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Sample records for human exposure study

  1. Community Engagement in Observational Human Exposure Studies

    Science.gov (United States)

    Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

  2. Human exposures to parabens in cosmetics - a literature study

    OpenAIRE

    Aarflot, Ragnhild Lønseth

    2013-01-01

    A literature study was performed in order to assess and compare evidence of human exposure to parabens in cosmetics. The focus of the thesis is on human concentrations, the rate of dermal absorption, metabolism and excretion; in order to increase our understanding of human exposures to endocrine disrupting chemicals in cosmetics. High detection rates of native and total parabens in blood and urine were identified. GMs of native parabens were lower than total paraben levels in urine as expecte...

  3. 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

  4. 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

  5. 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

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

    DEFF Research Database (Denmark)

    Myren, Maja; Mose, Tina; Mathiesen, Line;

    2007-01-01

    , 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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. (ACR)

  8. Comparison study of the sensitivities of some indices of DDT exposure in human blood and urine

    Energy Technology Data Exchange (ETDEWEB)

    Nhachi, C.F.B.; Loewenson, R. (Univ. of Zimbabwe (South Africa))

    1989-10-01

    Although exposure to DDT (2,2-bis(p-chlorophenyl1)1,1,1,-trichloroethane) is not normally associated with fatality or chronic adverse effects to human life, it is a known hazard to the ecosystem. Blood levels of DDT and some of its derivatives have been used to assess extent of exposure or the body load of DDT in humans. In experimental studies, ingestion of DDT has been associated with reduced liver stores of vitamin A, and increased serum levels of vitamin A. The same study also revealed a significant correlation of vitamin A and DDE serum levels. Generally an increase in excreted 17-B-hydroxycortisone has been associated with DDT exposure. Increased excretion of 6-B-hydroxycortisol has been noted in workers who were involved in the formulation of DDT. The objective of this study was to compare the sensitivities of some indices of DDT exposure in humans. The indices which were compared are serum vitamin A and DDE levels and urinary 17-B-hydroxycortisol.

  9. A review of adverse pregnancy outcomes and formaldehyde exposure in human and animal studies.

    Science.gov (United States)

    Collins, J J; Ness, R; Tyl, R W; Krivanek, N; Esmen, N A; Hall, T A

    2001-08-01

    We examine the potential for reproductive and developmental effects from formaldehyde exposure. Formaldehyde is unlikely to reach the reproductive system in humans in concentrations sufficient to cause damage since it is rapidly metabolized and detoxified upon contact with the respiratory tract. While there are effects seen in in vitro studies or after injection, there is little evidence of reproductive or developmental toxicity in animal studies under exposure levels and routes relevant to humans. Most of the epidemiology studies examined spontaneous abortion and showed some evidence of increased risk (meta-relative risk=1.4, 95% CI 0.9-2.1). We found evidence of reporting biases and publication biases among the epidemiology studies and when these biases were taken into account, we found no evidence of increased risk of spontaneous abortion among workers exposed to formaldehyde (meta-relative risk=0.7, 95% CI 0.5-1.0). The small number of studies on birth defects, low birth weight, and infertility among formaldehyde workers; the limitations in the design of these studies; and the inconsistent findings across these studies make it difficult to draw conclusions from the epidemiology data alone. However, information from experimental studies and studies of metabolism indicate reproductive impacts are unlikely at formaldehyde exposures levels observed in the epidemiology studies.

  10. 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.

  11. Human Exposure Database System (HEDS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Human Exposure Database System (HEDS) provides public access to data sets, documents, and metadata from EPA on human exposure. It is primarily intended for...

  12. Effects of inhaled acid aerosols on lung mechanics: an analysis of human exposure studies.

    Science.gov (United States)

    Utell, M J

    1985-11-01

    There exist significant gaps in our understanding of human health effects from inhalation of pollutants associated with acid precipitation. Controlled clinical studies examine effects of criteria pollutants almost exclusively by assessing changes in lung mechanics. One constituent of acid precipitation, sulfuric acid aerosols, has been shown to induce bronchoconstriction in exercising extrinsic asthmatics at near ambient levels. These asthmatics may be an order of magnitude more sensitive to sulfuric acid aerosols than normal adults. More recently, a second component nitrogen dioxide has been observed to provoke changes in lung mechanics at progressively lower concentrations. To date, virtually no data exist from clinical exposures to acidic aerosols for subjects with chronic obstructive pulmonary disease.

  13. Biomonitoring studies should be used by regulatory agencies to assess human exposure levels and safety of bisphenol A.

    Science.gov (United States)

    Vandenberg, Laura N; Chahoud, Ibrahim; Padmanabhan, Vasantha; Paumgartten, Francisco J R; Schoenfelder, Gilbert

    2010-08-01

    Within the past 3 years, four major evaluations of bisphenol A (BPA) safety have been undertaken. However, these assessments have arrived at quite different conclusions regarding the safety of BPA at current human exposure levels. We compared the reasons provided by the European Food Safety Authority (EFSA) BPA risk assessment panel for their conclusion that human exposures are negligible with the conclusions reached by the other panels, with all panels having the same body of literature at their disposal. The EFSA panel dismissed > or = 80 biomonitoring studies that documented significant levels of BPA exposure in humans, including internal exposures to unconjugated BPA, on the basis that they did not match a model of BPA metabolism. Instead, the EFSA panel relied on two toxicokinetic studies-conducted in 15 adults administered BPA-to draw conclusions about exposure levels in the population, including exposures of neonates. As with all exposure assessments, models should be developed to explain actual data that are collected. In the case of BPA, samples from a large number of human subjects clearly indicate that humans are internally exposed to unconjugated BPA. The dismissal of these biomonitoring studies simply because their results do not conform to a model violates scientific principles. Expert panels should evaluate all data-including human biomonitoring studies-to make informed risk assessments.

  14. The ethics of human volunteer studies involving experimental exposure to pesticides: unanswered dilemmas

    Directory of Open Access Journals (Sweden)

    London Leslie

    2010-08-01

    Full Text Available Abstract The controversy about the use of data from human volunteer studies involving experimental exposure to pesticides as part of regulatory risk assessment has been widely discussed, but the complex and interrelated scientific and ethical issues remain largely unresolved. This discussion paper, generated by authors who comprised a workgroup of the ICOH Scientific Committee on Rural Health, reviews the use of human experimental studies in regulatory risk assessment for pesticides with a view to advancing the debate as to when, if ever, such studies might be ethically justifiable. The discussion is based on three elements: (a a review of discussion papers on the topic of human testing of pesticides and the positions adopted by regulatory agencies in developed countries; (b an analysis of published and unpublished studies involving human testing with pesticides, both in the peer-reviewed literature and in the JMPR database; and (c application of an ethical analysis to the problem. The paper identifies areas of agreement which include general principles that may provide a starting point on which to base criteria for judgements as to the ethical acceptability of such studies. However, the paper also highlights ongoing unresolved differences of opinion inherent in ethical analysis of contentious issues, which we propose should form a starting point for further debate and the development of guidelines to achieve better resolution of this matter.

  15. The ethics of human volunteer studies involving experimental exposure to pesticides: unanswered dilemmas

    Science.gov (United States)

    2010-01-01

    The controversy about the use of data from human volunteer studies involving experimental exposure to pesticides as part of regulatory risk assessment has been widely discussed, but the complex and interrelated scientific and ethical issues remain largely unresolved. This discussion paper, generated by authors who comprised a workgroup of the ICOH Scientific Committee on Rural Health, reviews the use of human experimental studies in regulatory risk assessment for pesticides with a view to advancing the debate as to when, if ever, such studies might be ethically justifiable. The discussion is based on three elements: (a) a review of discussion papers on the topic of human testing of pesticides and the positions adopted by regulatory agencies in developed countries; (b) an analysis of published and unpublished studies involving human testing with pesticides, both in the peer-reviewed literature and in the JMPR database; and (c) application of an ethical analysis to the problem. The paper identifies areas of agreement which include general principles that may provide a starting point on which to base criteria for judgements as to the ethical acceptability of such studies. However, the paper also highlights ongoing unresolved differences of opinion inherent in ethical analysis of contentious issues, which we propose should form a starting point for further debate and the development of guidelines to achieve better resolution of this matter. PMID:20718963

  16. Multi-platform metabolomics assays for human lung lavage fluids in an air pollution exposure study.

    Science.gov (United States)

    Surowiec, Izabella; Karimpour, Masoumeh; Gouveia-Figueira, Sandra; Wu, Junfang; Unosson, Jon; Bosson, Jenny A; Blomberg, Anders; Pourazar, Jamshid; Sandström, Thomas; Behndig, Annelie F; Trygg, Johan; Nording, Malin L

    2016-07-01

    Metabolomics protocols are used to comprehensively characterize the metabolite content of biological samples by exploiting cutting-edge analytical platforms, such as gas chromatography (GC) or liquid chromatography (LC) coupled to mass spectrometry (MS) assays, as well as nuclear magnetic resonance (NMR) assays. We have developed novel sample preparation procedures combined with GC-MS, LC-MS, and NMR metabolomics profiling for analyzing bronchial wash (BW) and bronchoalveolar lavage (BAL) fluid from 15 healthy volunteers following exposure to biodiesel exhaust and filtered air. Our aim was to investigate the responsiveness of metabolite profiles in the human lung to air pollution exposure derived from combustion of biofuels, such as rapeseed methyl ester biodiesel, which are increasingly being promoted as alternatives to conventional fossil fuels. Our multi-platform approach enabled us to detect the greatest number of unique metabolites yet reported in BW and BAL fluid (82 in total). All of the metabolomics assays indicated that the metabolite profiles of the BW and BAL fluids differed appreciably, with 46 metabolites showing significantly different levels in the corresponding lung compartments. Furthermore, the GC-MS assay revealed an effect of biodiesel exhaust exposure on the levels of 1-monostearylglycerol, sucrose, inosine, nonanoic acid, and ethanolamine (in BAL) and pentadecanoic acid (in BW), whereas the LC-MS assay indicated a shift in the levels of niacinamide (in BAL). The NMR assay only identified lactic acid (in BW) as being responsive to biodiesel exhaust exposure. Our findings demonstrate that the proposed multi-platform approach is useful for wide metabolomics screening of BW and BAL fluids and can facilitate elucidation of metabolites responsive to biodiesel exhaust exposure. Graphical Abstract Graphical abstract illustrating the study workflow. NMR Nuclear Magnetic Resonance, LC-TOFMS Liquid chromatography-Time Of Flight Mass Spectrometry, GC Gas

  17. Thermal effects of continuous wave CO sub 2 laser exposure on human teeth: An in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Miserendino, L.J.; Neiburger, E.J.; Walia, H.; Luebke, N.; Brantley, W.

    1989-07-01

    The thermal effects of continuous wave carbon dioxide laser irradiation on human teeth were investigated. Internal temperature changes were monitored by means of electrical thermistors implanted within the pulp chambers of 20 extracted, unerupted human molar teeth. One-hundred test exposures at various powers and durations were obtained. Linear regression/correlation analysis of the data suggests a direct relationship between the independent variable, exposure energy (joules), and the dependent variable, internal temperature, under the conditions of this study.

  18. Biomarkers of human exposure to personal care products: Results from the Flemish Environment and Health Study (FLEHS 2007-2011)

    OpenAIRE

    Den Hond, Elly; Paulussen, Melissa; Geens, Tinne; Bruckers, Liesbeth; Baeyens, Willy; David, Frank; Dumont, Emmie; Loots, Ilse; Morrens, Bert; de Bellevaux, Benoit Nemery; Nelen, Vera; Schoeters, Greet; Van Larebeke, Nicolas; Covaci, Adrian

    2013-01-01

    Personal care products (PCPs), such as soaps, perfumes, cosmetics, lotions, etc., contain a variety of chemicals that have been described as potentially hormone disrupting chemicals. Therefore, it is important to assess the internal exposure of these chemicals in humans. Within the 2nd Flemish Environment and Health Study (FLEHS II, 2007-2011), the human exposure to three classes of pollutants that are present in a wide variety of PCPs - i.e. polycyclic musks (galaxolide, HHCB and tonalide, A...

  19. Mercury in human brain, blood, muscle and toenails in relation to exposure: an autopsy study

    Directory of Open Access Journals (Sweden)

    Morild Inge

    2007-10-01

    Full Text Available Abstract Background The main forms of mercury (Hg exposure in the general population are methylmercury (MeHg from seafood, inorganic mercury (I-Hg from food, and mercury vapor (Hg0 from dental amalgam restorations. While the distribution of MeHg in the body is described by a one compartment model, the distribution of I-Hg after exposure to elemental mercury is more complex, and there is no biomarker for I-Hg in the brain. The aim of this study was to elucidate the relationships between on the one hand MeHg and I-Hg in human brain and other tissues, including blood, and on the other Hg exposure via dental amalgam in a fish-eating population. In addition, the use of blood and toenails as biological indicator media for inorganic and organic mercury (MeHg in the tissues was evaluated. Methods Samples of blood, brain (occipital lobe cortex, pituitary, thyroid, abdominal muscle and toenails were collected at autopsy of 30 deceased individuals, age from 47 to 91 years of age. Concentrations of total-Hg and I-Hg in blood and brain cortex were determined by cold vapor atomic fluorescence spectrometry and total-Hg in other tissues by sector field inductively coupled plasma-mass spectrometry (ICP-SFMS. Results The median concentrations of MeHg (total-Hg minus I-Hg and I-Hg in blood were 2.2 and 1.0 μg/L, and in occipital lobe cortex 4 and 5 μg/kg, respectively. There was a significant correlation between MeHg in blood and occipital cortex. Also, total-Hg in toenails correlated with MeHg in both blood and occipital lobe. I-Hg in both blood and occipital cortex, as well as total-Hg in pituitary and thyroid were strongly associated with the number of dental amalgam surfaces at the time of death. Conclusion In a fish-eating population, intake of MeHg via the diet has a marked impact on the MeHg concentration in the brain, while exposure to dental amalgam restorations increases the I-Hg concentrations in the brain. Discrimination between mercury species is

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

    Science.gov (United States)

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

    2015-10-01

    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.

  1. Toxicogenomic studies of human neural cells following exposure to organophosphorus chemical warfare nerve agent VX.

    Science.gov (United States)

    Gao, Xiugong; Lin, Hsiuling; Ray, Radharaman; Ray, Prabhati

    2013-05-01

    Organophosphorus (OP) compounds represent an important group of chemical warfare nerve agents that remains a significant and constant military and civilian threat. OP compounds are considered acting primarily via cholinergic pathways by binding irreversibly to acetylcholinesterase, an important regulator of the neurotransmitter acetylcholine. Many studies over the past years have suggested that other mechanisms of OP toxicity exist, which need to be unraveled by a comprehensive and systematic approach such as genome-wide gene expression analysis. Here we performed a microarray study in which cultured human neural cells were exposed to 0.1 or 10 μM of VX for 1 h. Global gene expression changes were analyzed 6, 24, and 72 h post exposure. Functional annotation and pathway analysis of the differentially expressed genes has revealed many genes, networks and canonical pathways that are related to nervous system development and function, or to neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, and Parkinson's disease. In particular, the neuregulin pathway impacted by VX exposure has important implications in many nervous system diseases including schizophrenia. These results provide useful information valuable in developing suitable antidotes for more effective prevention and treatment of, as well as in developing biomarkers for, VX-induced chronic neurotoxicity.

  2. Human aflatoxin exposure in Kenya, 2007: a cross-sectional study

    Science.gov (United States)

    Yard, Ellen E.; Daniel, Johnni H.; Lewis, Lauren S.; Rybak, Michael E.; Paliakov, Ekaterina M.; Kim, Andrea A.; Montgomery, Joel M.; Bunnell, Rebecca; Abudo, Mamo Umuro; Akhwale, Willis; Breiman, Robert F.; Sharif, Shahnaaz K.

    2013-01-01

    Aflatoxins contaminate approximately 25% of agricultural products worldwide. They can cause liver failure and liver cancer. Kenya has experienced multiple aflatoxicosis outbreaks in recent years, often resulting in fatalities. However, the full extent of aflatoxin exposure in Kenya has been unknown. Our objective was to quantify aflatoxin exposure across Kenya. We analysed aflatoxin levels in serum specimens from the 2007 Kenya AIDS Indicator Survey – a nationally representative, cross-sectional serosurvey. KAIS collected 15,853 blood specimens. Of the 3180 human immunodeficiency virus-negative specimens with ≥1 mL sera, we randomly selected 600 specimens stratified by province and sex. We analysed serum specimens for aflatoxin albumin adducts by using isotope dilution MS/MS to quantify aflatoxin B1-lysine, and normalised with serum albumin. Aflatoxin concentrations were then compared by demographic, socioeconomic and geographic characteristics. We detected serum aflatoxin B1-lysine in 78% of serum specimens (range = Aflatoxin exposure did not vary by sex, age group, marital status, religion or socioeconomic characteristics. Aflatoxin exposure varied by province (p aflatoxin exposure is a public health problem throughout Kenya, and it could be substantially impacting human health. Wide-scale, evidence-based interventions are urgently needed to decrease exposure and subsequent health effects. PMID:23767939

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

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2016-01-01

    To extend the results of a previous study on the effects of carbon dioxide (CO2) and bioeffluents on humans, the new study reported in this paper was carried out. The purpose of this study was to examine, whether exposure to CO2 at 5000 ppm would cause sensory discomfort, evoke acute health...... was added to the supply air to create an exposure condition with CO2 at 5000 ppm (the measured exposure level was ca. 4900 ppm). Ten healthy college-age students were exposed twice to each of the two conditions for 2.5 h in a design balanced for order of presentation. The raised CO2 concentration had...

  4. Clinical Exposure Boost Predictions by Integrating Cytochrome P450 3A4-Humanized Mouse Studies With PBPK Modeling.

    Science.gov (United States)

    Zhang, Jin; Heimbach, Tycho; Scheer, Nico; Barve, Avantika; Li, Wenkui; Lin, Wen; He, Handan

    2016-04-01

    NVS123 is a poorly water-soluble protease 56 inhibitor in clinical development. Data from in vitro hepatocyte studies suggested that NVS123 is mainly metabolized by CYP3A4. As a consequence of limited solubility, NVS123 therapeutic plasma exposures could not be achieved even with high doses and optimized formulations. One approach to overcome NVS123 developability issues was to increase plasma exposure by coadministrating it with an inhibitor of CYP3A4 such as ritonavir. A clinical boost effect was predicted by using physiologically based pharmacokinetic (PBPK) modeling. However, initial boost predictions lacked sufficient confidence because a key parameter, fraction of drug metabolized by CYP3A4 (fmCYP3A4), could not be estimated with accuracy on account of disconnects between in vitro and in vivo preclinical data. To accurately estimate fmCYP3A4 in human, an in vivo boost effect study was conducted using CYP3A4-humanized mouse model which showed a 33- to 56-fold exposure boost effect. Using a top-down approach, human fmCYP3A4 for NVS123 was estimated to be very high and included in the human PBPK modeling to support subsequent clinical study design. The combined use of the in vivo boost study in CYP3A4-humanized mouse model mice along with PBPK modeling accurately predicted the clinical outcome and identified a significant NVS123 exposure boost (∼42-fold increase) with ritonavir.

  5. Identification of fipronil metabolites by time-of-flight mass spectrometry for application in a human exposure study.

    Science.gov (United States)

    McMahen, Rebecca L; Strynar, Mark J; Dagnino, Sonia; Herr, David W; Moser, Virginia C; Garantziotis, Stavros; Andersen, Erik M; Freeborn, Danielle L; McMillan, Larry; Lindstrom, Andrew B

    2015-05-01

    Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks for human exposure associated with fipronil, urine and serum from dosed Long Evans adult rats (5 and 10mg/kg bw) were analyzed to identify metabolites as potential biomarkers for use in human biomonitoring studies. Urine from treated rats was found to contain seven unique metabolites, two of which had not been previously reported-M4 and M7 which were putatively identified as a nitroso compound and an imine, respectively. Fipronil sulfone was confirmed to be the primary metabolite in rat serum. The fipronil metabolites identified in the respective matrices were then evaluated in matched human urine (n=84) and serum (n=96) samples from volunteers with no known pesticide exposures. Although no fipronil or metabolites were detected in human urine, fipronil sulfone was present in the serum of approximately 25% of the individuals at concentrations ranging from 0.1 to 4ng/mL. These results indicate that many fipronil metabolites are produced following exposures in rats and that fipronil sulfone is a useful biomarker in human serum. Furthermore, human exposure to fipronil may occur regularly and require more extensive characterization.

  6. Biomarkers of human exposure to personal care products: results from the Flemish Environment and Health Study (FLEHS 2007-2011).

    Science.gov (United States)

    Den Hond, Elly; Paulussen, Melissa; Geens, Tinne; Bruckers, Liesbeth; Baeyens, Willy; David, Frank; Dumont, Emmie; Loots, Ilse; Morrens, Bert; de Bellevaux, Benoit Nemery; Nelen, Vera; Schoeters, Greet; Van Larebeke, Nicolas; Covaci, Adrian

    2013-10-01

    Personal care products (PCPs), such as soaps, perfumes, cosmetics, lotions, etc., contain a variety of chemicals that have been described as potentially hormone disrupting chemicals. Therefore, it is important to assess the internal exposure of these chemicals in humans. Within the 2nd Flemish Environment and Health Study (FLEHS II, 2007-2011), the human exposure to three classes of pollutants that are present in a wide variety of PCPs--i.e. polycyclic musks (galaxolide, HHCB and tonalide, AHTN in blood), parabens (urinary para-hydroxybenzoic acid, HBA) and triclosan (urinary TCS)--was assessed in 210 Flemish adolescents (14-15 years) and in 204 adults (20-40 years) randomly selected from the general population according to a stratified two stage clustered study design. The aim of this study was to define average levels of exposure in the general Flemish population and to identify determinants of exposure. Average levels (GM (95% CI)) in the Flemish adolescents were 0.717 (0.682-0.753) μg/L for blood HHCB; 0.118 (0.108-0.128) μg/L for blood AHTN; 1022 (723-1436) μg/L for urinary HBA and 2.19 (1.64-2.92) μg/L for urinary TCS. In the adults, levels of HBA were on average 634 (471-970) μg/L. Inter-individual variability was small for HHCB and AHTN, intermediate for HBA, and large for TCS. All biomarkers were positively associated with the use of PCPs. Additionally, levels of HHCB and AHTN increased with higher educational level of the adolescents. Both in adults and adolescents, urinary HBA levels were negatively correlated with BMI. We define here Flemish exposure values for biomarkers of PCPs, which can serve as baseline exposure levels to identify exposure trends in future biomonitoring campaigns.

  7. Study of p53 expression and post-transcriptional modifications after GSM-900 radiofrequency exposure of human amniotic cells.

    Science.gov (United States)

    Bourthoumieu, Sylvie; Magnaudeix, Amandine; Terro, Faraj; Leveque, Philippe; Collin, Alice; Yardin, Catherine

    2013-01-01

    The potential effects of radiofrequency (RF) exposure on the genetic material of cells are very important to determine since genome instability of somatic cells may be linked to cancer development. In response to genetic damage, the p53 protein is activated and can induce cell cycle arrest allowing more time for DNA repair or elimination of damaged cells through apoptosis. The objective of this study was to investigate whether the exposure to RF electromagnetic fields, similar to those emitted by mobile phones of the second generation standard, Global System for Mobile Communications (GSM), may induce expression of the p53 protein and its activation by post-translational modifications in cultured human cells. The potential induction of p53 expression and activation by GSM-900 was investigated after in vitro exposure of human amniotic cells for 24 h to average specific absorption rates (SARs) of 0.25, 1, 2, and 4 W/kg in the temperature range of 36.3-39.7 °C. The exposures were carried out using a wire-patch cell (WPC) under strictly controlled conditions of temperature. Expression and activation of p53 by phosphorylation at serine 15 and 37 were studied using Western blot assay immediately after three independent exposures of cell cultures provided from three different donors. Bleomycin-exposed cells were used as a positive control. According to our results, no significant changes in the expression and activation of the p53 protein by phosphorylation at serine 15 and 37 were found following exposure to GSM-900 for 24 h at average SARs up to 4 W/kg in human embryonic cells.

  8. Human exposure from pulsed magnetic field therapy mats: a numerical case study with three commercial products.

    Science.gov (United States)

    De Santis, Valerio; Douglas, Mark; Nadakuduti, Jagadish; Benkler, Stefan; Chen, Xi Lin; Kuster, Niels

    2015-02-01

    A previous study found that incident magnetic field exposure from pulsed magnetic field therapy (PMFT) mats can exceed ICNIRP 1998 reference levels. Due to the popularity of PMFT mats for private therapeutic use, regulators need to know if the products are compliant with the basic restrictions and how overexposure can be determined. This case study's objective was to test if such products are intrinsically compliant with ICNIRP 1998 and ICNIRP 2010 basic restrictions by evaluating three different commercially-available PMFT products. In the first step, experimentally validated numerical models of these mats were developed. As a second step, the induced fields were evaluated in high-resolution anatomical models of the IT'IS Virtual Population for various lying positions and compared to the safety guidelines. As expected, a strong influence of exposure on the PMFT design, anatomy, lying position and body orientation was found. The maximum exposure of one PMFT exceeds 3.1 times the basic restrictions of ICNIRP 1998 for the central nervous system tissues and 1.36 times the limit of ICNIRP 2010 for the peripheral tissues. Body loops can significantly increase the electric fields close to the skin, e.g., when the hand and thigh are in contact during mat use. In conclusion, PMFT products are not intrinsically compliant with ICNIRP 1998 and ICNIRP 2010 basic restrictions and therefore require special considerations. © 2015 Wiley Periodicals, Inc.

  9. STUDIES ON HUMAN SPERMATOZOAL MOTILITY WITH THE USE OF THE MULTIPLE EXPOSURE PHOTOGRAPHY METHOD - EFFECTS OF VARIOUS COMPOUNDS -

    OpenAIRE

    羽間, 稔

    1982-01-01

    The effects of various compounds, such as Kallikrein, 17β-estradiol, progesterone, prolactin, L-arginine, caffeine, and Solcoseryl, on sperm motility were studied. These compounds were added to fresh human semen offered by 28 volunteers who had presented with various findings, and the percentage of motile sperm and spermatozoal velocity were evaluated by objective semen analysis with the new multiple exposure photography (MEP) method using a stroboscope for photography and a computer for data...

  10. Exposure Setup and Dosimetry for a Study on Effects of Mobile Communication Signals on Human Hematopoietic Stem Cells in vitro

    Science.gov (United States)

    Rohland, Martina; Baaske, Kai; Gläser, Katharina; Hintzsche, Henning; Stopper, Helga; Kleine-Ostmann, Thomas; Schrader, Thorsten

    2017-09-01

    In this paper we describe the design of an exposure setup used to study possible non-thermal effects due to the exposure of human hematopoietic stem cells to GSM, UMTS and LTE mobile communication signals. The experiments are performed under fully blinded conditions in a TEM waveguide located inside an incubator to achieve defined environmental conditions as required for the living cells. Chamber slides containing the cells in culture medium are placed on the septum of the waveguide. The environmental and exposure parameters such as signal power, temperatures, relative humidity and CO2 content of the surrounding atmosphere are monitored permanently during the exposure experiment. The power of the exposure signals required to achieve specific absorption rates of 0.5, 1, 2 and 4 W kg-1 are determined by numerical calculation of the field distribution inside the cell culture medium at 900 MHz (GSM), 1950 MHz (UMTS) and 2535 MHz (LTE). The dosimetry is verified both with scattering parameter measurements on the waveguide with and without containers filled with cell culture medium and with temperature measurements with non-metallic probes in separate heating experiments.

  11. Exposure Setup and Dosimetry for a Study on Effects of Mobile Communication Signals on Human Hematopoietic Stem Cells in vitro

    Directory of Open Access Journals (Sweden)

    M. Rohland

    2017-09-01

    Full Text Available In this paper we describe the design of an exposure setup used to study possible non-thermal effects due to the exposure of human hematopoietic stem cells to GSM, UMTS and LTE mobile communication signals. The experiments are performed under fully blinded conditions in a TEM waveguide located inside an incubator to achieve defined environmental conditions as required for the living cells. Chamber slides containing the cells in culture medium are placed on the septum of the waveguide. The environmental and exposure parameters such as signal power, temperatures, relative humidity and CO2 content of the surrounding atmosphere are monitored permanently during the exposure experiment. The power of the exposure signals required to achieve specific absorption rates of 0.5, 1, 2 and 4 W kg−1 are determined by numerical calculation of the field distribution inside the cell culture medium at 900 MHz (GSM, 1950 MHz (UMTS and 2535 MHz (LTE. The dosimetry is verified both with scattering parameter measurements on the waveguide with and without containers filled with cell culture medium and with temperature measurements with non-metallic probes in separate heating experiments.

  12. Cytogenetic observations in human peripheral blood leukocytes following in vitro exposure to THz radiation: a pilot study.

    Science.gov (United States)

    Zeni, O; Gallerano, G P; Perrotta, A; Romanò, M; Sannino, A; Sarti, M; D'Arienzo, M; Doria, A; Giovenale, E; Lai, A; Messina, G; Scarfì, M R

    2007-04-01

    Emerging technologies are considering the possible use of Terahertz radiation in different fields ranging from telecommunications to biology and biomedicine. The study of the potential effects of Terahertz radiation on biological systems is therefore an important issue in order to safely develop a variety of applications. This paper describes a pilot study devoted to determine if Terahertz radiation could induce genotoxic effects in human peripheral blood leukocytes. For this purpose, human whole blood samples from healthy donors were exposed for 20 min to Terahertz radiation. Since, to our knowledge, this is the first study devoted to the evaluation of possible genotoxic effects of such radiation, different electromagnetic conditions were considered. In particular, the frequencies of 120 and 130 GHz were chosen: the first one was tested at a specific absorption rate (SAR) of 0.4 mW g-1, while the second one was tested at SAR levels of 0.24, 1.4, and 2 mW g-1. Chromosomal damage was evaluated by means of the cytokinesis block micronucleus technique, which also gives information on cell cycle kinetics. Moreover, human whole blood samples exposed to 130 GHz at SAR levels of 1.4 and 2 mW g-1 were also tested for primary DNA damage by applying the alkaline comet assay immediately after exposure. The results obtained indicate that THz exposure, in the explored electromagnetic conditions, is not able to induce either genotoxicity or alteration of cell cycle kinetics in human blood cells from healthy subjects.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-08-01

    The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer-induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations, and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-08-01

    The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer-induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations, and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy.

  15. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study

    NARCIS (Netherlands)

    J.W. van Strien (Jan); L.A. Isbell (Lynne A.)

    2017-01-01

    textabstractStudies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to pa

  16. Development of a Biomarker for Penconazole: A Human Oral Dosing Study and a Survey of UK Residents’ Exposure

    Directory of Open Access Journals (Sweden)

    Craig Sams

    2016-05-01

    Full Text Available Penconazole is a widely used fungicide in the UK; however, to date, there have been no peer-reviewed publications reporting human metabolism, excretion or biological monitoring data. The objectives of this study were to i develop a robust analytical method, ii determine biomarker levels in volunteers exposed to penconazole, and, finally, to iii measure the metabolites in samples collected as part of a large investigation of rural residents’ exposure. An LC-MS/MS method was developed for penconazole and two oxidative metabolites. Three volunteers received a single oral dose of 0.03 mg/kg body weight and timed urine samples were collected and analysed. The volunteer study demonstrated that both penconazole-OH and penconazole-COOH are excreted in humans following an oral dose and are viable biomarkers. Excretion is rapid with a half-life of less than four hours. Mean recovery of the administered dose was 47% (range 33%–54% in urine treated with glucuronidase to hydrolyse any conjugates. The results from the residents’ study showed that levels of penconazole-COOH in this population were low with >80% below the limit of detection. Future sampling strategies that include both end of exposure and next day urine samples, as well as contextual data about the route and time of exposure, are recommended.

  17. Ambient air pollution exposure and damage to male gametes: human studies and in situ 'sentinel' animal experiments.

    Science.gov (United States)

    Somers, Christopher M

    2011-02-01

    Globally there is concern that adverse reproductive outcomes and fertility impairment in humans may be caused by exposure to environmental contaminants. Air pollution in particular has been linked to DNA damage, abnormal sperm morphology, and reduced sperm performance in men. Experimental studies using model species (mice and rats) exposed in situ provide evidence that ambient air pollution can cause damage to the respiratory system and other tissues or organs. This can take the form of DNA damage and other genetic changes throughout the body, including induced mutations, DNA strand breaks, and altered methylation patterns in male germ cells. Human and animal studies together provide strong evidence that air pollution, especially airborne particulate matter, at commonly occurring ambient levels is genotoxic to male germ cells. The mechanistic link between air pollution exposure and induced genetic changes in male germ cells is currently unclear. 'Sentinel' animal experiments explicitly examining air pollution affects on sperm quality in laboratory rodents have not been conducted and would provide a critical link to observations in humans. The importance of air pollution compared to other factors affecting fertility and reproductive outcomes in humans is not clear and warrants further investigation.

  18. Human Exposure Modeling - Databases to Support Exposure Modeling

    Science.gov (United States)

    Human exposure modeling relates pollutant concentrations in the larger environmental media to pollutant concentrations in the immediate exposure media. The models described here are available on other EPA websites.

  19. Effects of inhaled acid aerosols on lung mechanics: an analysis of human exposure studies.

    OpenAIRE

    Utell, M J

    1985-01-01

    There exist significant gaps in our understanding of human health effects from inhalation of pollutants associated with acid precipitation. Controlled clinical studies examine effects of criteria pollutants almost exclusively by assessing changes in lung mechanics. One constituent of acid precipitation, sulfuric acid aerosols, has been shown to induce bronchoconstriction in exercising extrinsic asthmatics at near ambient levels. These asthmatics may be an order of magnitude more sensitive to ...

  20. Carcinogen derived biomarkers: applications in studies of human exposure to secondhand tobacco smoke

    OpenAIRE

    Hecht, S

    2004-01-01

    Objective: To review the literature on carcinogen derived biomarkers of exposure to secondhand tobacco smoke (SHS). These biomarkers are specifically related to known carcinogens in tobacco smoke and include urinary metabolites, DNA adducts, and blood protein adducts.

  1. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study.

    Science.gov (United States)

    Van Strien, Jan W; Isbell, Lynne A

    2017-04-07

    Studies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to partially exposed snake models and scale patterns on the snake skin. Here, we examined whether snake skin patterns and partially exposed snakes elicit a larger EPN in humans. In Task 1, we employed pictures with close-ups of snake skins, lizard skins, and bird plumage. In task 2, we employed pictures of partially exposed snakes, lizards, and birds. Participants watched a random rapid serial visual presentation of these pictures. The EPN was scored as the mean activity (225-300 ms after picture onset) at occipital and parieto-occipital electrodes. Consistent with previous studies, and with the Snake Detection Theory, the EPN was significantly larger for snake skin pictures than for lizard skin and bird plumage pictures, and for lizard skin pictures than for bird plumage pictures. Likewise, the EPN was larger for partially exposed snakes than for partially exposed lizards and birds. The results suggest that the EPN snake effect is partly driven by snake skin scale patterns which are otherwise rare in nature.

  2. Phthalate Exposure and Human Semen Quality in Shanghai A Cross-sectional Study

    Institute of Scientific and Technical Information of China (English)

    YUN-HUI ZHANG; LI-XING ZHENG; BING-HENG CHEN

    2006-01-01

    Objective To monitor the level of phthalates in human semen samples and to analyze the relationship between phthalate levels and semen parameters. Methods Concentrations of three kinds of commonly used phthalates (di-ethyl phthalate, DEP; di-n-butyl phthalate, DBP; di-2-ethylhexyl phthalate, DEHP) were measured using reversed-phase HPLC. Semen parameters were measured by computer aided sperm analysis (CASA). Results The three phthalates were detected in most of the biological samples, With median levels of 0.30 mg/L (0.08-1.32 mg/L) in semen specimens. There was a significant positive association between liquefied time of semen and phthalate concentrations of semen. The correlation coefficient was 0.456 for DEP, 0.475 for DBP, and 0.457 for DEHP, respectively. There was no significant difference between phthalate concentrations of semen and sperm density or livability, though the correlation coefficients were negative. Conclusion These results suggest that people who reside in Shanghai are exposed to phthalates, especially to DBP and DEHP. Although the level of phthalates is relatively mild, an association of phthalate levels and reduced quality of human semen has been shown in the present study.

  3. Human biological monitoring of occupational genotoxic exposures

    DEFF Research Database (Denmark)

    Knudsen, Lisbeth E.; Sorsa, M

    1993-01-01

    ) 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......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...... for and the biomonitoring results should preferentially be linked with accurate ambient air monitoring. In persons occupationally exposed to styrene the endpoints of DNA-damage and DNA-repair in genetic monitoring are methods of choice in exposure situations above the current Danish (25 ppm) or Finnish (20 ppm...

  4. Early Exposure to Soy Isoflavones and Effects on Reproductive Health: A Review of Human and Animal Studies

    Directory of Open Access Journals (Sweden)

    Wendy E. Ward

    2010-11-01

    Full Text Available Soy isoflavones are phytoestrogens with potential hormonal activity due to their similar chemical structure to 17-β-estradiol. The increasing availability of soy isoflavones throughout the food supply and through use of supplements has prompted extensive research on biological benefits to humans in chronic disease prevention and health maintenance. While much of this research has focused on adult populations, infants fed soy protein based infant formulas are exposed to substantial levels of soy isoflavones, even when compared to adult populations that consume a higher quantity of soy-based foods. Infant exposure, through soy formula, primarily occurs from birth to one year of life, a stage of development that is particularly sensitive to dietary and environmental compounds. This has led investigators to study the potential hormonal effects of soy isoflavones on later reproductive health outcomes. Such studies have included minimal human data with the large majority of studies using animal models. This review discusses key aspects of the current human and animal studies and identifies critical areas to be investigated as there is no clear consensus in this research field.

  5. Early exposure to soy isoflavones and effects on reproductive health: a review of human and animal studies.

    Science.gov (United States)

    Dinsdale, Elsa C; Ward, Wendy E

    2010-11-01

    Soy isoflavones are phytoestrogens with potential hormonal activity due to their similar chemical structure to 17-β-estradiol. The increasing availability of soy isoflavones throughout the food supply and through use of supplements has prompted extensive research on biological benefits to humans in chronic disease prevention and health maintenance. While much of this research has focused on adult populations, infants fed soy protein based infant formulas are exposed to substantial levels of soy isoflavones, even when compared to adult populations that consume a higher quantity of soy-based foods. Infant exposure, through soy formula, primarily occurs from birth to one year of life, a stage of development that is particularly sensitive to dietary and environmental compounds. This has led investigators to study the potential hormonal effects of soy isoflavones on later reproductive health outcomes. Such studies have included minimal human data with the large majority of studies using animal models. This review discusses key aspects of the current human and animal studies and identifies critical areas to be investigated as there is no clear consensus in this research field.

  6. Pilot study testing a European human biomonitoring framework for biomarkers of chemical exposure in children and their mothers

    DEFF Research Database (Denmark)

    Exley, Karen; Aerts, Dominique; Biot, Pierre;

    2015-01-01

    Exposure to a number of environmental chemicals in UK mothers and children has been assessed as part of the European biomonitoring pilot study, Demonstration of a Study to Coordinate and Perform Human Biomonitoring on a European Scale (DEMOCOPHES). For the European-funded project, 17 countries...... tested the biomonitoring guidelines and protocols developed by COPHES. The results from the pilot study in the UK are presented; 21 school children aged 6-11 years old and their mothers provided hair samples to measure mercury and urine samples, to measure cadmium, cotinine and several phthalate...... on environment, health and lifestyle. Mercury in hair was higher in children who reported frequent consumption of fish (geometric mean 0.35 μg/g) compared to those that ate fish less frequently (0.13 μg/g, p = 0.002). Cadmium accumulates with age as demonstrated by higher levels of urinary cadmium in the mothers...

  7. Study of spatiotemporal variation of atmospheric mercury and its human exposure around an integrated steel plant, India

    Science.gov (United States)

    Pervez, S.; Koshle, A.; Pervez, Y.

    2010-06-01

    Mercury release by coal combustion has been significantly increased in India. Mercury content in coal has been analyzed to 0.272 ppm by Central Pollution Control Board. Toxicological effects of elemental Hg (Hg0) exposure include respiratory and renal failures, cardiac arrest, and cerebral oedema, while subclinical exposure may induce kidney, behavioral, and cognitive dysfunctions. The present work is focused on dispersion pattern and inter-phase exchange phenomena of ambient mercury between air-particulate matter evaluations of alongwith dominance of various major routes of human exposure-dose response using regression analysis around an integrated steel plant in central India. Source-downwind type stratified random sampling plan using longitudinal study design has been adopted for ambient monitoring of total mercury, while representative sampling plant has been adopted for persona exposure-dose response study In space-time framework. Control sites and subjects have been chosen from uncontaminated area (100 km away from any industrial activities). 06 ambient air monitoring stations and 17 subjects from workers, non-workers but local residents' categories and from controlled sites have been chosen for the study. Samples of mercury biomarkers (blood, breast milk and urine) have also been collected from same subjects in each month during sampling period. The sampling period was March 2005 to February 2006 . Samples of 30% acidified KMnO4 for air-Hg absorption, PM10, RPM and biological samples were analyzed for total mercury by ICP-AES using standard methods. Local soils and ground water were also monitored for total mercury content during the sampling period. Results have shown that mercury concentration is very high compared to prescribed limits in all receptors. Results of exchange phenomenon have shown the higher transfer of mercury from air to particulate during combustion in steel plant environment due to presence of huge amount of iron particles, in contrast to

  8. 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.

  9. 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.

  10. Experimental study on human exposure to occupant generated pollutants in rooms with ductless personalized ventilation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Bolashikov, Zhecho Dimitrov; Lu, Pengfei

    2014-01-01

    thermal manikins were used to simulate occupants. Tracer gases were used to simulate human bioeffluents (feet, groins, armpits and exhaled air) released from one manikin, simulating polluting occupant. The second manikin simulated exposed occupant. Different combinations of supply flow rates and operation...

  11. Identification of fipronil metabolites in rodents by time-of-flight mass spectrometry for application in a human exposure study

    Science.gov (United States)

    Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks associated with fipronil, dosed Long Evans rats were evaluated for metabolites to develop a set of biomarkers for use in human exposur...

  12. Identification of fipronil metabolites in rodents by time-of-flight mass spectrometry for application in a human exposure study

    Science.gov (United States)

    Fipronil is a phenylpyrazole insecticide commonly used in residential and agricultural applications. To understand more about the potential risks associated with fipronil, dosed Long Evans rats were evaluated for metabolites to develop a set of biomarkers for use in human exposur...

  13. Design and dosimetric analysis of a 385 MHz TETRA head exposure system for use in human provocation studies.

    Science.gov (United States)

    Schmid, Gernot; Bolz, Thomas; Uberbacher, Richard; Escorihuela-Navarro, Ana; Bahr, Achim; Dorn, Hans; Sauter, Cornelia; Eggert, Torsten; Danker-Hopfe, Heidi

    2012-10-01

    A new head exposure system for double-blind provocation studies investigating possible effects of terrestrial trunked radio (TETRA)-like exposure (385 MHz) on central nervous processes was developed and dosimetrically analyzed. The exposure system allows localized exposure in the temporal brain, similar to the case of operating a TETRA handset at the ear. The system and antenna concept enables exposure during wake and sleep states while an electroencephalogram (EEG) is recorded. The dosimetric assessment and uncertainty analysis yield high efficiency of 14 W/kg per Watt of accepted antenna input power due to an optimized antenna directly worn on the subject's head. Beside sham exposure, high and low exposure at 6 and 1.5 W/kg (in terms of maxSAR10g in the head) were implemented. Double-blind control and monitoring of exposure is enabled by easy-to-use control software. Exposure uncertainty was rigorously evaluated using finite-difference time-domain (FDTD)-based computations, taking into account anatomical differences of the head, the physiological range of the dielectric tissue properties including effects of sweating on the antenna, possible influences of the EEG electrodes and cables, variations in antenna input reflection coefficients, and effects on the specific absorption rate (SAR) distribution due to unavoidable small variations in the antenna position. This analysis yielded a reasonable uncertainty of analysis.

  14. The effect of oxythioquinox exposure on normal human mammary epithelial cell gene expression: A microarray analysis study

    Directory of Open Access Journals (Sweden)

    Weston Ainsley

    2004-09-01

    Full Text Available Abstract Background Inter-individual variation in normal human mammary epithelial cells in response to oxythioquinox (OTQ is reported. Gene expression signatures resulting from chemical exposures are generally created from analysis of exposures in rat, mouse or other genetically similar animal models, limiting information about inter-individual variations. This study focused on the effect of inter-individual variation in gene expression signatures. Methods Gene expression was studied in primary normal human mammary epithelial cells (NHMECs derived from four women undergoing reduction mammoplasty [Cooperative Human Tissue Network (National Cancer Institute and National Disease Research Interchange]. Gene transcription in each cell strain was analyzed using high-density oligonucleotide DNA microarrays (HuGeneFL, Affymetrix™ and changes in the expression of selected genes were verified by real-time polymerase chain reaction at extended time points (ABI. DNA microarrays were hybridized to materials prepared from total RNA that was collected after OTQ treatment for 15, 60 and 120 min. RNA was harvested from the vehicle control (DMSO at 120 min. The gene expression profile included all genes altered by at least a signal log ratio (SLR of ± 0.6 and p value ≤ 0.05 in three of four cell strains analyzed. Results RNA species were clustered in various patterns of expression highlighting genes with altered expression in one or more of the cell strains, including metabolic enzymes and transcription factors. Of the clustered RNA species, only 36 were found to be altered at one time point in three or more of the cell strains analyzed (13 up-regulated, 23 down-regulated. Cluster analysis examined the effects of OTQ on the cells with specific p53 polymorphisms. The two strains expressing the major variant of p53 had 83 common genes altered (35 increased, 48 decreased at one or more time point by at least a 0.6 signal log ratio (SLR. The intermediate variant

  15. Ethanol consumption modifies the body turnover of cadmium: a study in a rat model of human exposure.

    Science.gov (United States)

    Brzóska, Malgorzata M; Galażyn-Sidorczuk, Malgorzata; Dzwilewska, Ilona

    2013-08-01

    Ethanol (Et) abusers may also be exposed to excessive amounts of cadmium (Cd). Thus, the study was aimed at estimating the influence of Et on the body turnover of Cd in a rat model reflecting excessive alcohol consumption in humans chronically exposed to moderate and relatively high levels of this metal. For this purpose, Cd apparent absorption, retention in the body and concentration in the blood, stomach, duodenum, liver, kidney, spleen, brain, heart, testis and femur as well as its fecal and urinary excretion in the rats exposed to 5 and 50mg Cd l(-1) (in drinking water; for 16 weeks from the fifth week of the animal's life) and/or Et (5 g kg(-1) b.w. per 24 h, by oral gavage; for 12 weeks from the ninth week of life) were estimated. Moreover, the duodenal, liver and kidney pool of the nonmetallothionein (Mt)-bound Cd was evaluated. The administration of Et during the exposure to 5 or 50mg Cd l(-1) increased Cd accumulation in the gastrointestinal tract and its urinary excretion, and decreased Cd concentration in the blood, femur and numerous soft tissues (including liver and kidney) as well as the total pool of this metal in internal organs. Et modified or not the pool of the non-Mt-bound Cd, depending on the level of treatment with this metal. The results show that excessive Et consumption during Cd exposure may decrease the body burden of this metal, at least partly, by its lower absorption and increased urinary excretion. Based on this study, it can be concluded that Cd concentration in the blood and tissues of alcohol abusers chronically exposed to moderate and relatively high levels of this metal may be lower, whereas its urinary excretion is higher than in their nondrinking counterparts. However, since Et is toxic itself, the decreased body burden of Cd owing to alcohol consumption does not allow for the conclusion that the risk of health damage may be lower at co-exposure to these xenobiotics. In a further study, it will be investigated how the Et

  16. Chlorinated and brominated organic contaminants in fish from Shanghai markets: a case study of human exposure.

    Science.gov (United States)

    Qiu, Yanling; Strid, Anna; Bignert, Anders; Zhu, Zhiliang; Zhao, Jianfu; Athanasiadou, Maria; Athanassiadis, Ioannis; Bergman, Åke

    2012-10-01

    In the present study were two favorite edible fish species for local residents, i.e., mandarin fish and crawfish, collected from the Shanghai market and analyzed for selected organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), hexabromocyclododecane (HBCDD), polybrominated diphenyl ethers (PBDEs) and methoxylated PBDEs (MeO-PBDEs). Efforts were also made to identify the potential sources of these contaminants. Comparable concentrations of hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and HBCDD were found in muscle tissue of mandarin fish from Guangdong (GDF), the Pearl River Delta and from Taihu Lake (TLF), the Yangtze River Delta. Levels of chlordanes, PCBs and PBDEs were about one magnitude lower in TLF compared to GDF. The concentrations of OCPs in the butter-like gland of the crawfish (CFB) were 2-5 times of those in the crawfish muscle (CFM) while concentrations of PCBs, PBDEs and MeO-PBDEs were comparable. The different patterns and levels of chlorinated and brominated organohalogen contaminants seen in mandarin fish from GDF and TLF indicates that different types of chemicals might be used in the two delta regions. The present study also shows a good correlation between the concentrations of hexachlorobenzene (HCB) and pentachloroanisol (PCA) in fish for the first time. Fish consumption limits based on chemical contaminants with non-carcinogenic effects were calculated. The estimated maximum daily consumption limit for GDF, TLF, CFM and CFB were 1.5, 2.6, 3.7 and 0.08 kg, respectively, indicating no significant risk regarding the persistent organic pollutants measured in the present study.

  17. Common studied polymorphisms do not affect plasma cytokine levels upon endotoxin exposure in humans

    DEFF Research Database (Denmark)

    Taudorf, Sarah; Krabbe, K.S.; Berg, R.M.

    2008-01-01

    The aim of this study was to investigate to what extent single nucleotide polymorphisms (SNPs) in promoter regions of genes of Toll-like receptor (TLR)-4, tumour necrosis factor (TNF)-alpha, interleukin (IL)-18, interferon (IFN)-gamma, IL-6 and IL-10 affect the cytokine response during a controll......-10 in healthy young men. Previous reports of a major heritability factor in the inflammatory response may be due to other target genes or effects in older age groups or women Udgivelsesdato: 2008/4...

  18. Common studied polymorphisms do not affect plasma cytokine levels upon endotoxin exposure in humans

    DEFF Research Database (Denmark)

    Taudorf, S.; Krabbe, K.S.; Berg, R.M.

    2008-01-01

    -607, IFN-gamma+874, IL-6-174, IL-10-592 and IL-10-1082) and endotoxin-induced changes in plasma levels of TNF-alpha, IL-6 and IL-10. IL-18 levels were unaffected by endotoxin. In conclusion, the investigated SNPs did not affect endotoxin-induced low-grade cytokine production of TNF-alpha, IL-6, IL-18 or IL......The aim of this study was to investigate to what extent single nucleotide polymorphisms (SNPs) in promoter regions of genes of Toll-like receptor (TLR)-4, tumour necrosis factor (TNF)-alpha, interleukin (IL)-18, interferon (IFN)-gamma, IL-6 and IL-10 affect the cytokine response during a controlled...... low-grade inflammatory response in vivo. Two hundred healthy young male volunteers were genotyped, and cytokine levels were measured in response to a low-dose intravenous bolus of Escherichia coli endotoxin. No association was detected between SNPs (TLR-4299, TLR-4399, TNF-308, IL-18-137, IL-18...

  19. Linking Meteorology, Air Quality Models and Observations to Characterize Human Exposures in Support of the Environmental Health Studies

    Science.gov (United States)

    Epidemiologic studies are critical in establishing the association between exposure to air pollutants and adverse health effects. Results of epidemiologic studies are used by U.S. EPA in developing air quality standards to protect the public from the health effects of air polluta...

  20. Ultraviolet Radiation: Human Exposure and Health Risks.

    Science.gov (United States)

    Tenkate, Thomas D.

    1998-01-01

    Provides an overview of human exposure to ultraviolet radiation and associated health effects as well as risk estimates for acute and chronic conditions resulting from such exposure. Demonstrates substantial reductions in health risk that can be achieved through preventive actions. Also includes a risk assessment model for skin cancer. Contains 36…

  1. PARTNERING TO IMPROVE HUMAN EXPOSURE METHODS

    Science.gov (United States)

    Methods development research is an application-driven scientific area that addresses programmatic needs. The goals are to reduce measurement uncertainties, address data gaps, and improve existing analytical procedures for estimating human exposures. Partnerships have been develop...

  2. Challenging conventional risk assessment with respect to human exposure to multiple food contaminants in food: A case study using maize.

