WorldWideScience

Sample records for direct human exposure

  1. A model of human nasal epithelial cells adapted for direct and repeated exposure to airborne pollutants.

    Science.gov (United States)

    Bardet, Gaëlle; Achard, Sophie; Loret, Thomas; Desauziers, Valérie; Momas, Isabelle; Seta, Nathalie

    2014-08-17

    Airway epithelium lining the nasal cavity plays a pivotal role in respiratory tract defense and protection mechanisms. Air pollution induces alterations linked to airway diseases such as asthma. Only very few in vitro studies to date have succeeded in reproducing physiological conditions relevant to cellular type and chronic atmospheric pollution exposure. We therefore, set up an in vitro model of human Airway Epithelial Cells of Nasal origin (hAECN) close to real human cell functionality, specifically adapted to study the biological effects of exposure to indoor gaseous pollution at the environmental level. hAECN were exposed under air-liquid interface, one, two, or three-times at 24 h intervals for 1 h, to air or formaldehyde (200 μg/m(3)), an indoor air gaseous pollutant. All experiments were ended at day 4, when both cellular viability and cytokine production were assessed. Optimal adherence and confluence of cells were obtained 96 h after cell seeding onto collagen IV-precoated insert. Direct and repeated exposure to formaldehyde did not produce any cellular damage or IL-6 production change, although weak lower IL-8 production was observed only after the third exposure. Our model is significantly better than previous ones due to cell type and the repeated exposure protocol. Copyright © 2014. Published by Elsevier Ireland Ltd.

  2. Gamma irradiation does not induce detectable changes in DNA methylation directly following exposure of human cells.

    Directory of Open Access Journals (Sweden)

    Christoph Lahtz

    Full Text Available Environmental chemicals and radiation have often been implicated in producing alterations of the epigenome thus potentially contributing to cancer and other diseases. Ionizing radiation, released during accidents at nuclear power plants or after atomic bomb explosions, is a potentially serious health threat for the exposed human population. This type of high-energy radiation causes DNA damage including single- and double-strand breaks and induces chromosomal rearrangements and mutations, but it is not known if ionizing radiation directly induces changes in the epigenome of irradiated cells. We treated normal human fibroblasts and normal human bronchial epithelial cells with different doses of γ-radiation emitted from a cesium 137 ((137Cs radiation source. After a seven-day recovery period, we analyzed global DNA methylation patterns in the irradiated and control cells using the methylated-CpG island recovery assay (MIRA in combination with high-resolution microarrays. Bioinformatics analysis revealed only a small number of potential methylation changes with low fold-difference ratios in the irradiated cells. These minor methylation differences seen on the microarrays could not be verified by COBRA (combined bisulfite restriction analysis or bisulfite sequencing of selected target loci. Our study shows that acute γ-radiation treatment of two types of human cells had no appreciable direct effect on DNA cytosine methylation patterns in exposed cells.

  3. Human exposure to trace elements through the skin by direct contact with clothing: Risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rovira, Joaquim [Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain); Environmental Engineering Laboratory, Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia (Spain); Nadal, Martí [Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain); Schuhmacher, Marta [Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain); Environmental Engineering Laboratory, Departament d' Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia (Spain); Domingo, José L., E-mail: joseluis.domingo@urv.cat [Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia (Spain)

    2015-07-15

    Metals in textile products and clothing are used for many purposes, such as metal complex dyes, pigments, mordant, catalyst in synthetic fabrics manufacture, synergists of flame retardants, antimicrobials, or as water repellents and odour-preventive agents. When present in textile materials, heavy metals may mean a potential danger to human health. In the present study, the concentrations of a number of elements (Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Tl, V, and Zn) were determined in skin-contact clothes. Analysed clothes were made of different materials, colours, and brands. Interestingly, we found high levels of Cr in polyamide dark clothes (605 mg/kg), high Sb concentrations in polyester clothes (141 mg/kg), and great Cu levels in some green cotton fabrics (around 280 mg/kg). Dermal contact exposure and human health risks for adult males, adult females, and for <1-year-old children were assessed. Non-carcinogenic and carcinogenic risks were below safe (HQ<1) and acceptable (<10{sup −6}) limits, respectively, according to international standards. However, for Sb, non-carcinogenic risk was above 10% of the safety limit (HQ>0.1) for dermal contact with clothes. - Highlights: • We determined in skin-contact clothes the concentrations of a number of metals. • Dermal contact exposure and health risks for adults and for 1-year-old children were assessed. • Carcinogenic risks were considered as acceptable (<10{sup −6}). • For non-carcinogenic risks, only Sb exceeded a 10% of the HQ for dermal contact with clothes.

  4. Human exposure to trace elements through the skin by direct contact with clothing: Risk assessment

    International Nuclear Information System (INIS)

    Rovira, Joaquim; Nadal, Martí; Schuhmacher, Marta; Domingo, José L.

    2015-01-01

    Metals in textile products and clothing are used for many purposes, such as metal complex dyes, pigments, mordant, catalyst in synthetic fabrics manufacture, synergists of flame retardants, antimicrobials, or as water repellents and odour-preventive agents. When present in textile materials, heavy metals may mean a potential danger to human health. In the present study, the concentrations of a number of elements (Al, As, B, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, Pb, Sb, Sc, Se, Sm, Sn, Sr, Tl, V, and Zn) were determined in skin-contact clothes. Analysed clothes were made of different materials, colours, and brands. Interestingly, we found high levels of Cr in polyamide dark clothes (605 mg/kg), high Sb concentrations in polyester clothes (141 mg/kg), and great Cu levels in some green cotton fabrics (around 280 mg/kg). Dermal contact exposure and human health risks for adult males, adult females, and for <1-year-old children were assessed. Non-carcinogenic and carcinogenic risks were below safe (HQ<1) and acceptable (<10 −6 ) limits, respectively, according to international standards. However, for Sb, non-carcinogenic risk was above 10% of the safety limit (HQ>0.1) for dermal contact with clothes. - Highlights: • We determined in skin-contact clothes the concentrations of a number of metals. • Dermal contact exposure and health risks for adults and for 1-year-old children were assessed. • Carcinogenic risks were considered as acceptable (<10 −6 ). • For non-carcinogenic risks, only Sb exceeded a 10% of the HQ for dermal contact with clothes

  5. The morphologic changes in the wall of the human urinary tracts after direct electro pulse exposure: the in vitro research

    Directory of Open Access Journals (Sweden)

    A.V. Gudkov

    2013-02-01

    Full Text Available The aim – study of the morphological changes in the wall of the human urinary tracts, developing after direct electro pulse exposure (DEPE. Materials and methods – The fragments of the surgical material obtained after the pelvis (n=25, ureter (n=33 and urinary bladder (n=20 open operations, were used in the research. DEPE was carried out by single (from 1 to 20 nanosecond pulses with the power of 0.8 J (joule and 1.0 J made by the electro pulse “Urolit-105M” lithotriptor probe on the fragments’ mucous tunic placed in the Petri dishes with 0.9% NaCl solution. The fragments were fixed in the formalin and after the processing, and pouring with paraffin, the tissue slices were prepared. Results – The kidney pelvis wall, where changes like epithelium desquamation, the basal membrane disorganization, paretic capillary expansion did not go beyond sub mucous layer even after exposure by 10 pulses with the power 1.0 J each, aimed at one point, proved to be the most resistant to DEPE. In the fragments of ureter and urinary bladder the same changes were detected after exposure by 5 pulses with the power of 1.0 J each, whereas after exposure by 10 pulses with the power 1.0 J each the changes occurred which were restricted by the muscular layer. Conclusion – The DEPEon the mucous tunic of the isolated urinary tracts fragments by the means of 10 pulses with the power of 1.0 J each looks safe, causes morphologic changes, restricted by the muscular layer and does not lead to the wall perforation.

  6. 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.

  7. 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

  8. 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

  9. Directed Differentiation of Human Embryonic Stem Cells into Prostate Organoids In Vitro and its Perturbation by Low-Dose Bisphenol A Exposure.

    Directory of Open Access Journals (Sweden)

    Esther L Calderon-Gierszal

    Full Text Available Studies using rodent and adult human prostate stem-progenitor cell models suggest that developmental exposure to the endocrine disruptor Bisphenol-A (BPA can predispose to prostate carcinogenesis with aging. Unknown at present is whether the embryonic human prostate is equally susceptible to BPA during its natural developmental window. To address this unmet need, we herein report the construction of a pioneer in vitro human prostate developmental model to study the effects of BPA. The directed differentiation of human embryonic stem cells (hESC into prostatic organoids in a spatial system was accomplished with precise temporal control of growth factors and steroids. Activin-induced definitive endoderm was driven to prostate specification by combined exposure to WNT10B and FGF10. Matrigel culture for 20-30 days in medium containing R-Spondin-1, Noggin, EGF, retinoic acid and testosterone was sufficient for mature prostate organoid development. Immunofluorescence and gene expression analysis confirmed that organoids exhibited cytodifferentiation and functional properties of the human prostate. Exposure to 1 nM or 10 nM BPA throughout differentiation culture disturbed early morphogenesis in a dose-dependent manner with 1 nM BPA increasing and 10 nM BPA reducing the number of branched structures formed. While differentiation of branched structures to mature organoids seemed largely unaffected by BPA exposure, the stem-like cell population increased, appearing as focal stem cell nests that have not properly entered lineage commitment rather than the rare isolated stem cells found in normally differentiated structures. These findings provide the first direct evidence that low-dose BPA exposure targets hESC and perturbs morphogenesis as the embryonic cells differentiate towards human prostate organoids, suggesting that the developing human prostate may be susceptible to disruption by in utero BPA exposures.

  10. Evaluation of E-Cigarette Liquid Vapor and Mainstream Cigarette Smoke after Direct Exposure of Primary Human Bronchial Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Stefanie Scheffler

    2015-04-01

    Full Text Available E-cigarettes are emerging products, often described as “reduced-risk” nicotine products or alternatives to combustible cigarettes. Many smokers switch to e-cigarettes to quit or significantly reduce smoking. However, no regulations for e-cigarettes are currently into force, so that the quality and safety of e-liquids is not necessarily guaranteed. We exposed primary human bronchial epithelial cells of two different donors to vapor of e-cigarette liquid with or without nicotine, vapor of the carrier substances propylene glycol and glycerol as well as to mainstream smoke of K3R4F research cigarettes. The exposure was done in a CULTEX® RFS compact  module, allowing the exposure of the cells at the air-liquid interface. 24 h post-exposure, cell viability and oxidative stress levels in the cells were analyzed. We found toxicological effects of e-cigarette vapor and the pure carrier substances, whereas the nicotine concentration did not have an effect on the cell viability. The viability of mainstream smoke cigarette exposed cells was 4.5–8 times lower and the oxidative stress levels 4.5–5 times higher than those of e-cigarette vapor exposed cells, depending on the donor. Our experimental setup delivered reproducible data and thus provides the opportunity for routine testing of e-cigarette liquids to ensure safety and quality for the user.

  11. Evaluation of E-cigarette liquid vapor and mainstream cigarette smoke after direct exposure of primary human bronchial epithelial cells.

    Science.gov (United States)

    Scheffler, Stefanie; Dieken, Hauke; Krischenowski, Olaf; Förster, Christine; Branscheid, Detlev; Aufderheide, Michaela

    2015-04-08

    E-cigarettes are emerging products, often described as "reduced-risk" nicotine products or alternatives to combustible cigarettes. Many smokers switch to e-cigarettes to quit or significantly reduce smoking. However, no regulations for e-cigarettes are currently into force, so that the quality and safety of e-liquids is not necessarily guaranteed. We exposed primary human bronchial epithelial cells of two different donors to vapor of e-cigarette liquid with or without nicotine, vapor of the carrier substances propylene glycol and glycerol as well as to mainstream smoke of K3R4F research cigarettes. The exposure was done in a CULTEX® RFS compact  module, allowing the exposure of the cells at the air-liquid interface. 24 h post-exposure, cell viability and oxidative stress levels in the cells were analyzed. We found toxicological effects of e-cigarette vapor and the pure carrier substances, whereas the nicotine concentration did not have an effect on the cell viability. The viability of mainstream smoke cigarette exposed cells was 4.5-8 times lower and the oxidative stress levels 4.5-5 times higher than those of e-cigarette vapor exposed cells, depending on the donor. Our experimental setup delivered reproducible data and thus provides the opportunity for routine testing of e-cigarette liquids to ensure safety and quality for the user.

  12. Direct exposure of guinea pig CNS to human luteinizing hormone increases cerebrospinal fluid and cerebral beta amyloid levels.

    Science.gov (United States)

    Wahjoepramono, Eka J; Wijaya, Linda K; Taddei, Kevin; Bates, Kristyn A; Howard, Matthew; Martins, Georgia; deRuyck, Karl; Matthews, Paul M; Verdile, Giuseppe; Martins, Ralph N

    2011-01-01

    Luteinizing hormone (LH) has been shown to alter the metabolism of beta amyloid (Aβ), a key protein in Alzheimer's disease (AD) pathogenesis. While LH and components required for LH receptor signalling are present in the brain, their role in the CNS remains unclear. In vitro, LH has been shown to facilitate neurosteroid production and alter Aβ metabolism. However, whether LH can directly modulate cerebral Aβ levels in vivo has not previously been studied. In this study, we investigated the effect of chronic administration of LH to the guinea pig CNS on cerebral Aβ levels. Gonadectomised male animals were administered, via cortical placement, either placebo or LH slow-release pellets. At 14 and 28 days after treatment, animals were sacrificed. Brain, plasma and CSF were collected and Aβ levels measured via ELISA. Levels of the Aβ precursor protein (APP) and the neurosteroidogenic enzyme cytochrome P450 side-chain cleavage enzyme (P450scc) were also assayed. An increase in CSF Aβ40 levels was observed 28 days following treatment. These CSF data also reflected changes in Aβ40 levels observed in brain homogenates. No change was observed in plasma Aβ40 levels but APP and its C-terminal fragments (APP-CTF) were significantly increased in response to LH exposure. Protein expression of P450scc was increased after 28 days of LH exposure, suggesting activation of the LH receptor. These data indicate that direct exposure of guinea pig CNS to LH results in altered brain Aβ levels, perhaps due to altered APP expression/metabolism. Copyright © 2011 S. Karger AG, Basel.

  13. 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.

  14. 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.

  15. 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

  16. Direct dating of human fossils.

    Science.gov (United States)

    Grün, Rainer

    2006-01-01

    The methods that can be used for the direct dating of human remains comprise of radiocarbon, U-series, electron spin resonance (ESR), and amino acid racemization (AAR). This review gives an introduction to these methods in the context of dating human bones and teeth. Recent advances in ultrafiltration techniques have expanded the dating range of radiocarbon. It now seems feasible to reliably date bones up to 55,000 years. New developments in laser ablation mass spectrometry permit the in situ analysis of U-series isotopes, thus providing a rapid and virtually non-destructive dating method back to about 300,000 years. This is of particular importance when used in conjunction with non-destructive ESR analysis. New approaches in AAR analysis may lead to a renaissance of this method. The potential and present limitations of these direct dating techniques are discussed for sites relevant to the reconstruction of modern human evolution, including Florisbad, Border Cave, Tabun, Skhul, Qafzeh, Vindija, Banyoles, and Lake Mungo. (c) 2006 Wiley-Liss, Inc.

  17. Human exposure, health hazards, and environmental regulations

    International Nuclear Information System (INIS)

    Steinemann, Anne

    2004-01-01

    United States environmental regulations, intended to protect human health, generally fail to address major sources of pollutants that endanger human health. These sources are surprisingly close to us and within our control, such as consumer products and building materials that we use within our homes, workplaces, schools, and other indoor environments. Even though these indoor sources account for nearly 90% of our pollutant exposure, they are virtually unregulated by existing laws. Even pollutant levels found in typical homes, if found outdoors, would often violate federal environmental standards. This article examines the importance of human exposure as a way to understand and reduce effects of pollutants on human health. Results from exposure studies challenge traditional thinking about pollutant hazards, and reveal deficiencies in our patchwork of laws. And results from epidemiological studies, showing increases in exposure-related diseases, underscore the need for new protections. Because we cannot rely solely on regulations to protect us, and because health effects from exposures can develop insidiously, greater efforts are needed to reduce and prevent significant exposures before they occur. Recommendations include the development and use of safer alternatives to common products, public education on ways to reduce exposure, systematic monitoring of human exposure to pollutants, and a precautionary approach in decision-making

  18. Exposure to UV radiation and human health

    Science.gov (United States)

    Kimlin, Michael G.

    2005-08-01

    This paper will overview the significant issues facing researchers in relating the impact of exposure to sunlight and human health. Exposure to solar ultraviolet radiation is the major causative factor in most sun-related skin and eye disorders, however, very little is known quantitatively about human UV exposures. Interestingly, human exposure to sunlight also has a nutritional impact, namely the development of pre-Vitamin D, which is an important nutrient in bone health. New research suggest that low vitamin D status may be a causative factor in the development of selective types of cancer and autoimminue diseases, as well as a contributing factor in bone health. The 'health duality' aspect of sunlight exposure is an interesting and controversial topic that is a research focus of Kimlin's research group.

  19. Human exposure to dioxin from combustion sources

    International Nuclear Information System (INIS)

    Hattemer-Frey, H.A.; Travis, C.C.

    1988-01-01

    Because of their extreme toxicity, much concern and debate has arisen about the nature and extent of human exposure to dioxin. Since municipal solid waste (MSW) incinerators are known to emit polychorinated dibenzo-p-dioxins (PCDDs) and polycholorinated dibenzofurnas (PCDFs) many people who live near MSW incinerators fear that they will be exposed to high levels of dioxin and subsequently develop cancer. What is often overlooked in this debate, however, is the fact that the general population is continuously being exposed to trace amounts of dioxin as exemplified by the fact that virtually all human adipose tissue samples contain dioxin at levels of 3 parts per trillion (ppt) or greater. This paper provides a perspective on MSW incineration as a source of human exposure to dioxin by comparing this exposure source with exposure to background environmental contamination and evaluates some of the potential key sources of PCDD/PCDF input into the enviroment. 32 refs., 3 tabs

  20. Atmospheric Ionizing Radiation and Human Exposure

    Science.gov (United States)

    Wilson, John W.; Mertens, Christopher J.; Goldhagen, Paul; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

    2005-01-01

    Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes. especially along the coastal plain and interior low lands, and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

  1. Atmospheric Ionizing Radiation and Human Exposure

    Science.gov (United States)

    Wilson, J. W.; Goldhagen, P.; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

    2004-01-01

    Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes especially along the coastal plain and interior low lands and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

  2. Assessment of Human Exposure to ENMs.

    Science.gov (United States)

    Jiménez, Araceli Sánchez; van Tongeren, Martie

    2017-01-01

    Human exposure assessment of engineered nanomaterials (ENMs) is hampered, among other factors, by the difficulty to differentiate ENM from other nanomaterials (incidental to processes or naturally occurring) and the lack of a single metric that can be used for health risk assessment. It is important that the exposure assessment is carried out throughout the entire life-cycle as releases can occur at the different stages of the product life-cycle, from the synthesis, manufacture of the nano-enable product (occupational exposure) to the professional and consumer use of nano-enabled product (consumer exposure) and at the end of life.Occupational exposure surveys should follow a tiered approach, increasing in complexity in terms of instruments used and sampling strategy applied with higher tiers in order tailor the exposure assessment to the specific materials used and workplace exposure scenarios and to reduce uncertainty in assessment of exposure. Assessment of consumer exposure and of releases from end-of-life processes currently relies on release testing of nano-enabled products in laboratory settings.

  3. 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.

  4. Variation in calculated human exposure. Comparison of calculations with seven European human exposure models

    NARCIS (Netherlands)

    Swartjes F; ECO

    2003-01-01

    Twenty scenarios, differing with respect to land use, soil type and contaminant, formed the basis for calculating human exposure from soil contaminants with the use of models contributed by seven European countries (one model per country). Here, the human exposures to children and children

  5. Harmonizing human exposure and toxicity characterization

    DEFF Research Database (Denmark)

    Fantke, Peter; Jolliet, O.; McKone, T.E.

    2017-01-01

    The UNEP-SETAC Life Cycle Initiative has launched a project to provide global guidance and build consensus on environmental life cycle impact assessment (LCIA) indicators. Human health effects from exposure to toxic chemicals was selected as impact category due to high relevance of human toxicity...... and harmonizing human toxicity characterization in LCIA. Building on initial work for the far-field and indoor air environments, and combining it with latest work on near-field consumer and occupational exposure assessment, dose-response and severity data, we aim at providing revised guidance on the development...... and use of impact factors for toxic chemicals. We propose to couple fate processes in consumer and occupational environments with existing environmental compartments and processes via a consistent and mass balance-based set of transfer fractions to quantify overall aggregated exposure to toxic substances...

  6. Human health effects of exposure to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Hallenbeck, W.H.

    1986-01-01

    The health effects of human exposure to cadmium are discussed with emphases on intake, absorption, body burden, and excretion; osteomalacia in Japan; hypertension; and proteinuria, emphysema, osteomalacia, and cancer in workers. Elevated blood pressure has not been observed as a result of excessive exposures to cadmium in Japan or the workplace. Renal tubular dysfunction and consequent proteinuria is generally accepted as the main effect following long-term, low-level exposure to cadmium. Studies of workers show that proteinuria may develop after the first year of exposure or many years after the last exposure. Proteinuria and deterioration of renal function may continue even after cessation of exposure. The immediate health significance of low-level proteinuria is still under debate. However, there is evidence that long-term renal tubular dysfunction may lead to abnormalities of calcium metabolism and osteomalacia. The few autopsy and cross-sectional studies of workers do not permit conclusions to be drawn regarding the relationship between cadmium exposure and emphysema. Retrospective and historical-prospective studies are needed to settle this important question. No conclusive evidence has been published regarding cadmium-induced cancer in humans. However, there is sufficient evidence to regard cadmium as a suspect renal and prostate carcinogen. Because of equivocal results and the absence of dose-response relationships, the studies reviewed should be used with caution in making regulatory decisions and low-dose risk assessments. 62 references.

  7. Human health effects of exposure to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Hallenbeck, W.H.

    1984-02-15

    The health effects of human exposure to cadmium are discussed with emphasis on intake, absorption, body burden, and excretion; osteomalacia in Japan; hypertension; and proteinuria, emphysema, osteomalacia, and cancer in workers. Elevated blood pressure has not been observed as a result of excessive exposures to cadmium in Japan or the workplace. Renal tubular dysfunction and consequent proteinuria is generally accepted as the main effect following long-term, low-level exposure to cadmium. Studies of workers show that proteinuria may develop after the first year of exposure or many years after the last exposure. Proteinuria and deterioration of renal function may continue even after cessation of exposure. The immediate health significance of low-level proteinuria is still under debate. However, there is evidence that long-term renal tubular dysfunction may lead to abnormalities of calcium metabolism and osteomalacia. The few autopsy and cross-sectional studies of workers do not permit conclusions to be drawn regarding the relationship between cadmium exposure and emphysema. Retrospective and historical-prospective studies are needed to settle this important question. No conclusive evidence has been published regarding cadmium-induced cancer in humans. However, there is sufficient evidence to regard cadmium as a suspect renal and prostate carcinogen. Because of equivocal results and the absence of dose-response relationships, the studies reviewed should be used with caution in making regulatory decisions and low-dose risk assessments.

  8. 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...

  9. [Effects of radiation exposure on human body].

    Science.gov (United States)

    Kamiya, Kenji; Sasatani, Megumi

    2012-03-01

    There are two types of radiation health effect; acute disorder and late on-set disorder. Acute disorder is a deterministic effect that the symptoms appear by exposure above a threshold. Tissues and cells that compose the human body have different radiation sensitivity respectively, and the symptoms appear in order, from highly radiosensitive tissues. The clinical symptoms of acute disorder begin with a decrease in lymphocytes, and then the symptoms appear such as alopecia, skin erythema, hematopoietic damage, gastrointestinal damage, central nervous system damage with increasing radiation dose. Regarding the late on-set disorder, a predominant health effect is the cancer among the symptoms of such as cancer, non-cancer disease and genetic effect. Cancer and genetic effect are recognized as stochastic effects without the threshold. When radiation dose is equal to or more than 100 mSv, it is observed that the cancer risk by radiation exposure increases linearly with an increase in dose. On the other hand, the risk of developing cancer through low-dose radiation exposure, less 100 mSv, has not yet been clarified scientifically. Although uncertainty still remains regarding low level risk estimation, ICRP propound LNT model and conduct radiation protection in accordance with LNT model in the low-dose and low-dose rate radiation from a position of radiation protection. Meanwhile, the mechanism of radiation damage has been gradually clarified. The initial event of radiation-induced diseases is thought to be the damage to genome such as radiation-induced DNA double-strand breaks. Recently, it is clarified that our cells could recognize genome damage and induce the diverse cell response to maintain genome integrity. This phenomenon is called DNA damage response which induces the cell cycle arrest, DNA repair, apoptosis, cell senescence and so on. These responses act in the direction to maintain genome integrity against genome damage, however, the death of large number of

  10. Human exposure to low level ionising radiation

    International Nuclear Information System (INIS)

    Paix, David

    1988-01-01

    This paper describes the low-level radiation sources and their effects on human populations, from a global perspective. 'Low-level' means exposures in the range of the natural background to which everybody is exposed. The quoted values are whole-world averages, but individual variations are mentioned in a few cases. (author). 22 refs

  11. Human health and exposure to electromagnetic radiation

    International Nuclear Information System (INIS)

    Dennis, J.A.; Muirhead, C.R.; Ennis, J.R.

    1992-07-01

    This review consists of three main parts. In the first the general features of electromagnetic fields and their interactions with the human body are described. The second part deals with the epidemiological evidence for effects on general health and birth outcome. The third part describes the epidemiological evidence from occupational and residential studies of a possible association between electromagnetic field exposures and cancer. (author)

  12. Post exposure prophylaxis against human immunodeficiency virus ...

    African Journals Online (AJOL)

    Objective: To determine the level of awareness, knowledge and practice of human immunodeficiency virus post exposure prophylaxis (HIV PEP) among paediatricians in Nigeria. Methodology: The study was a cross sectional questionnairebased survey conducted among paediatrcians that attended the Paediatric ...

  13. A translatable predictor of human radiation exposure.

    Science.gov (United States)

    Lucas, Joseph; Dressman, Holly K; Suchindran, Sunil; Nakamura, Mai; Chao, Nelson J; Himburg, Heather; Minor, Kerry; Phillips, Gary; Ross, Joel; Abedi, Majid; Terbrueggen, Robert; Chute, John P

    2014-01-01

    Terrorism using radiological dirty bombs or improvised nuclear devices is recognized as a major threat to both public health and national security. In the event of a radiological or nuclear disaster, rapid and accurate biodosimetry of thousands of potentially affected individuals will be essential for effective medical management to occur. Currently, health care providers lack an accurate, high-throughput biodosimetric assay which is suitable for the triage of large numbers of radiation injury victims. Here, we describe the development of a biodosimetric assay based on the analysis of irradiated mice, ex vivo-irradiated human peripheral blood (PB) and humans treated with total body irradiation (TBI). Interestingly, a gene expression profile developed via analysis of murine PB radiation response alone was inaccurate in predicting human radiation injury. In contrast, generation of a gene expression profile which incorporated data from ex vivo irradiated human PB and human TBI patients yielded an 18-gene radiation classifier which was highly accurate at predicting human radiation status and discriminating medically relevant radiation dose levels in human samples. Although the patient population was relatively small, the accuracy of this classifier in discriminating radiation dose levels in human TBI patients was not substantially confounded by gender, diagnosis or prior exposure to chemotherapy. We have further incorporated genes from this human radiation signature into a rapid and high-throughput chemical ligation-dependent probe amplification assay (CLPA) which was able to discriminate radiation dose levels in a pilot study of ex vivo irradiated human blood and samples from human TBI patients. Our results illustrate the potential for translation of a human genetic signature for the diagnosis of human radiation exposure and suggest the basis for further testing of CLPA as a candidate biodosimetric assay.

  14. A translatable predictor of human radiation exposure.

    Directory of Open Access Journals (Sweden)

    Joseph Lucas

    Full Text Available Terrorism using radiological dirty bombs or improvised nuclear devices is recognized as a major threat to both public health and national security. In the event of a radiological or nuclear disaster, rapid and accurate biodosimetry of thousands of potentially affected individuals will be essential for effective medical management to occur. Currently, health care providers lack an accurate, high-throughput biodosimetric assay which is suitable for the triage of large numbers of radiation injury victims. Here, we describe the development of a biodosimetric assay based on the analysis of irradiated mice, ex vivo-irradiated human peripheral blood (PB and humans treated with total body irradiation (TBI. Interestingly, a gene expression profile developed via analysis of murine PB radiation response alone was inaccurate in predicting human radiation injury. In contrast, generation of a gene expression profile which incorporated data from ex vivo irradiated human PB and human TBI patients yielded an 18-gene radiation classifier which was highly accurate at predicting human radiation status and discriminating medically relevant radiation dose levels in human samples. Although the patient population was relatively small, the accuracy of this classifier in discriminating radiation dose levels in human TBI patients was not substantially confounded by gender, diagnosis or prior exposure to chemotherapy. We have further incorporated genes from this human radiation signature into a rapid and high-throughput chemical ligation-dependent probe amplification assay (CLPA which was able to discriminate radiation dose levels in a pilot study of ex vivo irradiated human blood and samples from human TBI patients. Our results illustrate the potential for translation of a human genetic signature for the diagnosis of human radiation exposure and suggest the basis for further testing of CLPA as a candidate biodosimetric assay.

  15. 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.

  16. Environmental chemical exposures and human epigenetics

    Science.gov (United States)

    Hou, Lifang; Zhang, Xiao; Wang, Dong; Baccarelli, Andrea

    2012-01-01

    Every year more than 13 million deaths worldwide are due to environmental pollutants, and approximately 24% of diseases are caused by environmental exposures that might be averted through preventive measures. Rapidly growing evidence has linked environmental pollutants with epigenetic variations, including changes in DNA methylation, histone modifications and microRNAs. Environ mental chemicals and epigenetic changes All of these mechanisms are likely to play important roles in disease aetiology, and their modifications due to environmental pollutants might provide further understanding of disease aetiology, as well as biomarkers reflecting exposures to environmental pollutants and/or predicting the risk of future disease. We summarize the findings on epigenetic alterations related to environmental chemical exposures, and propose mechanisms of action by means of which the exposures may cause such epigenetic changes. We discuss opportunities, challenges and future directions for future epidemiology research in environmental epigenomics. Future investigations are needed to solve methodological and practical challenges, including uncertainties about stability over time of epigenomic changes induced by the environment, tissue specificity of epigenetic alterations, validation of laboratory methods, and adaptation of bioinformatic and biostatistical methods to high-throughput epigenomics. In addition, there are numerous reports of epigenetic modifications arising following exposure to environmental toxicants, but most have not been directly linked to disease endpoints. To complete our discussion, we also briefly summarize the diseases that have been linked to environmental chemicals-related epigenetic changes. PMID:22253299

  17. Biocides Steering Group on human exposure assessment: a preliminary report.

    Science.gov (United States)

    van Hemmen, J J

    1999-06-30

    In a project granted by DG XI of the European Commission, it is attempted to collate experimental and theoretical data on human (workers and consumers) exposure assessment to biocidal products, and to outline the methodology for sampling and measurement. On the basis of the available evidence, approaches are presented for the exposure assessment to be used for estimation of risks in authorization procedures under the recently accepted Directive 98/8/EC. Gaps in knowledge are indicated, making it possible to study the issues involved in a comprehensive and cost-effective way. Some recommendations are given on how to best do this. The current project has been detailed in a final report.

  18. 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.

  19. 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

  20. 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...

  1. Directly measured secondhand smoke exposure and COPD health outcomes

    Directory of Open Access Journals (Sweden)

    Balmes John

    2006-06-01

    Full Text Available Abstract Background Although personal cigarette smoking is the most important cause and modulator of chronic obstructive pulmonary disease (COPD, secondhand smoke (SHS exposure could influence the course of the disease. Despite the importance of this question, the impact of SHS exposure on COPD health outcomes remains unknown. Methods We used data from two waves of a population-based multiwave U.S. cohort study of adults with COPD. 77 non-smoking respondents with a diagnosis of COPD completed direct SHS monitoring based on urine cotinine and a personal badge that measures nicotine. We evaluated the longitudinal impact of SHS exposure on validated measures of COPD severity, physical health status, quality of life (QOL, and dyspnea measured at one year follow-up. Results The highest level of SHS exposure, as measured by urine cotinine, was cross-sectionally associated with poorer COPD severity (mean score increment 4.7 pts; 95% CI 0.6 to 8.9 and dyspnea (1.0 pts; 95% CI 0.4 to 1.7 after controlling for covariates. In longitudinal analysis, the highest level of baseline cotinine was associated with worse COPD severity (4.7 points; 95% CI -0.1 to 9.4; p = 0.054, disease-specific QOL (2.9 pts; -0.16 to 5.9; p = 0.063, and dyspnea (0.9 pts; 95% CI 0.2 to 1.6 pts; p Conclusion Directly measured SHS exposure appears to adversely influence health outcomes in COPD, independent of personal smoking. Because SHS is a modifiable risk factor, clinicians should assess SHS exposure in their patients and counsel its avoidance. In public health terms, the effects of SHS exposure on this vulnerable subpopulation provide a further rationale for laws prohibiting public smoking.

  2. 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....

  3. Disorders induced by direct occupational exposure to noise: Systematic review

    Directory of Open Access Journals (Sweden)

    Andrea Domingo-Pueyo

    2016-01-01

    Full Text Available Background: To review the available scientific literature about the effects on health by occupational exposure to noise. Materials and Methods: A systematic review of the retrieved scientific literature from the databases MEDLINE (via PubMed, ISI-Web of Knowledge (Institute for Scientific Information, Cochrane Library Plus, SCOPUS, and SciELO (collection of scientific journals was conducted. The following terms were used as descriptors and were searched in free text: “Noise, Occupational,” “Occupational Exposure,” and “Occupational Disease.” The following limits were considered: “Humans,” “Adult (more than 18 years,” and “Comparative Studies.” Results: A total of 281 references were retrieved, and after applying inclusion/exclusion criteria, 25 articles were selected. Of these selected articles, 19 studies provided information about hearing disturbance, four on cardiovascular disorders, one regarding respiratory alteration, and one on other disorders. Conclusions: It can be interpreted that the exposure to noise causes alterations in humans with different relevant outcomes, and therefore appropriate security measures in the work environment must be employed to minimize such an exposure and thereby to reduce the number of associated disorders.

  4. Human-directed aggression in the cat.

    Science.gov (United States)

    Curtis, Terry Marie

    2008-09-01

    Feline aggression-between cats or directed at humans-is, after inappropriate elimination and urine-marking behaviors, the second most common reason cats are seen by behavioral specialists. For diagnosis and treatment it is important to determine the motivation for the aggression. The more common causes for human-directed aggression in cats include play, fear, petting intolerance, and redirected aggression. Other causes include pain and maternal behavior. Sexually motivated and status related aggression are much more rare. Treatment includes a combination of behavioral modification, environmental modification, and, in some cases, medication.

  5. A radiopharmacological study without human radiation exposure

    International Nuclear Information System (INIS)

    Loew, D.; Graul, E.H.; Kunkel, R.

    1984-01-01

    The development, study and control of new drugs today is hardly conceivable without nuclear medicine studies. Nuclear physicians on ethical commissions bear great responsibility in the planning and execution of such studies. In order to protect subjects and patients those nuclear techniques are therefore to be welcome which do not include exposure to radiation. Nuclear techniques used in in-vitro diagnostics (RIA) and the determination of naturally occurring nuclides incorporated in the human body belong to this category. With the aid of a clinico-pharmacological study of a new combination of diuretics it is shown that both methods supply valuable pharmacodynamic evidence. (orig.) [de

  6. Human Physiological Responses to Acute and Chronic Cold Exposure

    Science.gov (United States)

    Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

    2001-01-01

    When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

  7. Human Health Effects Associated with Exposure to Cyanobacteria and Cyanotoxins: What Do We Know?

    Science.gov (United States)

    The study of environmental health typically focuses on human populations. However, companion animals, livestock and wildlife also experience adverse health effects from environmental pollutants. Animals may experience direct exposure to pollutants unlike people in most ambient ex...

  8. Assessment of genetic risk for human exposure to radiation

    International Nuclear Information System (INIS)

    Sevcenko, V.A.; Rubanovic, A.V.

    2002-01-01

    Full text: The methodology of assessing the genetic risk of radiation exposure is based on the concept of 'hitting the target' in development of which N.V. Timofeeff-Ressovsky has played and important role. To predict genetic risk posed by irradiation, the U N Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has worked out direct and indirect methods of assessment, extrapolation, integral and palpitation criteria of risk analysis that together permit calculating the risk from human exposure on the basis of data obtained for mice. Based on the reports of UNSCEAR for the period from 1958 to 2001 the paper presents a retrospective analysis of the use of direct methods and the doubling dose method for quantitative determination of the genetic risk of human exposure expressed as different hereditary diseases. As early as 1962 UNSCEAR estimated the doubling dose (a dose causing as many mutations as those occurring spontaneously during one generation) at 1 Gy for cases of exposure to ionizing radiations with low LET at a low dose rate and this value was confirmed in the next UNSCEAR reports up to now. For cases of acute irradiation the doubling dose was estimated at 0,3-0,4 Gy for the period under review. The paper considers the evolution of the concepts of human natural hereditary variability which is a basis for assessing the risk of exposure by the doubling dose method. The level of human natural genetic variability per 1 000 000 newborns is estimated at 738 000 hereditary diseases including mendelian, chromosomal and multifactorial ones. The greatest difficulties in assessing the doubling dose value were found to occur in the case of multifactorial diseases the pheno typical expression of which depends on mutational events in polygenic systems and on numerous environmental factors. The introduction in calculations of the potential recoverability correction factor (RPCF) made it possible to assess the genetic risk taking into account this class of

  9. Sampling strategy for estimating human exposure pathways to consumer chemicals

    NARCIS (Netherlands)

    Papadopoulou, Eleni; Padilla-Sanchez, Juan A.; Collins, Chris D.; Cousins, Ian T.; Covaci, Adrian; de Wit, Cynthia A.; Leonards, Pim E.G.; Voorspoels, Stefan; Thomsen, Cathrine; Harrad, Stuart; Haug, Line S.

    2016-01-01

    Human exposure to consumer chemicals has become a worldwide concern. In this work, a comprehensive sampling strategy is presented, to our knowledge being the first to study all relevant exposure pathways in a single cohort using multiple methods for assessment of exposure from each exposure pathway.

  10. A flexible matrix-based human exposure assessment framework suitable for LCA and CAA

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Ernstoff, Alexi; Huang, Lei

    2016-01-01

    are not applicable to all types of near-field chemical releases from consumer products, e.g. direct dermal application. A consistent near-and far-field framework is needed for life cycle assessment (LCA) and chemical alternative assessment (CAA) to inform mitigation of human exposure to harmful chemicals. To close......Humans can be exposed to chemicals via near-field exposure pathways (e.g. through consumer product use) and far-field exposure pathways (e.g. through environmental emissions along product life cycles). Pathways are often complex where chemicals can transfer directly from products to humans during...... use or exchange between near-and far-field compartments until sub -fractions reach humans via inhalation, ingestion or dermal uptake. Currently, however, multimedia exposure models mainly focus on far-field exposure pathways. Metrics and modeling approaches used in far-field, emission-based models...

  11. EFFECTS OF ARSENIC EXPOSURE IN HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Aline Sueli de Lima Rodrigues

    2008-10-01

    Full Text Available In recent years, ingestion of inorganic arsenic from drinking water has emerged as an important public health concern. It enters drinking water supplies from natural deposits in the earth or from agricultural and industrial practices, mainly the mining. The health consequences of chronic arsenic exposure include increased risk for various forms of cancer and numerous pathologic effects, such as cutaneous effects (hyperpigmentation and hyperkeratoses, gastrointestinal effects, vascular effects, diabetes mellitus, and peripheral neuropathy. This way, this study presents through a critical revision of the literature, the more relevant current aspects on the immunological consequences, carcinogenic and resulting genetics of the human intoxication for arsenic. They were identified and analyzed 50 works published on the subject among the years of 1979 and 2008, being used as main sources LILACS-BIREME MEDLINE/Index Medicus, SciELO and PubMed. The specific Arsênio e saúde humana effects of the intoxication for arsenic about the human health are not still completely elucidated. Thus, is possible that this element affects functions still unknown, becoming important the scientificexploration on the subject.

  12. Human-Robot Interaction Directed Research Project

    Science.gov (United States)

    Rochlis, Jennifer; Ezer, Neta; Sandor, Aniko

    2011-01-01

    Human-robot interaction (HRI) is about understanding and shaping the interactions between humans and robots (Goodrich & Schultz, 2007). It is important to evaluate how the design of interfaces and command modalities affect the human s ability to perform tasks accurately, efficiently, and effectively (Crandall, Goodrich, Olsen Jr., & Nielsen, 2005) It is also critical to evaluate the effects of human-robot interfaces and command modalities on operator mental workload (Sheridan, 1992) and situation awareness (Endsley, Bolt , & Jones, 2003). By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed that support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for design. Because the factors associated with interfaces and command modalities in HRI are too numerous to address in 3 years of research, the proposed research concentrates on three manageable areas applicable to National Aeronautics and Space Administration (NASA) robot systems. These topic areas emerged from the Fiscal Year (FY) 2011 work that included extensive literature reviews and observations of NASA systems. The three topic areas are: 1) video overlays, 2) camera views, and 3) command modalities. Each area is described in detail below, along with relevance to existing NASA human-robot systems. In addition to studies in these three topic areas, a workshop is proposed for FY12. The workshop will bring together experts in human-robot interaction and robotics to discuss the state of the practice as applicable to research in space robotics. Studies proposed in the area of video overlays consider two factors in the implementation of augmented reality (AR) for operator displays during teleoperation. The first of these factors is the type of navigational guidance provided by AR symbology. In the proposed

  13. Early androgen exposure and human gender development.

    Science.gov (United States)

    Hines, Melissa; Constantinescu, Mihaela; Spencer, Debra

    2015-01-01

    During early development, testosterone plays an important role in sexual differentiation of the mammalian brain and has enduring influences on behavior. Testosterone exerts these influences at times when the testes are active, as evidenced by higher concentrations of testosterone in developing male than in developing female animals. This article critically reviews the available evidence regarding influences of testosterone on human gender-related development. In humans, testosterone is elevated in males from about weeks 8 to 24 of gestation and then again during early postnatal development. Individuals exposed to atypical concentrations of testosterone or other androgenic hormones prenatally, for example, because of genetic conditions or because their mothers were prescribed hormones during pregnancy, have been consistently found to show increased male-typical juvenile play behavior, alterations in sexual orientation and gender identity (the sense of self as male or female), and increased tendencies to engage in physically aggressive behavior. Studies of other behavioral outcomes following dramatic androgen abnormality prenatally are either too small in their numbers or too inconsistent in their results, to provide similarly conclusive evidence. Studies relating normal variability in testosterone prenatally to subsequent gender-related behavior have produced largely inconsistent results or have yet to be independently replicated. For studies of prenatal exposures in typically developing individuals, testosterone has been measured in single samples of maternal blood or amniotic fluid. These techniques may not be sufficiently powerful to consistently detect influences of testosterone on behavior, particularly in the relatively small samples that have generally been studied. The postnatal surge in testosterone in male infants, sometimes called mini-puberty, may provide a more accessible opportunity for measuring early androgen exposure during typical development. This

  14. Quantifying human exposure to air pollution--moving from static monitoring to spatio-temporally resolved personal exposure assessment.

    Science.gov (United States)

    Steinle, Susanne; Reis, Stefan; Sabel, Clive Eric

    2013-01-15

    Quantifying human exposure to air pollutants is a challenging task. Ambient concentrations of air pollutants at potentially harmful levels are ubiquitous in urban areas and subject to high spatial and temporal variability. At the same time, every individual has unique activity-patterns. Exposure results from multifaceted relationships and interactions between environmental and human systems, adding complexity to the assessment process. Traditionally, approaches to quantify human exposure have relied on pollutant concentrations from fixed air quality network sites and static population distributions. New developments in sensor technology now enable us to monitor personal exposure to air pollutants directly while people are moving through their activity spaces and varying concentration fields. The literature review on which this paper is based on reflects recent developments in the assessment of human exposure to air pollution. This includes the discussion of methodologies and concepts, and the elaboration of approaches and study designs applied in the field. We identify shortcomings of current approaches and discuss future research needs. We close by proposing a novel conceptual model for the integrated assessment of human exposure to air pollutants taking into account latest technological capabilities and contextual information. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. [Advance directives, a tool to humanize care].

    Science.gov (United States)

    Olmari-Ebbing, M; Zumbach, C N; Forest, M I; Rapin, C H

    2000-07-01

    The relationship between the patient and a medical care giver is complex specially as it implies to the human, juridical and practical points of view. It depends on legal and deontological considerations, but also on professional habits. Today, we are confronted to a fundamental modification of this relationship. Professional guidelines exist, but are rarely applied and rarely taught in universities. However, patients are eager to move from a paternalistic relationship to a true partnership, more harmonious and more respectful of individual values ("value based medicine"). Advance directives give us an opportunity to improve our practices and to provide care consistent with the needs and wishes of each patient.

  16. Human exposure to bovine polyomavirus: a zoonosis

    Energy Technology Data Exchange (ETDEWEB)

    Parry, J V; Gardner, S D

    1986-01-01

    A competitive-type solid phase radioimmunoassay (RIA) was developed for the detection of antibody to bovine polyomavirus. Comparison of RIA and counter-immunoelectrophoresis (CIE) results on 273 cattle sera indicated that both techniques were detecting antibody of like specificity. Human sera from 256 blood donors, 219 people recently vaccinated against polio, rubella or rabies, 50 immunosuppressed patients and 472 people with various occupational exposure to cattle were tested for antibody to bovine polyomavirus, the foetal rhesus monkey kidney strain, (anti-FRKV) by RIA. Apart from one blood donor and one of 108 rabies vaccinees only those in close contact with cattle possessed anti-FRKV. Compared with 62 per cent seropositive in the natural hosts, cattle, 71 per cent of veterinary surgeons, 50 per cent of cattle farmers, 40 per cent of abattoir workers, 16 per cent of veterinary institute technical staff and 10 per cent of veterinary students were anti-FRKV positive. Our findings indicate that the theoretical hazard of FRKV infection from undetected contamination of current tissue culture derived vaccines may, in practice, be remote. Proposed wider use of primate kidney cells as substrates for new vaccines may increase this risk.

  17. Ultraviolet radiation directly induces pigment production by cultured human melanocytes

    International Nuclear Information System (INIS)

    Friedmann, P.S.; Gilchrest, B.A.

    1987-01-01

    In humans the major stimulus for cutaneous pigmentation is ultraviolet radiation (UVR). Little is known about the mechanism underlying this response, in part because of the complexity of interactions in whole epidermis. Using a recently developed culture system, human melanocytes were exposed daily to a physiologic range of UVR doses from a solar simulator. Responses were determined 24 hours after the last exposure. There was a dose-related increase in melanin content per cell and uptake of 14 C-DOPA, accompanied by growth inhibition. Cells from donors of different racial origin gave proportionately similar increases in melanin, although there were approximately tenfold differences in basal values. Light and electron microscopy revealed UVR-stimulated increases in dendricity as well as melanosome number and degree of melanization, analogous to the well-recognized melanocyte changes following sun exposure of intact skin. Similar responses were seen with Cloudman S91 melanoma cells, although this murine cell line required lower UVR dosages and fewer exposures for maximal stimulation. These data establish that UVR is capable of directly stimulating melanogenesis. Because cyclic AMP elevation has been associated in some settings with increased pigment production by cultured melanocytes, preliminary experiments were conducted to see if the effects of UVR were mediated by cAMP. Both alpha-MSH and isobutylmethylxanthine (IBMX), as positive controls, caused a fourfold increase in cAMP level in human melanocytes and/or S91 cells, but following a dose of UVR sufficient to stimulate pigment production there was no change in cAMP level up to 4 hours after exposure. Thus, it appears that the UVR-induced melanogenesis is mediated by cAMP-independent mechanisms

  18. Human movement is both diffusive and directed.

    Directory of Open Access Journals (Sweden)

    Mark Padgham

    Full Text Available Understanding the influence of the built environment on human movement requires quantifying spatial structure in a general sense. Because of the difficulty of this task, studies of movement dynamics often ignore spatial heterogeneity and treat movement through journey lengths or distances alone. This study analyses public bicycle data from central London to reveal that, although journey distances, directions, and frequencies of occurrence are spatially variable, their relative spatial patterns remain largely constant, suggesting the influence of a fixed spatial template. A method is presented to describe this underlying space in terms of the relative orientation of movements toward, away from, and around locations of geographical or cultural significance. This produces two fields: one of convergence and one of divergence, which are able to accurately reconstruct the observed spatial variations in movement. These two fields also reveal categorical distinctions between shorter journeys merely serving diffusion away from significant locations, and longer journeys intentionally serving transport between spatially distinct centres of collective importance. Collective patterns of human movement are thus revealed to arise from a combination of both diffusive and directed movement, with aggregate statistics such as mean travel distances primarily determined by relative numbers of these two kinds of journeys.

  19. Human exposure assessment to environmental chemicals using biomonitoring.

    Science.gov (United States)

    Calafat, Antonia M; Ye, Xiaoyun; Silva, Manori J; Kuklenyik, Zsuzsanna; Needham, Larry L

    2006-02-01

    In modern societies, humans may be exposed to a wide spectrum of environmental chemicals. Although the health significance of this exposure for many chemicals is unknown, studies to investigate the prevalence of exposure are warranted because of the chemicals' potential harmful health effects, as often indicated in animal studies. Three tools have been used to assess exposure: exposure history/questionnaire information, environmental monitoring, and biomonitoring (i.e. measuring concentrations of the chemicals, their metabolites, or their adducts in human specimens). We present an overview on the use of biomonitoring in exposure assessment using phthalates, bisphenol A and other environmental phenols, and perfluorinated chemicals as examples. We discuss some factors relevant for interpreting and understanding biomonitoring data, including selection of both biomarkers of exposure and human matrices, and toxicokinetic information. The use of biomonitoring in human risk assessment is not discussed.

  20. Progress in human exposure assessment for biocidal products

    NARCIS (Netherlands)

    Hemmen, J.J. van

    2004-01-01

    An important shortcoming in our present knowledge required for risk assessment of biocidal products is the assessment of human exposure. This knowledge gap has been filled in a preliminary fashion with the TNsG on human exposure to biocidal products (available from the ECB website). Explicit User

  1. Human exposure assessment: Approaches for chemicals (REACH) and biocides (BPD)

    NARCIS (Netherlands)

    Hemmen, J.J. van; Gerritsen-Ebben, R.

    2008-01-01

    The approaches that are indicated in the various guidance documents for the assessment of human exposure for chemicals and biocides are summarised. This reflects the TNsG (Technical notes for Guidance) version 2: human exposure assessment for biocidal products (1) under the BPD (Biocidal Products

  2. Patient radiation exposure dose evaluation of whole spine scanography due to exposure direction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Su; Seo, Deok Nam [Dept. of Bio-convergence Engineering, Graduate School of Korea University, Seoul (Korea, Republic of); Kwon, Soon Mu [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of); Kim, Jung Min [Dept. of Radiological Science, Korea University, Seoul (Korea, Republic of)

    2015-04-15

    Whole spine scanography (WSS) is a radiological examination that exposes the whole body of the individual being examined to x-ray radiation. WSS is often repeated during the treatment period, which results in a much greater radiation exposure than that in routine x-ray examinations. The aims of the current study were to evaluate the patient dose of WSS using computer simulation, image magnification and angulation of phantom image using different patient position. We evaluated the effective dose(ED) of 23 consecutive patients (M : F = 13:10) who underwent WSS, based on the automatic image pasting method for multiple exposure digital radiography. The Anterior-Posterior position(AP) and Posterior-Anterior position( PA) projection EDs were evaluated based on the PC based Monte Carlo simulation. We measured spine transverse process distance and angulation using DICOM measurement. For all patient, the average ED was 0.069 mSv for AP position and 0.0361 mSv for PA position. AP position calculated double exposure then PA position. For male patient, the average ED was 0.089 mSv(AP) and 0.050 mSv(PA). For female patient, the average ED was 0.0431 mSv(AP) and 0.026 mSv(PA). The transverse process of PA spine image measured 5% higher than AP but angulation of transverse process was no significant differences. In clinical practice, just by change the patient position was conformed to reduce the ED of patient. Therefore we need to redefine of protocol for digital radiography such as WSS, whole spine scanography, effective dose, patient exposure dose, exposure direction, protocol optimization.

  3. Relative biological effectiveness if alpha radiation for human lung exposure

    International Nuclear Information System (INIS)

    Yarmoshenko, I.; Kirdin, I.; Zhukovsky, M.

    2006-01-01

    Full text of publication follows: The concept of RBE, which introduced by ICRP and ICRU about 50 years ago to compare biological effects of ionizing radiation of different types, still continues to be the essential element of current and projected radiation protection systems in terms of deriving quantities (quality factor and radiation weighting factor). For example, RBE for the stochastic effects induction has to be considered for appropriate radiation weighting of the absorbed dose while estimating equivalent dose. Simulation of lung cancer radiation risk for the cases of inhalation of radon progeny and incorporation of plutonium in lung in comparison with external reference radiation allows assessment of RBE for alpha-radiation. Specific radiation risk models were developed by results of the direct epidemiological studies and used for such simulation. Simulation included published risk models for nuclear workers of the Mayak facilities in the former Soviet Union exposed to incorporated plutonium (Kreisheimer et al., 2003; Gilbert et al., 2004) and underground miners exposed to radon progenies (BEIR VI, 1999). Additionally lung cancer risk model was developed for a case of population indoor radon exposure. Lung cancer risk related to external exposure is estimated using the risk model develop ed using data of Life Span Study of Japanese atomic bomb survivors. By results of lifetime lung cancer risk simulation using Monte Carlo approach estimated median value of RBE in case of indoor radon exposure is 1.5 (with 90% range 0.4 to 7). In case of the two models developed by BEIR VI for lung cancer risk due to radon exposure in underground miners the median values of RBE are 2.1 and 4.4 (with 90% ranges 0.3 to 17 and 0.7 to 45) respectively.Two different models for lung cancer risk related to plutonium exposure resulted in close estimates of RBE: median value of 12 and 13 (with 90% range 4 to 104 and 4 to 136) respectively. Considerable discrepancy between RBE

  4. Case definitions for human poisonings postulated to palytoxins exposure.

    Science.gov (United States)

    Tubaro, A; Durando, P; Del Favero, G; Ansaldi, F; Icardi, G; Deeds, J R; Sosa, S

    2011-03-01

    A series of case reports and anecdotal references describe the adverse effects on human health ascribed to the marine toxin palytoxin (PLTX) after different exposure routes. They include poisonings after oral intake of contaminated seafood, but also inhalation and cutaneous/systemic exposures after direct contact with aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing cnidarian zoanthids. The symptoms commonly recorded during PLTX intoxication are general malaise and weakness, associated with myalgia, respiratory effects, impairment of the neuromuscular apparatus and abnormalities in cardiac function. Systemic symptoms are often recorded together with local damages whose intensity varies according to the route and length of exposure. Gastrointestinal malaise or respiratory distress is common for oral and inhalational exposure, respectively. In addition, irritant properties of PLTX probably account for the inflammatory reactions typical of cutaneous and inhalational contact. Unfortunately, the toxin identification and/or quantification are often incomplete or missing and cases of poisoning are indirectly ascribed to PLTXs, according only to symptoms, anamnesis and environmental/epidemiological investigations (i.e. zoanthid handling or ingestion of particular seafood). Based on the available literature, we suggest a "case definition of PLTX poisonings" according to the main exposure routes, and, we propose the main symptoms to be checked, as well as, hemato-clinical analysis to be carried out. We also suggest the performance of specific analyses both on biological specimens of patients, as well as, on the contaminated materials responsible for the poisoning. A standardized protocol for data collection could provide a more rapid and reliable diagnosis of palytoxin-poisoning, but also the collection of necessary data for the risk assessment for this family of toxins. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Direct numerical simulation of human phonation

    Science.gov (United States)

    Bodony, Daniel; Saurabh, Shakti

    2017-11-01

    The generation and propagation of the human voice in three-dimensions is studied using direct numerical simulation. A full body domain is employed for the purpose of directly computing the sound in the region past the speaker's mouth. The air in the vocal tract is modeled as a compressible and viscous fluid interacting with the elastic vocal folds. The vocal fold tissue material properties are multi-layered, with varying stiffness, and a linear elastic transversely isotropic model is utilized and implemented in a quadratic finite element code. The fluid-solid domains are coupled through a boundary-fitted interface and utilize a Poisson equation-based mesh deformation method. A kinematic constraint based on a specified minimum gap between the vocal folds is applied to prevent collision during glottal closure. Both near VF flow dynamics and far-field acoustics have been studied. A comparison is drawn to current two-dimensional simulations as well as to data from the literature. Near field vocal fold dynamics and glottal flow results are studied and in good agreement with previous three-dimensional phonation studies. Far-field acoustic characteristics, when compared to their two-dimensional counterpart, are shown to be sensitive to the dimensionality. Supported by the National Science Foundation (CAREER Award Number 1150439).

  6. Human-Robot Interaction Directed Research Project

    Science.gov (United States)

    Sandor, Aniko; Cross, Ernest V., II; Chang, Mai Lee

    2014-01-01

    Human-robot interaction (HRI) is a discipline investigating the factors affecting the interactions between humans and robots. It is important to evaluate how the design of interfaces and command modalities affect the human's ability to perform tasks accurately, efficiently, and effectively when working with a robot. By understanding the effects of interface design on human performance, workload, and situation awareness, interfaces can be developed to appropriately support the human in performing tasks with minimal errors and with appropriate interaction time and effort. Thus, the results of research on human-robot interfaces have direct implications for the design of robotic systems. This DRP concentrates on three areas associated with interfaces and command modalities in HRI which are applicable to NASA robot systems: 1) Video Overlays, 2) Camera Views, and 3) Command Modalities. The first study focused on video overlays that investigated how Augmented Reality (AR) symbology can be added to the human-robot interface to improve teleoperation performance. Three types of AR symbology were explored in this study, command guidance (CG), situation guidance (SG), and both (SCG). CG symbology gives operators explicit instructions on what commands to input, whereas SG symbology gives operators implicit cues so that operators can infer the input commands. The combination of CG and SG provided operators with explicit and implicit cues allowing the operator to choose which symbology to utilize. The objective of the study was to understand how AR symbology affects the human operator's ability to align a robot arm to a target using a flight stick and the ability to allocate attention between the symbology and external views of the world. The study evaluated the effects type of symbology (CG and SG) has on operator tasks performance and attention allocation during teleoperation of a robot arm. The second study expanded on the first study by evaluating the effects of the type of

  7. Carcinogen biomonitoring in human exposures and laboratory research: validation and application to human occupational exposures.

    Science.gov (United States)

    Talaska, Glenn; Maier, Andrew; Henn, Scott; Booth-Jones, Angela; Tsuneoka, Yutaka; Vermeulen, Roel; Schumann, Brenda L

    2002-08-05

    A multiple biomarker approach is required to integrate for metabolism, temporal response and exposure-response kinetics, biological relevance, and positive predictive value. Carcinogen DNA adduct analysis can be used in animal and in vitro studies to detect absorption permutations caused by mixture interactions, and to control metabolic variation when specific CYP450 genes (1A1 or 1A2) are knocked out. These enzymes are not critical to the metabolic activation of model Polycyclic Aromatic Compounds (PAC) and aromatic amines, respectively, as suggested by in vitro analysis. Several human studies have been carried out where multiple biomarkers have been measured. In a study of benzidine workers, the similarities in elimination kinetics between urinary metabolites and mutagenicity is likely responsible for a better correlation between these markers than to BZ-DNA adducts in exfoliated cells. In a study of rubber workers, the relationship between specific departments, urinary 1 HP and DNA adducts in exfoliated cells coincided with the historical urinary bladder cancer risk in these departments; the same relationship did not hold for urinary mutagenicity. In a study of automotive mechanics, biomarkers were used to monitor the effectiveness of exposure interventions. These data reinforce the notion that carcinogen biomarkers are useful to monitor exposure, but that a complementary approaches involving effect and perhaps susceptibility biomarkers is necessary to obtain the necessary information.

  8. Direct methods for measuring radionuclides in the human body

    International Nuclear Information System (INIS)

    1996-01-01

    Occupational exposure leading to intakes of internally incorporated radionuclides can occur as a result of various activities. This includes work associated with the different stages of the nuclear fuel cycle, the use of radioactive sources in medicine, scientific research, agriculture and industry, and occupations which involve exposure to enhanced levels of naturally occurring radionuclides. In 1987 the IAEA published a Safety Guide on basic principles for occupational radiation monitoring which set forth principles and objectives of a strategy for monitoring exposures of workers. Since drafting of the present Safety Practice commenced, the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) have been issued. On the basis of the principles laid down in the BSS, the 1987 Safety Guide is also being revised, and recommendations on the assessment of the occupational intake of radioactive materials are to be added. The present Safety Practice, which deals with direct measurement of radionuclides in the human body, is the first to be published in this area. Refs, figs, tabs

  9. Cadmium osteotoxicity in experimental animals: Mechanisms and relationship to human exposures

    International Nuclear Information System (INIS)

    Bhattacharyya, Maryka H.

    2009-01-01

    Extensive epidemiological studies have recently demonstrated increased cadmium exposure correlating significantly with decreased bone mineral density and increased fracture incidence in humans at lower exposure levels than ever before evaluated. Studies in experimental animals have addressed whether very low concentrations of dietary cadmium can negatively impact the skeleton. This overview evaluates results in experimental animals regarding mechanisms of action on bone and the application of these results to humans. Results demonstrate that long-term dietary exposures in rats, at levels corresponding to environmental exposures in humans, result in increased skeletal fragility and decreased mineral density. Cadmium-induced demineralization begins soon after exposure, within 24 h of an oral dose to mice. In bone culture systems, cadmium at low concentrations acts directly on bone cells to cause both decreases in bone formation and increases in bone resorption, independent of its effects on kidney, intestine, or circulating hormone concentrations. Results from gene expression microarray and gene knock-out mouse models provide insight into mechanisms by which cadmium may affect bone. Application of the results to humans is considered with respect to cigarette smoke exposure pathways and direct vs. indirect effects of cadmium. Clearly, understanding the mechanism(s) by which cadmium causes bone loss in experimental animals will provide insight into its diverse effects in humans. Preventing bone loss is critical to maintaining an active, independent lifestyle, particularly among elderly persons. Identifying environmental factors such as cadmium that contribute to increased fractures in humans is an important undertaking and a first step to prevention.

  10. Wood smoke in a controlled exposure experiment with human volunteers

    DEFF Research Database (Denmark)

    Riddervold, Ingunn Skogstad; Bønløkke, Jakob Hjort; Mølhave, Lars

    2011-01-01

    Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung...... function and normal bronchial reactivity were randomly exposed for 3h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m3 (low) and 400 µg/m3 (high) under controlled environmental conditions.......0007), “irritative body perceptions” (p = 0.0127), “psychological/neurological effects” (p = 0.0075) and “weak inflammatory responses” (p = 0.0003). Furthermore, significant effects (p = 0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating...

  11. 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.

