Programme is assessed and their limitations are compared with more advanced (and more speculative) concepts. An important issue is the question of which material (structure, breeder, multiplier, coatings) will limit the performance and what improvement would be possible with a 'better' structural material. This evaluation is based on the premise that the performance of the power plant will be limited by the blankets (including first wall) and not by other components, e.g. divertors, or the plasma itself. However, the justness of this premise remains to be seen. It is shown that the different blanket concepts cover a large range of allowable power densities and achievable thermal efficiencies, and it is concluded that there is a high incentive to go for better performance in spite of possibly higher blanket cost. However, such high performance blankets are usually based on materials and technologies not yet developed and there is a rather high risk that the development could fail. Therefore, it is explained that a part of the development effort should be devoted to concepts where the materials and technologies are more or less in hand in order to ensure that blankets for a DEMO reactor can be developed and tested in a given time frame. (orig.)

  2. Effects of exposure imprecision on estimation of the benchmark dose

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Esben; Keiding, Niels; Grandjean, Philippe

    2004-01-01

    In regression analysis failure to adjust for imprecision in the exposure variable is likely to lead to underestimation of the exposure effect. However, the consequences of exposure error for determination of safe doses of toxic substances have so far not received much attention. The benchmark...... approach is one of the most widely used methods for development of exposure limits. An important advantage of this approach is that it can be applied to observational data. However, in this type of data, exposure markers are seldom measured without error. It is shown that, if the exposure error is ignored......, then the benchmark approach produces results that are biased toward higher and less protective levels. It is therefore important to take exposure measurement error into account when calculating benchmark doses. Methods that allow this adjustment are described and illustrated in data from an epidemiological study...

  3. Exposure Modeling for Polychlorinated Biphenyls in School Buildings

    Science.gov (United States)

    There is limited research on characterizing exposures from PCB sources for occupants of school buildings. PCB measurement results from six schools were used to estimate potential exposure distributions for four age groups (4-5, 6-10, 11-14, 14-18 year-olds) using the Stochastic...

  4. Trends in occupational exposure within the UK civil nuclear industry

    International Nuclear Information System (INIS)

    Hughes, J.S.

    1996-01-01

    The UK civil nuclear industry was established in the 1950s and workers in the industry have received occupational radiation exposures since that time. Data on occupational exposures over this period show a reduction in annual doses. This trend was initiated by more restrictive statutory dose limitation requirements, and was achieved by greater emphasis on radiation protection methods. (Author)

  5. Toxicity Data to Determine Refrigerant Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Calm, James M.

    2000-09-30

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  6. Dose limits to the eye lens

    International Nuclear Information System (INIS)

    Sion, N.

    2016-01-01

    Protecting the human body from the effects of ionizing radiation is essential to forestall stochastic effects and require placing limits on the effective dose. Dose limits on specific organs are also necessary to reduce the deterministic effects and tissue reactions. The standard for radiation protection was ISO 15382 (2002) which mainly dealt with beta radiation for nuclear power plant workers. Clearly an update is required to allow for new technology and the proliferative use of radiation in medical practices. There is a need for more explicit radiation monitoring to operators and staff. ICRP118 (International Commission on Radiological Protection), Ref. 1, evolved their recommendations to include eye lens doses as a follow on to their publication 103 and to focus on radiation exposures. It provides updated estimates of 'practical' threshold doses for tissue injury at the level of 1% incidence. This paper discusses the current status and the recommendation for a drastic reduction of the dose limit to the eye lens. (author)

  7. Radiation exposure during ESWL

    International Nuclear Information System (INIS)

    McCullough, D.L.; Van Swearingen, F.L.; Dyer, R.B.; Appel, B.

    1987-01-01

    This paper discusses exposure to ionizing radiation by the ESWL patient and for health professionals. Although the patient is exposed acutely to the highest level of radiation, the lithotripter team is chronically exposed to ionizing radiation at varying levels. Attention to detail is important in reducing that exposure. The operator should follow the guidelines set forth in this chapter in order to minimize exposure to the patient, himself or herself, and to all co-workers. At the present time, investigation of an alternative modality for stone localization, ultrasound, is being investigated

  8. The principles of dose limitation in radiation protection

    International Nuclear Information System (INIS)

    Kaul, A.

    1988-01-01

    The aim of radiation protection is to protect individuals, their offspring and the population as a whole against harmful effects from ionizing radiation and radioactive substances. Harmful effects may be either somatic, i.e. occurring in the exposed person himself/herself, or hereditary, i.e. occurring in the exposed person's offspring. Successful radiation protection involves (a) protective measures based on the results of research into the biological and biophysical effects of radiation and (b) ensuring that activities necessitating exposure are justified and that the degree of exposure is minimal. This benefit/risk principle ceases to apply if a radiation source is out of control, since the main aim is then to introduce risk limitation measures, provided that these are of positive net benefit to the individual and the population as a whole. This paper discusses the principles of dose limitation as a function of exposure conditions, i.e. controlled or uncontrolled exposure to a source of radiation

  9. Age Limit of Pediatrics.

    Science.gov (United States)

    Hardin, Amy Peykoff; Hackell, Jesse M

    2017-09-01

    Pediatrics is a multifaceted specialty that encompasses children's physical, psychosocial, developmental, and mental health. Pediatric care may begin periconceptionally and continues through gestation, infancy, childhood, adolescence, and young adulthood. Although adolescence and young adulthood are recognizable phases of life, an upper age limit is not easily demarcated and varies depending on the individual patient. The establishment of arbitrary age limits on pediatric care by health care providers should be discouraged. The decision to continue care with a pediatrician or pediatric medical or surgical subspecialist should be made solely by the patient (and family, when appropriate) and the physician and must take into account the physical and psychosocial needs of the patient and the abilities of the pediatric provider to meet these needs. Copyright © 2017 by the American Academy of Pediatrics.

  10. FTU pump limiter

    International Nuclear Information System (INIS)

    Alessandrini, C.; Ciotti, M.; Mattei, A. De; Maddaluno, G.; Mazzitelli, G.

    1989-01-01

    The control of the refuelling and recycling of the plasma is crucial in providing enhanced performances in tokamaks and steady-state operation in future reactors. In this paper, we report details of the design and analysis for the pump limiter to be incorporated into the FTU tokamak. The FTU, presently under commissioning, is a compact high field (B=8T), medium high density, circular cross section machine with small accesses. The dimensions of the equatorial port (width 8 cm) would reduce the length of the entrance throat to a few centimeters, which is unacceptable for efficient particle trapping. We have, therefore, designed a rotating blade of the pump limiter head that, in the working position, extends in the toroidal direction inside the vacuum chamber. (author) 8 refs., 4 figs

  11. Current limiter circuit system

    Science.gov (United States)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  12. Limits of Nuclear Stability

    CERN Document Server

    Nerlo-Pomorska, B; Kleban, M

    2003-01-01

    The modern version of the liquid-drop model (LSD) is compared with the macroscopic part of the binding energy evaluated within the Hartree-Fock- Bogoliubov procedure with the Gogny force and the relativistic mean field theory. The parameters of a liquid-drop like mass formula which approximate on the average the self-consistent results are compared with other models. The limits of nuclear stability predicted by these models are discussed.

  13. Are Limit Orders Rational?

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Martin

    2007-01-01

    Roč. 14, č. 4 (2007), s. 32-38 ISSN 0572-3043 R&D Projects: GA ČR(CZ) GA402/06/1417; GA ČR GA402/04/1294; GA ČR GD402/03/H057 Institutional research plan: CEZ:AV0Z10750506 Keywords : market microstructure * limit order market * portfolio selection Subject RIV: AH - Economics

  14. INAA - application and limitation

    International Nuclear Information System (INIS)

    Heydorn, K.

    1990-01-01

    The uncertainties associated with performing Instrumental Neutron Activation Analysis (INAA) are discussed in relation to their category. The Comite International de Poids et Mesure (CIPM) distinguishes between uncertainties according to how their contribution to the overall uncertainty is evaluated. INAA is a potentially definitive method, if all sources of uncertainty can be accounted for. The limitation of the method is reached when uncertainties, which cannot be accounted for, assume significance, and the method cannot be brought in statistical control. (orig.)

  15. Density limits in Tokamaks

    International Nuclear Information System (INIS)

    Tendler, M.

    1984-06-01

    The energy loss from a tokamak plasma due to neutral hydrogen radiation and recycling is of great importance for the energy balance at the periphery. It is shown that the requirement for thermal equilibrium implies a constraint on the maximum attainable edge density. The relation to other density limits is discussed. The average plasma density is shown to be a strong function of the refuelling deposition profile. (author)

  16. Photovoltaic energy cost limit

    International Nuclear Information System (INIS)

    Coiante, D.

    1992-01-01

    Referring to a photovoltaic system for grid connected applications, a parametric expression of kWh cost is derived. The limit of kWh cost is carried out extrapolating the values of cost components to their lowest figure. The reliability of the forecast is checked by disaggregating kWh cost in direct and indirect costs and by discussing the possible cost reduction of each component

  17. Heat flux limiting sleeves

    Science.gov (United States)

    Harris, William G.

    1985-01-01

    A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

  18. Human mutagens: evidence from paternal exposure

    International Nuclear Information System (INIS)

    Narod, S.A.; Douglas, G.R.; Nestmann, E.R.; Blakey, D.H.

    1988-01-01

    The importance of inherited mutations as a cause of human disease has been established clearly through examples of well-defined genetic anomalies, such as Down syndrome and retinoblastoma. Furthermore, it is suspected that environmental contaminants induce mutations resulting in increased risk for such defects in subsequent generations of persons exposed. The present lack of direct evidence for induced inherited genetic disorders in human beings hampers the development of risk estimation techniques for extrapolation from animal models. The most extensive prospective epidemiologic studies of inherited genetic effects have involved survivors of atomic bomb detonations and patients treated with cancer chemotherapy. In neither case has a significant elevation in inherited genetic effects or cancer been detected in the offspring of exposed individuals. Epidemiologic studies of subjects receiving chronic exposure may be confounded by the effect of maternal exposure during pregnancy. Consideration of only paternal exposure can minimize the confounding influence of teratogenicity, enhancing the resolving power of studies for inherited effects. Using this approach, retrospective (case-control) studies of childhood cancer patients have provided limited but suggestive evidence for inheritance of induced effects. Endpoints, such as congenital malformations and spontaneous abortion following paternal exposure, can also be considered as indicators of heritable mutagenic effects. For example, there is limited evidence suggesting that paternal exposure to anaesthetic gases may cause miscarriage and congenital abnormalities as a result of induced male germ cell mutations. 104 references

  19. Superconductive AC current limiter

    International Nuclear Information System (INIS)

    Bekhaled, M.

    1987-01-01

    This patent describes an AC current limiter for a power transport line including a power supply circuit and feeding a load circuit via an overload circuit-breaker member. The limiter comprises a transformer having a primary winding connected in series between the power supply circuit and the load circuit and at least one secondary winding of superconductor material contained in a cryogenic enclosure and short-circuited on itself. The leakage reactance of the transformer as seen from the primary winding is low, and the resistance of the at least one secondary winding when in the non-superconducting state and as seen from the primary is much greater than the nominal impedance of the transformer. The improvement whereby the at least one secondary winding of the transformer comprises an active winding in association with a set of auxiliary windings. The set of auxiliary windings is constituted by an even number of series-connected auxiliary windings wound in opposite directions, with the total number of turns in one direction being equal to the total number of turns in the opposite direction, and with the thermal capacity of the secondary winding as a whole being sufficiently high to limit the expansion thereof to a value which remains small during the time it takes the circuit-breaking member to operate

  20. Foreign Language Educators' Exposure to Research: Reported Experiences, Exposure via Citations, and a Proposal for Action

    Science.gov (United States)

    Marsden, Emma; Kasprowicz, Rowena

    2017-01-01

    This article reports on 2 connected studies that provide data about the flow of research to foreign language (FL) educators in majority Anglophone contexts. The first study investigated exposure to research among FL educators in the United Kingdom using 2 surveys (n = 391; n = 183). The data showed (a) some limited exposure to research via…

  1. Personal Chemical Exposure informatics

    Science.gov (United States)

    Chemical Exposure science is the study of human contact with chemicals (from manufacturing facilities, everyday products, waste) occurring in their environments and advances knowledge of the mechanisms and dynamics of events that cause or prevent adverse health outcomes. (adapted...

  2. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2002-01-01

    Behavioral, neurochemical, and immunocytochemical studies characterized the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and permethrin (PM...

  3. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2001-01-01

    Behavioral, neurochemical, and immunocytochemical studies characterized the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and permethrin (PM...

  4. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2003-01-01

    Behavioral, neurochemical, and immunocytochemical studies are characterizing the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and/or permethrin (PM...

  5. Minimizing Exposure at Work

    Science.gov (United States)

    ; Environment Human Health Animal Health Safe Use Practices Food Safety Environment Air Water Soil Wildlife Home Page Pesticide Health and Safety Information Safe Use Practices Minimizing Exposure at Work Pesticides - Pennsylvania State University Cooperative Extension Personal Protective Equipment for Working

  6. Radiation Exposure and Pregnancy

    Science.gov (United States)

    Fact Sheet Adopted: June 2010 Updated: June 2017 Health Physics Society Specialists in Radiation Safety Radiation Exposure and ... radiation and pregnancy can be found on the Health Physics Society " Ask the Experts" Web site. she should ...

  7. Human Exposure and Health

    Science.gov (United States)

    The ROE is divided into 5 themes: Air, Water, Land, Human Exposure and Health and Ecological Condition. From these themes, the report indicators address fundamental questions that the ROE attempts to answer. For human health there are 3 questions.

  8. Radiation exposure management

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1985-01-01

    Radiation exposure management includes administrative control, education and training, monitoring and dose assessments and planning of work and radiation protection. The information and discussion given in the paper are based on experiences in Sweden mainly from nuclear power installations. (Author)

  9. Fetal exposure to pimozide

    DEFF Research Database (Denmark)

    Bjarnason, Nina H; Rode, Line; Dalhoff, Kim

    2006-01-01

    Pimozide is an antidopaminergic, antipsychotic drug. Exposure during human pregnancy has not been reported previously, and recommendations on its use are based on extrapolation from other antipsychotics with antidopaminergic activity....

  10. Radiation exposure during ureteroscopy

    International Nuclear Information System (INIS)

    Bagley, D.H.; Cubler-Goodman, A.

    1990-01-01

    Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room

  11. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  12. Persuasion Via Mere Exposure

    Science.gov (United States)

    Tucker, Raymond K.; Ware, Paul D.

    1971-01-01

    Describes an experiment which sought to effect persuasion by merely exposing subjects to the name of a stimulus object for a specified number of times. Through illustration, explains the theoretical basis and methodology employed in a mere exposure experiment. (Author)

  13. Current estimates of radiation risks and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    The publication of the 1988 report of UNSCEAR represents a major step forward in that there is an international consensus on the estimation of risk from exposure to ionising radiation. The estimates of fatal cancers in the UNSCEAR report are up to 4 times the values in the 1977 review. This paper will describe the reasons for the increase, the remaining uncertainties and the implications for dose limits in occupational and public exposure. (author)

  14. DOE occupational radiation exposure 1996 report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    The goal of the US Department of Energy (DOE) is to conduct its radiological operations to ensure the health and safety of all DOE employees including contractors and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures and releases to levels that are ``As Low As Reasonably Achievable`` (ALARA). The DOE Occupational Radiation Exposure Report, 1996 provides summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE and precursor agency sites, and energy research. Collective exposure at DOE has declined by 80% over the past decade due to a cessation in opportunities for exposure during the transition in DOE mission from weapons production to cleanup, deactivation and decommissioning, and changes in reporting requirements and dose calculation methodology. In 1996, the collective dose decreased by 10% from the 1995 value due to decreased doses at five of the seven highest-dose DOE sites. For 1996, these sites attributed the reduction in collective dose to the completion of several decontamination and decommissioning projects, reduced spent fuel storage activities, and effective ALARA practices. This report is intended to be a valuable tool for managers in their management of radiological safety programs and commitment of resources.

  15. Exposure of the orthopaedic surgeon to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Kiyonobu; Koga, Takamasa; Matsuzaki, Akio; Kido, Masaki; Satoh, Tetsunori [Fukuoka Univ. (Japan). Chikushi Hospital

    1995-09-01

    We monitored the amount of radiation received by surgeons and assistants during surgery carried out with fluoroscopic assistance. The radiation was monitored with the use of MYDOSE MINIX PDM107 made by Aloka Co. Over a one year period from Aug 20, 1992 to Aug 19, 1993, a study was undertaken to evaluate exposure of the groin level to radiation with or without use of the lead apron during 106 operation (Group-1). In another group, radiation was monitored at the breast and groin level outside of the lead apron during 39 operations (Group-2). In Group-1, the average exposure per person during one year was 46.0 {mu}SV and the average exposure for each procedure was 1.68 {mu}SV. The use of the lead apron affirmed its protective value; the average radiation dose at the groin level out-side of the apron was 9.11 {mu}SV, the measured dose beneath the apron 0.61 {mu}SV. The average dose of exposure to the head, breast at groin level outside of the lead apron, were 7.68 {mu}SV, 16.24 {mu}SV, 32.04 {mu}SV respectively. This study and review of the literature indicate that the total amount of radiation exposure during surgery done with fluoroscopic control remains well within maximum exposure limits. (author).