    Science.gov (United States)

    Clarke, R; Connolly, L; Frizzell, C; Elliott, C T

    2015-10-01

    Mycotoxins and heavy metals are ubiquitous in the environment and contaminate many foods. The widespread use of pesticides in crop production to control disease contributes further to the chemical contamination of foods. Thus multiple chemical contaminants threaten the safety of many food commodities; hence the present study used maize as a model crop to identify the severity in terms of human exposure when multiple contaminants are present. High Content Analysis (HCA) measuring multiple endpoints was used to determine cytotoxicity of complex mixtures of mycotoxins, heavy metals and pesticides. Endpoints included nuclear intensity (NI), nuclear area (NA), plasma membrane permeability (PMP), mitochondrial membrane potential (MMP) and mitochondrial mass (MM). At concentrations representing legal limits of each individual contaminant in maize (3ng/ml ochratoxin A (OTA), 1μg/ml fumonisin B1 (FB1), 2ng/ml aflatoxin B1 (AFB1), 100ng/ml cadmium (Cd), 150ng/ml arsenic (As), 50ng/ml chlorpyrifos (CP) and 5μg/ml pirimiphos methyl (PM), the mixtures (tertiary mycotoxins plus Cd/As) and (tertiary mycotoxins plus Cd/As/CP/PM) were cytotoxic for NA and MM endpoints with a difference of up to 13.6% (p≤0.0001) and 12% (p≤0.0001) respectively from control values. The most cytotoxic mixture was (tertiary mycotoxins plus Cd/As/CP/PM) across all 4 endpoints (NA, NI, MM and MMP) with increases up to 61.3%, 23.0%, 61.4% and 36.3% (p≤0.0001) respectively. Synergy was evident for two endpoints (NI and MM) at concentrations contaminating maize above legal limits, with differences between expected and measured values of (6.2-12.4% (p≤0.05-p≤0.001) and 4.5-12.3% (p≤0.05-p≤0.001) for NI and MM, respectively. The study introduces for the first time, a holistic approach to identify the impact in terms of toxicity to humans when multiple chemical contaminants are present in foodstuffs. Governmental regulatory bodies must begin to contemplate how to safeguard the population when

  3. Space Radiation and Human Exposures, A Primer.

    Science.gov (United States)

    Nelson, Gregory A

    2016-04-01

    The space radiation environment is a complex field comprised primarily of charged particles spanning energies over many orders of magnitude. The principal sources of these particles are galactic cosmic rays, the Sun and the trapped radiation belts around the earth. Superimposed on a steady influx of cosmic rays and a steady outward flux of low-energy solar wind are short-term ejections of higher energy particles from the Sun and an 11-year variation of solar luminosity that modulates cosmic ray intensity. Human health risks are estimated from models of the radiation environment for various mission scenarios, the shielding of associated vehicles and the human body itself. Transport models are used to propagate the ambient radiation fields through realistic shielding levels and materials to yield radiation field models inside spacecraft. Then, informed by radiobiological experiments and epidemiology studies, estimates are made for various outcome measures associated with impairments of biological processes, losses of function or mortality. Cancer-associated risks have been formulated in a probabilistic model while management of non-cancer risks are based on permissible exposure limits. This article focuses on the various components of the space radiation environment and the human exposures that it creates.

  4. Detailed diesel exhaust characteristics including particle surface area and lung deposited dose for better understanding of health effects in human chamber exposure studies

    Science.gov (United States)

    Wierzbicka, Aneta; Nilsson, Patrik T.; Rissler, Jenny; Sallsten, Gerd; Xu, Yiyi; Pagels, Joakim H.; Albin, Maria; Österberg, Kai; Strandberg, Bo; Eriksson, Axel; Bohgard, Mats; Bergemalm-Rynell, Kerstin; Gudmundsson, Anders

    2014-04-01

    Several diesel exhaust (DE) characteristics, comprising both particle and gas phase, recognized as important when linking with health effects, are not reported in human chamber exposure studies. In order to understand effects of DE on humans there is a need for better characterization of DE when performing exposure studies. The aim of this study was to determine and quantify detailed DE characteristics during human chamber exposure. Additionally to compare to reported DE properties in conducted human exposures. A wide battery of particle and gas phase measurement techniques have been used to provide detailed DE characteristics including the DE particles (DEP) surface area, fraction and dose deposited in the lungs, chemical composition of both particle and gas phase such as NO, NO2, CO, CO2, volatile organic compounds (including aldehydes, benzene, toluene) and polycyclic aromatic hydrocarbons (PAHs). Eyes, nose and throat irritation effects were determined. Exposure conditions with PM1 (<1 μm) mass concentration 280 μg m-3, number concentration 4 × 105 cm-3 and elemental to total carbon fraction of 82% were generated from a diesel vehicle at idling. When estimating the lung deposited dose it was found that using the size dependent effective density (in contrast to assuming unity density) reduced the estimated respiratory dose by 132% by mass. Accounting for agglomerated structure of DEP prevented underestimation of lung deposited dose by surface area by 37% in comparison to assuming spherical particles. Comparison of DE characteristics reported in conducted chamber exposures showed that DE properties vary to a great extent under the same DEP mass concentration and engine load. This highlights the need for detailed and standardized approach for measuring and reporting of DE properties. Eyes irritation effects, most probably caused by aldehydes in the gas phase, as well as nose irritation were observed at exposure levels below current occupational exposure limit

  5. Tracking the pathways of human exposure to perfluorocarboxylates.

    Science.gov (United States)

    Vestergren, Robin; Cousins, Ian T

    2009-08-01

    Recent analyses of perfluorooctanoate (PFOA) in human blood sera show that the background-exposed population in industrialized countries worldwide exhibits a narrow concentration range; arithmetic means of published studies range between 2 and 8 microg/L PFOA, with the exception of a few outlier studies. The globally comparable human serum concentrations of PFOA and characteristic dominance of PFOA with respect to other perfluorocarboxylate (PFCA) homologues indicate that exposure pathways of humans differ from those of wildlife, where perfluorononanoate (PFNA) is often the dominant homologue. The observed correlations between perfluorooctane sulfonate (PFOS) and PFOA in human serum together with a simultaneous downward time trend of these compounds in human blood sera and blood spots from the year 2000 onward indicate a connection between historical perfluorooctanesulfonyl (POSF) production (phased out by the major manufacturer in 2000-2002) and exposure to both PFOS and PFOA. A comparison of estimated daily intakes to humans based on samples from exposure media (collected post 2000) indicates that food intake is the major contemporary exposure pathway for the background population, whereas drinking water exposure is dominant for populations near sources of contaminated drinking water. A one-compartment pharmacokinetic model used to back-calculate daily intakes from serum levels is shown to provide agreement within a factor of 1.5-5.5 of the daily intakes derived from exposure media, which provides further supporting evidence that dietary exposure is a major ongoing exposure pathway of PFOA to the background population.

  6. Institutional review board challenges related to community-based participatory research on human exposure to environmental toxins: A case study

    Directory of Open Access Journals (Sweden)

    Rudel Ruthann A

    2010-07-01

    Full Text Available Abstract Background We report on the challenges of obtaining Institutional Review Board (IRB coverage for a community-based participatory research (CBPR environmental justice project, which involved reporting biomonitoring and household exposure results to participants, and included lay participation in research. Methods We draw on our experiences guiding a multi-partner CBPR project through university and state Institutional Review Board reviews, and other CBPR colleagues' written accounts and conference presentations and discussions. We also interviewed academics involved in CBPR to learn of their challenges with Institutional Review Boards. Results We found that Institutional Review Boards are generally unfamiliar with CBPR, reluctant to oversee community partners, and resistant to ongoing researcher-participant interaction. Institutional Review Boards sometimes unintentionally violate the very principles of beneficence and justice which they are supposed to uphold. For example, some Institutional Review Boards refuse to allow report-back of individual data to participants, which contradicts the CBPR principles that guide a growing number of projects. This causes significant delays and may divert research and dissemination efforts. Our extensive education of our university Institutional Review Board convinced them to provide human subjects protection coverage for two community-based organizations in our partnership. Conclusions IRBs and funders should develop clear, routine review guidelines that respect the unique qualities of CBPR, while researchers and community partners can educate IRB staff and board members about the objectives, ethical frameworks, and research methods of CBPR. These strategies can better protect research participants from the harm of unnecessary delays and exclusion from the research process, while facilitating the ethical communication of study results to participants and communities.

  7. Assessing exposure to phthalates - the human biomonitoring approach.

    Science.gov (United States)

    Wittassek, Matthias; Koch, Holger Martin; Angerer, Jürgen; Brüning, Thomas

    2011-01-01

    Some phthalates are developmental and reproductive toxicants in animals. Exposure to phthalates is considered to be potentially harmful to human health as well. Based on a comprehensive literature research, we present an overview of the sources of human phthalate exposure and results of exposure assessments with special focus on human biomonitoring data. Among the general population, there is widespread exposure to a number of phthalates. Foodstuff is the major source of phthalate exposure, particularly for the long-chain phthalates such as di(2-ethylhexyl) phthalate. For short-chain phthalates such as di-n-butyl-phthalate, additional pathways are of relevance. In general, children are exposed to higher phthalate doses than adults. Especially, high exposures can occur through some medications or medical devices. By comparing exposure data with existing limit values, one can also assess the risks associated with exposure to phthalates. Within the general population, some individuals exceed tolerable daily intake values for one or more phthalates. In high exposure groups, (intensive medical care, medications) tolerable daily intake transgressions can be substantial. Recent findings from animal studies suggest that a cumulative risk assessment for phthalates is warranted, and a cumulative exposure assessment to phthalates via human biomonitoring is a major step into this direction.

  8. Human Genotoxic Study Carried Out Two Years after Oil Exposure during the Clean-up Activities Using Two Different Biomarkers

    Directory of Open Access Journals (Sweden)

    Gloria Biern

    2015-11-01

    Full Text Available Micronuclei, comet and chromosome alterations assays are the most widely used biomarkers for determining the genotoxic damage in a population exposed to genotoxic chemicals. While chromosome alterations are an excellent biomarker to detect short- and long-term genotoxic effects, the comet assay only measures early biological effects, and furthermore it is unknown whether nuclear abnormalies, such as those measured in the micronucleus test, remain detectable long-term after an acute exposure. In our previous study, an increase in structural chromosome alterations in fishermen involved in the clean-up of the Prestige oil spill, two years after acute exposure, was detected. The aim of this study is to investigate whether, in lymphocytes from peripheral blood, the nuclear abnormalies (micronucleus, nucleoplasmic bridges and nuclear buds have a similar sensitivity to the chromosome damage analysis for genotoxic detection two years after oil exposure in the same non-smoker individuals and in the same peripheral blood extraction. No significant differences in nuclear abnormalies frequencies between exposed and non-exposed individuals were found (p > 0.05. However, chromosome damage, in the same individuals, was higher in exposed vs. non-exposed individuals, especially for chromosome lesions (p < 0.05. These findings, despite the small sample size, suggest that nuclear abnormalities are probably less-successful biomarkers than are chromosome alterations to evaluate genotoxic effects two or more years after an exposure to oil. Due to the great advantage of micronucleus automatic determination, which allows for a rapid study of hundreds of individuals exposed to genotoxic chemical exposure, further studies are needed to confirm whether this assay is or is not useful in long-term genotoxic studies after the toxic agent is no longer present.

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

    Science.gov (United States)

    Riddervold, I S; Bønløkke, J H; Mølhave, L; Massling, A; Jensen, B; Grønborg, T K; Bossi, R; Forchhammer, L; Kjærgaard, S K; Sigsgaard, T

    2011-04-01

    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 3 h 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. The range for PM₂.₅ load observed for single experiments was 165-303 µg/m³ for the low exposure and 205-662 µg/m³ for the high exposure, whereas particle loads during clean air exposure most often were below the detection limit (humans. The knowledge gained in this study on subjective-rated symptoms may be important for understanding human response to wood-smoke exposure.

  10. Modelling Human Exposure to Chemicals in Food

    NARCIS (Netherlands)

    Slob W

    1993-01-01

    Exposure to foodborne chemicals is often estimated using the average consumption pattern in the human population. To protect the human population instead of the average individual, however, interindividual variability in consumption behaviour must be taken into account. This report shows how food

  11. Comparative systems toxicology analysis of cigarette smoke and aerosol from a candidate modified risk tobacco product in organotypic human gingival epithelial cultures: A 3-day repeated exposure study.

    Science.gov (United States)

    Zanetti, Filippo; Titz, Bjoern; Sewer, Alain; Lo Sasso, Giuseppe; Scotti, Elena; Schlage, Walter K; Mathis, Carole; Leroy, Patrice; Majeed, Shoaib; Torres, Laura Ortega; Keppler, Brian R; Elamin, Ashraf; Trivedi, Keyur; Guedj, Emmanuel; Martin, Florian; Frentzel, Stefan; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

    2017-03-01

    Smoking is one of the major lifestyle-related risk factors for periodontal diseases. Modified risk tobacco products (MRTP) offer a promising alternative in the harm reduction strategy for adult smokers unable to quit. Using a systems toxicology approach, we investigated and compared the exposure effects of a reference cigarette (3R4F) and a heat-not-burn technology-based candidate MRTP, the Tobacco Heating System (THS) 2.2. Human gingival epithelial organotypic cultures were repeatedly exposed (3 days) for 28 min at two matching concentrations of cigarette smoke (CS) or THS2.2 aerosol. Results showed only minor histopathological alterations and minimal cytotoxicity upon THS2.2 aerosol exposure compared to CS (1% for THS2.2 aerosol vs. 30% for CS, at the high concentration). Among the 14 proinflammatory mediators analyzed, only 5 exhibited significant alterations with THS2.2 exposure compared with 11 upon CS exposure. Transcriptomic and metabolomic analysis indicated a general reduction of the impact in THS2.2 aerosol-exposed samples with respect to CS (∼79% lower biological impact for the high THS2.2 aerosol concentration compared to CS, and 13 metabolites significantly perturbed for THS2.2 vs. 181 for CS). This study indicates that exposure to THS2.2 aerosol had a lower impact on the pathophysiology of human gingival organotypic cultures than CS. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. 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.

  13. 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...

  14. 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.

  15. Polycyclic aromatic hydrocarbons in edible grain: a pilot study of agricultural crops as a human exposure pathway for environmental contaminants using wheat as a model crop.

    Science.gov (United States)

    Kobayashi, Reiko; Okamoto, Robert A; Maddalena, Randy L; Kado, Norman Y

    2008-06-01

    The concentrations of polycyclic aromatic hydrocarbons (PAHs) were investigated in a pilot study of field wheat grain as a model indicator for environmental contamination. The edible grain would serve as a portal for human exposure. Wheat grain was initially studied since it is one of the major food crops consumed internationally by many including infants and children. Wheat grain samples from five different geographical growing locations in California that span approximately 450 km were collected during the same growing season. The same variety of grain was harvested and analyzed for PAHs that ranged from 2- to 6-rings. PAHs were detected in all grain samples and were mainly 2- to 4-ring PAHs with naphthalene the most abundant among them. There were geographical differences in the levels of PAHs in the grain. The sources of the PAHs were not known in this pilot study, but the principal component analysis indicates that the major source is similar in all locations except for naphthalene. Grain naphthalene concentrations may reflect local naphthalene emissions. Diesel-fueled harvesting operations did not appear to contribute to the observed PAH concentrations in the grain. An estimate of naphthalene intake from eating grain compared to inhalation intake demonstrated the potential importance of field contamination of grain as a possible portal of human exposure. The relationship between PAH concentrations in grain and air should be quantitatively investigated to better quantitate exposure and to identify effective measures to lower the risk from PAH exposure through eating grain.

  16. 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

  17. A comparative study of human exposures to household air pollution from commonly used cookstoves in Sri Lanka.

    Science.gov (United States)

    Chartier, R; Phillips, M; Mosquin, P; Elledge, M; Bronstein, K; Nandasena, S; Thornburg, V; Thornburg, J; Rodes, C

    2017-01-01

    Solid fuel burning cookstoves are a major source of household air pollution (HAP) and a significant environmental health risk in Sri Lanka. We report results of the first field study in Sri Lanka to include direct measurements of both real-time indoor concentrations and personal exposures of fine particulate matter (PM2.5 ) in households using the two most common stove types in Sri Lanka. A purposive sample of 53 households was selected in the rural community of Kopiwatta in central Sri Lanka, roughly balanced for stove type (traditional or improved 'Anagi') and ventilation (chimney present or absent). At each household, 48-h continuous real-time measurements of indoor kitchen PM2.5 and personal (primary cook) PM2.5 concentrations were measured using the RTI MicroPEM(™) personal exposure monitor. Questionnaires were used to collect data related to household demographics, characteristics, and self-reported health symptoms. All primary cooks were female and of an average age of 47 years, with 66% having completed primary education. Median income was slightly over half the national median monthly income. Use of Anagi stoves was positively associated with a higher education level of the primary cook (P = 0.026), although not associated with household income (P = 0.18). The MicroPEM monitors were well-received by participants, and this study's valid data capture rate exceeded 97%. Participant wearing compliance during waking hours was on average 87.2% on Day 1 and 83.3% on Day 2. Periods of non-compliance occurred solely during non-cooking times. The measured median 48-h average indoor PM2.5 concentration for households with Anagi stoves was 64 μg/m(3) if a chimney was present and 181 μg/m(3) if not. For households using traditional stoves, these values were 70 μg/m(3) if a chimney was present and 371 μg/m(3) if not. Overall, measured indoor PM2.5 concentrations ranged from a minimum of 33 μg/m(3) to a maximum of 940 μg/m(3) , while personal exposure

  18. Parabens as Urinary Biomarkers of Exposure in Humans

    OpenAIRE

    Ye, Xiaoyun; Bishop, Amber M.; Reidy, John A; Needham, Larry L.; Calafat, Antonia M

    2006-01-01

    Background Parabens appear frequently as antimicrobial preservatives in cosmetic products, in pharmaceuticals, and in food and beverage processing. In vivo and in vitro studies have revealed weak estrogenic activity of some parabens. Widespread use has raised concerns about the potential human health risks associated with paraben exposure. Objectives Assessing human exposure to parabens usually involves measuring in urine the conjugated or free species of parabens or their metabolites. In ani...

  19. Comparative Plasma Exposure and Lung Distribution of Two Human Use Commercial Azithromycin Formulations Assessed in Murine Model: A Preclinical Study

    OpenAIRE

    Virginia Rivulgo; Mónica Sparo; Mónica Ceci; Elida Fumuso; Alejandra Confalonieri; Gastón Delpech; Sánchez Bruni, Sergio F.

    2013-01-01

    Azithromycin(AZM)therapeutic failure and relapses of patients treated with generic -35 formulations have been observed in clinical practice.The main goal of this research was 36 to compare in a pre-clinical study the serum exposure and lung tissue concentrationof 37 two commercial formulations AZM-based in murine model. The current study involved 38 264 healthy Balb-C.Mice were divided in two groups (n=44): Animals of Group A 39 (Reference Formulation ?R-) were orally treated with AZM suspens...

  20. Comparative Plasma Exposure and Lung Distribution of Two Human Use Commercial Azithromycin Formulations Assessed in Murine Model: A Preclinical Study

    OpenAIRE

    Virginia Rivulgo; Mónica Sparo; Mónica Ceci; Elida Fumuso; Alejandra Confalonieri; Gastón Delpech; Sánchez Bruni, Sergio F.

    2016-01-01

    Azithromycin(AZM)therapeutic failure and relapses of patients treated with generic -35 formulations have been observed in clinical practice.The main goal of this research was 36 to compare in a pre-clinical study the serum exposure and lung tissue concentrationof 37 two commercial formulations AZM-based in murine model. The current study involved 38 264 healthy Balb-C.Mice were divided in two groups (n=44): Animals of Group A 39 (Reference Formulation ?R-) were orally treated with AZM suspens...

  1. A FEASIBILITY STUDY EXAMINING THE POTENTIAL FOR HUMAN HEALTH EXPOSURE TO PET-BORNE DIAZINON RESIDUES FOLLOWING RESIDENTIAL TURF APPLICATIONS

    Science.gov (United States)

    The domestic dog may be a vehicle for translocation of pesticide residues following residential applications to turf. In addition, human occupants may be exposed to residues deposited inside homes by pets or by intimate contacts with them. This study examines the potential of a...

  2. Susceptibility of human populations to environmental exposure to organic contaminants.

    Science.gov (United States)

    Undeman, Emma; Brown, Trevor N; Wania, Frank; McLachlan, Michael S

    2010-08-15

    Environmental exposure to organic contaminants is a complex function of environmental conditions, food chain characteristics, and chemical properties. In this study the susceptibility of various human populations to environmental exposure to neutral organic contaminants was compared. An environmental fate model and a linked bioaccumulation model were parametrized to describe ecosystems in different climatic regions (temperate, arctic, tropical, and steppe). The human body burden resulting from constant emissions of hypothetical chemicals was estimated for each region. An exposure susceptibility index was defined as the body burden in the region of interest normalized to the burden of the same chemical in a reference human from the temperate region eating an average diet. For most persistent chemicals emitted to air, the Arctic had the highest susceptibility index (max 520). Susceptibility to exposure was largely determined by the food web properties. The properties of the physical environment only had a marked effect when air or water, not food, was the dominant source of human exposure. Shifting the mode of emission markedly changed the relative susceptibility of the ecosystems in some cases. The exposure arising from chemical use clearly varies between ecosystems, which makes an understanding of ecosystem susceptibility to exposure important for chemicals management.

  3. 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.

  4. Controlled human exposures to ambient pollutant particles in susceptible populations

    Directory of Open Access Journals (Sweden)

    Ghio Andrew J

    2009-07-01

    Full Text Available Abstract Epidemiologic studies have established an association between exposures to air pollution particles and human mortality and morbidity at concentrations of particles currently found in major metropolitan areas. The adverse effects of pollution particles are most prominent in susceptible subjects, including the elderly and patients with cardiopulmonary diseases. Controlled human exposure studies have been used to confirm the causal relationship between pollution particle exposure and adverse health effects. Earlier studies enrolled mostly young healthy subjects and have largely confirmed the capability of particles to cause adverse health effects shown in epidemiological studies. In the last few years, more studies involving susceptible populations have been published. These recent studies in susceptible populations, however, have shown that the adverse responses to particles appear diminished in these susceptible subjects compared to those in healthy subjects. The present paper reviewed and compared control human exposure studies to particles and sought to explain the "unexpected" response to particle exposure in these susceptible populations and make recommendations for future studies. We found that the causes for the discrepant results are likely multifactorial. Factors such as medications, the disease itself, genetic susceptibility, subject selection bias that is intrinsic to many controlled exposure studies and nonspecificity of study endpoints may explain part of the results. Future controlled exposure studies should select endpoints that are more closely related to the pathogenesis of the disease and reflect the severity of particle-induced health effects in the specific populations under investigation. Future studies should also attempt to control for medications and genetic susceptibility. Using a different study design, such as exposing subjects to filtered air and ambient levels of particles, and assessing the improvement in

  5. Design and implementation of an epidemiological study for the characterization of potential pathway human exposure in a contaminated estuary environment

    OpenAIRE

    Dias, Carlos Matias; Machado, Ausenda; Paixão, Eleonora; Mateus, Inês; Joaquin, Toro; Caeiro, Sandra

    2011-01-01

    Introduction Sado River estuary is located in the west coast of Portugal. Previous environmental studies identified industrial contamination, non-point anthropogenic sources and contamination coming from the river, all promoting accumulation of polluted sediments with known impacts on the ecological system. Surrounding human populations have intense economic fishery activities. Together with agriculture, estuary fishing products are available to local residents. Food usage previously chara...

  6. 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

  7. Human reproductive system disturbances and pesticide exposure in Brazil

    OpenAIRE

    Sergio Koifman; Rosalina Jorge Koifman; Armando Meyer

    2002-01-01

    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 ...

  8. Human lead (Pb) exposure via dust from different land use settings of Pakistan: A case study from two urban mountainous cities.

    Science.gov (United States)

    Eqani, Syed Ali Musstjab Akber Shah; Khalid, Ramsha; Bostan, Nazish; Saqib, Zafeer; Mohmand, Jawad; Rehan, Mohammad; Ali, Nadeem; Katsoyiannis, Ioannis A; Shen, Heqing

    2016-07-01

    The current study aims to determine the dust-borne lead (Pb) levels into outdoor dust, which were collected from the areas nearby the cities/districts of Islamabad and Swat in Pakistan. In general dust samples from all land use settings (industrial, urban and rural) showed significantly higher (patmospheric deposition from surrounding polluted areas. According to the calculated chemical daily intake (mg/kg-day) values, dust ingestion is one of the major routes of human exposure for lead. Hazard Index (HI) values, calculated for both adult and children populations, were above unity in industrial and urban areas, indicating serious health risks especially to the children populations.

  9. Human solvent exposure. Factors influencing the pharmacokinetics and acute toxicity

    DEFF Research Database (Denmark)

    Bælum, Jesper

    1991-01-01

    exposed to mixtures of solvents experience an increased frequency of work related irritative and neurological symptoms although the exposure has been far below the occupational exposure limits. A series of controlled human exposure studies was carried out. Different groups of persons were exposed...... to the most frequent solvent, toluene. Toluene in alveolar air and the urinary excretion of the metabolites were measured and the acute effects of toluene were assessed by the performance in a series of test of the perceptual and psychomotor functions as well as a standardized registration of annoyance...

  10. Assessment of human hair as an indicator of exposure to organophosphate flame retardants. Case study on a Norwegian mother-child cohort.

    Science.gov (United States)

    Kucharska, Agnieszka; Cequier, Enrique; Thomsen, Cathrine; Becher, Georg; Covaci, Adrian; Voorspoels, Stefan

    2015-10-01

    A major challenge of non-invasive human biomonitoring using hair is to assess whether it can be used as an indicator of exposure to Flame Retardants, such as Organophosphate Flame Retardants (PFRs), since the contribution of atmospheric deposition (air and/or dust) cannot be neglected. Therefore, the aim of this study was to evaluate the suitability of using human hair more thoroughly by comparison of (i) levels of PFRs in human hair (from 48 mothers and 54 children), with levels measured in dust and air in their respective households; and (ii) levels of selected PFRs in hair with the levels of corresponding PFR metabolites in matching urine samples collected simultaneously. Most PFRs (tri-n-butyl phosphate (TNBP), 2-ethyl-hexyldiphenyl phosphate (EHDPHP), tri-phenyl phosphate (TPHP), tri-iso-butyl phosphate (TIBP), and tris(2-butoxyethyl) phosphate (TBOEP)) were detected in all human hair samples, tris(2-ethylhexyl) phosphate (TEHP) and tris(1,3-dichloro-iso-propyl) phosphate (TDCIPP) in 93%, tri-cresyl-phosphate (TCP) in 69% and tris(2-chloroethyl) phosphate (TCEP) in 21% of the samples. Levels of individual PFRs ranged between dust from the participants' homes. Several statistically significant associations between PFR levels in human hair and PFR levels in house dust and/or air were found, e.g. Spearman correlation (rS = 0.561, p < 0.05) between TBOEP in children's hair and in indoor air. Also, associations were found between TDCIPP in hair and its metabolite bis(1,3-dichloro-iso-propyl) phosphate (BDCIPP) in urine; they were stronger for children (e.g. Pearson correlation rP = 0.475; p = 0.001) than for mothers (rP = 0.395, p = 0.01). Levels of diphenyl phosphate (DPHP) in mothers' and children's urine were slightly correlated (rS = 0.409, p = 0.008), suggesting similar sources of exposure. To the best of our knowledge, this is the first study with such design and our findings might help to understand human exposure to and body burdens of PFRs.

  11. Large organic aerosols in a human exposure chamber : Applications in occupational dermatology and lung medicine

    OpenAIRE

    Lundgren, Lennart

    2006-01-01

    Exposure to large organic aerosol particles may cause respiratory and skin reactions. The use of human exposure chambers offers possibilities for experimental exposure challenges carried out with patients, in research and for investigations of the effects of exposure on the skin and in the respiratory tract. The present aim was to study the performance of modern human whole-body exposure chambers during generation of large organic particles, and to develop and test new me...

  12. 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.

  13. Human exposure to organic arsenic species from seafood.

    Science.gov (United States)

    Taylor, Vivien; Goodale, Britton; Raab, Andrea; Schwerdtle, Tanja; Reimer, Ken; Conklin, Sean; Karagas, Margaret R; Francesconi, Kevin A

    2017-02-15

    Seafood, including finfish, shellfish, and seaweed, is the largest contributor to arsenic (As) exposure in many human populations. In contrast to the predominance of inorganic As in water and many terrestrial foods, As in marine-derived foods is present primarily in the form of organic compounds. To date, human exposure and toxicological assessments have focused on inorganic As, while organic As has generally been considered to be non-toxic. However, the high concentrations of organic As in seafood, as well as the often complex As speciation, can lead to complications in assessing As exposure from diet. In this report, we evaluate the presence and distribution of organic As species in seafood, and combined with consumption data, address the current capabilities and needs for determining human exposure to these compounds. The analytical approaches and shortcomings for assessing these compounds are reviewed, with a focus on the best practices for characterization and quantitation. Metabolic pathways and toxicology of two important classes of organic arsenicals, arsenolipids and arsenosugars, are examined, as well as individual variability in absorption of these compounds. Although determining health outcomes or assessing a need for regulatory policies for organic As exposure is premature, the extensive consumption of seafood globally, along with the preliminary toxicological profiles of these compounds and their confounding effect on assessing exposure to inorganic As, suggests further investigations and process-level studies on organic As are needed to fill the current gaps in knowledge.

  14. A comparative study of leukaemia inhibitory factor and interleukin-1alpha intracellular content in a human keratinocyte cell line after exposure to cosmetic fragrances and sodium dodecyl sulphate.

    Science.gov (United States)

    Parodi, Alessandro; Sanguineti, Roberta; Catalano, Mariafrancesca; Penco, Susanna; Pronzato, Maria Adelaide; Scanarotti, Chiara; Bassi, Anna Maria

    2010-02-01

    According to European laws animal testing in cosmetic industry will be prohibited in a few years and it will be replaced by alternative methods based on cell and tissue culture. Many ingredients of cosmetic formulations are potentially causes of skin inflammation and sensibilization. Since cytotoxicity is known, among other factors, to trigger irritation, in an alternative model for evaluation of skin irritation, it can be considered also the precocious release of inflammatory mediators, i.e. cytokines, originating mainly from keratinocytes. In this in vitro study we have analysed some parameters directly or indirectly related to irritation/inflammation, in NCTC 2544 human keratinocytes during short-time exposure to some potential irritants cosmetic fragrances, included in the European Laws 2003/15/EEC. IIC50 was extrapolated by MTT and NRU viability indexes after exposure of cell ultures to Geraniol Limonene and Benzylic Alcohol for 1, 3 and 6h. NCTC cells were then exposed to sub-toxic doses of selected compounds and interleukin-1alpha (IL-1alpha) and leukaemia inhibitory factor (LIF) expressions were analysed as early proinflammatory cytokines. To our knowledge our findings demonstrated for the first time that NCTC cells synthesize and modulate LIF after exposure to selected irritating stimuli. Moreover, our results give evidence on LIF role as in vitro precocious endpoint for the assessment of the risk in cosmetic field, because its response under irritation stimuli is very quick and comparable to IL-1alpha. 2009 Elsevier Ireland Ltd. All rights reserved.

  15. How Questionnaires and Multimedia Measurements collected in the U.S. EPA’s Observational Human Exposure Measurement Studies Inform Exposures

    Science.gov (United States)

    In the last decade, the U.S. EPA has conducted and/or funded numerous observational humanexposure measurement studies where questionnaires were administered to the study participants in addition tothe collection of multimedia measurements. Questionnaire responses provide ancillar...

  16. How Questionnaires and Multimedia Measurements collected in the U.S. EPA’s Observational Human Exposure Measurement Studies Inform Exposures

    Science.gov (United States)

    In the last decade, the U.S. EPA has conducted and/or funded numerous observational humanexposure measurement studies where questionnaires were administered to the study participants in addition tothe collection of multimedia measurements. Questionnaire responses provide ancillar...

  17. [Human exposure to trihalomethanes in drinking water].

    Science.gov (United States)

    Tominaga, M Y; Midio, A F

    1999-08-01

    Halogenated hydrocarbon compounds, some of them recognized as carcinogenic to different animal species can be found in drinking water. Chloroform, bromodichloromethane, dibromochloromethane and bromoform are the most important trihalomethanes found in potable water. They are produced in natural waters during chlorinated desinfection by the halogenation of precursors, specially humic and fulvic compounds. The review, in the MEDLINE covers the period from 1974 to 1998, presents the general aspects of the formation of trihalomethanes, sources of human exposure and their toxicological meaning for exposed organisms: toxicokinetic disposition and spectrum of toxic effects (carcinogenic, mutagenic and teratogenic).

  18. 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.

  19. Assessment of human exposure effects of nitrous acid

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, T.R.; Kjaergaard, S.K. (University of Aarhus. Institute of Environmental and Occupational Medicine (Denmark)); Brauer, M. (Harvard School of Public Health. Department of Environmental Health, Exposure Assessment and Engineering Program (United States))

    1993-01-01

    The study aimed at an estimation of the relative contribution of nitrous acid to measurable human exposure effects in relation to indoor environments with unvented gas combustion. Fifteen medically examined totally healthy non-smoker adults aged between 22 and 57 years were exposed in a double-blind, balanced design (3x3 latin square) to clean air and nitrous acid (HONO) concentration in an empty 74 m[sup 3] climate chamber. 3 teams of 5 subjects each were randomly exposed and the latin square was selected at random. Each exposure period was 3.5 hours and preceded by a 1 hour base-line pre-exposure measurement period. After 1 hr 40 minutes the subjects exercised for ten minutes on bicycle ergometers in order to increase the uptake of HONO by increasing ventilatory rate 3-4 fold. Workloads were calculated individually and ranged from 21800-34600 kpm/h. During the 10 minutes the test subjects were mouth-breathing to encourage deeper penetration of nitrous acid in the respiratory system so as to induce a mild cooling which would increase their responsiveness to irritants. The amount of deliverable H[sup +] was estimated at 16.350 nmoles with exposure to 395 ppb HONO with subjects breathing at the rate of 5 L min[sup -1]. It was assumed that HONO is efficiently absorbed into the respiratory system. Details are given of the results. Findings were highly variable, largely negative effects of exposure to nitrous acid which appear similiar to results seen in nitrogen dioxide exposure studies. It is concluded to be unlikely that HONO exposures alone can be responsible for exposure misclassification in NO[sub 2] exposure studies. (AB) (52 refs.).

  20. Assessment of human exposure effects of nitrous acid

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, T.R.; Kjaergaard, S.K. [University of Aarhus. Institute of Environmental and Occupational Medicine (Denmark); Brauer, M. [Harvard School of Public Health. Department of Environmental Health, Exposure Assessment and Engineering Program (United States)

    1993-01-01

    The study aimed at an estimation of the relative contribution of nitrous acid to measurable human exposure effects in relation to indoor environments with unvented gas combustion. Fifteen medically examined totally healthy non-smoker adults aged between 22 and 57 years were exposed in a double-blind, balanced design (3x3 latin square) to clean air and nitrous acid (HONO) concentration in an empty 74 m{sup 3} climate chamber. 3 teams of 5 subjects each were randomly exposed and the latin square was selected at random. Each exposure period was 3.5 hours and preceded by a 1 hour base-line pre-exposure measurement period. After 1 hr 40 minutes the subjects exercised for ten minutes on bicycle ergometers in order to increase the uptake of HONO by increasing ventilatory rate 3-4 fold. Workloads were calculated individually and ranged from 21800-34600 kpm/h. During the 10 minutes the test subjects were mouth-breathing to encourage deeper penetration of nitrous acid in the respiratory system so as to induce a mild cooling which would increase their responsiveness to irritants. The amount of deliverable H{sup +} was estimated at 16.350 nmoles with exposure to 395 ppb HONO with subjects breathing at the rate of 5 L min{sup -1}. It was assumed that HONO is efficiently absorbed into the respiratory system. Details are given of the results. Findings were highly variable, largely negative effects of exposure to nitrous acid which appear similiar to results seen in nitrogen dioxide exposure studies. It is concluded to be unlikely that HONO exposures alone can be responsible for exposure misclassification in NO{sub 2} exposure studies. (AB) (52 refs.).

  1. Effectiveness of a New Lead-Shielding Device and Additional Filter for Reducing Staff and Patient Radiation Exposure During Videofluoroscopic Swallowing Study Using a Human Phantom.

    Science.gov (United States)

    Morishima, Yoshiaki; Chida, Koichi; Muroya, Yoshikazu; Utsumi, Yoshiya

    2017-09-18

    Interventional radiology procedures often involve lengthy exposure to fluoroscopy-derived radiation. We therefore devised a videofluoroscopic swallowing study (VFSS) procedure using a human phantom that proved to protect the patient and physician by reducing the radiation dose. We evaluated a new lead-shielding device and separately attached additional filters (1.0-, 2.0-, and 3.0-mm Al filters and a 0.5-mm Cu filter) during VFSS to reduce the patient's entrance skin dose (ESD). A monitor attached to the human phantom's neck measured the ESD. We also developed another lead shield (VFSS Shielding Box, 1.0-mm Pb equivalent) and tested its efficacy using the human phantom and an ionization chamber radiation survey meter with and without protection from scattered radiation at the physician's position on the phantom. We then measured the scattered radiation (at 90 and 150 cm above the floor) after combining the filters with the VFSS Shielding Box. With the additional filters, the ESD was reduced by 15.4-55.1%. With the VFSS Shielding Box alone, the scattered radiation was reduced by about 10% compared with the dose without additional shielding. With the VFSS Shielding Box and filters combined, the scattered radiation dose was reduced by a maximum of about 44% at the physician's position. Thus, the additional lead-shielding device effectively provided protection from scattered radiation during fluoroscopy. These results indicate that the combined VFSS Shielding Box and filters can effectively reduce the physician's and patient's radiation doses.

  2. Chronic boron exposure and human semen parameters.

    Science.gov (United States)

    Robbins, Wendie A; Xun, Lin; Jia, Juan; Kennedy, Nola; Elashoff, David A; Ping, Liu

    2010-04-01

    Boron found as borates in soil, food, and water has important industrial and medical applications. A panel reviewing NTP reproductive toxicants identified boric acid as high priority for occupational studies to determine safe versus adverse reproductive effects. To address this, we collected boron exposure/dose measures in workplace inhalable dust, dietary food/fluids, blood, semen, and urine from boron workers and two comparison worker groups (n=192) over three months and determined correlations between boron and semen parameters (total sperm count, sperm concentration, motility, morphology, DNA breakage, apoptosis and aneuploidy). Blood boron averaged 499.2 ppb for boron workers, 96.1 and 47.9 ppb for workers from high and low environmental boron areas (pBoron concentrated in seminal fluid. No significant correlations were found between blood or urine boron and adverse semen parameters. Exposures did not reach those causing adverse effects published in animal toxicology work but exceeded those previously published for boron occupational groups.

  3. Identifying Housing and Meteorological Conditions Influencing Residential Air Exchange Rates in the DEARS and RIOPA Studies: Development of Distributions for Human Exposure Modeling

    Science.gov (United States)

    Appropriate prediction of residential air exchange rate (AER) is important for estimating human exposures in the residential microenvironment, as AER drives the infiltration of outdoor-generated air pollutants indoors. AER differences among homes may result from a number of fact...

  4. Asbestos exposure increases human bronchial epithelial cell fibrinolytic activity.

    Science.gov (United States)

    Gross, T J; Cobb, S M; Gruenert, D C; Peterson, M W

    1993-03-01

    Chronic exposure to asbestos fibers results in fibrotic lung disease. The distal pulmonary epithelium is an early target of asbestos-mediated injury. Local plasmin activity may be important in modulating endoluminal inflammatory responses in the lung. We studied the effects of asbestos exposure on cell-mediated plasma clot lysis as a marker of pericellular plasminogen activation. Exposing human bronchial epithelial (HBE) cells to 100 micrograms/ml of asbestos fibers for 24 h resulted in increased plasma clot lysis. Fibrinolytic activity was augmented in a dose-dependent fashion, was not due to secreted protease, and occurred only when there was direct contact between the plasma clot and the epithelial monolayer. Further analysis showed that asbestos exposure increased HBE cell-associated urokinase-type plasminogen activator (uPA) activity in a time-dependent manner. The increased cell-associated PA activity could be removed by acid washing. The increase in PA activity following asbestos exposure required new protein synthesis because it was abrogated by treatment with either cycloheximide or actinomycin D. Therefore, asbestos exposure increases epithelial-mediated fibrinolysis by augmenting expression of uPA activity at the cell surface by mechanisms that require new RNA and protein synthesis. These observations suggest a novel mechanism whereby exposure of the distal epithelium to inhaled particulates may result in a chronic inflammatory response that culminates in the development of fibrotic lung disease.

  5. Linearity of dose-response relationships for human carcinogenic exposures

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.H. (Univ. of California, Berkeley (USA))

    The shape of dose-response relationships is a critical factor in considering cancer risks for the work place and environmental exposure to carcinogens. Markedly different risk estimates result from assumptions of linearity versus sublinear and threshold assumptions. This paper presents evidence that the relationship between the relative risk of development of cancer and the dose rate to carcinogenic exposures is frequently linear with no evidence for thresholds. Dose-response relationships from four studies of asbestos and lung cancer were examined, all of which were consistent with a linear relationship. Analysis of the relationship between the relative risk of lung cancer and exposure to nickel in a smelter study, selected because of relatively good exposure data, demonstrated a close agreement with a linear relationship. The relationship between the level of arsenic in drinking wter and the prevalence of skin cancer also was linear for males in the highest prevalence age group in Taiwan, although there was some evidence of sublinearity for females and younger persons. Also, the relationships between the number of cigarettes smoked per day and the relative risk of lung cancer was very close to linear in many studies. The analysis of these and other studies involving human exposure to carcinogens provides empirical evidence for linearity when the response variable is a rate ratio measure, rather than a risk difference measure. Linearity in dose-response is biologically plausible, without invoking a one-hit model. Except in special circumstances. the epidemiological evidence supports linear extrapolation of cancer relative risks.

  6. Silver percutaneous absorption after exposure to silver nanoparticles: a comparison study of three human skin graft samples used for clinical applications.

    Science.gov (United States)

    Bianco, C; Adami, G; Crosera, M; Larese, F; Casarin, S; Castagnoli, C; Stella, M; Maina, G

    2014-11-01

    Silver nanoparticles (AgNPs) are increasingly applied to a wide range of materials for biomedical use. These enable a close contact with human skin, thanks to the large release of silver ions that is responsible for a broad spectrum of antimicrobial activity. Silver can permeate the skin; however, there are no data available on silver permeation through skin grafts commonly used in burns recovery. The aim of our study was to evaluate silver penetration using fresh, cryopreserved, and glycerolized human skin grafts after exposure to a suspension of AgNPs in synthetic sweat using a Franz diffusion cell apparatus for 24 h. Silver permeation profiles revealed a significantly higher permeation through glycerolized skin compared with both fresh and cryopreserved skin: 24-h silver flux penetration was 0.2 ng cm(-2) h(-1) (lag time: 8.2 h) for fresh skin, 0.3 ng cm(-2) h(-1) (lag time: 10.9 h) for cryopreserved skin, and 3.8 ng cm(-2) h(-1) (lag time: 6.3 h) for glycerolized skin. Permeation through glycerolized skin is significantly higher compared to both fresh and cryopreserved skin. This result can generate relevant clinical implications for burns treatment with products containing AgNPs.

  7. Parabens as Urinary Biomarkers of Exposure in Humans

    Science.gov (United States)

    Ye, Xiaoyun; Bishop, Amber M.; Reidy, John A.; Needham, Larry L.; Calafat, Antonia M.

    2006-01-01

    Background Parabens appear frequently as antimicrobial preservatives in cosmetic products, in pharmaceuticals, and in food and beverage processing. In vivo and in vitro studies have revealed weak estrogenic activity of some parabens. Widespread use has raised concerns about the potential human health risks associated with paraben exposure. Objectives Assessing human exposure to parabens usually involves measuring in urine the conjugated or free species of parabens or their metabolites. In animals, parabens are mostly hydrolyzed to p-hydroxybenzoic acid and excreted in the urine as conjugates. Still, monitoring urinary concentrations of p-hydroxybenzoic acid is not necessarily the best way to assess exposure to parabens. p-Hydroxybenzoic acid is a nonspecific biomarker, and the varying estrogenic bioactivities of parabens require specific biomarkers. Therefore, we evaluated the use of free and conjugated parent parabens as new biomarkers for human exposure to these compounds. Results We measured the urinary concentrations of methyl, ethyl, n-propyl, butyl (n- and iso-), and benzyl parabens in a demographically diverse group of 100 anonymous adults. We detected methyl and n-propyl parabens at the highest median concentrations (43.9 ng/mL and 9.05 ng/mL, respectively) in nearly all (> 96%) of the samples. We also detected other parabens in more than half of the samples (ethyl, 58%; butyl, 69%). Most important, however, we found that parabens in urine appear predominantly in their conjugated forms. Conclusions The results, demonstrating the presence of urinary conjugates of parabens in humans, suggest that such conjugated parabens could be used as exposure biomarkers. Additionally, the fact that conjugates appear to be the main urinary products of parabens may be important for risk assessment. PMID:17185273

  8. Sun exposure and vitamin D supplementation in relation to vitamin D status of breastfeeding mothers and infants in the global exploration of human milk study.

    Science.gov (United States)

    Dawodu, Adekunle; Davidson, Barbara; Woo, Jessica G; Peng, Yong-Mei; Ruiz-Palacios, Guillermo M; de Lourdes Guerrero, Maria; Morrow, Ardythe L

    2015-02-05

    Although vitamin D (vD) deficiency is common in breastfed infants and their mothers during pregnancy and lactation, a standardized global comparison is lacking. We studied the prevalence and risk factors for vD deficiency using a standardized protocol in a cohort of breastfeeding mother-infant pairs, enrolled in the Global Exploration of Human Milk Study, designed to examine longitudinally the effect of environment, diet and culture. Mothers planned to provide breast milk for at least three months post-partum and were enrolled at four weeks postpartum in Shanghai, China (n=112), Cincinnati, Ohio (n=119), and Mexico City, Mexico (n=113). Maternal serum 25(OH)D was measured by radioimmunoassay (Mexico City) seen at 26 weeks of age during fall and winter seasons. Data collected prospectively included vD supplementation, season and sun index (sun exposure×body surface area exposed while outdoors). Differences and factors associated with vD deficiency were evaluated using appropriate statistical analysis. vD deficiency in order of magnitude was identified in 62%, 52% and 17% of Mexican, Shanghai and Cincinnati mothers, respectively (pseason (p=0.001) and sites (pSeason (p=0.022), adding formula feeding (p<0.001) and a higher sun index (p=0.085) predicted higher infant vD status. vD deficiency appears to be a global problem in mothers and infants, though the prevalence in diverse populations may depend upon sun exposure behaviors and vD supplementation. Greater attention to maternal and infant vD status starting during pregnancy is warranted worldwide.

  9. Chromosomal aberrations in lymphocytes predict human cancer independently of exposure to carcinogens. European Study Group on Cytogenetic Biomarkers and Health

    DEFF Research Database (Denmark)

    Bonassi, S; Hagmar, L; Strömberg, U

    2000-01-01

    An increased risk of cancer in healthy individuals with high levels of chromosomal aberrations (CAs) in peripheral blood lymphocytes has been described in recent epidemiological studies. This association did not appear to be modified by sex, age, country, or time since CA test, whereas the role p...

  10. 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.

  11. 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 gu

  12. 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 Di

  13. Human exposure to a 60 Hz, 1800 micro tesla magnetic field: a neuro behavioral study; Exposition humaine a un champ magnetique de 1 800 microtesla a 60 Hz: une etude neurocomportementale

    Energy Technology Data Exchange (ETDEWEB)

    Legros, A.; Corbacio, M.; Prato, F.S.; Thomas, A.W. [Lawson Health Research Institute and University of Western Ontario, St Joseph Health' s Care (Canada); Beuter, A. [Laboratoire IMS Institut de Polytechnique de Bordeaux, Universite de Bordeaux, 33 (France); Goulet, D. [Hydro-Quebec TransEnergie, Montreal (Canada); Lambrozo, J.; Souques, M. [Electricite de France, Service des Etudes Medicales, 75 - Paris (France); Plante, M. [Hydro-Quebec, Direction Sante et securite, Montreal (Canada)

    2010-05-15

    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 muT 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 muT MF exposure may modulate human involuntary motor control without being detected in the electrical activity of the brain. (authors)

  14. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

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

    1996-01-01

    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......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...... 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...

  15. [Advances on research of human exposure to triclosan].

    Science.gov (United States)

    Jin, Chenye; Chen, Yiming; Zhang, Peiqi; Xiong, Zhezhen; Wang, Caifeng; Tian, Ying

    2016-03-01

    Triclosan, a broad-spectrum antimicrobial agent, was reported to have been widely detected in various human biological samples such as urine, blood and human milk among foreign populations. In China, limited reports have been found on human exposure to triclosan, and the reported urinary triclosan concentrations were significantly lower than that of American populations. Besides, the potential influencing factors still remain unclear regarding human exposure to triclosan, but evidences suggest that those in middle age and with higher household income and higher social class tend to have higher urinary triclosan concentrations. Furthermore, triclosan exposure tend to differ by sex, geography, heredity, metabolism and life style.

  16. Human Exposure Risk Assessment Due to Heavy Metals in Groundwater by Pollution Index and Multivariate Statistical Methods: A Case Study from South Africa

    Directory of Open Access Journals (Sweden)

    Vetrimurugan Elumalai

    2017-04-01

    Full Text Available Heavy metals in surface and groundwater were analysed and their sources were identified using multivariate statistical tools for two towns in South Africa. Human exposure risk through the drinking water pathway was also assessed. Electrical conductivity values showed that groundwater is desirable to permissible for drinking except for six locations. Concentration of aluminium, lead and nickel were above the permissible limit for drinking at all locations. Boron, cadmium, iron and manganese exceeded the limit at few locations. Heavy metal pollution index based on ten heavy metals indicated that 85% of the area had good quality water, but 15% was unsuitable. Human exposure dose through the drinking water pathway indicated no risk due to boron, nickel and zinc, moderate risk due to cadmium and lithium and high risk due to silver, copper, manganese and lead. Hazard quotients were high in all sampling locations for humans of all age groups, indicating that groundwater is unsuitable for drinking purposes. Highly polluted areas were located near the coast, close to industrial operations and at a landfill site representing human-induced pollution. Factor analysis identified the four major pollution sources as: (1 industries; (2 mining and related activities; (3 mixed sources- geogenic and anthropogenic and (4 fertilizer application.

  17. Y-12 Uranium Exposure Study

    Energy Technology Data Exchange (ETDEWEB)

    Eckerman, K.F.; Kerr, G.D.

    1999-08-05

    Following the recent restart of operations at the Y-12 Plant, the Radiological Control Organization (RCO) observed that the enriched uranium exposures appeared to involve insoluble rather than soluble uranium that presumably characterized most earlier Y-12 operations. These observations necessitated changes in the bioassay program, particularly the need for routine fecal sampling. In addition, it was not reasonable to interpret the bioassay data using metabolic parameter values established during earlier Y-12 operations. Thus, the recent urinary and fecal bioassay data were interpreted using the default guidance in Publication 54 of the International Commission on Radiological Protection (ICRP); that is, inhalation of Class Y uranium with an activity median aerodynamic diameter (AMAD) of 1 {micro}m. Faced with apparently new workplace conditions, these actions were appropriate and ensured a cautionary approach to worker protection. As additional bioassay data were accumulated, it became apparent that the data were not consistent with Publication 54. Therefore, this study was undertaken to examine the situation.

  18. Sun Exposure and Vitamin D Supplementation in Relation to Vitamin D Status of Breastfeeding Mothers and Infants in the Global Exploration of Human Milk Study

    Directory of Open Access Journals (Sweden)

    Adekunle Dawodu

    2015-02-01

    Full Text Available Although vitamin D (vD deficiency is common in breastfed infants and their mothers during pregnancy and lactation, a standardized global comparison is lacking. We studied the prevalence and risk factors for vD deficiency using a standardized protocol in a cohort of breastfeeding mother-infant pairs, enrolled in the Global Exploration of Human Milk Study, designed to examine longitudinally the effect of environment, diet and culture. Mothers planned to provide breast milk for at least three months post-partum and were enrolled at four weeks postpartum in Shanghai, China (n = 112, Cincinnati, Ohio (n = 119, and Mexico City, Mexico (n = 113. Maternal serum 25(OHD was measured by radioimmunoassay (<50 nmol/L was categorized as deficient. Serum 25(OHD was measured in a subset of infants (35 Shanghai, 47 Cincinnati and 45 Mexico City seen at 26 weeks of age during fall and winter seasons. Data collected prospectively included vD supplementation, season and sun index (sun exposure × body surface area exposed while outdoors. Differences and factors associated with vD deficiency were evaluated using appropriate statistical analysis. vD deficiency in order of magnitude was identified in 62%, 52% and 17% of Mexican, Shanghai and Cincinnati mothers, respectively (p < 0.001. In regression analysis, vD supplementation (p < 0.01, obesity (p = 0.03, season (p = 0.001 and sites (p < 0.001 predicted maternal vD status. vD deficiency in order of  magnitude was found in 62%, 28%, and 6% of Mexican, Cincinnati and Shanghai infants, respectively (p < 0.001. Season (p = 0.022, adding formula feeding (p < 0.001 and a higher sun index (p = 0.085 predicted higher infant vD status. vD deficiency appears to be a global problem in mothers and infants, though the prevalence in diverse populations may depend upon sun exposure behaviors and vD supplementation. Greater attention to maternal and infant vD status starting during pregnancy is warranted worldwide.

  19. Arsenic exposure through drinking water leads to senescence and alteration of telomere length in humans: A case-control study in West Bengal, India.

    Science.gov (United States)

    Chatterjee, Debmita; Bhattacharjee, Pritha; Sau, Tanmoy J; Das, Jayanta K; Sarma, Nilendu; Bandyopadhyay, Apurba K; Roy, Sib Sankar; Giri, Ashok K

    2015-09-01

    Arsenic (As) induces pre-malignant and malignant dermatological lesions, non-dermatological health effects and cancers in humans. Senescence involves telomere length changes and acquisition of senescence-associated secretory phenotype (SASP), which promotes carcinogenesis. Though in vitro studies have shown that As induces senescence, population based studies are lacking. We investigated the arsenic-induced senescence, telomere length alteration and its contribution towards development of As-induced skin cancer. The study participants included 60 each of As-exposed individuals with skin lesion (WSL), without skin lesions (WOSL) and 60 unexposed controls. Exposure assessment of drinking water and urine was done. SA β-gal activity, ELISA, and quantification of senescence proteins, alternative lengthening of telomere (ALT) associated proteins and telomerase activity were performed. Relative telomere length (RTL) was determined by qPCR. A significantly higher number of senescent cells, over-expression of p53 and p21 were observed in the As-exposed individuals when compared to unexposed. SASP markers, MMP-1/MMP-3 were significantly higher in the WSL but not IL-6/IL-8. A significant increase of RTL was observed in the WSL group, which was telomerase-independent but exhibited an over-expression of ALT associated proteins TRF-1 and TRF-2 with higher increase in TRF-2. An increased risk for developing As-induced skin lesions was found for individuals having RTL greater than 0.827 (odds ratio, 13.75; 95% CI: 5.66-33.41; P telomere length might be useful for predicting the risk of development of As-induced skin lesions.