  12. Human Health Effects Associated with Exposure to Toxic Cyanobacteria

    Science.gov (United States)

    Reports of toxic cyanobacteria blooms are increasing worldwide. Warming and eutrophic surface water systems support the development of blooms. We examine the evidence for adverse human health effects associated with exposure to toxic blooms in drinking water, recreational water a...

  13. EVALUATION OF A PERSONAL NEPHELOMETER FOR HUMAN EXPOSURE MONITORING

    Science.gov (United States)

    Current particulate matter (PM) exposure studies are using continuous personal nephelometers (pDR-1000, MIE, Inc.) to measure human exposure to PM. The personal nephelometer is a passive sampler which uses light scattering technology to measure particles ranging in size from 0....

  14. Knowledge of human immunodeficiency virus post-exposure ...

    African Journals Online (AJOL)

    2011-05-21

    May 21, 2011 ... Appropriate post-exposure prophylaxis is an integral part of prevention, control and workplace safety. This study was undertaken to assess the level of knowledge of post-exposure prophylaxis (PEP) against human immunodeficiency virus (HIV) among doctors in Federal Medical Centre, Gombe, Nigeria.

  15. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

    Farmer, P.B.; Sepai, O.; Lawrence, R.

    1996-01-01

    for detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers...

  16. Population exposure from the fuel cycle: Review and future direction

    International Nuclear Information System (INIS)

    Richmond, C.R.

    1987-01-01

    The legacy of radiation exposures confronting man arises from two historical sources of energy, the sun and radioactive decay. Contemporary man continues to be dependent on these two energy sources, which include the nuclear fuel cycle. Radiation exposures from all energy sources should be examined, with particular emphasis on the nuclear fuel cycle, incidents such as Chernobyl and Three Mile Island. In addition to risk estimation, concepts such as de minimis, life shortening as a measure of risk, and competing risks as projected into the future must be considered in placing radiation exposures in perspective. The utility of these concepts is in characterizing population exposures for decision makers in a manner that the public may judge acceptable. All these viewpoints are essential in the evaluation of population exposure from the nuclear fuel cycle

  17. A margin-of-exposure approach to assessment of noncancer risks of dioxins based on human exposure and response data.

    Science.gov (United States)

    Aylward, Lesa L; Goodman, Julie E; Charnley, Gail; Rhomberg, Lorenz R

    2008-10-01

    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. We examined the feasibility of relying directly on human studies of exposure and potential responses to PCDD/PCDFs and related compounds in terms of measured lipid-adjusted concentrations to assess margin of exposure (MOE) in a quantitative, benchmark dose (BMD)-based framework using representative exposure and selected response data sets. We characterize estimated central tendency and upper-bound general U.S. population lipid-adjusted concentrations of PCDD/PCDFs from the 1970s and early 2000s based on available data sets. Estimates of benchmark concentrations for three example responses of interest (induction of cytochrome P4501A2 activity, dental anomalies, and neonatal thyroid hormone alterations) were derived based on selected human studies. The exposure data sets indicate that current serum lipid concentrations in young adults are approximately 6- to 7-fold lower than 1970s-era concentrations. Estimated MOEs for each end point based on current serum lipid concentrations range from 100 for dental anomalies-approximately 6-fold greater than would have existed during the 1970s. Human studies of dioxin exposure and outcomes can be used in a BMD framework for quantitative assessments of MOE. Incomplete exposure characterization can complicate the use of such studies in a BMD framework.

  18. Human exposure to emissions from building materials

    DEFF Research Database (Denmark)

    Kjærgaard, S.; Hauschildt, P.; Pejtersen, Jan

    1999-01-01

    found on peak flow, eye foam formation, tear fluid cells, or conjunctival epithelial damage. Among subjective evaluations only sound intensity rating was significant. A correlation was found between acute nose irritation rating and change in nasal volume.Conclusions. The findings indicate physiological......Objectives. Reactions to emissions from building matrials were studied in a climate chamber as part of an intervention study in an office building. New and existing flooring materials were compared with regard to comfort and health.Methods. Twenty subjects were exposed four times for six hours...... respectively to clean air, to emissions from linoleum, from carpet, and from an alternative new vinyl. Measurements of objective and subjective effects were made.Results. Tear film stability decreased after exposure to linoleum. The nasal volume decreased near-significantly for all exposures. No effects were...

  19. Human Health and Exposure to Electromagnetic Radiation

    Science.gov (United States)

    1992-07-01

    passed through volunteers from electrodes attached to their heads and bodies while they were subjected to a series of psychological tests (Bonnell et...al, 1985; Stollery, 1986). The pattern of current was equivalent to that produced by exposure to a 36 kV m- 1 field at 50 Hz. The psychological tests ...Silverman, 1977; Lilienfeld et al, 1978; Stopps and Janischewsky, 1979; Knave et al, 1979; Robinette et al, 1980; Marsh et al, 1982; Silverman, 1985

  20. Natural radiation exposure modified by human activities

    International Nuclear Information System (INIS)

    Fujimoto, Kenzo

    1995-01-01

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

  1. Relative significance of natural irradiation vs all human exposures

    International Nuclear Information System (INIS)

    Jammet, H.

    1985-01-01

    A review is made of the fundamentals allowing to quantitatively express the importance of the various sources of human exposure by an individual or collective approach. Following a summary of the components of normal exposure to natural sources, the various human actions at the origin of enhanced exposure are studied: 1) those modifying the relationship between natural sources and man (dwelling conditions, coal burning, geothermal energy production, exploitation of phosphate rock); 2) those creating new artificial sources (nuclear explosions in the atmosphere, nuclear power production, medical use of radiation and radionuclides). The effective dose equivalent commitments for these sources are compared with those necessarily involved by continuous normal exposure to the natural sources of exposure [fr

  2. An introduction to the indirect exposure assessment approach: modeling human exposure using microenvironmental measurements and the recent National Human Activity Pattern Survey.

    Science.gov (United States)

    Klepeis, N E

    1999-01-01

    Indirect exposure approaches offer a feasible and accurate method for estimating population exposures to indoor pollutants, including environmental tobacco smoke (ETS). In an effort to make the indirect exposure assessment approach more accessible to people in the health and risk assessment fields, this paper provides examples using real data from (italic>a(/italic>) a week-long personal carbon monoxide monitoring survey conducted by the author; and (italic>b(/italic>) the 1992 to 1994 National Human Activity Pattern Survey (NHAPS) for the United States. The indirect approach uses measurements of exposures in specific microenvironments (e.g., homes, bars, offices), validated microenvironmental models (based on the mass balance equation), and human activity pattern data obtained from questionnaires to predict frequency distributions of exposure for entire populations. This approach requires fewer resources than the direct approach to exposure assessment, for which the distribution of monitors to a representative sample of a given population is necessary. In the indirect exposure assessment approach, average microenvironmental concentrations are multiplied by the total time spent in each microenvironment to give total integrated exposure. By assuming that the concentrations encountered in each of 10 location categories are the same for different members of the U.S. population (i.e., the NHAPS respondents), the hypothetical contribution that ETS makes to the average 24-hr respirable suspended particle exposure for Americans working their main job is calculated in this paper to be 18 microg/m3. This article is an illustrative review and does not contain an actual exposure assessment or model validation. Images Figure 3 Figure 4 PMID:10350522

  3. Human population exposure to cosmic radiation

    International Nuclear Information System (INIS)

    Bouville, A.; Lowder, W.M.

    1988-01-01

    Critical evaluations of existing data on cosmic radiation in the atmosphere and in interplanetary space have been carried out in order to estimate the exposure of the world's population to this important component of natural background radiation. Data on population distribution and mean terrain heights on a 1 x 1 degree grid have been folded in to estimate regional and global dose distributions. The per caput annual dose equivalent at ground altitudes is estimated to be 270 μSv from charged particles and 50 μSv from neutrons. More than 100 million people receive more than 1 mSv in a year, and two million in excess of 5 mSv. Aircraft flight crews and frequent flyers receive an additional annual dose equivalent in the order of 1 mSv, though the global per caput annual dose equivalent from airplane flights is only about 1 μSv. Future space travellers on extended missions are likely to receive dose equivalents in the range 0.11 Sv, with the possibility of higher doses at relatively high dose rates from unusually large solar flares. These results indicate a critical need for a better understanding of the biological significance of chronic neutron and heavy charged particle exposure. (author)

  4. Direct and Indirect Effects of Print Exposure on Silent Reading Fluency

    Science.gov (United States)

    Mano, Quintino R.; Guerin, Julia M.

    2018-01-01

    Print exposure is an important causal factor in reading development. Little is known, however, of the mechanisms through which print exposure exerts an effect onto reading. To address this gap, we examined the direct and indirect effects of print exposure on silent reading fluency among college students (n = 52). More specifically, we focused on…

  5. Directed neuronal differentiation of human embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Noggle Scott A

    2003-10-01

    Full Text Available Abstract Background We have developed a culture system for the efficient and directed differentiation of human embryonic stem cells (HESCs to neural precursors and neurons. HESC were maintained by manual passaging and were differentiated to a morphologically distinct OCT-4+/SSEA-4- monolayer cell type prior to the derivation of embryoid bodies. Embryoid bodies were grown in suspension in serum free conditions, in the presence of 50% conditioned medium from the human hepatocarcinoma cell line HepG2 (MedII. Results A neural precursor population was observed within HESC derived serum free embryoid bodies cultured in MedII conditioned medium, around 7–10 days after derivation. The neural precursors were organized into rosettes comprised of a central cavity surrounded by ring of cells, 4 to 8 cells in width. The central cells within rosettes were proliferating, as indicated by the presence of condensed mitotic chromosomes and by phosphoHistone H3 immunostaining. When plated and maintained in adherent culture, the rosettes of neural precursors were surrounded by large interwoven networks of neurites. Immunostaining demonstrated the expression of nestin in rosettes and associated non-neuronal cell types, and a radial expression of Map-2 in rosettes. Differentiated neurons expressed the markers Map-2 and Neurofilament H, and a subpopulation of the neurons expressed tyrosine hydroxylase, a marker for dopaminergic neurons. Conclusion This novel directed differentiation approach led to the efficient derivation of neuronal cultures from HESCs, including the differentiation of tyrosine hydroxylase expressing neurons. HESC were morphologically differentiated to a monolayer OCT-4+ cell type, which was used to derive embryoid bodies directly into serum free conditions. Exposure to the MedII conditioned medium enhanced the derivation of neural precursors, the first example of the effect of this conditioned medium on HESC.

  6. Consolidated Human Activity Database (CHAD) for use in human exposure and health studies and predictive models

    Science.gov (United States)

    EPA scientists have compiled detailed data on human behavior from 22 separate exposure and time-use studies into CHAD. The database includes more than 54,000 individual study days of detailed human behavior.

  7. Exposure to Human Immunodeficiency Disease. What Precautions ...

    African Journals Online (AJOL)

    Background: The Human Immunodeficiency Virus (HIV) epidemic is more pronounced in sub-Saharan Africa. The ever-increasing prevalence of HIV infection and the continued improvement in clinical management has increased the likelihood of these patients being managed by healthcare workers. The aim of the review ...

  8. Post exposure prophylaxis against human immunodeficiency virus ...

    African Journals Online (AJOL)

    2015-11-23

    Nov 23, 2015 ... Abstract: Objective: To deter- mine the level of awareness, knowledge and practice of human immunodeficiency virus post ex- posure prophylaxis (HIV PEP) among paediatricians in Nigeria. Methodology: The study was a cross sectional questionnaire- based survey conducted among paediatrcians that ...

  9. High Throughput Heuristics for Prioritizing Human Exposure to ...

    Science.gov (United States)

    The risk posed to human health by any of the thousands of untested anthropogenic chemicals in our environment is a function of both the potential hazard presented by the chemical, and the possibility of being exposed. Without the capacity to make quantitative, albeit uncertain, forecasts of exposure, the putative risk of adverse health effect from a chemical cannot be evaluated. We used Bayesian methodology to infer ranges of exposure intakes that are consistent with biomarkers of chemical exposures identified in urine samples from the U.S. population by the National Health and Nutrition Examination Survey (NHANES). We perform linear regression on inferred exposure for demographic subsets of NHANES demarked by age, gender, and weight using high throughput chemical descriptors gleaned from databases and chemical structure-based calculators. We find that five of these descriptors are capable of explaining roughly 50% of the variability across chemicals for all the demographic groups examined, including children aged 6-11. For the thousands of chemicals with no other source of information, this approach allows rapid and efficient prediction of average exposure intake of environmental chemicals. The methods described by this manuscript provide a highly improved methodology for HTS of human exposure to environmental chemicals. The manuscript includes a ranking of 7785 environmental chemicals with respect to potential human exposure, including most of the Tox21 in vit

  10. Sampling strategy for estimating human exposure pathways to consumer chemicals

    Directory of Open Access Journals (Sweden)

    Eleni Papadopoulou

    2016-03-01

    Full Text Available Human exposure to consumer chemicals has become a worldwide concern. In this work, a comprehensive sampling strategy is presented, to our knowledge being the first to study all relevant exposure pathways in a single cohort using multiple methods for assessment of exposure from each exposure pathway. The selected groups of chemicals to be studied are consumer chemicals whose production and use are currently in a state of transition and are; per- and polyfluorinated alkyl substances (PFASs, traditional and “emerging” brominated flame retardants (BFRs and EBFRs, organophosphate esters (OPEs and phthalate esters (PEs. Information about human exposure to these contaminants is needed due to existing data gaps on human exposure intakes from multiple exposure pathways and relationships between internal and external exposure. Indoor environment, food and biological samples were collected from 61 participants and their households in the Oslo area (Norway on two consecutive days, during winter 2013-14. Air, dust, hand wipes, and duplicate diet (food and drink samples were collected as indicators of external exposure, and blood, urine, blood spots, hair, nails and saliva as indicators of internal exposure. A food diary, food frequency questionnaire (FFQ and indoor environment questionnaire were also implemented. Approximately 2000 samples were collected in total and participant views on their experiences of this campaign were collected via questionnaire. While 91% of our participants were positive about future participation in a similar project, some tasks were viewed as problematic. Completing the food diary and collection of duplicate food/drink portions were the tasks most frequent reported as “hard”/”very hard”. Nevertheless, a strong positive correlation between the reported total mass of food/drinks in the food record and the total weight of the food/drinks in the collection bottles was observed, being an indication of accurate performance

  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. Developing human health exposure scenarios for petroleum substances under REACH

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.; De Wilde, P.; Maksimainen, K.; Margary, A.; Money, C.; Pizzella, G.; Svanehav, T.; Tsang, W.; Urbanus, J.; Rohde, A.

    2012-12-15

    This report describes the approaches that were adopted by CONCAWE to prepare the human exposure estimates in the chemical safety assessments of the REACH registration dossiers for petroleum substances based on all applicable regulatory guidance. Separate exposure estimates were developed for workers and for consumers and included inhalation and dermal routes. The complex nature of petroleum substances required various scientifically justified refinements of the regulatory guidance.

  13. Foetal exposure to food and environmental carcinogens in human beings.

    Science.gov (United States)

    Myöhänen, Kirsi; Vähäkangas, Kirsi

    2012-02-01

    Exposure to many different chemicals during pregnancy through maternal circulation is possible. Transplacental transfer of xenobiotics can be demonstrated using human placental perfusion. Also, placental perfusion can give information about the placental kinetics as well as metabolism and accumulation in the placenta because it retains the tissue structure and function. Although human placental perfusion has been used extensively to study the transplacental transfer of drugs, the information on food and environmental carcinogens is much more limited. This review deals with the foetal exposure to food and environmental carcinogens in human beings. In particular, human transplacental transfer of the food carcinogens such as acrylamide, glycidamide and nitrosodimethylamine are in focus. Because these carcinogens are genotoxic, the functional capacity of human placenta to induce DNA adduct formation or metabolize these above mentioned CYP2E1 substrates is of interest in this context. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

  14. Inhale while Dreaming: Human Exposure to Pollutants while Sleeping

    DEFF Research Database (Denmark)

    Corsi, Richard; Spilak, Michal; Boor, E., Brandon

    2012-01-01

    of indoor pollutants, e.g., flame retardants to isocyanates. As such, there is a need for increased dialogue on this subject, end-point relevant research, and action to reduce exposures to high-risk contaminants for most of humanity. This workshop will involve an opening 5–minute presentation related...... discussion related to practical implications of new findings as well as past studies, geographic variations in emissions from mattresses and beddings, methods for reducing population exposures, and suggestions for future research that has practical endpoints and that can lead to reduced exposures....

  15. Perspectives for integrating human and environmental exposure assessments.

    Science.gov (United States)

    Ciffroy, P; Péry, A R R; Roth, N

    2016-10-15

    Integrated Risk Assessment (IRA) has been defined by the EU FP7 HEROIC Coordination action as "the mutual exploitation of Environmental Risk Assessment for Human Health Risk Assessment and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process" (Wilks et al., 2015). Since exposure assessment and hazard characterization are the pillars of risk assessment, integrating Environmental Exposure assessment (EEA) and Human Exposure assessment (HEA) is a major component of an IRA framework. EEA and HEA typically pursue different targets, protection goals and timeframe. However, human and wildlife species also share the same environment and they similarly inhale air and ingest water and food through often similar overlapping pathways of exposure. Fate models used in EEA and HEA to predict the chemicals distribution among physical and biological media are essentially based on common properties of chemicals, and internal concentration estimations are largely based on inter-species (i.e. biota-to-human) extrapolations. Also, both EEA and HEA are challenged by increasing scientific complexity and resources constraints. Altogether, these points create the need for a better exploitation of all currently existing data, experimental approaches and modeling tools and it is assumed that a more integrated approach of both EEA and HEA may be part of the solution. Based on the outcome of an Expert Workshop on Extrapolations in Integrated Exposure Assessment organized by the HEROIC project in January 2014, this paper identifies perspectives and recommendations to better harmonize and extrapolate exposure assessment data, models and methods between Human Health and Environmental Risk Assessments to support the further development and promotion of the concept of IRA. Ultimately, these recommendations may feed into guidance showing when and how to apply IRA in the regulatory decision

  16. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

    Farmer, P.B.; Sepai, O.; Lawrence, R.

    1996-01-01

    A coordinated study was carried out on the development, evaluation and application of biomonitoring procedures for populations exposed to environmental genotoxic pollutants. The procedures used involved both direct measurement of DNA or protein damage (adducts) and assessment of second biological...... spectrometry). The measurement of adducts was focused on those from genotoxicants that result from petrochemical combustion or processing, e.g. low-molecular-weight alkylating agents, PAHs and compounds that cause oxidative DNA damage. Cytogenetic analysis of lymphocytes was undertaken (micronuclei, chromosome...... aberrations and sister chromatid exchanges) and mutation frequency was estimated at a number of loci including the hprt gene and genes involving in cancer development. Blood and urine samples from individuals exposed to urban pollution were collected. Populations exposed through occupational or medical...

  17. Analysis of Cigarette Smoke Deposition Within an In Vitro Exposure System for Simulating Exposure in the Human Respiratory Tract

    Directory of Open Access Journals (Sweden)

    Ishikawa Shinkichi

    2016-01-01

    Full Text Available For the risk assessment of airborne chemicals, a variety of in vitro direct exposure systems have been developed to replicate airborne chemical exposure in vivo. Since cells at the air-liquid interface are exposed to cigarette smoke as an aerosol in direct exposure systems, it is possible to reproduce the situation of cigarette smoke exposure in the human respiratory system using this device. However it is difficult to know whether the exposed cigarette smoke in this system is consistent with the smoke retained in the human respiratory tract. The purpose of this study is to clarify this point using the CULTEX® RFS module which is a recently developed direct exposure system. For this purpose, solanesol and acetaldehyde were respectively chosen as the particulate and gas/vapor phase representatives of smoke constituents, and their deposition and balance per unit area of cell culture surface of the RFS module were measured (dosimetry. We also conducted human retention studies to compare with the dosimetry data. By comparing inhaled smoke and exhaled smoke under three inhalation conditions, we estimated the regional retention and balance of each representative per unit surface area of the respiratory tract (mouth, bronchi, and alveoli separately. The deposition of solanesol and acetaldehyde per unit area of cell culture surface in the RFS module decreased dependent on the dilution flow rate and ranged from 0.26-0.0076%/cm2 in our experimental conditions. The ratio of deposited acetaldehyde to deposited solanesol ranged from 0.96-1.96 in the RFS module. The retention of solanesol and acetaldehyde per unit surface area in the mouth and the bronchi ranged from 0.095-0.0083%/cm2 in this study. The retention per unit surface area of alveoli was far lower than in the other two regions (0.0000063%/cm2. The ratio of retained acetaldehyde to retained solanesol ranged from 0.54-1.97. From these results, we concluded that the CULTEX® RFS module can simulate

  18. Toxicity levels to humans during acute exposure to hydrogen fluoride

    International Nuclear Information System (INIS)

    Halton, D.M.; Dranitsaris, P.; Baynes, C.J.

    1984-11-01

    A literature review was conducted of the acute toxicity of hydrogen fluoride (HF) with emphasis on the effects of inhalation of gaseous HF. The data and findings of the relevant references were summarized under four categories: animal studies, controlled human studies, community exposure and industrial exposure. These were critically reviewed and then lethal concentration-time relationships were developed for humans, corresponding to LCsub(LO), LCsub(10) and LCsub(50) levels. The effects of age, health and other physiological variables on the sensitivity to HF were discussed, as well as antagonistic and synergistic effects with other substances

  19. Increased mitochondrial mass in cells with functionally compromised mitochondria after exposure to both direct gamma radiation and bystander factors.

    LENUS (Irish Health Repository)

    Nugent, Sharon M E

    2007-07-01

    The bystander effect describes radiation-like damage in unirradiated cells either in the vicinity of irradiated cells or exposed to medium from irradiated cells. This study aimed to further characterize the poorly understood mitochondrial response to both direct irradiation and bystander factor(s) in human keratinocytes (HPV-G) and Chinese hamster ovarian cells (CHO-K1). Oxygen consumption rates were determined during periods of state 4, state 3 and uncoupled respiration. Mitochondrial mass was determined using MitoTracker FM. CHO-K1 cells showed significantly reduced oxygen consumption rates 4 h after exposure to 5 Gy direct radiation and irradiated cell conditioned medium (ICCM) and an apparent recovery 12-24 h later. The apparent recovery was likely due to the substantial increase in mitochondrial mass observed in these cells as soon as 4 h after exposure. HPV-G cells, on the other hand, showed a sustained increase in oxygen consumption rates after ICCM exposure and a transient increase 4 h after exposure to 5 Gy direct radiation. A significant increase in mitochondrial mass per HPV-G cell was observed after exposure to both direct radiation and ICCM. These findings are indicative of a stress response to mitochondrial dysfunction that increases the number of mitochondria per cell.

  20. A dermatotoxicokinetic model of human exposures to jet fuel.

    Science.gov (United States)

    Kim, David; Andersen, Melvin E; Nylander-French, Leena A

    2006-09-01

    Workers, both in the military and the commercial airline industry, are exposed to jet fuel by inhalation and dermal contact. We present a dermatotoxicokinetic (DTK) model that quantifies the absorption, distribution, and elimination of aromatic and aliphatic components of jet fuel following dermal exposures in humans. Kinetic data were obtained from 10 healthy volunteers following a single dose of JP-8 to the forearm over a surface area of 20 cm2. Blood samples were taken before exposure (t = 0 h), after exposure (t = 0.5 h), and every 0.5 h for up to 3.5 h postexposure. The DTK model that best fit the data included five compartments: (1) surface, (2) stratum corneum (SC), (3) viable epidermis, (4) blood, and (5) storage. The DTK model was used to predict blood concentrations of the components of JP-8 based on dermal-exposure measurements made in occupational-exposure settings in order to better understand the toxicokinetic behavior of these compounds. Monte Carlo simulations of dermal exposure and cumulative internal dose demonstrated no overlap among the low-, medium-, and high-exposure groups. The DTK model provides a quantitative understanding of the relationship between the mass of JP-8 components in the SC and the concentrations of each component in the systemic circulation. The model may be used for the development of a toxicokinetic modeling strategy for multiroute exposure to jet fuel.

  1. National Surveillance of Occupational Exposure to the Human Immunodeficiency Virus

    Directory of Open Access Journals (Sweden)

    Maura Ricketts

    1992-01-01

    Full Text Available In September 1985, a prospective study was initiated to monitor the occurrence of occupational exposures to human immunodeficiency virus (HIV-infected blood and body fluids in Canada. This program was coordinated by the Federal Centre for acquired immune deficiency syndrome (AIDS (now the Division of HIV/AIDS Epidemiology at the Laboratory Centre for Disease Control. The objective was to determine the risk to workers of acquiring HIV infection as a result of exposure to HIV-infected blood and other body fluids. To be eligible, a worker must have sustained a documented parenteral, mucous membrane or skin contact exposure to blood or body fluids from an HIV-infected person. A baseline specimen was collected within a week of the exposure and then at six weeks, 12 weeks, six months and 12 months. Information concerning the type of exposure, precautions used and post exposure treatment was submitted to the Federal Centre for AIDS on standard data collection forms. All information was anonymous, identified only by a code number. Guidelines for counselling an exposed employee were provided with enrollment material. As of July 29, 1991, 414 employees have been included in the study. Two hundred and thirty-seven of the 414 exposures (57% were needlestick injuries of which 167 (70% were sustained by nurses. Other exposures consisted of open wound contamination, eye splashes, scalpel wounds and skin contact with blood and body fluids. To date, there have been no seroconversions among workers enrolled in the surveillance program.

  2. Integrating population dynamics into mapping human exposure to seismic hazard

    Directory of Open Access Journals (Sweden)

    S. Freire

    2012-11-01

    Full Text Available Disaster risk is not fully characterized without taking into account vulnerability and population exposure. Assessment of earthquake risk in urban areas would benefit from considering the variation of population distribution at more detailed spatial and temporal scales, and from a more explicit integration of this improved demographic data with existing seismic hazard maps. In the present work, "intelligent" dasymetric mapping is used to model population dynamics at high spatial resolution in order to benefit the analysis of spatio-temporal exposure to earthquake hazard in a metropolitan area. These night- and daytime-specific population densities are then classified and combined with seismic intensity levels to derive new spatially-explicit four-class-composite maps of human exposure. The presented approach enables a more thorough assessment of population exposure to earthquake hazard. Results show that there are significantly more people potentially at risk in the daytime period, demonstrating the shifting nature of population exposure in the daily cycle and the need to move beyond conventional residence-based demographic data sources to improve risk analyses. The proposed fine-scale maps of human exposure to seismic intensity are mainly aimed at benefiting visualization and communication of earthquake risk, but can be valuable in all phases of the disaster management process where knowledge of population densities is relevant for decision-making.

  3. Assessment of human dietary exposure to arsenic through rice.

    Science.gov (United States)

    Davis, Matthew A; Signes-Pastor, Antonio J; Argos, Maria; Slaughter, Francis; Pendergrast, Claire; Punshon, Tracy; Gossai, Anala; Ahsan, Habibul; Karagas, Margaret R

    2017-05-15

    Rice accumulates 10-fold higher inorganic arsenic (i-As), an established human carcinogen, than other grains. This review summarizes epidemiologic studies that examined the association between rice consumption and biomarkers of arsenic exposure. After reviewing the literature we identified 20 studies, among them included 18 observational and 2 human experimental studies that reported on associations between rice consumption and an arsenic biomarker. Among individuals not exposed to contaminated water, rice is a source of i-As exposure - rice consumption has been consistently related to arsenic biomarkers, and the relationship has been clearly demonstrated in experimental studies. Early-life i-As exposure is of particular concern due to its association with lifelong adverse health outcomes. Maternal rice consumption during pregnancy also has been associated with infant toenail total arsenic concentrations indicating that dietary exposure during pregnancy results in fetal exposure. Thus, the collective evidence indicates that rice is an independent source of arsenic exposure in populations around the world and highlights the importance of investigating its affect on health. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Human exposure to cyanotoxins and their effects on health.

    Science.gov (United States)

    Drobac, Damjana; Tokodi, Nada; Simeunović, Jelica; Baltić, Vladimir; Stanić, Dina; Svirčev, Zorica

    2013-06-01

    Cyanotoxins are secondary metabolites produced by cyanobacteria. They pose a threat to human health and the environment. This review summarises the existing data on human exposure to cyanotoxins through drinking water, recreational activities (e.g., swimming, canoeing or bathing), the aquatic food web, terrestrial plants, food supplements, and haemodialysis. Furthermore, it discusses the tolerable daily intake and guideline values for cyanotoxins (especially microcystins) as well as the need to implement risk management measures via national and international legislation.

  5. Human reproductive system disturbances and pesticide exposure in Brazil

    Directory of Open Access Journals (Sweden)

    Koifman Sergio

    2002-01-01

    Full Text Available The observation of reproductive disturbances in humans and in the wildlife has been reported in the last decade in different countries. Exposure to different chemicals possibly acting in the endocrine system or endocrine disruptors, including pesticides, has been a hypothesis raised to explain the observed changes. This paper aimed to present results of an epidemiological ecologic study carried out to explore population data on pesticides exposure in selected Brazilian states in the eighties and human reproductive outcomes in the nineties. Pearson correlation coefficients were ascertained between available data pesticides sales in eleven states in Brazil in 1985 and selected further reproductive outcomes or their surrogates. Moderate to high correlations were observed to infertility, testis, breast, prostate and ovarian cancer mortality. Despite the restrains of ecologic studies to establish cause-effect relationships, the observed results are in agreement with evidence supporting a possible association between pesticides exposure and the analyzed reproductive outcomes.

  6. Assessing Sources of Human Methylmercury Exposure Using Stable Mercury Isotopes

    DEFF Research Database (Denmark)

    Li, Miling; Sherman, Laura S; Blum, Joel D

    2014-01-01

    Seafood consumption is the primary route of methylmercury (MeHg) exposure for most populations. Inherent uncertainties in dietary survey data point to the need for an empirical tool to confirm exposure sources. We therefore explore the utility of Hg stable isotope ratios in human hair as a new...... method for discerning MeHg exposure sources. We characterized Hg isotope fractionation between humans and their diets using hair samples from Faroese whalers exposed to MeHg predominantly from pilot whales. We observed an increase of 1.75‰ in δ(202)Hg values between pilot whale muscle tissue and Faroese...... whalers' hair but no mass-independent fractionation. We found a similar offset in δ(202)Hg between consumed seafood and hair samples from Gulf of Mexico recreational anglers who are exposed to lower levels of MeHg from a variety of seafood sources. An isotope mixing model was used to estimate individual...

  7. The causes and consequences of human exposure to ionising radiation

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1991-01-01

    Few phenomena cause as much concern in developed countries as human exposure to artificial sources of radiation, and yet there are more potent threats to health: natural radiation is more pervasive and exposures more substantial; common practices such as smoking and drinking are more detrimental. Developing countries may be more anxious to establish radiological procedures than radiological protection. This paper gives the ranges of exposure to which people are subjected from natural and artificial sources which should help to put all doses in perspective. The relationship between dose and risk is established and used to show that exposures to radiation leak to low levels of risk. Finally, the new recommendations of ICRP for the control of radiation risk are presented. (Author)

  8. Assessment of Nicotine Exposure From Active Human Cigarette Smoking Time

    Directory of Open Access Journals (Sweden)

    Cahours Xavier

    2017-09-01

    Full Text Available The burning of a cigarette is a series of consecutive sequences of both passive and active burnings when a smoking cycle is applied to the cigarette. A previous study, using a smoking machine, showed that cigarette nicotine yields are dependent linearly on the difference between the time of smouldering (passive burning and the time of smoking (active burning. It is predicted that the smoker’s nicotine yield increases when the intensity of smoking increases, i.e., when the time to smoke a cigarette (smoking time decreases. Note that observations made on machines might not be comparable to human behaviours. The aim of this study was to determine whether nicotine mouth-level exposure could be predicted through measurement of human smoking time. A smoking behaviour study was conducted to compare human smoking nicotine yields obtained from both filter tip analysis and the cigarette burning time model. Results showed that smokers’ exposure to the smoke depends essentially on the speed at which the cigarette is smoked. An increase in human smoking intensity, resulting in a decrease in smoking time, generates an increase in smoke exposure, whatever the puff number, puff duration, puff volume and filter ventilation (open or blocked. The association of a machine smoking yield with a corresponding smoking time, and the time taken by a consumer to smoke the cigarette would provide information on the exposure to smoke constituents in a simple and effective manner.

  9. Traditional goat husbandry may substantially contribute to human toxoplasmosis exposure

    Science.gov (United States)

    Raising goats in settings that are highly contaminated with oocysts of Toxoplasma gondii may contribute significantly to human exposure to this zoonotic parasite. Increasing consumption of young goats in Romania, where goats are typically reared in backyards that are also home to cats (the definitiv...

  10. Spatial Analysis of Human Exposure and Vulnerability to Coastal ...

    African Journals Online (AJOL)

    Disasters in coastal cities have shown an ever-increasing frequency of occurrence. Population growth and urbanisation have increased the vulnerability of properties and societies in coastal flood-prone areas. Analysis of human exposure and vulnerability is one of the main strategies used to determine the necessary ...

  11. Radiation exposure and radiation hazards of human population. Pt. 1

    International Nuclear Information System (INIS)

    Jacobi, W.

    1982-01-01

    The present Part I provides a survey on the various sources of natural and artificial radiation exposure of human population. Furthermore, biological radiation effects and radiation damages are surveyed. In an appendix, radiation types, radiation doses, and radiation dose units are explained. (orig./GSCH) [de

  12. Human health risk assessment related to cyanotoxins exposure.

    Science.gov (United States)

    Funari, Enzo; Testai, Emanuela

    2008-01-01

    This review focuses on the risk assessment associated with human exposure to cyanotoxins, secondary metabolites of an ubiquitous group of photosynthetic procariota. Cyanobacteria occur especially in eutrophic inland and coastal surface waters, where under favorable conditions they attain high densities and may form blooms and scums. Cyanotoxins can be grouped according to their biological effects into hepatotoxins, neurotoxins, cytotoxins, and toxins with irritating potential, also acting on the gastrointestinal system. The chemical and toxicological properties of the main cyanotoxins, relevant for the evaluation of possible risks for human health, are presented. Humans may be exposed to cyanotoxins via several routes, with the oral one being by far the most important, occurring by ingesting contaminated drinking water, food, some dietary supplements, or water during recreational activities. Acute and short-term toxic effects have been associated in humans with exposure to high levels of cyanotoxins in drinking and bathing waters. However, the chronic exposure to low cyanotoxin levels remains a critical issue. This article identifies the actual risky exposure scenarios, provides toxicologically derived reference values, and discusses open issues and research needs.

  13. Biocides Steering Group on human exposure assessment: A preliminary report

    NARCIS (Netherlands)

    Hemmen, J.J. van

    1999-01-01

    In a project granted by DG XI of the European Commission, it is attempted to collate experimental and theoretical data on human (workers and consumers) exposure assessment to biocidal products, and to outline the methodology for sampling and measurement. On the basis of the available evidence,

  14. Human Bisphenol A Exposure and the “Diabesity Phenotype”

    Science.gov (United States)

    Leone, Alessandro; Battezzati, Alberto

    2015-01-01

    Bisphenol A (BPA), a known endocrine disruptor, is a food contaminant suspected of being a contributing factor to the present-day increase in obesity, diabetes, and cardiovascular disease. This issue is of increasing interest in the field of diabetes research and has become a matter of concern for regulatory agencies and food industries. Recently, the number of studies involving BPA has increased exponentially, but there are still many gaps in the knowledge of the relationship between actual BPA exposure and cardiometabolic risk and of the modalities of food intake exposure, all of which prevents sound judgments concerning the risks to human health. This review focuses on the association between human exposure to BPA and obesity, thyroid function, diabetes, insulin resistance, metabolic syndrome, cardiovascular diseases, and BPA content in food. Many cross-sectional studies support, sometimes contradictorily, an adverse effect of BPA exposure on obesity, diabetes, and cardiovascular diseases. Few prospective studies support an adverse effect of BPA exposure on such pathologies. Moreover, no intervention studies have been conducted to evaluate the causality of such associations. This is mainly due to lack of an appropriate database of BPA content in foods, thus hindering any estimation of the usual dietary BPA intake. PMID:26858585

  15. EVALUATION OF EMF EXPOSURE OF MOBILE PHONES ON HUMAN HEAD

    Directory of Open Access Journals (Sweden)

    N. I. Vtornikova

    2017-01-01

    Full Text Available Introduction. Mobile phones are worldwide spread nowadays. Smartphones penetration is growing year after year. Numerous studies indicate the negative effect of EMF exposure of these devices on humans. Therefore, it is important to study the peculiarities of their influence on the target organ-the brain. It is important for solving this problem to find out the real situation of the distribution of energy flux density (EFD of EMF exposure near the front panel of the apparatus.The aim of the study is to determine and compare EMF exposure from smartphones and classic mobile phones on human head.Material and methods. The original method patented in the Russian Federation was used in this study. The used original measuring setup is also patented, developed and assembled by the authors of the study. The object of the study was classical mobile phones and smartphones widespread at the time of work.Results. We got the graphic of matrices of distribution of energy flux density (EFD of EMF exposure in the plane against the front panel of 10 apparatus corresponding to the topography of a human head. The study revealed peculiarities of this distribution in smartphones and the classic mobile phones and got the values of energy flux density (EFD of EMF exposure in the investigated devices acting primarily on the brain.Conclusions. The design of smartphones and mobile phones determines the overall picture of distribution of EFD of EMF exposure in the plane against the front panel for devices of a particular type. This picture must be taken into account when planning epidemiological and experimental studies to obtain comparable results. Progress in the development of mobile communication technologies has led to an increase in the electromagnetic load on users of modern devices.

  16. Ozone exposure increases respiratory epithelial permeability in humans

    International Nuclear Information System (INIS)

    Kehrl, H.R.; Vincent, L.M.; Kowalsky, R.J.; Horstman, D.H.; O'Neil, J.J.; McCartney, W.H.; Bromberg, P.A.

    1987-01-01

    Ozone is a respiratory irritant that has been shown to cause an increase in the permeability of the respiratory epithelium in animals. We used inhaled aerosolized /sup 99m/Tc-labeled diethylene triamine pentacetic acid (/sup 99m/Tc-DTPA) to investigate whether human respiratory epithelial permeability is similarly affected by exposure to ozone. In a randomized, crossover double-blinded study, 8 healthy, nonsmoking young men were exposed for 2 h to purified air and 0.4 ppm ozone while performing intermittent high intensity treadmill exercise (minute ventilation = 66.8 L/min). SRaw and FVC were measured before and at the end of exposures. Seventy-five minutes after the exposures, the pulmonary clearance of /sup 99m/Tc-DTPA was measured by sequential posterior lung imaging with a computer-assisted gamma camera. Ozone exposure caused respiratory symptoms in all 8 subjects and was associated with a 14 +/- 2.8% (mean +/- SEM) decrement in FVC (p less than 0.001) and a 71 +/- 22% increase in SRaw (p = 0.04). Compared with the air exposure day, 7 of the 8 subjects showed increased /sup 99m/Tc-DTPA clearance after the ozone exposure, with the mean value increasing from 0.59 +/- 0.08 to 1.75 +/- 0.43%/min (p = 0.03). These data show that ozone exposure sufficient to produce decrements in the pulmonary function of human subjects also causes an increase in /sup 99m/Tc-DTPA clearance

  17. ASSESSING CHILDREN'S EXPOSURES TO PESTICIDES: AN IMPORTANT APPLICATION OF THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION MODEL (SHEDS)

    Science.gov (United States)

    Accurately quantifying human exposures and doses of various populations to environmental pollutants is critical for the Agency to assess and manage human health risks. For example, the Food Quality Protection Act of 1996 (FQPA) requires EPA to consider aggregate human exposure ...

  18. Naphthalene distributions and human exposure in Southern California

    Science.gov (United States)

    Lu, Rong; Wu, Jun; Turco, Richard P.; Winer, Arthur M.; Atkinson, Roger; Arey, Janet; Paulson, Suzanne E.; Lurmann, Fred W.; Miguel, Antonio H.; Eiguren-Fernandez, Arantzazu

    The regional distribution of, and human exposure to, naphthalene are investigated for Southern California. A comprehensive approach is taken in which advanced models are linked for the first time to quantify population exposure to the emissions of naphthalene throughout Southern California. Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons found in polluted urban environments, and has been detected in both outdoor and indoor air samples. Exposure to high concentrations of naphthalene may have adverse health effects, possibly causing cancer in humans. Among the significant emission sources are volatilization from naphthalene-containing products, petroleum refining, and combustion of fossil fuels and wood. Gasoline and diesel engine exhaust, with related vaporization from fuels, are found to contribute roughly half of the daily total naphthalene burden in Southern California. As part of this study, the emission inventory for naphthalene has been verified against new field measurements of the naphthalene-to-benzene ratio in a busy traffic tunnel in Los Angeles, supporting the modeling work carried out here. The Surface Meteorology and Ozone Generation (SMOG) airshed model is used to compute the spatial and temporal distributions of naphthalene and its photooxidation products in Southern California. The present simulations reveal a high degree of spatial variability in the concentrations of naphthalene-related species, with large diurnal and seasonal variations as well. Peak naphthalene concentrations are estimated to occur in the early morning hours in the winter season. The naphthalene concentration estimates obtained from the SMOG model are employed in the Regional Human Exposure (REHEX) model to calculate population exposure statistics. Results show average hourly naphthalene exposures in Southern California under summer and winter conditions of 270 and 430 ng m -3, respectively. Exposure to significantly higher concentrations

  19. Human exposure to endocrine disrupting chemicals: effects on the male and female reproductive systems.

    Science.gov (United States)

    Sifakis, Stavros; Androutsopoulos, Vasilis P; Tsatsakis, Aristeidis M; Spandidos, Demetrios A

    2017-04-01

    Endocrine disrupting chemicals (EDCs) comprise a group of chemical compounds that have been examined extensively due to the potential harmful effects in the health of human populations. During the past decades, particular focus has been given to the harmful effects of EDCs to the reproductive system. The estimation of human exposure to EDCs can be broadly categorized into occupational and environmental exposure, and has been a major challenge due to the structural diversity of the chemicals that are derived by many different sources at doses below the limit of detection used by conventional methodologies. Animal and in vitro studies have supported the conclusion that endocrine disrupting chemicals affect the hormone dependent pathways responsible for male and female gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, the majority of the studies point towards an association between exposure to EDCs and male and/or female reproduction system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants is yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Future studies should focus on a uniform system of examining human populations with regard to the exposure to specific EDCs and the direct effect on the reproductive system. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Climate change impacts on human exposures to air pollution ...

    Science.gov (United States)

    This is an abstract for a presentations at the Annual Conference of the International Society on Exposure Science and Environmental Epidemiology. This presentation will serve as an introduction to the symposium. As we consider the potential health impacts of a warming planet, the relationships between climate change and air pollutants become increasingly important to understand. These relationships are complex and highly variable, causing a variety of environmental impacts at local, regional and global scales. Human exposures and health impacts for air pollutants have the potential to be altered by changes in climate through multiple factors that drive population exposures to these pollutants. Research on this topic will provide both state and local governments with the tools and scientific knowledge base to undertake any necessary adaptation of the air pollution regulations and/or public health management systems in the face of climate change.

  1. Guilt is more strongly associated with suicidal ideation among military personnel with direct combat exposure.

    Science.gov (United States)

    Bryan, Craig J; Ray-Sannerud, Bobbie; Morrow, Chad E; Etienne, Neysa

    2013-05-15

    Suicide rates in the U.S. military have been rising rapidly in the past decade. Research suggests guilt is a significant predictor of suicidal ideation among military personnel, and may be especially pronounced among those who have been exposure to combat-related traumas. The current study explored the interactive effect of direct combat exposure and guilt on suicidal ideation in a clinical sample of military personnel. Ninety-seven active duty U.S. Air Force personnel receiving outpatient mental health treatment at two military clinics completed self-report symptom measures of guilt, depression, hopelessness, perceived burdensomeness, posttraumatic stress disorder, and suicidal ideation. Generalized multiple regression analyses indicated a significant interaction of guilt and direct combat exposure (B=.124, SE=.053, p=.020), suggesting a stronger relationship of guilt with suicidal ideation among participants who had direct combat exposure as compared to those who had not. The interactions of direct combat exposure with depression (B=.004, SE=.040, p=.926), PTSD symptoms (B=.016, SE=.018, p=.382), perceived burdensomeness (B=.159, SE=.152, p=.300) and hopelessness (B=.069, SE=.036, p=.057) were nonsignificant. Although guilt is associated with more severe suicidal ideation in general among military personnel, it is especially pronounced among those who have had direct combat exposure. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Lead remediation and changes in human lead exposure: some physiological and biokinetic dimensions.

    Science.gov (United States)

    Mushak, Paul

    2003-02-15

    This paper presents a qualitative and quantitative analysis of the various aspects of lead remediation effectiveness with particular reference to human health risk assessment. One of the key elements of lead remediation efforts at such sites as those under the Superfund program deals with populations at elevated exposure and toxicity risk in the proximity of, or at, the site of remediation, especially remediation workers, workers at other tasks on sites that were remediated down to some action level of lead concentration in soils, and groups at risk in nearby communities. A second element has to do with how one measures or models lead exposure changes with special reference to baseline and post-remediation conditions. Various biomarkers of lead exposure can be employed, but their use requires detailed knowledge of what results using each means. The most commonly used approach is measurement of blood lead (Pb-B). Recognized limitations in the use of Pb-B has led to the use of predictive Pb exposure models, which are less vulnerable to the many behavioral, physiological, and environmental parameters that can distort isolated or 'single shot' Pb-B testings. A third aspect covered in this paper presents various physiological factors that affect the methods by which one evaluates Pb remediation effectiveness. Finally, this article offers an integrated look at how lead remediation actions directed at one lead source or pathway affect the total lead exposure picture for human populations at elevated lead exposure and toxicity risk.

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

    Science.gov (United States)

    Burcham, Philip C

    2017-01-17

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

  4. Ecological and human exposure assessment to PBDEs in Adige River.

    Science.gov (United States)

    Giulivo, Monica; Suciu, Nicoleta Alina; Eljarrat, Ethel; Gatti, Marina; Capri, Ettore; Barcelo, Damia

    2018-07-01

    The interest for environmental issues and the concern resulting from the potential exposure to contaminants were the starting point to develop methodologies in order to evaluate the consequences that those might have over both the environment and human health. Considering the feature of POPs, including PBDEs, such as bioaccumulation, biomagnification, long-range transport and adverse effects even long time after exposure, risk assessment of POPs requires specific approaches and tools. In this particular context, the MERLIN-Expo tool was used to assess the aquatic environmental exposure of Adige River to PBDEs and the accumulation of PBDEs in humans through the consumption of possible contaminated local aquatic food. The aquatic food web models provided as output of the deterministic simulation the time trend of concentrations for twenty years of BDE-47 and total PBDEs, expressed using the physico-chemical properties of BDE-47, in aquatic organisms of the food web of Adige River. For BDE-47, the highest accumulated concentrations were detected for two benthic species: Thymallus thymallus and Squalius cephalus whereas the lowest concentrations were obtained for the pelagic specie Salmo trutta marmoratus. The trend obtained for the total PBDEs, calculated using the physico-chemical properties of BDE-47, follows the one of BDE-47. For human exposure, different BDE-47 and total PBDEs concentration trends between children, adolescent, adults and elderly were observed, probably correlated with the human intake of fish products in the daily diet and the ability to metabolize these contaminants. In detail, for the adolescents, adults and elderly a continuous accumulation of the target contaminants during the simulation's years was observed, whereas for children a plateau at the end of the simulation period was perceived. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Human exposure to static magnetic fields and basic precautions

    International Nuclear Information System (INIS)

    Vulevic, B.

    1999-01-01

    The development of new technologies using the static magnetic fields and their application in the last several years has increased the possibility of higher human exposure to such fields what has raised an issue of potential adverse health effects. The object of this work is to point, on the basis of the past knowledge, to the significance of the problem and therefore to contribute to its popularization. (author)

  6. Workers exposure to 0-300 GHz electromagnetic fields - The New European Directive 2013/35/UE

    International Nuclear Information System (INIS)

    2013-01-01

    The non-ionizing radiations section of the French Society for Radiation Protection (SFRP) has organized this conference with the aim to present the new European Directive 2013/35/UE about the occupational exposure to electric, magnetic and electromagnetic fields. The topics approached have permitted to better understand its content, background and practical impact for labour physicians, safety engineers and any other people involved in labour risks monitoring. The document brings together 15 presentations (slides) and their corresponding abstract. Content is as follows: Session 1 - electromagnetic fields and health: What is an electromagnetic field? (Alain Azoulay (Consultant)); What are the health impacts of fields? (Isabelle Lagroye (IMS Bordeaux univ.)); Who are the most concerned workers? (Martine Souques (EDF)); Session 2 - Presentation of the directive, from its foundation to its transposition (Isabelle Magne (EDF)): ICNIRP's (International Commission on Non-Ionizing Radiation Protection) guidelines (Bernard Veyret (IMS Bordeaux univ.)); The New European Directive 2013/35/UE (Patrick Moureaux (INRS)); transposition works of the directive into French law (Peggy Mathieu (DGT)); Session 3 - Evaluation of electromagnetic fields exposure levels (Allal Ouberehil (TDF)): how to measure and electromagnetic field and to estimate its measurement uncertainty? (Emmanuel Nicolas (Bureau Veritas)); ELF - how to calculate the electric field induced in the human body and with which uncertainty? (Noel Burais (Ampere Univ. Lyon)); how to calculate the Specific Absorption Rate (SAR) in the human body and with which uncertainty? (Joe Wiart (Orange Labs)); Session 4 - Occupational exposures - overview and experience feedbacks (Martine SOUQUES (EDF)): overview of occupational exposures (Patrick Moureaux (INRS)); Implementation of the 2004/40/CE directive at TDF and perspectives of the 2013/35/UE directive (Allal Ouberehil (TDF)); Implementation of the 2004/40/CE directive at RTE

  7. Development of a ECOREA-II code for human exposures from radionuclides through food chain

    International Nuclear Information System (INIS)

    Yoo, D. H.; Choi, Y. H.

    2001-01-01

    The release of radionuclides from nuclear facilities following an accident into air results in human exposures through two pathways. One is direct human exposures by inhalation or dermal absorption of these radionucles. Another is indirect human exposures through food chain which includes intakes of plant products such as rice, vegetables from contaiminated soil and animal products such as meet, milk and eggs feeded by contaminated grasses or plants on the terrestial surface. This study presents efforts of the development of a computer code for the assessment of the indirect human exposure through such food chains. The purpose of ECOREA-II code is to develop appropriate models suitable for a specific soil condition in Korea based on previous experimental efforts and to provide a more user-friendly environment such as GUI for the use of the code. Therefore, the current code, when more fully developed, is expected to increase the understanding of environmental safety assessment of nuclear facilities following an accident and provide a reasonable regulatory guideline with respecte to food safety issues

  8. Human exposure, biomarkers, and fate of organotins in the environment.

    Science.gov (United States)

    Okoro, Hussein K; Fatoki, Olalekan S; Adekola, Folahan A; Ximba, Bhekumusa J; Snyman, Reinette G; Opeolu, Beatrice

    2011-01-01

    Organotin compounds result from the addition of organic moieties to inorganic tin.Thus, one or more tin-carbon bonds exist in each organotin molecule. The organo-tin compounds are ubiquitous in the environment. Organotin compounds have many uses, including those as fungicides and stabilizers in plastics, among others in industry. The widespread use of organotins as antifouling agents in boat paints has resulted in pollution of freshwater and marine ecosystems. The presence of organotin compounds in freshwater and marine ecosystems is now understood to be a threat, because of the amounts found in water and the toxicity of some organotin compounds to aquatic organisms, and perhaps to humans as well. Organotin com-pounds are regarded by many to be global pollutants of a stature similar to biphenyl,mercury, and the polychlorinated dibenzodioxins. This stature results from the high toxicity, persistence, bioaccumulation, and endocrine disruptive features of even very low levels of selected organotin compounds.Efforts by selected governmental agencies and others have been undertaken to find a global solution to organotin pollution. France was the first country to ban the use of the organotins in 1980. This occurred before the international maritime organization (IMO) called for a global treaty to ban the application of tributyltin (TBT)-based paints. In this chapter, we review the organotin compounds with emphasis on the human exposure, fate, and distribution of them in the environment. The widespread use of the organotins and their high stability have led to contamination of some aquatic ecosystems. As a result, residues of the organotins may reach humans via food consumption. Notwithstanding the risk of human exposure, only limited data are available on the levels at which the organotins exist in foodstuffs consumed by humans. Moreover, the response of marine species to the organotins, such as TBT, has not been thoroughly investigated. Therefore, more data on the

  9. Effects of flow gradients on directional radiation of human voice.

    Science.gov (United States)

    Pulkki, Ville; Lähivaara, Timo; Huhtakallio, Ilkka

    2018-02-01

    In voice communication in windy outdoor conditions, complex velocity gradients appear in the flow field around the source, the receiver, and also in the atmosphere. It is commonly known that voice emanates stronger towards the downstream direction when compared with the upstream direction. In literature, the atmospheric effects are used to explain the stronger emanation in the downstream direction. This work shows that the wind also has an effect to the directivity of voice also favouring the downstream direction. The effect is addressed by measurements and simulations. Laboratory measurements are conducted by using a large pendulum with a loudspeaker mimicking the human head, whereas practical measurements utilizing the human voice are realized by placing a subject through the roof window of a moving car. The measurements and a simulation indicate congruent results in the speech frequency range: When the source faces the downstream direction, stronger radiation coinciding with the wind direction is observed, and when it faces the upstream direction, radiation is not affected notably. The simulated flow gradients show a wake region in the downstream direction, and the simulated acoustic field in the flow show that the region causes a wave-guide effect focusing the sound in the direction.

  10. Moving toward exposure and risk evaluation of nanomaterials: challenges and future directions.

    Science.gov (United States)

    Thomas, Treye; Bahadori, Tina; Savage, Nora; Thomas, Karluss

    2009-01-01

    Nanotechnology, the commercial development of engineered nanomaterials, promises breakthrough innovations by enhancing the performance of existing consumer products and enabling development of new devices, architectures, and applications. Although these materials and applications are being developed at an explosive pace, a fundamental understanding of any potential human health and environmental risks resulting from exposure throughout the lifecycle of these materials has not advanced as rapidly. Past experience has demonstrated that successful introduction of a new technology occurs more readily if it is precipitated by a robust appreciation for any inherent risks associated with the technology. Such understanding allows the timely development of occupational and consumer exposure standards that might be needed to protect human health and the environment. Although risk is recognized as the product of hazard and exposure, too often exposure patterns are poorly characterized, and risk is based primarily or exclusively on the hazard characterization. The extent of exposure to nanomaterials in currently available commercial products is relatively unknown. Given the number of commercial products that claim to contain engineered nanomaterials, it is possible that human and environmental exposure to these materials is widespread. This paper is intended to highlight the importance of exposure assessment for determining the potential risks of nanomaterials. In essence, this is a call to action to the community of exposure scientists, toxicologists, and risk assessors to develop, consider, and incorporate requisite exposure information in the risk assessment of nanomaterials. Without an integrated approach, it will be difficult to meaningfully assess the risks of nanomaterials, realize their potential benefits, and foster their sustainable development. (c) 2009 John Wiley & Sons, Inc.

  11. Human performance analysis of industrial radiography radiation exposure events

    International Nuclear Information System (INIS)

    Reece, W.J.; Hill, S.G.

    1995-01-01

    A set of radiation overexposure event reports were reviewed as part of a program to examine human performance in industrial radiography for the US Nuclear Regulatory Commission. Incident records for a seven year period were retrieved from an event database. Ninety-five exposure events were initially categorized and sorted for further analysis. Descriptive models were applied to a subset of severe overexposure events. Modeling included: (1) operational sequence tables to outline the key human actions and interactions with equipment, (2) human reliability event trees, (3) an application of an information processing failures model, and (4) an extrapolated use of the error influences and effects diagram. Results of the modeling analyses provided insights into the industrial radiography task and suggested areas for further action and study to decrease overexposures

  12. Major national human biomonitoring programs in chemical exposure assessment

    Directory of Open Access Journals (Sweden)

    Judy Choi

    2015-07-01

    Full Text Available Human biomonitoring (HBM programs have been established in several countries around the world in order to monitor the levels of chemical exposures in the general population and qualify health risk assessment of national and international interest. Study design, population, sample collection, and chemical analysis must be considered when comparing and interpreting the results. In this review, the objectives and brief descriptions of the major national HBM programs in North America, Europe, and Asia are provided. Similarities and differences observed from a comparative analysis among these programs, including the stratification of data according to age, sex, socioeconomic background, etc. as well as the identification of chemical exposure associated with food intake, are discussed. Overall, although there are some discrepancies in the study designs among the reviewed national HBM programs, results from the programs can provide useful information such as chemical levels found within the general population of a country that can be compared. Furthermore, the results can be used by regulatory authorities or the government to enforce legislations in order to reduce the exposure of chemicals into the human body.

  13. The Human Exposure Potential from Propylene Releases to the Environment

    Directory of Open Access Journals (Sweden)

    David A. Morgott

    2018-01-01

    Full Text Available A detailed literature search was performed to assess the sources, magnitudes and extent of human inhalation exposure to propylene. Exposure evaluations were performed at both the community and occupational levels for those living or working in different environments. The results revealed a multitude of pyrogenic, biogenic and anthropogenic emission sources. Pyrogenic sources, including biomass burning and fossil fuel combustion, appear to be the primary contributors to atmospheric propylene. Despite a very short atmospheric lifetime, measurable levels could be detected in highly remote locations as a result of biogenic release. The indoor/outdoor ratio for propylene has been shown to range from about 2 to 3 in non-smoking homes, which indicates that residential sources may be the largest contributor to the overall exposure for those not occupationally exposed. In homes where smoking takes place, the levels may be up to thirty times higher than non-smoking residences. Atmospheric levels in most rural regions are typically below 2 ppbv, whereas the values in urban levels are much more variable ranging as high as 10 ppbv. Somewhat elevated propylene exposures may also occur in the workplace; especially for firefighters or refinery plant operators who may encounter levels up to about 10 ppmv.

  14. Development of human exposure standards for radio frequency fields

    International Nuclear Information System (INIS)

    Lin, James C.

    2000-01-01

    Historical aspects of the problem of developing human exposure standards for radio frequency (RF) electromagnetic fields are discussed. It is shown that biological effects and health implications of radiofrequency (RF) electromagnetic fields have been a subject of scientific investigation for more than 50 years. It has become a focus of attention because of the expanded use of RF radiation in the frequency range between 300 MHz and 6 GHz for wireless communication over the past decade. Another cause for the attention is the uncertainty of some observed responses and lack of understanding of the mechanism of interaction of RF electromagnetic fields with biological systems. At present, considerable efforts are devoted to developing and revising RF exposure standards. Each of these efforts should aim to make explicit the philosophy and process by which they reason and decide guidelines for deeming exposure as safe. Furthermore, the reconciliation of philosophies of protection will definitely be an asset, in practice, to those interested in international harmonization of RF exposure standards [ru

  15. Quantifying human exposure to air pollution - moving from static monitoring to spatio-temporally resolved personal exposure assessment

    DEFF Research Database (Denmark)

    Steinle, Susanne; Reis, Stefan; Sabel, Clive E

    2013-01-01

    exposure studies to accurately assess human health risks. ? We discuss potential and shortcomings of methods and tools with a focus on how their development influences study design. ? We propose a novel conceptual model for integrated health impact assessment of human exposure to air pollutants. ? We......Quantifying human exposure to air pollutants is a challenging task. Ambient concentrations of air pollutants at potentially harmful levels are ubiquitous in urban areas and subject to high spatial and temporal variability. At the same time, every individual has unique activity-patterns. Exposure...... results from multifaceted relationships and interactions between environmental and human systems, adding complexity to the assessment process. Traditionally, approaches to quantify human exposure have relied on pollutant concentrations from fixed air quality network sites and static population...

  16. Human exposure assessment to antibiotic-resistant Escherichia coli through drinking water.

    Science.gov (United States)

    O'Flaherty, E; Borrego, C M; Balcázar, J L; Cummins, E

    2018-03-01

    Antibiotic-resistant bacteria (ARB) are a potential threat to human health through drinking water with strong evidence of ARB presence in post treated tap water around the world. This study examines potential human exposure to antibiotic-resistant (AR) Escherichia coli (E. coli) through drinking water, the effect of different drinking water treatments on AR E. coli and the concentration of AR E. coli required in the source water for the EU Drinking Water Directive (DWD) (Council Directive 98/83/EC, 0CFU/100ml of E. coli in drinking water) to be exceeded. A number of scenarios were evaluated to examine different water treatment combinations and to reflect site specific conditions at a study site in Europe. A literature search was carried out to collate data on the effect of environmental conditions on AR E. coli, the effect of different water treatments on AR E. coli and typical human consumption levels of tap water. A human exposure assessment model was developed with probability distributions used to characterise uncertainty and variability in the input data. Overall results show the mean adult human exposure to AR E. coli from tap water consumption ranged between 3.44×10 -7 and 2.95×10 -1 cfu/day for the scenarios tested and varied depending on the water treatments used. The level of AR E. coli required in the source water pre-treatment to exceed the DWD varied between 1 and 5logcfu/ml, depending on the water treatments used. This can be used to set possible monitoring criteria in pre-treated water for potential ARB exposure in drinking water. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. In situ exposure to non-directional beacons for air traffic control.

    Science.gov (United States)

    Joseph, Wout; Goeminne, Francis; Vermeeren, Günter; Verloock, Leen; Martens, Luc

    2012-04-01

    In situ electromagnetic field exposure of workers and the general public due to non-directional beacons (NDB) for air traffic control is assessed and characterized. For occupational exposure, the maximal measured electric field value is 881.6 V/m and the maximal magnetic field value is 9.1 A/m. The maximum electric fields exceed the International Commission on Non-Ionizing Radiation Protection (ICNIRP) reference levels at all seven NDB sites, and the magnetic fields at two of the seven NDB sites (occupational exposure). Recommendations and compliance distances for workers and the general public are provided. © 2012 Wiley Periodicals, Inc.

  18. Human convective boundary layer and its impact on personal exposure

    DEFF Research Database (Denmark)

    Licina, Dusan

    generated by heat sources are gaining more prominent influence in space airflow formation and on the indoor environment overall. In such spaces with low air supply velocity, air mixing is minimized and the pollution emitted from localized indoor sources is non-uniformly distributed. The large spatial......People spend most of their time indoors and they are constantly exposed to pollution that affects their health, comfort and productivity. Due to strong economic and environmental pressures to reduce building energy consumption, low air velocity design is gaining popularity; hence buoyancy flows...... in inaccurate exposure prediction. This highlights the importance of a detailed understanding of the complex air movements that take place in the vicinity of the human body and their impact on personal exposure. The two objectives of the present work are: (i) to examine the extent to which the room air...

  19. Pre-exposure Prophylaxis Against Human Immunodeficiency Virus

    Directory of Open Access Journals (Sweden)

    Güle ÇINAR

    2018-03-01

    Full Text Available According to the Center for Disease Control and Prevention (CDC, there were 2.1 million new human immunodeficiency virus (HIV cases reported worldwide in 2015, which shows that siginificant work needs to be done to prevent the transmission of HIV. Research to date has focused mainly on high-risk men who have sex with men, but many women around the world are also at a high risk for HIV transmissions. In studies conducted, the incidence of HIV infection in high-risk individuals decreases over 90% when high-risk individuals use pre-exposure prophylaxis (PreP HIV, tenofovir disoproxil fumarate-emtricitabine (TDF-FTC safely. Current data and studies on pre-exposure prophylaxis were discussed in this review.