  16. Exposure of the orthopaedic surgeon to radiation

    International Nuclear Information System (INIS)

    Katoh, Kiyonobu; Koga, Takamasa; Matsuzaki, Akio; Kido, Masaki; Satoh, Tetsunori

    1995-01-01

    We monitored the amount of radiation received by surgeons and assistants during surgery carried out with fluoroscopic assistance. The radiation was monitored with the use of MYDOSE MINIX PDM107 made by Aloka Co. Over a one year period from Aug 20, 1992 to Aug 19, 1993, a study was undertaken to evaluate exposure of the groin level to radiation with or without use of the lead apron during 106 operation (Group-1). In another group, radiation was monitored at the breast and groin level outside of the lead apron during 39 operations (Group-2). In Group-1, the average exposure per person during one year was 46.0 μSV and the average exposure for each procedure was 1.68 μSV. The use of the lead apron affirmed its protective value; the average radiation dose at the groin level out-side of the apron was 9.11 μSV, the measured dose beneath the apron 0.61 μSV. The average dose of exposure to the head, breast at groin level outside of the lead apron, were 7.68 μSV, 16.24 μSV, 32.04 μSV respectively. This study and review of the literature indicate that the total amount of radiation exposure during surgery done with fluoroscopic control remains well within maximum exposure limits. (author)

  17. DOE occupational radiation exposure 1996 report

    International Nuclear Information System (INIS)

    1996-01-01

    The goal of the US Department of Energy (DOE) is to conduct its radiological operations to ensure the health and safety of all DOE employees including contractors and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures and releases to levels that are ''As Low As Reasonably Achievable'' (ALARA). The DOE Occupational Radiation Exposure Report, 1996 provides summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE and precursor agency sites, and energy research. Collective exposure at DOE has declined by 80% over the past decade due to a cessation in opportunities for exposure during the transition in DOE mission from weapons production to cleanup, deactivation and decommissioning, and changes in reporting requirements and dose calculation methodology. In 1996, the collective dose decreased by 10% from the 1995 value due to decreased doses at five of the seven highest-dose DOE sites. For 1996, these sites attributed the reduction in collective dose to the completion of several decontamination and decommissioning projects, reduced spent fuel storage activities, and effective ALARA practices. This report is intended to be a valuable tool for managers in their management of radiological safety programs and commitment of resources

  18. Aerosol exposure: Concepts, criteria, standards and applications

    International Nuclear Information System (INIS)

    Vincent, James H

    2009-01-01

    This paper places Inhaled Particles X in the context of the whole sequence of such symposia, going back to the first one in 1961. It draws together some of the essential principles that have been learned since that earlier meeting about the nature of exposure and exposure assessment and thus provides a framework by which to integrate the new knowledge presented at this latest one. In the process, the importance of understanding the formal definition of aerosol exposure is stressed, including the distinction between exposure intensity and exposure history, and how that relates to some measure of cumulative dose which, in turn, may be linked with knowledge about intrinsic toxicity, etc. This then leads to a definition of exposure standards, and the important ingredients of criteria, sampling and limit values. A summary is provided of the current set of particle size-selective criteria that have been widely agreed in the international occupational and environmental health community. Some ideas are presented about how this set might be expanded for certain applications, the important case of ultrafine aerosols being one of them.

  19. Development of a Job-Exposure Matrix (AsbJEM) to Estimate Occupational Exposure to Asbestos in Australia.

    Science.gov (United States)

    van Oyen, Svein C; Peters, Susan; Alfonso, Helman; Fritschi, Lin; de Klerk, Nicholas H; Reid, Alison; Franklin, Peter; Gordon, Len; Benke, Geza; Musk, Arthur W

    2015-07-01

    Occupational exposure data on asbestos are limited and poorly integrated in Australia so that estimates of disease risk and attribution of disease causation are usually calculated from data that are not specific for local conditions. To develop a job-exposure matrix (AsbJEM) to estimate occupational asbestos exposure levels in Australia, making optimal use of the available exposure data. A dossier of all available exposure data in Australia and information on industry practices and controls was provided to an expert panel consisting of three local industrial hygienists with thorough knowledge of local and international work practices. The expert panel estimated asbestos exposures for combinations of occupation, industry, and time period. Intensity and frequency grades were estimated to enable the calculation of annual exposure levels for each occupation-industry combination for each time period. Two indicators of asbestos exposure intensity (mode and peak) were used to account for different patterns of exposure between occupations. Additionally, the probable type of asbestos fibre was determined for each situation. Asbestos exposures were estimated for 537 combinations of 224 occupations and 60 industries for four time periods (1943-1966; 1967-1986; 1987-2003; ≥2004). Workers in the asbestos manufacturing, shipyard, and insulation industries were estimated to have had the highest average exposures. Up until 1986, 46 occupation-industry combinations were estimated to have had exposures exceeding the current Australian exposure standard of 0.1 f ml(-1). Over 90% of exposed occupations were considered to have had exposure to a mixture of asbestos varieties including crocidolite. The AsbJEM provides empirically based quantified estimates of asbestos exposure levels for Australian jobs since 1943. This exposure assessment application will contribute to improved understanding and prediction of asbestos-related diseases and attribution of disease causation. © The

  20. Human biological monitoring of occupational genotoxic exposures

    DEFF Research Database (Denmark)

    Knudsen, Lisbeth E.; Sorsa, M

    1993-01-01

    Human biological monitoring is a valuable tool for exposure assessment in groups of persons occupationally exposed to genotoxic agents. If the monitoring activity covers genetic material the term genetic monitoring is used. The methods used for genetic monitoring are either substance specific, e......) occupational exposure limit value of styrene in ambient air. The consideration of ethical issues in human genetic monitoring is an important but often overlooked aspect. This includes the scientific and preventional relevance of performing a test on individuals, pre- and post study information of donors...

  1. Strategic arms limitation

    Science.gov (United States)

    Allen Greb, G.; Johnson, Gerald W.

    1983-10-01

    Following World War II, American scientists and politicians proposed in the Baruch plan a radical solution to the problem of nuclear weapons: to eliminate them forever under the auspices of an international nuclear development authority. The Soviets, who as yet did not possess the bomb, rejected this plan. Another approach suggested by Secretary of War Henry Stimson to negotiate directly with the Soviet Union was not accepted by the American leadership. These initial arms limitation failures both reflected and exacerbated the hostile political relationship of the superpowers in the 1950s and 1960s. Since 1969, the more modest focus of the Soviet-American arms control process has been on limiting the numbers and sizes of both defensive and offensive strategic systems. The format for this effort has been the Strategic Arms Limitatins Talks (Salt) and more recently the Strategic Arms Reduction Talks (START). Both sides came to these negotiations convinced that nuclear arsenals had grown so large that some for of mutual restraint was needed. Although the SALT/START process has been slow and ponderous, it has produced several concrete the agreements and collateral benefits. The 1972 ABM Treaty restricts the deployment of ballistic missile defense systems, the 1972 Interim Agreement places a quantitative freeze on each side's land based and sea based strategic launchers, and the as yet unratified 1979 SALT II Treaty sets numerical limits on all offensive strategic systems and sublimits on MIRVed systems. Collateral benefits include improved verification procedures, working definitions and counting rules, and permanent bureaucratic apparatus which enhance stability and increase the chances for achieving additional agreements.

  2. Beta limits for ETF

    International Nuclear Information System (INIS)

    Helton, F.J.; Miller, R.L.

    1982-01-01

    ETF (Engineering Test Facility) one-dimensional transport simulations indicate that a volume-average beta of 4% is required for ignition. It is therefore important that theoretical beta limits, determined by requiring equilibria to be stable to all ideal modes, exceed 4%. This paper documents an ideal MHD analysis wherein it is shown that, with appropriate plasma cross-sectional shape and current profile optimization, operation near 5% is possible. The critical beta value, however, depends on the functional form used for ff', which suggests that higher critical betas could be achieved by directly optimizing the safety factor profile. (author)

  3. Limitations of Boltzmann's principle

    International Nuclear Information System (INIS)

    Lavenda, B.H.

    1995-01-01

    The usual form of Boltzmann's principle assures that maximum entropy, or entropy reduction, occurs with maximum probability, implying a unimodal distribution. Boltzmann's principle cannot be applied to nonunimodal distributions, like the arcsine law, because the entropy may be concave only over a limited portion of the interval. The method of subordination shows that the arcsine distribution corresponds to a process with a single degree of freedom, thereby confirming the invalidation of Boltzmann's principle. The fractalization of time leads to a new distribution in which arcsine and Cauchy distributions can coexist simultaneously for nonintegral degrees of freedom between √2 and 2

  4. Fault current limiter

    Science.gov (United States)

    Darmann, Francis Anthony

    2013-10-08

    A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

  5. Marketing with limited budget

    OpenAIRE

    Smirnova, Daria

    2017-01-01

    The purpose of this research-based thesis was to get an idea how managers of two small resembling hotels of a specific region deal with marketing process with a limited budget. In addition, the aim of the thesis was to examine if hotel managers who were interviewed perceive marketing only in the way of ‘promotion’ rather than marketing research, marketing mix and marketing environment theories. It was also found out if hotel managers of those hotels consider marketing as a key to successful h...

  6. Limitation of Auditors' Liability

    DEFF Research Database (Denmark)

    Werlauff, Erik; Foged-Ladefoged, Lise Kolding

    2014-01-01

    The article examines the question of whether rules on the limitation of auditors’ liability within the perspective of EU law are needed, and if so, which rules can provide an appropriate balance between the potential injured party’s interests and those of the auditing sector, including with respect...... to the fact that the insurance premiums associated with an unlimited liability must of course make the auditor’s tasks more expensive. Relevant EU recommendations and a comparative glance at other EU countries’ proposed solutions to the problem are included....

  7. Occupational exposures and chronic obstructive pulmonary disease (COPD): comparison of a COPD-specific job exposure matrix and expert-evaluated occupational exposures.

    Science.gov (United States)

    Kurth, Laura; Doney, Brent; Weinmann, Sheila

    2017-03-01

    To compare the occupational exposure levels assigned by our National Institute for Occupational Safety and Health chronic obstructive pulmonary disease-specific job exposure matrix (NIOSH COPD JEM) and by expert evaluation of detailed occupational information for various jobs held by members of an integrated health plan in the Northwest USA. We analysed data from a prior study examining COPD and occupational exposures. Jobs were assigned exposure levels using 2 methods: (1) the COPD JEM and (2) expert evaluation. Agreement (Cohen's κ coefficients), sensitivity and specificity were calculated to compare exposure levels assigned by the 2 methods for 8 exposure categories. κ indicated slight to moderate agreement (0.19-0.51) between the 2 methods and was highest for organic dust and overall exposure. Sensitivity of the matrix ranged from 33.9% to 68.5% and was highest for sensitisers, diesel exhaust and overall exposure. Specificity ranged from 74.7% to 97.1% and was highest for fumes, organic dust and mineral dust. This COPD JEM was compared with exposures assigned by experts and offers a generalisable approach to assigning occupational exposure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Limits to biofuels

    Directory of Open Access Journals (Sweden)

    Johansson S.

    2013-06-01

    Full Text Available Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays’ use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years’ agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2–6000TWh (biogas from residues and waste and ethanol from woody biomass in the more optimistic cases.

  9. Limits to biofuels

    Science.gov (United States)

    Johansson, S.

    2013-06-01

    Biofuel production is dependent upon agriculture and forestry systems, and the expectations of future biofuel potential are high. A study of the global food production and biofuel production from edible crops implies that biofuel produced from edible parts of crops lead to a global deficit of food. This is rather well known, which is why there is a strong urge to develop biofuel systems that make use of residues or products from forest to eliminate competition with food production. However, biofuel from agro-residues still depend upon the crop production system, and there are many parameters to deal with in order to investigate the sustainability of biofuel production. There is a theoretical limit to how much biofuel can be achieved globally from agro-residues and this amounts to approximately one third of todays' use of fossil fuels in the transport sector. In reality this theoretical potential may be eliminated by the energy use in the biomass-conversion technologies and production systems, depending on what type of assessment method is used. By surveying existing studies on biofuel conversion the theoretical limit of biofuels from 2010 years' agricultural production was found to be either non-existent due to energy consumption in the conversion process, or up to 2-6000TWh (biogas from residues and waste and ethanol from woody biomass) in the more optimistic cases.

  10. (Limiting the greenhouse effect)

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, S.

    1991-01-07

    Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

  11. Limitations of inclusive fitness.

    Science.gov (United States)

    Allen, Benjamin; Nowak, Martin A; Wilson, Edward O

    2013-12-10

    Until recently, inclusive fitness has been widely accepted as a general method to explain the evolution of social behavior. Affirming and expanding earlier criticism, we demonstrate that inclusive fitness is instead a limited concept, which exists only for a small subset of evolutionary processes. Inclusive fitness assumes that personal fitness is the sum of additive components caused by individual actions. This assumption does not hold for the majority of evolutionary processes or scenarios. To sidestep this limitation, inclusive fitness theorists have proposed a method using linear regression. On the basis of this method, it is claimed that inclusive fitness theory (i) predicts the direction of allele frequency changes, (ii) reveals the reasons for these changes, (iii) is as general as natural selection, and (iv) provides a universal design principle for evolution. In this paper we evaluate these claims, and show that all of them are unfounded. If the objective is to analyze whether mutations that modify social behavior are favored or opposed by natural selection, then no aspect of inclusive fitness theory is needed.

  12. Risk from fast neutron exposure

    International Nuclear Information System (INIS)

    Bond, V.P.

    1978-01-01

    The recommendations made by Rossi and Mays imply that the risk associated with the current annual dose equivalent limit of 5 rem for all radiations is unacceptably high, that this limit must be reduced by a factor of 10 or more, and that the conservative linear, no threshold hypothesis must be abandoned. It is shown here that these recommendations are not supported by the newly-analyzed neutron data, and certainly cannot be applied selectively to the annual absorbed dose limit for neutrons. In particular, the judgment that the risk of an annual exposure from 0.5 rad (5 rem) of neutrons is unacceptable high, although perhaps defensible as a personal opinion of the authors, does not follow either from the assumption of a linear-quadratic dose effect relation for low-LET radiation or from other radiobiological considerations. At issue is the level of risk that is to be considered acceptable, a question that is societal and thus not resolvable on purely technical or scientific grounds

  13. Cumulative exposure to phthalates from phthalate-containing drug products

    DEFF Research Database (Denmark)

    Ennis, Zandra Nymand; Broe, Anne; Pottegård, Anton

    2018-01-01

    European regulatory limit of exposure ranging between 380-1710 mg/year throughout the study period. Lithium-products constituted the majority of dibutyl phthalate exposure. Diethyl phthalate exposure, mainly caused by erythromycin, theophylline and diclofenac products, did not exceed the EMA regulatory...... to quantify annual cumulated phthalate exposure from drug products among users of phthalate-containing oral medications in Denmark throughout the period of 2004-2016. METHODS: We conducted a Danish nationwide cohort study using The Danish National Prescription Registry and an internal database held...

  14. Risks to the offspring from parental occupational exposures

    International Nuclear Information System (INIS)

    Haas, J.F.; Schottenfeld, D.

    1979-01-01

    Risks to the offspring of workers with occupational chemical exposures may derive from mutagenic, teratogenic or carcinogenic effects of industrial agents to which the parents are exposed. Evidence for impaired pregnancies and hazards to the offspring of working populations with chemical exposures is, however, very limited. Evidence is reviewed for hazards to the offspring resulting from parental occupational exposure to vinyl chloride, benzene, chloroprene, radiation and petroleum-derived hydrocarbons. Other environmental and behavioral factors with major effects on pregnancy outcome are considered. These include smoking, alcohol, and drug exposures. An approach to surveillance for chromosomal abnormalities in offspring of occupationally exposed parents is outlined

  15. Derived limits and their practical applications

    International Nuclear Information System (INIS)

    Minarik, F.

    1982-01-01

    Attention is devoted to the approach and methodological procedure in determining derived limits for surface contamination with special regard to external exposure of hands, inhalation of resuspended activity, contamination of the skin and with regard to ingestion of radioactive material from the skin. In the practical part of the article, results are given of measuring contamination by radionuclides 134 Cs, 133 Cs and 60 Co, and the resulting annual equivalent dose rates and their comparison with derived air contamination in the sense of ICRP Publ. No. 30. (author)

  16. Dose. Detriment. Limit assessment; Dosis. Schadensmass. Grenzwertsetzung

    Energy Technology Data Exchange (ETDEWEB)

    Breckow, J. [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2015-07-01

    One goal of radiation protection is the limitation of stochastic effects due to radiation exposure. The probability of occurrence of a radiation induced stochastic effect, however, is only one of several other parameters which determine the radiation detriment. Though the ICRP-concept of detriment is a quantitative definition, the kind of detriment weighting includes somewhat subjective elements. In this sense, the detriment-concept of ICRP represents already at the stage of effective dose a kind of assessment. Thus, by comparing radiation protection standards and concepts interconvertible or with those of environment or occupational protection one should be aware of the possibly different principles of detriment assessment.

  17. Exposure of pregnant mice to carbon black by intratracheal instillation

    DEFF Research Database (Denmark)

    Jackson, Petra; Hougaard, Karin S.; Vogel, Ulla

    2011-01-01

    Exposure to nanomaterials (NM) during sensitive developmental stages may predispose organisms to diseases later in life. However, direct translocation of NM from mother to fetus through the placenta is limited. The present study tests the hypothesis that pulmonary exposure to NM and NM-induced re......Exposure to nanomaterials (NM) during sensitive developmental stages may predispose organisms to diseases later in life. However, direct translocation of NM from mother to fetus through the placenta is limited. The present study tests the hypothesis that pulmonary exposure to NM and NM...... only in the high dose group. Analysis of newborn livers by DNA microarrays revealed that female offspring were more sensitive to maternal exposure than male offspring. Cellular signalling, inflammation, cell cycle and lipid metabolism were among the biological pathways affected in female offspring...

  18. Laser-limiting materials for medical use

    Science.gov (United States)

    Podgaetsky, Vitaly M.; Kopylova, Tat'yana N.; Tereshchenko, Sergey A.; Reznichenko, Alexander V.; Selishchev, Sergey V.