  20. Respiratory effects of particulate matter air pollution: studies on diesel exhaust, road tunnel, subway and wood smoke exposure in human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Sehlstedt, Maria

    2011-07-01

    Background: Ambient air pollution is associated with adverse health effects, but the sources and components, which cause these effects is still incompletely understood. The aim of this thesis was to investigate the pulmonary effects of a variety of common air pollutants, including diesel exhaust, biomass smoke, and road tunnel and subway station environments. Healthy non-smoking volunteers were exposed in random order to the specific air pollutants and air/control, during intermittent exercise, followed by bronchoscopy. Methods and results: In study I, exposures were performed with diesel exhaust (DE) generated at transient engine load and air for 1 hour with bronchoscopy at 6 hours post-exposure. Immunohistochemical analyses of bronchial mucosal biopsies showed that DE exposure significantly increased the endothelial adhesion molecule expression of p-selectin and VCAM-1, together with increased bronchoalveolar lavage (BAL) eosinophils. In study II, the subjects were exposed for 1 hour to DE generated during idling with bronchoscopy at 6 hours. The bronchial mucosal biopsies showed significant increases in neutrophils, mast cells and lymphocytes together with bronchial wash neutrophils. Additionally, DE exposure significantly increased the nuclear translocation of the aryl hydrocarbon receptor (AhR) and phosphorylated c-jun in the bronchial epithelium. In contrast, the phase II enzyme NAD(P)H-quinone oxidoreductase 1 (NQO1) decreased after DE. In study III, the 2-hour exposures took place in a road tunnel with bronchoscopy 14 hours later. The road tunnel exposure significantly increased the total numbers of lymphocytes and alveolar macrophages in BAL, whereas NK cell and CD56+/T cell numbers significantly decreased. Additionally, the nuclear expression of phosphorylated c-jun in the bronchial epithelium was significantly increased after road tunnel exposure. In study IV, the subjects were exposed to metal-rich particulate aerosol for 2 hours at a subway station

  1. Human performance analysis of industrial radiography radiation exposure events

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-01

    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.

  2. Autopsy tissues as biological monitors of human exposure to environmental pollutants. A case study: Concentrations of metals and PCDD/Fs in subjects living near a hazardous waste incinerator.

    Science.gov (United States)

    Domingo, José L; García, Francisco; Nadal, Martí; Schuhmacher, Marta

    2017-04-01

    Human biomonitoring is of tremendous importance to prevent potential adverse effects derived from human exposure to chemicals. Blood and urine are among the biological monitors more frequently used. However, biological matrices such as breast milk, hair, nails, saliva, feces, teeth, and expired air are also often used. In addition, and focused mainly on long-term exposure, adipose tissue and other human tissues like bone, liver, brain or kidney, are also used as biological monitors of certain substances, especially for long-term biomonitoring. However, for this kind of tissues sampling is always a limiting factor. In this paper, we have examined the role of autopsy tissues as biological monitors of human exposure to environmental pollutants. For it, we have used a case study conducted near a hazardous waste incinerator (HWI) in Catalonia (Spain), in which the concentrations of metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), have been periodically determined in autopsy tissues of subjects living in the area under potential influence of the facility. This case study does not show advantages -in comparison to other appropriate biomonitors such as blood- in using autopsy tissues in the monitoring of long-term exposure to metals and PCDD/Fs. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Arsenic exposure and calpain-10 polymorphisms impair the function of pancreatic beta-cells in humans: a pilot study of risk factors for T2DM.

    Directory of Open Access Journals (Sweden)

    Andrea Díaz-Villaseñor

    Full Text Available The incidence of type 2 diabetes mellitus (T2DM is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs in the calpain-10 gene (CAPN-10, which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2 in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function.

  4. Arsenic Exposure and Calpain-10 Polymorphisms Impair the Function of Pancreatic Beta-Cells in Humans: A Pilot Study of Risk Factors for T2DM

    Science.gov (United States)

    Díaz-Villaseñor, Andrea; Cruz, Laura; Cebrián, Arturo; Hernández-Ramírez, Raúl U.; Hiriart, Marcia; García-Vargas, Gonzálo; Bassol, Susana; Sordo, Monserrat; Gandolfi, A. Jay; Klimecki, Walter T.; López-Carillo, Lizbeth; Cebrián, Mariano E.; Ostrosky-Wegman, Patricia

    2013-01-01

    The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs) in the calpain-10 gene (CAPN-10), which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs) through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function) and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2) in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function. PMID:23349674

  5. Protective effect of Aronia melanocarpa polyphenols against cadmium-induced disorders in bone metabolism: a study in a rat model of lifetime human exposure to this heavy metal.

    Science.gov (United States)

    Brzóska, Malgorzata M; Rogalska, Joanna; Galazyn-Sidorczuk, Malgorzata; Jurczuk, Maria; Roszczenko, Alicja; Tomczyk, Michal

    2015-03-05

    It was investigated, in a female rat model of low and moderate lifetime human exposure to cadmium (Cd), whether polyphenols from Aronia melanocarpa berries (chokeberry; AMP) may offer protection from this heavy metal-induced disorders in bone metabolism. For this purpose, numerous indices of bone formation (osteocalcin, alkaline phosphatase, osteoprotegerin) and resorption (carboxy-terminal cross-linking telopeptides of type I collagen, soluble receptor activator of nuclear factor-κB ligand) in the serum and/or distal femur epiphysis (trabecular bone region), as well as bone mineral status (volumetric bone mineral density of the femur and content of mineral components, including calcium, in the bone tissue at the distal femur epiphysis) were evaluated in female Wistar rats that received a 0.1% aqueous extract of AMP, as the only drinking fluid (prepared from lyophilized extract by Adamed Consumer Healthcare), and/or Cd in diet (1 and 5mg/kg) for 3, 10, 17, and 24 months. Examination of the phytochemical profile of the aronia extract revealed high content of polyphenols (612.40 ± 3.33 mg/g), including anthocyanins, proanthocyanidins, phenolic acids, and flavonoids. Among detected compounds anthocyanins were identified as dominating. The exposure to Cd, dose- and duration-dependently, enhanced resorption and inhibited formation of the bone tissue resulting in its decreased mineralization. The administration of AMP under the exposure to 1 and 5 mgCd/kg diet provided important protection from this heavy metal-induced disturbances in the bone turnover and changes in the bone mineral status, and the beneficial impact of polyphenols resulted from their independent action and interaction with Cd. These findings suggest that consumption of Aronia melanocarpa polyphenols may play a role in prevention against female skeleton damage due to chronic exposure to Cd and that chokeberry represents the good natural plant candidate for further investigations of its prophylactic use

  6. Australian work exposures studies: occupational exposure to pesticides.

    Science.gov (United States)

    Jomichen, Jasmine; El-Zaemey, Sonia; Heyworth, Jane S; Carey, Renee N; Darcey, Ellie; Reid, Alison; Glass, Deborah C; Driscoll, Tim; Peters, Susan; Abramson, Michael; Fritschi, Lin

    2017-01-01

    Pesticides are widely used in some occupational settings. Some pesticides have been classified as carcinogens; however, data on the number of workers exposed to pesticides are not available in Australia. The main aim of this study was to estimate the current prevalence of pesticide exposure in Australian workplaces. The analysis used data from the Australian Work Exposures Study, a series of nationwide telephone surveys which investigated work-related prevalence and exposure to carcinogens and asthmagens, including pesticides, among current Australian workers. Information about the respondents' current job and various demographic factors was collected in a telephone interview using the web-based tool OccIDEAS. Workers were considered exposed to pesticides if they reported applying or mixing pesticides in their current job. Of the 10 371 respondents, 410 (4%) respondents were assessed as being exposed to pesticides in the workplace, with exposure being more likely among males, individuals born in Australia, individuals with lower education level and those residing in regional or remote areas. Glyphosate was the most common active ingredient used by workers. This is the first study to describe the prevalence of occupational pesticide exposure in Australia and one of the few recent studies internationally. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    Humans spend approximately 1/3 of their total life asleep, typically on a mattress or other bedding. Despite the fact that there is no other location where most of humanity spends more time, this microenvironment has received little attention from the standpoint of human exposure to a wide range ...

  8. Exposure of human cartilage tissue to low concentrations of blood for a short period of time leads to prolonged cartilage damage: An in vitro study

    NARCIS (Netherlands)

    Jansen, N.W.D.; Roosendaal, G.; Bijlsma, J.W.J.; Groot, J. de; Lafeber, F.P.J.G.

    2007-01-01

    Objective. Joint bleeding, or hemarthrosis, leads in time to severe joint damage. This study was carried out to test the in vitro thresholds of exposure time and concentration that lead to irreversible joint damage, to add to the discussion on the usefulness of aspiration of the joint after a hemorr

  9. Use of human bronchial epithelial cells (BEAS-2B) to study immunological markers resulting from exposure to PM(2.5) organic extract from Puerto Rico.

    Science.gov (United States)

    Fuentes-Mattei, Enrique; Rivera, Evasomary; Gioda, Adriana; Sanchez-Rivera, Diana; Roman-Velazquez, Felix R; Jimenez-Velez, Braulio D

    2010-03-15

    Fine particulate air pollutants, mainly their organic fraction, have been demonstrated to be associated with cardiovascular and respiratory health problems. Puerto Rico has been reported to have the highest prevalence of pulmonary diseases (e.g., asthma) in the United States. The aim of this study was to assess, for the first time, the immunological response of human bronchial epithelial cells (BEAS-2B) to organic extracts isolated from airborne particulate matter (PM(2.5)) in Puerto Rico. Organic extracts from PM(2.5) collected throughout an 8-month period (2000-2001) were pooled (composite) in order to perform chemical analysis and biological activity testing. BEAS-2B cells were exposed to PM(2.5) organic extract to assess cytotoxicity, levels of cytokines and relative gene expression of MHC-II, hPXR and CYP3A5. Our findings show that organic PM(2.5) consist of toxic as well as bioactive components that can regulate the secretion of cytokines in BEAS-2B, which could modulate inflammatory response in the lung. Trace element analyses confirmed the presence of metals in organic extracts highlighting the relative high abundance of Cu and Zn in polar organic extracts. Polar organic extracts exhibited dose-dependant toxicity and were found to significantly induce the release of interleukin 6 (IL-6), IL-1beta and IL-7 while significantly inhibiting the secretion of IL-8, G-CSF and MCP-1. Moreover, MHC-II transcriptional activity was up-regulated after 24 h of exposure, whereas PXR and CYP3A5 were down-regulated. This research provides a new insight into the effects of PM(2.5) organic fractions on specific effectors and their possible role in the development of respiratory inflammatory diseases in Puerto Rico.

  10. Measurement of metal bioaccessibility in vegetables to improve human exposure assessments: field study of soil-plant-atmosphere transfers in urban areas, South China.

    Science.gov (United States)

    Xiong, TianTian; Dumat, Camille; Pierart, Antoine; Shahid, Muhammad; Kang, Yuan; Li, Ning; Bertoni, Georges; Laplanche, Christophe

    2016-12-01

    The quality of cultivated consumed vegetables in relation to environmental pollution is a crucial issue for urban and peri-urban areas, which host the majority of people at the global scale. In order to evaluate the fate of metals in urban soil-plant-atmosphere systems and their consequences on human exposure, a field study was conducted at two different sites near a waste incinerator (site A) and a highway (site B). Metal concentrations were measured in the soil, settled atmospheric particulate matter (PM) and vegetables. A risk assessment was performed using both total and bioaccessible metal concentrations in vegetables. Total metal concentrations in PM were (mg kg(-1)): (site A) 417 Cr, 354 Cu, 931 Zn, 6.3 Cd and 168 Pb; (site B) 145 Cr, 444 Cu, 3289 Zn, 2.9 Cd and 396 Pb. Several total soil Cd and Pb concentrations exceeded China's Environmental Quality Standards. At both sites, there was significant metal enrichment from the atmosphere to the leafy vegetables (correlation between Pb concentrations in PM and leaves: r = 0.52, p plant species. Total Cr, Cd and Pb concentrations in vegetables were therefore above or just under the maximum limit levels for foodstuffs according to Chinese and European Commission regulations. High metal bioaccessibility in the vegetables (60-79 %, with maximum value for Cd) was also observed. The bioaccessible hazard index was only above 1 for site B, due to moderate Pb and Cd pollution from the highway. In contrast, site A was considered as relatively safe for urban agriculture.

  11. 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

  12. Environmental pathways and human exposure to manganese in southern Brazil

    Directory of Open Access Journals (Sweden)

    NADIR HERMES

    2013-01-01

    Full Text Available The study of environmental pathways and human exposure to Manganese (Mn in Southern Brazil was performed using two steps. The first step consisted of taking water samples from the surface of the Pardinho River. The average results from this technique showed a significant increase of pollutants, including increased levels of Mn, above the environmentally acceptable standard recommended by the Brazilian National Environment Council. Additionally, 64 soil samples were taken from areas with and without agricultural activity. Many results were above the mean crust and did not indicate significant differences of Mn levels between the sampled areas. For the second step, 12 families were selected and assessed for exposure to Mn in a region with high levels of Mn in the soil. Most of the analyzed foods contained amounts of Mn above the reference values, indicating that food can be an important source of exposure. The Mn content from the hair of most subjects studied was also high compared to reference values from non-exposed populations. Although the contamination appeared to come from a natural origin, the results found in the present study showed that the Mn levels present in the Pardinho River Basin are a relevant public health issue.

  13. 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...

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

    African Journals Online (AJOL)

    Knowledge of human immunodeficiency virus post-exposure prophylaxis among doctors in a Nigerian tertiary hospital. ... of PEP policy in the hospital. The level of knowledge concerning the high-risk fluid and three drugs used in PEP is high.

  15. 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...

  16. Human exposure to acrolein: Time-dependence and individual variation in eye irritation.

    Science.gov (United States)

    Claeson, Anna-Sara; Lind, Nina

    2016-07-01

    The aim of the study was to examine the time dependence on sensory irritation detection following exposure to threshold levels of acrolein, in humans. The exposures occurred in an exposure chamber and the subjects were breathing fresh air through a mask that covered the nose and mouth. All participants participated in four exposure conditions, of which three consisted of a mixture of acrolein and heptane and one of only heptane. Exposure to acrolein at a concentration half of the TLV-C lead to sensory irritation. The perceived sensory irritation resulted in both increased detectability and sensory irritation after about 6.8min of exposure in 58% of the participants. The study confirm the previously suggested LOAEL of about 0.34mg/m(3) for eye irritation due to acrolein exposure. The sensory irritation was still significant 10min after exposure. These results have implications for risk assessment and limit setting in occupational hygiene.

  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. Pesticide flow analysis to assess human exposure in greenhouse flower production in Colombia.

    Science.gov (United States)

    Lesmes-Fabian, Camilo; Binder, Claudia R

    2013-03-25

    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.

  19. Assessing human variability in kinetics for exposures to multiple environmental chemicals: a physiologically based pharmacokinetic modeling case study with dichloromethane, benzene, toluene, ethylbenzene, and m-xylene.

    Science.gov (United States)

    Valcke, Mathieu; Haddad, Sami

    2015-01-01

    The objective of this study was to compare the magnitude of interindividual variability in internal dose for inhalation exposure to single versus multiple chemicals. Physiologically based pharmacokinetic models for adults (AD), neonates (NEO), toddlers (TODD), and pregnant women (PW) were used to simulate inhalation exposure to "low" (RfC-like) or "high" (AEGL-like) air concentrations of benzene (Bz) or dichloromethane (DCM), along with various levels of toluene alone or toluene with ethylbenzene and xylene. Monte Carlo simulations were performed and distributions of relevant internal dose metrics of either Bz or DCM were computed. Area under the blood concentration of parent compound versus time curve (AUC)-based variability in AD, TODD, and PW rose for Bz when concomitant "low" exposure to mixtures of increasing complexities occurred (coefficient of variation (CV) = 16-24%, vs. 12-15% for Bz alone), but remained unchanged considering DCM. Conversely, AUC-based CV in NEO fell (15 to 5% for Bz; 12 to 6% for DCM). Comparable trends were observed considering production of metabolites (AMET), except for NEO's CYP2E1-mediated metabolites of Bz, where an increased CV was observed (20 to 71%). For "high" exposure scenarios, Cmax-based variability of Bz and DCM remained unchanged in AD and PW, but decreased in NEO (CV= 11-16% to 2-6%) and TODD (CV= 12-13% to 7-9%). Conversely, AMET-based variability for both substrates rose in every subpopulation. This study analyzed for the first time the impact of multiple exposures on interindividual variability in toxicokinetics. Evidence indicates that this impact depends upon chemical concentrations and biochemical properties, as well as the subpopulation and internal dose metrics considered.

  20. New approach for assessing human perfluoroalkyl exposure via hair.

    Science.gov (United States)

    Alves, Andreia; Jacobs, Griet; Vanermen, Guido; Covaci, Adrian; Voorspoels, Stefan

    2015-11-01

    In the recent years hair has been increasingly used as alternative matrix in human biomonitoring (HBM) of environmental pollutants. Sampling advantages and time integration of exposure assessment seems the most attractive features of hair matrix. In the current study, a novel miniaturized method was developed and validated for measuring 15 perfluoroalkyl substances (PFAS), including perfluoro n-butanoic acid (PFBA), perfluoro n-pentanoic acid (PFPeA), perfluoro n-hexanoic acid (PFHxA), perfluoro n-heptanoic acid (PFHpA), perfluor n-octanoic acid (PFOA), perfluoro n-nonanoic acid (PFNA), perfluoro tetradecanoic acid (PFTeDA), perfluorobutane sulfonic acid (PFBS), perfluoro pentane sulfonic acid (PFPeS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), perfluorononane sulfonic acid (PFNS), perfluorodecane sulfonic acid (PFDS) and perfluorododecane sulfonic acid (PFDoS) in human hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). After extraction using ethyl acetate, dispersive ENVI-Carb was used for clean-up. Good intra- and inter-day precision for low (LQ 5 ng/g hair) and high spike (HQ 15n g/g) levels were achieved (in general RSD hair and 3-13 pg/g hair, respectively. The method limit of quantification (LOQm) ranged between 6 and 301 pg/g hair. The PFAS levels were measured in 30 human hair samples indicating that the levels are low (14-1534 pg/g hair). Some PFAS were not present in any hair sample (e.g. PFHpA, PFTeDA, PFNA, PFPeS, PFHpS, PFOS and PFNS), while other PFAS were frequently detected (PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, PFOS, PFDS and PFDoS) in human hair. Although levels in general were low, there is evidence of higher human exposure to some analytes, such as PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, and PFDoS. The current study shows that hair is a suitable alternative non-invasive matrix for exposure assessment of PFAS.

  1. Exposure to perfluorinated compounds and human semen quality in arctic and European populations

    DEFF Research Database (Denmark)

    Toft, Gunnar; 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....

  2. 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...

  3. Human exposure to arsenic in groundwater from Lahore district, Pakistan.

    Science.gov (United States)

    Bibi, Mehwish; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem

    2015-01-01

    In the present study we determined As concentrations in healthy volunteers from three different age groups (children, adults and old age) residing in Lahore, Pakistan to gain insight into arsenic exposure to humans via drinking water. The results revealed that the concentrations of As were significantly (p<0.05) different among different sites, while non significant trends were observed among different age classes. As concentrations in blood and nails samples showed a significant (p<0.05) positive correlation. The mean concentrations of As were higher in nails samples (1.43μg/g) followed by blood samples (1.15μg/L); urine samples (0.82μg/l) and hair samples (0.74μg/g) based on all sites. The antioxidants enzyme activities in blood samples showed a significant (p<0.01) decrease with the increase in As concentrations. The result suggests that urgent action is needed to prevent further human exposure to As.

  4. 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.

  5. Structural change of human hair induced by mercury exposure.

    Science.gov (United States)

    Xing, Xueqing; Du, Rong; Li, Yufeng; Li, Bai; Cai, Quan; Mo, Guang; Gong, Yu; Chen, Zhongjun; Wu, Zhonghua

    2013-10-01

    Mercury is one of the most hazardous pollutants in the environment. In this paper, the structural change of human hair induced by mercury exposure was studied. Human hair samples were, respectively, collected from the normal Beijing area and the Hg-contaminated Wanshan area of the Guizhou Province, China. Inductively coupled plasma mass spectroscopy was used to detect the element contents. A small angle X-ray scattering technique was used to probe the structural change. Three reflections with 8.8, 6.7, and 4.5 nm spacing were compared between the normal and the Hg-contaminated hair samples. The results confirm that the 4.5 nm reflection is from the ordered fibrillar structure of glycosaminoglycan (GAG) in proteoglycan (PG) that composes the matrix around the intermediate filaments. The increase of Ca content makes the regular oriented fibrillar structure of GAG transform to a random oriented one, broadening the angular extent of the reflection with 4.5 nm spacing. However, overdose Hg makes the core proteins where the ordered fibrils of GAG are attached become coiled, which destroys the ordered arrangements of fibrillar GAG in PG, resulting in the disappearance of the reflections with 4.5 nm spacing. The disappearance of the 4.5 nm reflection can be used as a bioindicator of overdose Hg contamination to the human body. A supercoiled-coil model of hair nanoscale structure and a possible mechanism of mercury effect in human hair are proposed in this paper.

  6. Integrating Human Indoor Air Pollutant Exposure within Life Cycle Impact Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hellweg, Stefanie; Demou, Evangelia; Bruzzi, Raffaella; Meijer, Arjen; Rosenbaum, Ralph K.; Huijbregts, Mark A.J.; McKone, Thomas E.

    2008-12-21

    Neglecting health effects from indoor pollutant emissions and exposure, as currently done in Life Cycle Assessment (LCA), may result in product or process optimizations at the expense of workers? or consumers? health. To close this gap, methods for considering indoor exposure to chemicals are needed to complement the methods for outdoor human exposure assessment already in use. This paper summarizes the work of an international expert group on the integration of human indoor and outdoor exposure in LCA, within the UNEP/SETAC Life Cycle Initiative. A new methodological framework is proposed for a general procedure to include human-health effects from indoor exposure in LCA. Exposure models from occupational hygiene and household indoor air quality studies and practices are critically reviewed and recommendations are provided on the appropriateness of various model alternatives in the context of LCA. A single-compartment box model is recommended for use as a default in LCA, enabling one to screen occupational and household exposures consistent with the existing models to assess outdoor emission in a multimedia environment. An initial set of model parameter values was collected. The comparison between indoor and outdoor human exposure per unit of emission shows that for many pollutants, intake per unit of indoor emission may be several orders of magnitude higher than for outdoor emissions. It is concluded that indoor exposure should be routinely addressed within LCA.

  7. Human exposure to pulsed fields in the frequency range from 6 to 100 GHz

    Science.gov (United States)

    Laakso, Ilkka; Morimoto, Ryota; Heinonen, Juhani; Jokela, Kari; Hirata, Akimasa

    2017-09-01

    Restrictions on human exposure to electromagnetic waves at frequencies higher than 3-10 GHz are defined in terms of the incident power density to prevent excessive temperature rise in superficial tissue. However, international standards and guidelines differ in their definitions of how the power density is interpreted for brief exposures. This study investigated how the temperature rise was affected by exposure duration at frequencies higher than 6 GHz. Far-field exposure of the human face to pulses shorter than 10 s at frequencies from 6 to 100 GHz was modelled using the finite-difference time-domain method. The bioheat transfer equation was used for thermal modelling. We investigated the effects of frequency, polarization, exposure duration, and depth below the skin surface on the temperature rise. The results indicated limitations in the current human exposure guidelines and showed that radiant exposure, i.e. energy absorption per unit area, can be used to limit temperature rise for pulsed exposure. The data are useful for the development of human exposure guidelines at frequencies higher than 6 GHz.

  8. The human milk study, HUMIS. Presentation of a birth cohort study which aims to collect milk samples from 6000 mothers, for the assessment of persistent organic pollutants (POPS), relating it to exposure factors and health outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Eggesboe, M.; Stigum, H.; Becher, G.; Magnus, P. [Norwegian Inst. of Public Health, Oslo (Norway); Polder, A.; Skaare, J.U. [The Norwegian School of Veterinay Science, Oslo (Norway); Lindstroem, G. [Orebro Univ., Orebro (Sweden)

    2004-09-15

    Although PCB has been forbidden for more than 20 years now, and its levels in human milk is declining, it remains among the chemicals in human milk causing most concern with regard to its possible detrimental effects on the fetus and the breastfed child. Due to our industry, amongst others, the Norwegian population has been rather heavily exposed to PCB. Furthermore, new environmental toxicants are steadily entering the scene, such as the Brominated flame retardants. The level of Brominated flame retardants in human milk has shown an exponential increase during the last ten years, and this group of chemicals, are causing increasingly more concern. Studies from Sweden has shown that the levels differ greatly between individuals, however, for reasons yet unknown. In Norway, the highest levels of Brominated flame retardants ever measured in the world was reported from fish in Mjoesa. Surprisingly few attempts has been made to identify dietary habits or other life style factors that are associated with the levels of these toxicants in human milk. Such knowledge is needed in order for accurate prophylactic measures to be taken by the population and of special importance to women before and during child bearing age, in order to keep the levels in human milk as low as possible. Furthermore, there is great need for more knowledge of the effects of these toxicants on child health. The need for more research in this field, especially the need for prospective exposure data and the need for interdisciplinary approaches has been specifically targeted. Therefore a research initiative was taken in Norway to establish a prospective birth cohort which aims to recruit 6000 mother/child pairs, in whom human milk samples are collected in infancy and information on health outcomes are collected throughout the child's first seven years of life. The aim of this presentation is to describe this project in more detail and to give some preliminary results.

  9. Eco-toxicity and human estrogenic exposure risks from OH-initiated photochemical transformation of four phthalates in water: A computational study.

    Science.gov (United States)

    Gao, Yanpeng; An, Taicheng; Ji, Yuemeng; Li, Guiying; Zhao, Cunyuan

    2015-11-01

    Transformation products (TPs) of emerging organic contaminates (EOCs) in water are still rarely considered in environmental risk assessment, although some have been found to be concern. OH is believed as an important reactive species both in indirect phototransformation and advanced oxidation technology. Thus, eco-toxicity and human estrogenic exposure risks of four phthalates and TPs during the OH-initiated photochemical process were investigated using computational approach. Four phthalates can be degraded through OH-addition and H-transfer pathways. The OH-addition TPs were predominant for dimethyl phthalates, while H-transfer TPs were predominant for other three phthalates. Compared with phthalates, OH-addition TPs (o-OH-phthalates) were one level more toxic to aquatic organisms, and m-OH-phthalates exhibit higher estrogenic activity. Although H-transfer TPs were less harmful than OH-addition TPs, some of them still have aquatic toxicity and estrogenic activity. Therefore, more attentions should be paid to photochemical TPs and original EOCs, particularly those exhibiting high estrogenic activity to humans.

  10. 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.

  11. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis.

    Science.gov (United States)

    Williams, Amy Lavin; Watson, Rebecca E; DeSesso, John M

    2012-01-01

    Glyphosate is the active ingredient of several widely used herbicide formulations. Glyphosate targets the shikimate metabolic pathway, which is found in plants but not in animals. Despite the relative safety of glyphosate, various adverse developmental and reproductive problems have been alleged as a result of exposure in humans and animals. To assess the developmental and reproductive safety of glyphosate, an analysis of the available literature was conducted. Epidemiological and animal reports, as well as studies on mechanisms of action related to possible developmental and reproductive effects of glyphosate, were reviewed. An evaluation of this database found no consistent effects of glyphosate exposure on reproductive health or the developing offspring. Furthermore, no plausible mechanisms of action for such effects were elucidated. Although toxicity was observed in studies that used glyphosate-based formulations, the data strongly suggest that such effects were due to surfactants present in the formulations and not the direct result of glyphosate exposure. To estimate potential human exposure concentrations to glyphosate as a result of working directly with the herbicide, available biomonitoring data were examined. These data demonstrated extremely low human exposures as a result of normal application practices. Furthermore, the estimated exposure concentrations in humans are >500-fold less than the oral reference dose for glyphosate of 2 mg/kg/d set by the U.S. Environmental Protection Agency (U.S. EPA 1993). In conclusion, the available literature shows no solid evidence linking glyphosate exposure to adverse developmental or reproductive effects at environmentally realistic exposure concentrations.

  12. Human exposure to endocrine disruptors and breast milk.

    Science.gov (United States)

    Stefanidou, M; Maravelias, C; Spiliopoulou, C

    2009-09-01

    Endocrine system is one of the most sensitive communication networks of the human body which influences all aspects of human health and well-being, including reproductive potential, cognitive functions, thyroid and metabolism, digestion and hormonal balance. In recent years basic laboratory research has been focused on the potential relationship between environmental contaminants and cellular endocrine function. Environmental contaminants are ubiquitous in the environment, alter endocrine physiology and produce endocrine disruption without acting as classic toxicants. These endocrine disruptors (EDCs) are lipophilic and stored for long periods of time in the adipose tissue. Maternal exposure to EDCs during pregnancy and lactation has as a result the exposure of the fetus and neonate through placenta and breast milk. It has been recognized that human milk is the best natural food for neonates providing immunologic, developmental and practical advantages throughout childhood. However, contamination of human milk by the presence of environmental toxicants is widespread through the past decades due to inadequately controlled pollution. Persistent pesticides, chemical solvents and others tend to invade slowly the environment, to bioaccumulate in the food chain and to have long half-lives in animals and humans. During the past fifteen years, the scientific interest has been focused on xenoestrogens, i.e.,environmental chemicals with estrogen disrupting activity. Certain adverse health and reproductive outcomes are attributed to these chemicals in wildlife, in laboratory animals, as well as in humans. Although most toxic agents are hazardous in high doses, the human health risks associated with EDCs concern exposure to low doses. The human health risks that may be associated with these low-level but constant exposures are still largely unknown and highly controversial. In this paper, we review available data on environmental chemicals present in breast milk that may

  13. Mercury Human Exposure in Populations Living Around Lake Tana (Ethiopia).

    Science.gov (United States)

    Habiba, G; Abebe, G; Bravo, Andrea G; Ermias, D; Staffan, Ǻ; Bishop, K

    2017-02-01

    A survey carried out in Lake Tana in 2015 found that Hg levels in some fish species exceeded internationally accepted safe levels for fish consumption. The current study assesses human exposure to Hg through fish consumption around the Lake Tana. Of particular interest was that a dietary intake of fishes is currently a health risk for Bihar Dar residents and anglers. Hair samples were collected from three different groups: anglers, college students and teachers, and daily laborers. A questionary includes gender, age, weight, activity. Frequency of fish consumption and origin of the eaten fish were completed by each participant. Mercury concentrations in hair were significantly higher (P value mercury and age associated with mercury concentration in scalp hair. Mercury concentrations in the hair of men were on average twice the value of the women. Also, users of skin lightening soap on a daily basis had 2.5 times greater mercury in scalp hair than non-users. Despite the different sources of mercury exposure mentioned above, the mercury concentrations of the scalp hair of participants of this study were below levels deemed to pose a threat to health.

  14. Human dermal exposure to galaxolide from personal care products.

    Science.gov (United States)

    Correia, P; Cruz, A; Santos, L; Alves, A

    2013-06-01

    Musks are synthetic fragrances applied on personal care and household products as fixatives, by retarding the release of other fragrances with higher volatility. Galaxolide is the most used polycyclic musk since the 90th decade, and it has been detected in several environmental and biological matrices, particularly in human tissues and fluids. For exposure assessment purposes, large-monitoring data need to be obtained and rapid but reliable analytical techniques are requested. The main objective of this study is to develop and validate a new and fast analytical methodology to quantify galaxolide in personal care products and to apply this method to real matrices like skin care products (creams and lotions), shower products (soap bar), hair care products (shampoo and hair conditioner) and oral care products (toothpaste), to evaluate the human dermal exposure risk. A dispersive solid-phase extraction is proposed, using QuEChERS methodology, followed by HPLC with fluorescence detection. Some extraction parameters were studied, like the ratio of sample/solvent amounts, the homogenization time, the salt addition effect and the used sorbents. The validation parameters of the developed method were the following: a linearity range of 0.005-1.002 mg kg⁻¹ sample, a limit of detection of 0.001 mg kg⁻¹ sample, repeatability between 0.7% and 11.3% (variation coefficient of six standard injections), an intermediate precision of 2.5% (variation coefficient of six independent analysis of the same sample), mean recoveries ranging from 65% (soap bar) to 95% (body cream) and 3% of global uncertainty in most of the working range. The time of analysis, including the extraction steps, is 60 min, allowing a throughput of 4 samples h⁻¹ . Galaxolide was detected in all of the seven analysed products in concentrations ranging from 0.04 ± 0.01 mg kg⁻¹ sample (toothpaste) to 280.78 ± 8.19 mg kg⁻¹ sample (perfumed body cream), which may correspond to a significant estimated

  15. 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......Summary: Humans are exposed to diverse hazardous chemicals daily. Although an exposure to these chemicals is suspected to have adverse effects on human health, mechanistic insights into how they interact with the human body are still limited. Therefore, acquisition of curated data and development......–protein interactions have been enriched with a quality-scored human protein–protein interaction network, a protein–protein association network and a chemical–chemical interaction network, thus allowing the study of environmental chemicals through formation of protein complexes and phenotypic outcomes enrichment...

  16. 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

  17. A test chamber for experimental hydrogen fluoride exposure in humans.

    Science.gov (United States)

    Søstrand, P; Kongerud, J; Eduard, W; Nilsen, T; Skogland, M; Boe, J

    1997-07-01

    An inhalation chamber was built to perform experimental studies with hydrogen fluoride (HF), other gases, and particulate matter. The present study sought to describe a new gas delivery system and the distribution and concentration of HF gas in the chamber. The aluminum chamber has a volume of 19.2 m3 and a variable ventilation rate of about 1 to 10 air changes per hour. The negative pressure difference between the chamber and outside air can be regulated from 0 to 300 Pa. HF was fed at concentrations of up to 4000 mg/m3 directly into the ventilation duct feeding the chamber through openings with diameters as small as 50 microns, oriented opposite to the airflow. Gas flow was varied from about 0.1 dm3/min at a pressure of 4 atm. The dilution factor of HF concentration from cylinder to chamber was on the order of 10(3) to 10(4). The standard deviation (SD) of the HF concentrations at a fixed measurement point during a 1-hour test was typically 0.05 mg/m3 at a time-weighted average (TWA) concentration of 2.66 mg/m3. The SD of the TWA HF concentrations at six locations in the chamber was typically 0.05 mg/m3 and 0.29 mg/m3 at 0.61 and 3.46 mg/m3, respectively. Human exposure could be predicted from calculations based on ventilation data, gas flow, and observed ratio between calculated and measured concentrations. When the target exposure concentration was 1.5 mg/m3, the measured mean exposure concentration was typically 1.54 mg/m3 (range: 1.4-1.7 mg/m3, SD 0.09 mg/m3, n = 8). The chamber is well-suited for inhalation studies in humans. Chamber atmosphere was controlled and has proved to be stable and homogeneous, even in tests with HF, a highly reactive gas in the class of superacids.

  18. 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.

  19. 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...... using a suction sampler worn on the chest or lapel that measures breathing zone concentration; a more useful exposure parameter for pollen allergy sufferers is the amount of pollen inhaled, i.e. the dose. The objective of this study was to investigate how well monitoring station data reflect actual...... exposure, something that is currently not well understood. Methods: Exposure samples were collected during the 2011 grass pollen season in an area of abundant unmaintained grass coverage close to the centre of Aarhus, Denmark. Sampling was performed at two-hourly intervals between 12:00 and 20:00 on 14...

  20. Human exposure to emissions from building materials

    DEFF Research Database (Denmark)

    Kjærgaard, Søren K.; Hauschildt, P.; Pejtersen, J.

    1999-01-01

    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...... effects by linoleum and carpet used and that changing to vinyl flooring may reduce these....

  1. Human disease resulting from exposure to electromagnetic fields.

    Science.gov (United States)

    Carpenter, David O

    2013-01-01

    Electromagnetic fields (EMFs) include everything from cosmic rays through visible light to the electric and magnetic fields associated with electricity. While the high frequency fields have sufficient energy to cause cancer, the question of whether there are human health hazards associated with communication radiofrequency (RF) EMFs and those associated with use of electricity remains controversial. The issue is more important than ever given the rapid increase in the use of cell phones and other wireless devices. This review summarizes the evidence stating that excessive exposure to magnetic fields from power lines and other sources of electric current increases the risk of development of some cancers and neurodegenerative diseases, and that excessive exposure to RF radiation increases risk of cancer, male infertility, and neurobehavioral abnormalities. The relative impact of various sources of exposure, the great range of standards for EMF exposure, and the costs of doing nothing are also discussed.

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

    DEFF Research Database (Denmark)

    Licina, Dusan

    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...... differences in pollution concentration mean that personal exposure, rather than average space concentration, determines the risk of elevated exposure. Current room air distribution design practice does not take into account the air movement induced by the thermal flows from occupants, which often results...... 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...

  3. 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...

  4. Biomonitoring human exposure to environmental carcinogenic chemicals

    NARCIS (Netherlands)

    Farmer, P.B.; Sepai, O.; Lawrence, R.; Autrup, H.; Nielsen, P.S.; Baan, R.A.; Delft, J.H.M. van; Steenwinkel, M.J.S.T.; et al.

    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 secondary biological

  5. 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...

  6. A Chain Modeling Approach To Estimate the Impact of Soil Cadmium Pollution on Human Dietary Exposure

    NARCIS (Netherlands)

    Franz, E.; Romkens, P.F.A.M.; Raamsdonk, van L.W.D.; Fels-Klerx, van der H.J.

    2008-01-01

    Cadmium in soil poses a risk for human health, due to its accumulation in food and feed crops. The extent of accumulation depends strongly on soil type and the degree of pollution. The objective of the present study was to develop a predictive model to estimate human dietary cadmium exposure from so

  7. 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...

  8. 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, appro

  9. Scientific and Ethical Approaches for Observational Exposure Studies

    Science.gov (United States)

    Researchers conduct observational human exposure studies to understand how and the extent to which people come into contact with chemicals and environmental stressors in their everyday lives, through the air they breathe, the food and liquids they consume, and the things they tou...

  10. Monitoring human exposure to 2-hydroxyethylating carcinogens

    DEFF Research Database (Denmark)

    Farmer, P.B.; Cordero, Rosa; Autrup, Herman

    1996-01-01

    agents was also studied by the analysis of umbilical cord hemoglobin. The adduct levels in smokers were significantly higher than those in nonsmokers. The adduct levels in umbilical cord blood globin were quantitatively related to those in maternal blood (maternal:fetal ratio 2.7 in smokers and 2...

  11. 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.

  12. Nonthermal Effects of Radar Exposure on Human: A Review Article

    Directory of Open Access Journals (Sweden)

    vida zaroushani

    2014-01-01

    Full Text Available ABSTRACT Microwave is part of the electromagnetic spectrum that has different application such as communications, military, air-traffic Control and etc... Previous studies showed that radar frequency could be a health hazard agent. This review article mentioned some of the studies that investigated non-thermal effects of radar frequencies. Reproductive effects, cancers, blood effects, genetic, adverse immune effects and mental effects are non-thermal effects that presented in this report. There are many unknown aspects of the biological effects and many of them did not determined very well such as oxidative stress and mental effects. Compliance with permissible exposure limits, reduction in exposure, and shielding are some of the controlling methods to protect workers from the exposure of microwave and among them, The use of shielding is a superior method for prevention of microwave exposure and among them, electromagnetic Nano composites shields is appropriate for protection of workers from radar exposure.

  13. Mixtures of endocrine disrupting contaminants modelled on human high end exposures

    DEFF Research Database (Denmark)

    Christiansen, Sofie; Kortenkamp, A.; Petersen, Marta Axelstad

    2012-01-01

    in vivo endocrine disrupting effects and information about human exposures was available, including phthalates, pesticides, UV‐filters, bisphenol A, parabens and the drug paracetamol. The mixture ratio was chosen to reflect high end human intakes. To make decisions about the dose levels for studies...... though each individual chemical is present at low, ineffective doses, but the effects of mixtures modelled based on human intakes have not previously been investigated. To address this issue for the first time, we selected 13 chemicals for a developmental mixture toxicity study in rats where data about...... in the rat, we employed the point of departure index (PODI) approach, which sums up ratios between estimated exposure levels and no‐observed‐adverse‐effect‐level (NOAEL) values of individual substances. For high end human exposures to the 13 selected chemicals, we calculated a PODI of 0.016. As only a PODI...

  14. Effects of exposure to oil spills on human health: Updated review.

    Science.gov (United States)

    Laffon, Blanca; Pásaro, Eduardo; Valdiglesias, Vanessa

    2016-01-01

    Oil spills may involve health risks for people participating in the cleanup operations and coastal inhabitants, given the toxicological properties of the oil components. In spite of this, only after a few major oil spills (crude oil or fuel oil no. 6) have studies on effects of exposure to diverse aspects of human health been performed. Previously, Aguilera et al. (2010) examined all documents published to that date dealing with any type of human health outcome in populations exposed to oil spills. The aim of the present review was to compile all new information available and determine whether evidence reported supports the existence of an association between exposure and adverse human health risks. Studies were classified in three groups according to type of health outcome addressed: (i) effects on mental health, (ii) physical/physiological effects, and (iii) genotoxic, immunotoxic, and endocrine toxicity. New studies published on oil-spill-exposed populations-coastal residents in the vicinity of the spills or participants in cleanup operations-provide additional support to previous evidence on adverse health effects related to exposure regarding different parameters in all three categories considered. Some of the observed effects even indicated that several symptoms may persist for some years after exposure. Hence, (1) health protection in these individuals should be a matter of concern; and (2) health risk assessment needs to be carried out not only at the time of exposure but also for prolong periods following exposure, to enable early detection of any potential exposure-related harmful effects.

  15. Three dimensional visualisation of human facial exposure to solar ultraviolet.

    Science.gov (United States)

    Downs, Nathan; Parisi, Alfio

    2007-01-01

    A three dimensional computer model of the human face has been developed to represent solar ultraviolet exposures recorded by dosimeter measurements on a manikin headform under low cloud conditions and various solar zenith angles. Additionally, polysulfone dosimeters have been successfully miniaturised to provide the detailed measurements required across the face. The headform used in this research was scanned at 709 individual locations to make a wireframe mesh consisting of 18 vertical contours and 49 horizontal contours covering half the manikin's frontal facial topography. Additionally, the back of the headform and neck have also been scanned at 576 locations. Each scanned location has been used as a viable dosimeter position on the headform and represents a grid intersection point on the developed computer wireframe. A series of exposures recorded by dosimeters have been translated into three dimensional exposure ratio maps, representing ambient solar ultraviolet exposure. High dosimeter density has allowed for the development of individual topographic contour models which take into account complex variation in the face and improve upon previously employed techniques which utilise fewer dosimeters to interpolate exposure across facial contours. Exposure ratios for solar zenith angle ranges of 0 degrees -30 degrees, 30 degrees -50 degrees, and 50 degrees -80 degrees have been developed.

  16. 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.

  17. Automated scoring of lymphocyte micronuclei by the MetaSystems Metafer image cytometry system and its application in studies of human mutagen sensitivity and biodosimetry of genotoxin exposure.

    Science.gov (United States)

    Rossnerova, Andrea; Spatova, Milada; Schunck, Christian; Sram, Radim J

    2011-01-01

    Automated image analysis scoring of micronuclei (MN) in cells can facilitate the objective and rapid measurement of genetic damage in mammalian and human cells. This approach was repeatedly developed and tested over the past two decades but none of the systems were sufficiently robust for routine analysis of MN until recently. New methodological, hardware and software developments have now allowed more advanced systems to become available. This mini-review presents the current stage of development and validation of the Metasystems Metafer MNScore system for automated image analysis scoring of MN in cytokinesis-blocked binucleated lymphocytes, which is the best-established method for studying MN formation in humans. The results and experience of users of this system from 2004 until today are reviewed in this paper. Significant achievements in the application of this method in research related to mutagen sensitivity phenotype in cancer risk, radiation biodosimetry and biomonitoring studies of air pollution (enriched by new data) are described. Advantages as well as limitations of automated image analysis in comparison with traditional visual analysis are discussed. The current increased use of the Metasystems Metafer MNScore system in various studies and the growing number of publications based on automated image analysis scoring of MN is promising for the ongoing and future application of this approach.

  18. Effects of ozone exposure on lipid metabolism in human alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, M.; Madden, M.C.; Samet, J.M.; Koren, H.S.

    1991-01-01

    Alveolar macrophages (AM) store arachidonic acid (AA) which is esterified in cellular phospholipids until liberated by phospholipase A2 or C after exposure to inflammatory stimuli. Following release, there can be subsequent metabolism of AA into various potent, biological active mediators including prostaglandins and platelet activating factor (PAF). To examine the possibility that these mediators may account for some of the pathophysiologic alterations seen in the lung following O3 exposure, human AM were collected by bronchoalveolar lavage of normal subjects, plated into tissue culture dishes, and the adherent cells were incubated with 3H-AA or 3H-lysoPAF. Human AM exposed 1.0 ppm O3 for 2 hr released 65 + or - 12% more tritium, derived from 3H-AA, than paired air-exposed controls into media supernatants. In other studies using a similar O3 exposure protocol, there was also a significant increase in human AM PGE2 production (2.0 + or - 0.5 fold-increase above air-exposure values, p<0.01, n=17). In additional studies, using a similar O3 exposure protocol (1.0 ppm for 1 hr), there was also a significant increase in human AM PAF content (1.7 + or - 0.2 fold-increase above air-exposure values, p<0.02, n=5).

  19. Tumor promotion by exposure to radiofrequency electromagnetic fields below exposure limits for humans.

    Science.gov (United States)

    Lerchl, Alexander; Klose, Melanie; Grote, Karen; Wilhelm, Adalbert F X; Spathmann, Oliver; Fiedler, Thomas; Streckert, Joachim; Hansen, Volkert; Clemens, Markus

    2015-04-17

    The vast majority of in vitro and in vivo studies did not find cancerogenic effects of exposure to electromagnetic fields (RF-EMF), i.e. emitted by mobile phones and base stations. Previously published results from a pilot study with carcinogen-treated mice, however, suggested tumor-promoting effects of RF-EMF (Tillmann et al., 2010). We have performed a replication study using higher numbers of animals per group and including two additional exposure levels (0 (sham), 0.04, 0.4 and 2 W/kg SAR). We could confirm and extend the originally reported findings. Numbers of tumors of the lungs and livers in exposed animals were significantly higher than in sham-exposed controls. In addition, lymphomas were also found to be significantly elevated by exposure. A clear dose-response effect is absent. We hypothesize that these tumor-promoting effects may be caused by metabolic changes due to exposure. Since many of the tumor-promoting effects in our study were seen at low to moderate exposure levels (0.04 and 0.4 W/kg SAR), thus well below exposure limits for the users of mobile phones, further studies are warranted to investigate the underlying mechanisms. Our findings may help to understand the repeatedly reported increased incidences of brain tumors in heavy users of mobile phones.

  20. 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.

  1. Human arsenic exposure and risk assessment at the landscape level: a review.

    Science.gov (United States)

    Khan, Nasreen Islam; Owens, Gary; Bruce, David; Naidu, Ravi

    2009-04-01

    Groundwater contaminated with arsenic (As), when extensively used for irrigation, causes potentially long term detrimental effects to the landscape. Such contamination can also directly affect human health when irrigated crops are primarily used for human consumption. Therefore, a large number of humans are potentially at risk worldwide due to daily As exposure. Numerous previous studies have been severely limited by small sample sizes which are not reliably extrapolated to large populations or landscapes. Human As exposure and risk assessment are no longer simple assessments limited to a few food samples from a small area. The focus of more recent studies has been to perform risk assessment at the landscape level involving the use of biomarkers to identify and quantify appropriate health problems and large surveys of human dietary patterns, supported by analytical testing of food, to quantify exposure. This approach generates large amounts of data from a wide variety of sources and geographic information system (GIS) techniques have been used widely to integrate the various spatial, demographic, social, field, and laboratory measured datasets. With the current worldwide shift in emphasis from qualitative to quantitative risk assessment, it is likely that future research efforts will be directed towards the integration of GIS, statistics, chemistry, and other dynamic models within a common platform to quantify human health risk at the landscape level. In this paper we review the present and likely future trends of human As exposure and GIS application in risk assessment at the landscape level.

  2. Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure.

    Science.gov (United States)

    Castellani, John W; Young, Andrew J

    2016-04-01

    Cold exposure in humans causes specific acute and chronic physiological responses. This paper will review both the acute and long-term physiological responses and external factors that impact these physiological responses. Acute physiological responses to cold exposure include cutaneous vasoconstriction and shivering thermogenesis which, respectively, decrease heat loss and increase metabolic heat production. Vasoconstriction is elicited through reflex and local cooling. In combination, vasoconstriction and shivering operate to maintain thermal balance when the body is losing heat. Factors (anthropometry, sex, race, fitness, thermoregulatory fatigue) that influence the acute physiological responses to cold exposure are also reviewed. The physiological responses to chronic cold exposure, also known as cold acclimation/acclimatization, are also presented. Three primary patterns of cold acclimatization have been observed, a) habituation, b) metabolic adjustment, and c) insulative adjustment. Habituation is characterized by physiological adjustments in which the response is attenuated compared to an unacclimatized state. Metabolic acclimatization is characterized by an increased thermogenesis, whereas insulative acclimatization is characterized by enhancing the mechanisms that conserve body heat. The pattern of acclimatization is dependent on changes in skin and core temperature and the exposure duration.

  3. Biological Monitoring of Inhaled Nanoparticles in Patients: An Appealing Approach To Study Causal Link between Human Respiratory Pathology and Exposure to Nanoparticles.

    Science.gov (United States)

    Forest, Valérie; Vergnon, Jean-Michel; Pourchez, Jérémie

    2017-09-18

    Although necessary, in vitro and in vivo studies are not fully successful at predicting nanomaterials toxicity. We propose to associate such assays to the biological monitoring of nanoparticles in clinical samples to get more relevant data on the chemical and physical nature and dose of nanoparticles found in humans. The concept is to establish the load of nanoparticles in biological samples of patients. Then, by comparing samples from different patient groups, nanoparticles of interest could be identified and a potential link between a given nanoparticle type and toxicity could be suggested. It must be confirmed by investigating the biological effects induced by these nanoparticles using in vitro or in vivo models (mechanistic or dose-response studies). This translational approach from the bedside to the bench and vice versa could allow a better understanding of the nanoparticle effects and mechanisms of toxicity that can contribute, at least in part, to a disease.

  4. Assessing hazardous risks of human exposure to temple airborne polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Chiang, Kuo-Chih; Chio, Chia-Pin; Chiang, Yu-Hui; Liao, Chung-Min

    2009-07-30

    We proposed an integrated probabilistic risk assessment framework based on reported data to quantify human health risks of temple goers/workers to airborne polycyclic aromatic hydrocarbons (PAHs) from incense burning in typical Taiwanese temples. The framework probabilistically integrates exposure, human respiratory tract, and incremental lifetime cancer risk (ILCR) models to quantitatively estimate size-dependent PAHs exposure in human lung regions and cancer risks for temple goers (moderate and high exposures) and temple workers (extreme exposure). Our results show that the ILCRs are greater than the acceptable level of 10(-6) for extreme and high exposure groups through inhalation route. The result also indicates that the higher ILCRs (10(-6) to 10(-4)) are found in ingestion and dermal contact routes for temple goers/workers. For personal extreme exposure to carcinogenic PAH in the temple, 95% probability total ILCR (TILCR) (9.87 x 10(-4) to 1.13 x 10(-3)) is much greater than the range of 10(-6) to 10(-4), indicating high potential health risk to temple workers. For temple goers with high and moderate exposure groups, however, the 95% probability TILCRs were estimated from 6.44 x 10(-5) to 7.50 x 10(-5) and 5.75 x 10(-6) to 6.99 x 10(-6), respectively. This study successfully offers a scientific basis for risk analysis due to incense burning to enhance broad risk management strategies for temple indoor air quality.

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

    OpenAIRE

    Jolyon H Hendry; Simon, Steven L.; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; 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 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 li...

  6. Human urinary mutagenicity after wood smoke exposure during traditional temazcal use

    OpenAIRE

    Long, Alexandra S.; Lemieux, Christine L.; Yousefi, Paul; Ruiz-Mercado, Ilse; Lam, Nicholas L.; Orellana, Carolina Romero; White, Paul A.; Smith, Kirk R.; Holland, Nina

    2014-01-01

    In Central America, the traditional temazcales or wood-fired steam baths, commonly used by many Native American populations, are often heated by wood fires with little ventilation, and this use results in high wood smoke exposure. Urinary mutagenicity has been previously employed as a non-invasive biomarker of human exposure to combustion emissions. This study examined the urinary mutagenicity in 19 indigenous Mayan families from the highlands of Guatemala who regularly use temazcales (N = 32...

  7. The potential utility of animal poisoning data to identify human exposure to environmental toxins.

    Science.gov (United States)

    Hungerford, L L; Trammel, H L; Clark, J M

    1995-04-01

    The database of the National Animal Poison Control Center (NAPCC) was evaluated as a source for animal poison data indicating human health hazards in indoor and outdoor environments. From 14,150 calls in the 1985 database, 259 cases were identified with histories suggesting human exposure. A subgroup of 25 cases with known human exposure was found. Dogs were the most common sentinel animal, but bird cases represented the highest proportional selection from the total 1985 call list. Indoor exposures represented 43.2% of cases; the most common toxicants were insecticides, lead and toxic fumes. Exposures associated with lawns were mainly due to insecticides and herbicides and constituted 25.5% of cases. Other outdoor exposures composed the remaining 31.7% of cases, with insecticides, herbicides and unidentified toxins the leading categories. Many of the specific agents identified, such as organophosphate insecticides, lead, gas and fume toxins, and phenoxy herbicides are also risk factors in human diseases. This study indicates that databases such as NAPCC could serve as sources of sentinel animal intoxications for followup studies to evaluate known and potential human health hazards.