  20. Human exposure to herpesvirus B-seropositive macaques, Bali, Indonesia.

    Science.gov (United States)

    Engel, Gregory A; Jones-Engel, Lisa; Schillaci, Michael A; Suaryana, Komang Gde; Putra, Artha; Fuentes, Agustin; Henkel, Richard

    2002-08-01

    Herpesvirus B (Cercopithecine herpesvirus 1) has been implicated as the cause of approximately 40 cases of meningoencephalitis affecting persons in direct or indirect contact with laboratory macaques. However, the threat of herpesvirus B in nonlaboratory settings worldwide remains to be addressed. We investigated the potential for exposure to herpesvirus B in workers at a "monkey forest" (a temple that has become a tourist attraction because of its monkeys) in Bali, Indonesia. In July 2000, 105 workers at the Sangeh Monkey Forest in Central Bali were surveyed about contact with macaques (Macaca fascicularis). Nearly half of those interviewed had either been bitten or scratched by a macaque. Prevalence of injury was higher in those who fed macaques. Serum from 31 of 38 Sangeh macaques contained antibodies to herpesvirus B. We conclude that workers coming into contact with macaques at the Sangeh Monkey Forest are at risk for exposure to herpesvirus B.

  1. Assessment of genetic risk for human exposure to radiation. State of the art

    International Nuclear Information System (INIS)

    Shevchenko, V.A.

    2000-01-01

    Historical aspects of the conception of genetic risk of human irradiation for recent 40 years. Methodology of assessing the genetic risk of radiation exposure is based on the concept of hitting the target. To predict genetic risk of irradiation, the direct and indirect methods of assessment, extrapolation, integral and populational criteria of risk analysis is widely used. Combination of these methods permits to calculate the risk from human exposure on the basis of data obtained for mice. Method of doubling dose based on determination of the dose doubling the level of natural mutational process in humans is the main one used to predict the genetic risk. Till 1972 the main model for assessing the genetic risk was the human/mouse model (the use of data on the spontaneous human variability and data on the frequency of induced mutations in mice). In the period from 1972 till 1994 the mouse/mouse model was intensively elaborated in many laboratories. This model was also used in this period to analyse the genetic risk of human irradiation. Recent achievements associated with the study of molecular nature of many hereditary human diseases as well as the criticism of a fundamental principles of the mouse/mouse model for estimating the genetic risk on a new basis. Estimates of risk for the different classes of genetic diseases have been obtained using the doubling-dose method [ru

  2. Dosimetry Methods for Human Exposure to Non-Ionising Radiation

    International Nuclear Information System (INIS)

    Poljak, D.; Sarolic, A.; Doric, V.; Peratta, C.; Peratta, A.

    2011-01-01

    The paper deals with human exposure to electromagnetic fields from extremely low frequencies (ELF) to GSM frequencies. The problem requires (1) the assessment of external field generated by electromagnetic interference (EMI) source at a given frequency (incident field dosimetry) and then (2) the assessment of corresponding fields induced inside the human body (internal field dosimetry). Several methods used in theoretical and experimental dosimetry are discussed within this work. Theoretical dosimetry models at low frequencies are based on quasistatic approaches, while analyses at higher frequencies use the full-wave models. Experimental techniques involve near and far field measurement. Human exposure to power lines, transformer substations, power line communication (PLC) systems, Radio Frequency Identification (RFID) antennas and GSM base station antenna systems is analyzed. The results o are compared to the exposure limits proposed by relevant safety guidelines. Theoretical incident dosimetry used in this paper is based on the set of Pocklington integro-differential equations for the calculation of the current distribution and subsequently radiated field from power lines. Experimental incident dosimetry techniques involve measurement techniques of fields radiated by RFID antennas and GSM base station antennas. First example set of numerical results is related to the internal dosimetry of realistic well-grounded body model exposed to vertical component of the electric field E = 10 kV/m generated by high voltage power line. The results obtained via the HNA model exceed the ICNIRP basic restrictions for public exposure (2 mA/m 2 ) in knee (8.6 mA/m 2 ) and neck (9.8 mA/m 2 ) and for occupational exposure (10 mA/m 2 ) in ankle (32 mA/m 2 ). In the case of a conceptual model of a realistic human body inside a transformer substation room touching a control panel at the potential φ0 = 400 V and with two scenarios for dry-air between worker's hand and panel, the values

  3. Direct evidence of milk consumption from ancient human dental calculus

    DEFF Research Database (Denmark)

    Warinner, C.; Hendy, J.; Speller, C.

    2014-01-01

    directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG...... is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker leading up...

  4. Evidence of directional and stabilizing selection in contemporary humans.

    Science.gov (United States)

    Sanjak, Jaleal S; Sidorenko, Julia; Robinson, Matthew R; Thornton, Kevin R; Visscher, Peter M

    2018-01-02

    Modern molecular genetic datasets, primarily collected to study the biology of human health and disease, can be used to directly measure the action of natural selection and reveal important features of contemporary human evolution. Here we leverage the UK Biobank data to test for the presence of linear and nonlinear natural selection in a contemporary population of the United Kingdom. We obtain phenotypic and genetic evidence consistent with the action of linear/directional selection. Phenotypic evidence suggests that stabilizing selection, which acts to reduce variance in the population without necessarily modifying the population mean, is widespread and relatively weak in comparison with estimates from other species.

  5. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    Science.gov (United States)

    Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

  6. Arsenic exposure induces the Warburg effect in cultured human cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Fei; Severson, Paul; Pacheco, Samantha; Futscher, Bernard W.; Klimecki, Walter T., E-mail: klimecki@pharmacy.arizona.edu

    2013-08-15

    Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75 ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases. - Highlights: • Chronic arsenite exposure induces aerobic glycolysis, dubbed the “Warburg effect”. • Arsenite-induced Warburg effect is a general phenomenon in cultured human cells. • HIF-1A may mediate arsenite induced Warburg effect.

  7. Arsenic exposure induces the Warburg effect in cultured human cells

    International Nuclear Information System (INIS)

    Zhao, Fei; Severson, Paul; Pacheco, Samantha; Futscher, Bernard W.; Klimecki, Walter T.

    2013-01-01

    Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75 ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases. - Highlights: • Chronic arsenite exposure induces aerobic glycolysis, dubbed the “Warburg effect”. • Arsenite-induced Warburg effect is a general phenomenon in cultured human cells. • HIF-1A may mediate arsenite induced Warburg effect

  8. Long-term human exposure to lead from different media and intake pathways.

    Science.gov (United States)

    Pizzol, Massimo; Thomsen, Marianne; Andersen, Mikael Skou

    2010-10-15

    Lead (Pb) is well known as an environmental pollutant: it can accumulate in various media, so actual lead exposure reflects both historical and present contaminations. Two main challenges then emerge: obtaining updated information to gain an overall picture of the sources of exposure, and predicting the resulting internal body exposure levels and effects that occur under long-term exposure conditions. In this paper, a modeling approach is used to meet these challenges with reference to Danish exposure conditions. Levels of lead content in various media have been coupled with data for lead intake and absorption in the human body, for both children and adults. An age-dependent biokinetic model allows then for determination of the blood lead levels resulting from chronic exposure. The study shows that the actual intake of lead is up to 27% of the Provisional Tolerable Daily Intake (PTDI) for children and around 8% for adults. It is confirmed that the critical route of exposure is via ingestion, accounting for 99% of total lead intake, while inhalation contributes only to 1% of total lead intake. The resulting lead levels in the blood after 2 years of exposure to actual contamination conditions have been estimated as up to 2.2μg/dl in children and almost 1μg/dl in adults. Impacts from lead can occur even at such levels. The role of historical and present sources to lead in the environment is discussed, and, for specific child and adult exposure scenarios, external-internal concentration relationships for the direct linkage between lead in environmental media and resulting concentrations of lead in blood are then presented. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Prenatal Exposure to Progesterone Affects Sexual Orientation in Humans.

    Science.gov (United States)

    Reinisch, June M; Mortensen, Erik Lykke; Sanders, Stephanie A

    2017-07-01

    Prenatal sex hormone levels affect physical and behavioral sexual differentiation in animals and humans. Although prenatal hormones are theorized to influence sexual orientation in humans, evidence is sparse. Sexual orientation variables for 34 prenatally progesterone-exposed subjects (17 males and 17 females) were compared to matched controls (M age = 23.2 years). A case-control double-blind design was used drawing on existing data from the US/Denmark Prenatal Development Project. Index cases were exposed to lutocyclin (bioidentical progesterone = C 21 H 30 O 2 ; M W : 314.46) and no other hormonal preparation. Controls were matched on 14 physical, medical, and socioeconomic variables. A structured interview conducted by a psychologist and self-administered questionnaires were used to collect data on sexual orientation, self-identification, attraction to the same and other sex, and history of sexual behavior with each sex. Compared to the unexposed, fewer exposed males and females identified as heterosexual and more of them reported histories of same-sex sexual behavior, attraction to the same or both sexes, and scored higher on attraction to males. Measures of heterosexual behavior and scores on attraction to females did not differ significantly by exposure. We conclude that, regardless of sex, exposure appeared to be associated with higher rates of bisexuality. Prenatal progesterone may be an underappreciated epigenetic factor in human sexual and psychosexual development and, in light of the current prevalence of progesterone treatment during pregnancy for a variety of pregnancy complications, warrants further investigation. These data on the effects of prenatal exposure to exogenous progesterone also suggest a potential role for natural early perturbations in progesterone levels in the development of sexual orientation.

  10. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  11. Early Childhood Media Exposure and Self-Regulation: Bi-Directional Longitudinal Associations.

    Science.gov (United States)

    Cliff, Dylan P; Howard, Steven J; Radesky, Jenny S; McNeill, Jade; Vella, Stewart A

    2018-04-26

    To investigate: i) prospective associations between media exposure (television viewing, computers, and electronic games) at 2 years and self-regulation at 4 and 6 years, and ii) bi-directional associations between media exposure and self-regulation at 4 and 6 years. We hypothesized that media exposure and self-regulation would display a negative prospective association and subsequent bi-directional inverse associations. Data from the nationally-representative Longitudinal Study of Australian Children (LSAC) when children were aged 2 (n=2786) and 4/6 years (n=3527) were used. Primary caregivers reported children's weekly electronic media exposure. A composite measure of self-regulation was computed from caregivers-, teacher-, and observer-report data. Associations were examined using linear regression and cross-lagged panel models, accounting for covariates. Lower television viewing and total media exposure at 2 years were associated with higher self-regulation at 4 years (both β -0.02; 95% confidence interval [CI] -0.03, -0.01). Lower self-regulation at 4 years was also significantly associated with higher television viewing (β -0.15; 95% CI -0.21, -0.08), electronic game use (β -0.05; 95% CI -0.09, -0.01), and total media exposure (β -0.19; 95% CI -0.29, -0.09) at 6 years. However, media exposure at 4 years was not associated with self-regulation at 6 years. Although media exposure duration at 2 years was associated with later self-regulation, and self-regulation at 4 years was associated with later media exposure, associations were of small magnitude. More research is needed examining content quality, social context, and mobile media use and child self-regulation. Copyright © 2018. Published by Elsevier Inc.

  12. A systematic review of Bisphenol A "low dose" studies in the context of human exposure: a case for establishing standards for reporting "low-dose" effects of chemicals.

    Science.gov (United States)

    Teeguarden, Justin G; Hanson-Drury, Sesha

    2013-12-01

    Human exposure to the chemical Bisphenol A is almost ubiquitous in surveyed industrialized societies. Structural features similar to estrogen confer the ability of Bisphenol A (BPA) to bind estrogen receptors, giving BPA membership in the group of environmental pollutants called endocrine disruptors. References by scientists, the media, political entities, and non-governmental organizations to many toxicity studies as "low dose" has led to the belief that exposure levels in these studies are similar to humans, implying that BPA is toxic to humans at current exposures. Through systematic, objective comparison of our current, and a previous compilation of the "low-dose" literature to multiple estimates of human external and internal exposure levels, we found that the "low-dose" moniker describes exposures covering 8-12 orders of magnitude, the majority (91-99% of exposures) being greater than the upper bound of human exposure in the general infant, child and adult U.S. Population. "low dose" is therefore a descriptor without specific meaning regarding human exposure. Where human exposure data are available, for BPA and other environmental chemicals, reference to toxicity study exposures by direct comparison to human exposure would be more informative, more objective, and less susceptible to misunderstanding. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Sarin Exposures in A Cohort of British Military Participants in Human Experimental Research at Porton Down 1945-1987.

    Science.gov (United States)

    Keegan, Thomas J; Carpenter, Lucy M; Brooks, Claire; Langdon, Toby; Venables, Katherine M

    2017-12-15

    The effects of exposure to chemical warfare agents in humans are topical. Porton Down is the UK's centre for research on chemical warfare where, since WWI, a programme of experiments involving ~30000 participants drawn from the UK armed services has been undertaken. Our aim is to report on exposures to nerve agents, particularly sarin, using detailed exposure data not explored in a previous analysis. In this paper, we have used existing data on exposures to servicemen who attended the human volunteer programme at Porton Down to examine exposures to nerve agents in general and to sarin in particular. Six principal nerve agents were tested on humans between 1945 and 1987. Of all 4299 nerve agent tests recorded, 3511 (82%) were with sarin, most commonly in an exposure chamber, with inhalation being the commonest exposure route (85%). Biological response to sarin exposure was expressed as percentage change in cholinesterase activity and, less commonly, change in pupil size. For red blood cell cholinesterase, median inhibition for inhalation tests was 41% (interquartile range 28-51%), with a maximum of 87%. For dermal exposures the maximum inhibition recorded was 99%. There was a clear association between increasing exposure to sarin and depression of cholinesterase activity but the strength and direction of the association varied by exposure route and the presence of chemical or physical protection. Pupil size decreased with increased exposure but this relationship was less clear when modifiers, such as atropine drops, were present. These results, drawn from high quality experimental data, offer a unique insight into the effects of these chemical agents on humans. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  14. Structural behavior of human lumbar intervertebral disc under direct shear.

    Science.gov (United States)

    Schmidt, Hendrik; Häussler, Kim; Wilke, Hans-Joachim; Wolfram, Uwe

    2015-03-18

    The intervertebral disc (IVD) is a complex, flexible joint between adjacent vertebral bodies that provides load transmission while permitting movements of the spinal column. Finite element models can be used to help clarify why and how IVDs fail or degenerate. To do so, it is of importance to validate those models against controllable experiments. Due to missing experimental data, shear properties are not used thus far in validating finite element models. This study aimed to investigate the structural shear properties of human lumbar IVDs in posteroanterior (PA) and laterolateral (LL) loading directions. Fourteen lumbar IVDs (median age: 49 years) underwent direct shear in PA and LL loading directions. A custom-build shear device was used in combination with a materials testing machine to load the specimens until failure. Shear stiffness, ultimate shear force and displacement, and work to failure were determined. Each specimen was tested until complete or partial disruption. Median stiffness in PA direction was 490 N/mm and in LL direction 568 N/mm. Median ultimate shear force in the PA direction was 2,877 N and in the LL direction 3,199 N. Work to failure was 12 Nm in the PA and 9 Nm in the LL direction. This study was an experiment to subject IVDs to direct shear. The results could help us to understand the structure and function of IVDs with regard to mechanical spinal stability, and they can be used to validate finite element models of the IVD.

  15. Environmental and human exposure as a result of radioactive discharges

    International Nuclear Information System (INIS)

    2010-02-01

    Nuclear accidents can lead to the discharge of radioactive particulates, gases, and liquid effluents into the environment. Effluents are characterized by their composition, duration and by other characteristics which can influence the dispersion of radioactivity in the environment. Populations can be exposed directly or through the contamination of the terrestrial and aquatic environments. Therefore, it is necessary to take into consideration both the environmental contamination pathways and the human contamination pathways through the environment. This document summarizes these different pathways: contamination by atmospheric discharge (surface contamination, surface waters, terrestrial fauna and flora); contamination by liquid discharge; spreading of contaminated areas; human contamination pathways (external irradiation, internal contamination, skin contamination). (J.S.)

  16. Human mercury exposure associated with small-scale gold mining in Burkina Faso.

    Science.gov (United States)

    Tomicic, Catherine; Vernez, David; Belem, Tounaba; Berode, Michèle

    2011-06-01

    In Burkina Faso, gold ore is one of the main sources of income for an important part of the active population. Artisan gold miners use mercury in the extraction, a toxic metal whose human health risks are well known. The aim of the present study was to assess mercury exposure as well as to understand the exposure determinants of gold miners in Burkinabe small-scale mines. The examined gold miners' population on the different selected gold mining sites was composed by persons who were directly and indirectly related to gold mining activities. But measurement of urinary mercury was performed on workers most susceptible to be exposed to mercury. Thus, occupational exposure to mercury was evaluated among ninety-three workers belonging to eight different gold mining sites spread in six regions of Burkina Faso. Among others, work-related exposure determinants were taken into account for each person during urine sampling as for example amalgamating or heating mercury. All participants were medically examined by a local medical team in order to identify possible symptoms related to the toxic effect of mercury. Mercury levels were high, showing that 69% of the measurements exceeded the ACGIH (American Conference of Industrial Hygienists) biological exposure indice (BEI) of 35 μg per g of creatinine (μg/g-Cr) (prior to shift) while 16% even exceeded 350 μg/g-Cr. Basically, unspecific but also specific symptoms related to mercury toxicity could be underlined among the persons who were directly related to gold mining activities. Only one-third among the studied subpopulation reported about less than three symptoms possibly associated to mercury exposure and nearly half of them suffered from at least five of these symptoms. Ore washers were more involved in the direct handling of mercury while gold dealers in the final gold recovery activities. These differences may explain the overexposure observed in gold dealers and indicate that the refining process is the major source

  17. Exposure to particulate matter in India: A synthesis of findings and future directions.

    Science.gov (United States)

    Pant, Pallavi; Guttikunda, Sarath K; Peltier, Richard E

    2016-05-01

    Air pollution poses a critical threat to human health with ambient and household air pollution identified as key health risks in India. While there are many studies investigating concentration, composition, and health effects of air pollution, investigators are only beginning to focus on estimating or measuring personal exposure. Further, the relevance of exposures studies from the developed countries in developing countries is uncertain. This review summarizes existing research on exposure to particulate matter (PM) in India, identifies gaps and offers recommendations for future research. There are a limited number of studies focused on exposure to PM and/or associated health effects in India, but it is evident that levels of exposure are much higher than those reported in developed countries. Most studies have focused on coarse aerosols, with a few studies on fine aerosols. Additionally, most studies have focused on a handful of cities, and there are many unknowns in terms of ambient levels of PM as well as personal exposure. Given the high mortality burden associated with air pollution exposure in India, a deeper understanding of ambient pollutant levels as well as source strengths is crucial, both in urban and rural areas. Further, the attention needs to expand beyond the handful large cities that have been studied in detail. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Natural and anthropogenic radiation exposure of humans in Germany

    International Nuclear Information System (INIS)

    Koelzer, Winfried

    2016-12-01

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

  19. Human exposure to soil contaminants in subarctic Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Ellen Stephanie Reyes

    2015-05-01

    Full Text Available Background: Chemical contaminants in the Canadian subarctic present a health risk with exposures primarily occurring via the food consumption. Objective: Characterization of soil contaminants is needed in northern Canada due to increased gardening and agricultural food security initiatives and the presence of known point sources of pollution. Design: A field study was conducted in the western James Bay Region of Ontario, Canada, to examine the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethane and its metabolites (ΣDDT, other organochlorines, and metals/metalloids in potentially contaminated agriculture sites. Methods: Exposure pathways were assessed by comparing the estimated daily intake to acceptable daily intake values. Ninety soil samples were collected at random (grid sampling from 3 plots (A, B, and C in Fort Albany (on the mainland, subarctic Ontario, Canada. The contaminated-soil samples were analysed by gas chromatography with an electron capture detector or inductively coupled plasma mass spectrometer. Results: The range of ΣDDT in 90 soil samples was below the limit of detection to 4.19 mg/kg. From the 3 soil plots analysed, Plot A had the highest ΣDDT mean concentration of 1.12 mg/kg, followed by Plot B and Plot C which had 0.09 and 0.01 mg/kg, respectively. Concentrations of other organic contaminants and metals in the soil samples were below the limit of detection or found in low concentrations in all plots and did not present a human health risk. Conclusions: Exposure analyses showed that the human risk was below regulatory thresholds. However, the ΣDDT concentration in Plot A exceeded soil guidelines set out by the Canadian Council of Ministers of the Environment of 0.7 mg/kg, and thus the land should not be used for agricultural or recreational purposes. Both Plots B and C were below threshold limits, and this land can be used for agricultural purposes.

  20. Domestic dogs and puppies can use human voice direction referentially.

    Science.gov (United States)

    Rossano, Federico; Nitzschner, Marie; Tomasello, Michael

    2014-06-22

    Domestic dogs are particularly skilled at using human visual signals to locate hidden food. This is, to our knowledge, the first series of studies that investigates the ability of dogs to use only auditory communicative acts to locate hidden food. In a first study, from behind a barrier, a human expressed excitement towards a baited box on either the right or left side, while sitting closer to the unbaited box. Dogs were successful in following the human's voice direction and locating the food. In the two following control studies, we excluded the possibility that dogs could locate the box containing food just by relying on smell, and we showed that they would interpret a human's voice direction in a referential manner only when they could locate a possible referent (i.e. one of the boxes) in the environment. Finally, in a fourth study, we tested 8-14-week-old puppies in the main experimental test and found that those with a reasonable amount of human experience performed overall even better than the adult dogs. These results suggest that domestic dogs' skills in comprehending human communication are not based on visual cues alone, but are instead multi-modal and highly flexible. Moreover, the similarity between young and adult dogs' performances has important implications for the domestication hypothesis.

  1. Epidemiological characteristics and post-exposure prophylaxis of human rabies in Chongqing, China, 2007-2016.

    Science.gov (United States)

    Qi, Li; Su, Kun; Shen, Tao; Tang, Wenge; Xiao, Bangzhong; Long, Jiang; Zhao, Han; Chen, Xi; Xia, Yu; Xiong, Yu; Xiao, Dayong; Feng, Liangui; Li, Qin

    2018-01-03

    According to the global framework of eliminating human rabies, China is responding to achieve the target of zero human death from dog-mediated rabies by 2030. Chongqing is the largest municipality directly under central government in China. We described the epidemiological characteristics and post-exposure prophylaxis (PEP) of human rabies in this area, in order to provide a reliable epidemiology basis for further control and prevention of human rabies. The most updated epidemiological data for human rabies cases from 2007 to 2016 in Chongqing were collected from the National Disease Reporting Information System. A standardized questionnaire was applied to the human rabies cases or family members of cases as proxy to investigate the PEP situation. A total of 809 fatal human rabies cases were reported in Chongqing from 2007 to 2016. There was a trend of gradual annual decline about number of cases from 2007 to 2013, followed by stable levels until 2016. Rabies was mostly reported in summer and autumn; a majority of cases were noted in farmers (71.8%), especially in males (65.3%). The cases aged 35-74 and 5-14 years old accounted for 83.8% of all the cases. We collected information of 548 human rabies cases' rabies exposure and PEP situation. Of those, 95.8% of human rabies cases were victims of dog bites or scratch, and 53.3% of these dogs were identified as stray dogs. Only 4.0% of the domestic dogs were reported to have been vaccinated previously. After exposure, 87.8% of the 548 human rabies cases did not seek any medical services. Further investigation showed that none of the 548 cases received timely and properly standardized PEP. Human rabies remains a major public health problem in Chongqing, China. Dogs are the main reservoir and source of human rabies infection. Unsuccessful control of canine rabies and inadequate PEP of cases might be the main factors leading to the serious human rabies epidemic in this area. An integrated "One Health" approach should be

  2. Direct dating of Early Upper Palaeolithic human remains from Mladec.

    Science.gov (United States)

    Wild, Eva M; Teschler-Nicola, Maria; Kutschera, Walter; Steier, Peter; Trinkaus, Erik; Wanek, Wolfgang

    2005-05-19

    The human fossil assemblage from the Mladec Caves in Moravia (Czech Republic) has been considered to derive from a middle or later phase of the Central European Aurignacian period on the basis of archaeological remains (a few stone artefacts and organic items such as bone points, awls, perforated teeth), despite questions of association between the human fossils and the archaeological materials and concerning the chronological implications of the limited archaeological remains. The morphological variability in the human assemblage, the presence of apparently archaic features in some specimens, and the assumed early date of the remains have made this fossil assemblage pivotal in assessments of modern human emergence within Europe. We present here the first successful direct accelerator mass spectrometry radiocarbon dating of five representative human fossils from the site. We selected sample materials from teeth and from one bone for 14C dating. The four tooth samples yielded uncalibrated ages of approximately 31,000 14C years before present, and the bone sample (an ulna) provided an uncertain more-recent age. These data are sufficient to confirm that the Mladec human assemblage is the oldest cranial, dental and postcranial assemblage of early modern humans in Europe and is therefore central to discussions of modern human emergence in the northwestern Old World and the fate of the Neanderthals.

  3. Assessment of human exposure to environmental sources of nickel in Europe: Inhalation exposure.

    Science.gov (United States)

    Buekers, Jurgen; De Brouwere, Katleen; Lefebvre, Wouter; Willems, Hanny; Vandenbroele, Marleen; Van Sprang, Patrick; Eliat-Eliat, Maxime; Hicks, Keegan; Schlekat, Christian E; Oller, Adriana R

    2015-07-15

    The paper describes the inhalation nickel (Ni) exposure of humans via the environment for the regional scale in the EU, together with a tiered approach for assessing additional local exposure from industrial emissions. The approach was designed, in the context of REACH, for the purpose of assessing and controlling emissions and air quality in the neighbourhood of Ni producers and downstream users. Two Derived No Effect Level (DNEL) values for chronic inhalation exposure to total Ni in PM10 (20 and 60ngNi/m(3)) were considered. The value of 20ngNi/m(3) is the current EU air quality guidance value. The value of 60ngNi/m(3) is derived here based on recently published Ni data (Oller et al., 2014). Both values are protective for respiratory toxicity and carcinogenicity but differ in the application of toxicokinetic adjustments and cancer threshold considerations. Estimates of air Ni concentrations at the European regional scale were derived from the database of the European Environment Agency. The 50th and 90th percentile regional exposures were below both DNEL values. To assess REACH compliance at the local scale, measured ambient air data are preferred but are often unavailable. A tiered approach for the use of modelled ambient air concentrations was developed, starting with the application of the default EUSES model and progressing to more sophisticated models. As an example, the tiered approach was applied to 33 EU Ni sulphate producers' and downstream users' sites. Applying the EUSES model demonstrates compliance with a DNEL of 60ngNi/m(3) for the majority of sites, while the value of the refined modelling is demonstrated when a DNEL of 20ngNi/m(3) is considered. The proposed approach, applicable to metals in general, can be used in the context of REACH, for refining the risk characterisation and guiding the selection of risk management measures. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Reduction of radiation exposure for the examiner in angiography using a direct dosimeter

    International Nuclear Information System (INIS)

    Kamusella, Peter; Wissgott, C.; Scheer, F.; Andresen, R.; Wiggermann, P.

    2013-01-01

    Purpose: To evaluate whether a reduction in radiation exposure can be achieved using a direct dosimeter with an acoustic warning signal (model EDD-30, Unfors Instruments, Billdal, Sweden). Materials and Methods: A total of 183 diagnostic and interventional angiographies of the pelvis and lower limbs using a direct dosimeter were analyzed. The vascular interventions were performed either by an experienced examiner (> 5000 interventions), an intermediate examiner (> 1000 interventions) or by a beginner (< 200 interventions). The measuring sensor of the direct dosimeter was attached to the back of the left hand, below the sterile glove, and was worn throughout the examination. If the limit values set on the dosimeter were exceeded, an acoustic signal sounded. At the end of the examination, the mean dose and the mean dose rate could be read off directly. Results: Exposure is clearly dependent on the experience of the examiner. The highest mean dose rate was found for the beginner, followed by the intermediate examiner. The lowest dose rate was shown by the experienced examiner, even though he mostly performed complex interventions. Over the course of 3 months, an improvement in the average dose rate can be shown in the third month for the intermediate examiner. Conclusion: The use of a direct dosimeter with an acoustic warning signal is a practicable tool for sensitizing interventional radiologists to unavoidable radiation exposure, with the aim of reducing the dose. 'Real-time' dosimetry represents a sensible extension of indirect protection of the radiation-exposed examiner in angiography. (orig.)

  5. Human exposure assessment for biocides in the EU development of step by step guidance and worked examples

    NARCIS (Netherlands)

    Gerritsen-Ebben, R.M.G.; Hemmen, J.J. van

    2007-01-01

    Directive 98/8/EC(1) concerns EU harmonisation of placing biocidal products on the market. In the present short paper the preliminary results of an ongoing project are presented in which step by step guidance on human exposure assessment with worked examples is developed. For all 23 biocidal product

  6. Environmental exposure to human carcinogens in teenagers and the association with DNA damage

    International Nuclear Information System (INIS)

    Franken, Carmen; Koppen, Gudrun; Lambrechts, Nathalie; Govarts, Eva; Bruckers, Liesbeth; Den Hond, Elly; Loots, Ilse; Nelen, Vera; Sioen, Isabelle; Nawrot, Tim S.; Baeyens, Willy; Van Larebeke, Nicolas; Boonen, Francis; Ooms, Daniëlla; Wevers, Mai; Jacobs, Griet; Covaci, Adrian; Schettgen, Thomas; Schoeters, Greet

    2017-01-01

    Background: We investigated whether human environmental exposure to chemicals that are labeled as (potential) carcinogens leads to increased (oxidative) damage to DNA in adolescents. Material and methods: Six hundred 14–15-year-old youngsters were recruited all over Flanders (Belgium) and in two areas with important industrial activities. DNA damage was assessed by alkaline and formamidopyrimidine DNA glycosylase (Fpg) modified comet assays in peripheral blood cells and analysis of urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Personal exposure to potentially carcinogenic compounds was measured in urine, namely: chromium, cadmium, nickel, 1-hydroxypyrene as a proxy for exposure to other carcinogenic polycyclic aromatic hydrocarbons (PAHs), t,t-muconic acid as a metabolite of benzene, 2,5-dichlorophenol (2,5-DCP), organophosphate pesticide metabolites, and di(2-ethylhexyl) phthalate (DEHP) metabolites. In blood, arsenic, polychlorinated biphenyl (PCB) congeners 118 and 156, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and perfluorooctanoic acid (PFOA) were analyzed. Levels of methylmercury (MeHg) were measured in hair. Multiple linear regression models were used to establish exposure-response relationships. Results: Biomarkers of exposure to PAHs and urinary chromium were associated with higher levels of both 8-OHdG in urine and DNA damage detected by the alkaline comet assay. Concentrations of 8-OHdG in urine increased in relation with increasing concentrations of urinary t,t-muconic acid, cadmium, nickel, 2,5-DCP, and DEHP metabolites. Increased concentrations of PFOA in blood were associated with higher levels of DNA damage measured by the alkaline comet assay, whereas DDT was associated in the same direction with the Fpg-modified comet assay. Inverse associations were observed between blood arsenic, hair MeHg, PCB 156 and HCB, and urinary 8-OHdG. The latter exposure biomarkers were also associated with higher fish intake. Urinary nickel

  7. Environmental exposure to human carcinogens in teenagers and the association with DNA damage

    Energy Technology Data Exchange (ETDEWEB)

    Franken, Carmen, E-mail: carmen.franken@vito.be [Flemish Institute for Technological Research (VITO), Mol (Belgium); Department of Biomedical Sciences, University of Antwerp, Antwerp (Belgium); Koppen, Gudrun; Lambrechts, Nathalie; Govarts, Eva [Flemish Institute for Technological Research (VITO), Mol (Belgium); Bruckers, Liesbeth [Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Hasselt (Belgium); Den Hond, Elly [Flemish Institute for Technological Research (VITO), Mol (Belgium); Loots, Ilse [Political and Social Sciences, University of Antwerp, Antwerp (Belgium); Nelen, Vera [Provincial Institute for Hygiene, Antwerp (Belgium); Sioen, Isabelle [Department of Public Health, Ghent University, Ghent (Belgium); Department of Food Safety and Food Quality, Ghent University, Ghent (Belgium); Nawrot, Tim S. [Centre for Environmental Sciences, Hasselt University, Diepenbeek (Belgium); Department of Public Health & Primary Care, Leuven University, Leuven (Belgium); Baeyens, Willy [Department of Analytical and Environmental Chemistry, Vrije Universiteit Brussel, Brussels (Belgium); Van Larebeke, Nicolas [Department of Analytical and Environmental Chemistry, Vrije Universiteit Brussel, Brussels (Belgium); Department of Radiotherapy and Experimental Cancerology, Ghent University, Ghent (Belgium); Boonen, Francis; Ooms, Daniëlla; Wevers, Mai; Jacobs, Griet [Flemish Institute for Technological Research (VITO), Mol (Belgium); Covaci, Adrian [Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Antwerp (Belgium); Schettgen, Thomas [Department of Occupational and Social Medicine, RWTH Aachen University, Aachen (Germany); Schoeters, Greet [Flemish Institute for Technological Research (VITO), Mol (Belgium); Department of Biomedical Sciences, University of Antwerp, Antwerp (Belgium); University of Southern Denmark, Institute of Public Health, Department of Environmental Medicine, Odense (Denmark)

    2017-01-15

    Background: We investigated whether human environmental exposure to chemicals that are labeled as (potential) carcinogens leads to increased (oxidative) damage to DNA in adolescents. Material and methods: Six hundred 14–15-year-old youngsters were recruited all over Flanders (Belgium) and in two areas with important industrial activities. DNA damage was assessed by alkaline and formamidopyrimidine DNA glycosylase (Fpg) modified comet assays in peripheral blood cells and analysis of urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Personal exposure to potentially carcinogenic compounds was measured in urine, namely: chromium, cadmium, nickel, 1-hydroxypyrene as a proxy for exposure to other carcinogenic polycyclic aromatic hydrocarbons (PAHs), t,t-muconic acid as a metabolite of benzene, 2,5-dichlorophenol (2,5-DCP), organophosphate pesticide metabolites, and di(2-ethylhexyl) phthalate (DEHP) metabolites. In blood, arsenic, polychlorinated biphenyl (PCB) congeners 118 and 156, hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (DDT) and perfluorooctanoic acid (PFOA) were analyzed. Levels of methylmercury (MeHg) were measured in hair. Multiple linear regression models were used to establish exposure-response relationships. Results: Biomarkers of exposure to PAHs and urinary chromium were associated with higher levels of both 8-OHdG in urine and DNA damage detected by the alkaline comet assay. Concentrations of 8-OHdG in urine increased in relation with increasing concentrations of urinary t,t-muconic acid, cadmium, nickel, 2,5-DCP, and DEHP metabolites. Increased concentrations of PFOA in blood were associated with higher levels of DNA damage measured by the alkaline comet assay, whereas DDT was associated in the same direction with the Fpg-modified comet assay. Inverse associations were observed between blood arsenic, hair MeHg, PCB 156 and HCB, and urinary 8-OHdG. The latter exposure biomarkers were also associated with higher fish intake. Urinary nickel

  8. Human-directed social behaviour in dogs shows significant heritability.

    Science.gov (United States)

    Persson, M E; Roth, L S V; Johnsson, M; Wright, D; Jensen, P

    2015-04-01

    Through domestication and co-evolution with humans, dogs have developed abilities to attract human attention, e.g. in a manner of seeking assistance when faced with a problem solving task. The aims of this study were to investigate within breed variation in human-directed contact seeking in dogs and to estimate its genetic basis. To do this, 498 research beagles, bred and kept under standardized conditions, were tested in an unsolvable problem task. Contact seeking behaviours recorded included both eye contact and physical interactions. Behavioural data was summarized through a principal component analysis, resulting in four components: test interactions, social interactions, eye contact and physical contact. Females scored significantly higher on social interactions and physical contact and age had an effect on eye contact scores. Narrow sense heritabilities (h(2) ) of the two largest components were estimated at 0.32 and 0.23 but were not significant for the last two components. These results show that within the studied dog population, behavioural variation in human-directed social behaviours was sex dependent and that the utilization of eye contact seeking increased with age and experience. Hence, heritability estimates indicate a significant genetic contribution to the variation found in human-directed social interactions, suggesting that social skills in dogs have a genetic basis, but can also be shaped and enhanced through individual experiences. This research gives the opportunity to further investigate the genetics behind dogs' social skills, which could also play a significant part into research on human social disorders such as autism. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  9. Weighing serological evidence of human exposure to animal influenza viruses - a literature review.

    Science.gov (United States)

    Sikkema, Reina Saapke; Freidl, Gudrun Stephanie; de Bruin, Erwin; Koopmans, Marion

    2016-11-03

    Assessing influenza A virus strains circulating in animals and their potential to cross the species barrier and cause human infections is important to improve human influenza surveillance and preparedness. We reviewed studies describing serological evidence of human exposure to animal influenza viruses. Comparing serological data is difficult due to a lack of standardisation in study designs and in laboratory methods used in published reports. Therefore, we designed a scoring system to assess and weigh specificity of obtained serology results in the selected articles. Many studies report reliable evidence of antibodies to swine influenza viruses among persons occupationally exposed to pigs. Most avian influenza studies target H5, H7 and H9 subtypes and most serological evidence of human exposure to avian influenza viruses is reported for these subtypes. Avian influenza studies receiving a low grade in this review often reported higher seroprevalences in humans compared with studies with a high grade. Official surveillance systems mainly focus on avian H5 and H7 viruses. Swine influenza viruses and avian subtypes other than H5 and H7 (emphasising H9) should be additionally included in official surveillance systems. Surveillance efforts should also be directed towards understudied geographical areas, such as Africa and South America. This article is copyright of The Authors, 2016.

  10. Weighing serological evidence of human exposure to animal influenza viruses − a literature review

    Science.gov (United States)

    Sikkema, Reina Saapke; Freidl, Gudrun Stephanie; de Bruin, Erwin; Koopmans, Marion

    2016-01-01

    Assessing influenza A virus strains circulating in animals and their potential to cross the species barrier and cause human infections is important to improve human influenza surveillance and preparedness. We reviewed studies describing serological evidence of human exposure to animal influenza viruses. Comparing serological data is difficult due to a lack of standardisation in study designs and in laboratory methods used in published reports. Therefore, we designed a scoring system to assess and weigh specificity of obtained serology results in the selected articles. Many studies report reliable evidence of antibodies to swine influenza viruses among persons occupationally exposed to pigs. Most avian influenza studies target H5, H7 and H9 subtypes and most serological evidence of human exposure to avian influenza viruses is reported for these subtypes. Avian influenza studies receiving a low grade in this review often reported higher seroprevalences in humans compared with studies with a high grade. Official surveillance systems mainly focus on avian H5 and H7 viruses. Swine influenza viruses and avian subtypes other than H5 and H7 (emphasising H9) should be additionally included in official surveillance systems. Surveillance efforts should also be directed towards understudied geographical areas, such as Africa and South America. PMID:27874827

  11. Human Exposure Model (HEM): A modular, web-based application to characterize near-field chemical exposures and releases

    Science.gov (United States)

    The U.S. EPA’s Chemical Safety and Sustainability research program is developing the Human Exposure Model (HEM) to assess near-field exposures to chemicals that occur in various populations over the entire life cycle of a consumer product. The model will be implemented as a...

  12. Human exposure to ionizing radiation for medical reasons

    International Nuclear Information System (INIS)

    Thomas, R.H.; Busick, D.D.

    1977-01-01

    The central issue in this debate is not whether there is a threshold dose below which deleterious effects in humans occur nor whether the dose-effect relationship is linear or curvilinear. The central issue is whether there is merit in a continuing effort to reduce radiation exposures to patients no matter at what level. This should be determined by a careful balancing of potential risks against expected benefits. It is this element of risk-benefit analysis that is absent in Morgan's philosophy. A good example of the changing nature on the risk-benefit balance is that of the use of mass radiography programs to diagnose tuberculosis. Before the Second World War this disease was a terrible scourge of the poor who could ill-afford adequate medical care. The use of mass radiography programs have played a large part in the elimination of this disease

  13. Survival of human lymphocytes after exposure to densely ionizing radiations

    International Nuclear Information System (INIS)

    Madhvanath, U.; Raju, M.R.; Kelly, L.S.

    1976-01-01

    Interphase death of human blood lymphocytes cultured in vitro was studied after exposure to 60 Co gamma rays and to accelerated ions of 1 H, 4 He, 7 Li, 11 B, 12 C, 20 Ne, 40 Ar, and π - meson beam under aerobic conditions. Exposures were also conducted under hypoxic conditions with 60 Co gamma rays, 4 He, 7 Li, and 12 C ion beams. Time course of interphase death was followed for 6 days after irradiation. Percent survivals were determined by using the trypan blue exclusion method. Survival curves at 5 days postirradiation were exponential for all radiations studied. These observations indicate that the production of interphase death of lymphocytes by densely ionizing radiations follows a pattern similar to that observed with colony-forming mammalian cells. However, the reproductive capacity of the latter cells is impaired with maximum effectiveness at energy densities associated with 220 keV/μm for the beam conditions used in this investigation. The much lower energy densities required to kill a lymphocyte suggest that a sensitive structure other than DNA may be responsible for the production of lymphocyte death, perhaps the membranes. The calculated inactivation cross sections for high-LET radiations above 650 keV/μm yielded values larger than the actual cell dimensions. It appears that contributions from delta rays become appreciable in this system at these LET's

  14. Inflammatory aetiology of human myometrial activation tested using directed graphs.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available THERE ARE THREE MAIN HYPOTHESES FOR THE ACTIVATION OF THE HUMAN UTERUS AT LABOUR: functional progesterone withdrawal, inflammatory stimulation, and oxytocin receptor activation. To test these alternatives we have taken information and data from the literature to develop causal pathway models for the activation of human myometrium. The data provided quantitative RT-PCR results on key genes from samples taken before and during labour. Principal component analysis showed that pre-labour samples form a homogenous group compared to those during labour. We therefore modelled the alternative causal pathways in non-labouring samples using directed graphs and statistically compared the likelihood of the different models using structural equations and D-separation approaches. Using the computer program LISREL, inflammatory activation as a primary event was highly consistent with the data (p = 0.925, progesterone withdrawal, as a primary event, is plausible (p = 0.499, yet comparatively unlikely, oxytocin receptor mediated initiation is less compatible with the data (p = 0.091. DGraph, a software program that creates directed graphs, produced similar results (p= 0.684, p= 0.280, and p = 0.04, respectively. This outcome supports an inflammatory aetiology for human labour. Our results demonstrate the value of directed graphs in determining the likelihood of causal relationships in biology in situations where experiments are not possible.

  15. Direct evidence of milk consumption from ancient human dental calculus.

    Science.gov (United States)

    Warinner, C; Hendy, J; Speller, C; Cappellini, E; Fischer, R; Trachsel, C; Arneborg, J; Lynnerup, N; Craig, O E; Swallow, D M; Fotakis, A; Christensen, R J; Olsen, J V; Liebert, A; Montalva, N; Fiddyment, S; Charlton, S; Mackie, M; Canci, A; Bouwman, A; Rühli, F; Gilbert, M T P; Collins, M J

    2014-11-27

    Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker leading up to the abandonment of the Norse Greenland colonies in the 15(th) century CE.

  16. Development of a physiologically based pharmacokinetic model for assessment of human exposure to bisphenol A

    International Nuclear Information System (INIS)

    Yang, Xiaoxia; Doerge, Daniel R.; Teeguarden, Justin G.; Fisher, Jeffrey W.

    2015-01-01

    A previously developed physiologically based pharmacokinetic (PBPK) model for bisphenol A (BPA) in adult rhesus monkeys was modified to characterize the pharmacokinetics of BPA and its phase II conjugates in adult humans following oral ingestion. Coupled with in vitro studies on BPA metabolism in the liver and the small intestine, the PBPK model was parameterized using oral pharmacokinetic data with deuterated-BPA (d 6 -BPA) delivered in cookies to adult humans after overnight fasting. The availability of the serum concentration time course of unconjugated d 6 -BPA offered direct empirical evidence for the calibration of BPA model parameters. The recalibrated PBPK adult human model for BPA was then evaluated against published human pharmacokinetic studies with BPA. A hypothesis of decreased oral uptake was needed to account for the reduced peak levels observed in adult humans, where d 6 -BPA was delivered in soup and food was provided prior to BPA ingestion, suggesting the potential impact of dosing vehicles and/or fasting on BPA disposition. With the incorporation of Monte Carlo analysis, the recalibrated adult human model was used to address the inter-individual variability in the internal dose metrics of BPA for the U.S. general population. Model-predicted peak BPA serum levels were in the range of pM, with 95% of human variability falling within an order of magnitude. This recalibrated PBPK model for BPA in adult humans provides a scientific basis for assessing human exposure to BPA that can serve to minimize uncertainties incurred during extrapolations across doses and species. - Highlights: • A PBPK model predicts the kinetics of bisphenol A (BPA) in adult humans. • Serum concentrations of aglycone BPA are available for model calibration. • Model predicted peak BPA serum levels for adult humans were in the range of pM. • Model predicted 95% of human variability fell within an order of magnitude.

  17. Development of a physiologically based pharmacokinetic model for assessment of human exposure to bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaoxia, E-mail: xiaoxia.yang@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Doerge, Daniel R. [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States); Teeguarden, Justin G. [Health Effects and Exposure Science, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Fisher, Jeffrey W. [Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079 (United States)

    2015-12-15

    A previously developed physiologically based pharmacokinetic (PBPK) model for bisphenol A (BPA) in adult rhesus monkeys was modified to characterize the pharmacokinetics of BPA and its phase II conjugates in adult humans following oral ingestion. Coupled with in vitro studies on BPA metabolism in the liver and the small intestine, the PBPK model was parameterized using oral pharmacokinetic data with deuterated-BPA (d{sub 6}-BPA) delivered in cookies to adult humans after overnight fasting. The availability of the serum concentration time course of unconjugated d{sub 6}-BPA offered direct empirical evidence for the calibration of BPA model parameters. The recalibrated PBPK adult human model for BPA was then evaluated against published human pharmacokinetic studies with BPA. A hypothesis of decreased oral uptake was needed to account for the reduced peak levels observed in adult humans, where d{sub 6}-BPA was delivered in soup and food was provided prior to BPA ingestion, suggesting the potential impact of dosing vehicles and/or fasting on BPA disposition. With the incorporation of Monte Carlo analysis, the recalibrated adult human model was used to address the inter-individual variability in the internal dose metrics of BPA for the U.S. general population. Model-predicted peak BPA serum levels were in the range of pM, with 95% of human variability falling within an order of magnitude. This recalibrated PBPK model for BPA in adult humans provides a scientific basis for assessing human exposure to BPA that can serve to minimize uncertainties incurred during extrapolations across doses and species. - Highlights: • A PBPK model predicts the kinetics of bisphenol A (BPA) in adult humans. • Serum concentrations of aglycone BPA are available for model calibration. • Model predicted peak BPA serum levels for adult humans were in the range of pM. • Model predicted 95% of human variability fell within an order of magnitude.

  18. Earliest directly-dated human skull-cups.

    Directory of Open Access Journals (Sweden)

    Silvia M Bello

    Full Text Available BACKGROUND: The use of human braincases as drinking cups and containers has extensive historic and ethnographic documentation, but archaeological examples are extremely rare. In the Upper Palaeolithic of western Europe, cut-marked and broken human bones are widespread in the Magdalenian (∼15 to 12,000 years BP and skull-cup preparation is an element of this tradition. PRINCIPAL FINDINGS: Here we describe the post-mortem processing of human heads at the Upper Palaeolithic site of Gough's Cave (Somerset, England and identify a range of modifications associated with the production of skull-cups. New analyses of human remains from Gough's Cave demonstrate the skilled post-mortem manipulation of human bodies. Results of the research suggest the processing of cadavers for the consumption of body tissues (bone marrow, accompanied by meticulous shaping of cranial vaults. The distribution of cut-marks and percussion features indicates that the skulls were scrupulously 'cleaned' of any soft tissues, and subsequently modified by controlled removal of the facial region and breakage of the cranial base along a sub-horizontal plane. The vaults were also 'retouched', possibly to make the broken edges more regular. This manipulation suggests the shaping of skulls to produce skull-cups. CONCLUSIONS: Three skull-cups have been identified amongst the human bones from Gough's Cave. New ultrafiltered radiocarbon determinations provide direct dates of about 14,700 cal BP, making these the oldest directly dated skull-cups and the only examples known from the British Isles.

  19. Micronucleus formation in cultured human keratinocytes following exposure to mitomycin C and cyclophosphamide.

    Science.gov (United States)

    van Pelt, F N; Haring, R M; Overkamp, M J; Weterings, P J

    1991-02-01

    A method is described to investigate the induction of micronuclei in cultured human keratinocytes after short-term exposure to known clastogenic agents. The cytokinesis-block method was applied to facilitate the scoring of micronucleated cells. Mitomycin C, a direct-acting compound, caused a 5-20-fold increase in micronuclei over the controls at the highest concentration tested (1 microgram/ml). Cyclophosphamide, an agent requiring metabolic activation, did not induce the formation of micronuclei in cultured keratinocytes. However, after pretreatment of the keratinocyte cultures with Aroclor 1254 for 72 h, exposure to cyclophosphamide resulted in a 3-fold increase in micronucleus frequency over the controls. No cytogenetic effect of Aroclor 1254 was observed in control experiments.

  20. Direct media exposure of MEMS multi-sensor systems using a potted-tube packaging concept

    DEFF Research Database (Denmark)

    Hyldgård, Anders; Birkelund, Karen; Janting, Jakob

    2008-01-01

    in the filling material is measured. The packaging concept is used to encapsulate a microfabricated multi-sensor (measuring temperature, water conductivity, pressure and light intensity). The direct exposure of the sensors results in high sensitivity and fast response time. The design of an elongated multi-sensor......A packaging concept for Data Storage Tags is presented. A potted-tube packaging concept, using a polystyrene tube and different epoxies as filling material that allows for direct sensor exposure is investigated. The curing temperature, water uptake and the diffusion coefficient for water...... is described and effectiveness of the packaging is demonstrated with the precise measurement of water conductivity using the packaged multi-sensor. The packaging concept is very promising for high accuracy measurements in harsh environments....

  1. Using Information on Exposure to Characterizing Risks to Human Health from Concurrent Exposures to Multiple Chemicals

    NARCIS (Netherlands)

    Mr Price, PSP

    2012-01-01

    This thesis explores the concept of using exposure information to understand, organize, and manage the risks associated with cumulative exposures to chemicals (exposures to multiple chemicals from multiple sources). The issue of cumulative exposures was identified in more than 30 years ago, but in

  2. Estimating the human exposure to chemical substances and radiation. Definition report

    International Nuclear Information System (INIS)

    Vermeire, T.G.; Van Veen, M.P.

    1995-06-01

    This report aims at boosting the human exposure assessment activities of the RIVM with regard to chemical substances and radiation. It is the result of thorough discussions with RIVM-experts. The report starts with an overview of past developments in the area of human exposure assessment at the RIVM and continues describing recent projects. Major developments outside the Institute are also discussed. An attempt is made to harmonize definitions which are relevant for exposure assessment, i.e. definitions on exposure, intake, uptake and dose. Important gaps in the human exposure assessment work at the RIVM are identified, leading to proposals for future work. 2 figs., 31 refs., 3 appendices

  3. The recovery of the human organism after radiation exposure

    International Nuclear Information System (INIS)

    Gerber, G.B.

    1976-01-01

    The repair of radiation damage in the human organism is reviewed. A distinction is made between the single repair steps, first the molecular repair of sublethal damage during the periods of 30 min to 2 h and several days to months, second the substitution of the whole cells during a period of reproduction which is specific for the kind and persistence of the cells. One example is the radiosensitive stem cell with a reproduction rate of 40% and a redoublication time of 10 d at 100 rads and the very low reproduction rate of 1% with redoublication time of 7 d after a dose of 400 rads. 5 rads seems to be acceptable for systems with recovery and repeated exposure, single doses normally should not exceed 25 rads, not 100 rads/d for to save human life, and not a total dose of 500 rads. About 20% of irradiation damage is not repaired and leads to late effects, for example the induction of tumors, the shortening of life span and an increase in embryonic mortality. The author recommends the acceptance of a radiation dose leading to 20 additional cases of leucemia in the whole population of Germany and an increase of tumor frequency of 1%. The shortening of life span should not exceed 0,5%. The equivalent residual dose (ERD) can be calculated by the following equation: ERD = last effective dose minus 5 rads x number of days. (AJ) [de

  4. Do gender and directness of trauma exposure moderate PTSD's latent structure?

    Science.gov (United States)

    Frankfurt, Sheila B; Armour, Cherie; Contractor, Ateka A; Elhai, Jon D

    2016-11-30

    The PTSD diagnosis and latent structure were substantially revised in the transition from DSM-IV to DSM-5. However, three alternative models (i.e., anhedonia model, externalizing behavior model, and hybrid model) of PTSD fit the DSM-5 symptom criteria better than the DSM-5 factor model. Thus, the psychometric performance of the DSM-5 and alternative models' PTSD factor structure needs to be critically evaluated. The current study examined whether gender or trauma directness (i.e., direct or indirect trauma exposure) moderates the PTSD latent structure when using the DSM-5 or alternative models. Model performance was evaluated with measurement invariance testing procedures on a large undergraduate sample (n=455). Gender and trauma directness moderated the DSM-5 PTSD and externalizing behavior model and did not moderate the anhedonia and hybrid models' latent structure. Clinical implications and directions for future research are discussed. Published by Elsevier Ireland Ltd.

  5. Directional and balancing selection in human beta-defensins

    Directory of Open Access Journals (Sweden)

    Armour John AL

    2008-04-01

    Full Text Available Abstract Background In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. Results We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93, is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Conclusion Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.

  6. Directional and balancing selection in human beta-defensins.

    Science.gov (United States)

    Hollox, Edward J; Armour, John A L

    2008-04-16

    In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93), is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.

  7. Exhaled human breath measurement method for assessing exposure to halogenated volatile organic compounds.

    Science.gov (United States)

    Pleil, J D; Lindstrom, A B

    1997-05-01

    The organic constituents of exhaled human breath are representative of blood-borne concentrations through gas exchange in the blood/breath interface in the lungs. The presence of specific compounds can be an indicator of recent exposure or represent a biological response of the subject. For volatile organic compounds (VOCs), sampling and analysis of breath is preferred to direct measurement from blood samples because breath collection is noninvasive, potentially infectious waste is avoided, and the measurement of gas-phase analytes is much simpler in a gas matrix rather than in a complex biological tissue such as blood. To exploit these advantages, we have developed the "single breath canister" (SBC) technique, a simple direct collection method for individual alveolar breath samples, and adapted conventional gas chromatography-mass spectrometry analytical methods for trace-concentration VOC analysis. The focus of this paper is to describe briefly the techniques for making VOC measurements in breath, to present some specific applications for which these methods are relevant, and to demonstrate how to estimate exposure to example VOCs on the basis of breath elimination. We present data from three different exposure scenarios: (a) vinyl chloride and cis-1,2-dichloroethene from showering with contaminated water from a private well, (b) chloroform and bromodichloromethane from high-intensity swimming in chlorinated pool water, and (c) trichloroethene from a controlled exposure chamber experiment. In all cases, for all subjects, the experiment is the same: preexposure breath measurement, exposure to halogenated VOC, and a postexposure time-dependent series of breath measurements. Data are presented only to demonstrate the use of the method and how to interpret the analytical results.

  8. Human exposure to piroplasms in Central and Northern Italy

    Directory of Open Access Journals (Sweden)

    Simona Gabrielli

    2014-03-01

    Full Text Available A serosurvey has been conducted in Northern and Central Italy to investigate the presence in humans of antibodies against zoonotic Babesia and Theileria species. The study focused on a total of 432 volunteers, of which 290 were persistently exposed to tick bites because of their jobs (forester employees, livestock keepers, veterinary practitioners, farmers and hunters and 142 resident in the same area less frequently exposed. An indirect fluorescent antibody test (IFAT for humans was used to detect antibodies to Babesia microti, IFAT tests for veterinary use were modified to detect reactivity to Babesia bovis, Babesia canis and Theileria equi. A laboratory-derived ELISA was employed to detect antibodies to Babesia divergens. Both reactive and 10 negative sera were analysed against plasmodial antigens to evaluate possible aspecificity. A high reactivity to piroplasm antigens was found, showing significant difference between the sera of the two groups of volunteers (24% vs 7.0%; p<0.001. No cross-reactivity was observed, while each professional group showed reactivity that would fit with the professional risk exposure. In particular, a high reactivity to B. microti and B. divergens antigens was observed in foresters and hunters (32% and 12%, respectively. This is the first report on the human seroreactivity to piroplasms in Italy; it also provides additional epidemiological information on these tick-borne zoonoses in Europe. Our findings suggest the possible occurrence of piroplasm infections in Italy and alert physicians to consider these otherwise neglected parasitic diseases when dealing with any febrile illness, especially in subjects exposed to tick bites.

  9. The prediction of human exposure to substances and radiation. The status of RIVM research

    International Nuclear Information System (INIS)

    Vermeire, T.; Veeren, M. van; Janssen, M.

    1998-03-01

    In 1994, the substances and risks sector of the National Institute of Public Health and the Environment (RIVM) decided to strengthen its research into risk assessment methodology strategically. To further this goal, this report describes the area of RIVM research dealing with the prediction of human exposure. A representative selection of the models used to predict human exposure to both chemical substances and radiation is analysed. The analysis considers aspects of the models such as the aims, basic principles, the extent to which the models have been analysed and values of default parameters. For comparison purposes, a model used to assess human exposure to micro-organisms is also included. All models are being, or are about to be, used operationally to produce risk assessments in the substances and risks sector and also in the public health and environmental research sectors. All the models discussed have a defined area of application and are directly available in support of policy implementation. Comparison of areas of research dealing with exposure assessment for substances and radiation reveals many methodological similarities. However, at the level of models and parameters, an in-depth analysis of these similarities and explained or unexplained differences is lacking. A first attempt is made in this report. Detailed examination of organisational aspects and RIVM-models for human exposure prediction reveals that all relevant areas of interest are covered. The range of methodology for the prediction of actual risks and exposures is great, for all exposure routes. The coverage is more uniform for radiation than for chemical substances, however. For both areas the prediction and recording of emissions could be improved. The development of risk assessment systems and related harmonisation projects have been underway for many years (for example CSOIL, USES, RIBRON). The methodology for the prediction of actual exposures and risks still requires further

  10. Human Mercury Exposure in Yanomami Indigenous Villages from the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Claudia M. Vega

    2018-05-01

    Full Text Available In the Brazilian Amazon, where the majority of Yanomami villages are settled, mercury (Hg exposure due to artisanal small-scale gold mining (ASGM has been reported since the 1980s. This study assessed mercury exposure in the Yanomami reserve and whether the level of contamination was related to the ASGM geographical location. It was conducted using a cross-sectional study of 19 villages. Direct interviews were performed and hair samples were used as a bioindicator of Hg exposure. The Prevalence-Ratio (PR was estimated as an indicator of association between ASGM geographical locations and human exposure to mercury. Mercury levels (239 hair samples ranged between 0.4 and 22.1 μg·g−1 and presented substantial differences amongst the villages. In the Waikas-Aracaça region, where current ASGM was reported, we observed the highest Hg concentrations (median = 15.5 μg·g−1. Almost all participants presented with hair-Hg levels >6 μg·g−1 (prevalence = 92.3%. In the Paapiu region, we observed the lowest concentrations (median = 3.2 μg·g−1; prevalence = 6.7%. Our findings showed that the Waikas Ye’kuana and Waikas Aracaca villages presented with 4.4 (PR = 4.4; Confidence Interval (CI 95% = 2.2–9.0 and 14.0 (PR = 14.0; CI 95% = 7.9–24.9 times higher prevalence of hair-Hg concentration, respectively, compared with Paapiu. Considering seasonal variation of Hg-exposure, the lowest concentrations were observed during the wet season (June–September and the highest in the dry season (December–April. Our study suggests that there is an association between mercury exposure and ASGM geographical locations.

  11. Human Mercury Exposure in Yanomami Indigenous Villages from the Brazilian Amazon.

    Science.gov (United States)

    Vega, Claudia M; Orellana, Jesem D Y; Oliveira, Marcos W; Hacon, Sandra S; Basta, Paulo C

    2018-05-23

    In the Brazilian Amazon, where the majority of Yanomami villages are settled, mercury (Hg) exposure due to artisanal small-scale gold mining (ASGM) has been reported since the 1980s. This study assessed mercury exposure in the Yanomami reserve and whether the level of contamination was related to the ASGM geographical location. It was conducted using a cross-sectional study of 19 villages. Direct interviews were performed and hair samples were used as a bioindicator of Hg exposure. The Prevalence-Ratio (PR) was estimated as an indicator of association between ASGM geographical locations and human exposure to mercury. Mercury levels (239 hair samples) ranged between 0.4 and 22.1 μg·g -1 and presented substantial differences amongst the villages. In the Waikas-Aracaça region, where current ASGM was reported, we observed the highest Hg concentrations (median = 15.5 μg·g -1 ). Almost all participants presented with hair-Hg levels >6 μg·g -1 (prevalence = 92.3%). In the Paapiu region, we observed the lowest concentrations (median = 3.2 μg·g -1 ; prevalence = 6.7%). Our findings showed that the Waikas Ye'kuana and Waikas Aracaca villages presented with 4.4 (PR = 4.4; Confidence Interval (CI) 95% = 2.2⁻9.0) and 14.0 (PR = 14.0; CI 95% = 7.9⁻24.9) times higher prevalence of hair-Hg concentration, respectively, compared with Paapiu. Considering seasonal variation of Hg-exposure, the lowest concentrations were observed during the wet season (June⁻September) and the highest in the dry season (December⁻April). Our study suggests that there is an association between mercury exposure and ASGM geographical locations.

  12. Direct-to-consumer television advertising exposure, diagnosis with high cholesterol, and statin use.

    Science.gov (United States)

    Niederdeppe, Jeff; Byrne, Sahara; Avery, Rosemary J; Cantor, Jonathan

    2013-07-01

    While statin drugs are recommended for secondary prevention of coronary heart disease (CHD), there is no medical consensus on whether or not a statin should be added to lifestyle change efforts for primary prevention of CHD. Previous research suggests that exposure to direct-to-consumer advertising (DTCA) increases drug demand among those at comparatively low risk. Research has yet to examine whether individual-level DTCA exposure may influence statin use among men and women at high, moderate, or low risk for future cardiac events. To determine the relationship between estimated exposure to DTCA for statin drugs and two clinical variables: diagnosis with high cholesterol and statin use. We used logistic regression to analyze repeated cross-sectional surveys of the United States population, merged with data on the frequency of DTCA appearances on national, cable, and local television, between 2001 and 2007. American adults (n=106,685) aged 18 and older. Levels of exposure to statin DTCA, based on ad appearances and TV viewing patterns; self-reports of whether or not a respondent has been diagnosed with high cholesterol, and whether or not a respondent took a statin in the past year. Adjusting for potential confounders, we estimate that exposure to statin ads increased the odds of being diagnosed with high cholesterol by 16 to 20 %, and increased statin use by 16 to 22 %, among both men and women (p<0.05). These associations were driven almost exclusively by men and women at low risk for future cardiac events. There was also evidence of a negative association between DTCA exposure and statin use among high-risk women (p<0.05) CONCLUSIONS: This study provides new evidence that DTCA may promote over-diagnosis of high cholesterol and over-treatment for populations where risks of statin use may outweigh potential benefits.