    2004-03-01

    The important problem of modern laser medicine is the decrease of an exposure of biological tissues outside of an operational field and can be solved by optical radiation limiting. Organic dyes with reversibly darkening can be placed onto surfaces of irradiated tissues or can be introduced in solder for laser welding of vessels. The limiting properties of a set of nontoxic organic compounds were investigated. Nonlinear optical properties of dyes having reverse saturable absorption (pyran styryl derivatives, cyanine and porphyrine compounds) were studied under XeCl and YAG:Nd (II harmonics) lasers excitation. The effect of attenuation of a visible laser radiation is obtained for ethanol solutions of cyanines: radiation attenuation coefficient ( AC) = 25-35 at N/S = 100-250 MW/cm2. In water solutions of such compounds in UV spectrum range AC ~ 10. The spectral characteristics of compounds appeared expedient enough to operational use in laser limiters (broad passband in visible range of a spectrum). Under the data of Z-scanning (the scheme F/10) value AC ~ 70 was reached. The limiting of power laser radiation in visible (λ = 532 nm) and UV- (λ = 308 nm) spectral region and nanosecond pulse duration (7 -13 ns) across porphyrine solutions and their complexes with some metals (13 compounds) was investigated too. The comparative study of optical limiting dependence on intensity of laser radiation, solvent type and concentration of solutions was carried out for selecte wavelength. There was shown a possible use of pyran styryl derivatives DCM as limiters of visual laser radiation. To understand a mechanism of laser radiation limitation the light induced processes were experimentally and theoretically studied in organic molecules. The quantum-chemical investigation of one cyanine compound was carried out. There were noted the perspectives of laser radiation limiting by application of inverted schemes of traditional laser shutters. Usage of phenomena of light -induced

  19. The limitation and modification of flux-limited diffusion theory

    International Nuclear Information System (INIS)

    Liu Chengan; Huang Wenkai

    1986-01-01

    The limitation of various typical flux-limited diffusion theory and advantages of asymptotic diffusion theory with time absorption constant are analyzed and compared. The conclusions are as following: Though the flux-limited problem in neutron diffusion theory are theoretically solved by derived flux-limited diffusion equation, it's going too far to limit flux due to the inappropriate assumption in deriving flux-limited diffusion equation. The asymptotic diffusion theory with time absorption constant has eliminated the above-mentioned limitation, and it is more accurate than flux-limited diffusion theory in describing neutron transport problem

  20. Trends in occupational exposure control

    International Nuclear Information System (INIS)

    Wrixon, A.D.

    1996-01-01

    The latest recommendations of the International Commission on Radiological Protection were agreed in 1990. A major component was the revision of its recommended dose limits, prompted by the revised risk factors relating to exposure to ionising radiation that became available in the second half of the 1980s. But other changes were introduced which necessitated development. In particular a Task Group has been developing guidance on the implementation of the recommendations relating to the protection of workers. This guidance is intended to replace that given in Publication 35. The proposed guidance will be considered by ICRP at its meeting in Paris in November 1996. A guide on occupational radiation protection is also being prepared by the International Atomic Energy Agency. The intention is to develop the principles given in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, account being taken of the work of the ICRP Task Group. Members States of the European Communities are obliged to comply with the requirements of a Directive dealing with the basic standards for radiation protection. This Directive has recently been revised in the light of the ICRP recommendations. This paper will discuss these developments and their possible impact on the control of occupational exposure in the UK. (author)

  1. Limits of Lubrication in

    DEFF Research Database (Denmark)

    Olsson, David Dam

    as delivered stainless steel surfaces implying microstructure changes in terms of larger ratio of closed lubricant pockets due to selective grain boundary etching. Strategic surfaces have also been created by macroscopic texturing using spherical indentations having a very small edge slope in order to promote...... by strategic surfaces in comparison to normal stainless steel surfaces implying a larger extent of bi-axial stretching. Numerical simulations have been applied in order to evaluate limits of lubrication in the simulative strip reduction based on predictions of critical parameters appearing in terms......-models corresponds well to experimental results in terms of lubricant film breakdown and subsequently pick-up development. Punching and blanking have been investigated regarding tribological conditions in case of using stainless steel workpiece materials. However, this has called for development of a new test method...

  2. Personal Freedom beyond Limits

    Directory of Open Access Journals (Sweden)

    Juan Fernando Sellés

    2013-07-01

    Full Text Available In this work we distinguish between freedom in the human manifestations (intelligence, will,actions and personal freedom in the personal intimacy. This second is beyond the freedom reached bythe classic and modern thought, since it takes root in the personnel act of being. Because of it, it is not possible to characterize this freedom like the classic description as ‘domain over the own acts’, becauseit is a description of ‘categorial’ order; neither like present day ‘autonomy’ or ‘independence’, becausethe existence of one person alone is impossible, since ‘person’ means relation, personal free openingto other persons, description of the ‘transcendental’ order and, therefore, to the margin of limits.

  3. [Does medicine limit enlightenment?].

    Science.gov (United States)

    Schipperges, H

    1977-01-01

    In the first, historical part the most important programs of "Medical Enlightenment", are pointed out, beginning with Leibniz, followed by the public health movement of the 18th century, up to the time of Immanuel Kant. Based on this historical background several concepts of a "Medical Culture" are analysed in detail, for instance the "Theorie einer Medizinal-Ordnung" by Johann Benjamin Ehrhard (1800), the "Medicinische Reform" by Rudolf Virchow (1848) and the programs of the "Gesellschaft Deutscher Naturforscher und Arzte" (about 1850-1890), the latter bearing both scientific and political character. Following the historical part, the question is raised whether "Enlightenment" is limited by medicine and whether medicine is able to provide a program for individual health education resulting in a more cultivated style of private life, and lastly how this might be realized.

  4. Doses from radiation exposure

    International Nuclear Information System (INIS)

    Menzel, H-G.; Harrison, J.D.

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection’s (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP’s 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effective dose. In preparation for the calculation of new dose coefficients, Committee 2 and its task groups have provided updated nuclear decay data (ICRP Publication 107) and adult reference computational phantoms (ICRP Publication 110). New dose coefficients for external exposures of workers are complete (ICRP Publication 116), and work is in progress on a series of reports on internal dose coefficients to workers from inhaled and ingested radionuclides. Reference phantoms for children will also be provided and used in the calculation of dose coefficients for public exposures. Committee 2 also has task groups on exposures to radiation in space and on the use of effective dose.

  5. 77 FR 76841 - Lending Limits

    Science.gov (United States)

    2012-12-31

    ... measuring the appropriate credit exposures of derivatives transactions and securities financing transactions... a credit exposure arising from a derivative transaction or securities financing transaction on or... derivative transactions or securities financing transactions from January 1, 2013 to July 1, 2013 in order to...

  6. Occupational exposure to beryllium in French enterprises: a survey of airborne exposure and surface levels.

    Science.gov (United States)

    Vincent, Raymond; Catani, Jacques; Créau, Yvon; Frocaut, Anne-Marie; Good, Andrée; Goutet, Pierre; Hou, Alain; Leray, Fabrice; André-Lesage, Marie-Ange; Soyez, Alain

    2009-06-01

    An assessment survey of occupational exposure to beryllium (Be) was conducted in France between late 2004 and the end of 2006. Exposure estimates were based on the analytical results of samples collected from workplace air and from work surfaces in 95 facilities belonging to 37 sectors of activity. The results of this study indicated airborne Be concentrations in excess of the occupational exposure limit value of 2 microg m(-3) recommended in France. Metallurgy and electronic component manufacturing represented the activities and occupations where workers had the highest arithmetic mean exposures to Be. Surface contamination levels were also high and frequently exceeded thresholds recommended by different bodies. These results should prompt the development of prevention programmes that include Be substitution, process control and surface decontamination, in conjunction with suitable medical surveillance.

  7. The Limits to Relevance

    Science.gov (United States)

    Averill, M.; Briggle, A.

    2006-12-01

    Science policy and knowledge production lately have taken a pragmatic turn. Funding agencies increasingly are requiring scientists to explain the relevance of their work to society. This stems in part from mounting critiques of the "linear model" of knowledge production in which scientists operating according to their own interests or disciplinary standards are presumed to automatically produce knowledge that is of relevance outside of their narrow communities. Many contend that funded scientific research should be linked more directly to societal goals, which implies a shift in the kind of research that will be funded. While both authors support the concept of useful science, we question the exact meaning of "relevance" and the wisdom of allowing it to control research agendas. We hope to contribute to the conversation by thinking more critically about the meaning and limits of the term "relevance" and the trade-offs implicit in a narrow utilitarian approach. The paper will consider which interests tend to be privileged by an emphasis on relevance and address issues such as whose goals ought to be pursued and why, and who gets to decide. We will consider how relevance, narrowly construed, may actually limit the ultimate utility of scientific research. The paper also will reflect on the worthiness of research goals themselves and their relationship to a broader view of what it means to be human and to live in society. Just as there is more to being human than the pragmatic demands of daily life, there is more at issue with knowledge production than finding the most efficient ways to satisfy consumer preferences or fix near-term policy problems. We will conclude by calling for a balanced approach to funding research that addresses society's most pressing needs but also supports innovative research with less immediately apparent application.

  8. Assessment of exposure to shiftwork mechanisms in the general population: the development of a new job-exposure matrix.

    Science.gov (United States)

    Fernandez, Renae C; Peters, Susan; Carey, Renee N; Davies, Michael J; Fritschi, Lin

    2014-10-01

    To develop a job-exposure matrix (JEM) that estimates exposure to eight variables representing different aspects of shiftwork among female workers. Occupational history and shiftwork exposure data were obtained from a population-based breast cancer case-control study. Exposure to light at night, phase shift, sleep disturbances, poor diet, lack of physical activity, lack of vitamin D, and graveyard and early morning shifts, was calculated by occupational code. Three threshold values based on the frequency of exposure were considered (10%, 30% and 50%) for use as cut-offs in determining exposure for each occupational code. JEM-based exposure classification was compared with that from the OccIDEAS application (job-specific questionnaires and assessment by rules) by assessing the effect on the OR for phase shift and breast cancer. Using data from the Australian Workplace Exposure Study, the specificity and sensitivity of the threshold values were calculated for each exposure variable. 127 of 413 occupational codes involved exposure to one or more shiftwork variables. Occupations with the highest probability of exposure shiftwork included nurses and midwives. Using the 30% threshold, the OR for the association between phase shift exposure and breast cancer was decreased and no longer statistically significant (OR=1.14, 95% CI 0.92 to 1.42). The 30% cut-off point demonstrated best specificity and sensitivity, although results varied between exposure variables. This JEM provides a set of indicators reflecting biologically plausible mechanisms for the potential impact of shiftwork on health and may provide an alternative method of exposure assessment in the absence of detailed job history and exposure data. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  9. Nature of activities and natural, artificial, accidental exposures. Magnitude of these exposures

    International Nuclear Information System (INIS)

    Aurengo, A.

    2009-01-01

    The exposure to ionizing radiation (I.R.) is linked to radioelements of organism (9%), earth (12%), cosmic radiation (10%), radon (37%), atmospheric fallout ( nuclear tests 2.5% and industry 0.5%) and to medical procedures (29%). The natural exposure varies in France from 2.5 to 5 mSv by year. In some areas in the world it reaches several tens of mSv by year. The medical exposure is very heterogeneous and concerns particularly old people. For a same examination, the patients exposure varies in an important way ( sometimes from 1 to 10) according to the country, even in France. In France, 250 000 persons are occupationally exposed to ionizing radiation. Among these ones, the most of cases exceeded regulatory limits for exposure to IR concern the health sector. The accidental exposures are in relation with industrial activities (51%) research (20%) civil nuclear (13%) or military (5%) and medical activities (11%). The exposures and then the consequences are very variable, ranging from death to unapparent consequences. in the most of cases a human error is involved and these accidents could have been avoided through measures of prevention and training. (N.C.)

  10. Digital radiography exposure indices: A review

    International Nuclear Information System (INIS)

    Mothiram, Ursula; Brennan, Patrick C; Lewis, Sarah J; Moran, Bernadette; Robinson, John

    2014-01-01

    Digital radiography (DR) technologies have the advantage of a wide dynamic range compared to their film-screen predecessors, however, this poses a potential for increased patient exposure if left unchecked. Manufacturers have developed the exposure index (EI) to counter this, which provides radiographers with feedback on the exposure reaching the detector. As these EIs were manufacturer-specific, a wide variety of EIs existed. To offset this, the international standardised EI has been developed by the International Electrotechnical Commission (IEC) and the American Association of Physicists in Medicine (AAPM). The purpose of this article is to explore the current literature relating to EIs, beginning with the historical development of the EI, the development of the standardised EI and an exploration of common themes and studies as evidenced in the research literature. It is anticipated that this review will provide radiographers with a useful guide to understanding EIs, their application in clinical practice, limitations and suggestions for further research

  11. Radioecological activity limits for radioactive waste disposal

    International Nuclear Information System (INIS)

    Ahmet, E. Osmanlioglu

    2006-01-01

    Full text: Near surface disposal is an option used by many countries for the disposal of radioactive waste containing mainly short lived radionuclides. Near surface disposal term includes broad range of facilities from simple trenches to concrete vaults. Principally, disposal of radioactive waste requires the implementation of measures that will provide safety for human health and environment now and in the future. For this reason preliminary activity limits should be determined to avoid radioecological problems. Radioactive waste has to be safely disposed in a regulated manner, consistent with internationally agreed principles and standards and with national legislations to avoid serious radioecological problems. The purpose of this study, presents a safety assessment approach to derive operational and post-closure radioecological activity limits for the disposal of radioactive waste. Disposal system has three components; the waste, the facility (incl. engineered barriers) and the site (natural barriers). Form of the waste (unconditioned or conditioned) is effective at the beginning of the migration scenerio. Existence of the engineered barriers in the facility will provide long term isolation of the waste from environment. The site characteristics (geology, groundwater, seismicity, climate etc.) are important for the safety of the system. Occupational exposure of a worker shall be controlled so that the following dose limits are not exceeded: an effective dose of 20mSv/y averaged over 5 consecutive years; and an effective dose of 50mSv in any single year. The effective dose limit for members of the public recommended by ICRP and IAEA is 1 mSv/y for exposures from all man-made sources [1,2]. Dose constraints are typically a fraction of the dose limit and ICRP recommendations (0.3 mSv/y) could be applied [3,4]. Radioecological activity concentration limits of each radionuclide in the waste (Bq/kg) were calculated. As a result of this study radioecological activity

  12. Americans' Average Radiation Exposure

    International Nuclear Information System (INIS)

    2000-01-01

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

  13. Problems in evaluating health effects of occupational and environmental exposures

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1981-01-01

    The assessment of health effects from low-level exposure to radiation is a matter of considerable controversy. Existing standards for exposure are based primarily on estimates of health effects obtained by extrapolation from effects of high-level exposures such as those experienced at Hiroshima and Nagasaki. Occupational and environmental exposures provide one source of data for this task. A number of studies of populations exposed in this manner have attracted recent attention. Because of the size of most of the groups and the magnitude of the exposures received, the amount that can be learned from such populations is severely limited. A number of the problems involved in analyzing and interpreting such data are addressed. Many of these problems are illustrated by a current study of the effects on mortality of occupational exposure to radiation at the Hanford plant

  14. Occupational exposure of NRM spectrometrists to static and radiofrequency fields

    International Nuclear Information System (INIS)

    Berlana, Tania; Ubeda, Alejandro

    2017-01-01

    Occupational exposure to static and radiofrequency fields emitted by nuclear magnetic resonance spectrometers was assessed through systematic field metering during operation of 19 devices in nine research centers. Whereas no measurable levels of radiofrequency radiation were registered outside the spectrometers, significant exposure to static field was detected, with maximum values recorded at the user s hand (B = 683.00 mT) and head thorax (B = 135.70 mT) during spectrometer manipulation. All values were well below the exposure limits set by the European standard for workers protection against the effects of acute field exposure only. As for potential effects of chronic exposure, waiting for more complete knowledge, adoption of technical and operational strategies for exposure minimizing is advisable. In this respect, the data revealed that compared with standard magnetic shielding, ultra-shield technology allows a 20-65-fold reduction of the field strength received by the operator. (authors)

  15. John Deakin: Double Exposures

    Directory of Open Access Journals (Sweden)

    Paul Rousseau

    2015-11-01

    Full Text Available In this series of short films made by Jonathan Law, the art historian James Boaden, and the curator of The John Deakin Archive, Paul Rousseau, discuss the double-exposure images made by the photographer John Deakin (1912-1972 in the 1950s and 1960s. The films ask you, firstly, to look closely at the images being discussed. Each one begins with a sustained and intense shot of a single image before opening up to a wide-ranging discussion about Deakin, double exposures, and photography.

  16. Modelling exposure opportunities

    DEFF Research Database (Denmark)

    Sabel, Clive E.; Gatrell, Anthony C.; Löytönen, Markku

    2000-01-01

    This paper addresses the issues surrounding an individual's exposure to potential environmental risk factors, which can be implicated in the aetiology of a disease. We hope to further elucidate the 'lag' or latency period between the initial exposure to potential pathogens and the physical...... boundaries.We use kernel estimation to model space-time patterns. Raised relative risk is assessed by adopting appropriate adjustments for the underlying population at risk, with the use of controls. Significance of the results is assessed using Monte Carlo simulation, and comparisons are made with results...

  17. Four exposure holography system

    International Nuclear Information System (INIS)

    Mix, L.P.; Kessler, R.W.

    1977-03-01

    A four exposure holographic interferometry system, designed for studying transient phenomena occurring on nanosecond time scales and particularly those associated with relativistic electron beams, is described. This system permits four holographic exposures of a single transient event to be made with independently adjustable interpulse spacings of from 6 to 28 nsec. The system is portable, allows for a wide range of image magnifications, features colinear scene beams to facilitate alignment and large aperture imaging lenses to minimize refraction phenomena. The various design parameters are discussed and typical holograms presented to indicate the types of data which may be obtained

  18. Radiographic constant exposure technique

    DEFF Research Database (Denmark)

    Domanus, Joseph Czeslaw

    1985-01-01

    The constant exposure technique has been applied to assess various industrial radiographic systems. Different X-ray films and radiographic papers of two producers were compared. Special attention was given to fast film and paper used with fluorometallic screens. Radiographic image quality...... was tested by the use of ISO wire IQI's and ASTM penetrameters used on Al and Fe test plates. Relative speed and reduction of kilovoltage obtained with the constant exposure technique were calculated. The advantages of fast radiographic systems are pointed out...

  19. Natural radio-exposure

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Although the amounts are small, man is exposed on a daily basis to alpha, beta, and gamma radiation emitted by radioactive elements present in the earth's crust. The natural radioactive elements are measurable, either by physicochemical means or by radiometric methods and can be the cause of external or internal exposure in man. Also of importance is cosmic radiation. Of galactic or solar origin, primary cosmic rays cause external radiation exposure. The majority of these particles disintegrate rapidly. They reach the ground at a mean rate of the order of one particle per square centimeter per minute

  20. Limit, breakthrough and prosperity

    International Nuclear Information System (INIS)

    Takahashi, Minoru

    1973-01-01

    It is pointed out that the flow toward serious crises is in progress with regard to energy and industrial problems. Technical and industrial preparation and countermeasure to the flow are proposed, and the existence of a certain new world attainable on the assumption that the countermeasure is successful is described. The relation between oil output and the increasing demand for energy is pointed out as a subject matter of the crisis. The contribution of oil energy to total energy, after the output turns to decreasing process, decreases by 177.87x10 6 tons (converted to coal at the rate 6848 kcal/kg) per year at maximum. Converted to the GNP of the world, this becomes (425 dollar/ton x 177.87 x 10 6 ton=75.6 x 10 9 dollar). This fluctuation width in a year must be compensated by the change of industrial structure and energy supplying means. The countermeasure and preparation are proposed from the viewpoints of the energy and the industrial structure in which nuclear power generation plays important role. The largest production on the earth limited by energy consumption and the temperature balance on the earth is investigated, and the perspective in the future is given. (Yamamoto, Y.)