  8. Humanities, Digital Humanities, Media studies, Internet studies

    DEFF Research Database (Denmark)

    Brügger, Niels

    the interplay between four areas which until now to a certain extent have been separated: Traditional Hu- manities, Digital Humanities, Media studies, and Internet studies. The vision is followed by an outline of how it can be unfolded in concrete activities, in the form of research projects, research...

  9. 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.

  10. Exposure assessment in studies on health effects of traffic exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Setaelae, S. [Association for the Pulmonary Disabled, Helsinki (Finland); Jaakkola, J.J.K. [Helsinki Univ. (Finland). Dept. of Public Health

    1995-12-31

    A main source of outdoor air pollution is road traffic, which produces a complex mixture of nitrogen oxides, carbon monoxide, volatile hydrocarbons, airborne particles and some other compounds. Traffic exhaust affects also the concentrations of ozone and other photo chemical oxidants. In earlier studies those components have had remarkable health effects. Several studies on occupational exposure to automobile exhaust have been published and several studies have been observed an association between both outdoor and indoor pollutant levels and health outcomes. However, there are only a few epidemiological studies in which traffic exhaust, a complex mixture, has been studied in its entirety. During recent years, interesting epidemiological studies of the health effects of this complex mixture have been published. Human exposure assessment for traffic exhaust can be categorized according to the environment of exposure (indoors, outdoors, in-traffic) or to the method of exposure assessment (direct or indirect methods). In this presentation the methods are further categorized into (1) traffic activity, (2) air concentration measurements, and (3) dispersion models, in order to better understand the advantages and disadvantages of different approaches. The objective of this presentation is to make a critical review of exposure assessments in the epidemiological studies on health effects of traffic exhaust. (author)

  11. Arsenic Exposure and the Induction of Human Cancers

    Directory of Open Access Journals (Sweden)

    Victor D. Martinez

    2011-01-01

    Full Text Available Arsenic is a metalloid, that is, considered to be a human carcinogen. Millions of individuals worldwide are chronically exposed through drinking water, with consequences ranging from acute toxicities to development of malignancies, such as skin and lung cancer. Despite well-known arsenic-related health effects, the molecular mechanisms involved are not fully understood; however, the arsenic biotransformation process, which includes methylation changes, is thought to play a key role. This paper explores the relationship of arsenic exposure with cancer development and summarizes current knowledge of the potential mechanisms that may contribute to the neoplastic processes observed in arsenic exposed human populations.

  12. Exposure to phthalates in 5-6 years old primary school starters in Germany--a human biomonitoring study and a cumulative risk assessment.

    Science.gov (United States)

    Koch, Holger M; Wittassek, Matthias; Brüning, Thomas; Angerer, Jürgen; Heudorf, Ursel

    2011-06-01

    We determined the internal exposure of 111 German primary school starters by analyzing urinary metabolites of six phthalates: butyl benzyl phthalate (BBzP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di (2-ethylhexyl) phthalate (DEHP), di-iso-nonyl phthalate (DiNP) and di-iso-decylphthalate (DiDP). From the urinary metabolite levels, we calculated daily intakes and related these values to Tolerable Daily Intake (TDI) values. By introducing the concept of a relative cumulative Tolerable Daily Intake (TDI(cum)) value, we tried to account for the cumulative exposure to several of the above-mentioned phthalates. The TDI(cum) was derived as follows: the daily intake (DI) calculated from the metabolite level was divided by the TDI for each phthalate; this ratio was multiplied by 100% indicating the TDI percentage for which the DI accounted. Finally the % TDIs of the different phthalates were totalled to get the TDI(cum). A TDI(cum) above 100% is a potential cause for concern. We confirmed the ubiquitous exposure of the children to all phthalates investigated. Exposures were within range of levels previously reported for GerES, albeit slightly lower. Regarding daily intakes, two children exceeded the TDI for DnBP, whereas one child closely approached the TDI for DEHP. 24% of the children exceeded the TDI(cum) for the three most critical phthalates: DEHP, DnBP and DiBP. Furthermore, 54% of the children had total exposures that used up more than 50% the TDI(cum). Therefore, the overall exposure to a number of phthalates, and the knowledge that these phthalates (and other anti-androgens) act in a dose-additive manner, urgently warrants a cumulative risk assessment approach.

  13. Pesticides: an update of human exposure and toxicity.

    Science.gov (United States)

    Mostafalou, Sara; Abdollahi, Mohammad

    2017-02-01

    Pesticides are a family of compounds which have brought many benefits to mankind in the agricultural, industrial, and health areas, but their toxicities in both humans and animals have always been a concern. Regardless of acute poisonings which are common for some classes of pesticides like organophosphoruses, the association of chronic and sub-lethal exposure to pesticides with a prevalence of some persistent diseases is going to be a phenomenon to which global attention has been attracted. In this review, incidence of various malignant, neurodegenerative, respiratory, reproductive, developmental, and metabolic diseases in relation to different routes of human exposure to pesticides such as occupational, environmental, residential, parental, maternal, and paternal has been systematically criticized in different categories of pesticide toxicities like carcinogenicity, neurotoxicity, pulmonotoxicity, reproductive toxicity, developmental toxicity, and metabolic toxicity. A huge body of evidence exists on the possible role of pesticide exposures in the elevated incidence of human diseases such as cancers, Alzheimer, Parkinson, amyotrophic lateral sclerosis, asthma, bronchitis, infertility, birth defects, attention deficit hyperactivity disorder, autism, diabetes, and obesity. Most of the disorders are induced by insecticides and herbicides most notably organophosphorus, organochlorines, phenoxyacetic acids, and triazine compounds.

  14. A review of human exposure to polybrominated diphenyl ethers (PBDEs) in China.

    Science.gov (United States)

    Ni, Kun; Lu, Yonglong; Wang, Tieyu; Kannan, Kurunthachalam; Gosens, Jorrit; Xu, Li; Li, Qiushuang; Wang, Lin; Liu, Shijie

    2013-11-01

    This paper reviews recent studies on human exposure to polybrominated diphenyl ethers (PBDEs) in China, with particular focus on external exposure routes (e.g. diet and dust ingestion, inhalation of air) and internal doses based on biomonitoring studies of PBDEs (e.g. breast milk, blood and hair). PBDE concentrations reported for fish samples collected from electronic waste (e-waste) recycling sites, PBDE manufacturing sites, local markets in selected cities and estuarine areas in China have been compiled. House dust has been a significant contributor to human exposure to PBDEs in many countries. This is especially true for toddlers, who are exposed to significantly higher doses of PBDEs than adults. Infants are also exposed to high levels of PBDEs via breast-feeding. The general population's inhalation exposure to PBDEs from household products is likely a less significant source into the indoor environment. In addition, the contribution of several exposure pathways to PBDEs among various age groups was analyzed. We found that house dust contributed most to the daily exposure to PBDEs for both toddlers and adults in urban areas of China. Furthermore, workers and residents in and around electronic recycling and PBDE manufacturing sites are exposed to the highest PBDE levels among all populations studied thus far. For the occupationally exposed populations, BDE209 was the dominant congener, in most cases. Rigorous pollution prevention and occupational protection measures are needed in China to mitigate potential health effects associated with PBDE exposures.

  15. Humanities, Digital Humanities, Media studies, Internet studies

    DEFF Research Database (Denmark)

    Brügger, Niels

    the interplay between four areas which until now to a certain extent have been separated: Traditional Hu- manities, Digital Humanities, Media studies, and Internet studies. The vision is followed by an outline of how it can be unfolded in concrete activities, in the form of research projects, research......Todays expanding digital landscape constitutes an important research object as well as the research environment for the Humanities at the beginning of the 21st century. Taking this state of affairs as a starting point this inaugural lecture presents a vision for how the digital affects...

  16. Study of frequency of chromosomal disorders occurrence in human lymphocytes after exposure to various doses of deuterons in vitro, under the protection of adeturone

    Energy Technology Data Exchange (ETDEWEB)

    Bulanova, M.D.; Ivanov, B.A.; Mileva, M.S.; Ryzhov, N.I.; Gerasimenko, V.N. (Institut Mediko-Biologicheskikh Problem, Moscow (USSR))

    1982-07-01

    Dependence of chromosomal aberration yield in the culture of human lymphocytes on irradiation in the G/sub 0/ stage with 4.2 GeV/nucleon deuterons under normal conditions and conditions of prophylactic intake of adetourone has been studied. It is shown that the nature of dose dependence of the number of chromosomal aberrations in blood protected with adeturone and unprotected is similar. Some antiactinic protective adetourone effect on lymphocytes during the action of high energy deuterons is noted. Coefficients of total biologic efficiency (TBE) of deuterons with respect to dicentric yield constituted 2.04 and with respect to the total number of aberrations - 1.63. Cause of relatively high values of TBE of radiations under investigation is discussed.

  17. Large-scale projects in the amazon and human exposure to mercury: The case-study of the Tucuruí Dam.

    Science.gov (United States)

    Arrifano, Gabriela P F; Martín-Doimeadios, Rosa C Rodríguez; Jiménez-Moreno, María; Ramírez-Mateos, Vanesa; da Silva, Núbia F S; Souza-Monteiro, José Rogério; Augusto-Oliveira, Marcus; Paraense, Ricardo S O; Macchi, Barbarella M; do Nascimento, José Luiz M; Crespo-Lopez, Maria Elena

    2017-08-28

    The Tucuruí Dam is one of the largest dams ever built in the Amazon. The area is not highly influenced by gold mining as a source of mercury contamination. Still, we recently noted that one of the most consumed fishes (Cichla sp.) is possibly contaminated with methylmercury. Therefore, this work evaluated the mercury content in the human population living near the Tucuruí Dam. Strict exclusion/inclusion criteria were applied for the selection of participants avoiding those with altered hepatic and/or renal functions. Methylmercury and total mercury contents were analyzed in hair samples. The median level of total mercury in hair was above the safe limit (10µg/g) recommended by the World Health Organization, with values up to 75µg/g (about 90% as methylmercury). A large percentage of the participants (57% and 30%) showed high concentrations of total mercury (≥ 10µg/g and ≥ 20µg/g, respectively), with a median value of 12.0µg/g. These are among the highest concentrations ever detected in populations living near Amazonian dams. Interestingly, the concentrations are relatively higher than those currently shown for human populations highly influenced by gold mining areas. Although additional studies are needed to confirm the possible biomagnification and bioaccumulation of mercury by the dams in the Amazon, our data already support the importance of adequate impact studies and continuous monitoring. More than 400 hydropower dams are operational or under construction in the Amazon, and an additional 334 dams are presently planned/proposed. Continuous monitoring of the populations will assist in the development of prevention strategies and government actions to face the problem of the impacts caused by the dams. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Preimplantation Exposure to Bisphenol A and Triclosan May Lead to Implantation Failure in Humans

    Directory of Open Access Journals (Sweden)

    Mu Yuan

    2015-01-01

    Full Text Available Endocrine disrupting chemicals (EDCs are chemicals that have the capacity to interfere with normal endocrine systems. Two EDCs, bisphenol A (BPA and triclosan (TCS, are mass-produced and widespread. They both have estrogenic properties and similar chemical structures and pharmacokinetic features and have been detected in human fluids and tissues. Clinical evidence has suggested a positive association between BPA exposure and implantation failure in IVF patients. Studies in mouse models have suggested that preimplantation exposure to BPA and TCS can lead to implantation failure. This paper reviews the relationship between preimplantation exposure to BPA and TCS and implantation failure and discusses the remaining problems and possible solutions.

  19. Human health implications from co-exposure to aflatoxins and fumonisins in maize-based foods in Latin America: Guatemala as a case study

    Science.gov (United States)

    Co-occurence of fumonisin B1 (FB1) and aflatoxin B1 (AFB1) in maize has been demonstrated in many surveys. Combined-exposure to FB1 and AFB1 was of concern to the Joint FAO/WHO Expert Committee on Food Additives because of the known genotoxicity of AFB1 and the ability of FB1 to induce regenerative...

  20. Managing occupational HIV exposures: a Canadian study.

    Science.gov (United States)

    Reutter, L I; Northcott, H C

    1995-10-01

    The findings reported in this paper are part of a larger study that explored how nurses cope with the risk of acquiring HIV infection while caring for persons with AIDS (PWAs). The data were collected through in-depth interviews with 13 nurses who cared for PWAs in a large Western Canadian hospital. Seven of these nurses perceived that they had been exposed to HIV-infected blood or body fluids. This paper describes how these seven nurses coped with actual exposures to HIV-infected blood or body fluids. Data were analyzed using the methodology of grounded theory. Nurses' coping efforts after exposure were grouped into four categories: minimizing the effect of exposures, reducing a sense of vulnerability, selective disclosure to others, and assigning meaning. Nurses minimized the physical effects of exposure through measures such as 'bleeding' the needlestick injury and immersing the affected area in bleach solution. Nurses reduced their sense of vulnerability by assessing the possibility of harm, avoiding situations that aroused fear, and confronting the decision for HIV testing. Nurses limited their disclosures to co-workers to avoid rejection and to preserve professional self-esteem. Disclousre to significant others was influenced primarily by the support nurses perceived they would receive. Finally, nurses attempted to assign meaning to the exposure by determining why the event occurred and by evaluating the implications it has had on their lives. The article concludes with implications for nursing practice.

  1. TOWARDS RELIABLE AND COST-EFFECTIVE OZONE EXPOSURE ASSESSMENT: PARAMETER EVALUATION AND MODEL VALIDATION USING THE HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    Science.gov (United States)

    Accurate assessment of chronic human exposure to atmospheric criteria pollutants, such as ozone, is critical for understanding human health risks associated with living in environments with elevated ambient pollutant concentrations. In this study, we analyzed a data set from a...

  2. Potential Role of Pet Cats As a Sentinel Species for Human Exposure to Flame Retardants

    Directory of Open Access Journals (Sweden)

    Luis A. Henríquez-Hernández

    2017-05-01

    Full Text Available Flame retardants are a wide group of chemicals used by the industry to avoid combustion of materials. These substances are commonly found in plastics, electronic equipment, fabrics, and in many other everyday articles. Subsequently, ubiquitous environmental contamination by these common chemical is frequently reported. In the present study, we have evaluated the level of exposure to polychlorinated biphenyls (PCBs, brominated diphenyl ethers (BDEs, and organophosphorous flame retardants (OPFRs in pet cats through the analysis of their serum. We also analyzed the level exposure to such chemicals in a series of 20 cat owners, trying to disclose the role of pet cats as sentinel species of human exposure to FRs. Our results showed that PCBs, banned 40 years ago, showed the lowest levels of exposure, followed by BDEs—banned recently. Congeners PCB-138 and PCB-180 were detected in ≥50% of the series, while BDE-47 was detected in near 90% of the pet cats. On the other hand, the highest levels were that of OPFRs, whose pattern of detection was similar to that observed in humans, thus suggesting a potential role of cats as a sentinel species for human exposure to these currently used FRs. Six out of 11 OPFRs determined [2-ethylhexyldiphenyl phosphate, tributylphosphate, triisobutylphosphate, triphenylphosphate, tris (2-chloroethyl phosphate, and tris (2-chloroisopropyl phosphate] were detected in 100% of the samples. It will be interesting to perform future studied aimed to elucidating the potential toxicological effects of these highly detected chemicals both, in cats and humans.

  3. Human health risk assessment from exposure to trihalomethanes in Canadian cities.

    Science.gov (United States)

    Chowdhury, Shakhawat; Hall, Kevin

    2010-07-01

    Lifetime exposure to trihalomethanes (THMs) through ingestion, inhalation and dermal contacts may pose risks to human health. Current approaches may under predict THMs exposure by using THMs in cold water during showering and bathing. Warming of chlorinated water during showering may increase THMs formation through reactions between organics and residual chlorine, which can increase human health risks. In this study, THMs concentrations in shower water were estimated using THMs rate increase model. Using cold water THMs, exposure through ingestion was estimated, while THMs exposure during showering was estimated using THMs in warm water. Human health cancer risks and additional expenses for 20 most populated Canadian cities from exposure to THMs were estimated. Inhalation and dermal contact during showering contributed 30% to 50% of total cancer risks, while risks from inhalation and dermal contacts were comparable for all cities. Overall cancer risks were estimated between 7.2 x 10(-6) and 6.4 x 10(-5) for these cities. Cancer incidents were estimated highest for Montreal (94/year) followed by Toronto (53/year), which may require additional medical expenses of 18.8 and 10.7 million dollars/year for Montreal and Toronto respectively. Cancer risks from exposure to THMs can be controlled by reducing THMs in water supply and varying shower stall volume, shower duration and air exchange rate in shower stall. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. 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.

  5. Local Adaptation of Sun-Exposure-Dependent Gene Expression Regulation in Human Skin

    Science.gov (United States)

    Kita, Ryosuke; Fraser, Hunter B.

    2016-01-01

    Sun-exposure is a key environmental variable in the study of human evolution. Several skin-pigmentation genes serve as classical examples of positive selection, suggesting that sun-exposure has significantly shaped worldwide genomic variation. Here we investigate the interaction between genetic variation and sun-exposure, and how this impacts gene expression regulation. Using RNA-Seq data from 607 human skin samples, we identified thousands of transcripts that are differentially expressed between sun-exposed skin and non-sun-exposed skin. We then tested whether genetic variants may influence each individual’s gene expression response to sun-exposure. Our analysis revealed 10 sun-exposure-dependent gene expression quantitative trait loci (se-eQTLs), including genes involved in skin pigmentation (SLC45A2) and epidermal differentiation (RASSF9). The allele frequencies of the RASSF9 se-eQTL across diverse populations correlate with the magnitude of solar radiation experienced by these populations, suggesting local adaptation to varying levels of sunlight. These results provide the first examples of sun-exposure-dependent regulatory variation and suggest that this variation has contributed to recent human adaptation. PMID:27760139

  6. Exposure profiles and human papillomavirus infection in skin cancer: an analysis of 25 genus beta-types in a population-based study.

    Science.gov (United States)

    Patel, Anita S; Karagas, Margaret R; Perry, Ann E; Nelson, Heather H

    2008-12-01

    An increasing number of studies report that genus beta human papillomaviruses (HPVs) are associated with skin cancer, with suggestions of specificity for squamous cell carcinoma (SCC) of the skin. We have conducted a systematic examination of HPV DNA in tumors from immunocompetent hosts, including SCC and basal cell carcinoma (BCC), using a highly sensitive methodology and population-based samples to test the hypothesis that a differential prevalence of beta-HPVs exists between SCC (n=101) and BCC (n=101) tumors. When testing for all known beta-HPV types, we found no significant difference in HPV prevalence between the two histologies. However, SCC lesions were significantly more likely to be infected with HPV genus beta-species 1 (includes types 5 and 8), than BCC samples (P=0.01); this difference was not observed for any other species. A histologic difference was also observed for those HPV types previously reported to be important in skin cancer (P=0.003). SCC samples showed a higher rate of infectivity (that is, were positive for multiple types) than BCC tumors (P=0.02). These data highlight the potential importance of various genus beta-HPV types, in particular genus beta-species 1 in SCC, and support the hypothesis of a behavioral difference of the virus within the two major histological skin cancers.

  7. Longitudinal study of pesticide residue levels in human milk from Western Australia during 12 months of lactation: Exposure assessment for infants

    Science.gov (United States)

    Du, Jian; Gridneva, Zoya; Gay, Melvin C. L.; Lai, Ching T.; Trengove, Robert D.; Hartmann, Peter E.; Geddes, Donna T.

    2016-12-01

    The presence of pesticides in human milk (HM) is of great concern due to the potential health effects for the breastfed infant. To determine the relationships between HM pesticides and infant growth and development, a longitudinal study was conducted. HM samples (n = 99) from 16 mothers were collected at 2, 5, 9 and 12 months of lactation. A validated QuEChERS method and Gas chromatography-tandem mass spectrometry (GC-MS/MS) were used for the analysis of 88 pesticides in HM. Only p,p’-DDE, p,p’-DDT and β-HCH were detected with a mean concentration (±SD) of 52.25 ± 49.88 ng/g fat, 27.67 ± 20.96 ng/g fat and 48.00 ± 22.46 ng/g fat respectively. The concentrations of the detected pesticides decreased significantly throughout the first year of lactation. No significant relationships between HM p,p’-DDE and infant growth outcomes: weight, length, head circumference and percentage fat mass were detected. The actual daily intake (ADI) of total DDTs in this cohort was 14-1000 times lower than the threshold reference and significantly lower than the estimated daily intake (EDI). Further, the ADI decreased significantly throughout the first 12 months of lactation.

  8. Modeling Human Exposure to Phthalate Esters: A Comparison of Indirect and Biomonitoring Estimation Methods

    Science.gov (United States)

    Clark, Kathryn E.; David, Raymond M.; Guinn, Richard; Kramarz, Kurt W.; Lampi, Mark A.; Staples, Charles A.

    2011-01-01

    Humans are potentially exposed to phthalate esters (PEs) through ingestion, inhalation, and dermal contact. Studies quantifying exposure to PEs include “biomarker studies” and “indirect studies.” Biomarker studies use measurements of PE metabolites in urine to back-calculate exposure to the parent diester, while indirect studies use the concentration of the PE in each medium of exposure and the rate of intake of that medium to quantify intake of the PE. In this review, exposure estimates from biomarker and indirect studies are compiled and compared for seven PEs to determine if there are regional differences and if there is a preferred approach. The indirect and biomarker methods generally agree with each other within an order of magnitude and discrepancies are explained by difficulties in accounting for use of consumer products, uncertainty concerning absorption, regional differences, and temporal changes. No single method is preferred for estimating intake of all PEs; it is suggested that biomarker estimates be used for low molecular weight PEs for which it is difficult to quantify all sources of exposure and either indirect or biomarker methods be used for higher molecular weight PEs. The indirect methods are useful in identifying sources of exposure while the biomarker methods quantify exposure. PMID:23087593

  9. DUAL ION EXPOSURE VS. SPLIT-DOSE EXPOSURES IN HUMAN CELL NEOPLASTIC TRANSFORMATION.

    Energy Technology Data Exchange (ETDEWEB)

    BENNETT, P.V.; CUTTER, N.C.; SUTHERLAND, B.M.

    2006-06-05

    Since radiation fields of space contain many-fold more protons than high atomic number, high energy (HZE) particles, cells in astronaut crews will experience on average several proton hits before an HZE hit. Thus radiation regimes of proton exposure before HZE particle exposure simulate space radiation exposure, and measurement of the frequency of neoplastic transformation of human primary cells to anchorage-independent growth simulates in initial step in cancer induction. Previously our group found that exposure to 20 cGy 1 GeV/n protons followed within about 1 hr by a HZE ion (20 cGy 1 GeV/n Fe or Ti ions) hit gave about a 3-fold increase in transformation frequency ([1]). To provide insight into the H-HZE induced increased transformation frequencies, we asked if split doses of the same ion gave similar increased transformation frequencies. However, the data show that the split dose of 20 cGy plus 20 cGy of either H or HZE ions gave about the same effect as the 40 cGy uninterrupted dose, quite different from the effect of the mixed ion H + HZE irradiation. We also asked if lower proton doses than 20 cGy followed 15 minutes later by 20 cGy of HZE ions gave greater than additive transformation frequencies. Substantial increases in transformation levels were observed for all proton doses tested, including 1 cGy. These results point to the signal importance of protons in affecting the effect of space radiation on human cells.

  10. 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

  11. 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

  12. 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,

  13. 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, urb

  14. 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.

  15. 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 = C21H30O2; 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.

  16. Scanning electron microscopy study of the effect of the brushing time on the human tooth dentin after exposure to acidic softdrinks.

    Science.gov (United States)

    Kwoni, Eri; Choi, Samjin; Cheong, Youjin; Park, Ki-Ho; Park, Hun-Kuk

    2012-07-01

    Scanning electron microscopy (SEM) was used to examine the abrasive and erosive potential of the brushing time on the dentin surface eroded by acidic soft drinks to suggest an optimized toothbrushing start time after the consumption of cola (pH 2.52) in children. Thirty-six non-carious primary central incisors were assigned to 12 experimental groups (n = 3) based on the erosive and abrasive treatment protocols. Cola exposure was used as the erosive treatment. Three brushing durations (5, 15, and 30 sec) and four brushing start times (immediately, 30 min, 60 min, and 120 min) after an erosive pre-treatment were used for the abrasive treatment. Toothbrushing after exposure to acidic soft drinks led to an increase in the open-tubule fraction and microstructural changes. Toothbrushing immediately after the erosive pre-treatment showed the largest abrasive and erosive potential on the dentin whereas that 60 and 120 min after the pre-treatment showed the least abrasive and erosive potential on the dentin. Toothbrushing for both 60 and 120 min after the pre-treatment showed similar erosive and abrasive potentials on the dentin. The brushing duration showed no effect on the erosive and abrasive potential on the dentin. Therefore, to achieve the desired tooth surface cleaning and less surface lesion on the dentin surface, toothbrushing should be performed at least 1 hour after cola consumption. Three-minute brushing after cola consumption is sufficient to prevent dental lesions, and prolonged brushing can irritate the gingival tissues.

  17. Biological effects of short-term, high-concentration exposure to methyl isocyanate. I. Study objectives and inhalation exposure design.

    OpenAIRE

    Dodd, D E; Frank, F R; Fowler, E H; Troup, C M; Milton, R M

    1987-01-01

    Early reports from India indicated that humans were dying within minutes to a few hours from exposure to methyl isocyanate (MIC). Attempts to explain the cause(s) of these rapid mortalities is where Union Carbide Corporation concentrated its post-Bhopal toxicologic investigations. The MIC studies involving rats and guinea pigs focused primarily on the consequences of acute pulmonary damage. All MIC inhalation exposures were acute, of short duration (mainly 15 min), and high in concentration (...

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

    DEFF Research Database (Denmark)

    Breckenkamp, Jürgen; Berg, Gabriele; Blettner, Maria

    2003-01-01

    electromagnetic pulses similar to those after a nuclear explosion. In all studies (except one that used a qualitative job-exposure-matrix) either the duration of occupational work as an approximation to actual exposure was determined or a simple yes/no differentiation was used based on a definition of high......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...... person years). As exposures were defined: dielectric heaters in a plastic manufacturing plant, working with radio devices (professional and amateur), production of wireless communication technologies, radar devices of the Canadian police, radar units used by the military as well as artificially produced...

  19. Bioanalytical techniques for detecting biomarkers of response to human asbestos exposure

    Science.gov (United States)

    Mesaros, Clementina; Worth, Andrew J; Snyder, Nathaniel W; Christofidou-Solomidou, Melpo; Vachani, Anil; Albelda, Steven M; Blair, Ian A

    2015-01-01

    Asbestos exposure is known to cause lung cancer and mesothelioma and its health and economic impacts have been well documented. The exceptionally long latency periods of most asbestos-related diseases have hampered preventative and precautionary steps thus far. We aimed to summarize the state of knowledge on biomarkers of response to asbestos exposure. Asbestos is not present in human biological fluids; rather it is inhaled and trapped in lung tissue. Biomarkers of response, which reflect a change in biologic function in response to asbestos exposure, are analyzed. Several classes of molecules have been studied and evaluated for their potential utility as biomarkers of asbestos exposure. These studies range from small molecule oxidative stress biomarkers to proteins involved in immune responses. PMID:26039812

  20. Bioanalytical techniques for detecting biomarkers of response to human asbestos exposure.

    Science.gov (United States)

    Mesaros, Clementina; Worth, Andrew J; Snyder, Nathaniel W; Christofidou-Solomidou, Melpo; Vachani, Anil; Albelda, Steven M; Blair, Ian A

    2015-01-01

    Asbestos exposure is known to cause lung cancer and mesothelioma and its health and economic impacts have been well documented. The exceptionally long latency periods of most asbestos-related diseases have hampered preventative and precautionary steps thus far. We aimed to summarize the state of knowledge on biomarkers of response to asbestos exposure. Asbestos is not present in human biological fluids; rather it is inhaled and trapped in lung tissue. Biomarkers of response, which reflect a change in biologic function in response to asbestos exposure, are analyzed. Several classes of molecules have been studied and evaluated for their potential utility as biomarkers of asbestos exposure. These studies range from small molecule oxidative stress biomarkers to proteins involved in immune responses.

  1. 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...

  2. 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...

  3. A systematic review on human exposure to organophosphorus pesticides in Iran.

    Science.gov (United States)

    Shadboorestan, Amir; Vardanjani, Hossein Molavi; Abdollahi, Mohammad; Goharbari, Mohammad Hadi; Khanjani, Narges

    2016-07-02

    Human exposure to organophosphorus (OP) pesticides is a serious health challenge. We conducted a systematic review by searching international and national databases for published literature on any human exposure to OPs in Iran from 1990 to March 2015. Qualified papers were in two categories including studies in which biomarkers of exposure were assessed (n = 13; total no. of subjects = 759) and studies that had reported prevalence of OPs-induced poisoning (OPP) and mortality (n = 26; total no. of subjects = 5428). The mean level of activity of acetyl-cholinesterase and butyryl-cholinesterase were 68.65% and 74.2%, respectively. Overall proportion (%) of OPP was estimated (16; 95% CI, 14 to 19).

  4. Development and Evaluation of a New Air Exchange Rate Algorithm for the Stochastic Human Exposure and Dose Simulation Model (ISES Presentation)

    Science.gov (United States)

    Previous exposure assessment panel studies have observed considerable seasonal, between-home and between-city variability in residential pollutant infiltration. This is likely a result of differences in home ventilation, or air exchange rates (AER). The Stochastic Human Exposure ...

  5. 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

  6. Effects of Long-term Exposure to Hydrogen Sulfide on Human Red Blood Cells

    Directory of Open Access Journals (Sweden)

    A Saeedi

    2015-01-01

    Full Text Available Background: Hydrogen sulfide (H2S exhibits both physiological and toxicological roles in the biological systems. Acute exposure to high levels of H2S is life threatening while long-term exposure to ambient levels of H2S elicits human health effects. Objective: To study the harmful effects of long-term exposure to low levels of H2S on human blood cells. Methods: 110 adult workers from Iran who were occupationally exposed to 0–90 ppb H2S for 1–30 years were studied. The participants aged between 18 and 60 years and were exposed directly or indirectly to sulfur compounds (exposed group. The origin of H2S was natural gas processing plants. A control group consisting of 110 males who were not in contact with H2S was also studied. For all participants, hematological profile including total hemoglobin and red blood cell count and sulfhemoglobin, methemoglobin levels were measured. Results: Among all parameters evaluated in this study the mean methemoglobin and sulfhemoglobin levels were significantly higher among workers who were exposed to sulfur compounds than the control group. Major differences throughout the study period for sulfhemoglobinemia among exposed groups were observed. Conclusion: Long-term exposure to even low levels of H2S in workplaces may have potential harmful effects on human health.

  7. 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.

  8. Controlled exposures of human volunteers to sulfate aerosols. Health effects and aerosol characterization.

    Science.gov (United States)

    Avol, E L; Jones, M P; Bailey, R M; Chang, N M; Kleinman, M T; Linn, W S; Bell, K A; Hackney, J D

    1979-08-01

    Our laboratory has undertaken the study of possible acute adverse health effects of sulfate aerosols through controlled exposures of volunteer human subjects. Both healthy and asthmatic adult men were exposed for 2-hour periods (with intermittent exercise) to ammonium sulfate, ammonium bisulfate, and sulfuric acid of particle size distributions and concentrations intended to simulate "worst case" exposures during Los Angeles smog episodes. Lung function tests were performed by the subjects on entering and before exiting from a carefully controlled environmental chamber. Subject symptoms were evluated in a standardized manner. Aerosol concentrations and size distributions were determined by an on-line computer/aerometric monitoring system; gravimetric and chemical analyses were performed on impactor and total filter samples after test exposures. We found little or no evidence of adverse health effects from 2-hour multiple-day exposures to any of the compounds at "worst case" ambient concentrations.

  9. Use of Mass-Participation Outdoor Events to Assess Human Exposure to Tickborne Pathogens.

    Science.gov (United States)

    Hall, Jessica L; Alpers, Kathrin; Bown, Kevin J; Martin, Stephen J; Birtles, Richard J

    2017-03-01

    Mapping the public health threat of tickborne pathogens requires quantification of not only the density of infected host-seeking ticks but also the rate of human exposure to these ticks. To efficiently sample a high number of persons in a short time, we used a mass-participation outdoor event. In June 2014, we sampled ≈500 persons competing in a 2-day mountain marathon run across predominantly tick-infested habitat in Scotland. From the number of tick bites recorded and prevalence of tick infection with Borrelia burgdoferi sensu lato and B. miyamotoi, we quantified the frequency of competitor exposure to the pathogens. Mass-participation outdoor events have the potential to serve as excellent windows for epidemiologic study of tickborne pathogens; their concerted use should improve spatial and temporal mapping of human exposure to infected ticks.

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

  12. Virtual Reality Exposure and Imaginal Exposure in the Treatment of Fear of Flying: A Pilot Study

    Science.gov (United States)

    Rus-Calafell, Mar; Gutierrez-Maldonado, Jose; Botella, Cristina; Banos, Rosa M.

    2013-01-01

    Fear of flying (FF) is an impairing psychological disorder that is extremely common in developed countries. The most effective treatment for this particular type of phobia is exposure therapy. However, there are few studies comparing imaginal exposure (IE) and virtual reality (VR) exposure for the treatment of FF. The present study compared the…

  13. Virtual Reality Exposure and Imaginal Exposure in the Treatment of Fear of Flying: A Pilot Study

    Science.gov (United States)

    Rus-Calafell, Mar; Gutierrez-Maldonado, Jose; Botella, Cristina; Banos, Rosa M.

    2013-01-01

    Fear of flying (FF) is an impairing psychological disorder that is extremely common in developed countries. The most effective treatment for this particular type of phobia is exposure therapy. However, there are few studies comparing imaginal exposure (IE) and virtual reality (VR) exposure for the treatment of FF. The present study compared the…

  14. 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.

  15. GLI3 Links Environmental Arsenic Exposure and Human Fetal Growth.

    Science.gov (United States)

    Winterbottom, Emily F; Fei, Dennis L; Koestler, Devin C; Giambelli, Camilla; Wika, Eric; Capobianco, Anthony J; Lee, Ethan; Marsit, Carmen J; Karagas, Margaret R; Robbins, David J

    2015-06-01

    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.

  16. Effect of JP-8 jet fuel exposure on protein expression in human keratinocyte cells in culture.

    Science.gov (United States)

    Witzmann, F A; Monteiro-Riviere, N A; Inman, A O; Kimpel, M A; Pedrick, N M; Ringham, H N; Riviere, J E

    2005-12-30

    Dermal exposure to jet fuel is a significant occupational hazard. Previous studies have investigated its absorption and disposition in skin, and the systemic biochemical and immunotoxicological sequelae to exposure. Despite studies of JP-8 jet fuel components in murine, porcine or human keratinocyte cell cultures, proteomic analysis of JP-8 exposure has not been investigated. This study was conducted to examine the effect of JP-8 administration on the human epidermal keratinocyte (HEK) proteome. Using a two-dimensional electrophoretic approach combined with mass spectrometric-based protein identification, we analyzed protein expression in HEK exposed to 0.1% JP-8 in culture medium for 24 h. JP-8 exposure resulted in significant expression differences (p<0.02) in 35 of the 929 proteins matched and analyzed. Approximately, a third of these alterations were increased in protein expression, two-thirds declined with JP-8 exposure. Peptide mass fingerprint identification of effected proteins revealed a variety of functional implications. In general, altered proteins involved endocytotic/exocytotic mechanisms and their cytoskeletal components, cell stress, and those involved in vesicular function.

  17. Tumorigenic effects in Wistar rats orally administered benzo[a] pyrene for two years (gavage studies). Implications for human cancer risks associated with oral exposure to polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Kroese ED; Muller JJA; Mohn GR; Dortant PM; Wester PW; LEO; LPI; CSR

    2002-01-01

    Humans are exposed via the environment and via food to Polycyclic Aromatic Hydrocarbons (PAH), mixtures considered carcinogenic by IARC. A quantitative cancer risk assessment for oral exposure is hampered by the absence of adequate data. The need for experimental data is substantiated by the fact th

  18. Impact of iron and steel industry and waste incinerators on human exposure to dioxins, PCBs, and heavy metals: results of a cross-sectional study in Belgium.

    Science.gov (United States)

    Fierens, Sébastien; Mairesse, Hélène; Heilier, Jean-François; Focant, Jean-François; Eppe, Gauthier; De Pauw, Edwin; Bernard, Alfred

    2007-02-01

    We evaluated the impact of two iron and steel plants and two municipal solid waste incinerators (MSWI) in Wallonia (Belgium) on the exposure of residents to dioxins, polychlorinated biphenyls (PCBs), and heavy metals. In total, 142 volunteers living around these facilities were recruited and compared with 63 referents from a rural area with no industrial source of pollution. Information about smoking habits, dietary habits, anthropometric characteristics, residential history, and health status was obtained from a self-administered questionnaire. The volunteers provided blood under fasting conditions in order to evaluate the body burden of dioxins (17 polychlorinated dibenzo-p-dioxins/dibenzofurans [PCDD/Fs] congeners) and PCBs. Samples of blood and urine were also taken for the determination of cadmium, mercury, and lead. After adjustment for covariates, concentrations of cadmium, mercury, and lead in urine or blood were not increased in subjects living in the vicinity of MSWIs or sinter plants by comparison with referents. Residents around the sinter plants and the MSWI located in the industrial area had concentrations of dioxins and PCBs in serum similar to that of referents. By contrast, subjects living in the vicinity of the MSWI in the rural area showed significantly higher serum levels of dioxins (geometric mean, 38 vs. 24 pg TEQ/g fat) and coplanar PCBs (geometric mean, 10.8 vs. 7.0 pg TEQ/g fat). Although age-adjusted dioxin levels in referents did not vary with local animal fat consumption, concentrations of dioxins in subjects living around the incinerators correlated positively with their intake of local animal fat, with almost a doubling in subjects with the highest fat intake. These results indicate that dioxins and coplanar PCBs emitted by MSWIs can indeed accumulate in the body of residents who regularly consume animal products of local origin.

  19. Human exposure to soil contamination: a qualitative and quantitative analysis towards proposals for human toxicological intervention values (partly revised edition)

    NARCIS (Netherlands)

    Berg R van den; LBG

    1994-01-01

    In view of a revision of the Dutch Soil Protection act, proposals are presented in this report for human toxicologically based intervention values for soil and groundwater, calculated from human toxicological guideline values and human exposure. To this purpose the exposure model CSOIL is presented

  20. Effects of ozone exposure on lipid metabolism in human alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, M.; Madden, M.C.; Samet, J.M. (Univ. of North Carolina, Chapel Hill, NC (United States)); Koren, H.S. (Environmental Protection Agency, Research Triangle Park, NC (United States))

    1992-07-01

    Alveolar macrophages (AM) store arachidonic acid (AA), which is esterified in cellular phospholipids until liberated by phospholipase A[sub C] or C after exposure to inflammatory stimuli. After release, there can be subsequent metabolism of AA into various potent, biologically active mediators including prostaglandins and platelet-activating factor (PAF). To examine the possibility that these mediators may account for some of the pathophysiologic alterations seen in the lung after ozone (O[sub 3]) exposure, human AM were collected by bronchoalveolar lavage of normal subjects, plated into tissue culture dishes, and the adherent cells were incubated with [[sup 3]H]AA or [[sup 3]H]lysoPAF. Human AM exposed to 1.0 ppm O[sub 3] for 2 hr released 65 [+-] 12% more tritium, derived from [[sup 3]H]AA, than paired, air-exposed controls into media supernatants. In other studies using a similar O[sub 3] exposure protocol, there was also a significant increase in human AM prostaglandin E[sub 2] production (2.0 [+-] 0.5-fold increase above air-exposure values, p < 0.02, n = 5). These potent lipid mediators, originally derived from human AM, may play an important role in the mechanisms of O[sub 3] lung toxicity. 25 refs., 2 figs., 5 tabs.

  1. Local-Scale Air Quality Modeling in Support of Human Health and Exposure Research (Invited)

    Science.gov (United States)

    Isakov, V.

    2010-12-01

    Spatially- and temporally-sparse information on air quality is a key concern for air-pollution-related environmental health studies. Monitor networks are sparse in both space and time, are costly to maintain, and are often designed purposely to avoid detecting highly localized sources. Recent studies have shown that more narrowly defining the geographic domain of the study populations and improvements in the measured/estimated ambient concentrations can lead to stronger associations between air pollution and hospital admissions and mortality records. Traditionally, ambient air quality measurements have been used as a primary input to support human health and exposure research. However, there is increasing evidence that the current ambient monitoring network is not capturing sharp gradients in exposure due to the presence of high concentration levels near, for example, major roadways. Many air pollutants exhibit large concentration gradients near large emitters such as major roadways, factories, ports, etc. To overcome these limitations, researchers are now beginning to use air quality models to support air pollution exposure and health studies. There are many advantages to using air quality models over traditional approaches based on existing ambient measurements alone. First, models can provide spatially- and temporally-resolved concentrations as direct input to exposure and health studies and thus better defining the concentration levels for the population in the geographic domain. Air quality models have a long history of use in air pollution regulations, and supported by regulatory agencies and a large user community. Also, models can provide bidirectional linkages between sources of emissions and ambient concentrations, thus allowing exploration of various mitigation strategies to reduce risk to exposure. In order to provide best estimates of air concentrations to support human health and exposure studies, model estimates should consider local-scale features

  2. Human exposure pathways of heavy metals in a lead-zinc mining area, Jiangsu Province, China.

    Directory of Open Access Journals (Sweden)

    Chang-Sheng Qu

    Full Text Available Heavy metal pollution is becoming a serious issue in developing countries such as China, and the public is increasingly aware of its adverse health impacts in recent years. We assessed the potential health risks in a lead-zinc mining area and attempted to identify the key exposure pathways. We evaluated the spatial distributions of personal exposure using indigenous exposure factors and field monitoring results of water, soil, food, and indoor and outdoor air samples. The risks posed by 10 metals and the contribution of inhalation, ingestion and dermal contact pathways to these risks were estimated. Human hair samples were also analyzed to indicate the exposure level in the human body. Our results show that heavy metal pollution may pose high potential health risks to local residents, especially in the village closest to the mine (V1, mainly due to Pb, Cd and Hg. Correspondingly, the residents in V1 had higher Pb (8.14 mg/kg levels in hair than those in the other two villages. Most of the estimated risks came from soil, the intake of self-produced vegetables and indoor air inhalation. This study highlights the importance of site-specific multipathway health risk assessments in studying heavy-metal exposures in China.

  3. 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.

  4. Chromosome distribution studies after inorganic lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Verschaeve, L.; Driesen, M.; Kirsch-Volders, M.; Hens, L.; Susanne, C.

    1979-06-19

    We studied the chromosome distribution in persons professionally exposed to inorganic lead. The degree of lead exposure was evaluated by biochemical measurements and cytogenetic analysis. The chromosome distribution was analyzed from trypsin banded karyotypes; in particular we studied centromere distances (delta2) and centromere-metaphase-center distances (d2) which were obtained by computer-aided mathematical transformation of the individual metaphase coordinates. Higher concentrations of blood lead and urine delta-ALA and a statistically significant increase in aneuploidy, hypoploidy, and type-B chromosome aberrations revealed appreciable exposure although none of the subjects showed signs of excessive lead absorption. However, study of the chromosome distribution showed no major differences with that of the controls indicating that lead acts preferentially (directly or indirectly) on the chromosomes rather than on the spindle apparatus. A dissociation of the acrocentric chromosomes was observed in the lead group when compared with the controls. This is thought to reflect a secondary action of lead on the nucleolar organizer regions.

  5. 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

    Altitude exposure has been associated with loss of appetite and weight loss in healthy humans; however, the endocrine factors that contribute to these changes remain unclear. Leptin and glucagon-like peptide-1 (GLP-1) are peptide hormones that contribute to the regulation of appetite. Leptin...... 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...... to normobaric hypoxia (fraction of inspired oxygen of 12.5%, simulating approximately 4100 m). Plasma leptin was assessed before the meal, and GLP-1 was assessed premeal, at 20 min postmeal, and at 40 min postmeal. We found that hypoxia caused a significant elevation in plasma leptin levels (normoxia, 4.9 +/- 0...

  6. Biological effects of short-term, high-concentration exposure to methyl isocyanate. I. Study objectives and inhalation exposure design

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, D.E.; Frank, F.R.; Fowler, E.H.; Troup, C.M.; Milton, R.M.

    1987-06-01

    Early reports from India indicated that humans were dying within minutes to a few hours from exposure to methyl isocyanate (MIC). Attempts to explain the cause(s) of these rapid mortalities is where Union Carbide Corporation concentrated its post-Bhopal toxicologic investigations. The MIC studies involving rats and guinea pigs focused primarily on the consequences of acute pulmonary damage. All MIC inhalation exposures were acute, of short duration (mainly 15 min), and high in concentration. MIC vapors were statically generated in a double chamber exposure design. Precautionary measures taken during exposures are discussed. Guinea pigs were more susceptible than rats to MIC exposure-related early mortality. A greater than one order of magnitude difference was observed between an MIC concentration that caused no early mortality in rats (3506 ppm) and an MIC concentration that caused partial (6%) early mortality in guinea pigs (225 ppm) for exposures of 10 to 15 min duration. For both species, the most noteworthy clinical signs during exposure were lacrimation, blepharospasm, and mouth breathing. Fifteen minute LC/sub 50/ tests with 14-day postexposure follow-up were conducted, and the LC/sub 50/ (95% confidence limit) values were 171 (114-256) ppm for rats and 112 (61-204) ppm for guinea pigs. Target exposure concentrations for the toxicologic investigations of MIC-induced early mortality were established. A short summary of pertinent results of Union Carbide Corporation's post-Bhopal toxicologic investigations is presented.

  7. Human exposure to fipronil from dogs treated with frontline.

    Science.gov (United States)

    Jennings, K A; Canerdy, T D; Keller, R J; Atieh, B H; Doss, R B; Gupta, R C

    2002-10-01

    This investigation determined fipronil residues on gloves worn while petting dogs after Frontline application. Frontline contains 9.8% fipronil, which controls fleas and ticks on dogs for at least 30 d. Frontline (1.34 ml) was applied topically on adult household dogs and gloves worn for 5 min during pettingwere collected 24 hr and 1, 2, 3, 4 and 5 w post-Frontline application for fipronil residue determinations using GC/MS. The highest concentration of fipronil (589.3 +/- 205.7ppm) was detected 24 h after Frontline application and was undetectable in the gloves collected at 5w. Repeated exposure to such contamination can pose human health risks.

  8. LIPOPOLYSACCHARIDE INDUCES EXPOSURE OF FIBRINOGEN RECEPTORS ON HUMAN PLATELETS

    Institute of Scientific and Technical Information of China (English)

    于希春; 吴其夏

    1995-01-01

    The effect of lipopolysaccharide (LPS) on the exposure of platelet fibrinogen receptors was investigated.The results showed that:1)LPS increased the binding of fibrinogen-gold complexes to platelets and the labels were primarily limited to shape-changed platelets;2)LPS caused a dose-dependent rise in intracellular Ca2+ concentration in platelets;3)LPS induced the activation of platelet protein kinase C(PKC) and the phosphorylation of glycoprotein llla (GP llla) which was inhibited by H-7.All these results suggest that stimulation of platelets with LPS causes a conformational change in glycoprotein llb/Illa (GPllb/llla) through platelet shape change and/or phosphorylation of GPllla via PKC,which serves to expose the fibrinogen binding sites of GPllb/llla on human platelets.

  9. 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.

  10. 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.

  11. 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

    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...... for the integrated assessment of human exposure to air pollutants taking into account latest technological capabilities and contextual information. Highlights ? We review and discuss recent developments and advances of research into personal exposure to air pollution. ? We emphasise the importance of personal...

  12. 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.

  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. 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

  15. 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.

  16. Leptospira Exposure and Gardeners: A Case-Control Seroprevalence Study

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Hernandez-Tinoco, Jesus; Sanchez-Anguiano, Luis Francisco; Ramos-Nevarez, Agar; Cerrillo-Soto, Sandra Margarita; Guido-Arreola, Carlos Alberto

    2016-01-01

    Background Leptospira can be found in soil. However, it is unclear whether occupational exposure to soil may represent a risk for Leptospira infection in humans. Therefore, we sought to determine the association of Leptospira IgG seroprevalence with the occupation of gardener, and to determine the epidemiological characteristics of gardeners associated with Leptospira exposure. Methods We performed a case-control study in 168 gardeners and 168 age- and gender-matched control subjects without gardening occupation in Durango City, Mexico. The seroprevalence of anti-Leptospira IgG antibodies in cases and controls was determined using an enzyme immunoassay. Bivariate and multivariate analyses were used to assess the association of Leptospira exposure and the characteristics of the gardeners. Results Anti-Leptospira IgG antibodies were found in 10 (6%) of 168 gardeners and in 15 (8.9%) of 168 control subjects (odds ratio (OR): 0.64; 95% confidence interval (CI): 0.28 - 1.48; P = 0.40). Multivariate analysis showed that Leptospira seropositivity was positively associated with female gender (OR: 5.82; 95% CI: 1.11 - 30.46; P = 0.03), and negatively associated with eating while working (OR: 0.21; 95% CI: 0.05 - 0.87; P = 0.03). In addition, multivariate analysis showed that high anti-Leptospira levels were associated with consumption of boar meat (OR: 28.00; 95% CI: 1.20 - 648.80; P = 0.03). Conclusions This is the first case-control study of Leptospira exposure in gardeners. Results do not support an association of Leptospira exposure with the occupation of gardener. However, further studies to confirm the lack of this association are needed. The potential role of consumption of boar meat in Leptospira infection deserves further investigation. PMID:26668679

  17. Exposure to phthalates affects calcium handling and intercellular connectivity of human stem cell-derived cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Nikki Gillum Posnack

    Full Text Available The pervasive nature of plastics has raised concerns about the impact of continuous exposure to plastic additives on human health. Of particular concern is the use of phthalates in the production of flexible polyvinyl chloride (PVC products. Di-2-ethylhexyl-phthalate (DEHP is a commonly used phthalate ester plasticizer that imparts flexibility and elasticity to PVC products. Recent epidemiological studies have reported correlations between urinary phthalate concentrations and cardiovascular disease, including an increased risk of high blood pressure and coronary risk. Yet, there is little direct evidence linking phthalate exposure to adverse effects in human cells, including cardiomyocytes.The effect of DEHP on calcium handling was examined using monolayers of gCAMP3 human embryonic stem cell-derived cardiomyocytes, which contain an endogenous calcium sensor. Cardiomyocytes were exposed to DEHP (5 - 50 μg/mL, and calcium transients were recorded using a Zeiss confocal imaging system. DEHP exposure (24 - 72 hr had a negative chronotropic and inotropic effect on cardiomyocytes, increased the minimum threshold voltage required for external pacing, and modified connexin-43 expression. Application of Wy-14,643 (100 μM, an agonist for the peroxisome proliferator-activated receptor alpha, did not replicate DEHP's effects on calcium transient morphology or spontaneous beating rate.Phthalates can affect the normal physiology of human cardiomyocytes, including DEHP elicited perturbations in cardiac calcium handling and intercellular connectivity. Our findings call for additional studies to clarify the extent by which phthalate exposure can alter cardiac function, particularly in vulnerable patient populations who are at risk for high phthalate exposure.

  18. 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

  19. Chronic Exposure to Particulate Chromate Induces Premature Centrosome Separation and Centriole Disengagement in Human Lung Cells

    Science.gov (United States)

    Martino, Julieta; Holmes, Amie L.; Xie, Hong; Wise, Sandra S.; Wise, John Pierce

    2015-01-01

    Particulate hexavalent chromium (Cr(VI)) is a well-established human lung carcinogen. Lung tumors are characterized by structural and numerical chromosome instability. Centrosome amplification is a phenotype commonly found in solid tumors, including lung tumors, which strongly correlates with chromosome instability. Human lung cells exposed to Cr(VI) exhibit centrosome amplification but the underlying phenotypes and mechanisms remain unknown. In this study, we further characterize the phenotypes of Cr(VI)-induced centrosome abnormalities. We show that Cr(VI)-induced centrosome amplification correlates with numerical chromosome instability. We also show chronic exposure to particulate Cr(VI) induces centrosomes with supernumerary centrioles and acentriolar centrosomes in human lung cells. Moreover, chronic exposure to particulate Cr(VI) affects the timing of important centriolar events. Specifically, chronic exposure to particulate Cr(VI) causes premature centriole disengagement in S and G2 phase cells. It also induces premature centrosome separation in interphase. Altogether, our data suggest that chronic exposure to particulate Cr(VI) targets the protein linkers that hold centrioles together. These centriolar linkers are important for key events of the centrosome cycle and their premature disruption might underlie Cr(VI)-induced centrosome amplification. PMID:26293554

  20. Guide to the evaluation of human exposure to noise from large wind turbines

    Science.gov (United States)

    Stephens, D. G.; Shepherd, K. P.; Hubbard, H. H.; Grosveld, F.

    1982-01-01

    Guidance for evaluating human exposure to wind turbine noise is provided and includes consideration of the source characteristics, the propagation to the receiver location, and the exposure of the receiver to the noise. The criteria for evaluation of human exposure are based on comparisons of the noise at the receiver location with the human perception thresholds for wind turbine noise and noise-induced building vibrations in the presence of background noise.