  13. Direct pulp capping after a carious exposure versus root canal treatment: a cost-effectiveness analysis.

    Science.gov (United States)

    Schwendicke, Falk; Stolpe, Michael

    2014-11-01

    Excavation of deep caries often leads to pulpal exposure even in teeth with sensible, nonsymptomatic pulps. Although direct pulp capping (DPC) aims to maintain pulpal health, it frequently requires follow-up treatments like root canal treatment (RCT), which could have been performed immediately after the exposure, with possibly improved outcomes. We quantified and compared the long-term cost-effectiveness of both strategies. A Markov model was constructed following a molar with an occlusally located exposure of a sensible, nonsymptomatic pulp in a 20-year-old male patient over his lifetime. Transition probabilities or hazard functions were estimated based on systematically and nonsystematically assessed literature. Costs were estimated based on German health care, and cost-effectiveness was analyzed using Monte Carlo microsimulations. Despite requiring follow-up treatments significantly earlier, teeth treated by DPC were retained for long periods of time (52 years) at significantly reduced lifetime costs (545 vs 701 Euro) compared with teeth treated by RCT. For teeth with proximal instead of occlusal exposures or teeth in patients >50 years of age, this cost-effectiveness ranking was reversed. Although sensitivity analyses found substantial uncertainty regarding the effectiveness of both strategies, DPC was usually found to be less costly than RCT. We found both DPC and RCT suitable to treat exposed vital, nonsymptomatic pulps. DPC was more cost-effective in younger patients and for occlusal exposure sites, whereas RCT was more effective in older patients or teeth with proximal exposures. These findings might change depending on the health care system and underlying literature-based probabilities. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. ASSESSING HUMAN EXPOSURE TO GRASS POLLEN IN DENMARK

    DEFF Research Database (Denmark)

    Peel, Robert George; Hertel, Ole; Herbert, Rob

    Objectives: Exposure to pollen is typically assessed using data collected at fixed roof-top monitoring stations, which give a general picture of airborne pollen concentrations over a wide region. Actual exposure levels can be obtained through personal exposure monitoring. This is typically done u...

  15. Negative Effects of High Glucose Exposure in Human Gonadotropin-Releasing Hormone Neurons

    Directory of Open Access Journals (Sweden)

    Annamaria Morelli

    2013-01-01

    Full Text Available Metabolic disorders are often associated with male hypogonadotropic hypogonadism, suggesting that hypothalamic defects involving GnRH neurons may impair the reproductive function. Among metabolic factors hyperglycemia has been implicated in the control of the reproductive axis at central level, both in humans and in animal models. To date, little is known about the direct effects of pathological high glucose concentrations on human GnRH neurons. In this study, we investigated the high glucose effects in the human GnRH-secreting FNC-B4 cells. Gene expression profiling by qRT-PCR, confirmed that FNC-B4 cells express GnRH and several genes relevant for GnRH neuron function (KISS1R, KISS1, sex steroid and leptin receptors, FGFR1, neuropilin 2, and semaphorins, along with glucose transporters (GLUT1, GLUT3, and GLUT4. High glucose exposure (22 mM; 40 mM significantly reduced gene and protein expression of GnRH, KISS1R, KISS1, and leptin receptor, as compared to normal glucose (5 mM. Consistent with previous studies, leptin treatment significantly induced GnRH mRNA expression at 5 mM glucose, but not in the presence of high glucose concentrations. In conclusion, our findings demonstrate a deleterious direct contribution of high glucose on human GnRH neurons, thus providing new insights into pathogenic mechanisms linking metabolic disorders to reproductive dysfunctions.

  16. Dynamic exposure model analysis of continuous laser direct writing in Polar-coordinate

    Science.gov (United States)

    Zhang, Shan; Lv, Yingjun; Mao, Wenjie

    2018-01-01

    In order to exactly predict the continuous laser direct writing quality in Polar-coordinate, we take into consideration the effect of the photoresist absorbing beam energy, the Gaussian attribute of the writing beam and the dynamic exposure process, and establish a dynamic exposure model to describe the influence of the tangential velocity of the normal incident facular center and laser power on the line width and sidewall angle. Numerical simulation results indicate that while writing velocity remains unchanged, the line width and sidewall angle are all increased as the laser power increases; while laser power remains unchanged, the line width and sidewall angle are all decreased as the writing velocity increases; at the same time the line profile in the exposure section is asymmetry and the center of the line has tiny excursion toward the Polar-coordinate origin compared with the facular center. Then it is necessary to choose the right writing velocity and laser power to obtain the ideal line profile. The model makes up the shortcomings of traditional models that can only predict line width or estimate the profile of the writing line in the absence of photoresist absorption, and can be considered as an effect analysis method for optimizing the parameters of fabrication technique of laser direct writing.

  17. Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets.

    Science.gov (United States)

    Pantelic, J; Tham, K W; Licina, D

    2015-12-01

    The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal manikin at distances between 1 and 4 m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced the inhalation intake fraction compared to mixing ventilation for all investigated distances and orientations of the cough release. The results point out that the orientation between the cough source and the breathing zone of the exposed occupant is an important factor that substantially influences exposure. Exposure to cough droplets was reduced with increasing distance between cough source and exposed occupant. The results from this study show that an advanced air distribution system such as personalized ventilation reduces exposure to cough-released droplets better than commonly applied overhead mixing ventilation. This work can inform HVAC engineers about different aspects of air distribution systems’ performance and can serve as an aid in making critical design decisions. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. A changing climate: impacts on human exposures to O3 using an integrated modeling methodology

    Science.gov (United States)

    Predicting the impacts of changing climate on human exposure to air pollution requires future scenarios that account for changes in ambient pollutant concentrations, population sizes and distributions, and housing stocks. An integrated methodology to model changes in human exposu...

  19. Abundant Rodent Furan-Derived Urinary Metabolites Are Associated with Tobacco Smoke Exposure in Humans.

    Science.gov (United States)

    Grill, Alex E; Schmitt, Thaddeus; Gates, Leah A; Lu, Ding; Bandyopadhyay, Dipankar; Yuan, Jian-Min; Murphy, Sharon E; Peterson, Lisa A

    2015-07-20

    Furan, a possible human carcinogen, is found in heat treated foods and tobacco smoke. Previous studies have shown that humans are capable of converting furan to its reactive metabolite, cis-2-butene-1,4-dial (BDA), and therefore may be susceptible to furan toxicity. Human risk assessment of furan exposure has been stymied because of the lack of mechanism-based exposure biomarkers. Therefore, a sensitive LC-MS/MS assay for six furan metabolites was applied to measure their levels in urine from furan-exposed rodents as well as in human urine from smokers and nonsmokers. The metabolites that result from direct reaction of BDA with lysine (BDA-N(α)-acetyllysine) and from cysteine-BDA-lysine cross-links (N-acetylcysteine-BDA-lysine, N-acetylcysteine-BDA-N(α)-acetyllysine, and their sulfoxides) were targeted in this study. Five of the six metabolites were identified in urine from rodents treated with furan by gavage. BDA-N(α)-acetyllysine, N-acetylcysteine-BDA-lysine, and its sulfoxide were detected in most human urine samples from three different groups. The levels of N-acetylcysteine-BDA-lysine sulfoxide were more than 10 times higher than that of the corresponding sulfide in many samples. The amount of this metabolite was higher in smokers relative to that in nonsmokers and was significantly reduced following smoking cessation. Our results indicate a strong relationship between BDA-derived metabolites and smoking. Future studies will determine if levels of these biomarkers are associated with adverse health effects in humans.

  20. Association of direct exposure to terrorism, media exposure to terrorism, and other trauma with emotional and behavioral problems in preschool children.

    Science.gov (United States)

    Wang, Yanping; Nomura, Yoko; Pat-Horenczyk, Ruth; Doppelt, Osnat; Abramovitz, Robert; Brom, Daniel; Chemtob, Claude

    2006-12-01

    This study examined the differential impact of various types of trauma exposure on emotional and behavioral problems in preschool children. Participants were 95 mothers of 1- to 4-year-old children in Israel. Results suggested a differential pattern of associations between the types of trauma exposure (i.e., direct exposure to terrorism, media exposure to terrorism, and other trauma) and children's internalizing and externalizing problems. This line of research is important for the identification of risk factors and the development of effective prevention and intervention strategies to promote resilience in preschool children exposed to specific type(s) of trauma.

  1. Human exposure to polybrominated diphenyl ethers at production area, China.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian

    2010-05-01

    The concentrations of polybrominated diphenyl ethers (PBDEs) were detected in air and aquatic products in PBDEs production areas which are located at the south coast area of Laizhou Bay, Shandong province, China in this study. Concentrations of SigmaPBDEs in the air ranged from 0.47 ng/m3 to 161 ng/m3. In aquatic products, concentrations of SigmaPBDEs ranged from 2.7 ng/g wet weight to 42 ng/g wet weight. The mean dietary intake of SigmaPBDEs via aquatic products consumption in this study was 218 ng/day. Daily intake of SigmaPBDEs via inhalation in this study was 612 ng for men and 455 ng for women. With a contribution of 80%, BDE-209 was predominant in the total intake. Dietary intake and breathing inhalation contributed 29 and 71%, respectively, to the total PBDEs intake. The results indicate that breathing inhalation also plays a very significant pathway for the population of the PBDEs production area. Compared with similar studies in other countries, human exposure to PBDEs via diet and inhalation in this study was the highest in the world. Copyright (c) 2010 SETAC.

  2. Foreign Direct Investments and Human Capital Development in Subsaharan Africa

    Directory of Open Access Journals (Sweden)

    Luc NEMBOT NDEFFO

    2010-12-01

    Full Text Available The objective of the present study is to estimate the impact of foreign direct investments on human capital development in 32 Subsaharan African countries over the period 1980 – 2005. Human capital is captured by the percentage of children in full-time education in primary and secondary schools. Panel data regressions are used for the estimations. The results show a correlation not only between FDI and the percentage of children in full-time education in primary school but also between the FDI and the percentage of children in full-time education in secondary school. These results are not significant for that. This shows that FDI directed towards Sub-Saharan Africa still remain insufficient. That is why a lot of effort should be made in order to favour the attraction of FDI in this part of the continent. The other variables which have a positive and significant impact on the percentage of children in full-time education are: the domestic investment rate, public sector expenditures, life expectancy at birth and the growth rate of the gross domestic product per capita.

  3. Human platelet vasopressin receptor identification by direct ultraviolet photoaffinity labeling

    International Nuclear Information System (INIS)

    Thibonnier, M.

    1987-01-01

    Tritiated vasopressin ([ 3 H]AVP) was directly crosslinked to its human platelet receptor by using an ultraviolet irradiation procedure. After preincubation with [ 3 H]AVP, the hydrodynamic parameters of the hormone-receptor complexes solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate were derived from Sephacryl S-300 superfine gel filtration and from sucrose density gradient ultracentrifugation experiments. The following values were obtained: Stoke's radius = 5.48 +/- 0.1 nm, apparent sedimentation coefficient = 5.55 +/- 0.1 S, and calculated molecular weight = 132,000. On sodium dodecyl sulfate-8% polyacrylamide slab gel electrophoresis under reducing conditions, [ 3 H]AVP preferentially and specifically labeled a 125,000-dalton protein. The labeling of this protein was suppressed by addition of excess cold vasopressin, whereas angiotensin II did not inhibit incorporation of tritiated vasopressin in this protein. These results suggest that direct UV-photoaffinity labelling with [ 3 H]AVP is a suitable tool for the purification of the human platelet vasopressin receptor

  4. Directional asymmetries in human smooth pursuit eye movements.

    Science.gov (United States)

    Ke, Sally R; Lam, Jessica; Pai, Dinesh K; Spering, Miriam

    2013-06-27

    Humans make smooth pursuit eye movements to bring the image of a moving object onto the fovea. Although pursuit accuracy is critical to prevent motion blur, the eye often falls behind the target. Previous studies suggest that pursuit accuracy differs between motion directions. Here, we systematically assess asymmetries in smooth pursuit. In experiment 1, binocular eye movements were recorded while observers (n = 20) tracked a small spot of light moving along one of four cardinal or diagonal axes across a featureless background. We analyzed pursuit latency, acceleration, peak velocity, gain, and catch-up saccade latency, number, and amplitude. In experiment 2 (n = 22), we examined the effects of spatial location and constrained stimulus motion within the upper or lower visual field. Pursuit was significantly faster (higher acceleration, peak velocity, and gain) and smoother (fewer and later catch-up saccades) in response to downward versus upward motion in both the upper and the lower visual fields. Pursuit was also more accurate and smoother in response to horizontal versus vertical motion. CONCLUSIONS. Our study is the first to report a consistent up-down asymmetry in human adults, regardless of visual field. Our findings suggest that pursuit asymmetries are adaptive responses to the requirements of the visual context: preferred motion directions (horizontal and downward) are more critical to our survival than nonpreferred ones.

  5. Human recreational exposure to antibiotic resistant bacteria in coastal bathing waters.

    Science.gov (United States)

    Leonard, Anne F C; Zhang, Lihong; Balfour, Andrew J; Garside, Ruth; Gaze, William H

    2015-09-01

    Infections caused by antibiotic resistant bacteria (ARB) are associated with poor health outcomes and are recognised globally as a serious health problem. Much research has been conducted on the transmission of ARB to humans. Yet the role the natural environment plays in the spread of ARB and antibiotic resistance genes is not well understood. Antibiotic resistant bacteria have been detected in natural aquatic environments, and ingestion of seawater during water sports is one route by which many people could be directly exposed. The aim was to estimate the prevalence of resistance to one clinically important class of antibiotics (third-generation cephalosporins (3GCs)) amongst Escherichia coli in coastal surface waters in England and Wales. Prevalence data was used to quantify ingestion of 3GC-resistant E. coli (3GCREC) by people participating in water sports in designated coastal bathing waters. A further aim was to use this value to derive a population-level estimate of exposure to these bacteria during recreational use of coastal waters in 2012. The prevalence of 3GC-resistance amongst E. coli isolated from coastal surface waters was estimated using culture-based methods. This was combined with the density of E. coli reported in designated coastal bathing waters along with estimations of the volumes of water ingested during various water sports reported in the literature to calculate the mean number of 3GCREC ingested during different water sports. 0.12% of E. coli isolated from surface waters were resistant to 3GCs. This value was used to estimate that in England and Wales over 6.3 million water sport sessions occurred in 2012 that resulted in the ingestion of at least one 3GCREC. Despite the low prevalence of resistance to 3GCs amongst E. coli in surface waters, there is an identifiable human exposure risk for water users, which varies with the type of water sport undertaken. The relative importance of this exposure is likely to be greater in areas where a

  6. Mere exposure effect: A consequence of direct and indirect fluency-preference links.

    Science.gov (United States)

    Willems, Sylvie; Van der Linden, Martial

    2006-06-01

    In three experiments, picture quality between test items was manipulated to examine whether subjects' expectations about the fluency normally associated with these different stimuli might influence the effects of fluency on preference or familiarity-based recognition responses. The results showed that fluency due to pre-exposure influenced responses less when objects were presented with high picture quality, suggesting that attributions of fluency to preference and familiarity are adjusted according to expectations about the different test pictures. However, this expectations influence depended on subjects' awareness of these different quality levels. Indeed, imperceptible differences seemed not to induce expectations about the test item fluency. In this context, fluency due to both picture quality and pre-exposure influenced direct responses. Conversely, obvious, and noticed, differences in test picture quality did no affect responses, suggesting that expectations moderated attributions of fluency only when fluency normally associated with these different stimuli was perceptible but difficult to assess.

  7. Sleep-dependent directional coupling between human neocortex and hippocampus.

    Science.gov (United States)

    Wagner, Tobias; Axmacher, Nikolai; Lehnertz, Klaus; Elger, Christian E; Fell, Jürgen

    2010-02-01

    Complex interactions between neocortex and hippocampus are the neural basis of memory formation. Two-step theories of memory formation suggest that initial encoding of novel information depends on the induction of rapid plasticity within the hippocampus, and is followed by a second sleep-dependent step of memory consolidation. These theories predict information flow from the neocortex into the hippocampus during waking state and in the reverse direction during sleep. However, experimental evidence that interactions between hippocampus and neocortex have a predominant direction which reverses during sleep rely on cross-correlation analysis of data from animal experiments and yielded inconsistent results. Here, we investigated directional coupling in intracranial EEG data from human subjects using a phase-modeling approach which is well suited to reveal functional interdependencies in oscillatory data. In general, we observed that the anterior hippocampus predominantly drives nearby and remote brain regions. Surprisingly, however, the influence of neocortical regions on the hippocampus significantly increased during sleep as compared to waking state. These results question the standard model of hippocampal-neocortical interactions and suggest that sleep-dependent consolidation is accomplished by an active retrieval of hippocampal information by the neocortex. Copyright 2009 Elsevier Srl. All rights reserved.

  8. Computational Strategy for Quantifying Human Pesticide Exposure based upon a Saliva Measurement

    Directory of Open Access Journals (Sweden)

    Charles eTimchalk

    2015-05-01

    Full Text Available Quantitative exposure data is important for evaluating toxicity risk and biomonitoring is a critical tool for evaluating human exposure. Direct personal monitoring provides the most accurate estimation of a subject’s true dose, and non-invasive methods are advocated for quantifying exposure to xenobiotics. In this regard, there is a need to identify chemicals that are cleared in saliva at concentrations that can be quantified to support the implementation of this approach. This manuscript reviews the computational modeling approaches that are coupled to in vivo and in vitro experiments to predict salivary uptake and clearance of xenobiotics and provides additional insight on species-dependent differences in partitioning that are of key importance for extrapolation. The primary mechanism by which xenobiotics leave the blood and enter saliva involves paracellular transport, passive transcellular diffusion, or trancellular active transport with the majority of xenobiotics transferred by passive diffusion. The transcellular or paracellular diffusion of unbound chemicals in plasma to saliva has been computationally modeled using compartmental and physiologically based approaches. Of key importance for determining the plasma:saliva partitioning was the utilization of the Schmitt algorithm that calculates partitioning based upon the tissue composition, pH, chemical pKa and plasma protein-binding. Sensitivity analysis identified that both protein-binding and pKa (for weak acids and bases have significant impact on determining partitioning and species dependent differences based upon physiological variance. Future strategies are focused on an in vitro salivary acinar cell based system to experimentally determine and computationally predict salivary gland uptake and clearance for xenobiotics. It is envisioned that a combination of salivary biomonitoring and computational modeling will enable the non-invasive measurement of chemical exposures in human

  9. HExpoChem: a systems biology resource to explore human exposure to chemicals

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Jacobsen, Ulrik Plesner; Kalhauge, Christian Gram

    2013-01-01

    of computational biology approaches are needed to assess the health risks of chemical exposure. Here we present HExpoChem, a tool based on environmental chemicals and their bioactivities on human proteins with the objective of aiding the qualitative exploration of human exposure to chemicals. The chemical...

  10. Exposure to perfluorinated compounds and human semen quality in Arctic and European populations

    DEFF Research Database (Denmark)

    Toft, G; Jönsson, B A G; Lindh, C H

    2012-01-01

    Perfluorinated compounds (PFCs) have been suspected to adversely affect human reproductive health. The aim of this study was to investigate the associations between PFC exposure and male semen quality.......Perfluorinated compounds (PFCs) have been suspected to adversely affect human reproductive health. The aim of this study was to investigate the associations between PFC exposure and male semen quality....

  11. Data sources and methods for ascertaining human exposure to drugs.

    Science.gov (United States)

    Jones, J K; Kennedy, D L

    Estimates of population exposure based on drug use data are critical elements in the post marketing surveillance of drugs and provide a context for assessing the various risks and benefits associated with drug treatment. Such information is important in predicting morbidity and planning public health protection strategies, indepth studies, and regulatory actions. Knowledge that a population of one thousand instead of one million may potentially be exposed to a drug can help determine how a particular regulatory problem will be handled and would obviously be a major determinant in designing a case-control or cohort study. National estimates of drug use give an overview of the most commonly used drug therapies in current practice. They also furnish valuable comparison data for specific studies of drug use limited to one group of drugs, one geographic region, or one medical care setting. The FDA has access to several different national drug use data bases, each measuring a different point in the drug distribution channels. None covers the entire spectrum of drug exposures. The major "holes" in this patchwork of data bases are the inability to measure OTC drug use with any accuracy and the lack of qualitative information on drug use in hospitals. In addition, there is no patient linkage with the data. The data can only show trends in drug use. They impart no sense of the longitudinal use of drugs for individual patients. There is no direct connection between the different data bases, all of which have their own sampling frames and their own projection methodologies. The market research companies have complete control over these methodologies and they are subject to periodic changes, a situation not entirely satisfactory for epidemiologic research. Sometimes it is a struggle to keep up with these changes. Over the past two years, every one of these data bases has undergone some type of sampling or projection methodology change. One important limitation to the use of all

  12. Quantitative analysis of untreated human nails for monitoring human exposure to heavy metals

    International Nuclear Information System (INIS)

    Sera, Koichiro; Futatsugawa, Shouji; Murao, Satoshi; Clemente, E.

    2002-01-01

    In order to address global environmental issues, a standard-free method developed by ourselves has been successfully applied to various kinds of bio-samples. Especially, a method for untreated hairs has been applied in many polluted areas to study human exposure to toxic elements. In addition to hair, nail is expected to give us valuable information about human exposure to toxic elements. However, the analysis requires relatively large amounts of samples and laborious sample preparation techniques which necessitate internal standards. In this work, we have developed a quantitative method for untreated human-nail analysis based on the standard-free method. It requires neither large amounts of nails nor complicated target preparation procedure. Furthermore, it is perfectly free from any ambiguity in target preparation such as volatilization of certain elements and contamination of the sample during chemical ashing. The optimum conditions of irradiating nail samples are established, and accuracy and reproducibility of the present method are confirmed. It is found that ultrasonic washing in distilled water is effective for many nail samples preventing the loss of elements from the sample. It is also found that elemental concentration in nails strongly depends on their sampling positions. (author)

  13. Cytogenetic adaptive response induced by pre-exposure in human lymphocytes and marrow cells of mice

    International Nuclear Information System (INIS)

    Zhang Lianzhen; Deng Zhicheng

    1993-01-01

    The cytogenetic adaptive response induced by pre-exposure in human lymphocytes and marrow cells of mice were studied. The results of this study showed that human lymphocytes in vitro and mouse marrow cells in vivo can become adapted to low-level irradiation from 3 H-TdR or exposure to a low dose of X-or γ-irradiation, so that they become less sensitive to the chromosomal damage effects of subsequent exposures. (4 tabs.)

  14. Effectiveness of a personalized ventilation system in reducing personal exposure against directly released simulated cough droplets

    DEFF Research Database (Denmark)

    Pantelic, J.; Tham, K. W.; Licina, Dusan

    2015-01-01

    manikin at distances between 1 and 4m. Cough droplet concentration was measured with an aerosol spectrometer in the breathing zone of a thermal manikin. Particle image velocimetry was used to characterize the velocity field in the breathing zone. Desktop personalized ventilation substantially reduced......The inhalation intake fraction was used as an indicator to compare effects of desktop personalized ventilation and mixing ventilation on personal exposure to directly released simulated cough droplets. A cough machine was used to simulate cough release from the front, back, and side of a thermal...

  15. Human exposure to unconventional natural gas development: A public health demonstration of periodic high exposure to chemical mixtures in ambient air.

    Science.gov (United States)

    Brown, David R; Lewis, Celia; Weinberger, Beth I

    2015-01-01

    hydraulic fracturing stage. Over one year, compressor station emissions created 118 peak exposure levels and a gas processing plant produced 99 peak exposures over one year. The screening model identified the periods during the day and the specific weather conditions when the highest potential exposures would occur. The periodicity of occurrence of extreme exposures is similar to the episodic nature of the health complaints reported in Washington County and in the literature. This study demonstrates the need to determine the aggregate quantitative impact on health when multiple facilities are placed near residences, schools, daycare centers and other locations where people are present. It shows that understanding the influence of air stability and wind direction is essential to exposure assessment at the residential level. The model can be applied to other emissions and similar sites. Profiles such as this will assist health providers in understanding the frequency and intensity of the human exposures when diagnosing and treating patients living near unconventional natural gas development.

  16. Human Rights Engagement and Exposure: New Scales to Challenge Social Work Education

    Science.gov (United States)

    McPherson, Jane; Abell, Neil

    2012-01-01

    Objectives: Advancing human rights is a core competency of U.S. social work education; yet, human rights attitudes and behaviors have never been measured in the social work literature. Thus, this article describes the development and initial validation of two scales, Human Rights Engagement in Social Work (HRESW) and Human Rights Exposure in…

  17. Reconstruction of human exposure to heavy metals using synchrotron radiation microbeams in prehistoric and modern humans

    International Nuclear Information System (INIS)

    Koizumi, Akio; Azechi, Miki; Shirasawa, Koyo

    2009-01-01

    Teeth can serve as records of environmental exposure to heavy metals during their formation. We applied a new technology - synchrotron radiation microbeams (SRXRF) - for analysis of heavy metals in human permanent teeth in modern and historical samples. Each tooth was cut in half. A longitudinal section 200 μm in thickness was subjected to the determination of the heavy metal content by SRXRF or conventional analytical methods (ICP-MS analysis or reduction-aeration atomic absorption spectrometry). The relative concentrations of Pb, Hg, Cu and Zn measured by SRXRF were translated in concentrations (in g of heavy metal/g of enamel) using calibration curves by the two analytical methods. Concentrations in teeth in the modern females (n=5) were 1.2±0.5 μg/g (n=5) for Pb; 1.7±0.2 ng/g for Hg; 0.9±1.1 μg/g for Cu; 150±24.6 μg/g for Zn. The levels of Pb were highest in the teeth samples obtained from the humans of the Edo era (1603-1868 AD) (0.5-4.0 μg/g, n=4). No trend was observed in this study in the Hg content in teeth during 3,000 years. The concentrations of Cu were highest in teeth of two medieval craftsmen (57.0 and 220 μg/g). The levels of Zn were higher in modern subjects (P<0.05) than those in the Jomon (∼1000 BC) to Edo periods [113.2±27.4 (μg/g, n=11)]. Reconstruction of developmental exposure history to lead in a famous court painter of the Edo period (18th century) revealed high levels of Pb (7.1-22.0 μg/g) in his childhood. SRXRF is useful a method for reconstructing human exposures in very long trends. (author)

  18. Infant and Early Childhood Exposure to Adult-Directed and Child-Directed Television Programming: Relations with Cognitive Skills at Age Four

    Science.gov (United States)

    Barr, Rachel; Lauricella, Alexis; Zach, Elizabeth; Calvert, Sandra L.

    2010-01-01

    This study described the relations among the amount of child-directed versus adult-directed television exposure at ages 1 and 4 with cognitive outcomes at age 4. Sixty parents completed 24-hour television diaries when their children were 1 and 4 years of age. At age 4, their children also completed a series of cognitive measures and parents…

  19. Human exposure to per- and polyfluoroalkyl substances (PFASs) via house dust in Korea: Implication to exposure pathway.

    Science.gov (United States)

    Tian, Zhexi; Kim, Seung-Kyu; Shoeib, Mahiba; Oh, Jeong-Eun; Park, Jong-Eun

    2016-05-15

    A wide range of per- and polyfluoroalkyl substances (PFASs), including fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamidoethanols (FOSEs), perfluoroalkyl carboxylic acids (PFCAs), and perfluoroalkane sulfonic acids (PFSAs), were measured in fifteen house dust and two nonresidential indoor dust of Korea. Total concentrations of PFASs in house dust ranged from 29.9 to 97.6 ng g(-1), with a dominance of perfluorooctane sulfonic acid (PFOS), followed by 8:2 FTOH, N-Ethyl perfluorooctane sulfonamidoethanol (EtFOSE), perfluoroctanoic acid (PFOA). In a typical exposure scenario, the estimated daily intakes (EDIs) of total PFASs via house dust ingestion were 2.83 ng d(-1) for toddlers and 1.13 ng d(-1) for adults, which were within the range of the mean EDIs reported from several countries. For PFOA and PFOS exposure via house dust ingestion, indirect exposure (via precursors) was a minor contributor, accounting for 5% and 12%, respectively. An aggregated exposure (hereafter, overall-EDIs) of PFOA and PFOS occurring via all pathways, estimated using data compiled from the literature, were 53.6 and 14.8 ng d(-1) for toddlers, and 20.5 and 40.6 ng d(-1) for adults, respectively, in a typical scenario. These overall-EDIs corresponded to 82% (PFOA) and 92% (PFOS) of a pharmacokinetic model-based EDIs estimated from adults' serum data. Direct dietary exposure was a major contributor (>89% of overall-EDI) to PFOS in both toddlers and adults, and PFOA in toddlers. As for PFOA exposure of adults, however direct exposure via tap water drinking (37%) and indirect exposure via inhalation (22%) were as important as direct dietary exposure (41%). House dust-ingested exposure (direct+indirect) was responsible for 5% (PFOS in toddlers) and house-dust ingestion was a minor contributor in this study, but should not be ignored for toddlers' PFOS exposure due to its significance in the worst-case scenario. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Mechanical impedance of the human body in vertical direction.

    Science.gov (United States)

    Holmlund, P; Lundström, R; Lindberg, L

    2000-08-01

    The mechanical impedance of the human body in sitting posture and vertical direction was measured during different experimental conditions, such as vibration level (0.5-1.4 m/s2), frequency (2-100 Hz), body weight (57-92 kg), relaxed and erect upper body posture. The outcome shows that impedance increases with frequency up to a peak at about 5 Hz after which it decreases in a complex manner which includes two additional peaks. The frequency at which the first and second impedance peak occurs decreases with higher vibration level. Erect, compared with relaxed body posture resulted in higher impedance magnitudes and with peaks located at somewhat higher frequencies. Heavy persons show higher impedance magnitudes and peaks at lower frequencies.

  1. Characterization of monoclonal antibodies directed against human thyroid stimulating hormone

    International Nuclear Information System (INIS)

    Soos, M.; Siddle, K.

    1982-01-01

    Monoclonal antibodies directed against human thyroid stimulating hormone (TSH) were obtained from hybrid myelomas, following fusion of mouse NSI myeloma cells with mouse spleen cells. Ten different antibodies were obtained from 4 separate fusions. Eight antibodies were of the IgG 1 subclass. Affinities of antibodies for TSH were in the range 2 x 10 8 -5 x 10 10 M -1 . Five of the antibodies were specific for TSH and did not react with LH, FSH or hCG. The remaining antibodies reacted with all these hormones and were assumed to recognise their common (α) subunit. The 5 specific antibodies fell into 3 subgroups recognising distinct antigenic determinants, whereas the 5 non-specific antibodies recognised a single determinant or closely related set of sites. It is concluded that these antibodies should be valuable reagents for use in sensitive and specific two-site immunoradiometric assays. (Auth.)

  2. Physiological responses to exposure to carbon dioxide and human bioeffluents

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2015-01-01

    Present paper describes physiological responses as a result of exposures to CO2 (between 500 ppm to 3,000 ppm) with and without bioeffluents. Twenty-five subjects participated. They were exposed in the climate chamber for 255 minutes in groups of five at a time. During exposure, they performed di...

  3. Risk of human exposure to polycyclic aromatic hydrocarbons: A case study in Beijing, China

    International Nuclear Information System (INIS)

    Yu, Yanxin; Li, Qi; Wang, Hui; Wang, Bin; Wang, Xilong; Ren, Aiguo; Tao, Shu

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAHs) can cause adverse effects on human health. The relative contributions of their two major intake routes (diet and inhalation) to population PAH exposure are still unclear. We modeled the contributions of diet and inhalation to the overall PAH exposure of the population of Beijing in China, and assessed their human incremental lifetime cancer risks (ILCR) using a Mont Carlo simulation approach. The results showed that diet accounted for about 85% of low-molecular-weight PAH (L-PAH) exposure, while inhalation accounted for approximately 57% of high-molecular-weight PAH (H-PAH) exposure of the Beijing population. Meat and cereals were the main contributors to dietary PAH exposure. Both gaseous- and particulate-phase PAHs contributed to L-PAH exposure through inhalation, whereas exposure to H-PAHs was mostly from the particulate-phase. To reduce the cancer incidence of the Beijing population, more attention should be given to inhaled particulate-phase PAHs with considerable carcinogenic potential. - Highlights: • We modeled the contributions of diet and inhalation to population PAH exposure. • Diet contributed 85% of population exposure to low molecular-weight PAHs. • Inhalation contributed 57% of population exposure to high molecular-weight PAHs. • The PAH exposure level with body-weight adjustment decreased with age increasing. • The population cancer risk of PAH exposure is lower than the serious risk level. - The exposure of the Beijing population to carcinogenic polycyclic aromatic hydrocarbons was mainly from inhaled particulate matter

  4. Computational strategy for quantifying human pesticide exposure based upon a saliva measurement

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Charles; Weber, Thomas J.; Smith, Jordan N.

    2015-05-27

    The National Research Council of the National Academies report, Toxicity Testing in the 21st Century: A Vision and Strategy, highlighted the importance of quantitative exposure data for evaluating human toxicity risk and noted that biomonitoring is a critical tool for quantitatively evaluating exposure from both environmental and occupational settings. Direct measurement of chemical exposures using personal monitoring provides the most accurate estimation of a subject’s true exposure, and non-invasive methods have also been advocated for quantifying the pharmacokinetics and bioavailability of drugs and xenobiotics. In this regard, there is a need to identify chemicals that are readily cleared in saliva at concentrations that can be quantified to support the implementation of this approach.. The current manuscript describes the use of computational modeling approaches that are closely coupled to in vivo and in vitro experiments to predict salivary uptake and clearance of xenobiotics. The primary mechanism by which xenobiotics leave the blood and enter saliva is thought to involve paracellular transport, passive transcellular diffusion, or trancellular active transport with the majority of drugs and xenobiotics cleared from plasma into saliva by passive diffusion. The transcellular or paracellular diffusion of unbound chemicals in plasma to saliva has been computational modeled using a combination of compartmental and physiologically based approaches. Of key importance for determining the plasma:saliva partitioning was the utilization of a modified Schmitt algorithm that calculates partitioning based upon the tissue composition, pH, chemical pKa and plasma protein-binding. Sensitivity analysis of key model parameters specifically identified that both protein-binding and pKa (for weak acids and bases) had the most significant impact on the determination of partitioning and that there were clear species dependent differences based upon physiological variance between

  5. Geographical distribution of radiation risk unaccountable by direct exposure dose in hiroshima A-bomb victims

    International Nuclear Information System (INIS)

    Tonda, Tetsuji; Satoh, Kenichi; Ohani, Keiko

    2012-01-01

    Death risks due to solid cancer were estimated from region to region where the A-bomb survivors had been actually exposed, to visualize the risk distribution on the map, which resulting in risk regional difference that had been unaccountable by direct exposure dose estimation. Analysis was performed with 3 hazard models of the previous one, + direct exposed dose as a confounding factor and, further, + spatial distance from the explosion point. Subjects were 37,382 A-bomb survivors at Jan. 1, 1970 with known positional coordinate at explosion, followed until Dec. 31, 2009, whose endpoint was set by 4,371 deaths due to cancer except leukemia, cancers of thyroid and breast. Confounding factors in the previous hazard model were sex, age at the exposure, dose and shielding. With the previous model, risk distribution was observed in a concentric circular region around the hypocenter and in an additional west to northwestern suburbs. The latter risk distribution was also seen with the second model in the same region, where dose decreased with -7 powers of the distance. When adjusted with -3 powers of the distance with the third model, the actual risk distribution was found best fitted, indicating the presence of distance-dependent risk. It was suggested that the region exposed to additional dose possibly derived from fallout had been the actual black rainfall area as those regions agreed with each other. (T.T.)

  6. Human genome sequencing with direct x-ray holographic imaging

    International Nuclear Information System (INIS)

    Rhodes, C.K.

    1993-01-01

    Direct holographic imaging of biological materials is widely applicable to the study of the structure, properties and action of genetic material. This particular application involves the sequencing of the human genome where prospective genomic imaging technology is composed of three subtechnologies, name an x-ray holographic camera, suitable chemistry and enzymology for the preparation of tagged DNA samples, and the illuminator in the form of an x-ray laser. We report appropriate x-ray camera, embodied by the instrument developed by MCR, is available and that suitable chemical and enzymatic procedures exist for the preparation of the necessary tagged DNA strands. Concerning the future development of the x-ray illuminator. We find that a practical small scale x-ray light source is indeed feasible. This outcome requires the use of unconventional physical processes in order to achieve the necessary power-compression in the amplifying medium. The understanding of these new physical mechanisms is developing rapidly. Importantly, although the x-ray source does not currently exist, the understanding of these new physical mechanisms is developing rapidly and the research has established the basic scaling laws that will determine the properties of the x-ray illuminator. When this x-ray source becomes available, an extremely rapid and cost effective instrument for 3-D imaging of biological materials can be applied to a wide range of biological structural assays, including the base-pair sequencing of the human genome and many questions regarding its higher levels of organization

  7. Direct Electrical Stimulation in the Human Brain Disrupts Melody Processing.

    Science.gov (United States)

    Garcea, Frank E; Chernoff, Benjamin L; Diamond, Bram; Lewis, Wesley; Sims, Maxwell H; Tomlinson, Samuel B; Teghipco, Alexander; Belkhir, Raouf; Gannon, Sarah B; Erickson, Steve; Smith, Susan O; Stone, Jonathan; Liu, Lynn; Tollefson, Trenton; Langfitt, John; Marvin, Elizabeth; Pilcher, Webster H; Mahon, Bradford Z

    2017-09-11

    Prior research using functional magnetic resonance imaging (fMRI) [1-4] and behavioral studies of patients with acquired or congenital amusia [5-8] suggest that the right posterior superior temporal gyrus (STG) in the human brain is specialized for aspects of music processing (for review, see [9-12]). Intracranial electrical brain stimulation in awake neurosurgery patients is a powerful means to determine the computations supported by specific brain regions and networks [13-21] because it provides reversible causal evidence with high spatial resolution (for review, see [22, 23]). Prior intracranial stimulation or cortical cooling studies have investigated musical abilities related to reading music scores [13, 14] and singing familiar songs [24, 25]. However, individuals with amusia (congenitally, or from a brain injury) have difficulty humming melodies but can be spared for singing familiar songs with familiar lyrics [26]. Here we report a detailed study of a musician with a low-grade tumor in the right temporal lobe. Functional MRI was used pre-operatively to localize music processing to the right STG, and the patient subsequently underwent awake intraoperative mapping using direct electrical stimulation during a melody repetition task. Stimulation of the right STG induced "music arrest" and errors in pitch but did not affect language processing. These findings provide causal evidence for the functional segregation of music and language processing in the human brain and confirm a specific role of the right STG in melody processing. VIDEO ABSTRACT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Human exposure to airborne fungi from genera used as biocontrol agents in plant production.

    Science.gov (United States)

    Madsen, Anne Mette; Hansen, Vinni Mona; Meyling, Nicolai Vitt; Eilenberg, Jørgen

    2007-01-01

    The fungi Trichoderma harzianum, T. polysporum, T. viride, Paeciliomyces fumosoroseus, P. lilacinus, Verticillium/lecanicillium lecanii, Ulocladium oudemansii, U. atrum and Beauveria bassiana are used or considered to be used for biocontrol of pests and plant diseases. Human exposure to these fungi in environments where they may naturally occur or are used as biocontrol agents has not been directly investigated to date. This review aims to provide an overview of the current knowledge of human exposure to fungi from the relevant genera. The subject of fungal taxonomy due to the rapid development of this issue is also discussed. B. bassiana, V. lecanii, T. harzianum, T. polysporum, P. lilacinus and U. oudemansii were infrequently present in the air and thus people in general seem to be seldom exposed to these fungi. However, when V. lecanii was present, high concentrations were measured. Fungi from the genera Trichoderma, Paecilomyces and Ulocladium were rarely identified to the species level and sometimes high concentrations were reported. T. viride and U. atrum were detected frequently in different environments and sometimes with a high frequency of presence in samples. Thus, people seem to be frequently exposed to these fungi. Sequence data have led to recent revisions of fungal taxonomy, and in future studies it is important to specify the taxonomy used for identification, thus making comparisons possible.

  9. Pulmonary Inflammatory Responses to Acute Meteorite Dust Exposures - Implications for Human Space Exploration

    Science.gov (United States)

    Harrington, A. D.; McCubbin, F. M.; Vander Kaaden, K. E.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

    2018-01-01

    New initiatives to send humans to Mars within the next few decades are illustrative of the resurgence of interest in space travel. However, as with all exploration, there are risks. The Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts.

  10. Comparison of skin decontamination efficacy of commercial decontamination products following exposure to VX on human skin.

    Science.gov (United States)

    Thors, L; Koch, M; Wigenstam, E; Koch, B; Hägglund, L; Bucht, A

    2017-08-01

    The decontamination efficacy of four commercially available skin decontamination products following exposure to the nerve agent VX was evaluated in vitro utilizing a diffusion cell and dermatomed human skin. The products included were Reactive Skin Decontamination Lotion (RSDL), the Swedish decontamination powder 104 (PS104), the absorbent Fuller's Earth and the aqueous solution alldecontMED. In addition, various decontamination procedures were assessed to further investigate important mechanisms involved in the specific products, e.g. decontamination removal from skin, physical removal by sponge swabbing and activation of degradation mechanisms. The efficacy of each decontamination product was evaluated 5 or 30 min after dermal application of VX (neat or diluted to 20% in water). The RSDL-lotion was superior in reducing the penetration of VX through human skin, both when exposed as neat agent and when diluted to 20% in water. Swabbing with the RSDL-sponge during 2 min revealed decreased efficacy compared to applying the RSDL-lotion directly on the skin for 30 min. Decontamination with Fuller's Earth and alldecontMED significantly reduced the penetration of neat concentration of VX through human skin. PS104-powder was insufficient for decontamination of VX at both time-points, independently of the skin contact time of PS104. The PS104-slurry (a mixture of PS104-powder and water), slightly improved the decontamination efficacy. Comparing the time-points for initiated decontamination revealed less penetrated VX for RSDL and Fuller's Earth when decontamination was initiated after 5 min compared to 30 min post-exposure, while alldecontMED displayed similar efficacy at both time-points. Decontamination by washing with water only resulted in a significant reduction of penetrated VX when washing was performed 5 min after exposure, but not when decontamination was delayed to 30 min post-exposure of neat VX. In conclusion, early initiated decontamination with the

  11. The U.S. National Health and Nutrition Examination Survey and human exposure to environmental chemicals.

    Science.gov (United States)

    Calafat, Antonia M

    2012-02-01

    Researchers are increasingly interested in using human biomonitoring - the measurement of chemicals, their metabolites or specific reaction products in biological specimens/body fluids - for investigating exposure to environmental chemicals. General population human biomonitoring programs are useful for investigating human exposure to environmental chemicals and an important tool for integrating environment and health. One of these programs, the National Health and Nutrition Examination Survey (NHANES), conducted in the United States is designed to collect data on the health and nutritional status of the noninstitutionalized, civilian U.S. population. NHANES includes a physical examination, collecting a detailed medical history, and collecting biological specimens (i.e., blood and urine). These biological specimens can be used to assess exposure to environmental chemicals. NHANES human biomonitoring data can be used to establish reference ranges for selected chemicals, provide exposure data for risk assessment, and monitor exposure trends. Published by Elsevier GmbH.

  12. Climate change impacts on human exposures to air pollution

    Science.gov (United States)

    This is an abstract for a presentations at the Annual Conference of the International Society on Exposure Science and Environmental Epidemiology. This presentation will serve as an introduction to the symposium.

  13. Campylobacter fetus infections in humans : exposure and disease

    NARCIS (Netherlands)

    Wagenaar, Jaap A; van Bergen, Marcel A P; Blaser, Martin J; Tauxe, Robert V; Newell, Diane G; van Putten, Jos P M

    Campylobacter fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided

  14. Dosimetric significance of cytogenetic examinations in human accidental over exposures

    International Nuclear Information System (INIS)

    Doloy-Biola, M.T.; Lego, R.; Ducatez, G.; Lepetit, J.; Bourguignon, M.

    1975-01-01

    The damage to 13 workers following accidental exposures was assessed from lymphocyte chromosomal aberrations, and the results compared with those supplied by physical dosimetry and the clinical syndromes [fr

  15. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Elwafa Abdallah, Mohamed, E-mail: mae_abdallah@yahoo.co.uk [Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Department of Analytical Chemistry, Faculty of Pharmacy, Assiut University, 71526 Assiut (Egypt); Pawar, Gopal; Harrad, Stuart [Division of Environmental Health and Risk Management, School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2016-01-15

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm{sup 2}, finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24 h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P > 0.05). Estimated permeability constants (K{sub p}, cm/h) showed a significant negative correlation with log K{sub ow} for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs = 36 ng/kg bw day) than adults (median ΣPFRs = 4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure. - Highlights: • Human dermal absorption of PFRs was studied using human ex vivo skin and EPISKIN™. • Absorbed fractions of TCEP, TCIPP and TDCIPP were 28%, 25% and 13% of applied dose. • Permeability constants showed significant negative correlation to log K{sub ow} of PFRs. • Skin washing reduced the overall dermal

  16. Human dermal absorption of chlorinated organophosphate flame retardants; implications for human exposure

    International Nuclear Information System (INIS)

    Abou-Elwafa Abdallah, Mohamed; Pawar, Gopal; Harrad, Stuart

    2016-01-01

    Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP) are organophosphate flame retardants (PFRs) widely applied in a plethora of consumer products despite their carcinogenic potential. Human dermal absorption of these PFRs is investigated for the first time using human ex vivo skin and EPISKIN™ models. Results of human ex vivo skin experiments revealed 28%, 25% and 13% absorption of the applied dose (500 ng/cm 2 , finite dose) of TCEP, TCIPP and TDCIPP, respectively after 24 h exposure. The EPISKIN™ model showed enhanced permeability values (i.e. weaker barrier), that were respectively 16%, 11% and 9% for TCEP, TCIPP and TDCIPP compared to human ex vivo skin. However, this difference was not significant (P > 0.05). Estimated permeability constants (K p , cm/h) showed a significant negative correlation with log K ow for the studied contaminants. The effect of hand-washing on dermal absorption of PFRs was investigated. Washing reduced overall dermal absorption, albeit to varying degrees depending on the physicochemical properties of the target PFRs. Moreover, slight variations of the absorbed dose were observed upon changing the dosing solution from acetone to 20% Tween 80 in water, indicating the potential influence of the dose vehicle on the dermal absorption of PFRs. Finally, estimated dermal uptake of the studied PFRs via contact with indoor dust was higher in UK toddlers (median ΣPFRs = 36 ng/kg bw day) than adults (median ΣPFRs = 4 ng/kg bw day). More research is required to fully elucidate the toxicological implications of such exposure. - Highlights: • Human dermal absorption of PFRs was studied using human ex vivo skin and EPISKIN™. • Absorbed fractions of TCEP, TCIPP and TDCIPP were 28%, 25% and 13% of applied dose. • Permeability constants showed significant negative correlation to log K ow of PFRs. • Skin washing reduced the overall dermal absorption of target PFRs

  17. Pesticide Flow Analysis to Assess Human Exposure in Greenhouse Flower Production in Colombia

    Directory of Open Access Journals (Sweden)

    Claudia R. Binder

    2013-03-01

    Full Text Available Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.

  18. Characterizing the impact of projected changes in climate and air quality on human exposures to ozone.

    Science.gov (United States)

    Dionisio, Kathie L; Nolte, Christopher G; Spero, Tanya L; Graham, Stephen; Caraway, Nina; Foley, Kristen M; Isaacs, Kristin K

    2017-05-01

    The impact of climate change on human and environmental health is of critical concern. Population exposures to air pollutants both indoors and outdoors are influenced by a wide range of air quality, meteorological, behavioral, and housing-related factors, many of which are also impacted by climate change. An integrated methodology for modeling changes in human exposures to tropospheric ozone (O 3 ) owing to potential future changes in climate and demographics was implemented by linking existing modeling tools for climate, weather, air quality, population distribution, and human exposure. Human exposure results from the Air Pollutants Exposure Model (APEX) for 12 US cities show differences in daily maximum 8-h (DM8H) exposure patterns and levels by sex, age, and city for all scenarios. When climate is held constant and population demographics are varied, minimal difference in O 3 exposures is predicted even with the most extreme demographic change scenario. In contrast, when population is held constant, we see evidence of substantial changes in O 3 exposure for the most extreme change in climate. Similarly, we see increases in the percentage of the population in each city with at least one O 3 exposure exceedance above 60 p.p.b and 70 p.p.b thresholds for future changes in climate. For these climate and population scenarios, the impact of projected changes in climate and air quality on human exposure to O 3 are much larger than the impacts of changing demographics. These results indicate the potential for future changes in O 3 exposure as a result of changes in climate that could impact human health.

  19. Coupled motions direct electrons along human microsomal P450 Chains.

    Directory of Open Access Journals (Sweden)

    Christopher R Pudney

    2011-12-01

    Full Text Available Protein domain motion is often implicated in biological electron transfer, but the general significance of motion is not clear. Motion has been implicated in the transfer of electrons from human cytochrome P450 reductase (CPR to all microsomal cytochrome P450s (CYPs. Our hypothesis is that tight coupling of motion with enzyme chemistry can signal "ready and waiting" states for electron transfer from CPR to downstream CYPs and support vectorial electron transfer across complex redox chains. We developed a novel approach to study the time-dependence of dynamical change during catalysis that reports on the changing conformational states of CPR. FRET was linked to stopped-flow studies of electron transfer in CPR that contains donor-acceptor fluorophores on the enzyme surface. Open and closed states of CPR were correlated with key steps in the catalytic cycle which demonstrated how redox chemistry and NADPH binding drive successive opening and closing of the enzyme. Specifically, we provide evidence that reduction of the flavin moieties in CPR induces CPR opening, whereas ligand binding induces CPR closing. A dynamic reaction cycle was created in which CPR optimizes internal electron transfer between flavin cofactors by adopting closed states and signals "ready and waiting" conformations to partner CYP enzymes by adopting more open states. This complex, temporal control of enzyme motion is used to catalyze directional electron transfer from NADPH→FAD→FMN→heme, thereby facilitating all microsomal P450-catalysed reactions. Motions critical to the broader biological functions of CPR are tightly coupled to enzyme chemistry in the human NADPH-CPR-CYP redox chain. That redox chemistry alone is sufficient to drive functionally necessary, large-scale conformational change is remarkable. Rather than relying on stochastic conformational sampling, our study highlights a need for tight coupling of motion to enzyme chemistry to give vectorial electron

  20. A Review of Human Health and Ecological Risks due to CO2 Exposure

    Science.gov (United States)

    Hepple, R. P.; Benson, S. M.

    2001-05-01

    This paper presents an overview of the human health and ecological consequences of exposure to elevated levels of carbon dioxide (CO2) in the context of geologic carbon sequestration. The purpose of this effort is to provide a baseline of information to guide future efforts in risk assessment for CO2 sequestration. Scenarios for hazardous CO2 exposure include surface facility leaks, leaks from abandoned or aging wells, and leakage from geologic CO2 storage structures. Amounts of carbon in various reservoirs, systems, and applications were summarized, and the levels of CO2 encountered in nature and everyday life were compared along with physiologically relevant concentrations. Literature pertaining to CO2 occupational exposure limits, regulations, monitoring, and ecological consequences was reviewed. The OSHA, NIOSH, and ACGIH occupational exposure standards are 0.5% CO2 averaged over a 40 hour week, 3% average for a short-term (15 minute) exposure, and 4% as the maximum instantaneous limit considered immediately dangerous to life and health. All three conditions must be satisfied at all times. Any detrimental effects of low-level CO2 exposure are reversible, including the long-term metabolic compensation required by chronic exposure to 3% CO2. Breathing rate doubles at 3% CO2 and is four times the normal rate at 5% CO2. According to occupational exposure and controlled atmosphere research into CO2 toxicology, CO2 is hazardous via direct toxicity at levels above 5%, concentrations not encountered in nature outside of volcanic settings and water-logged soils. Small leaks do not present any danger to people unless the CO2 does not disperse quickly enough through atmospheric mixing but accumulates instead in depressions and confined spaces. These dangers are the result of CO2 being more dense than air. Carbon dioxide is regulated for diverse purposes but never as a toxic substance. Catastrophic incidents involving large amounts and/or rapid release of CO2 such as Lake

  1. Highly pathogenic avian influenza (H5N1: pathways of exposure at the animal-human interface, a systematic review.

    Directory of Open Access Journals (Sweden)

    Maria D Van Kerkhove

    Full Text Available BACKGROUND: The threat posed by highly pathogenic avian influenza A H5N1 viruses to humans remains significant, given the continued occurrence of sporadic human cases (499 human cases in 15 countries with a high case fatality rate (approximately 60%, the endemicity in poultry populations in several countries, and the potential for reassortment with the newly emerging 2009 H1N1 pandemic strain. Therefore, we review risk factors for H5N1 infection in humans. METHODS AND FINDINGS: Several epidemiologic studies have evaluated the risk factors associated with increased risk of H5N1 infection among humans who were exposed to H5N1 viruses. Our review shows that most H5N1 cases are attributed to exposure to sick poultry. Most cases are sporadic, while occasional limited human-to-human transmission occurs. The most commonly identified factors associated with H5N1 virus infection included exposure through contact with infected blood or bodily fluids of infected poultry via food preparation practices; touching and caring for infected poultry; [corrected] exposure to H5N1 via swimming or bathing in potentially virus laden ponds; and exposure to H5N1 at live bird markets. CONCLUSIONS: Research has demonstrated that despite frequent and widespread contact with poultry, transmission of the H5N1 virus from poultry to humans is rare. Available research has identified several risk factors that may be associated with infection including close direct contact with poultry and transmission via the environment. However, several important data gaps remain that limit our understanding of the epidemiology of H5N1 in humans. Although infection in humans with H5N1 remains rare, human cases continue to be reported and H5N1 is now considered endemic among poultry in parts of Asia and in Egypt, providing opportunities for additional human infections and for the acquisition of virus mutations that may lead to more efficient spread among humans and other mammalian species

  2. Weighing serological evidence of human exposure to animal influenza viruses − A literature review

    NARCIS (Netherlands)

    Sikkema, R.S. (Reina S.); G.S. Freidl (Gudrun); E.I. de Bruin (Esther); M.P.G. Koopmans D.V.M. (Marion)

    2016-01-01

    textabstractAssessing influenza A virus strains circulating in animals and their potential to cross the species barrier and cause human infections is important to improve human influenza surveillance and preparedness. We reviewed studies describing serological evidence of human exposure to animal

  3. The role of dietary habits in human internal exposure

    International Nuclear Information System (INIS)

    Travnikova, I.G.; Balonov, M.I.; Bruck, G.J.; Shutov, V.N.

    2002-01-01

    The diversity of the dietary habits of the inhabitants living in the areas contaminated with long-lived radionuclides is an important factor for finding out the ways and specific features of internal dose formation of the population. The diet and structure of food consumption of different contingents of the population in several regions subjected to the radioactive accidents were studied. Using the specially developed questionnaire, we surveyed in Russia over 3000 inhabitants of the Bryansk region, and found out their food rations before the Chernobyl accident and during different time periods after it. In the Urals, we surveyed 102 inhabitants of the village Muslyumovo located on the bank of the Techa river that was contaminated as a result of releases of products of processing nuclear fuel and also more than 136 people residing in the area of the East Ural Radioactive Trace. In the North of the European part of Russia we investigated 310 local inhabitants including 114 reindeer herders. In Kazakhstan, we polled over 114 residents of the Semipalatinsk nuclear test site area, including 23 herdsmen and members of their families. The dietary habits of all investigated groups of the population strongly differ both due to climatic conditions and national and confessional traditions. Besides that, they are strongly influenced by the sources of the contamination of local food products that also differ both by radionuclide composition and by the time period elapsed since contamination of the considered areas. On the basis of the obtained results, we calculated the internal doses for the population of mentioned regions, which are in good coincidence with the data of direct measurements of radionuclides content in human body. We have determined, which products have the leading role in internal dose formation during different time periods after depositions

  4. Human immunotoxicologic markers of chemical exposures: preliminary validation studies.

    Science.gov (United States)

    Wartenberg, D; Laskin, D; Kipen, H

    1993-01-01

    The circulating cells of the immune system are sensitive to environmental contaminants, and effects are often manifested as changes in the cell surface differentiation antigens of affected populations of cells, particularly lymphocytes. In this investigation, we explore the likelihood that variation in the expression of the surface markers of immune cells can be used as an index of exposure to toxic chemicals. We recruited 38 healthy New Jersey men to study pesticides effects: 19 orchard farmers (high exposure); 13 berry farmers (low exposure); and 6 hardware store owners (no exposure). Immunophenotyping was performed assaying the following cell surface antigens: CD2, CD4, CD8, CD14, CD20, CD26, CD29, CD45R, CD56, and PMN. Data were analyzed using univariate and multivariate methods. There were no significant differences among the groups with respect to routine medical histories, physical examinations, or routine laboratory parameters. No striking differences between groups were seen in univariate tests. Multivariate tests suggested some differences among groups and limited ability to correctly classify individuals based on immunophenotyping results. Immunophenotyping represents a fruitful area of research for improved exposure classification. Work is needed both on mechanistic understanding of the patterns observed and on the statistical interpretation of these patterns.

  5. Comparison of direct measurement methods for headset noise exposure in the workplace

    Directory of Open Access Journals (Sweden)

    Flora G Nassrallah

    2016-01-01

    Full Text Available The measurement of noise exposure from communication headsets poses a methodological challenge. Although several standards describe methods for general noise measurements in occupational settings, these are not directly applicable to noise assessments under communication headsets. For measurements under occluded ears, specialized methods have been specified by the International Standards Organization (ISO 11904 such as the microphone in a real ear and manikin techniques. Simpler methods have also been proposed in some national standards such as the use of general purpose artificial ears and simulators in conjunction with single number corrections to convert measurements to the equivalent diffuse field. However, little is known about the measurement agreement between these various methods and the acoustic manikin technique. Twelve experts positioned circum-aural, supra-aural and insert communication headsets on four different measurement setups (Type 1, Type 2, Type 3.3 artificial ears, and acoustic manikin. Fit-refit measurements of four audio communication signals were taken under quiet laboratory conditions. Data were transformed into equivalent diffuse-field sound levels using third-octave procedures. Results indicate that the Type 1 artificial ear is not suited for the measurement of sound exposure under communication headsets, while Type 2 and Type 3.3 artificial ears are in good agreement with the acoustic manikin technique. Single number corrections were found to introduce a large measurement uncertainty, making the use of the third-octave transformation preferable.

  6. African American patients' attitudes toward proactive health behaviors after exposure to direct-to-consumer advertising.

    Science.gov (United States)

    Yang, Yi; Gourley, Dick R; Gourley, Greta A; Faris, Richard J; Womeodu, Robin J; Yang, Jun; Likens, Carol C

    2010-05-01

    Previous research on direct-to-consumer advertising (DTCA) has not focused exclusively on the African American population. The purpose of this study was to explore African Americans' attitudes toward proactive health behaviors following exposure to DTCA of atorvastatin calcium (Lipitor, Pfizer Inc). One-hundred fifty African American patients participated in the study. Participants' functional health literacy and health locus of control were assessed. The participants were asked to view a DTCA of Lipitor, followed by face-to-face interviews. After watching the DTCA of Lipitor, 89.4% of participants agreed that they would talk to their physician about their cholesterol, 88.6% agreed that they would ask their physician to test their cholesterol level, and 47.3% agreed that they would ask their physician to write them a prescription for Lipitor. Those who had a history of high cholesterol were more likely to agree to ask their physician to test their cholesterol levels. Low household income, having public health insurance, and prior experience with taking Lipitor were significant positive predictors of patients agreeing to ask their physician to write a prescription of the advertised drug. African American patients showed favorable attitudes toward proactive health behaviors after exposure to DTCA of Lipitor.

  7. Malfunction of cardiac devices after radiotherapy without direct exposure to ionizing radiation: mechanisms and experimental data.

    Science.gov (United States)

    Zecchin, Massimo; Morea, Gaetano; Severgnini, Mara; Sergi, Elisabetta; Baratto Roldan, Anna; Bianco, Elisabetta; Magnani, Silvia; De Luca, Antonio; Zorzin Fantasia, Anna; Salvatore, Luca; Milan, Vittorino; Giannini, Gianrossano; Sinagra, Gianfranco

    2016-02-01

    Malfunctions of cardiac implantable electronical devices (CIED) have been described after high-energy radiation therapy even in the absence of direct exposure to ionizing radiation, due to diffusion of neutrons (n) causing soft errors in inner circuits. The purpose of the study was to analyse the effect of scattered radiation on different types and models of CIED and the possible sources of malfunctions. Fifty-nine explanted CIED were placed on an anthropomorphous phantom of tissue-equivalent material, and a high-energy photon (15 MV) radiotherapy course (total dose = 70 Gy) for prostate treatment was performed. All devices were interrogated before and after radiation. Radiation dose, the electromagnetic field, and neutron fluence at the CIED site were measured. Thirty-four pacemakers (PM) and 25 implantable cardioverter-defibrillators (ICD) were analysed. No malfunctions were detected before radiation. After radiation a software malfunction was evident in 13 (52%) ICD and 6 (18%) PM; no significant electromagnetic field or photon radiations were detected in the thoracic region. Neutron capture was demonstrated by the presence of the (198)Au((197)Au + n) or (192)Ir((191)Ir + n) isotope activation; it was significantly greater in ICD than in PM and non-significantly greater in damaged devices. A greater effect in St Jude PM (2/2 damaged), Boston (9/11), and St Jude ICD (3/6) and in older ICD models was observed; the year of production was not relevant in PM. High-energy radiation can cause different malfunctions on CIED, particularly ICD, even without direct exposure to ionizing radiation due to scattered radiation of neutrons produced by the linear accelerator. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  8. 77 FR 52025 - Notification of a Public Teleconference of the Science Advisory Board; Exposure and Human Health...

    Science.gov (United States)

    2012-08-28

    ... Science Advisory Board; Exposure and Human Health Committee AGENCY: Environmental Protection Agency (EPA... Office announces a public teleconference of the SAB Exposure and Human Health Committee to discuss its... hereby given that the SAB Exposure and Human Health Committee (EHHC) will hold a public teleconference to...