  1. What value, detection limits

    International Nuclear Information System (INIS)

    Currie, L.A.

    1986-01-01

    Specific approaches and applications of LLD's to nuclear and ''nuclear-related'' measurements are presented in connection with work undertaken for the U.S. Nuclear Regulatory Commission and the International Atomic Energy Agency. In this work, special attention was given to assumptions and potential error sources, as well as to different types of analysis. For the former, the authors considered random and systematic error associated with the blank and the calibration and sample preparation processes, as well as issues relating to the nature of the random error distributions. Analysis types considered included continuous monitoring, ''simple counting'' involving scalar quantities, and spectrum fitting involving data vectors. The investigation of data matrices and multivariate analysis is also described. The most important conclusions derived from this study are: that there is a significant lack of communication and compatibility resulting from diverse terminology and conceptual bases - including no-basis ''ad hoc'' definitions; that the distinction between detection decisions and detection limits is frequently lost sight of; and that quite erroneous LOD estimates follow from inadequate consideration of the actual variability of the blank, and systematic error associated with the blank, the calibration-recovery factor, matrix effects, and ''black box'' data reduction models

  2. Exposure Monitoring and Risk Assessment of Biphenyl in the Workplace

    Directory of Open Access Journals (Sweden)

    Hyeon-Yeong Kim

    2015-05-01

    Full Text Available This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m3, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10−4 (central tendency exposure and 0.56 × 10−4 (reasonable maximum exposure, which is below the acceptable risk value of 1.0 × 10−4. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

  3. Exposure monitoring and risk assessment of biphenyl in the workplace.

    Science.gov (United States)

    Kim, Hyeon-Yeong; Shin, Sae-Mi; Ham, Miran; Lim, Cheol-Hong; Byeon, Sang-Hoon

    2015-05-13

    This study was performed to assess exposure to and the risk caused by biphenyl in the workplace. Biphenyl is widely used as a heat transfer medium and as an emulsifier and polish in industry. Vapor or high levels of dust inhalation and dermal exposure to biphenyl can cause eye inflammation, irritation of respiratory organs, and permanent lesions in the liver and nervous system. In this study, the workplace environment concentrations were assessed as central tendency exposure and reasonable maximum exposure and were shown to be 0.03 and 0.12 mg/m³, respectively. In addition, the carcinogenic risk of biphenyl as determined by risk assessment was 0.14 × 10⁻⁴ (central tendency exposure) and 0.56 × 10⁻⁴ (reasonable maximum exposure), which is below the acceptable risk value of 1.0 × 10⁻⁴. Furthermore, the central tendency exposure and reasonable maximum exposure hazard quotients were 0.01 and 0.06 for oral toxicity, 0.05 and 0.23 for inhalation toxicity, and 0.08 and 0.39 for reproduction toxicity, respectively, which are all lower than the acceptable hazard quotient of 1.0. Therefore, exposure to biphenyl was found to be safe in current workplace environments. Because occupational exposure limits are based on socioeconomic assessment, they are generally higher than true values seen in toxicity experiments. Based on the results of exposure monitoring of biphenyl, the current occupational exposure limits in Korea could be reviewed.

  4. Comparison of personal radio frequency electromagnetic field exposure in different urban areas across Europe

    International Nuclear Information System (INIS)

    Joseph, Wout; Frei, Patrizia; Rooesli, Martin; Thuroczy, Gyoergy; Gajsek, Peter; Trcek, Tomaz; Bolte, John; Vermeeren, Guenter; Mohler, Evelyn; Juhasz, Peter; Finta, Viktoria; Martens, Luc

    2010-01-01

    Background: Only limited data are available on personal radio frequency electromagnetic field (RF-EMF) exposure in everyday life. Several European countries performed measurement studies in this area of research. However, a comparison between countries regarding typical exposure levels is lacking. Objectives: To compare for the first time mean exposure levels and contributions of different sources in specific environments between different European countries. Methods: In five countries (Belgium, Switzerland, Slovenia, Hungary, and the Netherlands), measurement studies were performed using the same personal exposure meters. The pooled data were analyzed using the robust regression on order statistics (ROS) method in order to allow for data below the detection limit. Mean exposure levels were compared between different microenvironments such as homes, public transports, or outdoor. Results: Exposure levels were of the same order of magnitude in all countries and well below the international exposure limits. In all countries except for the Netherlands, the highest total exposure was measured in transport vehicles (trains, car, and busses), mainly due to radiation from mobile phone handsets (up to 97%). Exposure levels were in general lower in private houses or flats than in offices and outdoors. At home, contributions from various sources were quite different between countries. Conclusions: Highest total personal RF-EMF exposure was measured inside transport vehicles and was well below international exposure limits. This is mainly due to mobile phone handsets. Mobile telecommunication can be considered to be the main contribution to total RF-EMF exposure in all microenvironments.

  5. Chronic particulate exposure, mortality and cardiovascular outcomes in the nurses health study

    Science.gov (United States)

    Adverse health effects of exposures to acute air pollution have been well studied. Fewer studies have examined effects of chronic exposure. Previous studies used exposure estimates for narrow time periods and were limited by the geographic distribution of pollution monitors. This...

  6. The Cruelest Cure? Ethical Issues in the Implementation of Exposure-Based Treatments

    Science.gov (United States)

    Olatunji, Bunmi O.; Deacon, Brett J.; Abramowitz, Jonathan S.

    2009-01-01

    Numerous studies have provided supportive evidence for the efficacy of exposure-based treatments for many psychological disorders. However, surprisingly few therapists use exposure therapy in the clinical setting. Although the limited use of exposure-based treatments may be partially attributable to a shortage of suitably trained therapists,…

  7. ASSESSMENT OF HUMAN EXPOSURE TO TOLUENE DIISOCYANATE

    Directory of Open Access Journals (Sweden)

    OLIVIA ANCA RUSU

    2011-03-01

    Full Text Available Assessment of human exposure to toluene diisocyanate. Toluene diisocyanate (TDI, an aromatic compound, may be dangerous for human health. Diisocyanates have wide industrial use in the fabrication of flexible and rigid foams, fibers, elastomers, and coatings such as paints and varnishes. Isocyanates are known skin and respiratory sensitizers, and proper engineering controls should be in place to prevent exposure to isocyanate liquid and vapor; exposure to TDI vapors is well documented to increase asthma risk. The study focused on the exposure of workers and nearby populations to toluene diisocyanate in a Polyurethane Foam Factory located in Baia Mare, Romania. Workplace air measurements were performed in different departments of the plant, after sampling either in fixed points or as personal monitoring. Sampling in four different locations of Baia Mare town was carried out, - during and after the foaming process. TDI sampling was performed on silica cartridge followed by GC-MS analysis. TDI concentration at workplace was lower than 0,035 mg/m³, which represents the permissible exposure limit, while in the city the TDI concentration had shown values below 0,20 μg/m³. Health assessment of a group of 49 workers was based on questionnaire interview, determination of TDI antibodies and lung function tests. Data collected until this stage do not show any negative effects of TDI on the employees health. Since this plant had only recently begun operating, continuous workplace and ambient air TDI monitoring, along with workers health surveillance, is deemed necessary.

  8. Assessing asbestos exposure potential in nonindustrial settings.

    Science.gov (United States)

    Chang, S N; White, L E; Scott, W D

    1987-01-01

    The presence of asbestos containing materials (ACM) in office and commercial buildings is a significant environmental problem. Asbestosis, mesothelioma and lung cancer have been linked with industrial exposure to airborne asbestos. The extensive use of asbestos products in buildings has raised concerns about the widespread exposure of the general public to asbestos in nonoccupational settings. The presence of asbestos in a building does not necessarily mean that significant exposure of the occupants of the building has occurred, but it is important that the asbestos be monitored regularly to ensure that fibers do not become airborne. If ACM are contained within a matrix and not disturbed, exposure is unlikely. However, if the asbestos becomes friable (crumbling) or if building maintenance, repair, renovation or other activities disturb ACM, airborne asbestos fibers may be a source of exposure to the occupants of the building. Currently, asbestos exposure assessment is conducted by a phase contrast light microscope (PCM) technique. Due to its inherent limitation in resolution and the generic counting rules used, analysis by the PCM method underestimates the airborne asbestos fiber concentration as compared to analysis by transmission electron microscopy (TEM). It is important that the air monitoring results analyzed by PCM be interpreted carefully in conjunction with a survey by a professional to judge the physical condition of the ACM in buildings. Exposure levels to airborne asbestos fibers vary from day to day and depend on the physical condition of the material involved and the type of operating and maintenance program in place.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Xylazine Exposures Reported to Texas Poison Centers.

    Science.gov (United States)

    Forrester, Mathias B

    2016-10-01

    Xylazine is a sedative, analgesic, anesthetic, and central muscle relaxant approved for animals but not humans. Although xylazine is an emerging drug of abuse, there are limited data on potentially adverse exposures to the drug. The intent of this study was to describe potentially adverse xylazine exposures reported to a large poison center system. All xylazine exposures reported to Texas poison centers between 2000 and 2014 were included. The distribution of cases by select variables was determined. Of 76 total cases, 93% of the patients were ≥20 years of age, and 54% were male. Fifty-one percent of the exposures occurred by injection, 28% by ingestion, 16% were dermal, 14% were ocular, and 3% by inhalation. Sixty-four percent of the exposures were unintentional, 32% were intentional, and 1% each was related to malicious use and adverse reaction. Sixty-seven percent of the patients were already at or en route to a health care facility when the poison center was contacted, 21% were managed on-site, and 9% were referred to a health care facility. The most common clinical effects were drowsiness or lethargy (47%), bradycardia (20%), hypotension (11%), hypertension (9%), puncture or wound (8%), and slurred speech (8%). Xylazine exposures tended to involve patients who were adult males, exposures were typically unintentional; and most often occurred by injection. Most of the patients were already at or en route to a health care facility when a poison center was contacted. The most frequently reported adverse effects were cardiovascular or neurologic in nature. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Evaluation of concentration limits of radionuclides produced by accelerators

    International Nuclear Information System (INIS)

    Shibata, Tokushi; Ohkubo, Tohru; Uwamino, Yoshitomo; Iwai, Satoshi; Satoh, Osamu; Rintsu, Yukoh; Fukumoto, Toshiharu.

    1992-01-01

    This report describes the evaluation of concentration limits of 78 radionuclides typically produced by accelerator facilities and not listed in ICRP Pub. 30. The evaluation method and system have been developed in the present study. The evaluated values were compared with tremendously severe concentration limits given in the Annex Table 2 of the Science and Technology Agency Notification No. 15 which describes the concentration limits of the nuclides of which concentration limits are not given in the Annex Table 1 of the Agency Notification No. 15. The results show that two to nine order larger limits should be used. The new limits rationalize greatly the internal exposure control and the design of accelerator facilities. Simple and convenient techniques are also discussed for finding concentration limits of very-short-lived nuclides without knowing detail information about the nuclides such as decay scheme and metabolic data. (author)

  11. Tracking natural and anthropogenic Pb exposure to its geological source.

    Science.gov (United States)

    Evans, Jane; Pashley, Vanessa; Madgwick, Richard; Neil, Samantha; Chenery, Carolyn

    2018-01-31

    Human Pb exposure comes from two sources: (i) natural uptake through ingestion of soils and typified by populations that predate mining activity and (ii) anthropogenic exposure caused by the exposure to Pb derived from ore deposits. Currently, the measured concentration of Pb within a sample is used to discriminate between these two exposure routes, with the upper limit for natural exposure in skeletal studies given as 0.5 or 0.7 mg/kg in enamel and 0.5/0.7 μg/dL in blood. This threshold approach to categorising Pb exposure does not distinguish between the geological origins of the exposure types. However, Pb isotopes potentially provide a more definitive means of discriminating between sources. Whereas Pb from soil displays a crustal average 238 U/ 204 Pb (μ) value of c 9.7, Pb from ore displays a much wider range of evolution pathways. These characteristics are transferred into tooth enamel, making it possible to characterize human Pb exposure in terms of the primary source of ingested Pb and to relate mining activity to geotectonic domains. We surmise that this ability to discriminate between silicate and sulphide Pb exposure will lead to a better understanding of the evolution of early human mining activity and development of exposure models through the Anthropocene.

  12. Comparison of modeling approaches to prioritize chemicals based on estimates of exposure and exposure potential.

    Science.gov (United States)

    Mitchell, Jade; Arnot, Jon A; Jolliet, Olivier; Georgopoulos, Panos G; Isukapalli, Sastry; Dasgupta, Surajit; Pandian, Muhilan; Wambaugh, John; Egeghy, Peter; Cohen Hubal, Elaine A; Vallero, Daniel A

    2013-08-01

    While only limited data are available to characterize the potential toxicity of over 8 million commercially available chemical substances, there is even less information available on the exposure and use-scenarios that are required to link potential toxicity to human and ecological health outcomes. Recent improvements and advances such as high throughput data gathering, high performance computational capabilities, and predictive chemical inherency methodology make this an opportune time to develop an exposure-based prioritization approach that can systematically utilize and link the asymmetrical bodies of knowledge for hazard and exposure. In response to the US EPA's need to develop novel approaches and tools for rapidly prioritizing chemicals, a "Challenge" was issued to several exposure model developers to aid the understanding of current systems in a broader sense and to assist the US EPA's effort to develop an approach comparable to other international efforts. A common set of chemicals were prioritized under each current approach. The results are presented herein along with a comparative analysis of the rankings of the chemicals based on metrics of exposure potential or actual exposure estimates. The analysis illustrates the similarities and differences across the domains of information incorporated in each modeling approach. The overall findings indicate a need to reconcile exposures from diffuse, indirect sources (far-field) with exposures from directly, applied chemicals in consumer products or resulting from the presence of a chemical in a microenvironment like a home or vehicle. Additionally, the exposure scenario, including the mode of entry into the environment (i.e. through air, water or sediment) appears to be an important determinant of the level of agreement between modeling approaches. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Comparison of modeling approaches to prioritize chemicals based on estimates of exposure and exposure potential

    Science.gov (United States)

    Mitchell, Jade; Arnot, Jon A.; Jolliet, Olivier; Georgopoulos, Panos G.; Isukapalli, Sastry; Dasgupta, Surajit; Pandian, Muhilan; Wambaugh, John; Egeghy, Peter; Cohen Hubal, Elaine A.; Vallero, Daniel A.

    2014-01-01

    While only limited data are available to characterize the potential toxicity of over 8 million commercially available chemical substances, there is even less information available on the exposure and use-scenarios that are required to link potential toxicity to human and ecological health outcomes. Recent improvements and advances such as high throughput data gathering, high performance computational capabilities, and predictive chemical inherency methodology make this an opportune time to develop an exposure-based prioritization approach that can systematically utilize and link the asymmetrical bodies of knowledge for hazard and exposure. In response to the US EPA’s need to develop novel approaches and tools for rapidly prioritizing chemicals, a “Challenge” was issued to several exposure model developers to aid the understanding of current systems in a broader sense and to assist the US EPA’s effort to develop an approach comparable to other international efforts. A common set of chemicals were prioritized under each current approach. The results are presented herein along with a comparative analysis of the rankings of the chemicals based on metrics of exposure potential or actual exposure estimates. The analysis illustrates the similarities and differences across the domains of information incorporated in each modeling approach. The overall findings indicate a need to reconcile exposures from diffuse, indirect sources (far-field) with exposures from directly, applied chemicals in consumer products or resulting from the presence of a chemical in a microenvironment like a home or vehicle. Additionally, the exposure scenario, including the mode of entry into the environment (i.e. through air, water or sediment) appears to be an important determinant of the level of agreement between modeling approaches. PMID:23707726

  14. A Technique: Exposure Therapy

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-08-01

    Conclusion: Exposure with response prevention is a basic and effective technique. Every cognitive behavior therapist must be able to implement this technique and be cognizant of pearls of this procedure. (Journal of Cognitive Behavioral Psychotherapy and Research 2013, 2: 121-128 [JCBPR 2013; 2(2.000: 121-128

  15. NTPR Radiation Exposure Reports

    Science.gov (United States)

    History Documents US Underground Nuclear Test History Reports NTPR Radiation Exposure Reports Enewetak Atoll Cleanup Documents TRAC About Who We Are Our Values History Locations Our Leadership Director Support Center Contact Us FAQ Sheet Links Success Stories Contracts Business Opportunities Current

  16. Probabilistic dietary exposure models

    NARCIS (Netherlands)

    Boon, Polly E.; Voet, van der H.

    2015-01-01

    Exposure models are used to calculate the amount of potential harmful chemicals ingested by a human population. Examples of harmful chemicals are residues of pesticides, chemicals entering food from the environment (such as dioxins, cadmium, lead, mercury), and chemicals that are generated via

  17. Human exposure to nickel

    Energy Technology Data Exchange (ETDEWEB)

    Grandjean, P

    1984-01-01

    In order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. Thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. Occupational exposures may lead to the retention of 100 micrograms of nickel per day. Environmental nickel levels depend particularly on natural sources, pollution from nickel-manufacturing industries and airborne particles from combustion of fossil fuels. Absorption from atmospheric nickel pollution is of minor concern. Vegetables usually contain more nickel than do other food items. Certain products, such as baking powder and cocoa powder, have been found to contain excessive amounts of nickel, perhaps related to nickel leaching during the manufacturing process. Soft drinking-water and acid beverages may dissolve nickel from pipes and containers. Scattered studies indicate a highly variable dietary intake of nickel, but most averages are about 200-300 micrograms/day. In addition, skin contact to a multitude of metal objects may be of significance to the large number of individuals suffering from contact dermatitis and nickel allergy. Finally, nickel alloys are often used in nails and prostheses for orthopaedic surgery, and various sources may contaminate intravenous fluids. Thus, human nickel exposure originates from a variety of sources and is highly variable. Occupational nickel exposure is of major significance, and leaching of nickel may add to dietary intakes and to cutaneous exposures. 79 references.