  1. Biomonitoring of human exposures to chlorinated derivatives and structural analogs of bisphenol A.

    Science.gov (United States)

    Andra, Syam S; Charisiadis, Pantelis; Arora, Manish; van Vliet-Ostaptchouk, Jana V; Makris, Konstantinos C

    2015-12-01

    The high reactivity of bisphenol A (BPA) with disinfectant chlorine is evident in the instantaneous formation of chlorinated BPA derivatives (ClxBPA) in various environmental media that show increased estrogen-activity when compared with that of BPA. The documented health risks associated with BPA exposures have led to the gradual market entry of BPA structural analogs, such as bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), etc. A suite of exposure sources to ClxBPA and BPA analogs in the domestic environment is anticipated to drive the nature and range of halogenated BPA derivatives that can form when residual BPA comes in contact with disinfectant in tap water and/or consumer products. The primary objective of this review was to survey all available studies reporting biomonitoring protocols of ClxBPA and structural BPA analogs (BPS, BPF, BPB, etc.) in human matrices. Focus was paid on describing the analytical methodologies practiced for the analysis of ClxBPA and BPA analogs using hyphenated chromatography and mass spectrometry techniques, because current methodologies for human matrices are complex. During the last decade, an increasing number of ecotoxicological, cell-culture and animal-based and human studies dealing with ClxBPA exposure sources and routes of exposure, metabolism and toxicity have been published. Up to date findings indicated the association of ClxBPA with metabolic conditions, such as obesity, lipid accumulation, and type 2 diabetes mellitus, particularly in in-vitro and in-vivo studies. We critically discuss the limitations, research needs and future opportunities linked with the inclusion of ClxBPA and BPA analogs into exposure assessment protocols of relevant epidemiological studies.

  2. Urinary, Circulating, and Tissue Biomonitoring Studies Indicate Widespread Exposure to Bisphenol A

    OpenAIRE

    Laura N Vandenberg; Ibrahim Chahoud; Heindel, Jerrold J.; Vasantha Padmanabhan; Paumgartten, Francisco J. R.; Gilbert Schoenfelder

    2012-01-01

    Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. We examined many possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions. More than 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other f...

  3. 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.

  4. Embryonic atrazine exposure alters zebrafish and human miRNAs associated with angiogenesis, cancer, and neurodevelopment.

    Science.gov (United States)

    Wirbisky, Sara E; Weber, Gregory J; Schlotman, Kelly E; Sepúlveda, Maria S; Freeman, Jennifer L

    2016-12-01

    MicroRNAs (miRNAs) are short, single-stranded RNA that regulate post-transcriptional control of mRNA translation. Knowledge on the role of these critical regulators in toxicological responses in increasing, but is still limited. Atrazine is a herbicide used throughout the Midwestern US that is reported to frequently contaminate potable water supplies above the maximum contaminant level of 3 parts per billion. Atrazine is a suspected endocrine disrupting chemical and studies have begun to investigate the genetic mechanisms of toxicity; however, studies investigating epigenetic mechanisms are limited. In this study both zebrafish and human miRNAs were significantly altered in response to an embryonic atrazine exposure of 0.3, 3, or 30 ppb in zebrafish. Altered miRNAs are known to play a role in angiogenesis, cancer, or neuronal development, differentiation, and maturation. Targeted analysis of altered human miRNAs with genes previously identified to be altered by atrazine exposure revealed several targets linked to cell cycle and cell signaling. Further analysis of hsa-miRNA-126-3p, which had altered expression in all three atrazine treatments at 72 hpf, revealed alterations also occurred at 60 hpf in the 30 ppb treatment group. Results from this study indicate miRNA deregulation in zebrafish and human miRNAs following an embryonic atrazine exposure in zebrafish. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Bisphenol-A exposure and gene expression in human luteinized membrana granulosa cells in vitro.

    Science.gov (United States)

    Mansur, Abdallah; Israel, Ariel; Combelles, Catherine M H; Adir, Michal; Racowsky, Catherine; Hauser, Russ; Baccarelli, Andrea A; Machtinger, Ronit

    2017-02-01

    Does bisphenol-A (BPA) affect gene expression in human membrana granulosa cells (MGC)? In vitro, short exposure to supra-physiological concentrations of BPA alters human MGC gene expression. Exposure to BPA may interfere with reproductive endocrine signaling. In vitro studies, mostly in animal models, have shown an inverse correlation between exposure to BPA and follicular growth, meiosis, and steroid hormone production in granulosa cells. Primary cultures of MGC obtained from 24 patients undergoing IVF (for PGD, male factor infertility or unexplained infertility) were exposed to various concentrations of BPA (0, 0.02, 0.2, 2 or 20 µg/ml) for 48 h. The study was conducted in a university-affiliated hospital. Microarray analysis was used to identify genes exhibiting expression changes following BPA exposure. Genes significantly altered were identified based on changes greater than 2-fold relative to the control group (not treated by BPA) and a Student's t-test P-value <0.05. Statistical significance was adjusted for multiple comparisons using the Benjamini-Hochberg method. Alterations in the expression of genes that are involved in the enriched functional annotations altered by BPA at the concentration of 20 µg/ml were confirmed by real-time PCR. A distinct pattern of gene expression was observed in primary cultures of MGC exposed to the highest BPA concentration compared with untreated cells. We identified 652 genes that exhibited at least 2-fold differences in expression after BPA exposure (all P < 0.05 versus untreated). These genes were significantly enriched for annotations related to cell cycle progression, segregation of chromosomes, steroid metabolism, apoptosis, lipid synthesis, oocyte maturation and chromosomal alignment. No significant changes in gene expression were found at the lower doses of BPA most relevant to human exposure. N/A. Human exposure to BPA in vivo occurs over long periods of time. In this in vitro model, cells were exposed to the

  6. Ochratoxin A in Portugal: A Review to Assess Human Exposure

    Directory of Open Access Journals (Sweden)

    Sofia C. Duarte

    2010-06-01

    Full Text Available In Portugal, the climate, dietary habits, and food contamination levels present the characteristics for higher population susceptibility to ochratoxin A (OTA, one of the known mycotoxins with the greatest public health and agro-economic importance. In this review, following a brief historical insight on OTA research, a summary of the available data on OTA occurrence in food (cereals, bread, wine, meat and biological fluids (blood, urine is made. With this data, an estimation of intake is made to ascertain and update the risk exposure estimation of the Portuguese population, in comparison to previous studies and other populations.

  7. Psychiatric epidemiologic study of occupational lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Parkinson, D.K.; Ryan, C.; Bromet, E.J.; Connell, M.M.

    1986-02-01

    The association of occupational lead exposure with neuropsychiatric functioning was evaluated using data collected in 1982 in eastern Pennsylvania from 288 lead-exposed workers and 181 nonexposed subjects. Both current and cumulative exposure indices were used. After controlling for age, education, and income, few meaningful differences between exposed and control workers were found on either neuropsychologic or psychosocial variables. Dose-response analyses indicated that among lead-exposed workers, cumulative and current exposure were unrelated to neuropsychologic performance. The only meaningful associations occurred between exposure and level of conflict in interpersonal relationships. The results thus give evidence against hypotheses suggesting adverse neuropsychologic effects.

  8. 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

    of near-and far-field pathways and helps to understand the contribution of individual pathways to overall human exposure in various product application contexts. When combined with toxicity information this approach is a resourceful way to inform LCA and CAA and minimize human exposure to toxic chemicals......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...

  9. Mitochondrial function in human skeletal muscle following high-altitude exposure

    DEFF Research Database (Denmark)

    Jacobs, Robert A; Boushel, Robert; Wright-Paradis, Cynthia

    2013-01-01

    Studies regarding mitochondrial modifications in human skeletal muscle following acclimatization to high altitude are conflicting, and these inconsistencies may be due to the prevalence of representing mitochondrial function through static and isolated measurements of specific mitochondrial.......059) to limit mass-specific maximal oxidative phosphorylation capacity. These data suggest that 9-11 days of exposure to high altitude do not markedly modify integrated measures of mitochondrial functional capacity in skeletal muscle despite significant decrements in the concentrations of enzymes involved...

  10. The Influence of the Environment and Clothing on Human Exposure to Ultraviolet Light

    OpenAIRE

    Jin Liu; Wei Zhang

    2015-01-01

    Objection The aim of this study is to determine the effect of clothing and the environment on human exposure to ultraviolet light. Methods The ultraviolet (ultraviolet A and ultraviolet B) light intensity was measured, and air quality parameters were recorded in 2014 in Beijing, China. Three types of clothing (white polyester cloth, pure cotton white T-shirt, and pure cotton black T-shirt) were individually placed on a mannequin. The ultraviolet (ultraviolet A and ultraviolet B) light intensi...

  11. Human exposure to environmental health concern by types of urban environment: The case of Tel Aviv.

    Science.gov (United States)

    Schnell, Izhak; Potchter, Oded; Yaakov, Yaron; Epstein, Yoram

    2016-01-01

    This study classifies urban environments into types characterized by different exposure to environmental risk factors measured by general sense of discomfort and Heart Rate Variability (HRV). We hypothesize that a set of environmental factors (micro-climatic, CO, noise and individual heart rate) that were measured simultaneously in random locations can provide a better understanding of the distribution of human exposure to environmental loads throughout the urban space than results calculated based on measurements from close fixed stations. We measured micro-climatic and thermal load, CO and noise, individual Heart Rate, Subjective Social Load and Sense of Discomfort (SD) were tested by questionnaire survey. The results demonstrate significant differences in exposure to environmental factors among 8 types of urban environments. It appears that noise and social load are the more significant environmental factors to enhance health risks and general sense of discomfort.

  12. Low-Frequency Electromagnetic Field Exposure Enhances Extracellular Trap Formation by Human Neutrophils through the NADPH Pathway.

    Science.gov (United States)

    Golbach, Lieke A; Scheer, Marleen H; Cuppen, Jan J M; Savelkoul, Huub; Verburg-van Kemenade, B M Lidy

    2015-01-01

    Low-frequency (LF) electromagnetic fields (EMFs) are abundantly present in modern society, and the potential biological consequences of exposure to these fields are under intense debate. Immune cells are suggested as possible target cells, though a clear mechanism is lacking. Considering their crucial role in innate immune activation, we selected an ex vivo exposure set-up with human neutrophils to investigate a possible correlation between neutrophil extracellular trap (NET) formation and LF EMF exposure. Our study shows that formation of NETs is enhanced by LF EMF exposure. Enhanced NET formation leads to increased antimicrobial properties as well as damage to surrounding cells. We found that LF-EMF-induced NET formation is dependent on the NADPH oxidase pathway and production of reactive oxygen species. Additionally, LF EMF exposure does not influence autophagy and PAD4 activity. Our study provides a mechanism by which exposure to LF EMFs could influence the innate immune system.

  13. 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...

  14. Developmental exposure to estrogen alters differentiation and epigenetic programming in a human fetal prostate xenograft model.

    Directory of Open Access Journals (Sweden)

    Camelia M Saffarini

    Full Text Available Prostate cancer is the most frequent non-cutaneous malignancy in men. There is strong evidence in rodents that neonatal estrogen exposure plays a role in the development of this disease. However, there is little information regarding the effects of estrogen in human fetal prostate tissue. This study explored early life estrogen exposure, with and without a secondary estrogen and testosterone treatment in a human fetal prostate xenograft model. Histopathological lesions, proliferation, and serum hormone levels were evaluated at 7, 30, 90, and 200-day time-points after xenografting. The expression of 40 key genes involved in prostatic glandular and stromal growth, cell-cycle progression, apoptosis, hormone receptors and tumor suppressors was evaluated using a custom PCR array. Epigenome-wide analysis of DNA methylation was performed on whole tissue, and laser capture-microdissection (LCM isolated epithelial and stromal compartments of 200-day prostate xenografts. Combined initial plus secondary estrogenic exposures had the most severe tissue changes as revealed by the presence of hyperplastic glands at day 200. Gene expression changes corresponded with the cellular events in the KEGG prostate cancer pathway, indicating that initial plus secondary exposure to estrogen altered the PI3K-Akt signaling pathway, ultimately resulting in apoptosis inhibition and an increase in cell cycle progression. DNA methylation revealed that differentially methylated CpG sites significantly predominate in the stromal compartment as a result of estrogen-treatment, thereby providing new targets for future investigation. By using human fetal prostate tissue and eliminating the need for species extrapolation, this study provides novel insights into the gene expression and epigenetic effects related to prostate carcinogenesis following early life estrogen exposure.

  15. 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

  16. Modulation of human alveolar macrophage properties by ozone exposure in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Becker, S.; Madden, M.C.; Newman, S.L.; Devlin, R.B.; Koren, H.S.

    1991-01-01

    The study investigated changes in human alveolar macrophage (HAM) function after exposure in vitro to ozone (O3)(0.1-1.0 ppm for 2-4 hr). The functions studied reflect concern that O3 is detrimental to host defense mechanisms in the bronchoalveolar spaces. Exposure of HAM to O3 caused a concentration-dependent increase in release of prostaglandin E2(PGE2), an important modulator of inflammation, phagocytosis, and oxidative burst. Although phagocytosis of particulate immune complexes was decreased by O3, the authors found no change in the quantity of Fc receptors and complement receptors on the HAM surface. Superoxide (O2) production in response to phorbol ester was reduced after exposure of HAM to O3 while the basal O2 release in response to plastic adherence was not affected. Growth inhibition of the opportunistic yeast Cryptococcus neoformans by HAM was not affected by O3 exposure. The production of inflammatory mediators and immune modulators such as tumor necrosis factor-alpha, interleukin 1, and interleukin 6 were not induced by exposure to O3. However, compared to controls, O3-exposed HAM produced significantly lower levels of these cytokines when simulated with bacterial lipopolysaccharide (LPS).

  17. Human exposure to polychlorinated biphenyls at toxic waste sites: investigations in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Stehr-Green, P.A.; Welty, E.; Burse, V.W.

    1988-11-01

    Beginning in 1982, environmental and population data were evaluated from waste sites contaminated with polychlorinated biphenyls (PCBs). Pilot exposure assessment studies were conducted at 12 sites where risks of human exposure were thought to be greatest. Serum PCB levels in persons at highest risk of nonoccupationally related exposures (because of their self-reported frequencies and types of activities in contaminated areas) at 10 sites were within background ranges, even though environmental contamination levels as high as 2.5 parts per billion (ppb) in monitoring well water samples and 330,000 ppb in soil samples were measured. At the 2 remaining sites, elevated serum levels were found in these high-risk persons, which require further evaluation by community surveys. These results illustrate that, despite elevated environmental contaminant levels, unless uptake of chemicals above background exposure levels can be demonstrated, adverse health effects cannot be attributed to waste site chemicals. However, health risks due to background exposure levels, as well as in populations with elevated PCB body burdens need further study.

  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. 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

  20. Assessment of mercury exposure in human populations: A status report from Augusta Bay (southern Italy).

    Science.gov (United States)

    Bonsignore, Maria; Andolfi, Nunzia; Barra, Marco; Madeddu, Anselmo; Tisano, Francesco; Ingallinella, Vincenzo; Castorina, Maria; Sprovieri, Mario

    2016-10-01

    Here we investigate mercury concentrations in the blood (HgB), urine (HgU) and human hair (HgH) of 224 individuals from a coastal area (Eastern Sicily, SE Italy) strongly affected by Hg contamination from one of the largest chlor-alkali plants in Europe. The factors affecting the distribution of Hg and the extent of the exposure of individuals have been explored with a multidisciplinary approach. Multiple regression analyses, together with evidence of high levels of HgB (exceeding the HBMI recommended levels in 50% of cases) and HgH (exceeding the EPA reference dose in 70% of cases), primarily suggest that the consumption of local fish is the main source of Hg for humans. no. significant exposure to inorganic mercury was identified. Toxicokinetic calculations produced a provisional tolerable weekly intake (PTWI) level that, in most cases, exceeds international recommendations, particularly for residents in the studied area. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. 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.

  2. Modulation of human alveolar macrophage properties by ozone exposure in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Becker, S.; Madden, M.C.; Newman, S.L.; Devlin, R.B.; Koren, H.S. (ABB Environmental Services, Inc., Chapel Hill, NC (United States))

    1991-09-15

    The authors have investigated changes in human alveolar macrophage (HAM) function after exposure in vitro to ozone (O3). The functions studied reflect concern that O3 is detrimental to host defense mechanisms in the bronchoalveolar spaces. Exposure of HAM to O3 caused a concentration-dependent increase in release of prostaglandin E2 (PGE2), an important modulator of inflammation, phagocytosis, and oxidative burst. Although phagocytosis of particulate immune complexes was decreased by O3, we found no change in the quantity of Fc receptors and complement receptors on the HAM surface. Superoxide (O2-) production in response to phorbol ester was reduced after exposure of HAM to O3 while the basal O2- release in response to plastic adherence was not affected. Growth inhibition of the opportunistic yeast Cryptococcus neoformans by HAM was not affected by O3 exposure. The production of inflammatory mediators and immune modulators such as tumor necrosis factor-alpha, interleukin 1, and interleukin 6 were not induced by exposure to O3. However, compared to controls, O3- exposed HAM produced significantly lower levels of these cytokines when stimulated with bacterial lipopolysaccharide (LPS). Two-dimensional gel electrophoretic analysis of proteins made by HAM following in vitro exposure to O3 identified 11 proteins whose rate of synthesis was significantly altered. Thus, these studies show that exposure to O3 alters the functional competence of HAM. While there is a minimal effect on protein expression or synthesis, the responses of HAM to particulate immune complexes, to bacterial LPS, and to PMA are impaired. The release of arachidonic acid and PGE2 suggest that the effect of O3 is primarily targeted to the HAM cell membrane. These changes may ultimately result in increased susceptibility to inhaled infectious agents in the O3-exposed individual.

  3. Exposure Measurement Error in PM2.5 Health Effects Studies: A Pooled Analysis of Eight Personal Exposure Validation Studies

    Science.gov (United States)

    Background: Exposure measurement error is a concern in long-term PM2.5 health studies using ambient concentrations as exposures. We assessed error magnitude by estimating calibration coefficients as the association between personal PM2.5 exposures from validation studies and typ...

  4. 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.

  5. In vitro exposure of human chondrocytes to pulsed electromagnetic fields

    Directory of Open Access Journals (Sweden)

    V Nicolin

    2009-08-01

    Full Text Available The effect of pulsed electromagnetic fields (PEMFs on the proliferation and survival of matrix-induced autologous chondrocyte implantation (MACI®-derived cells was studied to ascertain the healing potential of PEMFs. MACI-derived cells were taken from cartilage biopsies 6 months after surgery and cultured. No dedifferentiation towards the fibroblastic phenotype occurred, indicating the success of the surgical implantation. The MACI-derived cultured chondrocytes were exposed to 12 h/day (short term or 4 h/day (long term PEMFs exposure (magnetic field intensity, 2 mT; frequency, 75 Hz and proliferation rate determined by flow cytometric analysis. The PEMFs exposure elicited a significant increase of cell number in the SG2M cell cycle phase. Moreover, cells isolated from MACI® scaffolds showed the presence of collagen type II, a typical marker of chondrocyte functionality. The results show that MACI® membranes represent an optimal bioengineering device to support chondrocyte growth and proliferation in surgical implants. The surgical implant of MACI® combined with physiotherapy is suggested as a promising approach for a faster and safer treatment of cartilage traumatic lesions.

  6. Short GSM mobile phone exposure does not alter human auditory brainstem response

    Directory of Open Access Journals (Sweden)

    Thuróczy György

    2007-11-01

    Full Text Available Abstract Background There are about 1.6 billion GSM cellular phones in use throughout the world today. Numerous papers have reported various biological effects in humans exposed to electromagnetic fields emitted by mobile phones. The aim of the present study was to advance our understanding of potential adverse effects of the GSM mobile phones on the human hearing system. Methods Auditory Brainstem Response (ABR was recorded with three non-polarizing Ag-AgCl scalp electrodes in thirty young and healthy volunteers (age 18–26 years with normal hearing. ABR data were collected before, and immediately after a 10 minute exposure to 900 MHz pulsed electromagnetic field (EMF emitted by a commercial Nokia 6310 mobile phone. Fifteen subjects were exposed to genuine EMF and fifteen to sham EMF in a double blind and counterbalanced order. Possible effects of irradiation was analyzed by comparing the latency of ABR waves I, III and V before and after genuine/sham EMF exposure. Results Paired sample t-test was conducted for statistical analysis. Results revealed no significant differences in the latency of ABR waves I, III and V before and after 10 minutes of genuine/sham EMF exposure. Conclusion The present results suggest that, in our experimental conditions, a single 10 minute exposure of 900 MHz EMF emitted by a commercial mobile phone does not produce measurable immediate effects in the latency of auditory brainstem waves I, III and V.

  7. The Human Bitumen Study: executive summary.

    Science.gov (United States)

    Raulf-Heimsoth, Monika; Pesch, Beate; Rühl, Reinhold; Brüning, Thomas

    2011-06-01

    Bitumen has attracted attention from the scientific community and regulating agencies. The debate on health effects of exposure to vapours and aerosols of bitumen during the hot application of bitumen ranges from respiratory and neurological effects to carcinogenicity. In 2000, the German Hazardous Substances Committee (AGS), in collaboration with the German Bitumen Forum, initiated the examination of a group of mastic asphalt workers and a same number of construction workers without exposure bitumen using a cross-shift design. The study was then extended to the Human Bitumen Study, and the recruitment was finished in 2008 after examination of 500 workers on 80 construction sites. Three hundred and twenty workers exposed to vapours and aerosols of bitumen at high processing temperatures and 118 workers at outdoor construction sites were included. In the Human Bitumen Study external exposure to vapours and aerosols of bitumen, internal exposure to PAH by analysing urinary 1-hydroxypyrene, the sum of hydroxyphenanthrenes and the sum of 1- and 2-hydroxynaphthalenes, irritative effects in the upper and lower airways and genotoxic effects in blood cells were investigated. The study turned out to be one of the largest investigations of workers exposed to vapours and aerosols of bitumen under current exposure conditions. The present paper summarizes its background and main topics.

  8. USE OF DISPOSABLE DIAPERS TO COLLECT URINE IN EXPOSURE STUDIES

    Science.gov (United States)

    Large studies of children's health as it relates to exposures to chemicals in the environment often require measurements of biomarkers of chemical exposures or effects in urine samples. But collection of urine samples from infants and toddlers is difficult. For large exposure s...

  9. The uses of exposure and risk in road safety studies.

    NARCIS (Netherlands)

    Hakkert, A.S. & Braimaister, L.

    2002-01-01

    This report explores the theoretical possibilities of defining exposure and risk, discusses the problems associated with the use of exposure and risk, and gives examples of various safety studies in which use is made of exposure and risk indicators. The report sets out with a definition of the three

  10. Acute Meteorite Dust Exposure and Pulmonary Inflammation - Implications for Human Space Exploration

    Science.gov (United States)

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

    2017-01-01

    The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness [1-3]" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure [4]. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles [1]. Due to the prevalence of these high exposures, 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 [5]. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive [2, 6-9], and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz [6]. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary

  11. Pulmonary Inflammatory Responses To Acute Meteorite Dust Exposures - Implications For Human Space Exploration

    Science.gov (United States)

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

    2017-01-01

    The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, 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. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive, and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative

  12. Air Pollution Exposure Modeling for Health Studies | Science ...

    Science.gov (United States)

    Dr. Michael Breen is leading the development of air pollution exposure models, integrated with novel personal sensor technologies, to improve exposure and risk assessments for individuals in health studies. He is co-investigator for multiple health studies assessing the exposure and effects of air pollutants. These health studies include participants with asthma, diabetes, and coronary artery disease living in various U.S. cities. He has developed, evaluated, and applied novel exposure modeling and time-activity tools, which includes the Exposure Model for Individuals (EMI), GPS-based Microenvironment Tracker (MicroTrac) and Exposure Tracker models. At this seminar, Dr. Breen will present the development and application of these models to predict individual-level personal exposures to particulate matter (PM) for two health studies in central North Carolina. These health studies examine the association between PM and adverse health outcomes for susceptible individuals. During Dr. Breen’s visit, he will also have the opportunity to establish additional collaborations with researchers at Harvard University that may benefit from the use of exposure models for cohort health studies. These research projects that link air pollution exposure with adverse health outcomes benefit EPA by developing model-predicted exposure-dose metrics for individuals in health studies to improve the understanding of exposure-response behavior of air pollutants, and to reduce participant

  13. Dermal absorption and skin damage following hydrofluoric acid exposure in an ex vivo human skin model.

    Science.gov (United States)

    Dennerlein, Kathrin; Kiesewetter, Franklin; Kilo, Sonja; Jäger, Thomas; Göen, Thomas; Korinth, Gintautas; Drexler, Hans

    2016-04-25

    The wide industrial use of hydrofluoric acid (HF) poses a high risk for accidental dermal exposure. Despite local and systemic hazards associated with HF, information on percutaneous penetration and tissue damage is rare. In the present ex vivo study, the dermal absorption of HF (detected in terms of fluoride ions) was quantified and the skin damaging potential as a function of concentration and exposure duration was assessed. Percutaneous penetration of HF (c=5, 30, and 50%) at 3 exposure durations (3, 5, and 10 min) was investigated in a static diffusion cell model using freshly excised human skin. Alterations of skin were histologically evaluated. HF rapidly penetrated through skin under formation of a considerable intradermal reservoir (∼ 13-67% of total absorbed fluoride). Histologically, epidermal alterations were detected already after exposure to 5% HF for 3 min. The degree of skin damage increased with rising concentration and exposure duration leading to coagulation necrosis. For HF concentrations of ≥ 30%, skin damage progressed into deeper skin layers. Topically applied HF concentration was the principal parameter determining HF induced skin effects. The intradermal HF retention capacity associated with progression and prolongation of HF induced skin effects must be considered in the review of skin decontamination procedures.

  14. International issues on human health effects of exposure to chemical mixtures.

    Science.gov (United States)

    Feron, Victor J; Cassee, Flemming R; Groten, John P; van Vliet, Petronella W; van Zorge, Job A

    2002-12-01

    In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a tool in safety evaluation of complex mixtures. A "bottom-up" approach for chemosensory detection of mixtures has recently been presented. Other topics include a method for the safety evaluation of natural flavoring complexes, and an evaluation of the possible health effects of the simultaneous intake of food additives. Examples of issues related to mixtures of airborne chemicals are potential interaction of fine particles and gaseous pollutants in ambient air, nasal cancer associated with inhaled chemical mixtures, and the recommendation of a limit value for volatile organic compounds. Topics of a more strategic nature include studies concerning the public health effects of large airports, and the development of criteria for a harmonized classification of chemical mixtures. This overview illustrates that strategies to tackle the safety evaluation of combined exposures and complex mixtures as well as models facilitating the interpretation of findings in the context of risk assessment of mixtures have become increasingly important. It is true that exposure of humans to chemical mixtures is the rule rather than the exception, and therefore health risk assessments should focus on mixtures and not on single chemicals. It is also true, however, that humans have learned to cope with exposure to huge numbers of chemicals simultaneously (food, water, air, soil, and consumer products). Therefore, in view of limited resources for toxicological research, the focus in toxicology should be

  15. 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.

  16. Human urinary mutagenicity after wood smoke exposure during traditional temazcal use.

    Science.gov (United States)

    Long, Alexandra S; Lemieux, Christine L; Yousefi, Paul; Ruiz-Mercado, Ilse; Lam, Nicholas L; Orellana, Carolina Romero; White, Paul A; Smith, Kirk R; Holland, Nina

    2014-09-01

    In Central America, the traditional temazcales or wood-fired steam baths, commonly used by many Native American populations, are often heated by wood fires with little ventilation, and this use results in high wood smoke exposure. Urinary mutagenicity has been previously employed as a non-invasive biomarker of human exposure to combustion emissions. This study examined the urinary mutagenicity in 19 indigenous Mayan families from the highlands of Guatemala who regularly use temazcales (N = 32), as well as control (unexposed) individuals from the same population (N = 9). Urine samples collected before and after temazcal exposure were enzymatically deconjugated and extracted using solid-phase extraction. The creatinine-adjusted mutagenic potency of urine extracts was assessed using the plate-incorporation version of the Salmonella mutagenicity assay with strain YG1041 in the presence of exogenous metabolic activation. The post-exposure mutagenic potency of urine extracts were, on average, 1.7-fold higher than pre-exposure samples (P temazcal use (P temazcal were positively associated with urinary mutagenic potency (i.e. P temazcal use contributes to increased excretion of conjugated mutagenic metabolites. Moreover, urinary mutagenic potency is correlated with other metrics of exposure (i.e. exhaled CO, duration of exposure). Since urinary mutagenicity is a biomarker associated with genetic damage, temazcal use may therefore be expected to contribute to an increased risk of DNA damage and mutation, effects associated with the initiation of cancer. © The Author 2014. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society.

  17. Effects of bright light exposure during daytime on peripheral clock gene expression in humans

    Science.gov (United States)

    Sato, Maki; Wakamura, Tomoko; Morita, Takeshi; Okamoto, Akihiko; Akashi, Makoto; Matsui, Takuya; Sato, Motohiko

    2016-12-01

    Light is the strongest synchronizer controlling circadian rhythms. The intensity and duration of light change throughout the year, thereby influencing body weight, food preferences, and melatonin secretion in humans and animals. Although the expression of clock genes has been examined using human samples, it currently remains unknown whether bright light during the daytime affects the expression of these genes in humans. Therefore, we herein investigated the effects of bright light exposure during the daytime on clock gene expression in the hair follicular and root cells of the human scalp. Seven healthy men (20.4 ± 2.2 years old; 172.3 ± 5.8 cm; 64.3 ± 8.5 kg; BMI 21.7 ± 3.1 kg/m2, mean ± SD) participated in this study. Subjects completed 3-day experimental sessions twice in 1 month during which they were exposed to bright and dim light conditions. The mRNA expression of Per1-3, Cry1-2, Rev-erb-α (Nr1d1), Rev-erb-β (Nr1d2), and Dec1 was analyzed using branched DNA probes. No significant changes were observed in the expression of Per1, Per2, Per3, Cry1, Cry2, Rev-erb-α (Nr1d1), or Dec1 following exposure to bright light conditions. However, the expression of Rev-erb-β (Nr1d2) tended to be stronger under bright light than dim light conditions. These results suggest that the bright light stimulus did not influence the expression of clock genes in humans. Long-lasting bright light exposure during the daytime may be required to change the expression of clock genes in humans.

  18. LC-MS/MS-based multibiomarker approaches for the assessment of human exposure to mycotoxins.

    Science.gov (United States)

    Warth, Benedikt; Sulyok, Michael; Krska, Rudolf

    2013-07-01

    Mycotoxins are toxic fungal secondary metabolites that frequently contaminate food and feed worldwide, and hence represent a major hazard for food and feed safety. To estimate human exposure arising from contaminated food, so-called biomarker approaches have been developed as a complementary biomonitoring tool besides traditional food analysis. The first methods based on radioimmunoassays and enzyme-linked immunosorbent assays as well as on liquid chromatography were developed in the late 1980s and early 1990s for the carcinogenic aflatoxins and in the last two decades further tailor-made methods for some major mycotoxins have been published. Since 2010, there has been a clear trend towards the development and application of multianalyte methods based on liquid chromatography-electrospray ionization tandem mass spectrometry for assessment of mycotoxin exposure made possible by the increased sensitivity and selectivity of modern mass spectrometry instrumentation and sophisticated sample cleanup approaches. With use of these advanced methods, traces of mycotoxins and relevant breakdown and conjugation products can be quantified simultaneously in human urine as so-called biomarkers and can be used to precisely describe the real exposure, toxicokinetics, and bioavailability of the toxins present. In this article, a short overview and comparison of published multibiomarker methods focusing on the determination of mycotoxins and relevant excretion products in human urine is presented. Special attention is paid to the main challenges when analyzing these toxic food contaminants in urine, i.e., very low analyte concentrations, appropriate sample preparation, matrix effects, and a lack of authentic, NMR-confirmed calibrants and reference materials. Finally, the progress in human exposure assessment studies facilitated by these analytical methods is described and an outlook on probable developments and possibilities is presented.

  19. 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

  20. [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

  1. Predicting pulmonary fibrosis in humans after exposure to multi-walled carbon nanotubes (MWCNTs).

    Science.gov (United States)

    Sharma, Monita; Nikota, Jake; Halappanavar, Sabina; Castranova, Vincent; Rothen-Rutishauser, Barbara; Clippinger, Amy J

    2016-07-01

    The increased production and use of multi-walled carbon nanotubes (MWCNTs) in a diverse array of consumer, medical, and industrial applications have raised concerns about potential human exposure to these materials in the workplace and ambient environments. Inhalation is a primary route of exposure to MWCNTs, and the existing data indicate that they are potentially hazardous to human health. While a 90-day rodent inhalation test (e.g., OECD Test No. 413: subchronic inhalation toxicity: 90-day study or EPA Health Effects Test Guidelines OPPTS 870.3465 90-day inhalation toxicity) is recommended by the U.S. Environmental Protection Agency Office of Pollution Prevention and Toxics for MWCNTs (and other CNTs) if they are to be commercially produced (Godwin et al. in ACS Nano 9:3409-3417, 2015), this test is time and cost-intensive and subject to scientific and ethical concerns. As a result, there has been much interest in transitioning away from studies on animals and moving toward human-based in vitro and in silico models. However, given the multiple mechanisms of toxicity associated with subchronic exposure to inhaled MWCNTs, a battery of non-animal tests will likely be needed to evaluate the key endpoints assessed by the 90-day rodent study. Pulmonary fibrosis is an important adverse outcome related to inhalation exposure to MWCNTs and one that the non-animal approach should be able to assess. This review summarizes the state-of-the-science regarding in vivo and in vitro toxicological methods for predicting MWCNT-induced pulmonary fibrosis.

  2. 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.

  3. 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…

  4. 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…

  5. Developing and evaluating distributions for probabilistic human exposure assessments

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy L.; McKone, Thomas E.

    2002-08-01

    reviewing it. For deterministic risk assessments, the use of default inputs has improved the ease and the consistency of both performing and reviewing assessments. By analogy, it is expected that similar advantage will be seen in the field of probabilistic risk assessment through the introduction of default distributions. In Part 2 of this report, we consider when a default distribution might be appropriate for use in PRA and work towards development of recommended task-specific distributions for several frequently used exposure factors. An approach that we develop using body weight and exposure duration as case studies offers a transparent way for developing task-specific exposure factor distributions. A third case study using water intake highlights the need for further study aimed at improving the relevance of ''short-term'' data before recommendations on task-specific distributions of water intake can be made.

  6. 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...

  7. Limiting criteria for human exposure to low humidity indoors

    DEFF Research Database (Denmark)

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

    2002-01-01

    % 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...

  8. Occurrence and human exposure of parabens and their chlorinated derivatives in swimming pools.

    Science.gov (United States)

    Li, Wenhui; Shi, Yali; Gao, Lihong; Liu, Jiemin; Cai, Yaqi

    2015-11-01

    As an emerging group of endocrine-disrupting chemicals, parabens have attracted growing attention due to their potential effects on human health. In the present study, the occurrence and distribution of eight parabens, four chlorinated parabens, and their common hydrolysis product, p-hydroxybenzoic acid (PHBA), were investigated in 39 swimming pools in Beijing, China. Methyl paraben and propyl paraben were the predominant compounds in swimming pools, accounting for 91.2 % of the total parabens. It is noteworthy that octyl paraben, a paraben with longer chain, was firstly detected in this study. There were several factors affecting the levels of parabens among the 39 swimming pools. The concentrations of parabens and chlorinated derivatives detected in indoor pools (144 ng L(-1)) were roughly 20-fold higher than those in outdoor pools (6.78 ng L(-1)). Hotel pools appear to present higher level of target compounds (361 ng L(-1)) than that in health club (228 ng L(-1)), municipal (130 ng L(-1)), school (75.6 ng L(-1)), and community pools (63.0 ng L(-1)). Moreover, the level of these compounds in pools during weekends (174 ng L(-1)) was much higher than that during weekdays (52.3 ng L(-1)). The dynamics of target compounds were also investigated to provide a general trend of the level of parabens in a school indoor swimming pool during a 14-week period. Human exposure assessment was conducted to estimate the potential risk of exposure to parabens and their chlorinated derivatives in swimming pools. Considering the total exposure dose of multiple parabens, human exposure to parabens from the water of swimming pools is negligible. However, the threat of these parabens to children in swimming pool should be concerned.

  9. Does D-cycloserine enhance exposure therapy for anxiety disorders in humans? A meta-analysis.

    Directory of Open Access Journals (Sweden)

    Helga Rodrigues

    Full Text Available The treatment of anxiety is on the edge of a new era of combinations of pharmacologic and psychosocial interventions. A new wave of translational research has focused on the use of pharmacological agents as psychotherapy adjuvants using neurobiological insights into the mechanism of the action of certain psychological treatments such as exposure therapy. Recently, d-cycloserine (DCS an antibiotic used to treat tuberculosis has been applied to enhance exposure-based treatment for anxiety and has proved to be a promising, but as yet unproven intervention. The present study aimed to evaluate the efficacy of DCS in the enhancement of exposure therapy in anxiety disorders. A systematic review/meta-analysis was conducted. Electronic searches were conducted in the databases ISI-Web of Science, Pubmed and PsycINFO. We included only randomized, double-blind, placebo-controlled trials with humans, focusing on the role of DCS in enhancing the action of exposure therapy for anxiety disorders. We identified 328 references, 13 studies were included in our final sample: 4 on obsessive-compulsive disorder, 2 on panic disorder, 2 on social anxiety disorder, 2 on posttraumatic stress disorder, one on acrophobia, and 2 on snake phobia. The results of the present meta-analysis show that DCS enhances exposure therapy in the treatment of anxiety disorders (Cohen d =  -0.34; CI: -0.54 to -0.14, facilitating the specific process of extinction of fear. DCS seems to be effective when administered at a time close to the exposure therapy, at low doses and a limited number of times. DCS emerges as a potential new therapeutic approach for patients with refractory anxiety disorders that are unresponsive to the conventional treatments available. When administered correctly, DCS is a promising strategy for augmentation of CBT and could reduce health care costs, drop-out rates and bring faster relief to patients.

  10. Human biomonitoring pilot study DEMOCOPHES in Germany

    DEFF Research Database (Denmark)

    Schwedler, Gerda; Seiwert, Margarete; Fiddicke, Ulrike

    2017-01-01

    on a European Scale) and DEMOCOPHES (Demonstration of a study to Coordinate and Perform Human Biomonitoring on a European Scale) were formed, comprising 35 partners from 27 European countries. In COPHES a research scheme and guidelines were developed to exemplarily measure in a pilot study mercury in hair......Human biomonitoring (HBM) is an effective tool to assess human exposure to environmental pollutants, but comparable HBM data in Europe are lacking. In order to expedite harmonization of HBM studies on a European scale, the twin projects COPHES (Consortium to Perform Human Biomonitoring......, cadmium, cotinine and several phthalate metabolites in urine of 6–11 year old children and their mothers in an urban and a rural region. Seventeen European countries simultaneously conducted this cross-sectional DEMOCOPHES feasibility study. The German study population was taken in the city of Bochum...

  11. Novel Insights in the Regulation of Phosphatidylserine Exposure in Human Red Blood Cells

    Directory of Open Access Journals (Sweden)

    Mauro C. Wesseling

    2016-10-01

    Full Text Available Background/Aims: In previous publications we were able to demonstrate the exposure of phosphatidylserine (PS in the outer membrane leaflet after activation of red blood cells (RBCs by lysophosphatidic acid (LPA, phorbol-12 myristate-13acetate (PMA, or 4-bromo-A23187 (A23187. It has been concluded that three different mechanisms are responsible for the PS exposure in human RBCs: (i Ca2+-stimulated scramblase activation (and flippase inhibition by A23187, LPA, and PMA; (ii PKCα activation by LPA and PMA; and (iii enhanced lipid flip flop caused by LPA. Further studies aimed to elucidate interconnections between the increased Ca2+ content, scramblase- and PKCα-activation. In addition, the role of the Ca2+-activated K+ channel (Gardos channel activity in the process of PS exposure needs to be investigated. Methods: The intracellular Ca2+ content and the PS exposure of RBCs have been investigated after treatment with LPA (2.5 µM, PMA (6 µM, or A23187 (2 µM. Fluo-4 and annexin V-FITC has been used to detect intracellular Ca2+ content and PS exposure, respectively. Both parameters (Ca2+ content, PS exposure were studied using flow cytometry. Inhibitors of the scramblase, the PKCα, and the Gardos channel have been applied. Results: The percentage of RBCs showing PS exposure after activation with LPA, PMA, or A23187 is significantly reduced after inhibition of the scramblase using the specific inhibitor R5421 as well as after the inhibition of the PKCα using chelerythrine chloride or calphostin C. The inhibitory effect is more pronounced when the scramblase and the PKCα are inhibited simultaneously. Additionally, the inhibition of the Gardos channel using charybdotoxin resulted in a significant reduction of the percentage of RBCs showing PS exposure under all conditions measured. Similar results were obtained when the Gardos channel activity was suppressed by increased extracellular K+ content. Conclusion: PS exposure is mediated by the Ca2

  12. Secretion of interferon gamma from human immune cells is altered by exposure to tributyltin and dibutyltin.

    Science.gov (United States)

    Lawrence, Shanieek; Reid, Jacqueline; Whalen, Margaret

    2015-05-01

    Tributyltin (TBT) and dibutyltin (DBT) are widespread environmental contaminants found in food, beverages, and human blood samples. Both of these butyltins (BTs) interfere with the ability of human natural killer (NK) cells to lyse target cells and alter secretion of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) from human immune cells in vitro. The capacity of BTs to interfere with secretion of other pro-inflammatory cytokines has not been examined. Interferon gamma (IFNγ) is a modulator of adaptive and innate immune responses, playing an important role in overall immune competence. This study shows that both TBT and DBT alter secretion of IFNγ from human immune cells. Peripheral blood cell preparations that were increasingly reconstituted were used to determine if exposures to either TBT or DBT affected IFNγ secretion and how the makeup of the cell preparation influenced that effect. IFNγ secretion was examined after 24 h, 48 h, and 6 day exposures to TBT (200 - 2.5 nM) and DBT (5 - 0.05 µM) in highly enriched human NK cells, a monocyte-depleted preparation of PBMCs, and monocyte-containing PBMCs. Both BTs altered IFNγ secretion from immune cells at most of the conditions tested (either increasing or decreasing secretion). However, there was significant variability among donors as to the concentrations and time points that showed changes as well as the baseline secretion of IFNγ. The majority of donors showed an increase in IFNγ secretion in response to at least one concentration of TBT or DBT at a minimum of one length of exposure.

  13. Phthalates and parabens in personal care products from China: concentrations and human exposure.

    Science.gov (United States)

    Guo, Ying; Wang, Lei; Kannan, Kurunthachalam

    2014-01-01

    Our previous studies showed that populations in China are widely exposed to phthalates and parabens. Nevertheless, sources of Chinese exposure to phthalates and parabens are not well understood. In this study, we measured concentrations of nine phthalates and six parabens in five categories of personal care products (PCPs, N = 52) collected from Tianjin, China, and estimated human exposure doses to these compounds. The most frequently detected phthalates and parabens in PCPs were diethyl phthalate (DEP) (detection frequency 54 %), methyl paraben (MeP), and n-propyl paraben (PrP) (~75 %). The concentrations of DEP in PCPs ranged from not detected (ND; parabens through dermal application of PCPs in China was estimated at 18,700 μg/d, which was two orders of magnitude greater than that calculated for phthalates (45.5 μg/d). Hand and body lotions were the major contributors to exposures, and the daily exposure doses for DEP, MeP, and PrP from these products were 38.4, 10,200 and 4,890 μg, respectively.

  14. Organophosphorus flame retardants in house dust from the Philippines: occurrence and assessment of human exposure.

    Science.gov (United States)

    Kim, Joon-Woo; Isobe, Tomohiko; Sudaryanto, Agus; Malarvannan, Govindan; Chang, Kwang-Hyeon; Muto, Mamoru; Prudente, Maricar; Tanabe, Shinsuke

    2013-02-01

    The use of organophosphorus flame retardants (PFRs) as flame retardants and plasticizers has increased due to the ban on common polybrominated diphenyl ether mixtures. However, only limited information on PFR contamination is available so far from Southeast Asia. In the present study, residual levels of PFRs in house dust and exposure through dust ingestion were investigated in the Philippines. House dust samples (n = 37) were collected from Malate (residential area) and Payatas (municipal dumping area) in the Philippines and analyzed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. Among the targeted seven PFRs, triphenyl phosphate (TPP) was the predominant compound. Median levels of ΣPFRs in Malate (530 ng/g) were two times higher (p < 0.05) than in Payatas (240 ng/g). The estimated daily intake of PFRs in the Philippines (of areas studied) via house dust ingestion was below the guideline values. House dust may be an important contributor in the overall exposure of humans to TPP even when considering dietary sources. To our knowledge, this is a first report on PFR contamination in house dust from developing country. PFRs were ubiquitously detected in the home environments in the Philippines. Although estimated exposure levels through dust ingestion were below the guideline, it was suggested that toddlers are at higher risk. Therefore, further investigations to understand the behavior of PFRs in house and other microenvironments and overall exposure pathways for the country's populace to PFRs are necessary.

  15. Bisphenol A in supermarket receipts and its exposure to human in Shenzhen, China.

    Science.gov (United States)

    Lu, Shao-You; Chang, Wen-Jing; Sojinu, Samuel O; Ni, Hong-Gang

    2013-08-01

    Paper receipt has been documented as one major source of bisphenol A (BPA) for human exposure but little has been done by researchers to elaborate the potential health risk caused by handling paper receipt up to date. In the present study, BPA was analyzed in 42 supermarket receipts collected from Shenzhen, China. BPA was detected in all samples at concentrations ranging from 2.58 to 14.7mgg(-1). In most cases, the total amount of BPA on the receipt was at least one thousand times the amount found in the epoxy lining of a food can, another controversial use of the chemical. The estimated daily intakes (EDI) of BPA via handling of supermarket receipt ranged from 2 to 347μgday(-1) (mean, 40.4μgday(-1)) for a supermarket cashier and from 0.24 to 3.98μgday(-1) (mean, 0.69μgday(-1)) for general population. Based on the cumulative probability distribution of the calculated daily exposure to BPA via handling supermarket receipt, the EDI at the 0.1th and 1th percentile for supermarket cashier and general population, were already larger than 100ng (kgbw)(-1)day(-1), while at the 0.2th and 71th percentile, the EDI for both populations reached 1000ng (kgbw)(-1)day(-1). Considering the adverse endocrine disruptive effects of BPA and the dosage exposure level (from tens to hundreds ng (kgbw)(-1)day(-1)), human exposure to BPA in Shenzhen deserves more attention. Sensitivity analysis result showed that the handling time and frequency of supermarket receipts are the most important variables that contributed to most of the total variance of exposure.

  16. Human exposure to polychlorinated diphenyl ethers through the diet in Catalonia, Spain.

    Science.gov (United States)

    Bocio, Ana; Llobet, Juan M; Domingo, Jose L

    2004-03-24

    Although polychlorinated diphenyl ethers (PCDEs) are recognized environmental pollutants, information concerning human exposure to these organic substances is very scarce. For the present study the concentrations of PCDEs in a number of foodstuffs acquired in Catalonia, Spain, were determined. The dietary intake of PCDEs was estimated for various age groups of the general population living in this Spanish region. With the exception of fish and shellfish, PCDE concentrations were under the limit of detection in the 10 remaining food groups analyzed. For an adult (20-65 years old) male of 70 kg average body weight, the estimated total dietary intake of PCDEs was 41 ng/day. It was assumed that if a PCDE congener was below the detection limit, the concentration was equal to half of the limit of detection. The highest exposure to PCDEs through the diet corresponded to the group aged 51-65 years, whereas the lowest intake corresponded to the youngest group (4-9 years). With the exception of the group aged >65 years, PCDE intake was always higher in males than in females. The results of this study should be of interest for future assessments of time trends in human exposure to PCDEs through the diet.

  17. Phthalates in indoor dust in Kuwait: implications for non-dietary human exposure.

    Science.gov (United States)

    Gevao, B; Al-Ghadban, A N; Bahloul, M; Uddin, S; Zafar, J

    2013-04-01

    Phthalates are semivolatile organic compounds with a ubiquitous environmental distribution. Their presence in indoor environments is linked to their use in a variety of consumer products such as children's toys, cosmetics, food packaging, flexible PVC flooring among others. The goal of this study was to investigate the occurrence and concentration of phthalates in dust from homes in Kuwait and to assess non-dietary human exposure to these phthalates. Dust samples were randomly collected from 21 homes and analyzed for eight phthalates. The concentrations of total phthalates were log normally distributed and ranged from 470 to 7800 μg/g. Five phthalates [Di(2-ethylhexyl) phthalate (DEHP), Di-n-octyl phthalate (DnOP), Di-n-butyl phthalate (DBP), Benzyl butyl phthalate (BzBP), and Dicyclohexyl phthalate (DcHP)] were routinely detected. The major phthalate compound was DEHP at a geometric mean concentration of 1704 μg/g (median, 2256 μg/g) accounting for 92% of the total phthalates measured. Using the measured concentrations and estimates of dust ingestion rates for children and adults, estimated human non-dietary exposure based on median phthalate concentrations ranged from 938 ng/kg-bd/day for adults to 13362 ng/kg-bd/day for toddlers. The difference in exposure estimates between children and adults in this study supports previous reports that children are at greater risk from pollutants that accumulate indoors.

  18. Current issues in human lead exposure and regulation of lead.

    Science.gov (United States)

    Davis, J M; Elias, R W; Grant, L D

    1993-01-01

    Concern about lead as a significant public health problem has increased as epidemiological and experimental evidence has mounted regarding adverse health effects at successively lower levels of lead exposure. This concern has led to downward revision of criteria for acceptable blood lead concentrations to the 10 micrograms/dL mark now designated by EPA as a target level for regulatory development and enforcement/clean-up purposes. Much progress has been made in reducing lead exposures during the past 10-15 years, with marked declines evident both in air lead and blood lead concentrations in parallel to the phase-down of lead in gasoline and notable decreases in food lead exposure due to elimination of lead soldered cans by U.S. food processors. With the lessening of exposure from these sources, the importance of other components of multimedia exposure pathways has grown and stimulated increasing regulatory attention and abatement efforts to reduce health risks associated with lead exposure from drinking water, from lead-based paint, and from household dust and soil contaminated by deteriorating paint, smelter emissions, or various other sources. Increasing attention is also being accorded to reduction of occupational lead exposures (including those related to lead abatement activities), with particular concern for protection of men and women during their reproductive years.

  19. Assessing human exposure risk to cadmium through inhalation and seafood consumption

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Yun-Ru; Chen, Wei-Yu [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei10617, Taiwan, ROC (China); Liao, Chung-Min, E-mail: cmliao@ccms.ntu.edu.tw [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei10617, Taiwan, ROC (China)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Trophically available fraction in seafood and bioaccessibility is linked. Black-Right-Pointing-Pointer Human health risk to Cd can via inhalation and seafood consumption. Black-Right-Pointing-Pointer Female had the higher Cd accumulation in urine and blood than male. Black-Right-Pointing-Pointer Cigarette smoking is a major determinant of human Cd intake. - Abstract: The role of cadmium (Cd) bioaccessibility in risk assessment is less well studied. The aim of this study was to assess human health risk to Cd through inhalation and seafood consumption by incorporating bioaccessibility. The relationships between trophically available Cd and bioaccessibility were constructed based on available experimental data. We estimated Cd concentrations in human urine and blood via daily intake from seafood consumption and inhalation based on a physiologically-based pharmacokinetic (PBPK) model. A Hill-based dose-response model was used to assess human renal dysfunction and peripheral arterial disease risks for long-term Cd exposure. Here we showed that fish had higher bioaccessibility ({approx}83.7%) than that of shellfish ({approx}73.2%) for human ingestion. Our results indicated that glomerular and tubular damage among different genders and smokers ranged from 18.03 to 18.18%. Our analysis showed that nonsmokers had 50% probability of peripheral arterial disease level exceeding from 3.28 to 8.80%. Smoking populations had 2-3 folds higher morbidity risk of peripheral arterial disease than those of nonsmokers. Our study concluded that the adverse effects of Cd exposure are exacerbated when high seafood consumption coincides with cigarette smoking. Our work provides a framework that could more accurately address risk dose dependency of Cd hazard.

  20. Reconstruction of Exposure to m-Xylene from Human Biomonitoring Data Using PBPK Modelling, Bayesian Inference, and Markov Chain Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    Kevin McNally

    2012-01-01

    Full Text Available There are numerous biomonitoring programs, both recent and ongoing, to evaluate environmental exposure of humans to chemicals. Due to the lack of exposure and kinetic data, the correlation of biomarker levels with exposure concentrations leads to difficulty in utilizing biomonitoring data for biological guidance values. Exposure reconstruction or reverse dosimetry is the retrospective interpretation of external exposure consistent with biomonitoring data. We investigated the integration of physiologically based pharmacokinetic modelling, global sensitivity analysis, Bayesian inference, and Markov chain Monte Carlo simulation to obtain a population estimate of inhalation exposure to m-xylene. We used exhaled breath and venous blood m-xylene and urinary 3-methylhippuric acid measurements from a controlled human volunteer study in order to evaluate the ability of our computational framework to predict known inhalation exposures. We also investigated the importance of model structure and dimensionality with respect to its ability to reconstruct exposure.

  1. Reconstruction of Exposure to m-Xylene from Human Biomonitoring Data Using PBPK Modelling, Bayesian Inference, and Markov Chain Monte Carlo Simulation.

    Science.gov (United States)

    McNally, Kevin; Cotton, Richard; Cocker, John; Jones, Kate; Bartels, Mike; Rick, David; Price, Paul; Loizou, George

    2012-01-01

    There are numerous biomonitoring programs, both recent and ongoing, to evaluate environmental exposure of humans to chemicals. Due to the lack of exposure and kinetic data, the correlation of biomarker levels with exposure concentrations leads to difficulty in utilizing biomonitoring data for biological guidance values. Exposure reconstruction or reverse dosimetry is the retrospective interpretation of external exposure consistent with biomonitoring data. We investigated the integration of physiologically based pharmacokinetic modelling, global sensitivity analysis, Bayesian inference, and Markov chain Monte Carlo simulation to obtain a population estimate of inhalation exposure to m-xylene. We used exhaled breath and venous blood m-xylene and urinary 3-methylhippuric acid measurements from a controlled human volunteer study in order to evaluate the ability of our computational framework to predict known inhalation exposures. We also investigated the importance of model structure and dimensionality with respect to its ability to reconstruct exposure.