  9. DIRECT AIR BLAST EXPOSURE EFFECTS IN ANIMALS, OPERATION UPSHOT-KNOTHOLE, PROJECT 4.2

    Energy Technology Data Exchange (ETDEWEB)

    DRAEGER, R.H. (UNITED STATES NAVY - DEPARTMENT OF); LEE, R.H. (UNITED STATES NAVY - DEPARTMENT OF)

    1953-12-31

    Project 4.2 was designed to study direct (primary) air blast injury, in animals, from an atomic weapon in the range of 20 to 50 psi under circumstances affording protection against missiles, thermal and ionizing radiation and to estimate the probable direct air blast hazard in man. The pressure levels at which atomic weapons direct air blast injuries occur will determine, to a large extent, the number of blast casualties likely to be encountered. It is probable that fatal overpressures are not reached until well within the range at which indirect (secondary) blast, thermal and ionizing radiation are practically certain to prove fatal. Only in special situations affording partial protection from other injuries are blast injuries likely to be of practical importance. Two animal species of widely different body weights (700 rats and 56 dogs) were exposed, together with air pressure recorders, in aluminum cylinders, covered by sandbags and dirt but open at both ends, at seven stations distributed within the intended overpressure range of 20 to 50 psi of Shot 10« About 200 rats were likewise exposed in Shot 9. Unfortunately, the destructive effect of the air blast of Shot 10 was much greater than anticipated. Many of the exposure cylinders were displaced and their contents destroyed. Only a partial recovery of the animals was possible due to the excessive radioactive contamination which greatly limited the time in the area. Most of the animals were dead upon recovery. Those living were in a state of severe shock. Autopsy findings showed remarkably few traumatic lesions and lung hemorrhages in spite of the rough treatment and high overpressure to which they were subjected. The rats recovered from Shot 9 were exposed to a recorded pressure of 18 to 2k psi. The autopsy findings showed moderate lung hemorrhage in most of the animals undoubtedly due to direct air blast injury. The findings were typical of those seen following exposure to air blast from HE or in the shock

  10. Human Bronchial Epithelial Cell Response to Heavy Particle Exposure

    Science.gov (United States)

    Story, Michael; Ding, Liang-Hao; Minna, John; Park, Seong-mi; Peyton, Michael; Larsen, Jill

    2012-07-01

    A battery of non-oncogenically immortalized human bronchial epithelial cells (HBECs) are being used to examine the molecular changes that lead to lung carcinogenesis after exposure to heavy particles found in the free space environment. The goal is to ultimately identify biomarkers of radioresponse that can be used for prediction of carcinogenic risk for fatal lung cancer. Our initial studies have focused on the cell line HBEC3 KT and the isogenic variant HBEC3 KTR53, which overexpresses the RASv12 mutant and where p53 has been knocked down by shRNA, and is considered to be a more oncogenically progressed variant. We have previously described the response of HBEC3 KT at the cellular and molecular level, however, the focus here is on the rate of cellular transformation after HZE radiation exposure and the molecular changes in transformed cells. When comparing the two cell lines we find that there is a maximum rate of cellular transformation at 0.25 Gy when cells are exposed to 1 GeV Fe particles, and, for the HBEC3 KTR53 there are multiple pathways upregulated that promote anchorage independent growth including the mTOR pathway, the TGF-1 pathway, RhoA signaling and the ERK/MAPK pathway as early as 2 weeks after radiation. This does not occur in the HBEC3 KT cell line. Transformed HBEC3 KT cells do not show any morphologic or phenotypic changes when grown as cell cultures. HBEC3 KTR53 cells on the other hand show substantial changes in morphology from a cobblestone epithelial appearance to a mesenchymal appearance with a lack of contact inhibition. This epithelial to mesenchymal change in morphology is accompanied by the expression of vimentin and a reduction in the expression of E-cadherin, which are hallmarks of epithelial to mesenchymal transition. Interestingly, for HBEC3 KT transformed cells there are no mutations in the p53 gene, 2 of 15 clones were found to be heterozygous for the RASV12 mutation, and 3 of 15 clones expressed high levels of BigH3, a TGFB

  11. Combined Toxic Exposures and Human Health: Biomarkers of Exposure and Effect

    Directory of Open Access Journals (Sweden)

    Johan Högberg

    2011-02-01

    Full Text Available Procedures for risk assessment of chemical mixtures, combined and cumulative exposures are under development, but the scientific database needs considerable expansion. In particular, there is a lack of knowledge on how to monitor effects of complex exposures, and there are few reviews on biomonitoring complex exposures. In this review we summarize articles in which biomonitoring techniques have been developed and used. Most examples describe techniques for biomonitoring effects which may detect early changes induced by many chemical stressors and which have the potential to accelerate data gathering. Some emphasis is put on endocrine disrupters acting via epigenetic mechanisms and on carcinogens. Solid evidence shows that these groups of chemicals can interact and even produce synergistic effects. They may act during sensitive time windows and biomonitoring their effects in epidemiological studies is a challenging task.

  12. Human exposure to mercury in a compact fluorescent lamp manufacturing area: By food (rice and fish) consumption and occupational exposure

    International Nuclear Information System (INIS)

    Liang, Peng; Feng, Xinbin; Zhang, Chan; Zhang, Jin; Cao, Yucheng; You, Qiongzhi; Leung, Anna Oi Wah; Wong, Ming-Hung; Wu, Sheng-Chun

    2015-01-01

    To investigate human Hg exposure by food consumption and occupation exposure in a compact fluorescent lamp (CFL) manufacturing area, human hair and rice samples were collected from Gaohong town, Zhejiang Province, China. The mean values of total mercury (THg) and methylmercury (MeHg) concentrations in local cultivated rice samples were significantly higher than in commercial rice samples which indicated that CFL manufacturing activities resulted in Hg accumulation in local rice samples. For all of the study participants, significantly higher THg concentrations in human hair were observed in CFL workers compared with other residents. In comparison, MeHg concentrations in human hair of residents whose diet consisted of local cultivated rice were significantly higher than those who consumed commercial rice. These results demonstrated that CFL manufacturing activities resulted in THg accumulation in the hair of CFL workers. However, MeHg in hair were mainly affected by the sources of rice of the residents. - Highlights: • Rice samples were contaminated by Compact fluorescent lamp (CFL) manufacturing. • CFL manufacturing lead to THg accumulation in human hair. • MeHg in human hair were mainly affected by the sources of rice. • MeHg intake from fish consumption was lower than that from rice consumption. • PDI of MeHg by food consumption was below the guidelines for public health concern. - CFL manufacturing activities result in Hg accumulation in local rice samples and hair of CFL workers. However, MeHg in hair were mainly affected by sources of rice

  13. Hexachlorobenzene sources, levels and human exposure in the environment of China

    NARCIS (Netherlands)

    Wang, G.; Lu, Y.L.; Han, Jingyi; Luo, W.; Shi, Y.J.; Wang, T.Y.; Sun, Y.M.

    2010-01-01

    This article summarizes the published scientific data on sources, levels and human exposure of hexachlorobenzene (HCB) in China. Potential sources of unintended HCB emission were assessed by production information, emission factors and environmental policies. HCB was observed in various

  14. In vivo plasma concentration for lindane after 6 hour exposure in human skin

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dataset is a time course description of lindane disappearance in blood plasma after dermal exposure in human volunteers. This dataset is associated with the...

  15. Probabilistic estimation of residential air exchange rates for population-based human exposure modeling

    Science.gov (United States)

    Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER meas...

  16. A Quantitative ADME-base Tool for Exploring Human Exposure to Consumer Product Ingredients

    Science.gov (United States)

    Exposure to a wide range of chemicals through our daily habits and routines is ubiquitous and largely unavoidable within modern society. The potential for human exposure, however, has not been quantified for the vast majority of chemicals with wide commercial use. Creative advanc...

  17. In Vivo Lipopolysaccharide Exposure of Human Blood Leukocytes Induces Cross-Tolerance to Multiple TLR Ligands

    NARCIS (Netherlands)

    de Vos, Alex F.; Pater, Jennie M.; van den Pangaart, Petra S.; de Kruif, Martijn D.; van 't Veer, Cornelis; van der Poll, Tom

    2009-01-01

    In vitro and in vivo experiments in mice have shown that exposure of cells to the TLR4 ligand LPS induces tolerance toward a second exposure to LPS and induces cross-tolerance to certain other TLR ligands. Recently, we found that LPS tolerance in experimental human endotoxemia and Gram-negative

  18. The Progression of Circadian Phase during Light Exposure in Animals and Humans

    NARCIS (Netherlands)

    Beersma, Domien G. M.; Comas, Marian; Hut, Roelof A.; Gordijn, Marijke C. M.; Rueger, Melanie; Daan, Serge

    Studies in humans and mice revealed that circadian phase shifting effects of light are larger at the beginning of a light exposure interval than during subsequent exposure. Little is known about the dynamics of this response reduction phenomenon. Here the authors propose a method to obtain

  19. Separation of uncertainty and interindividual variability in human exposure modeling.

    NARCIS (Netherlands)

    Ragas, A.M.J.; Brouwer, F.P.E.; Buchner, F.L.; Hendriks, H.W.; Huijbregts, M.A.J.

    2009-01-01

    The NORMTOX model predicts the lifetime-averaged exposure to contaminants through multiple environmental media, that is, food, air, soil, drinking and surface water. The model was developed to test the coherence of Dutch environmental quality objectives (EQOs). A set of EQOs is called coherent if

  20. GLI3 Links Environmental Arsenic Exposure and Human Fetal Growth

    Directory of Open Access Journals (Sweden)

    Emily F. Winterbottom

    2015-06-01

    Full Text Available Although considerable evidence suggests that in utero arsenic exposure affects children's health, these data are mainly from areas of the world where groundwater arsenic levels far exceed the World Health Organization limit of 10 μg/L. We, and others, have found that more common levels of in utero arsenic exposure may also impact children's health. However, the underlying molecular mechanisms are poorly understood. To address this issue, we analyzed the expression of key developmental genes in fetal placenta in a birth cohort of women using unregulated water supplies in a US region with elevated groundwater arsenic. We identified several genes whose expression associated with maternal arsenic exposure in a fetal sex-specific manner. In particular, expression of the HEDGEHOG pathway component, GLI3, in female placentae was both negatively associated with arsenic exposure and positively associated with infant birth weight. This suggests that modulation of GLI3 in the fetal placenta, and perhaps in other fetal tissues, contributes to arsenic's detrimental effects on fetal growth. We showed previously that arsenic-exposed NIH3T3 cells have reduced GLI3 repressor protein. Together, these studies identify GLI3 as a key signaling node that is affected by arsenic, mediating a subset of its effects on developmental signaling and fetal health.

  1. Aquatic Sentinels Forecasting Human Exposure To Emerging Contaminants

    Science.gov (United States)

    Most of us have heard the axiom, “canary in the coal mine”. These melodious exposure indicators - a necessity in U.K. mines well into the 20th century - were especially sensitive to methane and carbon monoxide gases, and would cease singing (and oftentimes die) at le...

  2. Strategies for estimating human exposure to mycotoxins via food

    NARCIS (Netherlands)

    Nijs, De M.; Mengelers, M.J.B.; Boon, P.E.; Heyndrickx, E.; Hoogenboom, L.A.P.; Lopez, P.; Mol, H.G.J.

    2016-01-01

    In this review, five strategies to estimate mycotoxin exposure of a (sub-)population via food, including data collection, are discussed with the aim to identify the added values and limitations of each strategy for risk assessment of these chemicals. The well-established point estimate, observed

  3. Mathematical Models of Human Hematopoiesis Following Acute Radiation Exposure

    Science.gov (United States)

    2014-05-01

    response of 11 subjects from Chernobyl 1986 . . . . . . 104 B.8 Chernobyl case studies: Platelet data . . . . . . . . . . . . . . . . . . . . . . 105 B...9 Chernobyl case studies: Granulocyte data . . . . . . . . . . . . . . . . . . . 106 B.10 Chernobyl case studies: Lymphocyte data...information for use in nuclear disaster preparedness planning. Understanding how biological systems change after radiation exposure provides insight on the

  4. Human health effects of dust exposure in anmial confinement buildings

    NARCIS (Netherlands)

    Iversen, M.; Kirychuk, S.; Drost, H.; Jacobson, L.

    2001-01-01

    Work in swine and poultry units is associated with exposure to significant levels of organic dust and endotoxins with the highest concentrations found in poultry houses, whereas values found in dairy and in cattle farming are much lower. Corresponding to this is an excess of work-related respiratory

  5. Modeling human exposure to hazardous-waste sites: a question of completeness

    International Nuclear Information System (INIS)

    Daniels, J.I.; McKone, T.E.

    1991-01-01

    In risk analysis, we use human-exposure assessments to translate contaminant sources into quantitative estimates of the amount of contaminant that comes in contact with human-environment boundaries, that is, the lungs, the gastrointestinal tract, and the skin surface of individuals within a specified population. An assessment of intake requires that we determine how much crosses these boundaries. Exposure assessments often rely implicitly in the assumption that exposure can be linked by simple parameters to ambient concentration in air, water, and soil. However, more realistic exposure models require that we abandon such simple assumptions. To link contaminant concentrations in water, air, or soil with potential human intakes, we constrict pathway-exposure factors (PEFs). For each PEF we combine information in environmental partitioning as well as human anatomy, physiology, and patterns into an algebraic term that converts concentrations of contaminants (in mg/L water, mg/m 3 air, and mg/kg soil) into a daily intake per unit body weight in mg/kg-d for a specific rout of exposure such as inhalation, ingestion, or dermal uptake. Using examples involving human exposure to either a radionuclide (tritium, 3 H) or a toxic organic chemical (tetrachloroethylene, PCE) in soil, water, and air, we illustrate the use of PEFs and consider the implications for risk assessment. (au)

  6. 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.

  7. 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.

  8. The exposures to natural radioactivity as a result of human activities

    International Nuclear Information System (INIS)

    Rannou, A.; Dupuis, M.; Bottollier-Depois, J.F.; Leprieur, F.; Pasquier, J.L.; Doremus, P.; Pierre, J.P.; Bernhard, S.; Delporte, V.; Servent, J.P.; Marchand, D.; Dupuis, M.; Bottollier-Depois, J.F.; Leprieur, F.; Pasquier, J.L.; Doremus, P.; Pierre, J.P.; Surbeck, H.; Degrange, J.P.

    2005-01-01

    The new regulation in matter of radiation protection, coming from the transposition of the European directive 96/29/EURATOM modifies the code of the public health and the labour code. The exposures to natural radioactivity by the very fact of human activities are the object of specific dispositions. These new dispositions apply to professional areas that were, until now, little concerned by the regulation relative to ionizing radiations. The S.F.R.P., in relationship with the Minister in charge of labour, and the A.F.T.I.M. (French organisation of safety technicians and engineers and labour physicians) organizes two days of information and exchange on the subject. This meeting concerns industry and research departments but also inspectors and labour physicians and other actors having a look on the risk management in societies. After some reminder on radioactivity and its effects, the regulation and the global risk management on working place, several actual examples are presented, covering the different known situations of exposure to the natural radioactivity ( radon, cosmic rays, use of radioactive material in an industrial process, production of radioactive waste). The days finish by a round table conference on the stakes and practical entailment of the new regulation. (N.C.)

  9. CONTROLLED EXPOSURES OF HUMAN VOLUNTEERS TO DIESEL ENGINE EXHAUST: BIOMARKERS OF EXPOSURE AND HEALTH OUTCOMES

    Science.gov (United States)

    Combustion of diesel fuel contributes to ambient air pollutant fine particulate matter (PM) and gases. Fine PM exposure has been associated with increased mortality due to adverse cardiac events, and morbidity, such as increased hospitalization for asthma symptoms and lung infect...

  10. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  11. Indicative and complementary effects of human biological indicators for heavy metal exposure assessment.

    Science.gov (United States)

    Xing, Ruiya; Li, Yonghua; Zhang, Biao; Li, Hairong; Liao, Xiaoyong

    2017-10-01

    Although human biological indicators have been widely utilized for biomonitoring environmental pollutants in health exposure assessment, the relationship between internal and external exposure has not yet been adequately established. In this study, we collected and analyzed 61 rice, 56 pepper, and 58 soil samples, together with 107 hair, 107 blood, and 107 urine samples from residents living in selected intensive mining areas in China. Concentrations of most of the four elements considered (Pb, Cd, Hg, and Se) exceeded national standards, implying high exposure risk in the study areas. Regression analysis also revealed a correlation (0.33, P human hair (as well as in human blood); to some extent, Pb content in hair and blood could therefore be used to characterize external Pb exposure. The correlation between Hg in rice and in human hair (up to 0.5, P human hair for Hg exposure. A significant correlation was also noted between concentrations of some elements in different human samples, for example, between Hg in hair and blood (0.641, P assessing heavy metal exposure.

  12. Assessment of human exposure to fumonisin B1

    NARCIS (Netherlands)

    Nijs, M. de; Egmond, H.P. van; Nauta, M.; Rombouts, F.M.; Notermans, S.H.W.

    1998-01-01

    Fumonisin B1 is currently regarded as the most significant mycotoxin produced by Fusarium spp. It has carcinogenic properties and may play a role in the etiology of human esophageal cancer. The human population is exposed to fumonisin B1 primarily by intake of fumonisin B1-contaminated maize. Maize

  13. Can profiles of poly- and Perfluoroalkyl substances (PFASs) in human serum provide information on major exposure sources?

    DEFF Research Database (Denmark)

    Hu, Xindi C; Dassuncao, Clifton; Zhang, Xianming

    2018-01-01

    BACKGROUND: Humans are exposed to poly- and perfluoroalkyl substances (PFASs) from diverse sources and this has been associated with negative health impacts. Advances in analytical methods have enabled routine detection of more than 15 PFASs in human sera, allowing better profiling of PFAS......) and their precursors are ubiquitous in multiple exposure sources. However, their composition varies among sources, which may impact associated adverse health effects. METHODS: We use available PFAS concentrations from several demographic groups in a North Atlantic seafood consuming population (Faroe Islands...... sulfonamidoacetate (N-EtFOSAA), which are directly used or metabolized from fluorochemicals in consumer products such as carpet and food packaging. We find that the same compounds are associated with the same exposure sources in two North American populations, suggesting generalizability of results from the Faroese...

  14. A systematic review of the human body burden of e-waste exposure in China.

    Science.gov (United States)

    Song, Qingbin; Li, Jinhui

    2014-07-01

    As China is one of the countries facing the most serious pollution and human exposure effects of e-waste in the world, much of the population there is exposed to potentially hazardous substances due to informal e-waste recycling processes. This report reviews recent studies on human exposure to e-waste in China, with particular focus on exposure routes (e.g. dietary intake, inhalation, and soil/dust ingestion) and human body burden markers (e.g. placenta, umbilical cord blood, breast milk, blood, hair, and urine) and assesses the evidence for the association between such e-waste exposure and the human body burden in China. The results suggest that residents in the e-waste exposure areas, located mainly in the three traditional e-waste recycling sites (Taizhou, Guiyu, and Qingyuan), are faced with a potential higher daily intake of these pollutants than residents in the control areas, especially via food ingestion. Moreover, pollutants (PBBs, PBDEs, PCBs, PCDD/Fs, and heavy metals) from the e-waste recycling processes were all detectable in the tissue samples at high levels, showing that they had entered residents' bodies through the environment and dietary exposure. Children and neonates are the groups most sensitive to the human body effects of e-waste exposure. We also recorded plausible outcomes associated with exposure to e-waste, including 7 types of human body burden. Although the data suggest that exposure to e-waste is harmful to health, better designed epidemiological investigations in vulnerable populations, especially neonates and children, are needed to confirm these associations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Cigarette smoke exposure inhibits extracellular MMP-2 (gelatinase A activity in human lung fibroblasts

    Directory of Open Access Journals (Sweden)

    Cappello Francesco

    2007-03-01

    Full Text Available Abstract Background Exposure to cigarette smoke is considered a major risk factor for the development of lung diseases, since its causative role has been assessed in the induction and maintenance of an inflamed state in the airways. Lung fibroblasts can contribute to these processes, due to their ability to produce proinflammatory chemotactic molecules and extracellular matrix remodelling proteinases. Among proteolytic enzymes, gelatinases A and B have been studied for their role in tissue breakdown and mobilisation of matrix-derived signalling molecules. Multiple reports linked gelatinase deregulation and overexpression to the development of inflammatory chronic lung diseases such as COPD. Methods In this study we aimed to determine variations in the gelatinolytic pattern of human lung fibroblasts (HFL-1 cell line exposed to cigarette smoke extract (CSE. Gelatinolytic activity levels were determined by using gelatin zymography for the in-gel detection of the enzymes (proenzyme and activated forms, and the subsequent semi-quantitative densitometric evaluation of lytic bands. Expression of gelatinases was evaluated also by RT-PCR, zymography of the cell lysates and by western blotting. Results CSE exposure at the doses used (1–10% did not exert any significant cytotoxic effects on fibroblasts. Zymographic analysis showed that CSE exposure resulted in a linear decrease of the activity of gelatinase A. Control experiments allowed excluding a direct inhibitory effect of CSE on gelatinases. Zymography of cell lysates confirmed the expression of MMP-2 in all conditions. Semi-quantitative evaluation of mRNA expression allowed assessing a reduced transcription of the enzyme, as well as an increase in the expression of TIMP-2. Statistical analyses showed that the decrease of MMP-2 activity in conditioned media reached the statistical significance (p = 0.0031 for 24 h and p = 0.0012 for 48 h, while correlation analysis showed that this result was

  16. Detection of antibodies in human serum using trimellityl-erythrocytes: direct and indirect haemagglutination and haemolysis.

    Science.gov (United States)

    Turner, E S; Pruzansky, J J; Patterson, R; Zeiss, C R; Roberts, M

    1980-02-01

    Utilizing trimellityl-erythrocytes (TM-E), antibodies were detected in sera of seven workers with trimellitic anhydride (TMA) induced airway syndromes by direct haemagglutination, indirect haemagglutination with anti-human IgG, IgA or IgM or by haemolysis. Detectable levels of antibody were obtained with all three methods. The most sensitive technique was indirect haemagglutination using anti-IgG. When added as an inhibitor, TM-human serum albumin produced a 10- to 800-fold reduction in titres. TM-ovalbumin of similar epitope density was less inhibitory and sodium trimellitate the least inhibitory on a molar basis. All of the assays using haptenized human red cells were also capable of detecting anti-TM antibodies in Rhesus monkeys whose airways had been exposed to TMA. These assays are useful for detecting anti-TM antibodies and may also be adapted to demonstrate antibodies induced against other inhaled haptens in sera of environmentally exposed individuals or in animal models of such exposure.

  17. Controlled human exposure to indoor air, dust, and ozone; XDOZ

    DEFF Research Database (Denmark)

    Elholm, Grethe; Bønløkke, Jakob; Schlünssen, Vivi

    2017-01-01

    . All participants were subjected to four different exposure scenarios in the climate chamber.Exp. 1: Dust (250 – 300 µg/m3)Exp. 2: Ozone (100 ppb)Exp. 3: Dust (250 – 300 µg/m3) + ozone (100 ppb)Exp. 4: Filtered air (<20µg/m3)The exposure time was 5½ hours for each session.The health effects were...... evaluated at baseline and specific follow-up times in relation to selected respiratory and cardiovascular outcomes, such as; nasal volume, exhaled nitric oxide (FENO), spirometry (FEV1 and FVC), exhaled breath condensate (EBC), nasal lavage, blood samples, EndoPat. Questionnaires were used for assessment...

  18. The human placenta--an alternative for studying foetal exposure

    DEFF Research Database (Denmark)

    Myren, Maja; Mose, Tina; Mathiesen, Line

    2007-01-01

    Pregnant women are daily exposed to a wide selection of foreign substances. Sources are as different as lifestyle factors (smoking, daily care products, alcohol consumption, etc.), maternal medication or occupational/environmental exposures. The placenta provides the link between mother and foetus......, and though its main task is to act as a barrier and transport nutrients and oxygen to the foetus, many foreign compounds are transported across the placenta to some degree and may therefore influence the unborn child. Foetal exposures to environmental and medicinal products may have impact on the growth...... of the foetus (e.g. cigarette smoke) and development of the foetal organs (e.g. methylmercury and thalidomide). The scope of this review is to give insight to the placental anatomy, development and function. Furthermore, the compounds physical properties and the transfer mechanism across the placental barrier...

  19. Novel Human Radiation Exposure Biomarker Panel Applicable for Population Triage

    Energy Technology Data Exchange (ETDEWEB)

    Bazan, Jose G. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Chang, Polly; Balog, Robert; D' Andrea, Annalisa; Shaler, Thomas; Lin, Hua; Lee, Shirley; Harrison, Travis [SRI International, Menlo Park, California (United States); Shura, Lei; Schoen, Lucy; Knox, Susan J. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Cooper, David E., E-mail: david.cooper@sri.com [SRI International, Menlo Park, California (United States)

    2014-11-01

    Purpose: To identify a panel of radiation-responsive plasma proteins that could be used in a point-of-care biologic dosimeter to detect clinically significant levels of ionizing radiation exposure. Methods and Materials: Patients undergoing preparation for hematopoietic cell transplantation using radiation therapy (RT) with either total lymphoid irradiation or fractionated total body irradiation were eligible. Plasma was examined from patients with potentially confounding conditions and from normal individuals. Each plasma sample was analyzed for a panel of 17 proteins before RT was begun and at several time points after RT exposure. Paired and unpaired t tests between the dose and control groups were performed. Conditional inference trees were constructed based on panels of proteins to compare the non-RT group with the RT group. Results: A total of 151 patients (62 RT, 41 infection, 48 trauma) were enrolled on the study, and the plasma from an additional 24 healthy control individuals was analyzed. In comparison with to control individuals, tenascin-C was upregulated and clusterin was downregulated in patients receiving RT. Salivary amylase was strongly radiation responsive, with upregulation in total body irradiation patients and slight downregulation in total lymphoid irradiation patients compared with control individuals. A panel consisting of these 3 proteins accurately distinguished between irradiated patients and healthy control individuals within 3 days after exposure: 97% accuracy, 0.5% false negative rate, 2% false positive rate. The accuracy was diminished when patients with trauma, infection, or both were included (accuracy, 74%-84%; false positive rate, 14%-33%, false negative rate: 8%-40%). Conclusions: A panel of 3 proteins accurately distinguishes unirradiated healthy donors from those exposed to RT (0.8-9.6 Gy) within 3 days of exposure. These findings have significant implications in terms of triaging individuals in the case of nuclear or other

  20. Lead Exposure Induces Telomere Instability in Human Cells.

    Directory of Open Access Journals (Sweden)

    Géraldine Pottier

    Full Text Available Lead (Pb is an important environmental contaminant due to its widespread use over many centuries. While it affects primarily every organ system of the body, the most pernicious effects of Pb are on the central nervous system leading to cognitive and behavioral modification. Despite decades of research, the mechanisms responsible for Pb toxicity remain poorly understood. Recent work has suggested that Pb exposure may have consequences on chromosomal integrity as it was shown that Pb exposure leads to the generation of γH2Ax foci, a well-established biomarker for DNA double stranded break (DSB formation. As the chromosomal localization of γH2Ax foci plays an important role in determining the molecular mechanism responsible for their formation, we examined the localization of Pb-induced foci with respect to telomeres. Indeed, short or dysfunctional telomeres (uncapped or damaged telomeres may be recognized as DSB by the DNA repair machinery, leading to "telomere-Induced Foci" (TIFs. In the current study, we show that while Pb exposure did not increase intra-chromosomal foci, it significantly induced TIFs, leading in some cases, to chromosomal abnormalities including telomere loss. The evidence suggests that these chromosomal abnormalities are likely due to perturbation of telomere replication, in particular on the lagging DNA strand. We propose a mechanism by which Pb exposure leads to the loss of telomere maintenance. As numerous studies have demonstrated a role for telomere maintenance in brain development and tissue homeostasis, our results suggest a possible mechanism for lead-induced neurotoxicity.

  1. Acute effects of acrolein in human volunteers during controlled exposure.

    Science.gov (United States)

    Dwivedi, Aishwarya M; Johanson, Gunnar; Lorentzen, Johnny C; Palmberg, Lena; Sjögren, Bengt; Ernstgård, Lena

    2015-01-01

    Acrolein is a reactive aldehyde mainly formed by combustion. The critical effect is considered to be irritation of the eyes and airways; however, the scarce data available make it difficult to assess effect levels. The aim of the study was to determine thresholds for acute irritation for acrolein. Nine healthy volunteers of each sex were exposed at six occasions for 2 h at rest to: clean air, 15 ppm ethyl acetate (EA), and 0.05 ppm and 0.1 ppm acrolein with and without EA (15 ppm) to mask the potential influence of odor. Symptoms related to irritation and central nervous system effects were rated on 100-mm Visual Analogue Scales. The ratings of eye irritation were slightly but significantly increased during exposure to acrolein in a dose-dependent manner (p acrolein alone but not during any of the other five exposure conditions. Based on subjective ratings, the present study showed minor eye irritation by exposure to 0.1 ppm acrolein.

  2. Sensitivity analysis for direct and indirect effects in the presence of exposure-induced mediator-outcome confounders

    Science.gov (United States)

    Chiba, Yasutaka

    2014-01-01

    Questions of mediation are often of interest in reasoning about mechanisms, and methods have been developed to address these questions. However, these methods make strong assumptions about the absence of confounding. Even if exposure is randomized, there may be mediator-outcome confounding variables. Inference about direct and indirect effects is particularly challenging if these mediator-outcome confounders are affected by the exposure because in this case these effects are not identified irrespective of whether data is available on these exposure-induced mediator-outcome confounders. In this paper, we provide a sensitivity analysis technique for natural direct and indirect effects that is applicable even if there are mediator-outcome confounders affected by the exposure. We give techniques for both the difference and risk ratio scales and compare the technique to other possible approaches. PMID:25580387

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-06-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  6. Critical elements for human health risk assessment of less than lifetime exposures.

    Science.gov (United States)

    Geraets, Liesbeth; Nijkamp, Monique M; Ter Burg, Wouter

    2016-11-01

    Less than lifetime exposure has confronted risk assessors as to how to interpret the risks for human health in case a chronic health-based limit is exceeded. Intermittent, fluctuating and peak exposures do not match with the basis of the chronic limit values possibly leading to conservative outcomes. This paper presents guidance on how to deal with human risk assessment of less than lifetime exposure. Important steps to be considered are characterization of the human exposure situation, evaluation whether the human less than lifetime exposure scenario corresponds to a non-chronic internal exposure: toxicokinetic and toxicodynamic considerations, and, finally, re-evaluation of the risk assessment. Critical elements for these steps are the mode of action, Haber's rule, and toxicokinetics (ADME) amongst others. Previous work for the endpoints non-genotoxic carcinogenicity and developmental toxicity is included in the guidance. The guidance provides a way to consider the critical elements, without setting default factors to correct for the less than lifetime exposure in risk assessment. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Wildfire smoke exposure and human health: Significant gaps in research for a growing public health issue.

    Science.gov (United States)

    Black, Carolyn; Tesfaigzi, Yohannes; Bassein, Jed A; Miller, Lisa A

    2017-10-01

    Understanding the effect of wildfire smoke exposure on human health represents a unique interdisciplinary challenge to the scientific community. Population health studies indicate that wildfire smoke is a risk to human health and increases the healthcare burden of smoke-impacted areas. However, wildfire smoke composition is complex and dynamic, making characterization and modeling difficult. Furthermore, current efforts to study the effect of wildfire smoke are limited by availability of air quality measures and inconsistent air quality reporting among researchers. To help address these issues, we conducted a substantive review of wildfire smoke effects on population health, wildfire smoke exposure in occupational health, and experimental wood smoke exposure. Our goal was to evaluate the current literature on wildfire smoke and highlight important gaps in research. In particular we emphasize long-term health effects of wildfire smoke, recovery following wildfire smoke exposure, and health consequences of exposure in children. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivana Vukanac

    2012-09-01

    Full Text Available Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they fall out from air and water onto the ground and build into the foodstuff and drinking water resulting in radiation doses to human beings. The short overview of presence of artificial radioactivity in human environment and its impact on human life is presented in this paper.

  9. HUMAN EXPOSURE TO THE ARTIFICIAL RADIONUCLIDES IN ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ivana Vukanac

    2012-09-01

    Full Text Available Artificial radionuclides are product of different human activities and their presence in the environment is negative side effect of civilization progress. They have been spread in the environment by events such as nuclear weapon tests, nuclear accidents and by deliberate and negligent discharge of radioactive waste from nuclear and other installation. Once released in to the nature, the artificial radionuclides start to circle in the same manner as naturally occurring ones, and finally they fall out from air and water onto the ground and build into the foodstuff and drinking water resulting in radiation doses to human beings. The short overview of presence of artificial radioactivity in human environment and its impact on human life is presented in this paper

  10. Investigating Intergenerational Differences in Human PCB Exposure due to Variable Emissions and Reproductive Behaviors

    Science.gov (United States)

    Quinn, Cristina L.; Wania, Frank; Czub, Gertje; Breivik, Knut

    2011-01-01

    Background Reproductive behaviors—such as age of childbearing, parity, and breast-feeding prevalence—have changed over the same historical time period as emissions of polychlorinated biphenyls (PCB) and may produce intergenerational differences in human PCB exposure. Objectives Our goal in this study was to estimate prenatal, postnatal, and lifetime PCB exposures for women at different ages according to year of birth, and to evaluate the impact of reproductive characteristics on intergenerational differences in exposure. Methods We used the time-variant mechanistic model CoZMoMAN to calculate human bioaccumulation of PCBs, assuming both hypothetical constant and realistic time-variant emissions. Results Although exposure primarily depends on when an individual was born relative to the emission history of PCBs, reproductive behaviors can have a significant impact. Our model suggests that a mother’s reproductive history has a greater influence on the prenatal and postnatal exposures of her children than it does on her own cumulative lifetime exposure. In particular, a child’s birth order appears to have a strong influence on their prenatal exposure, whereas postnatal exposure is determined by the type of milk (formula or breast milk) fed to the infant. Conclusions Prenatal PCB exposure appears to be delayed relative to the time of PCB emissions, particularly among those born after the PCB production phaseout. Consequently, the health repercussions of environmental PCBs can be expected to persist for several decades, despite bans on their production for > 40 years. PMID:21156396

  11. An approach for assessing human exposures to chemical mixtures in the environment

    International Nuclear Information System (INIS)

    Rice, Glenn; MacDonell, Margaret; Hertzberg, Richard C.; Teuschler, Linda; Picel, Kurt; Butler, Jim; Chang, Young-Soo; Hartmann, Heidi

    2008-01-01

    Humans are exposed daily to multiple chemicals, including incidental exposures to complex chemical mixtures released into the environment and to combinations of chemicals that already co-exist in the environment because of previous releases from various sources. Exposures to chemical mixtures can occur through multiple pathways and across multiple routes. In this paper, we propose an iterative approach for assessing exposures to environmental chemical mixtures; it is similar to single-chemical approaches. Our approach encompasses two elements of the Risk Assessment Paradigm: Problem Formulation and Exposure Assessment. Multiple phases of the assessment occur in each element of the paradigm. During Problem Formulation, analysts identify and characterize the source(s) of the chemical mixture, ensure that dose-response and exposure assessment measures are concordant, and develop a preliminary evaluation of the mixture's fate. During Exposure Assessment, analysts evaluate the fate of the chemicals comprising the mixture using appropriate models and measurement data, characterize the exposure scenario, and estimate human exposure to the mixture. We also describe the utility of grouping the chemicals to be analyzed based on both physical-chemical properties and an understanding of environmental fate. In the article, we also highlight the need for understanding of changes in the mixture composition in the environment due to differential transport, differential degradation, and differential partitioning to other media. The section describes the application of the method to various chemical mixtures, highlighting issues associated with assessing exposures to chemical mixtures in the environment

  12. Florida Red Tide and Human Health: A Pilot Beach Conditions Reporting System to Minimize Human Exposure

    Science.gov (United States)

    Kirkpatrick, Barbara; Currier, Robert; Nierenberg, Kate; Reich, Andrew; Backer, Lorraine C.; Stumpf, Richard; Fleming, Lora; Kirkpatrick, Gary

    2008-01-01

    With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While may of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida’s west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway lower symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting

  13. Multi-scale spatial modeling of human exposure from local sources to global intake

    DEFF Research Database (Denmark)

    Wannaz, Cedric; Fantke, Peter; Jolliet, Olivier

    2018-01-01

    Exposure studies, used in human health risk and impact assessments of chemicals are largely performed locally or regionally. It is usually not known how global impacts resulting from exposure to point source emissions compare to local impacts. To address this problem, we introduce Pangea......, an innovative multi-scale, spatial multimedia fate and exposure assessment model. We study local to global population exposure associated with emissions from 126 point sources matching locations of waste-to-energy plants across France. Results for three chemicals with distinct physicochemical properties...... occur within a 100 km radius from the source. This suggests that, by neglecting distant low-level exposure, local assessments might only account for fractions of global cumulative intakes. We also study ~10,000 emission locations covering France more densely to determine per chemical and exposure route...

  14. Human Infection with MERS coronavirus after exposure to infected camels, Saudi Arabia, 2013

    NARCIS (Netherlands)

    Memish, Ziad A.; Cotten, Matthew; Meyer, Benjamin; Watson, Simon J.; Alsahafi, Abdullah J.; Al Rabeeah, Abdullah A.; Corman, Victor Max; Sieberg, Andrea; Makhdoom, Hatem Q.; Assiri, Abdullah; Al Masri, Malaki; Aldabbagh, Souhaib; Bosch, Berend Jan|info:eu-repo/dai/nl/273306049; Beer, Martin; Müller, Marcel A.; Kellam, Paul; Drosten, Christian

    2014-01-01

    We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species

  15. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1981-05-01

    The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures

  16. Overnight hypoxic exposure and glucagon-like peptide-1 and leptin levels in humans

    DEFF Research Database (Denmark)

    Snyder, Eric M; Carr, Richard D; Deacon, Carolyn F

    2008-01-01

    increases with hypoxia; however, the influence of hypoxia on GLP-1 has not been studied in animals or humans to date. We sought to determine the influence of normobaric hypoxia on plasma leptin and GLP-1 levels in 25 healthy humans. Subjects ingested a control meal during normoxia and after 17 h of exposure...

  17. COMPARING THE UTILITY OF MULTIMEDIA MODELS FOR HUMAN AND ECOLOGICAL EXPOSURE ANALYSIS: TWO CASES

    Science.gov (United States)

    A number of models are available for exposure assessment; however, few are used as tools for both human and ecosystem risks. This discussion will consider two modeling frameworks that have recently been used to support human and ecological decision making. The study will compare ...

  18. Assessment of indirect human exposure to environmental sources of nickel: oral exposure and risk characterization for systemic effects.

    Science.gov (United States)

    De Brouwere, Katleen; Buekers, Jurgen; Cornelis, Christa; Schlekat, Christian E; Oller, Adriana R

    2012-03-01

    This paper describes the indirect human exposure to Ni via the oral route for the regional scale in the EU, together with a method to assess additional local exposure from industrial emissions. The approach fills a gap in the generic REACH guidance which is inadequate for assessing indirect environmental exposure of metals. Estimates of regional scale Ni dietary intake were derived from Ni dietary studies performed in the EU. Typical and Reasonable Worst Case dietary Ni intakes for the general population in the EU were below the oral Derived No Effect Level (DNEL) of Ni sulfate for systemic effects. Estimates for the Ni dietary intake at the local scale take into account the influence of aerial Ni deposition and transfer from soil to crops grown near industrial plants emitting Ni. The additional dietary exposure via this local contribution was small. Despite the use of conservative parameters for these processes, this method may underestimate dietary exposure around older industrial sites because REACH guidance does not account for historical soil contamination. Nevertheless, the method developed here can also be used as a screening tool for community-based risk assessment, as it accounts for historical soil pollution. Nickel exposure via drinking water was derived from databases on Ni tap water quality. A small proportion of the EU population (<5%) is likely to be exposed to tap water exceeding the EU standard (20 μg Ni/l). Taking into account the relative gastrointestinal absorption of Ni from water (30%) versus from solid matrices (5%), water intake constitutes, after dietary intake, the second most important pathway for oral Ni intake. Incidental ingestion of Ni from soil/dust at the regional scale, and also at the local scale, was low in comparison with dietary intake. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Dendritic coarsening of γ' phase in a directionally solidified superalloy during 24,000 h of exposure at 1173 K

    International Nuclear Information System (INIS)

    Li, H.; Wang, L.; Lou, L.H.

    2010-01-01

    Dendritic coarsening of γ' was investigated in a directionally solidified Ni-base superalloy during exposure at 1173 K for 24,000 h. Chemical homogeneity along different directions and residual internal strain in the experimental superalloy were measured by electronic probe microanalysis (EPMA) and electron back-scattered diffraction (EBSD) technique. It was indicated that the gradient of element distribution was anisotropic and the inner strain between dendrite core and interdendritic regions was different even after 24,000 h of exposure at 1173 K, which influenced the kinetics for the dendrite coarsening of γ' phase.

  20. Effect of the European directive on medical exposure on patients doses

    Energy Technology Data Exchange (ETDEWEB)

    Wade, P.; Heaton, B. [Aberdeen Royal Infirmary, Aberdeen (United Kingdom)

    2006-07-01

    Full text of publication follows: In 2000 the European Directive on medical exposures was incorporated into United Kingdom law. Whilst the primary aim was to ensure that all uses of ionising radiation in medical practice were justified and a benefit to the patient or volunteer was identified, there was an understanding that patient doses would be controlled and collective doses reduced. The Ionising Radiation (Medical Exposure) Regulations 2000 made a lot of new demands on radiology and Nuclear Medicine departments. No department is too small or specialized to ignore these regulations and the impact can be major. The Aberdeen Radiation Protection Service advises a number of users of ionising radiation on the implementation of these regulations ranging from single person dental practices to large radiology departments in busy regional hospitals. The particular problems and issues affecting different departments will be discussed. The regulations identified new key roles with Employers, Referrers, Practitioners and Operators all having specific responsibilities. Each of these groups needs to be identified, informed of their responsibilities and trained as necessary. The problems this has raised for the various staff groups will be discussed. A large number of procedures had to be written from how a patient is uniquely identified to how incidents are reported and investigated. There is much emphasis on optimising the use of equipment and techniques used, paying particular attention to women of child bearing age and children. Again there are problems in implementing this in practice and these issues will be discussed. A formal procedure for reporting 'near misses' and actual incidents of overexposure, were introduced. Each reported event is reviewed to identify issues and lessons which can be learnt by others. There is often a lateral thinking exercise involved to reduce the probability of an incident happening again and some novel solutions have been

  1. Effect of the European directive on medical exposure on patients doses

    International Nuclear Information System (INIS)

    Wade, P.; Heaton, B.

    2006-01-01

    Full text of publication follows: In 2000 the European Directive on medical exposures was incorporated into United Kingdom law. Whilst the primary aim was to ensure that all uses of ionising radiation in medical practice were justified and a benefit to the patient or volunteer was identified, there was an understanding that patient doses would be controlled and collective doses reduced. The Ionising Radiation (Medical Exposure) Regulations 2000 made a lot of new demands on radiology and Nuclear Medicine departments. No department is too small or specialized to ignore these regulations and the impact can be major. The Aberdeen Radiation Protection Service advises a number of users of ionising radiation on the implementation of these regulations ranging from single person dental practices to large radiology departments in busy regional hospitals. The particular problems and issues affecting different departments will be discussed. The regulations identified new key roles with Employers, Referrers, Practitioners and Operators all having specific responsibilities. Each of these groups needs to be identified, informed of their responsibilities and trained as necessary. The problems this has raised for the various staff groups will be discussed. A large number of procedures had to be written from how a patient is uniquely identified to how incidents are reported and investigated. There is much emphasis on optimising the use of equipment and techniques used, paying particular attention to women of child bearing age and children. Again there are problems in implementing this in practice and these issues will be discussed. A formal procedure for reporting 'near misses' and actual incidents of overexposure, were introduced. Each reported event is reviewed to identify issues and lessons which can be learnt by others. There is often a lateral thinking exercise involved to reduce the probability of an incident happening again and some novel solutions have been implemented

  2. 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....

  3. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 7. Organ doses due to parallel and environmental exposure geometries

    Energy Technology Data Exchange (ETDEWEB)

    Zankl, M. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Drexler, G. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Petoussi-Henss, N. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Saito, K. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1997-03-01

    This report presents a tabulation of organ and tissue equivalent dose as well as effective dose conversion coefficients, normalised to air kerma free in air, for occupational exposures and environmental exposures of the public to external photon radiation. For occupational exposures, whole-body irradiation with idealised geometries, i.e. broad parallel beams and fully isotropic radiation incidence, is considered. The directions of incidence for the parallel beams are anterior-posterior, posterior-anterior, left lateral, right lateral and a full 360 rotation around the body`s longitudinal axis. The influence of beam divergence on the body doses is also considered as well as the dependence of effective dose on the angle of radiation incidence. Regarding exposure of the public to environmental sources, three source geometries are considered: exposure from a radioactive cloud, from ground contamination and from the natural radionuclides distributed homogeneously in the ground. The precise angular and energy distributions of the gamma rays incident on the human body were taken into account. The organ dose conversion coefficients given in this catalogue were calculated using a Monte Carlo code simulating the photon transport in mathematical models of an adult male and an adult female, respectively. Conversion coefficients are given for the equivalent dose of 23 organs and tissues as well as for effective dose and the equivalent dose of the so-called `remainder`. The organ equivalent dose conversion coefficients are given separately for the adult male and female models and - as arithmetic mean of the conversion coefficients of both - for an average adult. Fitted data of the coefficients are presented in tables; the primary raw data as resulting from the Monte Carlo calculation are shown in figures together with the fitted data. (orig.)

  4. The calculation of dose from external photon exposures using reference human phantoms and Monte Carlo methods. Pt. 7. Organ doses due to parallel and environmental exposure geometries

    International Nuclear Information System (INIS)

    Zankl, M.

    1997-03-01

    This report presents a tabulation of organ and tissue equivalent dose as well as effective dose conversion coefficients, normalised to air kerma free in air, for occupational exposures and environmental exposures of the public to external photon radiation. For occupational exposures, whole-body irradiation with idealised geometries, i.e. broad parallel beams and fully isotropic radiation incidence, is considered. The directions of incidence for the parallel beams are anterior-posterior, posterior-anterior, left lateral, right lateral and a full 360 rotation around the body's longitudinal axis. The influence of beam divergence on the body doses is also considered as well as the dependence of effective dose on the angle of radiation incidence. Regarding exposure of the public to environmental sources, three source geometries are considered: exposure from a radioactive cloud, from ground contamination and from the natural radionuclides distributed homogeneously in the ground. The precise angular and energy distributions of the gamma rays incident on the human body were taken into account. The organ dose conversion coefficients given in this catalogue were calculated using a Monte Carlo code simulating the photon transport in mathematical models of an adult male and an adult female, respectively. Conversion coefficients are given for the equivalent dose of 23 organs and tissues as well as for effective dose and the equivalent dose of the so-called 'remainder'. The organ equivalent dose conversion coefficients are given separately for the adult male and female models and - as arithmetic mean of the conversion coefficients of both - for an average adult. Fitted data of the coefficients are presented in tables; the primary raw data as resulting from the Monte Carlo calculation are shown in figures together with the fitted data. (orig.)

  5. Exposure, uptake, distribution and toxicity of nanomaterials in humans.

    Science.gov (United States)

    Holgate, Stephen T

    2010-02-01

    The last decade has witnessed an unprecedented explosion in nanotechnology to take advantage of the unique physicochemical properties that emerge at the nanoscale including quantum effects. However, the excitement generated by new applications of nanotechnology in products has not been matched by a parallel appreciation or understanding of their potential toxic effects in humans and the wider ecology. This review draws some parallels to what we already know about the toxicity of particles in the workplace and in association with air pollution, and then discusses what is known about the toxicology of nanomaterials in mammals including humans. The review identifies substantial gaps in knowledge and makes some recommendations for future research.

  6. Potential teratogenicity of methimazole: exposure of zebrafish embryos to methimazole causes similar developmental anomalies to human methimazole embryopathy.

    Science.gov (United States)

    Komoike, Yuta; Matsuoka, Masato; Kosaki, Kenjiro

    2013-06-01

    While methimazole (MMI) is widely used in the therapy for hyperthyroidism, several groups have reported that maternal exposure to MMI results in a variety of congenital anomalies, including choanal and esophageal atresia, iridic and retinal coloboma, and delayed neurodevelopment. Thus, adverse effects of maternal exposure to MMI on fetal development have long been suggested; however, direct evidence for the teratogenicity of MMI has not been presented. Therefore, we studied the effects of MMI on early development by using zebrafish as a model organism. The fertilized eggs of zebrafish were collected immediately after spawning and grown in egg culture water containing MMI at various concentrations. External observation of the embryos revealed that exposure to high concentrations of MMI resulted in loss of pigmentation, hypoplastic hindbrain, turbid tissue in the forebrain, swelling of the notochord, and curly trunk. Furthermore, these effects occurred in a dose-dependent manner. Precise observation of the serial cross-sections of MMI-exposed embryos elucidated delayed development and hypoplasia of the whole brain and spinal cord, narrowing of the pharynx and esophagus, severe disruption of the retina, and aberrant structure of the notochord. These neuronal, pharyngeal, esophageal, and retinal anomalous morphologies have a direct analogy to the congenital anomalies observed in children exposed to MMI in utero. Here, we show the teratogenic effects of MMI on the development of zebrafish and provide the first experimental evidence for the connection between exposure to MMI and human MMI embryopathy. © 2013 Wiley Periodicals, Inc.

  7. High Throughput Heuristics for Prioritizing Human Exposure to Environmental Chemicals

    Science.gov (United States)

    The risk posed to human health by any of the thousands of untested anthropogenic chemicals in our environment is a function of both the potential hazard presented by the chemical, and the possibility of being exposed. Without the capacity to make quantitative, albeit uncertain, f...

  8. Human volunteer study with PGME: Eye irritation during vapour exposure

    NARCIS (Netherlands)

    Emmen, H.H.; Muijser, H.; Arts, J.H.E.; Prinsen, M.K.

    2003-01-01

    The objective of this study was to establish the possible occurrence of eye irritation and subjective symptoms in human volunteers exposed to propylene glycol monomethyl ether (PGME) vapour at concentrations of 0, 100 and 150 ppm. Testing was conducted in 12 healthy male volunteers using a repeated

  9. A changing climate: impacts on human exposures to O3 using ...

    Science.gov (United States)

    Predicting the impacts of changing climate on human exposure to air pollution requires future scenarios that account for changes in ambient pollutant concentrations, population sizes and distributions, and housing stocks. An integrated methodology to model changes in human exposures due to these impacts was developed by linking climate, air quality, land-use, and human exposure models. This methodology was then applied to characterize changes in predicted human exposures to O3 under multiple future scenarios. Regional climate projections for the U.S. were developed by downscaling global circulation model (GCM) scenarios for three of the Intergovernmental Panel on Climate Change’s (IPCC’s) Representative Concentration Pathways (RCPs) using the Weather Research and Forecasting (WRF) model. The regional climate results were in turn used to generate air quality (concentration) projections using the Community Multiscale Air Quality (CMAQ) model. For each of the climate change scenarios, future U.S. census-tract level population distributions from the Integrated Climate and Land Use Scenarios (ICLUS) model for four future scenarios based on the IPCC’s Special Report on Emissions Scenarios (SRES) storylines were used. These climate, air quality, and population projections were used as inputs to EPA’s Air Pollutants Exposure (APEX) model for 12 U.S. cities. Probability density functions show changes in the population distribution of 8 h maximum daily O3 exposur

  10. Probabilistic integrated risk assessment of human exposure risk to environmental bisphenol A pollution sources.

    Science.gov (United States)

    Fu, Keng-Yen; Cheng, Yi-Hsien; Chio, Chia-Pin; Liao, Chung-Min

    2016-10-01

    Environmental bisphenol A (BPA) exposure has been linked to a variety of adverse health effects such as developmental and reproductive issues. However, establishing a clear association between BPA and the likelihood of human health is complex yet fundamentally uncertain. The purpose of this study was to assess the potential exposure risks from environmental BPA among Chinese population based on five human health outcomes, namely immune response, uterotrophic assay, cardiovascular disease (CVD), diabetes, and behavior change. We addressed these health concerns by using a stochastic integrated risk assessment approach. The BPA dose-dependent likelihood of effects was reconstructed by a series of Hill models based on animal models or epidemiological data. We developed a physiologically based pharmacokinetic (PBPK) model that allows estimation of urinary BPA concentration from external exposures. Here we showed that the daily average exposure concentrations of BPA and urinary BPA estimates were consistent with the published data. We found that BPA exposures were less likely to pose significant risks for infants (0-1 year) and adults (male and female >20 years) with human long-term BPA susceptibility in relation to multiple exposure pathways, and for informing the public of the negligible magnitude of environmental BPA pollution impacts on human health.

  11. Gene expression signatures that predict radiation exposure in mice and humans.

    Directory of Open Access Journals (Sweden)

    Holly K Dressman

    2007-04-01

    Full Text Available The capacity to assess environmental inputs to biological phenotypes is limited by methods that can accurately and quantitatively measure these contributions. One such example can be seen in the context of exposure to ionizing radiation.We have made use of gene expression analysis of peripheral blood (PB mononuclear cells to develop expression profiles that accurately reflect prior radiation exposure. We demonstrate that expression profiles can be developed that not only predict radiation exposure in mice but also distinguish the level of radiation exposure, ranging from 50 cGy to 1,000 cGy. Likewise, a molecular signature of radiation response developed solely from irradiated human patient samples can predict and distinguish irradiated human PB samples from nonirradiated samples with an accuracy of 90%, sensitivity of 85%, and specificity of 94%. We further demonstrate that a radiation profile developed in the mouse can correctly distinguish PB samples from irradiated and nonirradiated human patients with an accuracy of 77%, sensitivity of 82%, and specificity of 75%. Taken together, these data demonstrate that molecular profiles can be generated that are highly predictive of different levels of radiation exposure in mice and humans.We suggest that this approach, with additional refinement, could provide a method to assess the effects of various environmental inputs into biological phenotypes as well as providing a more practical application of a rapid molecular screening test for the diagnosis of radiation exposure.

  12. Estimating human exposure to perfluoroalkyl acids via solid food and drinks : Implementation and comparison of different dietary assessment methods

    NARCIS (Netherlands)

    Papadopoulou, Eleni; Poothong, Somrutai; Koekkoek, Jacco; Lucattini, Luisa; Padilla-Sánchez, Juan Antonio; Haugen, Margaretha; Herzke, Dorte; Valdersnes, Stig; Maage, Amund; Cousins, Ian T.; Leonards, Pim E.G.; Småstuen Haug, Line

    2017-01-01

    Background Diet is a major source of human exposure to hazardous environmental chemicals, including many perfluoroalkyl acids (PFAAs). Several assessment methods of dietary exposure to PFAAs have been used previously, but there is a lack of comparisons between methods. Aim To assess human exposure

  13. Developing and evaluating distributions for probabilistic human exposure assessments

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy L.; McKone, Thomas E.

    2002-08-01

    This report describes research carried out at the Lawrence Berkeley National Laboratory (LBNL) to assist the U. S. Environmental Protection Agency (EPA) in developing a consistent yet flexible approach for evaluating the inputs to probabilistic risk assessments. The U.S. EPA Office of Emergency and Remedial Response (OERR) recently released Volume 3 Part A of Risk Assessment Guidance for Superfund (RAGS), as an update to the existing two-volume set of RAGS. The update provides policy and technical guidance on performing probabilistic risk assessment (PRA). Consequently, EPA risk managers and decision-makers need to review and evaluate the adequacy of PRAs for supporting regulatory decisions. A critical part of evaluating a PRA is the problem of evaluating or judging the adequacy of input distributions PRA. Although the overarching theme of this report is the need to improve the ease and consistency of the regulatory review process, the specific objectives are presented in two parts. The objective of Part 1 is to develop a consistent yet flexible process for evaluating distributions in a PRA by identifying the critical attributes of an exposure factor distribution and discussing how these attributes relate to the task-specific adequacy of the input. This objective is carried out with emphasis on the perspective of a risk manager or decision-maker. The proposed evaluation procedure provides consistency to the review process without a loss of flexibility. As a result, the approach described in Part 1 provides an opportunity to apply a single review framework for all EPA regions and yet provide the regional risk manager with the flexibility to deal with site- and case-specific issues in the PRA process. However, as the number of inputs to a PRA increases, so does the complexity of the process for calculating, communicating and managing risk. As a result, there is increasing effort required of both the risk professionals performing the analysis and the risk manager

  14. Multiplexed activity-based protein profiling of the human pathogen Aspergillus fumigatus reveals large functional changes upon exposure to human serum.

    Science.gov (United States)

    Wiedner, Susan D; Burnum, Kristin E; Pederson, LeeAnna M; Anderson, Lindsey N; Fortuin, Suereta; Chauvigné-Hines, Lacie M; Shukla, Anil K; Ansong, Charles; Panisko, Ellen A; Smith, Richard D; Wright, Aaron T

    2012-09-28

    Environmental adaptability is critical for survival of the fungal human pathogen Aspergillus fumigatus in the immunocompromised host lung. We hypothesized that exposure of the fungal pathogen to human serum would lead to significant alterations to the organism's physiology, including metabolic activity and stress response. Shifts in functional pathway and corresponding enzyme reactivity of A. fumigatus upon exposure to the human host may represent much needed prognostic indicators of fungal infection. To address this, we employed a multiplexed activity-based protein profiling (ABPP) approach coupled to quantitative mass spectrometry-based proteomics to measure broad enzyme reactivity of the fungus cultured with and without human serum. ABPP showed a shift from aerobic respiration to ethanol fermentation and utilization over time in the presence of human serum, which was not observed in serum-free culture. Our approach provides direct insight into this pathogen's ability to survive, adapt, and proliferate. Additionally, our multiplexed ABPP approach captured a broad swath of enzyme reactivity and functional pathways and provides a method for rapid assessment of the A. fumigatus response to external stimuli.

  15. Multiplexed Activity-based Protein Profiling of the Human Pathogen Aspergillus fumigatus Reveals Large Functional Changes upon Exposure to Human Serum*

    Science.gov (United States)

    Wiedner, Susan D.; Burnum, Kristin E.; Pederson, LeeAnna M.; Anderson, Lindsey N.; Fortuin, Suereta; Chauvigné-Hines, Lacie M.; Shukla, Anil K.; Ansong, Charles; Panisko, Ellen A.; Smith, Richard D.; Wright, Aaron T.

    2012-01-01

    Environmental adaptability is critical for survival of the fungal human pathogen Aspergillus fumigatus in the immunocompromised host lung. We hypothesized that exposure of the fungal pathogen to human serum would lead to significant alterations to the organism's physiology, including metabolic activity and stress response. Shifts in functional pathway and corresponding enzyme reactivity of A. fumigatus upon exposure to the human host may represent much needed prognostic indicators of fungal infection. To address this, we employed a multiplexed activity-based protein profiling (ABPP) approach coupled to quantitative mass spectrometry-based proteomics to measure broad enzyme reactivity of the fungus cultured with and without human serum. ABPP showed a shift from aerobic respiration to ethanol fermentation and utilization over time in the presence of human serum, which was not observed in serum-free culture. Our approach provides direct insight into this pathogen's ability to survive, adapt, and proliferate. Additionally, our multiplexed ABPP approach captured a broad swath of enzyme reactivity and functional pathways and provides a method for rapid assessment of the A. fumigatus response to external stimuli. PMID:22865858

  16. Mutagenic potential assessment associated with human exposure to natural radioactivity.

    Science.gov (United States)

    Marcon, Alexandre Endres; Navoni, Julio Alejandro; de Oliveira Galvão, Marcos Felipe; Garcia, Anuska Conde Fagundes Soares; do Amaral, Viviane Souza; Petta, Reinaldo Antônio; Campos, Thomas Ferreira da Costa; Panosso, Renata; Quinelato, Antônio Luiz; de Medeiros, Sílvia Regina Batistuzzo

    2017-01-01

    Lucrécia city, known to harbor a high cancer rate, is located in a semiarid region characterized by the presence of mineral reservoirs, facing a high exposure to metal and natural radioactivity. The present study aimed to assess the environmental scenario at a semiarid region located in Northeastern Brazil. Metal concentration, alpha and beta radiation, and cyanobacteria content in tap water along with indoor radon and gamma emitters (U, K and Th) concentrations were measured. In addition, mutagenic and nuclear instability effects were assessed using buccal micronucleus cytome assay. The study included five samplings corresponding to a period between 2007 and 2009. Drinking water from Lucrécia city presented levels of Mn, Ni and Cr along with cyanobacteria in concentrations one to four times higher than regulatory guidelines considered. Furthermore, high levels of all the tested radionuclides were found. A high percentage of the houses included in this study presented indoor radon concentrations over 100 Bq m -3 . The mean annual effective dose from Lucrécia houses was six times higher than observed in a control region. The levels of exposure in most of the Lucrécia houses were classified as middle to high. A significant mutagenic effect, represented as an increase of micronuclei (MN) frequency and nuclear abnormalities as nuclear buds (NB), binucleated cells (BN), and pyknotic cells (PYC) were found. The results obtained highlight the role of high background radioactivity on the observed mutagenic effect and could help to explain the exacerbated cancer rate reported in this locality. Copyright © 2016. Published by Elsevier Ltd.

  17. Relationship between vapor intrusion and human exposure to trichloroethylene.

    Science.gov (United States)

    Archer, Natalie P; Bradford, Carrie M; Villanacci, John F; Crain, Neil E; Corsi, Richard L; Chambers, David M; Burk, Tonia; Blount, Benjamin C

    2015-01-01

    Trichloroethylene (TCE) in groundwater has the potential to volatilize through soil into indoor air where it can be inhaled. The purpose of this study was to determine whether individuals living above TCE-contaminated groundwater are exposed to TCE through vapor intrusion. We examined associations between TCE concentrations in various environmental media and TCE concentrations in residents. For this assessment, indoor air, outdoor air, soil gas, and tap water samples were collected in and around 36 randomly selected homes; blood samples were collected from 63 residents of these homes. Additionally, a completed exposure survey was collected from each participant. Environmental and blood samples were analyzed for TCE. Mixed model multiple linear regression analyses were performed to determine associations between TCE in residents' blood and TCE in indoor air, outdoor air, and soil gas. Blood TCE concentrations were above the limit of quantitation (LOQ; ≥ 0.012 µg L(-1)) in 17.5% of the blood samples. Of the 36 homes, 54.3%, 47.2%, and >84% had detectable concentrations of TCE in indoor air, outdoor air, and soil gas, respectively. Both indoor air and soil gas concentrations were statistically significantly positively associated with participants' blood concentrations (P = 0.0002 and P = 0.04, respectively). Geometric mean blood concentrations of residents from homes with indoor air concentrations of >1.6 µg m(-3) were approximately 50 times higher than geometric mean blood TCE concentrations in participants from homes with no detectable TCE in indoor air (P < .0001; 95% CI 10.4-236.4). This study confirms the occurrence of vapor intrusion and demonstrates the magnitude of exposure from vapor intrusion of TCE in a residential setting.

  18. Functional corticostriatal connection topographies predict goal directed behaviour in humans

    NARCIS (Netherlands)

    Marquand, A.F.; Haak, K.V.; Beckmann, C.F.

    2017-01-01

    Anatomical tracing studies in non-human primates have suggested that corticostriatal connectivity is topographically organized: nearby locations in striatum are connected with nearby locations in cortex. The topographic organization of corticostriatal connectivity is thought to underpin many

  19. New experimental data on the human dermal absorption of Simazine and Carbendazim help to refine the assessment of human exposure.

    Science.gov (United States)

    Bányiová, Katarína; Nečasová, Anežka; Kohoutek, Jiří; Justan, Ivan; Čupr, Pavel

    2016-02-01

    Due to their widespread usage, people are exposed to pesticides on a daily basis. Although these compounds may have adverse effects on their health, there is a gap in the data and the methodology needed to reliably quantify the risks of non-occupational human dermal exposure to pesticides. We used Franz cells and human skin in order to measure the dermal absorption kinetics (steady-state flux, lag time and permeability coefficient) of Carbendazim and Simazine. These parameters were then used to refine the dermal exposure model and a probabilistic simulation was used to quantify risks resulting from exposure to pesticide-polluted waters. The experimentally derived permeability coefficient was 0.0034 cm h(-1) for Carbendazim and 0.0047 cm h(-1) for Simazine. Two scenarios (varying exposure duration and concentration, i.e. environmentally relevant and maximum solubility) were used to quantify the human health risks (hazard quotients) for Carbendazim and Simazine. While no risks were determined in the case of either scenario, the permeability coefficient, which is concentration independent and donor, formulation, compound and membrane specific, may be used in other scenarios and exposure models to quantify more precisely the dermally absorbed dose during exposure to polluted water. To the best of our knowledge, the dermal absorption kinetics parameters defined here are being published for the first time. The usage of experimental permeability parameters in combination with probabilistic risk assessment thus provides a new tool for quantifying the risks of human dermal exposure to pesticides. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. The human gut microbiome: current knowledge, challenges, and future directions.