  18. Fetal Alcohol Exposure

    Science.gov (United States)

    ... categories: 4 » Fetal Alcohol Syndrome (FAS) » Partial FAS (pFAS) » Alcohol-Related Neurodevelopmental Disorder (ARND) » Alcohol-Related Birth ... either prenatally, after birth, or both Partial FAS (pFAS) Partial FAS (pFAS) involves prenatal alcohol exposure, and ...

  19. The limits of deterrence

    International Nuclear Information System (INIS)

    Tertrais, Bruno

    2009-01-01

    The objective of this contribution is to propose a better insight of the validity of the theory of deterrence, and of related doctrines in more complex and more various situations than in the past: emergence of powers like China and India, of new nuclear States like North Korea and Pakistan, of countries planning to acquire nuclear weapons like Iran, and possibility of a new wave of nuclear proliferation in Middle-East and north-eastern Asia. It also aims at providing arguments in the debates on the struggle against nuclear proliferation and on the future of deterrence. The author first presents and comments the principles of deterrence, and illustrates them by more or less recent historical situations (Iran during the war with Iraq, USA after Pearl Harbour, Arab-Israeli wars, Iraq, and so on). He notably outlines that the notion of deterrence is present in Islamic culture, and that Iran has well integrated it in its defence strategy. Examples of statements and behaviours of other Arab leaders are discussed. The author also briefly indicates how the deterrence strategy is present in the official doctrines of Russia, India, Pakistan, and North Korea. In a second part, based on various examples, the author analyses the practical limitations of deterrence by distinguishing the psychological dimension (bounded rationality, political leaders suffering from various psychological problems, importance of the ideological and spiritual dimension, values prevailing on interests, the case of Iran), and the strategic dimension (good understanding of the enemy, sensitivity of the threat of massive damages, existence of a single decision centre and of an efficient communication). The author finally proposes seven recommendations for better deterrence efficiency

  20. Over the limit.

    Science.gov (United States)

    Qu, G

    1989-01-01

    With over 1 billion population, China is adding some 15 million to that total each year. And in the 18 years from 1982 to 2000, the net increase of Chinese population is expected to exceed 200 million. Because of the gigantic pressure from population and some mistakes in policies, the levels of ecological destruction and environment pollution are both serious. This includes deforestation, grassland degradation, desert encroachment, water resources shortage, and waste of mineral resources. Natural disasters including floods and droughts caused by those problems happen more and more frequently. If development damages the resource base, it can only result in a false prosperity, the so-called hollow economy. A large number of environmental problems result directly or indirectly from the pressure of population growth. Studies show that the appropriate number of people that can be supported by China's 9.6 million sq. km is about 700 million. However, this limit is now exceeded by over 300 million people, and will be exceeded by 500 million by the end of this century. Therefore, the task is to implement a birth control policy. At present, in urban areas, the goal of family planning has been reached, but in rural areas hard work is needed. Population control in urban areas, especially in big and medium-sized cities, includes dealing with the inflow of migrants from the countryside. There are 13 cities with a population above 2 million, 37 cities above 1-2 million, and 75 cities above 0.5-1 million. A lot of cities are very crowded, exerting great pressure on the environment. The booming of rural enterprises could provide a good solution to control the flow of rural people into big and medium-sized cities. The relationship between population, resources, environment, and development should be managed properly.

  1. UV exposure in cars.

    Science.gov (United States)

    Moehrle, Matthias; Soballa, Martin; Korn, Manfred

    2003-08-01

    There is increasing knowledge about the hazards of solar and ultraviolet (UV) radiation to humans. Although people spend a significant time in cars, data on UV exposure during traveling are lacking. The aim of this study was to obtain basic information on personal UV exposure in cars. UV transmission of car glass samples, windscreen, side and back windows and sunroof, was determined. UV exposure of passengers was evaluated in seven German middle-class cars, fitted with three different types of car windows. UV doses were measured with open or closed windows/sunroof of Mercedes-Benz E 220 T, E 320, and S 500, and in an open convertible car (Mercedes-Benz CLK). Bacillus subtilis spore film dosimeters (Viospor) were attached to the front, vertex, cheeks, upper arms, forearms and thighs of 'adult' and 'child' dummies. UV wavelengths longer than >335 nm were transmitted through car windows, and UV irradiation >380 nm was transmitted through compound glass windscreens. There was some variation in the spectral transmission of side windows according to the type of glass. On the arms, UV exposure was 3-4% of ambient radiation when the car windows were shut, and 25-31% of ambient radiation when the windows were open. In the open convertible car, the relative personal doses reached 62% of ambient radiation. The car glass types examined offer substantial protection against short-wave UV radiation. Professional drivers should keep car windows closed on sunny days to reduce occupational UV exposure. In individuals with polymorphic light eruption, produced by long-wave UVA, additional protection by plastic films, clothes or sunscreens appears necessary.

  2. Chernobyl accident. Exposures and effects

    International Nuclear Information System (INIS)

    Bennett, B.; Bouville, A.; Hall, P.; Savkin, M.; Storm, H.

    2000-01-01

    The Chernobyl accident that occurred in Ukraine in April 1986 happened during an experimental test of the electrical control system as the reactor was being shut down for routine maintenance. The operators, in violation of safety regulations, had switched off important control systems and allowed the reactor to reach unstable, low-power conditions. A sudden power surge caused a steam explosion that ruptured the reactor vessel and allowed further violent fuel-steam interactions that destroyed the reactor and the reactor building. The Chernobyl accident was the most serious to have ever occurred in the nuclear power industry. The accident caused the early death of 30 power plant employees and fire fighters and resulted in widespread radioactive contamination in areas of Belarus, the Russian Federation, and Ukraine inhabited by several million people. Radionuclides released from the reactor that caused exposure of individuals were mainly iodine-131, caesium-134 and caesium-137. Iodine-131 has a short radioactive half-life (8 days), but it can be transferred relatively rapidly through milk and leafy vegetables to humans. Iodine becomes localized in the thyroid gland. For reasons of intake of these foods, size of thyroid gland and metabolism, the thyroid doses are usually greater to infants and children than to adults. The isotopes of caesium have relatively long half-lives (caesium-134: 2 years; caesium-137: 30 years). These radionuclides cause long-term exposures through the ingestion pathway and from external exposure to these radionuclides deposited on the ground. In addition to radiation exposure, the accident caused long-term changes in the lives of people living in the contaminated regions, since measures intended to limit radiation doses included resettlements, changes in food supplies, and restrictions in activities of individuals and families. These changes were accompanied by major economic, social and political changes in the affected countries resulting

  3. Exposure mode study to xenon-133 in a reactor building

    International Nuclear Information System (INIS)

    Perier, Aurelien

    2014-01-01

    The work described in this thesis focuses on the external and internal dose assessment to xenon-133. During the nuclear reactor operation, fission products and radioactive inert gases, as 133 Xe, are generated and might be responsible for the exposure of workers in case of clad defect. Particle Monte Carlo transport code is adapted in radioprotection to quantify dosimetric quantities. The study of exposure to xenon-133 is conducted by using Monte-Carlo simulations based on GEANT4, an anthropomorphic phantom, a realistic geometry of the reactor building, and compartmental models. The external exposure inside a reactor building is conducted with a realistic and conservative exposure scenario. The effective dose rate and the eye lens equivalent dose rate are determined by Monte-Carlo simulations. Due to the particular emission spectrum of xenon-133, the equivalent dose rate to the lens of eyes is discussed in the light of expected new eye dose limits. The internal exposure occurs while xenon-133 is inhaled. The lungs are firstly exposed by inhalation, and their equivalent dose rate is obtained by Monte-Carlo simulations. A biokinetic model is used to evaluate the internal exposure to xenon-133. This thesis gives us a better understanding to the dosimetric quantities related to external and internal exposure to xenon-133. Moreover the impacts of the dosimetric changes are studied on the current and future dosimetric limits. The dosimetric quantities are lower than the current and future dosimetric limits. (author)

  4. Maternal exposure to alkali, alkali earth, transition and other metals: Concentrations and predictors of exposure

    International Nuclear Information System (INIS)

    Hinwood, A.L.; Stasinska, A.; Callan, A.C.; Heyworth, J.; Ramalingam, M.; Boyce, M.; McCafferty, P.; Odland, J.Ø.

    2015-01-01

    Most studies of metals exposure focus on the heavy metals. There are many other metals (the transition, alkali and alkaline earth metals in particular) in common use in electronics, defense industries, emitted via combustion and which are naturally present in the environment, that have received limited attention in terms of human exposure. We analysed samples of whole blood (172), urine (173) and drinking water (172) for antimony, beryllium, bismuth, cesium, gallium, rubidium, silver, strontium, thallium, thorium and vanadium using ICPMS. In general most metals concentrations were low and below the analytical limit of detection with some high concentrations observed. Few factors examined in regression models were shown to influence biological metals concentrations and explained little of the variation. Further study is required to establish the source of metals exposures at the high end of the ranges of concentrations measured and the potential for any adverse health impacts in children. - This study has demonstrated exposure to alkali, alkali earth and transition metals in pregnant women with factors such as breastfeeding, fish oil use and diet affecting exposures

  5. Biological dosimetry, scopes and limitations

    International Nuclear Information System (INIS)

    Guerrero C, C.; Brena V, M.

    1999-01-01

    The analysis of the aberrations in chromosomes is an alternative to establish the exposure dose to the radiation, when the information provided by the traditional physical methods is insufficient. There are diverse causes by which it can reached to apply an alternative system, such is the case of exposures of another persons to the management of radiation sources, which not carry physical dosemeter. Contrary case is to the occupational exposure personnel (OEP), what must to utilize some system for determining the exposure dose, even so can be needed the case for more information. In any case, the cells from the affected person are the alternative without the biological system be overlap to the physical, it is complementary. (Author)

  6. Prevention and risks limitation of the radioactive installations

    International Nuclear Information System (INIS)

    San Segundo, T.

    1983-01-01

    Associated risks to the ionizing radiation, in general, and to the radioactive installations, in particular, are exposed; as well as the prevention and limitation techniques applied in order to keep risk into acceptable levels are detatched. Finally, the effect in the human life of the radioactivity use and other activities are compared and man-made occupational and public exposures are explained. (author)

  7. Evaluation of environmental radiation exposure

    International Nuclear Information System (INIS)

    Imai, Kazuhiko

    1974-01-01

    The environmental radiation exposure due to radioactive rare gases is most important both at the time of reactor accidents and also in the long-term normal operation of reactor plants. The exposure dose is usually calculated by means of computers. The procedure of the calculation on environmental exposure dose is divided in several consecutive steps. The calculational formulae frequently used and those proposed recently are given with the explanation on released radionuclides, release to the atmosphere, concentration in the atmosphere, β-ray exposure, γ-ray exposure, and calculation of long-term exposure dose. (Mori, K.)

  8. Metal dust exposure and lung function deterioration among steel workers: an exposure-response relationship.

    Science.gov (United States)

    Hamzah, Nurul Ainun; Mohd Tamrin, Shamsul Bahri; Ismail, Noor Hassim

    2016-07-01

    Metallic dust is a heterogeneous substance with respiratory sensitizing properties. Its long term exposure adversely affected lung function, thus may cause acute or chronic respiratory diseases. A cross-sectional study was conducted in a steel factory in Terengganu, Malaysia to assess the metal dust exposure and its relationship to lung function values among 184 workers. Metal dust concentrations values (Co, Cr, and Ni) for each worker were collected using air personal sampling. Lung function values (FEV 1 , FVC, and %FEV 1 /FVC) were determined using spirometer. Exposure to cobalt and chromium were 1-3 times higher than permissible exposure limit (PEL) while nickel was not exceeding the PEL. Cumulative of chromium was the predictor to all lung function values (FEV 1 , FVC, and %FEV 1 /FVC). Frequency of using mask was positively associated with FVC (Adj b = 0.263, P = 0.011) while past respiratory illnesses were negatively associated with %FEV 1 /FVC (Adj b = -1.452, P = 0.026). Only few workers (36.4%) were found to wear their masks all times during the working hours. There was an exposure-response relationship of cumulative metal dust exposure with the deterioration of lung function values. Improvement of control measures as well as proper and efficient use or personal protection equipment while at work could help to protect the respiratory health of workers.

  9. X-ray exposures given with various combinations of film and screen

    International Nuclear Information System (INIS)

    Schlenker, R.A.; Kirsh, I.E.

    A comparison of entrance exposure doses of patients for various film and screen combinations and xeroradiographs showed that moderate speed screen and film gave exposures 4 to 7 times greater than fast film and screen and that xeroradiographs produced exposures 20 to 40 times greater than fast film and screen. Xeroradiographs produced table top incident exposures which exceeded Illinois Department of Health limits, while conventional film-screen combinations did not. (U.S.)

  10. Temporal Variability of Daily Personal Magnetic Field Exposure Metrics in Pregnant Women

    OpenAIRE

    Lewis, Ryan C.; Evenson, Kelly R.; Savitz, David A.; Meeker, John D.

    2014-01-01

    Recent epidemiology studies of power-frequency magnetic fields and reproductive health have characterized exposures using data collected from personal exposure monitors over a single day, possibly resulting in exposure misclassification due to temporal variability in daily personal magnetic field exposure metrics, but relevant data in adults are limited. We assessed the temporal variability of daily central tendency (time-weighted average, median) and peak (upper percentiles, maximum) persona...

  11. Limit of probability of causation in the compensation of radiation induced malignant diseases

    International Nuclear Information System (INIS)

    Sun Shiquan

    1989-01-01

    Etiological relationship between previous radiation exposure and malignant diseases concerned could be estimated from NIH Epidemiological Tables expressed as Probability of Causation (PC). But the limit of PC in the compensation of radiation induced malignant diseases has not been decided definitely. In this paper PC calculations were made for populations of occupational exposure with typical distribution of individual doses and levels of exposure. The results show that it is feasible to choice PC ≥ 50% as a limit of compensation for leukemia and radon induced lung cancer. Some lenient limits may be taken for other radiation related solid carcinomas

  12. Doses from radiation exposure

    CERN Document Server

    Menzel, H G

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection's (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP's 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effecti...

  13. Occupational exposure in hemodynamic

    International Nuclear Information System (INIS)

    Silva, Amanda J.; Fernandes, Ivani M.; Silva, Paula P. Nou; Sordi, Gian Maria A.A.; Carneiro, Janete C.G.G.

    2011-01-01

    This paper has an objective to perform a radiometric survey at a hemodynamic service. Besides, it was intended to evaluate the effective dose of health professionals and to provide data which can contribute with minimization of exposures during the realization of hemodynamic procedure. The radiometric survey was realized in the real environment of work simulating the conditions of a hemodynamic study with a ionization chamber

  14. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma-edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  15. FED pumped limiter configuration issues

    International Nuclear Information System (INIS)

    Haines, J.R.; Fuller, G.M.

    1983-01-01

    Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge

  16. The reduction of retinal autofluorescence caused by light exposure.

    Science.gov (United States)

    Morgan, Jessica I W; Hunter, Jennifer J; Merigan, William H; Williams, David R

    2009-12-01

    A prior study showed that long exposure to 568-nm light at levels below the maximum permissible exposure safety limit produces retinal damage preceded by a transient reduction in the autofluorescence of retinal pigment epithelial (RPE) cells in vivo. The present study shows how the effects of exposure power and duration combine to produce this autofluorescence reduction and find the minimum exposure causing a detectable autofluorescence reduction. Macaque retinas were imaged using a fluorescence adaptive optics scanning laser ophthalmoscope to resolve individual RPE cells in vivo. The retina was exposed to 568-nm light over a square subtending 0.5 degrees with energies ranging from 1 to 788 J/cm(2), where power and duration were independently varied. In vivo exposures of 5 J/cm(2) and higher caused an immediate decrease in autofluorescence followed by either full autofluorescence recovery (exposures or= 247 J/cm(2)). No significant autofluorescence reduction was observed for exposures of 2 J/cm(2) and lower. Reciprocity of exposure power and duration held for the exposures tested, implying that the total energy delivered to the retina, rather than its distribution in time, determines the amount of autofluorescence reduction. That reciprocity held is consistent with a photochemical origin, which may or may not cause retinal degeneration. The implementation of safe methods for delivering light to the retina requires a better understanding of the mechanism causing autofluorescence reduction. Finally, RPE imaging was demonstrated using light levels that do not cause a detectable reduction in autofluorescence.

  17. Radiofrequency radiation exposure from RF-generating plant

    International Nuclear Information System (INIS)

    Wright, J.M.; Bell, K.M.

    2000-01-01

    As part of an intervention to assist industry improve the control of risks associated with the use of RF-generating plant, exposure to radiofrequency radiation (RFR) was assessed in 30 workplaces. Information about the workplace, work practices and knowledge about RFR and its control was also collected. The study found that: 1. For 72% of operators and 35% of bystanders, the spatially averaged exposure exceeded the exposure limits. These figures approximately halved when the duty cycle was applied; 2. Assessment of RFR levels was not common; 3. Task rotation was used to limit exposure of operators; 4. Access was not controlled to areas where RFR sources were used; 5. There was lack of knowledge about RF shielding practices in industry; 6. Nearly 50% of workplaces did not maintain the plant regularly; and 7. There had been no health surveillance on any plant operators in any of the workplaces in the study. Copyright (2000) Australasian Radiation Protection Society Inc

  18. Charter Halibut Limited Access Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This limited access system limits the number of charter vessels that may participate in the guided sport fishery for halibut in area 2C and 3A. NMFS issues a charter...

  19. Benzene exposures in urban areas

    International Nuclear Information System (INIS)

    Valerio, F.; Pala, M.; Cipolla, M.; Stella, A.

    2001-01-01

    Benzene exposures in urban areas were reviewed. Available data confirm that both in USA and Europe, benzene concentrations measured by fixed outdoor monitoring stations underestimate personal exposures of urban residents. Indoor sources, passive smoke and the high exposures during commuting time may explain this difference. Measures in European towns confirm that very frequently mean daily personal exposures to benzene exceed 10 μg/m 3 , current European air quality guideline for this carcinogenic compound [it

  20. Derived release limits for airborne effluents at TRIGA - INR Reactor

    International Nuclear Information System (INIS)

    Toma, A.; Dulama, C.; Hirica, O.; Mihai, S.; Oprea, I.