  2. The basal kinetic parameters of glycogen synthase in human myotube cultures are not affected by chronic high insulin exposure

    DEFF Research Database (Denmark)

    Gaster, M; Schrøder, H D; Handberg, A

    2001-01-01

    There is no consensus regarding the results from in vivo and in vitro studies on the impact of chronic high insulin and/or high glucose exposure on acute insulin stimulation of glycogen synthase (GS) kinetic parameters in human skeletal muscle. The aim of this study was to evaluate the kinetic...... parameters of glycogen synthase activity in human myotube cultures at conditions of chronic high insulin combined or not with high glucose exposure, before and after a subsequent acute insulin stimulation. Acute insulin stimulation significantly increased the fractional activity (FV(0.1)) of GS, increased...

  3. The effect of dust emissions from open storage piles to particle ambient concentration and human exposure.

    Science.gov (United States)

    Chalvatzaki, E; Aleksandropoulou, V; Glytsos, T; Lazaridis, M

    2012-12-01

    The current study focus on the determination of dust emissions from piles in open storage yards of a municipal solid waste (MSW) composting site and the subsequent atmospheric dust dispersion. The ISC3-ST (Industrial Source Complex Version 3 - Short Term) model was used for the evaluation of the PM(10) ambient concentrations associated with the dispersion of MSW compost dust emissions in air. Dust emission rates were calculated using the United States Environmental Protection Agency proposed dust resuspension formulation from open storage piles using local meteorological data. The dispersion modelling results on the spatial distribution of PM(10) source depletion showed that the maximum concentrations were observed at a distance 25-75 m downwind of the piles in the prevailing wind direction. Sensitivity calculations were performed also to reveal the effect of the compost pile height, the friction velocity and the receptor height on the ambient PM(10) concentration. It was observed that PM(10) concentrations (downwind in the prevailing wind direction) increased with increasing the friction velocity, increasing the pile height (for distances greater than 125 m from the source) and decreasing the receptor height (for distances greater than 125 m from the source). Furthermore, the results of ISC3-ST were analysed with the ExDoM (Exposure Dose Model) human exposure model. The ExDoM is a model for calculating the human exposure and the deposition dose, clearance, and finally retention of aerosol particles in the human respiratory tract (RT). PM(10) concentration at the composting site was calculated as the sum of the concentration from compost pile dust resuspension and the background concentration. It was found that the exposure to PM(10) and deposited lung dose for an adult Caucasian male who is not working at the composting site is less by 20-74% and 29-84%, respectively, compared to those for a worker exposed to PM concentrations at the composting site.

  4. Immunomodulation of human monocytes following exposure to Lutzomyia intermedia saliva

    Directory of Open Access Journals (Sweden)

    Barral Aldina

    2008-04-01

    Full Text Available Abstract Background Sand fly saliva contains potent and complex pharmacologic molecules that are able to modulate the host's hemostatic, inflammatory, and immune systems. In this study, we evaluated the effects of salivary gland sonicate (SGS of Lutzomyia intermedia, the natural vector of Leishmania braziliensis, on monocytes obtained from the peripheral blood mononuclear cells (PBMC of healthy volunteers. We investigated the effects of sand fly saliva on cytokine production and surface molecule expression of LPS-stimulated human monocytes uninfected or infected with L. braziliensis. Results Pre-treatment of non-infected human monocytes with L. intermedia SGS followed by LPS-stimulation led to a significant decrease in IL-10 production accompanied by a significant increase in CD86, CD80, and HLA-DR expression. Pre-treatment with SGS followed by LPS stimulation and L. braziliensis infection led to a significant increase in TNF-α, IL-6, and IL-8 production without significant alterations in co-stimulatory molecule expression. However, pre-treatment with L. intermedia SGS did not result in significant changes in the infection rate of human monocytes. Conclusion Our data indicate that L. intermedia saliva is able to modulate monocyte response, and, although this modulation is dissociated from enhanced infection with L. braziliensis, it may be associated with successful parasitism.

  5. Early and Late Damages in Chromosome 3 of Human Lymphocytes After Radiation Exposure

    Science.gov (United States)

    Sunagawa, Mayumi; Mangala, Lingegowda; Zhang, Ye; Kahdim, Munira; Wilson, Bobby; Cucinotta, Francis A.; Wu, Honglu

    2011-01-01

    Tumor formation in humans or animals is a multi-step process. An early stage of cancer development is believed to be genomic instability (GI) which accelerates the mutation rate in the descendants of the cells surviving radiation exposure. GI is defined as elevated or persistent genetic damages occurring many generations after the cells are exposed. While early studies have demonstrated radiation-induced GI in several cell types as detected in endpoints such as mutation, apoptosis and damages in chromosomes, the dependence of GI on the quality of radiation remains uncertain. To investigate GI in human lymphocytes induced by both low- and high-LET radiation, we initially exposed white blood cells collected from healthy subjects to gamma rays in vitro, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis post irradiation and at several intervals during the culture period. Among a number of biological endpoints planned for the project, the multi-color banding fluorescent in situ hybridization (mBAND) allows identification of inversions that were expected to be stable. We present here early and late chromosome aberrations detected with mBAND in chromosome 3 after gamma exposure. Comparison of chromosome damages in between human lymphocytes and human epithelial cells is also discussed

  6. 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

    2014-01-01

    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 in

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

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2015-01-01

    different cognitive tasks and assessed their comfort and acute health symptoms. Besides, the following were determined: heart rate, blood pressure, oxygen saturation of blood, respiration rate, minute ventilation rate, nasal peak flow, forced expiratory volume, and the end-tidal CO2 pressure (ETCO2). Saliva...... with bioeffluents, the performance of Tsai-Partington test was reduced, and diastolic blood pressure and alpha-amylase increased after exposure compared with their levels before exposure, which may suggest higher arousal/stress. During exposure to CO2 without bioeffluents, the performance of Tsai-Partington test...... also was lower, which may suggest higher stress/arousal, too. However, no effects on blood pressure and alpha-amylase were seen for this exposure....

  8. 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.

  9. Influence of radiation exposure on our society and epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimoto, Yasuhiko [National Inst. of Radiological Sciences, Chiba (Japan)

    1997-03-01

    A brief epidemiological review of risk assessment of radiation was discussed with respect to two periods; before and after the establishment of the United Nations Scientific Committee on the Effects of Atomic Radiation. Selected topics were the studies of atomic bomb survivors and people living in the contaminated areas due to Chernobyl nuclear power plant accident. An ethical view to ensure that potential social benefits of epidemiology are maximized was emphasized as well as a scientific view. On the other hand it should be recognized that there are the limitations of epidemiological studies on the basis of the observations on man in which the animal-experimental setting generally cannot be controlled over. Informing people about the professional confidence and caution of radiation exposure is needed to resolve social concern associated with low dose, low dose rate of radiation. Also there are guidelines for the investigation of clusters of adverse health events. In the future an appropriate strategy for decontamination might be expected to unusual radiation exposure as a consequence of a nuclear power plant accident. Justification for the implementations can be determined only through the assessment of the effects both on the environment and health of humans after the accident. (author)

  10. 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.

  11. Polycyclic Aromatic Hydrocarbon (PAH Exposure and DNA Adduct Semi-Quantitation in Archived Human Tissues

    Directory of Open Access Journals (Sweden)

    M. Margaret Pratt

    2011-06-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs are combustion products of organic materials, mixtures of which contain multiple known and probable human carcinogens. PAHs occur in indoor and outdoor air, as well as in char-broiled meats and fish. Human exposure to PAHs occurs by inhalation, ingestion and topical absorption, and subsequently formed metabolites are either rendered hydrophilic and excreted, or bioactivated and bound to cellular macromolecules. The formation of PAH-DNA adducts (DNA binding products, considered a necessary step in PAH-initiated carcinogenesis, has been widely studied in experimental models and has been documented in human tissues. This review describes immunohistochemistry (IHC studies, which reveal localization of PAH-DNA adducts in human tissues, and semi-quantify PAH-DNA adduct levels using the Automated Cellular Imaging System (ACIS. These studies have shown that PAH-DNA adducts concentrate in: basal and supra-basal epithelium of the esophagus, cervix and vulva; glandular epithelium of the prostate; and cytotrophoblast cells and syncitiotrophoblast knots of the placenta. The IHC photomicrographs reveal the ubiquitous nature of PAH-DNA adduct formation in human tissues as well as PAH-DNA adduct accumulation in specific, vulnerable, cell types. This semi-quantative method for PAH-DNA adduct measurement could potentially see widespread use in molecular epidemiology studies.

  12. A Crew Exposure Study. Volume I. Offshore.

    Science.gov (United States)

    1982-03-15

    but had to be removed because the information was not available due to the nature of the substance. The LI:L, UEL, STEL, STIL, and Odor Threshold were...aam-- pressor itself. The emissions from the flotation cell on platform C coulC casily be detected by smell, although the odor was not specially...OF PLANT NOISE USING DEPARTMENT OF LABOR REGULATIONS* * Unit: Unit 7 Operator: C Utility Exposure Duty Area SL Meas. tact tallow Fraction Burner Area

  13. Impact of Hot and Cold Exposure on Human Skeletal Muscle Gene Expression

    Science.gov (United States)

    Zak, Roksana B.; Shute, Robert J.; Heesch, Matthew W.S.; La Salle, D. Taylor; Bubak, Matthew P.; Dinan, Nicholas E.; Laursen, Terence L.; Slivka, Dustin R.

    2017-01-01

    Many human diseases lead to a loss of skeletal muscle metabolic function and mass. Local and environmental temperature can modulate the exercise-stimulated response of several genes involved in mitochondrial biogenesis and skeletal muscle function in a human model. However, the impact of environmental temperature, independent of exercise, has not been addressed in a human model. Thus, the purpose of this study was to compare the effects of exposure to hot, cold, and room temperature conditions on skeletal muscle gene expression related to mitochondrial biogenesis and muscle mass. METHODS Recreationally trained male subjects (n=12) had muscle biopsies taken from the vastus lateralis before and after 3 h exposure to hot (33 °C), cold (7 °C), or room temperature (20 °C) conditions. RESULTS Temperature had no effect on most of the genes related to mitochondrial biogenesis, myogenesis, or proteolysis (p > 0.05). Core temperature was significantly higher in hot and cold environments compared to room temperature (37.2 ± 0.1 °C, p = 0.001; 37.1 ± 0.1 °C, p = 0.013; 36.9 ± 0.1 °C, respectively). Whole body oxygen consumption was also significantly higher in hot and cold compared to room temperature (0.38 ± 0.01 L·min−1, p < 0.001; 0.52 ± 0.03 L·min−1, p < 0.001; 0.35 ± 0.01 L·min−1, respectively). CONCLUSIONS These data show that acute temperature exposure alone does not elicit significant changes in skeletal muscle gene expression. When considered in conjunction with previous research, exercise appears to be a necessary component to observe gene expression alterations between different environmental temperatures in humans. PMID:28177744

  14. The metabolic fingerprint of p,p'-DDE and HCB exposure in humans.

    Science.gov (United States)

    Salihovic, Samira; Ganna, Andrea; Fall, Tove; Broeckling, Corey D; Prenni, Jessica E; van Bavel, Bert; Lind, P Monica; Ingelsson, Erik; Lind, Lars

    2016-03-01

    Dichlorodiphenyldichloroethylene (p,p'-DDE) and hexachlorobenzene (HCB) are organochlorine pesticides with well-known endocrine disrupting properties. Exposure to p,p'-DDE and HCB concerns human populations worldwide and has been linked to metabolic disorders such as obesity and type 2 diabetes, but details about these associations in humans from the general population are largely unknown. We investigated the associations between p,p'-DDE and HCB exposure and global metabolomic profiles in serum samples from 1016 participants from the Swedish population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study. HCB and p,p'-DDE levels were determined using gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS). Metabolite levels were determined by using a non-targeted metabolomics approach with ultra-performance liquid chromatography coupled to time-of- flight mass spectrometry (UPLC-TOFMS). Association analyses were performed using multivariate linear regression. We found circulating levels of p,p-DDE and HCB to be significantly associated with circulating levels of 16 metabolites following adjustment for age, sex, education level, exercise habits, smoking, energy intake, and alcohol intake. The majority of the 16 metabolites belong to lipid metabolism pathways and include fatty acids, glycerophospholipids, sphingolipids, and glycerolipids. Overall, p,p'-DDE and HCB levels were found to be correlated to different metabolites, which suggests that different metabolic fingerprints may be related to circulating levels of these two pesticides. Our findings establish a link between human exposure to organochlorine pesticides and metabolites of key metabolic processes mainly related to human lipid metabolism. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Human Infection with MERS Coronavirus after Exposure to Infected Camels, Saudi Arabia, 2013

    OpenAIRE

    Memish, Ziad A.; Cotten, Matthew; Meyer, Benjamin; Simon J Watson; 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; Beer, Martin; Müller, Marcel A.

    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 transmission. Camels may act as a direct source of human MERS-CoV infection.

  16. Occupational electromagnetic field exposures associated with sleep quality: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Hui Liu

    Full Text Available Exposure to electromagnetic field (EMF emitted by mobile phone and other machineries concerns half the world's population and raises the problem of their impact on human health. The present study aims to explore the effects of electromagnetic field exposures on sleep quality and sleep duration among workers from electric power plant.A cross-sectional study was conducted in an electric power plant of Zhejiang Province, China. A total of 854 participants were included in the final analysis. The detailed information of participants was obtained by trained investigators using a structured questionnaire, which including socio-demographic characteristics, lifestyle variables, sleep variables and electromagnetic exposures. Physical examination and venous blood collection were also carried out for every study subject.After grouping daily occupational electromagnetic exposure into three categories, subjects with long daily exposure time had a significantly higher risk of poor sleep quality in comparison to those with short daily exposure time. The adjusted odds ratios were 1.68 (95%CI: 1.18, 2.39 and 1.57 (95%CI: 1.10, 2.24 across tertiles. Additionally, among the subjects with long-term occupational exposure, the longer daily occupational exposure time apparently increased the risk of poor sleep quality (OR (95%CI: 2.12 (1.23∼3.66 in the second tertile; 1.83 (1.07∼3.15 in the third tertile. There was no significant association of long-term occupational exposure duration, monthly electric fee or years of mobile-phone use with sleep quality or sleep duration.The findings showed that daily occupational EMF exposure was positively associated with poor sleep quality. It implies EMF exposure may damage human sleep quality rather than sleep duration.

  17. Development of a microarray-based method to detect exposure of human basophils to IL-3.

    Science.gov (United States)

    MacGlashan, Donald

    2012-11-30

    Human basophils are an accessible participant of the human allergic reaction. There is natural variation in various functional endpoints and in signaling molecule expression but there has been only a limited effort to place this information in the context of mRNA expression profiles. The goal of these studies was to develop gene transcript profiles associated with IL-3 exposure for use in probing basophil phenotypes. Highly purified human basophils were cultured under several conditions and the cells subsequently analyzed by microarray analysis of gene transcript expression. Basophils were cultured with or without IL-3 for 24 h and the expression profile, relative to pre-culture, analyzed for transcripts that act in a reciprocal fashion depending on the condition. A 51-gene transcript set was identified that was composed of 34 transcripts that increased with IL-3 and decreased without IL-3 and a further 17 transcripts that did the reverse. This set of transcripts was validated on two microarray chips. The changes induced by IL-3 were stable in time, with 3 day cultures generating a signature concordant with 1 day cultures. The inverted nature of the response to ±IL-3 suggested that the normal circulating basophil is balanced between a state of high and low IL-3 exposure and thus is very sensitive to changes in IL-3. For example, the basophil could detect the early generation of IL-3 that follows IgE-mediated stimulation of basophils. When this signature tool was applied to freshly isolated basophils, it was observed that the signature was similar for the same subjects' basophil sampled weeks apart. It was also shown that the 51-gene transcript was insensitive to the method of preparing purified basophils. Finally, these studies provided an estimate for the normal in vivo exposure of circulating basophils to IL-3 or IL-3-like functionality. These studies identified an IL-3 signature to probe changes in basophils occurring in vivo.

  18. Children's advertising exposure and materialistic orientations: A longitudinal study

    NARCIS (Netherlands)

    Opree, S.J.; Valkenburg, P.M.; Reijmersdal, E.A. van; Buijzen, M.A.

    2012-01-01

    As many as nine out of 10 parents worry that children's frequent exposure to advertising makes them materialistic. In this study we not only aim to investigate if children's advertising exposure indeed affects their materialism, but also how it affects their materialism (i.e., by studying the mediat

  19. Children's advertising exposure and materialistic orientations: A longitudinal study

    NARCIS (Netherlands)

    Opree, S.J.; Valkenburg, P.M.; Reijmersdal, E.A. van; Buijzen, M.A.

    2012-01-01

    As many as nine out of 10 parents worry that children's frequent exposure to advertising makes them materialistic. In this study we not only aim to investigate if children's advertising exposure indeed affects their materialism, but also how it affects their materialism (i.e., by studying the

  20. 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

    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......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...... compounds, PBDEs accumulate in lipid-rich tissues. Consequently, food items like fish from high trophic levels or lipid-rich oils have been found to contain relatively high concentrations of PBDEs, thus presenting an important exposure pathway to humans. The presence of PBDEs in various products of everyday...

  1. Human Exposure to Electromagnetic Fields from Parallel Wireless Power Transfer Systems

    Directory of Open Access Journals (Sweden)

    Feng Wen

    2017-02-01

    Full Text Available The scenario of multiple wireless power transfer (WPT systems working closely, synchronously or asynchronously with phase difference often occurs in power supply for household appliances and electric vehicles in parking lots. Magnetic field leakage from the WPT systems is also varied due to unpredictable asynchronous working conditions. In this study, the magnetic field leakage from parallel WPT systems working with phase difference is predicted, and the induced electric field and specific absorption rate (SAR in a human body standing in the vicinity are also evaluated. Computational results are compared with the restrictions prescribed in the regulations established to limit human exposure to time-varying electromagnetic fields (EMFs. The results show that the middle region between the two WPT coils is safer for the two WPT systems working in-phase, and the peripheral regions are safer around the WPT systems working anti-phase. Thin metallic plates larger than the WPT coils can shield the magnetic field leakage well, while smaller ones may worsen the situation. The orientation of the human body will influence the maximum magnitude of induced electric field and its distribution within the human body. The induced electric field centralizes in the trunk, groin, and genitals with only one exception: when the human body is standing right at the middle of the two WPT coils working in-phase, the induced electric field focuses on lower limbs. The SAR value in the lungs always seems to be greater than in other organs, while the value in the liver is minimal. Human exposure to EMFs meets the guidelines of the International Committee on Non-Ionizing Radiation Protection (ICNIRP, specifically reference levels with respect to magnetic field and basic restrictions on induced electric fields and SAR, as the charging power is lower than 3.1 kW and 55.5 kW, respectively. These results are positive with respect to the safe applications of parallel WPT systems

  2. Human Exposure to Electromagnetic Fields from Parallel Wireless Power Transfer Systems

    Science.gov (United States)

    Wen, Feng; Huang, Xueliang

    2017-01-01

    The scenario of multiple wireless power transfer (WPT) systems working closely, synchronously or asynchronously with phase difference often occurs in power supply for household appliances and electric vehicles in parking lots. Magnetic field leakage from the WPT systems is also varied due to unpredictable asynchronous working conditions. In this study, the magnetic field leakage from parallel WPT systems working with phase difference is predicted, and the induced electric field and specific absorption rate (SAR) in a human body standing in the vicinity are also evaluated. Computational results are compared with the restrictions prescribed in the regulations established to limit human exposure to time-varying electromagnetic fields (EMFs). The results show that the middle region between the two WPT coils is safer for the two WPT systems working in-phase, and the peripheral regions are safer around the WPT systems working anti-phase. Thin metallic plates larger than the WPT coils can shield the magnetic field leakage well, while smaller ones may worsen the situation. The orientation of the human body will influence the maximum magnitude of induced electric field and its distribution within the human body. The induced electric field centralizes in the trunk, groin, and genitals with only one exception: when the human body is standing right at the middle of the two WPT coils working in-phase, the induced electric field focuses on lower limbs. The SAR value in the lungs always seems to be greater than in other organs, while the value in the liver is minimal. Human exposure to EMFs meets the guidelines of the International Committee on Non-Ionizing Radiation Protection (ICNIRP), specifically reference levels with respect to magnetic field and basic restrictions on induced electric fields and SAR, as the charging power is lower than 3.1 kW and 55.5 kW, respectively. These results are positive with respect to the safe applications of parallel WPT systems working

  3. Photosensitized rose Bengal-induced phototoxicity on human melanoma cell line under natural sunlight exposure.

    Science.gov (United States)

    Srivastav, Ajeet K; Mujtaba, Syed Faiz; Dwivedi, Ashish; Amar, Saroj K; Goyal, Shruti; Verma, Ankit; Kushwaha, Hari N; Chaturvedi, Rajnish K; Ray, Ratan Singh

    2016-03-01

    Rose Bengal (RB) is an anionic water-soluble xanthene dye, which used for many years to assess eye cornea and conjunctiva damage. RB showed strong absorption maxima (λmax) under visible light followed by UV-B and UV-A. RB under sunlight exposure showed a time-dependent photodegradation. Our results show that photosensitized RB generates (1)O2 via Type-II photodynamic pathway and induced DNA damage under sunlight/UV-R exposure. 2'dGuO degradation, micronuclei formation, and single- and double-strand breakage were the outcome of photogenotoxicity caused by RB. Quenching studies with NaN3 advocate the involvement of (1)O2 in RB photogenotoxicity. RB induced linoleic acid photoperoxidation, which was parallel to (1)O2-mediated DNA damage. Oxidative stress in A375 cell line (human melanoma cell line) was detected through DCF-DA assay. Photosensitized RB decreased maximum cellular viability under sunlight followed by UV-B and UV-A exposures. Apoptosis was detected as a pattern of cell death through the increased of caspase-3 activity, decreased mitochondrial membrane potential, and PS translocation through inner to outer plasma membrane. Increased cytosolic levels of Bax also advocate the apoptotic cell death. We propose a p53-mediated apoptosis via increased expression of Bax gene and protein. Thus, the exact mechanism behind RB phototoxicity was the involvement of (1)O2, which induced oxidative stress-mediated DNA and membrane damage, finally apoptotic cell death under natural sunlight exposure. The study suggests that after the use of RB, sunlight exposure may avoid to prevent from its harmful effects. Copyright © 2015. Published by Elsevier B.V.

  4. Lung Tumors in Mice Induced by “Whole Life” Inorganic Arsenic Exposure at Human Relevant Doses

    OpenAIRE

    Waalkes, Michael P.; Qu, Wei; Tokar, Erik J.; Kissling, Grace E.; Dixon, Darlene

    2014-01-01

    In mice, inorganic arsenic in the drinking water in the parts per million (ppm) range via the dam during in utero life or with whole life exposure is a multi-site carcinogen in the offspring. However, human arsenic exposure is typically in the parts per billion (ppb) range. Thus, we studied “whole life” inorganic arsenic carcinogenesis in mice at levels more relevant to humans. Breeder male and female CD1 mice were exposed to 0, 50, 500 or 5000 ppb arsenic (as sodium arsenite) in the drinking...

  5. 40 CFR 26.1203 - Prohibition of research involving intentional exposure of any human subject who is a pregnant...

    Science.gov (United States)

    2010-07-01

    ... intentional exposure of any human subject who is a pregnant woman (and therefore her fetus), a nursing woman... Exposure of Human Subjects who are Children or Pregnant or Nursing Women § 26.1203 Prohibition of research involving intentional exposure of any human subject who is a pregnant woman (and therefore her fetus),...

  6. Evaluation of AirGIS: a GIS-based air pollution and human exposure modelling system

    DEFF Research Database (Denmark)

    Ketzel, Matthias; Berkowicz, Ruwim; Hvidberg, Martin

    2011-01-01

    This study describes in brief the latest extensions of the Danish Geographic Information System (GIS)-based air pollution and human exposure modelling system (AirGIS), which has been developed in Denmark since 2001 and gives results of an evaluation with measured air pollution data. The system...... shows, in general, a good performance for both long-term averages (annual and monthly averages), short-term averages (hourly and daily) as well as when reproducing spatial variation in air pollution concentrations. Some shortcomings and future perspectives of the system are discussed too....

  7. The research of human exposure to polybrominated diphenyl ethers and perfluoroocatane sulfonate

    Institute of Scientific and Technical Information of China (English)

    WANG YaWei; JIANG GuiBin

    2008-01-01

    As two kinds of emerging chemicals, the pollution of polybrominated diphenyl ethers (PBDEs) and perfluoroocatane sulfonate (PFOS) has been becoming a global environmental problem. Also, research of the transport, transfer, bioaccumulation in organism, and toxicology of these two kinds of pollutant is a hotspot in environmental sciences now. In this paper, we summarize and critically review the status and progress of PBDEs and PFOS exposure to human beings. Further, data analyses based on statistical methods are done to study the characters of PBDEs and PCBs concentrations in different regions in the world.

  8. Groundwater: Quality Levels and Human Exposure, SW Nigeria

    Directory of Open Access Journals (Sweden)

    Olusola Adeyemi

    2017-04-01

    Full Text Available Groundwater serves as a source of freshwater for agricultural, industrial and domestic purposes and it accounts for about 42%, 27% and 36% respectively. As it remains the only source of all-year-round supply of freshwater globally, it is of vital importance as regards water security, human survival and sustainable agriculture. The main goal of this study is to identify the main cause-effect relationship between human activities and the state of groundwater quality using a communication tool (the DPSIR Model; Drivers, Pressures, State, Impact and Response. A total of twenty-one samples were collected from ten peri-urban communities scattered across three conterminous Local Government Areas in Southwestern Nigeria. Each of the groundwater samples was tested for twelve parameters - total dissolved solids, pH, bicarbonate, chloride, lead, electrical conductivity, dissolved oxygen, nitrate, sulphate, magnesium and total suspended solids. The study revealed that the concentrations of DO and Pb were above threshold limits, while pH and N were just below the threshold and others elements were within acceptable limits based on Guidelines for Drinking Water Quality and Nigeria Standard for Drinking Water Quality. The study revealed that groundwater quality levels from the sampled wells are under pressure leading to reduction in the amount of freshwater availability. This is a first-order setback in achieving access to freshwater as a sustainable development goal across Less Developed Communities (LDCs globally. To combat this threat, there is the need for an integrated approach in response towards groundwater conservation and sustainability by all stakeholders.

  9. Risk assessment of human health from exposure to the discharged ballast water after full-scale electrolysis treatment.

    Science.gov (United States)

    Zhang, Nahui; Wang, Yidan; Xue, Junzeng; Yuan, Lin; Wang, Qiong; Liu, Liang; Wu, Huixian; Hu, Kefeng

    2016-06-01

    The presence of disinfection by-products (DBPs) releasing from ballast water management systems (BWMS) can cause a possible adverse effects on humans. The objectives of this study were to compute the Derived No Effect Levels (DNELs) for different exposure scenarios and to compare these levels with the exposure levels from the measured DBPs in treated ballast water. The risk assessment showed that when using animal toxicity data, all the DNELs values were approximately 10(3)-10(12) times higher than the exposure levels of occupational and general public exposure scenarios, indicating the level of risk was low (risk characterization ratios (RCRs) risk of adverse effects on human were significant. This implies that there are apparent discrepancies between risk characterization from animal and human data, which may affect the overall results. We therefore recommend that when appropriate, human data should be used in risk assessment as much as possible, although human data are very limited. Moreover, more appropriate assessment factors can be considered to be employed in estimating the DNELs for human when the animal data is selected as the dose descriptors. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. FDTD assessment of human exposure to electromagnetic fields from WiFi and bluetooth devices in some operating situations.

    Science.gov (United States)

    Martínez-Búrdalo, M; Martín, A; Sanchis, A; Villar, R

    2009-02-01

    In this work, the numerical dosimetry in human exposure to the electromagnetic fields from antennas of wireless devices, such as those of wireless local area networks (WLAN) access points or phone and computer peripherals with Bluetooth antennas, is analyzed with the objective of assessing guidelines compliance. Several geometrical configurations are considered to simulate possible exposure situations of a person to the fields from WLAN or Bluetooth antennas operating at 2400 MHz. The exposure to radiation from two sources of different frequencies when using a 1800 MHz GSM mobile phone connected via Bluetooth with a hands-free car kit is also considered. The finite-difference time-domain (FDTD) method is used to calculate electric and magnetic field values in the vicinity of the antennas and specific absorption rates (SAR) in a high-resolution model of the human head and torso, to be compared with the limits from the guidelines (reference levels and basic restrictions, respectively). Results show that the exposure levels in worst-case situations studied are lower than those obtained when analyzing the exposure to mobile phones, as could be expected because of the low power of the signals and the distance between the human and the antennas, with both field and SAR values being far below the limits established by the guidelines, even when considering the combined exposure to both a GSM and a Bluetooth antenna.

  11. Urinary, circulating, and tissue biomonitoring studies indicate widespread exposure to bisphenol A.

    Science.gov (United States)

    Vandenberg, Laura N; Chahoud, Ibrahim; Heindel, Jerrold J; Padmanabhan, Vasantha; Paumgartten, Francisco J R; Schoenfelder, Gilbert

    2012-02-01

    Bisphenol A (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Thus, there are concerns that the amount of BPA to which humans are exposed may cause adverse health effects. We examined many possibilities for why biomonitoring and toxicokinetic studies could come to seemingly conflicting conclusions. More than 80 published human biomonitoring studies that measured BPA concentrations in human tissues, urine, blood, and other fluids, along with two toxicokinetic studies of human BPA metabolism were examined. Unconjugated BPA was routinely detected in blood (in the nanograms per milliliter range), and conjugated BPA was routinely detected in the vast majority of urine samples (also in the nanograms per milliliter range). In stark contrast, toxicokinetic studies proposed that humans are not internally exposed to BPA. Available data from biomonitoring studies clearly indicate that the general population is exposed to BPA and is at risk from internal exposure to unconjugated BPA. The two toxicokinetic studies that suggested human BPA exposure is negligible have significant deficiencies, are directly contradicted by hypothesis-driven studies, and are therefore not reliable for risk assessment purposes.

  12. Developing a Salivary Antibody Multiplex Immunoassay to Measure Human Exposure to Environmental Pathogens

    Science.gov (United States)

    The etiology and impacts of human exposure to environmental pathogens are of major concern worldwide and, thus, the ability to assess exposure and infections using cost effective, high-throughput approaches would be indispensable. The principal objective of this work is to devel...

  13. 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...

  14. Human exposure to methylmercury through rice intake in mercury mining areas, Guizhou province, China.

    Science.gov (United States)

    Feng, Xinbin; Li, Ping; Qiu, Guangle; Wang, Shaofeng; Li, Guanghui; Shang, Lihai; Meng, Bo; Jiang, Hongmei; Bai, Weiyang; Li, Zhonggen; Fu, Xuewu

    2008-01-01

    The toxicity of methylmercury (Me-Hg) has caused widespread public human concern as a result of several widely publicized disasters. Me-Hg is highly toxic, and the nervous system is its principal target tissue for humans. Although the general population is primarily exposed to Me-Hg through contaminated fish and marine mammals, in Hg mining areas a long history of mining activities can produce serious Hg pollution to the local environment In a study of 98 persons from the Wanshan Hg mining area, hair Me-Hg levels indicated Me-Hg exposure. Rice, the staple food of the local inhabitants also showed high total Hg (T-Hg) and Me-Hg levels. The geometric mean concentration of T-Hg and mean concentration of Me-Hg in rice samples collected from 3 villages in Wanshan Hg mining area were 36.2 (ranging from 4.9 to 214.7), and 8.5 (ranging from 1.9 to 27.6) microg/kg, respectively, which were significantly elevated compared to the rice samples collected from a reference area, where the mean T-Hg and Me-Hg concentrations were 7.0 (3.2-15.1) and 2.5 (0.8-4.3) microg/kg, respectively. Pork meat, vegetable, and drinking water samples collected in Wanshan Hg mining area contained highly elevated T-Hg, but very low levels of Me-Hg. The relationships between the estimated rice Me-Hg intake and hair Me-Hg levels (r = 0.65, p levels indeed was the main route of Me-Hg exposure for the local residents in the Wanshan Hg mining area. From our study, we can conclude that the main human exposure to Me-Hg via food consumption is not restricted to fish, but in some cases in mining areas of China to frequent rice meals.

  15. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  16. 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...

  17. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  18. A SIMPLE COLORIMETRIC METHOD TO DETECT BIOLOGICAL EVIDENCE OF HUMAN EXPOSURE TO MICROCYSTINS

    Science.gov (United States)

    Toxic cyanobacteria are contaminants of surface waters worldwide. Microcystins are some of the most commonly detected toxins. Biological evidence of human exposure may be difficult to obtain due to limitations associated with cost, laboratory capacity, analytic support, and exp...

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

    Science.gov (United States)

    Stanton, Bruce A; Caldwell, Kathleen; Congdon, Clare Bates; Disney, Jane; Donahue, Maria; Ferguson, Elizabeth; Flemings, Elsie; Golden, Meredith; Guerinot, Mary Lou; Highman, Jay; James, Karen; Kim, Carol; Lantz, R Clark; Marvinney, Robert G; Mayer, Greg; Miller, David; Navas-Acien, Ana; Nordstrom, D Kirk; Postema, Sonia; Rardin, Laurie; Rosen, Barry; SenGupta, Arup; Shaw, Joseph; Stanton, Elizabeth; Susca, Paul

    2015-09-01

    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 international standards. Although the US Environmental Protection Agency (EPA) has set a limit of 10 μg/L in public water supplies and the WHO has recommended an upper limit of 10 μg/L, recent studies indicate that these limits are not protective enough. In addition, there are currently few standards for arsenic in food. Those who participated in the Summit support citizens, scientists, policymakers, industry, and educators at the local, state, national, and international levels to (1) establish science-based evidence for setting standards at the local, state, national, and global levels for arsenic in water and food; (2) work with government agencies to set regulations for arsenic in water and food, to establish and strengthen non-regulatory programs, and to strengthen collaboration among government agencies, NGOs, academia, the private sector, industry, and others; (3) develop novel and cost-effective technologies for identification and reduction of exposure to arsenic in water; (4) develop novel and cost-effective approaches to reduce arsenic exposure in juice, rice, and other relevant foods; and (5) develop an Arsenic Education Plan to guide the development of science curricula as well as community outreach and education programs that serve to inform students and consumers about arsenic exposure and engage them in well water testing and development of remediation strategies.

  20. Environment and human exposure to persistent organic pollutants (POPs) in India: a systematic review of recent and historical data.

    Science.gov (United States)

    Sharma, Brij Mohan; Bharat, Girija K; Tayal, Shresth; Nizzetto, Luca; Cupr, Pavel; Larssen, Thorjørn

    2014-05-01

    Persistent organic pollutants (POPs) have been used in a wide range of agricultural and industrial commodities, resulting in vigorous deterioration of environment and human health. A number of studies on the occurrence of POPs confirm their presence in various environmental compartments and human body. In order to deal with this global concern, India has recently prepared the National Implementation Plan (NIP) of the Stockholm Convention. Common beliefs point at India as a hot spot of POP contamination and human exposure; however no systematic analysis was ever performed so far considering all available past data on POP occurrence. This review aims to examine the distribution pattern of POPs in multicompartment environment and human samples, meta-analysis of time trends in exposure levels to environment and humans, and cross country comparison of POP contamination with China. Based on this review, it can be concluded that the Indian environment and human population are highly contaminated by DDTs and HCHs; however scarcity of data on other POPs makes it challenging to assess their nationwide human and environmental exposure. No evidence of a general decline in DDT and HCH residues in the environment and human body come out from the meta-analysis of time trend. While comparing contamination levels between India and China, tendency towards decline in POP contamination is visible in China, unlike India. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. A COMPARATIVE STUDY OF WHOLE-BODY VIBRATION EXPOSURE IN TRAIN AND CAR PASSENGERS: A CASE STUDY IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    M.M. Rahman

    2011-12-01

    Full Text Available Trains and cars are the most important modes of transportation throughout the world. In highly developed countries, trains have become essential for human use as the most well-known form of public transportation, whereas the car plays a significant role in prompt human travel from one place to another. The high magnitude of vibration caused by trains and cars may cause health problems in humans, especially low back pain. The aim of this study was to evaluate and validate the values of daily exposure to vibration A(8 and the vibration dose value (VDV in passengers travelling by train and car and to assess the effects produced by this exposure on the human body. Moreover, this study introduces a newly developed whole-body vibration measurement instrumentation system. One train travelling from the east coast to the south of Malaysia was chosen to conduct the study. Whole-body vibration exposure was measured over 8 hours, which is equal to the duration of normal occupational exposure. One car was chosen randomly and whole-body vibration exposure was measured for 5 min and 10 min. All the data were computed using an IEPE(ICPTM accelerometer sensor connected to a DT9837 device which is capable of effectively measuring and analysing vibration. The vibration results were displayed on a personal computer using a custom graphical user interface (GUI. Matlab software was used to interpret the data. From the results, the whole-body vibration exposure level could be determined. It can be concluded that the whole-body vibration absorbed by the human body is enhanced when the magnitude of the vibration exposure experienced by the passengers increased. This was shown by the increased values of daily exposure to vibration A(8 and VDV calculated in the study.

  2. Ultrasonication and the quality of human milk: variation of power and time of exposure.

    Science.gov (United States)

    Christen, Lukas; Lai, Ching Tat; Hartmann, Peter E

    2012-08-01

    Donor human milk is pasteurized to prevent the potential risk of the transmission of pathogens to preterm infants. Currently, Holder pasteurization (human milk held at 62·5°C for 30 min) is used in most human milk banks, but has the disadvantage that it results in excessive inactivation of important bioactive components. Power-ultrasound (20-100 kHz) is an emerging technology for the preservation of foods and could be an alternative method for the treatment of human milk. The aim of this study was to investigate the effect of different ultrasound settings on the elimination of Escherichia coli and the retention of bile salt stimulated lipase (BSSL) activity. Ultrasonication with a constant power decreased Esch. coli viability exponentially over time until the processing temperature increased to sub-pasteurization level to between 51·4 and 58·5°C, then a log10 1·3 decrease was observed (Phuman milk using high ultrasound power over a short exposure time to ensure that the temperature remains below the critical level for protein denaturation. Alternatively, the use of lower power settings such as the 26 W used in the present studies would require a cooling system to ensure the human milk BSSL was protected against temperature denaturation.

  3. Effects of subchronic exposures to concentrated ambient particles in mice. IX. Integral assessment and human health implications of subchronic exposures of mice to CAPs.

    Science.gov (United States)

    Lippmann, Morton; Gordon, Terry; Chen, Lung Chi

    2005-04-01

    In order to examine the biologic plausibility of adverse chronic cardiopulmonary effects in humans associated with ambient particulate matter (PM) exposure, we exposed groups of normal mice (C57) and knockout mice that develop atherosclerotic plaque (ApoE-/- and ApoE-/- LDLr-/-) for 6 h/day, 5 days/wk for 5 or 6 mo during the spring/summer of 2003 to either filtered air or 10-fold concentrated ambient particles (CAPs) in Tuxedo, NY (average PM2.5 concentration during exposure = 110 microg/m3). Some of the mice had implanted electrocardiographic monitors. We demonstrated that: (1) this complex interdisciplinary study was technically feasible in terms of daily exposure, collection of air quality monitoring data, the collection, analysis, and interpretation of continuous data on cardiac function, and the collection and analyses of tissues of the animals sacrificed at the end of the study; (2) the daily variations in CAPs were significantly associated, in ApoE-/- mice, with daily variations in cardiac functions; (3) there were significant differences between CAPs and sham-exposed ApoE-/- mice in terms of cardiac function after the end of exposure period, as well as small differences in atherosclerotic plaque density, coronary artery disease, and cell density in the substantia nigra in the brain in the ApoE-/- mice; (4) there are suggestive indications of gene expression changes for genes associated with the control of circadian rhythm in the ApoE-/- LDLr-/- double knockout (DK) mice. These various CAPs-related effects on cardiac function and the development of histological evidence of increased risk of clinically significant disease at the end of exposures in animal models of atherosclerosis provide biological plausibility for the premature mortality associated with PM2.5 exposure in human subjects and provide suggestive evidence for neurogenic disease as well.

  4. A comparative study on non-confluent and confluent human malignant brain cancer metabolic response to He-Ne laser exposures: evidence for laser enhanced cellular production of H2O2 and laser induced bystander effect

    Science.gov (United States)

    Tata, Darrell B.; Waynant, Ronald W.

    2009-02-01

    Continuous wave He-Ne laser exposures (Intensity = 35 mW/cm2, λ=632.8nm, Fluence range: 1J/cm2 to 50 J/cm2) on non-confluent and fully confluent human malignant glioblastoma cells was found to increase the cellular production levels of H2O2. Modulations in the cellular metabolic activity were detected (through the MTS assay) three days after the laser irradiation. The metabolic activity was found to be dependent on the laser fluence for both cell growth conditions. Furthermore, three days after the laser exposure, the potential laser induced "bystander" effect was tested through the transfer of growth media from laser irradiated cells onto non-irradiated cells. After two additional days of incubation (5 days post exposure), the non-laser irradiated cells grown under the non-confluent condition were found to have a significant increase in their metabolic activities, whereas minimal to null response was found for the fully confluent condition. For cells grown under the non-confluent conditions, modulations in the metabolic activities in the non-irradiated cells were found to be laser fluence dependent from the initial laser exposed cells treatment conditions. The results herein support the hypothesis of an important role for light enhanced cellular H2O2 generation to yield bio-modulatory effects locally and at a distance. The classical "bi-phasic" modulation response of cells to light irradiation is hypothesized to depend upon the quantity of light enhanced H2O2 molecules generated from the mitochondria and the number of cells which interact with the H2O2 molecules.

  5. 18. Adduct detection in human monitoring for carcinogen exposure

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Determination of the covalently bound products (adducts) of carcinogens with DNA or proteins may be used for the monitoring of exposure to these compounds. Protein adducts are generally stable and are not enzymatically repaired, and the use of these for cxposure monitoring is normally carried out with globin or albumin, because

  6. Co-exposure to nickel and cobalt chloride enhances cytotoxicity and oxidative stress in human lung epithelial cells.

    Science.gov (United States)

    Patel, Eshan; Lynch, Christine; Ruff, Victoria; Reynolds, Mindy

    2012-02-01

    Nickel and cobalt are heavy metals found in land, water, and air that can enter the body primarily through the respiratory tract and accumulate to toxic levels. Nickel compounds are known to be carcinogenic to humans and animals, while cobalt compounds produce tumors in animals and are probably carcinogenic to humans. People working in industrial and manufacturing settings have an increased risk of exposure to these metals. The cytotoxicity of nickel and cobalt has individually been demonstrated; however, the underlying mechanisms of co-exposure to these heavy metals have not been explored. In this study, we investigated the effect of exposure of H460 human lung epithelial cells to nickel and cobalt, both alone and in combination, on cell survival, apoptotic mechanisms, and the generation of reactive oxygen species and double strand breaks. For simultaneous exposure, cells were exposed to a constant dose of 150 μM cobalt or nickel, which was found to be relatively nontoxic in single exposure experiments. We demonstrated that cells exposed simultaneously to cobalt and nickel exhibit a dose-dependent decrease in survival compared to the cells exposed to a single metal. The decrease in survival was the result of enhanced caspase 3 and 7 activation and cleavage of poly (ADP-ribose) polymerase. Co-exposure increased the production of ROS and the formation of double strand breaks. Pretreatment with N-acetyl cysteine alleviated the toxic responses. Collectively, this study demonstrates that co-exposure to cobalt and nickel is significantly more toxic than single exposure and that toxicity is related to the formation of ROS and DSB. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Individual differences in the effects of mobile phone exposure on human sleep: rethinking the problem.

    Science.gov (United States)

    Loughran, Sarah P; McKenzie, Raymond J; Jackson, Melinda L; Howard, Mark E; Croft, Rodney J

    2012-01-01

    Mobile phone exposure-related effects on the human electroencephalogram (EEG) have been shown during both waking and sleep states, albeit with slight differences in the frequency affected. This discrepancy, combined with studies that failed to find effects, has led many to conclude that no consistent effects exist. We hypothesised that these differences might partly be due to individual variability in response, and that mobile phone emissions may in fact have large but differential effects on human brain activity. Twenty volunteers from our previous study underwent an adaptation night followed by two experimental nights in which they were randomly exposed to two conditions (Active and Sham), followed by a full-night sleep episode. The EEG spectral power was increased in the sleep spindle frequency range in the first 30 min of non-rapid eye movement (non-REM) sleep following Active exposure. This increase was more prominent in the participants that showed an increase in the original study. These results confirm previous findings of mobile phone-like emissions affecting the EEG during non-REM sleep. Importantly, this low-level effect was also shown to be sensitive to individual variability. Furthermore, this indicates that previous negative results are not strong evidence for a lack of an effect and, given the far-reaching implications of mobile phone research, we may need to rethink the interpretation of results and the manner in which research is conducted in this field.

  8. Urinary concentrations of parabens in Chinese young adults: implications for human exposure.

    Science.gov (United States)

    Ma, Wan-Li; Wang, Lei; Guo, Ying; Liu, Li-Yan; Qi, Hong; Zhu, Ning-Zheng; Gao, Chong-Jing; Li, Yi-Fan; Kannan, Kurunthachalam

    2013-10-01

    Parabens are widely used as preservatives in foods, cosmetics, and pharmaceuticals. However, recent studies have indicated that high and systemic exposure to parabens can be harmful to human health. Although a few studies have reported urinary paraben levels in western countries, studies on paraben exposure in the Chinese population are limited. China is currently a major producer of parabens in the world. In this study, 109 urine samples collected from Chinese young adults (approximately 20 years old) were analyzed for five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl-parabens) by high-performance liquid chromatography-tandem mass spectrometry. Methyl-, propyl-, and ethyl-parabens were the three major paraben analogues found in all (100%) samples. The concentration of the sum of the five parabens ranged from 0.82 to 728 ng/mL with a geometric mean value of 17.4 ng/mL. Urinary concentration of parabens was 2-fold greater in females than in males. Based on the measured urinary concentrations, daily intake of parabens by the Chinese young adults was estimated and compared with those reported for United States adults. The estimated daily intakes (EDIurine) of parabens were 18.4 and 40.8 μg/kg bw/day for Chinese males and females, respectively, values that were lower than those reported for United States adults (74.7 μg/kg bw/day). Based on the reported concentrations of parabens in foods from China and the United States, the contribution of dietary intake to EDIurine was estimated to be 5.5, 2.6, and 0.42% for Chinese males, Chinese females, and United States adults, respectively, which indicates the significance of nondietary sources of parabens to human exposures.

  9. Biological effects of exposure to static electric fields in humans and vertebrates: a systematic review.

    Science.gov (United States)

    Petri, Anne-Kathrin; Schmiedchen, Kristina; Stunder, Dominik; Dechent, Dagmar; Kraus, Thomas; Bailey, William H; Driessen, Sarah

    2017-04-17

    High-voltage direct current (HVDC) lines are the technology of choice for the transport of large amounts of energy over long distances. The operation of these lines produces static electric fields (EF), but the data reviewed in previous assessments were not sufficient to assess the need for any environmental limit. The aim of this systematic review was to update the current state of research and to evaluate biological effects of static EF. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) recommendations, we collected and evaluated experimental and epidemiological studies examining biological effects of exposure to static EF in humans (n = 8) and vertebrates (n = 40). There is good evidence that humans and animals are able to perceive the presence of static EF at sufficiently high levels. Hair movements caused by electrostatic forces may play a major role in this perception. A large number of studies reported responses of animals (e.g., altered metabolic, immunologic or developmental parameters) to a broad range of static EF strengths as well, but these responses are likely secondary physiological responses to sensory stimulation. Furthermore, the quality of many of the studies reporting physiological responses is poor, which raises concerns about confounding. The weight of the evidence from the literature reviewed did not indicate that static EF have adverse biological effects in humans or animals. The evidence strongly supported the role of superficial sensory stimulation of hair and skin as the basis for perception of the field, as well as reported indirect behavioral and physiological responses. Physical considerations also preclude any direct effect of static EF on internal physiology, and reports that some physiological processes are affected in minor ways may be explained by other factors. While this literature does not support a level of concern about biological effects of exposure to static EF, the conditions

  10. Assessment of human body influence on exposure measurements of electric field in indoor enclosures.

    Science.gov (United States)

    de Miguel-Bilbao, Silvia; García, Jorge; Ramos, Victoria; Blas, Juan

    2015-02-01

    Personal exposure meters (PEMs) used for measuring exposure to electromagnetic fields (EMF) are typically used in epidemiological studies. As is well known, these measurement devices cause a perturbation of real EMF exposure levels due to the presence of the human body in the immediate proximity. This paper aims to model the alteration caused by the body shadow effect (BSE) in motion conditions and in indoor enclosures at the Wi-Fi frequency of 2.4 GHz. For this purpose, simulation techniques based on ray-tracing have been carried out, and their results have been verified experimentally. A good agreement exists between simulation and experimental results in terms of electric field (E-field) levels, and taking into account the cumulative distribution function (CDF) of the spatial distribution of amplitude. The Kolmogorov-Smirnov (KS) test provides a P-value greater than 0.05, in fact close to 1. It has been found that the influence of the presence of the human body can be characterized as an angle of shadow that depends on the dimensions of the indoor enclosure. The CDFs show that the E-field levels in indoor conditions follow a lognormal distribution in the absence of the human body and under the influence of BSE. In conclusion, the perturbation caused by BSE in PEMs readings cannot be compensated for by correction factors. Although the mean value is well adjusted, BSE causes changes in CDF that would require improvements in measurement protocols and in the design of measuring devices to subsequently avoid systematic errors.

  11. POPULATION EXPOSURE AND DOSE MODEL FOR AIR TOXICS: A BENZENE CASE STUDY

    Science.gov (United States)

    The EPA's National Exposure Research Laboratory (NERL) is developing a human exposure and dose model called the Stochastic Human Exposure and Dose Simulation model for Air Toxics (SHEDS-AirToxics) to characterize population exposure to air toxics in support of the National Air ...

  12. Additional human exposure information for gasoline substance risk assessment (period 2002-2007)

    Energy Technology Data Exchange (ETDEWEB)

    Bomer, R.; Carter, M.; Dmytrasz, B.; Mulari, M.; Pizzella, G.; Roth, S.; Van de Sandt, P.

    2009-06-15

    This report provides an update on human exposure information for gasoline-related activities for which previous assessments had suggested that exposure was either elevated or highly variable or available data were considered out-of-date. In addition data are presented for several activities for which no information had been available previously. The occupational exposures activities described in this report include railcar loading, refinery maintenance, laboratory operations, aviation gasoline refuelling, gasoline pump maintenance and repair, gasoline pump calibration, and the operation of gasoline-powered gardening equipment. In addition, general public exposure levels are described, particularly relating to residency near service stations.

  13. Delayed initiation of breast development in girls with higher prenatal dioxin exposure: A longitudinal cohort study

    NARCIS (Netherlands)

    Leijs, M.M.; Koppe, J.G.; Olie, K.; van Aalderen, W.M.C.; de Voogt, P.; Vulsma, T.; Westra, M.; ten Tusscher, G.W.

    2008-01-01

    Objectives: While many studies have assessed the health impacts of PCDD/Fs and PCBs on animals and humans, long-term consequences for especially adolescents, have not (yet) been well documented. This is certainly also true for the effects of PBDE exposure. As part of a longitudinal cohort study, now

  14. Low dose perfluorooctanoate exposure promotes cell proliferation in a human non-tumor liver cell line

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongxia; Cui, Ruina [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Guo, Xuejiang [State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 210029 (China); Hu, Jiayue [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China); Dai, Jiayin, E-mail: daijy@ioz.ac.cn [Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101 (China)

    2016-08-05

    Highlights: • Differential expression of proteins induced by PFOA in HL-7702 was identified. • Most of the differentially expressed proteins are related to cell proliferation. • A low dose of PFOA stimulates HL-7702 cell proliferation. • A high dose of PFOA inhibits HL-7702 cell proliferation. - Abstract: Perfluorooctanoate (PFOA) is a well-known persistent organic pollutant widely found in the environment, wildlife and humans. Medical surveillance and experimental studies have investigated the potential effects of PFOA on human livers, but the hepatotoxicity of PFOA on humans and its underlying mechanism remain to be clarified. We exposed a human liver cell line (HL-7702) to 50 μM PFOA for 48 h and 96 h, and identified 111 significantly differentially expressed proteins by iTRAQ analysis. A total of 46 proteins were related to cell proliferation and apoptosis. Through further analysis of the cell cycle, apoptosis and their related proteins, we found that low doses of PFOA (50–100 μM) promoted cell proliferation and numbers by promoting cells from the G1 to S phases, whereas high doses of PFOA (200–400 μM) led to reduced HL-7702 cell numbers compared with that of the control mainly due to cell cycle arrest in the G0/G1 phase. To our knowledge, this is the first report on the promotion of cell cycle progression in human cells following PFOA exposure.

  15. 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

  16. Human brain derived cells respond in a type-specific manner after exposure to urban particulate matter (PM).

    Science.gov (United States)

    Campbell, Arezoo; Daher, Nancy; Solaimani, Parrisa; Mendoza, Kriscelle; Sioutas, Constantinos

    2014-10-01

    Exposure to particulate matter (PM), a component of urban air pollution, may cause adverse effects in the brain. Although the exact mechanisms involved are unknown, both oxidative and inflammatory responses have been reported. Since the main route of exposure to particulate matter is through inhalation, there is a potential for compounds to directly enter the brain and alter normal cellular function. Enhancement in both oxidative stress and neuroinflammatory markers has been observed in neurodegenerative disorders and PM-induced potentiation of these events may accelerate the disease process. The objective of this pilot study was to use normal human brain cells, a model system which has not been previously used, to assess cell-type-specific responses after exposure to ultrafine particles (UFP). Human microglia, neurons, and astrocytes were grown separately or as co-cultures and then exposed to aqueous UFP suspensions. Reactive Oxygen Species (ROS) formation and the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) were measured as markers of oxidative stress or inflammation respectively. Our results revealed that after exposure to 2 μg/ml of particles, normal human neurons exhibit a decrease in ROS formation and an increase in TNF-α. The observed decrease in ROS formation persisted in the presence of glial cells, which contrasts previous studies done in rodent cells reporting that PM-induced microglial activation modulates neuronal responses. Our study indicates that human CNS cells may respond differently compared to rodent cells and that their use may be more predictive in risk assessment.