    Science.gov (United States)

    Dave, Maneesh; Higgins, Peter D; Middha, Sumit; Rioux, Kevin P

    2012-10-01

    The Human Genome Project was completed a decade ago, leaving a legacy of process, tools, and infrastructure now being turned to the study of the microbes that reside in and on the human body as determinants of health and disease, and has been branded "The Human Microbiome Project." Of the various niches under investigation, the human gut houses the most complex and abundant microbial community and is an arena for important host-microbial interactions that have both local and systemic impact. Initial studies of the human microbiome have been largely descriptive, a testing ground for innovative molecular techniques and new hypotheses. Methods for studying the microbiome have quickly evolved from low-resolution surveys of microbial community structure to high-definition description of composition, function, and ecology. Next-generation sequencing technologies combined with advanced bioinformatics place us at the doorstep of revolutionary insight into the composition, capability, and activity of the human intestinal microbiome. Renewed efforts to cultivate previously "uncultivable" microbes will be important to the overall understanding of gut ecology. There remain numerous methodological challenges to the effective study and understanding of the gut microbiome, largely relating to study design, sample collection, and the number of predictor variables. Strategic collaboration of clinicians, microbiologists, molecular biologists, computational scientists, and bioinformaticians is the ideal paradigm for success in this field. Meaningful interpretation of the gut microbiome requires that host genetic and environmental influences be controlled or accounted for. Understanding the gut microbiome in healthy humans is a foundation for discovering its influence in various important gastrointestinal and nutritional diseases (eg, inflammatory bowel disease, diabetes, and obesity), and for rational translation to human health gains. Copyright © 2012 Mosby, Inc. All rights

  1. Consciousness in humans and non-human animals: recent advances and future directions.

    Science.gov (United States)

    Boly, Melanie; Seth, Anil K; Wilke, Melanie; Ingmundson, Paul; Baars, Bernard; Laureys, Steven; Edelman, David B; Tsuchiya, Naotsugu

    2013-10-31

    This joint article reflects the authors' personal views regarding noteworthy advances in the neuroscience of consciousness in the last 10 years, and suggests what we feel may be promising future directions. It is based on a small conference at the Samoset Resort in Rockport, Maine, USA, in July of 2012, organized by the Mind Science Foundation of San Antonio, Texas. Here, we summarize recent advances in our understanding of subjectivity in humans and other animals, including empirical, applied, technical, and conceptual insights. These include the evidence for the importance of fronto-parietal connectivity and of "top-down" processes, both of which enable information to travel across distant cortical areas effectively, as well as numerous dissociations between consciousness and cognitive functions, such as attention, in humans. In addition, we describe the development of mental imagery paradigms, which made it possible to identify covert awareness in non-responsive subjects. Non-human animal consciousness research has also witnessed substantial advances on the specific role of cortical areas and higher order thalamus for consciousness, thanks to important technological enhancements. In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states. Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence. Along with reviewing these findings, each author suggests future avenues for research in their field of investigation.

  2. Prenatal Exposure to Progesterone Affects Sexual Orientation in Humans

    DEFF Research Database (Denmark)

    Reinisch, June M.; Mortensen, Erik Lykke; Sanders, Stephanie A.

    2017-01-01

    Prenatal sex hormone levels affect physical and behavioral sexual differentiation in animals and humans. Although prenatal hormones are theorized to influence sexual orientation in humans, evidence is sparse. Sexual orientation variables for 34 prenatally progesterone-exposed subjects (17 males...... and 17 females) were compared to matched controls (M age = 23.2 years). A case–control double-blind design was used drawing on existing data from the US/Denmark Prenatal Development Project. Index cases were exposed to lutocyclin (bioidentical progesterone = C21H30O2; MW: 314.46) and no other hormonal...... preparation. Controls were matched on 14 physical, medical, and socioeconomic variables. A structured interview conducted by a psychologist and self-administered questionnaires were used to collect data on sexual orientation, self-identification, attraction to the same and other sex, and history of sexual...

  3. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    OpenAIRE

    Park, Jung-Duck; Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability o...

  4. 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)

  5. Key provisions humanities research advertising and advertising exposure

    OpenAIRE

    A. A. Sogorin

    2015-01-01

    The basic directions of advertising studying as part of the research subject of separate social and humanitarian sciences. The definition of advertising is given. It’s considered as a holistic socio­economic phenomenon, which consists of three basic components: advertising as a product, the final incarnation in the material and ideal forms of the customer’s ideas; advertising as an activity that is advertising as a profession; advertising as an integral part of the social space of the individ...

  6. Use of chromosome translocations for measuring prior environment exposures in humans

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, J. D.

    1997-05-01

    Recent advances in cytogenetic methodology are beginning to have a major impact upon our ability to provide assessments of environmental exposure in humans. The advent of fluorescent-based techniques for `painting` whole chromosomes has made the analysis of chromosome translocations rapid, specific, sensitive and routine. Chromosome painting has been used to address a wide variety of scientific questions, resulting in an increased understanding of the biological consequences of adverse environmental exposure. This paper describes the use of chromosome translocations as a biological marker of exposure and effect in humans. The relevance of translocations is discussed, as are the advantages and disadvantages of painting compared to classical cytogenetic methods for translocation evaluation. The factors to consider in the use of translocations as a retrospective indicator of exposure are then described. Several theoretical parameters that are important to the use of translocations are provided, and the paper concludes with a vision for the future of cytogenetic methodology.

  7. Human internal and external exposure to PBDEs--a review of levels and sources

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Thomsen, Marianne

    2009-01-01

    This paper reviews the existing literature on human exposure to polybrominated diphenyl ethers (PBDEs), with particular focus on external exposure routes (e.g. dust, diet, and air) and the resulting internal exposure to PBDEs (e.g. breast milk and blood). Being lipophilic and persistent organic...... ingest more dust than adults. Infants are also exposed to PBDEs via breast milk. Internal human exposure has generally been found to be one order of magnitude larger in North America than in Europe and Asia. These differences cannot solely be explained by the dietary intake as meat products are the only...... food group where some differences has been observed. However, indoor air and dust concentrations have been found to be approximately one order of magnitude higher in North America than in Europe, possibly a result of different fire safety standards. Within Europe, higher PBDE concentrations in dust...

  8. Human bromethalin exposures reported to a U.S. Statewide Poison Control System.

    Science.gov (United States)

    Huntington, Serena; Fenik, Yelena; Vohra, Rais; Geller, Richard J

    2016-03-01

    Bromethalin is an increasingly used alternative to long-acting anticoagulant and cholecalciferol rodenticides. There are few reports of human exposures, and no existing professional society guidelines on medical management of bromethalin ingestions. The aim of this retrospective data review is to characterize bromethalin exposures reported to the California Poison Control System (CPCS) between 1997 and 2014. This is an observational retrospective case review of our statewide poison control system's electronic medical records. Following Institutional Board Review and Research Committee approvals, poison center exposures related to bromethalin were extracted using substance code and free text search strategies. Case notes of bromethalin exposures were reviewed for demographic, clinical, laboratory, and outcome information; inclusion criteria for the study was single-substance, human exposure to bromethalin. There were 129 calls related to human bromethalin exposures (three cases met exclusion criteria). The age range of cases was 7 months-90 years old, with the majority of exposures (89 cases; 70.6%), occurring in children younger than 5 years of age (median age of 2 years). Most exposures occurred in the pediatric population as a result of exploratory oral exposure. One hundred and thirteen patients (89.7%) had no effects post exposure, while 10 patients (7.9%) had a minor outcome. Adverse effects were minor, self-limited, and mostly gastrointestinal upset. There were no moderate, major, or fatal effects in our study population. The approximate ingested dose, available in six cases, ranged from 0.067 mg/kg to 0.3 mg/kg (milligrams of bromethalin ingested per kilogram of body weight), and no dose-symptom threshold could be established from this series. Exposures were not confirmed through urine or serum laboratory testing. The prognosis for most accidental ingestions appears to be excellent. However, bromethalin exposures may result in a higher number of

  9. Considerations for the design and technical setup of a human whole-body exposure chamber.

    Science.gov (United States)

    Monsé, Christian; Sucker, Kirsten; van Thriel, Christoph; Broding, Horst Christoph; Jettkant, Birger; Berresheim, Hans; Wiethege, Thorsten; Käfferlein, Heiko; Merget, Rolf; Bünger, Jürgen; Brüning, Thomas

    2012-01-01

    Exposures to air contaminants, such as chemical vapors and particulate matter, pose important health hazards at workplaces. Short-term experimental exposures to chemical vapors and particles in humans are a promising attempt to investigate acute effects of such hazards. However, a significant challenge in this field is the determination of effects of co-exposures to more than one chemical or mixtures of chemical vapors and/or particles. To overcome such a challenge, studies have to be conducted under standardized exposure characterization and real time measurements, if possible. A new exposure laboratory (ExpoLab) was installed at IPA, combining sophisticated engineering designs with new analytical techniques, to fulfill these requirements. Low-dose as well as high-dose exposure scenarios are achieved by means of a calibration-gas-generator. Exposure monitoring can be carried out with a high performance real time mass spectrometer and other suitable analyzers (e.g. gas chromatograph). Numerous automated security facilities guarantee the physical integrity of the volunteers, and the waste atmosphere is removed using either charcoal filtration or catalytic post-combustion. Measurements of sulfur hexafluoride, carbon dioxide, aniline and carbon black are presented to demonstrate the performance of the exposure unit with respect to the temporal and spatial stability of generated atmospheres. The variations of generated contents in the atmospheres at steady state are slightly higher than the measurement precision of the analyzers (the typical standard deviation of generated atmospheres is standards in validity and reliability of generating and measuring exposure atmospheres.

  10. Serum metabolome biomarkers associate low-level environmental perfluorinated compound exposure with oxidative /nitrosative stress in humans.

    Science.gov (United States)

    Wang, Xiaofei; Liu, Liangpo; Zhang, Weibing; Zhang, Jie; Du, Xiaoyan; Huang, Qingyu; Tian, Meiping; Shen, Heqing

    2017-10-01

    Previous in vivo and in vitro studies have linked perfluorinated compound (PFC) exposure with metabolic interruption, but the inter-species difference and high treatment doses usually make the results difficult to be extrapolated to humans directly. The best strategy for identifying the metabolic interruption may be to establish the direct correlations between monitored PFCs data and metabolic data on human samples. In this study, serum metabolome data and PFC concentrations were acquired for a Chinese adult male cohort. The most abundant PFCs are PFOA and PFOS with concentration medians 7.56 and 12.78 nM, respectively; in together they count around 81.6% of the total PFCs. PFC concentration-related serum metabolic profile changes and the related metabolic biomarkers were explored by using partial least squares-discriminant analysis (PLS-DA). Respectively taking PFOS, PFOA and total PFC as the classifiers, serum metabolome can be differentiated between the lowest dose group (1st quartile PFCs) and the highest PFC dose group (4th quartile PFCs). Ten potential PFC biomarkers were identified, mainly involving in pollutant detoxification, antioxidation and nitric oxide (NO) signal pathways. These suggested that low-level environmental PFC exposure has significantly adverse impacts on glutathione (GSH) cycle, Krebs cycle, nitric oxide (NO) generation and purine oxidation in humans. To the best of our knowledge, this is the first report investigating the association of environmental PFC exposure with human serum metabolome alteration. Given the important biological functions of the identified biomarkers, we suggest that PFC could increase the metabolism syndromes risk including diabetes and cardiovascular diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Direct detection of a single photon by humans

    Science.gov (United States)

    Tinsley, Jonathan N.; Molodtsov, Maxim I.; Prevedel, Robert; Wartmann, David; Espigulé-Pons, Jofre; Lauwers, Mattias; Vaziri, Alipasha

    2016-01-01

    Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds. PMID:27434854

  12. Plutonium content of human placental tissues after occupational exposure

    International Nuclear Information System (INIS)

    Russell, J.J.; Sikov, M.R.; Kathren, R.L.

    2003-01-01

    The placenta and umbilical cord were obtained following a normal live delivery from a volunteer donor who had received an accidental inhalation intake of plutonium 12 years prior to her pregnancy (Case 0777). Her employer estimated the intake to be about 73 Bq Class W plutonium. Based on bioassay results and clearance models in use at that time, they calculated her body content at the beginning of pregnancy to be about 5.6 Bq with an average concentration of approximately 60 mBq kg -1 . The placenta and cord from this pregnancy, along with the placenta and cord from a donor with no known exposure to plutonium (Case 0835), were divided and assayed for plutonium by ultrasensitive fission track analysis at two collaborating laboratories. Placental 239 Pu concentration values obtained by the two laboratories for Case 0777 agreed within a factor of 2 and were several-fold greater than for the control, Case 0835, as well as values that had been reported by others for unexposed populations. There was no elevated concentration of plutonium in the umbilical cord from the exposed person. The data yielded values of 0.16 and 0.27 for placental to maternal concentrations (C PI :C M ) that were of the same order of magnitude as the value of 0.1 the ICRP calculated for intakes before pregnancy. (author)

  13. Plutonium content of human placental tissues after occupational exposure

    Energy Technology Data Exchange (ETDEWEB)

    Russell, J.J.; Sikov, M.R.; Kathren, R.L

    2003-07-01

    The placenta and umbilical cord were obtained following a normal live delivery from a volunteer donor who had received an accidental inhalation intake of plutonium 12 years prior to her pregnancy (Case 0777). Her employer estimated the intake to be about 73 Bq Class W plutonium. Based on bioassay results and clearance models in use at that time, they calculated her body content at the beginning of pregnancy to be about 5.6 Bq with an average concentration of approximately 60 mBq kg{sup -1}. The placenta and cord from this pregnancy, along with the placenta and cord from a donor with no known exposure to plutonium (Case 0835), were divided and assayed for plutonium by ultrasensitive fission track analysis at two collaborating laboratories. Placental {sup 239}Pu concentration values obtained by the two laboratories for Case 0777 agreed within a factor of 2 and were several-fold greater than for the control, Case 0835, as well as values that had been reported by others for unexposed populations. There was no elevated concentration of plutonium in the umbilical cord from the exposed person. The data yielded values of 0.16 and 0.27 for placental to maternal concentrations (C{sub PI}:C{sub M}) that were of the same order of magnitude as the value of 0.1 the ICRP calculated for intakes before pregnancy. (author)

  14. Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population

    OpenAIRE

    Ellis, James K; Athersuch, Toby J; Thomas, Laura DK; Teichert, Friederike; Pérez-Trujillo, Miriam; Svendsen, Claus; Spurgeon, David J; Singh, Rajinder; Järup, Lars; Bundy, Jacob G; Keun, Hector C

    2012-01-01

    Background: The ‘exposome’ represents the accumulation of all environmental exposures across a lifetime. Topdown strategies are required to assess something this comprehensive, and could transform our understanding of how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics) defines an individual’s metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure, and could also reveal intermediate biomarkers...

  15. The evaluation of stack metal emissions from hazardous waste incinerators: assessing human exposure through noninhalation pathways.

    OpenAIRE

    Sedman, R M; Polisini, J M; Esparza, J R

    1994-01-01

    Potential public health effects associated with exposure to metal emissions from hazardous waste incinerators through noninhalation pathways were evaluated. Instead of relying on modeling the movement of toxicants through various environmental media, an approach based on estimating changes from baseline levels of exposure was employed. Changes in soil and water As, Cd, Hg, Pb, Cr, and Be concentrations that result from incinerator emissions were first determined. Estimates of changes in human...

  16. A four factor model for estimating human radiation exposure to radon daughters in the home

    International Nuclear Information System (INIS)

    McCullough, R.S.; Letourneau, E.G.; Waight, P.J.

    1981-01-01

    This model is intended to represent the exposure received by individuals who spend any part of their day in a private home. Variables are defined to represent (1) different human groups, (2) basement and other levels in a house, (3) the four seasons of the year, and (4) activities within the home. The model is extremely flexible and appears to be applicable to other exposure circumstances. The number and definition of each of the variables can be changed easily. (author)

  17. Naphthalene and Naphthoquinone: Distributions and Human Exposure in the Los Angeles Basin

    Science.gov (United States)

    Lu, R.; Wu, J.; Turco, R.; Winer, A. M.; Atkinson, R.; Paulson, S.; Arey, J.; Lurmann, F.

    2003-12-01

    Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons (PAHs). Naphthalene is found primarily in the gas-phase and has been detected in both outdoor and indoor samples. Evaporation from naphthalene-containing products (including gasoline), and during refining operations, are important sources of naphthalene in air. Naphthalene is also emitted during the combustion of fossil fuels and wood, and is a component of vehicle exhaust. Exposure to high concentrations of naphthalene can damage or destroy red blood cells, causing hemolytic anemia. If inhaled over a long period of time, naphthalene may cause kidney and liver damage, skin allergy and dermatitis, cataracts and retinal damage, as well as attack the central nervous system. Naphthalene has been found to cause cancer as a result of inhalation in animal tests. Naphthoquinones are photooxidation products of naphthalene and the potential health effects of exposure to these quinones are a current focus of research. We are developing and applying models that can be used to assess human exposure to naphthalene and its photooxidation products in major air basins such as California South Coast Air Basin (SoCAB). The work utilizes the Surface Meteorology and Ozone Generation (SMOG) airshed model, and the REgional Human EXposure (REHEX) model, including an analysis of individual exposure. We will present and discuss simulations of basin-wide distributions of, and human exposures to, naphthalene and naphthoquinone, with emphasis on the uncertainties in these estimates of atmospheric concentrations and human exposure. Regional modeling of pollutant sources and exposures can lead to cost-effective and optimally health-protective emission control strategies.

  18. [Some aspects of animal-to-human approximation of low frequency electromagnetic field exposure conditions].

    Science.gov (United States)

    Vasin, A L

    2003-01-01

    Appropriateness of representation of a biological object surface as an equipotential surface has been proved for conditions of a quasistatic exposure to EMF of frequencies lower than 1 MHz. The conditions, at which a self capacitance of a biological object is its basic electrical parameter, have been considered. A factor of animal-to-human approximation of low-frequency EMF exposure conditions was estimated on the basis of equal dose loading in biological objects of different geometric sizes.

  19. Can profiles of poly- and Perfluoroalkyl substances (PFASs) in human serum provide information on major exposure sources?

    Science.gov (United States)

    Hu, Xindi C; Dassuncao, Clifton; Zhang, Xianming; Grandjean, Philippe; Weihe, Pál; Webster, Glenys M; Nielsen, Flemming; Sunderland, Elsie M

    2018-02-01

    Humans are exposed to poly- and perfluoroalkyl substances (PFASs) from diverse sources and this has been associated with negative health impacts. Advances in analytical methods have enabled routine detection of more than 15 PFASs in human sera, allowing better profiling of PFAS exposures. The composition of PFASs in human sera reflects the complexity of exposure sources but source identification can be confounded by differences in toxicokinetics affecting uptake, distribution, and elimination. Common PFASs, such as perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS) and their precursors are ubiquitous in multiple exposure sources. However, their composition varies among sources, which may impact associated adverse health effects. We use available PFAS concentrations from several demographic groups in a North Atlantic seafood consuming population (Faroe Islands) to explore whether chemical fingerprints in human sera provide insights into predominant exposure sources. We compare serum PFAS profiles from Faroese individuals to other North American populations to investigate commonalities in potential exposure sources. We compare individuals with similar demographic and physiological characteristics and samples from the same years to reduce confounding by toxicokinetic differences and changing environmental releases. Using principal components analysis (PCA) confirmed by hierarchical clustering, we assess variability in serum PFAS concentrations across three Faroese groups. The first principal component (PC)/cluster consists of C9-C12 perfluoroalkyl carboxylates (PFCAs) and is consistent with measured PFAS profiles in consumed seafood. The second PC/cluster includes perfluorohexanesulfonic acid (PFHxS) and the PFOS precursor N-ethyl perfluorooctane sulfonamidoacetate (N-EtFOSAA), which are directly used or metabolized from fluorochemicals in consumer products such as carpet and food packaging. We find that the same compounds are associated with the same

  20. Mechanical impedance of the sitting human body in single-axis compared to multi-axis whole-body vibration exposure.

    Science.gov (United States)

    Holmlund, P; Lundström, R

    2001-01-01

    The study was aimed to investigate the mechanical impedance of the sitting human body and to compare data obtained in laboratory single-axis investigations with multi-axis data from in vehicle measurements. The experiments were performed in a laboratory for single-axis measurements. The multi-axis exposure was generated with an eight-seat minibus where the rear seats had been replaced with a rigid one. The subjects in the multi-axis experiment all participated in the single-axis experiments. There are quite a few investigations in the literature describing the human response to single-axis exposure. The response from the human body can be expected to be affected by multi-axis input in a different way than from a single-axis exposure. The present knowledge of the effect of multiple axis exposure is very limited. The measurements were performed using a specially designed force and accelerometer plate. This plate was placed between the subject and the hard seat. Outcome shows a clear difference between mechanical impedance for multi-axis exposure compared to single-axis. This is especially clear in the x-direction where the difference is very large. The conclusion is that it seems unlikely that single-axis mechanical impedance data can be directly transferred to a multi-axis environment. This is due to the force cross-talk between different directions.

  1. Long-term human exposure to lead from different media and intake pathways

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Thomsen, Marianne; Andersen, Mikael Skou

    2010-01-01

    , and predicting the resulting internal body exposure levels and effects that occur under long-term exposure conditions. In this paper, a modeling approach is used to meet these challenges with reference to Danish exposure conditions. Levels of lead content in various media have been coupled with data for lead......Lead (Pb) is well known as an environmental pollutant: it can accumulate in various media, so actual lead exposure reflects both historical and present contaminations. Two main challenges then emerge: obtaining updated information to gain an overall picture of the sources of exposure......–internalconcentration relationships for the direct linkage between lead in environmental media and resultingconcentrations of lead in blood are then presented....

  2. Final report on the Project Research 'Assessment of Human Exposure to Environmental Radiation'

    International Nuclear Information System (INIS)

    1989-03-01

    This is the final report of the Project Research, 'Assessment of Human Exposure to Environmental Radiation', which has been conducted during the period 1983-1988. With the objective of assessing risk of environmental radioactivity to the population, the Project was divided into the following five research groups: (1) research for establishing calculation models and parameters in transfer of radionuclides from crop species through the human body; (2) research for analyzing transfer of radionuclides in the ocean and their contributions to exposure doses in the human body; (3) research for surveying accuracy of exposure models for the external body and respiratory organ and the influential factors; (4) research for determining uptake and biokinetics of radionuclides in the body; and (5) research for estimating and evaluating physical and physiological characteristics of reference Japanese man and the populaltion doses. Effluents from nuclear power plants and reprocessing plants were regarded as radionuclide sources in the water and atmosphere. (N.K.)

  3. A comprehensive assessment of human exposure to phthalates from environmental media and food in Tianjin, China.

    Science.gov (United States)

    Ji, Yaqin; Wang, Fumei; Zhang, Leibo; Shan, Chunyan; Bai, Zhipeng; Sun, Zengrong; Liu, Lingling; Shen, Boxiong

    2014-08-30

    A total of 448 samples including foodstuffs (rice, steamed bun, vegetables, meat, poultry, fish, milk and fruits), ambient PM10, drinking water, soil, indoor PM10 and indoor dust samples from Tianjin were obtained to determine the distribution of six priority phthalates (PAEs) and assess the human exposure to them. The results indicated that DBP and DEHP were the most frequently detected PAEs in these samples. The concentrations of PAEs in environmental media were higher than those in food. We estimated the daily intake (DI) of PAEs via ingestion, inhalation and dermal absorption from five sources (food, water, air, dust and soil). Dietary intake was the main exposure source to DEP, BBP, DEHP and DOP, whereas water ingestion/absorption was the major source of exposure to DBP, DEHP and DOP. Although food and water were the overwhelmingly predominant sources of PAEs intake by Tianjin population, contaminated air was another important source of DMP, DEP and DBP contributing to up to 45% of the exposure. The results of this study will help in understanding the major pathways of human exposure to PAEs. These findings also suggest that human exposure to phthalate esters via the environment should not be overlooked. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Quantitative assessment of human and pet exposure to Salmonella associated with dry pet foods.

    Science.gov (United States)

    Lambertini, Elisabetta; Buchanan, Robert L; Narrod, Clare; Ford, Randall M; Baker, Robert C; Pradhan, Abani K

    2016-01-04

    Recent Salmonella outbreaks associated with dry pet foods and treats highlight the importance of these foods as previously overlooked exposure vehicles for both pets and humans. In the last decade efforts have been made to raise the safety of this class of products, for instance by upgrading production equipment, cleaning protocols, and finished product testing. However, no comprehensive or quantitative risk profile is available for pet foods, thus limiting the ability to establish safety standards and assess the effectiveness of current and proposed Salmonella control measures. This study sought to develop an ingredients-to-consumer quantitative microbial exposure assessment model to: 1) estimate pet and human exposure to Salmonella via dry pet food, and 2) assess the impact of industry and household-level mitigation strategies on exposure. Data on prevalence and concentration of Salmonella in pet food ingredients, production process parameters, bacterial ecology, and contact transfer in the household were obtained through literature review, industry data, and targeted research. A probabilistic Monte Carlo modeling framework was developed to simulate the production process and basic household exposure routes. Under the range of assumptions adopted in this model, human exposure due to handling pet food is null to minimal if contamination occurs exclusively before extrusion. Exposure increases considerably if recontamination occurs post-extrusion during coating with fat, although mean ingested doses remain modest even at high fat contamination levels, due to the low percent of fat in the finished product. Exposure is highly variable, with the distribution of doses ingested by adult pet owners spanning 3Log CFU per exposure event. Child exposure due to ingestion of 1g of pet food leads to significantly higher doses than adult doses associated with handling the food. Recontamination after extrusion and coating, e.g., via dust or equipment surfaces, may also lead to

  5. Biological effects on human health due to radiofrequency/microwave exposure

    DEFF Research Database (Denmark)

    Breckenkamp, Jürgen; Berg, Gabriele; Blettner, Maria

    2003-01-01

    We evaluated the methods and results of nine cohort studies dealing with the biological effects on human health from exposure to radiofrequencies/microwaves, published between 1980 and 2002. The size of the cohorts varied between 304 (3,362 person years) and nearly 200,000 persons (2.7 million......, however, inconsistent. The most important limitations of the studies were the lack of measurements referring to past and current exposures and, thus, the unknown details on actual exposure, the use of possibly biased data as well as the lack of adjustment for potential confounders and the use of indirect...

  6. Direct action of endocrine disrupting chemicals on human sperm

    DEFF Research Database (Denmark)

    Schiffer, Christian; Müller, Astrid; Egeberg, Dorte L

    2014-01-01

    Synthetic endocrine disrupting chemicals (EDCs), omnipresent in food, household, and personal care products, have been implicated in adverse trends in human reproduction, including infertility and increasing demand for assisted reproduction. Here, we study the action of 96 ubiquitous EDCs on huma...

  7. Directional dominance on stature and cognition in diverse human populations

    NARCIS (Netherlands)

    Joshi, Peter K.; Esko, Tonu; Mattsson, Hannele; Eklund, Niina; Gandin, Ilaria; Nutile, Teresa; Jackson, Anne U.; Schurmann, Claudia; Smith, Albert V.; Zhang, Weihua; Okada, Yukinori; Stancakova, Alena; Faul, Jessica D.; Zhao, Wei; Bartz, Traci M.; Concas, Maria Pina; Franceschini, Nora; Enroth, Stefan; Vitart, Veronique; Trompet, Stella; Guo, Xiuqing; Chasman, Daniel I.; O'Connel, Jeffrey R.; Corre, Tanguy; Nongmaithem, Suraj S.; Chen, Yuning; Mangino, Massimo; Ruggiero, Daniela; Traglia, Michela; Farmaki, Aliki-Eleni; Kacprowski, Tim; Bjonnes, Andrew; van der Spek, Ashley; Wu, Ying; Giri, Anil K.; Yanek, Lisa R.; Wang, Lihua; Hofer, Edith; Rietveld, Cornelius A.; McLeod, Olga; Cornelis, Marilyn C.; Pattaro, Cristian; Verweij, Niek; Baumbach, Clemens; Abdellaoui, Abdel; Warren, Helen R.; Vuckovic, Dragana; Mei, Hao; Bouchard, Claude; Perry, John R. B.; Cappellani, Stefania; Mirza, Saira S.; Benton, Miles C.; Broeckel, Ulrich; Medland, Sarah E.; Lind, PenelopeA.; Malerba, Giovanni; Drong, Alexander; Yengo, Loic; Bielak, Lawrence F.; Zhi, Degui; van der Most, Peter J.; Shriner, Daniel; Maegi, Reedik; Hemani, Gibran; Karaderi, Tugce; Wang, Zhaoming; Liu, Tian; Demuth, Ilja; Zhao, Jing Hua; Meng, Weihua; Lataniotis, Lazaros; van der Laan, Sander W.; Bradfield, Jonathan P.; Wood, Andrew R.; Bonnefond, Amelie; Ahluwalia, Tarunveer S.; Hall, LeanneM.; Salvi, Erika; Yazar, Seyhan; Carstensen, Lisbeth; de Haan, Hugoline G.; Abney, Mark; Afzal, Uzma; Allison, Matthew A.; Amin, Najaf; Asselbergs, Folkert W.; Bakker, Stephan J. L.; Barr, R. Graham; Baumeister, Sebastian E.; Benjamin, Daniel J.; Bergmann, Sven; Boerwinkle, Eric; Bottinger, Erwin P.; Campbell, Archie; Chakravarti, Aravinda; Chan, Yingleong; Chanock, Stephen J.; Chen, Constance; Chen, Y. -D. Ida; Collins, Francis S.; Connell, John; Correa, Adolfo; Cupples, L. Adrienne; Smith, George Davey; Davies, Gail; Doerr, Marcus; Ehret, Georg; Ellis, Stephen B.; Feenstra, Bjarke; Feitosa, Mary F.; Ford, Ian; Fox, Caroline S.; Frayling, Timothy M.; Friedrich, Nele; Geller, Frank; Scotland, Generation; Gillham-Nasenya, Irina; Gottesman, Omri; Graff, Misa; Grodstein, Francine; Gu, Charles; Haley, Chris; Hammond, Christopher J.; Harris, Sarah E.; Harris, Tamara B.; Hastie, Nicholas D.; Heard-Costa, Nancy L.; Heikkila, Kauko; Hocking, Lynne J.; Homuth, Georg; Hottenga, Jouke-Jan; Huang, Jinyan; Huffman, Jennifer E.; Hysi, Pirro G.; Ikram, M. Arfan; Ingelsson, Erik; Joensuu, Anni; Johansson, Asa; Jousilahti, Pekka; Jukema, J. Wouter; Kahonen, Mika; Kamatani, Yoichiro; Kanoni, Stavroula; Kerr, Shona M.; Khan, Nazir M.; Koellinger, Philipp; Koistinen, Heikki A.; Kooner, Manraj K.; Kubo, Michiaki; Kuusisto, Johanna; Lahti, Jari; Launer, Lenore J.; Lea, Rodney A.; Lehne, Benjamin; Lehtimaki, Terho; Liewald, David C. M.; Lind, Lars; Loh, Marie; Lokki, Marja-Liisa; London, Stephanie J.; Loomis, Stephanie J.; Loukola, Anu; Lu, Yingchang; Lumley, Thomas; Lundqvist, Annamari; Mannisto, Satu; Marques-Vidal, Pedro; Masciullo, Corrado; Matchan, Angela; Mathias, Rasika A.; Matsuda, Koichi; Meigs, James B.; Meisinger, Christa; Meitinger, Thomas; Menni, Cristina; Mentch, Frank D.; Mihailov, Evelin; Milani, Lili; Montasser, May E.; Montgomery, GrantW.; Morrison, Alanna; Myers, Richard H.; Nadukuru, Rajiv; Navarro, Pau; Nelis, Mari; Nieminen, Markku S.; Nolte, Ilja M.; O'Connor, George T.; Ogunniyi, Adesola; Padmanabhan, Sandosh; Palmas, Walter R.; Pankow, James S.; Patarcic, Inga; Pavani, Francesca; Peyser, Patricia A.; Pietilainen, Kirsi; Poulter, Neil; Prokopenko, Inga; Ralhan, Sarju; Redmond, Paul; Rich, Stephen S.; Rissanen, Harri; Robino, Antonietta; Rose, Lynda M.; Rose, Richard; Sala, Cinzia; Salako, Babatunde; Salomaa, Veikko; Sarin, Antti-Pekka; Saxena, Richa; Schmidt, Helena; Scott, Laura J.; Scott, William R.; Sennblad, Bengt; Seshadri, Sudha; Sever, Peter; Shrestha, Smeeta; Smith, Blair H.; Smith, Jennifer A.; Soranzo, Nicole; Sotoodehnia, Nona; Southam, Lorraine; Stanton, Alice V.; Stathopoulou, Maria G.; Strauch, Konstantin; Strawbridge, Rona J.; Suderman, Matthew J.; Tandon, Nikhil; Tang, Sian-Tsun; Taylor, Kent D.; Tayo, Bamidele O.; Toeglhofer, Anna Maria; Tomaszewski, Maciej; Tsernikova, Natalia; Tuomilehto, Jaakko; Uitterlinden, Andre G.; Vaidya, Dhananjay; Vlieg, Astrid van Hylckama; van Setten, Jessica; Vasankari, Tuula; Vedantam, Sailaja; Vlachopoulou, Efthymia; Vozzi, Diego; Vuoksimaa, Eero; Waldenberger, Melanie; Ware, Erin B.; Wentworth-Shields, William; Whitfield, John B.; Wild, Sarah; Willemsen, Gonneke; Yajnik, Chittaranjan S.; Yao, Jie; Zaza, Gianluigi; Zhu, Xiaofeng; Salem, Rany M.; Melbye, Mads; Bisgaard, Hans; Samani, Nilesh J.; Cusi, Daniele; Mackey, David A.; Cooper, Richard S.; Froguel, Philippe; Pasterkamp, Gerard; Grant, Struan F. A.; Hakonarson, Hakon; Ferrucci, Luigi; Scott, Robert A.; Morris, Andrew D.; Palmer, Colin N. A.; Dedoussis, George; Deloukas, Panos; Bertram, Lars; Lindenberger, Ulman; Berndt, Sonja I.; Lindgren, Cecilia M.; Timpson, Nicholas J.; Toenjes, Anke; Munroe, Patricia B.; Sorensen, Thorkild I. A.; Rotimi, Charles N.; Arnett, Donna K.; Oldehinkel, Albertine J.; Kardia, Sharon L. R.; Balkau, Beverley; Gambaro, Giovanni; Morris, Andrew P.; Eriksson, Johan G.; Wright, Margie J.; Martin, Nicholas G.; Hunt, Steven C.; Starr, John M.; Deary, Ian J.; Griffiths, Lyn R.; Tiemeier, Henning; Pirastu, Nicola; Kaprio, Jaakko; Wareham, Nicholas J.; Perusse, Louis; Wilson, James G.; Girotto, Giorgia; Caulfield, Mark J.; Raitakari, Olli; Boomsma, Dorret I.; Gieger, Christian; van der Harst, Pim; Hicks, Andrew A.; Kraft, Peter; Sinisalo, Juha; Knekt, Paul; Johannesson, Magnus; Magnusson, Patrik K. E.; Hamsten, Anders; Schmidt, Reinhold; Borecki, Ingrid B.; Vartiainen, Erkki; Becker, Diane M.; Bharadwaj, Dwaipayan; Mohlke, Karen L.; Boehnke, Michael; van Duijn, Cornelia M.; Sanghera, Dharambir K.; Teumer, Alexander; Zeggini, Eleftheria; Metspalu, Andres; Gasparini, Paolo; Ulivi, Sheila; Ober, Carole; Toniolo, Daniela; Rudan, Igor; Porteous, David J.; Ciullo, Marina; Spector, Tim D.; Hayward, Caroline; Dupuis, Josee; Loos, Ruth J. F.; Wright, Alan F.; Chandak, Giriraj R.; Vollenweider, Peter; Shuldiner, Alan R.; Ridker, Paul M.; Rotter, Jerome I.; Sattar, Naveed; Gyllensten, Ulf; North, Kari E.; Pirastu, Mario; Psaty, Bruce M.; Weir, David R.; Laakso, Markku; Gudnason, Vilmundur; Takahashi, Atsushi; Chambers, John C.; Kooner, Jaspal S.; Strachan, David P.; Campbell, Harry; Hirschhorn, Joel N.; Perola, Markus; Polasek, Ozren; Wilson, James F.

    2015-01-01

    Homozygosity has long been associated with rare, often devastating, Mendelian disorders(1), and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness(2). However, the effect of the more distant parental relatedness that is common in modern human populations is less

  8. Direct human impacts on the peatland carbon sink

    Science.gov (United States)

    Jukka Laine; Kari Minkkinen; Carl Trettin

    2009-01-01

    Northern peatlands occupy over 3 million km2 globally and contain the largest carbon (C) pool (typically >100 kg C m-2) among terrestrial ecosystems. Agriculture, forestry, and peat harvesting are the principal human-induced activities that alter the peatland and hence the distribution and flux of carbon. As a prerequisite to those uses, the peatland is usually...

  9. Legon at 60: New Directions for the Humanities | Oduyoye | Legon ...

    African Journals Online (AJOL)

    Legon Journal of the Humanities. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 21 (2010) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

  10. Directional dominance on stature and cognition in diverse human populations

    NARCIS (Netherlands)

    P.K. Joshi (Peter); T. Esko (Tõnu); H. Mattsson (Hannele); N. Eklund (Niina); I. Gandin (Ilaria); T. Nutile; A.U. Jackson (Anne); C. Schurmann (Claudia); G.D. Smith; W. Zhang (Weihua); Y. Okada (Yukinori); A. Stancáková (Alena); J.D. Faul (Jessica D.); W. Zhao (Wei); T.M. Bartz (Traci M.); M.P. Concas (Maria Pina); N. Franceschini (Nora); S. Enroth (Stefan); V. Vitart (Veronique); S. Trompet (Stella); X. Guo (Xiuqing); D.I. Chasman (Daniel); J.R. O'Connel (Jeffrey R.); T. Corre (Tanguy); S.S. Nongmaithem (Suraj S.); Y. Chen (Yuning); M. Mangino (Massimo); D. Ruggiero; M. Traglia (Michela); A.-E. Farmaki (Aliki-Eleni); T. Kacprowski (Tim); A. Bjonnes (Andrew); A. van der Spek (Ashley); Y. Wu (Ying); A.K. Giri (Anil K.); L.R. Yanek (Lisa); L. Wang (Lihua); E. Hofer (Edith); C.A. Rietveld (Niels); O. McLeod (Olga); M. Cornelis (Marilyn); C. Pattaro (Cristian); N. Verweij (Niek); C. Baumbach (Clemens); A. Abdellaoui (Abdel); H. Warren (Helen); D. Vuckovic (Dragana); H. Mei (Hao); C. Bouchard (Claude); J.R.B. Perry (John); S. Cappellani (Stefania); S.S. Mirza (Saira); M.C. Benton (Miles C.); U. Broeckel (Ulrich); S.E. Medland (Sarah Elizabeth); P.A. Lind (Penelope); G. Malerba (Giovanni); A. Drong (Alexander); L. Yengo (Loic); L.F. Bielak (Lawrence F.); D. Zhi (Degui); P.J. van der Most (Peter); D. Shriner (Daniel); R. Mägi (Reedik); G. Hemani; T. Karaderi (Tugce); Z. Wang (Zhaoming); T. Liu (Tian); I. Demuth (Ilja); J.H. Zhao (Jing Hua); W. Meng (Weihua); L. Lataniotis (Lazaros); S.W. Van Der Laan (Sander W.); J.P. Bradfield (Jonathan); A.R. Wood (Andrew); A. Bonnefond (Amélie); T.S. Ahluwalia (Tarunveer Singh); L.M. Hall (Leanne M.); E. Salvi (Erika); S. Yazar (Seyhan); L. Carstensen (Lisbeth); H.G. De Haan (Hugoline G.); M. Abney (Mark); U. Afzal (Uzma); M.A. Allison (Matthew); N. Amin (Najaf); F.W. Asselbergs (Folkert W.); S.J.L. Bakker (Stephan); R.G. Barr (Graham); S.E. Baumeister (Sebastian); D.J. Benjamin (Daniel J.); S. Bergmann (Sven); E.A. Boerwinkle (Eric); E.P. Bottinger (Erwin P.); A. Campbell (Archie); A. Chakravarti (Aravinda); Y. Chan (Yingleong); S.J. Chanock (Stephen); C. Chen (Constance); Y.-D.I. Chen (Y.-D. Ida); F.S. Collins (Francis); J. Connell (John); A. Correa (Adolfo); L.A. Cupples (Adrienne); G.D. Smith; G. Davies (Gail); M. Dörr (Marcus); G.B. Ehret (Georg); S.B. Ellis (Stephen B.); B. Feenstra (Bjarke); M.F. Feitosa (Mary Furlan); I. Ford; C.S. Fox (Caroline); T.M. Frayling (Timothy); N. Friedrich (Nele); F. Geller (Frank); G. Scotland (Generation); I. Gillham-Nasenya (Irina); R.F. Gottesman (Rebecca); M.J. Graff (Maud J.L.); F. Grodstein (Francine); C. Gu (Charles); C. Haley (Chris); C.J. Hammond (Christopher); S.E. Harris (Sarah); T.B. Harris (Tamara); N. Hastie (Nick); N.L. Heard-Costa (Nancy); K. Heikkilä (Kauko); L.J. Hocking (Lynne); G. Homuth (Georg); J.J. Hottenga (Jouke Jan); J. Huang (Jian); J.E. Huffman (Jennifer); P.G. Hysi (Pirro); M.A. Ikram (Arfan); E. Ingelsson (Erik); A. Joensuu (Anni); A. Johansson (Åsa); P. Jousilahti (Pekka); J.W. Jukema (Jan Wouter); M. Kähönen (Mika); Y. Kamatani (Yoichiro); S. Kanoni (Stavroula); S.M. Kerr (Shona); N.M. Khan (Nazir M.); Ph.D. Koellinger (Philipp); H.A. Koistinen (Heikki A.); M.K. Kooner (Manraj K.); M. Kubo (Michiaki); J. Kuusisto (Johanna); J. Lahti (Jari); L.J. Launer (Lenore); R.A. Lea (Rodney A.); B. Lehne (Benjamin); T. Lehtimäki (Terho); D.C. Liewald (David C.); L. Lind (Lars); M. Loh (Marie); M.L. Lokki; S.J. London (Stephanie J.); S.J. Loomis (Stephanie J.); A. Loukola (Anu); Y. Lu (Yingchang); T. Lumley (Thomas); A. Lundqvist (Annamari); S. Männistö (Satu); P. Marques-Vidal (Pedro); C. Masciullo (Corrado); A. Matchan (Angela); J. Mathias (Jasmine); K. Matsuda (Koichi); J.B. Meigs (James); C. Meisinger (Christa); T. Meitinger (Thomas); C. Menni (Cristina); F.D. Mentch (Frank); E. Mihailov (Evelin); L. Milani (Lili); M.E. Montasser (May E.); G.W. Montgomery (Grant); A.C. Morrison (Alanna); R.H. Myers (Richard); R. Nadukuru (Rajiv); P. Navarro (Pau); M. Nalis (Mari); M.S. Nieminen (Markku S.); I.M. Nolte (Ilja M.); G.T. O'Connor (George); A. Ogunniyi (Adesola); S. Padmanabhan (Sandosh); W. Palmas (Walter); J.S. Pankow (James); I. Patarcic (Inga); F. Pavani (Francesca); P.A. Peyser (Patricia A.); K.H. Pietilainen (Kirsi Hannele); N.R. Poulter (Neil); I. Prokopenko (Inga); S. Ralhan (Sarju); P. Redmond (Paul); S.S. Rich (Stephen S.); H. Rissanen (Harri); A. Robino (Antonietta); L.M. Rose (Lynda M.); R.J. Rose (Richard J.); C. Sala (Cinzia); B. Salako (Babatunde); V. Salomaa (Veikko); A.-P. Sarin; R. Saxena (Richa); R. Schmidt (Reinhold); L.J. Scott (Laura); W.R. Scott (William R.); B. Sennblad (Bengt); S. Seshadri (Sudha); P. Sever (Peter); S. Shrestha (Smeeta); B.H. Smith (Blair); J.A. Smith (Jennifer A); N. Soranzo (Nicole); N. Sotoodehnia (Nona); L. Southam (Lorraine); A. Stanton (Alice); M.G. Stathopoulou (Maria G); K. Strauch (Konstantin); R.J. Strawbridge (Rona); M.J. Suderman (Matthew J.); N. Tandon (Nikhil); S.-T. Tang (Sian-Tsun); K.D. Taylor (Kent D.); B. Tayo (Bamidele); A.M. Töglhofer (Anna Maria); M. Tomaszewski (Maciej); N. Tsernikova (Natalia); J. Tuomilehto (Jaakko); A.G. Uitterlinden (André); D. Vaidya (Dhananjay); A. van Hylckama Vlieg (Astrid); J. van Setten (Jessica); T. Vasankari (Tuula); S. Vedantam (Sailaja); E. Vlachopoulou (Efthymia); D. Vozzi (Diego); E. Vuoksimaa (Eero); M. Waldenberger (Melanie); E.B. Ware (Erin B.); W. Wentworth-Shields (William); J. Whitfield (John); S. Wild (Sarah); G.A.H.M. Willemsen (Gonneke); C.S. Yajnik (Chittaranjan S.); J. Yao (Jie); G. Zaza (Gianluigi); X. Zhu (Xiaofeng); R.M. Salem (Rany); M. Melbye (Mads); H. Bisgaard (Hans); N.J. Samani (Nilesh); D. Cusi (Daniele); D.A. Mackey (David A.); R.S. Cooper (Richard S.); P. Froguel (Philippe); G. Pasterkamp (Gerard); S.F.A. Grant (Struan F.A.); H. Hakonarson (Hakon); L. Ferrucci (Luigi); R.A. Scott (Robert); A.D. Morris (Andrew); C.N.A. Palmer (Colin); G.V. Dedoussis (George V.); P. Deloukas (Panagiotis); L. Bertram (Lars); U. Lindenberger (Ulman); S.I. Berndt (Sonja); C.M. Lindgren (Cecilia); N.J. Timpson (Nicholas); A. Tönjes (Anke); P. Munroe (Patricia); T.I.A. Sørensen (Thorkild I.A.); C. Rotimi (Charles); D.K. Arnett (Donna); A.J. Oldehinkel (Albertine); S.L.R. Kardia (Sharon); B. Balkau (Beverley); G. Gambaro (Giovanni); A.P. Morris (Andrew); J.G. Eriksson (Johan G.); M.J. Wright (Margaret); N.G. Martin (Nicholas); S.C. Hunt (Steven); J.M. Starr (John); I.J. Deary (Ian J.); L.R. Griffiths (Lyn R.); H.W. Tiemeier (Henning); N. Pirastu (Nicola); J. Kaprio (Jaakko); N.J. Wareham (Nick); L. Perusse (Louis); J.G. Wilson (James); S. Girotto; M. Caulfield (Mark); O.T. Raitakari (Olli T.); D.I. Boomsma (Dorret); C. Gieger (Christian); P. van der Harst; A.A. Hicks (Andrew); P. Kraft (Peter); J. Sinisalo (Juha); P. Knekt; M. Johannesson (Magnus); P.K.E. Magnusson (Patrik K. E.); A. Hamsten (Anders); R. Schmidt (Reinhold); I.B. Borecki (Ingrid); E. Vartiainen (Erkki); D.M. Becker (Diane); D. Bharadwaj (Dwaipayan); K.L. Mohlke (Karen); M. Boehnke (Michael); C.M. van Duijn (Cornelia); D.K. Sanghera (Dharambir); A. Teumer (Alexander); E. Zeggini (Eleftheria); A. Metspalu (Andres); P. Gasparini (Paolo); S. Ulivi (Shelia); C. Ober (Carole); D. Toniolo (Daniela); I. Rudan (Igor); D.J. Porteous (David J.); M. Ciullo; T.D. Spector (Timothy); C. Hayward (Caroline); J. Dupuis (Josée); R.J.F. Loos (Ruth); A. Wright (Alan); G.R. Chandak (Giriraj); P. Vollenweider (Peter); A.R. Shuldiner (Alan); P.M. Ridker (Paul); J.I. Rotter (Jerome I.); N. Sattar (Naveed); U. Gyllensten (Ulf); K.E. North (Kari); M. Pirastu (Mario); B.M. Psaty (Bruce); D.R. Weir (David); M. Laakso (Markku); V. Gudnason (Vilmundur); A. Takahashi (Atsushi); J.C. Chambers (John C.); J.S. Kooner (Jaspal S.); D.P. Strachan (David P.); H. Campbell (Harry); J.N. Hirschhorn (Joel N.); M. Perola (Markus); O. Polasek (Ozren); J.F. Wilson (James)

    2015-01-01

    textabstractHomozygosity has long been associated with rare, often devastating, Mendelian disorders, and Darwin was one of the first to recognize that inbreeding reduces evolutionary fitness. However, the effect of the more distant parental relatedness that is common in modern human populations is

  11. Population exposure from the nuclear fuel cycle: Review and future direction

    International Nuclear Information System (INIS)

    Richmond, C.R.

    1988-01-01

    The legacy of radiation exposures confronting man arises from two historical sources of energy, the sun and radioactive decay. Contemporary man continues to be dependent on these two energy sources, which include the nuclear fuel cycle. Radiation exposures from all energy sources should be examined, with particular emphasis on the nuclear fuel cycle, including incidents such as Chernobyl and Three Mile Island. In addition to risk estimation, concepts such as de minimis, life shortening as a measure of risk, and competing risks as projected into the future must be considered in placing radiation exposures in perspective. The utility of these concepts is in characterizing population exposures for decision makers in a manner that the public may judge acceptable. All these viewpoints are essential in the evaluation of population exposure from the nuclear fuel cycle

  12. Occurrence, sources and human exposure assessment of SCCPs in indoor dust of northeast China.

    Science.gov (United States)

    Liu, Li-Hua; Ma, Wan-Li; Liu, Li-Yan; Huo, Chun-Yan; Li, Wen-Long; Gao, Chong-Jing; Li, Hai-Ling; Li, Yi-Fan; Chan, Hing Man

    2017-06-01

    Short-chain chlorinated paraffins (SCCPs) are widely used chemicals in household products and might cause adverse human health effects. However, limited information is available on the occurrence of SCCPs in indoor environments and their exposure risks on humans. In this study the concentrations, profiles and human exposure of SCCPs in indoor dust from five different indoor environments, including commercial stores, residential apartments, dormitories, offices and laboratories were characterized. The SCCPs levels ranged from 10.1 to 173.0 μg/g, with the median and mean concentration of 47.2 and 53.6 μg/g, respectively. No significant difference was found on concentrations among the five microenvironments. The most abundant compounds in indoor dust samples were homologues of C 13 group, Cl 7 group and N 20 (N is the total number of C and Cl) group. In the five microenvironments, commercial stores were more frequently exposed to shorter carbon chained and higher chlorinated homologues. Three potential sources for SCCPs were identified by the multiple linear regression of factor score model and correspondence analysis. The major sources of SCCPs in indoor dust were technical mixtures of CP-42 (42% chlorine, w/w) and CP-52 b (52% chlorine, w/w). The total daily exposure doses and hazard quotients (HQ) were calculated by the human exposure models, and they were all below the reference doses and threshold values, respectively. Monte Carlo simulation was applied to predict the human exposure risk of SCCPs. Infants and toddlers were at risk of SCCPs based on predicted HQ values, which were exceeded the threshold for neoplastic effects in the worst case. Our results on the occurrences, sources and human exposures of SCCPs will be useful to provide a better understanding of SCCPs behaviors in indoor environment in China, and to support environmental risk evaluation and regulation of SCCPs in the world. Copyright © 2017. Published by Elsevier Ltd.

  13. Human exposure to a 60 Hz, 1800 micro tesla magnetic field: a neuro behavioral study

    International Nuclear Information System (INIS)

    Legros, A.; Corbacio, M.; Prato, F.S.; Thomas, A.W.; Beuter, A.; Goulet, D.; Lambrozo, J.; Souques, M.; Plante, M.

    2010-01-01

    The effects of time-varying magnetic fields (MF) on humans have been actively investigated for the past three decades. One important unanswered question that scientists continue to investigate is the potential for MF exposure to have acute effects on human biology. Different strategies have been used to tackle this question using various physiological, neuro-physiological and behavioral indicators. For example, researchers investigating electro-encephalography (EEG) have reported that Extremely Low Frequency (ELF, < 300 Hz) MF can increase the resting occipital alpha rhythm (8-12 Hz) [1, 2]. Interestingly, other studies have demonstrated that human motor behavior can be modulated by ELF MF exposure, reporting that such an exposure can reduce anteroposterior standing balance oscillations [3, 4] or decrease physiological tremor intensity [5]. However, the main limitation in this domain is the difficulty of reproducing the results. A possible reason for this is the large variety of experimental approaches employed. Therefore, the aim of this project is to investigate the effects of a 60 Hz, 1800 μT MF exposure on physiological (i.e. heart rate and peripheral blood perfusion), neuro-physiological (brain electrical activity), and behavioral (postural oscillations, voluntary motor functions, and physiological tremor) aspects in humans using a single experimental procedure.Though the results from this study suggest a subtle reduction of human standing balance as well as a subtle increase of physiological tremor amplitude with MF exposure, no effect appeared on other investigated parameters, suggesting that one hour of 60 Hz, 1800 μT MF exposure may modulate human involuntary motor control without being detected in the electrical activity of the brain. (authors)

  14. Elevated personal exposure to particulate matter from human activities in a residence.

    Science.gov (United States)

    Ferro, Andrea R; Kopperud, Royal J; Hildemann, Lynn M

    2004-01-01

    Continuous laser particle counters collocated with time-integrated filter samplers were used to measure personal, indoor, and outdoor particulate matter (PM) concentrations for a variety of prescribed human activities during a 5-day experimental period in a home in Redwood City, CA, USA. The mean daytime personal exposures to PM(2.5) and PM(5) during prescribed activities were 6 and 17 times, respectively, as high as the pre-activity indoor background concentration. Activities that resulted in the highest exposures of PM(2.5), PM(5), and PM(10) were those that disturbed dust reservoirs on furniture and textiles, such as dry dusting, folding clothes and blankets, and making a bed. The vigor of activity and type of flooring were also important factors for dust resuspension. Personal exposures to PM(2.5) and PM(5) were 1.4 and 1.6 times, respectively, as high as the indoor concentration as measured by a stationary monitor. The ratio of personal exposure to the indoor concentration was a function of both particle size and the distance of the human activity from the stationary indoor monitor. The results demonstrate that a wide variety of indoor human resuspension activities increase human exposure to PM and contribute to the "personal cloud" effect.

  15. Impact assessment on the human exposure to environmental radiation

    International Nuclear Information System (INIS)

    Kim, Y.J.; Lee, K.S.; Kim, J.B.; Chun, K.J.; Kim, S.R.; Chung, K.H.

    1983-01-01

    1. The Terrestrial Ecosystem in the Vicinity of Kori Nuclear Power Plant. In order to evaluate the effects of radiation or radionuclides released from the nuclear power plants on human population, field surveys on the terrestrial ecosystem such as the fauna and flora in the vicinity within 15 km from the Kori nuclear power plant were carried out. 2. Level of radionuclides, Metabolism and Chromosome Aberration. The present study was undertaken with the purpose for evaluating 1) the level of Sr-90 in the Korean vertebra, 2) the metabolism of Sr-90 in the rats, 3) the levels of Sr-90 and Cs-137 in the pine needles (Pinus densiflora), 4) the level of Sr-90 in the frogs (Rana nigromaculata) and 5) the radiation effects by internal Sr-90 on the bone marrow. (Author)

  16. Dose-rate models for human survival after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1987-01-01

    This paper reviews new estimates of the LD 50 in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD 50 s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively

  17. Dose-rate models for human survival after exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1986-01-01

    This paper reviews new estimates of the L 50 in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD 50 s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively

  18. Directed Differentiation of Human Pluripotent Stem Cells to Microglia

    Directory of Open Access Journals (Sweden)

    Panagiotis Douvaras

    2017-06-01

    Full Text Available Microglia, the immune cells of the brain, are crucial to proper development and maintenance of the CNS, and their involvement in numerous neurological disorders is increasingly being recognized. To improve our understanding of human microglial biology, we devised a chemically defined protocol to generate human microglia from pluripotent stem cells. Myeloid progenitors expressing CD14/CX3CR1 were generated within 30 days of differentiation from both embryonic and induced pluripotent stem cells (iPSCs. Further differentiation of the progenitors resulted in ramified microglia with highly motile processes, expressing typical microglial markers. Analyses of gene expression and cytokine release showed close similarities between iPSC-derived (iPSC-MG and human primary microglia as well as clear distinctions from macrophages. iPSC-MG were able to phagocytose and responded to ADP by producing intracellular Ca2+ transients, whereas macrophages lacked such response. The differentiation protocol was highly reproducible across several pluripotent stem cell lines.

  19. Direct Fusion Drive for a Human Mars Orbital Mission

    Energy Technology Data Exchange (ETDEWEB)

    Paluszek, Michael [Princeton Satellite Systems; Pajer, Gary [Princeton Satellite Systems; Razin, Yosef [Princeton Satellite Systems; Slonaker, James [Princeton Satellite Systems; Cohen, Samuel [PPPL; Feder, Russ [PPPL; Griffin, Kevin [Princeton University; Walsh, Matthew [Princeton University

    2014-08-01

    The Direct Fusion Drive (DFD) is a nuclear fusion engine that produces both thrust and electric power. It employs a field reversed configuration with an odd-parity rotating magnetic field heating system to heat the plasma to fusion temperatures. The engine uses deuterium and helium-3 as fuel and additional deuterium that is heated in the scrape-off layer for thrust augmentation. In this way variable exhaust velocity and thrust is obtained.

  20. Dynamics of the transcriptome response of cultured human embryonic stem cells to ionizing radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, Mykyta V., E-mail: sokolovm@mail.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States); Panyutin, Irina V., E-mail: ipanyutinv@mail.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States); Panyutin, Igor G., E-mail: igorp@helix.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States); Neumann, Ronald D., E-mail: rneumann@mail.nih.gov [Nuclear Medicine Division, Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 (United States)

    2011-05-10

    One of the key consequences of exposure of human cells to genotoxic agents is the activation of DNA damage responses (DDR). While the mechanisms underpinning DDR in fully differentiated somatic human cells have been studied extensively, molecular signaling events and pathways involved in DDR in pluripotent human embryonic stem cells (hESC) remain largely unexplored. We studied changes in the human genome-wide transcriptome of H9 hESC line following exposures to 1 Gy of gamma-radiation at 2 h and 16 h post-irradiation. Quantitative real-time PCR was performed to verify the expression data for a subset of genes. In parallel, the cell growth, DDR kinetics, and expression of pluripotency markers in irradiated hESC were monitored. The changes in gene expression in hESC after exposure to ionizing radiation (IR) are substantially different from those observed in somatic human cell lines. Gene expression patterns at 2 h post-IR showed almost an exclusively p53-dependent, predominantly pro-apoptotic, signature with a total of only 30 up-regulated genes. In contrast, the gene expression patterns at 16 h post-IR showed 354 differentially expressed genes, mostly involved in pro-survival pathways, such as increased expression of metallothioneins, ubiquitin cycle, and general metabolism signaling. Cell growth data paralleled trends in gene expression changes. DDR in hESC followed the kinetics reported for human somatic differentiated cells. The expression of pluripotency markers characteristic of undifferentiated hESC was not affected by exposure to IR during the time course of our analysis. Our data on dynamics of transcriptome response of irradiated hESCs may provide a valuable tool to screen for markers of IR exposure of human cells in their most naive state; thus unmasking the key elements of DDR; at the same time, avoiding the complexity of interpreting distinct cell type-dependent genotoxic stress responses of terminally differentiated cells.

  1. Dynamics of the transcriptome response of cultured human embryonic stem cells to ionizing radiation exposure

    International Nuclear Information System (INIS)

    Sokolov, Mykyta V.; Panyutin, Irina V.; Panyutin, Igor G.; Neumann, Ronald D.

    2011-01-01

    One of the key consequences of exposure of human cells to genotoxic agents is the activation of DNA damage responses (DDR). While the mechanisms underpinning DDR in fully differentiated somatic human cells have been studied extensively, molecular signaling events and pathways involved in DDR in pluripotent human embryonic stem cells (hESC) remain largely unexplored. We studied changes in the human genome-wide transcriptome of H9 hESC line following exposures to 1 Gy of gamma-radiation at 2 h and 16 h post-irradiation. Quantitative real-time PCR was performed to verify the expression data for a subset of genes. In parallel, the cell growth, DDR kinetics, and expression of pluripotency markers in irradiated hESC were monitored. The changes in gene expression in hESC after exposure to ionizing radiation (IR) are substantially different from those observed in somatic human cell lines. Gene expression patterns at 2 h post-IR showed almost an exclusively p53-dependent, predominantly pro-apoptotic, signature with a total of only 30 up-regulated genes. In contrast, the gene expression patterns at 16 h post-IR showed 354 differentially expressed genes, mostly involved in pro-survival pathways, such as increased expression of metallothioneins, ubiquitin cycle, and general metabolism signaling. Cell growth data paralleled trends in gene expression changes. DDR in hESC followed the kinetics reported for human somatic differentiated cells. The expression of pluripotency markers characteristic of undifferentiated hESC was not affected by exposure to IR during the time course of our analysis. Our data on dynamics of transcriptome response of irradiated hESCs may provide a valuable tool to screen for markers of IR exposure of human cells in their most naive state; thus unmasking the key elements of DDR; at the same time, avoiding the complexity of interpreting distinct cell type-dependent genotoxic stress responses of terminally differentiated cells.

  2. Brief oral stimulation, but especially oral fat exposure, elevates serum triglycerides in humans

    Science.gov (United States)

    Mattes, Richard D.