    2008-01-01

    Beginning from fulfilling the purposes of dose limitation system recommended by ICRP, and now accepted in radiation protection, this paper presents an environmental transfer model to calculate derived release limits for airborne and gaseous radioactive effluents at TRIGA-INR, 14 MW Steady State Reactor, in function on INR-Pitesti site. The methodology consists in determination of the principal exposure pathways for different groups of population and dose calculations for each radionuclide. The characterization of radionuclides transfer to environment was made using the compartmental model. The parameter transfer concept was used to describe the distribution of radionuclides between the different compartments. Atmospheric dispersion was very carefully treated, because it is the primary mechanism of the transfer of radionuclides in the environment and it determines all exposure pathways. Calculation of the atmospheric dispersion was made using ORION-II computer code based on the Gaussian plume model which takes account of site's specific climate and relief conditions. Default values recommended by literature were used to calculate some of the parameters when specific site values were not available. After identification of all transfer parameters which characterize the most important exposure pathways, the release rate corresponding to the individual dose rate limit was calculated. This maximum release rate is the derived release limit for each radionuclide and source. In the paper, the derived release limits are calculated for noble gases, radioiodine and other airborne particulate radionuclides, which can be released on the TRIGA-INR reactor stack, and are important to radiation protection. (authors)

  1. Tolerance limits of X-ray image intensity

    International Nuclear Information System (INIS)

    Stargardt, A.; Juran, R.; Brandt, G.A.

    1985-01-01

    Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author)

  2. Nuclide-related exemption limits for radioactive materials

    International Nuclear Information System (INIS)

    Przyborowski, S.; Scheler, R.

    1984-01-01

    A procedure has been proposed for setting nuclide-related exemption limits for radioactive materials. It consists in grading the radionuclides into 4 groups of radiotoxicity and assigning only one activity limit to each of them. Examples are given for about 200 radionuclides. The radiation exposures resulting from a continuous steady release of activity fractions or from short-period release of the entire activity were assessed to remain below 0.1 ALI in both of these borderline cases, thus justifying the license-free utilization of radioactive materials below the exemption limits. (author)

  3. Principles for limiting releases of radioactive effluents into the environment

    International Nuclear Information System (INIS)

    1986-01-01

    This publication is concerned with the subject of limiting releases of radioactive effluents during normal, controlled operation of nuclear installations. It does not deal with releases from accidents where it is only possible to limit exposures by intervention. In 1978 the IAEA published guidance on the concepts and principles for use by the competent authorities in setting limits for planned releases of radioactive material into the environment (Safety Series No. 45). This publication is a complete revision of Safety Series No. 45 and its Annex

  4. Sulfonylurea herbicides – methodological challenges in setting aquatic limit values

    DEFF Research Database (Denmark)

    Rosenkrantz, Rikke Tjørnhøj; Baun, Anders; Kusk, Kresten Ole

    according to the EU Water Framework Directive, the resulting Water Quality Standards (WQSs) are below the analytical quantification limit, making it difficult to verify compliance with the limit values. However, several methodological concerns may be raised in relation to the very low effect concentrations...... and rimsulfuron. The following parameters were varied during testing: pH, exposure duration, temperature and light/dark cycle. Preliminary results show that a decrease in pH causes an increase in toxicity for all compounds. Exposure to a high concentration for 24 hours caused a reduction in growth rate, from...... for setting limit values for SUs or if more detailed information should be gained by taking methodological considerations into account....

  5. Post-Exposure Prophylaxis (PEP)

    Science.gov (United States)

    ... Child Transmission of HIV Post-Exposure Prophylaxis (PEP) Pre-Exposure Prophylaxis (PrEP) HIV Treatment HIV Treatment: The Basics Just ... to HIV frequently. Another HIV prevention method, called pre-exposure prophylaxis or PrEP, is when people at high risk ...

  6. Normas y estándares aplicables a los campos electromagnéticos de radiofrecuencias en América Latina: guía para los límites de exposición y los protocolos de medición Norms and standards for radiofrequency electromagnetic fields in Latin America: guidelines for exposure limits and measurement protocols

    Directory of Open Access Journals (Sweden)

    Jorge Skvarca

    2006-09-01

    Full Text Available Las nuevas tecnologías que utilizan campos electromagnéticos (CEM ofrecen a la humanidad inmensos beneficios. Además de emplearse en la transmisión de energía eléctrica, las telecomunicaciones y en equipos industriales, médicos y electrodomésticos, los CEM tienen otras muchas y muy diversas aplicaciones. Algunos estudios demuestran que la exposición a los CEM podría producir efectos adversos a la salud, como cáncer y cambios en el comportamiento de las personas. Aunque hasta el presente no se ha demostrado que la exposición a CEM de baja intensidad provoque estos efectos, se trabaja por lograr un consenso científico al respecto y por establecer normas de seguridad adecuadas. La responsabilidad de desarrollar y promover los estándares de seguridad ha recaído fundamentalmente en organizaciones y agencias especializadas reconocidas internacionalmente; sin embargo, las autoridades sanitarias nacionales deben participar activamente en ese proceso. La Organización Panamericana de la Salud ha decidido promover investigaciones científicas y epidemiológicas con vistas a proponer guías y estándares armonizados. Algunos países de América Latina, como Argentina, Bolivia, Brasil, Chile, Colombia, Costa Rica, Ecuador, México, Perú y Venezuela ya cuentan con leyes específicas, aunque generalmente parciales o incompletas, basadas en las recomendaciones internacionales. En este artículo se describen las normas establecidas en América Latina y se analizan los diferentes enfoques de cada una de ellas.New technologies that use electromagnetic fields (EMF have proved greatly beneficial to humankind. EMF are used in a variety of ways in the transmission of electrical energy and in telecommunications, industry, and medicine. However, some studies have shown that EMF could be detrimental to one's health, having found an association between exposure to EMF on the one hand, and the incidence of some types of cancer as well as behavioral changes

  7. Irradiation Stability of Uranium Alloys at High Exposures

    International Nuclear Information System (INIS)

    McDonell, W.R.

    2001-01-01

    Postirradiation examinations were begun of a series of unrestrained dilute uranium alloy specimens irradiated to exposures up to 13,000 MWD/T in NaK-containing stainless steel capsules. This test, part of a program of development of uranium metal fuels for desalination and power reactors sponsored by the Division of Reactor Development and Technology, has the objective of defining the temperature and exposure limits of swelling resistance of the alloyed uranium. This paper discusses those test results

  8. Health Effects Related to Wind Turbine Noise Exposure

    DEFF Research Database (Denmark)

    Schmidt, Jesper Hvass; Klokker, Mads

    2014-01-01

    BACKGROUND: Wind turbine noise exposure and suspected health-related effects thereof have attracted substantial attention. Various symptoms such as sleep-related problems, headache, tinnitus and vertigo have been described by subjects suspected of having been exposed to wind turbine noise...... existing statistically-significant evidence indicating any association between wind turbine noise exposure and tinnitus, hearing loss, vertigo or headache. LIMITATIONS: Selection bias and information bias of differing magnitudes were found to be present in all current studies investigating wind turbine...

  9. Exposure levels and determinants of inhalable dust exposure in bakeries.

    Science.gov (United States)

    Burstyn, I; Teschke, K; Kennedy, S M

    1997-12-01

    The study's objectives were to measure full-shift exposure to inhalable dust in bakeries and define the determinants of full-shift exposure. Inhalable dust was measured gravimetrically. Ninety-six bakery workers, employed in seven different bakeries, participated in the study. Two side-by-side full-shift inhalable dust samples were obtained from each study participant on a single occasion. Samples were collected on 18 days selected at random. During the entire sampling period, bakers were observed and information on 14 different tasks was recorded at 15 min intervals. Other production characteristics were also recorded for each sampling day. These task and production variables were used in statistical modelling to identify significant predictors of exposure. The mean full-shift inhalable dust exposure was 8.2 mg/m3 (range: 0.1-110 mg/m3). A regression model explained 79% of the variability in exposure. The model indicated that tasks such as weighing, pouring and operating dough-brakers and reversible sheeters increased the exposure, while packing, catching and decorating decreased the exposure. Bread and bun production lines were associated with increased full-shift inhalable dust exposure, while cake production and substitution of dusting with the use of divider oil were associated with decreased exposure. Production tasks and characteristics are strong predictors of personal full-shift exposures to flour dust among bakers; these can be altered to reduce exposure levels.

  10. Retrospective benzene and total hydrocarbon exposure assessment for a petroleum marketing and distribution worker epidemiology study.

    Science.gov (United States)

    Armstrong, T W; Pearlman, E D; Schnatter, A R; Bowes, S M; Murray, N; Nicolich, M J

    1996-04-01

    A quantitative exposure-estimating algorithm for benzene and total hydrocarbons was developed for a case control study of petroleum marketing and distribution workers. The algorithm used a multiplicative model to adjust recently measured quantitative exposure data to past scenarios for which representative exposure measurement data did not exist. This was accomplished through the development of exposure modifiers to account for differences in the workplace, the materials handled, the environmental conditions, and the tasks performed. Values for exposure modifiers were obtained empirically and through physical/chemical relationships. Dates for changes that altered exposure potential were obtained from archive records, retired employee interviews, and from current operations personnel. Exposure modifiers were used multiplicatively, adjusting available measured data to represent the relevant exposure scenario and time period. Changes in exposure modifiers translated to step changes in exposure estimates. Though limited by availability of data, a validation exercise suggested that the algorithm provided accurate exposure estimates for benzene (compared with measured data in industrial hygiene survey reports); the estimates generally differed by an average of less than 20% from the measured values. This approach is proposed to quantify exposures retrospectively where there are sufficient data to develop reliable current era estimates and where a historical accounting of key exposure modifiers can be developed, but where there are insufficient historic exposure measurements to directly assess historic exposures.

  11. [Exposure to addictogenic substances, conditioned response and treatment of the exposure with response prevention].

    Science.gov (United States)

    Khazaal, Y; Frésard, E; Zullino, D

    2007-01-01

    Exposure to drugs or related cues is associated with psycho-physiological reactivity. These responses are conditioned during periods of active consumption. Exposure with response prevention (EPR) is a treatment established for anxiety disorder and aims to reduce anxiety by an extinction of previously conditioned responses. The conditioning recognized in additive processes has led to research into EPR's therapeutic potential for treating addiction. This paper is a review of the main studies on reactivity to cues, and EPR, particularly with respect to addiction to alcohol, opiates, cocaine and tobacco. This review is based on information from the Medline database, dealing with cue reactivity, attentional bias during exposure to cues and exposure treatment for addiction in general and, in particular, for each of the aforementioned substances. Exposure to drug-related cues is clearly associated with psycho-physiological reactivity and with attentional bias. Those phenomena are associated with craving and more difficulty in maintaining abstinence. The subject's attention is thus held by a large number of drug-related environmental stimuli. These observations are linked with conditioning phenomena and suggest the possibility of treatment by EPR conditioning extinction procedures. EPR has been most widely studied for abuse and alcohol addiction. Case reports give favourable outcomes. Results from controlled studies are less clear. Studies on patients addicted to cocaine or heroine are still limited and not conclusive. Different controlled studies on EPR for nicotine addiction have not produced conclusions in favour of this treatment. Generally, the EPR procedures used vary among studies. Studies focussing particularly on the evolution of physiological responses in a laboratory setting after EPR have demonstrated reduced autonomic nervous system activity. These results do not consistently lead to a reduction in consumption behaviour and in craving when the patient is in

  12. Dose limits to the eye lens

    Energy Technology Data Exchange (ETDEWEB)

    Sion, N.

    2016-09-15

    Protecting the human body from the effects of ionizing radiation is essential to forestall stochastic effects and require placing limits on the effective dose. Dose limits on specific organs are also necessary to reduce the deterministic effects and tissue reactions. The standard for radiation protection was ISO 15382 (2002) which mainly dealt with beta radiation for nuclear power plant workers. Clearly an update is required to allow for new technology and the proliferative use of radiation in medical practices. There is a need for more explicit radiation monitoring to operators and staff. ICRP118 (International Commission on Radiological Protection), Ref. 1, evolved their recommendations to include eye lens doses as a follow on to their publication 103 and to focus on radiation exposures. It provides updated estimates of 'practical' threshold doses for tissue injury at the level of 1% incidence. This paper discusses the current status and the recommendation for a drastic reduction of the dose limit to the eye lens. (author)

  13. Chicago transit authority train noise exposure.

    Science.gov (United States)

    Phan, Linh T; Jones, Rachael M

    2017-06-01

    To characterize noise exposure of riders on Chicago Transit Authority (CTA) trains, we measured noise levels twice on each segment of 7 of the 8 CTA train lines, which are named after colors, yielding 48 time-series measurements. We found the Blue Line has the highest noise levels compared to other train lines, with mean 76.9 dBA; and that the maximum noise level, 88.9 dBA occurred in the tunnel between the Chicago and Grand stations. Train segments involving travel through a tunnel had significantly higher noise levels than segments with travel on elevated and ground level tracks. While 8-hr doses inside the passenger cars were not estimated to exceed occupational exposure limits, train operators ride in a separate cab with operational windows and may therefore have higher noise exposures than riders. Despite the low risk of hearing loss for riders on CTA trains, in part because transit noise accounts for a small part of total daily noise exposure, 1-min average noise levels exceeded 85 dBA at times. This confirms anecdotal observations of discomfort due to noise levels, and indicates a need for noise management, particularly in tunnels.

  14. Socio-economic exposure to natural disasters

    Energy Technology Data Exchange (ETDEWEB)

    Marin, Giovanni, E-mail: giovanni.marin@uniurb.it [Department of Economics, Society, Politics, University of Urbino ' Carlo Bo' , via Aurelio Saffi, 2, 61029 Urbino (Italy); IRCrES - CNR, Research Institute on Sustainable Economic Growth, Via Corti 12, 20133 - Milano (Italy); SEEDS, Ferrara (Italy); Modica, Marco, E-mail: marco.modica@ircres.cnr.it [IRCrES - CNR, Research Institute on Sustainable Economic Growth, Via Corti 12, 20133 - Milano (Italy); SEEDS, Ferrara (Italy)

    2017-05-15

    Even though the correct assessment of risks is a key aspect of the risk management analysis, we argue that limited effort has been devoted in the assessment of comprehensive measures of economic exposure at very low scale. For this reason, we aim at providing a series of suitable methodologies to provide a complete and detailed list of the exposure of economic activities to natural disasters. We use Input-Output models to provide information about several socio-economic variables, such as population density, employment density, firms' turnover and capital stock, that can be seen as direct and indirect socio-economic exposure to natural disasters. We then provide an application to the Italian context. These measures can be easily incorporated into risk assessment models to provide a clear picture of the disaster risk for local areas. - Highlights: • Ex ante assessment of economic exposure to disasters at very low geographical scale • Assessment of the cost of natural disasters in ex-post perspective • IO model and spatial autocorrelation to get information on socio-economic variables • Indicators supporting risk assessment and risk management models.

  15. Sound exposure during outdoor music festivals

    Directory of Open Access Journals (Sweden)

    Tron V Tronstad

    2016-01-01

    Full Text Available Most countries have guidelines to regulate sound exposure at concerts and music festivals. These guidelines limit the allowed sound pressure levels and the concert/festival’s duration. In Norway, where there is such a guideline, it is up to the local authorities to impose the regulations. The need to prevent hearing-loss among festival participants is self-explanatory, but knowledge of the actual dose received by visitors is extremely scarce. This study looks at two Norwegian music festivals where only one was regulated by the Norwegian guideline for concert and music festivals. At each festival the sound exposure of four participants was monitored with noise dose meters. This study compared the exposures experienced at the two festivals, and tested them against the Norwegian guideline and the World Health Organization’s recommendations. Sound levels during the concerts were higher at the festival not regulated by any guideline, and levels there exceeded both the national and the Worlds Health Organization’s recommendations. The results also show that front-of-house measurements reliably predict participant exposure.

  16. Sound Exposure During Outdoor Music Festivals

    Science.gov (United States)

    Tronstad, Tron V.; Gelderblom, Femke B.

    2016-01-01

    Most countries have guidelines to regulate sound exposure at concerts and music festivals. These guidelines limit the allowed sound pressure levels and the concert/festival's duration. In Norway, where there is such a guideline, it is up to the local authorities to impose the regulations. The need to prevent hearing-loss among festival participants is self-explanatory, but knowledge of the actual dose received by visitors is extremely scarce. This study looks at two Norwegian music festivals where only one was regulated by the Norwegian guideline for concert and music festivals. At each festival the sound exposure of four participants was monitored with noise dose meters. This study compared the exposures experienced at the two festivals, and tested them against the Norwegian guideline and the World Health Organization's recommendations. Sound levels during the concerts were higher at the festival not regulated by any guideline, and levels there exceeded both the national and the Worlds Health Organization's recommendations. The results also show that front-of-house measurements reliably predict participant exposure. PMID:27569410

  17. Socio-economic exposure to natural disasters

    International Nuclear Information System (INIS)

    Marin, Giovanni; Modica, Marco

    2017-01-01

    Even though the correct assessment of risks is a key aspect of the risk management analysis, we argue that limited effort has been devoted in the assessment of comprehensive measures of economic exposure at very low scale. For this reason, we aim at providing a series of suitable methodologies to provide a complete and detailed list of the exposure of economic activities to natural disasters. We use Input-Output models to provide information about several socio-economic variables, such as population density, employment density, firms' turnover and capital stock, that can be seen as direct and indirect socio-economic exposure to natural disasters. We then provide an application to the Italian context. These measures can be easily incorporated into risk assessment models to provide a clear picture of the disaster risk for local areas. - Highlights: • Ex ante assessment of economic exposure to disasters at very low geographical scale • Assessment of the cost of natural disasters in ex-post perspective • IO model and spatial autocorrelation to get information on socio-economic variables • Indicators supporting risk assessment and risk management models

  18. Neurobehavioural effects of occupational exposure to lead.

    Science.gov (United States)

    Williamson, A M; Teo, R K

    1986-06-01

    A set of neurobehavioural tests selected on the basis of information processing theory was used to study the effect of low level occupational lead exposure on 59 lead workers compared with a matched control group of the same number. Only one of the lead exposed group had a blood lead concentration above the current threshold limit value of 3.81 mumol/l at the time of testing (mean 2.36 mumol/l, range 1.19-3.92 mumol/l) and none had been detected above that level in the previous three years. Nevertheless, most neurobehavioural functions tested showed some impairment in the lead workers. Visual sensory function was affected and, perhaps as a consequence, sustained attention and psychomotor tasks were performed more slowly by the lead exposed group. Cognitive functions were also impaired, with sensory store memory, short term memory, and learning abilities all showing deficits in lead workers. Such cognitive deficits may also be partly due to initial degradation of the visual input. Long term memory performance compared equally with control levels possibly because of development of a compensatory strategy such as rehearsal by the lead exposed subjects. Multiple linear regression analysis relating to lead workers test performance and their lead exposure showed that performance on the sensory store memory test alone was significantly related to exposure. This was probably due to the homogeneity of the lead exposed group with regard to blood lead concentrations and the use of blood lead as a measure of chronic lead exposure.