  17. Occurrence and profiles of phthalates in foodstuffs from China and their implications for human exposure.

    Science.gov (United States)

    Guo, Ying; Zhang, Zifeng; Liu, Liyan; Li, Yifan; Ren, Nanqi; Kannan, Kurunthachalam

    2012-07-11

    Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of humans to phthalates are limited. In this study, nine phthalate esters were analyzed in eight categories of foodstuffs (n = 78) collected from Harbin and Shanghai, China, in 2011. Dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), benzyl butyl phthalate (BzBP), and diethylhexyl phthalate (DEHP) were frequently detected in food samples. DEHP was the major compound found in most of the food samples, with concentrations that ranged from below the limit of quantification (LOQ) to 762 ng/g wet weight (wt). The concentrations of phthalates in food samples from China were comparable to concentrations reported for several other countries, but the profiles were different; DMP was found more frequently in Chinese foods than in foods from other countries. The estimated daily dietary intake of phthalates (EDIdiet) was calculated based on the concentrations measured and the daily ingestion rates of food items. The EDIdiet values for DMP, DEP, DIBP, DBP, BzBP, and DEHP (based on mean concentrations) were 0.092, 0.051, 0.505, 0.703, 0.022, and 1.60 μg/kg-bw/d, respectively, for Chinese adults. The EDIdiet values calculated for phthalates were below the reference doses suggested by the United States Environmental Protection Agency (EPA). Comparison of total daily intakes, reported previously based on a biomonitoring study, with the current dietary intake estimates suggests that diet is the main source of DEHP exposure in China. Nevertheless, diet accounted for only phthalates.

  18. Human Exposure to Herpesvirus B–Seropositive Macaques, Bali, Indonesia

    Science.gov (United States)

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

    2002-01-01

    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. PMID:12141963

  19. 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.

  20. 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.

  1. 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

  2. Subtleties of human exposure and response to chemical mixtures from spills.

    Science.gov (United States)

    Phetxumphou, Katherine; Dietrich, Andrea M; Shanaiah, Narasimhamurthy; Smiley, Elizabeth; Gallagher, Daniel L

    2016-07-01

    Worldwide, chemical spills degrade drinking water quality and threaten human health through ingestion and inhalation. Spills are often mixtures of chemicals; thus, understanding the interaction of chemical and biological properties of the major and minor components is critical to assessing human exposure. The crude (4-methylcyclohexyl)methanol (MCHM) spill provides an opportunity to assess such subtleties. This research determined the relative amounts, volatilization, and biological odor properties of minor components cis- and trans-methyl-4-methylcyclohexanecarboxylate (MMCHC) isomers and major components cis- and trans-4-MCHM, then compared properties and human exposure differences among them. (1)H nuclear magnetic resonance and chromatography revealed that the minor MMCHC isomers were about 1% of the major MCHM isomers. At typical showering temperature of 40 °C, Henry's law constants were 1.50 × 10(-2) and 2.23 × 10(-2) for cis- and trans-MMCHC, respectively, which is 20-50 fold higher than for 4-MCHM isomers. The odor thresholds were 1.83 and 0.02 ppb-v air for cis- and trans-MMCHC, which were both described as predominantly sweet. These data are compared to the higher 120 ppb-v air and 0.06 ppb-v odor thresholds for cis- and trans-4-MCHM, for which the trans-isomer had a dominant licorice descriptor. Application of a shower model demonstrated that while MMCHC isomers are only about 1% of the MCHM isomers, during showering, the MMCHC isomers are 13.8% by volume (16.3% by mass) because of their higher volatility. Trans-4-MCHM contributed about 82% of the odor because of higher volatility and lower odor threshold, trans-MMCHC, which represents 0.3% of the mass, contributed 18% of the odor. This study, with its unique human sensory component to assess exposure, reaffirmed that hazard assessment must not be based solely on relative concentration, but also consider the chemical fate, transport, and biological properties to determine the actual levels of

  3. Molecular effects of 1-naphthyl-methylcarbamate and solar radiation exposures on human melanocytes.

    Science.gov (United States)

    Ferrucio, Bianca; Tiago, Manoela; Fannin, Richard D; Liu, Liwen; Gerrish, Kevin; Maria-Engler, Silvya Stuchi; Paules, Richard S; Barros, Silvia Berlanga de Moraes

    2017-02-01

    Carbaryl (1-naphthyl-methylcarbamate), a broad-spectrum insecticide, has recently been associated with the development of cutaneous melanoma in an epidemiological cohort study with U.S. farm workers also exposed to ultraviolet radiation, the main etiologic factor for skin carcinogenesis. We hypothesized that carbaryl exposure may increase deleterious effects of UV solar radiation on skin melanocytes. This study aimed to characterize human melanocytes after individual or combined exposure to carbaryl (100μM) and solar radiation (375mJ/cm(2)). In a microarray analysis, carbaryl, but not solar radiation, induced an oxidative stress response, evidenced by the upregulation of antioxidant genes, such as Hemeoxygenase-1 (HMOX1), and downregulation of Microphtalmia-associated Transcription Factor (MITF), the main regulator of melanocytic activity; results were confirmed by qRT-PCR. Carbaryl and solar radiation induced a gene response suggestive of DNA damage and cell cycle alteration. The expression of CDKN1A, BRCA1/2 and MDM2 genes was notably more intense in the combined treatment group, in a synergistic manner. Flow cytometry assays demonstrated S-phase cell cycle arrest, reduced apoptosis levels and faster induction of cyclobutane pyrimidine dimers (CPD) lesions in carbaryl treated groups. Our data suggests that carbaryl is genotoxic to human melanocytes, especially when associated with solar radiation.

  4. Mitochondrial tolerance to single and repeat exposure to simulated sunlight in human epidermal and dermal skin cells.

    Science.gov (United States)

    Kelly, J; Murphy, J E J

    2016-12-01

    Sunlight represents the primary threat to mitochondrial integrity in skin given the unique nature of the mitochondrial genome and its proximity to the electron transport chain. The accumulation of mitochondrial DNA (mtDNA) mutations is a key factor in many human pathologies and this is linked to key roles of mitochondrial function in terms of energy production and cell regulation. The main objective of this study was to evaluate solar radiation induced changes in mitochondrial integrity, function and dynamics in human skin cells using a Q-Sun solar simulator to deliver a close match to the intensity of summer sunlight. Spontaneously immortalised human skin epidermal keratinocytes (HaCaT) and Human Dermal Fibroblasts (HDFn) were divided into two groups. Group A were irradiated once and Group B twice 7days apart and evaluated using cell survival, viability and mitochondrial membrane potential (MMP) and mass at 1, 4 and 7days post one exposure for Group A and 1, 4, 7 and 14days post second exposure for Group B. Viability and survival of HaCaT and HDFn cells decreased after repeat exposure to Simulated Sunlight Irradiation (SSI) with no recovery. HDFn cells showed no loss in MMP after one or two exposures to SSI compared to HaCaT cells which showed a periodic loss of MMP after one exposure with a repeat exposure causing a dramatic decrease from which cells did not recover. Mitochondrial Mass in exposed HDFn cells was consistent with control after one or two exposures to SSI; however mitochondrial mass was significantly decreased in HaCaT cells. Data presented here suggests that mitochondria in epidermal cells are more sensitive to sunlight damage compared to mitochondria in dermal cells, despite their origin, confirming a skin layer specific sensitivity to sunlight, but not as expected. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Sun Exposure and Its Effects on Human Health: Mechanisms through Which Sun Exposure Could Reduce the Risk of Developing Obesity and Cardiometabolic Dysfunction

    Science.gov (United States)

    Fleury, Naomi; Geldenhuys, Sian; Gorman, Shelley

    2016-01-01

    Obesity is a significant burden on global healthcare due to its high prevalence and associations with chronic health conditions. In our animal studies, ongoing exposure to low dose ultraviolet radiation (UVR, found in sunlight) reduced weight gain and the development of signs of cardiometabolic dysfunction in mice fed a high fat diet. These observations suggest that regular exposure to safe levels of sunlight could be an effective means of reducing the burden of obesity. However, there is limited knowledge around the nature of associations between sun exposure and the development of obesity and cardiometabolic dysfunction, and we do not know if sun exposure (independent of outdoor activity) affects the metabolic processes that determine obesity in humans. In addition, excessive sun exposure has strong associations with a number of negative health consequences such as skin cancer. This means it is very important to “get the balance right” to ensure that we receive benefits without increasing harm. In this review, we detail the evidence around the cardiometabolic protective effects of UVR and suggest mechanistic pathways through which UVR could be beneficial. PMID:27727191

  6. Sun Exposure and Its Effects on Human Health: Mechanisms through Which Sun Exposure Could Reduce the Risk of Developing Obesity and Cardiometabolic Dysfunction

    Directory of Open Access Journals (Sweden)

    Naomi Fleury

    2016-10-01

    Full Text Available Obesity is a significant burden on global healthcare due to its high prevalence and associations with chronic health conditions. In our animal studies, ongoing exposure to low dose ultraviolet radiation (UVR, found in sunlight reduced weight gain and the development of signs of cardiometabolic dysfunction in mice fed a high fat diet. These observations suggest that regular exposure to safe levels of sunlight could be an effective means of reducing the burden of obesity. However, there is limited knowledge around the nature of associations between sun exposure and the development of obesity and cardiometabolic dysfunction, and we do not know if sun exposure (independent of outdoor activity affects the metabolic processes that determine obesity in humans. In addition, excessive sun exposure has strong associations with a number of negative health consequences such as skin cancer. This means it is very important to “get the balance right” to ensure that we receive benefits without increasing harm. In this review, we detail the evidence around the cardiometabolic protective effects of UVR and suggest mechanistic pathways through which UVR could be beneficial.

  7. Manganese exposure induces α-synuclein aggregation in the frontal cortex of non-human primates.

    Science.gov (United States)

    Verina, Tatyana; Schneider, Jay S; Guilarte, Tomás R

    2013-03-13

    Aggregation of α-synuclein (α-syn) in the brain is a defining pathological feature of neurodegenerative disorders classified as synucleinopathies. They include Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). Occupational and environmental exposure to manganese (Mn) is associated with a neurological syndrome consisting of psychiatric symptoms, cognitive impairment and parkinsonism. In this study, we examined α-syn immunoreactivity in the frontal cortex of Cynomolgus macaques as part of a multidisciplinary assessment of the neurological effects produced by exposure to moderate levels of Mn. We found increased α-syn-positive cells in the gray matter of Mn-exposed animals, typically observed in pyramidal and medium-sized neurons in deep cortical layers. Some of these neurons displayed loss of Nissl staining with α-syn-positive spherical aggregates. In the white matter we also observed α-syn-positive glial cells and in some cases α-syn-positive neurites. These findings suggest that Mn exposure promotes α-syn aggregation in neuronal and glial cells that may ultimately lead to degeneration in the frontal cortex gray and white matter. To our knowledge, this is the first report of Mn-induced neuronal and glial cell α-syn accumulation and aggregation in the frontal cortex of non-human primates.

  8. Biomonitoring of Human Exposure to Prestige Oil: Effects on DNA and Endocrine Parameters

    Directory of Open Access Journals (Sweden)

    Beatriz Pérez-Cadahía

    2008-01-01

    Full Text Available Since 1960, about 400 tankers spilled more than 377765 tons of oil, with the Prestige accident (Galician coast, NW Spain, November 2002 the most recent. Taking into account the consistent large number of individuals exposed to oil that exists all over the world, it seems surprising the absence in the literature of studies focused on the chronic effects of this exposure on human health. In this work we evaluated the level of DNA damage by means of comet assay, and the potential endocrine alterations (prolactin and cortisol caused by Prestige oil exposure in a population of 180 individuals, classified in 3 groups according to the tasks performed, and 60 controls. Heavy metals in blood were determined as exposure biomarkers, obtaining significant increases of aluminum, nickel and lead in the exposed groups as compared to controls. Higher levels of genetic damage and endocrine alterations were also observed in the exposed population. DNA damage levels were influenced by age, sex, and the use of protective clothes, and prolactin concentrations by the last two factors. Surprisingly, the use of mask did not seem to protect individuals from genetic or endocrine alterations. Moreover, polymorphisms in genes encoding for the main enzymes involved in the metabolism of oil components were analyzed as susceptibility biomarkers. CYP1A1-3’UTR and EPHX1 codons 113 and 139 variant alleles were related to higher damage levels, while lower DNA damage was observed in GSTM1 and GSTT1 null individuals.

  9. Biomonitoring of Human Exposure to Prestige Oil: Effects on DNA and Endocrine Parameters

    Science.gov (United States)

    Pérez-Cadahía, Beatriz; Méndez, Josefina; Pásaro, Eduardo; Lafuente, Anunciación; Cabaleiro, Teresa; Laffon, Blanca

    2008-01-01

    Since 1960, about 400 tankers spilled more than 377765 tons of oil, with the Prestige accident (Galician coast, NW Spain, November 2002) the most recent. Taking into account the consistent large number of individuals exposed to oil that exists all over the world, it seems surprising the absence in the literature of studies focused on the chronic effects of this exposure on human health. In this work we evaluated the level of DNA damage by means of comet assay, and the potential endocrine alterations (prolactin and cortisol) caused by Prestige oil exposure in a population of 180 individuals, classified in 3 groups according to the tasks performed, and 60 controls. Heavy metals in blood were determined as exposure biomarkers, obtaining significant increases of aluminum, nickel and lead in the exposed groups as compared to controls. Higher levels of genetic damage and endocrine alterations were also observed in the exposed population. DNA damage levels were influenced by age, sex, and the use of protective clothes, and prolactin concentrations by the last two factors. Surprisingly, the use of mask did not seem to protect individuals from genetic or endocrine alterations. Moreover, polymorphisms in genes encoding for the main enzymes involved in the metabolism of oil components were analyzed as susceptibility biomarkers. CYP1A1-3′UTR and EPHX1 codons 113 and 139 variant alleles were related to higher damage levels, while lower DNA damage was observed in GSTM1 and GSTT1 null individuals. PMID:21572833

  10. 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

    Nyos in Cameroon, Mammoth Mountain in California, Dieng Volcanic Complex in Java, Indonesia, and industrial accidents with CO2 fire suppression systems teach that slow leakage rates and effective dilution must be proven to ensure human and environmental safety. Monitoring CO2 levels in occupational settings is done with reliable IR sensors. Remote sensing of low levels of CO2 over long distances cannot be done easily yet, although LIDAR, an airborne laser technique under development, may have good potential. The environmental impacts of elevated CO2 levels on vegetation are being investigated now in free-air CO2 enrichment studies. In general, persistent elevated CO2 levels cause a change in species composition, favoring C3 plants over C4 or CAM. The ecological effects of catastrophic releases are severe but depend upon (a) release rate and amount, (b) surface topography and rate of atmospheric mixing (c) exposure concentrations and duration, (d) the respiratory mechanism of the form of life under discussion, (e) its tolerance for oxygen deprivation, and (f) its ability to maintain homeostatic pH levels. Suppression of root respiration due to elevated soil-gas CO2 concentrations and acidifiction of the root zone are known mechanisms of tree-kill. Soil-gas CO2 in the tree-kill areas at Mammoth Mountain exceeded 20-30% at 15 cm depth. Surface masses of concentrated CO2 probably smother the canopy through oxygen deprivation, but the precise mechanism is not known. Lake Nyos and Mammoth Mountain reveal that catastrophic releases can result in complete dead zones.

  11. Influence of exposure history on the immunology and development of resistance to human Schistosomiasis mansoni.

    Directory of Open Access Journals (Sweden)

    Carla L Black

    2010-03-01

    Full Text Available Previous studies suggest that humans can acquire immunity to reinfection with schistosomes, most probably due to immunologic mechanisms acquired after exposure to dying schistosome worms.We followed longitudinally two cohorts of adult males occupationally exposed to Schistosoma mansoni by washing cars (120 men or harvesting sand (53 men in Lake Victoria. Men were treated with praziquantel each time S. mansoni infection was detected. In car washers, a significant increase in resistance to reinfection, as measured by the number of cars washed between cure and reinfection, was observed after the car washers had experienced, on average, seven cures. In the car washers who developed resistance, the level of schistosome-specific IgE increased between baseline and the time at which development of resistance was first evidenced. In the sand harvesters, a significant increase in resistance, as measured by the number of days worked in the lake between cure and reinfection, was observed after only two cures. History of exposure to S. mansoni differed between the two cohorts, with the majority of sand harvesters being lifelong residents of a village endemic for S. mansoni and the majority of car washers having little exposure to the lake before they began washing cars. Immune responses at study entry were indicative of more recent infections in car washers and more chronic infections in sand harvesters.Resistance to reinfection with S. mansoni can be acquired or augmented by adults after multiple rounds of reinfection and cure, but the rate at which resistance is acquired by this means depends on immunologic status and history of exposure to S. mansoni infection.

  12. Personal exposure to particulate PAHs and anthraquinone and oxidative DNA damages in humans.

    Science.gov (United States)

    Wei, Yongjie; Han, In-Kyu; Hu, Min; Shao, Min; Zhang, Junfeng Jim; Tang, Xiaoyan

    2010-11-01

    Recent studies suggest that DNA oxidative damage be related to the chemical constituents of ambient particles. The purpose of this study was to examine whether particulate polycyclic aromatic hydrocarbons (PAHs) and quinone-structure chemicals increase body burden of oxidative stress in human exposed to heavy traffic volume. We recruited two nonsmoking security guards who worked at a university campus gate near a heavily trafficked road. Each subject wore a personal air sampler for 24h per day to estimate exposures to 24 PAHs and anthraquinone (AnQ) in PM(2.5). Daily pre- and post-work shift spot urines were collected for 29d from each subject. Urine samples were analyzed for 8-hydroxy-2'-deoxyguanosine (8-OHdG). Additionally, using 19 organic tracers other than 24 PAHs and AnQ, a receptor source apportionment model of chemical mass balance was applied to determine the contributions of sources on the PM: gasoline vehicle, diesel vehicle, coal burning, vegetable debris, cooking, natural gas and biomass burning. The relationship among urinary 8-OHdG, individual PAH, and AnQ was demonstrated as follows: the average urinary concentration of 8-OHdG was increased more than three times after 8-h work-shift than those before the work shift. All the 24 PAH and AnQ levels were positively and significantly associated with the post-work urinary 8-OHdG. The results from source apportionment suggest vehicular emission to be the dominant source of personal exposure to PM(2.5). Our finding indicates that personal air exposures to 24 individual PAHs and AnQ originating from traffic emissions are important in increasing oxidative burdens in human body.

  13. 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.

  14. Histological study of soybeans injured by exposure to sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Irving, P. M.; Martinson, D. J.; Miller, J. E.

    1979-01-15

    Since it is now known that crop yields may be reduced by exposure to sulfur dioxide without accompanying visible damage, a technique for quantifying both visible and hidden damage to crop plants after exposure to SO/sub 2/ would be extremely useful. A preliminary histological study of soybean leaves exposed to SO/sub 2/ gas was undertaken to examine the possibility that a microscopic determination of cell death is related to SO/sub 2/ exposure and crop yield. Soybean leaf tissue samples were collected from two field plots which had been exposed to a gradient of acute SO/sub 2/ concentrations. The results from this preliminary investigation suggest that yield decreases will occur in soybeans when approximately 3.5 to 4% of the leaf cells are killed by SO/sub 2/ exposure during an acute episode and that cell death also results from chronic SO/sub 2/ exposures, even though visible damage is not observed. (JGB)

  15. Depleted uranium contamination by inhalation exposure and its detection after approximately 20 years: implications for human health assessment.

    Science.gov (United States)

    Parrish, Randall R; Horstwood, Matthew; Arnason, John G; Chenery, Simon; Brewer, Tim; Lloyd, Nicholas S; Carpenter, David O

    2008-02-01

    Inhaled depleted uranium (DU) aerosols are recognised as a distinct human health hazard and DU has been suggested to be responsible in part for illness in both military and civilian populations that may have been exposed. This study aimed to develop and use a testing procedure capable of detecting an individual's historic milligram-quantity aerosol exposure to DU up to 20 years after the event. This method was applied to individuals associated with or living proximal to a DU munitions plant in Colonie New York that were likely to have had a significant DU aerosol inhalation exposure, in order to improve DU-exposure screening reliability and gain insight into the residence time of DU in humans. We show using sensitive mass spectrometric techniques that when exposure to aerosol has been unambiguous and in sufficient quantity, urinary excretion of DU can be detected more than 20 years after primary DU inhalation contamination ceased, even when DU constitutes only approximately 1% of the total excreted uranium. It seems reasonable to conclude that a chronically DU-exposed population exists within the contamination 'footprint' of the munitions plant in Colonie, New York. The method allows even a modest DU exposure to be identified where other less sensitive methods would have failed entirely. This should allow better assessment of historical exposure incidence than currently exists.

  16. Depleted uranium contamination by inhalation exposure and its detection after {approx} 20 years: Implications for human health assessment

    Energy Technology Data Exchange (ETDEWEB)

    Parrish, Randall R. [Department of Geology, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Notts, NG12 5GG (United Kingdom)], E-mail: rrp@nigl.nerc.ac.uk; Horstwood, Matthew [NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Notts, NG12 5GG (United Kingdom); Arnason, John G. [Department of Earth and Atmospheric Sciences, University at Albany, 1400 Washington Avenue, Albany NY 12222 (United States); Chenery, Simon [British Geological Survey, Keyworth, Notts, NG12 5GG (United Kingdom); Brewer, Tim [Department of Geology, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Lloyd, Nicholas S. [Department of Geology, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); British Geological Survey, Keyworth, Notts, NG12 5GG (United Kingdom); Carpenter, David O. [Institute for Health and the Environment, University at Albany, Five University Place, Room A217, Rensselaer, NY 12144-3456 (United States)

    2008-02-01

    Inhaled depleted uranium (DU) aerosols are recognised as a distinct human health hazard and DU has been suggested to be responsible in part for illness in both military and civilian populations that may have been exposed. This study aimed to develop and use a testing procedure capable of detecting an individual's historic milligram-quantity aerosol exposure to DU up to 20 years after the event. This method was applied to individuals associated with or living proximal to a DU munitions plant in Colonie New York that were likely to have had a significant DU aerosol inhalation exposure, in order to improve DU-exposure screening reliability and gain insight into the residence time of DU in humans. We show using sensitive mass spectrometric techniques that when exposure to aerosol has been unambiguous and in sufficient quantity, urinary excretion of DU can be detected more than 20 years after primary DU inhalation contamination ceased, even when DU constitutes only {approx} 1% of the total excreted uranium. It seems reasonable to conclude that a chronically DU-exposed population exists within the contamination 'footprint' of the munitions plant in Colonie, New York. The method allows even a modest DU exposure to be identified where other less sensitive methods would have failed entirely. This should allow better assessment of historical exposure incidence than currently exists.

  17. Studying cumulative ozone exposures in Europe during a 7-year period

    Science.gov (United States)

    Bastrup-Birk, Annemarie; Brandt, JøRgen; Zlatev, Zahari; Uria, Ignacio

    1997-10-01

    Ozone is one of the most harmful pollutants in the troposphere. High ozone concentrations can damage plants, animals and humans. The damaging effects depend on the magnitude of a critical level of a special parameter, the cumulative ozone exposure. This is why cumulative ozone exposures must be carefully studied. It is important to determine the relationships between relevant emissions (NOx emissions, human-made VOC emissions, and/or a combination of NOx emissions and human-made VOC emissions) and cumulative ozone exposures. All these issues are discussed in this paper. Meteorological data from seven consecutive years, from 1989 to 1995, have been used in the experiments with different scenarios for varying the emissions (the NOx emissions, the human-made VOC emissions, as well as both the NOx emissions and the human-made VOC emissions). The particular air pollution model used in this study is the Danish Eulerian Model. Several hundred runs with different input data (meteorological data and/or emission data) have been performed. Advanced visualization techniques are used to interpret the large amount of digital data collected in these runs and to show clearly different trends and relationships that are normally hidden behind millions and millions of numbers. The model results were compared with measurements taken at more than 80 stations located in different European countries. The experiments indicate that it is sufficient to carry out computations over 5 consecutive years in order to eliminate the influence of extreme meteorological conditions (very warm or very cold summer months) on the cumulative ozone exposures, while this effect is clearly seen if less than 5 years are used in the experiments. It is shown that the relationship between the emissions (NOx and/or human-made VOC emissions) and the cumulative ozone exposures is in general nonlinear. Finally, it is illustrated that the critical values for ozone exposures are exceeded in most of Europe (in many

  18. Toddler exposure to flame retardant chemicals: Magnitude, health concern and potential risk- or protective factors of exposure: Observational studies summarized in a systematic review.

    Science.gov (United States)

    Sugeng, Eva J; de Cock, Marijke; Schoonmade, Linda J; van de Bor, Margot

    2017-10-01

    Endocrine disrupting flame retardant (FR) chemicals form a human health concern, that is investigated mostly from the perspective of adult- and early life exposure. No overview of studies on toddler exposure and health effects exist. However, toddlerhood is a critical developmental period and toddlers are at increased risk for exposure because of their age-specific behavior. This systematic review encompasses toddler FR exposure studies in three countries, associated health effects and potential environmental, demographic, or behavioral risk- or protective factors for toddler exposure. A systematic literature search in four databases (PubMed, Embase.com, The Cochrane Library (via Wiley) and Web of Science Core collection) resulted in the identification of ten publications representing seven unique studies that measured brominated and/or phosphorylated FRs in toddlers' (8-24 month-old) serum, urine, hand wipes and feces. This review showed that toddlers are exposed to a range of FRs, that thyroid hormone disruption is associated with FR exposure and that factors in the indoor environment, including products such as plastic toys, might increase FR exposure. Considering the limited amount of studies, and the variety of biological matrices, FRs, and risk- and protective factors, this review did not reveal a uniform pattern of toddler exposure across the different cohorts studied. More evidence is necessary and considering the feasibility of invasive sampling in young children, we suggest to emphasize research on non-invasive matrices. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Lung tumors in mice induced by "whole-life" inorganic arsenic exposure at human-relevant doses.

    Science.gov (United States)

    Waalkes, Michael P; Qu, Wei; Tokar, Erik J; Kissling, Grace E; Dixon, Darlene

    2014-08-01

    In mice, inorganic arsenic in the drinking water in the parts per million range via the dam during in utero life or with whole-life exposure is a multi-site carcinogen in the offspring. However, human arsenic exposure is typically in the parts per billion (ppb) range. Thus, we studied "whole-life" inorganic arsenic carcinogenesis in mice at levels more relevant to humans. Breeder male and female CD1 mice were exposed to 0, 50, 500 or 5,000 ppb arsenic (as sodium arsenite) in the drinking water for 3 weeks prior to breeding, during pregnancy and lactation, and after weaning (at week 3) groups of male and female offspring (initial n = 40) were exposed for up to 2 years. Tumors were assessed in these offspring. Arsenic exposure had no effect on pregnant dam weights or water consumption, litter size, offspring birthweight or weight at weaning compared to control. In male offspring mice, arsenic exposure increased (p ppb group (51 %) and 500-ppb group (54 %), but not at 5,000-ppb group (28 %) compared to control (22 %). These arsenic-induced bronchiolo-alveolar tumors included increased (p ppb group (27 %) compared to controls (8 %). An increase (p ppb group compared to control (11 %) occurred in female offspring. Thus, in CD1 mice whole-life arsenic exposure induced lung tumors at human-relevant doses (i.e., 50 and 500 ppb).

  20. Lung Tumors in Mice Induced by “Whole Life” Inorganic Arsenic Exposure at Human Relevant Doses

    Science.gov (United States)

    Qu, Wei; Tokar, Erik J.; Kissling, Grace E.; Dixon, Darlene

    2014-01-01

    In mice, inorganic arsenic in the drinking water in the parts per million (ppm) range via the dam during in utero life or with whole life exposure is a multi-site carcinogen in the offspring. However, human arsenic exposure is typically in the parts per billion (ppb) range. Thus, we studied “whole life” inorganic arsenic carcinogenesis in mice at levels more relevant to humans. Breeder male and female CD1 mice were exposed to 0, 50, 500 or 5000 ppb arsenic (as sodium arsenite) in the drinking water for three weeks prior to breeding, during pregnancy and lactation, and after weaning (at week 3) groups of male and female offspring (initial n = 40) were exposed for up to 2 years. Tumors were assessed in these offspring. Arsenic exposure had no effect on pregnant dam weights or water consumption, litter size, offspring birth weight, or weight at weaning compared to control. In male offspring mice, arsenic exposure increased (p ppb (51%) and 500 ppb (54%), but not at 5000 ppb (28%) compared to control (22%). These arsenic-induced bronchiolo-alveolar tumors included increased (p ppb (27%) compared to controls (8%). An increase (p ppb group compared to control (11%) occurred in female offspring. Thus, in CD1 mice whole life arsenic exposure induced lung tumors at human relevant doses (i.e. 50 and 500 ppb). PMID:25005685

  1. Human Parotid Gland Alpha-Amylase Secretion as a Function of Chronic Hyperbaric Exposure

    Science.gov (United States)

    1979-01-01

    parotid ...Pullman, WA 99163 Gilman, S. C, G. J. Fischer, R. J. Biersner, R. D. Thornton, and D. A. Miller. 1979. Human parotid gland alpha-amylase secretion...as a function of chronic hyperbaric exposure. Undersea Biomed. Res. 6(3):303-307.—Secretion of a-amylase by the human parotid gland increased

  2. 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; 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 trans

  3. Co-exposure to nickel and cobalt chloride enhances cytotoxicity and oxidative stress in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Eshan; Lynch, Christine; Ruff, Victoria; Reynolds, Mindy, E-mail: mreynolds2@washcoll.edu

    2012-02-01

    Nickel and cobalt are heavy metals found in land, water, and air that can enter the body primarily through the respiratory tract and accumulate to toxic levels. Nickel compounds are known to be carcinogenic to humans and animals, while cobalt compounds produce tumors in animals and are probably carcinogenic to humans. People working in industrial and manufacturing settings have an increased risk of exposure to these metals. The cytotoxicity of nickel and cobalt has individually been demonstrated; however, the underlying mechanisms of co-exposure to these heavy metals have not been explored. In this study, we investigated the effect of exposure of H460 human lung epithelial cells to nickel and cobalt, both alone and in combination, on cell survival, apoptotic mechanisms, and the generation of reactive oxygen species and double strand breaks. For simultaneous exposure, cells were exposed to a constant dose of 150 μM cobalt or nickel, which was found to be relatively nontoxic in single exposure experiments. We demonstrated that cells exposed simultaneously to cobalt and nickel exhibit a dose-dependent decrease in survival compared to the cells exposed to a single metal. The decrease in survival was the result of enhanced caspase 3 and 7 activation and cleavage of poly (ADP-ribose) polymerase. Co-exposure increased the production of ROS and the formation of double strand breaks. Pretreatment with N-acetyl cysteine alleviated the toxic responses. Collectively, this study demonstrates that co-exposure to cobalt and nickel is significantly more toxic than single exposure and that toxicity is related to the formation of ROS and DSB. -- Highlights: ► Decreased survival following simultaneous exposure to NiCl{sub 2} and CoCl{sub 2}. ► Enhanced caspase and PARP cleavage following co-exposure. ► Increased formation of ROS in dual exposed cells. ► N-acetyl cysteine pretreatment decreases Co and Ni toxicity. ► Co-exposure to Ni and Co enhances the formation of double

  4. 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.

  5. Evaluation of Human Exposure to metals from some popular brands of underarm cosmetics in Nigeria.

    Science.gov (United States)

    Iwegbue, Chukwujindu M A

    2015-08-01

    The concentrations of metals (Cd, Pb, Ni, Cr, Cu, Co, Fe, Mn, Zn and Al) were determined in thirty brands of popular of underarm cosmetics in Nigeria with a view to providing information on the levels of metals and the risk of exposure to metals by humans through long time usage of these products. The concentrations of metals in these samples of underarm cosmetics were measured by using atomic absorption spectrometry after acid digestion. The concentrations of metals in these types of underarm cosmetics studied ranged from cosmetics at concentrations below the regulatory control limits for metal impurities in color additives for cosmetics and suggested limits following good manufacturing practice. The estimated margin of safety (MoS) indicated that the concentrations of the examined metals in these underarm cosmetic products present no potential risk to the users. The continuous use of these brands of underarm cosmetics represents a potential source of human exposure to metals such as aluminum in the local area of the breast, particularly to the upper outer quadrant.

  6. Polybrominated diphenyl ethers (PBDEs) in foodstuffs: human exposure through the diet.

    Science.gov (United States)

    Bocio, A; Llobet, J M; Domingo, J L; Corbella, J; Teixidó, A; Casas, C

    2003-05-07

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in a variety of materials, including synthetic polymers and textiles. Although these chemicals have been detected in environmental samples and human tissues, there is little information about human exposure to PBDEs through the diet. In the present study, we determined the concentrations of PBDEs in a number of food samples acquired in Catalonia (Spain) during 2000. The dietary intake of PBDEs was estimated for the general population living in this Spanish region. The highest PBDE concentrations were found in oils and fats, fish and shellfish, meat and meat products, and eggs, while the lowest levels corresponded to fruits, vegetables, and tubers. The dietary intake of PBDEs for an adult male was 97.3 ng/day (assuming not detected (ND) = (1)/(2) limit of detection (LOD)) or 81.9 ng/day (assuming ND = 0) The greatest contribution to these values corresponded to fish and shellfish, with approximately one-third of the total intake. TetraBDEs and pentaBDEs were the homologues showing the highest percentages of contribution to the sum of total PBDEs. The comparison of the current dietary intake with the suggested lowest observed adverse effect level value of 1 mg/kg/day for the most sensitive endpoints for toxic effects of PBDEs results in a safety factor over 5 orders of magnitude in relation to PBDE exposure from food.

  7. 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.

  8. 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

    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 (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.

  9. Incorporating exposure into aquatic toxicological studies: an imperative.

    Science.gov (United States)

    Wang, Wen-Xiong

    2011-10-01

    The field of aquatic toxicology has been expanding rapidly in recent years. The ecotoxicological study of environmental toxicants encompasses three basic frameworks: environmental behavior/transport, bioavailability/bioaccumulation (exposure), and toxicity at different biological levels. Environmental risk assessments are then based on this knowledge to provide sound advice for environmental management and policies. In this article I will highlight the need to further understand the exposure to toxicants and its direct relationship with toxicological responses at different levels. Exposure considerations generally include the route, species, concentration and duration of exposure, among which the importance of the exposure route has been little considered. A typical aquatic toxicological study simply exposes the organisms to toxicants in the water for a certain period of time under different concentrations. This approach may not be environmentally relevant. Future studies should attempt to understand the toxicology under different exposure regimes. Incorporating exposure will allow aquatic toxicology to be placed in a context of environmental relevance and enhance our understanding of the impacts of toxicants on our living environments. 2011 Elsevier B.V. All rights reserved.

  10. Exposure measurement of aflatoxins and aflatoxin metabolites in human body fluids. A short review.

    Science.gov (United States)

    Leong, Yin-Hui; Latiff, Aishah A; Ahmad, Nurul Izzah; Rosma, Ahmad

    2012-05-01

    Aflatoxins are highly toxic secondary fungal metabolites mainly produced by Aspergillus flavus and A. parasiticus. Human exposure to aflatoxins may result directly from ingestion of contaminated foods, or indirectly from consumption of foods from animals previously exposed to aflatoxins in feeds. This paper focuses on exposure measurement of aflatoxins and aflatoxin metabolites in various human body fluids. Research on different metabolites present in blood, urine, breast milk, and other human fluids or tissues including their detection techniques is reviewed. The association between dietary intake of aflatoxins and biomarker measurement is also highlighted. Finally, aspects related to the differences between aflatoxin determination in food versus the biomarker approach are discussed.

  11. Novel biomarkers of prenatal methamphetamine exposure in human meconium

    Science.gov (United States)

    Gray, Teresa R.; Kelly, Tamsin; LaGasse, Linda L.; Smith, Lynne M.; Derauf, Chris; Haning, William; Grant, Penny; Shah, Rizwan; Arria, Amelia; Strauss, Arthur; Lester, Barry M.; Huestis, Marilyn A.

    2008-01-01

    Meconium analysis can detect fetal exposure to drugs taken by the mother during pregnancy. Methamphetamine and amphetamine have previously been observed in meconium of methamphetamine-exposed neonates; the presence of other metabolites has not been investigated. Detection of such analytes may lead to more sensitive identification and, thus improved medical treatment of affected infants. Methods and Materials Forty-three methamphetamine-positive meconium specimens were analyzed for newly identified methamphetamine biomarkers, p-hydroxymethamphetamine, p-hydroxyamphetamine, and norephedrine. Due to methamphetamine adulteration in illicit ecstasy and to simultaneously monitor 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine prenatal exposure, MDMA, its metabolites and related sympathomimetic amines were assayed. Results Methamphetamine, amphetamine and unconjugated p-hydroxymethamphetamine were the most prevalent and abundant analytes present in meconium; however, unconjugated p-hydroxyamphetamine and norephedrine also were identified. Discussion It is possible that one of these additional analytes could be important for predicting toxicity or maternal or neonatal outcome measures in fetuses exposed to methamphetamine at specific gestational ages or with different metabolic capabilities. Although these new biomarkers were present in lower concentrations than methamphetamine and amphetamine in the meconium of previously confirmed specimens, additional research will determine if inclusion of these analytes can increase identification of methamphetamine-exposed neonates. Conclusion Novel methamphetamine biomarker concentrations were characterized in meconium of infants exposed in utero to methamphetamine. PMID:19125148

  12. Comparison of PBDE congener profiles and concentration levels in human specimens from China and the US and identification of human exposure sources

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In an effort to investigate the status of human exposure to PBDEs in China,available monitoring data in human specimens(including breast milk,serums,and blood) was collected from the general population as well as specific groups that are occupationally exposed.PBDEs exposure profiles and concentration levels were compared with their counterparts in the United States of America.It was found that PBDE burdens in general Chinese population are one order lower and have different congener profiles from that in the US,showing higher percentages of BDE-28 or BDE-153 in human specimens from China.Workers and residents in electronic wastes recycling regions or areas of commercial PBDE manufacturing have the highest PBDE exposure levels reported worldwide,which are close or higher than the exposure levels of the general population in the US. Highly brominated congeners,such as BDE-207 and 209,are among the major PBDE congeners,and BDE-209 has the highest percentage(above 50%) for all occupational populations studied.Principal components analysis(PCA) demonstrates that the exposure of the general population in the US is closely related to penta-BDE while the human burden in China is not.The PBDE in indoor air(gas phase) in the US is highly correlated with the PBDE burden in the general population in the US,indicating a major exposure pathway.For the occupationally exposed populations in China,the congener profiles are closely related to the commercial deca-BDE products.Examination of exposure profiles for general and occupational populations in China suggests that it is essential to include more highly brominated congeners,such as BDE-207 and 209,in future human exposure studies,in order to assess the real burdens and profiles of PBDEs exposure in China.Strict pollution prevention and occupational protection procedures are in need in China to avoid the PBDE contamination problem that has occurred in the US.

  13. Patterns of Exposure of Iberian Wolves (Canis lupus) to Canine Viruses in Human-Dominated Landscapes.

    Science.gov (United States)

    Millán, Javier; López-Bao, José Vicente; García, Emilio J; Oleaga, Álvaro; Llaneza, Luis; Palacios, Vicente; de la Torre, Ana; Rodríguez, Alejandro; Dubovi, Edward J; Esperón, Fernando

    2016-03-01

    Wildlife inhabiting human-dominated landscapes is at risk of pathogen spill-over from domestic species. With the aim of gaining knowledge in the dynamics of viral infections in Iberian wolves (Canis lupus) living in anthropized landscapes of northern Spain, we analysed between 2010 and 2013 the samples of 54 wolves by serology and polymerase chain reaction (PCR) for exposure to four pathogenic canine viruses: canine distemper virus (CDV), canine parvovirus-2 (CPV), canine adenovirus 1 and 2 (CAV-1 and CAV-2) and canine herpesvirus. Overall, 76% of the studied wolves presented evidence of exposure to CPV (96% by HI, 66% by PCR) and 75% to CAV (75% by virus neutralization (VN), 76% by PCR, of which 70% CAV-1 and 6% CAV-2). This represents the first detection of CAV-2 infection in a wild carnivore. CPV/CAV-1 co-infection occurred in 51% of the wolves. The probability of wolf exposure to CPV was positively and significantly correlated with farm density in a buffer zone around the place where the wolf was found, indicating that rural dogs might be the origin of CPV infecting wolves. CPV and CAV-1 appear to be enzootic in the Iberian wolf population, which is supported by the absence of seasonal and inter-annual variations in the proportion of positive samples detected. However, while CPV may depend on periodical introductions by dogs, CAV-1 may be maintained within the wolf population. All wolves were negative for exposure to CDV (by VN and PCR) and CHV (by PCR). The absence of acquired immunity against CDV in this population may predispose it to an elevated rate of mortality in the event of a distemper spill-over via dogs.

  14. Exposure to titanium dioxide and other metallic oxide nanoparticles induces cytotoxicity on human neural cells and fibroblasts

    Directory of Open Access Journals (Sweden)

    James C K Lai

    2008-12-01

    Full Text Available James C K Lai1, Maria B Lai1, Sirisha Jandhyam1, Vikas V Dukhande1, Alok Bhushan1, Christopher K Daniels1, Solomon W Leung21Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, and Biomedical Research Institute; 2Department of Civil and Environmental Engineering, College of Engineering and Biomedical Research Institute, Idaho State University, Pocatello, ID, USAAbstract: The use of titanium dioxide (TiO2 in various industrial applications (eg, production of paper, plastics, cosmetics, and paints has been expanding thereby increasing the occupational and other environmental exposure of these nanoparticles to humans and other species. However, the health effects of exposure to TiO2 nanoparticles have not been systematically assessed even though recent studies suggest that such exposure induces inflammatory responses in lung tissue and cells. Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts. We found that TiO2 micro- and nanoparticles induced cell death on both human cell types in a concentration-related manner. We further noted that zinc oxide (ZnO nanoparticles were the most effective, TiO2 nanoparticles the second most effective, and magnesium oxide (MgO nanoparticles the least effective in inducing cell death in U87 cells. The cell death mechanisms underlying the effects of TiO2 micro- and nanoparticles on U87 cells include apoptosis, necrosis, and possibly apoptosis-like and necrosis-like cell death types. Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.Keywords: cytotoxicity of titanium dioxide micro- and nanoparticles, cytotoxicity of zinc oxide and magnesium oxide nanoparticles, human neural cells

  15. [Human exposures to veterinary medicines reported to the Poisons Information Centre Erfurt from 2003 to 2012].

    Science.gov (United States)

    Hentschel, H; Prasa, D; Bergmann, I; Enden, G; Frimlova, G; Just, S; Plenert, B; Stürzebecher, A; Deters, M

    2014-02-01

    The purpose of this study was to get information on all human exposures to veterinary medicines (HEVM) reported to the Poisons Information Centre (PIC) over a 10-year period. A retrospective analysis of all HEVM was undertaken and a comparison was made to all human exposures (HE) registered by the PIC from the beginning of 2003 to the end of 2012 according to frequencies, circumstances of exposure, symptom severity, age groups, and substances involved in HEVM. In total, 389 cases of HEVM with 409 veterinary medicines were registered (0.30% of all HE, 360 monoexposures). The relative frequency of children and adults in HEVM (children: 52.4%, adults: 46.0%) and all HE (children: 48.7%, adults 48.7%) was the same with significant (pveterinary medicines (ATCvet) in HEVM were antiparasitic substances, insecticides and repellents (n=185), substances for the nervous system (n=48), substances for the cardiovascular system (n=35), and immunologicals (n=35). HEVM mostly resulted in no or mild symptoms (83.8%) and rarely in moderate (10/389, 2.6%) or even severe symptoms (5/389, 1.3%). In 4 of 5 cases of HEVM with severe symptoms, veterinary surgeons used products for animal euthanasia (n=3) or methadone (n=1). Once, self-medication with anthelmintics for several days by a goatherd resulted in transient blindness. In comparison to other HE, HEVM are rare. Most accidental HEVM in laymen result only in none to mild symptoms. If veterinary surgeons, however, swallow or inject products for animal euthanasia or opioids in suicidal intention, severe symptoms can be expected. © Georg Thieme Verlag KG Stuttgart · New York.

  16. 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 BACKGROUND: 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. METHODS AND FINDINGS: 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. CONCLUSIONS: 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.

  17. 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

  18. A novel application of capnography during controlled human exposure to air pollution

    Directory of Open Access Journals (Sweden)

    Fila Michael

    2006-10-01

    waves in controlled human air pollution exposure studies is a feasible tool for characterization of cardio-pulmonary effects of such exposures.

  19. Modeling Air Pollution Exposure Metrics for the Diabetes and Environment Panel Study (DEPS)

    Science.gov (United States)

    Air pollution health studies of fine particulate matter (PM) often use outdoor concentrations as exposure surrogates. To improve exposure assessments, we developed and evaluated an exposure model for individuals (EMI), which predicts five tiers of individual-level exposure metric...

  20. Numerical compliance testing of human exposure to electromagnetic radiation from smart-watches

    Science.gov (United States)

    Hong, Seon-Eui; Lee, Ae-Kyoung; Kwon, Jong-Hwa; Pack, Jeong-Ki

    2016-10-01

    In this study, we investigated the electromagnetic dosimetry for smart-watches. At present, the standard for compliance testing of body-mounted and handheld devices specifies the use of a flat phantom to provide conservative estimates of the peak spatial-averaged specific absorption rate (SAR). This means that the estimated SAR using a flat phantom should be higher than the SAR in the exposure part of an anatomical human-body model. To verify this, we numerically calculated the SAR for a flat phantom and compared it with the numerical calculation of the SAR for four anatomical human-body models of different ages. The numerical analysis was performed using the finite difference time domain method (FDTD). The smart-watch models were used in the three antennas: the shorted planar inverted-F antenna (PIFA), loop antenna, and monopole antenna. Numerical smart-watch models were implemented for cellular commutation and wireless local-area network operation at 835, 1850, and 2450 MHz. The peak spatial-averaged SARs of the smart-watch models are calculated for the flat phantom and anatomical human-body model for the wrist-worn and next to mouth positions. The results show that the flat phantom does not provide a consistent conservative SAR estimate. We concluded that the difference in the SAR results between an anatomical human-body model and a flat phantom can be attributed to the different phantom shapes and tissue structures.

  1. Calcium montmorillonite clay reduces urinary biomarkers of fumonisin B₁ exposure in rats and humans.

    Science.gov (United States)

    Robinson, A; Johnson, N M; Strey, A; Taylor, J F; Marroquin-Cardona, A; Mitchell, N J; Afriyie-Gyawu, E; Ankrah, N A; Williams, J H; Wang, J S; Jolly, P E; Nachman, R J; Phillips, T D

    2012-01-01

    Fumonisin B₁ (FB₁) is often a co-contaminant with aflatoxin (AF) in grains and may enhance AF's carcinogenicity by acting as a cancer promoter. Calcium montmorillonite (i.e. NovaSil, NS) is a possible dietary intervention to help decrease chronic aflatoxin exposure where populations are at risk. Previous studies show that an oral dose of NS clay was able to reduce AF exposure in a Ghanaian population. In vitro analyses from our laboratory indicated that FB₁ (like aflatoxin) could also be sorbed onto the surfaces of NS. Hence, our objectives were to evaluate the efficacy of NS clay to reduce urinary FB₁ in a rodent model and then in a human population highly exposed to AF. In the rodent model, male Fisher rats were randomly assigned to either FB₁ control, FB₁ + 2% NS or absolute control group. FB₁ alone or with clay was given as a single dose by gavage. For the human trial, participants received NS (1.5 or 3 g day⁻¹) or placebo (1.5 g day⁻¹) for 3 months. Urines from weeks 8 and 10 were collected from the study participants for analysis. In rats, NS significantly reduced urinary FB₁ biomarker by 20% in 24 h and 50% after 48 h compared to controls. In the humans, 56% of the urine samples analysed (n = 186) had detectable levels of FB₁. Median urinary FB₁ levels were significantly (p 90% in the high dose NS group (3 g day⁻¹) compared to the placebo. This work indicates that our study participants in Ghana were exposed to FB₁ (in addition to AFs) from the diet. Moreover, earlier studies have shown conclusively that NS reduces the bioavailability of AF and the findings from this study suggest that NS clay also reduces the bioavailability FB₁. This is important since AF is a proven dietary risk factor for hepatocellular carcinoma (HCC) in humans and FB₁ is suspected to be a dietary risk factor for HCC and oesophageal cancer in humans.

  2. Widespread occurrence of perchlorate in water, foodstuffs and human urine collected from Kuwait and its contribution to human exposure.

    Science.gov (United States)

    Alomirah, Husam F; Al-Zenki, Sameer F; Alaswad, Marivi C; Alruwaih, Noor A; Wu, Qian; Kannan, Kurunthachalam

    2016-06-01

    Perchlorate is a thyroid hormone-disrupting compound and is reported to occur widely in the environment. Little is known on human exposure to perchlorate in Kuwait. In this study, 218 water samples, 618 commonly consumed foodstuffs and 532 urine samples collected from Kuwait were analysed to assess the exposure of the Kuwaiti population to perchlorate. For the estimation of daily intake of perchlorate, food consumption rates were obtained from the National Nutrition Survey in the State of Kuwait (NNSSK). The results showed that leafy vegetables accounted for a major share of perchlorate exposure among the Kuwaiti population at 0.062 µg kg(-)(1) bw day(-)(1) (36.2%), followed by fruits at 0.026 µg kg(-)(1) bw day(-)(1) (15.3%) and non-leafy vegetables at 0.017 µg kg(-)(1) bw day(-)(1) (10.1%). The urinary perchlorate geometric mean (GM) concentrations ranged from 8.51 to 17.1 µg l(-)(1) for the five age groups, which were higher than those reported in other countries. The estimated urinary perchlorate exposure for the Kuwaiti general population was 0.42 µg kg(-)(1) bw day(-)(1), which was higher than that reported for the United States. The dietary intake of perchlorate for the Kuwaiti population ranged from 0.14 to 0.67 µg kg(-)(1) bw day(-)(1) for the five age groups, with a mean total daily intake of 0.17 µg kg(-)(1) bw day(-)(1) for the general population. The highest estimated dietary mean daily intake of perchlorate (0.67 µg kg(-)(1) bw day(-)(1)) was found for children at 3-5 years. The estimated dietary perchlorate exposure in Kuwait is higher than the recommended mean reference dose (RfD) but lower than that of provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

  3. Human Resource Challenges to Integrating HIV Pre-Exposure ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    We documented consultation discussions through note taking. Human resource .... coordinators, and nursing officer in-charges. Interviews were ... shifting as playing an important role in PrEP .... counseling, and to high patient volume and longer wait times on the ... about the safety and efficacy of PrEP, which may influence ...

  4. Assessment of dietary exposure and effect in humans

    NARCIS (Netherlands)

    Duynhoven, Van John P.M.; Jacobs, Doris M.

    2016-01-01

    In human nutritional science progress has always depended strongly on analytical measurements for establishing relationships between diet and health. This field has undergone significant changes as a result of the development of NMR and mass spectrometry methods for large scale detection, identif

  5. Leaching of the plasticizer di(2-ethylhexyl)phthalate (DEHP) from plastic containers and the question of human exposure.

    Science.gov (United States)

    Erythropel, Hanno C; Maric, Milan; Nicell, Jim A; Leask, Richard L; Yargeau, Viviane

    2014-12-01

    Di(2-ethylhexyl)phthalate (DEHP) is a widely used plasticizer to render poly(vinyl chloride) (PVC) soft and malleable. Plasticized PVC is used in hospital equipment, food wrapping, and numerous other commercial and industrial products. Unfortunately, plasticizers can migrate within the material and leach out of it over time, ending up in the environment and, frequently, the human body. DEHP has come under increased scrutiny as its breakdown products are believed to be endocrine disruptors and more toxic than DEHP itself. DEHP and its breakdown products have been identified as ubiquitous environmental contaminants, and daily human exposure is estimated to be in the microgram per kilogram level. The objective of this review is to summarize and comment on published sources of DEHP exposure and to give an overview of its environmental fate. Exposure through bottled water was examined specifically, as this concern is raised frequently, yet only little exposure to DEHP occurs through bottled water, and DEHP exposure is unlikely to stem from the packaging material itself. Packaged food was also examined and showed higher levels of DEHP contamination compared to bottled water. Exposure to DEHP also occurs in hospital environments, where DEHP leaches directly into liquids that passed through PVC/DEHP tubing and equipment. The latter exposure is at considerably higher levels compared to food and bottled water, specifically putting patients with chronic illnesses at risk. Overall, levels of DEHP in food and bottled water were below current tolerable daily intake (TDI) values. However, our understanding of the risks of DEHP exposure is still evolving. Given the prevalence of DEHP in our atmosphere and environment, and the uncertainty revolving around it, the precautionary principle would suggest its phaseout and replacement. Increased efforts to develop viable replacement compounds, which necessarily includes rigorous leaching, toxicity, and impact assessment studies, are

  6. Physiologically based pharmacokinetic toolkit to evaluate environmental exposures: Applications of the dioxin model to study real life exposures.

    Science.gov (United States)

    Emond, Claude; Ruiz, Patricia; Mumtaz, Moiz

    2017-01-15

    Chlorinated dibenzo-p-dioxins (CDDs) are a series of mono- to octa-chlorinated homologous chemicals commonly referred to as polychlorinated dioxins. One of the most potent, well-known, and persistent member of this family is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). As part of translational research to make computerized models accessible to health risk assessors, we present a Berkeley Madonna recoded version of the human physiologically based pharmacokinetic (PBPK) model used by the U.S. Environmental Protection Agency (EPA) in the recent dioxin assessment. This model incorporates CYP1A2 induction, which is an important metabolic vector that drives dioxin distribution in the human body, and it uses a variable elimination half-life that is body burden dependent. To evaluate the model accuracy, the recoded model predictions were compared with those of the original published model. The simulations performed with the recoded model matched well with those of the original model. The recoded model was then applied to available data sets of real life exposure studies. The recoded model can describe acute and chronic exposures and can be useful for interpreting human biomonitoring data as part of an overall dioxin and/or dioxin-like compounds risk assessment. Copyright © 2016. Published by Elsevier Inc.