    2009-01-01

    Oral exposure to dietary fat results in an early initial spike, followed by a prolonged elevation, of serum triglycerides in humans. The physiological and pathophysiological implications remain unknown. This study sought to determine the incidence of the effect, the required fat exposure duration, and its reliability. Thirty-four healthy adults participated in four to six response-driven trials held at least a week apart. They reported to the laboratory after an overnight fast, a catheter was placed in an antecubital vein, and a blood sample was obtained. Participants then ingested 50 g of safflower oil in capsules with 500 ml of water within 15 min to mimic a high fat meal but without oral fat exposure. Blood was collected 0, 10, 20, 30, 40, 50, 60, 120, 240, 360, and 480 min after capsule ingestion with different forms (full fat, nonfat, none) and durations of oral fat exposures (10 s, 5 min, 20 min, and/or 2 h). A triglyceride response (increase of triglyceride >10 mg/dl within 30 min) was observed in 88.2%, 70.5%, and 50% of participants with full-fat, nonfat, and no oral exposure, respectively. Test-retest reliability was 75% with full-fat exposure but only 45.4% with nonfat exposure. Full-fat and nonfat exposures led to comparable significant elevations of triglyceride over no oral stimulation with 10-s exposures, but full fat led to a greater rise than nonfat with 20 min of exposure. These data indicate that nutritionally relevant oral fat exposures reliably elevate serum triglyceride concentrations in most people. PMID:19074638

  3. High-resolution simulations of the thermophysiological effects of human exposure to 100 MHz RF energy

    International Nuclear Information System (INIS)

    Nelson, David A; Curran, Allen R; Nyberg, Hans A; Marttila, Eric A; Mason, Patrick A; Ziriax, John M

    2013-01-01

    Human exposure to radio frequency (RF) electromagnetic energy is known to result in tissue heating and can raise temperatures substantially in some situations. Standards for safe exposure to RF do not reflect bio-heat transfer considerations however. Thermoregulatory function (vasodilation, sweating) may mitigate RF heating effects in some environments and exposure scenarios. Conversely, a combination of an extreme environment (high temperature, high humidity), high activity levels and thermally insulating garments may exacerbate RF exposure and pose a risk of unsafe temperature elevation, even for power densities which might be acceptable in a normothermic environment. A high-resolution thermophysiological model, incorporating a heterogeneous tissue model of a seated adult has been developed and used to replicate a series of whole-body exposures at a frequency (100 MHz) which approximates that of human whole-body resonance. Exposures were simulated at three power densities (4, 6 and 8 mW cm −2 ) plus a sham exposure and at three different ambient temperatures (24, 28 and 31 °C). The maximum hypothalamic temperature increase over the course of a 45 min exposure was 0.28 °C and occurred in the most extreme conditions (T amb = 31 °C, PD = 8 mW cm −2 ). Skin temperature increases attributable to RF exposure were modest, with the exception of a ‘hot spot’ in the vicinity of the ankle where skin temperatures exceeded 39 °C. Temperature increases in internal organs and tissues were small, except for connective tissue and bone in the lower leg and foot. Temperature elevation also was noted in the spinal cord, consistent with a hot spot previously identified in the literature. (paper)

  4. Contact variables for exposure to avian influenza H5N1 virus at the human-animal interface.

    Science.gov (United States)

    Rabinowitz, P; Perdue, M; Mumford, E

    2010-06-01

    Although the highly pathogenic avian influenza H5N1 virus continues to cause infections in both avian and human populations, the specific zoonotic risk factors remain poorly understood. This review summarizes available evidence regarding types of contact associated with transmission of H5N1 virus at the human-animal interface. A systematic search of the published literature revealed five analytical studies and 15 case reports describing avian influenza transmission from animals to humans for further review. Risk factors identified in analytical studies were compared, and World Health Organization-confirmed cases, identified in case reports, were classified according to type of contact reported using a standardized algorithm. Although cases were primarily associated with direct contact with sick/unexpectedly dead birds, some cases reported only indirect contact with birds or contaminated environments or contact with apparently healthy birds. Specific types of contacts or activities leading to exposure could not be determined from data available in the publications reviewed. These results support previous reports that direct contact with sick birds is not the only means of human exposure to avian influenza H5N1 virus. To target public health measures and disease awareness messaging for reducing the risk of zoonotic infection with avian influenza H5N1 virus, the specific types of contacts and activities leading to transmission need to be further understood. The role of environmental virus persistence, shedding of virus by asymptomatic poultry and disease pathophysiology in different avian species relative to human zoonotic risk, as well as specific modes of zoonotic transmission, should be determined.

  5. Key provisions humanities research advertising and advertising exposure

    Directory of Open Access Journals (Sweden)

    A. A. Sogorin

    2015-05-01

    Full Text Available The basic directions of advertising studying as part of the research subject of separate social and humanitarian sciences. The definition of advertising is given. It’s considered as a holistic socio­economic phenomenon, which consists of three basic components: advertising as a product, the final incarnation in the material and ideal forms of the customer’s ideas; advertising as an activity that is advertising as a profession; advertising as an integral part of the social space of the individual. The boundaries of the social and humanitarian scientific field are defined. Accordingly, the study presents the main aspects of advertising in terms of art learning, sociology, cultural studies, history, psychology, political science, philosophy and linguistics. It is proved that the study of socio­humanitarian field is characterized with a permanent disciplinary interaction in the case study of advertising (the pairing of linguistics and psychology, political science and psychology, sociology and psychology. The chief strategies of advertising research within social and humanitarian fields include: a single basic approach strategy: the recognition of advertising as a two­way communication process; communication strategy: the rejection of research within the subject of a separate discipline, active interaction with the related sciences on the subject of the study; application of the principle of mutual academic enrichment; future strategy: focus on new technologies, methods, implementation of schemes of advertising in the social space, the attempts of futurological analysis. The article demonstrates the importance of interdisciplinary scientific cooperation in the study of advertising as a social phenomenon.

  6. Personal Care Products Are Only One of Many Exposure Routes of Natural Toxic Substances to Humans and the Environment

    Directory of Open Access Journals (Sweden)

    Thomas D. Bucheli

    2018-01-01

    Full Text Available The special issue “A Critical View on Natural Substances in Personal Care Products” is dedicated to addressing the multidisciplinary special challenges of natural ingredients in personal care products (PCP and addresses also environmental exposure. In this perspective article, we argue that environmental exposure is probably not so much dominated by PCP use, but in many cases by direct emission from natural or anthropogenically managed vegetation, including agriculture. In support of this hypothesis, we provide examples of environmental fate and behaviour studies for compound classes that are either listed in the International Nomenclature of Cosmetics Ingredients (INCI or have been discussed in a wider context of PCP applications and have been classified as potentially harmful to humans and the environment. Specifically, these include estrogenic isoflavones, the carcinogenic ptaquiloside and pyrrolizidine alkaloids, saponins, terpenes and terpenoids, such as artemisinin, and mycotoxins. Research gaps and challenges in the domains of human and environmental exposure assessment of natural products common to our currently rather separated research communities are highlighted.

  7. Neuromotor effects of acute ethanol inhalation exposure in humans: a preliminary study.

    Science.gov (United States)

    Nadeau, Véronique; Lamoureux, Daniel; Beuter, Anne; Charbonneau, Michel; Tardif, Robert

    2003-07-01

    Ethanol (ETOH) is added to unleaded gasoline to decrease environmental levels of carbon monoxide from automobiles emissions. Therefore, addition of ETOH in reformulated fuel will most likely increase and the involuntarily human exposure to this chemical will also increase. This preliminary study was undertaken to evaluate the possible neuromotor effects resulting from acute ETOH exposure by inhalation in humans. Five healthy non-smoking adult males, with no history of alcohol abuse, were exposed by inhalation, in a dynamic, controlled-environment exposure chamber, to various concentrations of ETOH (0, 250, 500 and 1,000 ppm in air) for six hours. Reaction time, body sway, hand tremor and rapid alternating movements were measured before and after each exposure session by using the CATSYS 7.0 system and a diadochokinesimeter. The concentrations of ETOH in blood and in alveolar air were also measured. ETOH was not detected in blood nor in alveolar air when volunteers were exposed to 250 and 500 ppm, but at the end of exposure to 1,000 ppm, blood and alveolar air concentrations were 0.443 mg/100ml and 253.1 ppm, respectively. The neuromotor tests did not show conclusively significant differences between the exposed and non-exposed conditions. In conclusion, this study suggests that acute exposure to ethanol at 1,000 ppm or lower or to concentrations that could be encountered upon refueling is not likely to cause any significant neuromotor alterations in healthy males.

  8. 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...

  9. Antiretroviral pre-exposure prophylaxis prevents vaginal transmission of HIV-1 in humanized BLT mice.

    Directory of Open Access Journals (Sweden)

    Paul W Denton

    2008-01-01

    Full Text Available Worldwide, vaginal transmission now accounts for more than half of newly acquired HIV-1 infections. Despite the urgency to develop and implement novel approaches capable of preventing HIV transmission, this process has been hindered by the lack of adequate small animal models for preclinical efficacy and safety testing. Given the importance of this route of transmission, we investigated the susceptibility of humanized mice to intravaginal HIV-1 infection.We show that the female reproductive tract of humanized bone marrow-liver-thymus (BLT mice is reconstituted with human CD4+ T and other relevant human cells, rendering these humanized mice susceptible to intravaginal infection by HIV-1. Effects of HIV-1 infection include CD4+ T cell depletion in gut-associated lymphoid tissue (GALT that closely mimics what is observed in HIV-1-infected humans. We also show that pre-exposure prophylaxis with antiretroviral drugs is a highly effective method for preventing vaginal HIV-1 transmission. Whereas 88% (7/8 of BLT mice inoculated vaginally with HIV-1 became infected, none of the animals (0/5 given pre-exposure prophylaxis of emtricitabine (FTC/tenofovir disoproxil fumarate (TDF showed evidence of infection (Chi square = 7.5, df = 1, p = 0.006.The fact that humanized BLT mice are susceptible to intravaginal infection makes this system an excellent candidate for preclinical evaluation of both microbicides and pre-exposure prophylactic regimens. The utility of humanized mice to study intravaginal HIV-1 transmission is particularly highlighted by the demonstration that pre-exposure prophylaxis can prevent intravaginal HIV-1 transmission in the BLT mouse model.

  10. Digital music exposure reliably induces temporary threshold shift (TTS) in normal hearing human subjects

    Science.gov (United States)

    Le Prell, C. G.; Dell, S.; Hensley, B.; Hall, J. W.; Campbell, K. C. M.; Antonelli, P. J.; Green, G. E.; Miller, J. M.; Guire, K.

    2012-01-01

    Objectives One of the challenges for evaluating new otoprotective agents for potential benefit in human populations is availability of an established clinical paradigm with real world relevance. These studies were explicitly designed to develop a real-world digital music exposure that reliably induces temporary threshold shift (TTS) in normal hearing human subjects. Design Thirty-three subjects participated in studies that measured effects of digital music player use on hearing. Subjects selected either rock or pop music, which was then presented at 93–95 (n=10), 98–100 (n=11), or 100–102 (n=12) dBA in-ear exposure level for a period of four hours. Audiograms and distortion product otoacoustic emissions (DPOAEs) were measured prior to and after music exposure. Post-music tests were initiated 15 min, 1 hr 15 min, 2 hr 15 min, and 3 hr 15 min after the exposure ended. Additional tests were conducted the following day and one week later. Results Changes in thresholds after the lowest level exposure were difficult to distinguish from test-retest variability; however, TTS was reliably detected after higher levels of sound exposure. Changes in audiometric thresholds had a “notch” configuration, with the largest changes observed at 4 kHz (mean=6.3±3.9dB; range=0–13 dB). Recovery was largely complete within the first 4 hours post-exposure, and all subjects showed complete recovery of both thresholds and DPOAE measures when tested 1-week post-exposure. Conclusions These data provide insight into the variability of TTS induced by music player use in a healthy, normal-hearing, young adult population, with music playlist, level, and duration carefully controlled. These data confirm the likelihood of temporary changes in auditory function following digital music player use. Such data are essential for the development of a human clinical trial protocol that provides a highly powered design for evaluating novel therapeutics in human clinical trials. Care must be

  11. Expression and site-directed mutagenesis of human dihydrofolate reductase

    Energy Technology Data Exchange (ETDEWEB)

    Prendergast, N.J.; Delcamp, T.J.; Smith, P.L.; Freisheim, J.H.

    1988-05-17

    A procaryotic high-level expression vector for human dihydrofolate reductase has been constructed and the protein characterized as a first step toward structure-function studies of this enzyme. A vector bearing the tac promoter, four synthetic oligodeoxynucleotides, and a restriction fragment from the dihydrofolate reductase cDNA were ligated in a manner which optimized the transcriptional and translational frequency of the enzyme mRNA. The reductase, comprising ca. 17% of the total soluble protein in the host bacteria, was purified to apparent homogeneity as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and characterized by amino acid composition, partial amino acid sequence, and steady-sate kinetic analysis. This expression vector has been used as a template for double-stranded plasmid DNA site-specific mutagenesis. Functional studies on a Cys-6 ..-->.. Ser-6 mutant enzyme support the contention that Cys-6 is obligatory for organomercurial activation of human dihydrofolate reductase. The Ser-6 mutant enzyme was not activated to any extent following a 24-h incubation with p-(hydroxymercuri)benzoate and nicotinamide adenine dinucleotide phosphate (reduced) (NADPH), whereas the k/sub cat/ for Cys-6 reductase increased 2-fold under identical conditions. The specific activities of the Cys-6 and Ser-6 enzymes were virtually identical as determined by methotrexate titration as were the K/sub m/ values for both dihydrofolate and NADPH. The Ser-6 mutant showed a decreased temperature stability and was more sensitive to inactivation by ..cap alpha..-chymotrypsin when compared to the wild-type enzyme. These results suggest that the Ser-6 mutant reductase is conformationally altered relative to the Cys-6 native enzyme.

  12. Expression and site-directed mutagenesis of human dihydrofolate reductase

    International Nuclear Information System (INIS)

    Prendergast, N.J.; Delcamp, T.J.; Smith, P.L.; Freisheim, J.H.

    1988-01-01

    A procaryotic high-level expression vector for human dihydrofolate reductase has been constructed and the protein characterized as a first step toward structure-function studies of this enzyme. A vector bearing the tac promoter, four synthetic oligodeoxynucleotides, and a restriction fragment from the dihydrofolate reductase cDNA were ligated in a manner which optimized the transcriptional and translational frequency of the enzyme mRNA. The reductase, comprising ca. 17% of the total soluble protein in the host bacteria, was purified to apparent homogeneity as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and characterized by amino acid composition, partial amino acid sequence, and steady-sate kinetic analysis. This expression vector has been used as a template for double-stranded plasmid DNA site-specific mutagenesis. Functional studies on a Cys-6 → Ser-6 mutant enzyme support the contention that Cys-6 is obligatory for organomercurial activation of human dihydrofolate reductase. The Ser-6 mutant enzyme was not activated to any extent following a 24-h incubation with p-(hydroxymercuri)benzoate and nicotinamide adenine dinucleotide phosphate (reduced) (NADPH), whereas the k/sub cat/ for Cys-6 reductase increased 2-fold under identical conditions. The specific activities of the Cys-6 and Ser-6 enzymes were virtually identical as determined by methotrexate titration as were the K/sub m/ values for both dihydrofolate and NADPH. The Ser-6 mutant showed a decreased temperature stability and was more sensitive to inactivation by α-chymotrypsin when compared to the wild-type enzyme. These results suggest that the Ser-6 mutant reductase is conformationally altered relative to the Cys-6 native enzyme

  13. Enhanced natural radiation exposure enhanced by human activity: the largest contributor to the Chinese population dose

    International Nuclear Information System (INIS)

    Pan Ziqiang; Liu Yanyang

    2011-01-01

    For the radiation exposure caused by human activities, the enhanced natural radiation exposure is the largest contributor to Chinese population dose. This problem has attracted social attention in recent years. Efforts have been made in several fields, such as radon indoors and in workplace, environmental problems associated with NORMs, occupational radiation hazards of non-uranium mine, and radiation dose evaluation for energy chain, but there are still many problems to be solved. In order to protect the health of workers and the public, while ensuring industrial production and economic development, it is also necessary to continue to strengthen research in all aspects above mentioned, and gradually promote the control of natural radiation exposure enhanced by human activities. (authors)

  14. Exposure to Carbon Nanotube Material: Assessment of Nanotube Cytotoxicity Using Human Keratinocyte Cells

    Science.gov (United States)

    Shvedova, Anna A.; Castranova, Vincent; Kisin, Elena R.; Schwegler-Berry, Diane; Murray, Ashley R.; Gandelsman, Vadim Z.; Maynard, Andrew; Baron, Paul

    2003-01-01

    Carbon nanotubes are new members of carbon allotropes similar to fullerenes and graphite. Because of their unique electrical, mechanical, and thermal properties, carbon nanotubes are important for novel applications in the electronics, aerospace, and computer industries. Exposure to graphite and carbon materials has been associated with increased incidence of skin diseases, such as carbon fiber dermatitis, hyperkeratosis, and naevi. We investigated adverse effects of single-wall carbon nanotubes (SWCNT) using a cell culture of immortalized human epidermal keratinocytes (HaCaT). After 18 h of exposure of HaCaT to SWCNT, oxidative stress and cellular toxicity were indicated by formation of free radicals, accumulation of peroxidative products, antioxidant depletion, and loss of cell viability. Exposure to SWCNT also resulted in ultrastructural and morphological changes in cultured skin cells. These data indicate that dermal exposure to unrefined SWCNT may lead to dermal toxicity due to accelerated oxidative stress in the skin of exposed workers.

  15. Exposure to Direct-to-Consumer Pharmaceutical Advertising and Medication Nonadherence Among Patients With Serious Mental Illness.

    Science.gov (United States)

    Green, Charee E; Mojtabai, Ramin; Cullen, Bernadette A; Spivak, Amethyst; Mitchell, Melissa; Spivak, Stanislav

    2017-12-01

    This study explored the association of exposure to direct-to-consumer advertising (DTCA) with medication nonadherence among individuals with serious mental disorders. Results of an anonymous survey administered at an inner-city mental health clinic were examined by using logistic regression. Nonadherence was defined as not taking prescribed medications for at least two out of seven days. Of 246 respondents, 48% reported DTCA exposure and 43% reported nonadherence. Sixty-one percent of those exposed to DTCA reported nonadherence, compared with 26% of those not exposed (adjusted odds ratio=4.96, 95% confidence interval=2.64-9.33, preporting nonadherence, 59% reported changing medication-taking behaviors or stopping prescribed medications because of side effect information in advertisements. Only a minority communicated with providers before becoming nonadherent. This study found an association between self-report of DTCA exposure and self-reported nonadherence. These results support further research on DTCA as a possible risk factor for nonadherence.

  16. Some aspects of miners' exposure to radon in Poland in view of international organizations recommendations and European Union directives

    International Nuclear Information System (INIS)

    Chruscielewski, W.; Liniecki, J.; Jankowski, J.

    1999-01-01

    Exposure of miners to natural radiation in which radon-222 plays the major role has been studied in Poland since the end of the nineteen sixties. The work environment measurements and personal monitoring methods have been developed for monitoring the exposure. A quite wide range of doses resulting from big differences in radon concentrations in mines is characteristic of miners' exposure. It was estimated that about 16% of miners received doses above 5 mSv per year. This group of miners should be provided with individual dosimetry. In this paper methodological and legal aspects of the situation in mines are analyzed. A large number of Polish recommendations and legal regulations must be changed in order to harmonize them with the directives of the European Union. (author)

  17. Outdoor and indoor cadmium distributions near an abandoned smelting works and their relations to human exposure

    International Nuclear Information System (INIS)

    Spurgeon, David J.; Lawlor, Alan; Hooper, Helen L.; Wadsworth, Richard; Svendsen, Claus; Thomas, Laura D.K.; Ellis, James K.; Bundy, Jacob G.; Keun, Hector C.; Jarup, Lars

    2011-01-01

    The relationship of measured or modelled Cd concentrations in soil, house dust and available to plants with human urinary Cd concentrations were assessed in a population living around a Cd/Pb/Zn smelter in the UK. Modelled air concentrations explained 35% of soil Cd variation indicating the smelter contributed to soil Cd loads. Multi-variate analysis confirmed a significant role of biological and life-style factors in determining urinary Cd levels. Significant correlations of urinary Cd with soil, house dust and modelled plant available Cd concentrations were not, however, found. Potential reasons for the absence of clear relationships include limited environmental contact in urban populations; the role of undefined factors in determining exposure; and the limited spatial scope of the survey which did not sample from the full pollution gradient. Further, the absence of any significant relationship indicates that environmental measures provide limited advantage over atmospheric model outputs for first stage human exposure assessment. - Highlights: → Environmental measurements indicate smelter pollution of a surrounding urban area. → Life-style and biology influenced U-Cd more than measured environmental levels. → Limited contact with outdoor environments may limit Cd uptake in urban populations. → Better life-style data could improve the attribution of human Cd exposure routes. → Measured Cd levels provide limited added exposure insight over dispersion models. - Measured and modelled environmental cadmium concentrations provide limited additional explanation of human urinary cadmium concentrations.

  18. Climate change, ozone depletion and the impact on ultraviolet exposure of human skin

    International Nuclear Information System (INIS)

    Diffey, Brian

    2004-01-01

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population. (topical review)

  19. Concentrations of environmental organic contaminants in meat and meat products and human dietary exposure: A review.

    Science.gov (United States)

    Domingo, José L

    2017-09-01

    Meat and meat products is one of the most relevant food groups in an important number of human diets. Recently, the IARC, based on results of a number of epidemiological studies, classified the consumptions of red meat and processed meat as "probably carcinogenic to humans" and as "carcinogenic to humans", respectively. It was suggested that the substances responsible of the potential carcinogenicity would be mainly generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures. However, the exposure to environmental pollutants through meat consumption was not discussed. The purpose of the present paper was to review recent studies reporting the concentrations of PCDD/Fs, DL-PCBs and PAHs in meat and meat products, as well as the human exposure to these pollutants through the diet. It is concluded that the health risks derived from exposure to carcinogenic environmental contaminants must be considered in the context of each specific diet, which besides meat and meat products, includes other foodstuffs containing also chemical pollutants, some of them with carcinogenic potential. Anyhow, meat and meat products are not the main food group responsible of the dietary exposure to carcinogenic (or probably carcinogenic) environmental organic pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Relevancy of human exposure via house dust to the contaminants lead and asbestos

    NARCIS (Netherlands)

    Oomen AG; Lijzen JPA; SIR; LER

    2004-01-01

    The present report addresses the issues whether house dust is likely to contribute substantially to the exposure of humans, in particular for the contaminants lead and asbestos. House dust consists for 30-70% of soil material, indicating that contaminated soil can lead to contaminated house dust. It

  1. Oral bioaccessibility and human exposure to anthropogenic and geogenic mercury in urban, industrial and mining areas

    NARCIS (Netherlands)

    Rodrigues, S.M.; Coelho, C.; Cruz, N.; Monteiro, R.J.R.; Henriques, B.; Duarte, A.C.; Romkens, P.F.A.M.; Pereira, E.

    2014-01-01

    The objective of this study was to characterize the link between bioaccessibility and fractionation of mercury (Hg) in soils and to provide insight into human exposure to Hg due to inhalation of airborne soil particles and hand-to-mouth ingestion of Hg-bearing soil. Mercury in soils from mining,

  2. Phytoaccumulation of antimicrobials from biosolids: impacts on environmental fate and relevance to human exposure.

    Science.gov (United States)

    Aryal, Niroj; Reinhold, Dawn M

    2011-11-01

    Triclocarban and triclosan, two antimicrobials widely used in consumer products, can adversely affect ecosystems and potentially impact human health. The application of biosolids to agricultural fields introduces triclocarban and triclosan to soil and water resources. This research examined the phytoaccumulation of antimicrobials, effects of plant growth on migration of antimicrobials to water resources, and relevance of phytoaccumulation in human exposure to antimicrobials. Pumpkin, zucchini, and switch grass were grown in soil columns to which biosolids were applied. Leachate from soil columns was assessed every other week for triclocarban and triclosan. At the end of the trial, concentrations of triclocarban and triclosan were determined for soil, roots, stems, and leaves. Results indicated that plants can reduce leaching of antimicrobials to water resources. Pumpkin and zucchini growth significantly reduced soil concentrations of triclosan to less than 0.001 mg/kg, while zucchini significantly reduced soil concentrations of triclocarban to 0.04 mg/kg. Pumpkin, zucchini, and switch grass accumulated triclocarban and triclosan in mg per kg (dry) concentrations. Potential human exposure to triclocarban from consumption of pumpkin or zucchini was substantially less than exposure from product use, but was greater than exposure from drinking water consumption. Consequently, research indicated that pumpkin and zucchini may beneficially impact the fate of antimicrobials in agricultural fields, while presenting minimal acute risk to human health. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. EXHALED HUMAN BREATH MEASUREMENT OF JET FUEL CONSTITUENTS: DISTINGUISHING BETWEEN INHALATION AND DERMAL EXPOSURE ROUTES

    Science.gov (United States)

    In response to anecdotal reports, perceived health issues, and widespread complaints, the U.S. military launched an investigation into the occupational and environmental human exposure to jet fuel. The work described in the presentation assesses the correlation between two breat...

  4. Serum vitamin D levels are not altered after controlled diesel exhaust exposures in healthy human subjects

    Science.gov (United States)

    Past research has suggested that exposure to urban air pollution may be associated with vitamin D deficiency in human populations. Vitamin D is widely known for its importance in bone growth/remodeling, muscle metabolism, and its ability to promote calcium absorption in the gut; ...

  5. An Agent-Based Modeling Framework for Simulating Human Exposure to Environmental Stresses in Urban Areas

    Directory of Open Access Journals (Sweden)

    Liang Emlyn Yang

    2018-04-01

    Full Text Available Several approaches have been used to assess potential human exposure to environmental stresses and achieve optimal results under various conditions, such as for example, for different scales, groups of people, or points in time. A thorough literature review in this paper identifies the research gap regarding modeling approaches for assessing human exposure to environment stressors, and it indicates that microsimulation tools are becoming increasingly important in human exposure assessments of urban environments, in which each person is simulated individually and continuously. The paper further describes an agent-based model (ABM framework that can dynamically simulate human exposure levels, along with their daily activities, in urban areas that are characterized by environmental stresses such as air pollution and heat stress. Within the framework, decision-making processes can be included for each individual based on rule-based behavior in order to achieve goals under changing environmental conditions. The ideas described in this paper are implemented in a free and open source NetLogo platform. A basic modeling scenario of the ABM framework in Hamburg, Germany, demonstrates its utility in various urban environments and individual activity patterns, as well as its portability to other models, programs, and frameworks. The prototype model can potentially be extended to support environmental incidence management through exploring the daily routines of different groups of citizens, and comparing the effectiveness of different strategies. Further research is needed to fully develop an operational version of the model.

  6. Exposure to perfluorinated compounds and human semen quality in arctic and European populations

    NARCIS (Netherlands)

    Toft, G.; Jönsson, B.A.G.; Lindh, C.H.; Giwercman, A.; Spano, M.; Heederik, D.J.J.; Lenters, V.C.; Vermeulen, R.C.H.; Rylander, L.; Pedersen, H.S.; Ludwicki, J.K.; Zviezdai, V.; Bonde, J.P.

    2012-01-01

    BACKGROUND Perfluorinated compounds (PFCs) have been suspected to adversely affect human reproductive health. The aim of this study was to investigate the associations between PFC exposure and male semen quality. METHODS PFCs were measured in serum from 588 partners of pregnant women from Greenland,

  7. Outdoor and indoor cadmium distributions near an abandoned smelting works and their relations to human exposure

    Energy Technology Data Exchange (ETDEWEB)

    Spurgeon, David J., E-mail: dasp@ceh.ac.uk [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB (United Kingdom); Lawlor, Alan [Centre for Ecology and Hydrology, Lancaster, Bailrigg, Lancaster LA1 4AP (United Kingdom); Hooper, Helen L. [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB (United Kingdom); Wadsworth, Richard [Centre for Ecology and Hydrology, Lancaster, Bailrigg, Lancaster LA1 4AP (United Kingdom); Svendsen, Claus [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxon, OX10 8BB (United Kingdom); Thomas, Laura D.K. [MRC-HPA Centre for Environment and Health, Department of Epidemiology and Public health, Imperial College London (United Kingdom); Ellis, James K.; Bundy, Jacob G.; Keun, Hector C. [Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ (United Kingdom); Jarup, Lars [MRC-HPA Centre for Environment and Health, Department of Epidemiology and Public health, Imperial College London (United Kingdom)

    2011-12-15

    The relationship of measured or modelled Cd concentrations in soil, house dust and available to plants with human urinary Cd concentrations were assessed in a population living around a Cd/Pb/Zn smelter in the UK. Modelled air concentrations explained 35% of soil Cd variation indicating the smelter contributed to soil Cd loads. Multi-variate analysis confirmed a significant role of biological and life-style factors in determining urinary Cd levels. Significant correlations of urinary Cd with soil, house dust and modelled plant available Cd concentrations were not, however, found. Potential reasons for the absence of clear relationships include limited environmental contact in urban populations; the role of undefined factors in determining exposure; and the limited spatial scope of the survey which did not sample from the full pollution gradient. Further, the absence of any significant relationship indicates that environmental measures provide limited advantage over atmospheric model outputs for first stage human exposure assessment. - Highlights: > Environmental measurements indicate smelter pollution of a surrounding urban area. > Life-style and biology influenced U-Cd more than measured environmental levels. > Limited contact with outdoor environments may limit Cd uptake in urban populations. > Better life-style data could improve the attribution of human Cd exposure routes. > Measured Cd levels provide limited added exposure insight over dispersion models. - Measured and modelled environmental cadmium concentrations provide limited additional explanation of human urinary cadmium concentrations.

  8. Antimicrobial peptide exposure selects for Staphylococcus aureus resistance to human defence peptides

    DEFF Research Database (Denmark)

    Kubicek-Sutherland, Jessica Z.; Lofton, Hava; Vestergaard, Martin

    2017-01-01

    Background: The clinical development of antimicrobial peptides (AMPs) is currently under evaluation to combat the rapid increase in MDR bacterial pathogens. However, many AMPs closely resemble components of the human innate immune system and the ramifications of prolonged bacterial exposure to AM...

  9. Assessment of Human Exposure to Magnetic Fields Produced by Domestic Appliances (invited paper)

    International Nuclear Information System (INIS)

    Preece, A.W.; Kaune, W.T.; Grainger, P.; Golding, J.

    1999-01-01

    A study of 50 homes and their appliances examined whether a detailed appliance-use questionnaire and survey would yield data comparable with direct personal monitoring. This was coupled with direct measurement of the appliances in use to determine the field at 50 cm and 1 m. The findings were that individual time-weighted average (TWA) exposures calculated from questionnaire and activity diaries in conjunction with the appliance magnetic field were unrelated to actual personal exposure measurement. It was concluded that questionnaires are of little or no value for TWA estimation. However, peak exposure and short-term temporal variability could be modelled in subjects spending at least 15 min per day within 1 m of an operating microwave cooker or conventional cooker. This method could be extended to other appliances. (author)

  10. A hybrid modeling with data assimilation to evaluate human exposure level

    Science.gov (United States)

    Koo, Y. S.; Cheong, H. K.; Choi, D.; Kim, A. L.; Yun, H. Y.

    2015-12-01

    Exposure models are designed to better represent human contact with PM (Particulate Matter) and other air pollutants such as CO, SO2, O3, and NO2. The exposure concentrations of the air pollutants to human are determined by global and regional long range transport of global and regional scales from Europe and China as well as local emissions from urban and road vehicle sources. To assess the exposure level in detail, the multiple scale influence from background to local sources should be considered. A hybrid air quality modeling methodology combing a grid-based chemical transport model with a local plume dispersion model was used to provide spatially and temporally resolved air quality concentration for human exposure levels in Korea. In the hybrid modeling approach, concentrations from a grid-based chemical transport model and a local plume dispersion model are added to provide contributions from photochemical interactions, long-range (regional) transport and local-scale dispersion. The CAMx (Comprehensive Air quality Model with Extensions was used for the background concentrations from anthropogenic and natural emissions in East Asia including Korea while the road dispersion by vehicle emission was calculated by CALPUFF model. The total exposure level of the pollutants was finally assessed by summing the background and road contributions. In the hybrid modeling, the data assimilation method based on the optimal interpolation was applied to overcome the discrepancies between the model predicted concentrations and observations. The air quality data from the air quality monitoring stations in Korea. The spatial resolution of the hybrid model was 50m for the Seoul Metropolitan Ares. This example clearly demonstrates that the exposure level could be estimated to the fine scale for the exposure assessment by using the hybrid modeling approach with data assimilation.

  11. Modelling of human exposure to air pollution in the urban environment: a GPS-based approach.

    Science.gov (United States)

    Dias, Daniela; Tchepel, Oxana

    2014-03-01

    The main objective of this work was the development of a new modelling tool for quantification of human exposure to traffic-related air pollution within distinct microenvironments by using a novel approach for trajectory analysis of the individuals. For this purpose, mobile phones with Global Positioning System technology have been used to collect daily trajectories of the individuals with higher temporal resolution and a trajectory data mining, and geo-spatial analysis algorithm was developed and implemented within a Geographical Information System to obtain time-activity patterns. These data were combined with air pollutant concentrations estimated for several microenvironments. In addition to outdoor, pollutant concentrations in distinct indoor microenvironments are characterised using a probabilistic approach. An example of the application for PM2.5 is presented and discussed. The results obtained for daily average individual exposure correspond to a mean value of 10.6 and 6.0-16.4 μg m(-3) in terms of 5th-95th percentiles. Analysis of the results shows that the use of point air quality measurements for exposure assessment will not explain the intra- and inter-variability of individuals' exposure levels. The methodology developed and implemented in this work provides time-sequence of the exposure events thus making possible association of the exposure with the individual activities and delivers main statistics on individual's air pollution exposure with high spatio-temporal resolution.

  12. Biomonitoring of the mycotoxin Zearalenone: current state-of-the art and application to human exposure assessment.

    Science.gov (United States)

    Mally, Angela; Solfrizzo, Michele; Degen, Gisela H

    2016-06-01

    Zearalenone (ZEN), a mycotoxin with high estrogenic activity in vitro and in vivo, is a widespread food contaminant that is commonly detected in maize, wheat, barley, sorghum, rye and other grains. Human exposure estimates based on analytical data on ZEN occurrence in various food categories and food consumption data suggest that human exposure to ZEN and modified forms of ZEN may be close to or even exceed the tolerable daily intake (TDI) derived by the European Food Safety Authority (EFSA) for some consumer groups. Considering the inherent uncertainties in estimating dietary intake of ZEN that may lead to an under- or overestimation of ZEN exposure and consequently human risk and current lack of data on vulnerable consumer groups, there is a clear need for more comprehensive and reliable exposure data to refine ZEN risk assessment. Human biomonitoring (HBM) is increasingly being recognized as an efficient and cost-effective way of assessing human exposure to food contaminants, including mycotoxins. Based on animal and (limited) human data on the toxicokinetics of ZEN, it appears that excretion of ZEN and its major metabolites may present suitable biomarkers of ZEN exposure. In view of the limitations of available dietary exposure data on ZEN and its modified forms, the purpose of this review is to provide an overview of recent studies utilizing HBM to monitor and assess human exposure to ZEN. Considerations are given to animal and human toxicokinetic data relevant to HBM, analytical methods, and available HBM data on urinary biomarkers of ZEN exposure in different cohorts.

  13. 77 FR 14022 - Guidance for Industry: Testing for Salmonella Species in Human Foods and Direct-Human-Contact...

    Science.gov (United States)

    2012-03-08

    ...-contact animal foods, and the interpretation of test results, when the presence of Salmonella spp. in the... eggs) and direct-human-contact animal foods, and the interpretation of test results, when the presence... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-D-0091...

  14. Blood cholinesterases as human biomarkers of organophosphorus pesticide exposure.

    Science.gov (United States)

    Nigg, H N; Knaak, J B

    2000-01-01

    phosphorothioates and phosphorodithioates (e.g., parathion and azinphosmethyl, respectively) to the more toxic oxons (P = O(S to O)). In some cases, P-450 isozymes catalyze the oxidative cleavage of P-O-aryl bonds (e.g., parathion, methyl parathion, fenitrothion, and diazinon) to form inactive water-soluble alkyl phosphates and aryl leaving groups that are readily conjugated with glucuronic or sulfuric acids and excreted. In addition to the P-450 isozymes, mammalian tissues contain ('A' and 'B') esterases capable of reacting with OPs to produce hydrolysis products or phosphorylated enzymes. 'A'-esterases hydrolyze OPs (i.e., oxons), while 'B'-esterases with serine at the active center are inhibited by OPs. OPs possessing carboxylesters, such as malathion and isofenphos, are hydrolyzed by the direct action of 'B'-esterases (i.e., carboxylesterase, CaE). Metabolic pathways shown for isofenphos, parathion, and malathion define the order in which these reactions occur, while Michaelis-Menten kinetics define reaction parameters (Vmax, K(m)) for the enzymes and substrates involved, and rates of inhibition of 'B'-esterases (kis, bimolecular rate constants) by OPs and their oxons. OPs exert their insecticidal action by their ability to inhibit AChE at the cholinergic synapse, resulting in the accumulation of acetylcholine. The extent to which AChE or other 'B'-esterases are inhibited in workers is dependent upon the rate the OP pesticide is activated (i.e., oxon formation), metabolized to nontoxic products by tissue enzymes, its affinity for AChE and other 'B'-esterases, and esterase concentrations in tissues. Rapid recovery of OP BChE inhibition may be related to reactivation of inhibited forms. AChE, BChE, and CaE appear to function in vivo as scavengers, protecting workers against the inhibition of AChE at synapses. Species sensitivity to OPs varies widely and results in part from binding affinities (Ka) and rates of phosphorylation (kp) rather than rates of activation and detoxif

  15. Comparative study of neurologic effects of nano-TiO2 versus SiO2 after direct intracerebral exposure in mice

    International Nuclear Information System (INIS)

    Balvay, A; Bencsik, A; Thieriet, N; Lakhdar, L

    2013-01-01

    Titanium and silicon dioxide nanoparticles (TiO 2 and SiO 2 NPs) are now in daily use in many commercial products of which food, sunscreens, toothpastes or cosmetics. However, their effects on human body, especially on the central nervous system, are still unclear. The aim of this study was to determine whether direct exposition of the brain to TiO 2 and SiO 2 NPs results in alternations in nervous system function. C57Bl6 mice were exposed to 5 and 10 μg doses of TiO 2 and SiO 2 NPs through intracerebroventricular administration using a stereotaxic approach. Then the neurologic effects were investigated using motor performance parameters, measured on a rotarod at 20 rpm or at an accelerating rod (from 4 to 40 rpm). Before and after injection, motor activity is registered individually for each mouse exposed, once a week, for 8 weeks. Besides, a group of 3 mice is culled at 1, 2, 3, 4 and 8 weeks after exposure in order to study the time dependant effect on the histopathology of the brain (gliosis, inflammatory process...). Both rotarod tests (accelerating and at 20 rpm) showed that TiO 2 and SiO 2 NPs exposure could significantly impair the motor performances, even several weeks after initial acute exposure. The first examination of the brain histopathology revealed microglial activation. As it appeared to grow throughout the brain in a time dependant manner this suggests the induction of a long lasting neuroinflammation. These primary findings indicated that exposure to TiO 2 and SiO 2 NPs could possibly impair the locomotor ability and this deficit may be possibly attributed at least to an inflammatory process maintained till 8 weeks after exposure in the mouse brain. To fully investigate the neurotoxicological consequences of TiO 2 and SiO 2 NPs exposure, brain contents in these NPs will be also investigated as well as other alterations like neurotransmitter levels. These preliminary data already underline the necessity of more in vivo studies to better

  16. Comparative study of neurologic effects of nano-TiO2 versus SiO2 after direct intracerebral exposure in mice

    Science.gov (United States)

    Balvay, A.; Thieriet, N.; Lakhdar, L.; Bencsik, A.

    2013-04-01

    Titanium and silicon dioxide nanoparticles (TiO2 and SiO2 NPs) are now in daily use in many commercial products of which food, sunscreens, toothpastes or cosmetics. However, their effects on human body, especially on the central nervous system, are still unclear. The aim of this study was to determine whether direct exposition of the brain to TiO2 and SiO2 NPs results in alternations in nervous system function. C57Bl6 mice were exposed to 5 and 10 μg doses of TiO2 and SiO2 NPs through intracerebroventricular administration using a stereotaxic approach. Then the neurologic effects were investigated using motor performance parameters, measured on a rotarod at 20 rpm or at an accelerating rod (from 4 to 40 rpm). Before and after injection, motor activity is registered individually for each mouse exposed, once a week, for 8 weeks. Besides, a group of 3 mice is culled at 1, 2, 3, 4 and 8 weeks after exposure in order to study the time dependant effect on the histopathology of the brain (gliosis, inflammatory process...). Both rotarod tests (accelerating and at 20 rpm) showed that TiO2 and SiO2 NPs exposure could significantly impair the motor performances, even several weeks after initial acute exposure. The first examination of the brain histopathology revealed microglial activation. As it appeared to grow throughout the brain in a time dependant manner this suggests the induction of a long lasting neuroinflammation. These primary findings indicated that exposure to TiO2 and SiO2 NPs could possibly impair the locomotor ability and this deficit may be possibly attributed at least to an inflammatory process maintained till 8 weeks after exposure in the mouse brain. To fully investigate the neurotoxicological consequences of TiO2 and SiO2 NPs exposure, brain contents in these NPs will be also investigated as well as other alterations like neurotransmitter levels. These preliminary data already underline the necessity of more in vivo studies to better characterize TiO2

  17. Identification of proteins that may directly interact with human RPA.

    Science.gov (United States)

    Nakaya, Ryou; Takaya, Junichiro; Onuki, Takeshi; Moritani, Mariko; Nozaki, Naohito; Ishimi, Yukio

    2010-11-01

    RPA, which consisted of three subunits (RPA1, 2 and 3), plays essential roles in DNA transactions. At the DNA replication forks, RPA binds to single-stranded DNA region to stabilize the structure and to assemble other replication proteins. Interactions between RPA and several replication proteins have been reported but the analysis is not comprehensive. We systematically performed the qualitative analysis to identify RPA interaction partners to understand the protein-protein interaction at the replication forks. We expressed in insect cells the three subunits of human RPA, together with one replication protein, which is present at the forks under normal conditions and/or under the replication stress conditions, to examine the interaction. Among 30 proteins examined in total, it was found that at least 14 proteins interacted with RPA. RPA interacted with MCM3-7, MCM-BP and CDC45 proteins among the proteins that play roles in the initiation and the elongation of the DNA replication. RPA bound with TIPIN, CLASPIN and RAD17, which are involved in the DNA replication checkpoint functions. RPA also bound with cyclin-dependent kinases and an amino-terminal fragment of Rb protein that negatively regulates DNA replication. These results suggest that RPA interacts with the specific proteins among those that play roles in the regulation of the replication fork progression.

  18. Direct human DNA protection by Coriolus versicolor (Yunzhi) extract.

    Science.gov (United States)

    Szeto, Yim Tong; Lau, Po Chun; Kalle, Wouter; Pak, Sok Cheon

    2013-07-01

    Scientific evidence has shown Coriolus versicolor (L. ex Fr.) Quel (also known as Yunzhi) has the role of immunomodulator in therapeutic effect. The aim of this in vitro study was to investigate the antioxidative effect of Yunzhi and to explore the mechanisms behind its DNA protection. Commercial Yunzhi extract was dissolved in water and diluted in five concentrations (10(1)-10(5) μg/L) with appropriate buffers. Lymphocytes harvested from three healthy subjects were incubated with Yunzhi extract for 30 min. Cells were then subjected to 5 min oxidant challenge by 45 μM hydrogen peroxide. The standard alkaline comet (SAC) assay and lysed cell comet (LCC) assay were performed in parallel. DNA damage of each treatment was scored under a fluorescence microscope and compared with the cells without Yunzhi pretreatment. U-shaped dose-response was seen in both versions of the comet assay. Yunzhi at 10(4) μg/L demonstrated a genoprotective effect against oxidative damage in the SAC assay (25% decrease in comet score). In the LCC assay, a trend of protection in lymphocytes was observed but it did not reach statistical significance. A direct antioxidant effect of Yunzhi against oxidant challenge on the DNA of lymphocytes was evidenced. The active component in Yunzhi was likely to be membrane permeable.

  19. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    Directory of Open Access Journals (Sweden)

    Matthew J Kesic

    Full Text Available Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs human airway trypsin-like protease (HAT and transmembrane protease, serine 2 (TMPRSS2, whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI. Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.

  20. The Measure of Human Error: Direct and Indirect Performance Shaping Factors

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring; Candice D. Griffith; Jeffrey C. Joe

    2007-08-01

    The goal of performance shaping factors (PSFs) is to provide measures to account for human performance. PSFs fall into two categories—direct and indirect measures of human performance. While some PSFs such as “time to complete a task” are directly measurable, other PSFs, such as “fitness for duty,” can only be measured indirectly through other measures and PSFs, such as through fatigue measures. This paper explores the role of direct and indirect measures in human reliability analysis (HRA) and the implications that measurement theory has on analyses and applications using PSFs. The paper concludes with suggestions for maximizing the reliability and validity of PSFs.

  1. MEMS pressure sensor with maximum performances by using novel back-side direct-exposure concept featuring through glass vias

    Science.gov (United States)

    Mukhopadhyay, B.; Fritz, M.; Mackowiak, P.; Vu, T. C.; Ehrmann, O.; Lang, K.-D.; Ngo, H.-D.

    2013-05-01

    Design, simulation, fabrication, and characterization of novel MEMS pressure sensors with new back-side-direct-exposure packaging concept are presented. The sensor design is optimized for harsh environments e.g. space, military, offshore and medical applications. Unbreakable connection between the active side of the Si-sensor and the protecting glass capping was realized by anodic bonding using a thin layer of metal. To avoid signal corruption of the measured pressure caused by an encapsulation system, the media has direct contact to the backside of the Si membrane and can deflect it.

  2. Intermittent, low dose carbon monoxide exposure enhances survival and dopaminergic differentiation of human neural stem cells

    DEFF Research Database (Denmark)

    Dreyer-Andersen, Nanna; Almeida, Ana Sofia; Jensen, Pia

    2018-01-01

    Exploratory studies using human fetal tissue have suggested that intrastriatal transplantation of dopaminergic neurons may become a future treatment for patients with Parkinson's disease. However, the use of human fetal tissue is compromised by ethical, regulatory and practical concerns. Human stem...... cells constitute an alternative source of cells for transplantation in Parkinson's disease, but efficient protocols for controlled dopaminergic differentiation need to be developed. Short-term, low-level carbon monoxide (CO) exposure has been shown to affect signaling in several tissues, resulting...... in Parkinson's disease....

  3. Chronic Exposure to Particulate Nickel Induces Neoplastic Transformation in Human Lung Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Amie L. Holmes

    2013-11-01

    Full Text Available Nickel is a well-known human lung carcinogen with the particulate form being the most potent; however, the carcinogenic mechanism remains largely unknown. Few studies have investigated the genotoxicity and carcinogenicity of nickel in its target cell, human bronchial epithelial cells. Thus, the goal of this study was to investigate the effects of particulate nickel in human lung epithelial cells. We found that nickel subsulfide induced concentration- and time-dependent increases in both cytotoxicity and genotoxicity in human lung epithelial cells (BEP2D. Chronic exposure to nickel subsulfide readily induced cellular transformation, inducing 2.55, 2.9 and 2.35 foci per dish after exposure to 1, 2.5 and 5 μg/cm2 nickel subsulfide, respectively. Sixty-one, 100 and 70 percent of the foci isolated from 1, 2.5, and 5 μg/cm2 nickel subsulfide treatments formed colonies in soft agar and the degree of soft agar colony growth increased in a concentration-dependent manner. Thus, chronic exposure to particulate nickel induces genotoxicity and cellular transformation in human lung epithelial cells.

  4. A Realistic Human Exposure Assessment of Indoor Radon released from Groundwater

    International Nuclear Information System (INIS)

    Yu, Dong Han; Han, Moon Hee

    2002-01-01

    The work presents a realistic human exposure assessment of indoor radon released from groundwater in a house. At first, a two-compartment model is developed to describe the generation and transfer of radon in indoor air from groundwater. The model is used to estimate radon concentrations profile of indoor air in a house using by showering, washing clothes, and flushing toilets. Then, the study performs an uncertainty analysis of model input parameters to quantify the uncertainty in radon concentration profile. In order to estimate a daily internal dose of a specific tissue group in an adult through the inhalation of such indoor radon, a PBPK(Physiologically-Based Pharmaco-Kinetic) model is developed. Combining indoor radon profile and PBPK model is used to a realistic human assessment for such exposure. The results obtained from this study would be used to the evaluation of human risk by inhalation associated with the indoor radon released from groundwater

  5. Differential diagnosis and management of human-directed aggression in cats.

    Science.gov (United States)

    Frank, Diane; Dehasse, Joel

    2003-03-01

    Human-directed aggression in cats should be evaluated as a multifactorial problem. It results from the combined actions of heredity, environment, learning, human social requirements (or needs), client interactions, lack of understanding of normal feline behavior, unrealistic client expectations, and lack of meeting the cat's basic ethologic needs. Managing human-directed aggression in cats encompasses the use of environmental modification, therapies, and, when and if needed, regulatory drugs so as to increase learning capabilities and adaptation and decrease danger to the human victims.

  6. Direct Vocabulary Instruction in Preschool: A Comparison of Extended Instruction, Embedded Instruction, and Incidental Exposure

    Science.gov (United States)

    Loftus-Rattan, Susan M.; Mitchell, Alison M.; Coyne, Michael D.

    2016-01-01

    Based on its coincidence with a significant period in language development for children, preschool provides a favorable setting to foster vocabulary growth. The purpose of this study was to evaluate the effectiveness of two instructional conditions and an incidental exposure condition for teaching targeted vocabulary words to preschool students…

  7. Effect of Exposure to Non-ionizing Radiation (Electromagnetic Fields on Human System: A Literature Review

    Directory of Open Access Journals (Sweden)

    Paula Rubya Souza C and acirc;mara

    2014-08-01

    Full Text Available The indiscriminate presence of radio base stations, which emit non-ionizing radiation (NIR, as well as the frequent use of mobile phones, can cause increased susceptibility of populations to the emergence of diseases such as cancers of the head and neck, biochemical, hematopoietic and hepatic changes, among others. Exposure to physical contamination, including NIR, has been implicated in numerous diseases, raising concerns about the widespread sources of exposure to this type of radiation. This paper reviews studies that have assessed associations between likely exposure to electromagnetic fields, such as radiofrequency transmissions, and many kinds of human diseases including cancer, as well as alerts to the current knowledge on the association between environmental exposure to NIR and the risk of development of adverse human health effects. This way, there appears to be an urgent need to reconsider exposure limits for low frequency and static magnetic fields, based on combined experimental and epidemiological research. [J Interdiscipl Histopathol 2014; 2(4.000: 187-190

  8. Toxicity levels to humans during acute exposure to hydrogen fluoride - An update

    Energy Technology Data Exchange (ETDEWEB)

    Halton, D M

    1995-09-01

    In March 1993, the Atomic Energy Control Board (AECB) commissioned and update of a 1984 review on the acute toxicity of hydrogen fluoride (HF). The study places particular emphasis on the effects of inhalation of gaseous HF and is divided into two main parts: a literature review and a lethal concentration (LC) estimation. The literature review summarizes data under four categories: animal studies, controlled human studies, community exposure, and industrial exposure. Data in these areas were critically reviewed for their relevance to lethal concentrations at LC{sub LO}, LC{sub 10} and LC{sub 50} levels that were derived in the 1984 report. In the last ten years, only one relevant animal study has been published. No new controlled human studies were found but a community exposure incident was reported. There were three new industrial/accidental exposures reported since 1984. Evaluation of new data does not change the lethal concentration estimates made in the 1984 report, but does indicate the absence of appropriate models to estimate the lethality of irritant and corrosive gases. In the last 10 years, much literature on the evaluation of major hazards has been published and suggests that such assessments are of growing political, economic and social importance. Numerous articles have been published on the acute toxicity of HF from skin contact and chronic toxicity from repeated airborne exposure. These publications offer important insights into the nature of HF toxicity. Several avenues of investigative research are suggested. (author). 55 refs., 4 tabs.

  9. Toxicity levels to humans during acute exposure to hydrogen fluoride - An update

    International Nuclear Information System (INIS)

    Halton, D.M.

    1995-09-01

    In March 1993, the Atomic Energy Control Board (AECB) commissioned and update of a 1984 review on the acute toxicity of hydrogen fluoride (HF). The study places particular emphasis on the effects of inhalation of gaseous HF and is divided into two main parts: a literature review and a lethal concentration (LC) estimation. The literature review summarizes data under four categories: animal studies, controlled human studies, community exposure, and industrial exposure. Data in these areas were critically reviewed for their relevance to lethal concentrations at LC LO , LC 10 and LC 50 levels that were derived in the 1984 report. In the last ten years, only one relevant animal study has been published. No new controlled human studies were found but a community exposure incident was reported. There were three new industrial/accidental exposures reported since 1984. Evaluation of new data does not change the lethal concentration estimates made in the 1984 report, but does indicate the absence of appropriate models to estimate the lethality of irritant and corrosive gases. In the last 10 years, much literature on the evaluation of major hazards has been published and suggests that such assessments are of growing political, economic and social importance. Numerous articles have been published on the acute toxicity of HF from skin contact and chronic toxicity from repeated airborne exposure. These publications offer important insights into the nature of HF toxicity. Several avenues of investigative research are suggested. (author). 55 refs., 4 tabs

  10. Immunomodulatory effects of the herbicide propanil on cytokine production in humans: In vivo and in vitro exposure

    International Nuclear Information System (INIS)

    Corsini, Emanuela; Codeca, Ilaria; Mangiaratti, Simona; Birindelli, Sarah; Minoia, Claudio; Turci, Roberta; Viviani, Barbara; Facchi, Alessandra; Vitelli, Nora; Lucchi, Laura; Galli, Corrado L.; Marinovich, Marina; Colosio, Claudio

    2007-01-01

    Propanil, 3,4-dichloropropionanilide, a commonly used herbicide, has been shown to induce effects on the mouse immune system. The aim of this study was to assess the immunotoxicity of propanil in occupationally exposed agricultural workers and to characterize its molecular mechanism of action. Seven agricultural workers intermittently exposed to propanil and 7 healthy matched controls entered the study. Data were collected through physical examination, and laboratory investigations addressed at the main serum, cellular, and functional immune parameters. The levels of exposure were assessed by determining the urine concentration of the major propanil metabolite, 3,4-dichloroaniline. The investigation of serum, cellular, and functional immune parameters suggested that propanil exposure results in a modest immunomodulatory effect, characterized by an increase in the plasma level of IgG 1 and in LPS-induced IL-6 release and, by a reduction in PHA-induced IL-10 and IFN release, associated with a reduced IFN/IL-4 ratio. As observed, following in vivo exposure, in vitro treatment of human peripheral blood leukocytes with propanil resulted in a dose-dependent reduction in PHA-induced IFN-gamma and IL-10 production, while LPS-induced TNF-α production was not affected indicating a direct effect of propanil on selected immune parameters. We demonstrated that propanil interfering with PHA-induced intracellular calcium increase modulated IL-10 and IFN-gamma transcription and translation, which indicates that propanil acts on early events triggered by PHA. Overall, our results suggest that human exposure to propanil has slight immunomodulatory effects, and point out that the inhibition of the PHA-induced intracellular calcium rise is an important target of propanil. These findings improve our understanding of the mechanism underlying propanil-induced immunotoxicity

  11. Estimate of safe human exposure levels for lunar dust based on comparative benchmark dose modeling.

    Science.gov (United States)

    James, John T; Lam, Chiu-Wing; Santana, Patricia A; Scully, Robert R

    2013-04-01

    Brief exposures of Apollo astronauts to lunar dust occasionally elicited upper respiratory irritation; however, no limits were ever set for prolonged exposure to lunar dust. The United States and other space faring nations intend to return to the moon for extensive exploration within a few decades. In the meantime, habitats for that exploration, whether mobile or fixed, must be designed to limit human exposure to lunar dust to safe levels. Herein we estimate safe exposure limits for lunar dust collected during the Apollo 14 mission. We instilled three respirable-sized (∼2 μ mass median diameter) lunar dusts (two ground and one unground) and two standard dusts of widely different toxicities (quartz and TiO₂) into the respiratory system of rats. Rats in groups of six were given 0, 1, 2.5 or 7.5 mg of the test dust in a saline-Survanta® vehicle, and biochemical and cellular biomarkers of toxicity in lung lavage fluid were assayed 1 week and one month after instillation. By comparing the dose--response curves of sensitive biomarkers, we estimated safe exposure levels for astronauts and concluded that unground lunar dust and dust ground by two different methods were not toxicologically distinguishable. The safe exposure estimates were 1.3 ± 0.4 mg/m³ (jet-milled dust), 1.0 ± 0.5 mg/m³ (ball-milled dust) and 0.9 ± 0.3 mg/m³ (unground, natural dust). We estimate that 0.5-1 mg/m³ of lunar dust is safe for periodic human exposures during long stays in habitats on the lunar surface.

  12. Alcohol, Methamphetamine, and Marijuana Exposure Have Distinct Effects on the Human Placenta.

    Science.gov (United States)

    Carter, R Colin; Wainwright, Helen; Molteno, Christopher D; Georgieff, Michael K; Dodge, Neil C; Warton, Fleur; Meintjes, Ernesta M; Jacobson, Joseph L; Jacobson, Sandra W

    2016-04-01

    Animal studies have demonstrated adverse effects of prenatal alcohol exposure on placental development, but few studies have examined these effects in humans. Little is known about effects of prenatal exposure to methamphetamine, marijuana, and cigarette smoking on placental development. Placentas were collected from 103 Cape Coloured (mixed ancestry) pregnant women recruited at their first antenatal clinic visit in Cape Town, South Africa. Sixty-six heavy drinkers and 37 nondrinkers were interviewed about their alcohol, cigarette smoking, and drug use at 3 antenatal visits. A senior pathologist, blinded to exposure status, performed comprehensive pathology examinations on each placenta using a standardized protocol. In multivariable regression models, effects of prenatal exposure were examined on placental size, structure, and presence of infections and meconium. Drinkers reported a binge pattern of heavy drinking, averaging 8.0 drinks/occasion across pregnancy on 1.4 d/wk. 79.6% smoked cigarettes; 22.3% used marijuana; and 17.5% used methamphetamine. Alcohol exposure was related to decreased placental weight and a smaller placenta-to-birthweight ratio. By contrast, methamphetamine was associated with larger placental weight and a larger placenta-to-birthweight ratio. Marijuana was also associated with larger placental weight. Alcohol exposure was associated with increased risk of placental hemorrhage. Prenatal alcohol, drug, and cigarette use were not associated with chorioamnionitis, villitis, deciduitis, or maternal vascular underperfusion. Alcohol and cigarette smoking were associated with a decreased risk of intrauterine passing of meconium, a sign of acute fetal stress and/or hypoxia; methamphetamine, with an increased risk. This is the first human study to show that alcohol, methamphetamine, and marijuana were associated with distinct patterns of pathology, suggesting different mechanisms mediating their effects on placental development. Given the growing

  13. Digital music exposure reliably induces temporary threshold shift in normal-hearing human subjects.

    Science.gov (United States)

    Le Prell, Colleen G; Dell, Shawna; Hensley, Brittany; Hall, James W; Campbell, Kathleen C M; Antonelli, Patrick J; Green, Glenn E; Miller, James M; Guire, Kenneth

    2012-01-01

    One of the challenges for evaluating new otoprotective agents for potential benefit in human populations is the availability of an established clinical paradigm with real-world relevance. These studies were explicitly designed to develop a real-world digital music exposure that reliably induces temporary threshold shift (TTS) in normal-hearing human subjects. Thirty-three subjects participated in studies that measured effects of digital music player use on hearing. Subjects selected either rock or pop music, which was then presented at 93 to 95 (n = 10), 98 to 100 (n = 11), or 100 to 102 (n = 12) dBA in-ear exposure level for a period of 4 hr. Audiograms and distortion product otoacoustic emissions (DPOAEs) were measured before and after music exposure. Postmusic tests were initiated 15 min, 1 hr 15 min, 2 hr 15 min, and 3 hr 15 min after the exposure ended. Additional tests were conducted the following day and 1 week later. Changes in thresholds after the lowest-level exposure were difficult to distinguish from test-retest variability; however, TTS was reliably detected after higher levels of sound exposure. Changes in audiometric thresholds had a "notch" configuration, with the largest changes observed at 4 kHz (mean = 6.3 ± 3.9 dB; range = 0-14 dB). Recovery was largely complete within the first 4 hr postexposure, and all subjects showed complete recovery of both thresholds and DPOAE measures when tested 1 week postexposure. These data provide insight into the variability of TTS induced by music-player use in a healthy, normal-hearing, young adult population, with music playlist, level, and duration carefully controlled. These data confirm the likelihood of temporary changes in auditory function after digital music-player use. Such data are essential for the development of a human clinical trial protocol that provides a highly powered design for evaluating novel therapeutics in human clinical trials. Care must be taken to fully inform potential subjects in

  14. FDTD computation of human eye exposure to ultra-wideband electromagnetic pulses

    Energy Technology Data Exchange (ETDEWEB)

    Simicevic, Neven [Center for Applied Physics Studies, Louisiana Tech University, Ruston, LA 71272 (United States)], E-mail: neven@phys.latech.edu

    2008-03-21

    With an increase in the application of ultra-wideband (UWB) electromagnetic pulses in the communications industry, radar, biotechnology and medicine, comes an interest in UWB exposure safety standards. Despite an increase of the scientific research on bioeffects of exposure to non-ionizing UWB pulses, characterization of those effects is far from complete. A numerical computational approach, such as a finite-difference time domain (FDTD) method, is required to visualize and understand the complexity of broadband electromagnetic interactions. The FDTD method has almost no limits in the description of the geometrical and dispersive properties of the simulated material, it is numerically robust and appropriate for current computer technology. In this paper, a complete calculation of exposure of the human eye to UWB electromagnetic pulses in the frequency range of 3.1-10.6, 22-29 and 57-64 GHz is performed. Computation in this frequency range required a geometrical resolution of the eye of 0.1 mm and an arbitrary precision in the description of its dielectric properties in terms of the Debye model. New results show that the interaction of UWB pulses with the eye tissues exhibits the same properties as the interaction of the continuous electromagnetic waves (CWs) with the frequencies from the pulse's frequency spectrum. It is also shown that under the same exposure conditions the exposure to UWB pulses is from one to many orders of magnitude safer than the exposure to CW.

  15. FDTD computation of human eye exposure to ultra-wideband electromagnetic pulses.

    Science.gov (United States)

    Simicevic, Neven

    2008-03-21

    With an increase in the application of ultra-wideband (UWB) electromagnetic pulses in the communications industry, radar, biotechnology and medicine, comes an interest in UWB exposure safety standards. Despite an increase of the scientific research on bioeffects of exposure to non-ionizing UWB pulses, characterization of those effects is far from complete. A numerical computational approach, such as a finite-difference time domain (FDTD) method, is required to visualize and understand the complexity of broadband electromagnetic interactions. The FDTD method has almost no limits in the description of the geometrical and dispersive properties of the simulated material, it is numerically robust and appropriate for current computer technology. In this paper, a complete calculation of exposure of the human eye to UWB electromagnetic pulses in the frequency range of 3.1-10.6, 22-29 and 57-64 GHz is performed. Computation in this frequency range required a geometrical resolution of the eye of 0.1 mm and an arbitrary precision in the description of its dielectric properties in terms of the Debye model. New results show that the interaction of UWB pulses with the eye tissues exhibits the same properties as the interaction of the continuous electromagnetic waves (CWs) with the frequencies from the pulse's frequency spectrum. It is also shown that under the same exposure conditions the exposure to UWB pulses is from one to many orders of magnitude safer than the exposure to CW.