  19. Mitigating residential exposure to secondhand tobacco smoke

    Science.gov (United States)

    Klepeis, Neil E.; Nazaroff, William W.

    In a companion paper, we used a simulation model to explore secondhand tobacco smoke (SHS) exposures for typical conditions in residences. In the current paper, we extend this analysis to evaluate the effectiveness of physical mitigation approaches in reducing nonsmokers' exposure to airborne SHS particulate matter in a hypothetical 6-zone house. Measures investigated included closing doors or opening windows in response to smoking activity, modifying location patterns to segregate the nonsmoker and the active smoker, and operating particle filtration devices. We first performed 24 scripted simulation trials using hypothetical patterns of occupant location. We then performed cohort simulation trials across 25 mitigation scenarios using over 1000 pairs of nonsmoker and smoker time-location patterns that were selected from a survey of human activity patterns in US homes. We limited cohort pairs to cases where more than 10 cigarettes were smoked indoors at home each day and the nonsmoker was at home for more than two thirds of the day. We evaluated the effectiveness of each mitigation approach by examining its impact on the simulated frequency distribution of residential SHS particle exposure. The two most effective strategies were the isolation of the smoker in a closed room with an open window, and a ban on smoking whenever the nonsmoker was at home. The use of open windows to supply local or cross ventilation, or the operation of portable filtration devices in smoking rooms, provided moderate exposure reductions. Closed doors, by themselves, were not effective.

  20. Neurobehavioural effects of occupational exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, A.M.; Teo, R.K.

    1986-06-01

    A set of neurobehavioural tests selected on the basis of information processing theory was used to study the effect of low level occupational lead exposure on 59 lead workers compared with a matched control group of the same number. Only one of the lead exposed group had a blood lead concentration above the current threshold limit value of 3.81 mumol/l at the time of testing (mean 2.36 mumol/l, range 1.19-3.92 mumol/l) and none had been detected above that level in the previous three years. Nevertheless, most neurobehavioural functions tested showed some impairment in the lead workers. Visual sensory function was affected and, perhaps as a consequence, sustained attention and psychomotor tasks were performed more slowly by the lead exposed group. Cognitive functions were also impaired, with sensory store memory, short term memory, and learning abilities all showing deficits in lead workers. Such cognitive deficits may also be partly due to initial degradation of the visual input. Long term memory performance compared equally with control levels possibly because of development of a compensatory strategy such as rehearsal by the lead exposed subjects. Multiple linear regression analysis relating to lead workers test performance and their lead exposure showed that performance on the sensory store memory test alone was significantly related to exposure. This was probably due to the homogeneity of the lead exposed group with regard to blood lead concentrations and the use of blood lead as a measure of chronic lead exposure.

  1. Routine medicare and radiation exposure. Introductory remarks

    International Nuclear Information System (INIS)

    Hirata, Hideki; Saito, Tsutomu

    2013-01-01

    As an introduction of the title series, outlines of radiation in physics, chemistry, biochemistry, biological effect and protection are explained from the clinical doctors' aspect of routine medicare, and of radiation exposure in which people's interest is raised after the Fukushima Nuclear Power Plant Accident in 2011. For physics, ionizing effects of radiation are described in relation to its quantum energy transfer and its medical utilization like imaging and radiotherapy. Then mentioned in brief is the radiation from elements consisting of human body, cosmic ray and background radiation from the earth, with reference to natural and standardized limits of exposure doses. Radiations from 226 Rn and 40 K are explained as an instance of environmental natural sources together with the concepts of radioactive decay series/scheme, of internal exposure, of hazard like double strand break (DSB) and of medical use such as boron neutron capture therapy (BNCT). For an artifact radiation source, shown are fission products of 235 U by neutron, first yielded in 1945. Evidence of evolution in biochemical repair mechanisms of DSB is explained with a comparison of irradiated drosophila mutation where linear non-threshold (LNT) hypothesis is proposed, and human non-homologous end joining and homologous recombination. Historical process of occupational, medical, public exposures and their protection is finally described from the discovery of X-ray in 1895 to the first ICRP publication in 1958 via the A-bomb explosion in 1945. (T.T.)

  2. Preschool Personnel Exposure to Occupational Noise

    Directory of Open Access Journals (Sweden)

    Kaļužnaja Darja

    2016-10-01

    Full Text Available Increased noise, which is also below the occupational exposure values and is “hearing safe” noise, affects the exposed person’s health as a non-specific stressor. Increased noise level also creates an environment for additional vocal apparatus load. The objective of this study was to determine preschool personnel occupational noise and its relationship with subjective health complaints. Data were obtained with survey assistance through subjective answers of respondents about health complaints and noise exposure among Rīga preschool personnel. Objective noise measurements were made to assess real noise levels in the preschool environment. Data from 155 respondents and objective measurements of 37 preschool classrooms were obtained. The results showed that the average 8-h noise exposure among Rīga preschool educational institutions was 70 dB(A, which did not exceed the Latvian work environment noise limits, but exceeded the 35–40 dB(A noise limit in the educational environment guidelines recommended by the WHO. The survey results showed that loud noise is one of the most important workplace environmental factors (~70% of respondents feel a necessity to increase voice because of noise. A constant feeling of fatigue, headache, irritable feeling, and a desire to isolate oneself from others more often occurred in respondents exposed to increased noise, compared with those who noted that they were not exposed to increased noise. In general, loud noise was associated with increased subjective health complaints in preschool education institution personnel.

  3. On the Sen limit squared

    OpenAIRE

    Fullwood, James; Wang, Dongxu

    2018-01-01

    We introduce a class of F-theory vacua whose smooth elliptic fibers admit a vanishing $j$-invariant, and construct a weak coupling limit associated with such vacua which we view as the `square' of the Sen limit. We find that while Sen's limit is naturally viewed as an orientifold theory, the universal tadpole relation which equates the D3 charge between the associated F-theory compactification and the limit we construct suggests that perhaps the limiting theory is in fact an oriented theory c...

  4. Influence of exposure time on toxicity-An overview.

    Science.gov (United States)

    Connell, Des W; Yu, Qiming J; Verma, Vibha

    2016-04-29

    Data on toxicity of chemicals is usually reported as the LD50, or LC50, with the exposure time from experimental testing in the laboratory reported. But the exposure time is not considered to be a quantifiable variable which can be used to evaluate its importance in expressed toxicity, often described in general terms such as acute, chronic and so on. For the last hundred years Habers Rule has been successfully used to extrapolate from reported exposure times to other exposure times which may be needed for setting standards, health risk assessments and other applications. But it has limitations particularly in environmental applications where exposure levels are low and exposure times are relatively long. The Reduced Life Expectancy (RLE) model overcomes these problems and can be utilised under all exposure conditions. It can be expressed as ln(LT50)=-a (LC50)(ν)+b where the constants ν, a and b can be evaluated by fitting the model to experimental data on the LC50, and corresponding LT50, together with the Normal Life Expectancy (NLE) of the organism being considered as a data point when the LC50 is zero. The constant, ν, at a value of unity gives a linear relationship and where νmodel for fish, invertebrates and mammals involving 115 data sets and with a wide range of organic and inorganic toxicants the RLE model gave correlation coefficients of >0.8 with 107 sets of data. The RLE model can be used to extrapolate from a limited data set on exposure times and corresponding LT50 values to any exposure time and corresponding LT50 value. The discrepancy between Haber's Rule and RLE model increases as the exposure time increases. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  5. Occupational and environmental exposures to radon: A perspective for mitigators

    International Nuclear Information System (INIS)

    Sanchez, D.C.; Messing, M.; Saum, D.

    1989-01-01

    This paper compares normal environmental and occupational exposures to radon and radon decay products for the occupational group, including radon mitigators and diagnosticians. Occupational exposures to radon and radon decay products and the associated high incidence of radiation-induced lung cancer form the basis for current concern for limiting exposures to radon. While it is now known that radon is a ubiquitous environmental pollutant and estimates exist as to what this means in terms of cancer risk to the general population, similar estimates are not available for radon mitigators and diagnosticians

  6. Comprehensive European dietary exposure model (CEDEM) for food additives.

    Science.gov (United States)

    Tennant, David R

    2016-05-01

    European methods for assessing dietary exposures to nutrients, additives and other substances in food are limited by the availability of detailed food consumption data for all member states. A proposed comprehensive European dietary exposure model (CEDEM) applies summary data published by the European Food Safety Authority (EFSA) in a deterministic model based on an algorithm from the EFSA intake method for food additives. The proposed approach can predict estimates of food additive exposure provided in previous EFSA scientific opinions that were based on the full European food consumption database.

  7. Time and frequency weightings and the assessment of sound exposure

    DEFF Research Database (Denmark)

    Ordoñez, Rodrigo Pizarro; de Toro, Miguel Angel Aranda; Hammershøi, Dorte

    2010-01-01

    Since the development of averaging/integrating sound level meters and frequency weighting networks in the 1950’s, measurement of the physical characteristics of sound has not changed a great deal. Advances have occurred in how the measured values are used (day-night averages, limit and action...... of the exposure. This information is being used to investigate metrics that can differentiate temporal characteristics (impulsive, fluctuating) as well as frequency characteristics (narrow-band or tonal dominance) of sound exposures. This presentation gives an overview of the existing sound measurement...... and analysis methods, that can provide a better representation of the effects of sound exposures on the hearing system...

  8. Controlling radiation exposure during interventional procedures in childhood cancer patients

    International Nuclear Information System (INIS)

    Racadio, John M.

    2009-01-01

    Many pediatric cancer patients undergo multiple diagnostic and therapeutic radiologic procedures over the course of their illnesses and are therefore at high risk for radiation exposure. There are a variety of measures that radiologists can employ to reduce this risk. These include limiting the use of radiation whenever possible, using specific strategies to reduce radiation exposure during interventional procedures, using quality assurance programs to ensure compliance, and maintaining continuing staff radiation safety educational programs. Some of the diagnostic and therapeutic interventional radiologic procedures that are performed in pediatric oncology patients are discussed here, along with specific tips for managing radiation exposure. (orig.)

  9. Interference and memory capacity limitations.

    Science.gov (United States)

    Endress, Ansgar D; Szabó, Szilárd

    2017-10-01

    Working memory (WM) is thought to have a fixed and limited capacity. However, the origins of these capacity limitations are debated, and generally attributed to active, attentional processes. Here, we show that the existence of interference among items in memory mathematically guarantees fixed and limited capacity limits under very general conditions, irrespective of any processing assumptions. Assuming that interference (a) increases with the number of interfering items and (b) brings memory performance to chance levels for large numbers of interfering items, capacity limits are a simple function of the relative influence of memorization and interference. In contrast, we show that time-based memory limitations do not lead to fixed memory capacity limitations that are independent of the timing properties of an experiment. We show that interference can mimic both slot-like and continuous resource-like memory limitations, suggesting that these types of memory performance might not be as different as commonly believed. We speculate that slot-like WM limitations might arise from crowding-like phenomena in memory when participants have to retrieve items. Further, based on earlier research on parallel attention and enumeration, we suggest that crowding-like phenomena might be a common reason for the 3 major cognitive capacity limitations. As suggested by Miller (1956) and Cowan (2001), these capacity limitations might arise because of a common reason, even though they likely rely on distinct processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. A Margin-of-Exposure Approach to Assessment of Noncancer Risks of Dioxins Based on Human Exposure and Response Data

    OpenAIRE

    Aylward, Lesa L.; Goodman, Julie E.; Charnley, Gail; Rhomberg, Lorenz R.

    2008-01-01

    Background Risk assessment of human environmental exposure to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDFs) and other dioxin-like compounds is complicated by several factors, including limitations in measuring intakes because of the low concentrations of these compounds in foods and the environment and interspecies differences in pharmacokinetics and responses. Objectives We examined the feasibility of relying directly on human studies of exposure and potential responses to...

  11. Moving from Virtual Reality Exposure-Based Therapy to Augmented Reality Exposure-Based Therapy: A Review

    OpenAIRE

    Baus, Oliver; Bouchard, Stéphane

    2014-01-01

    This paper reviews the move from virtual reality exposure-based therapy to augmented reality exposure-based therapy (ARET). Unlike virtual reality (VR), which entails a complete virtual environment (VE), augmented reality (AR) limits itself to producing certain virtual elements to then merge them into the view of the physical world. Although, the general public may only have become aware of AR in the last few years, AR type applications have been around since beginning of the twentieth centur...

  12. Human exposure to aluminium.

    Science.gov (United States)

    Exley, Christopher

    2013-10-01

    Human activities have circumvented the efficient geochemical cycling of aluminium within the lithosphere and therewith opened a door, which was previously only ajar, onto the biotic cycle to instigate and promote the accumulation of aluminium in biota and especially humans. Neither these relatively recent activities nor the entry of aluminium into the living cycle are showing any signs of abating and it is thus now imperative that we understand as fully as possible how humans are exposed to aluminium and the future consequences of a burgeoning exposure and body burden. The aluminium age is upon us and there is now an urgent need to understand how to live safely and effectively with aluminium.

  13. Material limitations on the detection limit in refractometry.

    Science.gov (United States)

    Skafte-Pedersen, Peder; Nunes, Pedro S; Xiao, Sanshui; Mortensen, Niels Asger

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η, with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm) of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

  14. Material Limitations on the Detection Limit in Refractometry

    Directory of Open Access Journals (Sweden)

    Niels Asger Mortensen

    2009-10-01

    Full Text Available We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a bio-liquid environment, such as a water buffer. In the transparency window (λ ≳ 1100 nm of silicon the detection limit becomes almost independent on the filling fraction, while in the visible, the detection limit depends strongly on the filling fraction because the silicon absorbs strongly.

  15. Comparison of radon-daughter exposures calculated for US- underground uranium miners based on MSHA and company records

    International Nuclear Information System (INIS)

    Cooper, W.E.

    1981-01-01

    How accurate are past and present employee radon-daughter exposure records of underground uranium miners employed in the United States. This often-debated question is essential for future substantiation of safe exposure limits. An apparent discrepancy between company-reported exposures and Mining Enforcement and Safety Administration (MESA) projected exposures was detected in 1977. For these reasons a need for an updated comparison of these exposure data was indicated. This paper gives some of the conclusions of the earlier study and compares more recent exposure records compiled by the Atomic Industrial Forum, Inc., with projected exposures based on sampling by Federal mine inspectors

  16. Occupational exposure to benzene in South Korea.

    Science.gov (United States)

    Kang, Seong-Kyu; Lee, Mi-Young; Kim, Tae-Kyun; Lee, Jeong-Oh; Ahn, Yeon Soon

    2005-05-30

    Benzene has been used in various industries as glues or solvents in Korea. Since 1981, a preparation containing more than 1% benzene is not allowed to be manufactured, used or dealt with in the workplace, except in laboratories and in those situations benzene must be used in a completely sealed process as specified in Industrial Safety and Health Act (ISHA). Claims for compensation of hematopoietic diseases related to benzene have been rising even though the work environment has been improved. This study was conducted to assess the status of benzene exposure in different industries in Korea. We reviewed the claimed cases investigated by the Korea Occupational Safety and Health Agency (KOSHA) between 1992 and 2000. The Survey of National Work Environment Status in 1998 was analyzed to assume the number of workers and factories exposed to benzene. In 2000, six factories were investigated to evaluate benzene exposure. Personal air monitoring was performed in 61 workers and urine samples were collected from 57 workers to measure trans,trans-muconic acid (t,t-MA). Hematologic examination has performed. Thirty-four cases of hematopoietic diseases were investigated by KOSHA including eight cases of myelodysplastic syndrome and eight cases of acute myelocytic leukemia. Eight cases were accepted as related to benzene exposure. The number of workers possibly exposed to benzene can be estimated to be 196,182 workers from 6219 factories based on the database. The geometric mean of benzene in air was 0.094 (0.005-5.311) ppm. Seven samples were higher than 1 ppm but they did not go over the 10 ppm occupational exposure limit (OEL) value in Korea. The geometric mean of trans,trans-muconic acid in urine was 0.966 (0.24-2.74) mg/g creatinine. The benzene exposure level was low except in a factory where benzene was used to polymerize other chemicals. The ambient benzene from 0.1 to 1 ppm was significantly correlated with urine t,t-MA concentration (r=0.733, p<0.01). Hematologic

  17. Material Limitations on the Detection Limit in Refractometry

    OpenAIRE

    Skafte-Pedersen, Peder; Nunes, Pedro S.; Xiao, Sanshui; Mortensen, Niels Asger

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and filling fractions into account, the detection limit declines. As an example we discuss the fundamental limits of silicon-based high-Q resonators, such as photonic crystal resonators, for sensing in a...

  18. Thermodynamic limit for coherence-limited solar power conversion

    Science.gov (United States)

    Mashaal, Heylal; Gordon, Jeffrey M.

    2014-09-01

    The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

  19. The Mere Exposure Instruction Effect.

    Science.gov (United States)

    Van Dessel, Pieter; Mertens, Gaëtan; Smith, Colin Tucker; De Houwer, Jan

    2017-09-01

    The mere exposure effect refers to the well-established finding that people evaluate a stimulus more positively after repeated exposure to that stimulus. We investigated whether a change in stimulus evaluation can occur also when participants are not repeatedly exposed to a stimulus, but are merely instructed that one stimulus will occur frequently and another stimulus will occur infrequently. We report seven experiments showing that (1) mere exposure instructions influence implicit stimulus evaluations as measured with an Implicit Association Test (IAT), personalized Implicit Association Test (pIAT), or Affect Misattribution Procedure (AMP), but not with an Evaluative Priming Task (EPT), (2) mere exposure instructions influence explicit evaluations, and (3) the instruction effect depends on participants' memory of which stimulus will be presented more frequently. We discuss how these findings inform us about the boundary conditions of mere exposure instruction effects, as well as the mental processes that underlie mere exposure and mere exposure instruction effects.