  7. Effects of acute exercise on fear extinction in rats and exposure therapy in humans: Null findings from five experiments.

    Science.gov (United States)

    Jacquart, Jolene; Roquet, Rheall F; Papini, Santiago; Powers, Mark B; Rosenfield, David; Smits, Jasper A J; Monfils, Marie-H

    2017-08-01

    Exposure therapy is an established learning-based intervention for the treatment of anxiety disorders with an average response rate of nearly 50%, leaving room for improvement. Emerging strategies to enhance exposure therapy in humans and fear extinction retention in animal models are primarily pharmacological. These approaches are limited as many patients report preferring non-pharmacological approaches in therapy. With general cognitive enhancement effects, exercise has emerged as a plausible non-pharmacological augmentation strategy. The present study tested the hypothesis that fear extinction and exposure therapy would be enhanced by a pre-training bout of exercise. We conducted four experiments with rats that involved a standardized conditioning and extinction paradigm and a manipulation of exercise. In a fifth experiment, we manipulated vigorous-intensity exercise prior to a standardized virtual reality exposure therapy session among adults with fear of heights. In experiments 1-4, exercise did not facilitate fear extinction, long-term memory, or fear relapse tests. In experiment 5, human participants showed an overall reduction in fear of heights but exercise did not enhance symptom improvement. Although acute exercise prior to fear extinction or exposure therapy, as operationalized in the present 5 studies, did not enhance outcomes, these results must be interpreted within the context of a broader literature that includes positive findings. Taken all together, this suggests that more research is necessary to identify optimal parameters and key individual differences so that exercise can be implemented successfully to treat anxiety disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Prolonged exposure to acetaminophen reduces testosterone production by the human fetal testis in a xenograft model

    DEFF Research Database (Denmark)

    van den Driesche, Sander; Macdonald, Joni; Anderson, Richard A

    2015-01-01

    Most common male reproductive disorders are linked to lower testosterone exposure in fetal life, although the factors responsible for suppressing fetal testosterone remain largely unknown. Protracted use of acetaminophen during pregnancy is associated with increased risk of cryptorchidism in sons......, but effects on fetal testosterone production have not been demonstrated. We used a validated xenograft model to expose human fetal testes to clinically relevant doses and regimens of acetaminophen. Exposure to a therapeutic dose of acetaminophen for 7 days significantly reduced plasma testosterone (45......% reduction; P = 0.025) and seminal vesicle weight (a biomarker of androgen exposure; 18% reduction; P = 0.005) in castrate host mice bearing human fetal testis xenografts, whereas acetaminophen exposure for just 1 day did not alter either parameter. Plasma acetaminophen concentrations (at 1 hour after...

  10. Organophosphorus flame retardants and plasticizers: sources, occurrence, toxicity and human exposure.

    Science.gov (United States)

    Wei, Gao-Ling; Li, Ding-Qiang; Zhuo, Mu-Ning; Liao, Yi-Shan; Xie, Zhen-Yue; Guo, Tai-Long; Li, Jun-Jie; Zhang, Si-Yi; Liang, Zhi-Quan

    2015-01-01

    Due to the restricted use and ban of brominated flame retardants, organophosphorus compounds (OPs), extensively used as flame retardants and plasticizers, are ubiquitous in various environmental compartments worldwide. The present study shows that the release of OPs from a wide variety of commercial products and wastewater discharge might be considered as primary emission sources and that high potential of long-range atmospheric transport and persistence of OPs would be responsible for their presence in various matrices on a global scale. The occurrence and environmental behaviors of OPs in diverse matrices (e.g., dust, air, water, sediment, soil and biota) are reviewed. Human exposures to OPs via dermal contact, dust ingestion, inhalation and dietary intake are comprehensively evaluated. Finally, this study identifies gaps in the existing issues and generates a future agenda for the emerging contaminants OPs.

  11. Building-associated neurological damage modeled in human cells: a mechanism of neurotoxic effects by exposure to mycotoxins in the indoor environment.

    Science.gov (United States)

    Karunasena, Enusha; Larrañaga, Michael D; Simoni, Jan S; Douglas, David R; Straus, David C

    2010-12-01

    Damage to human neurological system cells resulting from exposure to mycotoxins confirms a previously controversial public health threat for occupants of water-damaged buildings. Leading scientific organizations disagree about the ability of inhaled mycotoxins in the indoor environment to cause adverse human health effects. Damage to the neurological system can result from exposure to trichothecene mycotoxins in the indoor environment. This study demonstrates that neurological system cell damage can occur from satratoxin H exposure to neurological cells at exposure levels that can be found in water-damaged buildings contaminated with fungal growth. The constant activation of inflammatory and apoptotic pathways at low levels of exposure in human brain capillary endothelial cells, astrocytes, and neural progenitor cells may amplify devastation to neurological tissues and lead to neurological system cell damage from indirect events triggered by the presence of trichothecenes.

  12. Micronuclei assay: A potential biomonitoring protocol in occupational exposure studies.

    Science.gov (United States)

    Palanikumar, L; Panneerselvam, N

    2011-09-01

    As micronuclei (MN) derive from chromosomal fragments and whole chromosomes lagging behind in anaphase, the MN assay can be used to show both clastogenic and aneugenic effects. This particularly concerns the use of MN as a biomarker ofgenotoxic exposure and effects, where differences in MN frequencies between exposed subjects and referents are expected to be small. The present paper reviews the use of the MN assay in biomonitoring of occupational exposure studies.

  13. Measurement of personal and integrated exposure to particulate matter and co-pollutant gases: a panel study.

    Science.gov (United States)

    Devi, J Jai; Gupta, Tarun; Jat, Rajmal; Tripathi, S N

    2013-03-01

    Personal exposure measurement can serve as an effective tool to understand the effect of exposure to air pollutants. Alternatively, exposure assessment using pollutant concentrations in different microenvironments and accurate time-activity information for the subjects can provide good information regarding human integrated exposure. A panel of 18 healthy students of Indian Institute of Technology (IIT) Kanpur in the age group of 18 to 30 years participated in the personal exposure measurements for particulate matter, CO, NO(2) and VOC during post-monsoon and pre-monsoon seasons. Overall, 432 h person exposure data was collected in this study. The major sources of particulate and gaseous co-pollutants were identified. These directly obtained personal exposure values were then compared to the indirectly estimated integrated exposure values. Personal and integrated exposures gave statistically similar results. Through this study, we have shown that integrated exposure values could closely estimate the personal exposure values for particulate matter that can significantly reduce time and cost involved in personal exposure studies. The lung parameters for all the subjects measured during the pre-monsoon and post-monsoon seasons showed statistically significant reduction during pre-monsoon. This was attributed to the high levels of coarse particles during pre-monsoon.

  14. Heavy metals in human teeth dentine: A bio-indicator of metals exposure and environmental pollution.

    Science.gov (United States)

    Asaduzzaman, Khandoker; Khandaker, Mayeen Uddin; Binti Baharudin, Nurul Atiqah; Amin, Yusoff Bin Mohd; Farook, Mohideen Salihu; Bradley, D A; Mahmoud, Okba

    2017-06-01

    With rapid urbanization and large-scale industrial activities, modern human populations are being increasingly subjected to chronic environmental heavy metal exposures. Elemental uptake in tooth dentine is a bioindicator, the uptake occurring during the formation and mineralization processes, stored to large extent over periods of many years. The uptake includes essential elements, most typically geogenic dietary sources, as well as non-essential elements arising through environmental insults. In this study, with the help of the Dental Faculty of the University of Malaya, a total of 50 separate human teeth were collected from dental patients of various ethnicity, age, gender, occupation, dietary habit, residency, etc. Analysis was conducted using inductively coupled plasma-mass spectrometry (ICP-MS), most samples indicating the presence of the following trace elements, placed in order of concentration, from least to greatest: As, Mn, Ba, Cu, Cr, Pb, Zn, Hg, Sb, Al, Sr, Sn. The concentrations have been observed to increase with age. Among the ethnic groups, the teeth of ethnic Chinese showed marginally greater metal concentrations than those of the Indians and Malays, the teeth dentine of females generally showing greater concentrations than that of males. Greater concentrations of Hg, Cu and Sn were found in molars while Pb, Sr, Sb and Zn were present in greater concentrations in incisors. With the elevated concentration levels of heavy metals in tooth dentine reflecting pollution from industrial emissions and urbanization, it is evident that human tooth dentine can provide chronological information on exposure, representing a reliable bio-indicator of environmental pollution.

  15. 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...

  16. An agent-based model of exposure to human toxocariasis: a multi-country validation.

    Science.gov (United States)

    Kanobana, K; Devleesschauwer, B; Polman, K; Speybroeck, N

    2013-07-01

    Seroprevalence data illustrate that human exposure to Toxocara is frequent. Environmental contamination with Toxocara spp. eggs is assumed to be the best indicator of human exposure, but increased risk of exposure has also been associated with many other factors. Reported associations are inconsistent, however, and there is still ambiguity regarding the factors driving the onset of Toxocara antibody positivity. The objective of this work was to assess the validity of our current conceptual understanding of the key processes driving human exposure to Toxocara. We constructed an agent-based model predicting Toxocara antibody positivity (as a measure of exposure) in children. Exposure was assumed to depend on the joint probability of 3 parameters: (1) environmental contamination with Toxocara spp. eggs, (2) larvation of these eggs and (3) the age-related contact with these eggs. This joint probability was linked to processes of acquired humoral immunity, influencing the rate of antibody seroreversion. The results of the simulation were validated against published data from 5 different geographical settings. Using simple rules and a stochastic approach with parameter estimates derived from the respective contexts, plausible serological patterns emerged from the model in nearly all settings. Our approach leads to novel insights in the transmission dynamics of Toxocara.

  17. Human Exposure to Legacy and Emerging Halogenated Flame Retardants via Inhalation and Dust Ingestion in a Norwegian Cohort.

    Science.gov (United States)

    Tay, Joo Hui; Sellström, Ulla; Papadopoulou, Eleni; Padilla-Sánchez, Juan Antonio; Haug, Line Småstuen; de Wit, Cynthia A

    2017-07-18

    In this study, we estimated human exposure to polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), and several emerging flame retardants (EFRs) via inhalation and dust ingestion. Sixty indoor stationary air samples, 13 personal air samples, and 60 settled dust samples were collected from a Norwegian cohort during winter 2013. PBDEs showed the highest median concentration in dust (1200 ng/g), followed by EFRs (730 ng/g) and HBCDDs (190 ng/g). The PBDE concentrations in dust were mainly driven by BDE-209 and those of EFRs by bis(2-ethylhexyl) tetrabromophthalate. EFRs predominated in stationary air samples, with 2-ethylhexyl 2,3,4,5-tetrabromobenzoate and 4-(1,2-dibromoethyl)-1,2-dibromocyclohexane having the highest median concentrations (150 and 25 pg/m(3) (sum of α- and β-isomers), respectively). Different profiles and concentrations were observed in personal air samples compared to the corresponding stationary air samples. In relation to inhalation exposure, dust ingestion appears to be the major exposure pathway to FRs (median total exposure 230 pg/kg bw/d, accounting for more than 65% of the total exposure) for the Norwegian cohort. The calculated exposure due to air inhalation was substantially lower when the stationary air concentrations were used rather than personal air concentrations (43 pg/kg bw/d versus 130 pg/kg bw/d). This suggests that other exposure situations (such as outdoors or in offices) contributed significantly to the overall personal exposure, which cannot be included by using only a stationary air sampling technique. The median and 95th percentile exposures for all target FRs did not exceed the reference dose.

  18. An epidemiological approach to characterise the human exposure pathways in a contaminated estuarine environment.

    Science.gov (United States)

    Machado, Ausenda; Fernandes, Ana Paula; Paixão, Eleonora; Caeiro, Sandra; Matias-Dias, Carlos

    2017-12-01

    This study's aim was to develop and implement an integrative epidemiologic cross-sectional study that allows identifying and characterising exposure pathways of populations living and working on the shores of a contaminated estuarine environment. Population residing in Carrasqueira, located on the Sado estuary with known contaminated areas was compared to another population on a noncontaminated estuary (Vila Nova de Mil Fontes - VNMF), considered a nonexposed population. Simple random samples of individuals were selected in each study population from the National Health Service Lists: 140 individuals were selected in Carrasqueira and 219 in VNMF. Participation rates were higher in the exposed group (62.5%, n=102 in Carrasqueira and 48.3%, n=100 individuals in VNMF). The same structured questionnaire was used in both populations, including questions on occupational activities, leisure activities, consumption of food (including fish and mollusks from the estuary) and use of water for human intake and agriculture. Results showed that a significantly higher proportion of Carrasqueira participants reported doing tasks in their job that promote direct (48.8% vs 1.2% in VNMF, p-valuecontamination from the contaminated estuarine environment. The study design and the selection of both populations were adequate for this type of epidemiologic study of potential routes of human contamination in a mixture of contaminated estuarine environment and can be used in other estuarine areas with similar environmental risk. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Human epidermal keratinocytes death and expression of protein markers of apoptosis after ionizing radiation exposure

    Directory of Open Access Journals (Sweden)

    Sharon Wong

    2013-12-01

    Full Text Available Purpose: Knowledge of the pathophysiology of the irradiated skin is important to understand the tolerance and cosmetic response of the human skin to radiation. There are limited studies on the effect of radiotherapy dosage and fraction size in inducing apoptotic cell death in human skin. The expression of apoptotic biomarkers within a controlled population in different fractionation schemes has also never been studied. This study aims to investigate radiation induced apoptotic cell death in human skin cells after fractionated radiation exposure and the expression of unique biomarkers that reflect cell death or biology using multiplexed immunoassays.Methods: Breast skin biopsies were obtained from a single individual and divided into small pieces. Each piece was irradiated under different radiotherapy treatment fractionation schedules to a total dose of 50Gy. The irradiated skin tissues were analysed using Tunnel, immunohistochemistry and Western blot assays for expression of apoptotic keratinocytes and biomarkers (p53, p21, and PCNA. Haematoxylin and eosin (H&E immunostaining was performed to study the morphological changes in the skin cells. Results: Radiation is mostly absorbed by the epidermal layers and observed to damage the epidermal keratinocytes leading to the activation of apoptotic proteins. Apoptotic proteins (p53, p21 and PCNA were confirmed to be up-regulated in radiation exposed skin cells as compared to normal skin cells with no radiation. There is strong correlation of apoptotic protein expressions with increased radiation dosage and dose fractionation. Statistical analysis with ANOVA revealed a significant increase of PCNA and p21 expression with increased radiation dosage and dose fractionation (p < 0.05. Immunohistochemically, 14 % (range 10.71% to 17.29% of the keratinocytes were positive for PCNA and 22.5% (range 18.28% to 27.2% for p21 after 2Gy of irradiation.  The most widespread, intense and uniform staining for PCNA

  20. The applied indicators of water quality may underestimate the risk of chemical exposure to human population in reservoirs utilized for human supply-Southern Brazil.

    Science.gov (United States)

    Dos Santos, Debora Regina; Yamamoto, Flávia Yoshie; Filipak Neto, Francisco; Randi, Marco Antônio Ferreira; Garcia, Juan Esquivel; Costa, Daniele Dietrich Moura; Liebel, Samuel; Campos, Sandro Xavier; Voigt, Carmen Lúcia; de Oliveira Ribeiro, Ciro Alberto

    2016-05-01

    The knowledge concerning associations between chronic chemical exposure and many disorders with complex etiology involving gene-environment interactions is increasing, and new methods must be developed to improve water quality monitoring. The complexity of chemical mixtures in polluted aquatic environments makes the evaluation of toxic potential in those sites difficult, but the use of biomarkers and bioindicators has been recognized as a reliable tool to assess risk of exposure to biota and also the human population. In order to evaluate the use of fish and biomarkers to assess toxic potential and bioavailability of chemicals in human-related hydric resources, an in situ experiment was accomplished in two water reservoirs designated for human supply, which were previously evaluated by the local environmental regulatory agency through a set of physical, chemical, and classical biological parameters. Molecular, biochemical, and morphological biomarkers were performed in caged Oreochromis niloticus kept for 6 months in the studied reservoirs to assess potentially useful biomarkers to evaluate the quality of water for human supply. Chemical analysis of toxic metals in liver and muscle and polycyclic aromatic hydrocarbons (PAHs) in bile was considered to assess the bioavailability of pollutants and highlight human activity impact. The reservoir previously classified by a governmental agency as less impacted presented more risk of exposure to biota. These results were supported by chemical analysis, vitellogenin expression, histopathological findings (gonads, liver, and gills), as well as indicators of neurotoxic effects and oxidative stress in liver. The inclusion of some biomarkers as parameters in regulatory monitoring programs in reservoirs designated for human supply is strongly suggested to evaluate the risks of exposure to the human population. Thus, a revision of the traditional biological and physicochemical analysis utilized to establish the conditions of

  1. Possible additional exposure to dioxin and dioxin-like compounds from waste incineration. Biomonitoring using human milk and animal samples

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, C.; M. Fatima Reis; J. Pereira Miguel [Inst. of Preventive Medicine, Univ. of Lisbon (Portugal); Murk, A. [Wageningen Univ., Dept. of Toxicology (Netherlands)

    2004-09-15

    In the ambit of an Environmental Health Survey Program relative to a MSW facility, which has been operating near to Lisbon since 1999 a biomonitoring study using human breast milk has been performed. Specific aims of this study were: (1) determine whether living in the vicinity of the incinerator increases dioxin maternal body burden and accordingly perinatal (intra-uterus and lactacional) exposure; (2) to investigate the possibility of increased human exposure to dioxins and dioxin-like compounds via locally produced food items from animal origin. Therefore, levels of dioxins and dioxin-like compounds have been determined in human milk samples collected in the vicinity of the incinerator and in a control area, for comparison. From the same areas, cow and sheep milk and eggs from free-range chickens have also been collected to get an indication of possible local additional exposure to air-borne dioxins via the food chain. Analyses of TCDD-equivalents (TEQs) were mainly performed with a reporter gene assay for dioxin-like activity, the DR-CALUX bioassay (Dioxin Responsive Chemical Activated LUciferase gene eXpression).To determine congeners profile, some human milk samples have also been analysed for PCDD/Fs and relevant dioxin-like PCBs, by using high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS). Both the Ethics Committees of the Faculty of Medicine, University of Lisbon, and of the Maternity Dr. Alfredo da Costa have approved the study protocol.

  2. Non-Hodgkin's lymphoma risk derived from exposure to organic solvents: a review of epidemiologic studies

    Directory of Open Access Journals (Sweden)

    Marco Antônio V. Rêgo

    Full Text Available The rate of non-Hodgkin's lymphomas (NHL has increased around the world during the last decades. Apart from the role of the human immunodeficiency virus (HIV infection in the development of NHL, exposure to chemical agents like phenoxyacetic pesticides, hair dyes, metal fumes and organic solvents are suspected to be involved. The present review evaluates the results of studies that directly or indirectly searched for an association between solvent exposure and NHL. The selected studies comprised those published from 1979 to 1997, designed to investigate risk factors for NHL, whether specifically looking for solvent exposure or for general risks in which solvent exposure could be included. In 25 of the 45 reviewed studies (55.5%, fifty-four statistically significant associations between NHL and solvent exposure related occupations or industries were reported. Statistical significance was more frequently shown in studies where solvent exposure was more accurately defined. In eighteen of such studies, 13 (72.2% defined or suggested organic solvents as possible risk factors for NHL.

  3. Human fetal exposure to triclosan and triclocarban in an urban population from Brooklyn, New York.

    Science.gov (United States)

    Pycke, Benny F G; Geer, Laura A; Dalloul, Mudar; Abulafia, Ovadia; Jenck, Alizee M; Halden, Rolf U

    2014-01-01

    Triclosan (TCS) and triclocarban (TCC) are antimicrobial agents formulated in a wide variety of consumer products (including soaps, toothpaste, medical devices, plastics, and fabrics) that are regulated by the U.S. Food and Drug Administration (FDA) and U.S. Environmental Protection Agency. In late 2014, the FDA will consider regulating the use of both chemicals, which are under scrutiny regarding lack of effectiveness, potential for endocrine disruption, and potential contribution to bacterial resistance to antibiotics. Here, we report on body burdens of TCS and TCC resulting from real-world exposures during pregnancy. Using liquid chromatography tandem mass spectrometry, we determined the concentrations of TCS, TCC, and its human metabolites (2'-hydroxy-TCC and 3'-hydroxy-TCC) as well as the manufacturing byproduct (3'-chloro-TCC) as total concentrations (Σ-) after conjugate hydrolysis in maternal urine and cord blood plasma from a cohort of 181 expecting mother/infant pairs in an urban multiethnic population from Brooklyn, NY recruited in 2007-09. TCS was detected in 100% of urine and 51% of cord blood samples after conjugate hydrolysis. The interquartile range (IQR) of detected TCS concentrations in urine was highly similar to the IQR reported previously for the age-matched population of the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2004, but typically higher than the IQR reported previously for the general population (detection frequency = 74.6%). Urinary levels of TCC are reported here for the first time from real-world exposures during pregnancy, showing a median concentration of 0.21 μg/L. Urinary concentrations of TCC correlated well with its phase-I metabolite ∑-2'-hydroxy-TCC (r = 0.49) and the manufacturing byproduct ∑-3'-chloro-TCC C (r = 0.79), and ∑-2'-hydroxy-TCC correlated strongly with ∑-3'-hydroxy-TCC (r = 0.99). This human biomonitoring study presents the first body burden data for TCC from exposures

  4. Arsenic exposure disrupts epigenetic regulation of SIRT1 in human keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Herbert, Katharine J. [School of Health Sciences, University of Tasmania, Launceston, TAS 7250 (Australia); Holloway, Adele [Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS 7000 (Australia); Cook, Anthony L. [School of Health Sciences, University of Tasmania, Launceston, TAS 7250 (Australia); Chin, Suyin P. [Menzies Research Institute Tasmania, University of Tasmania, Hobart, TAS 7000 (Australia); Snow, Elizabeth T., E-mail: elizabeth.snow@utas.edu.au [School of Health Sciences, University of Tasmania, Launceston, TAS 7250 (Australia)

    2014-11-15

    Arsenic is an environmental toxin which increases skin cancer risk for exposed populations worldwide; however the underlying biomolecular mechanism for arsenic-induced carcinogenesis is complex and poorly defined. Recent investigations show that histone deacetylase and DNA methyltransferase activity is impaired, and epigenetic patterns of gene regulation are consistently altered in cancers associated with arsenic exposure. Expression of the histone deacetylase SIRT1 is altered in solid tumours and haematological malignancies; however its role in arsenic-induced pathology is unknown. In this study we investigated the effect of arsenic on epigenetic regulation of SIRT1 and its targeting microRNA, miR-34a in primary human keratinocytes. Acetylation of histone H4 at lysine 16 (H4K16) increased in keratinocytes exposed to 0.5 μM arsenite [As(III)]; and this was associated with chromatin remodelling at the miR-34a promoter. Moreover, although SIRT1 protein initially increased in these As(III)-exposed cells, after 24 days expression was not significantly different from untreated controls. Extended exposure to low-dose As(III) (0.5 μM; > 5 weeks) compromised the pattern of CpG methylation at SIRT1 and miR-34a gene promoters, and this was associated with altered expression for both genes. We have found that arsenic alters epigenetic regulation of SIRT1 expression via structural reorganisation of chromatin at the miR-34a gene promoter in the initial 24 h of exposure; and over time, through shifts in miR-34a and SIRT1 gene methylation. Taken together, this investigation demonstrates that arsenic produces cumulative disruptions to epigenetic regulation of miR-34a expression, and this is associated with impaired coordination of SIRT1 functional activity. - Highlights: • Submicromolar arsenic concentrations disrupt SIRT1 activity and expression in human keratinocytes. • Arsenic-induced chromatin remodelling at the miR-34a gene promoter is associated with hyperacetylation

  5. Pro-inflammatory responses of human bronchial epithelial cells to acute nitrogen dioxide exposure.

    Science.gov (United States)

    Ayyagari, Vijayalakshmi N; Januszkiewicz, Adolph; Nath, Jayasree

    2004-04-15

    Nitrogen dioxide (NO2) is an environmental oxidant, known to be associated with lung epithelial injury. In the present study, cellular pro-inflammatory responses following exposure to a brief high concentration of NO2 (45 ppm) were assessed, using normal human bronchial epithelial (NHBE) cells as an in vitro model of inhalation injury. Generation and release of pro-inflammatory mediators such as nitric oxide (NO), IL-8, TNF-alpha, IFN-gamma and IL-1beta were assessed at different time intervals following NO2 exposure. Effects of a pre-existing inflammatory condition was tested by treating the NHBE cells with different inflammatory cytokines such as IFN-gamma, IL-8, TNF-alpha, IL-1beta, either alone or in combination, before exposing them to NO2. Immunofluorescence studies confirmed oxidant-induced formation of 3-nitrotyrosine in the NO2-exposed cells. A marked increase in the levels of nitrite (as an index of NO) and IL-8 were observed in the NO2-exposed cells, which were further enhanced in the presence of the cytokines. Effects of various NO inhibitors combined, with immunofluorescence and Western blotting data, indicated partial contribution of the nitric oxide synthases (NOSs) toward the observed increase in nitrite levels. Furthermore, a significant increase in IL-1beta and TNF-alpha generation was observed in the NO2-exposed cells. Although NO2 exposure alone did induce slight cytotoxicity (<12%), but presence of inflammatory cytokines such as TNF-alpha and IFN-gamma resulted in an increased cell death (28-36%). These results suggest a synergistic role of inflammatory mediators, particularly of NO and IL-8, in NO2-mediated early cellular changes. Our results also demonstrate an increased sensitivity of the cytokine-treated NHBE cells toward NO2, which may have significant functional implications in vivo.

  6. Modification by antioxidant supplementation of changes in human lung function associated with air pollutant exposure: A systematic review

    Directory of Open Access Journals (Sweden)

    Chow Katherine S

    2011-07-01

    Full Text Available Abstract Background Outdoor air pollution, given its demonstrated negative effects on the respiratory system, is a growing public health concern worldwide, particularly in urban cities. Human exposure to pollutants such as ozone, nitrogen oxides, combustion-related particulate matter and oxides of sulfur is responsible for significant cardiopulmonary morbidity and mortality in both adults and children. Several antioxidants have shown an ability to partially attenuate the negative physiological and functional impacts of air pollutants. This study systematically presents current data on the potential benefits of antioxidant supplementation on lung function outcomes associated with air pollutant exposures in intact humans. Methods Electronic databases (MEDLINE, EMBASE, BIOSIS Previews, Web of Sciences, Environmental Sciences & Pollution Management and TOXNET were systematically searched for all studies published up to April 2009. Search terms relating to the concepts of respiratory tract diseases, respiratory function tests, air pollution, and antioxidants were used. Data was systematically abstracted from original articles that satisfied selection criteria for inclusion. For inclusion, the studies needed to have evaluated human subjects, given supplemental antioxidants, under conditions of known levels of air pollutants with measured lung function before and after antioxidant administration and/or air pollution exposure. Selected studies were summarized and conclusions presented. Results Eight studies investigated the role of antioxidant supplementation on measured lung function outcomes after subject exposure to air pollutants under controlled conditions; 5 of these studies concluded that pollutant-induced airway hyper-responsiveness and diminution in lung function measurements were attenuated by antioxidant supplementation. The remaining five studies took place under ambient (uncontrolled exposures and unanimously concluded that antioxidant

  7. Quantitative exposure assessment in community-based studies

    NARCIS (Netherlands)

    Peters, S.M.|info:eu-repo/dai/nl/304822930

    2012-01-01

    Occupational epidemiology focuses on the associations between exposures at the workplace and disease outcomes, essentially concerned with the prevention of disease. Basically two types of studies can be distinguished in occupational epidemiology: industry-based studies which study a population at

  8. Steroids in marine aquaculture farms surrounding Hailing Island, South China: occurrence, bioconcentration, and human dietary exposure.

    Science.gov (United States)

    Liu, Shan; Chen, Hui; Xu, Xiang-Rong; Liu, Shuang-Shuang; Sun, Kai-Feng; Zhao, Jian-Liang; Ying, Guang-Guo

    2015-01-01

    The occurrence, bioconcentration, and human dietary exposure via seafood consumption of 24 steroids were investigated by rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) in six typical marine aquaculture farms surrounding Hailing Island, South China. Ten, 9, 10, 15 of 24 steroids were detected at concentrations ranging from 18 years), respectively. Even though no significant risk from dietary exposure arises from individual steroid, elevated risk to humans can result from the occurrence of multiple steroids in the seafood raised in the aquaculture farms, especially for the sensitive populations, such as pregnant women and children.

  9. Accidental occupational exposure of intravenous nurses to human immunodeficiency virus. Anticipating the consequences.

    Science.gov (United States)

    Meisenhelder, J B

    1998-01-01

    This descriptive study randomly surveyed all 302 Massachusetts members of the Intravenous Nurses Society in 1991 regarding their perceptions of nine possible consequences of human immunodeficiency virus (HIV) infection caused by accidental occupational exposure. Areas of highest concern were financial: adequacy of worker's compensation, ability of the employer to cover all healthcare costs, and job security. Nurses also were concerned about confidentiality of their HIV status and personal history jeopardizing their benefits. The i.v. nurses felt most secure in areas of their personal lives: housing and support of family and friends. Although some concerns correlated significantly with fear of contagion, others were unrelated, indicating a need for policy and attitude changes to promote comfort in working with HIV.

  10. Effects of exposure to noise and indoor air pollution on human perception and symptoms

    DEFF Research Database (Denmark)

    Witterseh, Thomas; Wargocki, Pawel; Fang, Lei

    1999-01-01

    The objective of the present study was to investigate human perception and SBS symptoms when people are exposed simultaneously to different levels of air pollution and ventilation noise. The air quality in an office was modified by placing or removing a carpet and the background noise level...... was modified by playing a recording of ventilation noise. Thirty female subjects, six at a time, occupied the office for 4.4 hours. The subjects assessed the air quality, the noise, and the indoor environment upon entering the office and on six occasions during occupation. Furthermore, SBS symptoms...... of the occupants were recorded throughout the exposure period. During occupation, the subjects performed simulated office work. The results show that elevated air pollution and noise in an office can interact and negatively affect office workers by increasing the prevalence of SBS symptoms. A moderate increase...

  11. Use of a new glass microfibre histamine release method to study the modulation of the host response in human schistosomiasis mansoni. Individuals with different degrees of exposure to the disease show differing antibody biological function

    DEFF Research Database (Denmark)

    Satti, M.Z.; Ebbesen, F.; Vennervald, B.;

    1996-01-01

    A new glass microfibre histamine release method was used to study the modulation of the host response in human schistosomiasis mansoni to improve our understanding of the role of basophils in the development of immunity in schistosomiasis mansoni. The histamine release from umbilical cord blood b...... basophils sensitized with sera from Sudanese individuals infected with Schistosoma mansoni was measured. Schistosomiasis sera (n=113) were able to passively sensitize basophils and induce a positive histamine release in response to whole worm homogenate (WWH)(chi(2)=40.5, P......A new glass microfibre histamine release method was used to study the modulation of the host response in human schistosomiasis mansoni to improve our understanding of the role of basophils in the development of immunity in schistosomiasis mansoni. The histamine release from umbilical cord blood...

  12. The assessment of human exposure to radionuclides from a uranium mill tailings release and mine dewatering effluent.

    Science.gov (United States)

    Ruttenber, A J; Kreiss, K; Douglas, R L; Buhl, T E; Millard, J

    1984-07-01

    This study provides an assessment of human exposure to radiation from a river system contaminated by radionuclides of the 238U decay series released through a dam break at a uranium mill tailings pond and by the continuous discharge of dewatering effluent from 2 uranium mines. The in vivo analyses of radionuclides in 6 Navajo Indians who lived near the river indicate no detectable elevations above background concentrations. Dose estimates for inhalation of suspended river sediment indicate a maximum annual 50-yr dose commitment of 204 mrem to the endosteum. Estimates of doses (50-yr dose commitments) from the ingestion of livestock range between 1 mrem (to liver) and 79 mrem (to bone) suggest that the major contribution to human exposure is from mine dewatering effluent that has been continuously released into the river system for many years. Although the estimated exposures do not exceed existing state or federal regulations, their magnitude justifies further measurement of radionuclides in animals and in the natural environment and the consideration of strategies to reduce radiation exposure to humans and animals.

  13. Human anthrax outbreak associated with livestock exposure: Georgia, 2012.

    Science.gov (United States)

    Navdarashvili, A; Doker, T J; Geleishvili, M; Haberling, D L; Kharod, G A; Rush, T H; Maes, E; Zakhashvili, K; Imnadze, P; Bower, W A; Walke, H T; Shadomy, S V

    2016-01-01

    Human anthrax cases reported in the country of Georgia increased 75% from 2011 (n = 81) to 2012 (n = 142). This increase prompted a case-control investigation using 67 culture- or PCR-confirmed cases and 134 controls matched by residence and gender to investigate risk factor(s) for infection during the month before case onset. Independent predictors most strongly associated with disease in the multivariable modelling were slaughtering animals [odds ratio (OR) 7·3, 95% confidence interval (CI) 2·9-18·1, P 1 km; 15 (12%) of 125 had sick livestock; and 11 (9%) of 128 respondents reported finding dead livestock. We recommend joint public health and veterinary anthrax case investigations to identify areas of increased risk for livestock anthrax outbreaks, annual anthrax vaccination of livestock in those areas, and public awareness education.

  14. Phthalates in dormitory and house dust of northern Chinese cities: Occurrence, human exposure, and risk assessment.

    Science.gov (United States)

    Li, Hai-Ling; Song, Wei-Wei; Zhang, Zi-Feng; Ma, Wan-Li; Gao, Chong-Jing; Li, Jia; Huo, Chun-Yan; Mohammed, Mohammed O A; Liu, Li-Yan; Kannan, Kurunthachalam; Li, Yi-Fan

    2016-09-15

    Phthalates are widely used chemicals in household products, which severely affect human health. However, there were limited studies emphasized on young adults' exposure to phthalates in dormitories. In this study, seven phthalates were extracted from indoor dust that collected in university dormitories in Harbin, Shenyang, and Baoding, in the north of China. Dust samples were also collected in houses in Harbin for comparison. The total concentrations of phthalates in dormitory dust in Harbin and Shenyang samples were significantly higher than those in Baoding samples. The total geometric mean concentration of phthalates in dormitory dust in Harbin was lower than in house dust. Di-(2-ethylhexyl) phthalate (DEHP) was the most abundant phthalate in both dormitory and house dust. The daily intakes of the total phthalates, carcinogenic risk (CR) of DEHP, hazard index (HI) of di-isobutyl phthalate (DiBP), dibutyl phthalate (DBP), and DEHP were estimated, the median values for all students in dormitories were lower than adults who live in the houses. Monte Carlo simulation was applied to predict the human exposure risk of phthalates. HI of DiBP, DBP, and DEHP was predicted according to the reference doses (RfD) provided by the United States Environmental Protection Agency (U.S.EPA) and the reference doses for anti-androgenicity (RfD AA) developed by Kortenkamp and Faust. The results indicated that the risks of some students had exceeded the limitation, however, the measured results were not exceeded the limitation. Risk quotients (RQ) of DEHP were predicted based on China specific No Significant Risk Level (NSRL) and Maximum Allowable Dose Level (MADL). The predicted results of CR and RQ of DEHP suggested that DEHP could pose a health risk through intake of indoor dust.

  15. Streptococci-human papilloma virus interaction with ethanol exposure leads to keratinocyte damage.

    Science.gov (United States)

    Schwartz, Joel; Pavlova, Sylvia; Kolokythas, Antonia; Lugakingira, Mulokozi; Tao, Lin; Miloro, Michael

    2012-08-01

    Ethanol, human papilloma virus (HPV), and poor oral hygiene are risk factors that have been attributed to oral carcinogenesis. Streptococci sp and HPV infections are common in the head and neck, often associated with sexual activity. Although HPV is linked to head and neck squamous cell carcinoma, it is unclear whether there is a similar role for Streptococci sp. This cell study examines whether Streptococci sp and HPV-16 with exposure to ethyl alcohol (ETOH) can act as cofactors in the malignant transformation of oral keratinocytes. ETOH (0.1%-20% vol/vol) was used to investigate Streptococci sp attachment with immortalized E6-expressing HPV/HOK-16B cells, human oral buccal keratinocytes, and foreskin keratinocytes. Streptococci sp (Streptococci mutans [LT11]) and various strains of acetaldehyde (AA) producer and nonproducer Streptococcus salivarius (110-1, 109-2, 101-7, and 107-1) and a lactic acid producer bacterium, Lactobacillus rhamnosus (24-1 and 25-2), were examined for interactions with keratinocytes by use of a green dye (percent of cells with colonies after 24 hours). Carcinogens, AA, malondialdehyde, DNA damage, and proliferation (5'-bromo-2-deoxyuridine) among keratinocytes were also quantified. AA and malondialdehyde production from permissible Streptococci sp significantly increased with attachment to keratinocytes, whereas L rhamnosus did not significantly attach to keratinocytes. This attachment was associated with enhanced levels of AA adduct formation, proliferation (5'-bromo-2-deoxyuridine incorporation), and enhanced migration through integrin-coated basement membrane by HPV oral keratinocytes, which are characteristics of a malignant phenotype. These cell studies suggest that oral Streptococci sp and HPV (HPV-16) cooperate to transform oral keratinocytes after low-level ETOH (1%) exposure. These results appear to suggest a significant clinical interaction, but further validation is warranted. Copyright © 2012 American Association of Oral and

  16. In vivo temperature rise in anesthetized human pulp during exposure to a polywave LED light curing unit.

    Science.gov (United States)

    Runnacles, Patrício; Arrais, Cesar Augusto Galvão; Pochapski, Marcia Thais; Dos Santos, Fábio André; Coelho, Ulisses; Gomes, João Carlos; De Goes, Mário Fernando; Gomes, Osnara Maria Mongruel; Rueggeberg, Frederick Allen

    2015-05-01

    This in vivo study evaluated pulp temperature (PT) rise in human premolars during exposure to a light curing unit (LCU) using selected exposure modes (EMs). After local Ethics Committee approval, intact first upper premolars, requiring extraction for orthodontic reasons, from 8 volunteers, received infiltrative and intraligamental anesthesia. The teeth (n=15) were isolated using rubber dam and a minute pulp exposure was attained. A sterile probe from a wireless, NIST-traceable, temperature acquisition system was inserted directly into the coronal pulp chamber, and real time PT (°C) was continuously monitored while the buccal surface was exposed to polywave light from a LED LCU (Bluephase 20i, Ivoclar Vivadent) using selected EMs allowing a 7-min span between each exposure: 10-s either in low (10-s/L) or high (10-s/H); 5-s-turbo (5-s/T); and 60-s-high (60-s/H) intensities. Peak PT values and PT increases from baseline (ΔT) after exposure were subjected to one-way, repeated measures ANOVAs, and Bonferroni's post hoc tests (α=0.05). Linear regression analysis was performed to establish the relationship between applied radiant exposure and ΔT. All EMs produced higher peak PT than the baseline temperature (p<0.001). The 60-s/H mode generated the highest peak PT and ΔT (p<0.001), with some teeth exhibiting ΔT higher than 5.5°C. A significant, positive relationship between applied radiant exposure and ΔT (r(2)=0.916; p<0.001) was noted. Exposing intact, in vivo anesthetized human upper premolars to a polywave LED LCU increases PT, and depending on EM and the tooth, PT increase can be higher than the critical ΔT, thought to be associated with pulpal necrosis. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  17. Determination of GHB in human hair by HPLC-MS/MS: Development and validation of a method and application to a study group and three possible single exposure cases.

    Science.gov (United States)

    Bertol, Elisabetta; Mari, Francesco; Vaiano, Fabio; Romano, Guido; Zaami, Simona; Baglìo, Giovanni; Busardò, Francesco Paolo

    2015-05-01

    Gamma-hydroxybutyrate (GHB) over the last two decades has generated increased notoriety as a euphoric and disinhibiting drug of abuse in cases of drug-related sexual assault and for this reason it is considered a 'date rape' drug. The first aim of this paper was to develop and fully validate a method for the detection of GHB in human hair by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) after liquid-liquid extraction (LLE). The second aim was the application of the method to hair samples of 30 GHB-free users in order to determine the basal level. The results obtained showed no significant differences in endogenous concentrations (p = 0.556) between hair samples of the three groups (black, blonde, and dyed hair) and the age and sex of the subjects did not affect the endogenous levels. Another 12 healthy volunteers, with no previous history of GHB use, were selected and a single dose (25 mg/Kg) was orally administered to all of them and hair samples were collected before the administration of the single dose and other two samples were collected one month and two months later, respectively. The segmental analysis of the latter two samples allowed us to calculate two ratios: 4.45:1 (95% C.I. 3.52-5.63) and 3.35:1 (95% C.I. 2.14-5.18), respectively, which can be recommended as reasonable values for a positive identification of GHB intake. Finally the method was applied to three real cases where a GHB single exposure probably occurred.

  18. The Adverse Effects of Heavy Metals with and without Noise Exposure on the Human Peripheral and Central Auditory System: A Literature Review

    Directory of Open Access Journals (Sweden)

    Marie-Josée Castellanos

    2016-12-01

    Full Text Available Exposure to some chemicals in the workplace can lead to occupational chemical-induced hearing loss. Attention has mainly focused on the adverse auditory effects of solvents. However, other chemicals such as heavy metals have been also identified as ototoxic agents. The aim of this work was to review the current scientific knowledge about the adverse auditory effects of heavy metal exposure with and without co-exposure to noise in humans. PubMed and Medline were accessed to find suitable articles. A total of 49 articles met the inclusion criteria. Results from the review showed that no evidence about the ototoxic effects in humans of manganese is available. Contradictory results have been found for arsenic, lead and mercury as well as for the possible interaction between heavy metals and noise. All studies found in this review have found that exposure to cadmium and mixtures of heavy metals induce auditory dysfunction. Most of the studies investigating the adverse auditory effects of heavy metals in humans have investigated human populations exposed to lead. Some of these studies suggest peripheral and central auditory dysfunction induced by lead exposure. It is concluded that further evidence from human studies about the adverse auditory effects of heavy metal exposure is still required. Despite this issue, audiologists and other hearing health care professionals should be aware of the possible auditory effects of heavy metals.

  19. The Adverse Effects of Heavy Metals with and without Noise Exposure on the Human Peripheral and Central Auditory System: A Literature Review.

    Science.gov (United States)

    Castellanos, Marie-Josée; Fuente, Adrian

    2016-12-09

    Exposure to some chemicals in the workplace can lead to occupational chemical-induced hearing loss. Attention has mainly focused on the adverse auditory effects of solvents. However, other chemicals such as heavy metals have been also identified as ototoxic agents. The aim of this work was to review the current scientific knowledge about the adverse auditory effects of heavy metal exposure with and without co-exposure to noise in humans. PubMed and Medline were accessed to find suitable articles. A total of 49 articles met the inclusion criteria. Results from the review showed that no evidence about the ototoxic effects in humans of manganese is available. Contradictory results have been found for arsenic, lead and mercury as well as for the possible interaction between heavy metals and noise. All studies found in this review have found that exposure to cadmium and mixtures of heavy metals induce auditory dysfunction. Most of the studies investigating the adverse auditory effects of heavy metals in humans have investigated human populations exposed to lead. Some of these studies suggest peripheral and central auditory dysfunction induced by lead exposure. It is concluded that further evidence from human studies about the adverse auditory effects of heavy metal exposure is still required. Despite this issue, audiologists and other hearing health care professionals should be aware of the possible auditory effects of heavy metals.

  20. Repeated Exposure to Dissection Does Not Influence Students’ Attitudes towards Human Body Donation for Anatomy Teaching

    Directory of Open Access Journals (Sweden)

    Philip Maseghe Mwachaka

    2016-01-01

    Full Text Available The use of unclaimed bodies for anatomical dissection has been the main method of instruction at our institution. There is however a shortage of cadavers for dissection given the increase in the number of medical schools as well as in the number of students enrolling in these schools. This shortage could be mitigated by having voluntary human body donation programs. This study aimed at assessing the attitudes of medical students and surgical residents towards body donation for anatomy learning. We conducted an online survey involving 72 first-year medical students and 41 surgical residents at University of Nairobi who had completed one year of anatomy dissection. For the medical students, this was their first dissection experience while it was the second exposure for the surgery trainees. Most of the surgical trainees (70.7% and medical students (68.1% were opposed to self-body donation. This was mainly due to cultural (37% and religious (20% barriers. Surprisingly, of those not willing to donate themselves, 67.9% (82.8% surgical trainees, 59.2% medical students would recommend the practice to other people. Exposure to repeated dissection does not change the perceptions towards body donation. It is noteworthy that culture and religion rank high as clear barriers amongst this “highly informed” group of potential donors.

  1. Assessment of human exposure to benzene through foods from the Belgian market.

    Science.gov (United States)

    Medeiros Vinci, Raquel; Jacxsens, Liesbeth; Van Loco, Joris; Matsiko, Eric; Lachat, Carl; de Schaetzen, Thibault; Canfyn, Michael; Van Overmeire, Ilse; Kolsteren, Patrick; De Meulenaer, Bruno

    2012-08-01

    Benzene is a volatile organic compound known to be carcinogenic to humans (Group 1) and may be present in food. In the present study, 455 food samples from the Belgian market were analyzed for benzene contents and some possible sources of its occurrence in the foodstuffs were evaluated. Benzene was found above the level of detection in 58% of analyzed samples with the highest contents found in processed foods such as smoked and canned fish, and foods which contained these as ingredients (up to 76.21 μg kg(-1)). Unprocessed foods such as raw meat, fish, and eggs contained much lower concentrations of benzene. Using the benzene concentrations in food, a quantitative dietary exposure assessment of benzene intake was conducted on a national representative sample of the Belgian population over 15 years of age. The mean benzene intake for all foods was 0.020 μg kg bw d(-1) according to a probabilistic analysis. These values are below the minimum risk level for oral chronic exposure to benzene (0.5 μg kg bw d(-1)).

  2. Effect of ultraviolet A exposure on transport of compatible organic osmolytes in human lens epithelial cells.

    Science.gov (United States)

    Wu, D Y; Zhang, J S

    2015-05-18

    Compatible organic osmolytes, such as betaine, myoinositol, and taurine, are involved in antioxidant defense, protein stabilization, and stress responses. This osmolyte strategy requires the expression of specific osmolyte transporters such as betaine (BGT-1), myoinositol (SMIT), and taurine (TAUT). In contrast to the kidney, keratinocytes, and neural cells, few studies have examined osmolytes in human lens epithelial cells (HLECs). We examined the expression of mRNA specific for BGT-1, SMIT, and TAUT in HLECs. In comparison to normoosmotic (305 mOsM) controls, there was a 3-5-fold time-dependent reaction of BGT-1, SMIT, and TAUT mRNA levels in HLECs exposed to hyperosmotic stress (405 mOsM). Maximal responses were obtained for BGT-1, SMIT, and TAUT mRNA expression after 3, 24 and 9 h of hyperosmotic exposure, respectively. This expression was correlated with increased osmolyte uptake. In contrast, hypoosmotic (205 mOsM) stimulation led to a significant efflux of osmolytes. Exposure to ultraviolet A (340-400 nm) radiation significantly stimulated osmolyte uptake. Increased osmolyte uptake was associated with upregulation of mRNA steady-state levels for osmolyte transporters in irradiated cells. These results demonstrate that ultraviolet A radiation leads to the accumulation of compatible organic osmolytes in HLECs as hyperosmotic pressure, which can maintain cellular environmental homeostasis.

  3. Repeated Exposure to Dissection Does Not Influence Students' Attitudes towards Human Body Donation for Anatomy Teaching.

    Science.gov (United States)

    Mwachaka, Philip Maseghe; Mandela, Pamela; Saidi, Hassan

    2016-01-01

    The use of unclaimed bodies for anatomical dissection has been the main method of instruction at our institution. There is however a shortage of cadavers for dissection given the increase in the number of medical schools as well as in the number of students enrolling in these schools. This shortage could be mitigated by having voluntary human body donation programs. This study aimed at assessing the attitudes of medical students and surgical residents towards body donation for anatomy learning. We conducted an online survey involving 72 first-year medical students and 41 surgical residents at University of Nairobi who had completed one year of anatomy dissection. For the medical students, this was their first dissection experience while it was the second exposure for the surgery trainees. Most of the surgical trainees (70.7%) and medical students (68.1%) were opposed to self-body donation. This was mainly due to cultural (37%) and religious (20%) barriers. Surprisingly, of those not willing to donate themselves, 67.9% (82.8% surgical trainees, 59.2% medical students) would recommend the practice to other people. Exposure to repeated dissection does not change the perceptions towards body donation. It is noteworthy that culture and religion rank high as clear barriers amongst this "highly informed" group of potential donors.

  4. The effect of environmental exposure to pyrethroids and DNA damage in human sperm.

    Science.gov (United States)

    Jurewicz, Joanna; Radwan, Michał; Wielgomas, Bartosz; Sobala, Wojciech; Piskunowicz, Marta; Radwan, Paweł; Bochenek, Michał; Hanke, Wojciech

    2015-01-01

    The present study was designed to investigate whether environmental exposure to pyrethroids was associated with sperm DNA damage. Between January 2008 and April 2011 286 men under 45 years of age with a normal sperm concentration of 15-300 10(6)/ml [WHO 2010] were recruited from an infertility clinic in Lodz, Poland. Participants were interviewed and provided urine, saliva, and semen samples. The pyrethroids metabolites: 3-phenoxybenzoic acid (3PBA), cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (CDCCA), trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (TDCCA), and cis-2,2-dibromovinyl-2,2-dimethylcyclopropane-carboxylic acid (DBCA) were analyzed in the urine using a validated gas chromatography ion-tap mass spectrometry method. Sperm DNA damage was assessed using a flow cytometry based on sperm chromatin structure assay (SCSA). A positive association was observed between CDCCA >50th percentile and the percentage of medium DNA fragmentation index (M DFI) and percentage of immature sperms (HDS) (p = 0.04, p = 0.04 respectively). The level of 3PBA >50th percentile in urine was positively related to the percentage of high DNA fragmentation index (H DFI) (p = 0.03). The TDCCA, DBCA levels, and the sum of pyrethroid metabolites were not associated with any sperm DNA damage measures. Our results suggest that environmental pyrethroid exposure may affect sperm DNA damage measures index indicated the reproductive effects of pyrethroid exposure on adult men. In view of the importance of human reproductive health and the widespread usage of pyrethroids, it is important to further investigate these correlations.

  5. Chinese population exposure to triclosan and triclocarban as measured via human urine and nails.

    Science.gov (United States)

    Yin, Jie; Wei, Ling; Shi, Ying; Zhang, Jing; Wu, Qingqing; Shao, Bing

    2016-10-01

    Triclosan (TCS) and triclocarban (TCC) exposures are highly concerned due to their suspected endocrine-disrupting effects. The present study investigated TCS and TCC exposure levels in the general Chinese population by biomonitoring human urine and nail samples. TCS (69-80 %) and TCC (99-100 %) were frequently detected, which demonstrates that the general Chinese population has extensive exposure to these chemicals. The geometric mean (GM) urinary concentrations were 0.40 μg/g creatinine (creat), 95 % confidence interval (CI) 0.30-0.56, for TCS and 0.40 μg/g creat, 95 % CI 0.29-0.56, for TCC. On the other hand, the GM levels of TCS and TCC were 13.57 (5.67 μg/kg) and 84.66 μg/kg (41.50 μg/kg) in fingernail (toenail) samples, respectively, indicating that the levels in fingernails were approximately twice as high as those in toenails. Pearson's correlation coefficients between the urine and fingernail (toenail) samples were 0.715 (0.614) for TCS and 0.829 (0.812) for TCC. These data suggest that nail samples can be applied to the biomonitoring for TCS and TCC in the general population. We observed that the levels of both chemicals were higher in females than in males for urine and fingernail samples, but no significant differences were found between different genders for either compound in toenails. Nineteen- to 29-year-olds had the highest TCS levels in their nail samples, whereas TCC levels did not differ with regard to age. Region of residence significantly influenced TCS and TCC concentrations in the three biological matrices measured.

  6. Human urinary biomarkers of dioxin exposure: analysis by metabolomics and biologically driven data dimensionality reduction.

    Science.gov (United States)

    Jeanneret, Fabienne; Boccard, Julien; Badoud, Flavia; Sorg, Olivier; Tonoli, David; Pelclova, Daniela; Vlckova, Stepanka; Rutledge, Douglas N; Samer, Caroline F; Hochstrasser, Denis; Saurat, Jean-Hilaire; Rudaz, Serge

    2014-10-15

    Untargeted metabolomic approaches offer new opportunities for a deeper understanding of the molecular events related to toxic exposure. This study proposes a metabolomic investigation of biochemical alterations occurring in urine as a result of dioxin toxicity. Urine samples were collected from Czech chemical workers submitted to severe dioxin occupational exposure in a herbicide production plant in the late 1960s. Experiments were carried out with ultra-high pressure liquid chromatography (UHPLC) coupled to high-resolution quadrupole time-of-flight (QTOF) mass spectrometry. A chemistry-driven feature selection was applied to focus on steroid-related metabolites. Supervised multivariate data analysis allowed biomarkers, mainly related to bile acids, to be highlighted. These results supported the hypothesis of liver damage and oxidative stress for long-term dioxin toxicity. As a second step of data analysis, the information gained from the urine analysis of Victor Yushchenko after his poisoning was examined. A subset of relevant urinary markers of acute dioxin toxicity from this extreme phenotype, including glucuro- and sulfo-conjugated endogenous steroid metabolites and bile acids, was assessed for its ability to detect long-term effects of exposure. The metabolomic strategy presented in this work allowed the determination of metabolic patterns related to dioxin effects in human and the discovery of highly predictive subsets of biologically m