  16. FDTD computation of human eye exposure to ultra-wideband electromagnetic pulses

    International Nuclear Information System (INIS)

    Simicevic, Neven

    2008-01-01

    With an increase in the application of ultra-wideband (UWB) electromagnetic pulses in the communications industry, radar, biotechnology and medicine, comes an interest in UWB exposure safety standards. Despite an increase of the scientific research on bioeffects of exposure to non-ionizing UWB pulses, characterization of those effects is far from complete. A numerical computational approach, such as a finite-difference time domain (FDTD) method, is required to visualize and understand the complexity of broadband electromagnetic interactions. The FDTD method has almost no limits in the description of the geometrical and dispersive properties of the simulated material, it is numerically robust and appropriate for current computer technology. In this paper, a complete calculation of exposure of the human eye to UWB electromagnetic pulses in the frequency range of 3.1-10.6, 22-29 and 57-64 GHz is performed. Computation in this frequency range required a geometrical resolution of the eye of 0.1 mm and an arbitrary precision in the description of its dielectric properties in terms of the Debye model. New results show that the interaction of UWB pulses with the eye tissues exhibits the same properties as the interaction of the continuous electromagnetic waves (CWs) with the frequencies from the pulse's frequency spectrum. It is also shown that under the same exposure conditions the exposure to UWB pulses is from one to many orders of magnitude safer than the exposure to CW

  17. Source attribution of human campylobacteriosis at the point of exposure by combining comparative exposure assessment and subtype comparison based on comparative genomic fingerprinting.

    Directory of Open Access Journals (Sweden)

    André Ravel

    Full Text Available Human campylobacteriosis is a common zoonosis with a significant burden in many countries. Its prevention is difficult because humans can be exposed to Campylobacter through various exposures: foodborne, waterborne or by contact with animals. This study aimed at attributing campylobacteriosis to sources at the point of exposure. It combined comparative exposure assessment and microbial subtype comparison with subtypes defined by comparative genomic fingerprinting (CGF. It used isolates from clinical cases and from eight potential exposure sources (chicken, cattle and pig manure, retail chicken, beef, pork and turkey meat, and surface water collected within a single sentinel site of an integrated surveillance system for enteric pathogens in Canada. Overall, 1518 non-human isolates and 250 isolates from domestically-acquired human cases were subtyped and their subtype profiles analyzed for source attribution using two attribution models modified to include exposure. Exposure values were obtained from a concurrent comparative exposure assessment study undertaken in the same area. Based on CGF profiles, attribution was possible for 198 (79% human cases. Both models provide comparable figures: chicken meat was the most important source (65-69% of attributable cases whereas exposure to cattle (manure ranked second (14-19% of attributable cases, the other sources being minor (including beef meat. In comparison with other attributions conducted at the point of production, the study highlights the fact that Campylobacter transmission from cattle to humans is rarely meat borne, calling for a closer look at local transmission from cattle to prevent campylobacteriosis, in addition to increasing safety along the chicken supply chain.

  18. Source attribution of human campylobacteriosis at the point of exposure by combining comparative exposure assessment and subtype comparison based on comparative genomic fingerprinting.

    Science.gov (United States)

    Ravel, André; Hurst, Matt; Petrica, Nicoleta; David, Julie; Mutschall, Steven K; Pintar, Katarina; Taboada, Eduardo N; Pollari, Frank

    2017-01-01

    Human campylobacteriosis is a common zoonosis with a significant burden in many countries. Its prevention is difficult because humans can be exposed to Campylobacter through various exposures: foodborne, waterborne or by contact with animals. This study aimed at attributing campylobacteriosis to sources at the point of exposure. It combined comparative exposure assessment and microbial subtype comparison with subtypes defined by comparative genomic fingerprinting (CGF). It used isolates from clinical cases and from eight potential exposure sources (chicken, cattle and pig manure, retail chicken, beef, pork and turkey meat, and surface water) collected within a single sentinel site of an integrated surveillance system for enteric pathogens in Canada. Overall, 1518 non-human isolates and 250 isolates from domestically-acquired human cases were subtyped and their subtype profiles analyzed for source attribution using two attribution models modified to include exposure. Exposure values were obtained from a concurrent comparative exposure assessment study undertaken in the same area. Based on CGF profiles, attribution was possible for 198 (79%) human cases. Both models provide comparable figures: chicken meat was the most important source (65-69% of attributable cases) whereas exposure to cattle (manure) ranked second (14-19% of attributable cases), the other sources being minor (including beef meat). In comparison with other attributions conducted at the point of production, the study highlights the fact that Campylobacter transmission from cattle to humans is rarely meat borne, calling for a closer look at local transmission from cattle to prevent campylobacteriosis, in addition to increasing safety along the chicken supply chain.

  19. Diminished embryonic movements of developing embryo by direct exposure of sidestream whole smoke solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ejaz, Sohail [Chonbuk National University, Biosafety Research Institute, Jeonju (Korea); Woong, Lim Chae [Chonbuk National University, Department of Pathology, Jeonju (Korea)

    2006-02-01

    Embryonic movements (EM) are considered to be the first sign of life and cigarette smoking during pregnancy has been linked to affect EM. Exposure to sidestream smoke, produced from the emissions of a smoldering cigarette, may result in poor pregnancy outcome and increased risk of serious perinatal morbidity and mortality. In this study, the chicken embryo bioassay was used to systematically assess the effects of short-term exposure to sidestream whole smoke solutions (SSWSS) on EM, recorded in real time by a video camera for 60 min and each EM was counted for every 3-min interval. Application of different types of SSWSS to the embryos caused significant changes in all types of EM from 15 to 18 min of recording time. Extensive reduction (P<0.001) and some time complete stoppage of swing-like movements and whole-body movements were observed in almost all treated embryos. Our data clearly link between exposure of SSWSS and substantial decrease in EM. It is unclear whether nicotine and/or other ingredients present in sidestream smoke are responsible for these alterations in EM. This article provides an outline of the relevance of SSWSS on EM for evolutionary developmental biology and this assay can be used to investigate the complex mixtures with regard to their effects on EM. (orig.)

  20. Plausible Roles for RAGE in Conditions Exacerbated by Direct and Indirect (Secondhand) Smoke Exposure.

    Science.gov (United States)

    Lewis, Joshua B; Hirschi, Kelsey M; Arroyo, Juan A; Bikman, Benjamin T; Kooyman, David L; Reynolds, Paul R

    2017-03-17

    Approximately 1 billion people smoke worldwide, and the burden placed on society by primary and secondhand smokers is expected to increase. Smoking is the leading risk factor for myriad health complications stemming from diverse pathogenic programs. First- and second-hand cigarette smoke contains thousands of constituents, including several carcinogens and cytotoxic chemicals that orchestrate chronic inflammatory responses and destructive remodeling events. In the current review, we outline details related to compromised pulmonary and systemic conditions related to smoke exposure. Specifically, data are discussed relative to impaired lung physiology, cancer mechanisms, maternal-fetal complications, cardiometabolic, and joint disorders in the context of smoke exposure exacerbations. As a general unifying mechanism, the receptor for advanced glycation end-products (RAGE) and its signaling axis is increasingly considered central to smoke-related pathogenesis. RAGE is a multi-ligand cell surface receptor whose expression increases following cigarette smoke exposure. RAGE signaling participates in the underpinning of inflammatory mechanisms mediated by requisite cytokines, chemokines, and remodeling enzymes. Understanding the biological contributions of RAGE during cigarette smoke-induced inflammation may provide critically important insight into the pathology of lung disease and systemic complications that combine during the demise of those exposed.

  1. MERS-CoV at the Animal-Human interface: inputs on exposure pathways from an Expert-Opinion elicitation

    Directory of Open Access Journals (Sweden)

    Anna Funk

    2016-10-01

    Full Text Available Nearly four years after the first report of the emergence of Middle-East respiratory syndrome Coronavirus (MERS-CoV and nearly 1800 human cases later, the ecology of MERS-CoV, its epidemiology, and risk factors of MERS-CoV transmission between camels are poorly understood. Knowledge about the pathways and mechanisms of transmission from animals to humans is limited; as of yet, transmission risks have not been quantified. Moreover the divergent sanitary situations and exposures to animals among populations in the Arabian Peninsula, where human primary cases appear to dominate, vs. other regions in the Middle East and Africa, with no reported human clinical cases and where the virus has been detected only in dromedaries, represents huge scientific and health challenges. Here, we have used expert opinion elicitation in order to obtain ideas on relative importance of MERS-CoV risk factors and estimates of transmission risks from various types of contact between humans and dromedaries. Fourteen (14 experts with diverse and extensive experience in MERS-CoV relevant fields were enrolled and completed an online questionnaire that examined pathways based on several scenarios e.g. camels-camels, camels-human, bats/other species to camels/humans and the role of diverse biological substances (milk, urine etc. and potential fomites.Experts believed that dromedary camels play the largest role in MERS-CoV infection of other dromedaries; however, they also indicated a significant influence of the season (i.e. calving or weaning periods on transmission risk. All experts thought that MERS-CoV infected dromedaries and asymptomatic humans play the most important role in infection of humans, with bats and other species presenting a possible, but yet undefined, risk. Direct and indirect contact of humans with dromedary camels were identified as the most risky types of contact, when compared to consumption of various camel products, with estimated 'most

  2. Screening organic chemicals in commerce for emissions in the context of environmental and human exposure.

    Science.gov (United States)

    Breivik, Knut; Arnot, Jon A; Brown, Trevor N; McLachlan, Michael S; Wania, Frank

    2012-08-01

    Quantitative knowledge of organic chemical release into the environment is essential to understand and predict human exposure as well as to develop rational control strategies for any substances of concern. While significant efforts have been invested to characterize and screen organic chemicals for hazardous properties, relatively less effort has been directed toward estimating emissions and hence also risks. Here, a rapid throughput method to estimate emissions of discrete organic chemicals in commerce has been developed, applied and evaluated to support screening studies aimed at ranking and identifying chemicals of potential concern. The method builds upon information in the European Union Technical Guidance Document and utilizes information on quantities in commerce (production and/or import rates), chemical function (use patterns) and physical-chemical properties to estimate emissions to air, soil and water within the OECD for five stages of the chemical life-cycle. The method is applied to 16,029 discrete substances (identified by CAS numbers) from five national and international high production volume lists. As access to consistent input data remains fragmented or even impossible, particular attention is given to estimating, evaluating and discussing uncertainties in the resulting emission scenarios. The uncertainty for individual substances typically spans 3 to 4 orders of magnitude for this initial tier screening method. Information on uncertainties in emissions is useful as any screening or categorization methods which solely rely on threshold values are at risk of leading to a significant number of either false positives or false negatives. A limited evaluation of the screening method's estimates for a sub-set of about 100 substances, compared against independent and more detailed emission scenarios presented in various European Risk Assessment Reports, highlights that up-to-date and accurate information on quantities in commerce as well as a detailed

  3. Risk factors for human-directed canine aggression in a referral level clinical population.

    Science.gov (United States)

    Lord, M; Casey, R A; Loftus, B A; Blackwell, E J

    2017-07-07

    Risk factors for human-directed aggression were investigated using retrospective analysis of data from a referral-level clinical behaviour population in the UK. A sample of 200 cases involving human-directed canine aggression and 200 control cases involving no instance of human-directed aggression were selected at random from a population of 746 cases. The final model suggested that clinical cases with human-directed aggression were significantly younger than those presenting with other undesired behaviours (P=0.008) and that male dogs were 1.4 times more likely to be aggressive towards human beings than female dogs (P=0.019). Dogs were 1.7 times more likely to be aggressive towards people if they had attended more than five puppy classes than if they had never attended puppy class (P=0.015) and that dogs were 2.8 times more likely to be aggressive towards human beings if there was another dog between 0 months and 24 months of age in the home (P=0.004). These factors only account for 7 per cent to 10 per cent of the variance between the human-directed aggression population and the control population, but factors such as attendance at puppy classes and numbers of dogs in the household suggest the need for longitudinal studies to investigate temporal relationships.

  4. Human biomonitoring of chromium and nickel from an experimental exposure to manual metal arc welding fumes of low and high alloyed steel.

    Science.gov (United States)

    Bertram, Jens; Brand, Peter; Schettgen, Thomas; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

    2015-05-01

    The uptake and elimination of metals from welding fumes is currently not fully understood. In the Aachen Workplace Simulation Laboratory (AWSL) it is possible to investigate the impact of welding fumes on human subjects under controlled exposure conditions. In this study, the uptake and elimination of chromium or chromium (VI) respectively as well as nickel was studied in subjects after exposure to the emissions of a manual metal arc welding process using low or high alloyed steel. In this present study 12 healthy male non-smokers, who never worked as welders before, were exposed for 6h to welding fumes of a manual metal arc welding process. In a three-fold crossover study design, subjects were exposed in randomized order to either clean air, emissions from welding low alloyed steel, and emissions from welding high alloyed steel. Particle mass concentration of the exposure aerosol was 2.5mg m(-3). The content of chromium and nickel in the air was determined by analysing air filter samples on a high emission scenario. Urine analysis for chromium and nickel was performed before and after exposure using methods of human biomonitoring. There were significantly elevated chromium levels after exposure to welding fumes from high alloyed steel compared to urinary chromium levels before exposure to high alloyed welding fumes, as well as compared to the other exposure scenarios. The mean values increased from 0.27 µg l(-1) to 18.62 µg l(-1). The results were in good agreement with already existing correlations between external and internal exposure (German exposure equivalent for carcinogenic working materials EKA). The variability of urinary chromium levels was high. For urinary nickel no significant changes could be detected at all. Six-hour exposure to 2.5mg m(-3) high alloyed manual metal arc welding fumes lead to elevated urinary chromium levels far higher (7.11-34.16 µg l(-1)) than the German biological exposure reference value (BAR) of 0.6 µg l(-1) directly after

  5. 77 FR 71695 - Secondary Direct Food Additives Permitted in Food for Human Consumption; Sodium...

    Science.gov (United States)

    2012-12-04

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 173 [Docket No. FDA-2011-F-0853] Secondary Direct Food Additives Permitted in Food for Human Consumption; Sodium... dodecylbenzenesulfonate (CAS No. 25155-30-0) as an antimicrobial agent for use in wash water for fruits and vegetables...

  6. Associative theories of goal-directed behaviour: a case for animal-human translational models

    NARCIS (Netherlands)

    de Wit, S.; Dickinson, A.

    2009-01-01

    Associative accounts of goal-directed action, developed in the fields of human ideomotor action and that of animal learning, can capture cognitive belief-desire psychology of human decision-making. Whereas outcome-response accounts can account for the fact that the thought of a goal can call to mind

  7. 76 FR 41687 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Hydroxypropyl Cellulose

    Science.gov (United States)

    2011-07-15

    ... Organization and the World Health Organization (FAO/WHO) Expert Committee for Food Additives (JECFA) has... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 172 [Docket No. FDA-2010-F-0103] Food Additives Permitted for Direct Addition to Food for Human Consumption...

  8. Human projected area factors for detailed direct and diffuse solar radiation analysis

    DEFF Research Database (Denmark)

    Kubaha, K.; Fiala, D.; Toftum, Jørn

    2004-01-01

    Projected area factors for individual segments of the standing and sedentary human body were modelled for both direct and diffuse solar radiation using detailed 3D geometry and radiation models. The local projected area factors with respect to direct short-wave radiation are a function of the solar...

  9. Sensory and Physiological Effects on Humans of Combined Exposures to Air Temperatures and Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Mølhave, Lars; Liu, Zunyong; Jørgensen, Anne Hempel

    1993-01-01

    Ten healthy humans were exposed to combinations of volatile organic compounds (VOCs) and air temperature (0 mg/m3 and 10 mg/m3 of a mixture of 22 volatile organic compounds and 18, 22 and 26° C). Previously demonstrated effects of VOCs and thermal exposures were replicated. For the first time nasal...... cross-sectional areas and nasal volumes, as measured by acoustic rhinometry, were shown to decrease with decreasing temperature and increasing VOC exposure. Temperature and pollutant exposures affected air quality, the need for more ventilation, skin humidity on the forehead, sweating, acute sensory...... irritation and possibly watering eyes in an additive way. Interactions were found for odor intensity (p = 0.1), perceived facial skin temperature and dryness, general well-being, tear film stability, and nasal cavity dimension. The presence of interactions implies that in the future guidelines for acceptable...

  10. Improving the relevance and efficiency of human exposure assessments within the process of regulatory risk assessment.

    Science.gov (United States)

    Money, Chris

    2018-01-24

    The process for undertaking exposure assessments varies dependent on its purpose. But for exposure assessments to be relevant and accurate, they are reliant on access to reliable information on key exposure determinants. Acquiring such information is seldom straightforward and can take significant time and resources. This articles examines how the application of tiered and targeted approaches to information acquisition, within the context of European human health risk assessments, can not only lead to improvements in the efficiency and effectiveness of the process but also in the confidence of stakeholders in its outputs. The article explores how the benefits might be further improved through the coordination of such activities, as well as those areas that represent barriers to wider international harmonisation.

  11. Use of human metabolic studies and urinary arsenic speciation is assessing arsenic exposure

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.R.; Farmer, J.G. (Memphis State Univ., TN (United States) Univ. of Edinburgh (United Kingdom))

    1991-01-01

    The use of hair and nail analyses to assess human exposure to the trace metalloid arsenic (As) is hindered by the possibility of external contamination. Even though urine represents the major excretory route, its use as an indicator of exposure is limited when no distinction is made between the nontoxic organoarsenical (arsenobetaine) excreted following the consumption of seafood and the toxic inorganic forms of As and related metabolites. The development of analytical techniques capable of separating the different chemical species of As in urine have shown that the ingestion of inorganic As (AsV or AsIII) by animals and man triggers an in vivo reduction/methylation process resulting in excretion of the less toxic species, monomethylarsonic acid (MMAA) and dimethylarsinic acid (DMAA). This paper establishes the uptake, bio-transformation and elimination patterns reflected in urinary As following carefully controlled experimental exposure.

  12. Radiological protection in two types of human activities and from potential exposure

    International Nuclear Information System (INIS)

    Li Deping

    1991-01-01

    The new ICPR recommendations emphasize the distinction in radiological protection in two different types of human activities, practice and intervention. The purpose of emphases and measures for controlling or reduction of exposure for each type of activity are discussed. Potential exposure is regarded as an part of radiological protection system in this new recommendations, in a practice, it can be significantly reduced by proper prevention and mitigation measures in design and management. It is pointed out that with modern safety technology, the probability of potential exposure situations can be lowered to many orders of magnitude, even though the estimated value of probability is not accurate. Situations requiring intervention and the principles in protection are also discussed

  13. Considering human exposure to pesticides in food products: Importance of dissipation dynamics

    DEFF Research Database (Denmark)

    Fantke, Peter; Juraske, Ronnie; Jolliet, Olivier

    2014-01-01

    The general public is continuously concerned about effects from pesticide exposure via residues in food crops. However, impacts from pesticide exposure are mostly neglected in food product-related LCAs. Time-to-harvest and dissipation from crops mainly drive residue dynamics with dissipation...... as most uncertain aspect in characterization modeling. We analyzed measured half-lives (n=4513) with 95% falling between 0.6 and 29 days. With ~500 pesticides authorized alone in the EU for several hundred crops, however, experimental stud-ies only cover few possible pesticide-crop combinations. Therefore......, we estimated dissipation from measured data and provide reference half-lives for 333 pesticides applied at 20°C under field conditions. Our framework allows for detailed explorations of dietary choices in LCA with respect to human health impacts from pesticide exposure via crop consumption. The next...

  14. Environmental Influences on the Epigenome: Exposure- Associated DNA Methylation in Human Populations.

    Science.gov (United States)

    Martin, Elizabeth M; Fry, Rebecca C

    2018-04-01

    DNA methylation is the most well studied of the epigenetic regulators in relation to environmental exposures. To date, numerous studies have detailed the manner by which DNA methylation is influenced by the environment, resulting in altered global and gene-specific DNA methylation. These studies have focused on prenatal, early-life, and adult exposure scenarios. The present review summarizes currently available literature that demonstrates a relationship between DNA methylation and environmental exposures. It includes studies on aflatoxin B 1 , air pollution, arsenic, bisphenol A, cadmium, chromium, lead, mercury, polycyclic aromatic hydrocarbons, persistent organic pollutants, tobacco smoke, and nutritional factors. It also addresses gaps in the literature and future directions for research. These gaps include studies of mixtures, sexual dimorphisms with respect to environmentally associated methylation changes, tissue specificity, and temporal stability of the methylation marks.

  15. Human health risks and socio-economic perspectives of arsenic exposure in Bangladesh: A scoping review.

    Science.gov (United States)

    Rahman, M Azizur; Rahman, A; Khan, M Zaved Kaiser; Renzaho, Andre M N

    2018-04-15

    Arsenic contamination of drinking water, which can occur naturally or because of human activities such as mining, is the single most important public health issue in Bangladesh. Fifty out of the 64 districts in the country have arsenic concentration of groundwater exceeding 50µgL -1 , the Bangladeshi threshold, affecting 35-77 million people or 21-48% of the total population. Chronic arsenic exposure through drinking water and other dietary sources is an important public health issue worldwide affecting hundreds of millions of people. Consequently, arsenic poisoning has attracted the attention of researchers and has been profiled extensively in the literature. Most of the literature has focused on characterising arsenic poisoning and factors associated with it. However, studies examining the socio-economic aspects of chronic exposure of arsenic through either drinking water or foods remain underexplored. The objectives of this paper are (i) to review arsenic exposure pathways to humans; (ii) to summarise public health impacts of chronic arsenic exposure; and (iii) to examine socio-economic implications and consequences of arsenicosis with a focus on Bangladesh. This scoping review evaluates the contributions of different exposure pathways by analysing arsenic concentrations in dietary and non-dietary sources. The socio-economic consequences of arsenicosis disease in Bangladesh are discussed in this review by considering food habits, nutritional status, socio-economic conditions, and socio-cultural behaviours of the people of the country. The pathways of arsenic exposure in Bangladesh include drinking water, various plant foods and non-dietary sources such as soil. Arsenic affected people are often abandoned by the society, lose their jobs and get divorced and are forced to live a sub-standard life. The fragile public health system in Bangladesh has been burdened by the management of thousands of arsenicosis victims in Bangladesh. Copyright © 2017 Elsevier Inc

  16. Relative source contributions for perchlorate exposures in a lactating human cohort

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Andrea B. [University of North Texas Health Sciences Center (United States); Dyke, Jason V. [University of Texas at Arlington (United States); Ohira, Shin-Ichi [Kumamoto University (Japan); Dasgupta, Purnendu K., E-mail: Dasgupta@uta.edu [University of Texas at Arlington (United States)

    2013-01-15

    Perchlorate is an iodine-uptake inhibitor and common contaminant of food and drinking water. Understanding the amount of perchlorate exposure occurring through non-water sources is essential for accurate estimates of human exposure levels, and establishment of drinking water limits for this pervasive contaminant. The study objective was to determine the amount of perchlorate intake derived from diet rather than water. Subjects provided drinking water samples, detailed fluid-intake records, 24 h urine collections and four milk samples for nine days. Samples were analyzed for perchlorate by isotope dilution ion chromatography–tandem mass spectrometry. Amounts of perchlorate derived from drinking water and dietary sources were calculated for each individual. Water of local origin was found to contribute a minor fraction of perchlorate intake. Estimated fraction intake from drinking water ranged from 0 to 36%. The mean and median dose of perchlorate derived from non-water sources by lactating women was 0.18 μg/kg/day (range: 0.06 to 0.36 μg/kg/day.) Lactating women consumed more fluid (mean 2.424 L/day) than has been assumed in recent risk assessments for perchlorate. The data reported here indicate that lactating women may be exposed to perchlorate through dietary sources at markedly higher levels than estimated previously. Exposures to perchlorate from non-water sources may be higher than recent estimates, including those used to develop drinking water standards. - Highlights: ► Residence in an area with perchlorate-contaminated water may be a poor predictor of exposure. ► Exposures to perchlorate from food are likely underestimated. ► The relative contributions for human perchlorate exposures should be weighted more heavily towards non-water sources.

  17. Detection of fluorotelomer alcohols in indoor environments and their relevance for human exposure.

    Science.gov (United States)

    Schlummer, Martin; Gruber, Ludwig; Fiedler, Dominik; Kizlauskas, Markus; Müller, Josef

    2013-07-01

    Fluorotelomer alcohols (FTOH) are important precursors of perfluorinated carboxylic acids (PFCA). These neutral and volatile compounds are frequently found in indoor air and may contribute to the overall human exposure to per- and polyfluorinated alkyl substances (PFAS). In this study air samples of ten workplace environments and a car interior were analysed. In addition, extracts and emissions from selected outdoor textiles were analysed in order to establish their potential contribution to the indoor levels of the above-mentioned compounds. Concentrations of FTOHs measured in air ranged from 0.15 to 46.8, 0.25 to 286, and 0.11 to 57.5ng/m(3) for 6:2, 8:2 and 10:2 FTOHs, respectively. The highest concentrations in air were identified in shops selling outdoor clothing, indicating outdoor textiles to be a relevant source of FTOH in indoor workplace environments. Total amounts of FTOH in materials of outdoor textiles accounted for selling outdoor textiles contains the highest levels of FTOH. Exposure of humans to perfluorooctanoic acid (PFOA) through absorption of FTOH and subsequent degradation is discussed on the basis of indoor air levels. Calculation of indoor air-related exposure using the median of the measured air levels revealed that exposure is on the same order of magnitude as the recently reported dietary intakes for a background-exposed population. On the basis of the 95th percentile, indoor air exposure to PFOA was estimated to exceed dietary exposure. However, indoor air-related intakes of FTOH are far below the tolerable daily intake (TDI) of PFOA, indicating that there is no risk to health, even when assuming an unrealistic complete degradation of FTOH into PFOA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. DNA repair and cell cycle biomarkers of radiation exposure and inflammation stress in human blood.

    Directory of Open Access Journals (Sweden)

    Helen Budworth

    Full Text Available DNA damage and repair are hallmarks of cellular responses to ionizing radiation. We hypothesized that monitoring the expression of DNA repair-associated genes would enhance the detection of individuals exposed to radiation versus other forms of physiological stress. We employed the human blood ex vivo radiation model to investigate the expression responses of DNA repair genes in repeated blood samples from healthy, non-smoking men and women exposed to 2 Gy of X-rays in the context of inflammation stress mimicked by the bacterial endotoxin lipopolysaccharide (LPS. Radiation exposure significantly modulated the transcript expression of 12 genes of 40 tested (2.2E-06human blood ex vivo dataset, and 100% accuracy for discriminating patients who received total body radiation. Three genes of this panel (CDKN1A, FDXR and BBC3 were also highly sensitive to LPS treatment in the absence of radiation exposure, and LPS co-treatment significantly affected their radiation responses. At the protein level, BAX and pCHK2-thr68 were elevated after radiation exposure, but the pCHK2-thr68 response was significantly decreased in the presence of LPS. Our combined panel yields an estimated 4-group accuracy of ∼90% to discriminate between radiation alone, inflammation alone, or combined exposures. Our findings suggest that DNA repair gene expression may be helpful to identify biodosimeters of exposure to radiation, especially within high-complexity exposure scenarios.

  19. In vitro atrazine-exposure inhibits human natural killer cell lytic granule release

    International Nuclear Information System (INIS)

    Rowe, Alexander M.; Brundage, Kathleen M.; Barnett, John B.

    2007-01-01

    The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test this hypothesis, flow cytometry and fluorescent microscopy were employed to analyze NK cell-target cell co-cultures following atrazine exposure. These assays demonstrated no significant decrease in the level of target cell binding. However, the levels of NK intracellular lytic protein retained and the amount of lytic protein released were assessed following a 4-h incubation with K562 target cells. The relative level of intracellular lytic protein was 25-50% higher, and the amount of lytic protein released was 55-65% less in atrazine-treated cells than vehicle-treated cells following incubation with the target cells. These results indicate that ATR exposure inhibits the ability of NK cells to lyse target cells by blocking lytic granule release without affecting the ability of the NK cell to form stable conjugates with target cells

  20. Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population

    Directory of Open Access Journals (Sweden)

    Ellis James K

    2012-06-01

    Full Text Available Abstract Background The 'exposome' represents the accumulation of all environmental exposures across a lifetime. Top-down strategies are required to assess something this comprehensive, and could transform our understanding of how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics defines an individual's metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure, and could also reveal intermediate biomarkers for disease risk that reflect adaptive response to exposure. We investigated changes in metabolism in volunteers living near a point source of environmental pollution: a closed zinc smelter with associated elevated levels of environmental cadmium. Methods High-resolution 1H NMR spectroscopy (metabonomics was used to acquire urinary metabolic profiles from 178 human volunteers. The spectral data were subjected to multivariate and univariate analysis to identify metabolites that were correlated with lifestyle or biological factors. Urinary levels of 8-oxo-deoxyguanosine were also measured, using mass spectrometry, as a marker of systemic oxidative stress. Results Six urinary metabolites, either associated with mitochondrial metabolism (citrate, 3-hydroxyisovalerate, 4-deoxy-erythronic acid or one-carbon metabolism (dimethylglycine, creatinine, creatine, were associated with cadmium exposure. In particular, citrate levels retained a significant correlation to urinary cadmium and smoking status after controlling for age and sex. Oxidative stress (as determined by urinary 8-oxo-deoxyguanosine levels was elevated in individuals with high cadmium exposure, supporting the hypothesis that heavy metal accumulation was causing mitochondrial dysfunction. Conclusions This study shows evidence that an NMR-based metabolic profiling study in an uncontrolled human population is capable of identifying intermediate biomarkers of response to toxicants at true environmental

  1. Surveillance of laboratory exposures to human pathogens and toxins: Canada 2016.

    Science.gov (United States)

    Bienek, A; Heisz, M; Su, M

    2017-11-02

    Canada recently enacted legislation to authorize the collection of data on laboratory incidents involving a biological agent. This is done by the Public Health Agency of Canada (PHAC) as part of a comprehensive national program that protects Canadians from the health and safety risks posed by human and terrestrial animal pathogens and toxins. To describe the first year of data on laboratory exposure incidents and/or laboratory-acquired infections in Canada since the Human Pathogens and Toxins Regulations came into effect. Incidents that occurred between January 1 and December 31, 2016 were self-reported by federally-regulated parties across Canada using a standardized form from the Laboratory Incident Notification Canada (LINC) surveillance system. Exposure incidents were described by sector, frequency of occurrence, timeliness of reporting, number of affected persons, human pathogens and toxins involved, causes and corrective actions taken. Microsoft Excel 2010 was used for basic descriptive analyses. In 2016, 46 exposure incidents were reported by holders of 835 active licences in Canada representing 1,352 physical areas approved for work involving a biological agent, for an overall incidence of 3.4%. The number of incidents was highest in the academic (n=16; 34.8%) and hospital (n=12; 26.1%) sectors, while the number of reported incidents was relatively low in the private industry sector. An average of four to five incidents occurred each month; the month of September presented as an outlier with 10 incidents. ​: A total of 100 people were exposed, with no reports of secondary exposure. Four incidents led to suspected (n=3) or confirmed (n=1) cases of laboratory-acquired infection. Most incidents involved pathogens classified at a risk group 2 level that were manipulated in a containment level 2 laboratory (91.3%). Over 22 different species of human pathogens and toxins were implicated, with bacteria the most frequent (34.8%), followed by viruses (26

  2. Mercury contamination in fish and human hair from Hainan Island, South China Sea: Implication for human exposure.

    Science.gov (United States)

    Liu, Jin-Ling; Xu, Xiang-Rong; Yu, Shen; Cheng, Hefa; Peng, Jia-Xi; Hong, Yi-Guo; Feng, Xin-Bin

    2014-11-01

    Hair has long been recognized as a good biomarker for human exposure to Hg. The mercury concentrations in 14 species of marine fish and hair samples from 177 coastal residents in Hainan, South China Sea were investigated to assess the status of mercury exposure associated with marine fish consumption. Concentrations of total Hg (THg) and methylmercury (MeHg) in the fish muscles were 0.094 ± 0.008 and 0.066 ± 0.006 μg/gww, respectively, which were far below the limit considered safe for consumption (0.5 μg/g). The average THg concentrations in hair of adults (1.02 ± 0.92 μg/g) were lower than the provisional tolerable weekly intake (PTWI) level of 2.2 μg/g. However, 23.7% of children had a hair THg level exceeding the RfD level of 1μg/g, indicating a great risk of Hg exposure to children via fish consumption. The concentration of THg in hair was significantly correlated with fish consumption but not with gender-specific fish intake. With higher fish consumption frequency, the fishermen had significantly elevated hair Hg levels compared to the students and the other general public, who had similar hair THg levels but different fish consumption patterns, indicating the existence of other sources of Hg exposure to the residents of Hainan Island. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Human exposure to rabid free-ranging cats: a continuing public health concern in Pennsylvania.

    Science.gov (United States)

    Campagnolo, E R; Lind, L R; Long, J M; Moll, M E; Rankin, J T; Martin, K F; Deasy, M P; Dato, V M; Ostroff, S M

    2014-08-01

    Rabid free-ranging cats have been a public health concern in Pennsylvania since raccoon variant rabies first was recognized in the state in the early 1980s. Over the last decade, between 1.5 and 2.5% of cats submitted to Pennsylvania's state laboratories for rabies testing have been positive. In this report, we describe the extent of rabies in free-ranging cats in Pennsylvania. We also present two examples of human exposure to rabid free-ranging cats that occurred in Pennsylvania during 2010-2011 and the public health actions taken to address rabies exposure in the humans and animals. We then describe the concerns surrounding the unvaccinated and free-ranging cat population in Pennsylvania and possible options in managing this public and animal health problem. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  4. Dose-rate models for human survival after exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T.D.; Morris, M.D.; Young, R.W.

    1986-01-01

    This paper reviews new estimates of the L/sub 50/ in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD/sub 50/s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively.

  5. Mobile phone radiofrequency exposure has no effect on DNA double strand breaks (DSB) in human lymphocytes.

    Science.gov (United States)

    Danese, Elisa; Lippi, Giuseppe; Buonocore, Ruggero; Benati, Marco; Bovo, Chiara; Bonaguri, Chiara; Salvagno, Gian Luca; Brocco, Giorgio; Roggenbuck, Dirk; Montagnana, Martina

    2017-07-01

    The use of mobile phones has been associated with an increased risk of developing certain type of cancer, especially in long term users. Therefore, this study was aimed to investigate the potential genotoxic effect of mobile phone radiofrequency exposure on human peripheral blood mononuclear cells in vitro. The study population consisted in 14 healthy volunteers. After collection of two whole blood samples, the former was placed in a plastic rack, 1 cm from the chassis of a commercial mobile phone (900 MHz carrier frequency), which was activated by a 30-min call. The second blood sample was instead maintained far from mobile phones or other RF sources. The influence of mobile phone RF on DNA integrity was assessed by analyzing γ-H2AX foci in lymphocytes using immunofluorescence staining kit on AKLIDES. No measure of γ-H2AX foci was significantly influenced by mobile phone RF exposure, nor mobile phone exposure was associated with significant risk of genetic damages in vitro (odds ratio comprised between 0.27 and 1.00). The results of this experimental study demonstrate that exposure of human lymphocytes to a conventional 900 MHz RF emitted by a commercial mobile phone for 30 min does not significantly impact DNA integrity.

  6. Exposure to CB-153 and p,p'-DDE and human sperm chromatin integrity

    Energy Technology Data Exchange (ETDEWEB)

    Rignell-Hydbom, A; Rylander, L; Joensson, B A.G.; Hagmar, L [Dept. of Occupational and Environmental Medicine, Lund Univ. Hospital (Sweden); Giwercman, A [Fertility Centre, Malmoe Univ. hospital (Sweden); Spano, M [Section of Toxicology and Biomedical Sciences, ENEA Casaccia Research Centre, Rome (Italy)

    2004-09-15

    In Sweden, the consumption of fatty fish from the Baltic Sea (off the Swedish east coast) is the single most important source of exposure to persistent organochlorine pollutants (POPs). Fishermen from the east coast have averagely higher plasma levels of polychlorinated biphenyls (PCBs) and total POP derived TEQ in plasma than both west coast fishermen and men from the general population. Dichlorodiphenyl dichloroethene (p,p'-DDE), a relevant biomarker for POP is still present in relatively high serum concentrations in men consuming fish from the Baltic Sea. Several studies have shown that POPs are capable of interfering with reproductive and endocrine function in animals. Human studies have shown that exposure to PCBs and polychlorinated dibenzofurans (PCDFs) has a negative effect on male reproductive function, and especially sperm motility seems vulnerable. However, studies relating to human sperm genetic integrity are few. The aim of the study was to investigate whether exposure to POP using 2,2',4,4',5,5'- hexachlorobiphenyl (CB-153) and p,p'-DDE as biomarkers, are associated with sperm chromatin integrity. In order to ensure a sufficient variation in POP exposure fishermen from both the Swedish east (''more exposed'') and west coasts (''less exposed'') formed the study base.

  7. Exposure to CB-153 and p,p'-DDE and human sperm chromatin integrity

    Energy Technology Data Exchange (ETDEWEB)

    Rignell-Hydbom, A.; Rylander, L.; Joensson, B.A.G.; Hagmar, L. [Dept. of Occupational and Environmental Medicine, Lund Univ. Hospital (Sweden); Giwercman, A. [Fertility Centre, Malmoe Univ. hospital (Sweden); Spano, M. [Section of Toxicology and Biomedical Sciences, ENEA Casaccia Research Centre, Rome (Italy)

    2004-09-15

    In Sweden, the consumption of fatty fish from the Baltic Sea (off the Swedish east coast) is the single most important source of exposure to persistent organochlorine pollutants (POPs). Fishermen from the east coast have averagely higher plasma levels of polychlorinated biphenyls (PCBs) and total POP derived TEQ in plasma than both west coast fishermen and men from the general population. Dichlorodiphenyl dichloroethene (p,p'-DDE), a relevant biomarker for POP is still present in relatively high serum concentrations in men consuming fish from the Baltic Sea. Several studies have shown that POPs are capable of interfering with reproductive and endocrine function in animals. Human studies have shown that exposure to PCBs and polychlorinated dibenzofurans (PCDFs) has a negative effect on male reproductive function, and especially sperm motility seems vulnerable. However, studies relating to human sperm genetic integrity are few. The aim of the study was to investigate whether exposure to POP using 2,2',4,4',5,5'- hexachlorobiphenyl (CB-153) and p,p'-DDE as biomarkers, are associated with sperm chromatin integrity. In order to ensure a sufficient variation in POP exposure fishermen from both the Swedish east (''more exposed'') and west coasts (''less exposed'') formed the study base.

  8. Evaluation of occupational exposure to ELF magnetic fields at power plants in Greece in the context of European directives

    International Nuclear Information System (INIS)

    Christopoulou, Maria; Govari, Chrysa; Tsaprouni, Panagiota; Karabetsos, Efthymios

    2015-01-01

    The scope of this paper is to comparatively present the extremely low-frequency (ELF) measurements performed at four power plants in Greece, focusing on: (a) the worst-case exposure conditions, (b) the existence of magnetic field harmonic components, (c) the technical similarities among the power plants and (d) comparison of the measured percentages of reference levels at typical working areas in the power plants. A detailed measurement methodology is proposed, including broadband on-site inspection of the working areas, weighted averaged root-mean-square and peak values of magnetic flux density, percentage of reference levels, according to 1998 ICNIRP guidelines and harmonic analysis of the multi-frequency magnetic fields. During the analysis of the occupational exposure in all power plants, the new Directive 2013/35/EU has been taken into account. The study concludes by proposing a mapping procedure of working areas into certain zones, in order to take measures for workers safety. (authors)

  9. Truncated Levy flights and agenda-based mobility are useful for the assessment of personal human exposure

    International Nuclear Information System (INIS)

    Schlink, Uwe; Ragas, Ad M.J.

    2011-01-01

    Receptor-oriented approaches can assess the individual-specific exposure to air pollution. In such an individual-based model we analyse the impact of human mobility to the personal exposure that is perceived by individuals simulated in an exemplified urban area. The mobility models comprise random walk (reference point mobility, RPM), truncated Levy flights (TLF), and agenda-based walk (RPMA). We describe and review the general concepts and provide an inter-comparison of these concepts. Stationary and ergodic behaviour are explained and applied as well as performance criteria for a comparative evaluation of the investigated algorithms. We find that none of the studied algorithm results in purely random trajectories. TLF and RPMA prove to be suitable for human mobility modelling, because they provide conditions for very individual-specific trajectories and exposure. Suggesting these models we demonstrate the plausibility of their results for exposure to air-borne benzene and the combined exposure to benzene and nonane. - Highlights: → Human exposure to air pollutants is influenced by a person's movement in the urban area. → We provide a simulation study of approaches to modelling personal exposure. → Agenda-based models and truncated Levy flights are recommended for exposure assessment. → The procedure is demonstrated for benzene exposure in an urban region. - Truncated Levy flights and agenda-based mobility are useful for the assessment of personal human exposure.

  10. Numerical modeling of heat and mass transfer in the human eye under millimeter wave exposure.

    Science.gov (United States)

    Karampatzakis, Andreas; Samaras, Theodoros

    2013-05-01

    Human exposure to millimeter wave (MMW) radiation is expected to increase in the next several years. In this work, we present a thermal model of the human eye under MMW illumination. The model takes into account the fluid dynamics of the aqueous humor and predicts a frequency-dependent reversal of its flow that also depends on the incident power density. The calculated maximum fluid velocity in the anterior chamber and the temperature rise at the corneal apex are reported for frequencies from 40 to 100 GHz and different values of incident power density. Copyright © 2013 Wiley Periodicals, Inc.

  11. Human exposure to non-ionizing radiation and potential adverse health effects

    International Nuclear Information System (INIS)

    Vulevic, B.; Maric, B.; Zivkovic, D.

    1999-01-01

    The problem of protection from the non-ionizing radiation has presented an actual subject in the last twenty years both worldwide and in our country. Great attention has been paid to this problem throughout the world and there is not almost a field of human activities that disregards the effect of non-ionizing radiation to the human health.The object of this work is to point concisely, on the basis of numerous domestic and foreign referential data, to the potential adverse health effects caused by uncontrolled exposure to non-ionizing radiation. (author)

  12. The impact of environmental conditions on human performance: A handbood of environmental exposures. Volume 1

    International Nuclear Information System (INIS)

    Echeverria, D.; Barnes, V.; Bittner, A.

    1994-09-01

    A comprehensive review of the technical literature was conducted regarding the impact of environmental conditions on hyman performance applicable to nuclear power plant workers. The environmental conditions considered were vibration, noise, heat, cold, and light. Research staff identified potential human performance deficits (e.g., decreased dexterity, impaired vision, hearing loss, memory deficiency) along a continuum of increasing occupational exposure, ranging from exposures that result in no deficit to exposures that resulted in significant performance problems. Specific deficits were included in the report if there was sound scientific evidence that environmental exposure resulted in those performance deficits. The levels associated with each deficit were then compared to the protection afforded by existing occupational exposure standards. Volume 1 is a handbook for use by NRC inspectors to help them determine the impact of specific environmental conditions on licensee personnel performance. it discusses the units used to measure each condition, discusses the effects of the condition on task performance, presents an example of the assessment of each condition in a nuclear power plant, and discusses potential methods for reducing the effects of

  13. Particle size fractionation and human exposure of polybrominated diphenyl ethers in indoor dust from Chicago.

    Science.gov (United States)

    Wei, Hua; Turyk, Mary; Cali, Salvatore; Dorevitch, Samuel; Erdal, Serap; Li, An

    2009-11-01

    The objective of this study was to investigate the concentration level, the mass distribution based on dust particle size, and the associated human exposure of polybrominated diphenyl ethers (PBDEs) in indoor dust. The total concentration of 13 PBDEs Sigma(13)(BDEs) was found to be 500-6,944 ng/g in indoor dusts, 4,000 ng/g in car interior dust, 260-300 ng/g in outdoor ambient air particles, 30 ng/g in carpet fibers, and as high as 0.5% in carpet padding. Selected dust samples were fractionated based on particle size, and over 80% of the Sigma(13)BDEs were associated with particles exposure of Americans to PBDEs via hand-to-mouth transfer of house dust was estimated under the central tendency exposure and reasonable maximum exposure scenarios. The results suggest that ingestion of PBDE-laden house dust via hand-to-mouth contact is likely a significant exposure pathway, especially for children.

  14. Human brain wave activity during exposure to radiofrequency field emissions from mobile phones

    International Nuclear Information System (INIS)

    D'Costa, H.; Cosic, I.

    2003-01-01

    The aim of this study was to determine whether there is an effect of mobile phone electromagnetic field emissions on the human electroencephalograph (EEG). EEG recordings from ten awake subjects were taken during exposure to radiofrequency (RF) emissions from a mobile phone positioned behind the head. Two experimental trials were conducted. In the first trial, RF exposures were generated by a GSM mobile phone with the speaker disabled and configured to transmit at full-radiated power. During the second trial, exposures were generated by a non-modified GSM mobile phone in active standby mode. For each trial, subjects were exposed in five minute intervals to a randomized, interrupted sequence of five active and five sham exposures. The experiment was conducted under single-blind conditions. The average EEG band power in active exposure recordings was compared to corresponding sham recordings. Statistical tests indicated significant difference in the full-power mode trial within the EEG alpha (8-13 Hz) and beta (13-32 Hz) bands. A subsequent statistical analysis of median spectral power in discrete EEG rhythms revealed significant differences in 7 of the 32 distinct frequencies overall. In conclusion, the results of this study lend support to EEG effects from mobile phones activated in talk-mode. Copyright (2003) Australasian College of Physical Scientists and Engineers in Medicine

  15. Hazard and risk assessment of human exposure to toxic metals using in vitro digestion assay

    Directory of Open Access Journals (Sweden)

    Hani A. Alhadrami

    2016-10-01

    Full Text Available Clean-up targets for toxic metals require that the site be “fit for purpose”. This means that targets are set with respect to defined receptors that reflect intended land-use. In this study, the likely threat of human exposure to toxic metals has been evaluated by simulating the human digestion process in vitro. The effects of key attributes (i.e. sample fraction size, pH, Kd and total metal concentrations on the bioavailability of Cu and Ni were also investigated. Total metal concentration was the key explanatory factor for Cu and Ni bioavailability. A comparative ranking of metal concentrations in the context of tolerable daily intakes for Cu and Ni confirmed that the pH has the greatest impact on metals bioavailability. Rapid screening of key attributes and total toxic metal doses can reveal the relative hazard imposed on human, and this approach should be considered when defining threshold values for human protection.

  16. Multi-pathway human exposure assessment of phthalate esters and DINCH.

    Science.gov (United States)

    Giovanoulis, Georgios; Bui, Thuy; Xu, Fuchao; Papadopoulou, Eleni; Padilla-Sanchez, Juan A; Covaci, Adrian; Haug, Line S; Cousins, Anna Palm; Magnér, Jörgen; Cousins, Ian T; de Wit, Cynthia A

    2018-03-01

    Phthalate esters are substances mainly used as plasticizers in various applications. Some have been restricted and phased out due to their adverse health effects and ubiquitous presence, leading to the introduction of alternative plasticizers, such as DINCH. Using a comprehensive dataset from a Norwegian study population, human exposure to DMP, DEP, DnBP, DiBP, BBzP, DEHP, DINP, DIDP, DPHP and DINCH was assessed by measuring their presence in external exposure media, allowing an estimation of the total intake, as well as the relative importance of different uptake pathways. Intake via different uptake routes, in particular inhalation, dermal absorption, and oral uptake was estimated and total intake based on all uptake pathways was compared to the calculated intake from biomonitoring data. Hand wipe results were used to determine dermal uptake and compared to other exposure sources such as air, dust and personal care products. Results showed that the calculated total intakes were similar, but slightly higher than those based on biomonitoring methods by 1.1 to 3 times (median), indicating a good understanding of important uptake pathways. The relative importance of different uptake pathways was comparable to other studies, where inhalation was important for lower molecular weight phthalates, and negligible for the higher molecular weight phthalates and DINCH. Dietary intake was the predominant exposure route for all analyzed substances. Dermal uptake based on hand wipes was much lower (median up to 2000 times) than the total dermal uptake via air, dust and personal care products. Still, dermal uptake is not a well-studied exposure pathway and several research gaps (e.g. absorption fractions) remain. Based on calculated intakes, the exposure for the Norwegian participants to the phthalates and DINCH was lower than health based limit values. Nevertheless, exposure to alternative plasticizers, such as DPHP and DINCH, is expected to increase in the future and continuous

  17. Clinical Requirements in the Implementation of the European Medical Exposure Directive

    International Nuclear Information System (INIS)

    Ringertz, H.

    2000-01-01

    The requirements of Directive 97/43/EURATOM are specific and explicit. There are significant resource implications at hospital, academic and state levels in order to comply with the Directive. At hospital level, implications for rapid patient throughput as is currently required need to be addressed. A key element in improving radiation protection at hospital level is a properly constituted and functioning Radiation Safety Committee including members from departments involved in the use of ionising radiation. It should promote quality assurance programmes and receive reports and may also be responsible for audit of radiation procedures and outcomes. The primary objective should be to put satisfactory arrangements in place at local and national level. This will prove challenging in the time scale provided given the rigorous requirements of the Directives. Harmonisation of radiation protection arrangements across Europe is a long-term ambition as diversity of medical, legal and social legislation within the EU is considerable. (author)

  18. Integrating Environmental and Human Health Databases in the Great Lakes Basin: Themes, Challenges and Future Directions

    Directory of Open Access Journals (Sweden)

    Kate L. Bassil

    2015-03-01

    Full Text Available Many government, academic and research institutions collect environmental data that are relevant to understanding the relationship between environmental exposures and human health. Integrating these data with health outcome data presents new challenges that are important to consider to improve our effective use of environmental health information. Our objective was to identify the common themes related to the integration of environmental and health data, and suggest ways to address the challenges and make progress toward more effective use of data already collected, to further our understanding of environmental health associations in the Great Lakes region. Environmental and human health databases were identified and reviewed using literature searches and a series of one-on-one and group expert consultations. Databases identified were predominantly environmental stressors databases, with fewer found for health outcomes and human exposure. Nine themes or factors that impact integration were identified: data availability, accessibility, harmonization, stakeholder collaboration, policy and strategic alignment, resource adequacy, environmental health indicators, and data exchange networks. The use and cost effectiveness of data currently collected could be improved by strategic changes to data collection and access systems to provide better opportunities to identify and study environmental exposures that may impact human health.

  19. Nasal colonization of humans with methicillin-resistant Staphylococcus aureus (MRSA CC398 with and without exposure to pigs.

    Directory of Open Access Journals (Sweden)

    Christiane Cuny

    Full Text Available BACKGROUND: Studies in several European countries and in North America revealed a frequent nasal colonization of livestock with MRSA CC398 and also in humans with direct professional exposure to colonized animals. The study presented here addresses the question of further transmission to non exposed humans. METHODS: After selecting 47 farms with colonized pigs in different regions of Germany we sampled the nares of 113 humans working daily with pigs and of their 116 non exposed family members. The same was performed in 18 veterinarians attending pig farms and in 44 of their non exposed family members. For investigating transmission beyond families we samples the nares of 462 pupils attending a secondary school in a high density pig farming area. MRSA were detected by direct culture on selective agar. The isolates were typed by means of spa-sequence typing and classification of SCCmec elements. For attribution of spa sequence types to clonal lineages as defined by multi locus sequence typing we used the BURP algorithm. Antibiotic susceptibility testing was performed by microbroth dilution assay. RESULTS: At the farms investigated 86% of humans exposed and only 4.3% of their family members were found to carry MRSA exhibiting spa-types corresponding to clonal complex CC398. Nasal colonization was also found in 45% of veterinarians caring for pig farms and in 9% of their non exposed family members. Multivariate analysis revealed that antibiotic usage prior to sampling beard no risk with respect to colonization. From 462 pupils only 3 were found colonized, all 3 were living on pig farms. CONCLUSION: These results indicate that so far the dissemination of MRSA CC398 to non exposed humans is infrequent and probably does not reach beyond familial communities.

  20. Activated human neonatal CD8+ T cells are subject to immunomodulation by direct TLR2 or TLR5 stimulation.

    LENUS (Irish Health Repository)

    McCarron, Mark

    2012-02-01

    In conditions of optimal priming, the neonate possesses competency to mount quantitatively adult-like responses. Vaccine formulations containing sufficiently potent adjuvants may overcome the neonate\\'s natural tendency for immunosuppression and provoke a similarly robust immune response. TLR expression on T cells represents the possibility of directly enhancing T cell immunity. We examined the ex vivo responsiveness of highly purified human cord blood-derived CD8(+) T cells to direct TLR ligation by a repertoire of TLR agonists. In concert with TCR stimulation, only Pam(3)Cys (palmitoyl-3-Cys-Ser-(Lys)(4)) and flagellin monomers significantly enhanced proliferation, CD25(+) expression, IL-2, IFN-gamma, TNF-alpha, and intracellular granzyme B expression. TLR2 and TLR5 mRNA was detected in the CD8(+) T cells. Blocking studies confirmed that the increase in IFN-gamma production was by the direct triggering of surface TLR2 or TLR5. The simultaneous exposure of CD8(+) T cells to both TLR agonists had an additive effect on IFN-gamma production. These data suggest that a combination of the two TLR ligands would be a potent T cell adjuvant. This may represent a new approach to TLR agonist-based adjuvant design for future human neonatal vaccination strategies requiring a CD8(+) component.

  1. Numerical evaluation of human exposure to WiMax patch antenna in tablet or laptop.

    Science.gov (United States)

    Siervo, Beatrice; Morelli, Maria Sole; Landini, Luigi; Hartwig, Valentina

    2018-04-30

    The use of wireless communication devices, such as tablets or laptops, is increasing among children. Only a few studies assess specific energy absorption rate (SAR) due to exposure from wireless-enabled tablets and laptops, in particular with Worldwide Interoperability for Microwave Access (WiMax) technology. This paper reports the estimation of the interaction between an E-shaped patch antenna (3.5 GHz) and human models, by means of finite-difference time-domain (FDTD) method. Specifically, four different human models (young adult male, young adult female, pre-teenager female, male child) in different exposure conditions (antenna at different distances from the human model, in different positions, and orientations) were considered and whole-body, 10 and 1 g local SAR and magnetic field value (Bmax) were evaluated. From our results, in some worst-case scenarios involving male and female children's exposure, the maximum radiofrequency energy absorption (hot spots) is located in more sensitive organs such as eye, genitals, and breast. Bioelectromagnetics. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  2. Mercury Exposure in Ireland: Results of the DEMOCOPHES Human Biomonitoring Study

    Directory of Open Access Journals (Sweden)

    Elizabeth Cullen

    2014-09-01

    Full Text Available Background: Monitoring of human exposure to mercury is important due to its adverse health effects. This study aimed to determine the extent of mercury exposure among mothers and their children in Ireland, and to identify factors associated with elevated levels. It formed part of the Demonstration of a study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES pilot biomonitoring study. Methods: Hair mercury concentrations were determined from a convenience sample of 120 mother/child pairs. Mothers also completed a questionnaire. Rigorous quality assurance within DEMOCOPHES guaranteed the accuracy and international comparability of results. Results: Mercury was detected in 79.2% of the samples from mothers, and 62.5% of children’s samples. Arithmetic mean levels in mothers (0.262 µg/g hair and children (0.149 µg /g hair did not exceed the US EPA guidance value. Levels were significantly higher for those with higher education, and those who consumed more fish. Conclusions: The study demonstrates the benefit of human biomonitoring for assessing and comparing internal exposure levels, both on a population and an individual basis. It enables the potential harmful impact of mercury to be minimised in those highly exposed, and can therefore significantly contribute to population health.

  3. A short review on human exposure to and tissue distribution of per- and polyfluoroalkyl substances (PFASs).

    Science.gov (United States)

    Jian, Jun-Meng; Chen, Da; Han, Fu-Juan; Guo, Ying; Zeng, Lixi; Lu, Xingwen; Wang, Fei

    2018-09-15

    PFASs are widely distributed in natural and living environment and can enter human bodies via different routes. Many studies have reported that PFASs may be associated with human diseases, such as urine acid and thyroid diseases. In this study, we reviewed PFAS levels in human bodies reported in past seven years, including blood, urine, milk, and tissues (hair and nails). Most studies focused on human blood. Blood type, spatiality, human age, and gender were found to have a strong relationship with PFAS levels in blood samples. The PFAS distribution in urine samples was reported to be associated with the chain length of PFASs and human gender. Urinary excretion was found to be an important pathway of PFAS elimination. PFAS levels in human milk might be affected by various factors, such as mothers' age, dietary habit, parity of mothers and the interval of interpregnancy. Data in hair and nails remain very limited, but these matrices offer a non-invasive approach to evaluate human exposure to PFASs. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Forecasting human exposure to atmospheric pollutants in Portugal - A modelling approach

    Science.gov (United States)

    Borrego, C.; Sá, E.; Monteiro, A.; Ferreira, J.; Miranda, A. I.

    2009-12-01

    Air pollution has become one main environmental concern because of its known impact on human health. Aiming to inform the population about the air they are breathing, several air quality modelling systems have been developed and tested allowing the assessment and forecast of air pollution ambient levels in many countries. However, every day, an individual is exposed to different concentrations of atmospheric pollutants as he/she moves from and to different outdoor and indoor places (the so-called microenvironments). Therefore, a more efficient way to prevent the population from the health risks caused by air pollution should be based on exposure rather than air concentrations estimations. The objective of the present study is to develop a methodology to forecast the human exposure of the Portuguese population based on the air quality forecasting system available and validated for Portugal since 2005. Besides that, a long-term evaluation of human exposure estimates aims to be obtained using one-year of this forecasting system application. Additionally, a hypothetical 50% emission reduction scenario has been designed and studied as a contribution to study emission reduction strategies impact on human exposure. To estimate the population exposure the forecasting results of the air quality modelling system MM5-CHIMERE have been combined with the population spatial distribution over Portugal and their time-activity patterns, i.e. the fraction of the day time spent in specific indoor and outdoor places. The population characterization concerning age, work, type of occupation and related time spent was obtained from national census and available enquiries performed by the National Institute of Statistics. A daily exposure estimation module has been developed gathering all these data and considering empirical indoor/outdoor relations from literature to calculate the indoor concentrations in each one of the microenvironments considered, namely home, office/school, and other

  5. A PROBABILISTIC EXPOSURE ASSESSMENT FOR CHILDREN WHO CONTACT CCA-TREATED PLAYSETS AND DECKS USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL FOR THE WOOD PRESERVATIVE EXPOSURE SCENARIO

    Science.gov (United States)

    The U.S. Environmental Protection Agency has conducted a probabilistic exposure and dose assessment on the arsenic (As) and chromium (Cr) components of Chromated Copper Arsenate (CCA) using the Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood...

  6. [Indoor dust as a pathway of human exposure to polybrominated diphenyl ethers (PBDEs)].

    Science.gov (United States)

    Góralczyk, Katarzyna; Struciński, Paweł; Hernik, Agnieszka; Czaja, Katarzyna; Korcz, Wojciech; Minorczyk, Maria; Ludwicki, Jan K

    2012-01-01

    The brominated diphenyl ethers (PBDEs) belong to a class of synthetic, additive brominated flame retardants (BFRs). PBDEs are used to reduce the flammability of commercial and household products such as textiles, various plastic polymers, furnishing foam, and electronic equipment. People spend a large percentage of their life-time indoors at home, in offices and cars, etc, providing many opportunities for lengthy exposure to PBDEs from residential settings and commercial products in an indoor environment. In recent time, the foodstuffs, mainly food of animal origin, have been indicated as the main pathway of human exposure to PBDEs. However, many studies have shown that the indoor environment, mainly indoor dust, can be also a significant source of exposure to PBDEs, especially for younger children (toddlers) because of their behavioral patterns, eg. putting fingers, toys, and other items in their mouth. Numerous studies show that the median intakes of PBDEs via dust for adult range from 1.41 to 277 ng x day(-1) is lower than that via food which range from 135 to 333 ng x day-', while the median intake of these compounds via indoor dust for children range from 101 to 404 ng x day(-1) is much higher than via food: 77-190 ng x day(-1). The congener pattern observed in the indoor dust is different to that found in food. The indoor dust is dominated by the congener BDE-209 vs. food where the most dominated congeners are BDE-47 and BDE-99. Human exposure to PBDEs and other brominated flame retardants (BFRs) is widely widespread throughout the world and it depends on a country range of usage, production and legislation concerning these chemicals as well as a citizen's behavior. Generally, human exposure has been found higher in North America than in Europe and Asia. Within European countries the significant highest concentrations in dust have been found in the United Kingdom. It should be noted that many uncertainty factors such as personal habits, dietary preferences

  7. Direct and Passive Prenatal Nicotine Exposure and the Development of Externalizing Psychopathology

    Science.gov (United States)

    Gatzke-Kopp, Lisa M.; Beauchaine, Theodore P.

    2007-01-01

    The association between maternal smoking during pregnancy and childhood antisocial outcomes has been demonstrated repeatedly across a variety of outcomes. Yet debate continues as to whether this association reflects a direct programming effect of nicotine on fetal brain development, or a phenotypic indicator of heritable liability passed from…

  8. Particle size: a missing factor in risk assessment of human exposure to toxic chemicals in settled indoor dust.

    Science.gov (United States)

    Cao, Zhi-Guo; Yu, Gang; Chen, Yong-Shan; Cao, Qi-Ming; Fiedler, Heidelore; Deng, Shu-Bo; Huang, Jun; Wang, Bin

    2012-11-15

    For researches on toxic chemicals in settled indoor dust, selection of dust fraction is a critical influencing factor to the accuracy of human exposure risk assessment results. However, analysis of the selection of dust fraction in recent studies revealed that there is no consensus. This study classified and presented researches on distribution of toxic chemicals according to dust particle size and on relationship between dust particle size and human exposure possibility. According to the literature, beyond the fact that there were no consistent conclusions on particle size distribution of adherent fraction, dust with particle size less than 100 μm should be paid more attention and that larger than 250 μm is neither adherent nor proper for human exposure risk assessment. Calculation results based on literature data show that with different selections of dust fractions, analytical results of toxic chemicals would vary up to 10-fold, which means that selecting dust fractions arbitrarily will lead to large errors in risk assessment of human exposure to toxic chemicals in settled dust. Taking into account the influence of dust particle size on risk assessment of human exposure to toxic chemicals, a new methodology for risk assessment of human exposure to toxic chemicals in settled indoor dust is proposed and human exposure parameter systems to settled indoor dust are advised to be established at national and regional scales all over the world. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Modelling ecological and human exposure to POPs in Venice lagoon - Part II: Quantitative uncertainty and sensitivity analysis in coupled exposure models.

    Science.gov (United States)

    Radomyski, Artur; Giubilato, Elisa; Ciffroy, Philippe; Critto, Andrea; Brochot, Céline; Marcomini, Antonio

    2016-11-01

    The study is focused on applying uncertainty and sensitivity analysis to support the application and evaluation of large exposure models where a significant number of parameters and complex exposure scenarios might be involved. The recently developed MERLIN-Expo exposure modelling tool was applied to probabilistically assess the ecological and human exposure to PCB 126 and 2,3,7,8-TCDD in the Venice lagoon (Italy). The 'Phytoplankton', 'Aquatic Invertebrate', 'Fish', 'Human intake' and PBPK models available in MERLIN-Expo library were integrated to create a specific food web to dynamically simulate bioaccumulation in various aquatic species and in the human body over individual lifetimes from 1932 until 1998. MERLIN-Expo is a high tier exposure modelling tool allowing propagation of uncertainty on the model predictions through Monte Carlo simulation. Uncertainty in model output can be further apportioned between parameters by applying built-in sensitivity analysis tools. In this study, uncertainty has been extensively addressed in the distribution functions to describe the data input and the effect on model results by applying sensitivity analysis techniques (screening Morris method, regression analysis, and variance-based method EFAST). In the exposure scenario developed for the Lagoon of Venice, the concentrations of 2,3,7,8-TCDD and PCB 126 in human blood turned out to be mainly influenced by a combination of parameters (half-lives of the chemicals, body weight variability, lipid fraction, food assimilation efficiency), physi