  20. View point of medical exposure

    International Nuclear Information System (INIS)

    Akahane, Keiichi

    2008-01-01

    This text contains the following subjects. (1) Introduction, (2) Progress of medical examinations by radiation, (2-1) Decision of applying radiation, (2-2) Irradiation method, (2-3) Irradiation dose, (3) Exposure at medical examinations by radiation, (3-1) Dose to express the exposure, (3-2) Dose at medical exposure, (4) Types of medical examinations by radiation, (4-1) Radiation diagnosis, (4-2) Radiation therapy, (4-3) Nuclear medicine, (5) Radiation effects, (5-1) Types of radiation effect, (5-2) Effects of medical exposure, (6) Present status of medical examination by radiation, (6-1) Actual status of medical exposure, (6-2) Medical examinations by radiation in Japan, (7) Assessment of medical exposure, (7-1) Exposure dose, (7-2) Papers on radiation risk, and (7-3) Radiation protection. (K.Y.)

  1. Exposure Research Going Mobile: A Smartphone-Based Measurement of Media Exposure to Political Information in a Convergent Media Environment

    DEFF Research Database (Denmark)

    Ohme, J.; Albaek, E.; H. de Vreese, C.

    2016-01-01

    platform modes. The study furthermore confirms limitations of mere usage time measurements of social media platforms in effects research and explores a range of actual content types that citizens encounter in social networks. It recommends more frequent use of mobile exposure measurements and argues...... for a content-related assessment of social media use in effects research. © 2016 Taylor & Francis.......In today’s convergent media environment, media exposure becomes increasingly channel-independent and social media-bound, and media content is more frequently accessed on mobile devices. This calls for new approaches to measuring media exposure. This study applies an innovative approach to survey (n...

  2. Quantifying commuter exposures to volatile organic compounds

    Science.gov (United States)

    Kayne, Ashleigh

    Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the

  3. Effects from placental exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, S [Radiation Effect Research Foundation, Hiroshima (Japan)

    1975-12-01

    Investigations of the effects on the people who had received placental exposure at either Hiroshima or Nagasaki were discussed. All of the subjects were children who had been born at either Hiroshima or Nagasaki between noon of 31, May, 1946 and the atomic-bomb detornation. Deaths of embryos and neonates were determined by the radiation dosage and the growth phase of embryos. Bifid uvula and a slight decrease of number of lumbar vertebra were observed in 14 males and 3 females at Nagasaki. Mental deficiency occurred in 25% of the children whose mothers had received radiation at Nagasaki, and in 8% at Hiroshima. The occurrence of microcephaly was high at both places in the children who had received placental exposure of more than 150 rad. A significant retardation of growth was observed in those who had had a high radiation dosage. Congenitally abnormal persistence of pupillary membrane was very frequently observed in the group which had received a high dosage of radiation. Concerning progeria, mortality of infants under one year of age was increased in the group which had received a high dosage of radiation, but mortality statistics should continue to be observed.

  4. 78 FR 37930 - Lending Limits

    Science.gov (United States)

    2013-06-25

    ... provision will be removed when the rule's temporary exception period for derivative and securities financing... than credit derivatives, and two methods for securities financing transactions.\\11\\ Unless required to... exposure arising from all derivative transactions and the same method for all securities financing...

  5. Exposure to Hedione Increases Reciprocity in Humans

    Directory of Open Access Journals (Sweden)

    Sebastian Berger

    2017-05-01

    Full Text Available Cooperation among unrelated humans is frequently regarded as a defining feature in the evolutionary success of our species. Whereas, much research has addressed the strategic and cognitive mechanisms that underlie cooperation, investigations into chemosensory processes have received very limited research attention. To bridge that gap, we build on recent research that has identified the chemically synthesized odorant Hedione (HED as a ligand for the putative human pheromone receptor (VN1R1 expressed in the olfactory mucosa, and hypothesize that exposure to HED may increase reciprocity. Applying behavioral economics paradigms, the present research shows that exposure to the ligand causes differentiated behavioral effects in reciprocal punishments (Study 1 as well as rewards (Study 2, two types of behaviors that are frequently regarded as essential for the development and maintenance of cooperation.

  6. Assessment of inhomogeneous ELF magnetic field exposures

    International Nuclear Information System (INIS)

    Leitgeb, N.; Cech, R.; Schroettner, J.

    2008-01-01

    In daily life as well as at workplaces, exposures to inhomogeneous magnetic fields become very frequent. This makes easily applicable compliance assessment methods increasingly important. Reference levels have been defined linking basic restrictions to levels of homogeneous fields at worst-case exposure conditions. If reference levels are met, compliance with basic restrictions can be assumed. If not, further investigations could still prove compliance. Because of the lower induction efficiency, inhomogeneous magnetic fields such as from electric appliances could be allowed exceeding reference levels. To easily assess inhomogeneous magnetic fields, a quick and flexible multi-step assessment procedure is proposed. On the basis of simulations with numerical, anatomical human models reference factors were calculated elevating reference levels to link hot-spot values measured at source surfaces to basic limits and allowing accounting for different source distance, size, orientation and position. Compliance rules are proposed minimising assessment efforts. (authors)

  7. Human response to combined indoor environment exposures

    DEFF Research Database (Denmark)

    Toftum, Jørn

    2002-01-01

    Most thermal comfort standards and guidelines presume sedentary, light activity and a neutral overall thermal sensation when predicting local thermal discomfort. In addition, current standards specify criteria for separate aspects of the indoor environment, e.g. thermal climate, air quality...... or noise, with only little consideration of possible interactions between the different types of exposure. The studies summarized in this article found a clear impact of activity and overall thermal sensation on human sensitivity to air movement, whereas no interaction effects of exposure to several local...... thermal discomfort factors were observed. Limited evidence was found of significant interactions between different aspects of the indoor environment. Only for the effect of air temperature and air humidity on sensory air quality were well-estabished relationships available....

  8. Pneumoconiosis and exposures of dental laboratory technicians

    International Nuclear Information System (INIS)

    Rom, W.N.; Lockey, J.E.; Lee, J.S.; Kimball, A.C.; Bang, K.M.; Leaman, H.; Johns, R.E. Jr.; Perrota, D.; Gibbons, H.L.

    1984-01-01

    One hundred and seventy-eight dental laboratory technicians and 69 non-exposed controls participated in an epidemiological respiratory study. Eight technicians who had a mean of 28 years grinding nonprecious metal alloys were diagnosed as having a simple pneumoconiosis by chest radiograph. Mean values for per cent predicted FVC and FEV1 were reduced among male nonsmoker technicians compared to male nonsmoker controls; after controlling for age, there was also a reduction in spirometry with increasing work-years. An industrial hygiene survey was conducted in 13 laboratories randomly selected from 42 laboratories stratified by size and type of operation in the Salt Lake City, Utah metropolitan area. Personal exposures to beryllium and cobalt exceeded the Threshold Limit Values (TLVs) in one laboratory. Occupational exposures in dental laboratories need to be controlled to prevent beryllium-related lung disorders as well as simple pneumoconiosis

  9. Exposure to Hedione Increases Reciprocity in Humans

    Science.gov (United States)

    Berger, Sebastian; Hatt, Hanns; Ockenfels, Axel

    2017-01-01

    Cooperation among unrelated humans is frequently regarded as a defining feature in the evolutionary success of our species. Whereas, much research has addressed the strategic and cognitive mechanisms that underlie cooperation, investigations into chemosensory processes have received very limited research attention. To bridge that gap, we build on recent research that has identified the chemically synthesized odorant Hedione (HED) as a ligand for the putative human pheromone receptor (VN1R1) expressed in the olfactory mucosa, and hypothesize that exposure to HED may increase reciprocity. Applying behavioral economics paradigms, the present research shows that exposure to the ligand causes differentiated behavioral effects in reciprocal punishments (Study 1) as well as rewards (Study 2), two types of behaviors that are frequently regarded as essential for the development and maintenance of cooperation. PMID:28512400

  10. Adolescent violence exposure, gender issues and impact.

    Science.gov (United States)

    Munni, Ray; Malhi, P

    2006-07-01

    Youth violence is a growing problem worldwide. Research on adolescent violence in India is limited. Fifteen hundred high school students were investigated to study the prevalence and demographic characteristics of witnesses, victims and perpetrators of violence and to see the impact of violence exposure on their psychosocial adjustments. Sixty nine percent of students had witnessed violence in real life and 28% were of serious nature. Media violence exposure was universal. The prevalence of victims and perpetrators was 27% and 13% respectively. Bullying was prevalent. Male sex was the most important predictive risk factor for witnessing and perpetrating violence (P gender differences exist. Its impact on their psychosocial adjustments is detrimental. Early identification and corrective interventions of these adolescents is vital.

  11. Human exposure to bisphenol A by biomonitoring: Methods, results and assessment of environmental exposures

    International Nuclear Information System (INIS)

    Dekant, Wolfgang; Voelkel, Wolfgang

    2008-01-01

    Human exposure to bisphenol A is controversially discussed. This review critically assesses methods for biomonitoring of bisphenol A exposures and reported concentrations of bisphenol A in blood and urine of non-occupationally ('environmentally') exposed humans. From the many methods published to assess bisphenol A concentrations in biological media, mass spectrometry-based methods are considered most appropriate due to high sensitivity, selectivity and precision. In human blood, based on the known toxicokinetics of bisphenol A in humans, the expected very low concentrations of bisphenol A due to rapid biotransformation and the very rapid excretion result in severe limitations in the use of reported blood levels of bisphenol A for exposure assessment. Due to the rapid and complete excretion of orally administered bisphenol A, urine samples are considered as the appropriate body fluid for bisphenol A exposure assessment. In urine samples from several cohorts, bisphenol A (as glucuronide) was present in average concentrations in the range of 1-3 μg/L suggesting that daily human exposure to bisphenol A is below 6 μg per person (< 0.1 μg/kg bw/day) for the majority of the population

  12. Assessment of nuclear power sources in Czechoslovakia with respect to radiation protection limits

    International Nuclear Information System (INIS)

    Melichar, Z.

    1985-01-01

    The principles are presented which underlie the determination of limits of planned population exposure during normal operation of nuclear installations and of reference levels of exceptional population exposure during nuclear power plant accidents. The introduction is discussed of authorized limits and levels in Czechoslovakia the USSR, CMEA countries and Sweden. An estimate is made of the radiation burden of the population during the development of the Czechoslovak nuclear power programme. (E.S.)

  13. Radiation protection requirements in the limitation of the release of radioactive effluents

    International Nuclear Information System (INIS)

    Beninson, D.

    1978-01-01

    The paper summarizes the requirements of radiation protection, as presented in the new ICRP recommendation, in relation to the limitation of the release of radioactive effluents. The concepts of effective dose equivalent and collective dose equivalent are used in the presentation of the optimization procedures and the dose limitation to individuals. The dose commitment is used for the procedures applied to control future exposures. An appendix describes the basic concepts and quantities used in assessments of human exposures and risks. (author)

  14. Testing of low Z coated limiters in tokamak fusion devices

    International Nuclear Information System (INIS)

    Whitely, J.B.; Mullendore, A.W.; Langley, R.A.

    1980-01-01

    Extensive testing on a laboratory scale has been used to select those coatings most suitable for this environment. From this testing which included pulsed electron beam heating, low energy ion bombardment and arcing, chemical vapor deposited coating of TiB 2 and TiC on Poco graphite substrates have been selected and tested as limiters in ISX. Both limiter materials gave clean, stable, reproducible tokamak discharges the first day of operation. After one weeks exposure, the TiC limiter showed only superficial damage with no coating failure. The TiB 2 limiter had some small areas of coating failure. TiC coated graphite limiters have also been briefly tested in the tokamaks Alcator and PDX with favorable results

  15. Application of maximum values for radiation exposure and principles for the calculation of radiation doses

    International Nuclear Information System (INIS)

    2007-08-01

    The guide presents the definitions of equivalent dose and effective dose, the principles for calculating these doses, and instructions for applying their maximum values. The limits (Annual Limit on Intake and Derived Air Concentration) derived from dose limits are also presented for the purpose of monitoring exposure to internal radiation. The calculation of radiation doses caused to a patient from medical research and treatment involving exposure to ionizing radiation is beyond the scope of this ST Guide

  16. Revised dose limits and new respiratory tract model and their implications for annual limits of intake of radioactive materials - A review of recent ICRP publications

    International Nuclear Information System (INIS)

    Schlesinger, T.; Silverman, I.; Shapira, M.

    1996-01-01

    Ionizing radiation may cause immediate and/or delayed biological damages to the body of the exposed person and/or his/her progeny. The exposure may be caused by an external source or may arise due to internal contamination by a radioactive material. In order to prevent such exposure, or to reduce the probability that it will occur, national authorities and international organizations that are engaged in radiation safety and protection have set limits for the exposure to ionizing radiation from either source. The sensitivity of the body to ionizing radiation usually decreases with age. For this reason and due to the limited possibilities to control the exposure of the general public, different limits have been set for for occupational exposure and for the exposure of members of the public of different age groups. The general principles of these limits and guidelines for their calculations are set by the International Commission on Radiological Protection (ICRP) and published in the Annals of the ICRP. The basic philosophy of the Commission, which includes the principles of justification, optimization and dose limits, the basic radiobiological models, and the distinction between stochastic and non-stochastic effects has been presented in its publication no. 26 . Based on this philosophy, the Commission issued between 1979 and 1988 a series of publications followed by annexes and addenda known as publication no. 30 . This series presented models describing the metabolism of radioactive materials which enter the body by inhalation and ingestion, the transfer of such materials from the respiratory tract and the gastrointestinal tract to the blood, and from there to the body organs and the excretion of the material from the body. This series presented also values for biokinetic parameters of these systems and transfer paths, and methods for calculating limits on intake which ensure that the exposure from internal contamination will not exceed the dose limits set by the

  17. Revised dose limits and new respiratory tract model and their implications for annual limits of intake of radioactive materials - A review of recent ICRP publications

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, T; Silverman, I; Shapira, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1996-12-01

    Ionizing radiation may cause immediate and/or delayed biological damages to the body of the exposed person and/or his/her progeny. The exposure may be caused by an external source or may arise due to internal contamination by a radioactive material. To prevent such exposure, or to reduce the probability that it will occur, national authorities and international organizations engaged in radiation safety and protection have set limits for the exposure to ionizing radiation from either source. The sensitivity of the body to ionizing radiation usually decreases with age. For this reason and due to the limited possibilities to control the exposure of the general public, different limits have been set for for occupational exposure and for the exposure of members of the public of different age groups. The general principles of these limits and guidelines for their calculations are set by the International Commission on Radiological Protection (ICRP) and published in the Annals of the ICRP. The basic philosophy of the Commission, which includes the principles of justification, optimization and dose limits, the basic radiobiological models, and the distinction between stochastic and non-stochastic effects has been presented in its publication no. 26. Based on this philosophy, the Commission issued between 1979 and 1988 a series of publications followed by annexes and addenda known as publication no. 30. This series presented models describing the metabolism of radioactive materials which enter the body by inhalation and ingestion, the transfer of such materials from the respiratory tract and the gastrointestinal tract to the blood, and from there to the body organs and the excretion of the material from the body. This series presented also values for biokinetic parameters of these systems and transfer paths, and methods for calculating limits on intake which ensure that the exposure from internal contamination will not exceed the dose limits set.

  18. Material limitations on the detection limit in refractometry

    DEFF Research Database (Denmark)

    Skafte-Pedersen, Peder; Nunes, Pedro; Xiao, Sanshui

    2009-01-01

    We discuss the detection limit for refractometric sensors relying on high-Q optical cavities and show that the ultimate classical detection limit is given by min {Δn} ≳ η with n + iη being the complex refractive index of the material under refractometric investigation. Taking finite Q factors and...

  19. Retrospective internal radiation exposure assessment in occupational epidemiology

    International Nuclear Information System (INIS)

    Neton, J.W.; Flora, J.T.; Spitz, H.B.; Taulbee, T.D.

    2000-01-01

    Epidemiologic studies of workers at U.S. Department of Energy facilities are being conducted by the U.S. National Institute for Occupational Safety and Health to evaluate the health risk associated with exposure to sources of external and internal ionizing radiation. While exposure to external sources of radiation can be estimated from personal dosimeter data, reconstruction of exposure due to internally deposited radioactivity is more challenging because bioassay monitoring data is frequently less complete. Although comprehensive monitoring was provided for workers with the highest internal exposures, the majority of workers were monitored relatively infrequently. This monitoring was conducted to demonstrate compliance with regulations rather than to evaluate exposure for use in epidemiologic studies. Attributes of past internal monitoring programs that challenge accurate exposure assessment include: incomplete characterization of the workplace source term; a lack of timely measurements; insensitive and/or nonspecific bioassay measurements; and the presence of censored data. In spite of these limitations, many facilities have collected a large amount of worker and workplace monitoring information that can be used to evaluate internal exposure while minimizing worker misclassification. This paper describes a systematic approach for using the available worker and workplace monitoring data that can lead to either a qualitative or quantitative retrospective assessment of internal exposures. Various aspects of data analysis will be presented, including the evaluation of minimum detectable dose, the treatment of censored data, and the use of combinations of bioassay and workplace data to characterize exposures. Examples of these techniques applied to a cohort study involving chronic exposure scenarios to uranium are provided. A strategy for expressing exposure or dose in fundamental, unweighted units related to the quantity of radiation delivered to an organ will also

  20. Further limitations on nuclear testing

    International Nuclear Information System (INIS)

    Brown, P.S.

    1991-11-01

    This document addresses a number of subjects related to further constraints on nuclear testing, briefly discussing each of the following topics: the current political situation, the kinds of steps that might next be taken in test limitations and the impacts of further testing limits, the need for a test ban readiness program, some issues related to verification, and the possibility of confidence building measures as alternative, or near-term, steps to further test limitations